ListView.java revision 70c9ffbc838271f0ea27a4780eb146287de53ef6
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.res.TypedArray; 24import android.graphics.Canvas; 25import android.graphics.Paint; 26import android.graphics.PixelFormat; 27import android.graphics.Rect; 28import android.graphics.drawable.ColorDrawable; 29import android.graphics.drawable.Drawable; 30import android.os.Parcel; 31import android.os.Parcelable; 32import android.util.AttributeSet; 33import android.util.LongSparseArray; 34import android.util.SparseBooleanArray; 35import android.view.FocusFinder; 36import android.view.KeyEvent; 37import android.view.MotionEvent; 38import android.view.SoundEffectConstants; 39import android.view.View; 40import android.view.ViewDebug; 41import android.view.ViewGroup; 42import android.view.ViewParent; 43import android.view.accessibility.AccessibilityEvent; 44 45import java.util.ArrayList; 46 47/* 48 * Implementation Notes: 49 * 50 * Some terminology: 51 * 52 * index - index of the items that are currently visible 53 * position - index of the items in the cursor 54 */ 55 56 57/** 58 * A view that shows items in a vertically scrolling list. The items 59 * come from the {@link ListAdapter} associated with this view. 60 * 61 * <p>See the <a href="{@docRoot}resources/tutorials/views/hello-listview.html">List View 62 * tutorial</a>.</p> 63 * 64 * @attr ref android.R.styleable#ListView_entries 65 * @attr ref android.R.styleable#ListView_divider 66 * @attr ref android.R.styleable#ListView_dividerHeight 67 * @attr ref android.R.styleable#ListView_choiceMode 68 * @attr ref android.R.styleable#ListView_headerDividersEnabled 69 * @attr ref android.R.styleable#ListView_footerDividersEnabled 70 */ 71public class ListView extends AbsListView { 72 /** 73 * Used to indicate a no preference for a position type. 74 */ 75 static final int NO_POSITION = -1; 76 77 /** 78 * Normal list that does not indicate choices 79 */ 80 public static final int CHOICE_MODE_NONE = 0; 81 82 /** 83 * The list allows up to one choice 84 */ 85 public static final int CHOICE_MODE_SINGLE = 1; 86 87 /** 88 * The list allows multiple choices 89 */ 90 public static final int CHOICE_MODE_MULTIPLE = 2; 91 92 /** 93 * When arrow scrolling, ListView will never scroll more than this factor 94 * times the height of the list. 95 */ 96 private static final float MAX_SCROLL_FACTOR = 0.33f; 97 98 /** 99 * When arrow scrolling, need a certain amount of pixels to preview next 100 * items. This is usually the fading edge, but if that is small enough, 101 * we want to make sure we preview at least this many pixels. 102 */ 103 private static final int MIN_SCROLL_PREVIEW_PIXELS = 2; 104 105 /** 106 * A class that represents a fixed view in a list, for example a header at the top 107 * or a footer at the bottom. 108 */ 109 public class FixedViewInfo { 110 /** The view to add to the list */ 111 public View view; 112 /** The data backing the view. This is returned from {@link ListAdapter#getItem(int)}. */ 113 public Object data; 114 /** <code>true</code> if the fixed view should be selectable in the list */ 115 public boolean isSelectable; 116 } 117 118 private ArrayList<FixedViewInfo> mHeaderViewInfos = Lists.newArrayList(); 119 private ArrayList<FixedViewInfo> mFooterViewInfos = Lists.newArrayList(); 120 121 Drawable mDivider; 122 int mDividerHeight; 123 124 private boolean mIsCacheColorOpaque; 125 private boolean mDividerIsOpaque; 126 private boolean mClipDivider; 127 128 private boolean mHeaderDividersEnabled; 129 private boolean mFooterDividersEnabled; 130 131 private boolean mAreAllItemsSelectable = true; 132 133 private boolean mItemsCanFocus = false; 134 135 private int mChoiceMode = CHOICE_MODE_NONE; 136 137 private SparseBooleanArray mCheckStates; 138 private LongSparseArray<Boolean> mCheckedIdStates; 139 140 // used for temporary calculations. 141 private final Rect mTempRect = new Rect(); 142 private Paint mDividerPaint; 143 144 // the single allocated result per list view; kinda cheesey but avoids 145 // allocating these thingies too often. 146 private final ArrowScrollFocusResult mArrowScrollFocusResult = new ArrowScrollFocusResult(); 147 148 // Keeps focused children visible through resizes 149 private FocusSelector mFocusSelector; 150 151 public ListView(Context context) { 152 this(context, null); 153 } 154 155 public ListView(Context context, AttributeSet attrs) { 156 this(context, attrs, com.android.internal.R.attr.listViewStyle); 157 } 158 159 public ListView(Context context, AttributeSet attrs, int defStyle) { 160 super(context, attrs, defStyle); 161 162 TypedArray a = context.obtainStyledAttributes(attrs, 163 com.android.internal.R.styleable.ListView, defStyle, 0); 164 165 CharSequence[] entries = a.getTextArray( 166 com.android.internal.R.styleable.ListView_entries); 167 if (entries != null) { 168 setAdapter(new ArrayAdapter<CharSequence>(context, 169 com.android.internal.R.layout.simple_list_item_1, entries)); 170 } 171 172 final Drawable d = a.getDrawable(com.android.internal.R.styleable.ListView_divider); 173 if (d != null) { 174 // If a divider is specified use its intrinsic height for divider height 175 setDivider(d); 176 } 177 178 // Use the height specified, zero being the default 179 final int dividerHeight = a.getDimensionPixelSize( 180 com.android.internal.R.styleable.ListView_dividerHeight, 0); 181 if (dividerHeight != 0) { 182 setDividerHeight(dividerHeight); 183 } 184 185 setChoiceMode(a.getInt(R.styleable.ListView_choiceMode, CHOICE_MODE_NONE)); 186 187 mHeaderDividersEnabled = a.getBoolean(R.styleable.ListView_headerDividersEnabled, true); 188 mFooterDividersEnabled = a.getBoolean(R.styleable.ListView_footerDividersEnabled, true); 189 190 a.recycle(); 191 } 192 193 /** 194 * @return The maximum amount a list view will scroll in response to 195 * an arrow event. 196 */ 197 public int getMaxScrollAmount() { 198 return (int) (MAX_SCROLL_FACTOR * (mBottom - mTop)); 199 } 200 201 /** 202 * Make sure views are touching the top or bottom edge, as appropriate for 203 * our gravity 204 */ 205 private void adjustViewsUpOrDown() { 206 final int childCount = getChildCount(); 207 int delta; 208 209 if (childCount > 0) { 210 View child; 211 212 if (!mStackFromBottom) { 213 // Uh-oh -- we came up short. Slide all views up to make them 214 // align with the top 215 child = getChildAt(0); 216 delta = child.getTop() - mListPadding.top; 217 if (mFirstPosition != 0) { 218 // It's OK to have some space above the first item if it is 219 // part of the vertical spacing 220 delta -= mDividerHeight; 221 } 222 if (delta < 0) { 223 // We only are looking to see if we are too low, not too high 224 delta = 0; 225 } 226 } else { 227 // we are too high, slide all views down to align with bottom 228 child = getChildAt(childCount - 1); 229 delta = child.getBottom() - (getHeight() - mListPadding.bottom); 230 231 if (mFirstPosition + childCount < mItemCount) { 232 // It's OK to have some space below the last item if it is 233 // part of the vertical spacing 234 delta += mDividerHeight; 235 } 236 237 if (delta > 0) { 238 delta = 0; 239 } 240 } 241 242 if (delta != 0) { 243 offsetChildrenTopAndBottom(-delta); 244 } 245 } 246 } 247 248 /** 249 * Add a fixed view to appear at the top of the list. If addHeaderView is 250 * called more than once, the views will appear in the order they were 251 * added. Views added using this call can take focus if they want. 252 * <p> 253 * NOTE: Call this before calling setAdapter. This is so ListView can wrap 254 * the supplied cursor with one that will also account for header and footer 255 * views. 256 * 257 * @param v The view to add. 258 * @param data Data to associate with this view 259 * @param isSelectable whether the item is selectable 260 */ 261 public void addHeaderView(View v, Object data, boolean isSelectable) { 262 263 if (mAdapter != null) { 264 throw new IllegalStateException( 265 "Cannot add header view to list -- setAdapter has already been called."); 266 } 267 268 FixedViewInfo info = new FixedViewInfo(); 269 info.view = v; 270 info.data = data; 271 info.isSelectable = isSelectable; 272 mHeaderViewInfos.add(info); 273 } 274 275 /** 276 * Add a fixed view to appear at the top of the list. If addHeaderView is 277 * called more than once, the views will appear in the order they were 278 * added. Views added using this call can take focus if they want. 279 * <p> 280 * NOTE: Call this before calling setAdapter. This is so ListView can wrap 281 * the supplied cursor with one that will also account for header and footer 282 * views. 283 * 284 * @param v The view to add. 285 */ 286 public void addHeaderView(View v) { 287 addHeaderView(v, null, true); 288 } 289 290 @Override 291 public int getHeaderViewsCount() { 292 return mHeaderViewInfos.size(); 293 } 294 295 /** 296 * Removes a previously-added header view. 297 * 298 * @param v The view to remove 299 * @return true if the view was removed, false if the view was not a header 300 * view 301 */ 302 public boolean removeHeaderView(View v) { 303 if (mHeaderViewInfos.size() > 0) { 304 boolean result = false; 305 if (((HeaderViewListAdapter) mAdapter).removeHeader(v)) { 306 mDataSetObserver.onChanged(); 307 result = true; 308 } 309 removeFixedViewInfo(v, mHeaderViewInfos); 310 return result; 311 } 312 return false; 313 } 314 315 private void removeFixedViewInfo(View v, ArrayList<FixedViewInfo> where) { 316 int len = where.size(); 317 for (int i = 0; i < len; ++i) { 318 FixedViewInfo info = where.get(i); 319 if (info.view == v) { 320 where.remove(i); 321 break; 322 } 323 } 324 } 325 326 /** 327 * Add a fixed view to appear at the bottom of the list. If addFooterView is 328 * called more than once, the views will appear in the order they were 329 * added. Views added using this call can take focus if they want. 330 * <p> 331 * NOTE: Call this before calling setAdapter. This is so ListView can wrap 332 * the supplied cursor with one that will also account for header and footer 333 * views. 334 * 335 * @param v The view to add. 336 * @param data Data to associate with this view 337 * @param isSelectable true if the footer view can be selected 338 */ 339 public void addFooterView(View v, Object data, boolean isSelectable) { 340 FixedViewInfo info = new FixedViewInfo(); 341 info.view = v; 342 info.data = data; 343 info.isSelectable = isSelectable; 344 mFooterViewInfos.add(info); 345 346 // in the case of re-adding a footer view, or adding one later on, 347 // we need to notify the observer 348 if (mDataSetObserver != null) { 349 mDataSetObserver.onChanged(); 350 } 351 } 352 353 /** 354 * Add a fixed view to appear at the bottom of the list. If addFooterView is called more 355 * than once, the views will appear in the order they were added. Views added using 356 * this call can take focus if they want. 357 * <p>NOTE: Call this before calling setAdapter. This is so ListView can wrap the supplied 358 * cursor with one that will also account for header and footer views. 359 * 360 * 361 * @param v The view to add. 362 */ 363 public void addFooterView(View v) { 364 addFooterView(v, null, true); 365 } 366 367 @Override 368 public int getFooterViewsCount() { 369 return mFooterViewInfos.size(); 370 } 371 372 /** 373 * Removes a previously-added footer view. 374 * 375 * @param v The view to remove 376 * @return 377 * true if the view was removed, false if the view was not a footer view 378 */ 379 public boolean removeFooterView(View v) { 380 if (mFooterViewInfos.size() > 0) { 381 boolean result = false; 382 if (((HeaderViewListAdapter) mAdapter).removeFooter(v)) { 383 mDataSetObserver.onChanged(); 384 result = true; 385 } 386 removeFixedViewInfo(v, mFooterViewInfos); 387 return result; 388 } 389 return false; 390 } 391 392 /** 393 * Returns the adapter currently in use in this ListView. The returned adapter 394 * might not be the same adapter passed to {@link #setAdapter(ListAdapter)} but 395 * might be a {@link WrapperListAdapter}. 396 * 397 * @return The adapter currently used to display data in this ListView. 398 * 399 * @see #setAdapter(ListAdapter) 400 */ 401 @Override 402 public ListAdapter getAdapter() { 403 return mAdapter; 404 } 405 406 /** 407 * Sets the data behind this ListView. 408 * 409 * The adapter passed to this method may be wrapped by a {@link WrapperListAdapter}, 410 * depending on the ListView features currently in use. For instance, adding 411 * headers and/or footers will cause the adapter to be wrapped. 412 * 413 * @param adapter The ListAdapter which is responsible for maintaining the 414 * data backing this list and for producing a view to represent an 415 * item in that data set. 416 * 417 * @see #getAdapter() 418 */ 419 @Override 420 public void setAdapter(ListAdapter adapter) { 421 if (null != mAdapter) { 422 mAdapter.unregisterDataSetObserver(mDataSetObserver); 423 } 424 425 resetList(); 426 mRecycler.clear(); 427 428 if (mHeaderViewInfos.size() > 0|| mFooterViewInfos.size() > 0) { 429 mAdapter = new HeaderViewListAdapter(mHeaderViewInfos, mFooterViewInfos, adapter); 430 } else { 431 mAdapter = adapter; 432 } 433 434 mOldSelectedPosition = INVALID_POSITION; 435 mOldSelectedRowId = INVALID_ROW_ID; 436 if (mAdapter != null) { 437 mAreAllItemsSelectable = mAdapter.areAllItemsEnabled(); 438 mOldItemCount = mItemCount; 439 mItemCount = mAdapter.getCount(); 440 checkFocus(); 441 442 mDataSetObserver = new AdapterDataSetObserver(); 443 mAdapter.registerDataSetObserver(mDataSetObserver); 444 445 mRecycler.setViewTypeCount(mAdapter.getViewTypeCount()); 446 447 int position; 448 if (mStackFromBottom) { 449 position = lookForSelectablePosition(mItemCount - 1, false); 450 } else { 451 position = lookForSelectablePosition(0, true); 452 } 453 setSelectedPositionInt(position); 454 setNextSelectedPositionInt(position); 455 456 if (mItemCount == 0) { 457 // Nothing selected 458 checkSelectionChanged(); 459 } 460 461 if (mChoiceMode != CHOICE_MODE_NONE && 462 mAdapter.hasStableIds() && 463 mCheckedIdStates == null) { 464 mCheckedIdStates = new LongSparseArray<Boolean>(); 465 } 466 467 } else { 468 mAreAllItemsSelectable = true; 469 checkFocus(); 470 // Nothing selected 471 checkSelectionChanged(); 472 } 473 474 if (mCheckStates != null) { 475 mCheckStates.clear(); 476 } 477 478 if (mCheckedIdStates != null) { 479 mCheckedIdStates.clear(); 480 } 481 482 requestLayout(); 483 } 484 485 486 /** 487 * The list is empty. Clear everything out. 488 */ 489 @Override 490 void resetList() { 491 // The parent's resetList() will remove all views from the layout so we need to 492 // cleanup the state of our footers and headers 493 clearRecycledState(mHeaderViewInfos); 494 clearRecycledState(mFooterViewInfos); 495 496 super.resetList(); 497 498 mLayoutMode = LAYOUT_NORMAL; 499 } 500 501 private void clearRecycledState(ArrayList<FixedViewInfo> infos) { 502 if (infos != null) { 503 final int count = infos.size(); 504 505 for (int i = 0; i < count; i++) { 506 final View child = infos.get(i).view; 507 final LayoutParams p = (LayoutParams) child.getLayoutParams(); 508 if (p != null) { 509 p.recycledHeaderFooter = false; 510 } 511 } 512 } 513 } 514 515 /** 516 * @return Whether the list needs to show the top fading edge 517 */ 518 private boolean showingTopFadingEdge() { 519 final int listTop = mScrollY + mListPadding.top; 520 return (mFirstPosition > 0) || (getChildAt(0).getTop() > listTop); 521 } 522 523 /** 524 * @return Whether the list needs to show the bottom fading edge 525 */ 526 private boolean showingBottomFadingEdge() { 527 final int childCount = getChildCount(); 528 final int bottomOfBottomChild = getChildAt(childCount - 1).getBottom(); 529 final int lastVisiblePosition = mFirstPosition + childCount - 1; 530 531 final int listBottom = mScrollY + getHeight() - mListPadding.bottom; 532 533 return (lastVisiblePosition < mItemCount - 1) 534 || (bottomOfBottomChild < listBottom); 535 } 536 537 538 @Override 539 public boolean requestChildRectangleOnScreen(View child, Rect rect, boolean immediate) { 540 541 int rectTopWithinChild = rect.top; 542 543 // offset so rect is in coordinates of the this view 544 rect.offset(child.getLeft(), child.getTop()); 545 rect.offset(-child.getScrollX(), -child.getScrollY()); 546 547 final int height = getHeight(); 548 int listUnfadedTop = getScrollY(); 549 int listUnfadedBottom = listUnfadedTop + height; 550 final int fadingEdge = getVerticalFadingEdgeLength(); 551 552 if (showingTopFadingEdge()) { 553 // leave room for top fading edge as long as rect isn't at very top 554 if ((mSelectedPosition > 0) || (rectTopWithinChild > fadingEdge)) { 555 listUnfadedTop += fadingEdge; 556 } 557 } 558 559 int childCount = getChildCount(); 560 int bottomOfBottomChild = getChildAt(childCount - 1).getBottom(); 561 562 if (showingBottomFadingEdge()) { 563 // leave room for bottom fading edge as long as rect isn't at very bottom 564 if ((mSelectedPosition < mItemCount - 1) 565 || (rect.bottom < (bottomOfBottomChild - fadingEdge))) { 566 listUnfadedBottom -= fadingEdge; 567 } 568 } 569 570 int scrollYDelta = 0; 571 572 if (rect.bottom > listUnfadedBottom && rect.top > listUnfadedTop) { 573 // need to MOVE DOWN to get it in view: move down just enough so 574 // that the entire rectangle is in view (or at least the first 575 // screen size chunk). 576 577 if (rect.height() > height) { 578 // just enough to get screen size chunk on 579 scrollYDelta += (rect.top - listUnfadedTop); 580 } else { 581 // get entire rect at bottom of screen 582 scrollYDelta += (rect.bottom - listUnfadedBottom); 583 } 584 585 // make sure we aren't scrolling beyond the end of our children 586 int distanceToBottom = bottomOfBottomChild - listUnfadedBottom; 587 scrollYDelta = Math.min(scrollYDelta, distanceToBottom); 588 } else if (rect.top < listUnfadedTop && rect.bottom < listUnfadedBottom) { 589 // need to MOVE UP to get it in view: move up just enough so that 590 // entire rectangle is in view (or at least the first screen 591 // size chunk of it). 592 593 if (rect.height() > height) { 594 // screen size chunk 595 scrollYDelta -= (listUnfadedBottom - rect.bottom); 596 } else { 597 // entire rect at top 598 scrollYDelta -= (listUnfadedTop - rect.top); 599 } 600 601 // make sure we aren't scrolling any further than the top our children 602 int top = getChildAt(0).getTop(); 603 int deltaToTop = top - listUnfadedTop; 604 scrollYDelta = Math.max(scrollYDelta, deltaToTop); 605 } 606 607 final boolean scroll = scrollYDelta != 0; 608 if (scroll) { 609 scrollListItemsBy(-scrollYDelta); 610 positionSelector(child); 611 mSelectedTop = child.getTop(); 612 invalidate(); 613 } 614 return scroll; 615 } 616 617 /** 618 * {@inheritDoc} 619 */ 620 @Override 621 void fillGap(boolean down) { 622 final int count = getChildCount(); 623 if (down) { 624 final int startOffset = count > 0 ? getChildAt(count - 1).getBottom() + mDividerHeight : 625 getListPaddingTop(); 626 fillDown(mFirstPosition + count, startOffset); 627 correctTooHigh(getChildCount()); 628 } else { 629 final int startOffset = count > 0 ? getChildAt(0).getTop() - mDividerHeight : 630 getHeight() - getListPaddingBottom(); 631 fillUp(mFirstPosition - 1, startOffset); 632 correctTooLow(getChildCount()); 633 } 634 } 635 636 /** 637 * Fills the list from pos down to the end of the list view. 638 * 639 * @param pos The first position to put in the list 640 * 641 * @param nextTop The location where the top of the item associated with pos 642 * should be drawn 643 * 644 * @return The view that is currently selected, if it happens to be in the 645 * range that we draw. 646 */ 647 private View fillDown(int pos, int nextTop) { 648 View selectedView = null; 649 650 int end = (mBottom - mTop) - mListPadding.bottom; 651 652 while (nextTop < end && pos < mItemCount) { 653 // is this the selected item? 654 boolean selected = pos == mSelectedPosition; 655 View child = makeAndAddView(pos, nextTop, true, mListPadding.left, selected); 656 657 nextTop = child.getBottom() + mDividerHeight; 658 if (selected) { 659 selectedView = child; 660 } 661 pos++; 662 } 663 664 return selectedView; 665 } 666 667 /** 668 * Fills the list from pos up to the top of the list view. 669 * 670 * @param pos The first position to put in the list 671 * 672 * @param nextBottom The location where the bottom of the item associated 673 * with pos should be drawn 674 * 675 * @return The view that is currently selected 676 */ 677 private View fillUp(int pos, int nextBottom) { 678 View selectedView = null; 679 680 int end = mListPadding.top; 681 682 while (nextBottom > end && pos >= 0) { 683 // is this the selected item? 684 boolean selected = pos == mSelectedPosition; 685 View child = makeAndAddView(pos, nextBottom, false, mListPadding.left, selected); 686 nextBottom = child.getTop() - mDividerHeight; 687 if (selected) { 688 selectedView = child; 689 } 690 pos--; 691 } 692 693 mFirstPosition = pos + 1; 694 695 return selectedView; 696 } 697 698 /** 699 * Fills the list from top to bottom, starting with mFirstPosition 700 * 701 * @param nextTop The location where the top of the first item should be 702 * drawn 703 * 704 * @return The view that is currently selected 705 */ 706 private View fillFromTop(int nextTop) { 707 mFirstPosition = Math.min(mFirstPosition, mSelectedPosition); 708 mFirstPosition = Math.min(mFirstPosition, mItemCount - 1); 709 if (mFirstPosition < 0) { 710 mFirstPosition = 0; 711 } 712 return fillDown(mFirstPosition, nextTop); 713 } 714 715 716 /** 717 * Put mSelectedPosition in the middle of the screen and then build up and 718 * down from there. This method forces mSelectedPosition to the center. 719 * 720 * @param childrenTop Top of the area in which children can be drawn, as 721 * measured in pixels 722 * @param childrenBottom Bottom of the area in which children can be drawn, 723 * as measured in pixels 724 * @return Currently selected view 725 */ 726 private View fillFromMiddle(int childrenTop, int childrenBottom) { 727 int height = childrenBottom - childrenTop; 728 729 int position = reconcileSelectedPosition(); 730 731 View sel = makeAndAddView(position, childrenTop, true, 732 mListPadding.left, true); 733 mFirstPosition = position; 734 735 int selHeight = sel.getMeasuredHeight(); 736 if (selHeight <= height) { 737 sel.offsetTopAndBottom((height - selHeight) / 2); 738 } 739 740 fillAboveAndBelow(sel, position); 741 742 if (!mStackFromBottom) { 743 correctTooHigh(getChildCount()); 744 } else { 745 correctTooLow(getChildCount()); 746 } 747 748 return sel; 749 } 750 751 /** 752 * Once the selected view as been placed, fill up the visible area above and 753 * below it. 754 * 755 * @param sel The selected view 756 * @param position The position corresponding to sel 757 */ 758 private void fillAboveAndBelow(View sel, int position) { 759 final int dividerHeight = mDividerHeight; 760 if (!mStackFromBottom) { 761 fillUp(position - 1, sel.getTop() - dividerHeight); 762 adjustViewsUpOrDown(); 763 fillDown(position + 1, sel.getBottom() + dividerHeight); 764 } else { 765 fillDown(position + 1, sel.getBottom() + dividerHeight); 766 adjustViewsUpOrDown(); 767 fillUp(position - 1, sel.getTop() - dividerHeight); 768 } 769 } 770 771 772 /** 773 * Fills the grid based on positioning the new selection at a specific 774 * location. The selection may be moved so that it does not intersect the 775 * faded edges. The grid is then filled upwards and downwards from there. 776 * 777 * @param selectedTop Where the selected item should be 778 * @param childrenTop Where to start drawing children 779 * @param childrenBottom Last pixel where children can be drawn 780 * @return The view that currently has selection 781 */ 782 private View fillFromSelection(int selectedTop, int childrenTop, int childrenBottom) { 783 int fadingEdgeLength = getVerticalFadingEdgeLength(); 784 final int selectedPosition = mSelectedPosition; 785 786 View sel; 787 788 final int topSelectionPixel = getTopSelectionPixel(childrenTop, fadingEdgeLength, 789 selectedPosition); 790 final int bottomSelectionPixel = getBottomSelectionPixel(childrenBottom, fadingEdgeLength, 791 selectedPosition); 792 793 sel = makeAndAddView(selectedPosition, selectedTop, true, mListPadding.left, true); 794 795 796 // Some of the newly selected item extends below the bottom of the list 797 if (sel.getBottom() > bottomSelectionPixel) { 798 // Find space available above the selection into which we can scroll 799 // upwards 800 final int spaceAbove = sel.getTop() - topSelectionPixel; 801 802 // Find space required to bring the bottom of the selected item 803 // fully into view 804 final int spaceBelow = sel.getBottom() - bottomSelectionPixel; 805 final int offset = Math.min(spaceAbove, spaceBelow); 806 807 // Now offset the selected item to get it into view 808 sel.offsetTopAndBottom(-offset); 809 } else if (sel.getTop() < topSelectionPixel) { 810 // Find space required to bring the top of the selected item fully 811 // into view 812 final int spaceAbove = topSelectionPixel - sel.getTop(); 813 814 // Find space available below the selection into which we can scroll 815 // downwards 816 final int spaceBelow = bottomSelectionPixel - sel.getBottom(); 817 final int offset = Math.min(spaceAbove, spaceBelow); 818 819 // Offset the selected item to get it into view 820 sel.offsetTopAndBottom(offset); 821 } 822 823 // Fill in views above and below 824 fillAboveAndBelow(sel, selectedPosition); 825 826 if (!mStackFromBottom) { 827 correctTooHigh(getChildCount()); 828 } else { 829 correctTooLow(getChildCount()); 830 } 831 832 return sel; 833 } 834 835 /** 836 * Calculate the bottom-most pixel we can draw the selection into 837 * 838 * @param childrenBottom Bottom pixel were children can be drawn 839 * @param fadingEdgeLength Length of the fading edge in pixels, if present 840 * @param selectedPosition The position that will be selected 841 * @return The bottom-most pixel we can draw the selection into 842 */ 843 private int getBottomSelectionPixel(int childrenBottom, int fadingEdgeLength, 844 int selectedPosition) { 845 int bottomSelectionPixel = childrenBottom; 846 if (selectedPosition != mItemCount - 1) { 847 bottomSelectionPixel -= fadingEdgeLength; 848 } 849 return bottomSelectionPixel; 850 } 851 852 /** 853 * Calculate the top-most pixel we can draw the selection into 854 * 855 * @param childrenTop Top pixel were children can be drawn 856 * @param fadingEdgeLength Length of the fading edge in pixels, if present 857 * @param selectedPosition The position that will be selected 858 * @return The top-most pixel we can draw the selection into 859 */ 860 private int getTopSelectionPixel(int childrenTop, int fadingEdgeLength, int selectedPosition) { 861 // first pixel we can draw the selection into 862 int topSelectionPixel = childrenTop; 863 if (selectedPosition > 0) { 864 topSelectionPixel += fadingEdgeLength; 865 } 866 return topSelectionPixel; 867 } 868 869 870 /** 871 * Fills the list based on positioning the new selection relative to the old 872 * selection. The new selection will be placed at, above, or below the 873 * location of the new selection depending on how the selection is moving. 874 * The selection will then be pinned to the visible part of the screen, 875 * excluding the edges that are faded. The list is then filled upwards and 876 * downwards from there. 877 * 878 * @param oldSel The old selected view. Useful for trying to put the new 879 * selection in the same place 880 * @param newSel The view that is to become selected. Useful for trying to 881 * put the new selection in the same place 882 * @param delta Which way we are moving 883 * @param childrenTop Where to start drawing children 884 * @param childrenBottom Last pixel where children can be drawn 885 * @return The view that currently has selection 886 */ 887 private View moveSelection(View oldSel, View newSel, int delta, int childrenTop, 888 int childrenBottom) { 889 int fadingEdgeLength = getVerticalFadingEdgeLength(); 890 final int selectedPosition = mSelectedPosition; 891 892 View sel; 893 894 final int topSelectionPixel = getTopSelectionPixel(childrenTop, fadingEdgeLength, 895 selectedPosition); 896 final int bottomSelectionPixel = getBottomSelectionPixel(childrenTop, fadingEdgeLength, 897 selectedPosition); 898 899 if (delta > 0) { 900 /* 901 * Case 1: Scrolling down. 902 */ 903 904 /* 905 * Before After 906 * | | | | 907 * +-------+ +-------+ 908 * | A | | A | 909 * | 1 | => +-------+ 910 * +-------+ | B | 911 * | B | | 2 | 912 * +-------+ +-------+ 913 * | | | | 914 * 915 * Try to keep the top of the previously selected item where it was. 916 * oldSel = A 917 * sel = B 918 */ 919 920 // Put oldSel (A) where it belongs 921 oldSel = makeAndAddView(selectedPosition - 1, oldSel.getTop(), true, 922 mListPadding.left, false); 923 924 final int dividerHeight = mDividerHeight; 925 926 // Now put the new selection (B) below that 927 sel = makeAndAddView(selectedPosition, oldSel.getBottom() + dividerHeight, true, 928 mListPadding.left, true); 929 930 // Some of the newly selected item extends below the bottom of the list 931 if (sel.getBottom() > bottomSelectionPixel) { 932 933 // Find space available above the selection into which we can scroll upwards 934 int spaceAbove = sel.getTop() - topSelectionPixel; 935 936 // Find space required to bring the bottom of the selected item fully into view 937 int spaceBelow = sel.getBottom() - bottomSelectionPixel; 938 939 // Don't scroll more than half the height of the list 940 int halfVerticalSpace = (childrenBottom - childrenTop) / 2; 941 int offset = Math.min(spaceAbove, spaceBelow); 942 offset = Math.min(offset, halfVerticalSpace); 943 944 // We placed oldSel, so offset that item 945 oldSel.offsetTopAndBottom(-offset); 946 // Now offset the selected item to get it into view 947 sel.offsetTopAndBottom(-offset); 948 } 949 950 // Fill in views above and below 951 if (!mStackFromBottom) { 952 fillUp(mSelectedPosition - 2, sel.getTop() - dividerHeight); 953 adjustViewsUpOrDown(); 954 fillDown(mSelectedPosition + 1, sel.getBottom() + dividerHeight); 955 } else { 956 fillDown(mSelectedPosition + 1, sel.getBottom() + dividerHeight); 957 adjustViewsUpOrDown(); 958 fillUp(mSelectedPosition - 2, sel.getTop() - dividerHeight); 959 } 960 } else if (delta < 0) { 961 /* 962 * Case 2: Scrolling up. 963 */ 964 965 /* 966 * Before After 967 * | | | | 968 * +-------+ +-------+ 969 * | A | | A | 970 * +-------+ => | 1 | 971 * | B | +-------+ 972 * | 2 | | B | 973 * +-------+ +-------+ 974 * | | | | 975 * 976 * Try to keep the top of the item about to become selected where it was. 977 * newSel = A 978 * olSel = B 979 */ 980 981 if (newSel != null) { 982 // Try to position the top of newSel (A) where it was before it was selected 983 sel = makeAndAddView(selectedPosition, newSel.getTop(), true, mListPadding.left, 984 true); 985 } else { 986 // If (A) was not on screen and so did not have a view, position 987 // it above the oldSel (B) 988 sel = makeAndAddView(selectedPosition, oldSel.getTop(), false, mListPadding.left, 989 true); 990 } 991 992 // Some of the newly selected item extends above the top of the list 993 if (sel.getTop() < topSelectionPixel) { 994 // Find space required to bring the top of the selected item fully into view 995 int spaceAbove = topSelectionPixel - sel.getTop(); 996 997 // Find space available below the selection into which we can scroll downwards 998 int spaceBelow = bottomSelectionPixel - sel.getBottom(); 999 1000 // Don't scroll more than half the height of the list 1001 int halfVerticalSpace = (childrenBottom - childrenTop) / 2; 1002 int offset = Math.min(spaceAbove, spaceBelow); 1003 offset = Math.min(offset, halfVerticalSpace); 1004 1005 // Offset the selected item to get it into view 1006 sel.offsetTopAndBottom(offset); 1007 } 1008 1009 // Fill in views above and below 1010 fillAboveAndBelow(sel, selectedPosition); 1011 } else { 1012 1013 int oldTop = oldSel.getTop(); 1014 1015 /* 1016 * Case 3: Staying still 1017 */ 1018 sel = makeAndAddView(selectedPosition, oldTop, true, mListPadding.left, true); 1019 1020 // We're staying still... 1021 if (oldTop < childrenTop) { 1022 // ... but the top of the old selection was off screen. 1023 // (This can happen if the data changes size out from under us) 1024 int newBottom = sel.getBottom(); 1025 if (newBottom < childrenTop + 20) { 1026 // Not enough visible -- bring it onscreen 1027 sel.offsetTopAndBottom(childrenTop - sel.getTop()); 1028 } 1029 } 1030 1031 // Fill in views above and below 1032 fillAboveAndBelow(sel, selectedPosition); 1033 } 1034 1035 return sel; 1036 } 1037 1038 private class FocusSelector implements Runnable { 1039 private int mPosition; 1040 private int mPositionTop; 1041 1042 public FocusSelector setup(int position, int top) { 1043 mPosition = position; 1044 mPositionTop = top; 1045 return this; 1046 } 1047 1048 public void run() { 1049 setSelectionFromTop(mPosition, mPositionTop); 1050 } 1051 } 1052 1053 @Override 1054 protected void onSizeChanged(int w, int h, int oldw, int oldh) { 1055 if (getChildCount() > 0) { 1056 View focusedChild = getFocusedChild(); 1057 if (focusedChild != null) { 1058 final int childPosition = mFirstPosition + indexOfChild(focusedChild); 1059 final int childBottom = focusedChild.getBottom(); 1060 final int offset = Math.max(0, childBottom - (h - mPaddingTop)); 1061 final int top = focusedChild.getTop() - offset; 1062 if (mFocusSelector == null) { 1063 mFocusSelector = new FocusSelector(); 1064 } 1065 post(mFocusSelector.setup(childPosition, top)); 1066 } 1067 } 1068 super.onSizeChanged(w, h, oldw, oldh); 1069 } 1070 1071 @Override 1072 protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { 1073 // Sets up mListPadding 1074 super.onMeasure(widthMeasureSpec, heightMeasureSpec); 1075 1076 int widthMode = MeasureSpec.getMode(widthMeasureSpec); 1077 int heightMode = MeasureSpec.getMode(heightMeasureSpec); 1078 int widthSize = MeasureSpec.getSize(widthMeasureSpec); 1079 int heightSize = MeasureSpec.getSize(heightMeasureSpec); 1080 1081 int childWidth = 0; 1082 int childHeight = 0; 1083 1084 mItemCount = mAdapter == null ? 0 : mAdapter.getCount(); 1085 if (mItemCount > 0 && (widthMode == MeasureSpec.UNSPECIFIED || 1086 heightMode == MeasureSpec.UNSPECIFIED)) { 1087 final View child = obtainView(0, mIsScrap); 1088 1089 measureScrapChild(child, 0, widthMeasureSpec); 1090 1091 childWidth = child.getMeasuredWidth(); 1092 childHeight = child.getMeasuredHeight(); 1093 1094 if (recycleOnMeasure() && mRecycler.shouldRecycleViewType( 1095 ((LayoutParams) child.getLayoutParams()).viewType)) { 1096 mRecycler.addScrapView(child); 1097 } 1098 } 1099 1100 if (widthMode == MeasureSpec.UNSPECIFIED) { 1101 widthSize = mListPadding.left + mListPadding.right + childWidth + 1102 getVerticalScrollbarWidth(); 1103 } 1104 1105 if (heightMode == MeasureSpec.UNSPECIFIED) { 1106 heightSize = mListPadding.top + mListPadding.bottom + childHeight + 1107 getVerticalFadingEdgeLength() * 2; 1108 } 1109 1110 if (heightMode == MeasureSpec.AT_MOST) { 1111 // TODO: after first layout we should maybe start at the first visible position, not 0 1112 heightSize = measureHeightOfChildren(widthMeasureSpec, 0, NO_POSITION, heightSize, -1); 1113 } 1114 1115 setMeasuredDimension(widthSize, heightSize); 1116 mWidthMeasureSpec = widthMeasureSpec; 1117 } 1118 1119 private void measureScrapChild(View child, int position, int widthMeasureSpec) { 1120 LayoutParams p = (LayoutParams) child.getLayoutParams(); 1121 if (p == null) { 1122 p = new LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, 1123 ViewGroup.LayoutParams.WRAP_CONTENT, 0); 1124 child.setLayoutParams(p); 1125 } 1126 p.viewType = mAdapter.getItemViewType(position); 1127 p.forceAdd = true; 1128 1129 int childWidthSpec = ViewGroup.getChildMeasureSpec(widthMeasureSpec, 1130 mListPadding.left + mListPadding.right, p.width); 1131 int lpHeight = p.height; 1132 int childHeightSpec; 1133 if (lpHeight > 0) { 1134 childHeightSpec = MeasureSpec.makeMeasureSpec(lpHeight, MeasureSpec.EXACTLY); 1135 } else { 1136 childHeightSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED); 1137 } 1138 child.measure(childWidthSpec, childHeightSpec); 1139 } 1140 1141 /** 1142 * @return True to recycle the views used to measure this ListView in 1143 * UNSPECIFIED/AT_MOST modes, false otherwise. 1144 * @hide 1145 */ 1146 @ViewDebug.ExportedProperty(category = "list") 1147 protected boolean recycleOnMeasure() { 1148 return true; 1149 } 1150 1151 /** 1152 * Measures the height of the given range of children (inclusive) and 1153 * returns the height with this ListView's padding and divider heights 1154 * included. If maxHeight is provided, the measuring will stop when the 1155 * current height reaches maxHeight. 1156 * 1157 * @param widthMeasureSpec The width measure spec to be given to a child's 1158 * {@link View#measure(int, int)}. 1159 * @param startPosition The position of the first child to be shown. 1160 * @param endPosition The (inclusive) position of the last child to be 1161 * shown. Specify {@link #NO_POSITION} if the last child should be 1162 * the last available child from the adapter. 1163 * @param maxHeight The maximum height that will be returned (if all the 1164 * children don't fit in this value, this value will be 1165 * returned). 1166 * @param disallowPartialChildPosition In general, whether the returned 1167 * height should only contain entire children. This is more 1168 * powerful--it is the first inclusive position at which partial 1169 * children will not be allowed. Example: it looks nice to have 1170 * at least 3 completely visible children, and in portrait this 1171 * will most likely fit; but in landscape there could be times 1172 * when even 2 children can not be completely shown, so a value 1173 * of 2 (remember, inclusive) would be good (assuming 1174 * startPosition is 0). 1175 * @return The height of this ListView with the given children. 1176 */ 1177 final int measureHeightOfChildren(int widthMeasureSpec, int startPosition, int endPosition, 1178 final int maxHeight, int disallowPartialChildPosition) { 1179 1180 final ListAdapter adapter = mAdapter; 1181 if (adapter == null) { 1182 return mListPadding.top + mListPadding.bottom; 1183 } 1184 1185 // Include the padding of the list 1186 int returnedHeight = mListPadding.top + mListPadding.bottom; 1187 final int dividerHeight = ((mDividerHeight > 0) && mDivider != null) ? mDividerHeight : 0; 1188 // The previous height value that was less than maxHeight and contained 1189 // no partial children 1190 int prevHeightWithoutPartialChild = 0; 1191 int i; 1192 View child; 1193 1194 // mItemCount - 1 since endPosition parameter is inclusive 1195 endPosition = (endPosition == NO_POSITION) ? adapter.getCount() - 1 : endPosition; 1196 final AbsListView.RecycleBin recycleBin = mRecycler; 1197 final boolean recyle = recycleOnMeasure(); 1198 final boolean[] isScrap = mIsScrap; 1199 1200 for (i = startPosition; i <= endPosition; ++i) { 1201 child = obtainView(i, isScrap); 1202 1203 measureScrapChild(child, i, widthMeasureSpec); 1204 1205 if (i > 0) { 1206 // Count the divider for all but one child 1207 returnedHeight += dividerHeight; 1208 } 1209 1210 // Recycle the view before we possibly return from the method 1211 if (recyle && recycleBin.shouldRecycleViewType( 1212 ((LayoutParams) child.getLayoutParams()).viewType)) { 1213 recycleBin.addScrapView(child); 1214 } 1215 1216 returnedHeight += child.getMeasuredHeight(); 1217 1218 if (returnedHeight >= maxHeight) { 1219 // We went over, figure out which height to return. If returnedHeight > maxHeight, 1220 // then the i'th position did not fit completely. 1221 return (disallowPartialChildPosition >= 0) // Disallowing is enabled (> -1) 1222 && (i > disallowPartialChildPosition) // We've past the min pos 1223 && (prevHeightWithoutPartialChild > 0) // We have a prev height 1224 && (returnedHeight != maxHeight) // i'th child did not fit completely 1225 ? prevHeightWithoutPartialChild 1226 : maxHeight; 1227 } 1228 1229 if ((disallowPartialChildPosition >= 0) && (i >= disallowPartialChildPosition)) { 1230 prevHeightWithoutPartialChild = returnedHeight; 1231 } 1232 } 1233 1234 // At this point, we went through the range of children, and they each 1235 // completely fit, so return the returnedHeight 1236 return returnedHeight; 1237 } 1238 1239 @Override 1240 int findMotionRow(int y) { 1241 int childCount = getChildCount(); 1242 if (childCount > 0) { 1243 if (!mStackFromBottom) { 1244 for (int i = 0; i < childCount; i++) { 1245 View v = getChildAt(i); 1246 if (y <= v.getBottom()) { 1247 return mFirstPosition + i; 1248 } 1249 } 1250 } else { 1251 for (int i = childCount - 1; i >= 0; i--) { 1252 View v = getChildAt(i); 1253 if (y >= v.getTop()) { 1254 return mFirstPosition + i; 1255 } 1256 } 1257 } 1258 } 1259 return INVALID_POSITION; 1260 } 1261 1262 /** 1263 * Put a specific item at a specific location on the screen and then build 1264 * up and down from there. 1265 * 1266 * @param position The reference view to use as the starting point 1267 * @param top Pixel offset from the top of this view to the top of the 1268 * reference view. 1269 * 1270 * @return The selected view, or null if the selected view is outside the 1271 * visible area. 1272 */ 1273 private View fillSpecific(int position, int top) { 1274 boolean tempIsSelected = position == mSelectedPosition; 1275 View temp = makeAndAddView(position, top, true, mListPadding.left, tempIsSelected); 1276 // Possibly changed again in fillUp if we add rows above this one. 1277 mFirstPosition = position; 1278 1279 View above; 1280 View below; 1281 1282 final int dividerHeight = mDividerHeight; 1283 if (!mStackFromBottom) { 1284 above = fillUp(position - 1, temp.getTop() - dividerHeight); 1285 // This will correct for the top of the first view not touching the top of the list 1286 adjustViewsUpOrDown(); 1287 below = fillDown(position + 1, temp.getBottom() + dividerHeight); 1288 int childCount = getChildCount(); 1289 if (childCount > 0) { 1290 correctTooHigh(childCount); 1291 } 1292 } else { 1293 below = fillDown(position + 1, temp.getBottom() + dividerHeight); 1294 // This will correct for the bottom of the last view not touching the bottom of the list 1295 adjustViewsUpOrDown(); 1296 above = fillUp(position - 1, temp.getTop() - dividerHeight); 1297 int childCount = getChildCount(); 1298 if (childCount > 0) { 1299 correctTooLow(childCount); 1300 } 1301 } 1302 1303 if (tempIsSelected) { 1304 return temp; 1305 } else if (above != null) { 1306 return above; 1307 } else { 1308 return below; 1309 } 1310 } 1311 1312 /** 1313 * Check if we have dragged the bottom of the list too high (we have pushed the 1314 * top element off the top of the screen when we did not need to). Correct by sliding 1315 * everything back down. 1316 * 1317 * @param childCount Number of children 1318 */ 1319 private void correctTooHigh(int childCount) { 1320 // First see if the last item is visible. If it is not, it is OK for the 1321 // top of the list to be pushed up. 1322 int lastPosition = mFirstPosition + childCount - 1; 1323 if (lastPosition == mItemCount - 1 && childCount > 0) { 1324 1325 // Get the last child ... 1326 final View lastChild = getChildAt(childCount - 1); 1327 1328 // ... and its bottom edge 1329 final int lastBottom = lastChild.getBottom(); 1330 1331 // This is bottom of our drawable area 1332 final int end = (mBottom - mTop) - mListPadding.bottom; 1333 1334 // This is how far the bottom edge of the last view is from the bottom of the 1335 // drawable area 1336 int bottomOffset = end - lastBottom; 1337 View firstChild = getChildAt(0); 1338 final int firstTop = firstChild.getTop(); 1339 1340 // Make sure we are 1) Too high, and 2) Either there are more rows above the 1341 // first row or the first row is scrolled off the top of the drawable area 1342 if (bottomOffset > 0 && (mFirstPosition > 0 || firstTop < mListPadding.top)) { 1343 if (mFirstPosition == 0) { 1344 // Don't pull the top too far down 1345 bottomOffset = Math.min(bottomOffset, mListPadding.top - firstTop); 1346 } 1347 // Move everything down 1348 offsetChildrenTopAndBottom(bottomOffset); 1349 if (mFirstPosition > 0) { 1350 // Fill the gap that was opened above mFirstPosition with more rows, if 1351 // possible 1352 fillUp(mFirstPosition - 1, firstChild.getTop() - mDividerHeight); 1353 // Close up the remaining gap 1354 adjustViewsUpOrDown(); 1355 } 1356 1357 } 1358 } 1359 } 1360 1361 /** 1362 * Check if we have dragged the bottom of the list too low (we have pushed the 1363 * bottom element off the bottom of the screen when we did not need to). Correct by sliding 1364 * everything back up. 1365 * 1366 * @param childCount Number of children 1367 */ 1368 private void correctTooLow(int childCount) { 1369 // First see if the first item is visible. If it is not, it is OK for the 1370 // bottom of the list to be pushed down. 1371 if (mFirstPosition == 0 && childCount > 0) { 1372 1373 // Get the first child ... 1374 final View firstChild = getChildAt(0); 1375 1376 // ... and its top edge 1377 final int firstTop = firstChild.getTop(); 1378 1379 // This is top of our drawable area 1380 final int start = mListPadding.top; 1381 1382 // This is bottom of our drawable area 1383 final int end = (mBottom - mTop) - mListPadding.bottom; 1384 1385 // This is how far the top edge of the first view is from the top of the 1386 // drawable area 1387 int topOffset = firstTop - start; 1388 View lastChild = getChildAt(childCount - 1); 1389 final int lastBottom = lastChild.getBottom(); 1390 int lastPosition = mFirstPosition + childCount - 1; 1391 1392 // Make sure we are 1) Too low, and 2) Either there are more rows below the 1393 // last row or the last row is scrolled off the bottom of the drawable area 1394 if (topOffset > 0) { 1395 if (lastPosition < mItemCount - 1 || lastBottom > end) { 1396 if (lastPosition == mItemCount - 1) { 1397 // Don't pull the bottom too far up 1398 topOffset = Math.min(topOffset, lastBottom - end); 1399 } 1400 // Move everything up 1401 offsetChildrenTopAndBottom(-topOffset); 1402 if (lastPosition < mItemCount - 1) { 1403 // Fill the gap that was opened below the last position with more rows, if 1404 // possible 1405 fillDown(lastPosition + 1, lastChild.getBottom() + mDividerHeight); 1406 // Close up the remaining gap 1407 adjustViewsUpOrDown(); 1408 } 1409 } else if (lastPosition == mItemCount - 1) { 1410 adjustViewsUpOrDown(); 1411 } 1412 } 1413 } 1414 } 1415 1416 @Override 1417 protected void layoutChildren() { 1418 final boolean blockLayoutRequests = mBlockLayoutRequests; 1419 if (!blockLayoutRequests) { 1420 mBlockLayoutRequests = true; 1421 } else { 1422 return; 1423 } 1424 1425 try { 1426 super.layoutChildren(); 1427 1428 invalidate(); 1429 1430 if (mAdapter == null) { 1431 resetList(); 1432 invokeOnItemScrollListener(); 1433 return; 1434 } 1435 1436 int childrenTop = mListPadding.top; 1437 int childrenBottom = mBottom - mTop - mListPadding.bottom; 1438 1439 int childCount = getChildCount(); 1440 int index = 0; 1441 int delta = 0; 1442 1443 View sel; 1444 View oldSel = null; 1445 View oldFirst = null; 1446 View newSel = null; 1447 1448 View focusLayoutRestoreView = null; 1449 1450 // Remember stuff we will need down below 1451 switch (mLayoutMode) { 1452 case LAYOUT_SET_SELECTION: 1453 index = mNextSelectedPosition - mFirstPosition; 1454 if (index >= 0 && index < childCount) { 1455 newSel = getChildAt(index); 1456 } 1457 break; 1458 case LAYOUT_FORCE_TOP: 1459 case LAYOUT_FORCE_BOTTOM: 1460 case LAYOUT_SPECIFIC: 1461 case LAYOUT_SYNC: 1462 break; 1463 case LAYOUT_MOVE_SELECTION: 1464 default: 1465 // Remember the previously selected view 1466 index = mSelectedPosition - mFirstPosition; 1467 if (index >= 0 && index < childCount) { 1468 oldSel = getChildAt(index); 1469 } 1470 1471 // Remember the previous first child 1472 oldFirst = getChildAt(0); 1473 1474 if (mNextSelectedPosition >= 0) { 1475 delta = mNextSelectedPosition - mSelectedPosition; 1476 } 1477 1478 // Caution: newSel might be null 1479 newSel = getChildAt(index + delta); 1480 } 1481 1482 1483 boolean dataChanged = mDataChanged; 1484 if (dataChanged) { 1485 handleDataChanged(); 1486 } 1487 1488 // Handle the empty set by removing all views that are visible 1489 // and calling it a day 1490 if (mItemCount == 0) { 1491 resetList(); 1492 invokeOnItemScrollListener(); 1493 return; 1494 } else if (mItemCount != mAdapter.getCount()) { 1495 throw new IllegalStateException("The content of the adapter has changed but " 1496 + "ListView did not receive a notification. Make sure the content of " 1497 + "your adapter is not modified from a background thread, but only " 1498 + "from the UI thread. [in ListView(" + getId() + ", " + getClass() 1499 + ") with Adapter(" + mAdapter.getClass() + ")]"); 1500 } 1501 1502 setSelectedPositionInt(mNextSelectedPosition); 1503 1504 // Pull all children into the RecycleBin. 1505 // These views will be reused if possible 1506 final int firstPosition = mFirstPosition; 1507 final RecycleBin recycleBin = mRecycler; 1508 1509 // reset the focus restoration 1510 View focusLayoutRestoreDirectChild = null; 1511 1512 1513 // Don't put header or footer views into the Recycler. Those are 1514 // already cached in mHeaderViews; 1515 if (dataChanged) { 1516 for (int i = 0; i < childCount; i++) { 1517 recycleBin.addScrapView(getChildAt(i)); 1518 if (ViewDebug.TRACE_RECYCLER) { 1519 ViewDebug.trace(getChildAt(i), 1520 ViewDebug.RecyclerTraceType.MOVE_TO_SCRAP_HEAP, index, i); 1521 } 1522 } 1523 } else { 1524 recycleBin.fillActiveViews(childCount, firstPosition); 1525 } 1526 1527 // take focus back to us temporarily to avoid the eventual 1528 // call to clear focus when removing the focused child below 1529 // from messing things up when ViewRoot assigns focus back 1530 // to someone else 1531 final View focusedChild = getFocusedChild(); 1532 if (focusedChild != null) { 1533 // TODO: in some cases focusedChild.getParent() == null 1534 1535 // we can remember the focused view to restore after relayout if the 1536 // data hasn't changed, or if the focused position is a header or footer 1537 if (!dataChanged || isDirectChildHeaderOrFooter(focusedChild)) { 1538 focusLayoutRestoreDirectChild = focusedChild; 1539 // remember the specific view that had focus 1540 focusLayoutRestoreView = findFocus(); 1541 if (focusLayoutRestoreView != null) { 1542 // tell it we are going to mess with it 1543 focusLayoutRestoreView.onStartTemporaryDetach(); 1544 } 1545 } 1546 requestFocus(); 1547 } 1548 1549 // Clear out old views 1550 detachAllViewsFromParent(); 1551 1552 switch (mLayoutMode) { 1553 case LAYOUT_SET_SELECTION: 1554 if (newSel != null) { 1555 sel = fillFromSelection(newSel.getTop(), childrenTop, childrenBottom); 1556 } else { 1557 sel = fillFromMiddle(childrenTop, childrenBottom); 1558 } 1559 break; 1560 case LAYOUT_SYNC: 1561 sel = fillSpecific(mSyncPosition, mSpecificTop); 1562 break; 1563 case LAYOUT_FORCE_BOTTOM: 1564 sel = fillUp(mItemCount - 1, childrenBottom); 1565 adjustViewsUpOrDown(); 1566 break; 1567 case LAYOUT_FORCE_TOP: 1568 mFirstPosition = 0; 1569 sel = fillFromTop(childrenTop); 1570 adjustViewsUpOrDown(); 1571 break; 1572 case LAYOUT_SPECIFIC: 1573 sel = fillSpecific(reconcileSelectedPosition(), mSpecificTop); 1574 break; 1575 case LAYOUT_MOVE_SELECTION: 1576 sel = moveSelection(oldSel, newSel, delta, childrenTop, childrenBottom); 1577 break; 1578 default: 1579 if (childCount == 0) { 1580 if (!mStackFromBottom) { 1581 final int position = lookForSelectablePosition(0, true); 1582 setSelectedPositionInt(position); 1583 sel = fillFromTop(childrenTop); 1584 } else { 1585 final int position = lookForSelectablePosition(mItemCount - 1, false); 1586 setSelectedPositionInt(position); 1587 sel = fillUp(mItemCount - 1, childrenBottom); 1588 } 1589 } else { 1590 if (mSelectedPosition >= 0 && mSelectedPosition < mItemCount) { 1591 sel = fillSpecific(mSelectedPosition, 1592 oldSel == null ? childrenTop : oldSel.getTop()); 1593 } else if (mFirstPosition < mItemCount) { 1594 sel = fillSpecific(mFirstPosition, 1595 oldFirst == null ? childrenTop : oldFirst.getTop()); 1596 } else { 1597 sel = fillSpecific(0, childrenTop); 1598 } 1599 } 1600 break; 1601 } 1602 1603 // Flush any cached views that did not get reused above 1604 recycleBin.scrapActiveViews(); 1605 1606 if (sel != null) { 1607 // the current selected item should get focus if items 1608 // are focusable 1609 if (mItemsCanFocus && hasFocus() && !sel.hasFocus()) { 1610 final boolean focusWasTaken = (sel == focusLayoutRestoreDirectChild && 1611 focusLayoutRestoreView.requestFocus()) || sel.requestFocus(); 1612 if (!focusWasTaken) { 1613 // selected item didn't take focus, fine, but still want 1614 // to make sure something else outside of the selected view 1615 // has focus 1616 final View focused = getFocusedChild(); 1617 if (focused != null) { 1618 focused.clearFocus(); 1619 } 1620 positionSelector(sel); 1621 } else { 1622 sel.setSelected(false); 1623 mSelectorRect.setEmpty(); 1624 } 1625 } else { 1626 positionSelector(sel); 1627 } 1628 mSelectedTop = sel.getTop(); 1629 } else { 1630 if (mTouchMode > TOUCH_MODE_DOWN && mTouchMode < TOUCH_MODE_SCROLL) { 1631 View child = getChildAt(mMotionPosition - mFirstPosition); 1632 if (child != null) positionSelector(child); 1633 } else { 1634 mSelectedTop = 0; 1635 mSelectorRect.setEmpty(); 1636 } 1637 1638 // even if there is not selected position, we may need to restore 1639 // focus (i.e. something focusable in touch mode) 1640 if (hasFocus() && focusLayoutRestoreView != null) { 1641 focusLayoutRestoreView.requestFocus(); 1642 } 1643 } 1644 1645 // tell focus view we are done mucking with it, if it is still in 1646 // our view hierarchy. 1647 if (focusLayoutRestoreView != null 1648 && focusLayoutRestoreView.getWindowToken() != null) { 1649 focusLayoutRestoreView.onFinishTemporaryDetach(); 1650 } 1651 1652 mLayoutMode = LAYOUT_NORMAL; 1653 mDataChanged = false; 1654 mNeedSync = false; 1655 setNextSelectedPositionInt(mSelectedPosition); 1656 1657 updateScrollIndicators(); 1658 1659 if (mItemCount > 0) { 1660 checkSelectionChanged(); 1661 } 1662 1663 invokeOnItemScrollListener(); 1664 } finally { 1665 if (!blockLayoutRequests) { 1666 mBlockLayoutRequests = false; 1667 } 1668 } 1669 } 1670 1671 /** 1672 * @param child a direct child of this list. 1673 * @return Whether child is a header or footer view. 1674 */ 1675 private boolean isDirectChildHeaderOrFooter(View child) { 1676 1677 final ArrayList<FixedViewInfo> headers = mHeaderViewInfos; 1678 final int numHeaders = headers.size(); 1679 for (int i = 0; i < numHeaders; i++) { 1680 if (child == headers.get(i).view) { 1681 return true; 1682 } 1683 } 1684 final ArrayList<FixedViewInfo> footers = mFooterViewInfos; 1685 final int numFooters = footers.size(); 1686 for (int i = 0; i < numFooters; i++) { 1687 if (child == footers.get(i).view) { 1688 return true; 1689 } 1690 } 1691 return false; 1692 } 1693 1694 /** 1695 * Obtain the view and add it to our list of children. The view can be made 1696 * fresh, converted from an unused view, or used as is if it was in the 1697 * recycle bin. 1698 * 1699 * @param position Logical position in the list 1700 * @param y Top or bottom edge of the view to add 1701 * @param flow If flow is true, align top edge to y. If false, align bottom 1702 * edge to y. 1703 * @param childrenLeft Left edge where children should be positioned 1704 * @param selected Is this position selected? 1705 * @return View that was added 1706 */ 1707 private View makeAndAddView(int position, int y, boolean flow, int childrenLeft, 1708 boolean selected) { 1709 View child; 1710 1711 1712 if (!mDataChanged) { 1713 // Try to use an exsiting view for this position 1714 child = mRecycler.getActiveView(position); 1715 if (child != null) { 1716 if (ViewDebug.TRACE_RECYCLER) { 1717 ViewDebug.trace(child, ViewDebug.RecyclerTraceType.RECYCLE_FROM_ACTIVE_HEAP, 1718 position, getChildCount()); 1719 } 1720 1721 // Found it -- we're using an existing child 1722 // This just needs to be positioned 1723 setupChild(child, position, y, flow, childrenLeft, selected, true); 1724 1725 return child; 1726 } 1727 } 1728 1729 // Make a new view for this position, or convert an unused view if possible 1730 child = obtainView(position, mIsScrap); 1731 1732 // This needs to be positioned and measured 1733 setupChild(child, position, y, flow, childrenLeft, selected, mIsScrap[0]); 1734 1735 return child; 1736 } 1737 1738 /** 1739 * Add a view as a child and make sure it is measured (if necessary) and 1740 * positioned properly. 1741 * 1742 * @param child The view to add 1743 * @param position The position of this child 1744 * @param y The y position relative to which this view will be positioned 1745 * @param flowDown If true, align top edge to y. If false, align bottom 1746 * edge to y. 1747 * @param childrenLeft Left edge where children should be positioned 1748 * @param selected Is this position selected? 1749 * @param recycled Has this view been pulled from the recycle bin? If so it 1750 * does not need to be remeasured. 1751 */ 1752 private void setupChild(View child, int position, int y, boolean flowDown, int childrenLeft, 1753 boolean selected, boolean recycled) { 1754 final boolean isSelected = selected && shouldShowSelector(); 1755 final boolean updateChildSelected = isSelected != child.isSelected(); 1756 final int mode = mTouchMode; 1757 final boolean isPressed = mode > TOUCH_MODE_DOWN && mode < TOUCH_MODE_SCROLL && 1758 mMotionPosition == position; 1759 final boolean updateChildPressed = isPressed != child.isPressed(); 1760 final boolean needToMeasure = !recycled || updateChildSelected || child.isLayoutRequested(); 1761 1762 // Respect layout params that are already in the view. Otherwise make some up... 1763 // noinspection unchecked 1764 AbsListView.LayoutParams p = (AbsListView.LayoutParams) child.getLayoutParams(); 1765 if (p == null) { 1766 p = new AbsListView.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, 1767 ViewGroup.LayoutParams.WRAP_CONTENT, 0); 1768 } 1769 p.viewType = mAdapter.getItemViewType(position); 1770 1771 if ((recycled && !p.forceAdd) || (p.recycledHeaderFooter && 1772 p.viewType == AdapterView.ITEM_VIEW_TYPE_HEADER_OR_FOOTER)) { 1773 attachViewToParent(child, flowDown ? -1 : 0, p); 1774 } else { 1775 p.forceAdd = false; 1776 if (p.viewType == AdapterView.ITEM_VIEW_TYPE_HEADER_OR_FOOTER) { 1777 p.recycledHeaderFooter = true; 1778 } 1779 addViewInLayout(child, flowDown ? -1 : 0, p, true); 1780 } 1781 1782 if (updateChildSelected) { 1783 child.setSelected(isSelected); 1784 } 1785 1786 if (updateChildPressed) { 1787 child.setPressed(isPressed); 1788 } 1789 1790 if (mChoiceMode != CHOICE_MODE_NONE && mCheckStates != null) { 1791 if (child instanceof Checkable) { 1792 ((Checkable) child).setChecked(mCheckStates.get(position)); 1793 } 1794 } 1795 1796 if (needToMeasure) { 1797 int childWidthSpec = ViewGroup.getChildMeasureSpec(mWidthMeasureSpec, 1798 mListPadding.left + mListPadding.right, p.width); 1799 int lpHeight = p.height; 1800 int childHeightSpec; 1801 if (lpHeight > 0) { 1802 childHeightSpec = MeasureSpec.makeMeasureSpec(lpHeight, MeasureSpec.EXACTLY); 1803 } else { 1804 childHeightSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED); 1805 } 1806 child.measure(childWidthSpec, childHeightSpec); 1807 } else { 1808 cleanupLayoutState(child); 1809 } 1810 1811 final int w = child.getMeasuredWidth(); 1812 final int h = child.getMeasuredHeight(); 1813 final int childTop = flowDown ? y : y - h; 1814 1815 if (needToMeasure) { 1816 final int childRight = childrenLeft + w; 1817 final int childBottom = childTop + h; 1818 child.layout(childrenLeft, childTop, childRight, childBottom); 1819 } else { 1820 child.offsetLeftAndRight(childrenLeft - child.getLeft()); 1821 child.offsetTopAndBottom(childTop - child.getTop()); 1822 } 1823 1824 if (mCachingStarted && !child.isDrawingCacheEnabled()) { 1825 child.setDrawingCacheEnabled(true); 1826 } 1827 } 1828 1829 @Override 1830 protected boolean canAnimate() { 1831 return super.canAnimate() && mItemCount > 0; 1832 } 1833 1834 /** 1835 * Sets the currently selected item. If in touch mode, the item will not be selected 1836 * but it will still be positioned appropriately. If the specified selection position 1837 * is less than 0, then the item at position 0 will be selected. 1838 * 1839 * @param position Index (starting at 0) of the data item to be selected. 1840 */ 1841 @Override 1842 public void setSelection(int position) { 1843 setSelectionFromTop(position, 0); 1844 } 1845 1846 /** 1847 * Sets the selected item and positions the selection y pixels from the top edge 1848 * of the ListView. (If in touch mode, the item will not be selected but it will 1849 * still be positioned appropriately.) 1850 * 1851 * @param position Index (starting at 0) of the data item to be selected. 1852 * @param y The distance from the top edge of the ListView (plus padding) that the 1853 * item will be positioned. 1854 */ 1855 public void setSelectionFromTop(int position, int y) { 1856 if (mAdapter == null) { 1857 return; 1858 } 1859 1860 if (!isInTouchMode()) { 1861 position = lookForSelectablePosition(position, true); 1862 if (position >= 0) { 1863 setNextSelectedPositionInt(position); 1864 } 1865 } else { 1866 mResurrectToPosition = position; 1867 } 1868 1869 if (position >= 0) { 1870 mLayoutMode = LAYOUT_SPECIFIC; 1871 mSpecificTop = mListPadding.top + y; 1872 1873 if (mNeedSync) { 1874 mSyncPosition = position; 1875 mSyncRowId = mAdapter.getItemId(position); 1876 } 1877 1878 requestLayout(); 1879 } 1880 } 1881 1882 /** 1883 * Makes the item at the supplied position selected. 1884 * 1885 * @param position the position of the item to select 1886 */ 1887 @Override 1888 void setSelectionInt(int position) { 1889 setNextSelectedPositionInt(position); 1890 boolean awakeScrollbars = false; 1891 1892 final int selectedPosition = mSelectedPosition; 1893 1894 if (selectedPosition >= 0) { 1895 if (position == selectedPosition - 1) { 1896 awakeScrollbars = true; 1897 } else if (position == selectedPosition + 1) { 1898 awakeScrollbars = true; 1899 } 1900 } 1901 1902 layoutChildren(); 1903 1904 if (awakeScrollbars) { 1905 awakenScrollBars(); 1906 } 1907 } 1908 1909 /** 1910 * Find a position that can be selected (i.e., is not a separator). 1911 * 1912 * @param position The starting position to look at. 1913 * @param lookDown Whether to look down for other positions. 1914 * @return The next selectable position starting at position and then searching either up or 1915 * down. Returns {@link #INVALID_POSITION} if nothing can be found. 1916 */ 1917 @Override 1918 int lookForSelectablePosition(int position, boolean lookDown) { 1919 final ListAdapter adapter = mAdapter; 1920 if (adapter == null || isInTouchMode()) { 1921 return INVALID_POSITION; 1922 } 1923 1924 final int count = adapter.getCount(); 1925 if (!mAreAllItemsSelectable) { 1926 if (lookDown) { 1927 position = Math.max(0, position); 1928 while (position < count && !adapter.isEnabled(position)) { 1929 position++; 1930 } 1931 } else { 1932 position = Math.min(position, count - 1); 1933 while (position >= 0 && !adapter.isEnabled(position)) { 1934 position--; 1935 } 1936 } 1937 1938 if (position < 0 || position >= count) { 1939 return INVALID_POSITION; 1940 } 1941 return position; 1942 } else { 1943 if (position < 0 || position >= count) { 1944 return INVALID_POSITION; 1945 } 1946 return position; 1947 } 1948 } 1949 1950 @Override 1951 public boolean dispatchPopulateAccessibilityEvent(AccessibilityEvent event) { 1952 boolean populated = super.dispatchPopulateAccessibilityEvent(event); 1953 1954 // If the item count is less than 15 then subtract disabled items from the count and 1955 // position. Otherwise ignore disabled items. 1956 if (!populated) { 1957 int itemCount = 0; 1958 int currentItemIndex = getSelectedItemPosition(); 1959 1960 ListAdapter adapter = getAdapter(); 1961 if (adapter != null) { 1962 final int count = adapter.getCount(); 1963 if (count < 15) { 1964 for (int i = 0; i < count; i++) { 1965 if (adapter.isEnabled(i)) { 1966 itemCount++; 1967 } else if (i <= currentItemIndex) { 1968 currentItemIndex--; 1969 } 1970 } 1971 } else { 1972 itemCount = count; 1973 } 1974 } 1975 1976 event.setItemCount(itemCount); 1977 event.setCurrentItemIndex(currentItemIndex); 1978 } 1979 1980 return populated; 1981 } 1982 1983 /** 1984 * setSelectionAfterHeaderView set the selection to be the first list item 1985 * after the header views. 1986 */ 1987 public void setSelectionAfterHeaderView() { 1988 final int count = mHeaderViewInfos.size(); 1989 if (count > 0) { 1990 mNextSelectedPosition = 0; 1991 return; 1992 } 1993 1994 if (mAdapter != null) { 1995 setSelection(count); 1996 } else { 1997 mNextSelectedPosition = count; 1998 mLayoutMode = LAYOUT_SET_SELECTION; 1999 } 2000 2001 } 2002 2003 @Override 2004 public boolean dispatchKeyEvent(KeyEvent event) { 2005 // Dispatch in the normal way 2006 boolean handled = super.dispatchKeyEvent(event); 2007 if (!handled) { 2008 // If we didn't handle it... 2009 View focused = getFocusedChild(); 2010 if (focused != null && event.getAction() == KeyEvent.ACTION_DOWN) { 2011 // ... and our focused child didn't handle it 2012 // ... give it to ourselves so we can scroll if necessary 2013 handled = onKeyDown(event.getKeyCode(), event); 2014 } 2015 } 2016 return handled; 2017 } 2018 2019 @Override 2020 public boolean onKeyDown(int keyCode, KeyEvent event) { 2021 return commonKey(keyCode, 1, event); 2022 } 2023 2024 @Override 2025 public boolean onKeyMultiple(int keyCode, int repeatCount, KeyEvent event) { 2026 return commonKey(keyCode, repeatCount, event); 2027 } 2028 2029 @Override 2030 public boolean onKeyUp(int keyCode, KeyEvent event) { 2031 return commonKey(keyCode, 1, event); 2032 } 2033 2034 private boolean commonKey(int keyCode, int count, KeyEvent event) { 2035 if (mAdapter == null) { 2036 return false; 2037 } 2038 2039 if (mDataChanged) { 2040 layoutChildren(); 2041 } 2042 2043 boolean handled = false; 2044 int action = event.getAction(); 2045 2046 if (action != KeyEvent.ACTION_UP) { 2047 if (mSelectedPosition < 0) { 2048 switch (keyCode) { 2049 case KeyEvent.KEYCODE_DPAD_UP: 2050 case KeyEvent.KEYCODE_DPAD_DOWN: 2051 case KeyEvent.KEYCODE_DPAD_CENTER: 2052 case KeyEvent.KEYCODE_ENTER: 2053 case KeyEvent.KEYCODE_SPACE: 2054 if (resurrectSelection()) { 2055 return true; 2056 } 2057 } 2058 } 2059 switch (keyCode) { 2060 case KeyEvent.KEYCODE_DPAD_UP: 2061 if (!event.isAltPressed()) { 2062 while (count > 0) { 2063 handled = arrowScroll(FOCUS_UP); 2064 count--; 2065 } 2066 } else { 2067 handled = fullScroll(FOCUS_UP); 2068 } 2069 break; 2070 2071 case KeyEvent.KEYCODE_DPAD_DOWN: 2072 if (!event.isAltPressed()) { 2073 while (count > 0) { 2074 handled = arrowScroll(FOCUS_DOWN); 2075 count--; 2076 } 2077 } else { 2078 handled = fullScroll(FOCUS_DOWN); 2079 } 2080 break; 2081 2082 case KeyEvent.KEYCODE_DPAD_LEFT: 2083 handled = handleHorizontalFocusWithinListItem(View.FOCUS_LEFT); 2084 break; 2085 case KeyEvent.KEYCODE_DPAD_RIGHT: 2086 handled = handleHorizontalFocusWithinListItem(View.FOCUS_RIGHT); 2087 break; 2088 2089 case KeyEvent.KEYCODE_DPAD_CENTER: 2090 case KeyEvent.KEYCODE_ENTER: 2091 if (mItemCount > 0 && event.getRepeatCount() == 0) { 2092 keyPressed(); 2093 } 2094 handled = true; 2095 break; 2096 2097 case KeyEvent.KEYCODE_SPACE: 2098 if (mPopup == null || !mPopup.isShowing()) { 2099 if (!event.isShiftPressed()) { 2100 pageScroll(FOCUS_DOWN); 2101 } else { 2102 pageScroll(FOCUS_UP); 2103 } 2104 handled = true; 2105 } 2106 break; 2107 } 2108 } 2109 2110 if (!handled) { 2111 handled = sendToTextFilter(keyCode, count, event); 2112 } 2113 2114 if (handled) { 2115 return true; 2116 } else { 2117 switch (action) { 2118 case KeyEvent.ACTION_DOWN: 2119 return super.onKeyDown(keyCode, event); 2120 2121 case KeyEvent.ACTION_UP: 2122 return super.onKeyUp(keyCode, event); 2123 2124 case KeyEvent.ACTION_MULTIPLE: 2125 return super.onKeyMultiple(keyCode, count, event); 2126 2127 default: // shouldn't happen 2128 return false; 2129 } 2130 } 2131 } 2132 2133 /** 2134 * Scrolls up or down by the number of items currently present on screen. 2135 * 2136 * @param direction either {@link View#FOCUS_UP} or {@link View#FOCUS_DOWN} 2137 * @return whether selection was moved 2138 */ 2139 boolean pageScroll(int direction) { 2140 int nextPage = -1; 2141 boolean down = false; 2142 2143 if (direction == FOCUS_UP) { 2144 nextPage = Math.max(0, mSelectedPosition - getChildCount() - 1); 2145 } else if (direction == FOCUS_DOWN) { 2146 nextPage = Math.min(mItemCount - 1, mSelectedPosition + getChildCount() - 1); 2147 down = true; 2148 } 2149 2150 if (nextPage >= 0) { 2151 int position = lookForSelectablePosition(nextPage, down); 2152 if (position >= 0) { 2153 mLayoutMode = LAYOUT_SPECIFIC; 2154 mSpecificTop = mPaddingTop + getVerticalFadingEdgeLength(); 2155 2156 if (down && position > mItemCount - getChildCount()) { 2157 mLayoutMode = LAYOUT_FORCE_BOTTOM; 2158 } 2159 2160 if (!down && position < getChildCount()) { 2161 mLayoutMode = LAYOUT_FORCE_TOP; 2162 } 2163 2164 setSelectionInt(position); 2165 invokeOnItemScrollListener(); 2166 if (!awakenScrollBars()) { 2167 invalidate(); 2168 } 2169 2170 return true; 2171 } 2172 } 2173 2174 return false; 2175 } 2176 2177 /** 2178 * Go to the last or first item if possible (not worrying about panning across or navigating 2179 * within the internal focus of the currently selected item.) 2180 * 2181 * @param direction either {@link View#FOCUS_UP} or {@link View#FOCUS_DOWN} 2182 * 2183 * @return whether selection was moved 2184 */ 2185 boolean fullScroll(int direction) { 2186 boolean moved = false; 2187 if (direction == FOCUS_UP) { 2188 if (mSelectedPosition != 0) { 2189 int position = lookForSelectablePosition(0, true); 2190 if (position >= 0) { 2191 mLayoutMode = LAYOUT_FORCE_TOP; 2192 setSelectionInt(position); 2193 invokeOnItemScrollListener(); 2194 } 2195 moved = true; 2196 } 2197 } else if (direction == FOCUS_DOWN) { 2198 if (mSelectedPosition < mItemCount - 1) { 2199 int position = lookForSelectablePosition(mItemCount - 1, true); 2200 if (position >= 0) { 2201 mLayoutMode = LAYOUT_FORCE_BOTTOM; 2202 setSelectionInt(position); 2203 invokeOnItemScrollListener(); 2204 } 2205 moved = true; 2206 } 2207 } 2208 2209 if (moved && !awakenScrollBars()) { 2210 awakenScrollBars(); 2211 invalidate(); 2212 } 2213 2214 return moved; 2215 } 2216 2217 /** 2218 * To avoid horizontal focus searches changing the selected item, we 2219 * manually focus search within the selected item (as applicable), and 2220 * prevent focus from jumping to something within another item. 2221 * @param direction one of {View.FOCUS_LEFT, View.FOCUS_RIGHT} 2222 * @return Whether this consumes the key event. 2223 */ 2224 private boolean handleHorizontalFocusWithinListItem(int direction) { 2225 if (direction != View.FOCUS_LEFT && direction != View.FOCUS_RIGHT) { 2226 throw new IllegalArgumentException("direction must be one of" 2227 + " {View.FOCUS_LEFT, View.FOCUS_RIGHT}"); 2228 } 2229 2230 final int numChildren = getChildCount(); 2231 if (mItemsCanFocus && numChildren > 0 && mSelectedPosition != INVALID_POSITION) { 2232 final View selectedView = getSelectedView(); 2233 if (selectedView != null && selectedView.hasFocus() && 2234 selectedView instanceof ViewGroup) { 2235 2236 final View currentFocus = selectedView.findFocus(); 2237 final View nextFocus = FocusFinder.getInstance().findNextFocus( 2238 (ViewGroup) selectedView, currentFocus, direction); 2239 if (nextFocus != null) { 2240 // do the math to get interesting rect in next focus' coordinates 2241 currentFocus.getFocusedRect(mTempRect); 2242 offsetDescendantRectToMyCoords(currentFocus, mTempRect); 2243 offsetRectIntoDescendantCoords(nextFocus, mTempRect); 2244 if (nextFocus.requestFocus(direction, mTempRect)) { 2245 return true; 2246 } 2247 } 2248 // we are blocking the key from being handled (by returning true) 2249 // if the global result is going to be some other view within this 2250 // list. this is to acheive the overall goal of having 2251 // horizontal d-pad navigation remain in the current item. 2252 final View globalNextFocus = FocusFinder.getInstance().findNextFocus( 2253 (ViewGroup) getRootView(), currentFocus, direction); 2254 if (globalNextFocus != null) { 2255 return isViewAncestorOf(globalNextFocus, this); 2256 } 2257 } 2258 } 2259 return false; 2260 } 2261 2262 /** 2263 * Scrolls to the next or previous item if possible. 2264 * 2265 * @param direction either {@link View#FOCUS_UP} or {@link View#FOCUS_DOWN} 2266 * 2267 * @return whether selection was moved 2268 */ 2269 boolean arrowScroll(int direction) { 2270 try { 2271 mInLayout = true; 2272 final boolean handled = arrowScrollImpl(direction); 2273 if (handled) { 2274 playSoundEffect(SoundEffectConstants.getContantForFocusDirection(direction)); 2275 } 2276 return handled; 2277 } finally { 2278 mInLayout = false; 2279 } 2280 } 2281 2282 /** 2283 * Handle an arrow scroll going up or down. Take into account whether items are selectable, 2284 * whether there are focusable items etc. 2285 * 2286 * @param direction Either {@link android.view.View#FOCUS_UP} or {@link android.view.View#FOCUS_DOWN}. 2287 * @return Whether any scrolling, selection or focus change occured. 2288 */ 2289 private boolean arrowScrollImpl(int direction) { 2290 if (getChildCount() <= 0) { 2291 return false; 2292 } 2293 2294 View selectedView = getSelectedView(); 2295 2296 int nextSelectedPosition = lookForSelectablePositionOnScreen(direction); 2297 int amountToScroll = amountToScroll(direction, nextSelectedPosition); 2298 2299 // if we are moving focus, we may OVERRIDE the default behavior 2300 final ArrowScrollFocusResult focusResult = mItemsCanFocus ? arrowScrollFocused(direction) : null; 2301 if (focusResult != null) { 2302 nextSelectedPosition = focusResult.getSelectedPosition(); 2303 amountToScroll = focusResult.getAmountToScroll(); 2304 } 2305 2306 boolean needToRedraw = focusResult != null; 2307 if (nextSelectedPosition != INVALID_POSITION) { 2308 handleNewSelectionChange(selectedView, direction, nextSelectedPosition, focusResult != null); 2309 setSelectedPositionInt(nextSelectedPosition); 2310 setNextSelectedPositionInt(nextSelectedPosition); 2311 selectedView = getSelectedView(); 2312 if (mItemsCanFocus && focusResult == null) { 2313 // there was no new view found to take focus, make sure we 2314 // don't leave focus with the old selection 2315 final View focused = getFocusedChild(); 2316 if (focused != null) { 2317 focused.clearFocus(); 2318 } 2319 } 2320 needToRedraw = true; 2321 checkSelectionChanged(); 2322 } 2323 2324 if (amountToScroll > 0) { 2325 scrollListItemsBy((direction == View.FOCUS_UP) ? amountToScroll : -amountToScroll); 2326 needToRedraw = true; 2327 } 2328 2329 // if we didn't find a new focusable, make sure any existing focused 2330 // item that was panned off screen gives up focus. 2331 if (mItemsCanFocus && (focusResult == null) 2332 && selectedView != null && selectedView.hasFocus()) { 2333 final View focused = selectedView.findFocus(); 2334 if (distanceToView(focused) > 0) { 2335 focused.clearFocus(); 2336 } 2337 } 2338 2339 // if the current selection is panned off, we need to remove the selection 2340 if (nextSelectedPosition == INVALID_POSITION && selectedView != null 2341 && !isViewAncestorOf(selectedView, this)) { 2342 selectedView = null; 2343 hideSelector(); 2344 2345 // but we don't want to set the ressurect position (that would make subsequent 2346 // unhandled key events bring back the item we just scrolled off!) 2347 mResurrectToPosition = INVALID_POSITION; 2348 } 2349 2350 if (needToRedraw) { 2351 if (selectedView != null) { 2352 positionSelector(selectedView); 2353 mSelectedTop = selectedView.getTop(); 2354 } 2355 if (!awakenScrollBars()) { 2356 invalidate(); 2357 } 2358 invokeOnItemScrollListener(); 2359 return true; 2360 } 2361 2362 return false; 2363 } 2364 2365 /** 2366 * When selection changes, it is possible that the previously selected or the 2367 * next selected item will change its size. If so, we need to offset some folks, 2368 * and re-layout the items as appropriate. 2369 * 2370 * @param selectedView The currently selected view (before changing selection). 2371 * should be <code>null</code> if there was no previous selection. 2372 * @param direction Either {@link android.view.View#FOCUS_UP} or 2373 * {@link android.view.View#FOCUS_DOWN}. 2374 * @param newSelectedPosition The position of the next selection. 2375 * @param newFocusAssigned whether new focus was assigned. This matters because 2376 * when something has focus, we don't want to show selection (ugh). 2377 */ 2378 private void handleNewSelectionChange(View selectedView, int direction, int newSelectedPosition, 2379 boolean newFocusAssigned) { 2380 if (newSelectedPosition == INVALID_POSITION) { 2381 throw new IllegalArgumentException("newSelectedPosition needs to be valid"); 2382 } 2383 2384 // whether or not we are moving down or up, we want to preserve the 2385 // top of whatever view is on top: 2386 // - moving down: the view that had selection 2387 // - moving up: the view that is getting selection 2388 View topView; 2389 View bottomView; 2390 int topViewIndex, bottomViewIndex; 2391 boolean topSelected = false; 2392 final int selectedIndex = mSelectedPosition - mFirstPosition; 2393 final int nextSelectedIndex = newSelectedPosition - mFirstPosition; 2394 if (direction == View.FOCUS_UP) { 2395 topViewIndex = nextSelectedIndex; 2396 bottomViewIndex = selectedIndex; 2397 topView = getChildAt(topViewIndex); 2398 bottomView = selectedView; 2399 topSelected = true; 2400 } else { 2401 topViewIndex = selectedIndex; 2402 bottomViewIndex = nextSelectedIndex; 2403 topView = selectedView; 2404 bottomView = getChildAt(bottomViewIndex); 2405 } 2406 2407 final int numChildren = getChildCount(); 2408 2409 // start with top view: is it changing size? 2410 if (topView != null) { 2411 topView.setSelected(!newFocusAssigned && topSelected); 2412 measureAndAdjustDown(topView, topViewIndex, numChildren); 2413 } 2414 2415 // is the bottom view changing size? 2416 if (bottomView != null) { 2417 bottomView.setSelected(!newFocusAssigned && !topSelected); 2418 measureAndAdjustDown(bottomView, bottomViewIndex, numChildren); 2419 } 2420 } 2421 2422 /** 2423 * Re-measure a child, and if its height changes, lay it out preserving its 2424 * top, and adjust the children below it appropriately. 2425 * @param child The child 2426 * @param childIndex The view group index of the child. 2427 * @param numChildren The number of children in the view group. 2428 */ 2429 private void measureAndAdjustDown(View child, int childIndex, int numChildren) { 2430 int oldHeight = child.getHeight(); 2431 measureItem(child); 2432 if (child.getMeasuredHeight() != oldHeight) { 2433 // lay out the view, preserving its top 2434 relayoutMeasuredItem(child); 2435 2436 // adjust views below appropriately 2437 final int heightDelta = child.getMeasuredHeight() - oldHeight; 2438 for (int i = childIndex + 1; i < numChildren; i++) { 2439 getChildAt(i).offsetTopAndBottom(heightDelta); 2440 } 2441 } 2442 } 2443 2444 /** 2445 * Measure a particular list child. 2446 * TODO: unify with setUpChild. 2447 * @param child The child. 2448 */ 2449 private void measureItem(View child) { 2450 ViewGroup.LayoutParams p = child.getLayoutParams(); 2451 if (p == null) { 2452 p = new ViewGroup.LayoutParams( 2453 ViewGroup.LayoutParams.MATCH_PARENT, 2454 ViewGroup.LayoutParams.WRAP_CONTENT); 2455 } 2456 2457 int childWidthSpec = ViewGroup.getChildMeasureSpec(mWidthMeasureSpec, 2458 mListPadding.left + mListPadding.right, p.width); 2459 int lpHeight = p.height; 2460 int childHeightSpec; 2461 if (lpHeight > 0) { 2462 childHeightSpec = MeasureSpec.makeMeasureSpec(lpHeight, MeasureSpec.EXACTLY); 2463 } else { 2464 childHeightSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED); 2465 } 2466 child.measure(childWidthSpec, childHeightSpec); 2467 } 2468 2469 /** 2470 * Layout a child that has been measured, preserving its top position. 2471 * TODO: unify with setUpChild. 2472 * @param child The child. 2473 */ 2474 private void relayoutMeasuredItem(View child) { 2475 final int w = child.getMeasuredWidth(); 2476 final int h = child.getMeasuredHeight(); 2477 final int childLeft = mListPadding.left; 2478 final int childRight = childLeft + w; 2479 final int childTop = child.getTop(); 2480 final int childBottom = childTop + h; 2481 child.layout(childLeft, childTop, childRight, childBottom); 2482 } 2483 2484 /** 2485 * @return The amount to preview next items when arrow srolling. 2486 */ 2487 private int getArrowScrollPreviewLength() { 2488 return Math.max(MIN_SCROLL_PREVIEW_PIXELS, getVerticalFadingEdgeLength()); 2489 } 2490 2491 /** 2492 * Determine how much we need to scroll in order to get the next selected view 2493 * visible, with a fading edge showing below as applicable. The amount is 2494 * capped at {@link #getMaxScrollAmount()} . 2495 * 2496 * @param direction either {@link android.view.View#FOCUS_UP} or 2497 * {@link android.view.View#FOCUS_DOWN}. 2498 * @param nextSelectedPosition The position of the next selection, or 2499 * {@link #INVALID_POSITION} if there is no next selectable position 2500 * @return The amount to scroll. Note: this is always positive! Direction 2501 * needs to be taken into account when actually scrolling. 2502 */ 2503 private int amountToScroll(int direction, int nextSelectedPosition) { 2504 final int listBottom = getHeight() - mListPadding.bottom; 2505 final int listTop = mListPadding.top; 2506 2507 final int numChildren = getChildCount(); 2508 2509 if (direction == View.FOCUS_DOWN) { 2510 int indexToMakeVisible = numChildren - 1; 2511 if (nextSelectedPosition != INVALID_POSITION) { 2512 indexToMakeVisible = nextSelectedPosition - mFirstPosition; 2513 } 2514 2515 final int positionToMakeVisible = mFirstPosition + indexToMakeVisible; 2516 final View viewToMakeVisible = getChildAt(indexToMakeVisible); 2517 2518 int goalBottom = listBottom; 2519 if (positionToMakeVisible < mItemCount - 1) { 2520 goalBottom -= getArrowScrollPreviewLength(); 2521 } 2522 2523 if (viewToMakeVisible.getBottom() <= goalBottom) { 2524 // item is fully visible. 2525 return 0; 2526 } 2527 2528 if (nextSelectedPosition != INVALID_POSITION 2529 && (goalBottom - viewToMakeVisible.getTop()) >= getMaxScrollAmount()) { 2530 // item already has enough of it visible, changing selection is good enough 2531 return 0; 2532 } 2533 2534 int amountToScroll = (viewToMakeVisible.getBottom() - goalBottom); 2535 2536 if ((mFirstPosition + numChildren) == mItemCount) { 2537 // last is last in list -> make sure we don't scroll past it 2538 final int max = getChildAt(numChildren - 1).getBottom() - listBottom; 2539 amountToScroll = Math.min(amountToScroll, max); 2540 } 2541 2542 return Math.min(amountToScroll, getMaxScrollAmount()); 2543 } else { 2544 int indexToMakeVisible = 0; 2545 if (nextSelectedPosition != INVALID_POSITION) { 2546 indexToMakeVisible = nextSelectedPosition - mFirstPosition; 2547 } 2548 final int positionToMakeVisible = mFirstPosition + indexToMakeVisible; 2549 final View viewToMakeVisible = getChildAt(indexToMakeVisible); 2550 int goalTop = listTop; 2551 if (positionToMakeVisible > 0) { 2552 goalTop += getArrowScrollPreviewLength(); 2553 } 2554 if (viewToMakeVisible.getTop() >= goalTop) { 2555 // item is fully visible. 2556 return 0; 2557 } 2558 2559 if (nextSelectedPosition != INVALID_POSITION && 2560 (viewToMakeVisible.getBottom() - goalTop) >= getMaxScrollAmount()) { 2561 // item already has enough of it visible, changing selection is good enough 2562 return 0; 2563 } 2564 2565 int amountToScroll = (goalTop - viewToMakeVisible.getTop()); 2566 if (mFirstPosition == 0) { 2567 // first is first in list -> make sure we don't scroll past it 2568 final int max = listTop - getChildAt(0).getTop(); 2569 amountToScroll = Math.min(amountToScroll, max); 2570 } 2571 return Math.min(amountToScroll, getMaxScrollAmount()); 2572 } 2573 } 2574 2575 /** 2576 * Holds results of focus aware arrow scrolling. 2577 */ 2578 static private class ArrowScrollFocusResult { 2579 private int mSelectedPosition; 2580 private int mAmountToScroll; 2581 2582 /** 2583 * How {@link android.widget.ListView#arrowScrollFocused} returns its values. 2584 */ 2585 void populate(int selectedPosition, int amountToScroll) { 2586 mSelectedPosition = selectedPosition; 2587 mAmountToScroll = amountToScroll; 2588 } 2589 2590 public int getSelectedPosition() { 2591 return mSelectedPosition; 2592 } 2593 2594 public int getAmountToScroll() { 2595 return mAmountToScroll; 2596 } 2597 } 2598 2599 /** 2600 * @param direction either {@link android.view.View#FOCUS_UP} or 2601 * {@link android.view.View#FOCUS_DOWN}. 2602 * @return The position of the next selectable position of the views that 2603 * are currently visible, taking into account the fact that there might 2604 * be no selection. Returns {@link #INVALID_POSITION} if there is no 2605 * selectable view on screen in the given direction. 2606 */ 2607 private int lookForSelectablePositionOnScreen(int direction) { 2608 final int firstPosition = mFirstPosition; 2609 if (direction == View.FOCUS_DOWN) { 2610 int startPos = (mSelectedPosition != INVALID_POSITION) ? 2611 mSelectedPosition + 1 : 2612 firstPosition; 2613 if (startPos >= mAdapter.getCount()) { 2614 return INVALID_POSITION; 2615 } 2616 if (startPos < firstPosition) { 2617 startPos = firstPosition; 2618 } 2619 2620 final int lastVisiblePos = getLastVisiblePosition(); 2621 final ListAdapter adapter = getAdapter(); 2622 for (int pos = startPos; pos <= lastVisiblePos; pos++) { 2623 if (adapter.isEnabled(pos) 2624 && getChildAt(pos - firstPosition).getVisibility() == View.VISIBLE) { 2625 return pos; 2626 } 2627 } 2628 } else { 2629 int last = firstPosition + getChildCount() - 1; 2630 int startPos = (mSelectedPosition != INVALID_POSITION) ? 2631 mSelectedPosition - 1 : 2632 firstPosition + getChildCount() - 1; 2633 if (startPos < 0) { 2634 return INVALID_POSITION; 2635 } 2636 if (startPos > last) { 2637 startPos = last; 2638 } 2639 2640 final ListAdapter adapter = getAdapter(); 2641 for (int pos = startPos; pos >= firstPosition; pos--) { 2642 if (adapter.isEnabled(pos) 2643 && getChildAt(pos - firstPosition).getVisibility() == View.VISIBLE) { 2644 return pos; 2645 } 2646 } 2647 } 2648 return INVALID_POSITION; 2649 } 2650 2651 /** 2652 * Do an arrow scroll based on focus searching. If a new view is 2653 * given focus, return the selection delta and amount to scroll via 2654 * an {@link ArrowScrollFocusResult}, otherwise, return null. 2655 * 2656 * @param direction either {@link android.view.View#FOCUS_UP} or 2657 * {@link android.view.View#FOCUS_DOWN}. 2658 * @return The result if focus has changed, or <code>null</code>. 2659 */ 2660 private ArrowScrollFocusResult arrowScrollFocused(final int direction) { 2661 final View selectedView = getSelectedView(); 2662 View newFocus; 2663 if (selectedView != null && selectedView.hasFocus()) { 2664 View oldFocus = selectedView.findFocus(); 2665 newFocus = FocusFinder.getInstance().findNextFocus(this, oldFocus, direction); 2666 } else { 2667 if (direction == View.FOCUS_DOWN) { 2668 final boolean topFadingEdgeShowing = (mFirstPosition > 0); 2669 final int listTop = mListPadding.top + 2670 (topFadingEdgeShowing ? getArrowScrollPreviewLength() : 0); 2671 final int ySearchPoint = 2672 (selectedView != null && selectedView.getTop() > listTop) ? 2673 selectedView.getTop() : 2674 listTop; 2675 mTempRect.set(0, ySearchPoint, 0, ySearchPoint); 2676 } else { 2677 final boolean bottomFadingEdgeShowing = 2678 (mFirstPosition + getChildCount() - 1) < mItemCount; 2679 final int listBottom = getHeight() - mListPadding.bottom - 2680 (bottomFadingEdgeShowing ? getArrowScrollPreviewLength() : 0); 2681 final int ySearchPoint = 2682 (selectedView != null && selectedView.getBottom() < listBottom) ? 2683 selectedView.getBottom() : 2684 listBottom; 2685 mTempRect.set(0, ySearchPoint, 0, ySearchPoint); 2686 } 2687 newFocus = FocusFinder.getInstance().findNextFocusFromRect(this, mTempRect, direction); 2688 } 2689 2690 if (newFocus != null) { 2691 final int positionOfNewFocus = positionOfNewFocus(newFocus); 2692 2693 // if the focus change is in a different new position, make sure 2694 // we aren't jumping over another selectable position 2695 if (mSelectedPosition != INVALID_POSITION && positionOfNewFocus != mSelectedPosition) { 2696 final int selectablePosition = lookForSelectablePositionOnScreen(direction); 2697 if (selectablePosition != INVALID_POSITION && 2698 ((direction == View.FOCUS_DOWN && selectablePosition < positionOfNewFocus) || 2699 (direction == View.FOCUS_UP && selectablePosition > positionOfNewFocus))) { 2700 return null; 2701 } 2702 } 2703 2704 int focusScroll = amountToScrollToNewFocus(direction, newFocus, positionOfNewFocus); 2705 2706 final int maxScrollAmount = getMaxScrollAmount(); 2707 if (focusScroll < maxScrollAmount) { 2708 // not moving too far, safe to give next view focus 2709 newFocus.requestFocus(direction); 2710 mArrowScrollFocusResult.populate(positionOfNewFocus, focusScroll); 2711 return mArrowScrollFocusResult; 2712 } else if (distanceToView(newFocus) < maxScrollAmount){ 2713 // Case to consider: 2714 // too far to get entire next focusable on screen, but by going 2715 // max scroll amount, we are getting it at least partially in view, 2716 // so give it focus and scroll the max ammount. 2717 newFocus.requestFocus(direction); 2718 mArrowScrollFocusResult.populate(positionOfNewFocus, maxScrollAmount); 2719 return mArrowScrollFocusResult; 2720 } 2721 } 2722 return null; 2723 } 2724 2725 /** 2726 * @param newFocus The view that would have focus. 2727 * @return the position that contains newFocus 2728 */ 2729 private int positionOfNewFocus(View newFocus) { 2730 final int numChildren = getChildCount(); 2731 for (int i = 0; i < numChildren; i++) { 2732 final View child = getChildAt(i); 2733 if (isViewAncestorOf(newFocus, child)) { 2734 return mFirstPosition + i; 2735 } 2736 } 2737 throw new IllegalArgumentException("newFocus is not a child of any of the" 2738 + " children of the list!"); 2739 } 2740 2741 /** 2742 * Return true if child is an ancestor of parent, (or equal to the parent). 2743 */ 2744 private boolean isViewAncestorOf(View child, View parent) { 2745 if (child == parent) { 2746 return true; 2747 } 2748 2749 final ViewParent theParent = child.getParent(); 2750 return (theParent instanceof ViewGroup) && isViewAncestorOf((View) theParent, parent); 2751 } 2752 2753 /** 2754 * Determine how much we need to scroll in order to get newFocus in view. 2755 * @param direction either {@link android.view.View#FOCUS_UP} or 2756 * {@link android.view.View#FOCUS_DOWN}. 2757 * @param newFocus The view that would take focus. 2758 * @param positionOfNewFocus The position of the list item containing newFocus 2759 * @return The amount to scroll. Note: this is always positive! Direction 2760 * needs to be taken into account when actually scrolling. 2761 */ 2762 private int amountToScrollToNewFocus(int direction, View newFocus, int positionOfNewFocus) { 2763 int amountToScroll = 0; 2764 newFocus.getDrawingRect(mTempRect); 2765 offsetDescendantRectToMyCoords(newFocus, mTempRect); 2766 if (direction == View.FOCUS_UP) { 2767 if (mTempRect.top < mListPadding.top) { 2768 amountToScroll = mListPadding.top - mTempRect.top; 2769 if (positionOfNewFocus > 0) { 2770 amountToScroll += getArrowScrollPreviewLength(); 2771 } 2772 } 2773 } else { 2774 final int listBottom = getHeight() - mListPadding.bottom; 2775 if (mTempRect.bottom > listBottom) { 2776 amountToScroll = mTempRect.bottom - listBottom; 2777 if (positionOfNewFocus < mItemCount - 1) { 2778 amountToScroll += getArrowScrollPreviewLength(); 2779 } 2780 } 2781 } 2782 return amountToScroll; 2783 } 2784 2785 /** 2786 * Determine the distance to the nearest edge of a view in a particular 2787 * direction. 2788 * 2789 * @param descendant A descendant of this list. 2790 * @return The distance, or 0 if the nearest edge is already on screen. 2791 */ 2792 private int distanceToView(View descendant) { 2793 int distance = 0; 2794 descendant.getDrawingRect(mTempRect); 2795 offsetDescendantRectToMyCoords(descendant, mTempRect); 2796 final int listBottom = mBottom - mTop - mListPadding.bottom; 2797 if (mTempRect.bottom < mListPadding.top) { 2798 distance = mListPadding.top - mTempRect.bottom; 2799 } else if (mTempRect.top > listBottom) { 2800 distance = mTempRect.top - listBottom; 2801 } 2802 return distance; 2803 } 2804 2805 2806 /** 2807 * Scroll the children by amount, adding a view at the end and removing 2808 * views that fall off as necessary. 2809 * 2810 * @param amount The amount (positive or negative) to scroll. 2811 */ 2812 private void scrollListItemsBy(int amount) { 2813 offsetChildrenTopAndBottom(amount); 2814 2815 final int listBottom = getHeight() - mListPadding.bottom; 2816 final int listTop = mListPadding.top; 2817 final AbsListView.RecycleBin recycleBin = mRecycler; 2818 2819 if (amount < 0) { 2820 // shifted items up 2821 2822 // may need to pan views into the bottom space 2823 int numChildren = getChildCount(); 2824 View last = getChildAt(numChildren - 1); 2825 while (last.getBottom() < listBottom) { 2826 final int lastVisiblePosition = mFirstPosition + numChildren - 1; 2827 if (lastVisiblePosition < mItemCount - 1) { 2828 last = addViewBelow(last, lastVisiblePosition); 2829 numChildren++; 2830 } else { 2831 break; 2832 } 2833 } 2834 2835 // may have brought in the last child of the list that is skinnier 2836 // than the fading edge, thereby leaving space at the end. need 2837 // to shift back 2838 if (last.getBottom() < listBottom) { 2839 offsetChildrenTopAndBottom(listBottom - last.getBottom()); 2840 } 2841 2842 // top views may be panned off screen 2843 View first = getChildAt(0); 2844 while (first.getBottom() < listTop) { 2845 AbsListView.LayoutParams layoutParams = (LayoutParams) first.getLayoutParams(); 2846 if (recycleBin.shouldRecycleViewType(layoutParams.viewType)) { 2847 detachViewFromParent(first); 2848 recycleBin.addScrapView(first); 2849 } else { 2850 removeViewInLayout(first); 2851 } 2852 first = getChildAt(0); 2853 mFirstPosition++; 2854 } 2855 } else { 2856 // shifted items down 2857 View first = getChildAt(0); 2858 2859 // may need to pan views into top 2860 while ((first.getTop() > listTop) && (mFirstPosition > 0)) { 2861 first = addViewAbove(first, mFirstPosition); 2862 mFirstPosition--; 2863 } 2864 2865 // may have brought the very first child of the list in too far and 2866 // need to shift it back 2867 if (first.getTop() > listTop) { 2868 offsetChildrenTopAndBottom(listTop - first.getTop()); 2869 } 2870 2871 int lastIndex = getChildCount() - 1; 2872 View last = getChildAt(lastIndex); 2873 2874 // bottom view may be panned off screen 2875 while (last.getTop() > listBottom) { 2876 AbsListView.LayoutParams layoutParams = (LayoutParams) last.getLayoutParams(); 2877 if (recycleBin.shouldRecycleViewType(layoutParams.viewType)) { 2878 detachViewFromParent(last); 2879 recycleBin.addScrapView(last); 2880 } else { 2881 removeViewInLayout(last); 2882 } 2883 last = getChildAt(--lastIndex); 2884 } 2885 } 2886 } 2887 2888 private View addViewAbove(View theView, int position) { 2889 int abovePosition = position - 1; 2890 View view = obtainView(abovePosition, mIsScrap); 2891 int edgeOfNewChild = theView.getTop() - mDividerHeight; 2892 setupChild(view, abovePosition, edgeOfNewChild, false, mListPadding.left, 2893 false, mIsScrap[0]); 2894 return view; 2895 } 2896 2897 private View addViewBelow(View theView, int position) { 2898 int belowPosition = position + 1; 2899 View view = obtainView(belowPosition, mIsScrap); 2900 int edgeOfNewChild = theView.getBottom() + mDividerHeight; 2901 setupChild(view, belowPosition, edgeOfNewChild, true, mListPadding.left, 2902 false, mIsScrap[0]); 2903 return view; 2904 } 2905 2906 /** 2907 * Indicates that the views created by the ListAdapter can contain focusable 2908 * items. 2909 * 2910 * @param itemsCanFocus true if items can get focus, false otherwise 2911 */ 2912 public void setItemsCanFocus(boolean itemsCanFocus) { 2913 mItemsCanFocus = itemsCanFocus; 2914 if (!itemsCanFocus) { 2915 setDescendantFocusability(ViewGroup.FOCUS_BLOCK_DESCENDANTS); 2916 } 2917 } 2918 2919 /** 2920 * @return Whether the views created by the ListAdapter can contain focusable 2921 * items. 2922 */ 2923 public boolean getItemsCanFocus() { 2924 return mItemsCanFocus; 2925 } 2926 2927 /** 2928 * @hide Pending API council approval. 2929 */ 2930 @Override 2931 public boolean isOpaque() { 2932 return (mCachingStarted && mIsCacheColorOpaque && mDividerIsOpaque && 2933 hasOpaqueScrollbars()) || super.isOpaque(); 2934 } 2935 2936 @Override 2937 public void setCacheColorHint(int color) { 2938 final boolean opaque = (color >>> 24) == 0xFF; 2939 mIsCacheColorOpaque = opaque; 2940 if (opaque) { 2941 if (mDividerPaint == null) { 2942 mDividerPaint = new Paint(); 2943 } 2944 mDividerPaint.setColor(color); 2945 } 2946 super.setCacheColorHint(color); 2947 } 2948 2949 @Override 2950 protected void dispatchDraw(Canvas canvas) { 2951 // Draw the dividers 2952 final int dividerHeight = mDividerHeight; 2953 final boolean drawDividers = dividerHeight > 0 && mDivider != null; 2954 2955 if (drawDividers) { 2956 // Only modify the top and bottom in the loop, we set the left and right here 2957 final Rect bounds = mTempRect; 2958 bounds.left = mPaddingLeft; 2959 bounds.right = mRight - mLeft - mPaddingRight; 2960 2961 final int count = getChildCount(); 2962 final int headerCount = mHeaderViewInfos.size(); 2963 final int itemCount = mItemCount; 2964 final int footerLimit = itemCount - mFooterViewInfos.size() - 1; 2965 final boolean headerDividers = mHeaderDividersEnabled; 2966 final boolean footerDividers = mFooterDividersEnabled; 2967 final int first = mFirstPosition; 2968 final boolean areAllItemsSelectable = mAreAllItemsSelectable; 2969 final ListAdapter adapter = mAdapter; 2970 // If the list is opaque *and* the background is not, we want to 2971 // fill a rect where the dividers would be for non-selectable items 2972 // If the list is opaque and the background is also opaque, we don't 2973 // need to draw anything since the background will do it for us 2974 final boolean fillForMissingDividers = drawDividers && isOpaque() && !super.isOpaque(); 2975 2976 if (fillForMissingDividers && mDividerPaint == null && mIsCacheColorOpaque) { 2977 mDividerPaint = new Paint(); 2978 mDividerPaint.setColor(getCacheColorHint()); 2979 } 2980 final Paint paint = mDividerPaint; 2981 2982 final int listBottom = mBottom - mTop - mListPadding.bottom + mScrollY; 2983 if (!mStackFromBottom) { 2984 int bottom = 0; 2985 2986 final int scrollY = mScrollY; 2987 for (int i = 0; i < count; i++) { 2988 if ((headerDividers || first + i >= headerCount) && 2989 (footerDividers || first + i < footerLimit)) { 2990 View child = getChildAt(i); 2991 bottom = child.getBottom(); 2992 // Don't draw dividers next to items that are not enabled 2993 if (drawDividers) { 2994 if ((areAllItemsSelectable || 2995 (adapter.isEnabled(first + i) && (i == count - 1 || 2996 adapter.isEnabled(first + i + 1))))) { 2997 bounds.top = bottom; 2998 bounds.bottom = bottom + dividerHeight; 2999 drawDivider(canvas, bounds, i); 3000 } else if (fillForMissingDividers) { 3001 bounds.top = bottom; 3002 bounds.bottom = bottom + dividerHeight; 3003 canvas.drawRect(bounds, paint); 3004 } 3005 } 3006 } 3007 } 3008 } else { 3009 int top; 3010 int listTop = mListPadding.top; 3011 3012 final int scrollY = mScrollY; 3013 3014 for (int i = 0; i < count; i++) { 3015 if ((headerDividers || first + i >= headerCount) && 3016 (footerDividers || first + i < footerLimit)) { 3017 View child = getChildAt(i); 3018 top = child.getTop(); 3019 // Don't draw dividers next to items that are not enabled 3020 if (drawDividers && top > listTop) { 3021 if ((areAllItemsSelectable || 3022 (adapter.isEnabled(first + i) && (i == count - 1 || 3023 adapter.isEnabled(first + i + 1))))) { 3024 bounds.top = top - dividerHeight; 3025 bounds.bottom = top; 3026 // Give the method the child ABOVE the divider, so we 3027 // subtract one from our child 3028 // position. Give -1 when there is no child above the 3029 // divider. 3030 drawDivider(canvas, bounds, i - 1); 3031 } else if (fillForMissingDividers) { 3032 bounds.top = top - dividerHeight; 3033 bounds.bottom = top; 3034 canvas.drawRect(bounds, paint); 3035 } 3036 } 3037 } 3038 } 3039 3040 if (count > 0 && scrollY > 0 && drawDividers) { 3041 bounds.top = listBottom; 3042 bounds.bottom = listBottom + dividerHeight; 3043 drawDivider(canvas, bounds, -1); 3044 } 3045 } 3046 } 3047 3048 // Draw the indicators (these should be drawn above the dividers) and children 3049 super.dispatchDraw(canvas); 3050 } 3051 3052 /** 3053 * Draws a divider for the given child in the given bounds. 3054 * 3055 * @param canvas The canvas to draw to. 3056 * @param bounds The bounds of the divider. 3057 * @param childIndex The index of child (of the View) above the divider. 3058 * This will be -1 if there is no child above the divider to be 3059 * drawn. 3060 */ 3061 void drawDivider(Canvas canvas, Rect bounds, int childIndex) { 3062 // This widget draws the same divider for all children 3063 final Drawable divider = mDivider; 3064 final boolean clipDivider = mClipDivider; 3065 3066 if (!clipDivider) { 3067 divider.setBounds(bounds); 3068 } else { 3069 canvas.save(); 3070 canvas.clipRect(bounds); 3071 } 3072 3073 divider.draw(canvas); 3074 3075 if (clipDivider) { 3076 canvas.restore(); 3077 } 3078 } 3079 3080 /** 3081 * Returns the drawable that will be drawn between each item in the list. 3082 * 3083 * @return the current drawable drawn between list elements 3084 */ 3085 public Drawable getDivider() { 3086 return mDivider; 3087 } 3088 3089 /** 3090 * Sets the drawable that will be drawn between each item in the list. If the drawable does 3091 * not have an intrinsic height, you should also call {@link #setDividerHeight(int)} 3092 * 3093 * @param divider The drawable to use. 3094 */ 3095 public void setDivider(Drawable divider) { 3096 if (divider != null) { 3097 mDividerHeight = divider.getIntrinsicHeight(); 3098 mClipDivider = divider instanceof ColorDrawable; 3099 } else { 3100 mDividerHeight = 0; 3101 mClipDivider = false; 3102 } 3103 mDivider = divider; 3104 mDividerIsOpaque = divider == null || divider.getOpacity() == PixelFormat.OPAQUE; 3105 requestLayoutIfNecessary(); 3106 } 3107 3108 /** 3109 * @return Returns the height of the divider that will be drawn between each item in the list. 3110 */ 3111 public int getDividerHeight() { 3112 return mDividerHeight; 3113 } 3114 3115 /** 3116 * Sets the height of the divider that will be drawn between each item in the list. Calling 3117 * this will override the intrinsic height as set by {@link #setDivider(Drawable)} 3118 * 3119 * @param height The new height of the divider in pixels. 3120 */ 3121 public void setDividerHeight(int height) { 3122 mDividerHeight = height; 3123 requestLayoutIfNecessary(); 3124 } 3125 3126 /** 3127 * Enables or disables the drawing of the divider for header views. 3128 * 3129 * @param headerDividersEnabled True to draw the headers, false otherwise. 3130 * 3131 * @see #setFooterDividersEnabled(boolean) 3132 * @see #addHeaderView(android.view.View) 3133 */ 3134 public void setHeaderDividersEnabled(boolean headerDividersEnabled) { 3135 mHeaderDividersEnabled = headerDividersEnabled; 3136 invalidate(); 3137 } 3138 3139 /** 3140 * Enables or disables the drawing of the divider for footer views. 3141 * 3142 * @param footerDividersEnabled True to draw the footers, false otherwise. 3143 * 3144 * @see #setHeaderDividersEnabled(boolean) 3145 * @see #addFooterView(android.view.View) 3146 */ 3147 public void setFooterDividersEnabled(boolean footerDividersEnabled) { 3148 mFooterDividersEnabled = footerDividersEnabled; 3149 invalidate(); 3150 } 3151 3152 @Override 3153 protected void onFocusChanged(boolean gainFocus, int direction, Rect previouslyFocusedRect) { 3154 super.onFocusChanged(gainFocus, direction, previouslyFocusedRect); 3155 3156 int closetChildIndex = -1; 3157 if (gainFocus && previouslyFocusedRect != null) { 3158 previouslyFocusedRect.offset(mScrollX, mScrollY); 3159 3160 final ListAdapter adapter = mAdapter; 3161 // Don't cache the result of getChildCount or mFirstPosition here, 3162 // it could change in layoutChildren. 3163 if (adapter.getCount() < getChildCount() + mFirstPosition) { 3164 mLayoutMode = LAYOUT_NORMAL; 3165 layoutChildren(); 3166 } 3167 3168 // figure out which item should be selected based on previously 3169 // focused rect 3170 Rect otherRect = mTempRect; 3171 int minDistance = Integer.MAX_VALUE; 3172 final int childCount = getChildCount(); 3173 final int firstPosition = mFirstPosition; 3174 3175 for (int i = 0; i < childCount; i++) { 3176 // only consider selectable views 3177 if (!adapter.isEnabled(firstPosition + i)) { 3178 continue; 3179 } 3180 3181 View other = getChildAt(i); 3182 other.getDrawingRect(otherRect); 3183 offsetDescendantRectToMyCoords(other, otherRect); 3184 int distance = getDistance(previouslyFocusedRect, otherRect, direction); 3185 3186 if (distance < minDistance) { 3187 minDistance = distance; 3188 closetChildIndex = i; 3189 } 3190 } 3191 } 3192 3193 if (closetChildIndex >= 0) { 3194 setSelection(closetChildIndex + mFirstPosition); 3195 } else { 3196 requestLayout(); 3197 } 3198 } 3199 3200 3201 /* 3202 * (non-Javadoc) 3203 * 3204 * Children specified in XML are assumed to be header views. After we have 3205 * parsed them move them out of the children list and into mHeaderViews. 3206 */ 3207 @Override 3208 protected void onFinishInflate() { 3209 super.onFinishInflate(); 3210 3211 int count = getChildCount(); 3212 if (count > 0) { 3213 for (int i = 0; i < count; ++i) { 3214 addHeaderView(getChildAt(i)); 3215 } 3216 removeAllViews(); 3217 } 3218 } 3219 3220 /* (non-Javadoc) 3221 * @see android.view.View#findViewById(int) 3222 * First look in our children, then in any header and footer views that may be scrolled off. 3223 */ 3224 @Override 3225 protected View findViewTraversal(int id) { 3226 View v; 3227 v = super.findViewTraversal(id); 3228 if (v == null) { 3229 v = findViewInHeadersOrFooters(mHeaderViewInfos, id); 3230 if (v != null) { 3231 return v; 3232 } 3233 v = findViewInHeadersOrFooters(mFooterViewInfos, id); 3234 if (v != null) { 3235 return v; 3236 } 3237 } 3238 return v; 3239 } 3240 3241 /* (non-Javadoc) 3242 * 3243 * Look in the passed in list of headers or footers for the view. 3244 */ 3245 View findViewInHeadersOrFooters(ArrayList<FixedViewInfo> where, int id) { 3246 if (where != null) { 3247 int len = where.size(); 3248 View v; 3249 3250 for (int i = 0; i < len; i++) { 3251 v = where.get(i).view; 3252 3253 if (!v.isRootNamespace()) { 3254 v = v.findViewById(id); 3255 3256 if (v != null) { 3257 return v; 3258 } 3259 } 3260 } 3261 } 3262 return null; 3263 } 3264 3265 /* (non-Javadoc) 3266 * @see android.view.View#findViewWithTag(String) 3267 * First look in our children, then in any header and footer views that may be scrolled off. 3268 */ 3269 @Override 3270 protected View findViewWithTagTraversal(Object tag) { 3271 View v; 3272 v = super.findViewWithTagTraversal(tag); 3273 if (v == null) { 3274 v = findViewTagInHeadersOrFooters(mHeaderViewInfos, tag); 3275 if (v != null) { 3276 return v; 3277 } 3278 3279 v = findViewTagInHeadersOrFooters(mFooterViewInfos, tag); 3280 if (v != null) { 3281 return v; 3282 } 3283 } 3284 return v; 3285 } 3286 3287 /* (non-Javadoc) 3288 * 3289 * Look in the passed in list of headers or footers for the view with the tag. 3290 */ 3291 View findViewTagInHeadersOrFooters(ArrayList<FixedViewInfo> where, Object tag) { 3292 if (where != null) { 3293 int len = where.size(); 3294 View v; 3295 3296 for (int i = 0; i < len; i++) { 3297 v = where.get(i).view; 3298 3299 if (!v.isRootNamespace()) { 3300 v = v.findViewWithTag(tag); 3301 3302 if (v != null) { 3303 return v; 3304 } 3305 } 3306 } 3307 } 3308 return null; 3309 } 3310 3311 @Override 3312 public boolean onTouchEvent(MotionEvent ev) { 3313 if (mItemsCanFocus && ev.getAction() == MotionEvent.ACTION_DOWN && ev.getEdgeFlags() != 0) { 3314 // Don't handle edge touches immediately -- they may actually belong to one of our 3315 // descendants. 3316 return false; 3317 } 3318 return super.onTouchEvent(ev); 3319 } 3320 3321 /** 3322 * @see #setChoiceMode(int) 3323 * 3324 * @return The current choice mode 3325 */ 3326 public int getChoiceMode() { 3327 return mChoiceMode; 3328 } 3329 3330 /** 3331 * Defines the choice behavior for the List. By default, Lists do not have any choice behavior 3332 * ({@link #CHOICE_MODE_NONE}). By setting the choiceMode to {@link #CHOICE_MODE_SINGLE}, the 3333 * List allows up to one item to be in a chosen state. By setting the choiceMode to 3334 * {@link #CHOICE_MODE_MULTIPLE}, the list allows any number of items to be chosen. 3335 * 3336 * @param choiceMode One of {@link #CHOICE_MODE_NONE}, {@link #CHOICE_MODE_SINGLE}, or 3337 * {@link #CHOICE_MODE_MULTIPLE} 3338 */ 3339 public void setChoiceMode(int choiceMode) { 3340 mChoiceMode = choiceMode; 3341 if (mChoiceMode != CHOICE_MODE_NONE) { 3342 if (mCheckStates == null) { 3343 mCheckStates = new SparseBooleanArray(); 3344 } 3345 if (mCheckedIdStates == null && mAdapter != null && mAdapter.hasStableIds()) { 3346 mCheckedIdStates = new LongSparseArray<Boolean>(); 3347 } 3348 } 3349 } 3350 3351 @Override 3352 public boolean performItemClick(View view, int position, long id) { 3353 boolean handled = false; 3354 3355 if (mChoiceMode != CHOICE_MODE_NONE) { 3356 handled = true; 3357 3358 if (mChoiceMode == CHOICE_MODE_MULTIPLE) { 3359 boolean newValue = !mCheckStates.get(position, false); 3360 mCheckStates.put(position, newValue); 3361 if (mCheckedIdStates != null && mAdapter.hasStableIds()) { 3362 if (newValue) { 3363 mCheckedIdStates.put(mAdapter.getItemId(position), Boolean.TRUE); 3364 } else { 3365 mCheckedIdStates.delete(mAdapter.getItemId(position)); 3366 } 3367 } 3368 } else { 3369 boolean newValue = !mCheckStates.get(position, false); 3370 if (newValue) { 3371 mCheckStates.clear(); 3372 mCheckStates.put(position, true); 3373 if (mCheckedIdStates != null && mAdapter.hasStableIds()) { 3374 mCheckedIdStates.clear(); 3375 mCheckedIdStates.put(mAdapter.getItemId(position), Boolean.TRUE); 3376 } 3377 } 3378 } 3379 3380 mDataChanged = true; 3381 rememberSyncState(); 3382 requestLayout(); 3383 } 3384 3385 handled |= super.performItemClick(view, position, id); 3386 3387 return handled; 3388 } 3389 3390 /** 3391 * Sets the checked state of the specified position. The is only valid if 3392 * the choice mode has been set to {@link #CHOICE_MODE_SINGLE} or 3393 * {@link #CHOICE_MODE_MULTIPLE}. 3394 * 3395 * @param position The item whose checked state is to be checked 3396 * @param value The new checked state for the item 3397 */ 3398 public void setItemChecked(int position, boolean value) { 3399 if (mChoiceMode == CHOICE_MODE_NONE) { 3400 return; 3401 } 3402 3403 if (mChoiceMode == CHOICE_MODE_MULTIPLE) { 3404 mCheckStates.put(position, value); 3405 if (mCheckedIdStates != null && mAdapter.hasStableIds()) { 3406 if (value) { 3407 mCheckedIdStates.put(mAdapter.getItemId(position), Boolean.TRUE); 3408 } else { 3409 mCheckedIdStates.delete(mAdapter.getItemId(position)); 3410 } 3411 } 3412 } else { 3413 boolean updateIds = mCheckedIdStates != null && mAdapter.hasStableIds(); 3414 // Clear all values if we're checking something, or unchecking the currently 3415 // selected item 3416 if (value || isItemChecked(position)) { 3417 mCheckStates.clear(); 3418 if (updateIds) { 3419 mCheckedIdStates.clear(); 3420 } 3421 } 3422 // this may end up selecting the value we just cleared but this way 3423 // we ensure length of mCheckStates is 1, a fact getCheckedItemPosition relies on 3424 if (value) { 3425 mCheckStates.put(position, true); 3426 if (updateIds) { 3427 mCheckedIdStates.put(mAdapter.getItemId(position), Boolean.TRUE); 3428 } 3429 } 3430 } 3431 3432 // Do not generate a data change while we are in the layout phase 3433 if (!mInLayout && !mBlockLayoutRequests) { 3434 mDataChanged = true; 3435 rememberSyncState(); 3436 requestLayout(); 3437 } 3438 } 3439 3440 /** 3441 * Returns the checked state of the specified position. The result is only 3442 * valid if the choice mode has been set to {@link #CHOICE_MODE_SINGLE} 3443 * or {@link #CHOICE_MODE_MULTIPLE}. 3444 * 3445 * @param position The item whose checked state to return 3446 * @return The item's checked state or <code>false</code> if choice mode 3447 * is invalid 3448 * 3449 * @see #setChoiceMode(int) 3450 */ 3451 public boolean isItemChecked(int position) { 3452 if (mChoiceMode != CHOICE_MODE_NONE && mCheckStates != null) { 3453 return mCheckStates.get(position); 3454 } 3455 3456 return false; 3457 } 3458 3459 /** 3460 * Returns the currently checked item. The result is only valid if the choice 3461 * mode has been set to {@link #CHOICE_MODE_SINGLE}. 3462 * 3463 * @return The position of the currently checked item or 3464 * {@link #INVALID_POSITION} if nothing is selected 3465 * 3466 * @see #setChoiceMode(int) 3467 */ 3468 public int getCheckedItemPosition() { 3469 if (mChoiceMode == CHOICE_MODE_SINGLE && mCheckStates != null && mCheckStates.size() == 1) { 3470 return mCheckStates.keyAt(0); 3471 } 3472 3473 return INVALID_POSITION; 3474 } 3475 3476 /** 3477 * Returns the set of checked items in the list. The result is only valid if 3478 * the choice mode has not been set to {@link #CHOICE_MODE_NONE}. 3479 * 3480 * @return A SparseBooleanArray which will return true for each call to 3481 * get(int position) where position is a position in the list, 3482 * or <code>null</code> if the choice mode is set to 3483 * {@link #CHOICE_MODE_NONE}. 3484 */ 3485 public SparseBooleanArray getCheckedItemPositions() { 3486 if (mChoiceMode != CHOICE_MODE_NONE) { 3487 return mCheckStates; 3488 } 3489 return null; 3490 } 3491 3492 /** 3493 * Returns the set of checked items ids. The result is only valid if the 3494 * choice mode has not been set to {@link #CHOICE_MODE_NONE}. 3495 * 3496 * @return A new array which contains the id of each checked item in the 3497 * list. 3498 * 3499 * @deprecated Use {@link #getCheckedItemIds()} instead. 3500 */ 3501 public long[] getCheckItemIds() { 3502 // Use new behavior that correctly handles stable ID mapping. 3503 if (mAdapter != null && mAdapter.hasStableIds()) { 3504 return getCheckedItemIds(); 3505 } 3506 3507 // Old behavior was buggy, but would sort of work for adapters without stable IDs. 3508 // Fall back to it to support legacy apps. 3509 if (mChoiceMode != CHOICE_MODE_NONE && mCheckStates != null && mAdapter != null) { 3510 final SparseBooleanArray states = mCheckStates; 3511 final int count = states.size(); 3512 final long[] ids = new long[count]; 3513 final ListAdapter adapter = mAdapter; 3514 3515 int checkedCount = 0; 3516 for (int i = 0; i < count; i++) { 3517 if (states.valueAt(i)) { 3518 ids[checkedCount++] = adapter.getItemId(states.keyAt(i)); 3519 } 3520 } 3521 3522 // Trim array if needed. mCheckStates may contain false values 3523 // resulting in checkedCount being smaller than count. 3524 if (checkedCount == count) { 3525 return ids; 3526 } else { 3527 final long[] result = new long[checkedCount]; 3528 System.arraycopy(ids, 0, result, 0, checkedCount); 3529 3530 return result; 3531 } 3532 } 3533 return new long[0]; 3534 } 3535 3536 /** 3537 * Returns the set of checked items ids. The result is only valid if the 3538 * choice mode has not been set to {@link #CHOICE_MODE_NONE} and the adapter 3539 * has stable IDs. ({@link ListAdapter#hasStableIds()} == {@code true}) 3540 * 3541 * @return A new array which contains the id of each checked item in the 3542 * list. 3543 */ 3544 public long[] getCheckedItemIds() { 3545 if (mChoiceMode == CHOICE_MODE_NONE || mCheckedIdStates == null || mAdapter == null) { 3546 return new long[0]; 3547 } 3548 3549 final LongSparseArray<Boolean> idStates = mCheckedIdStates; 3550 final int count = idStates.size(); 3551 final long[] ids = new long[count]; 3552 3553 for (int i = 0; i < count; i++) { 3554 ids[i] = idStates.keyAt(i); 3555 } 3556 3557 return ids; 3558 } 3559 3560 /** 3561 * Clear any choices previously set 3562 */ 3563 public void clearChoices() { 3564 if (mCheckStates != null) { 3565 mCheckStates.clear(); 3566 } 3567 if (mCheckedIdStates != null) { 3568 mCheckedIdStates.clear(); 3569 } 3570 } 3571 3572 static class SavedState extends BaseSavedState { 3573 SparseBooleanArray checkState; 3574 LongSparseArray<Boolean> checkIdState; 3575 3576 /** 3577 * Constructor called from {@link ListView#onSaveInstanceState()} 3578 */ 3579 SavedState(Parcelable superState, SparseBooleanArray checkState, 3580 LongSparseArray<Boolean> checkIdState) { 3581 super(superState); 3582 this.checkState = checkState; 3583 this.checkIdState = checkIdState; 3584 } 3585 3586 /** 3587 * Constructor called from {@link #CREATOR} 3588 */ 3589 private SavedState(Parcel in) { 3590 super(in); 3591 checkState = in.readSparseBooleanArray(); 3592 long[] idState = in.createLongArray(); 3593 3594 if (idState.length > 0) { 3595 checkIdState = new LongSparseArray<Boolean>(); 3596 checkIdState.setValues(idState, Boolean.TRUE); 3597 } 3598 } 3599 3600 @Override 3601 public void writeToParcel(Parcel out, int flags) { 3602 super.writeToParcel(out, flags); 3603 out.writeSparseBooleanArray(checkState); 3604 out.writeLongArray(checkIdState != null ? checkIdState.getKeys() : new long[0]); 3605 } 3606 3607 @Override 3608 public String toString() { 3609 return "ListView.SavedState{" 3610 + Integer.toHexString(System.identityHashCode(this)) 3611 + " checkState=" + checkState + "}"; 3612 } 3613 3614 public static final Parcelable.Creator<SavedState> CREATOR 3615 = new Parcelable.Creator<SavedState>() { 3616 public SavedState createFromParcel(Parcel in) { 3617 return new SavedState(in); 3618 } 3619 3620 public SavedState[] newArray(int size) { 3621 return new SavedState[size]; 3622 } 3623 }; 3624 } 3625 3626 @Override 3627 public Parcelable onSaveInstanceState() { 3628 Parcelable superState = super.onSaveInstanceState(); 3629 return new SavedState(superState, mCheckStates, mCheckedIdStates); 3630 } 3631 3632 @Override 3633 public void onRestoreInstanceState(Parcelable state) { 3634 SavedState ss = (SavedState) state; 3635 3636 super.onRestoreInstanceState(ss.getSuperState()); 3637 3638 if (ss.checkState != null) { 3639 mCheckStates = ss.checkState; 3640 } 3641 3642 if (ss.checkIdState != null) { 3643 mCheckedIdStates = ss.checkIdState; 3644 } 3645 } 3646} 3647