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