ListView.java revision bfb5d4b93bb739a012ecec604473838c1343c88a
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 Drawable mOverscrollHeader; 122 Drawable mOverscrollFooter; 123 124 private boolean mIsCacheColorOpaque; 125 private boolean mDividerIsOpaque; 126 private boolean mClipDivider; 127 128 private boolean mHeaderDividersEnabled; 129 private boolean mFooterDividersEnabled; 130 131 private boolean mAreAllItemsSelectable = true; 132 133 private boolean mItemsCanFocus = false; 134 135 private int mChoiceMode = CHOICE_MODE_NONE; 136 137 private SparseBooleanArray mCheckStates; 138 private LongSparseArray<Boolean> mCheckedIdStates; 139 140 // used for temporary calculations. 141 private final Rect mTempRect = new Rect(); 142 private Paint mDividerPaint; 143 144 // the single allocated result per list view; kinda cheesey but avoids 145 // allocating these thingies too often. 146 private final ArrowScrollFocusResult mArrowScrollFocusResult = new ArrowScrollFocusResult(); 147 148 // Keeps focused children visible through resizes 149 private FocusSelector mFocusSelector; 150 151 public ListView(Context context) { 152 this(context, null); 153 } 154 155 public ListView(Context context, AttributeSet attrs) { 156 this(context, attrs, com.android.internal.R.attr.listViewStyle); 157 } 158 159 public ListView(Context context, AttributeSet attrs, int defStyle) { 160 super(context, attrs, defStyle); 161 162 TypedArray a = context.obtainStyledAttributes(attrs, 163 com.android.internal.R.styleable.ListView, defStyle, 0); 164 165 CharSequence[] entries = a.getTextArray( 166 com.android.internal.R.styleable.ListView_entries); 167 if (entries != null) { 168 setAdapter(new ArrayAdapter<CharSequence>(context, 169 com.android.internal.R.layout.simple_list_item_1, entries)); 170 } 171 172 final Drawable d = a.getDrawable(com.android.internal.R.styleable.ListView_divider); 173 if (d != null) { 174 // If a divider is specified use its intrinsic height for divider height 175 setDivider(d); 176 } 177 178 final Drawable osHeader = a.getDrawable(com.android.internal.R.styleable.ListView_overscrollHeader); 179 if (osHeader != null) { 180 setOverscrollHeader(osHeader); 181 } 182 183 final Drawable osFooter = a.getDrawable(com.android.internal.R.styleable.ListView_overscrollFooter); 184 if (osFooter != null) { 185 setOverscrollFooter(osFooter); 186 } 187 188 // Use the height specified, zero being the default 189 final int dividerHeight = a.getDimensionPixelSize( 190 com.android.internal.R.styleable.ListView_dividerHeight, 0); 191 if (dividerHeight != 0) { 192 setDividerHeight(dividerHeight); 193 } 194 195 setChoiceMode(a.getInt(R.styleable.ListView_choiceMode, CHOICE_MODE_NONE)); 196 197 mHeaderDividersEnabled = a.getBoolean(R.styleable.ListView_headerDividersEnabled, true); 198 mFooterDividersEnabled = a.getBoolean(R.styleable.ListView_footerDividersEnabled, true); 199 200 a.recycle(); 201 } 202 203 /** 204 * @return The maximum amount a list view will scroll in response to 205 * an arrow event. 206 */ 207 public int getMaxScrollAmount() { 208 return (int) (MAX_SCROLL_FACTOR * (mBottom - mTop)); 209 } 210 211 /** 212 * Make sure views are touching the top or bottom edge, as appropriate for 213 * our gravity 214 */ 215 private void adjustViewsUpOrDown() { 216 final int childCount = getChildCount(); 217 int delta; 218 219 if (childCount > 0) { 220 View child; 221 222 if (!mStackFromBottom) { 223 // Uh-oh -- we came up short. Slide all views up to make them 224 // align with the top 225 child = getChildAt(0); 226 delta = child.getTop() - mListPadding.top; 227 if (mFirstPosition != 0) { 228 // It's OK to have some space above the first item if it is 229 // part of the vertical spacing 230 delta -= mDividerHeight; 231 } 232 if (delta < 0) { 233 // We only are looking to see if we are too low, not too high 234 delta = 0; 235 } 236 } else { 237 // we are too high, slide all views down to align with bottom 238 child = getChildAt(childCount - 1); 239 delta = child.getBottom() - (getHeight() - mListPadding.bottom); 240 241 if (mFirstPosition + childCount < mItemCount) { 242 // It's OK to have some space below the last item if it is 243 // part of the vertical spacing 244 delta += mDividerHeight; 245 } 246 247 if (delta > 0) { 248 delta = 0; 249 } 250 } 251 252 if (delta != 0) { 253 offsetChildrenTopAndBottom(-delta); 254 } 255 } 256 } 257 258 /** 259 * Add a fixed view to appear at the top of the list. If addHeaderView is 260 * called more than once, the views will appear in the order they were 261 * added. Views added using this call can take focus if they want. 262 * <p> 263 * NOTE: Call this before calling setAdapter. This is so ListView can wrap 264 * the supplied cursor with one that will also account for header and footer 265 * views. 266 * 267 * @param v The view to add. 268 * @param data Data to associate with this view 269 * @param isSelectable whether the item is selectable 270 */ 271 public void addHeaderView(View v, Object data, boolean isSelectable) { 272 273 if (mAdapter != null) { 274 throw new IllegalStateException( 275 "Cannot add header view to list -- setAdapter has already been called."); 276 } 277 278 FixedViewInfo info = new FixedViewInfo(); 279 info.view = v; 280 info.data = data; 281 info.isSelectable = isSelectable; 282 mHeaderViewInfos.add(info); 283 } 284 285 /** 286 * Add a fixed view to appear at the top of the list. If addHeaderView is 287 * called more than once, the views will appear in the order they were 288 * added. Views added using this call can take focus if they want. 289 * <p> 290 * NOTE: Call this before calling setAdapter. This is so ListView can wrap 291 * the supplied cursor with one that will also account for header and footer 292 * views. 293 * 294 * @param v The view to add. 295 */ 296 public void addHeaderView(View v) { 297 addHeaderView(v, null, true); 298 } 299 300 @Override 301 public int getHeaderViewsCount() { 302 return mHeaderViewInfos.size(); 303 } 304 305 /** 306 * Removes a previously-added header view. 307 * 308 * @param v The view to remove 309 * @return true if the view was removed, false if the view was not a header 310 * view 311 */ 312 public boolean removeHeaderView(View v) { 313 if (mHeaderViewInfos.size() > 0) { 314 boolean result = false; 315 if (((HeaderViewListAdapter) mAdapter).removeHeader(v)) { 316 mDataSetObserver.onChanged(); 317 result = true; 318 } 319 removeFixedViewInfo(v, mHeaderViewInfos); 320 return result; 321 } 322 return false; 323 } 324 325 private void removeFixedViewInfo(View v, ArrayList<FixedViewInfo> where) { 326 int len = where.size(); 327 for (int i = 0; i < len; ++i) { 328 FixedViewInfo info = where.get(i); 329 if (info.view == v) { 330 where.remove(i); 331 break; 332 } 333 } 334 } 335 336 /** 337 * Add a fixed view to appear at the bottom of the list. If addFooterView is 338 * called more than once, the views will appear in the order they were 339 * added. Views added using this call can take focus if they want. 340 * <p> 341 * NOTE: Call this before calling setAdapter. This is so ListView can wrap 342 * the supplied cursor with one that will also account for header and footer 343 * views. 344 * 345 * @param v The view to add. 346 * @param data Data to associate with this view 347 * @param isSelectable true if the footer view can be selected 348 */ 349 public void addFooterView(View v, Object data, boolean isSelectable) { 350 FixedViewInfo info = new FixedViewInfo(); 351 info.view = v; 352 info.data = data; 353 info.isSelectable = isSelectable; 354 mFooterViewInfos.add(info); 355 356 // in the case of re-adding a footer view, or adding one later on, 357 // we need to notify the observer 358 if (mDataSetObserver != null) { 359 mDataSetObserver.onChanged(); 360 } 361 } 362 363 /** 364 * Add a fixed view to appear at the bottom of the list. If addFooterView is called more 365 * than once, the views will appear in the order they were added. Views added using 366 * this call can take focus if they want. 367 * <p>NOTE: Call this before calling setAdapter. This is so ListView can wrap the supplied 368 * cursor with one that will also account for header and footer views. 369 * 370 * 371 * @param v The view to add. 372 */ 373 public void addFooterView(View v) { 374 addFooterView(v, null, true); 375 } 376 377 @Override 378 public int getFooterViewsCount() { 379 return mFooterViewInfos.size(); 380 } 381 382 /** 383 * Removes a previously-added footer view. 384 * 385 * @param v The view to remove 386 * @return 387 * true if the view was removed, false if the view was not a footer view 388 */ 389 public boolean removeFooterView(View v) { 390 if (mFooterViewInfos.size() > 0) { 391 boolean result = false; 392 if (((HeaderViewListAdapter) mAdapter).removeFooter(v)) { 393 mDataSetObserver.onChanged(); 394 result = true; 395 } 396 removeFixedViewInfo(v, mFooterViewInfos); 397 return result; 398 } 399 return false; 400 } 401 402 /** 403 * Returns the adapter currently in use in this ListView. The returned adapter 404 * might not be the same adapter passed to {@link #setAdapter(ListAdapter)} but 405 * might be a {@link WrapperListAdapter}. 406 * 407 * @return The adapter currently used to display data in this ListView. 408 * 409 * @see #setAdapter(ListAdapter) 410 */ 411 @Override 412 public ListAdapter getAdapter() { 413 return mAdapter; 414 } 415 416 /** 417 * Sets the data behind this ListView. 418 * 419 * The adapter passed to this method may be wrapped by a {@link WrapperListAdapter}, 420 * depending on the ListView features currently in use. For instance, adding 421 * headers and/or footers will cause the adapter to be wrapped. 422 * 423 * @param adapter The ListAdapter which is responsible for maintaining the 424 * data backing this list and for producing a view to represent an 425 * item in that data set. 426 * 427 * @see #getAdapter() 428 */ 429 @Override 430 public void setAdapter(ListAdapter adapter) { 431 if (null != mAdapter) { 432 mAdapter.unregisterDataSetObserver(mDataSetObserver); 433 } 434 435 resetList(); 436 mRecycler.clear(); 437 438 if (mHeaderViewInfos.size() > 0|| mFooterViewInfos.size() > 0) { 439 mAdapter = new HeaderViewListAdapter(mHeaderViewInfos, mFooterViewInfos, adapter); 440 } else { 441 mAdapter = adapter; 442 } 443 444 mOldSelectedPosition = INVALID_POSITION; 445 mOldSelectedRowId = INVALID_ROW_ID; 446 if (mAdapter != null) { 447 mAreAllItemsSelectable = mAdapter.areAllItemsEnabled(); 448 mOldItemCount = mItemCount; 449 mItemCount = mAdapter.getCount(); 450 checkFocus(); 451 452 mDataSetObserver = new AdapterDataSetObserver(); 453 mAdapter.registerDataSetObserver(mDataSetObserver); 454 455 mRecycler.setViewTypeCount(mAdapter.getViewTypeCount()); 456 457 int position; 458 if (mStackFromBottom) { 459 position = lookForSelectablePosition(mItemCount - 1, false); 460 } else { 461 position = lookForSelectablePosition(0, true); 462 } 463 setSelectedPositionInt(position); 464 setNextSelectedPositionInt(position); 465 466 if (mItemCount == 0) { 467 // Nothing selected 468 checkSelectionChanged(); 469 } 470 471 if (mChoiceMode != CHOICE_MODE_NONE && 472 mAdapter.hasStableIds() && 473 mCheckedIdStates == null) { 474 mCheckedIdStates = new LongSparseArray<Boolean>(); 475 } 476 477 } else { 478 mAreAllItemsSelectable = true; 479 checkFocus(); 480 // Nothing selected 481 checkSelectionChanged(); 482 } 483 484 if (mCheckStates != null) { 485 mCheckStates.clear(); 486 } 487 488 if (mCheckedIdStates != null) { 489 mCheckedIdStates.clear(); 490 } 491 492 requestLayout(); 493 } 494 495 496 /** 497 * The list is empty. Clear everything out. 498 */ 499 @Override 500 void resetList() { 501 // The parent's resetList() will remove all views from the layout so we need to 502 // cleanup the state of our footers and headers 503 clearRecycledState(mHeaderViewInfos); 504 clearRecycledState(mFooterViewInfos); 505 506 super.resetList(); 507 508 mLayoutMode = LAYOUT_NORMAL; 509 } 510 511 private void clearRecycledState(ArrayList<FixedViewInfo> infos) { 512 if (infos != null) { 513 final int count = infos.size(); 514 515 for (int i = 0; i < count; i++) { 516 final View child = infos.get(i).view; 517 final LayoutParams p = (LayoutParams) child.getLayoutParams(); 518 if (p != null) { 519 p.recycledHeaderFooter = false; 520 } 521 } 522 } 523 } 524 525 /** 526 * @return Whether the list needs to show the top fading edge 527 */ 528 private boolean showingTopFadingEdge() { 529 final int listTop = mScrollY + mListPadding.top; 530 return (mFirstPosition > 0) || (getChildAt(0).getTop() > listTop); 531 } 532 533 /** 534 * @return Whether the list needs to show the bottom fading edge 535 */ 536 private boolean showingBottomFadingEdge() { 537 final int childCount = getChildCount(); 538 final int bottomOfBottomChild = getChildAt(childCount - 1).getBottom(); 539 final int lastVisiblePosition = mFirstPosition + childCount - 1; 540 541 final int listBottom = mScrollY + getHeight() - mListPadding.bottom; 542 543 return (lastVisiblePosition < mItemCount - 1) 544 || (bottomOfBottomChild < listBottom); 545 } 546 547 548 @Override 549 public boolean requestChildRectangleOnScreen(View child, Rect rect, boolean immediate) { 550 551 int rectTopWithinChild = rect.top; 552 553 // offset so rect is in coordinates of the this view 554 rect.offset(child.getLeft(), child.getTop()); 555 rect.offset(-child.getScrollX(), -child.getScrollY()); 556 557 final int height = getHeight(); 558 int listUnfadedTop = getScrollY(); 559 int listUnfadedBottom = listUnfadedTop + height; 560 final int fadingEdge = getVerticalFadingEdgeLength(); 561 562 if (showingTopFadingEdge()) { 563 // leave room for top fading edge as long as rect isn't at very top 564 if ((mSelectedPosition > 0) || (rectTopWithinChild > fadingEdge)) { 565 listUnfadedTop += fadingEdge; 566 } 567 } 568 569 int childCount = getChildCount(); 570 int bottomOfBottomChild = getChildAt(childCount - 1).getBottom(); 571 572 if (showingBottomFadingEdge()) { 573 // leave room for bottom fading edge as long as rect isn't at very bottom 574 if ((mSelectedPosition < mItemCount - 1) 575 || (rect.bottom < (bottomOfBottomChild - fadingEdge))) { 576 listUnfadedBottom -= fadingEdge; 577 } 578 } 579 580 int scrollYDelta = 0; 581 582 if (rect.bottom > listUnfadedBottom && rect.top > listUnfadedTop) { 583 // need to MOVE DOWN to get it in view: move down just enough so 584 // that the entire rectangle is in view (or at least the first 585 // screen size chunk). 586 587 if (rect.height() > height) { 588 // just enough to get screen size chunk on 589 scrollYDelta += (rect.top - listUnfadedTop); 590 } else { 591 // get entire rect at bottom of screen 592 scrollYDelta += (rect.bottom - listUnfadedBottom); 593 } 594 595 // make sure we aren't scrolling beyond the end of our children 596 int distanceToBottom = bottomOfBottomChild - listUnfadedBottom; 597 scrollYDelta = Math.min(scrollYDelta, distanceToBottom); 598 } else if (rect.top < listUnfadedTop && rect.bottom < listUnfadedBottom) { 599 // need to MOVE UP to get it in view: move up just enough so that 600 // entire rectangle is in view (or at least the first screen 601 // size chunk of it). 602 603 if (rect.height() > height) { 604 // screen size chunk 605 scrollYDelta -= (listUnfadedBottom - rect.bottom); 606 } else { 607 // entire rect at top 608 scrollYDelta -= (listUnfadedTop - rect.top); 609 } 610 611 // make sure we aren't scrolling any further than the top our children 612 int top = getChildAt(0).getTop(); 613 int deltaToTop = top - listUnfadedTop; 614 scrollYDelta = Math.max(scrollYDelta, deltaToTop); 615 } 616 617 final boolean scroll = scrollYDelta != 0; 618 if (scroll) { 619 scrollListItemsBy(-scrollYDelta); 620 positionSelector(child); 621 mSelectedTop = child.getTop(); 622 invalidate(); 623 } 624 return scroll; 625 } 626 627 /** 628 * {@inheritDoc} 629 */ 630 @Override 631 void fillGap(boolean down) { 632 final int count = getChildCount(); 633 if (down) { 634 final int startOffset = count > 0 ? getChildAt(count - 1).getBottom() + mDividerHeight : 635 getListPaddingTop(); 636 fillDown(mFirstPosition + count, startOffset); 637 correctTooHigh(getChildCount()); 638 } else { 639 final int startOffset = count > 0 ? getChildAt(0).getTop() - mDividerHeight : 640 getHeight() - getListPaddingBottom(); 641 fillUp(mFirstPosition - 1, startOffset); 642 correctTooLow(getChildCount()); 643 } 644 } 645 646 /** 647 * Fills the list from pos down to the end of the list view. 648 * 649 * @param pos The first position to put in the list 650 * 651 * @param nextTop The location where the top of the item associated with pos 652 * should be drawn 653 * 654 * @return The view that is currently selected, if it happens to be in the 655 * range that we draw. 656 */ 657 private View fillDown(int pos, int nextTop) { 658 View selectedView = null; 659 660 int end = (mBottom - mTop) - mListPadding.bottom; 661 662 while (nextTop < end && pos < mItemCount) { 663 // is this the selected item? 664 boolean selected = pos == mSelectedPosition; 665 View child = makeAndAddView(pos, nextTop, true, mListPadding.left, selected); 666 667 nextTop = child.getBottom() + mDividerHeight; 668 if (selected) { 669 selectedView = child; 670 } 671 pos++; 672 } 673 674 return selectedView; 675 } 676 677 /** 678 * Fills the list from pos up to the top of the list view. 679 * 680 * @param pos The first position to put in the list 681 * 682 * @param nextBottom The location where the bottom of the item associated 683 * with pos should be drawn 684 * 685 * @return The view that is currently selected 686 */ 687 private View fillUp(int pos, int nextBottom) { 688 View selectedView = null; 689 690 int end = mListPadding.top; 691 692 while (nextBottom > end && pos >= 0) { 693 // is this the selected item? 694 boolean selected = pos == mSelectedPosition; 695 View child = makeAndAddView(pos, nextBottom, false, mListPadding.left, selected); 696 nextBottom = child.getTop() - mDividerHeight; 697 if (selected) { 698 selectedView = child; 699 } 700 pos--; 701 } 702 703 mFirstPosition = pos + 1; 704 705 return selectedView; 706 } 707 708 /** 709 * Fills the list from top to bottom, starting with mFirstPosition 710 * 711 * @param nextTop The location where the top of the first item should be 712 * drawn 713 * 714 * @return The view that is currently selected 715 */ 716 private View fillFromTop(int nextTop) { 717 mFirstPosition = Math.min(mFirstPosition, mSelectedPosition); 718 mFirstPosition = Math.min(mFirstPosition, mItemCount - 1); 719 if (mFirstPosition < 0) { 720 mFirstPosition = 0; 721 } 722 return fillDown(mFirstPosition, nextTop); 723 } 724 725 726 /** 727 * Put mSelectedPosition in the middle of the screen and then build up and 728 * down from there. This method forces mSelectedPosition to the center. 729 * 730 * @param childrenTop Top of the area in which children can be drawn, as 731 * measured in pixels 732 * @param childrenBottom Bottom of the area in which children can be drawn, 733 * as measured in pixels 734 * @return Currently selected view 735 */ 736 private View fillFromMiddle(int childrenTop, int childrenBottom) { 737 int height = childrenBottom - childrenTop; 738 739 int position = reconcileSelectedPosition(); 740 741 View sel = makeAndAddView(position, childrenTop, true, 742 mListPadding.left, true); 743 mFirstPosition = position; 744 745 int selHeight = sel.getMeasuredHeight(); 746 if (selHeight <= height) { 747 sel.offsetTopAndBottom((height - selHeight) / 2); 748 } 749 750 fillAboveAndBelow(sel, position); 751 752 if (!mStackFromBottom) { 753 correctTooHigh(getChildCount()); 754 } else { 755 correctTooLow(getChildCount()); 756 } 757 758 return sel; 759 } 760 761 /** 762 * Once the selected view as been placed, fill up the visible area above and 763 * below it. 764 * 765 * @param sel The selected view 766 * @param position The position corresponding to sel 767 */ 768 private void fillAboveAndBelow(View sel, int position) { 769 final int dividerHeight = mDividerHeight; 770 if (!mStackFromBottom) { 771 fillUp(position - 1, sel.getTop() - dividerHeight); 772 adjustViewsUpOrDown(); 773 fillDown(position + 1, sel.getBottom() + dividerHeight); 774 } else { 775 fillDown(position + 1, sel.getBottom() + dividerHeight); 776 adjustViewsUpOrDown(); 777 fillUp(position - 1, sel.getTop() - dividerHeight); 778 } 779 } 780 781 782 /** 783 * Fills the grid based on positioning the new selection at a specific 784 * location. The selection may be moved so that it does not intersect the 785 * faded edges. The grid is then filled upwards and downwards from there. 786 * 787 * @param selectedTop Where the selected item should be 788 * @param childrenTop Where to start drawing children 789 * @param childrenBottom Last pixel where children can be drawn 790 * @return The view that currently has selection 791 */ 792 private View fillFromSelection(int selectedTop, int childrenTop, int childrenBottom) { 793 int fadingEdgeLength = getVerticalFadingEdgeLength(); 794 final int selectedPosition = mSelectedPosition; 795 796 View sel; 797 798 final int topSelectionPixel = getTopSelectionPixel(childrenTop, fadingEdgeLength, 799 selectedPosition); 800 final int bottomSelectionPixel = getBottomSelectionPixel(childrenBottom, fadingEdgeLength, 801 selectedPosition); 802 803 sel = makeAndAddView(selectedPosition, selectedTop, true, mListPadding.left, true); 804 805 806 // Some of the newly selected item extends below the bottom of the list 807 if (sel.getBottom() > bottomSelectionPixel) { 808 // Find space available above the selection into which we can scroll 809 // upwards 810 final int spaceAbove = sel.getTop() - topSelectionPixel; 811 812 // Find space required to bring the bottom of the selected item 813 // fully into view 814 final int spaceBelow = sel.getBottom() - bottomSelectionPixel; 815 final int offset = Math.min(spaceAbove, spaceBelow); 816 817 // Now offset the selected item to get it into view 818 sel.offsetTopAndBottom(-offset); 819 } else if (sel.getTop() < topSelectionPixel) { 820 // Find space required to bring the top of the selected item fully 821 // into view 822 final int spaceAbove = topSelectionPixel - sel.getTop(); 823 824 // Find space available below the selection into which we can scroll 825 // downwards 826 final int spaceBelow = bottomSelectionPixel - sel.getBottom(); 827 final int offset = Math.min(spaceAbove, spaceBelow); 828 829 // Offset the selected item to get it into view 830 sel.offsetTopAndBottom(offset); 831 } 832 833 // Fill in views above and below 834 fillAboveAndBelow(sel, selectedPosition); 835 836 if (!mStackFromBottom) { 837 correctTooHigh(getChildCount()); 838 } else { 839 correctTooLow(getChildCount()); 840 } 841 842 return sel; 843 } 844 845 /** 846 * Calculate the bottom-most pixel we can draw the selection into 847 * 848 * @param childrenBottom Bottom pixel were children can be drawn 849 * @param fadingEdgeLength Length of the fading edge in pixels, if present 850 * @param selectedPosition The position that will be selected 851 * @return The bottom-most pixel we can draw the selection into 852 */ 853 private int getBottomSelectionPixel(int childrenBottom, int fadingEdgeLength, 854 int selectedPosition) { 855 int bottomSelectionPixel = childrenBottom; 856 if (selectedPosition != mItemCount - 1) { 857 bottomSelectionPixel -= fadingEdgeLength; 858 } 859 return bottomSelectionPixel; 860 } 861 862 /** 863 * Calculate the top-most pixel we can draw the selection into 864 * 865 * @param childrenTop Top pixel were children can be drawn 866 * @param fadingEdgeLength Length of the fading edge in pixels, if present 867 * @param selectedPosition The position that will be selected 868 * @return The top-most pixel we can draw the selection into 869 */ 870 private int getTopSelectionPixel(int childrenTop, int fadingEdgeLength, int selectedPosition) { 871 // first pixel we can draw the selection into 872 int topSelectionPixel = childrenTop; 873 if (selectedPosition > 0) { 874 topSelectionPixel += fadingEdgeLength; 875 } 876 return topSelectionPixel; 877 } 878 879 880 /** 881 * Fills the list based on positioning the new selection relative to the old 882 * selection. The new selection will be placed at, above, or below the 883 * location of the new selection depending on how the selection is moving. 884 * The selection will then be pinned to the visible part of the screen, 885 * excluding the edges that are faded. The list is then filled upwards and 886 * downwards from there. 887 * 888 * @param oldSel The old selected view. Useful for trying to put the new 889 * selection in the same place 890 * @param newSel The view that is to become selected. Useful for trying to 891 * put the new selection in the same place 892 * @param delta Which way we are moving 893 * @param childrenTop Where to start drawing children 894 * @param childrenBottom Last pixel where children can be drawn 895 * @return The view that currently has selection 896 */ 897 private View moveSelection(View oldSel, View newSel, int delta, int childrenTop, 898 int childrenBottom) { 899 int fadingEdgeLength = getVerticalFadingEdgeLength(); 900 final int selectedPosition = mSelectedPosition; 901 902 View sel; 903 904 final int topSelectionPixel = getTopSelectionPixel(childrenTop, fadingEdgeLength, 905 selectedPosition); 906 final int bottomSelectionPixel = getBottomSelectionPixel(childrenTop, fadingEdgeLength, 907 selectedPosition); 908 909 if (delta > 0) { 910 /* 911 * Case 1: Scrolling down. 912 */ 913 914 /* 915 * Before After 916 * | | | | 917 * +-------+ +-------+ 918 * | A | | A | 919 * | 1 | => +-------+ 920 * +-------+ | B | 921 * | B | | 2 | 922 * +-------+ +-------+ 923 * | | | | 924 * 925 * Try to keep the top of the previously selected item where it was. 926 * oldSel = A 927 * sel = B 928 */ 929 930 // Put oldSel (A) where it belongs 931 oldSel = makeAndAddView(selectedPosition - 1, oldSel.getTop(), true, 932 mListPadding.left, false); 933 934 final int dividerHeight = mDividerHeight; 935 936 // Now put the new selection (B) below that 937 sel = makeAndAddView(selectedPosition, oldSel.getBottom() + dividerHeight, true, 938 mListPadding.left, true); 939 940 // Some of the newly selected item extends below the bottom of the list 941 if (sel.getBottom() > bottomSelectionPixel) { 942 943 // Find space available above the selection into which we can scroll upwards 944 int spaceAbove = sel.getTop() - topSelectionPixel; 945 946 // Find space required to bring the bottom of the selected item fully into view 947 int spaceBelow = sel.getBottom() - bottomSelectionPixel; 948 949 // Don't scroll more than half the height of the list 950 int halfVerticalSpace = (childrenBottom - childrenTop) / 2; 951 int offset = Math.min(spaceAbove, spaceBelow); 952 offset = Math.min(offset, halfVerticalSpace); 953 954 // We placed oldSel, so offset that item 955 oldSel.offsetTopAndBottom(-offset); 956 // Now offset the selected item to get it into view 957 sel.offsetTopAndBottom(-offset); 958 } 959 960 // Fill in views above and below 961 if (!mStackFromBottom) { 962 fillUp(mSelectedPosition - 2, sel.getTop() - dividerHeight); 963 adjustViewsUpOrDown(); 964 fillDown(mSelectedPosition + 1, sel.getBottom() + dividerHeight); 965 } else { 966 fillDown(mSelectedPosition + 1, sel.getBottom() + dividerHeight); 967 adjustViewsUpOrDown(); 968 fillUp(mSelectedPosition - 2, sel.getTop() - dividerHeight); 969 } 970 } else if (delta < 0) { 971 /* 972 * Case 2: Scrolling up. 973 */ 974 975 /* 976 * Before After 977 * | | | | 978 * +-------+ +-------+ 979 * | A | | A | 980 * +-------+ => | 1 | 981 * | B | +-------+ 982 * | 2 | | B | 983 * +-------+ +-------+ 984 * | | | | 985 * 986 * Try to keep the top of the item about to become selected where it was. 987 * newSel = A 988 * olSel = B 989 */ 990 991 if (newSel != null) { 992 // Try to position the top of newSel (A) where it was before it was selected 993 sel = makeAndAddView(selectedPosition, newSel.getTop(), true, mListPadding.left, 994 true); 995 } else { 996 // If (A) was not on screen and so did not have a view, position 997 // it above the oldSel (B) 998 sel = makeAndAddView(selectedPosition, oldSel.getTop(), false, mListPadding.left, 999 true); 1000 } 1001 1002 // Some of the newly selected item extends above the top of the list 1003 if (sel.getTop() < topSelectionPixel) { 1004 // Find space required to bring the top of the selected item fully into view 1005 int spaceAbove = topSelectionPixel - sel.getTop(); 1006 1007 // Find space available below the selection into which we can scroll downwards 1008 int spaceBelow = bottomSelectionPixel - sel.getBottom(); 1009 1010 // Don't scroll more than half the height of the list 1011 int halfVerticalSpace = (childrenBottom - childrenTop) / 2; 1012 int offset = Math.min(spaceAbove, spaceBelow); 1013 offset = Math.min(offset, halfVerticalSpace); 1014 1015 // Offset the selected item to get it into view 1016 sel.offsetTopAndBottom(offset); 1017 } 1018 1019 // Fill in views above and below 1020 fillAboveAndBelow(sel, selectedPosition); 1021 } else { 1022 1023 int oldTop = oldSel.getTop(); 1024 1025 /* 1026 * Case 3: Staying still 1027 */ 1028 sel = makeAndAddView(selectedPosition, oldTop, true, mListPadding.left, true); 1029 1030 // We're staying still... 1031 if (oldTop < childrenTop) { 1032 // ... but the top of the old selection was off screen. 1033 // (This can happen if the data changes size out from under us) 1034 int newBottom = sel.getBottom(); 1035 if (newBottom < childrenTop + 20) { 1036 // Not enough visible -- bring it onscreen 1037 sel.offsetTopAndBottom(childrenTop - sel.getTop()); 1038 } 1039 } 1040 1041 // Fill in views above and below 1042 fillAboveAndBelow(sel, selectedPosition); 1043 } 1044 1045 return sel; 1046 } 1047 1048 private class FocusSelector implements Runnable { 1049 private int mPosition; 1050 private int mPositionTop; 1051 1052 public FocusSelector setup(int position, int top) { 1053 mPosition = position; 1054 mPositionTop = top; 1055 return this; 1056 } 1057 1058 public void run() { 1059 setSelectionFromTop(mPosition, mPositionTop); 1060 } 1061 } 1062 1063 @Override 1064 protected void onSizeChanged(int w, int h, int oldw, int oldh) { 1065 if (getChildCount() > 0) { 1066 View focusedChild = getFocusedChild(); 1067 if (focusedChild != null) { 1068 final int childPosition = mFirstPosition + indexOfChild(focusedChild); 1069 final int childBottom = focusedChild.getBottom(); 1070 final int offset = Math.max(0, childBottom - (h - mPaddingTop)); 1071 final int top = focusedChild.getTop() - offset; 1072 if (mFocusSelector == null) { 1073 mFocusSelector = new FocusSelector(); 1074 } 1075 post(mFocusSelector.setup(childPosition, top)); 1076 } 1077 } 1078 super.onSizeChanged(w, h, oldw, oldh); 1079 } 1080 1081 @Override 1082 protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { 1083 // Sets up mListPadding 1084 super.onMeasure(widthMeasureSpec, heightMeasureSpec); 1085 1086 int widthMode = MeasureSpec.getMode(widthMeasureSpec); 1087 int heightMode = MeasureSpec.getMode(heightMeasureSpec); 1088 int widthSize = MeasureSpec.getSize(widthMeasureSpec); 1089 int heightSize = MeasureSpec.getSize(heightMeasureSpec); 1090 1091 int childWidth = 0; 1092 int childHeight = 0; 1093 1094 mItemCount = mAdapter == null ? 0 : mAdapter.getCount(); 1095 if (mItemCount > 0 && (widthMode == MeasureSpec.UNSPECIFIED || 1096 heightMode == MeasureSpec.UNSPECIFIED)) { 1097 final View child = obtainView(0, mIsScrap); 1098 1099 measureScrapChild(child, 0, widthMeasureSpec); 1100 1101 childWidth = child.getMeasuredWidth(); 1102 childHeight = child.getMeasuredHeight(); 1103 1104 if (recycleOnMeasure() && mRecycler.shouldRecycleViewType( 1105 ((LayoutParams) child.getLayoutParams()).viewType)) { 1106 mRecycler.addScrapView(child); 1107 } 1108 } 1109 1110 if (widthMode == MeasureSpec.UNSPECIFIED) { 1111 widthSize = mListPadding.left + mListPadding.right + childWidth + 1112 getVerticalScrollbarWidth(); 1113 } 1114 1115 if (heightMode == MeasureSpec.UNSPECIFIED) { 1116 heightSize = mListPadding.top + mListPadding.bottom + childHeight + 1117 getVerticalFadingEdgeLength() * 2; 1118 } 1119 1120 if (heightMode == MeasureSpec.AT_MOST) { 1121 // TODO: after first layout we should maybe start at the first visible position, not 0 1122 heightSize = measureHeightOfChildren(widthMeasureSpec, 0, NO_POSITION, heightSize, -1); 1123 } 1124 1125 setMeasuredDimension(widthSize, heightSize); 1126 mWidthMeasureSpec = widthMeasureSpec; 1127 } 1128 1129 private void measureScrapChild(View child, int position, int widthMeasureSpec) { 1130 LayoutParams p = (LayoutParams) child.getLayoutParams(); 1131 if (p == null) { 1132 p = new LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, 1133 ViewGroup.LayoutParams.WRAP_CONTENT, 0); 1134 child.setLayoutParams(p); 1135 } 1136 p.viewType = mAdapter.getItemViewType(position); 1137 p.forceAdd = true; 1138 1139 int childWidthSpec = ViewGroup.getChildMeasureSpec(widthMeasureSpec, 1140 mListPadding.left + mListPadding.right, p.width); 1141 int lpHeight = p.height; 1142 int childHeightSpec; 1143 if (lpHeight > 0) { 1144 childHeightSpec = MeasureSpec.makeMeasureSpec(lpHeight, MeasureSpec.EXACTLY); 1145 } else { 1146 childHeightSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED); 1147 } 1148 child.measure(childWidthSpec, childHeightSpec); 1149 } 1150 1151 /** 1152 * @return True to recycle the views used to measure this ListView in 1153 * UNSPECIFIED/AT_MOST modes, false otherwise. 1154 * @hide 1155 */ 1156 @ViewDebug.ExportedProperty 1157 protected boolean recycleOnMeasure() { 1158 return true; 1159 } 1160 1161 /** 1162 * Measures the height of the given range of children (inclusive) and 1163 * returns the height with this ListView's padding and divider heights 1164 * included. If maxHeight is provided, the measuring will stop when the 1165 * current height reaches maxHeight. 1166 * 1167 * @param widthMeasureSpec The width measure spec to be given to a child's 1168 * {@link View#measure(int, int)}. 1169 * @param startPosition The position of the first child to be shown. 1170 * @param endPosition The (inclusive) position of the last child to be 1171 * shown. Specify {@link #NO_POSITION} if the last child should be 1172 * the last available child from the adapter. 1173 * @param maxHeight The maximum height that will be returned (if all the 1174 * children don't fit in this value, this value will be 1175 * returned). 1176 * @param disallowPartialChildPosition In general, whether the returned 1177 * height should only contain entire children. This is more 1178 * powerful--it is the first inclusive position at which partial 1179 * children will not be allowed. Example: it looks nice to have 1180 * at least 3 completely visible children, and in portrait this 1181 * will most likely fit; but in landscape there could be times 1182 * when even 2 children can not be completely shown, so a value 1183 * of 2 (remember, inclusive) would be good (assuming 1184 * startPosition is 0). 1185 * @return The height of this ListView with the given children. 1186 */ 1187 final int measureHeightOfChildren(int widthMeasureSpec, int startPosition, int endPosition, 1188 final int maxHeight, int disallowPartialChildPosition) { 1189 1190 final ListAdapter adapter = mAdapter; 1191 if (adapter == null) { 1192 return mListPadding.top + mListPadding.bottom; 1193 } 1194 1195 // Include the padding of the list 1196 int returnedHeight = mListPadding.top + mListPadding.bottom; 1197 final int dividerHeight = ((mDividerHeight > 0) && mDivider != null) ? mDividerHeight : 0; 1198 // The previous height value that was less than maxHeight and contained 1199 // no partial children 1200 int prevHeightWithoutPartialChild = 0; 1201 int i; 1202 View child; 1203 1204 // mItemCount - 1 since endPosition parameter is inclusive 1205 endPosition = (endPosition == NO_POSITION) ? adapter.getCount() - 1 : endPosition; 1206 final AbsListView.RecycleBin recycleBin = mRecycler; 1207 final boolean recyle = recycleOnMeasure(); 1208 final boolean[] isScrap = mIsScrap; 1209 1210 for (i = startPosition; i <= endPosition; ++i) { 1211 child = obtainView(i, isScrap); 1212 1213 measureScrapChild(child, i, widthMeasureSpec); 1214 1215 if (i > 0) { 1216 // Count the divider for all but one child 1217 returnedHeight += dividerHeight; 1218 } 1219 1220 // Recycle the view before we possibly return from the method 1221 if (recyle && recycleBin.shouldRecycleViewType( 1222 ((LayoutParams) child.getLayoutParams()).viewType)) { 1223 recycleBin.addScrapView(child); 1224 } 1225 1226 returnedHeight += child.getMeasuredHeight(); 1227 1228 if (returnedHeight >= maxHeight) { 1229 // We went over, figure out which height to return. If returnedHeight > maxHeight, 1230 // then the i'th position did not fit completely. 1231 return (disallowPartialChildPosition >= 0) // Disallowing is enabled (> -1) 1232 && (i > disallowPartialChildPosition) // We've past the min pos 1233 && (prevHeightWithoutPartialChild > 0) // We have a prev height 1234 && (returnedHeight != maxHeight) // i'th child did not fit completely 1235 ? prevHeightWithoutPartialChild 1236 : maxHeight; 1237 } 1238 1239 if ((disallowPartialChildPosition >= 0) && (i >= disallowPartialChildPosition)) { 1240 prevHeightWithoutPartialChild = returnedHeight; 1241 } 1242 } 1243 1244 // At this point, we went through the range of children, and they each 1245 // completely fit, so return the returnedHeight 1246 return returnedHeight; 1247 } 1248 1249 @Override 1250 int findMotionRow(int y) { 1251 int childCount = getChildCount(); 1252 if (childCount > 0) { 1253 for (int i = 0; i < childCount; i++) { 1254 View v = getChildAt(i); 1255 if (y <= v.getBottom()) { 1256 return mFirstPosition + i; 1257 } 1258 } 1259 } 1260 return INVALID_POSITION; 1261 } 1262 1263 /** 1264 * Put a specific item at a specific location on the screen and then build 1265 * up and down from there. 1266 * 1267 * @param position The reference view to use as the starting point 1268 * @param top Pixel offset from the top of this view to the top of the 1269 * reference view. 1270 * 1271 * @return The selected view, or null if the selected view is outside the 1272 * visible area. 1273 */ 1274 private View fillSpecific(int position, int top) { 1275 boolean tempIsSelected = position == mSelectedPosition; 1276 View temp = makeAndAddView(position, top, true, mListPadding.left, tempIsSelected); 1277 // Possibly changed again in fillUp if we add rows above this one. 1278 mFirstPosition = position; 1279 1280 View above; 1281 View below; 1282 1283 final int dividerHeight = mDividerHeight; 1284 if (!mStackFromBottom) { 1285 above = fillUp(position - 1, temp.getTop() - dividerHeight); 1286 // This will correct for the top of the first view not touching the top of the list 1287 adjustViewsUpOrDown(); 1288 below = fillDown(position + 1, temp.getBottom() + dividerHeight); 1289 int childCount = getChildCount(); 1290 if (childCount > 0) { 1291 correctTooHigh(childCount); 1292 } 1293 } else { 1294 below = fillDown(position + 1, temp.getBottom() + dividerHeight); 1295 // This will correct for the bottom of the last view not touching the bottom of the list 1296 adjustViewsUpOrDown(); 1297 above = fillUp(position - 1, temp.getTop() - dividerHeight); 1298 int childCount = getChildCount(); 1299 if (childCount > 0) { 1300 correctTooLow(childCount); 1301 } 1302 } 1303 1304 if (tempIsSelected) { 1305 return temp; 1306 } else if (above != null) { 1307 return above; 1308 } else { 1309 return below; 1310 } 1311 } 1312 1313 /** 1314 * Check if we have dragged the bottom of the list too high (we have pushed the 1315 * top element off the top of the screen when we did not need to). Correct by sliding 1316 * everything back down. 1317 * 1318 * @param childCount Number of children 1319 */ 1320 private void correctTooHigh(int childCount) { 1321 // First see if the last item is visible. If it is not, it is OK for the 1322 // top of the list to be pushed up. 1323 int lastPosition = mFirstPosition + childCount - 1; 1324 if (lastPosition == mItemCount - 1 && childCount > 0) { 1325 1326 // Get the last child ... 1327 final View lastChild = getChildAt(childCount - 1); 1328 1329 // ... and its bottom edge 1330 final int lastBottom = lastChild.getBottom(); 1331 1332 // This is bottom of our drawable area 1333 final int end = (mBottom - mTop) - mListPadding.bottom; 1334 1335 // This is how far the bottom edge of the last view is from the bottom of the 1336 // drawable area 1337 int bottomOffset = end - lastBottom; 1338 View firstChild = getChildAt(0); 1339 final int firstTop = firstChild.getTop(); 1340 1341 // Make sure we are 1) Too high, and 2) Either there are more rows above the 1342 // first row or the first row is scrolled off the top of the drawable area 1343 if (bottomOffset > 0 && (mFirstPosition > 0 || firstTop < mListPadding.top)) { 1344 if (mFirstPosition == 0) { 1345 // Don't pull the top too far down 1346 bottomOffset = Math.min(bottomOffset, mListPadding.top - firstTop); 1347 } 1348 // Move everything down 1349 offsetChildrenTopAndBottom(bottomOffset); 1350 if (mFirstPosition > 0) { 1351 // Fill the gap that was opened above mFirstPosition with more rows, if 1352 // possible 1353 fillUp(mFirstPosition - 1, firstChild.getTop() - mDividerHeight); 1354 // Close up the remaining gap 1355 adjustViewsUpOrDown(); 1356 } 1357 1358 } 1359 } 1360 } 1361 1362 /** 1363 * Check if we have dragged the bottom of the list too low (we have pushed the 1364 * bottom element off the bottom of the screen when we did not need to). Correct by sliding 1365 * everything back up. 1366 * 1367 * @param childCount Number of children 1368 */ 1369 private void correctTooLow(int childCount) { 1370 // First see if the first item is visible. If it is not, it is OK for the 1371 // bottom of the list to be pushed down. 1372 if (mFirstPosition == 0 && childCount > 0) { 1373 1374 // Get the first child ... 1375 final View firstChild = getChildAt(0); 1376 1377 // ... and its top edge 1378 final int firstTop = firstChild.getTop(); 1379 1380 // This is top of our drawable area 1381 final int start = mListPadding.top; 1382 1383 // This is bottom of our drawable area 1384 final int end = (mBottom - mTop) - mListPadding.bottom; 1385 1386 // This is how far the top edge of the first view is from the top of the 1387 // drawable area 1388 int topOffset = firstTop - start; 1389 View lastChild = getChildAt(childCount - 1); 1390 final int lastBottom = lastChild.getBottom(); 1391 int lastPosition = mFirstPosition + childCount - 1; 1392 1393 // Make sure we are 1) Too low, and 2) Either there are more rows below the 1394 // last row or the last row is scrolled off the bottom of the drawable area 1395 if (topOffset > 0) { 1396 if (lastPosition < mItemCount - 1 || lastBottom > end) { 1397 if (lastPosition == mItemCount - 1) { 1398 // Don't pull the bottom too far up 1399 topOffset = Math.min(topOffset, lastBottom - end); 1400 } 1401 // Move everything up 1402 offsetChildrenTopAndBottom(-topOffset); 1403 if (lastPosition < mItemCount - 1) { 1404 // Fill the gap that was opened below the last position with more rows, if 1405 // possible 1406 fillDown(lastPosition + 1, lastChild.getBottom() + mDividerHeight); 1407 // Close up the remaining gap 1408 adjustViewsUpOrDown(); 1409 } 1410 } else if (lastPosition == mItemCount - 1) { 1411 adjustViewsUpOrDown(); 1412 } 1413 } 1414 } 1415 } 1416 1417 @Override 1418 protected void layoutChildren() { 1419 final boolean blockLayoutRequests = mBlockLayoutRequests; 1420 if (!blockLayoutRequests) { 1421 mBlockLayoutRequests = true; 1422 } else { 1423 return; 1424 } 1425 1426 try { 1427 super.layoutChildren(); 1428 1429 invalidate(); 1430 1431 if (mAdapter == null) { 1432 resetList(); 1433 invokeOnItemScrollListener(); 1434 return; 1435 } 1436 1437 int childrenTop = mListPadding.top; 1438 int childrenBottom = mBottom - mTop - mListPadding.bottom; 1439 1440 int childCount = getChildCount(); 1441 int index = 0; 1442 int delta = 0; 1443 1444 View sel; 1445 View oldSel = null; 1446 View oldFirst = null; 1447 View newSel = null; 1448 1449 View focusLayoutRestoreView = null; 1450 1451 // Remember stuff we will need down below 1452 switch (mLayoutMode) { 1453 case LAYOUT_SET_SELECTION: 1454 index = mNextSelectedPosition - mFirstPosition; 1455 if (index >= 0 && index < childCount) { 1456 newSel = getChildAt(index); 1457 } 1458 break; 1459 case LAYOUT_FORCE_TOP: 1460 case LAYOUT_FORCE_BOTTOM: 1461 case LAYOUT_SPECIFIC: 1462 case LAYOUT_SYNC: 1463 break; 1464 case LAYOUT_MOVE_SELECTION: 1465 default: 1466 // Remember the previously selected view 1467 index = mSelectedPosition - mFirstPosition; 1468 if (index >= 0 && index < childCount) { 1469 oldSel = getChildAt(index); 1470 } 1471 1472 // Remember the previous first child 1473 oldFirst = getChildAt(0); 1474 1475 if (mNextSelectedPosition >= 0) { 1476 delta = mNextSelectedPosition - mSelectedPosition; 1477 } 1478 1479 // Caution: newSel might be null 1480 newSel = getChildAt(index + delta); 1481 } 1482 1483 1484 boolean dataChanged = mDataChanged; 1485 if (dataChanged) { 1486 handleDataChanged(); 1487 } 1488 1489 // Handle the empty set by removing all views that are visible 1490 // and calling it a day 1491 if (mItemCount == 0) { 1492 resetList(); 1493 invokeOnItemScrollListener(); 1494 return; 1495 } else if (mItemCount != mAdapter.getCount()) { 1496 throw new IllegalStateException("The content of the adapter has changed but " 1497 + "ListView did not receive a notification. Make sure the content of " 1498 + "your adapter is not modified from a background thread, but only " 1499 + "from the UI thread. [in ListView(" + getId() + ", " + getClass() 1500 + ") with Adapter(" + mAdapter.getClass() + ")]"); 1501 } 1502 1503 setSelectedPositionInt(mNextSelectedPosition); 1504 1505 // Pull all children into the RecycleBin. 1506 // These views will be reused if possible 1507 final int firstPosition = mFirstPosition; 1508 final RecycleBin recycleBin = mRecycler; 1509 1510 // reset the focus restoration 1511 View focusLayoutRestoreDirectChild = null; 1512 1513 1514 // Don't put header or footer views into the Recycler. Those are 1515 // already cached in mHeaderViews; 1516 if (dataChanged) { 1517 for (int i = 0; i < childCount; i++) { 1518 recycleBin.addScrapView(getChildAt(i)); 1519 if (ViewDebug.TRACE_RECYCLER) { 1520 ViewDebug.trace(getChildAt(i), 1521 ViewDebug.RecyclerTraceType.MOVE_TO_SCRAP_HEAP, index, i); 1522 } 1523 } 1524 } else { 1525 recycleBin.fillActiveViews(childCount, firstPosition); 1526 } 1527 1528 // take focus back to us temporarily to avoid the eventual 1529 // call to clear focus when removing the focused child below 1530 // from messing things up when ViewRoot assigns focus back 1531 // to someone else 1532 final View focusedChild = getFocusedChild(); 1533 if (focusedChild != null) { 1534 // TODO: in some cases focusedChild.getParent() == null 1535 1536 // we can remember the focused view to restore after relayout if the 1537 // data hasn't changed, or if the focused position is a header or footer 1538 if (!dataChanged || isDirectChildHeaderOrFooter(focusedChild)) { 1539 focusLayoutRestoreDirectChild = focusedChild; 1540 // remember the specific view that had focus 1541 focusLayoutRestoreView = findFocus(); 1542 if (focusLayoutRestoreView != null) { 1543 // tell it we are going to mess with it 1544 focusLayoutRestoreView.onStartTemporaryDetach(); 1545 } 1546 } 1547 requestFocus(); 1548 } 1549 1550 // Clear out old views 1551 detachAllViewsFromParent(); 1552 1553 switch (mLayoutMode) { 1554 case LAYOUT_SET_SELECTION: 1555 if (newSel != null) { 1556 sel = fillFromSelection(newSel.getTop(), childrenTop, childrenBottom); 1557 } else { 1558 sel = fillFromMiddle(childrenTop, childrenBottom); 1559 } 1560 break; 1561 case LAYOUT_SYNC: 1562 sel = fillSpecific(mSyncPosition, mSpecificTop); 1563 break; 1564 case LAYOUT_FORCE_BOTTOM: 1565 sel = fillUp(mItemCount - 1, childrenBottom); 1566 adjustViewsUpOrDown(); 1567 break; 1568 case LAYOUT_FORCE_TOP: 1569 mFirstPosition = 0; 1570 sel = fillFromTop(childrenTop); 1571 adjustViewsUpOrDown(); 1572 break; 1573 case LAYOUT_SPECIFIC: 1574 sel = fillSpecific(reconcileSelectedPosition(), mSpecificTop); 1575 break; 1576 case LAYOUT_MOVE_SELECTION: 1577 sel = moveSelection(oldSel, newSel, delta, childrenTop, childrenBottom); 1578 break; 1579 default: 1580 if (childCount == 0) { 1581 if (!mStackFromBottom) { 1582 final int position = lookForSelectablePosition(0, true); 1583 setSelectedPositionInt(position); 1584 sel = fillFromTop(childrenTop); 1585 } else { 1586 final int position = lookForSelectablePosition(mItemCount - 1, false); 1587 setSelectedPositionInt(position); 1588 sel = fillUp(mItemCount - 1, childrenBottom); 1589 } 1590 } else { 1591 if (mSelectedPosition >= 0 && mSelectedPosition < mItemCount) { 1592 sel = fillSpecific(mSelectedPosition, 1593 oldSel == null ? childrenTop : oldSel.getTop()); 1594 } else if (mFirstPosition < mItemCount) { 1595 sel = fillSpecific(mFirstPosition, 1596 oldFirst == null ? childrenTop : oldFirst.getTop()); 1597 } else { 1598 sel = fillSpecific(0, childrenTop); 1599 } 1600 } 1601 break; 1602 } 1603 1604 // Flush any cached views that did not get reused above 1605 recycleBin.scrapActiveViews(); 1606 1607 if (sel != null) { 1608 // the current selected item should get focus if items 1609 // are focusable 1610 if (mItemsCanFocus && hasFocus() && !sel.hasFocus()) { 1611 final boolean focusWasTaken = (sel == focusLayoutRestoreDirectChild && 1612 focusLayoutRestoreView.requestFocus()) || sel.requestFocus(); 1613 if (!focusWasTaken) { 1614 // selected item didn't take focus, fine, but still want 1615 // to make sure something else outside of the selected view 1616 // has focus 1617 final View focused = getFocusedChild(); 1618 if (focused != null) { 1619 focused.clearFocus(); 1620 } 1621 positionSelector(sel); 1622 } else { 1623 sel.setSelected(false); 1624 mSelectorRect.setEmpty(); 1625 } 1626 } else { 1627 positionSelector(sel); 1628 } 1629 mSelectedTop = sel.getTop(); 1630 } else { 1631 if (mTouchMode > TOUCH_MODE_DOWN && mTouchMode < TOUCH_MODE_SCROLL) { 1632 View child = getChildAt(mMotionPosition - mFirstPosition); 1633 if (child != null) positionSelector(child); 1634 } else { 1635 mSelectedTop = 0; 1636 mSelectorRect.setEmpty(); 1637 } 1638 1639 // even if there is not selected position, we may need to restore 1640 // focus (i.e. something focusable in touch mode) 1641 if (hasFocus() && focusLayoutRestoreView != null) { 1642 focusLayoutRestoreView.requestFocus(); 1643 } 1644 } 1645 1646 // tell focus view we are done mucking with it, if it is still in 1647 // our view hierarchy. 1648 if (focusLayoutRestoreView != null 1649 && focusLayoutRestoreView.getWindowToken() != null) { 1650 focusLayoutRestoreView.onFinishTemporaryDetach(); 1651 } 1652 1653 mLayoutMode = LAYOUT_NORMAL; 1654 mDataChanged = false; 1655 mNeedSync = false; 1656 setNextSelectedPositionInt(mSelectedPosition); 1657 1658 updateScrollIndicators(); 1659 1660 if (mItemCount > 0) { 1661 checkSelectionChanged(); 1662 } 1663 1664 invokeOnItemScrollListener(); 1665 } finally { 1666 if (!blockLayoutRequests) { 1667 mBlockLayoutRequests = false; 1668 } 1669 } 1670 } 1671 1672 /** 1673 * @param child a direct child of this list. 1674 * @return Whether child is a header or footer view. 1675 */ 1676 private boolean isDirectChildHeaderOrFooter(View child) { 1677 1678 final ArrayList<FixedViewInfo> headers = mHeaderViewInfos; 1679 final int numHeaders = headers.size(); 1680 for (int i = 0; i < numHeaders; i++) { 1681 if (child == headers.get(i).view) { 1682 return true; 1683 } 1684 } 1685 final ArrayList<FixedViewInfo> footers = mFooterViewInfos; 1686 final int numFooters = footers.size(); 1687 for (int i = 0; i < numFooters; i++) { 1688 if (child == footers.get(i).view) { 1689 return true; 1690 } 1691 } 1692 return false; 1693 } 1694 1695 /** 1696 * Obtain the view and add it to our list of children. The view can be made 1697 * fresh, converted from an unused view, or used as is if it was in the 1698 * recycle bin. 1699 * 1700 * @param position Logical position in the list 1701 * @param y Top or bottom edge of the view to add 1702 * @param flow If flow is true, align top edge to y. If false, align bottom 1703 * edge to y. 1704 * @param childrenLeft Left edge where children should be positioned 1705 * @param selected Is this position selected? 1706 * @return View that was added 1707 */ 1708 private View makeAndAddView(int position, int y, boolean flow, int childrenLeft, 1709 boolean selected) { 1710 View child; 1711 1712 1713 if (!mDataChanged) { 1714 // Try to use an exsiting view for this position 1715 child = mRecycler.getActiveView(position); 1716 if (child != null) { 1717 if (ViewDebug.TRACE_RECYCLER) { 1718 ViewDebug.trace(child, ViewDebug.RecyclerTraceType.RECYCLE_FROM_ACTIVE_HEAP, 1719 position, getChildCount()); 1720 } 1721 1722 // Found it -- we're using an existing child 1723 // This just needs to be positioned 1724 setupChild(child, position, y, flow, childrenLeft, selected, true); 1725 1726 return child; 1727 } 1728 } 1729 1730 // Make a new view for this position, or convert an unused view if possible 1731 child = obtainView(position, mIsScrap); 1732 1733 // This needs to be positioned and measured 1734 setupChild(child, position, y, flow, childrenLeft, selected, mIsScrap[0]); 1735 1736 return child; 1737 } 1738 1739 /** 1740 * Add a view as a child and make sure it is measured (if necessary) and 1741 * positioned properly. 1742 * 1743 * @param child The view to add 1744 * @param position The position of this child 1745 * @param y The y position relative to which this view will be positioned 1746 * @param flowDown If true, align top edge to y. If false, align bottom 1747 * edge to y. 1748 * @param childrenLeft Left edge where children should be positioned 1749 * @param selected Is this position selected? 1750 * @param recycled Has this view been pulled from the recycle bin? If so it 1751 * does not need to be remeasured. 1752 */ 1753 private void setupChild(View child, int position, int y, boolean flowDown, int childrenLeft, 1754 boolean selected, boolean recycled) { 1755 final boolean isSelected = selected && shouldShowSelector(); 1756 final boolean updateChildSelected = isSelected != child.isSelected(); 1757 final int mode = mTouchMode; 1758 final boolean isPressed = mode > TOUCH_MODE_DOWN && mode < TOUCH_MODE_SCROLL && 1759 mMotionPosition == position; 1760 final boolean updateChildPressed = isPressed != child.isPressed(); 1761 final boolean needToMeasure = !recycled || updateChildSelected || child.isLayoutRequested(); 1762 1763 // Respect layout params that are already in the view. Otherwise make some up... 1764 // noinspection unchecked 1765 AbsListView.LayoutParams p = (AbsListView.LayoutParams) child.getLayoutParams(); 1766 if (p == null) { 1767 p = new AbsListView.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, 1768 ViewGroup.LayoutParams.WRAP_CONTENT, 0); 1769 } 1770 p.viewType = mAdapter.getItemViewType(position); 1771 1772 if ((recycled && !p.forceAdd) || (p.recycledHeaderFooter && 1773 p.viewType == AdapterView.ITEM_VIEW_TYPE_HEADER_OR_FOOTER)) { 1774 attachViewToParent(child, flowDown ? -1 : 0, p); 1775 } else { 1776 p.forceAdd = false; 1777 if (p.viewType == AdapterView.ITEM_VIEW_TYPE_HEADER_OR_FOOTER) { 1778 p.recycledHeaderFooter = true; 1779 } 1780 addViewInLayout(child, flowDown ? -1 : 0, p, true); 1781 } 1782 1783 if (updateChildSelected) { 1784 child.setSelected(isSelected); 1785 } 1786 1787 if (updateChildPressed) { 1788 child.setPressed(isPressed); 1789 } 1790 1791 if (mChoiceMode != CHOICE_MODE_NONE && mCheckStates != null) { 1792 if (child instanceof Checkable) { 1793 ((Checkable) child).setChecked(mCheckStates.get(position)); 1794 } 1795 } 1796 1797 if (needToMeasure) { 1798 int childWidthSpec = ViewGroup.getChildMeasureSpec(mWidthMeasureSpec, 1799 mListPadding.left + mListPadding.right, p.width); 1800 int lpHeight = p.height; 1801 int childHeightSpec; 1802 if (lpHeight > 0) { 1803 childHeightSpec = MeasureSpec.makeMeasureSpec(lpHeight, MeasureSpec.EXACTLY); 1804 } else { 1805 childHeightSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED); 1806 } 1807 child.measure(childWidthSpec, childHeightSpec); 1808 } else { 1809 cleanupLayoutState(child); 1810 } 1811 1812 final int w = child.getMeasuredWidth(); 1813 final int h = child.getMeasuredHeight(); 1814 final int childTop = flowDown ? y : y - h; 1815 1816 if (needToMeasure) { 1817 final int childRight = childrenLeft + w; 1818 final int childBottom = childTop + h; 1819 child.layout(childrenLeft, childTop, childRight, childBottom); 1820 } else { 1821 child.offsetLeftAndRight(childrenLeft - child.getLeft()); 1822 child.offsetTopAndBottom(childTop - child.getTop()); 1823 } 1824 1825 if (mCachingStarted && !child.isDrawingCacheEnabled()) { 1826 child.setDrawingCacheEnabled(true); 1827 } 1828 } 1829 1830 @Override 1831 protected boolean canAnimate() { 1832 return super.canAnimate() && mItemCount > 0; 1833 } 1834 1835 /** 1836 * Sets the currently selected item. If in touch mode, the item will not be selected 1837 * but it will still be positioned appropriately. If the specified selection position 1838 * is less than 0, then the item at position 0 will be selected. 1839 * 1840 * @param position Index (starting at 0) of the data item to be selected. 1841 */ 1842 @Override 1843 public void setSelection(int position) { 1844 setSelectionFromTop(position, 0); 1845 } 1846 1847 /** 1848 * Sets the selected item and positions the selection y pixels from the top edge 1849 * of the ListView. (If in touch mode, the item will not be selected but it will 1850 * still be positioned appropriately.) 1851 * 1852 * @param position Index (starting at 0) of the data item to be selected. 1853 * @param y The distance from the top edge of the ListView (plus padding) that the 1854 * item will be positioned. 1855 */ 1856 public void setSelectionFromTop(int position, int y) { 1857 if (mAdapter == null) { 1858 return; 1859 } 1860 1861 if (!isInTouchMode()) { 1862 position = lookForSelectablePosition(position, true); 1863 if (position >= 0) { 1864 setNextSelectedPositionInt(position); 1865 } 1866 } else { 1867 mResurrectToPosition = position; 1868 } 1869 1870 if (position >= 0) { 1871 mLayoutMode = LAYOUT_SPECIFIC; 1872 mSpecificTop = mListPadding.top + y; 1873 1874 if (mNeedSync) { 1875 mSyncPosition = position; 1876 mSyncRowId = mAdapter.getItemId(position); 1877 } 1878 1879 requestLayout(); 1880 } 1881 } 1882 1883 /** 1884 * Makes the item at the supplied position selected. 1885 * 1886 * @param position the position of the item to select 1887 */ 1888 @Override 1889 void setSelectionInt(int position) { 1890 setNextSelectedPositionInt(position); 1891 boolean awakeScrollbars = false; 1892 1893 final int selectedPosition = mSelectedPosition; 1894 1895 if (selectedPosition >= 0) { 1896 if (position == selectedPosition - 1) { 1897 awakeScrollbars = true; 1898 } else if (position == selectedPosition + 1) { 1899 awakeScrollbars = true; 1900 } 1901 } 1902 1903 layoutChildren(); 1904 1905 if (awakeScrollbars) { 1906 awakenScrollBars(); 1907 } 1908 } 1909 1910 /** 1911 * Find a position that can be selected (i.e., is not a separator). 1912 * 1913 * @param position The starting position to look at. 1914 * @param lookDown Whether to look down for other positions. 1915 * @return The next selectable position starting at position and then searching either up or 1916 * down. Returns {@link #INVALID_POSITION} if nothing can be found. 1917 */ 1918 @Override 1919 int lookForSelectablePosition(int position, boolean lookDown) { 1920 final ListAdapter adapter = mAdapter; 1921 if (adapter == null || isInTouchMode()) { 1922 return INVALID_POSITION; 1923 } 1924 1925 final int count = adapter.getCount(); 1926 if (!mAreAllItemsSelectable) { 1927 if (lookDown) { 1928 position = Math.max(0, position); 1929 while (position < count && !adapter.isEnabled(position)) { 1930 position++; 1931 } 1932 } else { 1933 position = Math.min(position, count - 1); 1934 while (position >= 0 && !adapter.isEnabled(position)) { 1935 position--; 1936 } 1937 } 1938 1939 if (position < 0 || position >= count) { 1940 return INVALID_POSITION; 1941 } 1942 return position; 1943 } else { 1944 if (position < 0 || position >= count) { 1945 return INVALID_POSITION; 1946 } 1947 return position; 1948 } 1949 } 1950 1951 @Override 1952 public boolean dispatchPopulateAccessibilityEvent(AccessibilityEvent event) { 1953 boolean populated = super.dispatchPopulateAccessibilityEvent(event); 1954 1955 // If the item count is less than 15 then subtract disabled items from the count and 1956 // position. Otherwise ignore disabled items. 1957 if (!populated) { 1958 int itemCount = 0; 1959 int currentItemIndex = getSelectedItemPosition(); 1960 1961 ListAdapter adapter = getAdapter(); 1962 if (adapter != null) { 1963 final int count = adapter.getCount(); 1964 if (count < 15) { 1965 for (int i = 0; i < count; i++) { 1966 if (adapter.isEnabled(i)) { 1967 itemCount++; 1968 } else if (i <= currentItemIndex) { 1969 currentItemIndex--; 1970 } 1971 } 1972 } else { 1973 itemCount = count; 1974 } 1975 } 1976 1977 event.setItemCount(itemCount); 1978 event.setCurrentItemIndex(currentItemIndex); 1979 } 1980 1981 return populated; 1982 } 1983 1984 /** 1985 * setSelectionAfterHeaderView set the selection to be the first list item 1986 * after the header views. 1987 */ 1988 public void setSelectionAfterHeaderView() { 1989 final int count = mHeaderViewInfos.size(); 1990 if (count > 0) { 1991 mNextSelectedPosition = 0; 1992 return; 1993 } 1994 1995 if (mAdapter != null) { 1996 setSelection(count); 1997 } else { 1998 mNextSelectedPosition = count; 1999 mLayoutMode = LAYOUT_SET_SELECTION; 2000 } 2001 2002 } 2003 2004 @Override 2005 public boolean dispatchKeyEvent(KeyEvent event) { 2006 // Dispatch in the normal way 2007 boolean handled = super.dispatchKeyEvent(event); 2008 if (!handled) { 2009 // If we didn't handle it... 2010 View focused = getFocusedChild(); 2011 if (focused != null && event.getAction() == KeyEvent.ACTION_DOWN) { 2012 // ... and our focused child didn't handle it 2013 // ... give it to ourselves so we can scroll if necessary 2014 handled = onKeyDown(event.getKeyCode(), event); 2015 } 2016 } 2017 return handled; 2018 } 2019 2020 @Override 2021 public boolean onKeyDown(int keyCode, KeyEvent event) { 2022 return commonKey(keyCode, 1, event); 2023 } 2024 2025 @Override 2026 public boolean onKeyMultiple(int keyCode, int repeatCount, KeyEvent event) { 2027 return commonKey(keyCode, repeatCount, event); 2028 } 2029 2030 @Override 2031 public boolean onKeyUp(int keyCode, KeyEvent event) { 2032 return commonKey(keyCode, 1, event); 2033 } 2034 2035 private boolean commonKey(int keyCode, int count, KeyEvent event) { 2036 if (mAdapter == null) { 2037 return false; 2038 } 2039 2040 if (mDataChanged) { 2041 layoutChildren(); 2042 } 2043 2044 boolean handled = false; 2045 int action = event.getAction(); 2046 2047 if (action != KeyEvent.ACTION_UP) { 2048 if (mSelectedPosition < 0) { 2049 switch (keyCode) { 2050 case KeyEvent.KEYCODE_DPAD_UP: 2051 case KeyEvent.KEYCODE_DPAD_DOWN: 2052 case KeyEvent.KEYCODE_DPAD_CENTER: 2053 case KeyEvent.KEYCODE_ENTER: 2054 case KeyEvent.KEYCODE_SPACE: 2055 if (resurrectSelection()) { 2056 return true; 2057 } 2058 } 2059 } 2060 switch (keyCode) { 2061 case KeyEvent.KEYCODE_DPAD_UP: 2062 if (!event.isAltPressed()) { 2063 while (count > 0) { 2064 handled = arrowScroll(FOCUS_UP); 2065 count--; 2066 } 2067 } else { 2068 handled = fullScroll(FOCUS_UP); 2069 } 2070 break; 2071 2072 case KeyEvent.KEYCODE_DPAD_DOWN: 2073 if (!event.isAltPressed()) { 2074 while (count > 0) { 2075 handled = arrowScroll(FOCUS_DOWN); 2076 count--; 2077 } 2078 } else { 2079 handled = fullScroll(FOCUS_DOWN); 2080 } 2081 break; 2082 2083 case KeyEvent.KEYCODE_DPAD_LEFT: 2084 handled = handleHorizontalFocusWithinListItem(View.FOCUS_LEFT); 2085 break; 2086 case KeyEvent.KEYCODE_DPAD_RIGHT: 2087 handled = handleHorizontalFocusWithinListItem(View.FOCUS_RIGHT); 2088 break; 2089 2090 case KeyEvent.KEYCODE_DPAD_CENTER: 2091 case KeyEvent.KEYCODE_ENTER: 2092 if (mItemCount > 0 && event.getRepeatCount() == 0) { 2093 keyPressed(); 2094 } 2095 handled = true; 2096 break; 2097 2098 case KeyEvent.KEYCODE_SPACE: 2099 if (mPopup == null || !mPopup.isShowing()) { 2100 if (!event.isShiftPressed()) { 2101 pageScroll(FOCUS_DOWN); 2102 } else { 2103 pageScroll(FOCUS_UP); 2104 } 2105 handled = true; 2106 } 2107 break; 2108 } 2109 } 2110 2111 if (!handled) { 2112 handled = sendToTextFilter(keyCode, count, event); 2113 } 2114 2115 if (handled) { 2116 return true; 2117 } else { 2118 switch (action) { 2119 case KeyEvent.ACTION_DOWN: 2120 return super.onKeyDown(keyCode, event); 2121 2122 case KeyEvent.ACTION_UP: 2123 return super.onKeyUp(keyCode, event); 2124 2125 case KeyEvent.ACTION_MULTIPLE: 2126 return super.onKeyMultiple(keyCode, count, event); 2127 2128 default: // shouldn't happen 2129 return false; 2130 } 2131 } 2132 } 2133 2134 /** 2135 * Scrolls up or down by the number of items currently present on screen. 2136 * 2137 * @param direction either {@link View#FOCUS_UP} or {@link View#FOCUS_DOWN} 2138 * @return whether selection was moved 2139 */ 2140 boolean pageScroll(int direction) { 2141 int nextPage = -1; 2142 boolean down = false; 2143 2144 if (direction == FOCUS_UP) { 2145 nextPage = Math.max(0, mSelectedPosition - getChildCount() - 1); 2146 } else if (direction == FOCUS_DOWN) { 2147 nextPage = Math.min(mItemCount - 1, mSelectedPosition + getChildCount() - 1); 2148 down = true; 2149 } 2150 2151 if (nextPage >= 0) { 2152 int position = lookForSelectablePosition(nextPage, down); 2153 if (position >= 0) { 2154 mLayoutMode = LAYOUT_SPECIFIC; 2155 mSpecificTop = mPaddingTop + getVerticalFadingEdgeLength(); 2156 2157 if (down && position > mItemCount - getChildCount()) { 2158 mLayoutMode = LAYOUT_FORCE_BOTTOM; 2159 } 2160 2161 if (!down && position < getChildCount()) { 2162 mLayoutMode = LAYOUT_FORCE_TOP; 2163 } 2164 2165 setSelectionInt(position); 2166 invokeOnItemScrollListener(); 2167 if (!awakenScrollBars()) { 2168 invalidate(); 2169 } 2170 2171 return true; 2172 } 2173 } 2174 2175 return false; 2176 } 2177 2178 /** 2179 * Go to the last or first item if possible (not worrying about panning across or navigating 2180 * within the internal focus of the currently selected item.) 2181 * 2182 * @param direction either {@link View#FOCUS_UP} or {@link View#FOCUS_DOWN} 2183 * 2184 * @return whether selection was moved 2185 */ 2186 boolean fullScroll(int direction) { 2187 boolean moved = false; 2188 if (direction == FOCUS_UP) { 2189 if (mSelectedPosition != 0) { 2190 int position = lookForSelectablePosition(0, true); 2191 if (position >= 0) { 2192 mLayoutMode = LAYOUT_FORCE_TOP; 2193 setSelectionInt(position); 2194 invokeOnItemScrollListener(); 2195 } 2196 moved = true; 2197 } 2198 } else if (direction == FOCUS_DOWN) { 2199 if (mSelectedPosition < mItemCount - 1) { 2200 int position = lookForSelectablePosition(mItemCount - 1, true); 2201 if (position >= 0) { 2202 mLayoutMode = LAYOUT_FORCE_BOTTOM; 2203 setSelectionInt(position); 2204 invokeOnItemScrollListener(); 2205 } 2206 moved = true; 2207 } 2208 } 2209 2210 if (moved && !awakenScrollBars()) { 2211 awakenScrollBars(); 2212 invalidate(); 2213 } 2214 2215 return moved; 2216 } 2217 2218 /** 2219 * To avoid horizontal focus searches changing the selected item, we 2220 * manually focus search within the selected item (as applicable), and 2221 * prevent focus from jumping to something within another item. 2222 * @param direction one of {View.FOCUS_LEFT, View.FOCUS_RIGHT} 2223 * @return Whether this consumes the key event. 2224 */ 2225 private boolean handleHorizontalFocusWithinListItem(int direction) { 2226 if (direction != View.FOCUS_LEFT && direction != View.FOCUS_RIGHT) { 2227 throw new IllegalArgumentException("direction must be one of" 2228 + " {View.FOCUS_LEFT, View.FOCUS_RIGHT}"); 2229 } 2230 2231 final int numChildren = getChildCount(); 2232 if (mItemsCanFocus && numChildren > 0 && mSelectedPosition != INVALID_POSITION) { 2233 final View selectedView = getSelectedView(); 2234 if (selectedView != null && selectedView.hasFocus() && 2235 selectedView instanceof ViewGroup) { 2236 2237 final View currentFocus = selectedView.findFocus(); 2238 final View nextFocus = FocusFinder.getInstance().findNextFocus( 2239 (ViewGroup) selectedView, currentFocus, direction); 2240 if (nextFocus != null) { 2241 // do the math to get interesting rect in next focus' coordinates 2242 currentFocus.getFocusedRect(mTempRect); 2243 offsetDescendantRectToMyCoords(currentFocus, mTempRect); 2244 offsetRectIntoDescendantCoords(nextFocus, mTempRect); 2245 if (nextFocus.requestFocus(direction, mTempRect)) { 2246 return true; 2247 } 2248 } 2249 // we are blocking the key from being handled (by returning true) 2250 // if the global result is going to be some other view within this 2251 // list. this is to acheive the overall goal of having 2252 // horizontal d-pad navigation remain in the current item. 2253 final View globalNextFocus = FocusFinder.getInstance().findNextFocus( 2254 (ViewGroup) getRootView(), currentFocus, direction); 2255 if (globalNextFocus != null) { 2256 return isViewAncestorOf(globalNextFocus, this); 2257 } 2258 } 2259 } 2260 return false; 2261 } 2262 2263 /** 2264 * Scrolls to the next or previous item if possible. 2265 * 2266 * @param direction either {@link View#FOCUS_UP} or {@link View#FOCUS_DOWN} 2267 * 2268 * @return whether selection was moved 2269 */ 2270 boolean arrowScroll(int direction) { 2271 try { 2272 mInLayout = true; 2273 final boolean handled = arrowScrollImpl(direction); 2274 if (handled) { 2275 playSoundEffect(SoundEffectConstants.getContantForFocusDirection(direction)); 2276 } 2277 return handled; 2278 } finally { 2279 mInLayout = false; 2280 } 2281 } 2282 2283 /** 2284 * Handle an arrow scroll going up or down. Take into account whether items are selectable, 2285 * whether there are focusable items etc. 2286 * 2287 * @param direction Either {@link android.view.View#FOCUS_UP} or {@link android.view.View#FOCUS_DOWN}. 2288 * @return Whether any scrolling, selection or focus change occured. 2289 */ 2290 private boolean arrowScrollImpl(int direction) { 2291 if (getChildCount() <= 0) { 2292 return false; 2293 } 2294 2295 View selectedView = getSelectedView(); 2296 2297 int nextSelectedPosition = lookForSelectablePositionOnScreen(direction); 2298 int amountToScroll = amountToScroll(direction, nextSelectedPosition); 2299 2300 // if we are moving focus, we may OVERRIDE the default behavior 2301 final ArrowScrollFocusResult focusResult = mItemsCanFocus ? arrowScrollFocused(direction) : null; 2302 if (focusResult != null) { 2303 nextSelectedPosition = focusResult.getSelectedPosition(); 2304 amountToScroll = focusResult.getAmountToScroll(); 2305 } 2306 2307 boolean needToRedraw = focusResult != null; 2308 if (nextSelectedPosition != INVALID_POSITION) { 2309 handleNewSelectionChange(selectedView, direction, nextSelectedPosition, focusResult != null); 2310 setSelectedPositionInt(nextSelectedPosition); 2311 setNextSelectedPositionInt(nextSelectedPosition); 2312 selectedView = getSelectedView(); 2313 if (mItemsCanFocus && focusResult == null) { 2314 // there was no new view found to take focus, make sure we 2315 // don't leave focus with the old selection 2316 final View focused = getFocusedChild(); 2317 if (focused != null) { 2318 focused.clearFocus(); 2319 } 2320 } 2321 needToRedraw = true; 2322 checkSelectionChanged(); 2323 } 2324 2325 if (amountToScroll > 0) { 2326 scrollListItemsBy((direction == View.FOCUS_UP) ? amountToScroll : -amountToScroll); 2327 needToRedraw = true; 2328 } 2329 2330 // if we didn't find a new focusable, make sure any existing focused 2331 // item that was panned off screen gives up focus. 2332 if (mItemsCanFocus && (focusResult == null) 2333 && selectedView != null && selectedView.hasFocus()) { 2334 final View focused = selectedView.findFocus(); 2335 if (distanceToView(focused) > 0) { 2336 focused.clearFocus(); 2337 } 2338 } 2339 2340 // if the current selection is panned off, we need to remove the selection 2341 if (nextSelectedPosition == INVALID_POSITION && selectedView != null 2342 && !isViewAncestorOf(selectedView, this)) { 2343 selectedView = null; 2344 hideSelector(); 2345 2346 // but we don't want to set the ressurect position (that would make subsequent 2347 // unhandled key events bring back the item we just scrolled off!) 2348 mResurrectToPosition = INVALID_POSITION; 2349 } 2350 2351 if (needToRedraw) { 2352 if (selectedView != null) { 2353 positionSelector(selectedView); 2354 mSelectedTop = selectedView.getTop(); 2355 } 2356 if (!awakenScrollBars()) { 2357 invalidate(); 2358 } 2359 invokeOnItemScrollListener(); 2360 return true; 2361 } 2362 2363 return false; 2364 } 2365 2366 /** 2367 * When selection changes, it is possible that the previously selected or the 2368 * next selected item will change its size. If so, we need to offset some folks, 2369 * and re-layout the items as appropriate. 2370 * 2371 * @param selectedView The currently selected view (before changing selection). 2372 * should be <code>null</code> if there was no previous selection. 2373 * @param direction Either {@link android.view.View#FOCUS_UP} or 2374 * {@link android.view.View#FOCUS_DOWN}. 2375 * @param newSelectedPosition The position of the next selection. 2376 * @param newFocusAssigned whether new focus was assigned. This matters because 2377 * when something has focus, we don't want to show selection (ugh). 2378 */ 2379 private void handleNewSelectionChange(View selectedView, int direction, int newSelectedPosition, 2380 boolean newFocusAssigned) { 2381 if (newSelectedPosition == INVALID_POSITION) { 2382 throw new IllegalArgumentException("newSelectedPosition needs to be valid"); 2383 } 2384 2385 // whether or not we are moving down or up, we want to preserve the 2386 // top of whatever view is on top: 2387 // - moving down: the view that had selection 2388 // - moving up: the view that is getting selection 2389 View topView; 2390 View bottomView; 2391 int topViewIndex, bottomViewIndex; 2392 boolean topSelected = false; 2393 final int selectedIndex = mSelectedPosition - mFirstPosition; 2394 final int nextSelectedIndex = newSelectedPosition - mFirstPosition; 2395 if (direction == View.FOCUS_UP) { 2396 topViewIndex = nextSelectedIndex; 2397 bottomViewIndex = selectedIndex; 2398 topView = getChildAt(topViewIndex); 2399 bottomView = selectedView; 2400 topSelected = true; 2401 } else { 2402 topViewIndex = selectedIndex; 2403 bottomViewIndex = nextSelectedIndex; 2404 topView = selectedView; 2405 bottomView = getChildAt(bottomViewIndex); 2406 } 2407 2408 final int numChildren = getChildCount(); 2409 2410 // start with top view: is it changing size? 2411 if (topView != null) { 2412 topView.setSelected(!newFocusAssigned && topSelected); 2413 measureAndAdjustDown(topView, topViewIndex, numChildren); 2414 } 2415 2416 // is the bottom view changing size? 2417 if (bottomView != null) { 2418 bottomView.setSelected(!newFocusAssigned && !topSelected); 2419 measureAndAdjustDown(bottomView, bottomViewIndex, numChildren); 2420 } 2421 } 2422 2423 /** 2424 * Re-measure a child, and if its height changes, lay it out preserving its 2425 * top, and adjust the children below it appropriately. 2426 * @param child The child 2427 * @param childIndex The view group index of the child. 2428 * @param numChildren The number of children in the view group. 2429 */ 2430 private void measureAndAdjustDown(View child, int childIndex, int numChildren) { 2431 int oldHeight = child.getHeight(); 2432 measureItem(child); 2433 if (child.getMeasuredHeight() != oldHeight) { 2434 // lay out the view, preserving its top 2435 relayoutMeasuredItem(child); 2436 2437 // adjust views below appropriately 2438 final int heightDelta = child.getMeasuredHeight() - oldHeight; 2439 for (int i = childIndex + 1; i < numChildren; i++) { 2440 getChildAt(i).offsetTopAndBottom(heightDelta); 2441 } 2442 } 2443 } 2444 2445 /** 2446 * Measure a particular list child. 2447 * TODO: unify with setUpChild. 2448 * @param child The child. 2449 */ 2450 private void measureItem(View child) { 2451 ViewGroup.LayoutParams p = child.getLayoutParams(); 2452 if (p == null) { 2453 p = new ViewGroup.LayoutParams( 2454 ViewGroup.LayoutParams.MATCH_PARENT, 2455 ViewGroup.LayoutParams.WRAP_CONTENT); 2456 } 2457 2458 int childWidthSpec = ViewGroup.getChildMeasureSpec(mWidthMeasureSpec, 2459 mListPadding.left + mListPadding.right, p.width); 2460 int lpHeight = p.height; 2461 int childHeightSpec; 2462 if (lpHeight > 0) { 2463 childHeightSpec = MeasureSpec.makeMeasureSpec(lpHeight, MeasureSpec.EXACTLY); 2464 } else { 2465 childHeightSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED); 2466 } 2467 child.measure(childWidthSpec, childHeightSpec); 2468 } 2469 2470 /** 2471 * Layout a child that has been measured, preserving its top position. 2472 * TODO: unify with setUpChild. 2473 * @param child The child. 2474 */ 2475 private void relayoutMeasuredItem(View child) { 2476 final int w = child.getMeasuredWidth(); 2477 final int h = child.getMeasuredHeight(); 2478 final int childLeft = mListPadding.left; 2479 final int childRight = childLeft + w; 2480 final int childTop = child.getTop(); 2481 final int childBottom = childTop + h; 2482 child.layout(childLeft, childTop, childRight, childBottom); 2483 } 2484 2485 /** 2486 * @return The amount to preview next items when arrow srolling. 2487 */ 2488 private int getArrowScrollPreviewLength() { 2489 return Math.max(MIN_SCROLL_PREVIEW_PIXELS, getVerticalFadingEdgeLength()); 2490 } 2491 2492 /** 2493 * Determine how much we need to scroll in order to get the next selected view 2494 * visible, with a fading edge showing below as applicable. The amount is 2495 * capped at {@link #getMaxScrollAmount()} . 2496 * 2497 * @param direction either {@link android.view.View#FOCUS_UP} or 2498 * {@link android.view.View#FOCUS_DOWN}. 2499 * @param nextSelectedPosition The position of the next selection, or 2500 * {@link #INVALID_POSITION} if there is no next selectable position 2501 * @return The amount to scroll. Note: this is always positive! Direction 2502 * needs to be taken into account when actually scrolling. 2503 */ 2504 private int amountToScroll(int direction, int nextSelectedPosition) { 2505 final int listBottom = getHeight() - mListPadding.bottom; 2506 final int listTop = mListPadding.top; 2507 2508 final int numChildren = getChildCount(); 2509 2510 if (direction == View.FOCUS_DOWN) { 2511 int indexToMakeVisible = numChildren - 1; 2512 if (nextSelectedPosition != INVALID_POSITION) { 2513 indexToMakeVisible = nextSelectedPosition - mFirstPosition; 2514 } 2515 2516 final int positionToMakeVisible = mFirstPosition + indexToMakeVisible; 2517 final View viewToMakeVisible = getChildAt(indexToMakeVisible); 2518 2519 int goalBottom = listBottom; 2520 if (positionToMakeVisible < mItemCount - 1) { 2521 goalBottom -= getArrowScrollPreviewLength(); 2522 } 2523 2524 if (viewToMakeVisible.getBottom() <= goalBottom) { 2525 // item is fully visible. 2526 return 0; 2527 } 2528 2529 if (nextSelectedPosition != INVALID_POSITION 2530 && (goalBottom - viewToMakeVisible.getTop()) >= getMaxScrollAmount()) { 2531 // item already has enough of it visible, changing selection is good enough 2532 return 0; 2533 } 2534 2535 int amountToScroll = (viewToMakeVisible.getBottom() - goalBottom); 2536 2537 if ((mFirstPosition + numChildren) == mItemCount) { 2538 // last is last in list -> make sure we don't scroll past it 2539 final int max = getChildAt(numChildren - 1).getBottom() - listBottom; 2540 amountToScroll = Math.min(amountToScroll, max); 2541 } 2542 2543 return Math.min(amountToScroll, getMaxScrollAmount()); 2544 } else { 2545 int indexToMakeVisible = 0; 2546 if (nextSelectedPosition != INVALID_POSITION) { 2547 indexToMakeVisible = nextSelectedPosition - mFirstPosition; 2548 } 2549 final int positionToMakeVisible = mFirstPosition + indexToMakeVisible; 2550 final View viewToMakeVisible = getChildAt(indexToMakeVisible); 2551 int goalTop = listTop; 2552 if (positionToMakeVisible > 0) { 2553 goalTop += getArrowScrollPreviewLength(); 2554 } 2555 if (viewToMakeVisible.getTop() >= goalTop) { 2556 // item is fully visible. 2557 return 0; 2558 } 2559 2560 if (nextSelectedPosition != INVALID_POSITION && 2561 (viewToMakeVisible.getBottom() - goalTop) >= getMaxScrollAmount()) { 2562 // item already has enough of it visible, changing selection is good enough 2563 return 0; 2564 } 2565 2566 int amountToScroll = (goalTop - viewToMakeVisible.getTop()); 2567 if (mFirstPosition == 0) { 2568 // first is first in list -> make sure we don't scroll past it 2569 final int max = listTop - getChildAt(0).getTop(); 2570 amountToScroll = Math.min(amountToScroll, max); 2571 } 2572 return Math.min(amountToScroll, getMaxScrollAmount()); 2573 } 2574 } 2575 2576 /** 2577 * Holds results of focus aware arrow scrolling. 2578 */ 2579 static private class ArrowScrollFocusResult { 2580 private int mSelectedPosition; 2581 private int mAmountToScroll; 2582 2583 /** 2584 * How {@link android.widget.ListView#arrowScrollFocused} returns its values. 2585 */ 2586 void populate(int selectedPosition, int amountToScroll) { 2587 mSelectedPosition = selectedPosition; 2588 mAmountToScroll = amountToScroll; 2589 } 2590 2591 public int getSelectedPosition() { 2592 return mSelectedPosition; 2593 } 2594 2595 public int getAmountToScroll() { 2596 return mAmountToScroll; 2597 } 2598 } 2599 2600 /** 2601 * @param direction either {@link android.view.View#FOCUS_UP} or 2602 * {@link android.view.View#FOCUS_DOWN}. 2603 * @return The position of the next selectable position of the views that 2604 * are currently visible, taking into account the fact that there might 2605 * be no selection. Returns {@link #INVALID_POSITION} if there is no 2606 * selectable view on screen in the given direction. 2607 */ 2608 private int lookForSelectablePositionOnScreen(int direction) { 2609 final int firstPosition = mFirstPosition; 2610 if (direction == View.FOCUS_DOWN) { 2611 int startPos = (mSelectedPosition != INVALID_POSITION) ? 2612 mSelectedPosition + 1 : 2613 firstPosition; 2614 if (startPos >= mAdapter.getCount()) { 2615 return INVALID_POSITION; 2616 } 2617 if (startPos < firstPosition) { 2618 startPos = firstPosition; 2619 } 2620 2621 final int lastVisiblePos = getLastVisiblePosition(); 2622 final ListAdapter adapter = getAdapter(); 2623 for (int pos = startPos; pos <= lastVisiblePos; pos++) { 2624 if (adapter.isEnabled(pos) 2625 && getChildAt(pos - firstPosition).getVisibility() == View.VISIBLE) { 2626 return pos; 2627 } 2628 } 2629 } else { 2630 int last = firstPosition + getChildCount() - 1; 2631 int startPos = (mSelectedPosition != INVALID_POSITION) ? 2632 mSelectedPosition - 1 : 2633 firstPosition + getChildCount() - 1; 2634 if (startPos < 0) { 2635 return INVALID_POSITION; 2636 } 2637 if (startPos > last) { 2638 startPos = last; 2639 } 2640 2641 final ListAdapter adapter = getAdapter(); 2642 for (int pos = startPos; pos >= firstPosition; pos--) { 2643 if (adapter.isEnabled(pos) 2644 && getChildAt(pos - firstPosition).getVisibility() == View.VISIBLE) { 2645 return pos; 2646 } 2647 } 2648 } 2649 return INVALID_POSITION; 2650 } 2651 2652 /** 2653 * Do an arrow scroll based on focus searching. If a new view is 2654 * given focus, return the selection delta and amount to scroll via 2655 * an {@link ArrowScrollFocusResult}, otherwise, return null. 2656 * 2657 * @param direction either {@link android.view.View#FOCUS_UP} or 2658 * {@link android.view.View#FOCUS_DOWN}. 2659 * @return The result if focus has changed, or <code>null</code>. 2660 */ 2661 private ArrowScrollFocusResult arrowScrollFocused(final int direction) { 2662 final View selectedView = getSelectedView(); 2663 View newFocus; 2664 if (selectedView != null && selectedView.hasFocus()) { 2665 View oldFocus = selectedView.findFocus(); 2666 newFocus = FocusFinder.getInstance().findNextFocus(this, oldFocus, direction); 2667 } else { 2668 if (direction == View.FOCUS_DOWN) { 2669 final boolean topFadingEdgeShowing = (mFirstPosition > 0); 2670 final int listTop = mListPadding.top + 2671 (topFadingEdgeShowing ? getArrowScrollPreviewLength() : 0); 2672 final int ySearchPoint = 2673 (selectedView != null && selectedView.getTop() > listTop) ? 2674 selectedView.getTop() : 2675 listTop; 2676 mTempRect.set(0, ySearchPoint, 0, ySearchPoint); 2677 } else { 2678 final boolean bottomFadingEdgeShowing = 2679 (mFirstPosition + getChildCount() - 1) < mItemCount; 2680 final int listBottom = getHeight() - mListPadding.bottom - 2681 (bottomFadingEdgeShowing ? getArrowScrollPreviewLength() : 0); 2682 final int ySearchPoint = 2683 (selectedView != null && selectedView.getBottom() < listBottom) ? 2684 selectedView.getBottom() : 2685 listBottom; 2686 mTempRect.set(0, ySearchPoint, 0, ySearchPoint); 2687 } 2688 newFocus = FocusFinder.getInstance().findNextFocusFromRect(this, mTempRect, direction); 2689 } 2690 2691 if (newFocus != null) { 2692 final int positionOfNewFocus = positionOfNewFocus(newFocus); 2693 2694 // if the focus change is in a different new position, make sure 2695 // we aren't jumping over another selectable position 2696 if (mSelectedPosition != INVALID_POSITION && positionOfNewFocus != mSelectedPosition) { 2697 final int selectablePosition = lookForSelectablePositionOnScreen(direction); 2698 if (selectablePosition != INVALID_POSITION && 2699 ((direction == View.FOCUS_DOWN && selectablePosition < positionOfNewFocus) || 2700 (direction == View.FOCUS_UP && selectablePosition > positionOfNewFocus))) { 2701 return null; 2702 } 2703 } 2704 2705 int focusScroll = amountToScrollToNewFocus(direction, newFocus, positionOfNewFocus); 2706 2707 final int maxScrollAmount = getMaxScrollAmount(); 2708 if (focusScroll < maxScrollAmount) { 2709 // not moving too far, safe to give next view focus 2710 newFocus.requestFocus(direction); 2711 mArrowScrollFocusResult.populate(positionOfNewFocus, focusScroll); 2712 return mArrowScrollFocusResult; 2713 } else if (distanceToView(newFocus) < maxScrollAmount){ 2714 // Case to consider: 2715 // too far to get entire next focusable on screen, but by going 2716 // max scroll amount, we are getting it at least partially in view, 2717 // so give it focus and scroll the max ammount. 2718 newFocus.requestFocus(direction); 2719 mArrowScrollFocusResult.populate(positionOfNewFocus, maxScrollAmount); 2720 return mArrowScrollFocusResult; 2721 } 2722 } 2723 return null; 2724 } 2725 2726 /** 2727 * @param newFocus The view that would have focus. 2728 * @return the position that contains newFocus 2729 */ 2730 private int positionOfNewFocus(View newFocus) { 2731 final int numChildren = getChildCount(); 2732 for (int i = 0; i < numChildren; i++) { 2733 final View child = getChildAt(i); 2734 if (isViewAncestorOf(newFocus, child)) { 2735 return mFirstPosition + i; 2736 } 2737 } 2738 throw new IllegalArgumentException("newFocus is not a child of any of the" 2739 + " children of the list!"); 2740 } 2741 2742 /** 2743 * Return true if child is an ancestor of parent, (or equal to the parent). 2744 */ 2745 private boolean isViewAncestorOf(View child, View parent) { 2746 if (child == parent) { 2747 return true; 2748 } 2749 2750 final ViewParent theParent = child.getParent(); 2751 return (theParent instanceof ViewGroup) && isViewAncestorOf((View) theParent, parent); 2752 } 2753 2754 /** 2755 * Determine how much we need to scroll in order to get newFocus in view. 2756 * @param direction either {@link android.view.View#FOCUS_UP} or 2757 * {@link android.view.View#FOCUS_DOWN}. 2758 * @param newFocus The view that would take focus. 2759 * @param positionOfNewFocus The position of the list item containing newFocus 2760 * @return The amount to scroll. Note: this is always positive! Direction 2761 * needs to be taken into account when actually scrolling. 2762 */ 2763 private int amountToScrollToNewFocus(int direction, View newFocus, int positionOfNewFocus) { 2764 int amountToScroll = 0; 2765 newFocus.getDrawingRect(mTempRect); 2766 offsetDescendantRectToMyCoords(newFocus, mTempRect); 2767 if (direction == View.FOCUS_UP) { 2768 if (mTempRect.top < mListPadding.top) { 2769 amountToScroll = mListPadding.top - mTempRect.top; 2770 if (positionOfNewFocus > 0) { 2771 amountToScroll += getArrowScrollPreviewLength(); 2772 } 2773 } 2774 } else { 2775 final int listBottom = getHeight() - mListPadding.bottom; 2776 if (mTempRect.bottom > listBottom) { 2777 amountToScroll = mTempRect.bottom - listBottom; 2778 if (positionOfNewFocus < mItemCount - 1) { 2779 amountToScroll += getArrowScrollPreviewLength(); 2780 } 2781 } 2782 } 2783 return amountToScroll; 2784 } 2785 2786 /** 2787 * Determine the distance to the nearest edge of a view in a particular 2788 * direction. 2789 * 2790 * @param descendant A descendant of this list. 2791 * @return The distance, or 0 if the nearest edge is already on screen. 2792 */ 2793 private int distanceToView(View descendant) { 2794 int distance = 0; 2795 descendant.getDrawingRect(mTempRect); 2796 offsetDescendantRectToMyCoords(descendant, mTempRect); 2797 final int listBottom = mBottom - mTop - mListPadding.bottom; 2798 if (mTempRect.bottom < mListPadding.top) { 2799 distance = mListPadding.top - mTempRect.bottom; 2800 } else if (mTempRect.top > listBottom) { 2801 distance = mTempRect.top - listBottom; 2802 } 2803 return distance; 2804 } 2805 2806 2807 /** 2808 * Scroll the children by amount, adding a view at the end and removing 2809 * views that fall off as necessary. 2810 * 2811 * @param amount The amount (positive or negative) to scroll. 2812 */ 2813 private void scrollListItemsBy(int amount) { 2814 offsetChildrenTopAndBottom(amount); 2815 2816 final int listBottom = getHeight() - mListPadding.bottom; 2817 final int listTop = mListPadding.top; 2818 final AbsListView.RecycleBin recycleBin = mRecycler; 2819 2820 if (amount < 0) { 2821 // shifted items up 2822 2823 // may need to pan views into the bottom space 2824 int numChildren = getChildCount(); 2825 View last = getChildAt(numChildren - 1); 2826 while (last.getBottom() < listBottom) { 2827 final int lastVisiblePosition = mFirstPosition + numChildren - 1; 2828 if (lastVisiblePosition < mItemCount - 1) { 2829 last = addViewBelow(last, lastVisiblePosition); 2830 numChildren++; 2831 } else { 2832 break; 2833 } 2834 } 2835 2836 // may have brought in the last child of the list that is skinnier 2837 // than the fading edge, thereby leaving space at the end. need 2838 // to shift back 2839 if (last.getBottom() < listBottom) { 2840 offsetChildrenTopAndBottom(listBottom - last.getBottom()); 2841 } 2842 2843 // top views may be panned off screen 2844 View first = getChildAt(0); 2845 while (first.getBottom() < listTop) { 2846 AbsListView.LayoutParams layoutParams = (LayoutParams) first.getLayoutParams(); 2847 if (recycleBin.shouldRecycleViewType(layoutParams.viewType)) { 2848 detachViewFromParent(first); 2849 recycleBin.addScrapView(first); 2850 } else { 2851 removeViewInLayout(first); 2852 } 2853 first = getChildAt(0); 2854 mFirstPosition++; 2855 } 2856 } else { 2857 // shifted items down 2858 View first = getChildAt(0); 2859 2860 // may need to pan views into top 2861 while ((first.getTop() > listTop) && (mFirstPosition > 0)) { 2862 first = addViewAbove(first, mFirstPosition); 2863 mFirstPosition--; 2864 } 2865 2866 // may have brought the very first child of the list in too far and 2867 // need to shift it back 2868 if (first.getTop() > listTop) { 2869 offsetChildrenTopAndBottom(listTop - first.getTop()); 2870 } 2871 2872 int lastIndex = getChildCount() - 1; 2873 View last = getChildAt(lastIndex); 2874 2875 // bottom view may be panned off screen 2876 while (last.getTop() > listBottom) { 2877 AbsListView.LayoutParams layoutParams = (LayoutParams) last.getLayoutParams(); 2878 if (recycleBin.shouldRecycleViewType(layoutParams.viewType)) { 2879 detachViewFromParent(last); 2880 recycleBin.addScrapView(last); 2881 } else { 2882 removeViewInLayout(last); 2883 } 2884 last = getChildAt(--lastIndex); 2885 } 2886 } 2887 } 2888 2889 private View addViewAbove(View theView, int position) { 2890 int abovePosition = position - 1; 2891 View view = obtainView(abovePosition, mIsScrap); 2892 int edgeOfNewChild = theView.getTop() - mDividerHeight; 2893 setupChild(view, abovePosition, edgeOfNewChild, false, mListPadding.left, 2894 false, mIsScrap[0]); 2895 return view; 2896 } 2897 2898 private View addViewBelow(View theView, int position) { 2899 int belowPosition = position + 1; 2900 View view = obtainView(belowPosition, mIsScrap); 2901 int edgeOfNewChild = theView.getBottom() + mDividerHeight; 2902 setupChild(view, belowPosition, edgeOfNewChild, true, mListPadding.left, 2903 false, mIsScrap[0]); 2904 return view; 2905 } 2906 2907 /** 2908 * Indicates that the views created by the ListAdapter can contain focusable 2909 * items. 2910 * 2911 * @param itemsCanFocus true if items can get focus, false otherwise 2912 */ 2913 public void setItemsCanFocus(boolean itemsCanFocus) { 2914 mItemsCanFocus = itemsCanFocus; 2915 if (!itemsCanFocus) { 2916 setDescendantFocusability(ViewGroup.FOCUS_BLOCK_DESCENDANTS); 2917 } 2918 } 2919 2920 /** 2921 * @return Whether the views created by the ListAdapter can contain focusable 2922 * items. 2923 */ 2924 public boolean getItemsCanFocus() { 2925 return mItemsCanFocus; 2926 } 2927 2928 /** 2929 * @hide Pending API council approval. 2930 */ 2931 @Override 2932 public boolean isOpaque() { 2933 return (mCachingStarted && mIsCacheColorOpaque && mDividerIsOpaque && 2934 hasOpaqueScrollbars()) || super.isOpaque(); 2935 } 2936 2937 @Override 2938 public void setCacheColorHint(int color) { 2939 final boolean opaque = (color >>> 24) == 0xFF; 2940 mIsCacheColorOpaque = opaque; 2941 if (opaque) { 2942 if (mDividerPaint == null) { 2943 mDividerPaint = new Paint(); 2944 } 2945 mDividerPaint.setColor(color); 2946 } 2947 super.setCacheColorHint(color); 2948 } 2949 2950 void drawOverscrollHeader(Canvas canvas, Drawable drawable, Rect bounds) { 2951 final int height = drawable.getMinimumHeight(); 2952 2953 canvas.save(); 2954 canvas.clipRect(bounds); 2955 2956 final int span = bounds.bottom - bounds.top; 2957 if (span < height) { 2958 bounds.top = bounds.bottom - height; 2959 } 2960 2961 drawable.setBounds(bounds); 2962 drawable.draw(canvas); 2963 2964 canvas.restore(); 2965 } 2966 2967 void drawOverscrollFooter(Canvas canvas, Drawable drawable, Rect bounds) { 2968 final int height = drawable.getMinimumHeight(); 2969 2970 canvas.save(); 2971 canvas.clipRect(bounds); 2972 2973 final int span = bounds.bottom - bounds.top; 2974 if (span < height) { 2975 bounds.bottom = bounds.top + height; 2976 } 2977 2978 drawable.setBounds(bounds); 2979 drawable.draw(canvas); 2980 2981 canvas.restore(); 2982 } 2983 2984 @Override 2985 protected void dispatchDraw(Canvas canvas) { 2986 // Draw the dividers 2987 final int dividerHeight = mDividerHeight; 2988 final Drawable overscrollHeader = mOverscrollHeader; 2989 final Drawable overscrollFooter = mOverscrollFooter; 2990 final boolean drawOverscrollHeader = overscrollHeader != null; 2991 final boolean drawOverscrollFooter = overscrollFooter != null; 2992 final boolean drawDividers = dividerHeight > 0 && mDivider != null; 2993 2994 if (drawDividers || drawOverscrollHeader || drawOverscrollFooter) { 2995 // Only modify the top and bottom in the loop, we set the left and right here 2996 final Rect bounds = mTempRect; 2997 bounds.left = mPaddingLeft; 2998 bounds.right = mRight - mLeft - mPaddingRight; 2999 3000 final int count = getChildCount(); 3001 final int headerCount = mHeaderViewInfos.size(); 3002 final int itemCount = mItemCount; 3003 final int footerLimit = itemCount - mFooterViewInfos.size() - 1; 3004 final boolean headerDividers = mHeaderDividersEnabled; 3005 final boolean footerDividers = mFooterDividersEnabled; 3006 final int first = mFirstPosition; 3007 final boolean areAllItemsSelectable = mAreAllItemsSelectable; 3008 final ListAdapter adapter = mAdapter; 3009 // If the list is opaque *and* the background is not, we want to 3010 // fill a rect where the dividers would be for non-selectable items 3011 // If the list is opaque and the background is also opaque, we don't 3012 // need to draw anything since the background will do it for us 3013 final boolean fillForMissingDividers = drawDividers && isOpaque() && !super.isOpaque(); 3014 3015 if (fillForMissingDividers && mDividerPaint == null && mIsCacheColorOpaque) { 3016 mDividerPaint = new Paint(); 3017 mDividerPaint.setColor(getCacheColorHint()); 3018 } 3019 final Paint paint = mDividerPaint; 3020 3021 final int listBottom = mBottom - mTop - mListPadding.bottom + mScrollY; 3022 if (!mStackFromBottom) { 3023 int bottom = 0; 3024 3025 // Draw top divider or header for overscroll 3026 final int scrollY = mScrollY; 3027 if (count > 0 && scrollY < 0) { 3028 if (drawOverscrollHeader) { 3029 bounds.bottom = 0; 3030 bounds.top = scrollY; 3031 drawOverscrollHeader(canvas, overscrollHeader, bounds); 3032 } else if (drawDividers) { 3033 bounds.bottom = 0; 3034 bounds.top = -dividerHeight; 3035 drawDivider(canvas, bounds, -1); 3036 } 3037 } 3038 3039 for (int i = 0; i < count; i++) { 3040 if ((headerDividers || first + i >= headerCount) && 3041 (footerDividers || first + i < footerLimit)) { 3042 View child = getChildAt(i); 3043 bottom = child.getBottom(); 3044 // Don't draw dividers next to items that are not enabled 3045 if (drawDividers && 3046 (bottom < listBottom && !(drawOverscrollFooter && i == count - 1))) { 3047 if ((areAllItemsSelectable || 3048 (adapter.isEnabled(first + i) && (i == count - 1 || 3049 adapter.isEnabled(first + i + 1))))) { 3050 bounds.top = bottom; 3051 bounds.bottom = bottom + dividerHeight; 3052 drawDivider(canvas, bounds, i); 3053 } else if (fillForMissingDividers) { 3054 bounds.top = bottom; 3055 bounds.bottom = bottom + dividerHeight; 3056 canvas.drawRect(bounds, paint); 3057 } 3058 } 3059 } 3060 } 3061 3062 final int overFooterBottom = mBottom + mScrollY; 3063 if (drawOverscrollFooter && first + count == itemCount && 3064 overFooterBottom > bottom) { 3065 bounds.top = bottom; 3066 bounds.bottom = overFooterBottom; 3067 drawOverscrollFooter(canvas, overscrollFooter, bounds); 3068 } 3069 } else { 3070 int top; 3071 int listTop = mListPadding.top; 3072 3073 final int scrollY = mScrollY; 3074 3075 if (count > 0 && drawOverscrollHeader) { 3076 bounds.top = scrollY; 3077 bounds.bottom = getChildAt(0).getTop(); 3078 drawOverscrollHeader(canvas, overscrollHeader, bounds); 3079 } 3080 3081 final int start = drawOverscrollHeader ? 1 : 0; 3082 for (int i = start; i < count; i++) { 3083 if ((headerDividers || first + i >= headerCount) && 3084 (footerDividers || first + i < footerLimit)) { 3085 View child = getChildAt(i); 3086 top = child.getTop(); 3087 // Don't draw dividers next to items that are not enabled 3088 if (drawDividers && top > listTop) { 3089 if ((areAllItemsSelectable || 3090 (adapter.isEnabled(first + i) && (i == count - 1 || 3091 adapter.isEnabled(first + i + 1))))) { 3092 bounds.top = top - dividerHeight; 3093 bounds.bottom = top; 3094 // Give the method the child ABOVE the divider, so we 3095 // subtract one from our child 3096 // position. Give -1 when there is no child above the 3097 // divider. 3098 drawDivider(canvas, bounds, i - 1); 3099 } else if (fillForMissingDividers) { 3100 bounds.top = top - dividerHeight; 3101 bounds.bottom = top; 3102 canvas.drawRect(bounds, paint); 3103 } 3104 } 3105 } 3106 } 3107 3108 if (count > 0 && scrollY > 0) { 3109 if (drawOverscrollFooter) { 3110 final int absListBottom = mBottom; 3111 bounds.top = absListBottom; 3112 bounds.bottom = absListBottom + scrollY; 3113 drawOverscrollFooter(canvas, overscrollFooter, bounds); 3114 } else if (drawDividers) { 3115 bounds.top = listBottom; 3116 bounds.bottom = listBottom + dividerHeight; 3117 drawDivider(canvas, bounds, -1); 3118 } 3119 } 3120 } 3121 } 3122 3123 // Draw the indicators (these should be drawn above the dividers) and children 3124 super.dispatchDraw(canvas); 3125 } 3126 3127 /** 3128 * Draws a divider for the given child in the given bounds. 3129 * 3130 * @param canvas The canvas to draw to. 3131 * @param bounds The bounds of the divider. 3132 * @param childIndex The index of child (of the View) above the divider. 3133 * This will be -1 if there is no child above the divider to be 3134 * drawn. 3135 */ 3136 void drawDivider(Canvas canvas, Rect bounds, int childIndex) { 3137 // This widget draws the same divider for all children 3138 final Drawable divider = mDivider; 3139 final boolean clipDivider = mClipDivider; 3140 3141 if (!clipDivider) { 3142 divider.setBounds(bounds); 3143 } else { 3144 canvas.save(); 3145 canvas.clipRect(bounds); 3146 } 3147 3148 divider.draw(canvas); 3149 3150 if (clipDivider) { 3151 canvas.restore(); 3152 } 3153 } 3154 3155 /** 3156 * Returns the drawable that will be drawn between each item in the list. 3157 * 3158 * @return the current drawable drawn between list elements 3159 */ 3160 public Drawable getDivider() { 3161 return mDivider; 3162 } 3163 3164 /** 3165 * Sets the drawable that will be drawn between each item in the list. If the drawable does 3166 * not have an intrinsic height, you should also call {@link #setDividerHeight(int)} 3167 * 3168 * @param divider The drawable to use. 3169 */ 3170 public void setDivider(Drawable divider) { 3171 if (divider != null) { 3172 mDividerHeight = divider.getIntrinsicHeight(); 3173 mClipDivider = divider instanceof ColorDrawable; 3174 } else { 3175 mDividerHeight = 0; 3176 mClipDivider = false; 3177 } 3178 mDivider = divider; 3179 mDividerIsOpaque = divider == null || divider.getOpacity() == PixelFormat.OPAQUE; 3180 requestLayoutIfNecessary(); 3181 } 3182 3183 /** 3184 * @return Returns the height of the divider that will be drawn between each item in the list. 3185 */ 3186 public int getDividerHeight() { 3187 return mDividerHeight; 3188 } 3189 3190 /** 3191 * Sets the height of the divider that will be drawn between each item in the list. Calling 3192 * this will override the intrinsic height as set by {@link #setDivider(Drawable)} 3193 * 3194 * @param height The new height of the divider in pixels. 3195 */ 3196 public void setDividerHeight(int height) { 3197 mDividerHeight = height; 3198 requestLayoutIfNecessary(); 3199 } 3200 3201 /** 3202 * Enables or disables the drawing of the divider for header views. 3203 * 3204 * @param headerDividersEnabled True to draw the headers, false otherwise. 3205 * 3206 * @see #setFooterDividersEnabled(boolean) 3207 * @see #addHeaderView(android.view.View) 3208 */ 3209 public void setHeaderDividersEnabled(boolean headerDividersEnabled) { 3210 mHeaderDividersEnabled = headerDividersEnabled; 3211 invalidate(); 3212 } 3213 3214 /** 3215 * Enables or disables the drawing of the divider for footer views. 3216 * 3217 * @param footerDividersEnabled True to draw the footers, false otherwise. 3218 * 3219 * @see #setHeaderDividersEnabled(boolean) 3220 * @see #addFooterView(android.view.View) 3221 */ 3222 public void setFooterDividersEnabled(boolean footerDividersEnabled) { 3223 mFooterDividersEnabled = footerDividersEnabled; 3224 invalidate(); 3225 } 3226 3227 /** 3228 * Sets the drawable that will be drawn above all other list content. 3229 * This area can become visible when the user overscrolls the list. 3230 * 3231 * @param header The drawable to use 3232 */ 3233 public void setOverscrollHeader(Drawable header) { 3234 mOverscrollHeader = header; 3235 if (mScrollY < 0) { 3236 invalidate(); 3237 } 3238 } 3239 3240 /** 3241 * @return The drawable that will be drawn above all other list content 3242 */ 3243 public Drawable getOverscrollHeader() { 3244 return mOverscrollHeader; 3245 } 3246 3247 /** 3248 * Sets the drawable that will be drawn below all other list content. 3249 * This area can become visible when the user overscrolls the list, 3250 * or when the list's content does not fully fill the container area. 3251 * 3252 * @param footer The drawable to use 3253 */ 3254 public void setOverscrollFooter(Drawable footer) { 3255 mOverscrollFooter = footer; 3256 invalidate(); 3257 } 3258 3259 /** 3260 * @return The drawable that will be drawn below all other list content 3261 */ 3262 public Drawable getOverscrollFooter() { 3263 return mOverscrollFooter; 3264 } 3265 3266 @Override 3267 protected void onFocusChanged(boolean gainFocus, int direction, Rect previouslyFocusedRect) { 3268 super.onFocusChanged(gainFocus, direction, previouslyFocusedRect); 3269 3270 int closetChildIndex = -1; 3271 if (gainFocus && previouslyFocusedRect != null) { 3272 previouslyFocusedRect.offset(mScrollX, mScrollY); 3273 3274 final ListAdapter adapter = mAdapter; 3275 // Don't cache the result of getChildCount or mFirstPosition here, 3276 // it could change in layoutChildren. 3277 if (adapter.getCount() < getChildCount() + mFirstPosition) { 3278 mLayoutMode = LAYOUT_NORMAL; 3279 layoutChildren(); 3280 } 3281 3282 // figure out which item should be selected based on previously 3283 // focused rect 3284 Rect otherRect = mTempRect; 3285 int minDistance = Integer.MAX_VALUE; 3286 final int childCount = getChildCount(); 3287 final int firstPosition = mFirstPosition; 3288 3289 for (int i = 0; i < childCount; i++) { 3290 // only consider selectable views 3291 if (!adapter.isEnabled(firstPosition + i)) { 3292 continue; 3293 } 3294 3295 View other = getChildAt(i); 3296 other.getDrawingRect(otherRect); 3297 offsetDescendantRectToMyCoords(other, otherRect); 3298 int distance = getDistance(previouslyFocusedRect, otherRect, direction); 3299 3300 if (distance < minDistance) { 3301 minDistance = distance; 3302 closetChildIndex = i; 3303 } 3304 } 3305 } 3306 3307 if (closetChildIndex >= 0) { 3308 setSelection(closetChildIndex + mFirstPosition); 3309 } else { 3310 requestLayout(); 3311 } 3312 } 3313 3314 3315 /* 3316 * (non-Javadoc) 3317 * 3318 * Children specified in XML are assumed to be header views. After we have 3319 * parsed them move them out of the children list and into mHeaderViews. 3320 */ 3321 @Override 3322 protected void onFinishInflate() { 3323 super.onFinishInflate(); 3324 3325 int count = getChildCount(); 3326 if (count > 0) { 3327 for (int i = 0; i < count; ++i) { 3328 addHeaderView(getChildAt(i)); 3329 } 3330 removeAllViews(); 3331 } 3332 } 3333 3334 /* (non-Javadoc) 3335 * @see android.view.View#findViewById(int) 3336 * First look in our children, then in any header and footer views that may be scrolled off. 3337 */ 3338 @Override 3339 protected View findViewTraversal(int id) { 3340 View v; 3341 v = super.findViewTraversal(id); 3342 if (v == null) { 3343 v = findViewInHeadersOrFooters(mHeaderViewInfos, id); 3344 if (v != null) { 3345 return v; 3346 } 3347 v = findViewInHeadersOrFooters(mFooterViewInfos, id); 3348 if (v != null) { 3349 return v; 3350 } 3351 } 3352 return v; 3353 } 3354 3355 /* (non-Javadoc) 3356 * 3357 * Look in the passed in list of headers or footers for the view. 3358 */ 3359 View findViewInHeadersOrFooters(ArrayList<FixedViewInfo> where, int id) { 3360 if (where != null) { 3361 int len = where.size(); 3362 View v; 3363 3364 for (int i = 0; i < len; i++) { 3365 v = where.get(i).view; 3366 3367 if (!v.isRootNamespace()) { 3368 v = v.findViewById(id); 3369 3370 if (v != null) { 3371 return v; 3372 } 3373 } 3374 } 3375 } 3376 return null; 3377 } 3378 3379 /* (non-Javadoc) 3380 * @see android.view.View#findViewWithTag(String) 3381 * First look in our children, then in any header and footer views that may be scrolled off. 3382 */ 3383 @Override 3384 protected View findViewWithTagTraversal(Object tag) { 3385 View v; 3386 v = super.findViewWithTagTraversal(tag); 3387 if (v == null) { 3388 v = findViewTagInHeadersOrFooters(mHeaderViewInfos, tag); 3389 if (v != null) { 3390 return v; 3391 } 3392 3393 v = findViewTagInHeadersOrFooters(mFooterViewInfos, tag); 3394 if (v != null) { 3395 return v; 3396 } 3397 } 3398 return v; 3399 } 3400 3401 /* (non-Javadoc) 3402 * 3403 * Look in the passed in list of headers or footers for the view with the tag. 3404 */ 3405 View findViewTagInHeadersOrFooters(ArrayList<FixedViewInfo> where, Object tag) { 3406 if (where != null) { 3407 int len = where.size(); 3408 View v; 3409 3410 for (int i = 0; i < len; i++) { 3411 v = where.get(i).view; 3412 3413 if (!v.isRootNamespace()) { 3414 v = v.findViewWithTag(tag); 3415 3416 if (v != null) { 3417 return v; 3418 } 3419 } 3420 } 3421 } 3422 return null; 3423 } 3424 3425 @Override 3426 public boolean onTouchEvent(MotionEvent ev) { 3427 if (mItemsCanFocus && ev.getAction() == MotionEvent.ACTION_DOWN && ev.getEdgeFlags() != 0) { 3428 // Don't handle edge touches immediately -- they may actually belong to one of our 3429 // descendants. 3430 return false; 3431 } 3432 return super.onTouchEvent(ev); 3433 } 3434 3435 /** 3436 * @see #setChoiceMode(int) 3437 * 3438 * @return The current choice mode 3439 */ 3440 public int getChoiceMode() { 3441 return mChoiceMode; 3442 } 3443 3444 /** 3445 * Defines the choice behavior for the List. By default, Lists do not have any choice behavior 3446 * ({@link #CHOICE_MODE_NONE}). By setting the choiceMode to {@link #CHOICE_MODE_SINGLE}, the 3447 * List allows up to one item to be in a chosen state. By setting the choiceMode to 3448 * {@link #CHOICE_MODE_MULTIPLE}, the list allows any number of items to be chosen. 3449 * 3450 * @param choiceMode One of {@link #CHOICE_MODE_NONE}, {@link #CHOICE_MODE_SINGLE}, or 3451 * {@link #CHOICE_MODE_MULTIPLE} 3452 */ 3453 public void setChoiceMode(int choiceMode) { 3454 mChoiceMode = choiceMode; 3455 if (mChoiceMode != CHOICE_MODE_NONE) { 3456 if (mCheckStates == null) { 3457 mCheckStates = new SparseBooleanArray(); 3458 } 3459 if (mCheckedIdStates == null && mAdapter != null && mAdapter.hasStableIds()) { 3460 mCheckedIdStates = new LongSparseArray<Boolean>(); 3461 } 3462 } 3463 } 3464 3465 @Override 3466 public boolean performItemClick(View view, int position, long id) { 3467 boolean handled = false; 3468 3469 if (mChoiceMode != CHOICE_MODE_NONE) { 3470 handled = true; 3471 3472 if (mChoiceMode == CHOICE_MODE_MULTIPLE) { 3473 boolean newValue = !mCheckStates.get(position, false); 3474 mCheckStates.put(position, newValue); 3475 if (mCheckedIdStates != null && mAdapter.hasStableIds()) { 3476 if (newValue) { 3477 mCheckedIdStates.put(mAdapter.getItemId(position), Boolean.TRUE); 3478 } else { 3479 mCheckedIdStates.delete(mAdapter.getItemId(position)); 3480 } 3481 } 3482 } else { 3483 boolean newValue = !mCheckStates.get(position, false); 3484 if (newValue) { 3485 mCheckStates.clear(); 3486 mCheckStates.put(position, true); 3487 if (mCheckedIdStates != null && mAdapter.hasStableIds()) { 3488 mCheckedIdStates.clear(); 3489 mCheckedIdStates.put(mAdapter.getItemId(position), Boolean.TRUE); 3490 } 3491 } 3492 } 3493 3494 mDataChanged = true; 3495 rememberSyncState(); 3496 requestLayout(); 3497 } 3498 3499 handled |= super.performItemClick(view, position, id); 3500 3501 return handled; 3502 } 3503 3504 /** 3505 * Sets the checked state of the specified position. The is only valid if 3506 * the choice mode has been set to {@link #CHOICE_MODE_SINGLE} or 3507 * {@link #CHOICE_MODE_MULTIPLE}. 3508 * 3509 * @param position The item whose checked state is to be checked 3510 * @param value The new checked state for the item 3511 */ 3512 public void setItemChecked(int position, boolean value) { 3513 if (mChoiceMode == CHOICE_MODE_NONE) { 3514 return; 3515 } 3516 3517 if (mChoiceMode == CHOICE_MODE_MULTIPLE) { 3518 mCheckStates.put(position, value); 3519 if (mCheckedIdStates != null && mAdapter.hasStableIds()) { 3520 if (value) { 3521 mCheckedIdStates.put(mAdapter.getItemId(position), Boolean.TRUE); 3522 } else { 3523 mCheckedIdStates.delete(mAdapter.getItemId(position)); 3524 } 3525 } 3526 } else { 3527 boolean updateIds = mCheckedIdStates != null && mAdapter.hasStableIds(); 3528 // Clear all values if we're checking something, or unchecking the currently 3529 // selected item 3530 if (value || isItemChecked(position)) { 3531 mCheckStates.clear(); 3532 if (updateIds) { 3533 mCheckedIdStates.clear(); 3534 } 3535 } 3536 // this may end up selecting the value we just cleared but this way 3537 // we ensure length of mCheckStates is 1, a fact getCheckedItemPosition relies on 3538 if (value) { 3539 mCheckStates.put(position, true); 3540 if (updateIds) { 3541 mCheckedIdStates.put(mAdapter.getItemId(position), Boolean.TRUE); 3542 } 3543 } 3544 } 3545 3546 // Do not generate a data change while we are in the layout phase 3547 if (!mInLayout && !mBlockLayoutRequests) { 3548 mDataChanged = true; 3549 rememberSyncState(); 3550 requestLayout(); 3551 } 3552 } 3553 3554 /** 3555 * Returns the checked state of the specified position. The result is only 3556 * valid if the choice mode has been set to {@link #CHOICE_MODE_SINGLE} 3557 * or {@link #CHOICE_MODE_MULTIPLE}. 3558 * 3559 * @param position The item whose checked state to return 3560 * @return The item's checked state or <code>false</code> if choice mode 3561 * is invalid 3562 * 3563 * @see #setChoiceMode(int) 3564 */ 3565 public boolean isItemChecked(int position) { 3566 if (mChoiceMode != CHOICE_MODE_NONE && mCheckStates != null) { 3567 return mCheckStates.get(position); 3568 } 3569 3570 return false; 3571 } 3572 3573 /** 3574 * Returns the currently checked item. The result is only valid if the choice 3575 * mode has been set to {@link #CHOICE_MODE_SINGLE}. 3576 * 3577 * @return The position of the currently checked item or 3578 * {@link #INVALID_POSITION} if nothing is selected 3579 * 3580 * @see #setChoiceMode(int) 3581 */ 3582 public int getCheckedItemPosition() { 3583 if (mChoiceMode == CHOICE_MODE_SINGLE && mCheckStates != null && mCheckStates.size() == 1) { 3584 return mCheckStates.keyAt(0); 3585 } 3586 3587 return INVALID_POSITION; 3588 } 3589 3590 /** 3591 * Returns the set of checked items in the list. The result is only valid if 3592 * the choice mode has not been set to {@link #CHOICE_MODE_NONE}. 3593 * 3594 * @return A SparseBooleanArray which will return true for each call to 3595 * get(int position) where position is a position in the list, 3596 * or <code>null</code> if the choice mode is set to 3597 * {@link #CHOICE_MODE_NONE}. 3598 */ 3599 public SparseBooleanArray getCheckedItemPositions() { 3600 if (mChoiceMode != CHOICE_MODE_NONE) { 3601 return mCheckStates; 3602 } 3603 return null; 3604 } 3605 3606 /** 3607 * Returns the set of checked items ids. The result is only valid if the 3608 * choice mode has not been set to {@link #CHOICE_MODE_NONE}. 3609 * 3610 * @return A new array which contains the id of each checked item in the 3611 * list. 3612 * 3613 * @deprecated Use {@link #getCheckedItemIds()} instead. 3614 */ 3615 public long[] getCheckItemIds() { 3616 // Use new behavior that correctly handles stable ID mapping. 3617 if (mAdapter != null && mAdapter.hasStableIds()) { 3618 return getCheckedItemIds(); 3619 } 3620 3621 // Old behavior was buggy, but would sort of work for adapters without stable IDs. 3622 // Fall back to it to support legacy apps. 3623 if (mChoiceMode != CHOICE_MODE_NONE && mCheckStates != null && mAdapter != null) { 3624 final SparseBooleanArray states = mCheckStates; 3625 final int count = states.size(); 3626 final long[] ids = new long[count]; 3627 final ListAdapter adapter = mAdapter; 3628 3629 int checkedCount = 0; 3630 for (int i = 0; i < count; i++) { 3631 if (states.valueAt(i)) { 3632 ids[checkedCount++] = adapter.getItemId(states.keyAt(i)); 3633 } 3634 } 3635 3636 // Trim array if needed. mCheckStates may contain false values 3637 // resulting in checkedCount being smaller than count. 3638 if (checkedCount == count) { 3639 return ids; 3640 } else { 3641 final long[] result = new long[checkedCount]; 3642 System.arraycopy(ids, 0, result, 0, checkedCount); 3643 3644 return result; 3645 } 3646 } 3647 return new long[0]; 3648 } 3649 3650 /** 3651 * Returns the set of checked items ids. The result is only valid if the 3652 * choice mode has not been set to {@link #CHOICE_MODE_NONE} and the adapter 3653 * has stable IDs. ({@link ListAdapter#hasStableIds()} == {@code true}) 3654 * 3655 * @return A new array which contains the id of each checked item in the 3656 * list. 3657 */ 3658 public long[] getCheckedItemIds() { 3659 if (mChoiceMode == CHOICE_MODE_NONE || mCheckedIdStates == null || mAdapter == null) { 3660 return new long[0]; 3661 } 3662 3663 final LongSparseArray<Boolean> idStates = mCheckedIdStates; 3664 final int count = idStates.size(); 3665 final long[] ids = new long[count]; 3666 3667 for (int i = 0; i < count; i++) { 3668 ids[i] = idStates.keyAt(i); 3669 } 3670 3671 return ids; 3672 } 3673 3674 /** 3675 * Clear any choices previously set 3676 */ 3677 public void clearChoices() { 3678 if (mCheckStates != null) { 3679 mCheckStates.clear(); 3680 } 3681 if (mCheckedIdStates != null) { 3682 mCheckedIdStates.clear(); 3683 } 3684 } 3685 3686 static class SavedState extends BaseSavedState { 3687 SparseBooleanArray checkState; 3688 LongSparseArray<Boolean> checkIdState; 3689 3690 /** 3691 * Constructor called from {@link ListView#onSaveInstanceState()} 3692 */ 3693 SavedState(Parcelable superState, SparseBooleanArray checkState, 3694 LongSparseArray<Boolean> checkIdState) { 3695 super(superState); 3696 this.checkState = checkState; 3697 this.checkIdState = checkIdState; 3698 } 3699 3700 /** 3701 * Constructor called from {@link #CREATOR} 3702 */ 3703 private SavedState(Parcel in) { 3704 super(in); 3705 checkState = in.readSparseBooleanArray(); 3706 long[] idState = in.createLongArray(); 3707 3708 if (idState.length > 0) { 3709 checkIdState = new LongSparseArray<Boolean>(); 3710 checkIdState.setValues(idState, Boolean.TRUE); 3711 } 3712 } 3713 3714 @Override 3715 public void writeToParcel(Parcel out, int flags) { 3716 super.writeToParcel(out, flags); 3717 out.writeSparseBooleanArray(checkState); 3718 out.writeLongArray(checkIdState != null ? checkIdState.getKeys() : new long[0]); 3719 } 3720 3721 @Override 3722 public String toString() { 3723 return "ListView.SavedState{" 3724 + Integer.toHexString(System.identityHashCode(this)) 3725 + " checkState=" + checkState + "}"; 3726 } 3727 3728 public static final Parcelable.Creator<SavedState> CREATOR 3729 = new Parcelable.Creator<SavedState>() { 3730 public SavedState createFromParcel(Parcel in) { 3731 return new SavedState(in); 3732 } 3733 3734 public SavedState[] newArray(int size) { 3735 return new SavedState[size]; 3736 } 3737 }; 3738 } 3739 3740 @Override 3741 public Parcelable onSaveInstanceState() { 3742 Parcelable superState = super.onSaveInstanceState(); 3743 return new SavedState(superState, mCheckStates, mCheckedIdStates); 3744 } 3745 3746 @Override 3747 public void onRestoreInstanceState(Parcelable state) { 3748 SavedState ss = (SavedState) state; 3749 3750 super.onRestoreInstanceState(ss.getSuperState()); 3751 3752 if (ss.checkState != null) { 3753 mCheckStates = ss.checkState; 3754 } 3755 3756 if (ss.checkIdState != null) { 3757 mCheckedIdStates = ss.checkIdState; 3758 } 3759 } 3760} 3761