ListView.java revision 8350f7dbc3a62211b2891f35911e4073d24c4cc5
1/* 2 * Copyright (C) 2006 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17package android.widget; 18 19import com.android.internal.R; 20import com.google.android.collect.Lists; 21 22import android.content.Context; 23import android.content.Intent; 24import android.content.res.TypedArray; 25import android.graphics.Canvas; 26import android.graphics.Paint; 27import android.graphics.PixelFormat; 28import android.graphics.Rect; 29import android.graphics.drawable.ColorDrawable; 30import android.graphics.drawable.Drawable; 31import android.os.Parcel; 32import android.os.Parcelable; 33import android.util.AttributeSet; 34import android.util.LongSparseArray; 35import android.util.SparseBooleanArray; 36import android.view.ActionMode; 37import android.view.FocusFinder; 38import android.view.HapticFeedbackConstants; 39import android.view.KeyEvent; 40import android.view.Menu; 41import android.view.MenuItem; 42import android.view.MotionEvent; 43import android.view.SoundEffectConstants; 44import android.view.View; 45import android.view.ViewDebug; 46import android.view.ViewGroup; 47import android.view.ViewParent; 48import android.view.accessibility.AccessibilityEvent; 49import android.widget.RemoteViews.RemoteView; 50 51import java.util.ArrayList; 52 53/* 54 * Implementation Notes: 55 * 56 * Some terminology: 57 * 58 * index - index of the items that are currently visible 59 * position - index of the items in the cursor 60 */ 61 62 63/** 64 * A view that shows items in a vertically scrolling list. The items 65 * come from the {@link ListAdapter} associated with this view. 66 * 67 * @attr ref android.R.styleable#ListView_entries 68 * @attr ref android.R.styleable#ListView_divider 69 * @attr ref android.R.styleable#ListView_dividerHeight 70 * @attr ref android.R.styleable#ListView_choiceMode 71 * @attr ref android.R.styleable#ListView_headerDividersEnabled 72 * @attr ref android.R.styleable#ListView_footerDividersEnabled 73 */ 74@RemoteView 75public class ListView extends AbsListView { 76 /** 77 * Used to indicate a no preference for a position type. 78 */ 79 static final int NO_POSITION = -1; 80 81 /** 82 * Normal list that does not indicate choices 83 */ 84 public static final int CHOICE_MODE_NONE = 0; 85 86 /** 87 * The list allows up to one choice 88 */ 89 public static final int CHOICE_MODE_SINGLE = 1; 90 91 /** 92 * The list allows multiple choices 93 */ 94 public static final int CHOICE_MODE_MULTIPLE = 2; 95 96 /** 97 * The list allows multiple choices in a modal selection mode 98 */ 99 public static final int CHOICE_MODE_MULTIPLE_MODAL = 3; 100 101 /** 102 * When arrow scrolling, ListView will never scroll more than this factor 103 * times the height of the list. 104 */ 105 private static final float MAX_SCROLL_FACTOR = 0.33f; 106 107 /** 108 * When arrow scrolling, need a certain amount of pixels to preview next 109 * items. This is usually the fading edge, but if that is small enough, 110 * we want to make sure we preview at least this many pixels. 111 */ 112 private static final int MIN_SCROLL_PREVIEW_PIXELS = 2; 113 114 /** 115 * A class that represents a fixed view in a list, for example a header at the top 116 * or a footer at the bottom. 117 */ 118 public class FixedViewInfo { 119 /** The view to add to the list */ 120 public View view; 121 /** The data backing the view. This is returned from {@link ListAdapter#getItem(int)}. */ 122 public Object data; 123 /** <code>true</code> if the fixed view should be selectable in the list */ 124 public boolean isSelectable; 125 } 126 127 private ArrayList<FixedViewInfo> mHeaderViewInfos = Lists.newArrayList(); 128 private ArrayList<FixedViewInfo> mFooterViewInfos = Lists.newArrayList(); 129 130 Drawable mDivider; 131 int mDividerHeight; 132 133 private boolean mIsCacheColorOpaque; 134 private boolean mDividerIsOpaque; 135 private boolean mClipDivider; 136 137 private boolean mHeaderDividersEnabled; 138 private boolean mFooterDividersEnabled; 139 140 private boolean mAreAllItemsSelectable = true; 141 142 private boolean mItemsCanFocus = false; 143 144 private int mChoiceMode = CHOICE_MODE_NONE; 145 146 private SparseBooleanArray mCheckStates; 147 private LongSparseArray<Boolean> mCheckedIdStates; 148 149 // used for temporary calculations. 150 private final Rect mTempRect = new Rect(); 151 private Paint mDividerPaint; 152 153 // the single allocated result per list view; kinda cheesey but avoids 154 // allocating these thingies too often. 155 private final ArrowScrollFocusResult mArrowScrollFocusResult = new ArrowScrollFocusResult(); 156 157 // Keeps focused children visible through resizes 158 private FocusSelector mFocusSelector; 159 160 // Controls CHOICE_MODE_MULTIPLE_MODAL. null when inactive. 161 private ActionMode mChoiceActionMode; 162 private MultiChoiceModeWrapper mMultiChoiceModeCallback; 163 private int mCheckedItemCount; 164 165 public ListView(Context context) { 166 this(context, null); 167 } 168 169 public ListView(Context context, AttributeSet attrs) { 170 this(context, attrs, com.android.internal.R.attr.listViewStyle); 171 } 172 173 public ListView(Context context, AttributeSet attrs, int defStyle) { 174 super(context, attrs, defStyle); 175 176 TypedArray a = context.obtainStyledAttributes(attrs, 177 com.android.internal.R.styleable.ListView, defStyle, 0); 178 179 CharSequence[] entries = a.getTextArray( 180 com.android.internal.R.styleable.ListView_entries); 181 if (entries != null) { 182 setAdapter(new ArrayAdapter<CharSequence>(context, 183 com.android.internal.R.layout.simple_list_item_1, entries)); 184 } 185 186 final Drawable d = a.getDrawable(com.android.internal.R.styleable.ListView_divider); 187 if (d != null) { 188 // If a divider is specified use its intrinsic height for divider height 189 setDivider(d); 190 } 191 192 // Use the height specified, zero being the default 193 final int dividerHeight = a.getDimensionPixelSize( 194 com.android.internal.R.styleable.ListView_dividerHeight, 0); 195 if (dividerHeight != 0) { 196 setDividerHeight(dividerHeight); 197 } 198 199 setChoiceMode(a.getInt(R.styleable.ListView_choiceMode, CHOICE_MODE_NONE)); 200 201 mHeaderDividersEnabled = a.getBoolean(R.styleable.ListView_headerDividersEnabled, true); 202 mFooterDividersEnabled = a.getBoolean(R.styleable.ListView_footerDividersEnabled, true); 203 204 a.recycle(); 205 } 206 207 /** 208 * @return The maximum amount a list view will scroll in response to 209 * an arrow event. 210 */ 211 public int getMaxScrollAmount() { 212 return (int) (MAX_SCROLL_FACTOR * (mBottom - mTop)); 213 } 214 215 /** 216 * Make sure views are touching the top or bottom edge, as appropriate for 217 * our gravity 218 */ 219 private void adjustViewsUpOrDown() { 220 final int childCount = getChildCount(); 221 int delta; 222 223 if (childCount > 0) { 224 View child; 225 226 if (!mStackFromBottom) { 227 // Uh-oh -- we came up short. Slide all views up to make them 228 // align with the top 229 child = getChildAt(0); 230 delta = child.getTop() - mListPadding.top; 231 if (mFirstPosition != 0) { 232 // It's OK to have some space above the first item if it is 233 // part of the vertical spacing 234 delta -= mDividerHeight; 235 } 236 if (delta < 0) { 237 // We only are looking to see if we are too low, not too high 238 delta = 0; 239 } 240 } else { 241 // we are too high, slide all views down to align with bottom 242 child = getChildAt(childCount - 1); 243 delta = child.getBottom() - (getHeight() - mListPadding.bottom); 244 245 if (mFirstPosition + childCount < mItemCount) { 246 // It's OK to have some space below the last item if it is 247 // part of the vertical spacing 248 delta += mDividerHeight; 249 } 250 251 if (delta > 0) { 252 delta = 0; 253 } 254 } 255 256 if (delta != 0) { 257 offsetChildrenTopAndBottom(-delta); 258 } 259 } 260 } 261 262 /** 263 * Add a fixed view to appear at the top of the list. If addHeaderView is 264 * called more than once, the views will appear in the order they were 265 * added. Views added using this call can take focus if they want. 266 * <p> 267 * NOTE: Call this before calling setAdapter. This is so ListView can wrap 268 * the supplied cursor with one that will also account for header and footer 269 * views. 270 * 271 * @param v The view to add. 272 * @param data Data to associate with this view 273 * @param isSelectable whether the item is selectable 274 */ 275 public void addHeaderView(View v, Object data, boolean isSelectable) { 276 277 if (mAdapter != null) { 278 throw new IllegalStateException( 279 "Cannot add header view to list -- setAdapter has already been called."); 280 } 281 282 FixedViewInfo info = new FixedViewInfo(); 283 info.view = v; 284 info.data = data; 285 info.isSelectable = isSelectable; 286 mHeaderViewInfos.add(info); 287 } 288 289 /** 290 * Add a fixed view to appear at the top of the list. If addHeaderView is 291 * called more than once, the views will appear in the order they were 292 * added. Views added using this call can take focus if they want. 293 * <p> 294 * NOTE: Call this before calling setAdapter. This is so ListView can wrap 295 * the supplied cursor with one that will also account for header and footer 296 * views. 297 * 298 * @param v The view to add. 299 */ 300 public void addHeaderView(View v) { 301 addHeaderView(v, null, true); 302 } 303 304 @Override 305 public int getHeaderViewsCount() { 306 return mHeaderViewInfos.size(); 307 } 308 309 /** 310 * Removes a previously-added header view. 311 * 312 * @param v The view to remove 313 * @return true if the view was removed, false if the view was not a header 314 * view 315 */ 316 public boolean removeHeaderView(View v) { 317 if (mHeaderViewInfos.size() > 0) { 318 boolean result = false; 319 if (((HeaderViewListAdapter) mAdapter).removeHeader(v)) { 320 mDataSetObserver.onChanged(); 321 result = true; 322 } 323 removeFixedViewInfo(v, mHeaderViewInfos); 324 return result; 325 } 326 return false; 327 } 328 329 private void removeFixedViewInfo(View v, ArrayList<FixedViewInfo> where) { 330 int len = where.size(); 331 for (int i = 0; i < len; ++i) { 332 FixedViewInfo info = where.get(i); 333 if (info.view == v) { 334 where.remove(i); 335 break; 336 } 337 } 338 } 339 340 /** 341 * Add a fixed view to appear at the bottom of the list. If addFooterView is 342 * called more than once, the views will appear in the order they were 343 * added. Views added using this call can take focus if they want. 344 * <p> 345 * NOTE: Call this before calling setAdapter. This is so ListView can wrap 346 * the supplied cursor with one that will also account for header and footer 347 * views. 348 * 349 * @param v The view to add. 350 * @param data Data to associate with this view 351 * @param isSelectable true if the footer view can be selected 352 */ 353 public void addFooterView(View v, Object data, boolean isSelectable) { 354 FixedViewInfo info = new FixedViewInfo(); 355 info.view = v; 356 info.data = data; 357 info.isSelectable = isSelectable; 358 mFooterViewInfos.add(info); 359 360 // in the case of re-adding a footer view, or adding one later on, 361 // we need to notify the observer 362 if (mDataSetObserver != null) { 363 mDataSetObserver.onChanged(); 364 } 365 } 366 367 /** 368 * Add a fixed view to appear at the bottom of the list. If addFooterView is called more 369 * than once, the views will appear in the order they were added. Views added using 370 * this call can take focus if they want. 371 * <p>NOTE: Call this before calling setAdapter. This is so ListView can wrap the supplied 372 * cursor with one that will also account for header and footer views. 373 * 374 * 375 * @param v The view to add. 376 */ 377 public void addFooterView(View v) { 378 addFooterView(v, null, true); 379 } 380 381 @Override 382 public int getFooterViewsCount() { 383 return mFooterViewInfos.size(); 384 } 385 386 /** 387 * Removes a previously-added footer view. 388 * 389 * @param v The view to remove 390 * @return 391 * true if the view was removed, false if the view was not a footer view 392 */ 393 public boolean removeFooterView(View v) { 394 if (mFooterViewInfos.size() > 0) { 395 boolean result = false; 396 if (((HeaderViewListAdapter) mAdapter).removeFooter(v)) { 397 mDataSetObserver.onChanged(); 398 result = true; 399 } 400 removeFixedViewInfo(v, mFooterViewInfos); 401 return result; 402 } 403 return false; 404 } 405 406 /** 407 * Returns the adapter currently in use in this ListView. The returned adapter 408 * might not be the same adapter passed to {@link #setAdapter(ListAdapter)} but 409 * might be a {@link WrapperListAdapter}. 410 * 411 * @return The adapter currently used to display data in this ListView. 412 * 413 * @see #setAdapter(ListAdapter) 414 */ 415 @Override 416 public ListAdapter getAdapter() { 417 return mAdapter; 418 } 419 420 /** 421 * Sets up this AbsListView to use a remote views adapter which connects to a RemoteViewsService 422 * through the specified intent. 423 * @param intent the intent used to identify the RemoteViewsService for the adapter to connect to. 424 */ 425 @android.view.RemotableViewMethod 426 public void setRemoteViewsAdapter(Intent intent) { 427 super.setRemoteViewsAdapter(intent); 428 } 429 430 /** 431 * Sets the data behind this ListView. 432 * 433 * The adapter passed to this method may be wrapped by a {@link WrapperListAdapter}, 434 * depending on the ListView features currently in use. For instance, adding 435 * headers and/or footers will cause the adapter to be wrapped. 436 * 437 * @param adapter The ListAdapter which is responsible for maintaining the 438 * data backing this list and for producing a view to represent an 439 * item in that data set. 440 * 441 * @see #getAdapter() 442 */ 443 @Override 444 public void setAdapter(ListAdapter adapter) { 445 if (mAdapter != null && mDataSetObserver != null) { 446 mAdapter.unregisterDataSetObserver(mDataSetObserver); 447 } 448 449 resetList(); 450 mRecycler.clear(); 451 452 if (mHeaderViewInfos.size() > 0|| mFooterViewInfos.size() > 0) { 453 mAdapter = new HeaderViewListAdapter(mHeaderViewInfos, mFooterViewInfos, adapter); 454 } else { 455 mAdapter = adapter; 456 } 457 458 mOldSelectedPosition = INVALID_POSITION; 459 mOldSelectedRowId = INVALID_ROW_ID; 460 if (mAdapter != null) { 461 mAreAllItemsSelectable = mAdapter.areAllItemsEnabled(); 462 mOldItemCount = mItemCount; 463 mItemCount = mAdapter.getCount(); 464 checkFocus(); 465 466 mDataSetObserver = new AdapterDataSetObserver(); 467 mAdapter.registerDataSetObserver(mDataSetObserver); 468 469 mRecycler.setViewTypeCount(mAdapter.getViewTypeCount()); 470 471 int position; 472 if (mStackFromBottom) { 473 position = lookForSelectablePosition(mItemCount - 1, false); 474 } else { 475 position = lookForSelectablePosition(0, true); 476 } 477 setSelectedPositionInt(position); 478 setNextSelectedPositionInt(position); 479 480 if (mItemCount == 0) { 481 // Nothing selected 482 checkSelectionChanged(); 483 } 484 485 if (mChoiceMode != CHOICE_MODE_NONE && 486 mAdapter.hasStableIds() && 487 mCheckedIdStates == null) { 488 mCheckedIdStates = new LongSparseArray<Boolean>(); 489 } 490 491 } else { 492 mAreAllItemsSelectable = true; 493 checkFocus(); 494 // Nothing selected 495 checkSelectionChanged(); 496 } 497 498 if (mCheckStates != null) { 499 mCheckStates.clear(); 500 } 501 502 if (mCheckedIdStates != null) { 503 mCheckedIdStates.clear(); 504 } 505 506 requestLayout(); 507 } 508 509 510 /** 511 * The list is empty. Clear everything out. 512 */ 513 @Override 514 void resetList() { 515 // The parent's resetList() will remove all views from the layout so we need to 516 // cleanup the state of our footers and headers 517 clearRecycledState(mHeaderViewInfos); 518 clearRecycledState(mFooterViewInfos); 519 520 super.resetList(); 521 522 mLayoutMode = LAYOUT_NORMAL; 523 } 524 525 private void clearRecycledState(ArrayList<FixedViewInfo> infos) { 526 if (infos != null) { 527 final int count = infos.size(); 528 529 for (int i = 0; i < count; i++) { 530 final View child = infos.get(i).view; 531 final LayoutParams p = (LayoutParams) child.getLayoutParams(); 532 if (p != null) { 533 p.recycledHeaderFooter = false; 534 } 535 } 536 } 537 } 538 539 /** 540 * @return Whether the list needs to show the top fading edge 541 */ 542 private boolean showingTopFadingEdge() { 543 final int listTop = mScrollY + mListPadding.top; 544 return (mFirstPosition > 0) || (getChildAt(0).getTop() > listTop); 545 } 546 547 /** 548 * @return Whether the list needs to show the bottom fading edge 549 */ 550 private boolean showingBottomFadingEdge() { 551 final int childCount = getChildCount(); 552 final int bottomOfBottomChild = getChildAt(childCount - 1).getBottom(); 553 final int lastVisiblePosition = mFirstPosition + childCount - 1; 554 555 final int listBottom = mScrollY + getHeight() - mListPadding.bottom; 556 557 return (lastVisiblePosition < mItemCount - 1) 558 || (bottomOfBottomChild < listBottom); 559 } 560 561 562 @Override 563 public boolean requestChildRectangleOnScreen(View child, Rect rect, boolean immediate) { 564 565 int rectTopWithinChild = rect.top; 566 567 // offset so rect is in coordinates of the this view 568 rect.offset(child.getLeft(), child.getTop()); 569 rect.offset(-child.getScrollX(), -child.getScrollY()); 570 571 final int height = getHeight(); 572 int listUnfadedTop = getScrollY(); 573 int listUnfadedBottom = listUnfadedTop + height; 574 final int fadingEdge = getVerticalFadingEdgeLength(); 575 576 if (showingTopFadingEdge()) { 577 // leave room for top fading edge as long as rect isn't at very top 578 if ((mSelectedPosition > 0) || (rectTopWithinChild > fadingEdge)) { 579 listUnfadedTop += fadingEdge; 580 } 581 } 582 583 int childCount = getChildCount(); 584 int bottomOfBottomChild = getChildAt(childCount - 1).getBottom(); 585 586 if (showingBottomFadingEdge()) { 587 // leave room for bottom fading edge as long as rect isn't at very bottom 588 if ((mSelectedPosition < mItemCount - 1) 589 || (rect.bottom < (bottomOfBottomChild - fadingEdge))) { 590 listUnfadedBottom -= fadingEdge; 591 } 592 } 593 594 int scrollYDelta = 0; 595 596 if (rect.bottom > listUnfadedBottom && rect.top > listUnfadedTop) { 597 // need to MOVE DOWN to get it in view: move down just enough so 598 // that the entire rectangle is in view (or at least the first 599 // screen size chunk). 600 601 if (rect.height() > height) { 602 // just enough to get screen size chunk on 603 scrollYDelta += (rect.top - listUnfadedTop); 604 } else { 605 // get entire rect at bottom of screen 606 scrollYDelta += (rect.bottom - listUnfadedBottom); 607 } 608 609 // make sure we aren't scrolling beyond the end of our children 610 int distanceToBottom = bottomOfBottomChild - listUnfadedBottom; 611 scrollYDelta = Math.min(scrollYDelta, distanceToBottom); 612 } else if (rect.top < listUnfadedTop && rect.bottom < listUnfadedBottom) { 613 // need to MOVE UP to get it in view: move up just enough so that 614 // entire rectangle is in view (or at least the first screen 615 // size chunk of it). 616 617 if (rect.height() > height) { 618 // screen size chunk 619 scrollYDelta -= (listUnfadedBottom - rect.bottom); 620 } else { 621 // entire rect at top 622 scrollYDelta -= (listUnfadedTop - rect.top); 623 } 624 625 // make sure we aren't scrolling any further than the top our children 626 int top = getChildAt(0).getTop(); 627 int deltaToTop = top - listUnfadedTop; 628 scrollYDelta = Math.max(scrollYDelta, deltaToTop); 629 } 630 631 final boolean scroll = scrollYDelta != 0; 632 if (scroll) { 633 scrollListItemsBy(-scrollYDelta); 634 positionSelector(child); 635 mSelectedTop = child.getTop(); 636 invalidate(); 637 } 638 return scroll; 639 } 640 641 /** 642 * {@inheritDoc} 643 */ 644 @Override 645 void fillGap(boolean down) { 646 final int count = getChildCount(); 647 if (down) { 648 final int startOffset = count > 0 ? getChildAt(count - 1).getBottom() + mDividerHeight : 649 getListPaddingTop(); 650 fillDown(mFirstPosition + count, startOffset); 651 correctTooHigh(getChildCount()); 652 } else { 653 final int startOffset = count > 0 ? getChildAt(0).getTop() - mDividerHeight : 654 getHeight() - getListPaddingBottom(); 655 fillUp(mFirstPosition - 1, startOffset); 656 correctTooLow(getChildCount()); 657 } 658 } 659 660 /** 661 * Fills the list from pos down to the end of the list view. 662 * 663 * @param pos The first position to put in the list 664 * 665 * @param nextTop The location where the top of the item associated with pos 666 * should be drawn 667 * 668 * @return The view that is currently selected, if it happens to be in the 669 * range that we draw. 670 */ 671 private View fillDown(int pos, int nextTop) { 672 View selectedView = null; 673 674 int end = (mBottom - mTop) - mListPadding.bottom; 675 676 while (nextTop < end && pos < mItemCount) { 677 // is this the selected item? 678 boolean selected = pos == mSelectedPosition; 679 View child = makeAndAddView(pos, nextTop, true, mListPadding.left, selected); 680 681 nextTop = child.getBottom() + mDividerHeight; 682 if (selected) { 683 selectedView = child; 684 } 685 pos++; 686 } 687 688 return selectedView; 689 } 690 691 /** 692 * Fills the list from pos up to the top of the list view. 693 * 694 * @param pos The first position to put in the list 695 * 696 * @param nextBottom The location where the bottom of the item associated 697 * with pos should be drawn 698 * 699 * @return The view that is currently selected 700 */ 701 private View fillUp(int pos, int nextBottom) { 702 View selectedView = null; 703 704 int end = mListPadding.top; 705 706 while (nextBottom > end && pos >= 0) { 707 // is this the selected item? 708 boolean selected = pos == mSelectedPosition; 709 View child = makeAndAddView(pos, nextBottom, false, mListPadding.left, selected); 710 nextBottom = child.getTop() - mDividerHeight; 711 if (selected) { 712 selectedView = child; 713 } 714 pos--; 715 } 716 717 mFirstPosition = pos + 1; 718 719 return selectedView; 720 } 721 722 /** 723 * Fills the list from top to bottom, starting with mFirstPosition 724 * 725 * @param nextTop The location where the top of the first item should be 726 * drawn 727 * 728 * @return The view that is currently selected 729 */ 730 private View fillFromTop(int nextTop) { 731 mFirstPosition = Math.min(mFirstPosition, mSelectedPosition); 732 mFirstPosition = Math.min(mFirstPosition, mItemCount - 1); 733 if (mFirstPosition < 0) { 734 mFirstPosition = 0; 735 } 736 return fillDown(mFirstPosition, nextTop); 737 } 738 739 740 /** 741 * Put mSelectedPosition in the middle of the screen and then build up and 742 * down from there. This method forces mSelectedPosition to the center. 743 * 744 * @param childrenTop Top of the area in which children can be drawn, as 745 * measured in pixels 746 * @param childrenBottom Bottom of the area in which children can be drawn, 747 * as measured in pixels 748 * @return Currently selected view 749 */ 750 private View fillFromMiddle(int childrenTop, int childrenBottom) { 751 int height = childrenBottom - childrenTop; 752 753 int position = reconcileSelectedPosition(); 754 755 View sel = makeAndAddView(position, childrenTop, true, 756 mListPadding.left, true); 757 mFirstPosition = position; 758 759 int selHeight = sel.getMeasuredHeight(); 760 if (selHeight <= height) { 761 sel.offsetTopAndBottom((height - selHeight) / 2); 762 } 763 764 fillAboveAndBelow(sel, position); 765 766 if (!mStackFromBottom) { 767 correctTooHigh(getChildCount()); 768 } else { 769 correctTooLow(getChildCount()); 770 } 771 772 return sel; 773 } 774 775 /** 776 * Once the selected view as been placed, fill up the visible area above and 777 * below it. 778 * 779 * @param sel The selected view 780 * @param position The position corresponding to sel 781 */ 782 private void fillAboveAndBelow(View sel, int position) { 783 final int dividerHeight = mDividerHeight; 784 if (!mStackFromBottom) { 785 fillUp(position - 1, sel.getTop() - dividerHeight); 786 adjustViewsUpOrDown(); 787 fillDown(position + 1, sel.getBottom() + dividerHeight); 788 } else { 789 fillDown(position + 1, sel.getBottom() + dividerHeight); 790 adjustViewsUpOrDown(); 791 fillUp(position - 1, sel.getTop() - dividerHeight); 792 } 793 } 794 795 796 /** 797 * Fills the grid based on positioning the new selection at a specific 798 * location. The selection may be moved so that it does not intersect the 799 * faded edges. The grid is then filled upwards and downwards from there. 800 * 801 * @param selectedTop Where the selected item should be 802 * @param childrenTop Where to start drawing children 803 * @param childrenBottom Last pixel where children can be drawn 804 * @return The view that currently has selection 805 */ 806 private View fillFromSelection(int selectedTop, int childrenTop, int childrenBottom) { 807 int fadingEdgeLength = getVerticalFadingEdgeLength(); 808 final int selectedPosition = mSelectedPosition; 809 810 View sel; 811 812 final int topSelectionPixel = getTopSelectionPixel(childrenTop, fadingEdgeLength, 813 selectedPosition); 814 final int bottomSelectionPixel = getBottomSelectionPixel(childrenBottom, fadingEdgeLength, 815 selectedPosition); 816 817 sel = makeAndAddView(selectedPosition, selectedTop, true, mListPadding.left, true); 818 819 820 // Some of the newly selected item extends below the bottom of the list 821 if (sel.getBottom() > bottomSelectionPixel) { 822 // Find space available above the selection into which we can scroll 823 // upwards 824 final int spaceAbove = sel.getTop() - topSelectionPixel; 825 826 // Find space required to bring the bottom of the selected item 827 // fully into view 828 final int spaceBelow = sel.getBottom() - bottomSelectionPixel; 829 final int offset = Math.min(spaceAbove, spaceBelow); 830 831 // Now offset the selected item to get it into view 832 sel.offsetTopAndBottom(-offset); 833 } else if (sel.getTop() < topSelectionPixel) { 834 // Find space required to bring the top of the selected item fully 835 // into view 836 final int spaceAbove = topSelectionPixel - sel.getTop(); 837 838 // Find space available below the selection into which we can scroll 839 // downwards 840 final int spaceBelow = bottomSelectionPixel - sel.getBottom(); 841 final int offset = Math.min(spaceAbove, spaceBelow); 842 843 // Offset the selected item to get it into view 844 sel.offsetTopAndBottom(offset); 845 } 846 847 // Fill in views above and below 848 fillAboveAndBelow(sel, selectedPosition); 849 850 if (!mStackFromBottom) { 851 correctTooHigh(getChildCount()); 852 } else { 853 correctTooLow(getChildCount()); 854 } 855 856 return sel; 857 } 858 859 /** 860 * Calculate the bottom-most pixel we can draw the selection into 861 * 862 * @param childrenBottom Bottom pixel were children can be drawn 863 * @param fadingEdgeLength Length of the fading edge in pixels, if present 864 * @param selectedPosition The position that will be selected 865 * @return The bottom-most pixel we can draw the selection into 866 */ 867 private int getBottomSelectionPixel(int childrenBottom, int fadingEdgeLength, 868 int selectedPosition) { 869 int bottomSelectionPixel = childrenBottom; 870 if (selectedPosition != mItemCount - 1) { 871 bottomSelectionPixel -= fadingEdgeLength; 872 } 873 return bottomSelectionPixel; 874 } 875 876 /** 877 * Calculate the top-most pixel we can draw the selection into 878 * 879 * @param childrenTop Top pixel were children can be drawn 880 * @param fadingEdgeLength Length of the fading edge in pixels, if present 881 * @param selectedPosition The position that will be selected 882 * @return The top-most pixel we can draw the selection into 883 */ 884 private int getTopSelectionPixel(int childrenTop, int fadingEdgeLength, int selectedPosition) { 885 // first pixel we can draw the selection into 886 int topSelectionPixel = childrenTop; 887 if (selectedPosition > 0) { 888 topSelectionPixel += fadingEdgeLength; 889 } 890 return topSelectionPixel; 891 } 892 893 /** 894 * Smoothly scroll to the specified adapter position. The view will 895 * scroll such that the indicated position is displayed. 896 * @param position Scroll to this adapter position. 897 */ 898 @android.view.RemotableViewMethod 899 public void smoothScrollToPosition(int position) { 900 super.smoothScrollToPosition(position); 901 } 902 903 /** 904 * Smoothly scroll to the specified adapter position offset. The view will 905 * scroll such that the indicated position is displayed. 906 * @param offset The amount to offset from the adapter position to scroll to. 907 */ 908 @android.view.RemotableViewMethod 909 public void smoothScrollByOffset(int offset) { 910 super.smoothScrollByOffset(offset); 911 } 912 913 /** 914 * Fills the list based on positioning the new selection relative to the old 915 * selection. The new selection will be placed at, above, or below the 916 * location of the new selection depending on how the selection is moving. 917 * The selection will then be pinned to the visible part of the screen, 918 * excluding the edges that are faded. The list is then filled upwards and 919 * downwards from there. 920 * 921 * @param oldSel The old selected view. Useful for trying to put the new 922 * selection in the same place 923 * @param newSel The view that is to become selected. Useful for trying to 924 * put the new selection in the same place 925 * @param delta Which way we are moving 926 * @param childrenTop Where to start drawing children 927 * @param childrenBottom Last pixel where children can be drawn 928 * @return The view that currently has selection 929 */ 930 private View moveSelection(View oldSel, View newSel, int delta, int childrenTop, 931 int childrenBottom) { 932 int fadingEdgeLength = getVerticalFadingEdgeLength(); 933 final int selectedPosition = mSelectedPosition; 934 935 View sel; 936 937 final int topSelectionPixel = getTopSelectionPixel(childrenTop, fadingEdgeLength, 938 selectedPosition); 939 final int bottomSelectionPixel = getBottomSelectionPixel(childrenTop, fadingEdgeLength, 940 selectedPosition); 941 942 if (delta > 0) { 943 /* 944 * Case 1: Scrolling down. 945 */ 946 947 /* 948 * Before After 949 * | | | | 950 * +-------+ +-------+ 951 * | A | | A | 952 * | 1 | => +-------+ 953 * +-------+ | B | 954 * | B | | 2 | 955 * +-------+ +-------+ 956 * | | | | 957 * 958 * Try to keep the top of the previously selected item where it was. 959 * oldSel = A 960 * sel = B 961 */ 962 963 // Put oldSel (A) where it belongs 964 oldSel = makeAndAddView(selectedPosition - 1, oldSel.getTop(), true, 965 mListPadding.left, false); 966 967 final int dividerHeight = mDividerHeight; 968 969 // Now put the new selection (B) below that 970 sel = makeAndAddView(selectedPosition, oldSel.getBottom() + dividerHeight, true, 971 mListPadding.left, true); 972 973 // Some of the newly selected item extends below the bottom of the list 974 if (sel.getBottom() > bottomSelectionPixel) { 975 976 // Find space available above the selection into which we can scroll upwards 977 int spaceAbove = sel.getTop() - topSelectionPixel; 978 979 // Find space required to bring the bottom of the selected item fully into view 980 int spaceBelow = sel.getBottom() - bottomSelectionPixel; 981 982 // Don't scroll more than half the height of the list 983 int halfVerticalSpace = (childrenBottom - childrenTop) / 2; 984 int offset = Math.min(spaceAbove, spaceBelow); 985 offset = Math.min(offset, halfVerticalSpace); 986 987 // We placed oldSel, so offset that item 988 oldSel.offsetTopAndBottom(-offset); 989 // Now offset the selected item to get it into view 990 sel.offsetTopAndBottom(-offset); 991 } 992 993 // Fill in views above and below 994 if (!mStackFromBottom) { 995 fillUp(mSelectedPosition - 2, sel.getTop() - dividerHeight); 996 adjustViewsUpOrDown(); 997 fillDown(mSelectedPosition + 1, sel.getBottom() + dividerHeight); 998 } else { 999 fillDown(mSelectedPosition + 1, sel.getBottom() + dividerHeight); 1000 adjustViewsUpOrDown(); 1001 fillUp(mSelectedPosition - 2, sel.getTop() - dividerHeight); 1002 } 1003 } else if (delta < 0) { 1004 /* 1005 * Case 2: Scrolling up. 1006 */ 1007 1008 /* 1009 * Before After 1010 * | | | | 1011 * +-------+ +-------+ 1012 * | A | | A | 1013 * +-------+ => | 1 | 1014 * | B | +-------+ 1015 * | 2 | | B | 1016 * +-------+ +-------+ 1017 * | | | | 1018 * 1019 * Try to keep the top of the item about to become selected where it was. 1020 * newSel = A 1021 * olSel = B 1022 */ 1023 1024 if (newSel != null) { 1025 // Try to position the top of newSel (A) where it was before it was selected 1026 sel = makeAndAddView(selectedPosition, newSel.getTop(), true, mListPadding.left, 1027 true); 1028 } else { 1029 // If (A) was not on screen and so did not have a view, position 1030 // it above the oldSel (B) 1031 sel = makeAndAddView(selectedPosition, oldSel.getTop(), false, mListPadding.left, 1032 true); 1033 } 1034 1035 // Some of the newly selected item extends above the top of the list 1036 if (sel.getTop() < topSelectionPixel) { 1037 // Find space required to bring the top of the selected item fully into view 1038 int spaceAbove = topSelectionPixel - sel.getTop(); 1039 1040 // Find space available below the selection into which we can scroll downwards 1041 int spaceBelow = bottomSelectionPixel - sel.getBottom(); 1042 1043 // Don't scroll more than half the height of the list 1044 int halfVerticalSpace = (childrenBottom - childrenTop) / 2; 1045 int offset = Math.min(spaceAbove, spaceBelow); 1046 offset = Math.min(offset, halfVerticalSpace); 1047 1048 // Offset the selected item to get it into view 1049 sel.offsetTopAndBottom(offset); 1050 } 1051 1052 // Fill in views above and below 1053 fillAboveAndBelow(sel, selectedPosition); 1054 } else { 1055 1056 int oldTop = oldSel.getTop(); 1057 1058 /* 1059 * Case 3: Staying still 1060 */ 1061 sel = makeAndAddView(selectedPosition, oldTop, true, mListPadding.left, true); 1062 1063 // We're staying still... 1064 if (oldTop < childrenTop) { 1065 // ... but the top of the old selection was off screen. 1066 // (This can happen if the data changes size out from under us) 1067 int newBottom = sel.getBottom(); 1068 if (newBottom < childrenTop + 20) { 1069 // Not enough visible -- bring it onscreen 1070 sel.offsetTopAndBottom(childrenTop - sel.getTop()); 1071 } 1072 } 1073 1074 // Fill in views above and below 1075 fillAboveAndBelow(sel, selectedPosition); 1076 } 1077 1078 return sel; 1079 } 1080 1081 private class FocusSelector implements Runnable { 1082 private int mPosition; 1083 private int mPositionTop; 1084 1085 public FocusSelector setup(int position, int top) { 1086 mPosition = position; 1087 mPositionTop = top; 1088 return this; 1089 } 1090 1091 public void run() { 1092 setSelectionFromTop(mPosition, mPositionTop); 1093 } 1094 } 1095 1096 @Override 1097 protected void onSizeChanged(int w, int h, int oldw, int oldh) { 1098 if (getChildCount() > 0) { 1099 View focusedChild = getFocusedChild(); 1100 if (focusedChild != null) { 1101 final int childPosition = mFirstPosition + indexOfChild(focusedChild); 1102 final int childBottom = focusedChild.getBottom(); 1103 final int offset = Math.max(0, childBottom - (h - mPaddingTop)); 1104 final int top = focusedChild.getTop() - offset; 1105 if (mFocusSelector == null) { 1106 mFocusSelector = new FocusSelector(); 1107 } 1108 post(mFocusSelector.setup(childPosition, top)); 1109 } 1110 } 1111 super.onSizeChanged(w, h, oldw, oldh); 1112 } 1113 1114 @Override 1115 protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { 1116 // Sets up mListPadding 1117 super.onMeasure(widthMeasureSpec, heightMeasureSpec); 1118 1119 int widthMode = MeasureSpec.getMode(widthMeasureSpec); 1120 int heightMode = MeasureSpec.getMode(heightMeasureSpec); 1121 int widthSize = MeasureSpec.getSize(widthMeasureSpec); 1122 int heightSize = MeasureSpec.getSize(heightMeasureSpec); 1123 1124 int childWidth = 0; 1125 int childHeight = 0; 1126 1127 mItemCount = mAdapter == null ? 0 : mAdapter.getCount(); 1128 if (mItemCount > 0 && (widthMode == MeasureSpec.UNSPECIFIED || 1129 heightMode == MeasureSpec.UNSPECIFIED)) { 1130 final View child = obtainView(0, mIsScrap); 1131 1132 measureScrapChild(child, 0, widthMeasureSpec); 1133 1134 childWidth = child.getMeasuredWidth(); 1135 childHeight = child.getMeasuredHeight(); 1136 1137 if (recycleOnMeasure() && mRecycler.shouldRecycleViewType( 1138 ((LayoutParams) child.getLayoutParams()).viewType)) { 1139 mRecycler.addScrapView(child); 1140 } 1141 } 1142 1143 if (widthMode == MeasureSpec.UNSPECIFIED) { 1144 widthSize = mListPadding.left + mListPadding.right + childWidth + 1145 getVerticalScrollbarWidth(); 1146 } 1147 1148 if (heightMode == MeasureSpec.UNSPECIFIED) { 1149 heightSize = mListPadding.top + mListPadding.bottom + childHeight + 1150 getVerticalFadingEdgeLength() * 2; 1151 } 1152 1153 if (heightMode == MeasureSpec.AT_MOST) { 1154 // TODO: after first layout we should maybe start at the first visible position, not 0 1155 heightSize = measureHeightOfChildren(widthMeasureSpec, 0, NO_POSITION, heightSize, -1); 1156 } 1157 1158 setMeasuredDimension(widthSize, heightSize); 1159 mWidthMeasureSpec = widthMeasureSpec; 1160 } 1161 1162 private void measureScrapChild(View child, int position, int widthMeasureSpec) { 1163 LayoutParams p = (LayoutParams) child.getLayoutParams(); 1164 if (p == null) { 1165 p = new LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, 1166 ViewGroup.LayoutParams.WRAP_CONTENT, 0); 1167 child.setLayoutParams(p); 1168 } 1169 p.viewType = mAdapter.getItemViewType(position); 1170 p.forceAdd = true; 1171 1172 int childWidthSpec = ViewGroup.getChildMeasureSpec(widthMeasureSpec, 1173 mListPadding.left + mListPadding.right, p.width); 1174 int lpHeight = p.height; 1175 int childHeightSpec; 1176 if (lpHeight > 0) { 1177 childHeightSpec = MeasureSpec.makeMeasureSpec(lpHeight, MeasureSpec.EXACTLY); 1178 } else { 1179 childHeightSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED); 1180 } 1181 child.measure(childWidthSpec, childHeightSpec); 1182 } 1183 1184 /** 1185 * @return True to recycle the views used to measure this ListView in 1186 * UNSPECIFIED/AT_MOST modes, false otherwise. 1187 * @hide 1188 */ 1189 @ViewDebug.ExportedProperty 1190 protected boolean recycleOnMeasure() { 1191 return true; 1192 } 1193 1194 /** 1195 * Measures the height of the given range of children (inclusive) and 1196 * returns the height with this ListView's padding and divider heights 1197 * included. If maxHeight is provided, the measuring will stop when the 1198 * current height reaches maxHeight. 1199 * 1200 * @param widthMeasureSpec The width measure spec to be given to a child's 1201 * {@link View#measure(int, int)}. 1202 * @param startPosition The position of the first child to be shown. 1203 * @param endPosition The (inclusive) position of the last child to be 1204 * shown. Specify {@link #NO_POSITION} if the last child should be 1205 * the last available child from the adapter. 1206 * @param maxHeight The maximum height that will be returned (if all the 1207 * children don't fit in this value, this value will be 1208 * returned). 1209 * @param disallowPartialChildPosition In general, whether the returned 1210 * height should only contain entire children. This is more 1211 * powerful--it is the first inclusive position at which partial 1212 * children will not be allowed. Example: it looks nice to have 1213 * at least 3 completely visible children, and in portrait this 1214 * will most likely fit; but in landscape there could be times 1215 * when even 2 children can not be completely shown, so a value 1216 * of 2 (remember, inclusive) would be good (assuming 1217 * startPosition is 0). 1218 * @return The height of this ListView with the given children. 1219 */ 1220 final int measureHeightOfChildren(int widthMeasureSpec, int startPosition, int endPosition, 1221 final int maxHeight, int disallowPartialChildPosition) { 1222 1223 final ListAdapter adapter = mAdapter; 1224 if (adapter == null) { 1225 return mListPadding.top + mListPadding.bottom; 1226 } 1227 1228 // Include the padding of the list 1229 int returnedHeight = mListPadding.top + mListPadding.bottom; 1230 final int dividerHeight = ((mDividerHeight > 0) && mDivider != null) ? mDividerHeight : 0; 1231 // The previous height value that was less than maxHeight and contained 1232 // no partial children 1233 int prevHeightWithoutPartialChild = 0; 1234 int i; 1235 View child; 1236 1237 // mItemCount - 1 since endPosition parameter is inclusive 1238 endPosition = (endPosition == NO_POSITION) ? adapter.getCount() - 1 : endPosition; 1239 final AbsListView.RecycleBin recycleBin = mRecycler; 1240 final boolean recyle = recycleOnMeasure(); 1241 final boolean[] isScrap = mIsScrap; 1242 1243 for (i = startPosition; i <= endPosition; ++i) { 1244 child = obtainView(i, isScrap); 1245 1246 measureScrapChild(child, i, widthMeasureSpec); 1247 1248 if (i > 0) { 1249 // Count the divider for all but one child 1250 returnedHeight += dividerHeight; 1251 } 1252 1253 // Recycle the view before we possibly return from the method 1254 if (recyle && recycleBin.shouldRecycleViewType( 1255 ((LayoutParams) child.getLayoutParams()).viewType)) { 1256 recycleBin.addScrapView(child); 1257 } 1258 1259 returnedHeight += child.getMeasuredHeight(); 1260 1261 if (returnedHeight >= maxHeight) { 1262 // We went over, figure out which height to return. If returnedHeight > maxHeight, 1263 // then the i'th position did not fit completely. 1264 return (disallowPartialChildPosition >= 0) // Disallowing is enabled (> -1) 1265 && (i > disallowPartialChildPosition) // We've past the min pos 1266 && (prevHeightWithoutPartialChild > 0) // We have a prev height 1267 && (returnedHeight != maxHeight) // i'th child did not fit completely 1268 ? prevHeightWithoutPartialChild 1269 : maxHeight; 1270 } 1271 1272 if ((disallowPartialChildPosition >= 0) && (i >= disallowPartialChildPosition)) { 1273 prevHeightWithoutPartialChild = returnedHeight; 1274 } 1275 } 1276 1277 // At this point, we went through the range of children, and they each 1278 // completely fit, so return the returnedHeight 1279 return returnedHeight; 1280 } 1281 1282 @Override 1283 int findMotionRow(int y) { 1284 int childCount = getChildCount(); 1285 if (childCount > 0) { 1286 if (!mStackFromBottom) { 1287 for (int i = 0; i < childCount; i++) { 1288 View v = getChildAt(i); 1289 if (y <= v.getBottom()) { 1290 return mFirstPosition + i; 1291 } 1292 } 1293 } else { 1294 for (int i = childCount - 1; i >= 0; i--) { 1295 View v = getChildAt(i); 1296 if (y >= v.getTop()) { 1297 return mFirstPosition + i; 1298 } 1299 } 1300 } 1301 } 1302 return INVALID_POSITION; 1303 } 1304 1305 /** 1306 * Put a specific item at a specific location on the screen and then build 1307 * up and down from there. 1308 * 1309 * @param position The reference view to use as the starting point 1310 * @param top Pixel offset from the top of this view to the top of the 1311 * reference view. 1312 * 1313 * @return The selected view, or null if the selected view is outside the 1314 * visible area. 1315 */ 1316 private View fillSpecific(int position, int top) { 1317 boolean tempIsSelected = position == mSelectedPosition; 1318 View temp = makeAndAddView(position, top, true, mListPadding.left, tempIsSelected); 1319 // Possibly changed again in fillUp if we add rows above this one. 1320 mFirstPosition = position; 1321 1322 View above; 1323 View below; 1324 1325 final int dividerHeight = mDividerHeight; 1326 if (!mStackFromBottom) { 1327 above = fillUp(position - 1, temp.getTop() - dividerHeight); 1328 // This will correct for the top of the first view not touching the top of the list 1329 adjustViewsUpOrDown(); 1330 below = fillDown(position + 1, temp.getBottom() + dividerHeight); 1331 int childCount = getChildCount(); 1332 if (childCount > 0) { 1333 correctTooHigh(childCount); 1334 } 1335 } else { 1336 below = fillDown(position + 1, temp.getBottom() + dividerHeight); 1337 // This will correct for the bottom of the last view not touching the bottom of the list 1338 adjustViewsUpOrDown(); 1339 above = fillUp(position - 1, temp.getTop() - dividerHeight); 1340 int childCount = getChildCount(); 1341 if (childCount > 0) { 1342 correctTooLow(childCount); 1343 } 1344 } 1345 1346 if (tempIsSelected) { 1347 return temp; 1348 } else if (above != null) { 1349 return above; 1350 } else { 1351 return below; 1352 } 1353 } 1354 1355 /** 1356 * Check if we have dragged the bottom of the list too high (we have pushed the 1357 * top element off the top of the screen when we did not need to). Correct by sliding 1358 * everything back down. 1359 * 1360 * @param childCount Number of children 1361 */ 1362 private void correctTooHigh(int childCount) { 1363 // First see if the last item is visible. If it is not, it is OK for the 1364 // top of the list to be pushed up. 1365 int lastPosition = mFirstPosition + childCount - 1; 1366 if (lastPosition == mItemCount - 1 && childCount > 0) { 1367 1368 // Get the last child ... 1369 final View lastChild = getChildAt(childCount - 1); 1370 1371 // ... and its bottom edge 1372 final int lastBottom = lastChild.getBottom(); 1373 1374 // This is bottom of our drawable area 1375 final int end = (mBottom - mTop) - mListPadding.bottom; 1376 1377 // This is how far the bottom edge of the last view is from the bottom of the 1378 // drawable area 1379 int bottomOffset = end - lastBottom; 1380 View firstChild = getChildAt(0); 1381 final int firstTop = firstChild.getTop(); 1382 1383 // Make sure we are 1) Too high, and 2) Either there are more rows above the 1384 // first row or the first row is scrolled off the top of the drawable area 1385 if (bottomOffset > 0 && (mFirstPosition > 0 || firstTop < mListPadding.top)) { 1386 if (mFirstPosition == 0) { 1387 // Don't pull the top too far down 1388 bottomOffset = Math.min(bottomOffset, mListPadding.top - firstTop); 1389 } 1390 // Move everything down 1391 offsetChildrenTopAndBottom(bottomOffset); 1392 if (mFirstPosition > 0) { 1393 // Fill the gap that was opened above mFirstPosition with more rows, if 1394 // possible 1395 fillUp(mFirstPosition - 1, firstChild.getTop() - mDividerHeight); 1396 // Close up the remaining gap 1397 adjustViewsUpOrDown(); 1398 } 1399 1400 } 1401 } 1402 } 1403 1404 /** 1405 * Check if we have dragged the bottom of the list too low (we have pushed the 1406 * bottom element off the bottom of the screen when we did not need to). Correct by sliding 1407 * everything back up. 1408 * 1409 * @param childCount Number of children 1410 */ 1411 private void correctTooLow(int childCount) { 1412 // First see if the first item is visible. If it is not, it is OK for the 1413 // bottom of the list to be pushed down. 1414 if (mFirstPosition == 0 && childCount > 0) { 1415 1416 // Get the first child ... 1417 final View firstChild = getChildAt(0); 1418 1419 // ... and its top edge 1420 final int firstTop = firstChild.getTop(); 1421 1422 // This is top of our drawable area 1423 final int start = mListPadding.top; 1424 1425 // This is bottom of our drawable area 1426 final int end = (mBottom - mTop) - mListPadding.bottom; 1427 1428 // This is how far the top edge of the first view is from the top of the 1429 // drawable area 1430 int topOffset = firstTop - start; 1431 View lastChild = getChildAt(childCount - 1); 1432 final int lastBottom = lastChild.getBottom(); 1433 int lastPosition = mFirstPosition + childCount - 1; 1434 1435 // Make sure we are 1) Too low, and 2) Either there are more rows below the 1436 // last row or the last row is scrolled off the bottom of the drawable area 1437 if (topOffset > 0) { 1438 if (lastPosition < mItemCount - 1 || lastBottom > end) { 1439 if (lastPosition == mItemCount - 1) { 1440 // Don't pull the bottom too far up 1441 topOffset = Math.min(topOffset, lastBottom - end); 1442 } 1443 // Move everything up 1444 offsetChildrenTopAndBottom(-topOffset); 1445 if (lastPosition < mItemCount - 1) { 1446 // Fill the gap that was opened below the last position with more rows, if 1447 // possible 1448 fillDown(lastPosition + 1, lastChild.getBottom() + mDividerHeight); 1449 // Close up the remaining gap 1450 adjustViewsUpOrDown(); 1451 } 1452 } else if (lastPosition == mItemCount - 1) { 1453 adjustViewsUpOrDown(); 1454 } 1455 } 1456 } 1457 } 1458 1459 @Override 1460 protected void layoutChildren() { 1461 final boolean blockLayoutRequests = mBlockLayoutRequests; 1462 if (!blockLayoutRequests) { 1463 mBlockLayoutRequests = true; 1464 } else { 1465 return; 1466 } 1467 1468 try { 1469 super.layoutChildren(); 1470 1471 invalidate(); 1472 1473 if (mAdapter == null) { 1474 resetList(); 1475 invokeOnItemScrollListener(); 1476 return; 1477 } 1478 1479 int childrenTop = mListPadding.top; 1480 int childrenBottom = mBottom - mTop - mListPadding.bottom; 1481 1482 int childCount = getChildCount(); 1483 int index = 0; 1484 int delta = 0; 1485 1486 View sel; 1487 View oldSel = null; 1488 View oldFirst = null; 1489 View newSel = null; 1490 1491 View focusLayoutRestoreView = null; 1492 1493 // Remember stuff we will need down below 1494 switch (mLayoutMode) { 1495 case LAYOUT_SET_SELECTION: 1496 index = mNextSelectedPosition - mFirstPosition; 1497 if (index >= 0 && index < childCount) { 1498 newSel = getChildAt(index); 1499 } 1500 break; 1501 case LAYOUT_FORCE_TOP: 1502 case LAYOUT_FORCE_BOTTOM: 1503 case LAYOUT_SPECIFIC: 1504 case LAYOUT_SYNC: 1505 break; 1506 case LAYOUT_MOVE_SELECTION: 1507 default: 1508 // Remember the previously selected view 1509 index = mSelectedPosition - mFirstPosition; 1510 if (index >= 0 && index < childCount) { 1511 oldSel = getChildAt(index); 1512 } 1513 1514 // Remember the previous first child 1515 oldFirst = getChildAt(0); 1516 1517 if (mNextSelectedPosition >= 0) { 1518 delta = mNextSelectedPosition - mSelectedPosition; 1519 } 1520 1521 // Caution: newSel might be null 1522 newSel = getChildAt(index + delta); 1523 } 1524 1525 1526 boolean dataChanged = mDataChanged; 1527 if (dataChanged) { 1528 handleDataChanged(); 1529 } 1530 1531 // Handle the empty set by removing all views that are visible 1532 // and calling it a day 1533 if (mItemCount == 0) { 1534 resetList(); 1535 invokeOnItemScrollListener(); 1536 return; 1537 } else if (mItemCount != mAdapter.getCount()) { 1538 throw new IllegalStateException("The content of the adapter has changed but " 1539 + "ListView did not receive a notification. Make sure the content of " 1540 + "your adapter is not modified from a background thread, but only " 1541 + "from the UI thread. [in ListView(" + getId() + ", " + getClass() 1542 + ") with Adapter(" + mAdapter.getClass() + ")]"); 1543 } 1544 1545 setSelectedPositionInt(mNextSelectedPosition); 1546 1547 // Pull all children into the RecycleBin. 1548 // These views will be reused if possible 1549 final int firstPosition = mFirstPosition; 1550 final RecycleBin recycleBin = mRecycler; 1551 1552 // reset the focus restoration 1553 View focusLayoutRestoreDirectChild = null; 1554 1555 1556 // Don't put header or footer views into the Recycler. Those are 1557 // already cached in mHeaderViews; 1558 if (dataChanged) { 1559 for (int i = 0; i < childCount; i++) { 1560 recycleBin.addScrapView(getChildAt(i)); 1561 if (ViewDebug.TRACE_RECYCLER) { 1562 ViewDebug.trace(getChildAt(i), 1563 ViewDebug.RecyclerTraceType.MOVE_TO_SCRAP_HEAP, index, i); 1564 } 1565 } 1566 } else { 1567 recycleBin.fillActiveViews(childCount, firstPosition); 1568 } 1569 1570 // take focus back to us temporarily to avoid the eventual 1571 // call to clear focus when removing the focused child below 1572 // from messing things up when ViewRoot assigns focus back 1573 // to someone else 1574 final View focusedChild = getFocusedChild(); 1575 if (focusedChild != null) { 1576 // TODO: in some cases focusedChild.getParent() == null 1577 1578 // we can remember the focused view to restore after relayout if the 1579 // data hasn't changed, or if the focused position is a header or footer 1580 if (!dataChanged || isDirectChildHeaderOrFooter(focusedChild)) { 1581 focusLayoutRestoreDirectChild = focusedChild; 1582 // remember the specific view that had focus 1583 focusLayoutRestoreView = findFocus(); 1584 if (focusLayoutRestoreView != null) { 1585 // tell it we are going to mess with it 1586 focusLayoutRestoreView.onStartTemporaryDetach(); 1587 } 1588 } 1589 requestFocus(); 1590 } 1591 1592 // Clear out old views 1593 detachAllViewsFromParent(); 1594 1595 switch (mLayoutMode) { 1596 case LAYOUT_SET_SELECTION: 1597 if (newSel != null) { 1598 sel = fillFromSelection(newSel.getTop(), childrenTop, childrenBottom); 1599 } else { 1600 sel = fillFromMiddle(childrenTop, childrenBottom); 1601 } 1602 break; 1603 case LAYOUT_SYNC: 1604 sel = fillSpecific(mSyncPosition, mSpecificTop); 1605 break; 1606 case LAYOUT_FORCE_BOTTOM: 1607 sel = fillUp(mItemCount - 1, childrenBottom); 1608 adjustViewsUpOrDown(); 1609 break; 1610 case LAYOUT_FORCE_TOP: 1611 mFirstPosition = 0; 1612 sel = fillFromTop(childrenTop); 1613 adjustViewsUpOrDown(); 1614 break; 1615 case LAYOUT_SPECIFIC: 1616 sel = fillSpecific(reconcileSelectedPosition(), mSpecificTop); 1617 break; 1618 case LAYOUT_MOVE_SELECTION: 1619 sel = moveSelection(oldSel, newSel, delta, childrenTop, childrenBottom); 1620 break; 1621 default: 1622 if (childCount == 0) { 1623 if (!mStackFromBottom) { 1624 final int position = lookForSelectablePosition(0, true); 1625 setSelectedPositionInt(position); 1626 sel = fillFromTop(childrenTop); 1627 } else { 1628 final int position = lookForSelectablePosition(mItemCount - 1, false); 1629 setSelectedPositionInt(position); 1630 sel = fillUp(mItemCount - 1, childrenBottom); 1631 } 1632 } else { 1633 if (mSelectedPosition >= 0 && mSelectedPosition < mItemCount) { 1634 sel = fillSpecific(mSelectedPosition, 1635 oldSel == null ? childrenTop : oldSel.getTop()); 1636 } else if (mFirstPosition < mItemCount) { 1637 sel = fillSpecific(mFirstPosition, 1638 oldFirst == null ? childrenTop : oldFirst.getTop()); 1639 } else { 1640 sel = fillSpecific(0, childrenTop); 1641 } 1642 } 1643 break; 1644 } 1645 1646 // Flush any cached views that did not get reused above 1647 recycleBin.scrapActiveViews(); 1648 1649 if (sel != null) { 1650 // the current selected item should get focus if items 1651 // are focusable 1652 if (mItemsCanFocus && hasFocus() && !sel.hasFocus()) { 1653 final boolean focusWasTaken = (sel == focusLayoutRestoreDirectChild && 1654 focusLayoutRestoreView.requestFocus()) || sel.requestFocus(); 1655 if (!focusWasTaken) { 1656 // selected item didn't take focus, fine, but still want 1657 // to make sure something else outside of the selected view 1658 // has focus 1659 final View focused = getFocusedChild(); 1660 if (focused != null) { 1661 focused.clearFocus(); 1662 } 1663 positionSelector(sel); 1664 } else { 1665 sel.setSelected(false); 1666 mSelectorRect.setEmpty(); 1667 } 1668 } else { 1669 positionSelector(sel); 1670 } 1671 mSelectedTop = sel.getTop(); 1672 } else { 1673 if (mTouchMode > TOUCH_MODE_DOWN && mTouchMode < TOUCH_MODE_SCROLL) { 1674 View child = getChildAt(mMotionPosition - mFirstPosition); 1675 if (child != null) positionSelector(child); 1676 } else { 1677 mSelectedTop = 0; 1678 mSelectorRect.setEmpty(); 1679 } 1680 1681 // even if there is not selected position, we may need to restore 1682 // focus (i.e. something focusable in touch mode) 1683 if (hasFocus() && focusLayoutRestoreView != null) { 1684 focusLayoutRestoreView.requestFocus(); 1685 } 1686 } 1687 1688 // tell focus view we are done mucking with it, if it is still in 1689 // our view hierarchy. 1690 if (focusLayoutRestoreView != null 1691 && focusLayoutRestoreView.getWindowToken() != null) { 1692 focusLayoutRestoreView.onFinishTemporaryDetach(); 1693 } 1694 1695 mLayoutMode = LAYOUT_NORMAL; 1696 mDataChanged = false; 1697 mNeedSync = false; 1698 setNextSelectedPositionInt(mSelectedPosition); 1699 1700 updateScrollIndicators(); 1701 1702 if (mItemCount > 0) { 1703 checkSelectionChanged(); 1704 } 1705 1706 invokeOnItemScrollListener(); 1707 } finally { 1708 if (!blockLayoutRequests) { 1709 mBlockLayoutRequests = false; 1710 } 1711 } 1712 } 1713 1714 /** 1715 * @param child a direct child of this list. 1716 * @return Whether child is a header or footer view. 1717 */ 1718 private boolean isDirectChildHeaderOrFooter(View child) { 1719 1720 final ArrayList<FixedViewInfo> headers = mHeaderViewInfos; 1721 final int numHeaders = headers.size(); 1722 for (int i = 0; i < numHeaders; i++) { 1723 if (child == headers.get(i).view) { 1724 return true; 1725 } 1726 } 1727 final ArrayList<FixedViewInfo> footers = mFooterViewInfos; 1728 final int numFooters = footers.size(); 1729 for (int i = 0; i < numFooters; i++) { 1730 if (child == footers.get(i).view) { 1731 return true; 1732 } 1733 } 1734 return false; 1735 } 1736 1737 /** 1738 * Obtain the view and add it to our list of children. The view can be made 1739 * fresh, converted from an unused view, or used as is if it was in the 1740 * recycle bin. 1741 * 1742 * @param position Logical position in the list 1743 * @param y Top or bottom edge of the view to add 1744 * @param flow If flow is true, align top edge to y. If false, align bottom 1745 * edge to y. 1746 * @param childrenLeft Left edge where children should be positioned 1747 * @param selected Is this position selected? 1748 * @return View that was added 1749 */ 1750 private View makeAndAddView(int position, int y, boolean flow, int childrenLeft, 1751 boolean selected) { 1752 View child; 1753 1754 1755 if (!mDataChanged) { 1756 // Try to use an exsiting view for this position 1757 child = mRecycler.getActiveView(position); 1758 if (child != null) { 1759 if (ViewDebug.TRACE_RECYCLER) { 1760 ViewDebug.trace(child, ViewDebug.RecyclerTraceType.RECYCLE_FROM_ACTIVE_HEAP, 1761 position, getChildCount()); 1762 } 1763 1764 // Found it -- we're using an existing child 1765 // This just needs to be positioned 1766 setupChild(child, position, y, flow, childrenLeft, selected, true); 1767 1768 return child; 1769 } 1770 } 1771 1772 // Make a new view for this position, or convert an unused view if possible 1773 child = obtainView(position, mIsScrap); 1774 1775 // This needs to be positioned and measured 1776 setupChild(child, position, y, flow, childrenLeft, selected, mIsScrap[0]); 1777 1778 return child; 1779 } 1780 1781 /** 1782 * Add a view as a child and make sure it is measured (if necessary) and 1783 * positioned properly. 1784 * 1785 * @param child The view to add 1786 * @param position The position of this child 1787 * @param y The y position relative to which this view will be positioned 1788 * @param flowDown If true, align top edge to y. If false, align bottom 1789 * edge to y. 1790 * @param childrenLeft Left edge where children should be positioned 1791 * @param selected Is this position selected? 1792 * @param recycled Has this view been pulled from the recycle bin? If so it 1793 * does not need to be remeasured. 1794 */ 1795 private void setupChild(View child, int position, int y, boolean flowDown, int childrenLeft, 1796 boolean selected, boolean recycled) { 1797 final boolean isSelected = selected && shouldShowSelector(); 1798 final boolean updateChildSelected = isSelected != child.isSelected(); 1799 final int mode = mTouchMode; 1800 final boolean isPressed = mode > TOUCH_MODE_DOWN && mode < TOUCH_MODE_SCROLL && 1801 mMotionPosition == position; 1802 final boolean updateChildPressed = isPressed != child.isPressed(); 1803 final boolean needToMeasure = !recycled || updateChildSelected || child.isLayoutRequested(); 1804 1805 // Respect layout params that are already in the view. Otherwise make some up... 1806 // noinspection unchecked 1807 AbsListView.LayoutParams p = (AbsListView.LayoutParams) child.getLayoutParams(); 1808 if (p == null) { 1809 p = new AbsListView.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, 1810 ViewGroup.LayoutParams.WRAP_CONTENT, 0); 1811 } 1812 p.viewType = mAdapter.getItemViewType(position); 1813 1814 if ((recycled && !p.forceAdd) || (p.recycledHeaderFooter && 1815 p.viewType == AdapterView.ITEM_VIEW_TYPE_HEADER_OR_FOOTER)) { 1816 attachViewToParent(child, flowDown ? -1 : 0, p); 1817 } else { 1818 p.forceAdd = false; 1819 if (p.viewType == AdapterView.ITEM_VIEW_TYPE_HEADER_OR_FOOTER) { 1820 p.recycledHeaderFooter = true; 1821 } 1822 addViewInLayout(child, flowDown ? -1 : 0, p, true); 1823 } 1824 1825 if (updateChildSelected) { 1826 child.setSelected(isSelected); 1827 } 1828 1829 if (updateChildPressed) { 1830 child.setPressed(isPressed); 1831 } 1832 1833 if (mChoiceMode != CHOICE_MODE_NONE && mCheckStates != null) { 1834 if (child instanceof Checkable) { 1835 ((Checkable) child).setChecked(mCheckStates.get(position)); 1836 } 1837 } 1838 1839 if (needToMeasure) { 1840 int childWidthSpec = ViewGroup.getChildMeasureSpec(mWidthMeasureSpec, 1841 mListPadding.left + mListPadding.right, p.width); 1842 int lpHeight = p.height; 1843 int childHeightSpec; 1844 if (lpHeight > 0) { 1845 childHeightSpec = MeasureSpec.makeMeasureSpec(lpHeight, MeasureSpec.EXACTLY); 1846 } else { 1847 childHeightSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED); 1848 } 1849 child.measure(childWidthSpec, childHeightSpec); 1850 } else { 1851 cleanupLayoutState(child); 1852 } 1853 1854 final int w = child.getMeasuredWidth(); 1855 final int h = child.getMeasuredHeight(); 1856 final int childTop = flowDown ? y : y - h; 1857 1858 if (needToMeasure) { 1859 final int childRight = childrenLeft + w; 1860 final int childBottom = childTop + h; 1861 child.layout(childrenLeft, childTop, childRight, childBottom); 1862 } else { 1863 child.offsetLeftAndRight(childrenLeft - child.getLeft()); 1864 child.offsetTopAndBottom(childTop - child.getTop()); 1865 } 1866 1867 if (mCachingStarted && !child.isDrawingCacheEnabled()) { 1868 child.setDrawingCacheEnabled(true); 1869 } 1870 } 1871 1872 @Override 1873 protected boolean canAnimate() { 1874 return super.canAnimate() && mItemCount > 0; 1875 } 1876 1877 /** 1878 * Sets the currently selected item. If in touch mode, the item will not be selected 1879 * but it will still be positioned appropriately. If the specified selection position 1880 * is less than 0, then the item at position 0 will be selected. 1881 * 1882 * @param position Index (starting at 0) of the data item to be selected. 1883 */ 1884 @Override 1885 public void setSelection(int position) { 1886 setSelectionFromTop(position, 0); 1887 } 1888 1889 /** 1890 * Sets the selected item and positions the selection y pixels from the top edge 1891 * of the ListView. (If in touch mode, the item will not be selected but it will 1892 * still be positioned appropriately.) 1893 * 1894 * @param position Index (starting at 0) of the data item to be selected. 1895 * @param y The distance from the top edge of the ListView (plus padding) that the 1896 * item will be positioned. 1897 */ 1898 public void setSelectionFromTop(int position, int y) { 1899 if (mAdapter == null) { 1900 return; 1901 } 1902 1903 if (!isInTouchMode()) { 1904 position = lookForSelectablePosition(position, true); 1905 if (position >= 0) { 1906 setNextSelectedPositionInt(position); 1907 } 1908 } else { 1909 mResurrectToPosition = position; 1910 } 1911 1912 if (position >= 0) { 1913 mLayoutMode = LAYOUT_SPECIFIC; 1914 mSpecificTop = mListPadding.top + y; 1915 1916 if (mNeedSync) { 1917 mSyncPosition = position; 1918 mSyncRowId = mAdapter.getItemId(position); 1919 } 1920 1921 requestLayout(); 1922 } 1923 } 1924 1925 /** 1926 * Makes the item at the supplied position selected. 1927 * 1928 * @param position the position of the item to select 1929 */ 1930 @Override 1931 void setSelectionInt(int position) { 1932 setNextSelectedPositionInt(position); 1933 boolean awakeScrollbars = false; 1934 1935 final int selectedPosition = mSelectedPosition; 1936 1937 if (selectedPosition >= 0) { 1938 if (position == selectedPosition - 1) { 1939 awakeScrollbars = true; 1940 } else if (position == selectedPosition + 1) { 1941 awakeScrollbars = true; 1942 } 1943 } 1944 1945 layoutChildren(); 1946 1947 if (awakeScrollbars) { 1948 awakenScrollBars(); 1949 } 1950 } 1951 1952 /** 1953 * Find a position that can be selected (i.e., is not a separator). 1954 * 1955 * @param position The starting position to look at. 1956 * @param lookDown Whether to look down for other positions. 1957 * @return The next selectable position starting at position and then searching either up or 1958 * down. Returns {@link #INVALID_POSITION} if nothing can be found. 1959 */ 1960 @Override 1961 int lookForSelectablePosition(int position, boolean lookDown) { 1962 final ListAdapter adapter = mAdapter; 1963 if (adapter == null || isInTouchMode()) { 1964 return INVALID_POSITION; 1965 } 1966 1967 final int count = adapter.getCount(); 1968 if (!mAreAllItemsSelectable) { 1969 if (lookDown) { 1970 position = Math.max(0, position); 1971 while (position < count && !adapter.isEnabled(position)) { 1972 position++; 1973 } 1974 } else { 1975 position = Math.min(position, count - 1); 1976 while (position >= 0 && !adapter.isEnabled(position)) { 1977 position--; 1978 } 1979 } 1980 1981 if (position < 0 || position >= count) { 1982 return INVALID_POSITION; 1983 } 1984 return position; 1985 } else { 1986 if (position < 0 || position >= count) { 1987 return INVALID_POSITION; 1988 } 1989 return position; 1990 } 1991 } 1992 1993 @Override 1994 public boolean dispatchPopulateAccessibilityEvent(AccessibilityEvent event) { 1995 boolean populated = super.dispatchPopulateAccessibilityEvent(event); 1996 1997 // If the item count is less than 15 then subtract disabled items from the count and 1998 // position. Otherwise ignore disabled items. 1999 if (!populated) { 2000 int itemCount = 0; 2001 int currentItemIndex = getSelectedItemPosition(); 2002 2003 ListAdapter adapter = getAdapter(); 2004 if (adapter != null) { 2005 final int count = adapter.getCount(); 2006 if (count < 15) { 2007 for (int i = 0; i < count; i++) { 2008 if (adapter.isEnabled(i)) { 2009 itemCount++; 2010 } else if (i <= currentItemIndex) { 2011 currentItemIndex--; 2012 } 2013 } 2014 } else { 2015 itemCount = count; 2016 } 2017 } 2018 2019 event.setItemCount(itemCount); 2020 event.setCurrentItemIndex(currentItemIndex); 2021 } 2022 2023 return populated; 2024 } 2025 2026 /** 2027 * setSelectionAfterHeaderView set the selection to be the first list item 2028 * after the header views. 2029 */ 2030 public void setSelectionAfterHeaderView() { 2031 final int count = mHeaderViewInfos.size(); 2032 if (count > 0) { 2033 mNextSelectedPosition = 0; 2034 return; 2035 } 2036 2037 if (mAdapter != null) { 2038 setSelection(count); 2039 } else { 2040 mNextSelectedPosition = count; 2041 mLayoutMode = LAYOUT_SET_SELECTION; 2042 } 2043 2044 } 2045 2046 @Override 2047 public boolean dispatchKeyEvent(KeyEvent event) { 2048 // Dispatch in the normal way 2049 boolean handled = super.dispatchKeyEvent(event); 2050 if (!handled) { 2051 // If we didn't handle it... 2052 View focused = getFocusedChild(); 2053 if (focused != null && event.getAction() == KeyEvent.ACTION_DOWN) { 2054 // ... and our focused child didn't handle it 2055 // ... give it to ourselves so we can scroll if necessary 2056 handled = onKeyDown(event.getKeyCode(), event); 2057 } 2058 } 2059 return handled; 2060 } 2061 2062 @Override 2063 public boolean onKeyDown(int keyCode, KeyEvent event) { 2064 return commonKey(keyCode, 1, event); 2065 } 2066 2067 @Override 2068 public boolean onKeyMultiple(int keyCode, int repeatCount, KeyEvent event) { 2069 return commonKey(keyCode, repeatCount, event); 2070 } 2071 2072 @Override 2073 public boolean onKeyUp(int keyCode, KeyEvent event) { 2074 return commonKey(keyCode, 1, event); 2075 } 2076 2077 private boolean commonKey(int keyCode, int count, KeyEvent event) { 2078 if (mAdapter == null) { 2079 return false; 2080 } 2081 2082 if (mDataChanged) { 2083 layoutChildren(); 2084 } 2085 2086 boolean handled = false; 2087 int action = event.getAction(); 2088 2089 if (action != KeyEvent.ACTION_UP) { 2090 if (mSelectedPosition < 0) { 2091 switch (keyCode) { 2092 case KeyEvent.KEYCODE_DPAD_UP: 2093 case KeyEvent.KEYCODE_DPAD_DOWN: 2094 case KeyEvent.KEYCODE_DPAD_CENTER: 2095 case KeyEvent.KEYCODE_ENTER: 2096 case KeyEvent.KEYCODE_SPACE: 2097 if (resurrectSelection()) { 2098 return true; 2099 } 2100 } 2101 } 2102 switch (keyCode) { 2103 case KeyEvent.KEYCODE_DPAD_UP: 2104 if (!event.isAltPressed()) { 2105 while (count > 0) { 2106 handled = arrowScroll(FOCUS_UP); 2107 count--; 2108 } 2109 } else { 2110 handled = fullScroll(FOCUS_UP); 2111 } 2112 break; 2113 2114 case KeyEvent.KEYCODE_DPAD_DOWN: 2115 if (!event.isAltPressed()) { 2116 while (count > 0) { 2117 handled = arrowScroll(FOCUS_DOWN); 2118 count--; 2119 } 2120 } else { 2121 handled = fullScroll(FOCUS_DOWN); 2122 } 2123 break; 2124 2125 case KeyEvent.KEYCODE_DPAD_LEFT: 2126 handled = handleHorizontalFocusWithinListItem(View.FOCUS_LEFT); 2127 break; 2128 case KeyEvent.KEYCODE_DPAD_RIGHT: 2129 handled = handleHorizontalFocusWithinListItem(View.FOCUS_RIGHT); 2130 break; 2131 2132 case KeyEvent.KEYCODE_DPAD_CENTER: 2133 case KeyEvent.KEYCODE_ENTER: 2134 if (mItemCount > 0 && event.getRepeatCount() == 0) { 2135 keyPressed(); 2136 } 2137 handled = true; 2138 break; 2139 2140 case KeyEvent.KEYCODE_SPACE: 2141 if (mPopup == null || !mPopup.isShowing()) { 2142 if (!event.isShiftPressed()) { 2143 pageScroll(FOCUS_DOWN); 2144 } else { 2145 pageScroll(FOCUS_UP); 2146 } 2147 handled = true; 2148 } 2149 break; 2150 } 2151 } 2152 2153 if (!handled) { 2154 handled = sendToTextFilter(keyCode, count, event); 2155 } 2156 2157 if (handled) { 2158 return true; 2159 } else { 2160 switch (action) { 2161 case KeyEvent.ACTION_DOWN: 2162 return super.onKeyDown(keyCode, event); 2163 2164 case KeyEvent.ACTION_UP: 2165 return super.onKeyUp(keyCode, event); 2166 2167 case KeyEvent.ACTION_MULTIPLE: 2168 return super.onKeyMultiple(keyCode, count, event); 2169 2170 default: // shouldn't happen 2171 return false; 2172 } 2173 } 2174 } 2175 2176 /** 2177 * Scrolls up or down by the number of items currently present on screen. 2178 * 2179 * @param direction either {@link View#FOCUS_UP} or {@link View#FOCUS_DOWN} 2180 * @return whether selection was moved 2181 */ 2182 boolean pageScroll(int direction) { 2183 int nextPage = -1; 2184 boolean down = false; 2185 2186 if (direction == FOCUS_UP) { 2187 nextPage = Math.max(0, mSelectedPosition - getChildCount() - 1); 2188 } else if (direction == FOCUS_DOWN) { 2189 nextPage = Math.min(mItemCount - 1, mSelectedPosition + getChildCount() - 1); 2190 down = true; 2191 } 2192 2193 if (nextPage >= 0) { 2194 int position = lookForSelectablePosition(nextPage, down); 2195 if (position >= 0) { 2196 mLayoutMode = LAYOUT_SPECIFIC; 2197 mSpecificTop = mPaddingTop + getVerticalFadingEdgeLength(); 2198 2199 if (down && position > mItemCount - getChildCount()) { 2200 mLayoutMode = LAYOUT_FORCE_BOTTOM; 2201 } 2202 2203 if (!down && position < getChildCount()) { 2204 mLayoutMode = LAYOUT_FORCE_TOP; 2205 } 2206 2207 setSelectionInt(position); 2208 invokeOnItemScrollListener(); 2209 if (!awakenScrollBars()) { 2210 invalidate(); 2211 } 2212 2213 return true; 2214 } 2215 } 2216 2217 return false; 2218 } 2219 2220 /** 2221 * Go to the last or first item if possible (not worrying about panning across or navigating 2222 * within the internal focus of the currently selected item.) 2223 * 2224 * @param direction either {@link View#FOCUS_UP} or {@link View#FOCUS_DOWN} 2225 * 2226 * @return whether selection was moved 2227 */ 2228 boolean fullScroll(int direction) { 2229 boolean moved = false; 2230 if (direction == FOCUS_UP) { 2231 if (mSelectedPosition != 0) { 2232 int position = lookForSelectablePosition(0, true); 2233 if (position >= 0) { 2234 mLayoutMode = LAYOUT_FORCE_TOP; 2235 setSelectionInt(position); 2236 invokeOnItemScrollListener(); 2237 } 2238 moved = true; 2239 } 2240 } else if (direction == FOCUS_DOWN) { 2241 if (mSelectedPosition < mItemCount - 1) { 2242 int position = lookForSelectablePosition(mItemCount - 1, true); 2243 if (position >= 0) { 2244 mLayoutMode = LAYOUT_FORCE_BOTTOM; 2245 setSelectionInt(position); 2246 invokeOnItemScrollListener(); 2247 } 2248 moved = true; 2249 } 2250 } 2251 2252 if (moved && !awakenScrollBars()) { 2253 awakenScrollBars(); 2254 invalidate(); 2255 } 2256 2257 return moved; 2258 } 2259 2260 /** 2261 * To avoid horizontal focus searches changing the selected item, we 2262 * manually focus search within the selected item (as applicable), and 2263 * prevent focus from jumping to something within another item. 2264 * @param direction one of {View.FOCUS_LEFT, View.FOCUS_RIGHT} 2265 * @return Whether this consumes the key event. 2266 */ 2267 private boolean handleHorizontalFocusWithinListItem(int direction) { 2268 if (direction != View.FOCUS_LEFT && direction != View.FOCUS_RIGHT) { 2269 throw new IllegalArgumentException("direction must be one of" 2270 + " {View.FOCUS_LEFT, View.FOCUS_RIGHT}"); 2271 } 2272 2273 final int numChildren = getChildCount(); 2274 if (mItemsCanFocus && numChildren > 0 && mSelectedPosition != INVALID_POSITION) { 2275 final View selectedView = getSelectedView(); 2276 if (selectedView != null && selectedView.hasFocus() && 2277 selectedView instanceof ViewGroup) { 2278 2279 final View currentFocus = selectedView.findFocus(); 2280 final View nextFocus = FocusFinder.getInstance().findNextFocus( 2281 (ViewGroup) selectedView, currentFocus, direction); 2282 if (nextFocus != null) { 2283 // do the math to get interesting rect in next focus' coordinates 2284 currentFocus.getFocusedRect(mTempRect); 2285 offsetDescendantRectToMyCoords(currentFocus, mTempRect); 2286 offsetRectIntoDescendantCoords(nextFocus, mTempRect); 2287 if (nextFocus.requestFocus(direction, mTempRect)) { 2288 return true; 2289 } 2290 } 2291 // we are blocking the key from being handled (by returning true) 2292 // if the global result is going to be some other view within this 2293 // list. this is to acheive the overall goal of having 2294 // horizontal d-pad navigation remain in the current item. 2295 final View globalNextFocus = FocusFinder.getInstance().findNextFocus( 2296 (ViewGroup) getRootView(), currentFocus, direction); 2297 if (globalNextFocus != null) { 2298 return isViewAncestorOf(globalNextFocus, this); 2299 } 2300 } 2301 } 2302 return false; 2303 } 2304 2305 /** 2306 * Scrolls to the next or previous item if possible. 2307 * 2308 * @param direction either {@link View#FOCUS_UP} or {@link View#FOCUS_DOWN} 2309 * 2310 * @return whether selection was moved 2311 */ 2312 boolean arrowScroll(int direction) { 2313 try { 2314 mInLayout = true; 2315 final boolean handled = arrowScrollImpl(direction); 2316 if (handled) { 2317 playSoundEffect(SoundEffectConstants.getContantForFocusDirection(direction)); 2318 } 2319 return handled; 2320 } finally { 2321 mInLayout = false; 2322 } 2323 } 2324 2325 /** 2326 * Handle an arrow scroll going up or down. Take into account whether items are selectable, 2327 * whether there are focusable items etc. 2328 * 2329 * @param direction Either {@link android.view.View#FOCUS_UP} or {@link android.view.View#FOCUS_DOWN}. 2330 * @return Whether any scrolling, selection or focus change occured. 2331 */ 2332 private boolean arrowScrollImpl(int direction) { 2333 if (getChildCount() <= 0) { 2334 return false; 2335 } 2336 2337 View selectedView = getSelectedView(); 2338 2339 int nextSelectedPosition = lookForSelectablePositionOnScreen(direction); 2340 int amountToScroll = amountToScroll(direction, nextSelectedPosition); 2341 2342 // if we are moving focus, we may OVERRIDE the default behavior 2343 final ArrowScrollFocusResult focusResult = mItemsCanFocus ? arrowScrollFocused(direction) : null; 2344 if (focusResult != null) { 2345 nextSelectedPosition = focusResult.getSelectedPosition(); 2346 amountToScroll = focusResult.getAmountToScroll(); 2347 } 2348 2349 boolean needToRedraw = focusResult != null; 2350 if (nextSelectedPosition != INVALID_POSITION) { 2351 handleNewSelectionChange(selectedView, direction, nextSelectedPosition, focusResult != null); 2352 setSelectedPositionInt(nextSelectedPosition); 2353 setNextSelectedPositionInt(nextSelectedPosition); 2354 selectedView = getSelectedView(); 2355 if (mItemsCanFocus && focusResult == null) { 2356 // there was no new view found to take focus, make sure we 2357 // don't leave focus with the old selection 2358 final View focused = getFocusedChild(); 2359 if (focused != null) { 2360 focused.clearFocus(); 2361 } 2362 } 2363 needToRedraw = true; 2364 checkSelectionChanged(); 2365 } 2366 2367 if (amountToScroll > 0) { 2368 scrollListItemsBy((direction == View.FOCUS_UP) ? amountToScroll : -amountToScroll); 2369 needToRedraw = true; 2370 } 2371 2372 // if we didn't find a new focusable, make sure any existing focused 2373 // item that was panned off screen gives up focus. 2374 if (mItemsCanFocus && (focusResult == null) 2375 && selectedView != null && selectedView.hasFocus()) { 2376 final View focused = selectedView.findFocus(); 2377 if (distanceToView(focused) > 0) { 2378 focused.clearFocus(); 2379 } 2380 } 2381 2382 // if the current selection is panned off, we need to remove the selection 2383 if (nextSelectedPosition == INVALID_POSITION && selectedView != null 2384 && !isViewAncestorOf(selectedView, this)) { 2385 selectedView = null; 2386 hideSelector(); 2387 2388 // but we don't want to set the ressurect position (that would make subsequent 2389 // unhandled key events bring back the item we just scrolled off!) 2390 mResurrectToPosition = INVALID_POSITION; 2391 } 2392 2393 if (needToRedraw) { 2394 if (selectedView != null) { 2395 positionSelector(selectedView); 2396 mSelectedTop = selectedView.getTop(); 2397 } 2398 if (!awakenScrollBars()) { 2399 invalidate(); 2400 } 2401 invokeOnItemScrollListener(); 2402 return true; 2403 } 2404 2405 return false; 2406 } 2407 2408 /** 2409 * When selection changes, it is possible that the previously selected or the 2410 * next selected item will change its size. If so, we need to offset some folks, 2411 * and re-layout the items as appropriate. 2412 * 2413 * @param selectedView The currently selected view (before changing selection). 2414 * should be <code>null</code> if there was no previous selection. 2415 * @param direction Either {@link android.view.View#FOCUS_UP} or 2416 * {@link android.view.View#FOCUS_DOWN}. 2417 * @param newSelectedPosition The position of the next selection. 2418 * @param newFocusAssigned whether new focus was assigned. This matters because 2419 * when something has focus, we don't want to show selection (ugh). 2420 */ 2421 private void handleNewSelectionChange(View selectedView, int direction, int newSelectedPosition, 2422 boolean newFocusAssigned) { 2423 if (newSelectedPosition == INVALID_POSITION) { 2424 throw new IllegalArgumentException("newSelectedPosition needs to be valid"); 2425 } 2426 2427 // whether or not we are moving down or up, we want to preserve the 2428 // top of whatever view is on top: 2429 // - moving down: the view that had selection 2430 // - moving up: the view that is getting selection 2431 View topView; 2432 View bottomView; 2433 int topViewIndex, bottomViewIndex; 2434 boolean topSelected = false; 2435 final int selectedIndex = mSelectedPosition - mFirstPosition; 2436 final int nextSelectedIndex = newSelectedPosition - mFirstPosition; 2437 if (direction == View.FOCUS_UP) { 2438 topViewIndex = nextSelectedIndex; 2439 bottomViewIndex = selectedIndex; 2440 topView = getChildAt(topViewIndex); 2441 bottomView = selectedView; 2442 topSelected = true; 2443 } else { 2444 topViewIndex = selectedIndex; 2445 bottomViewIndex = nextSelectedIndex; 2446 topView = selectedView; 2447 bottomView = getChildAt(bottomViewIndex); 2448 } 2449 2450 final int numChildren = getChildCount(); 2451 2452 // start with top view: is it changing size? 2453 if (topView != null) { 2454 topView.setSelected(!newFocusAssigned && topSelected); 2455 measureAndAdjustDown(topView, topViewIndex, numChildren); 2456 } 2457 2458 // is the bottom view changing size? 2459 if (bottomView != null) { 2460 bottomView.setSelected(!newFocusAssigned && !topSelected); 2461 measureAndAdjustDown(bottomView, bottomViewIndex, numChildren); 2462 } 2463 } 2464 2465 /** 2466 * Re-measure a child, and if its height changes, lay it out preserving its 2467 * top, and adjust the children below it appropriately. 2468 * @param child The child 2469 * @param childIndex The view group index of the child. 2470 * @param numChildren The number of children in the view group. 2471 */ 2472 private void measureAndAdjustDown(View child, int childIndex, int numChildren) { 2473 int oldHeight = child.getHeight(); 2474 measureItem(child); 2475 if (child.getMeasuredHeight() != oldHeight) { 2476 // lay out the view, preserving its top 2477 relayoutMeasuredItem(child); 2478 2479 // adjust views below appropriately 2480 final int heightDelta = child.getMeasuredHeight() - oldHeight; 2481 for (int i = childIndex + 1; i < numChildren; i++) { 2482 getChildAt(i).offsetTopAndBottom(heightDelta); 2483 } 2484 } 2485 } 2486 2487 /** 2488 * Measure a particular list child. 2489 * TODO: unify with setUpChild. 2490 * @param child The child. 2491 */ 2492 private void measureItem(View child) { 2493 ViewGroup.LayoutParams p = child.getLayoutParams(); 2494 if (p == null) { 2495 p = new ViewGroup.LayoutParams( 2496 ViewGroup.LayoutParams.MATCH_PARENT, 2497 ViewGroup.LayoutParams.WRAP_CONTENT); 2498 } 2499 2500 int childWidthSpec = ViewGroup.getChildMeasureSpec(mWidthMeasureSpec, 2501 mListPadding.left + mListPadding.right, p.width); 2502 int lpHeight = p.height; 2503 int childHeightSpec; 2504 if (lpHeight > 0) { 2505 childHeightSpec = MeasureSpec.makeMeasureSpec(lpHeight, MeasureSpec.EXACTLY); 2506 } else { 2507 childHeightSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED); 2508 } 2509 child.measure(childWidthSpec, childHeightSpec); 2510 } 2511 2512 /** 2513 * Layout a child that has been measured, preserving its top position. 2514 * TODO: unify with setUpChild. 2515 * @param child The child. 2516 */ 2517 private void relayoutMeasuredItem(View child) { 2518 final int w = child.getMeasuredWidth(); 2519 final int h = child.getMeasuredHeight(); 2520 final int childLeft = mListPadding.left; 2521 final int childRight = childLeft + w; 2522 final int childTop = child.getTop(); 2523 final int childBottom = childTop + h; 2524 child.layout(childLeft, childTop, childRight, childBottom); 2525 } 2526 2527 /** 2528 * @return The amount to preview next items when arrow srolling. 2529 */ 2530 private int getArrowScrollPreviewLength() { 2531 return Math.max(MIN_SCROLL_PREVIEW_PIXELS, getVerticalFadingEdgeLength()); 2532 } 2533 2534 /** 2535 * Determine how much we need to scroll in order to get the next selected view 2536 * visible, with a fading edge showing below as applicable. The amount is 2537 * capped at {@link #getMaxScrollAmount()} . 2538 * 2539 * @param direction either {@link android.view.View#FOCUS_UP} or 2540 * {@link android.view.View#FOCUS_DOWN}. 2541 * @param nextSelectedPosition The position of the next selection, or 2542 * {@link #INVALID_POSITION} if there is no next selectable position 2543 * @return The amount to scroll. Note: this is always positive! Direction 2544 * needs to be taken into account when actually scrolling. 2545 */ 2546 private int amountToScroll(int direction, int nextSelectedPosition) { 2547 final int listBottom = getHeight() - mListPadding.bottom; 2548 final int listTop = mListPadding.top; 2549 2550 final int numChildren = getChildCount(); 2551 2552 if (direction == View.FOCUS_DOWN) { 2553 int indexToMakeVisible = numChildren - 1; 2554 if (nextSelectedPosition != INVALID_POSITION) { 2555 indexToMakeVisible = nextSelectedPosition - mFirstPosition; 2556 } 2557 2558 final int positionToMakeVisible = mFirstPosition + indexToMakeVisible; 2559 final View viewToMakeVisible = getChildAt(indexToMakeVisible); 2560 2561 int goalBottom = listBottom; 2562 if (positionToMakeVisible < mItemCount - 1) { 2563 goalBottom -= getArrowScrollPreviewLength(); 2564 } 2565 2566 if (viewToMakeVisible.getBottom() <= goalBottom) { 2567 // item is fully visible. 2568 return 0; 2569 } 2570 2571 if (nextSelectedPosition != INVALID_POSITION 2572 && (goalBottom - viewToMakeVisible.getTop()) >= getMaxScrollAmount()) { 2573 // item already has enough of it visible, changing selection is good enough 2574 return 0; 2575 } 2576 2577 int amountToScroll = (viewToMakeVisible.getBottom() - goalBottom); 2578 2579 if ((mFirstPosition + numChildren) == mItemCount) { 2580 // last is last in list -> make sure we don't scroll past it 2581 final int max = getChildAt(numChildren - 1).getBottom() - listBottom; 2582 amountToScroll = Math.min(amountToScroll, max); 2583 } 2584 2585 return Math.min(amountToScroll, getMaxScrollAmount()); 2586 } else { 2587 int indexToMakeVisible = 0; 2588 if (nextSelectedPosition != INVALID_POSITION) { 2589 indexToMakeVisible = nextSelectedPosition - mFirstPosition; 2590 } 2591 final int positionToMakeVisible = mFirstPosition + indexToMakeVisible; 2592 final View viewToMakeVisible = getChildAt(indexToMakeVisible); 2593 int goalTop = listTop; 2594 if (positionToMakeVisible > 0) { 2595 goalTop += getArrowScrollPreviewLength(); 2596 } 2597 if (viewToMakeVisible.getTop() >= goalTop) { 2598 // item is fully visible. 2599 return 0; 2600 } 2601 2602 if (nextSelectedPosition != INVALID_POSITION && 2603 (viewToMakeVisible.getBottom() - goalTop) >= getMaxScrollAmount()) { 2604 // item already has enough of it visible, changing selection is good enough 2605 return 0; 2606 } 2607 2608 int amountToScroll = (goalTop - viewToMakeVisible.getTop()); 2609 if (mFirstPosition == 0) { 2610 // first is first in list -> make sure we don't scroll past it 2611 final int max = listTop - getChildAt(0).getTop(); 2612 amountToScroll = Math.min(amountToScroll, max); 2613 } 2614 return Math.min(amountToScroll, getMaxScrollAmount()); 2615 } 2616 } 2617 2618 /** 2619 * Holds results of focus aware arrow scrolling. 2620 */ 2621 static private class ArrowScrollFocusResult { 2622 private int mSelectedPosition; 2623 private int mAmountToScroll; 2624 2625 /** 2626 * How {@link android.widget.ListView#arrowScrollFocused} returns its values. 2627 */ 2628 void populate(int selectedPosition, int amountToScroll) { 2629 mSelectedPosition = selectedPosition; 2630 mAmountToScroll = amountToScroll; 2631 } 2632 2633 public int getSelectedPosition() { 2634 return mSelectedPosition; 2635 } 2636 2637 public int getAmountToScroll() { 2638 return mAmountToScroll; 2639 } 2640 } 2641 2642 /** 2643 * @param direction either {@link android.view.View#FOCUS_UP} or 2644 * {@link android.view.View#FOCUS_DOWN}. 2645 * @return The position of the next selectable position of the views that 2646 * are currently visible, taking into account the fact that there might 2647 * be no selection. Returns {@link #INVALID_POSITION} if there is no 2648 * selectable view on screen in the given direction. 2649 */ 2650 private int lookForSelectablePositionOnScreen(int direction) { 2651 final int firstPosition = mFirstPosition; 2652 if (direction == View.FOCUS_DOWN) { 2653 int startPos = (mSelectedPosition != INVALID_POSITION) ? 2654 mSelectedPosition + 1 : 2655 firstPosition; 2656 if (startPos >= mAdapter.getCount()) { 2657 return INVALID_POSITION; 2658 } 2659 if (startPos < firstPosition) { 2660 startPos = firstPosition; 2661 } 2662 2663 final int lastVisiblePos = getLastVisiblePosition(); 2664 final ListAdapter adapter = getAdapter(); 2665 for (int pos = startPos; pos <= lastVisiblePos; pos++) { 2666 if (adapter.isEnabled(pos) 2667 && getChildAt(pos - firstPosition).getVisibility() == View.VISIBLE) { 2668 return pos; 2669 } 2670 } 2671 } else { 2672 int last = firstPosition + getChildCount() - 1; 2673 int startPos = (mSelectedPosition != INVALID_POSITION) ? 2674 mSelectedPosition - 1 : 2675 firstPosition + getChildCount() - 1; 2676 if (startPos < 0) { 2677 return INVALID_POSITION; 2678 } 2679 if (startPos > last) { 2680 startPos = last; 2681 } 2682 2683 final ListAdapter adapter = getAdapter(); 2684 for (int pos = startPos; pos >= firstPosition; pos--) { 2685 if (adapter.isEnabled(pos) 2686 && getChildAt(pos - firstPosition).getVisibility() == View.VISIBLE) { 2687 return pos; 2688 } 2689 } 2690 } 2691 return INVALID_POSITION; 2692 } 2693 2694 /** 2695 * Do an arrow scroll based on focus searching. If a new view is 2696 * given focus, return the selection delta and amount to scroll via 2697 * an {@link ArrowScrollFocusResult}, otherwise, return null. 2698 * 2699 * @param direction either {@link android.view.View#FOCUS_UP} or 2700 * {@link android.view.View#FOCUS_DOWN}. 2701 * @return The result if focus has changed, or <code>null</code>. 2702 */ 2703 private ArrowScrollFocusResult arrowScrollFocused(final int direction) { 2704 final View selectedView = getSelectedView(); 2705 View newFocus; 2706 if (selectedView != null && selectedView.hasFocus()) { 2707 View oldFocus = selectedView.findFocus(); 2708 newFocus = FocusFinder.getInstance().findNextFocus(this, oldFocus, direction); 2709 } else { 2710 if (direction == View.FOCUS_DOWN) { 2711 final boolean topFadingEdgeShowing = (mFirstPosition > 0); 2712 final int listTop = mListPadding.top + 2713 (topFadingEdgeShowing ? getArrowScrollPreviewLength() : 0); 2714 final int ySearchPoint = 2715 (selectedView != null && selectedView.getTop() > listTop) ? 2716 selectedView.getTop() : 2717 listTop; 2718 mTempRect.set(0, ySearchPoint, 0, ySearchPoint); 2719 } else { 2720 final boolean bottomFadingEdgeShowing = 2721 (mFirstPosition + getChildCount() - 1) < mItemCount; 2722 final int listBottom = getHeight() - mListPadding.bottom - 2723 (bottomFadingEdgeShowing ? getArrowScrollPreviewLength() : 0); 2724 final int ySearchPoint = 2725 (selectedView != null && selectedView.getBottom() < listBottom) ? 2726 selectedView.getBottom() : 2727 listBottom; 2728 mTempRect.set(0, ySearchPoint, 0, ySearchPoint); 2729 } 2730 newFocus = FocusFinder.getInstance().findNextFocusFromRect(this, mTempRect, direction); 2731 } 2732 2733 if (newFocus != null) { 2734 final int positionOfNewFocus = positionOfNewFocus(newFocus); 2735 2736 // if the focus change is in a different new position, make sure 2737 // we aren't jumping over another selectable position 2738 if (mSelectedPosition != INVALID_POSITION && positionOfNewFocus != mSelectedPosition) { 2739 final int selectablePosition = lookForSelectablePositionOnScreen(direction); 2740 if (selectablePosition != INVALID_POSITION && 2741 ((direction == View.FOCUS_DOWN && selectablePosition < positionOfNewFocus) || 2742 (direction == View.FOCUS_UP && selectablePosition > positionOfNewFocus))) { 2743 return null; 2744 } 2745 } 2746 2747 int focusScroll = amountToScrollToNewFocus(direction, newFocus, positionOfNewFocus); 2748 2749 final int maxScrollAmount = getMaxScrollAmount(); 2750 if (focusScroll < maxScrollAmount) { 2751 // not moving too far, safe to give next view focus 2752 newFocus.requestFocus(direction); 2753 mArrowScrollFocusResult.populate(positionOfNewFocus, focusScroll); 2754 return mArrowScrollFocusResult; 2755 } else if (distanceToView(newFocus) < maxScrollAmount){ 2756 // Case to consider: 2757 // too far to get entire next focusable on screen, but by going 2758 // max scroll amount, we are getting it at least partially in view, 2759 // so give it focus and scroll the max ammount. 2760 newFocus.requestFocus(direction); 2761 mArrowScrollFocusResult.populate(positionOfNewFocus, maxScrollAmount); 2762 return mArrowScrollFocusResult; 2763 } 2764 } 2765 return null; 2766 } 2767 2768 /** 2769 * @param newFocus The view that would have focus. 2770 * @return the position that contains newFocus 2771 */ 2772 private int positionOfNewFocus(View newFocus) { 2773 final int numChildren = getChildCount(); 2774 for (int i = 0; i < numChildren; i++) { 2775 final View child = getChildAt(i); 2776 if (isViewAncestorOf(newFocus, child)) { 2777 return mFirstPosition + i; 2778 } 2779 } 2780 throw new IllegalArgumentException("newFocus is not a child of any of the" 2781 + " children of the list!"); 2782 } 2783 2784 /** 2785 * Return true if child is an ancestor of parent, (or equal to the parent). 2786 */ 2787 private boolean isViewAncestorOf(View child, View parent) { 2788 if (child == parent) { 2789 return true; 2790 } 2791 2792 final ViewParent theParent = child.getParent(); 2793 return (theParent instanceof ViewGroup) && isViewAncestorOf((View) theParent, parent); 2794 } 2795 2796 /** 2797 * Determine how much we need to scroll in order to get newFocus in view. 2798 * @param direction either {@link android.view.View#FOCUS_UP} or 2799 * {@link android.view.View#FOCUS_DOWN}. 2800 * @param newFocus The view that would take focus. 2801 * @param positionOfNewFocus The position of the list item containing newFocus 2802 * @return The amount to scroll. Note: this is always positive! Direction 2803 * needs to be taken into account when actually scrolling. 2804 */ 2805 private int amountToScrollToNewFocus(int direction, View newFocus, int positionOfNewFocus) { 2806 int amountToScroll = 0; 2807 newFocus.getDrawingRect(mTempRect); 2808 offsetDescendantRectToMyCoords(newFocus, mTempRect); 2809 if (direction == View.FOCUS_UP) { 2810 if (mTempRect.top < mListPadding.top) { 2811 amountToScroll = mListPadding.top - mTempRect.top; 2812 if (positionOfNewFocus > 0) { 2813 amountToScroll += getArrowScrollPreviewLength(); 2814 } 2815 } 2816 } else { 2817 final int listBottom = getHeight() - mListPadding.bottom; 2818 if (mTempRect.bottom > listBottom) { 2819 amountToScroll = mTempRect.bottom - listBottom; 2820 if (positionOfNewFocus < mItemCount - 1) { 2821 amountToScroll += getArrowScrollPreviewLength(); 2822 } 2823 } 2824 } 2825 return amountToScroll; 2826 } 2827 2828 /** 2829 * Determine the distance to the nearest edge of a view in a particular 2830 * direction. 2831 * 2832 * @param descendant A descendant of this list. 2833 * @return The distance, or 0 if the nearest edge is already on screen. 2834 */ 2835 private int distanceToView(View descendant) { 2836 int distance = 0; 2837 descendant.getDrawingRect(mTempRect); 2838 offsetDescendantRectToMyCoords(descendant, mTempRect); 2839 final int listBottom = mBottom - mTop - mListPadding.bottom; 2840 if (mTempRect.bottom < mListPadding.top) { 2841 distance = mListPadding.top - mTempRect.bottom; 2842 } else if (mTempRect.top > listBottom) { 2843 distance = mTempRect.top - listBottom; 2844 } 2845 return distance; 2846 } 2847 2848 2849 /** 2850 * Scroll the children by amount, adding a view at the end and removing 2851 * views that fall off as necessary. 2852 * 2853 * @param amount The amount (positive or negative) to scroll. 2854 */ 2855 private void scrollListItemsBy(int amount) { 2856 offsetChildrenTopAndBottom(amount); 2857 2858 final int listBottom = getHeight() - mListPadding.bottom; 2859 final int listTop = mListPadding.top; 2860 final AbsListView.RecycleBin recycleBin = mRecycler; 2861 2862 if (amount < 0) { 2863 // shifted items up 2864 2865 // may need to pan views into the bottom space 2866 int numChildren = getChildCount(); 2867 View last = getChildAt(numChildren - 1); 2868 while (last.getBottom() < listBottom) { 2869 final int lastVisiblePosition = mFirstPosition + numChildren - 1; 2870 if (lastVisiblePosition < mItemCount - 1) { 2871 last = addViewBelow(last, lastVisiblePosition); 2872 numChildren++; 2873 } else { 2874 break; 2875 } 2876 } 2877 2878 // may have brought in the last child of the list that is skinnier 2879 // than the fading edge, thereby leaving space at the end. need 2880 // to shift back 2881 if (last.getBottom() < listBottom) { 2882 offsetChildrenTopAndBottom(listBottom - last.getBottom()); 2883 } 2884 2885 // top views may be panned off screen 2886 View first = getChildAt(0); 2887 while (first.getBottom() < listTop) { 2888 AbsListView.LayoutParams layoutParams = (LayoutParams) first.getLayoutParams(); 2889 if (recycleBin.shouldRecycleViewType(layoutParams.viewType)) { 2890 detachViewFromParent(first); 2891 recycleBin.addScrapView(first); 2892 } else { 2893 removeViewInLayout(first); 2894 } 2895 first = getChildAt(0); 2896 mFirstPosition++; 2897 } 2898 } else { 2899 // shifted items down 2900 View first = getChildAt(0); 2901 2902 // may need to pan views into top 2903 while ((first.getTop() > listTop) && (mFirstPosition > 0)) { 2904 first = addViewAbove(first, mFirstPosition); 2905 mFirstPosition--; 2906 } 2907 2908 // may have brought the very first child of the list in too far and 2909 // need to shift it back 2910 if (first.getTop() > listTop) { 2911 offsetChildrenTopAndBottom(listTop - first.getTop()); 2912 } 2913 2914 int lastIndex = getChildCount() - 1; 2915 View last = getChildAt(lastIndex); 2916 2917 // bottom view may be panned off screen 2918 while (last.getTop() > listBottom) { 2919 AbsListView.LayoutParams layoutParams = (LayoutParams) last.getLayoutParams(); 2920 if (recycleBin.shouldRecycleViewType(layoutParams.viewType)) { 2921 detachViewFromParent(last); 2922 recycleBin.addScrapView(last); 2923 } else { 2924 removeViewInLayout(last); 2925 } 2926 last = getChildAt(--lastIndex); 2927 } 2928 } 2929 } 2930 2931 private View addViewAbove(View theView, int position) { 2932 int abovePosition = position - 1; 2933 View view = obtainView(abovePosition, mIsScrap); 2934 int edgeOfNewChild = theView.getTop() - mDividerHeight; 2935 setupChild(view, abovePosition, edgeOfNewChild, false, mListPadding.left, 2936 false, mIsScrap[0]); 2937 return view; 2938 } 2939 2940 private View addViewBelow(View theView, int position) { 2941 int belowPosition = position + 1; 2942 View view = obtainView(belowPosition, mIsScrap); 2943 int edgeOfNewChild = theView.getBottom() + mDividerHeight; 2944 setupChild(view, belowPosition, edgeOfNewChild, true, mListPadding.left, 2945 false, mIsScrap[0]); 2946 return view; 2947 } 2948 2949 /** 2950 * Indicates that the views created by the ListAdapter can contain focusable 2951 * items. 2952 * 2953 * @param itemsCanFocus true if items can get focus, false otherwise 2954 */ 2955 public void setItemsCanFocus(boolean itemsCanFocus) { 2956 mItemsCanFocus = itemsCanFocus; 2957 if (!itemsCanFocus) { 2958 setDescendantFocusability(ViewGroup.FOCUS_BLOCK_DESCENDANTS); 2959 } 2960 } 2961 2962 /** 2963 * @return Whether the views created by the ListAdapter can contain focusable 2964 * items. 2965 */ 2966 public boolean getItemsCanFocus() { 2967 return mItemsCanFocus; 2968 } 2969 2970 /** 2971 * @hide Pending API council approval. 2972 */ 2973 @Override 2974 public boolean isOpaque() { 2975 return (mCachingStarted && mIsCacheColorOpaque && mDividerIsOpaque && 2976 hasOpaqueScrollbars()) || super.isOpaque(); 2977 } 2978 2979 @Override 2980 public void setCacheColorHint(int color) { 2981 final boolean opaque = (color >>> 24) == 0xFF; 2982 mIsCacheColorOpaque = opaque; 2983 if (opaque) { 2984 if (mDividerPaint == null) { 2985 mDividerPaint = new Paint(); 2986 } 2987 mDividerPaint.setColor(color); 2988 } 2989 super.setCacheColorHint(color); 2990 } 2991 2992 @Override 2993 protected void dispatchDraw(Canvas canvas) { 2994 // Draw the dividers 2995 final int dividerHeight = mDividerHeight; 2996 final boolean drawDividers = dividerHeight > 0 && mDivider != null; 2997 2998 if (drawDividers) { 2999 // Only modify the top and bottom in the loop, we set the left and right here 3000 final Rect bounds = mTempRect; 3001 bounds.left = mPaddingLeft; 3002 bounds.right = mRight - mLeft - mPaddingRight; 3003 3004 final int count = getChildCount(); 3005 final int headerCount = mHeaderViewInfos.size(); 3006 final int itemCount = mItemCount; 3007 final int footerLimit = itemCount - mFooterViewInfos.size() - 1; 3008 final boolean headerDividers = mHeaderDividersEnabled; 3009 final boolean footerDividers = mFooterDividersEnabled; 3010 final int first = mFirstPosition; 3011 final boolean areAllItemsSelectable = mAreAllItemsSelectable; 3012 final ListAdapter adapter = mAdapter; 3013 // If the list is opaque *and* the background is not, we want to 3014 // fill a rect where the dividers would be for non-selectable items 3015 // If the list is opaque and the background is also opaque, we don't 3016 // need to draw anything since the background will do it for us 3017 final boolean fillForMissingDividers = isOpaque() && !super.isOpaque(); 3018 3019 if (fillForMissingDividers && mDividerPaint == null && mIsCacheColorOpaque) { 3020 mDividerPaint = new Paint(); 3021 mDividerPaint.setColor(getCacheColorHint()); 3022 } 3023 final Paint paint = mDividerPaint; 3024 3025 final int listBottom = mBottom - mTop - mListPadding.bottom + mScrollY; 3026 if (!mStackFromBottom) { 3027 int bottom; 3028 3029 final int scrollY = mScrollY; 3030 for (int i = 0; i < count; i++) { 3031 if ((headerDividers || first + i >= headerCount) && 3032 (footerDividers || first + i < footerLimit)) { 3033 View child = getChildAt(i); 3034 bottom = child.getBottom(); 3035 // Don't draw dividers next to items that are not enabled 3036 if ((areAllItemsSelectable || 3037 (adapter.isEnabled(first + i) && (i == count - 1 || 3038 adapter.isEnabled(first + i + 1))))) { 3039 bounds.top = bottom; 3040 bounds.bottom = bottom + dividerHeight; 3041 drawDivider(canvas, bounds, i); 3042 } else if (fillForMissingDividers) { 3043 bounds.top = bottom; 3044 bounds.bottom = bottom + dividerHeight; 3045 canvas.drawRect(bounds, paint); 3046 } 3047 } 3048 } 3049 } else { 3050 int top; 3051 int listTop = mListPadding.top; 3052 3053 final int scrollY = mScrollY; 3054 3055 for (int i = 0; i < count; i++) { 3056 if ((headerDividers || first + i >= headerCount) && 3057 (footerDividers || first + i < footerLimit)) { 3058 View child = getChildAt(i); 3059 top = child.getTop(); 3060 // Don't draw dividers next to items that are not enabled 3061 if (top > listTop) { 3062 if ((areAllItemsSelectable || 3063 (adapter.isEnabled(first + i) && (i == count - 1 || 3064 adapter.isEnabled(first + i + 1))))) { 3065 bounds.top = top - dividerHeight; 3066 bounds.bottom = top; 3067 // Give the method the child ABOVE the divider, so we 3068 // subtract one from our child 3069 // position. Give -1 when there is no child above the 3070 // divider. 3071 drawDivider(canvas, bounds, i - 1); 3072 } else if (fillForMissingDividers) { 3073 bounds.top = top - dividerHeight; 3074 bounds.bottom = top; 3075 canvas.drawRect(bounds, paint); 3076 } 3077 } 3078 } 3079 } 3080 3081 if (count > 0 && scrollY > 0) { 3082 bounds.top = listBottom; 3083 bounds.bottom = listBottom + dividerHeight; 3084 drawDivider(canvas, bounds, -1); 3085 } 3086 } 3087 } 3088 3089 // Draw the indicators (these should be drawn above the dividers) and children 3090 super.dispatchDraw(canvas); 3091 } 3092 3093 /** 3094 * Draws a divider for the given child in the given bounds. 3095 * 3096 * @param canvas The canvas to draw to. 3097 * @param bounds The bounds of the divider. 3098 * @param childIndex The index of child (of the View) above the divider. 3099 * This will be -1 if there is no child above the divider to be 3100 * drawn. 3101 */ 3102 void drawDivider(Canvas canvas, Rect bounds, int childIndex) { 3103 // This widget draws the same divider for all children 3104 final Drawable divider = mDivider; 3105 final boolean clipDivider = mClipDivider; 3106 3107 if (!clipDivider) { 3108 divider.setBounds(bounds); 3109 } else { 3110 canvas.save(); 3111 canvas.clipRect(bounds); 3112 } 3113 3114 divider.draw(canvas); 3115 3116 if (clipDivider) { 3117 canvas.restore(); 3118 } 3119 } 3120 3121 /** 3122 * Returns the drawable that will be drawn between each item in the list. 3123 * 3124 * @return the current drawable drawn between list elements 3125 */ 3126 public Drawable getDivider() { 3127 return mDivider; 3128 } 3129 3130 /** 3131 * Sets the drawable that will be drawn between each item in the list. If the drawable does 3132 * not have an intrinsic height, you should also call {@link #setDividerHeight(int)} 3133 * 3134 * @param divider The drawable to use. 3135 */ 3136 public void setDivider(Drawable divider) { 3137 if (divider != null) { 3138 mDividerHeight = divider.getIntrinsicHeight(); 3139 mClipDivider = divider instanceof ColorDrawable; 3140 } else { 3141 mDividerHeight = 0; 3142 mClipDivider = false; 3143 } 3144 mDivider = divider; 3145 mDividerIsOpaque = divider == null || divider.getOpacity() == PixelFormat.OPAQUE; 3146 requestLayoutIfNecessary(); 3147 } 3148 3149 /** 3150 * @return Returns the height of the divider that will be drawn between each item in the list. 3151 */ 3152 public int getDividerHeight() { 3153 return mDividerHeight; 3154 } 3155 3156 /** 3157 * Sets the height of the divider that will be drawn between each item in the list. Calling 3158 * this will override the intrinsic height as set by {@link #setDivider(Drawable)} 3159 * 3160 * @param height The new height of the divider in pixels. 3161 */ 3162 public void setDividerHeight(int height) { 3163 mDividerHeight = height; 3164 requestLayoutIfNecessary(); 3165 } 3166 3167 /** 3168 * Enables or disables the drawing of the divider for header views. 3169 * 3170 * @param headerDividersEnabled True to draw the headers, false otherwise. 3171 * 3172 * @see #setFooterDividersEnabled(boolean) 3173 * @see #addHeaderView(android.view.View) 3174 */ 3175 public void setHeaderDividersEnabled(boolean headerDividersEnabled) { 3176 mHeaderDividersEnabled = headerDividersEnabled; 3177 invalidate(); 3178 } 3179 3180 /** 3181 * Enables or disables the drawing of the divider for footer views. 3182 * 3183 * @param footerDividersEnabled True to draw the footers, false otherwise. 3184 * 3185 * @see #setHeaderDividersEnabled(boolean) 3186 * @see #addFooterView(android.view.View) 3187 */ 3188 public void setFooterDividersEnabled(boolean footerDividersEnabled) { 3189 mFooterDividersEnabled = footerDividersEnabled; 3190 invalidate(); 3191 } 3192 3193 @Override 3194 protected void onFocusChanged(boolean gainFocus, int direction, Rect previouslyFocusedRect) { 3195 super.onFocusChanged(gainFocus, direction, previouslyFocusedRect); 3196 3197 int closetChildIndex = -1; 3198 if (gainFocus && previouslyFocusedRect != null) { 3199 previouslyFocusedRect.offset(mScrollX, mScrollY); 3200 3201 final ListAdapter adapter = mAdapter; 3202 // Don't cache the result of getChildCount or mFirstPosition here, 3203 // it could change in layoutChildren. 3204 if (adapter.getCount() < getChildCount() + mFirstPosition) { 3205 mLayoutMode = LAYOUT_NORMAL; 3206 layoutChildren(); 3207 } 3208 3209 // figure out which item should be selected based on previously 3210 // focused rect 3211 Rect otherRect = mTempRect; 3212 int minDistance = Integer.MAX_VALUE; 3213 final int childCount = getChildCount(); 3214 final int firstPosition = mFirstPosition; 3215 3216 for (int i = 0; i < childCount; i++) { 3217 // only consider selectable views 3218 if (!adapter.isEnabled(firstPosition + i)) { 3219 continue; 3220 } 3221 3222 View other = getChildAt(i); 3223 other.getDrawingRect(otherRect); 3224 offsetDescendantRectToMyCoords(other, otherRect); 3225 int distance = getDistance(previouslyFocusedRect, otherRect, direction); 3226 3227 if (distance < minDistance) { 3228 minDistance = distance; 3229 closetChildIndex = i; 3230 } 3231 } 3232 } 3233 3234 if (closetChildIndex >= 0) { 3235 setSelection(closetChildIndex + mFirstPosition); 3236 } else { 3237 requestLayout(); 3238 } 3239 } 3240 3241 3242 /* 3243 * (non-Javadoc) 3244 * 3245 * Children specified in XML are assumed to be header views. After we have 3246 * parsed them move them out of the children list and into mHeaderViews. 3247 */ 3248 @Override 3249 protected void onFinishInflate() { 3250 super.onFinishInflate(); 3251 3252 int count = getChildCount(); 3253 if (count > 0) { 3254 for (int i = 0; i < count; ++i) { 3255 addHeaderView(getChildAt(i)); 3256 } 3257 removeAllViews(); 3258 } 3259 } 3260 3261 /* (non-Javadoc) 3262 * @see android.view.View#findViewById(int) 3263 * First look in our children, then in any header and footer views that may be scrolled off. 3264 */ 3265 @Override 3266 protected View findViewTraversal(int id) { 3267 View v; 3268 v = super.findViewTraversal(id); 3269 if (v == null) { 3270 v = findViewInHeadersOrFooters(mHeaderViewInfos, id); 3271 if (v != null) { 3272 return v; 3273 } 3274 v = findViewInHeadersOrFooters(mFooterViewInfos, id); 3275 if (v != null) { 3276 return v; 3277 } 3278 } 3279 return v; 3280 } 3281 3282 /* (non-Javadoc) 3283 * 3284 * Look in the passed in list of headers or footers for the view. 3285 */ 3286 View findViewInHeadersOrFooters(ArrayList<FixedViewInfo> where, int id) { 3287 if (where != null) { 3288 int len = where.size(); 3289 View v; 3290 3291 for (int i = 0; i < len; i++) { 3292 v = where.get(i).view; 3293 3294 if (!v.isRootNamespace()) { 3295 v = v.findViewById(id); 3296 3297 if (v != null) { 3298 return v; 3299 } 3300 } 3301 } 3302 } 3303 return null; 3304 } 3305 3306 /* (non-Javadoc) 3307 * @see android.view.View#findViewWithTag(String) 3308 * First look in our children, then in any header and footer views that may be scrolled off. 3309 */ 3310 @Override 3311 protected View findViewWithTagTraversal(Object tag) { 3312 View v; 3313 v = super.findViewWithTagTraversal(tag); 3314 if (v == null) { 3315 v = findViewTagInHeadersOrFooters(mHeaderViewInfos, tag); 3316 if (v != null) { 3317 return v; 3318 } 3319 3320 v = findViewTagInHeadersOrFooters(mFooterViewInfos, tag); 3321 if (v != null) { 3322 return v; 3323 } 3324 } 3325 return v; 3326 } 3327 3328 /* (non-Javadoc) 3329 * 3330 * Look in the passed in list of headers or footers for the view with the tag. 3331 */ 3332 View findViewTagInHeadersOrFooters(ArrayList<FixedViewInfo> where, Object tag) { 3333 if (where != null) { 3334 int len = where.size(); 3335 View v; 3336 3337 for (int i = 0; i < len; i++) { 3338 v = where.get(i).view; 3339 3340 if (!v.isRootNamespace()) { 3341 v = v.findViewWithTag(tag); 3342 3343 if (v != null) { 3344 return v; 3345 } 3346 } 3347 } 3348 } 3349 return null; 3350 } 3351 3352 @Override 3353 public boolean onTouchEvent(MotionEvent ev) { 3354 if (mItemsCanFocus && ev.getAction() == MotionEvent.ACTION_DOWN && ev.getEdgeFlags() != 0) { 3355 // Don't handle edge touches immediately -- they may actually belong to one of our 3356 // descendants. 3357 return false; 3358 } 3359 return super.onTouchEvent(ev); 3360 } 3361 3362 /** 3363 * @see #setChoiceMode(int) 3364 * 3365 * @return The current choice mode 3366 */ 3367 public int getChoiceMode() { 3368 return mChoiceMode; 3369 } 3370 3371 /** 3372 * Defines the choice behavior for the List. By default, Lists do not have any choice behavior 3373 * ({@link #CHOICE_MODE_NONE}). By setting the choiceMode to {@link #CHOICE_MODE_SINGLE}, the 3374 * List allows up to one item to be in a chosen state. By setting the choiceMode to 3375 * {@link #CHOICE_MODE_MULTIPLE}, the list allows any number of items to be chosen. 3376 * 3377 * @param choiceMode One of {@link #CHOICE_MODE_NONE}, {@link #CHOICE_MODE_SINGLE}, or 3378 * {@link #CHOICE_MODE_MULTIPLE} 3379 */ 3380 public void setChoiceMode(int choiceMode) { 3381 mChoiceMode = choiceMode; 3382 if (mChoiceActionMode != null) { 3383 mChoiceActionMode.finish(); 3384 mChoiceActionMode = null; 3385 } 3386 if (mChoiceMode != CHOICE_MODE_NONE) { 3387 if (mCheckStates == null) { 3388 mCheckStates = new SparseBooleanArray(); 3389 } 3390 if (mCheckedIdStates == null && mAdapter != null && mAdapter.hasStableIds()) { 3391 mCheckedIdStates = new LongSparseArray<Boolean>(); 3392 } 3393 // Modal multi-choice mode only has choices when the mode is active. Clear them. 3394 if (mChoiceMode == CHOICE_MODE_MULTIPLE_MODAL) { 3395 clearChoices(); 3396 setLongClickable(true); 3397 } 3398 } 3399 } 3400 3401 /** 3402 * Set a {@link MultiChoiceModeListener} that will manage the lifecycle of the 3403 * selection {@link ActionMode}. Only used when the choice mode is set to 3404 * {@link #CHOICE_MODE_MULTIPLE_MODAL}. 3405 * 3406 * @param listener Listener that will manage the selection mode 3407 * 3408 * @see #setChoiceMode(int) 3409 */ 3410 public void setMultiChoiceModeListener(MultiChoiceModeListener listener) { 3411 if (mMultiChoiceModeCallback == null) { 3412 mMultiChoiceModeCallback = new MultiChoiceModeWrapper(); 3413 } 3414 mMultiChoiceModeCallback.setWrapped(listener); 3415 } 3416 3417 @Override 3418 boolean performLongPress(final View child, 3419 final int longPressPosition, final long longPressId) { 3420 boolean handled = false; 3421 if (mChoiceMode == CHOICE_MODE_MULTIPLE_MODAL) { 3422 handled = true; 3423 if (mChoiceActionMode == null) { 3424 mChoiceActionMode = startActionMode(mMultiChoiceModeCallback); 3425 setItemChecked(longPressPosition, true); 3426 } 3427 // TODO Should we select the long pressed item if we were already in 3428 // selection mode? (i.e. treat it like an item click?) 3429 performHapticFeedback(HapticFeedbackConstants.LONG_PRESS); 3430 } 3431 return handled | super.performLongPress(child, longPressPosition, longPressId); 3432 } 3433 3434 @Override 3435 public boolean performItemClick(View view, int position, long id) { 3436 boolean handled = false; 3437 3438 if (mChoiceMode != CHOICE_MODE_NONE) { 3439 handled = true; 3440 3441 if (mChoiceMode == CHOICE_MODE_MULTIPLE || 3442 (mChoiceMode == CHOICE_MODE_MULTIPLE_MODAL && mChoiceActionMode != null)) { 3443 boolean newValue = !mCheckStates.get(position, false); 3444 mCheckStates.put(position, newValue); 3445 if (mCheckedIdStates != null && mAdapter.hasStableIds()) { 3446 if (newValue) { 3447 mCheckedIdStates.put(mAdapter.getItemId(position), Boolean.TRUE); 3448 } else { 3449 mCheckedIdStates.delete(mAdapter.getItemId(position)); 3450 } 3451 } 3452 if (newValue) { 3453 mCheckedItemCount++; 3454 } else { 3455 mCheckedItemCount--; 3456 } 3457 if (mChoiceActionMode != null) { 3458 mMultiChoiceModeCallback.onItemCheckedStateChanged(mChoiceActionMode, 3459 position, id, newValue); 3460 } 3461 } else if (mChoiceMode == CHOICE_MODE_SINGLE) { 3462 boolean newValue = !mCheckStates.get(position, false); 3463 if (newValue) { 3464 mCheckStates.clear(); 3465 mCheckStates.put(position, true); 3466 if (mCheckedIdStates != null && mAdapter.hasStableIds()) { 3467 mCheckedIdStates.clear(); 3468 mCheckedIdStates.put(mAdapter.getItemId(position), Boolean.TRUE); 3469 } 3470 mCheckedItemCount = 1; 3471 } else if (mCheckStates.size() == 0 || !mCheckStates.valueAt(0)) { 3472 mCheckedItemCount = 0; 3473 } 3474 } 3475 3476 mDataChanged = true; 3477 rememberSyncState(); 3478 requestLayout(); 3479 } 3480 3481 handled |= super.performItemClick(view, position, id); 3482 3483 return handled; 3484 } 3485 3486 /** 3487 * Sets the checked state of the specified position. The is only valid if 3488 * the choice mode has been set to {@link #CHOICE_MODE_SINGLE} or 3489 * {@link #CHOICE_MODE_MULTIPLE}. 3490 * 3491 * @param position The item whose checked state is to be checked 3492 * @param value The new checked state for the item 3493 */ 3494 public void setItemChecked(int position, boolean value) { 3495 if (mChoiceMode == CHOICE_MODE_NONE) { 3496 return; 3497 } 3498 3499 // Start selection mode if needed. We don't need to if we're unchecking something. 3500 if (value && mChoiceMode == CHOICE_MODE_MULTIPLE_MODAL && mChoiceActionMode == null) { 3501 mChoiceActionMode = startActionMode(mMultiChoiceModeCallback); 3502 } 3503 3504 if (mChoiceMode == CHOICE_MODE_MULTIPLE || mChoiceMode == CHOICE_MODE_MULTIPLE_MODAL) { 3505 boolean oldValue = mCheckStates.get(position); 3506 mCheckStates.put(position, value); 3507 if (mCheckedIdStates != null && mAdapter.hasStableIds()) { 3508 if (value) { 3509 mCheckedIdStates.put(mAdapter.getItemId(position), Boolean.TRUE); 3510 } else { 3511 mCheckedIdStates.delete(mAdapter.getItemId(position)); 3512 } 3513 } 3514 if (oldValue != value) { 3515 if (value) { 3516 mCheckedItemCount++; 3517 } else { 3518 mCheckedItemCount--; 3519 } 3520 } 3521 if (mChoiceActionMode != null) { 3522 final long id = mAdapter.getItemId(position); 3523 mMultiChoiceModeCallback.onItemCheckedStateChanged(mChoiceActionMode, 3524 position, id, value); 3525 } 3526 } else { 3527 boolean updateIds = mCheckedIdStates != null && mAdapter.hasStableIds(); 3528 // Clear all values if we're checking something, or unchecking the currently 3529 // selected item 3530 if (value || isItemChecked(position)) { 3531 mCheckStates.clear(); 3532 if (updateIds) { 3533 mCheckedIdStates.clear(); 3534 } 3535 } 3536 // this may end up selecting the value we just cleared but this way 3537 // we ensure length of mCheckStates is 1, a fact getCheckedItemPosition relies on 3538 if (value) { 3539 mCheckStates.put(position, true); 3540 if (updateIds) { 3541 mCheckedIdStates.put(mAdapter.getItemId(position), Boolean.TRUE); 3542 } 3543 mCheckedItemCount = 1; 3544 } else if (mCheckStates.size() == 0 || !mCheckStates.valueAt(0)) { 3545 mCheckedItemCount = 0; 3546 } 3547 } 3548 3549 // Do not generate a data change while we are in the layout phase 3550 if (!mInLayout && !mBlockLayoutRequests) { 3551 mDataChanged = true; 3552 rememberSyncState(); 3553 requestLayout(); 3554 } 3555 } 3556 3557 /** 3558 * Returns the number of items currently selected. This will only be valid 3559 * if the choice mode is not {@link #CHOICE_MODE_NONE} (default). 3560 * 3561 * <p>To determine the specific items that are currently selected, use one of 3562 * the <code>getChecked*</code> methods. 3563 * 3564 * @return The number of items currently selected 3565 * 3566 * @see #getCheckedItemPosition() 3567 * @see #getCheckedItemPositions() 3568 * @see #getCheckedItemIds() 3569 */ 3570 public int getCheckedItemCount() { 3571 return mCheckedItemCount; 3572 } 3573 3574 /** 3575 * Returns the checked state of the specified position. The result is only 3576 * valid if the choice mode has been set to {@link #CHOICE_MODE_SINGLE} 3577 * or {@link #CHOICE_MODE_MULTIPLE}. 3578 * 3579 * @param position The item whose checked state to return 3580 * @return The item's checked state or <code>false</code> if choice mode 3581 * is invalid 3582 * 3583 * @see #setChoiceMode(int) 3584 */ 3585 public boolean isItemChecked(int position) { 3586 if (mChoiceMode != CHOICE_MODE_NONE && mCheckStates != null) { 3587 return mCheckStates.get(position); 3588 } 3589 3590 return false; 3591 } 3592 3593 /** 3594 * Returns the currently checked item. The result is only valid if the choice 3595 * mode has been set to {@link #CHOICE_MODE_SINGLE}. 3596 * 3597 * @return The position of the currently checked item or 3598 * {@link #INVALID_POSITION} if nothing is selected 3599 * 3600 * @see #setChoiceMode(int) 3601 */ 3602 public int getCheckedItemPosition() { 3603 if (mChoiceMode == CHOICE_MODE_SINGLE && mCheckStates != null && mCheckStates.size() == 1) { 3604 return mCheckStates.keyAt(0); 3605 } 3606 3607 return INVALID_POSITION; 3608 } 3609 3610 /** 3611 * Returns the set of checked items in the list. The result is only valid if 3612 * the choice mode has not been set to {@link #CHOICE_MODE_NONE}. 3613 * 3614 * @return A SparseBooleanArray which will return true for each call to 3615 * get(int position) where position is a position in the list, 3616 * or <code>null</code> if the choice mode is set to 3617 * {@link #CHOICE_MODE_NONE}. 3618 */ 3619 public SparseBooleanArray getCheckedItemPositions() { 3620 if (mChoiceMode != CHOICE_MODE_NONE) { 3621 return mCheckStates; 3622 } 3623 return null; 3624 } 3625 3626 /** 3627 * Returns the set of checked items ids. The result is only valid if the 3628 * choice mode has not been set to {@link #CHOICE_MODE_NONE}. 3629 * 3630 * @return A new array which contains the id of each checked item in the 3631 * list. 3632 * 3633 * @deprecated Use {@link #getCheckedItemIds()} instead. 3634 */ 3635 @Deprecated 3636 public long[] getCheckItemIds() { 3637 // Use new behavior that correctly handles stable ID mapping. 3638 if (mAdapter != null && mAdapter.hasStableIds()) { 3639 return getCheckedItemIds(); 3640 } 3641 3642 // Old behavior was buggy, but would sort of work for adapters without stable IDs. 3643 // Fall back to it to support legacy apps. 3644 if (mChoiceMode != CHOICE_MODE_NONE && mCheckStates != null && mAdapter != null) { 3645 final SparseBooleanArray states = mCheckStates; 3646 final int count = states.size(); 3647 final long[] ids = new long[count]; 3648 final ListAdapter adapter = mAdapter; 3649 3650 int checkedCount = 0; 3651 for (int i = 0; i < count; i++) { 3652 if (states.valueAt(i)) { 3653 ids[checkedCount++] = adapter.getItemId(states.keyAt(i)); 3654 } 3655 } 3656 3657 // Trim array if needed. mCheckStates may contain false values 3658 // resulting in checkedCount being smaller than count. 3659 if (checkedCount == count) { 3660 return ids; 3661 } else { 3662 final long[] result = new long[checkedCount]; 3663 System.arraycopy(ids, 0, result, 0, checkedCount); 3664 3665 return result; 3666 } 3667 } 3668 return new long[0]; 3669 } 3670 3671 /** 3672 * Returns the set of checked items ids. The result is only valid if the 3673 * choice mode has not been set to {@link #CHOICE_MODE_NONE} and the adapter 3674 * has stable IDs. ({@link ListAdapter#hasStableIds()} == {@code true}) 3675 * 3676 * @return A new array which contains the id of each checked item in the 3677 * list. 3678 */ 3679 public long[] getCheckedItemIds() { 3680 if (mChoiceMode == CHOICE_MODE_NONE || mCheckedIdStates == null || mAdapter == null) { 3681 return new long[0]; 3682 } 3683 3684 final LongSparseArray<Boolean> idStates = mCheckedIdStates; 3685 final int count = idStates.size(); 3686 final long[] ids = new long[count]; 3687 3688 for (int i = 0; i < count; i++) { 3689 ids[i] = idStates.keyAt(i); 3690 } 3691 3692 return ids; 3693 } 3694 3695 /** 3696 * Clear any choices previously set 3697 */ 3698 public void clearChoices() { 3699 if (mCheckStates != null) { 3700 mCheckStates.clear(); 3701 } 3702 if (mCheckedIdStates != null) { 3703 mCheckedIdStates.clear(); 3704 } 3705 mCheckedItemCount = 0; 3706 } 3707 3708 /** 3709 * A MultiChoiceModeListener receives events for {@link ListView#CHOICE_MODE_MULTIPLE_MODAL}. 3710 * It acts as the {@link ActionMode.Callback} for the selection mode and also receives 3711 * {@link #onItemCheckedStateChanged(ActionMode, int, long, boolean)} events when the user 3712 * selects and deselects list items. 3713 */ 3714 public interface MultiChoiceModeListener extends ActionMode.Callback { 3715 /** 3716 * Called when an item is checked or unchecked during selection mode. 3717 * 3718 * @param mode The {@link ActionMode} providing the selection mode 3719 * @param position Adapter position of the item that was checked or unchecked 3720 * @param id Adapter ID of the item that was checked or unchecked 3721 * @param checked <code>true</code> if the item is now checked, <code>false</code> 3722 * if the item is now unchecked. 3723 */ 3724 public void onItemCheckedStateChanged(ActionMode mode, 3725 int position, long id, boolean checked); 3726 } 3727 3728 private class MultiChoiceModeWrapper implements MultiChoiceModeListener { 3729 private MultiChoiceModeListener mWrapped; 3730 3731 public void setWrapped(MultiChoiceModeListener wrapped) { 3732 mWrapped = wrapped; 3733 } 3734 3735 public boolean onCreateActionMode(ActionMode mode, Menu menu) { 3736 if (mWrapped.onCreateActionMode(mode, menu)) { 3737 // Initialize checked graphic state? 3738 setLongClickable(false); 3739 return true; 3740 } 3741 return false; 3742 } 3743 3744 public boolean onPrepareActionMode(ActionMode mode, Menu menu) { 3745 return mWrapped.onPrepareActionMode(mode, menu); 3746 } 3747 3748 public boolean onActionItemClicked(ActionMode mode, MenuItem item) { 3749 return mWrapped.onActionItemClicked(mode, item); 3750 } 3751 3752 public void onDestroyActionMode(ActionMode mode) { 3753 mWrapped.onDestroyActionMode(mode); 3754 mChoiceActionMode = null; 3755 3756 // Ending selection mode means deselecting everything. 3757 clearChoices(); 3758 3759 mDataChanged = true; 3760 rememberSyncState(); 3761 requestLayout(); 3762 3763 setLongClickable(true); 3764 } 3765 3766 public void onItemCheckedStateChanged(ActionMode mode, 3767 int position, long id, boolean checked) { 3768 mWrapped.onItemCheckedStateChanged(mode, position, id, checked); 3769 3770 // If there are no items selected we no longer need the selection mode. 3771 if (getCheckedItemCount() == 0) { 3772 mode.finish(); 3773 } 3774 } 3775 } 3776 3777 static class SavedState extends BaseSavedState { 3778 SparseBooleanArray checkState; 3779 LongSparseArray<Boolean> checkIdState; 3780 3781 /** 3782 * Constructor called from {@link ListView#onSaveInstanceState()} 3783 */ 3784 SavedState(Parcelable superState, SparseBooleanArray checkState, 3785 LongSparseArray<Boolean> checkIdState) { 3786 super(superState); 3787 this.checkState = checkState; 3788 this.checkIdState = checkIdState; 3789 } 3790 3791 /** 3792 * Constructor called from {@link #CREATOR} 3793 */ 3794 private SavedState(Parcel in) { 3795 super(in); 3796 checkState = in.readSparseBooleanArray(); 3797 long[] idState = in.createLongArray(); 3798 3799 if (idState.length > 0) { 3800 checkIdState = new LongSparseArray<Boolean>(); 3801 checkIdState.setValues(idState, Boolean.TRUE); 3802 } 3803 } 3804 3805 @Override 3806 public void writeToParcel(Parcel out, int flags) { 3807 super.writeToParcel(out, flags); 3808 out.writeSparseBooleanArray(checkState); 3809 out.writeLongArray(checkIdState != null ? checkIdState.getKeys() : new long[0]); 3810 } 3811 3812 @Override 3813 public String toString() { 3814 return "ListView.SavedState{" 3815 + Integer.toHexString(System.identityHashCode(this)) 3816 + " checkState=" + checkState + "}"; 3817 } 3818 3819 public static final Parcelable.Creator<SavedState> CREATOR 3820 = new Parcelable.Creator<SavedState>() { 3821 public SavedState createFromParcel(Parcel in) { 3822 return new SavedState(in); 3823 } 3824 3825 public SavedState[] newArray(int size) { 3826 return new SavedState[size]; 3827 } 3828 }; 3829 } 3830 3831 @Override 3832 public Parcelable onSaveInstanceState() { 3833 Parcelable superState = super.onSaveInstanceState(); 3834 return new SavedState(superState, mCheckStates, mCheckedIdStates); 3835 } 3836 3837 @Override 3838 public void onRestoreInstanceState(Parcelable state) { 3839 SavedState ss = (SavedState) state; 3840 3841 super.onRestoreInstanceState(ss.getSuperState()); 3842 3843 if (ss.checkState != null) { 3844 mCheckStates = ss.checkState; 3845 } 3846 3847 if (ss.checkIdState != null) { 3848 mCheckedIdStates = ss.checkIdState; 3849 } 3850 } 3851} 3852