ListView.java revision fb60386b46d0c6216c765c10bd33ac42ca780917
1/* 2 * Copyright (C) 2006 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17package android.widget; 18 19import com.android.internal.R; 20import com.google.android.collect.Lists; 21 22import android.content.Context; 23import android.content.Intent; 24import android.content.res.TypedArray; 25import android.graphics.Canvas; 26import android.graphics.Paint; 27import android.graphics.PixelFormat; 28import android.graphics.Rect; 29import android.graphics.drawable.Drawable; 30import android.util.AttributeSet; 31import android.util.SparseBooleanArray; 32import android.view.FocusFinder; 33import android.view.KeyEvent; 34import android.view.MotionEvent; 35import android.view.SoundEffectConstants; 36import android.view.View; 37import android.view.ViewDebug; 38import android.view.ViewGroup; 39import android.view.ViewParent; 40import android.view.accessibility.AccessibilityEvent; 41import android.widget.RemoteViews.RemoteView; 42 43import java.util.ArrayList; 44 45/* 46 * Implementation Notes: 47 * 48 * Some terminology: 49 * 50 * index - index of the items that are currently visible 51 * position - index of the items in the cursor 52 */ 53 54 55/** 56 * A view that shows items in a vertically scrolling list. The items 57 * come from the {@link ListAdapter} associated with this view. 58 * 59 * <p>See the <a href="{@docRoot}resources/tutorials/views/hello-listview.html">List View 60 * tutorial</a>.</p> 61 * 62 * @attr ref android.R.styleable#ListView_entries 63 * @attr ref android.R.styleable#ListView_divider 64 * @attr ref android.R.styleable#ListView_dividerHeight 65 * @attr ref android.R.styleable#ListView_headerDividersEnabled 66 * @attr ref android.R.styleable#ListView_footerDividersEnabled 67 */ 68@RemoteView 69public class ListView extends AbsListView { 70 /** 71 * Used to indicate a no preference for a position type. 72 */ 73 static final int NO_POSITION = -1; 74 75 /** 76 * When arrow scrolling, ListView will never scroll more than this factor 77 * times the height of the list. 78 */ 79 private static final float MAX_SCROLL_FACTOR = 0.33f; 80 81 /** 82 * When arrow scrolling, need a certain amount of pixels to preview next 83 * items. This is usually the fading edge, but if that is small enough, 84 * we want to make sure we preview at least this many pixels. 85 */ 86 private static final int MIN_SCROLL_PREVIEW_PIXELS = 2; 87 88 /** 89 * A class that represents a fixed view in a list, for example a header at the top 90 * or a footer at the bottom. 91 */ 92 public class FixedViewInfo { 93 /** The view to add to the list */ 94 public View view; 95 /** The data backing the view. This is returned from {@link ListAdapter#getItem(int)}. */ 96 public Object data; 97 /** <code>true</code> if the fixed view should be selectable in the list */ 98 public boolean isSelectable; 99 } 100 101 private ArrayList<FixedViewInfo> mHeaderViewInfos = Lists.newArrayList(); 102 private ArrayList<FixedViewInfo> mFooterViewInfos = Lists.newArrayList(); 103 104 Drawable mDivider; 105 int mDividerHeight; 106 107 Drawable mOverScrollHeader; 108 Drawable mOverScrollFooter; 109 110 private boolean mIsCacheColorOpaque; 111 private boolean mDividerIsOpaque; 112 113 private boolean mHeaderDividersEnabled; 114 private boolean mFooterDividersEnabled; 115 116 private boolean mAreAllItemsSelectable = true; 117 118 private boolean mItemsCanFocus = false; 119 120 // used for temporary calculations. 121 private final Rect mTempRect = new Rect(); 122 private Paint mDividerPaint; 123 124 // the single allocated result per list view; kinda cheesey but avoids 125 // allocating these thingies too often. 126 private final ArrowScrollFocusResult mArrowScrollFocusResult = new ArrowScrollFocusResult(); 127 128 // Keeps focused children visible through resizes 129 private FocusSelector mFocusSelector; 130 131 public ListView(Context context) { 132 this(context, null); 133 } 134 135 public ListView(Context context, AttributeSet attrs) { 136 this(context, attrs, com.android.internal.R.attr.listViewStyle); 137 } 138 139 public ListView(Context context, AttributeSet attrs, int defStyle) { 140 super(context, attrs, defStyle); 141 142 TypedArray a = context.obtainStyledAttributes(attrs, 143 com.android.internal.R.styleable.ListView, defStyle, 0); 144 145 CharSequence[] entries = a.getTextArray( 146 com.android.internal.R.styleable.ListView_entries); 147 if (entries != null) { 148 setAdapter(new ArrayAdapter<CharSequence>(context, 149 com.android.internal.R.layout.simple_list_item_1, entries)); 150 } 151 152 final Drawable d = a.getDrawable(com.android.internal.R.styleable.ListView_divider); 153 if (d != null) { 154 // If a divider is specified use its intrinsic height for divider height 155 setDivider(d); 156 } 157 158 final Drawable osHeader = a.getDrawable( 159 com.android.internal.R.styleable.ListView_overScrollHeader); 160 if (osHeader != null) { 161 setOverscrollHeader(osHeader); 162 } 163 164 final Drawable osFooter = a.getDrawable( 165 com.android.internal.R.styleable.ListView_overScrollFooter); 166 if (osFooter != null) { 167 setOverscrollFooter(osFooter); 168 } 169 170 // Use the height specified, zero being the default 171 final int dividerHeight = a.getDimensionPixelSize( 172 com.android.internal.R.styleable.ListView_dividerHeight, 0); 173 if (dividerHeight != 0) { 174 setDividerHeight(dividerHeight); 175 } 176 177 mHeaderDividersEnabled = a.getBoolean(R.styleable.ListView_headerDividersEnabled, true); 178 mFooterDividersEnabled = a.getBoolean(R.styleable.ListView_footerDividersEnabled, true); 179 180 a.recycle(); 181 } 182 183 /** 184 * @return The maximum amount a list view will scroll in response to 185 * an arrow event. 186 */ 187 public int getMaxScrollAmount() { 188 return (int) (MAX_SCROLL_FACTOR * (mBottom - mTop)); 189 } 190 191 /** 192 * Make sure views are touching the top or bottom edge, as appropriate for 193 * our gravity 194 */ 195 private void adjustViewsUpOrDown() { 196 final int childCount = getChildCount(); 197 int delta; 198 199 if (childCount > 0) { 200 View child; 201 202 if (!mStackFromBottom) { 203 // Uh-oh -- we came up short. Slide all views up to make them 204 // align with the top 205 child = getChildAt(0); 206 delta = child.getTop() - mListPadding.top; 207 if (mFirstPosition != 0) { 208 // It's OK to have some space above the first item if it is 209 // part of the vertical spacing 210 delta -= mDividerHeight; 211 } 212 if (delta < 0) { 213 // We only are looking to see if we are too low, not too high 214 delta = 0; 215 } 216 } else { 217 // we are too high, slide all views down to align with bottom 218 child = getChildAt(childCount - 1); 219 delta = child.getBottom() - (getHeight() - mListPadding.bottom); 220 221 if (mFirstPosition + childCount < mItemCount) { 222 // It's OK to have some space below the last item if it is 223 // part of the vertical spacing 224 delta += mDividerHeight; 225 } 226 227 if (delta > 0) { 228 delta = 0; 229 } 230 } 231 232 if (delta != 0) { 233 offsetChildrenTopAndBottom(-delta); 234 } 235 } 236 } 237 238 /** 239 * Add a fixed view to appear at the top of the list. If addHeaderView is 240 * called more than once, the views will appear in the order they were 241 * added. Views added using this call can take focus if they want. 242 * <p> 243 * NOTE: Call this before calling setAdapter. This is so ListView can wrap 244 * the supplied cursor with one that will also account for header and footer 245 * views. 246 * 247 * @param v The view to add. 248 * @param data Data to associate with this view 249 * @param isSelectable whether the item is selectable 250 */ 251 public void addHeaderView(View v, Object data, boolean isSelectable) { 252 253 if (mAdapter != null) { 254 throw new IllegalStateException( 255 "Cannot add header view to list -- setAdapter has already been called."); 256 } 257 258 FixedViewInfo info = new FixedViewInfo(); 259 info.view = v; 260 info.data = data; 261 info.isSelectable = isSelectable; 262 mHeaderViewInfos.add(info); 263 } 264 265 /** 266 * Add a fixed view to appear at the top of the list. If addHeaderView is 267 * called more than once, the views will appear in the order they were 268 * added. Views added using this call can take focus if they want. 269 * <p> 270 * NOTE: Call this before calling setAdapter. This is so ListView can wrap 271 * the supplied cursor with one that will also account for header and footer 272 * views. 273 * 274 * @param v The view to add. 275 */ 276 public void addHeaderView(View v) { 277 addHeaderView(v, null, true); 278 } 279 280 @Override 281 public int getHeaderViewsCount() { 282 return mHeaderViewInfos.size(); 283 } 284 285 /** 286 * Removes a previously-added header view. 287 * 288 * @param v The view to remove 289 * @return true if the view was removed, false if the view was not a header 290 * view 291 */ 292 public boolean removeHeaderView(View v) { 293 if (mHeaderViewInfos.size() > 0) { 294 boolean result = false; 295 if (((HeaderViewListAdapter) mAdapter).removeHeader(v)) { 296 mDataSetObserver.onChanged(); 297 result = true; 298 } 299 removeFixedViewInfo(v, mHeaderViewInfos); 300 return result; 301 } 302 return false; 303 } 304 305 private void removeFixedViewInfo(View v, ArrayList<FixedViewInfo> where) { 306 int len = where.size(); 307 for (int i = 0; i < len; ++i) { 308 FixedViewInfo info = where.get(i); 309 if (info.view == v) { 310 where.remove(i); 311 break; 312 } 313 } 314 } 315 316 /** 317 * Add a fixed view to appear at the bottom of the list. If addFooterView is 318 * called more than once, the views will appear in the order they were 319 * added. Views added using this call can take focus if they want. 320 * <p> 321 * NOTE: Call this before calling setAdapter. This is so ListView can wrap 322 * the supplied cursor with one that will also account for header and footer 323 * views. 324 * 325 * @param v The view to add. 326 * @param data Data to associate with this view 327 * @param isSelectable true if the footer view can be selected 328 */ 329 public void addFooterView(View v, Object data, boolean isSelectable) { 330 FixedViewInfo info = new FixedViewInfo(); 331 info.view = v; 332 info.data = data; 333 info.isSelectable = isSelectable; 334 mFooterViewInfos.add(info); 335 336 // in the case of re-adding a footer view, or adding one later on, 337 // we need to notify the observer 338 if (mDataSetObserver != null) { 339 mDataSetObserver.onChanged(); 340 } 341 } 342 343 /** 344 * Add a fixed view to appear at the bottom of the list. If addFooterView is called more 345 * than once, the views will appear in the order they were added. Views added using 346 * this call can take focus if they want. 347 * <p>NOTE: Call this before calling setAdapter. This is so ListView can wrap the supplied 348 * cursor with one that will also account for header and footer views. 349 * 350 * 351 * @param v The view to add. 352 */ 353 public void addFooterView(View v) { 354 addFooterView(v, null, true); 355 } 356 357 @Override 358 public int getFooterViewsCount() { 359 return mFooterViewInfos.size(); 360 } 361 362 /** 363 * Removes a previously-added footer view. 364 * 365 * @param v The view to remove 366 * @return 367 * true if the view was removed, false if the view was not a footer view 368 */ 369 public boolean removeFooterView(View v) { 370 if (mFooterViewInfos.size() > 0) { 371 boolean result = false; 372 if (((HeaderViewListAdapter) mAdapter).removeFooter(v)) { 373 mDataSetObserver.onChanged(); 374 result = true; 375 } 376 removeFixedViewInfo(v, mFooterViewInfos); 377 return result; 378 } 379 return false; 380 } 381 382 /** 383 * Returns the adapter currently in use in this ListView. The returned adapter 384 * might not be the same adapter passed to {@link #setAdapter(ListAdapter)} but 385 * might be a {@link WrapperListAdapter}. 386 * 387 * @return The adapter currently used to display data in this ListView. 388 * 389 * @see #setAdapter(ListAdapter) 390 */ 391 @Override 392 public ListAdapter getAdapter() { 393 return mAdapter; 394 } 395 396 /** 397 * Sets up this AbsListView to use a remote views adapter which connects to a RemoteViewsService 398 * through the specified intent. 399 * @param intent the intent used to identify the RemoteViewsService for the adapter to connect to. 400 */ 401 @android.view.RemotableViewMethod 402 public void setRemoteViewsAdapter(Intent intent) { 403 super.setRemoteViewsAdapter(intent); 404 } 405 406 /** 407 * Sets the data behind this ListView. 408 * 409 * The adapter passed to this method may be wrapped by a {@link WrapperListAdapter}, 410 * depending on the ListView features currently in use. For instance, adding 411 * headers and/or footers will cause the adapter to be wrapped. 412 * 413 * @param adapter The ListAdapter which is responsible for maintaining the 414 * data backing this list and for producing a view to represent an 415 * item in that data set. 416 * 417 * @see #getAdapter() 418 */ 419 @Override 420 public void setAdapter(ListAdapter adapter) { 421 if (mAdapter != null && mDataSetObserver != null) { 422 mAdapter.unregisterDataSetObserver(mDataSetObserver); 423 } 424 425 resetList(); 426 mRecycler.clear(); 427 428 if (mHeaderViewInfos.size() > 0|| mFooterViewInfos.size() > 0) { 429 mAdapter = new HeaderViewListAdapter(mHeaderViewInfos, mFooterViewInfos, adapter); 430 } else { 431 mAdapter = adapter; 432 } 433 434 mOldSelectedPosition = INVALID_POSITION; 435 mOldSelectedRowId = INVALID_ROW_ID; 436 437 // AbsListView#setAdapter will update choice mode states. 438 super.setAdapter(adapter); 439 440 if (mAdapter != null) { 441 mAreAllItemsSelectable = mAdapter.areAllItemsEnabled(); 442 mOldItemCount = mItemCount; 443 mItemCount = mAdapter.getCount(); 444 checkFocus(); 445 446 mDataSetObserver = new AdapterDataSetObserver(); 447 mAdapter.registerDataSetObserver(mDataSetObserver); 448 449 mRecycler.setViewTypeCount(mAdapter.getViewTypeCount()); 450 451 int position; 452 if (mStackFromBottom) { 453 position = lookForSelectablePosition(mItemCount - 1, false); 454 } else { 455 position = lookForSelectablePosition(0, true); 456 } 457 setSelectedPositionInt(position); 458 setNextSelectedPositionInt(position); 459 460 if (mItemCount == 0) { 461 // Nothing selected 462 checkSelectionChanged(); 463 } 464 } else { 465 mAreAllItemsSelectable = true; 466 checkFocus(); 467 // Nothing selected 468 checkSelectionChanged(); 469 } 470 471 requestLayout(); 472 } 473 474 475 /** 476 * The list is empty. Clear everything out. 477 */ 478 @Override 479 void resetList() { 480 // The parent's resetList() will remove all views from the layout so we need to 481 // cleanup the state of our footers and headers 482 clearRecycledState(mHeaderViewInfos); 483 clearRecycledState(mFooterViewInfos); 484 485 super.resetList(); 486 487 mLayoutMode = LAYOUT_NORMAL; 488 } 489 490 private void clearRecycledState(ArrayList<FixedViewInfo> infos) { 491 if (infos != null) { 492 final int count = infos.size(); 493 494 for (int i = 0; i < count; i++) { 495 final View child = infos.get(i).view; 496 final LayoutParams p = (LayoutParams) child.getLayoutParams(); 497 if (p != null) { 498 p.recycledHeaderFooter = false; 499 } 500 } 501 } 502 } 503 504 /** 505 * @return Whether the list needs to show the top fading edge 506 */ 507 private boolean showingTopFadingEdge() { 508 final int listTop = mScrollY + mListPadding.top; 509 return (mFirstPosition > 0) || (getChildAt(0).getTop() > listTop); 510 } 511 512 /** 513 * @return Whether the list needs to show the bottom fading edge 514 */ 515 private boolean showingBottomFadingEdge() { 516 final int childCount = getChildCount(); 517 final int bottomOfBottomChild = getChildAt(childCount - 1).getBottom(); 518 final int lastVisiblePosition = mFirstPosition + childCount - 1; 519 520 final int listBottom = mScrollY + getHeight() - mListPadding.bottom; 521 522 return (lastVisiblePosition < mItemCount - 1) 523 || (bottomOfBottomChild < listBottom); 524 } 525 526 527 @Override 528 public boolean requestChildRectangleOnScreen(View child, Rect rect, boolean immediate) { 529 530 int rectTopWithinChild = rect.top; 531 532 // offset so rect is in coordinates of the this view 533 rect.offset(child.getLeft(), child.getTop()); 534 rect.offset(-child.getScrollX(), -child.getScrollY()); 535 536 final int height = getHeight(); 537 int listUnfadedTop = getScrollY(); 538 int listUnfadedBottom = listUnfadedTop + height; 539 final int fadingEdge = getVerticalFadingEdgeLength(); 540 541 if (showingTopFadingEdge()) { 542 // leave room for top fading edge as long as rect isn't at very top 543 if ((mSelectedPosition > 0) || (rectTopWithinChild > fadingEdge)) { 544 listUnfadedTop += fadingEdge; 545 } 546 } 547 548 int childCount = getChildCount(); 549 int bottomOfBottomChild = getChildAt(childCount - 1).getBottom(); 550 551 if (showingBottomFadingEdge()) { 552 // leave room for bottom fading edge as long as rect isn't at very bottom 553 if ((mSelectedPosition < mItemCount - 1) 554 || (rect.bottom < (bottomOfBottomChild - fadingEdge))) { 555 listUnfadedBottom -= fadingEdge; 556 } 557 } 558 559 int scrollYDelta = 0; 560 561 if (rect.bottom > listUnfadedBottom && rect.top > listUnfadedTop) { 562 // need to MOVE DOWN to get it in view: move down just enough so 563 // that the entire rectangle is in view (or at least the first 564 // screen size chunk). 565 566 if (rect.height() > height) { 567 // just enough to get screen size chunk on 568 scrollYDelta += (rect.top - listUnfadedTop); 569 } else { 570 // get entire rect at bottom of screen 571 scrollYDelta += (rect.bottom - listUnfadedBottom); 572 } 573 574 // make sure we aren't scrolling beyond the end of our children 575 int distanceToBottom = bottomOfBottomChild - listUnfadedBottom; 576 scrollYDelta = Math.min(scrollYDelta, distanceToBottom); 577 } else if (rect.top < listUnfadedTop && rect.bottom < listUnfadedBottom) { 578 // need to MOVE UP to get it in view: move up just enough so that 579 // entire rectangle is in view (or at least the first screen 580 // size chunk of it). 581 582 if (rect.height() > height) { 583 // screen size chunk 584 scrollYDelta -= (listUnfadedBottom - rect.bottom); 585 } else { 586 // entire rect at top 587 scrollYDelta -= (listUnfadedTop - rect.top); 588 } 589 590 // make sure we aren't scrolling any further than the top our children 591 int top = getChildAt(0).getTop(); 592 int deltaToTop = top - listUnfadedTop; 593 scrollYDelta = Math.max(scrollYDelta, deltaToTop); 594 } 595 596 final boolean scroll = scrollYDelta != 0; 597 if (scroll) { 598 scrollListItemsBy(-scrollYDelta); 599 positionSelector(INVALID_POSITION, child); 600 mSelectedTop = child.getTop(); 601 invalidate(); 602 } 603 return scroll; 604 } 605 606 /** 607 * {@inheritDoc} 608 */ 609 @Override 610 void fillGap(boolean down) { 611 final int count = getChildCount(); 612 if (down) { 613 int paddingTop = 0; 614 if ((mGroupFlags & CLIP_TO_PADDING_MASK) == CLIP_TO_PADDING_MASK) { 615 paddingTop = getListPaddingTop(); 616 } 617 final int startOffset = count > 0 ? getChildAt(count - 1).getBottom() + mDividerHeight : 618 paddingTop; 619 fillDown(mFirstPosition + count, startOffset); 620 correctTooHigh(getChildCount()); 621 } else { 622 int paddingBottom = 0; 623 if ((mGroupFlags & CLIP_TO_PADDING_MASK) == CLIP_TO_PADDING_MASK) { 624 paddingBottom = getListPaddingBottom(); 625 } 626 final int startOffset = count > 0 ? getChildAt(0).getTop() - mDividerHeight : 627 getHeight() - paddingBottom; 628 fillUp(mFirstPosition - 1, startOffset); 629 correctTooLow(getChildCount()); 630 } 631 } 632 633 /** 634 * Fills the list from pos down to the end of the list view. 635 * 636 * @param pos The first position to put in the list 637 * 638 * @param nextTop The location where the top of the item associated with pos 639 * should be drawn 640 * 641 * @return The view that is currently selected, if it happens to be in the 642 * range that we draw. 643 */ 644 private View fillDown(int pos, int nextTop) { 645 View selectedView = null; 646 647 int end = (mBottom - mTop); 648 if ((mGroupFlags & CLIP_TO_PADDING_MASK) == CLIP_TO_PADDING_MASK) { 649 end -= mListPadding.bottom; 650 } 651 652 while (nextTop < end && pos < mItemCount) { 653 // is this the selected item? 654 boolean selected = pos == mSelectedPosition; 655 View child = makeAndAddView(pos, nextTop, true, mListPadding.left, selected); 656 657 nextTop = child.getBottom() + mDividerHeight; 658 if (selected) { 659 selectedView = child; 660 } 661 pos++; 662 } 663 664 return selectedView; 665 } 666 667 /** 668 * Fills the list from pos up to the top of the list view. 669 * 670 * @param pos The first position to put in the list 671 * 672 * @param nextBottom The location where the bottom of the item associated 673 * with pos should be drawn 674 * 675 * @return The view that is currently selected 676 */ 677 private View fillUp(int pos, int nextBottom) { 678 View selectedView = null; 679 680 int end = 0; 681 if ((mGroupFlags & CLIP_TO_PADDING_MASK) == CLIP_TO_PADDING_MASK) { 682 end = mListPadding.top; 683 } 684 685 while (nextBottom > end && pos >= 0) { 686 // is this the selected item? 687 boolean selected = pos == mSelectedPosition; 688 View child = makeAndAddView(pos, nextBottom, false, mListPadding.left, selected); 689 nextBottom = child.getTop() - mDividerHeight; 690 if (selected) { 691 selectedView = child; 692 } 693 pos--; 694 } 695 696 mFirstPosition = pos + 1; 697 698 return selectedView; 699 } 700 701 /** 702 * Fills the list from top to bottom, starting with mFirstPosition 703 * 704 * @param nextTop The location where the top of the first item should be 705 * drawn 706 * 707 * @return The view that is currently selected 708 */ 709 private View fillFromTop(int nextTop) { 710 mFirstPosition = Math.min(mFirstPosition, mSelectedPosition); 711 mFirstPosition = Math.min(mFirstPosition, mItemCount - 1); 712 if (mFirstPosition < 0) { 713 mFirstPosition = 0; 714 } 715 return fillDown(mFirstPosition, nextTop); 716 } 717 718 719 /** 720 * Put mSelectedPosition in the middle of the screen and then build up and 721 * down from there. This method forces mSelectedPosition to the center. 722 * 723 * @param childrenTop Top of the area in which children can be drawn, as 724 * measured in pixels 725 * @param childrenBottom Bottom of the area in which children can be drawn, 726 * as measured in pixels 727 * @return Currently selected view 728 */ 729 private View fillFromMiddle(int childrenTop, int childrenBottom) { 730 int height = childrenBottom - childrenTop; 731 732 int position = reconcileSelectedPosition(); 733 734 View sel = makeAndAddView(position, childrenTop, true, 735 mListPadding.left, true); 736 mFirstPosition = position; 737 738 int selHeight = sel.getMeasuredHeight(); 739 if (selHeight <= height) { 740 sel.offsetTopAndBottom((height - selHeight) / 2); 741 } 742 743 fillAboveAndBelow(sel, position); 744 745 if (!mStackFromBottom) { 746 correctTooHigh(getChildCount()); 747 } else { 748 correctTooLow(getChildCount()); 749 } 750 751 return sel; 752 } 753 754 /** 755 * Once the selected view as been placed, fill up the visible area above and 756 * below it. 757 * 758 * @param sel The selected view 759 * @param position The position corresponding to sel 760 */ 761 private void fillAboveAndBelow(View sel, int position) { 762 final int dividerHeight = mDividerHeight; 763 if (!mStackFromBottom) { 764 fillUp(position - 1, sel.getTop() - dividerHeight); 765 adjustViewsUpOrDown(); 766 fillDown(position + 1, sel.getBottom() + dividerHeight); 767 } else { 768 fillDown(position + 1, sel.getBottom() + dividerHeight); 769 adjustViewsUpOrDown(); 770 fillUp(position - 1, sel.getTop() - dividerHeight); 771 } 772 } 773 774 775 /** 776 * Fills the grid based on positioning the new selection at a specific 777 * location. The selection may be moved so that it does not intersect the 778 * faded edges. The grid is then filled upwards and downwards from there. 779 * 780 * @param selectedTop Where the selected item should be 781 * @param childrenTop Where to start drawing children 782 * @param childrenBottom Last pixel where children can be drawn 783 * @return The view that currently has selection 784 */ 785 private View fillFromSelection(int selectedTop, int childrenTop, int childrenBottom) { 786 int fadingEdgeLength = getVerticalFadingEdgeLength(); 787 final int selectedPosition = mSelectedPosition; 788 789 View sel; 790 791 final int topSelectionPixel = getTopSelectionPixel(childrenTop, fadingEdgeLength, 792 selectedPosition); 793 final int bottomSelectionPixel = getBottomSelectionPixel(childrenBottom, fadingEdgeLength, 794 selectedPosition); 795 796 sel = makeAndAddView(selectedPosition, selectedTop, true, mListPadding.left, true); 797 798 799 // Some of the newly selected item extends below the bottom of the list 800 if (sel.getBottom() > bottomSelectionPixel) { 801 // Find space available above the selection into which we can scroll 802 // upwards 803 final int spaceAbove = sel.getTop() - topSelectionPixel; 804 805 // Find space required to bring the bottom of the selected item 806 // fully into view 807 final int spaceBelow = sel.getBottom() - bottomSelectionPixel; 808 final int offset = Math.min(spaceAbove, spaceBelow); 809 810 // Now offset the selected item to get it into view 811 sel.offsetTopAndBottom(-offset); 812 } else if (sel.getTop() < topSelectionPixel) { 813 // Find space required to bring the top of the selected item fully 814 // into view 815 final int spaceAbove = topSelectionPixel - sel.getTop(); 816 817 // Find space available below the selection into which we can scroll 818 // downwards 819 final int spaceBelow = bottomSelectionPixel - sel.getBottom(); 820 final int offset = Math.min(spaceAbove, spaceBelow); 821 822 // Offset the selected item to get it into view 823 sel.offsetTopAndBottom(offset); 824 } 825 826 // Fill in views above and below 827 fillAboveAndBelow(sel, selectedPosition); 828 829 if (!mStackFromBottom) { 830 correctTooHigh(getChildCount()); 831 } else { 832 correctTooLow(getChildCount()); 833 } 834 835 return sel; 836 } 837 838 /** 839 * Calculate the bottom-most pixel we can draw the selection into 840 * 841 * @param childrenBottom Bottom pixel were children can be drawn 842 * @param fadingEdgeLength Length of the fading edge in pixels, if present 843 * @param selectedPosition The position that will be selected 844 * @return The bottom-most pixel we can draw the selection into 845 */ 846 private int getBottomSelectionPixel(int childrenBottom, int fadingEdgeLength, 847 int selectedPosition) { 848 int bottomSelectionPixel = childrenBottom; 849 if (selectedPosition != mItemCount - 1) { 850 bottomSelectionPixel -= fadingEdgeLength; 851 } 852 return bottomSelectionPixel; 853 } 854 855 /** 856 * Calculate the top-most pixel we can draw the selection into 857 * 858 * @param childrenTop Top pixel were children can be drawn 859 * @param fadingEdgeLength Length of the fading edge in pixels, if present 860 * @param selectedPosition The position that will be selected 861 * @return The top-most pixel we can draw the selection into 862 */ 863 private int getTopSelectionPixel(int childrenTop, int fadingEdgeLength, int selectedPosition) { 864 // first pixel we can draw the selection into 865 int topSelectionPixel = childrenTop; 866 if (selectedPosition > 0) { 867 topSelectionPixel += fadingEdgeLength; 868 } 869 return topSelectionPixel; 870 } 871 872 /** 873 * Smoothly scroll to the specified adapter position. The view will 874 * scroll such that the indicated position is displayed. 875 * @param position Scroll to this adapter position. 876 */ 877 @android.view.RemotableViewMethod 878 public void smoothScrollToPosition(int position) { 879 super.smoothScrollToPosition(position); 880 } 881 882 /** 883 * Smoothly scroll to the specified adapter position offset. The view will 884 * scroll such that the indicated position is displayed. 885 * @param offset The amount to offset from the adapter position to scroll to. 886 */ 887 @android.view.RemotableViewMethod 888 public void smoothScrollByOffset(int offset) { 889 super.smoothScrollByOffset(offset); 890 } 891 892 /** 893 * Fills the list based on positioning the new selection relative to the old 894 * selection. The new selection will be placed at, above, or below the 895 * location of the new selection depending on how the selection is moving. 896 * The selection will then be pinned to the visible part of the screen, 897 * excluding the edges that are faded. The list is then filled upwards and 898 * downwards from there. 899 * 900 * @param oldSel The old selected view. Useful for trying to put the new 901 * selection in the same place 902 * @param newSel The view that is to become selected. Useful for trying to 903 * put the new selection in the same place 904 * @param delta Which way we are moving 905 * @param childrenTop Where to start drawing children 906 * @param childrenBottom Last pixel where children can be drawn 907 * @return The view that currently has selection 908 */ 909 private View moveSelection(View oldSel, View newSel, int delta, int childrenTop, 910 int childrenBottom) { 911 int fadingEdgeLength = getVerticalFadingEdgeLength(); 912 final int selectedPosition = mSelectedPosition; 913 914 View sel; 915 916 final int topSelectionPixel = getTopSelectionPixel(childrenTop, fadingEdgeLength, 917 selectedPosition); 918 final int bottomSelectionPixel = getBottomSelectionPixel(childrenTop, fadingEdgeLength, 919 selectedPosition); 920 921 if (delta > 0) { 922 /* 923 * Case 1: Scrolling down. 924 */ 925 926 /* 927 * Before After 928 * | | | | 929 * +-------+ +-------+ 930 * | A | | A | 931 * | 1 | => +-------+ 932 * +-------+ | B | 933 * | B | | 2 | 934 * +-------+ +-------+ 935 * | | | | 936 * 937 * Try to keep the top of the previously selected item where it was. 938 * oldSel = A 939 * sel = B 940 */ 941 942 // Put oldSel (A) where it belongs 943 oldSel = makeAndAddView(selectedPosition - 1, oldSel.getTop(), true, 944 mListPadding.left, false); 945 946 final int dividerHeight = mDividerHeight; 947 948 // Now put the new selection (B) below that 949 sel = makeAndAddView(selectedPosition, oldSel.getBottom() + dividerHeight, true, 950 mListPadding.left, true); 951 952 // Some of the newly selected item extends below the bottom of the list 953 if (sel.getBottom() > bottomSelectionPixel) { 954 955 // Find space available above the selection into which we can scroll upwards 956 int spaceAbove = sel.getTop() - topSelectionPixel; 957 958 // Find space required to bring the bottom of the selected item fully into view 959 int spaceBelow = sel.getBottom() - bottomSelectionPixel; 960 961 // Don't scroll more than half the height of the list 962 int halfVerticalSpace = (childrenBottom - childrenTop) / 2; 963 int offset = Math.min(spaceAbove, spaceBelow); 964 offset = Math.min(offset, halfVerticalSpace); 965 966 // We placed oldSel, so offset that item 967 oldSel.offsetTopAndBottom(-offset); 968 // Now offset the selected item to get it into view 969 sel.offsetTopAndBottom(-offset); 970 } 971 972 // Fill in views above and below 973 if (!mStackFromBottom) { 974 fillUp(mSelectedPosition - 2, sel.getTop() - dividerHeight); 975 adjustViewsUpOrDown(); 976 fillDown(mSelectedPosition + 1, sel.getBottom() + dividerHeight); 977 } else { 978 fillDown(mSelectedPosition + 1, sel.getBottom() + dividerHeight); 979 adjustViewsUpOrDown(); 980 fillUp(mSelectedPosition - 2, sel.getTop() - dividerHeight); 981 } 982 } else if (delta < 0) { 983 /* 984 * Case 2: Scrolling up. 985 */ 986 987 /* 988 * Before After 989 * | | | | 990 * +-------+ +-------+ 991 * | A | | A | 992 * +-------+ => | 1 | 993 * | B | +-------+ 994 * | 2 | | B | 995 * +-------+ +-------+ 996 * | | | | 997 * 998 * Try to keep the top of the item about to become selected where it was. 999 * newSel = A 1000 * olSel = B 1001 */ 1002 1003 if (newSel != null) { 1004 // Try to position the top of newSel (A) where it was before it was selected 1005 sel = makeAndAddView(selectedPosition, newSel.getTop(), true, mListPadding.left, 1006 true); 1007 } else { 1008 // If (A) was not on screen and so did not have a view, position 1009 // it above the oldSel (B) 1010 sel = makeAndAddView(selectedPosition, oldSel.getTop(), false, mListPadding.left, 1011 true); 1012 } 1013 1014 // Some of the newly selected item extends above the top of the list 1015 if (sel.getTop() < topSelectionPixel) { 1016 // Find space required to bring the top of the selected item fully into view 1017 int spaceAbove = topSelectionPixel - sel.getTop(); 1018 1019 // Find space available below the selection into which we can scroll downwards 1020 int spaceBelow = bottomSelectionPixel - sel.getBottom(); 1021 1022 // Don't scroll more than half the height of the list 1023 int halfVerticalSpace = (childrenBottom - childrenTop) / 2; 1024 int offset = Math.min(spaceAbove, spaceBelow); 1025 offset = Math.min(offset, halfVerticalSpace); 1026 1027 // Offset the selected item to get it into view 1028 sel.offsetTopAndBottom(offset); 1029 } 1030 1031 // Fill in views above and below 1032 fillAboveAndBelow(sel, selectedPosition); 1033 } else { 1034 1035 int oldTop = oldSel.getTop(); 1036 1037 /* 1038 * Case 3: Staying still 1039 */ 1040 sel = makeAndAddView(selectedPosition, oldTop, true, mListPadding.left, true); 1041 1042 // We're staying still... 1043 if (oldTop < childrenTop) { 1044 // ... but the top of the old selection was off screen. 1045 // (This can happen if the data changes size out from under us) 1046 int newBottom = sel.getBottom(); 1047 if (newBottom < childrenTop + 20) { 1048 // Not enough visible -- bring it onscreen 1049 sel.offsetTopAndBottom(childrenTop - sel.getTop()); 1050 } 1051 } 1052 1053 // Fill in views above and below 1054 fillAboveAndBelow(sel, selectedPosition); 1055 } 1056 1057 return sel; 1058 } 1059 1060 private class FocusSelector implements Runnable { 1061 private int mPosition; 1062 private int mPositionTop; 1063 1064 public FocusSelector setup(int position, int top) { 1065 mPosition = position; 1066 mPositionTop = top; 1067 return this; 1068 } 1069 1070 public void run() { 1071 setSelectionFromTop(mPosition, mPositionTop); 1072 } 1073 } 1074 1075 @Override 1076 protected void onSizeChanged(int w, int h, int oldw, int oldh) { 1077 if (getChildCount() > 0) { 1078 View focusedChild = getFocusedChild(); 1079 if (focusedChild != null) { 1080 final int childPosition = mFirstPosition + indexOfChild(focusedChild); 1081 final int childBottom = focusedChild.getBottom(); 1082 final int offset = Math.max(0, childBottom - (h - mPaddingTop)); 1083 final int top = focusedChild.getTop() - offset; 1084 if (mFocusSelector == null) { 1085 mFocusSelector = new FocusSelector(); 1086 } 1087 post(mFocusSelector.setup(childPosition, top)); 1088 } 1089 } 1090 super.onSizeChanged(w, h, oldw, oldh); 1091 } 1092 1093 @Override 1094 protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { 1095 // Sets up mListPadding 1096 super.onMeasure(widthMeasureSpec, heightMeasureSpec); 1097 1098 int widthMode = MeasureSpec.getMode(widthMeasureSpec); 1099 int heightMode = MeasureSpec.getMode(heightMeasureSpec); 1100 int widthSize = MeasureSpec.getSize(widthMeasureSpec); 1101 int heightSize = MeasureSpec.getSize(heightMeasureSpec); 1102 1103 int childWidth = 0; 1104 int childHeight = 0; 1105 int childState = 0; 1106 1107 mItemCount = mAdapter == null ? 0 : mAdapter.getCount(); 1108 if (mItemCount > 0 && (widthMode == MeasureSpec.UNSPECIFIED || 1109 heightMode == MeasureSpec.UNSPECIFIED)) { 1110 final View child = obtainView(0, mIsScrap); 1111 1112 measureScrapChild(child, 0, widthMeasureSpec); 1113 1114 childWidth = child.getMeasuredWidth(); 1115 childHeight = child.getMeasuredHeight(); 1116 childState = combineMeasuredStates(childState, child.getMeasuredState()); 1117 1118 if (recycleOnMeasure() && mRecycler.shouldRecycleViewType( 1119 ((LayoutParams) child.getLayoutParams()).viewType)) { 1120 mRecycler.addScrapView(child, -1); 1121 } 1122 } 1123 1124 if (widthMode == MeasureSpec.UNSPECIFIED) { 1125 widthSize = mListPadding.left + mListPadding.right + childWidth + 1126 getVerticalScrollbarWidth(); 1127 } else { 1128 widthSize |= (childState&MEASURED_STATE_MASK); 1129 } 1130 1131 if (heightMode == MeasureSpec.UNSPECIFIED) { 1132 heightSize = mListPadding.top + mListPadding.bottom + childHeight + 1133 getVerticalFadingEdgeLength() * 2; 1134 } 1135 1136 if (heightMode == MeasureSpec.AT_MOST) { 1137 // TODO: after first layout we should maybe start at the first visible position, not 0 1138 heightSize = measureHeightOfChildren(widthMeasureSpec, 0, NO_POSITION, heightSize, -1); 1139 } 1140 1141 setMeasuredDimension(widthSize , heightSize); 1142 mWidthMeasureSpec = widthMeasureSpec; 1143 } 1144 1145 private void measureScrapChild(View child, int position, int widthMeasureSpec) { 1146 LayoutParams p = (LayoutParams) child.getLayoutParams(); 1147 if (p == null) { 1148 p = new LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, 1149 ViewGroup.LayoutParams.WRAP_CONTENT, 0); 1150 child.setLayoutParams(p); 1151 } 1152 p.viewType = mAdapter.getItemViewType(position); 1153 p.forceAdd = true; 1154 1155 int childWidthSpec = ViewGroup.getChildMeasureSpec(widthMeasureSpec, 1156 mListPadding.left + mListPadding.right, p.width); 1157 int lpHeight = p.height; 1158 int childHeightSpec; 1159 if (lpHeight > 0) { 1160 childHeightSpec = MeasureSpec.makeMeasureSpec(lpHeight, MeasureSpec.EXACTLY); 1161 } else { 1162 childHeightSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED); 1163 } 1164 child.measure(childWidthSpec, childHeightSpec); 1165 } 1166 1167 /** 1168 * @return True to recycle the views used to measure this ListView in 1169 * UNSPECIFIED/AT_MOST modes, false otherwise. 1170 * @hide 1171 */ 1172 @ViewDebug.ExportedProperty(category = "list") 1173 protected boolean recycleOnMeasure() { 1174 return true; 1175 } 1176 1177 /** 1178 * Measures the height of the given range of children (inclusive) and 1179 * returns the height with this ListView's padding and divider heights 1180 * included. If maxHeight is provided, the measuring will stop when the 1181 * current height reaches maxHeight. 1182 * 1183 * @param widthMeasureSpec The width measure spec to be given to a child's 1184 * {@link View#measure(int, int)}. 1185 * @param startPosition The position of the first child to be shown. 1186 * @param endPosition The (inclusive) position of the last child to be 1187 * shown. Specify {@link #NO_POSITION} if the last child should be 1188 * the last available child from the adapter. 1189 * @param maxHeight The maximum height that will be returned (if all the 1190 * children don't fit in this value, this value will be 1191 * returned). 1192 * @param disallowPartialChildPosition In general, whether the returned 1193 * height should only contain entire children. This is more 1194 * powerful--it is the first inclusive position at which partial 1195 * children will not be allowed. Example: it looks nice to have 1196 * at least 3 completely visible children, and in portrait this 1197 * will most likely fit; but in landscape there could be times 1198 * when even 2 children can not be completely shown, so a value 1199 * of 2 (remember, inclusive) would be good (assuming 1200 * startPosition is 0). 1201 * @return The height of this ListView with the given children. 1202 */ 1203 final int measureHeightOfChildren(int widthMeasureSpec, int startPosition, int endPosition, 1204 final int maxHeight, int disallowPartialChildPosition) { 1205 1206 final ListAdapter adapter = mAdapter; 1207 if (adapter == null) { 1208 return mListPadding.top + mListPadding.bottom; 1209 } 1210 1211 // Include the padding of the list 1212 int returnedHeight = mListPadding.top + mListPadding.bottom; 1213 final int dividerHeight = ((mDividerHeight > 0) && mDivider != null) ? mDividerHeight : 0; 1214 // The previous height value that was less than maxHeight and contained 1215 // no partial children 1216 int prevHeightWithoutPartialChild = 0; 1217 int i; 1218 View child; 1219 1220 // mItemCount - 1 since endPosition parameter is inclusive 1221 endPosition = (endPosition == NO_POSITION) ? adapter.getCount() - 1 : endPosition; 1222 final AbsListView.RecycleBin recycleBin = mRecycler; 1223 final boolean recyle = recycleOnMeasure(); 1224 final boolean[] isScrap = mIsScrap; 1225 1226 for (i = startPosition; i <= endPosition; ++i) { 1227 child = obtainView(i, isScrap); 1228 1229 measureScrapChild(child, i, widthMeasureSpec); 1230 1231 if (i > 0) { 1232 // Count the divider for all but one child 1233 returnedHeight += dividerHeight; 1234 } 1235 1236 // Recycle the view before we possibly return from the method 1237 if (recyle && recycleBin.shouldRecycleViewType( 1238 ((LayoutParams) child.getLayoutParams()).viewType)) { 1239 recycleBin.addScrapView(child, -1); 1240 } 1241 1242 returnedHeight += child.getMeasuredHeight(); 1243 1244 if (returnedHeight >= maxHeight) { 1245 // We went over, figure out which height to return. If returnedHeight > maxHeight, 1246 // then the i'th position did not fit completely. 1247 return (disallowPartialChildPosition >= 0) // Disallowing is enabled (> -1) 1248 && (i > disallowPartialChildPosition) // We've past the min pos 1249 && (prevHeightWithoutPartialChild > 0) // We have a prev height 1250 && (returnedHeight != maxHeight) // i'th child did not fit completely 1251 ? prevHeightWithoutPartialChild 1252 : maxHeight; 1253 } 1254 1255 if ((disallowPartialChildPosition >= 0) && (i >= disallowPartialChildPosition)) { 1256 prevHeightWithoutPartialChild = returnedHeight; 1257 } 1258 } 1259 1260 // At this point, we went through the range of children, and they each 1261 // completely fit, so return the returnedHeight 1262 return returnedHeight; 1263 } 1264 1265 @Override 1266 int findMotionRow(int y) { 1267 int childCount = getChildCount(); 1268 if (childCount > 0) { 1269 if (!mStackFromBottom) { 1270 for (int i = 0; i < childCount; i++) { 1271 View v = getChildAt(i); 1272 if (y <= v.getBottom()) { 1273 return mFirstPosition + i; 1274 } 1275 } 1276 } else { 1277 for (int i = childCount - 1; i >= 0; i--) { 1278 View v = getChildAt(i); 1279 if (y >= v.getTop()) { 1280 return mFirstPosition + i; 1281 } 1282 } 1283 } 1284 } 1285 return INVALID_POSITION; 1286 } 1287 1288 /** 1289 * Put a specific item at a specific location on the screen and then build 1290 * up and down from there. 1291 * 1292 * @param position The reference view to use as the starting point 1293 * @param top Pixel offset from the top of this view to the top of the 1294 * reference view. 1295 * 1296 * @return The selected view, or null if the selected view is outside the 1297 * visible area. 1298 */ 1299 private View fillSpecific(int position, int top) { 1300 boolean tempIsSelected = position == mSelectedPosition; 1301 View temp = makeAndAddView(position, top, true, mListPadding.left, tempIsSelected); 1302 // Possibly changed again in fillUp if we add rows above this one. 1303 mFirstPosition = position; 1304 1305 View above; 1306 View below; 1307 1308 final int dividerHeight = mDividerHeight; 1309 if (!mStackFromBottom) { 1310 above = fillUp(position - 1, temp.getTop() - dividerHeight); 1311 // This will correct for the top of the first view not touching the top of the list 1312 adjustViewsUpOrDown(); 1313 below = fillDown(position + 1, temp.getBottom() + dividerHeight); 1314 int childCount = getChildCount(); 1315 if (childCount > 0) { 1316 correctTooHigh(childCount); 1317 } 1318 } else { 1319 below = fillDown(position + 1, temp.getBottom() + dividerHeight); 1320 // This will correct for the bottom of the last view not touching the bottom of the list 1321 adjustViewsUpOrDown(); 1322 above = fillUp(position - 1, temp.getTop() - dividerHeight); 1323 int childCount = getChildCount(); 1324 if (childCount > 0) { 1325 correctTooLow(childCount); 1326 } 1327 } 1328 1329 if (tempIsSelected) { 1330 return temp; 1331 } else if (above != null) { 1332 return above; 1333 } else { 1334 return below; 1335 } 1336 } 1337 1338 /** 1339 * Check if we have dragged the bottom of the list too high (we have pushed the 1340 * top element off the top of the screen when we did not need to). Correct by sliding 1341 * everything back down. 1342 * 1343 * @param childCount Number of children 1344 */ 1345 private void correctTooHigh(int childCount) { 1346 // First see if the last item is visible. If it is not, it is OK for the 1347 // top of the list to be pushed up. 1348 int lastPosition = mFirstPosition + childCount - 1; 1349 if (lastPosition == mItemCount - 1 && childCount > 0) { 1350 1351 // Get the last child ... 1352 final View lastChild = getChildAt(childCount - 1); 1353 1354 // ... and its bottom edge 1355 final int lastBottom = lastChild.getBottom(); 1356 1357 // This is bottom of our drawable area 1358 final int end = (mBottom - mTop) - mListPadding.bottom; 1359 1360 // This is how far the bottom edge of the last view is from the bottom of the 1361 // drawable area 1362 int bottomOffset = end - lastBottom; 1363 View firstChild = getChildAt(0); 1364 final int firstTop = firstChild.getTop(); 1365 1366 // Make sure we are 1) Too high, and 2) Either there are more rows above the 1367 // first row or the first row is scrolled off the top of the drawable area 1368 if (bottomOffset > 0 && (mFirstPosition > 0 || firstTop < mListPadding.top)) { 1369 if (mFirstPosition == 0) { 1370 // Don't pull the top too far down 1371 bottomOffset = Math.min(bottomOffset, mListPadding.top - firstTop); 1372 } 1373 // Move everything down 1374 offsetChildrenTopAndBottom(bottomOffset); 1375 if (mFirstPosition > 0) { 1376 // Fill the gap that was opened above mFirstPosition with more rows, if 1377 // possible 1378 fillUp(mFirstPosition - 1, firstChild.getTop() - mDividerHeight); 1379 // Close up the remaining gap 1380 adjustViewsUpOrDown(); 1381 } 1382 1383 } 1384 } 1385 } 1386 1387 /** 1388 * Check if we have dragged the bottom of the list too low (we have pushed the 1389 * bottom element off the bottom of the screen when we did not need to). Correct by sliding 1390 * everything back up. 1391 * 1392 * @param childCount Number of children 1393 */ 1394 private void correctTooLow(int childCount) { 1395 // First see if the first item is visible. If it is not, it is OK for the 1396 // bottom of the list to be pushed down. 1397 if (mFirstPosition == 0 && childCount > 0) { 1398 1399 // Get the first child ... 1400 final View firstChild = getChildAt(0); 1401 1402 // ... and its top edge 1403 final int firstTop = firstChild.getTop(); 1404 1405 // This is top of our drawable area 1406 final int start = mListPadding.top; 1407 1408 // This is bottom of our drawable area 1409 final int end = (mBottom - mTop) - mListPadding.bottom; 1410 1411 // This is how far the top edge of the first view is from the top of the 1412 // drawable area 1413 int topOffset = firstTop - start; 1414 View lastChild = getChildAt(childCount - 1); 1415 final int lastBottom = lastChild.getBottom(); 1416 int lastPosition = mFirstPosition + childCount - 1; 1417 1418 // Make sure we are 1) Too low, and 2) Either there are more rows below the 1419 // last row or the last row is scrolled off the bottom of the drawable area 1420 if (topOffset > 0) { 1421 if (lastPosition < mItemCount - 1 || lastBottom > end) { 1422 if (lastPosition == mItemCount - 1) { 1423 // Don't pull the bottom too far up 1424 topOffset = Math.min(topOffset, lastBottom - end); 1425 } 1426 // Move everything up 1427 offsetChildrenTopAndBottom(-topOffset); 1428 if (lastPosition < mItemCount - 1) { 1429 // Fill the gap that was opened below the last position with more rows, if 1430 // possible 1431 fillDown(lastPosition + 1, lastChild.getBottom() + mDividerHeight); 1432 // Close up the remaining gap 1433 adjustViewsUpOrDown(); 1434 } 1435 } else if (lastPosition == mItemCount - 1) { 1436 adjustViewsUpOrDown(); 1437 } 1438 } 1439 } 1440 } 1441 1442 @Override 1443 protected void layoutChildren() { 1444 final boolean blockLayoutRequests = mBlockLayoutRequests; 1445 if (!blockLayoutRequests) { 1446 mBlockLayoutRequests = true; 1447 } else { 1448 return; 1449 } 1450 1451 try { 1452 super.layoutChildren(); 1453 1454 invalidate(); 1455 1456 if (mAdapter == null) { 1457 resetList(); 1458 invokeOnItemScrollListener(); 1459 return; 1460 } 1461 1462 int childrenTop = mListPadding.top; 1463 int childrenBottom = mBottom - mTop - mListPadding.bottom; 1464 1465 int childCount = getChildCount(); 1466 int index = 0; 1467 int delta = 0; 1468 1469 View sel; 1470 View oldSel = null; 1471 View oldFirst = null; 1472 View newSel = null; 1473 1474 View focusLayoutRestoreView = null; 1475 1476 // Remember stuff we will need down below 1477 switch (mLayoutMode) { 1478 case LAYOUT_SET_SELECTION: 1479 index = mNextSelectedPosition - mFirstPosition; 1480 if (index >= 0 && index < childCount) { 1481 newSel = getChildAt(index); 1482 } 1483 break; 1484 case LAYOUT_FORCE_TOP: 1485 case LAYOUT_FORCE_BOTTOM: 1486 case LAYOUT_SPECIFIC: 1487 case LAYOUT_SYNC: 1488 break; 1489 case LAYOUT_MOVE_SELECTION: 1490 default: 1491 // Remember the previously selected view 1492 index = mSelectedPosition - mFirstPosition; 1493 if (index >= 0 && index < childCount) { 1494 oldSel = getChildAt(index); 1495 } 1496 1497 // Remember the previous first child 1498 oldFirst = getChildAt(0); 1499 1500 if (mNextSelectedPosition >= 0) { 1501 delta = mNextSelectedPosition - mSelectedPosition; 1502 } 1503 1504 // Caution: newSel might be null 1505 newSel = getChildAt(index + delta); 1506 } 1507 1508 1509 boolean dataChanged = mDataChanged; 1510 if (dataChanged) { 1511 handleDataChanged(); 1512 } 1513 1514 // Handle the empty set by removing all views that are visible 1515 // and calling it a day 1516 if (mItemCount == 0) { 1517 resetList(); 1518 invokeOnItemScrollListener(); 1519 return; 1520 } else if (mItemCount != mAdapter.getCount()) { 1521 throw new IllegalStateException("The content of the adapter has changed but " 1522 + "ListView did not receive a notification. Make sure the content of " 1523 + "your adapter is not modified from a background thread, but only " 1524 + "from the UI thread. [in ListView(" + getId() + ", " + getClass() 1525 + ") with Adapter(" + mAdapter.getClass() + ")]"); 1526 } 1527 1528 setSelectedPositionInt(mNextSelectedPosition); 1529 1530 // Pull all children into the RecycleBin. 1531 // These views will be reused if possible 1532 final int firstPosition = mFirstPosition; 1533 final RecycleBin recycleBin = mRecycler; 1534 1535 // reset the focus restoration 1536 View focusLayoutRestoreDirectChild = null; 1537 1538 // Don't put header or footer views into the Recycler. Those are 1539 // already cached in mHeaderViews; 1540 if (dataChanged) { 1541 for (int i = 0; i < childCount; i++) { 1542 recycleBin.addScrapView(getChildAt(i), firstPosition+i); 1543 if (ViewDebug.TRACE_RECYCLER) { 1544 ViewDebug.trace(getChildAt(i), 1545 ViewDebug.RecyclerTraceType.MOVE_TO_SCRAP_HEAP, index, i); 1546 } 1547 } 1548 } else { 1549 recycleBin.fillActiveViews(childCount, firstPosition); 1550 } 1551 1552 // take focus back to us temporarily to avoid the eventual 1553 // call to clear focus when removing the focused child below 1554 // from messing things up when ViewRoot assigns focus back 1555 // to someone else 1556 final View focusedChild = getFocusedChild(); 1557 if (focusedChild != null) { 1558 // TODO: in some cases focusedChild.getParent() == null 1559 1560 // we can remember the focused view to restore after relayout if the 1561 // data hasn't changed, or if the focused position is a header or footer 1562 if (!dataChanged || isDirectChildHeaderOrFooter(focusedChild)) { 1563 focusLayoutRestoreDirectChild = focusedChild; 1564 // remember the specific view that had focus 1565 focusLayoutRestoreView = findFocus(); 1566 if (focusLayoutRestoreView != null) { 1567 // tell it we are going to mess with it 1568 focusLayoutRestoreView.onStartTemporaryDetach(); 1569 } 1570 } 1571 requestFocus(); 1572 } 1573 1574 // Clear out old views 1575 detachAllViewsFromParent(); 1576 1577 switch (mLayoutMode) { 1578 case LAYOUT_SET_SELECTION: 1579 if (newSel != null) { 1580 sel = fillFromSelection(newSel.getTop(), childrenTop, childrenBottom); 1581 } else { 1582 sel = fillFromMiddle(childrenTop, childrenBottom); 1583 } 1584 break; 1585 case LAYOUT_SYNC: 1586 sel = fillSpecific(mSyncPosition, mSpecificTop); 1587 break; 1588 case LAYOUT_FORCE_BOTTOM: 1589 sel = fillUp(mItemCount - 1, childrenBottom); 1590 adjustViewsUpOrDown(); 1591 break; 1592 case LAYOUT_FORCE_TOP: 1593 mFirstPosition = 0; 1594 sel = fillFromTop(childrenTop); 1595 adjustViewsUpOrDown(); 1596 break; 1597 case LAYOUT_SPECIFIC: 1598 sel = fillSpecific(reconcileSelectedPosition(), mSpecificTop); 1599 break; 1600 case LAYOUT_MOVE_SELECTION: 1601 sel = moveSelection(oldSel, newSel, delta, childrenTop, childrenBottom); 1602 break; 1603 default: 1604 if (childCount == 0) { 1605 if (!mStackFromBottom) { 1606 final int position = lookForSelectablePosition(0, true); 1607 setSelectedPositionInt(position); 1608 sel = fillFromTop(childrenTop); 1609 } else { 1610 final int position = lookForSelectablePosition(mItemCount - 1, false); 1611 setSelectedPositionInt(position); 1612 sel = fillUp(mItemCount - 1, childrenBottom); 1613 } 1614 } else { 1615 if (mSelectedPosition >= 0 && mSelectedPosition < mItemCount) { 1616 sel = fillSpecific(mSelectedPosition, 1617 oldSel == null ? childrenTop : oldSel.getTop()); 1618 } else if (mFirstPosition < mItemCount) { 1619 sel = fillSpecific(mFirstPosition, 1620 oldFirst == null ? childrenTop : oldFirst.getTop()); 1621 } else { 1622 sel = fillSpecific(0, childrenTop); 1623 } 1624 } 1625 break; 1626 } 1627 1628 // Flush any cached views that did not get reused above 1629 recycleBin.scrapActiveViews(); 1630 1631 if (sel != null) { 1632 // the current selected item should get focus if items 1633 // are focusable 1634 if (mItemsCanFocus && hasFocus() && !sel.hasFocus()) { 1635 final boolean focusWasTaken = (sel == focusLayoutRestoreDirectChild && 1636 focusLayoutRestoreView.requestFocus()) || sel.requestFocus(); 1637 if (!focusWasTaken) { 1638 // selected item didn't take focus, fine, but still want 1639 // to make sure something else outside of the selected view 1640 // has focus 1641 final View focused = getFocusedChild(); 1642 if (focused != null) { 1643 focused.clearFocus(); 1644 } 1645 positionSelector(INVALID_POSITION, sel); 1646 } else { 1647 sel.setSelected(false); 1648 mSelectorRect.setEmpty(); 1649 } 1650 } else { 1651 positionSelector(INVALID_POSITION, sel); 1652 } 1653 mSelectedTop = sel.getTop(); 1654 } else { 1655 if (mTouchMode > TOUCH_MODE_DOWN && mTouchMode < TOUCH_MODE_SCROLL) { 1656 View child = getChildAt(mMotionPosition - mFirstPosition); 1657 if (child != null) positionSelector(mMotionPosition, child); 1658 } else { 1659 mSelectedTop = 0; 1660 mSelectorRect.setEmpty(); 1661 } 1662 1663 // even if there is not selected position, we may need to restore 1664 // focus (i.e. something focusable in touch mode) 1665 if (hasFocus() && focusLayoutRestoreView != null) { 1666 focusLayoutRestoreView.requestFocus(); 1667 } 1668 } 1669 1670 // tell focus view we are done mucking with it, if it is still in 1671 // our view hierarchy. 1672 if (focusLayoutRestoreView != null 1673 && focusLayoutRestoreView.getWindowToken() != null) { 1674 focusLayoutRestoreView.onFinishTemporaryDetach(); 1675 } 1676 1677 mLayoutMode = LAYOUT_NORMAL; 1678 mDataChanged = false; 1679 mNeedSync = false; 1680 setNextSelectedPositionInt(mSelectedPosition); 1681 1682 updateScrollIndicators(); 1683 1684 if (mItemCount > 0) { 1685 checkSelectionChanged(); 1686 } 1687 1688 invokeOnItemScrollListener(); 1689 } finally { 1690 if (!blockLayoutRequests) { 1691 mBlockLayoutRequests = false; 1692 } 1693 } 1694 } 1695 1696 /** 1697 * @param child a direct child of this list. 1698 * @return Whether child is a header or footer view. 1699 */ 1700 private boolean isDirectChildHeaderOrFooter(View child) { 1701 1702 final ArrayList<FixedViewInfo> headers = mHeaderViewInfos; 1703 final int numHeaders = headers.size(); 1704 for (int i = 0; i < numHeaders; i++) { 1705 if (child == headers.get(i).view) { 1706 return true; 1707 } 1708 } 1709 final ArrayList<FixedViewInfo> footers = mFooterViewInfos; 1710 final int numFooters = footers.size(); 1711 for (int i = 0; i < numFooters; i++) { 1712 if (child == footers.get(i).view) { 1713 return true; 1714 } 1715 } 1716 return false; 1717 } 1718 1719 /** 1720 * Obtain the view and add it to our list of children. The view can be made 1721 * fresh, converted from an unused view, or used as is if it was in the 1722 * recycle bin. 1723 * 1724 * @param position Logical position in the list 1725 * @param y Top or bottom edge of the view to add 1726 * @param flow If flow is true, align top edge to y. If false, align bottom 1727 * edge to y. 1728 * @param childrenLeft Left edge where children should be positioned 1729 * @param selected Is this position selected? 1730 * @return View that was added 1731 */ 1732 private View makeAndAddView(int position, int y, boolean flow, int childrenLeft, 1733 boolean selected) { 1734 View child; 1735 1736 1737 if (!mDataChanged) { 1738 // Try to use an existing view for this position 1739 child = mRecycler.getActiveView(position); 1740 if (child != null) { 1741 if (ViewDebug.TRACE_RECYCLER) { 1742 ViewDebug.trace(child, ViewDebug.RecyclerTraceType.RECYCLE_FROM_ACTIVE_HEAP, 1743 position, getChildCount()); 1744 } 1745 1746 // Found it -- we're using an existing child 1747 // This just needs to be positioned 1748 setupChild(child, position, y, flow, childrenLeft, selected, true); 1749 1750 return child; 1751 } 1752 } 1753 1754 // Make a new view for this position, or convert an unused view if possible 1755 child = obtainView(position, mIsScrap); 1756 1757 // This needs to be positioned and measured 1758 setupChild(child, position, y, flow, childrenLeft, selected, mIsScrap[0]); 1759 1760 return child; 1761 } 1762 1763 /** 1764 * Add a view as a child and make sure it is measured (if necessary) and 1765 * positioned properly. 1766 * 1767 * @param child The view to add 1768 * @param position The position of this child 1769 * @param y The y position relative to which this view will be positioned 1770 * @param flowDown If true, align top edge to y. If false, align bottom 1771 * edge to y. 1772 * @param childrenLeft Left edge where children should be positioned 1773 * @param selected Is this position selected? 1774 * @param recycled Has this view been pulled from the recycle bin? If so it 1775 * does not need to be remeasured. 1776 */ 1777 private void setupChild(View child, int position, int y, boolean flowDown, int childrenLeft, 1778 boolean selected, boolean recycled) { 1779 final boolean isSelected = selected && shouldShowSelector(); 1780 final boolean updateChildSelected = isSelected != child.isSelected(); 1781 final int mode = mTouchMode; 1782 final boolean isPressed = mode > TOUCH_MODE_DOWN && mode < TOUCH_MODE_SCROLL && 1783 mMotionPosition == position; 1784 final boolean updateChildPressed = isPressed != child.isPressed(); 1785 final boolean needToMeasure = !recycled || updateChildSelected || child.isLayoutRequested(); 1786 1787 // Respect layout params that are already in the view. Otherwise make some up... 1788 // noinspection unchecked 1789 AbsListView.LayoutParams p = (AbsListView.LayoutParams) child.getLayoutParams(); 1790 if (p == null) { 1791 p = new AbsListView.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, 1792 ViewGroup.LayoutParams.WRAP_CONTENT, 0); 1793 } 1794 p.viewType = mAdapter.getItemViewType(position); 1795 1796 if ((recycled && !p.forceAdd) || (p.recycledHeaderFooter && 1797 p.viewType == AdapterView.ITEM_VIEW_TYPE_HEADER_OR_FOOTER)) { 1798 attachViewToParent(child, flowDown ? -1 : 0, p); 1799 } else { 1800 p.forceAdd = false; 1801 if (p.viewType == AdapterView.ITEM_VIEW_TYPE_HEADER_OR_FOOTER) { 1802 p.recycledHeaderFooter = true; 1803 } 1804 addViewInLayout(child, flowDown ? -1 : 0, p, true); 1805 } 1806 1807 if (updateChildSelected) { 1808 child.setSelected(isSelected); 1809 } 1810 1811 if (updateChildPressed) { 1812 child.setPressed(isPressed); 1813 } 1814 1815 if (mChoiceMode != CHOICE_MODE_NONE && mCheckStates != null) { 1816 if (child instanceof Checkable) { 1817 ((Checkable) child).setChecked(mCheckStates.get(position)); 1818 } else if (getContext().getApplicationInfo().targetSdkVersion 1819 >= android.os.Build.VERSION_CODES.HONEYCOMB) { 1820 child.setActivated(mCheckStates.get(position)); 1821 } 1822 } 1823 1824 if (needToMeasure) { 1825 int childWidthSpec = ViewGroup.getChildMeasureSpec(mWidthMeasureSpec, 1826 mListPadding.left + mListPadding.right, p.width); 1827 int lpHeight = p.height; 1828 int childHeightSpec; 1829 if (lpHeight > 0) { 1830 childHeightSpec = MeasureSpec.makeMeasureSpec(lpHeight, MeasureSpec.EXACTLY); 1831 } else { 1832 childHeightSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED); 1833 } 1834 child.measure(childWidthSpec, childHeightSpec); 1835 } else { 1836 cleanupLayoutState(child); 1837 } 1838 1839 final int w = child.getMeasuredWidth(); 1840 final int h = child.getMeasuredHeight(); 1841 final int childTop = flowDown ? y : y - h; 1842 1843 if (needToMeasure) { 1844 final int childRight = childrenLeft + w; 1845 final int childBottom = childTop + h; 1846 child.layout(childrenLeft, childTop, childRight, childBottom); 1847 } else { 1848 child.offsetLeftAndRight(childrenLeft - child.getLeft()); 1849 child.offsetTopAndBottom(childTop - child.getTop()); 1850 } 1851 1852 if (mCachingStarted && !child.isDrawingCacheEnabled()) { 1853 child.setDrawingCacheEnabled(true); 1854 } 1855 1856 if (recycled && (((AbsListView.LayoutParams)child.getLayoutParams()).scrappedFromPosition) 1857 != position) { 1858 child.jumpDrawablesToCurrentState(); 1859 } 1860 } 1861 1862 @Override 1863 protected boolean canAnimate() { 1864 return super.canAnimate() && mItemCount > 0; 1865 } 1866 1867 /** 1868 * Sets the currently selected item. If in touch mode, the item will not be selected 1869 * but it will still be positioned appropriately. If the specified selection position 1870 * is less than 0, then the item at position 0 will be selected. 1871 * 1872 * @param position Index (starting at 0) of the data item to be selected. 1873 */ 1874 @Override 1875 public void setSelection(int position) { 1876 setSelectionFromTop(position, 0); 1877 } 1878 1879 /** 1880 * Sets the selected item and positions the selection y pixels from the top edge 1881 * of the ListView. (If in touch mode, the item will not be selected but it will 1882 * still be positioned appropriately.) 1883 * 1884 * @param position Index (starting at 0) of the data item to be selected. 1885 * @param y The distance from the top edge of the ListView (plus padding) that the 1886 * item will be positioned. 1887 */ 1888 public void setSelectionFromTop(int position, int y) { 1889 if (mAdapter == null) { 1890 return; 1891 } 1892 1893 if (!isInTouchMode()) { 1894 position = lookForSelectablePosition(position, true); 1895 if (position >= 0) { 1896 setNextSelectedPositionInt(position); 1897 } 1898 } else { 1899 mResurrectToPosition = position; 1900 } 1901 1902 if (position >= 0) { 1903 mLayoutMode = LAYOUT_SPECIFIC; 1904 mSpecificTop = mListPadding.top + y; 1905 1906 if (mNeedSync) { 1907 mSyncPosition = position; 1908 mSyncRowId = mAdapter.getItemId(position); 1909 } 1910 1911 requestLayout(); 1912 } 1913 } 1914 1915 /** 1916 * Makes the item at the supplied position selected. 1917 * 1918 * @param position the position of the item to select 1919 */ 1920 @Override 1921 void setSelectionInt(int position) { 1922 setNextSelectedPositionInt(position); 1923 boolean awakeScrollbars = false; 1924 1925 final int selectedPosition = mSelectedPosition; 1926 1927 if (selectedPosition >= 0) { 1928 if (position == selectedPosition - 1) { 1929 awakeScrollbars = true; 1930 } else if (position == selectedPosition + 1) { 1931 awakeScrollbars = true; 1932 } 1933 } 1934 1935 layoutChildren(); 1936 1937 if (awakeScrollbars) { 1938 awakenScrollBars(); 1939 } 1940 } 1941 1942 /** 1943 * Find a position that can be selected (i.e., is not a separator). 1944 * 1945 * @param position The starting position to look at. 1946 * @param lookDown Whether to look down for other positions. 1947 * @return The next selectable position starting at position and then searching either up or 1948 * down. Returns {@link #INVALID_POSITION} if nothing can be found. 1949 */ 1950 @Override 1951 int lookForSelectablePosition(int position, boolean lookDown) { 1952 final ListAdapter adapter = mAdapter; 1953 if (adapter == null || isInTouchMode()) { 1954 return INVALID_POSITION; 1955 } 1956 1957 final int count = adapter.getCount(); 1958 if (!mAreAllItemsSelectable) { 1959 if (lookDown) { 1960 position = Math.max(0, position); 1961 while (position < count && !adapter.isEnabled(position)) { 1962 position++; 1963 } 1964 } else { 1965 position = Math.min(position, count - 1); 1966 while (position >= 0 && !adapter.isEnabled(position)) { 1967 position--; 1968 } 1969 } 1970 1971 if (position < 0 || position >= count) { 1972 return INVALID_POSITION; 1973 } 1974 return position; 1975 } else { 1976 if (position < 0 || position >= count) { 1977 return INVALID_POSITION; 1978 } 1979 return position; 1980 } 1981 } 1982 1983 @Override 1984 public boolean dispatchPopulateAccessibilityEvent(AccessibilityEvent event) { 1985 boolean populated = super.dispatchPopulateAccessibilityEvent(event); 1986 1987 // If the item count is less than 15 then subtract disabled items from the count and 1988 // position. Otherwise ignore disabled items. 1989 if (!populated) { 1990 int itemCount = 0; 1991 int currentItemIndex = getSelectedItemPosition(); 1992 1993 ListAdapter adapter = getAdapter(); 1994 if (adapter != null) { 1995 final int count = adapter.getCount(); 1996 if (count < 15) { 1997 for (int i = 0; i < count; i++) { 1998 if (adapter.isEnabled(i)) { 1999 itemCount++; 2000 } else if (i <= currentItemIndex) { 2001 currentItemIndex--; 2002 } 2003 } 2004 } else { 2005 itemCount = count; 2006 } 2007 } 2008 2009 event.setItemCount(itemCount); 2010 event.setCurrentItemIndex(currentItemIndex); 2011 } 2012 2013 return populated; 2014 } 2015 2016 /** 2017 * setSelectionAfterHeaderView set the selection to be the first list item 2018 * after the header views. 2019 */ 2020 public void setSelectionAfterHeaderView() { 2021 final int count = mHeaderViewInfos.size(); 2022 if (count > 0) { 2023 mNextSelectedPosition = 0; 2024 return; 2025 } 2026 2027 if (mAdapter != null) { 2028 setSelection(count); 2029 } else { 2030 mNextSelectedPosition = count; 2031 mLayoutMode = LAYOUT_SET_SELECTION; 2032 } 2033 2034 } 2035 2036 @Override 2037 public boolean dispatchKeyEvent(KeyEvent event) { 2038 // Dispatch in the normal way 2039 boolean handled = super.dispatchKeyEvent(event); 2040 if (!handled) { 2041 // If we didn't handle it... 2042 View focused = getFocusedChild(); 2043 if (focused != null && event.getAction() == KeyEvent.ACTION_DOWN) { 2044 // ... and our focused child didn't handle it 2045 // ... give it to ourselves so we can scroll if necessary 2046 handled = onKeyDown(event.getKeyCode(), event); 2047 } 2048 } 2049 return handled; 2050 } 2051 2052 @Override 2053 public boolean onKeyDown(int keyCode, KeyEvent event) { 2054 return commonKey(keyCode, 1, event); 2055 } 2056 2057 @Override 2058 public boolean onKeyMultiple(int keyCode, int repeatCount, KeyEvent event) { 2059 return commonKey(keyCode, repeatCount, event); 2060 } 2061 2062 @Override 2063 public boolean onKeyUp(int keyCode, KeyEvent event) { 2064 return commonKey(keyCode, 1, event); 2065 } 2066 2067 private boolean commonKey(int keyCode, int count, KeyEvent event) { 2068 if (mAdapter == null) { 2069 return false; 2070 } 2071 2072 if (mDataChanged) { 2073 layoutChildren(); 2074 } 2075 2076 boolean handled = false; 2077 int action = event.getAction(); 2078 2079 if (action != KeyEvent.ACTION_UP) { 2080 if (mSelectedPosition < 0) { 2081 switch (keyCode) { 2082 case KeyEvent.KEYCODE_DPAD_UP: 2083 case KeyEvent.KEYCODE_DPAD_DOWN: 2084 case KeyEvent.KEYCODE_DPAD_CENTER: 2085 case KeyEvent.KEYCODE_ENTER: 2086 case KeyEvent.KEYCODE_SPACE: 2087 if (resurrectSelection()) { 2088 return true; 2089 } 2090 } 2091 } 2092 switch (keyCode) { 2093 case KeyEvent.KEYCODE_DPAD_UP: 2094 if (!event.isAltPressed()) { 2095 while (count > 0) { 2096 handled = arrowScroll(FOCUS_UP); 2097 count--; 2098 } 2099 } else { 2100 handled = fullScroll(FOCUS_UP); 2101 } 2102 break; 2103 2104 case KeyEvent.KEYCODE_DPAD_DOWN: 2105 if (!event.isAltPressed()) { 2106 while (count > 0) { 2107 handled = arrowScroll(FOCUS_DOWN); 2108 count--; 2109 } 2110 } else { 2111 handled = fullScroll(FOCUS_DOWN); 2112 } 2113 break; 2114 2115 case KeyEvent.KEYCODE_DPAD_LEFT: 2116 handled = handleHorizontalFocusWithinListItem(View.FOCUS_LEFT); 2117 break; 2118 case KeyEvent.KEYCODE_DPAD_RIGHT: 2119 handled = handleHorizontalFocusWithinListItem(View.FOCUS_RIGHT); 2120 break; 2121 2122 case KeyEvent.KEYCODE_DPAD_CENTER: 2123 case KeyEvent.KEYCODE_ENTER: 2124 if (mItemCount > 0 && event.getRepeatCount() == 0) { 2125 keyPressed(); 2126 } 2127 handled = true; 2128 break; 2129 2130 case KeyEvent.KEYCODE_SPACE: 2131 if (mPopup == null || !mPopup.isShowing()) { 2132 if (!event.isShiftPressed()) { 2133 pageScroll(FOCUS_DOWN); 2134 } else { 2135 pageScroll(FOCUS_UP); 2136 } 2137 handled = true; 2138 } 2139 break; 2140 } 2141 } 2142 2143 if (!handled) { 2144 handled = sendToTextFilter(keyCode, count, event); 2145 } 2146 2147 if (handled) { 2148 return true; 2149 } else { 2150 switch (action) { 2151 case KeyEvent.ACTION_DOWN: 2152 return super.onKeyDown(keyCode, event); 2153 2154 case KeyEvent.ACTION_UP: 2155 return super.onKeyUp(keyCode, event); 2156 2157 case KeyEvent.ACTION_MULTIPLE: 2158 return super.onKeyMultiple(keyCode, count, event); 2159 2160 default: // shouldn't happen 2161 return false; 2162 } 2163 } 2164 } 2165 2166 /** 2167 * Scrolls up or down by the number of items currently present on screen. 2168 * 2169 * @param direction either {@link View#FOCUS_UP} or {@link View#FOCUS_DOWN} 2170 * @return whether selection was moved 2171 */ 2172 boolean pageScroll(int direction) { 2173 int nextPage = -1; 2174 boolean down = false; 2175 2176 if (direction == FOCUS_UP) { 2177 nextPage = Math.max(0, mSelectedPosition - getChildCount() - 1); 2178 } else if (direction == FOCUS_DOWN) { 2179 nextPage = Math.min(mItemCount - 1, mSelectedPosition + getChildCount() - 1); 2180 down = true; 2181 } 2182 2183 if (nextPage >= 0) { 2184 int position = lookForSelectablePosition(nextPage, down); 2185 if (position >= 0) { 2186 mLayoutMode = LAYOUT_SPECIFIC; 2187 mSpecificTop = mPaddingTop + getVerticalFadingEdgeLength(); 2188 2189 if (down && position > mItemCount - getChildCount()) { 2190 mLayoutMode = LAYOUT_FORCE_BOTTOM; 2191 } 2192 2193 if (!down && position < getChildCount()) { 2194 mLayoutMode = LAYOUT_FORCE_TOP; 2195 } 2196 2197 setSelectionInt(position); 2198 invokeOnItemScrollListener(); 2199 if (!awakenScrollBars()) { 2200 invalidate(); 2201 } 2202 2203 return true; 2204 } 2205 } 2206 2207 return false; 2208 } 2209 2210 /** 2211 * Go to the last or first item if possible (not worrying about panning across or navigating 2212 * within the internal focus of the currently selected item.) 2213 * 2214 * @param direction either {@link View#FOCUS_UP} or {@link View#FOCUS_DOWN} 2215 * 2216 * @return whether selection was moved 2217 */ 2218 boolean fullScroll(int direction) { 2219 boolean moved = false; 2220 if (direction == FOCUS_UP) { 2221 if (mSelectedPosition != 0) { 2222 int position = lookForSelectablePosition(0, true); 2223 if (position >= 0) { 2224 mLayoutMode = LAYOUT_FORCE_TOP; 2225 setSelectionInt(position); 2226 invokeOnItemScrollListener(); 2227 } 2228 moved = true; 2229 } 2230 } else if (direction == FOCUS_DOWN) { 2231 if (mSelectedPosition < mItemCount - 1) { 2232 int position = lookForSelectablePosition(mItemCount - 1, true); 2233 if (position >= 0) { 2234 mLayoutMode = LAYOUT_FORCE_BOTTOM; 2235 setSelectionInt(position); 2236 invokeOnItemScrollListener(); 2237 } 2238 moved = true; 2239 } 2240 } 2241 2242 if (moved && !awakenScrollBars()) { 2243 awakenScrollBars(); 2244 invalidate(); 2245 } 2246 2247 return moved; 2248 } 2249 2250 /** 2251 * To avoid horizontal focus searches changing the selected item, we 2252 * manually focus search within the selected item (as applicable), and 2253 * prevent focus from jumping to something within another item. 2254 * @param direction one of {View.FOCUS_LEFT, View.FOCUS_RIGHT} 2255 * @return Whether this consumes the key event. 2256 */ 2257 private boolean handleHorizontalFocusWithinListItem(int direction) { 2258 if (direction != View.FOCUS_LEFT && direction != View.FOCUS_RIGHT) { 2259 throw new IllegalArgumentException("direction must be one of" 2260 + " {View.FOCUS_LEFT, View.FOCUS_RIGHT}"); 2261 } 2262 2263 final int numChildren = getChildCount(); 2264 if (mItemsCanFocus && numChildren > 0 && mSelectedPosition != INVALID_POSITION) { 2265 final View selectedView = getSelectedView(); 2266 if (selectedView != null && selectedView.hasFocus() && 2267 selectedView instanceof ViewGroup) { 2268 2269 final View currentFocus = selectedView.findFocus(); 2270 final View nextFocus = FocusFinder.getInstance().findNextFocus( 2271 (ViewGroup) selectedView, currentFocus, direction); 2272 if (nextFocus != null) { 2273 // do the math to get interesting rect in next focus' coordinates 2274 currentFocus.getFocusedRect(mTempRect); 2275 offsetDescendantRectToMyCoords(currentFocus, mTempRect); 2276 offsetRectIntoDescendantCoords(nextFocus, mTempRect); 2277 if (nextFocus.requestFocus(direction, mTempRect)) { 2278 return true; 2279 } 2280 } 2281 // we are blocking the key from being handled (by returning true) 2282 // if the global result is going to be some other view within this 2283 // list. this is to acheive the overall goal of having 2284 // horizontal d-pad navigation remain in the current item. 2285 final View globalNextFocus = FocusFinder.getInstance().findNextFocus( 2286 (ViewGroup) getRootView(), currentFocus, direction); 2287 if (globalNextFocus != null) { 2288 return isViewAncestorOf(globalNextFocus, this); 2289 } 2290 } 2291 } 2292 return false; 2293 } 2294 2295 /** 2296 * Scrolls to the next or previous item if possible. 2297 * 2298 * @param direction either {@link View#FOCUS_UP} or {@link View#FOCUS_DOWN} 2299 * 2300 * @return whether selection was moved 2301 */ 2302 boolean arrowScroll(int direction) { 2303 try { 2304 mInLayout = true; 2305 final boolean handled = arrowScrollImpl(direction); 2306 if (handled) { 2307 playSoundEffect(SoundEffectConstants.getContantForFocusDirection(direction)); 2308 } 2309 return handled; 2310 } finally { 2311 mInLayout = false; 2312 } 2313 } 2314 2315 /** 2316 * Handle an arrow scroll going up or down. Take into account whether items are selectable, 2317 * whether there are focusable items etc. 2318 * 2319 * @param direction Either {@link android.view.View#FOCUS_UP} or {@link android.view.View#FOCUS_DOWN}. 2320 * @return Whether any scrolling, selection or focus change occured. 2321 */ 2322 private boolean arrowScrollImpl(int direction) { 2323 if (getChildCount() <= 0) { 2324 return false; 2325 } 2326 2327 View selectedView = getSelectedView(); 2328 int selectedPos = mSelectedPosition; 2329 2330 int nextSelectedPosition = lookForSelectablePositionOnScreen(direction); 2331 int amountToScroll = amountToScroll(direction, nextSelectedPosition); 2332 2333 // if we are moving focus, we may OVERRIDE the default behavior 2334 final ArrowScrollFocusResult focusResult = mItemsCanFocus ? arrowScrollFocused(direction) : null; 2335 if (focusResult != null) { 2336 nextSelectedPosition = focusResult.getSelectedPosition(); 2337 amountToScroll = focusResult.getAmountToScroll(); 2338 } 2339 2340 boolean needToRedraw = focusResult != null; 2341 if (nextSelectedPosition != INVALID_POSITION) { 2342 handleNewSelectionChange(selectedView, direction, nextSelectedPosition, focusResult != null); 2343 setSelectedPositionInt(nextSelectedPosition); 2344 setNextSelectedPositionInt(nextSelectedPosition); 2345 selectedView = getSelectedView(); 2346 selectedPos = nextSelectedPosition; 2347 if (mItemsCanFocus && focusResult == null) { 2348 // there was no new view found to take focus, make sure we 2349 // don't leave focus with the old selection 2350 final View focused = getFocusedChild(); 2351 if (focused != null) { 2352 focused.clearFocus(); 2353 } 2354 } 2355 needToRedraw = true; 2356 checkSelectionChanged(); 2357 } 2358 2359 if (amountToScroll > 0) { 2360 scrollListItemsBy((direction == View.FOCUS_UP) ? amountToScroll : -amountToScroll); 2361 needToRedraw = true; 2362 } 2363 2364 // if we didn't find a new focusable, make sure any existing focused 2365 // item that was panned off screen gives up focus. 2366 if (mItemsCanFocus && (focusResult == null) 2367 && selectedView != null && selectedView.hasFocus()) { 2368 final View focused = selectedView.findFocus(); 2369 if (distanceToView(focused) > 0) { 2370 focused.clearFocus(); 2371 } 2372 } 2373 2374 // if the current selection is panned off, we need to remove the selection 2375 if (nextSelectedPosition == INVALID_POSITION && selectedView != null 2376 && !isViewAncestorOf(selectedView, this)) { 2377 selectedView = null; 2378 hideSelector(); 2379 2380 // but we don't want to set the ressurect position (that would make subsequent 2381 // unhandled key events bring back the item we just scrolled off!) 2382 mResurrectToPosition = INVALID_POSITION; 2383 } 2384 2385 if (needToRedraw) { 2386 if (selectedView != null) { 2387 positionSelector(selectedPos, selectedView); 2388 mSelectedTop = selectedView.getTop(); 2389 } 2390 if (!awakenScrollBars()) { 2391 invalidate(); 2392 } 2393 invokeOnItemScrollListener(); 2394 return true; 2395 } 2396 2397 return false; 2398 } 2399 2400 /** 2401 * When selection changes, it is possible that the previously selected or the 2402 * next selected item will change its size. If so, we need to offset some folks, 2403 * and re-layout the items as appropriate. 2404 * 2405 * @param selectedView The currently selected view (before changing selection). 2406 * should be <code>null</code> if there was no previous selection. 2407 * @param direction Either {@link android.view.View#FOCUS_UP} or 2408 * {@link android.view.View#FOCUS_DOWN}. 2409 * @param newSelectedPosition The position of the next selection. 2410 * @param newFocusAssigned whether new focus was assigned. This matters because 2411 * when something has focus, we don't want to show selection (ugh). 2412 */ 2413 private void handleNewSelectionChange(View selectedView, int direction, int newSelectedPosition, 2414 boolean newFocusAssigned) { 2415 if (newSelectedPosition == INVALID_POSITION) { 2416 throw new IllegalArgumentException("newSelectedPosition needs to be valid"); 2417 } 2418 2419 // whether or not we are moving down or up, we want to preserve the 2420 // top of whatever view is on top: 2421 // - moving down: the view that had selection 2422 // - moving up: the view that is getting selection 2423 View topView; 2424 View bottomView; 2425 int topViewIndex, bottomViewIndex; 2426 boolean topSelected = false; 2427 final int selectedIndex = mSelectedPosition - mFirstPosition; 2428 final int nextSelectedIndex = newSelectedPosition - mFirstPosition; 2429 if (direction == View.FOCUS_UP) { 2430 topViewIndex = nextSelectedIndex; 2431 bottomViewIndex = selectedIndex; 2432 topView = getChildAt(topViewIndex); 2433 bottomView = selectedView; 2434 topSelected = true; 2435 } else { 2436 topViewIndex = selectedIndex; 2437 bottomViewIndex = nextSelectedIndex; 2438 topView = selectedView; 2439 bottomView = getChildAt(bottomViewIndex); 2440 } 2441 2442 final int numChildren = getChildCount(); 2443 2444 // start with top view: is it changing size? 2445 if (topView != null) { 2446 topView.setSelected(!newFocusAssigned && topSelected); 2447 measureAndAdjustDown(topView, topViewIndex, numChildren); 2448 } 2449 2450 // is the bottom view changing size? 2451 if (bottomView != null) { 2452 bottomView.setSelected(!newFocusAssigned && !topSelected); 2453 measureAndAdjustDown(bottomView, bottomViewIndex, numChildren); 2454 } 2455 } 2456 2457 /** 2458 * Re-measure a child, and if its height changes, lay it out preserving its 2459 * top, and adjust the children below it appropriately. 2460 * @param child The child 2461 * @param childIndex The view group index of the child. 2462 * @param numChildren The number of children in the view group. 2463 */ 2464 private void measureAndAdjustDown(View child, int childIndex, int numChildren) { 2465 int oldHeight = child.getHeight(); 2466 measureItem(child); 2467 if (child.getMeasuredHeight() != oldHeight) { 2468 // lay out the view, preserving its top 2469 relayoutMeasuredItem(child); 2470 2471 // adjust views below appropriately 2472 final int heightDelta = child.getMeasuredHeight() - oldHeight; 2473 for (int i = childIndex + 1; i < numChildren; i++) { 2474 getChildAt(i).offsetTopAndBottom(heightDelta); 2475 } 2476 } 2477 } 2478 2479 /** 2480 * Measure a particular list child. 2481 * TODO: unify with setUpChild. 2482 * @param child The child. 2483 */ 2484 private void measureItem(View child) { 2485 ViewGroup.LayoutParams p = child.getLayoutParams(); 2486 if (p == null) { 2487 p = new ViewGroup.LayoutParams( 2488 ViewGroup.LayoutParams.MATCH_PARENT, 2489 ViewGroup.LayoutParams.WRAP_CONTENT); 2490 } 2491 2492 int childWidthSpec = ViewGroup.getChildMeasureSpec(mWidthMeasureSpec, 2493 mListPadding.left + mListPadding.right, p.width); 2494 int lpHeight = p.height; 2495 int childHeightSpec; 2496 if (lpHeight > 0) { 2497 childHeightSpec = MeasureSpec.makeMeasureSpec(lpHeight, MeasureSpec.EXACTLY); 2498 } else { 2499 childHeightSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED); 2500 } 2501 child.measure(childWidthSpec, childHeightSpec); 2502 } 2503 2504 /** 2505 * Layout a child that has been measured, preserving its top position. 2506 * TODO: unify with setUpChild. 2507 * @param child The child. 2508 */ 2509 private void relayoutMeasuredItem(View child) { 2510 final int w = child.getMeasuredWidth(); 2511 final int h = child.getMeasuredHeight(); 2512 final int childLeft = mListPadding.left; 2513 final int childRight = childLeft + w; 2514 final int childTop = child.getTop(); 2515 final int childBottom = childTop + h; 2516 child.layout(childLeft, childTop, childRight, childBottom); 2517 } 2518 2519 /** 2520 * @return The amount to preview next items when arrow srolling. 2521 */ 2522 private int getArrowScrollPreviewLength() { 2523 return Math.max(MIN_SCROLL_PREVIEW_PIXELS, getVerticalFadingEdgeLength()); 2524 } 2525 2526 /** 2527 * Determine how much we need to scroll in order to get the next selected view 2528 * visible, with a fading edge showing below as applicable. The amount is 2529 * capped at {@link #getMaxScrollAmount()} . 2530 * 2531 * @param direction either {@link android.view.View#FOCUS_UP} or 2532 * {@link android.view.View#FOCUS_DOWN}. 2533 * @param nextSelectedPosition The position of the next selection, or 2534 * {@link #INVALID_POSITION} if there is no next selectable position 2535 * @return The amount to scroll. Note: this is always positive! Direction 2536 * needs to be taken into account when actually scrolling. 2537 */ 2538 private int amountToScroll(int direction, int nextSelectedPosition) { 2539 final int listBottom = getHeight() - mListPadding.bottom; 2540 final int listTop = mListPadding.top; 2541 2542 final int numChildren = getChildCount(); 2543 2544 if (direction == View.FOCUS_DOWN) { 2545 int indexToMakeVisible = numChildren - 1; 2546 if (nextSelectedPosition != INVALID_POSITION) { 2547 indexToMakeVisible = nextSelectedPosition - mFirstPosition; 2548 } 2549 2550 final int positionToMakeVisible = mFirstPosition + indexToMakeVisible; 2551 final View viewToMakeVisible = getChildAt(indexToMakeVisible); 2552 2553 int goalBottom = listBottom; 2554 if (positionToMakeVisible < mItemCount - 1) { 2555 goalBottom -= getArrowScrollPreviewLength(); 2556 } 2557 2558 if (viewToMakeVisible.getBottom() <= goalBottom) { 2559 // item is fully visible. 2560 return 0; 2561 } 2562 2563 if (nextSelectedPosition != INVALID_POSITION 2564 && (goalBottom - viewToMakeVisible.getTop()) >= getMaxScrollAmount()) { 2565 // item already has enough of it visible, changing selection is good enough 2566 return 0; 2567 } 2568 2569 int amountToScroll = (viewToMakeVisible.getBottom() - goalBottom); 2570 2571 if ((mFirstPosition + numChildren) == mItemCount) { 2572 // last is last in list -> make sure we don't scroll past it 2573 final int max = getChildAt(numChildren - 1).getBottom() - listBottom; 2574 amountToScroll = Math.min(amountToScroll, max); 2575 } 2576 2577 return Math.min(amountToScroll, getMaxScrollAmount()); 2578 } else { 2579 int indexToMakeVisible = 0; 2580 if (nextSelectedPosition != INVALID_POSITION) { 2581 indexToMakeVisible = nextSelectedPosition - mFirstPosition; 2582 } 2583 final int positionToMakeVisible = mFirstPosition + indexToMakeVisible; 2584 final View viewToMakeVisible = getChildAt(indexToMakeVisible); 2585 int goalTop = listTop; 2586 if (positionToMakeVisible > 0) { 2587 goalTop += getArrowScrollPreviewLength(); 2588 } 2589 if (viewToMakeVisible.getTop() >= goalTop) { 2590 // item is fully visible. 2591 return 0; 2592 } 2593 2594 if (nextSelectedPosition != INVALID_POSITION && 2595 (viewToMakeVisible.getBottom() - goalTop) >= getMaxScrollAmount()) { 2596 // item already has enough of it visible, changing selection is good enough 2597 return 0; 2598 } 2599 2600 int amountToScroll = (goalTop - viewToMakeVisible.getTop()); 2601 if (mFirstPosition == 0) { 2602 // first is first in list -> make sure we don't scroll past it 2603 final int max = listTop - getChildAt(0).getTop(); 2604 amountToScroll = Math.min(amountToScroll, max); 2605 } 2606 return Math.min(amountToScroll, getMaxScrollAmount()); 2607 } 2608 } 2609 2610 /** 2611 * Holds results of focus aware arrow scrolling. 2612 */ 2613 static private class ArrowScrollFocusResult { 2614 private int mSelectedPosition; 2615 private int mAmountToScroll; 2616 2617 /** 2618 * How {@link android.widget.ListView#arrowScrollFocused} returns its values. 2619 */ 2620 void populate(int selectedPosition, int amountToScroll) { 2621 mSelectedPosition = selectedPosition; 2622 mAmountToScroll = amountToScroll; 2623 } 2624 2625 public int getSelectedPosition() { 2626 return mSelectedPosition; 2627 } 2628 2629 public int getAmountToScroll() { 2630 return mAmountToScroll; 2631 } 2632 } 2633 2634 /** 2635 * @param direction either {@link android.view.View#FOCUS_UP} or 2636 * {@link android.view.View#FOCUS_DOWN}. 2637 * @return The position of the next selectable position of the views that 2638 * are currently visible, taking into account the fact that there might 2639 * be no selection. Returns {@link #INVALID_POSITION} if there is no 2640 * selectable view on screen in the given direction. 2641 */ 2642 private int lookForSelectablePositionOnScreen(int direction) { 2643 final int firstPosition = mFirstPosition; 2644 if (direction == View.FOCUS_DOWN) { 2645 int startPos = (mSelectedPosition != INVALID_POSITION) ? 2646 mSelectedPosition + 1 : 2647 firstPosition; 2648 if (startPos >= mAdapter.getCount()) { 2649 return INVALID_POSITION; 2650 } 2651 if (startPos < firstPosition) { 2652 startPos = firstPosition; 2653 } 2654 2655 final int lastVisiblePos = getLastVisiblePosition(); 2656 final ListAdapter adapter = getAdapter(); 2657 for (int pos = startPos; pos <= lastVisiblePos; pos++) { 2658 if (adapter.isEnabled(pos) 2659 && getChildAt(pos - firstPosition).getVisibility() == View.VISIBLE) { 2660 return pos; 2661 } 2662 } 2663 } else { 2664 int last = firstPosition + getChildCount() - 1; 2665 int startPos = (mSelectedPosition != INVALID_POSITION) ? 2666 mSelectedPosition - 1 : 2667 firstPosition + getChildCount() - 1; 2668 if (startPos < 0) { 2669 return INVALID_POSITION; 2670 } 2671 if (startPos > last) { 2672 startPos = last; 2673 } 2674 2675 final ListAdapter adapter = getAdapter(); 2676 for (int pos = startPos; pos >= firstPosition; pos--) { 2677 if (adapter.isEnabled(pos) 2678 && getChildAt(pos - firstPosition).getVisibility() == View.VISIBLE) { 2679 return pos; 2680 } 2681 } 2682 } 2683 return INVALID_POSITION; 2684 } 2685 2686 /** 2687 * Do an arrow scroll based on focus searching. If a new view is 2688 * given focus, return the selection delta and amount to scroll via 2689 * an {@link ArrowScrollFocusResult}, otherwise, return null. 2690 * 2691 * @param direction either {@link android.view.View#FOCUS_UP} or 2692 * {@link android.view.View#FOCUS_DOWN}. 2693 * @return The result if focus has changed, or <code>null</code>. 2694 */ 2695 private ArrowScrollFocusResult arrowScrollFocused(final int direction) { 2696 final View selectedView = getSelectedView(); 2697 View newFocus; 2698 if (selectedView != null && selectedView.hasFocus()) { 2699 View oldFocus = selectedView.findFocus(); 2700 newFocus = FocusFinder.getInstance().findNextFocus(this, oldFocus, direction); 2701 } else { 2702 if (direction == View.FOCUS_DOWN) { 2703 final boolean topFadingEdgeShowing = (mFirstPosition > 0); 2704 final int listTop = mListPadding.top + 2705 (topFadingEdgeShowing ? getArrowScrollPreviewLength() : 0); 2706 final int ySearchPoint = 2707 (selectedView != null && selectedView.getTop() > listTop) ? 2708 selectedView.getTop() : 2709 listTop; 2710 mTempRect.set(0, ySearchPoint, 0, ySearchPoint); 2711 } else { 2712 final boolean bottomFadingEdgeShowing = 2713 (mFirstPosition + getChildCount() - 1) < mItemCount; 2714 final int listBottom = getHeight() - mListPadding.bottom - 2715 (bottomFadingEdgeShowing ? getArrowScrollPreviewLength() : 0); 2716 final int ySearchPoint = 2717 (selectedView != null && selectedView.getBottom() < listBottom) ? 2718 selectedView.getBottom() : 2719 listBottom; 2720 mTempRect.set(0, ySearchPoint, 0, ySearchPoint); 2721 } 2722 newFocus = FocusFinder.getInstance().findNextFocusFromRect(this, mTempRect, direction); 2723 } 2724 2725 if (newFocus != null) { 2726 final int positionOfNewFocus = positionOfNewFocus(newFocus); 2727 2728 // if the focus change is in a different new position, make sure 2729 // we aren't jumping over another selectable position 2730 if (mSelectedPosition != INVALID_POSITION && positionOfNewFocus != mSelectedPosition) { 2731 final int selectablePosition = lookForSelectablePositionOnScreen(direction); 2732 if (selectablePosition != INVALID_POSITION && 2733 ((direction == View.FOCUS_DOWN && selectablePosition < positionOfNewFocus) || 2734 (direction == View.FOCUS_UP && selectablePosition > positionOfNewFocus))) { 2735 return null; 2736 } 2737 } 2738 2739 int focusScroll = amountToScrollToNewFocus(direction, newFocus, positionOfNewFocus); 2740 2741 final int maxScrollAmount = getMaxScrollAmount(); 2742 if (focusScroll < maxScrollAmount) { 2743 // not moving too far, safe to give next view focus 2744 newFocus.requestFocus(direction); 2745 mArrowScrollFocusResult.populate(positionOfNewFocus, focusScroll); 2746 return mArrowScrollFocusResult; 2747 } else if (distanceToView(newFocus) < maxScrollAmount){ 2748 // Case to consider: 2749 // too far to get entire next focusable on screen, but by going 2750 // max scroll amount, we are getting it at least partially in view, 2751 // so give it focus and scroll the max ammount. 2752 newFocus.requestFocus(direction); 2753 mArrowScrollFocusResult.populate(positionOfNewFocus, maxScrollAmount); 2754 return mArrowScrollFocusResult; 2755 } 2756 } 2757 return null; 2758 } 2759 2760 /** 2761 * @param newFocus The view that would have focus. 2762 * @return the position that contains newFocus 2763 */ 2764 private int positionOfNewFocus(View newFocus) { 2765 final int numChildren = getChildCount(); 2766 for (int i = 0; i < numChildren; i++) { 2767 final View child = getChildAt(i); 2768 if (isViewAncestorOf(newFocus, child)) { 2769 return mFirstPosition + i; 2770 } 2771 } 2772 throw new IllegalArgumentException("newFocus is not a child of any of the" 2773 + " children of the list!"); 2774 } 2775 2776 /** 2777 * Return true if child is an ancestor of parent, (or equal to the parent). 2778 */ 2779 private boolean isViewAncestorOf(View child, View parent) { 2780 if (child == parent) { 2781 return true; 2782 } 2783 2784 final ViewParent theParent = child.getParent(); 2785 return (theParent instanceof ViewGroup) && isViewAncestorOf((View) theParent, parent); 2786 } 2787 2788 /** 2789 * Determine how much we need to scroll in order to get newFocus in view. 2790 * @param direction either {@link android.view.View#FOCUS_UP} or 2791 * {@link android.view.View#FOCUS_DOWN}. 2792 * @param newFocus The view that would take focus. 2793 * @param positionOfNewFocus The position of the list item containing newFocus 2794 * @return The amount to scroll. Note: this is always positive! Direction 2795 * needs to be taken into account when actually scrolling. 2796 */ 2797 private int amountToScrollToNewFocus(int direction, View newFocus, int positionOfNewFocus) { 2798 int amountToScroll = 0; 2799 newFocus.getDrawingRect(mTempRect); 2800 offsetDescendantRectToMyCoords(newFocus, mTempRect); 2801 if (direction == View.FOCUS_UP) { 2802 if (mTempRect.top < mListPadding.top) { 2803 amountToScroll = mListPadding.top - mTempRect.top; 2804 if (positionOfNewFocus > 0) { 2805 amountToScroll += getArrowScrollPreviewLength(); 2806 } 2807 } 2808 } else { 2809 final int listBottom = getHeight() - mListPadding.bottom; 2810 if (mTempRect.bottom > listBottom) { 2811 amountToScroll = mTempRect.bottom - listBottom; 2812 if (positionOfNewFocus < mItemCount - 1) { 2813 amountToScroll += getArrowScrollPreviewLength(); 2814 } 2815 } 2816 } 2817 return amountToScroll; 2818 } 2819 2820 /** 2821 * Determine the distance to the nearest edge of a view in a particular 2822 * direction. 2823 * 2824 * @param descendant A descendant of this list. 2825 * @return The distance, or 0 if the nearest edge is already on screen. 2826 */ 2827 private int distanceToView(View descendant) { 2828 int distance = 0; 2829 descendant.getDrawingRect(mTempRect); 2830 offsetDescendantRectToMyCoords(descendant, mTempRect); 2831 final int listBottom = mBottom - mTop - mListPadding.bottom; 2832 if (mTempRect.bottom < mListPadding.top) { 2833 distance = mListPadding.top - mTempRect.bottom; 2834 } else if (mTempRect.top > listBottom) { 2835 distance = mTempRect.top - listBottom; 2836 } 2837 return distance; 2838 } 2839 2840 2841 /** 2842 * Scroll the children by amount, adding a view at the end and removing 2843 * views that fall off as necessary. 2844 * 2845 * @param amount The amount (positive or negative) to scroll. 2846 */ 2847 private void scrollListItemsBy(int amount) { 2848 offsetChildrenTopAndBottom(amount); 2849 2850 final int listBottom = getHeight() - mListPadding.bottom; 2851 final int listTop = mListPadding.top; 2852 final AbsListView.RecycleBin recycleBin = mRecycler; 2853 2854 if (amount < 0) { 2855 // shifted items up 2856 2857 // may need to pan views into the bottom space 2858 int numChildren = getChildCount(); 2859 View last = getChildAt(numChildren - 1); 2860 while (last.getBottom() < listBottom) { 2861 final int lastVisiblePosition = mFirstPosition + numChildren - 1; 2862 if (lastVisiblePosition < mItemCount - 1) { 2863 last = addViewBelow(last, lastVisiblePosition); 2864 numChildren++; 2865 } else { 2866 break; 2867 } 2868 } 2869 2870 // may have brought in the last child of the list that is skinnier 2871 // than the fading edge, thereby leaving space at the end. need 2872 // to shift back 2873 if (last.getBottom() < listBottom) { 2874 offsetChildrenTopAndBottom(listBottom - last.getBottom()); 2875 } 2876 2877 // top views may be panned off screen 2878 View first = getChildAt(0); 2879 while (first.getBottom() < listTop) { 2880 AbsListView.LayoutParams layoutParams = (LayoutParams) first.getLayoutParams(); 2881 if (recycleBin.shouldRecycleViewType(layoutParams.viewType)) { 2882 detachViewFromParent(first); 2883 recycleBin.addScrapView(first, mFirstPosition); 2884 } else { 2885 removeViewInLayout(first); 2886 } 2887 first = getChildAt(0); 2888 mFirstPosition++; 2889 } 2890 } else { 2891 // shifted items down 2892 View first = getChildAt(0); 2893 2894 // may need to pan views into top 2895 while ((first.getTop() > listTop) && (mFirstPosition > 0)) { 2896 first = addViewAbove(first, mFirstPosition); 2897 mFirstPosition--; 2898 } 2899 2900 // may have brought the very first child of the list in too far and 2901 // need to shift it back 2902 if (first.getTop() > listTop) { 2903 offsetChildrenTopAndBottom(listTop - first.getTop()); 2904 } 2905 2906 int lastIndex = getChildCount() - 1; 2907 View last = getChildAt(lastIndex); 2908 2909 // bottom view may be panned off screen 2910 while (last.getTop() > listBottom) { 2911 AbsListView.LayoutParams layoutParams = (LayoutParams) last.getLayoutParams(); 2912 if (recycleBin.shouldRecycleViewType(layoutParams.viewType)) { 2913 detachViewFromParent(last); 2914 recycleBin.addScrapView(last, mFirstPosition+lastIndex); 2915 } else { 2916 removeViewInLayout(last); 2917 } 2918 last = getChildAt(--lastIndex); 2919 } 2920 } 2921 } 2922 2923 private View addViewAbove(View theView, int position) { 2924 int abovePosition = position - 1; 2925 View view = obtainView(abovePosition, mIsScrap); 2926 int edgeOfNewChild = theView.getTop() - mDividerHeight; 2927 setupChild(view, abovePosition, edgeOfNewChild, false, mListPadding.left, 2928 false, mIsScrap[0]); 2929 return view; 2930 } 2931 2932 private View addViewBelow(View theView, int position) { 2933 int belowPosition = position + 1; 2934 View view = obtainView(belowPosition, mIsScrap); 2935 int edgeOfNewChild = theView.getBottom() + mDividerHeight; 2936 setupChild(view, belowPosition, edgeOfNewChild, true, mListPadding.left, 2937 false, mIsScrap[0]); 2938 return view; 2939 } 2940 2941 /** 2942 * Indicates that the views created by the ListAdapter can contain focusable 2943 * items. 2944 * 2945 * @param itemsCanFocus true if items can get focus, false otherwise 2946 */ 2947 public void setItemsCanFocus(boolean itemsCanFocus) { 2948 mItemsCanFocus = itemsCanFocus; 2949 if (!itemsCanFocus) { 2950 setDescendantFocusability(ViewGroup.FOCUS_BLOCK_DESCENDANTS); 2951 } 2952 } 2953 2954 /** 2955 * @return Whether the views created by the ListAdapter can contain focusable 2956 * items. 2957 */ 2958 public boolean getItemsCanFocus() { 2959 return mItemsCanFocus; 2960 } 2961 2962 /** 2963 * @hide Pending API council approval. 2964 */ 2965 @Override 2966 public boolean isOpaque() { 2967 return (mCachingStarted && mIsCacheColorOpaque && mDividerIsOpaque && 2968 hasOpaqueScrollbars()) || super.isOpaque(); 2969 } 2970 2971 @Override 2972 public void setCacheColorHint(int color) { 2973 final boolean opaque = (color >>> 24) == 0xFF; 2974 mIsCacheColorOpaque = opaque; 2975 if (opaque) { 2976 if (mDividerPaint == null) { 2977 mDividerPaint = new Paint(); 2978 } 2979 mDividerPaint.setColor(color); 2980 } 2981 super.setCacheColorHint(color); 2982 } 2983 2984 void drawOverscrollHeader(Canvas canvas, Drawable drawable, Rect bounds) { 2985 final int height = drawable.getMinimumHeight(); 2986 2987 canvas.save(); 2988 canvas.clipRect(bounds); 2989 2990 final int span = bounds.bottom - bounds.top; 2991 if (span < height) { 2992 bounds.top = bounds.bottom - height; 2993 } 2994 2995 drawable.setBounds(bounds); 2996 drawable.draw(canvas); 2997 2998 canvas.restore(); 2999 } 3000 3001 void drawOverscrollFooter(Canvas canvas, Drawable drawable, Rect bounds) { 3002 final int height = drawable.getMinimumHeight(); 3003 3004 canvas.save(); 3005 canvas.clipRect(bounds); 3006 3007 final int span = bounds.bottom - bounds.top; 3008 if (span < height) { 3009 bounds.bottom = bounds.top + height; 3010 } 3011 3012 drawable.setBounds(bounds); 3013 drawable.draw(canvas); 3014 3015 canvas.restore(); 3016 } 3017 3018 @Override 3019 protected void dispatchDraw(Canvas canvas) { 3020 // Draw the dividers 3021 final int dividerHeight = mDividerHeight; 3022 final Drawable overscrollHeader = mOverScrollHeader; 3023 final Drawable overscrollFooter = mOverScrollFooter; 3024 final boolean drawOverscrollHeader = overscrollHeader != null; 3025 final boolean drawOverscrollFooter = overscrollFooter != null; 3026 final boolean drawDividers = dividerHeight > 0 && mDivider != null; 3027 3028 if (drawDividers || drawOverscrollHeader || drawOverscrollFooter) { 3029 // Only modify the top and bottom in the loop, we set the left and right here 3030 final Rect bounds = mTempRect; 3031 bounds.left = mPaddingLeft; 3032 bounds.right = mRight - mLeft - mPaddingRight; 3033 3034 final int count = getChildCount(); 3035 final int headerCount = mHeaderViewInfos.size(); 3036 final int itemCount = mItemCount; 3037 final int footerLimit = itemCount - mFooterViewInfos.size() - 1; 3038 final boolean headerDividers = mHeaderDividersEnabled; 3039 final boolean footerDividers = mFooterDividersEnabled; 3040 final int first = mFirstPosition; 3041 final boolean areAllItemsSelectable = mAreAllItemsSelectable; 3042 final ListAdapter adapter = mAdapter; 3043 // If the list is opaque *and* the background is not, we want to 3044 // fill a rect where the dividers would be for non-selectable items 3045 // If the list is opaque and the background is also opaque, we don't 3046 // need to draw anything since the background will do it for us 3047 final boolean fillForMissingDividers = isOpaque() && !super.isOpaque(); 3048 3049 if (fillForMissingDividers && mDividerPaint == null && mIsCacheColorOpaque) { 3050 mDividerPaint = new Paint(); 3051 mDividerPaint.setColor(getCacheColorHint()); 3052 } 3053 final Paint paint = mDividerPaint; 3054 3055 final int listBottom = mBottom - mTop - mListPadding.bottom + mScrollY; 3056 if (!mStackFromBottom) { 3057 int bottom = 0; 3058 3059 // Draw top divider or header for overscroll 3060 final int scrollY = mScrollY; 3061 if (count > 0 && scrollY < 0) { 3062 if (drawOverscrollHeader) { 3063 bounds.bottom = 0; 3064 bounds.top = scrollY; 3065 drawOverscrollHeader(canvas, overscrollHeader, bounds); 3066 } else if (drawDividers) { 3067 bounds.bottom = 0; 3068 bounds.top = -dividerHeight; 3069 drawDivider(canvas, bounds, -1); 3070 } 3071 } 3072 3073 for (int i = 0; i < count; i++) { 3074 if ((headerDividers || first + i >= headerCount) && 3075 (footerDividers || first + i < footerLimit)) { 3076 View child = getChildAt(i); 3077 bottom = child.getBottom(); 3078 // Don't draw dividers next to items that are not enabled 3079 3080 if (drawDividers && 3081 (bottom < listBottom && !(drawOverscrollFooter && i == count - 1))) { 3082 if ((areAllItemsSelectable || 3083 (adapter.isEnabled(first + i) && (i == count - 1 || 3084 adapter.isEnabled(first + i + 1))))) { 3085 bounds.top = bottom; 3086 bounds.bottom = bottom + dividerHeight; 3087 drawDivider(canvas, bounds, i); 3088 } else if (fillForMissingDividers) { 3089 bounds.top = bottom; 3090 bounds.bottom = bottom + dividerHeight; 3091 canvas.drawRect(bounds, paint); 3092 } 3093 } 3094 } 3095 } 3096 3097 final int overFooterBottom = mBottom + mScrollY; 3098 if (drawOverscrollFooter && first + count == itemCount && 3099 overFooterBottom > bottom) { 3100 bounds.top = bottom; 3101 bounds.bottom = overFooterBottom; 3102 drawOverscrollFooter(canvas, overscrollFooter, bounds); 3103 } 3104 } else { 3105 int top; 3106 int listTop = mListPadding.top; 3107 3108 final int scrollY = mScrollY; 3109 3110 if (count > 0 && drawOverscrollHeader) { 3111 bounds.top = scrollY; 3112 bounds.bottom = getChildAt(0).getTop(); 3113 drawOverscrollHeader(canvas, overscrollHeader, bounds); 3114 } 3115 3116 final int start = drawOverscrollHeader ? 1 : 0; 3117 for (int i = start; i < count; i++) { 3118 if ((headerDividers || first + i >= headerCount) && 3119 (footerDividers || first + i < footerLimit)) { 3120 View child = getChildAt(i); 3121 top = child.getTop(); 3122 // Don't draw dividers next to items that are not enabled 3123 if (top > listTop) { 3124 if ((areAllItemsSelectable || 3125 (adapter.isEnabled(first + i) && (i == count - 1 || 3126 adapter.isEnabled(first + i + 1))))) { 3127 bounds.top = top - dividerHeight; 3128 bounds.bottom = top; 3129 // Give the method the child ABOVE the divider, so we 3130 // subtract one from our child 3131 // position. Give -1 when there is no child above the 3132 // divider. 3133 drawDivider(canvas, bounds, i - 1); 3134 } else if (fillForMissingDividers) { 3135 bounds.top = top - dividerHeight; 3136 bounds.bottom = top; 3137 canvas.drawRect(bounds, paint); 3138 } 3139 } 3140 } 3141 } 3142 3143 if (count > 0 && scrollY > 0) { 3144 if (drawOverscrollFooter) { 3145 final int absListBottom = mBottom; 3146 bounds.top = absListBottom; 3147 bounds.bottom = absListBottom + scrollY; 3148 drawOverscrollFooter(canvas, overscrollFooter, bounds); 3149 } else if (drawDividers) { 3150 bounds.top = listBottom; 3151 bounds.bottom = listBottom + dividerHeight; 3152 drawDivider(canvas, bounds, -1); 3153 } 3154 } 3155 } 3156 } 3157 3158 // Draw the indicators (these should be drawn above the dividers) and children 3159 super.dispatchDraw(canvas); 3160 } 3161 3162 /** 3163 * Draws a divider for the given child in the given bounds. 3164 * 3165 * @param canvas The canvas to draw to. 3166 * @param bounds The bounds of the divider. 3167 * @param childIndex The index of child (of the View) above the divider. 3168 * This will be -1 if there is no child above the divider to be 3169 * drawn. 3170 */ 3171 void drawDivider(Canvas canvas, Rect bounds, int childIndex) { 3172 // This widget draws the same divider for all children 3173 final Drawable divider = mDivider; 3174 3175 divider.setBounds(bounds); 3176 divider.draw(canvas); 3177 } 3178 3179 /** 3180 * Returns the drawable that will be drawn between each item in the list. 3181 * 3182 * @return the current drawable drawn between list elements 3183 */ 3184 public Drawable getDivider() { 3185 return mDivider; 3186 } 3187 3188 /** 3189 * Sets the drawable that will be drawn between each item in the list. If the drawable does 3190 * not have an intrinsic height, you should also call {@link #setDividerHeight(int)} 3191 * 3192 * @param divider The drawable to use. 3193 */ 3194 public void setDivider(Drawable divider) { 3195 if (divider != null) { 3196 mDividerHeight = divider.getIntrinsicHeight(); 3197 } else { 3198 mDividerHeight = 0; 3199 } 3200 mDivider = divider; 3201 mDividerIsOpaque = divider == null || divider.getOpacity() == PixelFormat.OPAQUE; 3202 requestLayout(); 3203 invalidate(); 3204 } 3205 3206 /** 3207 * @return Returns the height of the divider that will be drawn between each item in the list. 3208 */ 3209 public int getDividerHeight() { 3210 return mDividerHeight; 3211 } 3212 3213 /** 3214 * Sets the height of the divider that will be drawn between each item in the list. Calling 3215 * this will override the intrinsic height as set by {@link #setDivider(Drawable)} 3216 * 3217 * @param height The new height of the divider in pixels. 3218 */ 3219 public void setDividerHeight(int height) { 3220 mDividerHeight = height; 3221 requestLayout(); 3222 invalidate(); 3223 } 3224 3225 /** 3226 * Enables or disables the drawing of the divider for header views. 3227 * 3228 * @param headerDividersEnabled True to draw the headers, false otherwise. 3229 * 3230 * @see #setFooterDividersEnabled(boolean) 3231 * @see #addHeaderView(android.view.View) 3232 */ 3233 public void setHeaderDividersEnabled(boolean headerDividersEnabled) { 3234 mHeaderDividersEnabled = headerDividersEnabled; 3235 invalidate(); 3236 } 3237 3238 /** 3239 * Enables or disables the drawing of the divider for footer views. 3240 * 3241 * @param footerDividersEnabled True to draw the footers, false otherwise. 3242 * 3243 * @see #setHeaderDividersEnabled(boolean) 3244 * @see #addFooterView(android.view.View) 3245 */ 3246 public void setFooterDividersEnabled(boolean footerDividersEnabled) { 3247 mFooterDividersEnabled = footerDividersEnabled; 3248 invalidate(); 3249 } 3250 3251 /** 3252 * Sets the drawable that will be drawn above all other list content. 3253 * This area can become visible when the user overscrolls the list. 3254 * 3255 * @param header The drawable to use 3256 */ 3257 public void setOverscrollHeader(Drawable header) { 3258 mOverScrollHeader = header; 3259 if (mScrollY < 0) { 3260 invalidate(); 3261 } 3262 } 3263 3264 /** 3265 * @return The drawable that will be drawn above all other list content 3266 */ 3267 public Drawable getOverscrollHeader() { 3268 return mOverScrollHeader; 3269 } 3270 3271 /** 3272 * Sets the drawable that will be drawn below all other list content. 3273 * This area can become visible when the user overscrolls the list, 3274 * or when the list's content does not fully fill the container area. 3275 * 3276 * @param footer The drawable to use 3277 */ 3278 public void setOverscrollFooter(Drawable footer) { 3279 mOverScrollFooter = footer; 3280 invalidate(); 3281 } 3282 3283 /** 3284 * @return The drawable that will be drawn below all other list content 3285 */ 3286 public Drawable getOverscrollFooter() { 3287 return mOverScrollFooter; 3288 } 3289 3290 @Override 3291 protected void onFocusChanged(boolean gainFocus, int direction, Rect previouslyFocusedRect) { 3292 super.onFocusChanged(gainFocus, direction, previouslyFocusedRect); 3293 3294 int closetChildIndex = -1; 3295 if (gainFocus && previouslyFocusedRect != null) { 3296 previouslyFocusedRect.offset(mScrollX, mScrollY); 3297 3298 final ListAdapter adapter = mAdapter; 3299 // Don't cache the result of getChildCount or mFirstPosition here, 3300 // it could change in layoutChildren. 3301 if (adapter.getCount() < getChildCount() + mFirstPosition) { 3302 mLayoutMode = LAYOUT_NORMAL; 3303 layoutChildren(); 3304 } 3305 3306 // figure out which item should be selected based on previously 3307 // focused rect 3308 Rect otherRect = mTempRect; 3309 int minDistance = Integer.MAX_VALUE; 3310 final int childCount = getChildCount(); 3311 final int firstPosition = mFirstPosition; 3312 3313 for (int i = 0; i < childCount; i++) { 3314 // only consider selectable views 3315 if (!adapter.isEnabled(firstPosition + i)) { 3316 continue; 3317 } 3318 3319 View other = getChildAt(i); 3320 other.getDrawingRect(otherRect); 3321 offsetDescendantRectToMyCoords(other, otherRect); 3322 int distance = getDistance(previouslyFocusedRect, otherRect, direction); 3323 3324 if (distance < minDistance) { 3325 minDistance = distance; 3326 closetChildIndex = i; 3327 } 3328 } 3329 } 3330 3331 if (closetChildIndex >= 0) { 3332 setSelection(closetChildIndex + mFirstPosition); 3333 } else { 3334 requestLayout(); 3335 } 3336 } 3337 3338 3339 /* 3340 * (non-Javadoc) 3341 * 3342 * Children specified in XML are assumed to be header views. After we have 3343 * parsed them move them out of the children list and into mHeaderViews. 3344 */ 3345 @Override 3346 protected void onFinishInflate() { 3347 super.onFinishInflate(); 3348 3349 int count = getChildCount(); 3350 if (count > 0) { 3351 for (int i = 0; i < count; ++i) { 3352 addHeaderView(getChildAt(i)); 3353 } 3354 removeAllViews(); 3355 } 3356 } 3357 3358 /* (non-Javadoc) 3359 * @see android.view.View#findViewById(int) 3360 * First look in our children, then in any header and footer views that may be scrolled off. 3361 */ 3362 @Override 3363 protected View findViewTraversal(int id) { 3364 View v; 3365 v = super.findViewTraversal(id); 3366 if (v == null) { 3367 v = findViewInHeadersOrFooters(mHeaderViewInfos, id); 3368 if (v != null) { 3369 return v; 3370 } 3371 v = findViewInHeadersOrFooters(mFooterViewInfos, id); 3372 if (v != null) { 3373 return v; 3374 } 3375 } 3376 return v; 3377 } 3378 3379 /* (non-Javadoc) 3380 * 3381 * Look in the passed in list of headers or footers for the view. 3382 */ 3383 View findViewInHeadersOrFooters(ArrayList<FixedViewInfo> where, int id) { 3384 if (where != null) { 3385 int len = where.size(); 3386 View v; 3387 3388 for (int i = 0; i < len; i++) { 3389 v = where.get(i).view; 3390 3391 if (!v.isRootNamespace()) { 3392 v = v.findViewById(id); 3393 3394 if (v != null) { 3395 return v; 3396 } 3397 } 3398 } 3399 } 3400 return null; 3401 } 3402 3403 /* (non-Javadoc) 3404 * @see android.view.View#findViewWithTag(String) 3405 * First look in our children, then in any header and footer views that may be scrolled off. 3406 */ 3407 @Override 3408 protected View findViewWithTagTraversal(Object tag) { 3409 View v; 3410 v = super.findViewWithTagTraversal(tag); 3411 if (v == null) { 3412 v = findViewTagInHeadersOrFooters(mHeaderViewInfos, tag); 3413 if (v != null) { 3414 return v; 3415 } 3416 3417 v = findViewTagInHeadersOrFooters(mFooterViewInfos, tag); 3418 if (v != null) { 3419 return v; 3420 } 3421 } 3422 return v; 3423 } 3424 3425 /* (non-Javadoc) 3426 * 3427 * Look in the passed in list of headers or footers for the view with the tag. 3428 */ 3429 View findViewTagInHeadersOrFooters(ArrayList<FixedViewInfo> where, Object tag) { 3430 if (where != null) { 3431 int len = where.size(); 3432 View v; 3433 3434 for (int i = 0; i < len; i++) { 3435 v = where.get(i).view; 3436 3437 if (!v.isRootNamespace()) { 3438 v = v.findViewWithTag(tag); 3439 3440 if (v != null) { 3441 return v; 3442 } 3443 } 3444 } 3445 } 3446 return null; 3447 } 3448 3449 @Override 3450 public boolean onTouchEvent(MotionEvent ev) { 3451 if (mItemsCanFocus && ev.getAction() == MotionEvent.ACTION_DOWN && ev.getEdgeFlags() != 0) { 3452 // Don't handle edge touches immediately -- they may actually belong to one of our 3453 // descendants. 3454 return false; 3455 } 3456 return super.onTouchEvent(ev); 3457 } 3458 3459 /** 3460 * Returns the set of checked items ids. The result is only valid if the 3461 * choice mode has not been set to {@link #CHOICE_MODE_NONE}. 3462 * 3463 * @return A new array which contains the id of each checked item in the 3464 * list. 3465 * 3466 * @deprecated Use {@link #getCheckedItemIds()} instead. 3467 */ 3468 @Deprecated 3469 public long[] getCheckItemIds() { 3470 // Use new behavior that correctly handles stable ID mapping. 3471 if (mAdapter != null && mAdapter.hasStableIds()) { 3472 return getCheckedItemIds(); 3473 } 3474 3475 // Old behavior was buggy, but would sort of work for adapters without stable IDs. 3476 // Fall back to it to support legacy apps. 3477 if (mChoiceMode != CHOICE_MODE_NONE && mCheckStates != null && mAdapter != null) { 3478 final SparseBooleanArray states = mCheckStates; 3479 final int count = states.size(); 3480 final long[] ids = new long[count]; 3481 final ListAdapter adapter = mAdapter; 3482 3483 int checkedCount = 0; 3484 for (int i = 0; i < count; i++) { 3485 if (states.valueAt(i)) { 3486 ids[checkedCount++] = adapter.getItemId(states.keyAt(i)); 3487 } 3488 } 3489 3490 // Trim array if needed. mCheckStates may contain false values 3491 // resulting in checkedCount being smaller than count. 3492 if (checkedCount == count) { 3493 return ids; 3494 } else { 3495 final long[] result = new long[checkedCount]; 3496 System.arraycopy(ids, 0, result, 0, checkedCount); 3497 3498 return result; 3499 } 3500 } 3501 return new long[0]; 3502 } 3503} 3504