ListView.java revision eeb55e673feca137bd0106ca31f9b68509a4ae36
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 1106 mItemCount = mAdapter == null ? 0 : mAdapter.getCount(); 1107 if (mItemCount > 0 && (widthMode == MeasureSpec.UNSPECIFIED || 1108 heightMode == MeasureSpec.UNSPECIFIED)) { 1109 final View child = obtainView(0, mIsScrap); 1110 1111 measureScrapChild(child, 0, widthMeasureSpec); 1112 1113 childWidth = child.getMeasuredWidth(); 1114 childHeight = child.getMeasuredHeight(); 1115 1116 if (recycleOnMeasure() && mRecycler.shouldRecycleViewType( 1117 ((LayoutParams) child.getLayoutParams()).viewType)) { 1118 mRecycler.addScrapView(child, -1); 1119 } 1120 } 1121 1122 if (widthMode == MeasureSpec.UNSPECIFIED) { 1123 widthSize = mListPadding.left + mListPadding.right + childWidth + 1124 getVerticalScrollbarWidth(); 1125 } 1126 1127 if (heightMode == MeasureSpec.UNSPECIFIED) { 1128 heightSize = mListPadding.top + mListPadding.bottom + childHeight + 1129 getVerticalFadingEdgeLength() * 2; 1130 } 1131 1132 if (heightMode == MeasureSpec.AT_MOST) { 1133 // TODO: after first layout we should maybe start at the first visible position, not 0 1134 heightSize = measureHeightOfChildren(widthMeasureSpec, 0, NO_POSITION, heightSize, -1); 1135 } 1136 1137 setMeasuredDimension(widthSize, heightSize); 1138 mWidthMeasureSpec = widthMeasureSpec; 1139 } 1140 1141 private void measureScrapChild(View child, int position, int widthMeasureSpec) { 1142 LayoutParams p = (LayoutParams) child.getLayoutParams(); 1143 if (p == null) { 1144 p = new LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, 1145 ViewGroup.LayoutParams.WRAP_CONTENT, 0); 1146 child.setLayoutParams(p); 1147 } 1148 p.viewType = mAdapter.getItemViewType(position); 1149 p.forceAdd = true; 1150 1151 int childWidthSpec = ViewGroup.getChildMeasureSpec(widthMeasureSpec, 1152 mListPadding.left + mListPadding.right, p.width); 1153 int lpHeight = p.height; 1154 int childHeightSpec; 1155 if (lpHeight > 0) { 1156 childHeightSpec = MeasureSpec.makeMeasureSpec(lpHeight, MeasureSpec.EXACTLY); 1157 } else { 1158 childHeightSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED); 1159 } 1160 child.measure(childWidthSpec, childHeightSpec); 1161 } 1162 1163 /** 1164 * @return True to recycle the views used to measure this ListView in 1165 * UNSPECIFIED/AT_MOST modes, false otherwise. 1166 * @hide 1167 */ 1168 @ViewDebug.ExportedProperty(category = "list") 1169 protected boolean recycleOnMeasure() { 1170 return true; 1171 } 1172 1173 /** 1174 * Measures the height of the given range of children (inclusive) and 1175 * returns the height with this ListView's padding and divider heights 1176 * included. If maxHeight is provided, the measuring will stop when the 1177 * current height reaches maxHeight. 1178 * 1179 * @param widthMeasureSpec The width measure spec to be given to a child's 1180 * {@link View#measure(int, int)}. 1181 * @param startPosition The position of the first child to be shown. 1182 * @param endPosition The (inclusive) position of the last child to be 1183 * shown. Specify {@link #NO_POSITION} if the last child should be 1184 * the last available child from the adapter. 1185 * @param maxHeight The maximum height that will be returned (if all the 1186 * children don't fit in this value, this value will be 1187 * returned). 1188 * @param disallowPartialChildPosition In general, whether the returned 1189 * height should only contain entire children. This is more 1190 * powerful--it is the first inclusive position at which partial 1191 * children will not be allowed. Example: it looks nice to have 1192 * at least 3 completely visible children, and in portrait this 1193 * will most likely fit; but in landscape there could be times 1194 * when even 2 children can not be completely shown, so a value 1195 * of 2 (remember, inclusive) would be good (assuming 1196 * startPosition is 0). 1197 * @return The height of this ListView with the given children. 1198 */ 1199 final int measureHeightOfChildren(int widthMeasureSpec, int startPosition, int endPosition, 1200 final int maxHeight, int disallowPartialChildPosition) { 1201 1202 final ListAdapter adapter = mAdapter; 1203 if (adapter == null) { 1204 return mListPadding.top + mListPadding.bottom; 1205 } 1206 1207 // Include the padding of the list 1208 int returnedHeight = mListPadding.top + mListPadding.bottom; 1209 final int dividerHeight = ((mDividerHeight > 0) && mDivider != null) ? mDividerHeight : 0; 1210 // The previous height value that was less than maxHeight and contained 1211 // no partial children 1212 int prevHeightWithoutPartialChild = 0; 1213 int i; 1214 View child; 1215 1216 // mItemCount - 1 since endPosition parameter is inclusive 1217 endPosition = (endPosition == NO_POSITION) ? adapter.getCount() - 1 : endPosition; 1218 final AbsListView.RecycleBin recycleBin = mRecycler; 1219 final boolean recyle = recycleOnMeasure(); 1220 final boolean[] isScrap = mIsScrap; 1221 1222 for (i = startPosition; i <= endPosition; ++i) { 1223 child = obtainView(i, isScrap); 1224 1225 measureScrapChild(child, i, widthMeasureSpec); 1226 1227 if (i > 0) { 1228 // Count the divider for all but one child 1229 returnedHeight += dividerHeight; 1230 } 1231 1232 // Recycle the view before we possibly return from the method 1233 if (recyle && recycleBin.shouldRecycleViewType( 1234 ((LayoutParams) child.getLayoutParams()).viewType)) { 1235 recycleBin.addScrapView(child, -1); 1236 } 1237 1238 returnedHeight += child.getMeasuredHeight(); 1239 1240 if (returnedHeight >= maxHeight) { 1241 // We went over, figure out which height to return. If returnedHeight > maxHeight, 1242 // then the i'th position did not fit completely. 1243 return (disallowPartialChildPosition >= 0) // Disallowing is enabled (> -1) 1244 && (i > disallowPartialChildPosition) // We've past the min pos 1245 && (prevHeightWithoutPartialChild > 0) // We have a prev height 1246 && (returnedHeight != maxHeight) // i'th child did not fit completely 1247 ? prevHeightWithoutPartialChild 1248 : maxHeight; 1249 } 1250 1251 if ((disallowPartialChildPosition >= 0) && (i >= disallowPartialChildPosition)) { 1252 prevHeightWithoutPartialChild = returnedHeight; 1253 } 1254 } 1255 1256 // At this point, we went through the range of children, and they each 1257 // completely fit, so return the returnedHeight 1258 return returnedHeight; 1259 } 1260 1261 @Override 1262 int findMotionRow(int y) { 1263 int childCount = getChildCount(); 1264 if (childCount > 0) { 1265 if (!mStackFromBottom) { 1266 for (int i = 0; i < childCount; i++) { 1267 View v = getChildAt(i); 1268 if (y <= v.getBottom()) { 1269 return mFirstPosition + i; 1270 } 1271 } 1272 } else { 1273 for (int i = childCount - 1; i >= 0; i--) { 1274 View v = getChildAt(i); 1275 if (y >= v.getTop()) { 1276 return mFirstPosition + i; 1277 } 1278 } 1279 } 1280 } 1281 return INVALID_POSITION; 1282 } 1283 1284 /** 1285 * Put a specific item at a specific location on the screen and then build 1286 * up and down from there. 1287 * 1288 * @param position The reference view to use as the starting point 1289 * @param top Pixel offset from the top of this view to the top of the 1290 * reference view. 1291 * 1292 * @return The selected view, or null if the selected view is outside the 1293 * visible area. 1294 */ 1295 private View fillSpecific(int position, int top) { 1296 boolean tempIsSelected = position == mSelectedPosition; 1297 View temp = makeAndAddView(position, top, true, mListPadding.left, tempIsSelected); 1298 // Possibly changed again in fillUp if we add rows above this one. 1299 mFirstPosition = position; 1300 1301 View above; 1302 View below; 1303 1304 final int dividerHeight = mDividerHeight; 1305 if (!mStackFromBottom) { 1306 above = fillUp(position - 1, temp.getTop() - dividerHeight); 1307 // This will correct for the top of the first view not touching the top of the list 1308 adjustViewsUpOrDown(); 1309 below = fillDown(position + 1, temp.getBottom() + dividerHeight); 1310 int childCount = getChildCount(); 1311 if (childCount > 0) { 1312 correctTooHigh(childCount); 1313 } 1314 } else { 1315 below = fillDown(position + 1, temp.getBottom() + dividerHeight); 1316 // This will correct for the bottom of the last view not touching the bottom of the list 1317 adjustViewsUpOrDown(); 1318 above = fillUp(position - 1, temp.getTop() - dividerHeight); 1319 int childCount = getChildCount(); 1320 if (childCount > 0) { 1321 correctTooLow(childCount); 1322 } 1323 } 1324 1325 if (tempIsSelected) { 1326 return temp; 1327 } else if (above != null) { 1328 return above; 1329 } else { 1330 return below; 1331 } 1332 } 1333 1334 /** 1335 * Check if we have dragged the bottom of the list too high (we have pushed the 1336 * top element off the top of the screen when we did not need to). Correct by sliding 1337 * everything back down. 1338 * 1339 * @param childCount Number of children 1340 */ 1341 private void correctTooHigh(int childCount) { 1342 // First see if the last item is visible. If it is not, it is OK for the 1343 // top of the list to be pushed up. 1344 int lastPosition = mFirstPosition + childCount - 1; 1345 if (lastPosition == mItemCount - 1 && childCount > 0) { 1346 1347 // Get the last child ... 1348 final View lastChild = getChildAt(childCount - 1); 1349 1350 // ... and its bottom edge 1351 final int lastBottom = lastChild.getBottom(); 1352 1353 // This is bottom of our drawable area 1354 final int end = (mBottom - mTop) - mListPadding.bottom; 1355 1356 // This is how far the bottom edge of the last view is from the bottom of the 1357 // drawable area 1358 int bottomOffset = end - lastBottom; 1359 View firstChild = getChildAt(0); 1360 final int firstTop = firstChild.getTop(); 1361 1362 // Make sure we are 1) Too high, and 2) Either there are more rows above the 1363 // first row or the first row is scrolled off the top of the drawable area 1364 if (bottomOffset > 0 && (mFirstPosition > 0 || firstTop < mListPadding.top)) { 1365 if (mFirstPosition == 0) { 1366 // Don't pull the top too far down 1367 bottomOffset = Math.min(bottomOffset, mListPadding.top - firstTop); 1368 } 1369 // Move everything down 1370 offsetChildrenTopAndBottom(bottomOffset); 1371 if (mFirstPosition > 0) { 1372 // Fill the gap that was opened above mFirstPosition with more rows, if 1373 // possible 1374 fillUp(mFirstPosition - 1, firstChild.getTop() - mDividerHeight); 1375 // Close up the remaining gap 1376 adjustViewsUpOrDown(); 1377 } 1378 1379 } 1380 } 1381 } 1382 1383 /** 1384 * Check if we have dragged the bottom of the list too low (we have pushed the 1385 * bottom element off the bottom of the screen when we did not need to). Correct by sliding 1386 * everything back up. 1387 * 1388 * @param childCount Number of children 1389 */ 1390 private void correctTooLow(int childCount) { 1391 // First see if the first item is visible. If it is not, it is OK for the 1392 // bottom of the list to be pushed down. 1393 if (mFirstPosition == 0 && childCount > 0) { 1394 1395 // Get the first child ... 1396 final View firstChild = getChildAt(0); 1397 1398 // ... and its top edge 1399 final int firstTop = firstChild.getTop(); 1400 1401 // This is top of our drawable area 1402 final int start = mListPadding.top; 1403 1404 // This is bottom of our drawable area 1405 final int end = (mBottom - mTop) - mListPadding.bottom; 1406 1407 // This is how far the top edge of the first view is from the top of the 1408 // drawable area 1409 int topOffset = firstTop - start; 1410 View lastChild = getChildAt(childCount - 1); 1411 final int lastBottom = lastChild.getBottom(); 1412 int lastPosition = mFirstPosition + childCount - 1; 1413 1414 // Make sure we are 1) Too low, and 2) Either there are more rows below the 1415 // last row or the last row is scrolled off the bottom of the drawable area 1416 if (topOffset > 0) { 1417 if (lastPosition < mItemCount - 1 || lastBottom > end) { 1418 if (lastPosition == mItemCount - 1) { 1419 // Don't pull the bottom too far up 1420 topOffset = Math.min(topOffset, lastBottom - end); 1421 } 1422 // Move everything up 1423 offsetChildrenTopAndBottom(-topOffset); 1424 if (lastPosition < mItemCount - 1) { 1425 // Fill the gap that was opened below the last position with more rows, if 1426 // possible 1427 fillDown(lastPosition + 1, lastChild.getBottom() + mDividerHeight); 1428 // Close up the remaining gap 1429 adjustViewsUpOrDown(); 1430 } 1431 } else if (lastPosition == mItemCount - 1) { 1432 adjustViewsUpOrDown(); 1433 } 1434 } 1435 } 1436 } 1437 1438 @Override 1439 protected void layoutChildren() { 1440 final boolean blockLayoutRequests = mBlockLayoutRequests; 1441 if (!blockLayoutRequests) { 1442 mBlockLayoutRequests = true; 1443 } else { 1444 return; 1445 } 1446 1447 try { 1448 super.layoutChildren(); 1449 1450 invalidate(); 1451 1452 if (mAdapter == null) { 1453 resetList(); 1454 invokeOnItemScrollListener(); 1455 return; 1456 } 1457 1458 int childrenTop = mListPadding.top; 1459 int childrenBottom = mBottom - mTop - mListPadding.bottom; 1460 1461 int childCount = getChildCount(); 1462 int index = 0; 1463 int delta = 0; 1464 1465 View sel; 1466 View oldSel = null; 1467 View oldFirst = null; 1468 View newSel = null; 1469 1470 View focusLayoutRestoreView = null; 1471 1472 // Remember stuff we will need down below 1473 switch (mLayoutMode) { 1474 case LAYOUT_SET_SELECTION: 1475 index = mNextSelectedPosition - mFirstPosition; 1476 if (index >= 0 && index < childCount) { 1477 newSel = getChildAt(index); 1478 } 1479 break; 1480 case LAYOUT_FORCE_TOP: 1481 case LAYOUT_FORCE_BOTTOM: 1482 case LAYOUT_SPECIFIC: 1483 case LAYOUT_SYNC: 1484 break; 1485 case LAYOUT_MOVE_SELECTION: 1486 default: 1487 // Remember the previously selected view 1488 index = mSelectedPosition - mFirstPosition; 1489 if (index >= 0 && index < childCount) { 1490 oldSel = getChildAt(index); 1491 } 1492 1493 // Remember the previous first child 1494 oldFirst = getChildAt(0); 1495 1496 if (mNextSelectedPosition >= 0) { 1497 delta = mNextSelectedPosition - mSelectedPosition; 1498 } 1499 1500 // Caution: newSel might be null 1501 newSel = getChildAt(index + delta); 1502 } 1503 1504 1505 boolean dataChanged = mDataChanged; 1506 if (dataChanged) { 1507 handleDataChanged(); 1508 } 1509 1510 // Handle the empty set by removing all views that are visible 1511 // and calling it a day 1512 if (mItemCount == 0) { 1513 resetList(); 1514 invokeOnItemScrollListener(); 1515 return; 1516 } else if (mItemCount != mAdapter.getCount()) { 1517 throw new IllegalStateException("The content of the adapter has changed but " 1518 + "ListView did not receive a notification. Make sure the content of " 1519 + "your adapter is not modified from a background thread, but only " 1520 + "from the UI thread. [in ListView(" + getId() + ", " + getClass() 1521 + ") with Adapter(" + mAdapter.getClass() + ")]"); 1522 } 1523 1524 setSelectedPositionInt(mNextSelectedPosition); 1525 1526 // Pull all children into the RecycleBin. 1527 // These views will be reused if possible 1528 final int firstPosition = mFirstPosition; 1529 final RecycleBin recycleBin = mRecycler; 1530 1531 // reset the focus restoration 1532 View focusLayoutRestoreDirectChild = null; 1533 1534 1535 // Don't put header or footer views into the Recycler. Those are 1536 // already cached in mHeaderViews; 1537 if (dataChanged) { 1538 for (int i = 0; i < childCount; i++) { 1539 recycleBin.addScrapView(getChildAt(i), firstPosition+i); 1540 if (ViewDebug.TRACE_RECYCLER) { 1541 ViewDebug.trace(getChildAt(i), 1542 ViewDebug.RecyclerTraceType.MOVE_TO_SCRAP_HEAP, index, i); 1543 } 1544 } 1545 } else { 1546 recycleBin.fillActiveViews(childCount, firstPosition); 1547 } 1548 1549 // take focus back to us temporarily to avoid the eventual 1550 // call to clear focus when removing the focused child below 1551 // from messing things up when ViewRoot assigns focus back 1552 // to someone else 1553 final View focusedChild = getFocusedChild(); 1554 if (focusedChild != null) { 1555 // TODO: in some cases focusedChild.getParent() == null 1556 1557 // we can remember the focused view to restore after relayout if the 1558 // data hasn't changed, or if the focused position is a header or footer 1559 if (!dataChanged || isDirectChildHeaderOrFooter(focusedChild)) { 1560 focusLayoutRestoreDirectChild = focusedChild; 1561 // remember the specific view that had focus 1562 focusLayoutRestoreView = findFocus(); 1563 if (focusLayoutRestoreView != null) { 1564 // tell it we are going to mess with it 1565 focusLayoutRestoreView.onStartTemporaryDetach(); 1566 } 1567 } 1568 requestFocus(); 1569 } 1570 1571 // Clear out old views 1572 detachAllViewsFromParent(); 1573 1574 switch (mLayoutMode) { 1575 case LAYOUT_SET_SELECTION: 1576 if (newSel != null) { 1577 sel = fillFromSelection(newSel.getTop(), childrenTop, childrenBottom); 1578 } else { 1579 sel = fillFromMiddle(childrenTop, childrenBottom); 1580 } 1581 break; 1582 case LAYOUT_SYNC: 1583 sel = fillSpecific(mSyncPosition, mSpecificTop); 1584 break; 1585 case LAYOUT_FORCE_BOTTOM: 1586 sel = fillUp(mItemCount - 1, childrenBottom); 1587 adjustViewsUpOrDown(); 1588 break; 1589 case LAYOUT_FORCE_TOP: 1590 mFirstPosition = 0; 1591 sel = fillFromTop(childrenTop); 1592 adjustViewsUpOrDown(); 1593 break; 1594 case LAYOUT_SPECIFIC: 1595 sel = fillSpecific(reconcileSelectedPosition(), mSpecificTop); 1596 break; 1597 case LAYOUT_MOVE_SELECTION: 1598 sel = moveSelection(oldSel, newSel, delta, childrenTop, childrenBottom); 1599 break; 1600 default: 1601 if (childCount == 0) { 1602 if (!mStackFromBottom) { 1603 final int position = lookForSelectablePosition(0, true); 1604 setSelectedPositionInt(position); 1605 sel = fillFromTop(childrenTop); 1606 } else { 1607 final int position = lookForSelectablePosition(mItemCount - 1, false); 1608 setSelectedPositionInt(position); 1609 sel = fillUp(mItemCount - 1, childrenBottom); 1610 } 1611 } else { 1612 if (mSelectedPosition >= 0 && mSelectedPosition < mItemCount) { 1613 sel = fillSpecific(mSelectedPosition, 1614 oldSel == null ? childrenTop : oldSel.getTop()); 1615 } else if (mFirstPosition < mItemCount) { 1616 sel = fillSpecific(mFirstPosition, 1617 oldFirst == null ? childrenTop : oldFirst.getTop()); 1618 } else { 1619 sel = fillSpecific(0, childrenTop); 1620 } 1621 } 1622 break; 1623 } 1624 1625 // Flush any cached views that did not get reused above 1626 recycleBin.scrapActiveViews(); 1627 1628 if (sel != null) { 1629 // the current selected item should get focus if items 1630 // are focusable 1631 if (mItemsCanFocus && hasFocus() && !sel.hasFocus()) { 1632 final boolean focusWasTaken = (sel == focusLayoutRestoreDirectChild && 1633 focusLayoutRestoreView.requestFocus()) || sel.requestFocus(); 1634 if (!focusWasTaken) { 1635 // selected item didn't take focus, fine, but still want 1636 // to make sure something else outside of the selected view 1637 // has focus 1638 final View focused = getFocusedChild(); 1639 if (focused != null) { 1640 focused.clearFocus(); 1641 } 1642 positionSelector(INVALID_POSITION, sel); 1643 } else { 1644 sel.setSelected(false); 1645 mSelectorRect.setEmpty(); 1646 } 1647 } else { 1648 positionSelector(INVALID_POSITION, sel); 1649 } 1650 mSelectedTop = sel.getTop(); 1651 } else { 1652 if (mTouchMode > TOUCH_MODE_DOWN && mTouchMode < TOUCH_MODE_SCROLL) { 1653 View child = getChildAt(mMotionPosition - mFirstPosition); 1654 if (child != null) positionSelector(mMotionPosition, child); 1655 } else { 1656 mSelectedTop = 0; 1657 mSelectorRect.setEmpty(); 1658 } 1659 1660 // even if there is not selected position, we may need to restore 1661 // focus (i.e. something focusable in touch mode) 1662 if (hasFocus() && focusLayoutRestoreView != null) { 1663 focusLayoutRestoreView.requestFocus(); 1664 } 1665 } 1666 1667 // tell focus view we are done mucking with it, if it is still in 1668 // our view hierarchy. 1669 if (focusLayoutRestoreView != null 1670 && focusLayoutRestoreView.getWindowToken() != null) { 1671 focusLayoutRestoreView.onFinishTemporaryDetach(); 1672 } 1673 1674 mLayoutMode = LAYOUT_NORMAL; 1675 mDataChanged = false; 1676 mNeedSync = false; 1677 setNextSelectedPositionInt(mSelectedPosition); 1678 1679 updateScrollIndicators(); 1680 1681 if (mItemCount > 0) { 1682 checkSelectionChanged(); 1683 } 1684 1685 invokeOnItemScrollListener(); 1686 } finally { 1687 if (!blockLayoutRequests) { 1688 mBlockLayoutRequests = false; 1689 } 1690 } 1691 } 1692 1693 /** 1694 * @param child a direct child of this list. 1695 * @return Whether child is a header or footer view. 1696 */ 1697 private boolean isDirectChildHeaderOrFooter(View child) { 1698 1699 final ArrayList<FixedViewInfo> headers = mHeaderViewInfos; 1700 final int numHeaders = headers.size(); 1701 for (int i = 0; i < numHeaders; i++) { 1702 if (child == headers.get(i).view) { 1703 return true; 1704 } 1705 } 1706 final ArrayList<FixedViewInfo> footers = mFooterViewInfos; 1707 final int numFooters = footers.size(); 1708 for (int i = 0; i < numFooters; i++) { 1709 if (child == footers.get(i).view) { 1710 return true; 1711 } 1712 } 1713 return false; 1714 } 1715 1716 /** 1717 * Obtain the view and add it to our list of children. The view can be made 1718 * fresh, converted from an unused view, or used as is if it was in the 1719 * recycle bin. 1720 * 1721 * @param position Logical position in the list 1722 * @param y Top or bottom edge of the view to add 1723 * @param flow If flow is true, align top edge to y. If false, align bottom 1724 * edge to y. 1725 * @param childrenLeft Left edge where children should be positioned 1726 * @param selected Is this position selected? 1727 * @return View that was added 1728 */ 1729 private View makeAndAddView(int position, int y, boolean flow, int childrenLeft, 1730 boolean selected) { 1731 View child; 1732 1733 1734 if (!mDataChanged) { 1735 // Try to use an existing view for this position 1736 child = mRecycler.getActiveView(position); 1737 if (child != null) { 1738 if (ViewDebug.TRACE_RECYCLER) { 1739 ViewDebug.trace(child, ViewDebug.RecyclerTraceType.RECYCLE_FROM_ACTIVE_HEAP, 1740 position, getChildCount()); 1741 } 1742 1743 // Found it -- we're using an existing child 1744 // This just needs to be positioned 1745 setupChild(child, position, y, flow, childrenLeft, selected, true); 1746 1747 return child; 1748 } 1749 } 1750 1751 // Make a new view for this position, or convert an unused view if possible 1752 child = obtainView(position, mIsScrap); 1753 1754 // This needs to be positioned and measured 1755 setupChild(child, position, y, flow, childrenLeft, selected, mIsScrap[0]); 1756 1757 return child; 1758 } 1759 1760 /** 1761 * Add a view as a child and make sure it is measured (if necessary) and 1762 * positioned properly. 1763 * 1764 * @param child The view to add 1765 * @param position The position of this child 1766 * @param y The y position relative to which this view will be positioned 1767 * @param flowDown If true, align top edge to y. If false, align bottom 1768 * edge to y. 1769 * @param childrenLeft Left edge where children should be positioned 1770 * @param selected Is this position selected? 1771 * @param recycled Has this view been pulled from the recycle bin? If so it 1772 * does not need to be remeasured. 1773 */ 1774 private void setupChild(View child, int position, int y, boolean flowDown, int childrenLeft, 1775 boolean selected, boolean recycled) { 1776 final boolean isSelected = selected && shouldShowSelector(); 1777 final boolean updateChildSelected = isSelected != child.isSelected(); 1778 final int mode = mTouchMode; 1779 final boolean isPressed = mode > TOUCH_MODE_DOWN && mode < TOUCH_MODE_SCROLL && 1780 mMotionPosition == position; 1781 final boolean updateChildPressed = isPressed != child.isPressed(); 1782 final boolean needToMeasure = !recycled || updateChildSelected || child.isLayoutRequested(); 1783 1784 // Respect layout params that are already in the view. Otherwise make some up... 1785 // noinspection unchecked 1786 AbsListView.LayoutParams p = (AbsListView.LayoutParams) child.getLayoutParams(); 1787 if (p == null) { 1788 p = new AbsListView.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, 1789 ViewGroup.LayoutParams.WRAP_CONTENT, 0); 1790 } 1791 p.viewType = mAdapter.getItemViewType(position); 1792 1793 if ((recycled && !p.forceAdd) || (p.recycledHeaderFooter && 1794 p.viewType == AdapterView.ITEM_VIEW_TYPE_HEADER_OR_FOOTER)) { 1795 attachViewToParent(child, flowDown ? -1 : 0, p); 1796 } else { 1797 p.forceAdd = false; 1798 if (p.viewType == AdapterView.ITEM_VIEW_TYPE_HEADER_OR_FOOTER) { 1799 p.recycledHeaderFooter = true; 1800 } 1801 addViewInLayout(child, flowDown ? -1 : 0, p, true); 1802 } 1803 1804 if (updateChildSelected) { 1805 child.setSelected(isSelected); 1806 } 1807 1808 if (updateChildPressed) { 1809 child.setPressed(isPressed); 1810 } 1811 1812 if (mChoiceMode != CHOICE_MODE_NONE && mCheckStates != null) { 1813 if (child instanceof Checkable) { 1814 ((Checkable) child).setChecked(mCheckStates.get(position)); 1815 } else if (getContext().getApplicationInfo().targetSdkVersion 1816 >= android.os.Build.VERSION_CODES.HONEYCOMB) { 1817 child.setActivated(mCheckStates.get(position)); 1818 } 1819 } 1820 1821 if (needToMeasure) { 1822 int childWidthSpec = ViewGroup.getChildMeasureSpec(mWidthMeasureSpec, 1823 mListPadding.left + mListPadding.right, p.width); 1824 int lpHeight = p.height; 1825 int childHeightSpec; 1826 if (lpHeight > 0) { 1827 childHeightSpec = MeasureSpec.makeMeasureSpec(lpHeight, MeasureSpec.EXACTLY); 1828 } else { 1829 childHeightSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED); 1830 } 1831 child.measure(childWidthSpec, childHeightSpec); 1832 } else { 1833 cleanupLayoutState(child); 1834 } 1835 1836 final int w = child.getMeasuredWidth(); 1837 final int h = child.getMeasuredHeight(); 1838 final int childTop = flowDown ? y : y - h; 1839 1840 if (needToMeasure) { 1841 final int childRight = childrenLeft + w; 1842 final int childBottom = childTop + h; 1843 child.layout(childrenLeft, childTop, childRight, childBottom); 1844 } else { 1845 child.offsetLeftAndRight(childrenLeft - child.getLeft()); 1846 child.offsetTopAndBottom(childTop - child.getTop()); 1847 } 1848 1849 if (mCachingStarted && !child.isDrawingCacheEnabled()) { 1850 child.setDrawingCacheEnabled(true); 1851 } 1852 1853 if (recycled && (((AbsListView.LayoutParams)child.getLayoutParams()).scrappedFromPosition) 1854 != position) { 1855 child.jumpDrawablesToCurrentState(); 1856 } 1857 } 1858 1859 @Override 1860 protected boolean canAnimate() { 1861 return super.canAnimate() && mItemCount > 0; 1862 } 1863 1864 /** 1865 * Sets the currently selected item. If in touch mode, the item will not be selected 1866 * but it will still be positioned appropriately. If the specified selection position 1867 * is less than 0, then the item at position 0 will be selected. 1868 * 1869 * @param position Index (starting at 0) of the data item to be selected. 1870 */ 1871 @Override 1872 public void setSelection(int position) { 1873 setSelectionFromTop(position, 0); 1874 } 1875 1876 /** 1877 * Sets the selected item and positions the selection y pixels from the top edge 1878 * of the ListView. (If in touch mode, the item will not be selected but it will 1879 * still be positioned appropriately.) 1880 * 1881 * @param position Index (starting at 0) of the data item to be selected. 1882 * @param y The distance from the top edge of the ListView (plus padding) that the 1883 * item will be positioned. 1884 */ 1885 public void setSelectionFromTop(int position, int y) { 1886 if (mAdapter == null) { 1887 return; 1888 } 1889 1890 if (!isInTouchMode()) { 1891 position = lookForSelectablePosition(position, true); 1892 if (position >= 0) { 1893 setNextSelectedPositionInt(position); 1894 } 1895 } else { 1896 mResurrectToPosition = position; 1897 } 1898 1899 if (position >= 0) { 1900 mLayoutMode = LAYOUT_SPECIFIC; 1901 mSpecificTop = mListPadding.top + y; 1902 1903 if (mNeedSync) { 1904 mSyncPosition = position; 1905 mSyncRowId = mAdapter.getItemId(position); 1906 } 1907 1908 requestLayout(); 1909 } 1910 } 1911 1912 /** 1913 * Makes the item at the supplied position selected. 1914 * 1915 * @param position the position of the item to select 1916 */ 1917 @Override 1918 void setSelectionInt(int position) { 1919 setNextSelectedPositionInt(position); 1920 boolean awakeScrollbars = false; 1921 1922 final int selectedPosition = mSelectedPosition; 1923 1924 if (selectedPosition >= 0) { 1925 if (position == selectedPosition - 1) { 1926 awakeScrollbars = true; 1927 } else if (position == selectedPosition + 1) { 1928 awakeScrollbars = true; 1929 } 1930 } 1931 1932 layoutChildren(); 1933 1934 if (awakeScrollbars) { 1935 awakenScrollBars(); 1936 } 1937 } 1938 1939 /** 1940 * Find a position that can be selected (i.e., is not a separator). 1941 * 1942 * @param position The starting position to look at. 1943 * @param lookDown Whether to look down for other positions. 1944 * @return The next selectable position starting at position and then searching either up or 1945 * down. Returns {@link #INVALID_POSITION} if nothing can be found. 1946 */ 1947 @Override 1948 int lookForSelectablePosition(int position, boolean lookDown) { 1949 final ListAdapter adapter = mAdapter; 1950 if (adapter == null || isInTouchMode()) { 1951 return INVALID_POSITION; 1952 } 1953 1954 final int count = adapter.getCount(); 1955 if (!mAreAllItemsSelectable) { 1956 if (lookDown) { 1957 position = Math.max(0, position); 1958 while (position < count && !adapter.isEnabled(position)) { 1959 position++; 1960 } 1961 } else { 1962 position = Math.min(position, count - 1); 1963 while (position >= 0 && !adapter.isEnabled(position)) { 1964 position--; 1965 } 1966 } 1967 1968 if (position < 0 || position >= count) { 1969 return INVALID_POSITION; 1970 } 1971 return position; 1972 } else { 1973 if (position < 0 || position >= count) { 1974 return INVALID_POSITION; 1975 } 1976 return position; 1977 } 1978 } 1979 1980 @Override 1981 public boolean dispatchPopulateAccessibilityEvent(AccessibilityEvent event) { 1982 boolean populated = super.dispatchPopulateAccessibilityEvent(event); 1983 1984 // If the item count is less than 15 then subtract disabled items from the count and 1985 // position. Otherwise ignore disabled items. 1986 if (!populated) { 1987 int itemCount = 0; 1988 int currentItemIndex = getSelectedItemPosition(); 1989 1990 ListAdapter adapter = getAdapter(); 1991 if (adapter != null) { 1992 final int count = adapter.getCount(); 1993 if (count < 15) { 1994 for (int i = 0; i < count; i++) { 1995 if (adapter.isEnabled(i)) { 1996 itemCount++; 1997 } else if (i <= currentItemIndex) { 1998 currentItemIndex--; 1999 } 2000 } 2001 } else { 2002 itemCount = count; 2003 } 2004 } 2005 2006 event.setItemCount(itemCount); 2007 event.setCurrentItemIndex(currentItemIndex); 2008 } 2009 2010 return populated; 2011 } 2012 2013 /** 2014 * setSelectionAfterHeaderView set the selection to be the first list item 2015 * after the header views. 2016 */ 2017 public void setSelectionAfterHeaderView() { 2018 final int count = mHeaderViewInfos.size(); 2019 if (count > 0) { 2020 mNextSelectedPosition = 0; 2021 return; 2022 } 2023 2024 if (mAdapter != null) { 2025 setSelection(count); 2026 } else { 2027 mNextSelectedPosition = count; 2028 mLayoutMode = LAYOUT_SET_SELECTION; 2029 } 2030 2031 } 2032 2033 @Override 2034 public boolean dispatchKeyEvent(KeyEvent event) { 2035 // Dispatch in the normal way 2036 boolean handled = super.dispatchKeyEvent(event); 2037 if (!handled) { 2038 // If we didn't handle it... 2039 View focused = getFocusedChild(); 2040 if (focused != null && event.getAction() == KeyEvent.ACTION_DOWN) { 2041 // ... and our focused child didn't handle it 2042 // ... give it to ourselves so we can scroll if necessary 2043 handled = onKeyDown(event.getKeyCode(), event); 2044 } 2045 } 2046 return handled; 2047 } 2048 2049 @Override 2050 public boolean onKeyDown(int keyCode, KeyEvent event) { 2051 return commonKey(keyCode, 1, event); 2052 } 2053 2054 @Override 2055 public boolean onKeyMultiple(int keyCode, int repeatCount, KeyEvent event) { 2056 return commonKey(keyCode, repeatCount, event); 2057 } 2058 2059 @Override 2060 public boolean onKeyUp(int keyCode, KeyEvent event) { 2061 return commonKey(keyCode, 1, event); 2062 } 2063 2064 private boolean commonKey(int keyCode, int count, KeyEvent event) { 2065 if (mAdapter == null) { 2066 return false; 2067 } 2068 2069 if (mDataChanged) { 2070 layoutChildren(); 2071 } 2072 2073 boolean handled = false; 2074 int action = event.getAction(); 2075 2076 if (action != KeyEvent.ACTION_UP) { 2077 if (mSelectedPosition < 0) { 2078 switch (keyCode) { 2079 case KeyEvent.KEYCODE_DPAD_UP: 2080 case KeyEvent.KEYCODE_DPAD_DOWN: 2081 case KeyEvent.KEYCODE_DPAD_CENTER: 2082 case KeyEvent.KEYCODE_ENTER: 2083 case KeyEvent.KEYCODE_SPACE: 2084 if (resurrectSelection()) { 2085 return true; 2086 } 2087 } 2088 } 2089 switch (keyCode) { 2090 case KeyEvent.KEYCODE_DPAD_UP: 2091 if (!event.isAltPressed()) { 2092 while (count > 0) { 2093 handled = arrowScroll(FOCUS_UP); 2094 count--; 2095 } 2096 } else { 2097 handled = fullScroll(FOCUS_UP); 2098 } 2099 break; 2100 2101 case KeyEvent.KEYCODE_DPAD_DOWN: 2102 if (!event.isAltPressed()) { 2103 while (count > 0) { 2104 handled = arrowScroll(FOCUS_DOWN); 2105 count--; 2106 } 2107 } else { 2108 handled = fullScroll(FOCUS_DOWN); 2109 } 2110 break; 2111 2112 case KeyEvent.KEYCODE_DPAD_LEFT: 2113 handled = handleHorizontalFocusWithinListItem(View.FOCUS_LEFT); 2114 break; 2115 case KeyEvent.KEYCODE_DPAD_RIGHT: 2116 handled = handleHorizontalFocusWithinListItem(View.FOCUS_RIGHT); 2117 break; 2118 2119 case KeyEvent.KEYCODE_DPAD_CENTER: 2120 case KeyEvent.KEYCODE_ENTER: 2121 if (mItemCount > 0 && event.getRepeatCount() == 0) { 2122 keyPressed(); 2123 } 2124 handled = true; 2125 break; 2126 2127 case KeyEvent.KEYCODE_SPACE: 2128 if (mPopup == null || !mPopup.isShowing()) { 2129 if (!event.isShiftPressed()) { 2130 pageScroll(FOCUS_DOWN); 2131 } else { 2132 pageScroll(FOCUS_UP); 2133 } 2134 handled = true; 2135 } 2136 break; 2137 } 2138 } 2139 2140 if (!handled) { 2141 handled = sendToTextFilter(keyCode, count, event); 2142 } 2143 2144 if (handled) { 2145 return true; 2146 } else { 2147 switch (action) { 2148 case KeyEvent.ACTION_DOWN: 2149 return super.onKeyDown(keyCode, event); 2150 2151 case KeyEvent.ACTION_UP: 2152 return super.onKeyUp(keyCode, event); 2153 2154 case KeyEvent.ACTION_MULTIPLE: 2155 return super.onKeyMultiple(keyCode, count, event); 2156 2157 default: // shouldn't happen 2158 return false; 2159 } 2160 } 2161 } 2162 2163 /** 2164 * Scrolls up or down by the number of items currently present on screen. 2165 * 2166 * @param direction either {@link View#FOCUS_UP} or {@link View#FOCUS_DOWN} 2167 * @return whether selection was moved 2168 */ 2169 boolean pageScroll(int direction) { 2170 int nextPage = -1; 2171 boolean down = false; 2172 2173 if (direction == FOCUS_UP) { 2174 nextPage = Math.max(0, mSelectedPosition - getChildCount() - 1); 2175 } else if (direction == FOCUS_DOWN) { 2176 nextPage = Math.min(mItemCount - 1, mSelectedPosition + getChildCount() - 1); 2177 down = true; 2178 } 2179 2180 if (nextPage >= 0) { 2181 int position = lookForSelectablePosition(nextPage, down); 2182 if (position >= 0) { 2183 mLayoutMode = LAYOUT_SPECIFIC; 2184 mSpecificTop = mPaddingTop + getVerticalFadingEdgeLength(); 2185 2186 if (down && position > mItemCount - getChildCount()) { 2187 mLayoutMode = LAYOUT_FORCE_BOTTOM; 2188 } 2189 2190 if (!down && position < getChildCount()) { 2191 mLayoutMode = LAYOUT_FORCE_TOP; 2192 } 2193 2194 setSelectionInt(position); 2195 invokeOnItemScrollListener(); 2196 if (!awakenScrollBars()) { 2197 invalidate(); 2198 } 2199 2200 return true; 2201 } 2202 } 2203 2204 return false; 2205 } 2206 2207 /** 2208 * Go to the last or first item if possible (not worrying about panning across or navigating 2209 * within the internal focus of the currently selected item.) 2210 * 2211 * @param direction either {@link View#FOCUS_UP} or {@link View#FOCUS_DOWN} 2212 * 2213 * @return whether selection was moved 2214 */ 2215 boolean fullScroll(int direction) { 2216 boolean moved = false; 2217 if (direction == FOCUS_UP) { 2218 if (mSelectedPosition != 0) { 2219 int position = lookForSelectablePosition(0, true); 2220 if (position >= 0) { 2221 mLayoutMode = LAYOUT_FORCE_TOP; 2222 setSelectionInt(position); 2223 invokeOnItemScrollListener(); 2224 } 2225 moved = true; 2226 } 2227 } else if (direction == FOCUS_DOWN) { 2228 if (mSelectedPosition < mItemCount - 1) { 2229 int position = lookForSelectablePosition(mItemCount - 1, true); 2230 if (position >= 0) { 2231 mLayoutMode = LAYOUT_FORCE_BOTTOM; 2232 setSelectionInt(position); 2233 invokeOnItemScrollListener(); 2234 } 2235 moved = true; 2236 } 2237 } 2238 2239 if (moved && !awakenScrollBars()) { 2240 awakenScrollBars(); 2241 invalidate(); 2242 } 2243 2244 return moved; 2245 } 2246 2247 /** 2248 * To avoid horizontal focus searches changing the selected item, we 2249 * manually focus search within the selected item (as applicable), and 2250 * prevent focus from jumping to something within another item. 2251 * @param direction one of {View.FOCUS_LEFT, View.FOCUS_RIGHT} 2252 * @return Whether this consumes the key event. 2253 */ 2254 private boolean handleHorizontalFocusWithinListItem(int direction) { 2255 if (direction != View.FOCUS_LEFT && direction != View.FOCUS_RIGHT) { 2256 throw new IllegalArgumentException("direction must be one of" 2257 + " {View.FOCUS_LEFT, View.FOCUS_RIGHT}"); 2258 } 2259 2260 final int numChildren = getChildCount(); 2261 if (mItemsCanFocus && numChildren > 0 && mSelectedPosition != INVALID_POSITION) { 2262 final View selectedView = getSelectedView(); 2263 if (selectedView != null && selectedView.hasFocus() && 2264 selectedView instanceof ViewGroup) { 2265 2266 final View currentFocus = selectedView.findFocus(); 2267 final View nextFocus = FocusFinder.getInstance().findNextFocus( 2268 (ViewGroup) selectedView, currentFocus, direction); 2269 if (nextFocus != null) { 2270 // do the math to get interesting rect in next focus' coordinates 2271 currentFocus.getFocusedRect(mTempRect); 2272 offsetDescendantRectToMyCoords(currentFocus, mTempRect); 2273 offsetRectIntoDescendantCoords(nextFocus, mTempRect); 2274 if (nextFocus.requestFocus(direction, mTempRect)) { 2275 return true; 2276 } 2277 } 2278 // we are blocking the key from being handled (by returning true) 2279 // if the global result is going to be some other view within this 2280 // list. this is to acheive the overall goal of having 2281 // horizontal d-pad navigation remain in the current item. 2282 final View globalNextFocus = FocusFinder.getInstance().findNextFocus( 2283 (ViewGroup) getRootView(), currentFocus, direction); 2284 if (globalNextFocus != null) { 2285 return isViewAncestorOf(globalNextFocus, this); 2286 } 2287 } 2288 } 2289 return false; 2290 } 2291 2292 /** 2293 * Scrolls to the next or previous item if possible. 2294 * 2295 * @param direction either {@link View#FOCUS_UP} or {@link View#FOCUS_DOWN} 2296 * 2297 * @return whether selection was moved 2298 */ 2299 boolean arrowScroll(int direction) { 2300 try { 2301 mInLayout = true; 2302 final boolean handled = arrowScrollImpl(direction); 2303 if (handled) { 2304 playSoundEffect(SoundEffectConstants.getContantForFocusDirection(direction)); 2305 } 2306 return handled; 2307 } finally { 2308 mInLayout = false; 2309 } 2310 } 2311 2312 /** 2313 * Handle an arrow scroll going up or down. Take into account whether items are selectable, 2314 * whether there are focusable items etc. 2315 * 2316 * @param direction Either {@link android.view.View#FOCUS_UP} or {@link android.view.View#FOCUS_DOWN}. 2317 * @return Whether any scrolling, selection or focus change occured. 2318 */ 2319 private boolean arrowScrollImpl(int direction) { 2320 if (getChildCount() <= 0) { 2321 return false; 2322 } 2323 2324 View selectedView = getSelectedView(); 2325 int selectedPos = mSelectedPosition; 2326 2327 int nextSelectedPosition = lookForSelectablePositionOnScreen(direction); 2328 int amountToScroll = amountToScroll(direction, nextSelectedPosition); 2329 2330 // if we are moving focus, we may OVERRIDE the default behavior 2331 final ArrowScrollFocusResult focusResult = mItemsCanFocus ? arrowScrollFocused(direction) : null; 2332 if (focusResult != null) { 2333 nextSelectedPosition = focusResult.getSelectedPosition(); 2334 amountToScroll = focusResult.getAmountToScroll(); 2335 } 2336 2337 boolean needToRedraw = focusResult != null; 2338 if (nextSelectedPosition != INVALID_POSITION) { 2339 handleNewSelectionChange(selectedView, direction, nextSelectedPosition, focusResult != null); 2340 setSelectedPositionInt(nextSelectedPosition); 2341 setNextSelectedPositionInt(nextSelectedPosition); 2342 selectedView = getSelectedView(); 2343 selectedPos = nextSelectedPosition; 2344 if (mItemsCanFocus && focusResult == null) { 2345 // there was no new view found to take focus, make sure we 2346 // don't leave focus with the old selection 2347 final View focused = getFocusedChild(); 2348 if (focused != null) { 2349 focused.clearFocus(); 2350 } 2351 } 2352 needToRedraw = true; 2353 checkSelectionChanged(); 2354 } 2355 2356 if (amountToScroll > 0) { 2357 scrollListItemsBy((direction == View.FOCUS_UP) ? amountToScroll : -amountToScroll); 2358 needToRedraw = true; 2359 } 2360 2361 // if we didn't find a new focusable, make sure any existing focused 2362 // item that was panned off screen gives up focus. 2363 if (mItemsCanFocus && (focusResult == null) 2364 && selectedView != null && selectedView.hasFocus()) { 2365 final View focused = selectedView.findFocus(); 2366 if (distanceToView(focused) > 0) { 2367 focused.clearFocus(); 2368 } 2369 } 2370 2371 // if the current selection is panned off, we need to remove the selection 2372 if (nextSelectedPosition == INVALID_POSITION && selectedView != null 2373 && !isViewAncestorOf(selectedView, this)) { 2374 selectedView = null; 2375 hideSelector(); 2376 2377 // but we don't want to set the ressurect position (that would make subsequent 2378 // unhandled key events bring back the item we just scrolled off!) 2379 mResurrectToPosition = INVALID_POSITION; 2380 } 2381 2382 if (needToRedraw) { 2383 if (selectedView != null) { 2384 positionSelector(selectedPos, selectedView); 2385 mSelectedTop = selectedView.getTop(); 2386 } 2387 if (!awakenScrollBars()) { 2388 invalidate(); 2389 } 2390 invokeOnItemScrollListener(); 2391 return true; 2392 } 2393 2394 return false; 2395 } 2396 2397 /** 2398 * When selection changes, it is possible that the previously selected or the 2399 * next selected item will change its size. If so, we need to offset some folks, 2400 * and re-layout the items as appropriate. 2401 * 2402 * @param selectedView The currently selected view (before changing selection). 2403 * should be <code>null</code> if there was no previous selection. 2404 * @param direction Either {@link android.view.View#FOCUS_UP} or 2405 * {@link android.view.View#FOCUS_DOWN}. 2406 * @param newSelectedPosition The position of the next selection. 2407 * @param newFocusAssigned whether new focus was assigned. This matters because 2408 * when something has focus, we don't want to show selection (ugh). 2409 */ 2410 private void handleNewSelectionChange(View selectedView, int direction, int newSelectedPosition, 2411 boolean newFocusAssigned) { 2412 if (newSelectedPosition == INVALID_POSITION) { 2413 throw new IllegalArgumentException("newSelectedPosition needs to be valid"); 2414 } 2415 2416 // whether or not we are moving down or up, we want to preserve the 2417 // top of whatever view is on top: 2418 // - moving down: the view that had selection 2419 // - moving up: the view that is getting selection 2420 View topView; 2421 View bottomView; 2422 int topViewIndex, bottomViewIndex; 2423 boolean topSelected = false; 2424 final int selectedIndex = mSelectedPosition - mFirstPosition; 2425 final int nextSelectedIndex = newSelectedPosition - mFirstPosition; 2426 if (direction == View.FOCUS_UP) { 2427 topViewIndex = nextSelectedIndex; 2428 bottomViewIndex = selectedIndex; 2429 topView = getChildAt(topViewIndex); 2430 bottomView = selectedView; 2431 topSelected = true; 2432 } else { 2433 topViewIndex = selectedIndex; 2434 bottomViewIndex = nextSelectedIndex; 2435 topView = selectedView; 2436 bottomView = getChildAt(bottomViewIndex); 2437 } 2438 2439 final int numChildren = getChildCount(); 2440 2441 // start with top view: is it changing size? 2442 if (topView != null) { 2443 topView.setSelected(!newFocusAssigned && topSelected); 2444 measureAndAdjustDown(topView, topViewIndex, numChildren); 2445 } 2446 2447 // is the bottom view changing size? 2448 if (bottomView != null) { 2449 bottomView.setSelected(!newFocusAssigned && !topSelected); 2450 measureAndAdjustDown(bottomView, bottomViewIndex, numChildren); 2451 } 2452 } 2453 2454 /** 2455 * Re-measure a child, and if its height changes, lay it out preserving its 2456 * top, and adjust the children below it appropriately. 2457 * @param child The child 2458 * @param childIndex The view group index of the child. 2459 * @param numChildren The number of children in the view group. 2460 */ 2461 private void measureAndAdjustDown(View child, int childIndex, int numChildren) { 2462 int oldHeight = child.getHeight(); 2463 measureItem(child); 2464 if (child.getMeasuredHeight() != oldHeight) { 2465 // lay out the view, preserving its top 2466 relayoutMeasuredItem(child); 2467 2468 // adjust views below appropriately 2469 final int heightDelta = child.getMeasuredHeight() - oldHeight; 2470 for (int i = childIndex + 1; i < numChildren; i++) { 2471 getChildAt(i).offsetTopAndBottom(heightDelta); 2472 } 2473 } 2474 } 2475 2476 /** 2477 * Measure a particular list child. 2478 * TODO: unify with setUpChild. 2479 * @param child The child. 2480 */ 2481 private void measureItem(View child) { 2482 ViewGroup.LayoutParams p = child.getLayoutParams(); 2483 if (p == null) { 2484 p = new ViewGroup.LayoutParams( 2485 ViewGroup.LayoutParams.MATCH_PARENT, 2486 ViewGroup.LayoutParams.WRAP_CONTENT); 2487 } 2488 2489 int childWidthSpec = ViewGroup.getChildMeasureSpec(mWidthMeasureSpec, 2490 mListPadding.left + mListPadding.right, p.width); 2491 int lpHeight = p.height; 2492 int childHeightSpec; 2493 if (lpHeight > 0) { 2494 childHeightSpec = MeasureSpec.makeMeasureSpec(lpHeight, MeasureSpec.EXACTLY); 2495 } else { 2496 childHeightSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED); 2497 } 2498 child.measure(childWidthSpec, childHeightSpec); 2499 } 2500 2501 /** 2502 * Layout a child that has been measured, preserving its top position. 2503 * TODO: unify with setUpChild. 2504 * @param child The child. 2505 */ 2506 private void relayoutMeasuredItem(View child) { 2507 final int w = child.getMeasuredWidth(); 2508 final int h = child.getMeasuredHeight(); 2509 final int childLeft = mListPadding.left; 2510 final int childRight = childLeft + w; 2511 final int childTop = child.getTop(); 2512 final int childBottom = childTop + h; 2513 child.layout(childLeft, childTop, childRight, childBottom); 2514 } 2515 2516 /** 2517 * @return The amount to preview next items when arrow srolling. 2518 */ 2519 private int getArrowScrollPreviewLength() { 2520 return Math.max(MIN_SCROLL_PREVIEW_PIXELS, getVerticalFadingEdgeLength()); 2521 } 2522 2523 /** 2524 * Determine how much we need to scroll in order to get the next selected view 2525 * visible, with a fading edge showing below as applicable. The amount is 2526 * capped at {@link #getMaxScrollAmount()} . 2527 * 2528 * @param direction either {@link android.view.View#FOCUS_UP} or 2529 * {@link android.view.View#FOCUS_DOWN}. 2530 * @param nextSelectedPosition The position of the next selection, or 2531 * {@link #INVALID_POSITION} if there is no next selectable position 2532 * @return The amount to scroll. Note: this is always positive! Direction 2533 * needs to be taken into account when actually scrolling. 2534 */ 2535 private int amountToScroll(int direction, int nextSelectedPosition) { 2536 final int listBottom = getHeight() - mListPadding.bottom; 2537 final int listTop = mListPadding.top; 2538 2539 final int numChildren = getChildCount(); 2540 2541 if (direction == View.FOCUS_DOWN) { 2542 int indexToMakeVisible = numChildren - 1; 2543 if (nextSelectedPosition != INVALID_POSITION) { 2544 indexToMakeVisible = nextSelectedPosition - mFirstPosition; 2545 } 2546 2547 final int positionToMakeVisible = mFirstPosition + indexToMakeVisible; 2548 final View viewToMakeVisible = getChildAt(indexToMakeVisible); 2549 2550 int goalBottom = listBottom; 2551 if (positionToMakeVisible < mItemCount - 1) { 2552 goalBottom -= getArrowScrollPreviewLength(); 2553 } 2554 2555 if (viewToMakeVisible.getBottom() <= goalBottom) { 2556 // item is fully visible. 2557 return 0; 2558 } 2559 2560 if (nextSelectedPosition != INVALID_POSITION 2561 && (goalBottom - viewToMakeVisible.getTop()) >= getMaxScrollAmount()) { 2562 // item already has enough of it visible, changing selection is good enough 2563 return 0; 2564 } 2565 2566 int amountToScroll = (viewToMakeVisible.getBottom() - goalBottom); 2567 2568 if ((mFirstPosition + numChildren) == mItemCount) { 2569 // last is last in list -> make sure we don't scroll past it 2570 final int max = getChildAt(numChildren - 1).getBottom() - listBottom; 2571 amountToScroll = Math.min(amountToScroll, max); 2572 } 2573 2574 return Math.min(amountToScroll, getMaxScrollAmount()); 2575 } else { 2576 int indexToMakeVisible = 0; 2577 if (nextSelectedPosition != INVALID_POSITION) { 2578 indexToMakeVisible = nextSelectedPosition - mFirstPosition; 2579 } 2580 final int positionToMakeVisible = mFirstPosition + indexToMakeVisible; 2581 final View viewToMakeVisible = getChildAt(indexToMakeVisible); 2582 int goalTop = listTop; 2583 if (positionToMakeVisible > 0) { 2584 goalTop += getArrowScrollPreviewLength(); 2585 } 2586 if (viewToMakeVisible.getTop() >= goalTop) { 2587 // item is fully visible. 2588 return 0; 2589 } 2590 2591 if (nextSelectedPosition != INVALID_POSITION && 2592 (viewToMakeVisible.getBottom() - goalTop) >= getMaxScrollAmount()) { 2593 // item already has enough of it visible, changing selection is good enough 2594 return 0; 2595 } 2596 2597 int amountToScroll = (goalTop - viewToMakeVisible.getTop()); 2598 if (mFirstPosition == 0) { 2599 // first is first in list -> make sure we don't scroll past it 2600 final int max = listTop - getChildAt(0).getTop(); 2601 amountToScroll = Math.min(amountToScroll, max); 2602 } 2603 return Math.min(amountToScroll, getMaxScrollAmount()); 2604 } 2605 } 2606 2607 /** 2608 * Holds results of focus aware arrow scrolling. 2609 */ 2610 static private class ArrowScrollFocusResult { 2611 private int mSelectedPosition; 2612 private int mAmountToScroll; 2613 2614 /** 2615 * How {@link android.widget.ListView#arrowScrollFocused} returns its values. 2616 */ 2617 void populate(int selectedPosition, int amountToScroll) { 2618 mSelectedPosition = selectedPosition; 2619 mAmountToScroll = amountToScroll; 2620 } 2621 2622 public int getSelectedPosition() { 2623 return mSelectedPosition; 2624 } 2625 2626 public int getAmountToScroll() { 2627 return mAmountToScroll; 2628 } 2629 } 2630 2631 /** 2632 * @param direction either {@link android.view.View#FOCUS_UP} or 2633 * {@link android.view.View#FOCUS_DOWN}. 2634 * @return The position of the next selectable position of the views that 2635 * are currently visible, taking into account the fact that there might 2636 * be no selection. Returns {@link #INVALID_POSITION} if there is no 2637 * selectable view on screen in the given direction. 2638 */ 2639 private int lookForSelectablePositionOnScreen(int direction) { 2640 final int firstPosition = mFirstPosition; 2641 if (direction == View.FOCUS_DOWN) { 2642 int startPos = (mSelectedPosition != INVALID_POSITION) ? 2643 mSelectedPosition + 1 : 2644 firstPosition; 2645 if (startPos >= mAdapter.getCount()) { 2646 return INVALID_POSITION; 2647 } 2648 if (startPos < firstPosition) { 2649 startPos = firstPosition; 2650 } 2651 2652 final int lastVisiblePos = getLastVisiblePosition(); 2653 final ListAdapter adapter = getAdapter(); 2654 for (int pos = startPos; pos <= lastVisiblePos; pos++) { 2655 if (adapter.isEnabled(pos) 2656 && getChildAt(pos - firstPosition).getVisibility() == View.VISIBLE) { 2657 return pos; 2658 } 2659 } 2660 } else { 2661 int last = firstPosition + getChildCount() - 1; 2662 int startPos = (mSelectedPosition != INVALID_POSITION) ? 2663 mSelectedPosition - 1 : 2664 firstPosition + getChildCount() - 1; 2665 if (startPos < 0) { 2666 return INVALID_POSITION; 2667 } 2668 if (startPos > last) { 2669 startPos = last; 2670 } 2671 2672 final ListAdapter adapter = getAdapter(); 2673 for (int pos = startPos; pos >= firstPosition; pos--) { 2674 if (adapter.isEnabled(pos) 2675 && getChildAt(pos - firstPosition).getVisibility() == View.VISIBLE) { 2676 return pos; 2677 } 2678 } 2679 } 2680 return INVALID_POSITION; 2681 } 2682 2683 /** 2684 * Do an arrow scroll based on focus searching. If a new view is 2685 * given focus, return the selection delta and amount to scroll via 2686 * an {@link ArrowScrollFocusResult}, otherwise, return null. 2687 * 2688 * @param direction either {@link android.view.View#FOCUS_UP} or 2689 * {@link android.view.View#FOCUS_DOWN}. 2690 * @return The result if focus has changed, or <code>null</code>. 2691 */ 2692 private ArrowScrollFocusResult arrowScrollFocused(final int direction) { 2693 final View selectedView = getSelectedView(); 2694 View newFocus; 2695 if (selectedView != null && selectedView.hasFocus()) { 2696 View oldFocus = selectedView.findFocus(); 2697 newFocus = FocusFinder.getInstance().findNextFocus(this, oldFocus, direction); 2698 } else { 2699 if (direction == View.FOCUS_DOWN) { 2700 final boolean topFadingEdgeShowing = (mFirstPosition > 0); 2701 final int listTop = mListPadding.top + 2702 (topFadingEdgeShowing ? getArrowScrollPreviewLength() : 0); 2703 final int ySearchPoint = 2704 (selectedView != null && selectedView.getTop() > listTop) ? 2705 selectedView.getTop() : 2706 listTop; 2707 mTempRect.set(0, ySearchPoint, 0, ySearchPoint); 2708 } else { 2709 final boolean bottomFadingEdgeShowing = 2710 (mFirstPosition + getChildCount() - 1) < mItemCount; 2711 final int listBottom = getHeight() - mListPadding.bottom - 2712 (bottomFadingEdgeShowing ? getArrowScrollPreviewLength() : 0); 2713 final int ySearchPoint = 2714 (selectedView != null && selectedView.getBottom() < listBottom) ? 2715 selectedView.getBottom() : 2716 listBottom; 2717 mTempRect.set(0, ySearchPoint, 0, ySearchPoint); 2718 } 2719 newFocus = FocusFinder.getInstance().findNextFocusFromRect(this, mTempRect, direction); 2720 } 2721 2722 if (newFocus != null) { 2723 final int positionOfNewFocus = positionOfNewFocus(newFocus); 2724 2725 // if the focus change is in a different new position, make sure 2726 // we aren't jumping over another selectable position 2727 if (mSelectedPosition != INVALID_POSITION && positionOfNewFocus != mSelectedPosition) { 2728 final int selectablePosition = lookForSelectablePositionOnScreen(direction); 2729 if (selectablePosition != INVALID_POSITION && 2730 ((direction == View.FOCUS_DOWN && selectablePosition < positionOfNewFocus) || 2731 (direction == View.FOCUS_UP && selectablePosition > positionOfNewFocus))) { 2732 return null; 2733 } 2734 } 2735 2736 int focusScroll = amountToScrollToNewFocus(direction, newFocus, positionOfNewFocus); 2737 2738 final int maxScrollAmount = getMaxScrollAmount(); 2739 if (focusScroll < maxScrollAmount) { 2740 // not moving too far, safe to give next view focus 2741 newFocus.requestFocus(direction); 2742 mArrowScrollFocusResult.populate(positionOfNewFocus, focusScroll); 2743 return mArrowScrollFocusResult; 2744 } else if (distanceToView(newFocus) < maxScrollAmount){ 2745 // Case to consider: 2746 // too far to get entire next focusable on screen, but by going 2747 // max scroll amount, we are getting it at least partially in view, 2748 // so give it focus and scroll the max ammount. 2749 newFocus.requestFocus(direction); 2750 mArrowScrollFocusResult.populate(positionOfNewFocus, maxScrollAmount); 2751 return mArrowScrollFocusResult; 2752 } 2753 } 2754 return null; 2755 } 2756 2757 /** 2758 * @param newFocus The view that would have focus. 2759 * @return the position that contains newFocus 2760 */ 2761 private int positionOfNewFocus(View newFocus) { 2762 final int numChildren = getChildCount(); 2763 for (int i = 0; i < numChildren; i++) { 2764 final View child = getChildAt(i); 2765 if (isViewAncestorOf(newFocus, child)) { 2766 return mFirstPosition + i; 2767 } 2768 } 2769 throw new IllegalArgumentException("newFocus is not a child of any of the" 2770 + " children of the list!"); 2771 } 2772 2773 /** 2774 * Return true if child is an ancestor of parent, (or equal to the parent). 2775 */ 2776 private boolean isViewAncestorOf(View child, View parent) { 2777 if (child == parent) { 2778 return true; 2779 } 2780 2781 final ViewParent theParent = child.getParent(); 2782 return (theParent instanceof ViewGroup) && isViewAncestorOf((View) theParent, parent); 2783 } 2784 2785 /** 2786 * Determine how much we need to scroll in order to get newFocus in view. 2787 * @param direction either {@link android.view.View#FOCUS_UP} or 2788 * {@link android.view.View#FOCUS_DOWN}. 2789 * @param newFocus The view that would take focus. 2790 * @param positionOfNewFocus The position of the list item containing newFocus 2791 * @return The amount to scroll. Note: this is always positive! Direction 2792 * needs to be taken into account when actually scrolling. 2793 */ 2794 private int amountToScrollToNewFocus(int direction, View newFocus, int positionOfNewFocus) { 2795 int amountToScroll = 0; 2796 newFocus.getDrawingRect(mTempRect); 2797 offsetDescendantRectToMyCoords(newFocus, mTempRect); 2798 if (direction == View.FOCUS_UP) { 2799 if (mTempRect.top < mListPadding.top) { 2800 amountToScroll = mListPadding.top - mTempRect.top; 2801 if (positionOfNewFocus > 0) { 2802 amountToScroll += getArrowScrollPreviewLength(); 2803 } 2804 } 2805 } else { 2806 final int listBottom = getHeight() - mListPadding.bottom; 2807 if (mTempRect.bottom > listBottom) { 2808 amountToScroll = mTempRect.bottom - listBottom; 2809 if (positionOfNewFocus < mItemCount - 1) { 2810 amountToScroll += getArrowScrollPreviewLength(); 2811 } 2812 } 2813 } 2814 return amountToScroll; 2815 } 2816 2817 /** 2818 * Determine the distance to the nearest edge of a view in a particular 2819 * direction. 2820 * 2821 * @param descendant A descendant of this list. 2822 * @return The distance, or 0 if the nearest edge is already on screen. 2823 */ 2824 private int distanceToView(View descendant) { 2825 int distance = 0; 2826 descendant.getDrawingRect(mTempRect); 2827 offsetDescendantRectToMyCoords(descendant, mTempRect); 2828 final int listBottom = mBottom - mTop - mListPadding.bottom; 2829 if (mTempRect.bottom < mListPadding.top) { 2830 distance = mListPadding.top - mTempRect.bottom; 2831 } else if (mTempRect.top > listBottom) { 2832 distance = mTempRect.top - listBottom; 2833 } 2834 return distance; 2835 } 2836 2837 2838 /** 2839 * Scroll the children by amount, adding a view at the end and removing 2840 * views that fall off as necessary. 2841 * 2842 * @param amount The amount (positive or negative) to scroll. 2843 */ 2844 private void scrollListItemsBy(int amount) { 2845 offsetChildrenTopAndBottom(amount); 2846 2847 final int listBottom = getHeight() - mListPadding.bottom; 2848 final int listTop = mListPadding.top; 2849 final AbsListView.RecycleBin recycleBin = mRecycler; 2850 2851 if (amount < 0) { 2852 // shifted items up 2853 2854 // may need to pan views into the bottom space 2855 int numChildren = getChildCount(); 2856 View last = getChildAt(numChildren - 1); 2857 while (last.getBottom() < listBottom) { 2858 final int lastVisiblePosition = mFirstPosition + numChildren - 1; 2859 if (lastVisiblePosition < mItemCount - 1) { 2860 last = addViewBelow(last, lastVisiblePosition); 2861 numChildren++; 2862 } else { 2863 break; 2864 } 2865 } 2866 2867 // may have brought in the last child of the list that is skinnier 2868 // than the fading edge, thereby leaving space at the end. need 2869 // to shift back 2870 if (last.getBottom() < listBottom) { 2871 offsetChildrenTopAndBottom(listBottom - last.getBottom()); 2872 } 2873 2874 // top views may be panned off screen 2875 View first = getChildAt(0); 2876 while (first.getBottom() < listTop) { 2877 AbsListView.LayoutParams layoutParams = (LayoutParams) first.getLayoutParams(); 2878 if (recycleBin.shouldRecycleViewType(layoutParams.viewType)) { 2879 detachViewFromParent(first); 2880 recycleBin.addScrapView(first, mFirstPosition); 2881 } else { 2882 removeViewInLayout(first); 2883 } 2884 first = getChildAt(0); 2885 mFirstPosition++; 2886 } 2887 } else { 2888 // shifted items down 2889 View first = getChildAt(0); 2890 2891 // may need to pan views into top 2892 while ((first.getTop() > listTop) && (mFirstPosition > 0)) { 2893 first = addViewAbove(first, mFirstPosition); 2894 mFirstPosition--; 2895 } 2896 2897 // may have brought the very first child of the list in too far and 2898 // need to shift it back 2899 if (first.getTop() > listTop) { 2900 offsetChildrenTopAndBottom(listTop - first.getTop()); 2901 } 2902 2903 int lastIndex = getChildCount() - 1; 2904 View last = getChildAt(lastIndex); 2905 2906 // bottom view may be panned off screen 2907 while (last.getTop() > listBottom) { 2908 AbsListView.LayoutParams layoutParams = (LayoutParams) last.getLayoutParams(); 2909 if (recycleBin.shouldRecycleViewType(layoutParams.viewType)) { 2910 detachViewFromParent(last); 2911 recycleBin.addScrapView(last, mFirstPosition+lastIndex); 2912 } else { 2913 removeViewInLayout(last); 2914 } 2915 last = getChildAt(--lastIndex); 2916 } 2917 } 2918 } 2919 2920 private View addViewAbove(View theView, int position) { 2921 int abovePosition = position - 1; 2922 View view = obtainView(abovePosition, mIsScrap); 2923 int edgeOfNewChild = theView.getTop() - mDividerHeight; 2924 setupChild(view, abovePosition, edgeOfNewChild, false, mListPadding.left, 2925 false, mIsScrap[0]); 2926 return view; 2927 } 2928 2929 private View addViewBelow(View theView, int position) { 2930 int belowPosition = position + 1; 2931 View view = obtainView(belowPosition, mIsScrap); 2932 int edgeOfNewChild = theView.getBottom() + mDividerHeight; 2933 setupChild(view, belowPosition, edgeOfNewChild, true, mListPadding.left, 2934 false, mIsScrap[0]); 2935 return view; 2936 } 2937 2938 /** 2939 * Indicates that the views created by the ListAdapter can contain focusable 2940 * items. 2941 * 2942 * @param itemsCanFocus true if items can get focus, false otherwise 2943 */ 2944 public void setItemsCanFocus(boolean itemsCanFocus) { 2945 mItemsCanFocus = itemsCanFocus; 2946 if (!itemsCanFocus) { 2947 setDescendantFocusability(ViewGroup.FOCUS_BLOCK_DESCENDANTS); 2948 } 2949 } 2950 2951 /** 2952 * @return Whether the views created by the ListAdapter can contain focusable 2953 * items. 2954 */ 2955 public boolean getItemsCanFocus() { 2956 return mItemsCanFocus; 2957 } 2958 2959 /** 2960 * @hide Pending API council approval. 2961 */ 2962 @Override 2963 public boolean isOpaque() { 2964 return (mCachingStarted && mIsCacheColorOpaque && mDividerIsOpaque && 2965 hasOpaqueScrollbars()) || super.isOpaque(); 2966 } 2967 2968 @Override 2969 public void setCacheColorHint(int color) { 2970 final boolean opaque = (color >>> 24) == 0xFF; 2971 mIsCacheColorOpaque = opaque; 2972 if (opaque) { 2973 if (mDividerPaint == null) { 2974 mDividerPaint = new Paint(); 2975 } 2976 mDividerPaint.setColor(color); 2977 } 2978 super.setCacheColorHint(color); 2979 } 2980 2981 void drawOverscrollHeader(Canvas canvas, Drawable drawable, Rect bounds) { 2982 final int height = drawable.getMinimumHeight(); 2983 2984 canvas.save(); 2985 canvas.clipRect(bounds); 2986 2987 final int span = bounds.bottom - bounds.top; 2988 if (span < height) { 2989 bounds.top = bounds.bottom - height; 2990 } 2991 2992 drawable.setBounds(bounds); 2993 drawable.draw(canvas); 2994 2995 canvas.restore(); 2996 } 2997 2998 void drawOverscrollFooter(Canvas canvas, Drawable drawable, Rect bounds) { 2999 final int height = drawable.getMinimumHeight(); 3000 3001 canvas.save(); 3002 canvas.clipRect(bounds); 3003 3004 final int span = bounds.bottom - bounds.top; 3005 if (span < height) { 3006 bounds.bottom = bounds.top + height; 3007 } 3008 3009 drawable.setBounds(bounds); 3010 drawable.draw(canvas); 3011 3012 canvas.restore(); 3013 } 3014 3015 @Override 3016 protected void dispatchDraw(Canvas canvas) { 3017 // Draw the dividers 3018 final int dividerHeight = mDividerHeight; 3019 final Drawable overscrollHeader = mOverScrollHeader; 3020 final Drawable overscrollFooter = mOverScrollFooter; 3021 final boolean drawOverscrollHeader = overscrollHeader != null; 3022 final boolean drawOverscrollFooter = overscrollFooter != null; 3023 final boolean drawDividers = dividerHeight > 0 && mDivider != null; 3024 3025 if (drawDividers || drawOverscrollHeader || drawOverscrollFooter) { 3026 // Only modify the top and bottom in the loop, we set the left and right here 3027 final Rect bounds = mTempRect; 3028 bounds.left = mPaddingLeft; 3029 bounds.right = mRight - mLeft - mPaddingRight; 3030 3031 final int count = getChildCount(); 3032 final int headerCount = mHeaderViewInfos.size(); 3033 final int itemCount = mItemCount; 3034 final int footerLimit = itemCount - mFooterViewInfos.size() - 1; 3035 final boolean headerDividers = mHeaderDividersEnabled; 3036 final boolean footerDividers = mFooterDividersEnabled; 3037 final int first = mFirstPosition; 3038 final boolean areAllItemsSelectable = mAreAllItemsSelectable; 3039 final ListAdapter adapter = mAdapter; 3040 // If the list is opaque *and* the background is not, we want to 3041 // fill a rect where the dividers would be for non-selectable items 3042 // If the list is opaque and the background is also opaque, we don't 3043 // need to draw anything since the background will do it for us 3044 final boolean fillForMissingDividers = isOpaque() && !super.isOpaque(); 3045 3046 if (fillForMissingDividers && mDividerPaint == null && mIsCacheColorOpaque) { 3047 mDividerPaint = new Paint(); 3048 mDividerPaint.setColor(getCacheColorHint()); 3049 } 3050 final Paint paint = mDividerPaint; 3051 3052 final int listBottom = mBottom - mTop - mListPadding.bottom + mScrollY; 3053 if (!mStackFromBottom) { 3054 int bottom = 0; 3055 3056 // Draw top divider or header for overscroll 3057 final int scrollY = mScrollY; 3058 if (count > 0 && scrollY < 0) { 3059 if (drawOverscrollHeader) { 3060 bounds.bottom = 0; 3061 bounds.top = scrollY; 3062 drawOverscrollHeader(canvas, overscrollHeader, bounds); 3063 } else if (drawDividers) { 3064 bounds.bottom = 0; 3065 bounds.top = -dividerHeight; 3066 drawDivider(canvas, bounds, -1); 3067 } 3068 } 3069 3070 for (int i = 0; i < count; i++) { 3071 if ((headerDividers || first + i >= headerCount) && 3072 (footerDividers || first + i < footerLimit)) { 3073 View child = getChildAt(i); 3074 bottom = child.getBottom(); 3075 // Don't draw dividers next to items that are not enabled 3076 3077 if (drawDividers && 3078 (bottom < listBottom && !(drawOverscrollFooter && i == count - 1))) { 3079 if ((areAllItemsSelectable || 3080 (adapter.isEnabled(first + i) && (i == count - 1 || 3081 adapter.isEnabled(first + i + 1))))) { 3082 bounds.top = bottom; 3083 bounds.bottom = bottom + dividerHeight; 3084 drawDivider(canvas, bounds, i); 3085 } else if (fillForMissingDividers) { 3086 bounds.top = bottom; 3087 bounds.bottom = bottom + dividerHeight; 3088 canvas.drawRect(bounds, paint); 3089 } 3090 } 3091 } 3092 } 3093 3094 final int overFooterBottom = mBottom + mScrollY; 3095 if (drawOverscrollFooter && first + count == itemCount && 3096 overFooterBottom > bottom) { 3097 bounds.top = bottom; 3098 bounds.bottom = overFooterBottom; 3099 drawOverscrollFooter(canvas, overscrollFooter, bounds); 3100 } 3101 } else { 3102 int top; 3103 int listTop = mListPadding.top; 3104 3105 final int scrollY = mScrollY; 3106 3107 if (count > 0 && drawOverscrollHeader) { 3108 bounds.top = scrollY; 3109 bounds.bottom = getChildAt(0).getTop(); 3110 drawOverscrollHeader(canvas, overscrollHeader, bounds); 3111 } 3112 3113 final int start = drawOverscrollHeader ? 1 : 0; 3114 for (int i = start; i < count; i++) { 3115 if ((headerDividers || first + i >= headerCount) && 3116 (footerDividers || first + i < footerLimit)) { 3117 View child = getChildAt(i); 3118 top = child.getTop(); 3119 // Don't draw dividers next to items that are not enabled 3120 if (top > listTop) { 3121 if ((areAllItemsSelectable || 3122 (adapter.isEnabled(first + i) && (i == count - 1 || 3123 adapter.isEnabled(first + i + 1))))) { 3124 bounds.top = top - dividerHeight; 3125 bounds.bottom = top; 3126 // Give the method the child ABOVE the divider, so we 3127 // subtract one from our child 3128 // position. Give -1 when there is no child above the 3129 // divider. 3130 drawDivider(canvas, bounds, i - 1); 3131 } else if (fillForMissingDividers) { 3132 bounds.top = top - dividerHeight; 3133 bounds.bottom = top; 3134 canvas.drawRect(bounds, paint); 3135 } 3136 } 3137 } 3138 } 3139 3140 if (count > 0 && scrollY > 0) { 3141 if (drawOverscrollFooter) { 3142 final int absListBottom = mBottom; 3143 bounds.top = absListBottom; 3144 bounds.bottom = absListBottom + scrollY; 3145 drawOverscrollFooter(canvas, overscrollFooter, bounds); 3146 } else if (drawDividers) { 3147 bounds.top = listBottom; 3148 bounds.bottom = listBottom + dividerHeight; 3149 drawDivider(canvas, bounds, -1); 3150 } 3151 } 3152 } 3153 } 3154 3155 // Draw the indicators (these should be drawn above the dividers) and children 3156 super.dispatchDraw(canvas); 3157 } 3158 3159 /** 3160 * Draws a divider for the given child in the given bounds. 3161 * 3162 * @param canvas The canvas to draw to. 3163 * @param bounds The bounds of the divider. 3164 * @param childIndex The index of child (of the View) above the divider. 3165 * This will be -1 if there is no child above the divider to be 3166 * drawn. 3167 */ 3168 void drawDivider(Canvas canvas, Rect bounds, int childIndex) { 3169 // This widget draws the same divider for all children 3170 final Drawable divider = mDivider; 3171 3172 divider.setBounds(bounds); 3173 divider.draw(canvas); 3174 } 3175 3176 /** 3177 * Returns the drawable that will be drawn between each item in the list. 3178 * 3179 * @return the current drawable drawn between list elements 3180 */ 3181 public Drawable getDivider() { 3182 return mDivider; 3183 } 3184 3185 /** 3186 * Sets the drawable that will be drawn between each item in the list. If the drawable does 3187 * not have an intrinsic height, you should also call {@link #setDividerHeight(int)} 3188 * 3189 * @param divider The drawable to use. 3190 */ 3191 public void setDivider(Drawable divider) { 3192 if (divider != null) { 3193 mDividerHeight = divider.getIntrinsicHeight(); 3194 } else { 3195 mDividerHeight = 0; 3196 } 3197 mDivider = divider; 3198 mDividerIsOpaque = divider == null || divider.getOpacity() == PixelFormat.OPAQUE; 3199 requestLayout(); 3200 invalidate(); 3201 } 3202 3203 /** 3204 * @return Returns the height of the divider that will be drawn between each item in the list. 3205 */ 3206 public int getDividerHeight() { 3207 return mDividerHeight; 3208 } 3209 3210 /** 3211 * Sets the height of the divider that will be drawn between each item in the list. Calling 3212 * this will override the intrinsic height as set by {@link #setDivider(Drawable)} 3213 * 3214 * @param height The new height of the divider in pixels. 3215 */ 3216 public void setDividerHeight(int height) { 3217 mDividerHeight = height; 3218 requestLayout(); 3219 invalidate(); 3220 } 3221 3222 /** 3223 * Enables or disables the drawing of the divider for header views. 3224 * 3225 * @param headerDividersEnabled True to draw the headers, false otherwise. 3226 * 3227 * @see #setFooterDividersEnabled(boolean) 3228 * @see #addHeaderView(android.view.View) 3229 */ 3230 public void setHeaderDividersEnabled(boolean headerDividersEnabled) { 3231 mHeaderDividersEnabled = headerDividersEnabled; 3232 invalidate(); 3233 } 3234 3235 /** 3236 * Enables or disables the drawing of the divider for footer views. 3237 * 3238 * @param footerDividersEnabled True to draw the footers, false otherwise. 3239 * 3240 * @see #setHeaderDividersEnabled(boolean) 3241 * @see #addFooterView(android.view.View) 3242 */ 3243 public void setFooterDividersEnabled(boolean footerDividersEnabled) { 3244 mFooterDividersEnabled = footerDividersEnabled; 3245 invalidate(); 3246 } 3247 3248 /** 3249 * Sets the drawable that will be drawn above all other list content. 3250 * This area can become visible when the user overscrolls the list. 3251 * 3252 * @param header The drawable to use 3253 */ 3254 public void setOverscrollHeader(Drawable header) { 3255 mOverScrollHeader = header; 3256 if (mScrollY < 0) { 3257 invalidate(); 3258 } 3259 } 3260 3261 /** 3262 * @return The drawable that will be drawn above all other list content 3263 */ 3264 public Drawable getOverscrollHeader() { 3265 return mOverScrollHeader; 3266 } 3267 3268 /** 3269 * Sets the drawable that will be drawn below all other list content. 3270 * This area can become visible when the user overscrolls the list, 3271 * or when the list's content does not fully fill the container area. 3272 * 3273 * @param footer The drawable to use 3274 */ 3275 public void setOverscrollFooter(Drawable footer) { 3276 mOverScrollFooter = footer; 3277 invalidate(); 3278 } 3279 3280 /** 3281 * @return The drawable that will be drawn below all other list content 3282 */ 3283 public Drawable getOverscrollFooter() { 3284 return mOverScrollFooter; 3285 } 3286 3287 @Override 3288 protected void onFocusChanged(boolean gainFocus, int direction, Rect previouslyFocusedRect) { 3289 super.onFocusChanged(gainFocus, direction, previouslyFocusedRect); 3290 3291 int closetChildIndex = -1; 3292 if (gainFocus && previouslyFocusedRect != null) { 3293 previouslyFocusedRect.offset(mScrollX, mScrollY); 3294 3295 final ListAdapter adapter = mAdapter; 3296 // Don't cache the result of getChildCount or mFirstPosition here, 3297 // it could change in layoutChildren. 3298 if (adapter.getCount() < getChildCount() + mFirstPosition) { 3299 mLayoutMode = LAYOUT_NORMAL; 3300 layoutChildren(); 3301 } 3302 3303 // figure out which item should be selected based on previously 3304 // focused rect 3305 Rect otherRect = mTempRect; 3306 int minDistance = Integer.MAX_VALUE; 3307 final int childCount = getChildCount(); 3308 final int firstPosition = mFirstPosition; 3309 3310 for (int i = 0; i < childCount; i++) { 3311 // only consider selectable views 3312 if (!adapter.isEnabled(firstPosition + i)) { 3313 continue; 3314 } 3315 3316 View other = getChildAt(i); 3317 other.getDrawingRect(otherRect); 3318 offsetDescendantRectToMyCoords(other, otherRect); 3319 int distance = getDistance(previouslyFocusedRect, otherRect, direction); 3320 3321 if (distance < minDistance) { 3322 minDistance = distance; 3323 closetChildIndex = i; 3324 } 3325 } 3326 } 3327 3328 if (closetChildIndex >= 0) { 3329 setSelection(closetChildIndex + mFirstPosition); 3330 } else { 3331 requestLayout(); 3332 } 3333 } 3334 3335 3336 /* 3337 * (non-Javadoc) 3338 * 3339 * Children specified in XML are assumed to be header views. After we have 3340 * parsed them move them out of the children list and into mHeaderViews. 3341 */ 3342 @Override 3343 protected void onFinishInflate() { 3344 super.onFinishInflate(); 3345 3346 int count = getChildCount(); 3347 if (count > 0) { 3348 for (int i = 0; i < count; ++i) { 3349 addHeaderView(getChildAt(i)); 3350 } 3351 removeAllViews(); 3352 } 3353 } 3354 3355 /* (non-Javadoc) 3356 * @see android.view.View#findViewById(int) 3357 * First look in our children, then in any header and footer views that may be scrolled off. 3358 */ 3359 @Override 3360 protected View findViewTraversal(int id) { 3361 View v; 3362 v = super.findViewTraversal(id); 3363 if (v == null) { 3364 v = findViewInHeadersOrFooters(mHeaderViewInfos, id); 3365 if (v != null) { 3366 return v; 3367 } 3368 v = findViewInHeadersOrFooters(mFooterViewInfos, id); 3369 if (v != null) { 3370 return v; 3371 } 3372 } 3373 return v; 3374 } 3375 3376 /* (non-Javadoc) 3377 * 3378 * Look in the passed in list of headers or footers for the view. 3379 */ 3380 View findViewInHeadersOrFooters(ArrayList<FixedViewInfo> where, int id) { 3381 if (where != null) { 3382 int len = where.size(); 3383 View v; 3384 3385 for (int i = 0; i < len; i++) { 3386 v = where.get(i).view; 3387 3388 if (!v.isRootNamespace()) { 3389 v = v.findViewById(id); 3390 3391 if (v != null) { 3392 return v; 3393 } 3394 } 3395 } 3396 } 3397 return null; 3398 } 3399 3400 /* (non-Javadoc) 3401 * @see android.view.View#findViewWithTag(String) 3402 * First look in our children, then in any header and footer views that may be scrolled off. 3403 */ 3404 @Override 3405 protected View findViewWithTagTraversal(Object tag) { 3406 View v; 3407 v = super.findViewWithTagTraversal(tag); 3408 if (v == null) { 3409 v = findViewTagInHeadersOrFooters(mHeaderViewInfos, tag); 3410 if (v != null) { 3411 return v; 3412 } 3413 3414 v = findViewTagInHeadersOrFooters(mFooterViewInfos, tag); 3415 if (v != null) { 3416 return v; 3417 } 3418 } 3419 return v; 3420 } 3421 3422 /* (non-Javadoc) 3423 * 3424 * Look in the passed in list of headers or footers for the view with the tag. 3425 */ 3426 View findViewTagInHeadersOrFooters(ArrayList<FixedViewInfo> where, Object tag) { 3427 if (where != null) { 3428 int len = where.size(); 3429 View v; 3430 3431 for (int i = 0; i < len; i++) { 3432 v = where.get(i).view; 3433 3434 if (!v.isRootNamespace()) { 3435 v = v.findViewWithTag(tag); 3436 3437 if (v != null) { 3438 return v; 3439 } 3440 } 3441 } 3442 } 3443 return null; 3444 } 3445 3446 @Override 3447 public boolean onTouchEvent(MotionEvent ev) { 3448 if (mItemsCanFocus && ev.getAction() == MotionEvent.ACTION_DOWN && ev.getEdgeFlags() != 0) { 3449 // Don't handle edge touches immediately -- they may actually belong to one of our 3450 // descendants. 3451 return false; 3452 } 3453 return super.onTouchEvent(ev); 3454 } 3455 3456 /** 3457 * Returns the set of checked items ids. The result is only valid if the 3458 * choice mode has not been set to {@link #CHOICE_MODE_NONE}. 3459 * 3460 * @return A new array which contains the id of each checked item in the 3461 * list. 3462 * 3463 * @deprecated Use {@link #getCheckedItemIds()} instead. 3464 */ 3465 @Deprecated 3466 public long[] getCheckItemIds() { 3467 // Use new behavior that correctly handles stable ID mapping. 3468 if (mAdapter != null && mAdapter.hasStableIds()) { 3469 return getCheckedItemIds(); 3470 } 3471 3472 // Old behavior was buggy, but would sort of work for adapters without stable IDs. 3473 // Fall back to it to support legacy apps. 3474 if (mChoiceMode != CHOICE_MODE_NONE && mCheckStates != null && mAdapter != null) { 3475 final SparseBooleanArray states = mCheckStates; 3476 final int count = states.size(); 3477 final long[] ids = new long[count]; 3478 final ListAdapter adapter = mAdapter; 3479 3480 int checkedCount = 0; 3481 for (int i = 0; i < count; i++) { 3482 if (states.valueAt(i)) { 3483 ids[checkedCount++] = adapter.getItemId(states.keyAt(i)); 3484 } 3485 } 3486 3487 // Trim array if needed. mCheckStates may contain false values 3488 // resulting in checkedCount being smaller than count. 3489 if (checkedCount == count) { 3490 return ids; 3491 } else { 3492 final long[] result = new long[checkedCount]; 3493 System.arraycopy(ids, 0, result, 0, checkedCount); 3494 3495 return result; 3496 } 3497 } 3498 return new long[0]; 3499 } 3500} 3501