ListView.java revision cb704cd1e05ecd9bbd9bebd16f3b816dcb0c5309
1/* 2 * Copyright (C) 2006 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17package android.widget; 18 19import com.android.internal.R; 20import com.google.android.collect.Lists; 21 22import android.content.Context; 23import android.content.res.TypedArray; 24import android.graphics.Canvas; 25import android.graphics.Paint; 26import android.graphics.PixelFormat; 27import android.graphics.Rect; 28import android.graphics.drawable.ColorDrawable; 29import android.graphics.drawable.Drawable; 30import android.os.Parcel; 31import android.os.Parcelable; 32import android.util.AttributeSet; 33import android.util.LongSparseArray; 34import android.util.SparseBooleanArray; 35import android.view.FocusFinder; 36import android.view.KeyEvent; 37import android.view.MotionEvent; 38import android.view.SoundEffectConstants; 39import android.view.View; 40import android.view.ViewDebug; 41import android.view.ViewGroup; 42import android.view.ViewParent; 43import android.view.accessibility.AccessibilityEvent; 44 45import java.util.ArrayList; 46 47/* 48 * Implementation Notes: 49 * 50 * Some terminology: 51 * 52 * index - index of the items that are currently visible 53 * position - index of the items in the cursor 54 */ 55 56 57/** 58 * A view that shows items in a vertically scrolling list. The items 59 * come from the {@link ListAdapter} associated with this view. 60 * 61 * @attr ref android.R.styleable#ListView_entries 62 * @attr ref android.R.styleable#ListView_divider 63 * @attr ref android.R.styleable#ListView_dividerHeight 64 * @attr ref android.R.styleable#ListView_choiceMode 65 * @attr ref android.R.styleable#ListView_headerDividersEnabled 66 * @attr ref android.R.styleable#ListView_footerDividersEnabled 67 */ 68public class ListView extends AbsListView { 69 /** 70 * Used to indicate a no preference for a position type. 71 */ 72 static final int NO_POSITION = -1; 73 74 /** 75 * Normal list that does not indicate choices 76 */ 77 public static final int CHOICE_MODE_NONE = 0; 78 79 /** 80 * The list allows up to one choice 81 */ 82 public static final int CHOICE_MODE_SINGLE = 1; 83 84 /** 85 * The list allows multiple choices 86 */ 87 public static final int CHOICE_MODE_MULTIPLE = 2; 88 89 /** 90 * When arrow scrolling, ListView will never scroll more than this factor 91 * times the height of the list. 92 */ 93 private static final float MAX_SCROLL_FACTOR = 0.33f; 94 95 /** 96 * When arrow scrolling, need a certain amount of pixels to preview next 97 * items. This is usually the fading edge, but if that is small enough, 98 * we want to make sure we preview at least this many pixels. 99 */ 100 private static final int MIN_SCROLL_PREVIEW_PIXELS = 2; 101 102 /** 103 * A class that represents a fixed view in a list, for example a header at the top 104 * or a footer at the bottom. 105 */ 106 public class FixedViewInfo { 107 /** The view to add to the list */ 108 public View view; 109 /** The data backing the view. This is returned from {@link ListAdapter#getItem(int)}. */ 110 public Object data; 111 /** <code>true</code> if the fixed view should be selectable in the list */ 112 public boolean isSelectable; 113 } 114 115 private ArrayList<FixedViewInfo> mHeaderViewInfos = Lists.newArrayList(); 116 private ArrayList<FixedViewInfo> mFooterViewInfos = Lists.newArrayList(); 117 118 Drawable mDivider; 119 int mDividerHeight; 120 121 private boolean mIsCacheColorOpaque; 122 private boolean mDividerIsOpaque; 123 private boolean mClipDivider; 124 125 private boolean mHeaderDividersEnabled; 126 private boolean mFooterDividersEnabled; 127 128 private boolean mAreAllItemsSelectable = true; 129 130 private boolean mItemsCanFocus = false; 131 132 private int mChoiceMode = CHOICE_MODE_NONE; 133 134 private SparseBooleanArray mCheckStates; 135 private LongSparseArray<Boolean> mCheckedIdStates; 136 137 // used for temporary calculations. 138 private final Rect mTempRect = new Rect(); 139 private Paint mDividerPaint; 140 141 // the single allocated result per list view; kinda cheesey but avoids 142 // allocating these thingies too often. 143 private final ArrowScrollFocusResult mArrowScrollFocusResult = new ArrowScrollFocusResult(); 144 145 // Keeps focused children visible through resizes 146 private FocusSelector mFocusSelector; 147 148 public ListView(Context context) { 149 this(context, null); 150 } 151 152 public ListView(Context context, AttributeSet attrs) { 153 this(context, attrs, com.android.internal.R.attr.listViewStyle); 154 } 155 156 public ListView(Context context, AttributeSet attrs, int defStyle) { 157 super(context, attrs, defStyle); 158 159 TypedArray a = context.obtainStyledAttributes(attrs, 160 com.android.internal.R.styleable.ListView, defStyle, 0); 161 162 CharSequence[] entries = a.getTextArray( 163 com.android.internal.R.styleable.ListView_entries); 164 if (entries != null) { 165 setAdapter(new ArrayAdapter<CharSequence>(context, 166 com.android.internal.R.layout.simple_list_item_1, entries)); 167 } 168 169 final Drawable d = a.getDrawable(com.android.internal.R.styleable.ListView_divider); 170 if (d != null) { 171 // If a divider is specified use its intrinsic height for divider height 172 setDivider(d); 173 } 174 175 // Use the height specified, zero being the default 176 final int dividerHeight = a.getDimensionPixelSize( 177 com.android.internal.R.styleable.ListView_dividerHeight, 0); 178 if (dividerHeight != 0) { 179 setDividerHeight(dividerHeight); 180 } 181 182 setChoiceMode(a.getInt(R.styleable.ListView_choiceMode, CHOICE_MODE_NONE)); 183 184 mHeaderDividersEnabled = a.getBoolean(R.styleable.ListView_headerDividersEnabled, true); 185 mFooterDividersEnabled = a.getBoolean(R.styleable.ListView_footerDividersEnabled, true); 186 187 a.recycle(); 188 } 189 190 /** 191 * @return The maximum amount a list view will scroll in response to 192 * an arrow event. 193 */ 194 public int getMaxScrollAmount() { 195 return (int) (MAX_SCROLL_FACTOR * (mBottom - mTop)); 196 } 197 198 /** 199 * Make sure views are touching the top or bottom edge, as appropriate for 200 * our gravity 201 */ 202 private void adjustViewsUpOrDown() { 203 final int childCount = getChildCount(); 204 int delta; 205 206 if (childCount > 0) { 207 View child; 208 209 if (!mStackFromBottom) { 210 // Uh-oh -- we came up short. Slide all views up to make them 211 // align with the top 212 child = getChildAt(0); 213 delta = child.getTop() - mListPadding.top; 214 if (mFirstPosition != 0) { 215 // It's OK to have some space above the first item if it is 216 // part of the vertical spacing 217 delta -= mDividerHeight; 218 } 219 if (delta < 0) { 220 // We only are looking to see if we are too low, not too high 221 delta = 0; 222 } 223 } else { 224 // we are too high, slide all views down to align with bottom 225 child = getChildAt(childCount - 1); 226 delta = child.getBottom() - (getHeight() - mListPadding.bottom); 227 228 if (mFirstPosition + childCount < mItemCount) { 229 // It's OK to have some space below the last item if it is 230 // part of the vertical spacing 231 delta += mDividerHeight; 232 } 233 234 if (delta > 0) { 235 delta = 0; 236 } 237 } 238 239 if (delta != 0) { 240 offsetChildrenTopAndBottom(-delta); 241 } 242 } 243 } 244 245 /** 246 * Add a fixed view to appear at the top of the list. If addHeaderView is 247 * called more than once, the views will appear in the order they were 248 * added. Views added using this call can take focus if they want. 249 * <p> 250 * NOTE: Call this before calling setAdapter. This is so ListView can wrap 251 * the supplied cursor with one that will also account for header and footer 252 * views. 253 * 254 * @param v The view to add. 255 * @param data Data to associate with this view 256 * @param isSelectable whether the item is selectable 257 */ 258 public void addHeaderView(View v, Object data, boolean isSelectable) { 259 260 if (mAdapter != null) { 261 throw new IllegalStateException( 262 "Cannot add header view to list -- setAdapter has already been called."); 263 } 264 265 FixedViewInfo info = new FixedViewInfo(); 266 info.view = v; 267 info.data = data; 268 info.isSelectable = isSelectable; 269 mHeaderViewInfos.add(info); 270 } 271 272 /** 273 * Add a fixed view to appear at the top of the list. If addHeaderView is 274 * called more than once, the views will appear in the order they were 275 * added. Views added using this call can take focus if they want. 276 * <p> 277 * NOTE: Call this before calling setAdapter. This is so ListView can wrap 278 * the supplied cursor with one that will also account for header and footer 279 * views. 280 * 281 * @param v The view to add. 282 */ 283 public void addHeaderView(View v) { 284 addHeaderView(v, null, true); 285 } 286 287 @Override 288 public int getHeaderViewsCount() { 289 return mHeaderViewInfos.size(); 290 } 291 292 /** 293 * Removes a previously-added header view. 294 * 295 * @param v The view to remove 296 * @return true if the view was removed, false if the view was not a header 297 * view 298 */ 299 public boolean removeHeaderView(View v) { 300 if (mHeaderViewInfos.size() > 0) { 301 boolean result = false; 302 if (((HeaderViewListAdapter) mAdapter).removeHeader(v)) { 303 mDataSetObserver.onChanged(); 304 result = true; 305 } 306 removeFixedViewInfo(v, mHeaderViewInfos); 307 return result; 308 } 309 return false; 310 } 311 312 private void removeFixedViewInfo(View v, ArrayList<FixedViewInfo> where) { 313 int len = where.size(); 314 for (int i = 0; i < len; ++i) { 315 FixedViewInfo info = where.get(i); 316 if (info.view == v) { 317 where.remove(i); 318 break; 319 } 320 } 321 } 322 323 /** 324 * Add a fixed view to appear at the bottom of the list. If addFooterView is 325 * called more than once, the views will appear in the order they were 326 * added. Views added using this call can take focus if they want. 327 * <p> 328 * NOTE: Call this before calling setAdapter. This is so ListView can wrap 329 * the supplied cursor with one that will also account for header and footer 330 * views. 331 * 332 * @param v The view to add. 333 * @param data Data to associate with this view 334 * @param isSelectable true if the footer view can be selected 335 */ 336 public void addFooterView(View v, Object data, boolean isSelectable) { 337 FixedViewInfo info = new FixedViewInfo(); 338 info.view = v; 339 info.data = data; 340 info.isSelectable = isSelectable; 341 mFooterViewInfos.add(info); 342 343 // in the case of re-adding a footer view, or adding one later on, 344 // we need to notify the observer 345 if (mDataSetObserver != null) { 346 mDataSetObserver.onChanged(); 347 } 348 } 349 350 /** 351 * Add a fixed view to appear at the bottom of the list. If addFooterView is called more 352 * than once, the views will appear in the order they were added. Views added using 353 * this call can take focus if they want. 354 * <p>NOTE: Call this before calling setAdapter. This is so ListView can wrap the supplied 355 * cursor with one that will also account for header and footer views. 356 * 357 * 358 * @param v The view to add. 359 */ 360 public void addFooterView(View v) { 361 addFooterView(v, null, true); 362 } 363 364 @Override 365 public int getFooterViewsCount() { 366 return mFooterViewInfos.size(); 367 } 368 369 /** 370 * Removes a previously-added footer view. 371 * 372 * @param v The view to remove 373 * @return 374 * true if the view was removed, false if the view was not a footer view 375 */ 376 public boolean removeFooterView(View v) { 377 if (mFooterViewInfos.size() > 0) { 378 boolean result = false; 379 if (((HeaderViewListAdapter) mAdapter).removeFooter(v)) { 380 mDataSetObserver.onChanged(); 381 result = true; 382 } 383 removeFixedViewInfo(v, mFooterViewInfos); 384 return result; 385 } 386 return false; 387 } 388 389 /** 390 * Returns the adapter currently in use in this ListView. The returned adapter 391 * might not be the same adapter passed to {@link #setAdapter(ListAdapter)} but 392 * might be a {@link WrapperListAdapter}. 393 * 394 * @return The adapter currently used to display data in this ListView. 395 * 396 * @see #setAdapter(ListAdapter) 397 */ 398 @Override 399 public ListAdapter getAdapter() { 400 return mAdapter; 401 } 402 403 /** 404 * Sets the data behind this ListView. 405 * 406 * The adapter passed to this method may be wrapped by a {@link WrapperListAdapter}, 407 * depending on the ListView features currently in use. For instance, adding 408 * headers and/or footers will cause the adapter to be wrapped. 409 * 410 * @param adapter The ListAdapter which is responsible for maintaining the 411 * data backing this list and for producing a view to represent an 412 * item in that data set. 413 * 414 * @see #getAdapter() 415 */ 416 @Override 417 public void setAdapter(ListAdapter adapter) { 418 if (null != mAdapter) { 419 mAdapter.unregisterDataSetObserver(mDataSetObserver); 420 } 421 422 resetList(); 423 mRecycler.clear(); 424 425 if (mHeaderViewInfos.size() > 0|| mFooterViewInfos.size() > 0) { 426 mAdapter = new HeaderViewListAdapter(mHeaderViewInfos, mFooterViewInfos, adapter); 427 } else { 428 mAdapter = adapter; 429 } 430 431 mOldSelectedPosition = INVALID_POSITION; 432 mOldSelectedRowId = INVALID_ROW_ID; 433 if (mAdapter != null) { 434 mAreAllItemsSelectable = mAdapter.areAllItemsEnabled(); 435 mOldItemCount = mItemCount; 436 mItemCount = mAdapter.getCount(); 437 checkFocus(); 438 439 mDataSetObserver = new AdapterDataSetObserver(); 440 mAdapter.registerDataSetObserver(mDataSetObserver); 441 442 mRecycler.setViewTypeCount(mAdapter.getViewTypeCount()); 443 444 int position; 445 if (mStackFromBottom) { 446 position = lookForSelectablePosition(mItemCount - 1, false); 447 } else { 448 position = lookForSelectablePosition(0, true); 449 } 450 setSelectedPositionInt(position); 451 setNextSelectedPositionInt(position); 452 453 if (mItemCount == 0) { 454 // Nothing selected 455 checkSelectionChanged(); 456 } 457 458 if (mChoiceMode != CHOICE_MODE_NONE && 459 mAdapter.hasStableIds() && 460 mCheckedIdStates == null) { 461 mCheckedIdStates = new LongSparseArray<Boolean>(); 462 } 463 464 } else { 465 mAreAllItemsSelectable = true; 466 checkFocus(); 467 // Nothing selected 468 checkSelectionChanged(); 469 } 470 471 if (mCheckStates != null) { 472 mCheckStates.clear(); 473 } 474 475 if (mCheckedIdStates != null) { 476 mCheckedIdStates.clear(); 477 } 478 479 requestLayout(); 480 } 481 482 483 /** 484 * The list is empty. Clear everything out. 485 */ 486 @Override 487 void resetList() { 488 // The parent's resetList() will remove all views from the layout so we need to 489 // cleanup the state of our footers and headers 490 clearRecycledState(mHeaderViewInfos); 491 clearRecycledState(mFooterViewInfos); 492 493 super.resetList(); 494 495 mLayoutMode = LAYOUT_NORMAL; 496 } 497 498 private void clearRecycledState(ArrayList<FixedViewInfo> infos) { 499 if (infos != null) { 500 final int count = infos.size(); 501 502 for (int i = 0; i < count; i++) { 503 final View child = infos.get(i).view; 504 final LayoutParams p = (LayoutParams) child.getLayoutParams(); 505 if (p != null) { 506 p.recycledHeaderFooter = false; 507 } 508 } 509 } 510 } 511 512 /** 513 * @return Whether the list needs to show the top fading edge 514 */ 515 private boolean showingTopFadingEdge() { 516 final int listTop = mScrollY + mListPadding.top; 517 return (mFirstPosition > 0) || (getChildAt(0).getTop() > listTop); 518 } 519 520 /** 521 * @return Whether the list needs to show the bottom fading edge 522 */ 523 private boolean showingBottomFadingEdge() { 524 final int childCount = getChildCount(); 525 final int bottomOfBottomChild = getChildAt(childCount - 1).getBottom(); 526 final int lastVisiblePosition = mFirstPosition + childCount - 1; 527 528 final int listBottom = mScrollY + getHeight() - mListPadding.bottom; 529 530 return (lastVisiblePosition < mItemCount - 1) 531 || (bottomOfBottomChild < listBottom); 532 } 533 534 535 @Override 536 public boolean requestChildRectangleOnScreen(View child, Rect rect, boolean immediate) { 537 538 int rectTopWithinChild = rect.top; 539 540 // offset so rect is in coordinates of the this view 541 rect.offset(child.getLeft(), child.getTop()); 542 rect.offset(-child.getScrollX(), -child.getScrollY()); 543 544 final int height = getHeight(); 545 int listUnfadedTop = getScrollY(); 546 int listUnfadedBottom = listUnfadedTop + height; 547 final int fadingEdge = getVerticalFadingEdgeLength(); 548 549 if (showingTopFadingEdge()) { 550 // leave room for top fading edge as long as rect isn't at very top 551 if ((mSelectedPosition > 0) || (rectTopWithinChild > fadingEdge)) { 552 listUnfadedTop += fadingEdge; 553 } 554 } 555 556 int childCount = getChildCount(); 557 int bottomOfBottomChild = getChildAt(childCount - 1).getBottom(); 558 559 if (showingBottomFadingEdge()) { 560 // leave room for bottom fading edge as long as rect isn't at very bottom 561 if ((mSelectedPosition < mItemCount - 1) 562 || (rect.bottom < (bottomOfBottomChild - fadingEdge))) { 563 listUnfadedBottom -= fadingEdge; 564 } 565 } 566 567 int scrollYDelta = 0; 568 569 if (rect.bottom > listUnfadedBottom && rect.top > listUnfadedTop) { 570 // need to MOVE DOWN to get it in view: move down just enough so 571 // that the entire rectangle is in view (or at least the first 572 // screen size chunk). 573 574 if (rect.height() > height) { 575 // just enough to get screen size chunk on 576 scrollYDelta += (rect.top - listUnfadedTop); 577 } else { 578 // get entire rect at bottom of screen 579 scrollYDelta += (rect.bottom - listUnfadedBottom); 580 } 581 582 // make sure we aren't scrolling beyond the end of our children 583 int distanceToBottom = bottomOfBottomChild - listUnfadedBottom; 584 scrollYDelta = Math.min(scrollYDelta, distanceToBottom); 585 } else if (rect.top < listUnfadedTop && rect.bottom < listUnfadedBottom) { 586 // need to MOVE UP to get it in view: move up just enough so that 587 // entire rectangle is in view (or at least the first screen 588 // size chunk of it). 589 590 if (rect.height() > height) { 591 // screen size chunk 592 scrollYDelta -= (listUnfadedBottom - rect.bottom); 593 } else { 594 // entire rect at top 595 scrollYDelta -= (listUnfadedTop - rect.top); 596 } 597 598 // make sure we aren't scrolling any further than the top our children 599 int top = getChildAt(0).getTop(); 600 int deltaToTop = top - listUnfadedTop; 601 scrollYDelta = Math.max(scrollYDelta, deltaToTop); 602 } 603 604 final boolean scroll = scrollYDelta != 0; 605 if (scroll) { 606 scrollListItemsBy(-scrollYDelta); 607 positionSelector(child); 608 mSelectedTop = child.getTop(); 609 invalidate(); 610 } 611 return scroll; 612 } 613 614 /** 615 * {@inheritDoc} 616 */ 617 @Override 618 void fillGap(boolean down) { 619 final int count = getChildCount(); 620 if (down) { 621 final int startOffset = count > 0 ? getChildAt(count - 1).getBottom() + mDividerHeight : 622 getListPaddingTop(); 623 fillDown(mFirstPosition + count, startOffset); 624 correctTooHigh(getChildCount()); 625 } else { 626 final int startOffset = count > 0 ? getChildAt(0).getTop() - mDividerHeight : 627 getHeight() - getListPaddingBottom(); 628 fillUp(mFirstPosition - 1, startOffset); 629 correctTooLow(getChildCount()); 630 } 631 } 632 633 /** 634 * Fills the list from pos down to the end of the list view. 635 * 636 * @param pos The first position to put in the list 637 * 638 * @param nextTop The location where the top of the item associated with pos 639 * should be drawn 640 * 641 * @return The view that is currently selected, if it happens to be in the 642 * range that we draw. 643 */ 644 private View fillDown(int pos, int nextTop) { 645 View selectedView = null; 646 647 int end = (mBottom - mTop) - mListPadding.bottom; 648 649 while (nextTop < end && pos < mItemCount) { 650 // is this the selected item? 651 boolean selected = pos == mSelectedPosition; 652 View child = makeAndAddView(pos, nextTop, true, mListPadding.left, selected); 653 654 nextTop = child.getBottom() + mDividerHeight; 655 if (selected) { 656 selectedView = child; 657 } 658 pos++; 659 } 660 661 return selectedView; 662 } 663 664 /** 665 * Fills the list from pos up to the top of the list view. 666 * 667 * @param pos The first position to put in the list 668 * 669 * @param nextBottom The location where the bottom of the item associated 670 * with pos should be drawn 671 * 672 * @return The view that is currently selected 673 */ 674 private View fillUp(int pos, int nextBottom) { 675 View selectedView = null; 676 677 int end = mListPadding.top; 678 679 while (nextBottom > end && pos >= 0) { 680 // is this the selected item? 681 boolean selected = pos == mSelectedPosition; 682 View child = makeAndAddView(pos, nextBottom, false, mListPadding.left, selected); 683 nextBottom = child.getTop() - mDividerHeight; 684 if (selected) { 685 selectedView = child; 686 } 687 pos--; 688 } 689 690 mFirstPosition = pos + 1; 691 692 return selectedView; 693 } 694 695 /** 696 * Fills the list from top to bottom, starting with mFirstPosition 697 * 698 * @param nextTop The location where the top of the first item should be 699 * drawn 700 * 701 * @return The view that is currently selected 702 */ 703 private View fillFromTop(int nextTop) { 704 mFirstPosition = Math.min(mFirstPosition, mSelectedPosition); 705 mFirstPosition = Math.min(mFirstPosition, mItemCount - 1); 706 if (mFirstPosition < 0) { 707 mFirstPosition = 0; 708 } 709 return fillDown(mFirstPosition, nextTop); 710 } 711 712 713 /** 714 * Put mSelectedPosition in the middle of the screen and then build up and 715 * down from there. This method forces mSelectedPosition to the center. 716 * 717 * @param childrenTop Top of the area in which children can be drawn, as 718 * measured in pixels 719 * @param childrenBottom Bottom of the area in which children can be drawn, 720 * as measured in pixels 721 * @return Currently selected view 722 */ 723 private View fillFromMiddle(int childrenTop, int childrenBottom) { 724 int height = childrenBottom - childrenTop; 725 726 int position = reconcileSelectedPosition(); 727 728 View sel = makeAndAddView(position, childrenTop, true, 729 mListPadding.left, true); 730 mFirstPosition = position; 731 732 int selHeight = sel.getMeasuredHeight(); 733 if (selHeight <= height) { 734 sel.offsetTopAndBottom((height - selHeight) / 2); 735 } 736 737 fillAboveAndBelow(sel, position); 738 739 if (!mStackFromBottom) { 740 correctTooHigh(getChildCount()); 741 } else { 742 correctTooLow(getChildCount()); 743 } 744 745 return sel; 746 } 747 748 /** 749 * Once the selected view as been placed, fill up the visible area above and 750 * below it. 751 * 752 * @param sel The selected view 753 * @param position The position corresponding to sel 754 */ 755 private void fillAboveAndBelow(View sel, int position) { 756 final int dividerHeight = mDividerHeight; 757 if (!mStackFromBottom) { 758 fillUp(position - 1, sel.getTop() - dividerHeight); 759 adjustViewsUpOrDown(); 760 fillDown(position + 1, sel.getBottom() + dividerHeight); 761 } else { 762 fillDown(position + 1, sel.getBottom() + dividerHeight); 763 adjustViewsUpOrDown(); 764 fillUp(position - 1, sel.getTop() - dividerHeight); 765 } 766 } 767 768 769 /** 770 * Fills the grid based on positioning the new selection at a specific 771 * location. The selection may be moved so that it does not intersect the 772 * faded edges. The grid is then filled upwards and downwards from there. 773 * 774 * @param selectedTop Where the selected item should be 775 * @param childrenTop Where to start drawing children 776 * @param childrenBottom Last pixel where children can be drawn 777 * @return The view that currently has selection 778 */ 779 private View fillFromSelection(int selectedTop, int childrenTop, int childrenBottom) { 780 int fadingEdgeLength = getVerticalFadingEdgeLength(); 781 final int selectedPosition = mSelectedPosition; 782 783 View sel; 784 785 final int topSelectionPixel = getTopSelectionPixel(childrenTop, fadingEdgeLength, 786 selectedPosition); 787 final int bottomSelectionPixel = getBottomSelectionPixel(childrenBottom, fadingEdgeLength, 788 selectedPosition); 789 790 sel = makeAndAddView(selectedPosition, selectedTop, true, mListPadding.left, true); 791 792 793 // Some of the newly selected item extends below the bottom of the list 794 if (sel.getBottom() > bottomSelectionPixel) { 795 // Find space available above the selection into which we can scroll 796 // upwards 797 final int spaceAbove = sel.getTop() - topSelectionPixel; 798 799 // Find space required to bring the bottom of the selected item 800 // fully into view 801 final int spaceBelow = sel.getBottom() - bottomSelectionPixel; 802 final int offset = Math.min(spaceAbove, spaceBelow); 803 804 // Now offset the selected item to get it into view 805 sel.offsetTopAndBottom(-offset); 806 } else if (sel.getTop() < topSelectionPixel) { 807 // Find space required to bring the top of the selected item fully 808 // into view 809 final int spaceAbove = topSelectionPixel - sel.getTop(); 810 811 // Find space available below the selection into which we can scroll 812 // downwards 813 final int spaceBelow = bottomSelectionPixel - sel.getBottom(); 814 final int offset = Math.min(spaceAbove, spaceBelow); 815 816 // Offset the selected item to get it into view 817 sel.offsetTopAndBottom(offset); 818 } 819 820 // Fill in views above and below 821 fillAboveAndBelow(sel, selectedPosition); 822 823 if (!mStackFromBottom) { 824 correctTooHigh(getChildCount()); 825 } else { 826 correctTooLow(getChildCount()); 827 } 828 829 return sel; 830 } 831 832 /** 833 * Calculate the bottom-most pixel we can draw the selection into 834 * 835 * @param childrenBottom Bottom pixel were children can be drawn 836 * @param fadingEdgeLength Length of the fading edge in pixels, if present 837 * @param selectedPosition The position that will be selected 838 * @return The bottom-most pixel we can draw the selection into 839 */ 840 private int getBottomSelectionPixel(int childrenBottom, int fadingEdgeLength, 841 int selectedPosition) { 842 int bottomSelectionPixel = childrenBottom; 843 if (selectedPosition != mItemCount - 1) { 844 bottomSelectionPixel -= fadingEdgeLength; 845 } 846 return bottomSelectionPixel; 847 } 848 849 /** 850 * Calculate the top-most pixel we can draw the selection into 851 * 852 * @param childrenTop Top pixel were children can be drawn 853 * @param fadingEdgeLength Length of the fading edge in pixels, if present 854 * @param selectedPosition The position that will be selected 855 * @return The top-most pixel we can draw the selection into 856 */ 857 private int getTopSelectionPixel(int childrenTop, int fadingEdgeLength, int selectedPosition) { 858 // first pixel we can draw the selection into 859 int topSelectionPixel = childrenTop; 860 if (selectedPosition > 0) { 861 topSelectionPixel += fadingEdgeLength; 862 } 863 return topSelectionPixel; 864 } 865 866 867 /** 868 * Fills the list based on positioning the new selection relative to the old 869 * selection. The new selection will be placed at, above, or below the 870 * location of the new selection depending on how the selection is moving. 871 * The selection will then be pinned to the visible part of the screen, 872 * excluding the edges that are faded. The list is then filled upwards and 873 * downwards from there. 874 * 875 * @param oldSel The old selected view. Useful for trying to put the new 876 * selection in the same place 877 * @param newSel The view that is to become selected. Useful for trying to 878 * put the new selection in the same place 879 * @param delta Which way we are moving 880 * @param childrenTop Where to start drawing children 881 * @param childrenBottom Last pixel where children can be drawn 882 * @return The view that currently has selection 883 */ 884 private View moveSelection(View oldSel, View newSel, int delta, int childrenTop, 885 int childrenBottom) { 886 int fadingEdgeLength = getVerticalFadingEdgeLength(); 887 final int selectedPosition = mSelectedPosition; 888 889 View sel; 890 891 final int topSelectionPixel = getTopSelectionPixel(childrenTop, fadingEdgeLength, 892 selectedPosition); 893 final int bottomSelectionPixel = getBottomSelectionPixel(childrenTop, fadingEdgeLength, 894 selectedPosition); 895 896 if (delta > 0) { 897 /* 898 * Case 1: Scrolling down. 899 */ 900 901 /* 902 * Before After 903 * | | | | 904 * +-------+ +-------+ 905 * | A | | A | 906 * | 1 | => +-------+ 907 * +-------+ | B | 908 * | B | | 2 | 909 * +-------+ +-------+ 910 * | | | | 911 * 912 * Try to keep the top of the previously selected item where it was. 913 * oldSel = A 914 * sel = B 915 */ 916 917 // Put oldSel (A) where it belongs 918 oldSel = makeAndAddView(selectedPosition - 1, oldSel.getTop(), true, 919 mListPadding.left, false); 920 921 final int dividerHeight = mDividerHeight; 922 923 // Now put the new selection (B) below that 924 sel = makeAndAddView(selectedPosition, oldSel.getBottom() + dividerHeight, true, 925 mListPadding.left, true); 926 927 // Some of the newly selected item extends below the bottom of the list 928 if (sel.getBottom() > bottomSelectionPixel) { 929 930 // Find space available above the selection into which we can scroll upwards 931 int spaceAbove = sel.getTop() - topSelectionPixel; 932 933 // Find space required to bring the bottom of the selected item fully into view 934 int spaceBelow = sel.getBottom() - bottomSelectionPixel; 935 936 // Don't scroll more than half the height of the list 937 int halfVerticalSpace = (childrenBottom - childrenTop) / 2; 938 int offset = Math.min(spaceAbove, spaceBelow); 939 offset = Math.min(offset, halfVerticalSpace); 940 941 // We placed oldSel, so offset that item 942 oldSel.offsetTopAndBottom(-offset); 943 // Now offset the selected item to get it into view 944 sel.offsetTopAndBottom(-offset); 945 } 946 947 // Fill in views above and below 948 if (!mStackFromBottom) { 949 fillUp(mSelectedPosition - 2, sel.getTop() - dividerHeight); 950 adjustViewsUpOrDown(); 951 fillDown(mSelectedPosition + 1, sel.getBottom() + dividerHeight); 952 } else { 953 fillDown(mSelectedPosition + 1, sel.getBottom() + dividerHeight); 954 adjustViewsUpOrDown(); 955 fillUp(mSelectedPosition - 2, sel.getTop() - dividerHeight); 956 } 957 } else if (delta < 0) { 958 /* 959 * Case 2: Scrolling up. 960 */ 961 962 /* 963 * Before After 964 * | | | | 965 * +-------+ +-------+ 966 * | A | | A | 967 * +-------+ => | 1 | 968 * | B | +-------+ 969 * | 2 | | B | 970 * +-------+ +-------+ 971 * | | | | 972 * 973 * Try to keep the top of the item about to become selected where it was. 974 * newSel = A 975 * olSel = B 976 */ 977 978 if (newSel != null) { 979 // Try to position the top of newSel (A) where it was before it was selected 980 sel = makeAndAddView(selectedPosition, newSel.getTop(), true, mListPadding.left, 981 true); 982 } else { 983 // If (A) was not on screen and so did not have a view, position 984 // it above the oldSel (B) 985 sel = makeAndAddView(selectedPosition, oldSel.getTop(), false, mListPadding.left, 986 true); 987 } 988 989 // Some of the newly selected item extends above the top of the list 990 if (sel.getTop() < topSelectionPixel) { 991 // Find space required to bring the top of the selected item fully into view 992 int spaceAbove = topSelectionPixel - sel.getTop(); 993 994 // Find space available below the selection into which we can scroll downwards 995 int spaceBelow = bottomSelectionPixel - sel.getBottom(); 996 997 // Don't scroll more than half the height of the list 998 int halfVerticalSpace = (childrenBottom - childrenTop) / 2; 999 int offset = Math.min(spaceAbove, spaceBelow); 1000 offset = Math.min(offset, halfVerticalSpace); 1001 1002 // Offset the selected item to get it into view 1003 sel.offsetTopAndBottom(offset); 1004 } 1005 1006 // Fill in views above and below 1007 fillAboveAndBelow(sel, selectedPosition); 1008 } else { 1009 1010 int oldTop = oldSel.getTop(); 1011 1012 /* 1013 * Case 3: Staying still 1014 */ 1015 sel = makeAndAddView(selectedPosition, oldTop, true, mListPadding.left, true); 1016 1017 // We're staying still... 1018 if (oldTop < childrenTop) { 1019 // ... but the top of the old selection was off screen. 1020 // (This can happen if the data changes size out from under us) 1021 int newBottom = sel.getBottom(); 1022 if (newBottom < childrenTop + 20) { 1023 // Not enough visible -- bring it onscreen 1024 sel.offsetTopAndBottom(childrenTop - sel.getTop()); 1025 } 1026 } 1027 1028 // Fill in views above and below 1029 fillAboveAndBelow(sel, selectedPosition); 1030 } 1031 1032 return sel; 1033 } 1034 1035 private class FocusSelector implements Runnable { 1036 private int mPosition; 1037 private int mPositionTop; 1038 1039 public FocusSelector setup(int position, int top) { 1040 mPosition = position; 1041 mPositionTop = top; 1042 return this; 1043 } 1044 1045 public void run() { 1046 setSelectionFromTop(mPosition, mPositionTop); 1047 } 1048 } 1049 1050 @Override 1051 protected void onSizeChanged(int w, int h, int oldw, int oldh) { 1052 if (getChildCount() > 0) { 1053 View focusedChild = getFocusedChild(); 1054 if (focusedChild != null) { 1055 final int childPosition = mFirstPosition + indexOfChild(focusedChild); 1056 final int childBottom = focusedChild.getBottom(); 1057 final int offset = Math.max(0, childBottom - (h - mPaddingTop)); 1058 final int top = focusedChild.getTop() - offset; 1059 if (mFocusSelector == null) { 1060 mFocusSelector = new FocusSelector(); 1061 } 1062 post(mFocusSelector.setup(childPosition, top)); 1063 } 1064 } 1065 super.onSizeChanged(w, h, oldw, oldh); 1066 } 1067 1068 @Override 1069 protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { 1070 // Sets up mListPadding 1071 super.onMeasure(widthMeasureSpec, heightMeasureSpec); 1072 1073 int widthMode = MeasureSpec.getMode(widthMeasureSpec); 1074 int heightMode = MeasureSpec.getMode(heightMeasureSpec); 1075 int widthSize = MeasureSpec.getSize(widthMeasureSpec); 1076 int heightSize = MeasureSpec.getSize(heightMeasureSpec); 1077 1078 int childWidth = 0; 1079 int childHeight = 0; 1080 1081 mItemCount = mAdapter == null ? 0 : mAdapter.getCount(); 1082 if (mItemCount > 0 && (widthMode == MeasureSpec.UNSPECIFIED || 1083 heightMode == MeasureSpec.UNSPECIFIED)) { 1084 final View child = obtainView(0, mIsScrap); 1085 1086 measureScrapChild(child, 0, widthMeasureSpec); 1087 1088 childWidth = child.getMeasuredWidth(); 1089 childHeight = child.getMeasuredHeight(); 1090 1091 if (recycleOnMeasure() && mRecycler.shouldRecycleViewType( 1092 ((LayoutParams) child.getLayoutParams()).viewType)) { 1093 mRecycler.addScrapView(child); 1094 } 1095 } 1096 1097 if (widthMode == MeasureSpec.UNSPECIFIED) { 1098 widthSize = mListPadding.left + mListPadding.right + childWidth + 1099 getVerticalScrollbarWidth(); 1100 } 1101 1102 if (heightMode == MeasureSpec.UNSPECIFIED) { 1103 heightSize = mListPadding.top + mListPadding.bottom + childHeight + 1104 getVerticalFadingEdgeLength() * 2; 1105 } 1106 1107 if (heightMode == MeasureSpec.AT_MOST) { 1108 // TODO: after first layout we should maybe start at the first visible position, not 0 1109 heightSize = measureHeightOfChildren(widthMeasureSpec, 0, NO_POSITION, heightSize, -1); 1110 } 1111 1112 setMeasuredDimension(widthSize, heightSize); 1113 mWidthMeasureSpec = widthMeasureSpec; 1114 } 1115 1116 private void measureScrapChild(View child, int position, int widthMeasureSpec) { 1117 LayoutParams p = (LayoutParams) child.getLayoutParams(); 1118 if (p == null) { 1119 p = new LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, 1120 ViewGroup.LayoutParams.WRAP_CONTENT, 0); 1121 child.setLayoutParams(p); 1122 } 1123 p.viewType = mAdapter.getItemViewType(position); 1124 p.forceAdd = true; 1125 1126 int childWidthSpec = ViewGroup.getChildMeasureSpec(widthMeasureSpec, 1127 mListPadding.left + mListPadding.right, p.width); 1128 int lpHeight = p.height; 1129 int childHeightSpec; 1130 if (lpHeight > 0) { 1131 childHeightSpec = MeasureSpec.makeMeasureSpec(lpHeight, MeasureSpec.EXACTLY); 1132 } else { 1133 childHeightSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED); 1134 } 1135 child.measure(childWidthSpec, childHeightSpec); 1136 } 1137 1138 /** 1139 * @return True to recycle the views used to measure this ListView in 1140 * UNSPECIFIED/AT_MOST modes, false otherwise. 1141 * @hide 1142 */ 1143 @ViewDebug.ExportedProperty 1144 protected boolean recycleOnMeasure() { 1145 return true; 1146 } 1147 1148 /** 1149 * Measures the height of the given range of children (inclusive) and 1150 * returns the height with this ListView's padding and divider heights 1151 * included. If maxHeight is provided, the measuring will stop when the 1152 * current height reaches maxHeight. 1153 * 1154 * @param widthMeasureSpec The width measure spec to be given to a child's 1155 * {@link View#measure(int, int)}. 1156 * @param startPosition The position of the first child to be shown. 1157 * @param endPosition The (inclusive) position of the last child to be 1158 * shown. Specify {@link #NO_POSITION} if the last child should be 1159 * the last available child from the adapter. 1160 * @param maxHeight The maximum height that will be returned (if all the 1161 * children don't fit in this value, this value will be 1162 * returned). 1163 * @param disallowPartialChildPosition In general, whether the returned 1164 * height should only contain entire children. This is more 1165 * powerful--it is the first inclusive position at which partial 1166 * children will not be allowed. Example: it looks nice to have 1167 * at least 3 completely visible children, and in portrait this 1168 * will most likely fit; but in landscape there could be times 1169 * when even 2 children can not be completely shown, so a value 1170 * of 2 (remember, inclusive) would be good (assuming 1171 * startPosition is 0). 1172 * @return The height of this ListView with the given children. 1173 */ 1174 final int measureHeightOfChildren(int widthMeasureSpec, int startPosition, int endPosition, 1175 final int maxHeight, int disallowPartialChildPosition) { 1176 1177 final ListAdapter adapter = mAdapter; 1178 if (adapter == null) { 1179 return mListPadding.top + mListPadding.bottom; 1180 } 1181 1182 // Include the padding of the list 1183 int returnedHeight = mListPadding.top + mListPadding.bottom; 1184 final int dividerHeight = ((mDividerHeight > 0) && mDivider != null) ? mDividerHeight : 0; 1185 // The previous height value that was less than maxHeight and contained 1186 // no partial children 1187 int prevHeightWithoutPartialChild = 0; 1188 int i; 1189 View child; 1190 1191 // mItemCount - 1 since endPosition parameter is inclusive 1192 endPosition = (endPosition == NO_POSITION) ? adapter.getCount() - 1 : endPosition; 1193 final AbsListView.RecycleBin recycleBin = mRecycler; 1194 final boolean recyle = recycleOnMeasure(); 1195 final boolean[] isScrap = mIsScrap; 1196 1197 for (i = startPosition; i <= endPosition; ++i) { 1198 child = obtainView(i, isScrap); 1199 1200 measureScrapChild(child, i, widthMeasureSpec); 1201 1202 if (i > 0) { 1203 // Count the divider for all but one child 1204 returnedHeight += dividerHeight; 1205 } 1206 1207 // Recycle the view before we possibly return from the method 1208 if (recyle && recycleBin.shouldRecycleViewType( 1209 ((LayoutParams) child.getLayoutParams()).viewType)) { 1210 recycleBin.addScrapView(child); 1211 } 1212 1213 returnedHeight += child.getMeasuredHeight(); 1214 1215 if (returnedHeight >= maxHeight) { 1216 // We went over, figure out which height to return. If returnedHeight > maxHeight, 1217 // then the i'th position did not fit completely. 1218 return (disallowPartialChildPosition >= 0) // Disallowing is enabled (> -1) 1219 && (i > disallowPartialChildPosition) // We've past the min pos 1220 && (prevHeightWithoutPartialChild > 0) // We have a prev height 1221 && (returnedHeight != maxHeight) // i'th child did not fit completely 1222 ? prevHeightWithoutPartialChild 1223 : maxHeight; 1224 } 1225 1226 if ((disallowPartialChildPosition >= 0) && (i >= disallowPartialChildPosition)) { 1227 prevHeightWithoutPartialChild = returnedHeight; 1228 } 1229 } 1230 1231 // At this point, we went through the range of children, and they each 1232 // completely fit, so return the returnedHeight 1233 return returnedHeight; 1234 } 1235 1236 @Override 1237 int findMotionRow(int y) { 1238 int childCount = getChildCount(); 1239 if (childCount > 0) { 1240 for (int i = 0; i < childCount; i++) { 1241 View v = getChildAt(i); 1242 if (y <= v.getBottom()) { 1243 return mFirstPosition + i; 1244 } 1245 } 1246 } 1247 return INVALID_POSITION; 1248 } 1249 1250 /** 1251 * Put a specific item at a specific location on the screen and then build 1252 * up and down from there. 1253 * 1254 * @param position The reference view to use as the starting point 1255 * @param top Pixel offset from the top of this view to the top of the 1256 * reference view. 1257 * 1258 * @return The selected view, or null if the selected view is outside the 1259 * visible area. 1260 */ 1261 private View fillSpecific(int position, int top) { 1262 boolean tempIsSelected = position == mSelectedPosition; 1263 View temp = makeAndAddView(position, top, true, mListPadding.left, tempIsSelected); 1264 // Possibly changed again in fillUp if we add rows above this one. 1265 mFirstPosition = position; 1266 1267 View above; 1268 View below; 1269 1270 final int dividerHeight = mDividerHeight; 1271 if (!mStackFromBottom) { 1272 above = fillUp(position - 1, temp.getTop() - dividerHeight); 1273 // This will correct for the top of the first view not touching the top of the list 1274 adjustViewsUpOrDown(); 1275 below = fillDown(position + 1, temp.getBottom() + dividerHeight); 1276 int childCount = getChildCount(); 1277 if (childCount > 0) { 1278 correctTooHigh(childCount); 1279 } 1280 } else { 1281 below = fillDown(position + 1, temp.getBottom() + dividerHeight); 1282 // This will correct for the bottom of the last view not touching the bottom of the list 1283 adjustViewsUpOrDown(); 1284 above = fillUp(position - 1, temp.getTop() - dividerHeight); 1285 int childCount = getChildCount(); 1286 if (childCount > 0) { 1287 correctTooLow(childCount); 1288 } 1289 } 1290 1291 if (tempIsSelected) { 1292 return temp; 1293 } else if (above != null) { 1294 return above; 1295 } else { 1296 return below; 1297 } 1298 } 1299 1300 /** 1301 * Check if we have dragged the bottom of the list too high (we have pushed the 1302 * top element off the top of the screen when we did not need to). Correct by sliding 1303 * everything back down. 1304 * 1305 * @param childCount Number of children 1306 */ 1307 private void correctTooHigh(int childCount) { 1308 // First see if the last item is visible. If it is not, it is OK for the 1309 // top of the list to be pushed up. 1310 int lastPosition = mFirstPosition + childCount - 1; 1311 if (lastPosition == mItemCount - 1 && childCount > 0) { 1312 1313 // Get the last child ... 1314 final View lastChild = getChildAt(childCount - 1); 1315 1316 // ... and its bottom edge 1317 final int lastBottom = lastChild.getBottom(); 1318 1319 // This is bottom of our drawable area 1320 final int end = (mBottom - mTop) - mListPadding.bottom; 1321 1322 // This is how far the bottom edge of the last view is from the bottom of the 1323 // drawable area 1324 int bottomOffset = end - lastBottom; 1325 View firstChild = getChildAt(0); 1326 final int firstTop = firstChild.getTop(); 1327 1328 // Make sure we are 1) Too high, and 2) Either there are more rows above the 1329 // first row or the first row is scrolled off the top of the drawable area 1330 if (bottomOffset > 0 && (mFirstPosition > 0 || firstTop < mListPadding.top)) { 1331 if (mFirstPosition == 0) { 1332 // Don't pull the top too far down 1333 bottomOffset = Math.min(bottomOffset, mListPadding.top - firstTop); 1334 } 1335 // Move everything down 1336 offsetChildrenTopAndBottom(bottomOffset); 1337 if (mFirstPosition > 0) { 1338 // Fill the gap that was opened above mFirstPosition with more rows, if 1339 // possible 1340 fillUp(mFirstPosition - 1, firstChild.getTop() - mDividerHeight); 1341 // Close up the remaining gap 1342 adjustViewsUpOrDown(); 1343 } 1344 1345 } 1346 } 1347 } 1348 1349 /** 1350 * Check if we have dragged the bottom of the list too low (we have pushed the 1351 * bottom element off the bottom of the screen when we did not need to). Correct by sliding 1352 * everything back up. 1353 * 1354 * @param childCount Number of children 1355 */ 1356 private void correctTooLow(int childCount) { 1357 // First see if the first item is visible. If it is not, it is OK for the 1358 // bottom of the list to be pushed down. 1359 if (mFirstPosition == 0 && childCount > 0) { 1360 1361 // Get the first child ... 1362 final View firstChild = getChildAt(0); 1363 1364 // ... and its top edge 1365 final int firstTop = firstChild.getTop(); 1366 1367 // This is top of our drawable area 1368 final int start = mListPadding.top; 1369 1370 // This is bottom of our drawable area 1371 final int end = (mBottom - mTop) - mListPadding.bottom; 1372 1373 // This is how far the top edge of the first view is from the top of the 1374 // drawable area 1375 int topOffset = firstTop - start; 1376 View lastChild = getChildAt(childCount - 1); 1377 final int lastBottom = lastChild.getBottom(); 1378 int lastPosition = mFirstPosition + childCount - 1; 1379 1380 // Make sure we are 1) Too low, and 2) Either there are more rows below the 1381 // last row or the last row is scrolled off the bottom of the drawable area 1382 if (topOffset > 0) { 1383 if (lastPosition < mItemCount - 1 || lastBottom > end) { 1384 if (lastPosition == mItemCount - 1) { 1385 // Don't pull the bottom too far up 1386 topOffset = Math.min(topOffset, lastBottom - end); 1387 } 1388 // Move everything up 1389 offsetChildrenTopAndBottom(-topOffset); 1390 if (lastPosition < mItemCount - 1) { 1391 // Fill the gap that was opened below the last position with more rows, if 1392 // possible 1393 fillDown(lastPosition + 1, lastChild.getBottom() + mDividerHeight); 1394 // Close up the remaining gap 1395 adjustViewsUpOrDown(); 1396 } 1397 } else if (lastPosition == mItemCount - 1) { 1398 adjustViewsUpOrDown(); 1399 } 1400 } 1401 } 1402 } 1403 1404 @Override 1405 protected void layoutChildren() { 1406 final boolean blockLayoutRequests = mBlockLayoutRequests; 1407 if (!blockLayoutRequests) { 1408 mBlockLayoutRequests = true; 1409 } else { 1410 return; 1411 } 1412 1413 try { 1414 super.layoutChildren(); 1415 1416 invalidate(); 1417 1418 if (mAdapter == null) { 1419 resetList(); 1420 invokeOnItemScrollListener(); 1421 return; 1422 } 1423 1424 int childrenTop = mListPadding.top; 1425 int childrenBottom = mBottom - mTop - mListPadding.bottom; 1426 1427 int childCount = getChildCount(); 1428 int index = 0; 1429 int delta = 0; 1430 1431 View sel; 1432 View oldSel = null; 1433 View oldFirst = null; 1434 View newSel = null; 1435 1436 View focusLayoutRestoreView = null; 1437 1438 // Remember stuff we will need down below 1439 switch (mLayoutMode) { 1440 case LAYOUT_SET_SELECTION: 1441 index = mNextSelectedPosition - mFirstPosition; 1442 if (index >= 0 && index < childCount) { 1443 newSel = getChildAt(index); 1444 } 1445 break; 1446 case LAYOUT_FORCE_TOP: 1447 case LAYOUT_FORCE_BOTTOM: 1448 case LAYOUT_SPECIFIC: 1449 case LAYOUT_SYNC: 1450 break; 1451 case LAYOUT_MOVE_SELECTION: 1452 default: 1453 // Remember the previously selected view 1454 index = mSelectedPosition - mFirstPosition; 1455 if (index >= 0 && index < childCount) { 1456 oldSel = getChildAt(index); 1457 } 1458 1459 // Remember the previous first child 1460 oldFirst = getChildAt(0); 1461 1462 if (mNextSelectedPosition >= 0) { 1463 delta = mNextSelectedPosition - mSelectedPosition; 1464 } 1465 1466 // Caution: newSel might be null 1467 newSel = getChildAt(index + delta); 1468 } 1469 1470 1471 boolean dataChanged = mDataChanged; 1472 if (dataChanged) { 1473 handleDataChanged(); 1474 } 1475 1476 // Handle the empty set by removing all views that are visible 1477 // and calling it a day 1478 if (mItemCount == 0) { 1479 resetList(); 1480 invokeOnItemScrollListener(); 1481 return; 1482 } else if (mItemCount != mAdapter.getCount()) { 1483 throw new IllegalStateException("The content of the adapter has changed but " 1484 + "ListView did not receive a notification. Make sure the content of " 1485 + "your adapter is not modified from a background thread, but only " 1486 + "from the UI thread. [in ListView(" + getId() + ", " + getClass() 1487 + ") with Adapter(" + mAdapter.getClass() + ")]"); 1488 } 1489 1490 setSelectedPositionInt(mNextSelectedPosition); 1491 1492 // Pull all children into the RecycleBin. 1493 // These views will be reused if possible 1494 final int firstPosition = mFirstPosition; 1495 final RecycleBin recycleBin = mRecycler; 1496 1497 // reset the focus restoration 1498 View focusLayoutRestoreDirectChild = null; 1499 1500 1501 // Don't put header or footer views into the Recycler. Those are 1502 // already cached in mHeaderViews; 1503 if (dataChanged) { 1504 for (int i = 0; i < childCount; i++) { 1505 recycleBin.addScrapView(getChildAt(i)); 1506 if (ViewDebug.TRACE_RECYCLER) { 1507 ViewDebug.trace(getChildAt(i), 1508 ViewDebug.RecyclerTraceType.MOVE_TO_SCRAP_HEAP, index, i); 1509 } 1510 } 1511 } else { 1512 recycleBin.fillActiveViews(childCount, firstPosition); 1513 } 1514 1515 // take focus back to us temporarily to avoid the eventual 1516 // call to clear focus when removing the focused child below 1517 // from messing things up when ViewRoot assigns focus back 1518 // to someone else 1519 final View focusedChild = getFocusedChild(); 1520 if (focusedChild != null) { 1521 // TODO: in some cases focusedChild.getParent() == null 1522 1523 // we can remember the focused view to restore after relayout if the 1524 // data hasn't changed, or if the focused position is a header or footer 1525 if (!dataChanged || isDirectChildHeaderOrFooter(focusedChild)) { 1526 focusLayoutRestoreDirectChild = focusedChild; 1527 // remember the specific view that had focus 1528 focusLayoutRestoreView = findFocus(); 1529 if (focusLayoutRestoreView != null) { 1530 // tell it we are going to mess with it 1531 focusLayoutRestoreView.onStartTemporaryDetach(); 1532 } 1533 } 1534 requestFocus(); 1535 } 1536 1537 // Clear out old views 1538 detachAllViewsFromParent(); 1539 1540 switch (mLayoutMode) { 1541 case LAYOUT_SET_SELECTION: 1542 if (newSel != null) { 1543 sel = fillFromSelection(newSel.getTop(), childrenTop, childrenBottom); 1544 } else { 1545 sel = fillFromMiddle(childrenTop, childrenBottom); 1546 } 1547 break; 1548 case LAYOUT_SYNC: 1549 sel = fillSpecific(mSyncPosition, mSpecificTop); 1550 break; 1551 case LAYOUT_FORCE_BOTTOM: 1552 sel = fillUp(mItemCount - 1, childrenBottom); 1553 adjustViewsUpOrDown(); 1554 break; 1555 case LAYOUT_FORCE_TOP: 1556 mFirstPosition = 0; 1557 sel = fillFromTop(childrenTop); 1558 adjustViewsUpOrDown(); 1559 break; 1560 case LAYOUT_SPECIFIC: 1561 sel = fillSpecific(reconcileSelectedPosition(), mSpecificTop); 1562 break; 1563 case LAYOUT_MOVE_SELECTION: 1564 sel = moveSelection(oldSel, newSel, delta, childrenTop, childrenBottom); 1565 break; 1566 default: 1567 if (childCount == 0) { 1568 if (!mStackFromBottom) { 1569 final int position = lookForSelectablePosition(0, true); 1570 setSelectedPositionInt(position); 1571 sel = fillFromTop(childrenTop); 1572 } else { 1573 final int position = lookForSelectablePosition(mItemCount - 1, false); 1574 setSelectedPositionInt(position); 1575 sel = fillUp(mItemCount - 1, childrenBottom); 1576 } 1577 } else { 1578 if (mSelectedPosition >= 0 && mSelectedPosition < mItemCount) { 1579 sel = fillSpecific(mSelectedPosition, 1580 oldSel == null ? childrenTop : oldSel.getTop()); 1581 } else if (mFirstPosition < mItemCount) { 1582 sel = fillSpecific(mFirstPosition, 1583 oldFirst == null ? childrenTop : oldFirst.getTop()); 1584 } else { 1585 sel = fillSpecific(0, childrenTop); 1586 } 1587 } 1588 break; 1589 } 1590 1591 // Flush any cached views that did not get reused above 1592 recycleBin.scrapActiveViews(); 1593 1594 if (sel != null) { 1595 // the current selected item should get focus if items 1596 // are focusable 1597 if (mItemsCanFocus && hasFocus() && !sel.hasFocus()) { 1598 final boolean focusWasTaken = (sel == focusLayoutRestoreDirectChild && 1599 focusLayoutRestoreView.requestFocus()) || sel.requestFocus(); 1600 if (!focusWasTaken) { 1601 // selected item didn't take focus, fine, but still want 1602 // to make sure something else outside of the selected view 1603 // has focus 1604 final View focused = getFocusedChild(); 1605 if (focused != null) { 1606 focused.clearFocus(); 1607 } 1608 positionSelector(sel); 1609 } else { 1610 sel.setSelected(false); 1611 mSelectorRect.setEmpty(); 1612 } 1613 } else { 1614 positionSelector(sel); 1615 } 1616 mSelectedTop = sel.getTop(); 1617 } else { 1618 if (mTouchMode > TOUCH_MODE_DOWN && mTouchMode < TOUCH_MODE_SCROLL) { 1619 View child = getChildAt(mMotionPosition - mFirstPosition); 1620 if (child != null) positionSelector(child); 1621 } else { 1622 mSelectedTop = 0; 1623 mSelectorRect.setEmpty(); 1624 } 1625 1626 // even if there is not selected position, we may need to restore 1627 // focus (i.e. something focusable in touch mode) 1628 if (hasFocus() && focusLayoutRestoreView != null) { 1629 focusLayoutRestoreView.requestFocus(); 1630 } 1631 } 1632 1633 // tell focus view we are done mucking with it, if it is still in 1634 // our view hierarchy. 1635 if (focusLayoutRestoreView != null 1636 && focusLayoutRestoreView.getWindowToken() != null) { 1637 focusLayoutRestoreView.onFinishTemporaryDetach(); 1638 } 1639 1640 mLayoutMode = LAYOUT_NORMAL; 1641 mDataChanged = false; 1642 mNeedSync = false; 1643 setNextSelectedPositionInt(mSelectedPosition); 1644 1645 updateScrollIndicators(); 1646 1647 if (mItemCount > 0) { 1648 checkSelectionChanged(); 1649 } 1650 1651 invokeOnItemScrollListener(); 1652 } finally { 1653 if (!blockLayoutRequests) { 1654 mBlockLayoutRequests = false; 1655 } 1656 } 1657 } 1658 1659 /** 1660 * @param child a direct child of this list. 1661 * @return Whether child is a header or footer view. 1662 */ 1663 private boolean isDirectChildHeaderOrFooter(View child) { 1664 1665 final ArrayList<FixedViewInfo> headers = mHeaderViewInfos; 1666 final int numHeaders = headers.size(); 1667 for (int i = 0; i < numHeaders; i++) { 1668 if (child == headers.get(i).view) { 1669 return true; 1670 } 1671 } 1672 final ArrayList<FixedViewInfo> footers = mFooterViewInfos; 1673 final int numFooters = footers.size(); 1674 for (int i = 0; i < numFooters; i++) { 1675 if (child == footers.get(i).view) { 1676 return true; 1677 } 1678 } 1679 return false; 1680 } 1681 1682 /** 1683 * Obtain the view and add it to our list of children. The view can be made 1684 * fresh, converted from an unused view, or used as is if it was in the 1685 * recycle bin. 1686 * 1687 * @param position Logical position in the list 1688 * @param y Top or bottom edge of the view to add 1689 * @param flow If flow is true, align top edge to y. If false, align bottom 1690 * edge to y. 1691 * @param childrenLeft Left edge where children should be positioned 1692 * @param selected Is this position selected? 1693 * @return View that was added 1694 */ 1695 private View makeAndAddView(int position, int y, boolean flow, int childrenLeft, 1696 boolean selected) { 1697 View child; 1698 1699 1700 if (!mDataChanged) { 1701 // Try to use an exsiting view for this position 1702 child = mRecycler.getActiveView(position); 1703 if (child != null) { 1704 if (ViewDebug.TRACE_RECYCLER) { 1705 ViewDebug.trace(child, ViewDebug.RecyclerTraceType.RECYCLE_FROM_ACTIVE_HEAP, 1706 position, getChildCount()); 1707 } 1708 1709 // Found it -- we're using an existing child 1710 // This just needs to be positioned 1711 setupChild(child, position, y, flow, childrenLeft, selected, true); 1712 1713 return child; 1714 } 1715 } 1716 1717 // Make a new view for this position, or convert an unused view if possible 1718 child = obtainView(position, mIsScrap); 1719 1720 // This needs to be positioned and measured 1721 setupChild(child, position, y, flow, childrenLeft, selected, mIsScrap[0]); 1722 1723 return child; 1724 } 1725 1726 /** 1727 * Add a view as a child and make sure it is measured (if necessary) and 1728 * positioned properly. 1729 * 1730 * @param child The view to add 1731 * @param position The position of this child 1732 * @param y The y position relative to which this view will be positioned 1733 * @param flowDown If true, align top edge to y. If false, align bottom 1734 * edge to y. 1735 * @param childrenLeft Left edge where children should be positioned 1736 * @param selected Is this position selected? 1737 * @param recycled Has this view been pulled from the recycle bin? If so it 1738 * does not need to be remeasured. 1739 */ 1740 private void setupChild(View child, int position, int y, boolean flowDown, int childrenLeft, 1741 boolean selected, boolean recycled) { 1742 final boolean isSelected = selected && shouldShowSelector(); 1743 final boolean updateChildSelected = isSelected != child.isSelected(); 1744 final int mode = mTouchMode; 1745 final boolean isPressed = mode > TOUCH_MODE_DOWN && mode < TOUCH_MODE_SCROLL && 1746 mMotionPosition == position; 1747 final boolean updateChildPressed = isPressed != child.isPressed(); 1748 final boolean needToMeasure = !recycled || updateChildSelected || child.isLayoutRequested(); 1749 1750 // Respect layout params that are already in the view. Otherwise make some up... 1751 // noinspection unchecked 1752 AbsListView.LayoutParams p = (AbsListView.LayoutParams) child.getLayoutParams(); 1753 if (p == null) { 1754 p = new AbsListView.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, 1755 ViewGroup.LayoutParams.WRAP_CONTENT, 0); 1756 } 1757 p.viewType = mAdapter.getItemViewType(position); 1758 1759 if ((recycled && !p.forceAdd) || (p.recycledHeaderFooter && 1760 p.viewType == AdapterView.ITEM_VIEW_TYPE_HEADER_OR_FOOTER)) { 1761 attachViewToParent(child, flowDown ? -1 : 0, p); 1762 } else { 1763 p.forceAdd = false; 1764 if (p.viewType == AdapterView.ITEM_VIEW_TYPE_HEADER_OR_FOOTER) { 1765 p.recycledHeaderFooter = true; 1766 } 1767 addViewInLayout(child, flowDown ? -1 : 0, p, true); 1768 } 1769 1770 if (updateChildSelected) { 1771 child.setSelected(isSelected); 1772 } 1773 1774 if (updateChildPressed) { 1775 child.setPressed(isPressed); 1776 } 1777 1778 if (mChoiceMode != CHOICE_MODE_NONE && mCheckStates != null) { 1779 if (child instanceof Checkable) { 1780 ((Checkable) child).setChecked(mCheckStates.get(position)); 1781 } 1782 } 1783 1784 if (needToMeasure) { 1785 int childWidthSpec = ViewGroup.getChildMeasureSpec(mWidthMeasureSpec, 1786 mListPadding.left + mListPadding.right, p.width); 1787 int lpHeight = p.height; 1788 int childHeightSpec; 1789 if (lpHeight > 0) { 1790 childHeightSpec = MeasureSpec.makeMeasureSpec(lpHeight, MeasureSpec.EXACTLY); 1791 } else { 1792 childHeightSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED); 1793 } 1794 child.measure(childWidthSpec, childHeightSpec); 1795 } else { 1796 cleanupLayoutState(child); 1797 } 1798 1799 final int w = child.getMeasuredWidth(); 1800 final int h = child.getMeasuredHeight(); 1801 final int childTop = flowDown ? y : y - h; 1802 1803 if (needToMeasure) { 1804 final int childRight = childrenLeft + w; 1805 final int childBottom = childTop + h; 1806 child.layout(childrenLeft, childTop, childRight, childBottom); 1807 } else { 1808 child.offsetLeftAndRight(childrenLeft - child.getLeft()); 1809 child.offsetTopAndBottom(childTop - child.getTop()); 1810 } 1811 1812 if (mCachingStarted && !child.isDrawingCacheEnabled()) { 1813 child.setDrawingCacheEnabled(true); 1814 } 1815 } 1816 1817 @Override 1818 protected boolean canAnimate() { 1819 return super.canAnimate() && mItemCount > 0; 1820 } 1821 1822 /** 1823 * Sets the currently selected item. If in touch mode, the item will not be selected 1824 * but it will still be positioned appropriately. If the specified selection position 1825 * is less than 0, then the item at position 0 will be selected. 1826 * 1827 * @param position Index (starting at 0) of the data item to be selected. 1828 */ 1829 @Override 1830 public void setSelection(int position) { 1831 setSelectionFromTop(position, 0); 1832 } 1833 1834 /** 1835 * Sets the selected item and positions the selection y pixels from the top edge 1836 * of the ListView. (If in touch mode, the item will not be selected but it will 1837 * still be positioned appropriately.) 1838 * 1839 * @param position Index (starting at 0) of the data item to be selected. 1840 * @param y The distance from the top edge of the ListView (plus padding) that the 1841 * item will be positioned. 1842 */ 1843 public void setSelectionFromTop(int position, int y) { 1844 if (mAdapter == null) { 1845 return; 1846 } 1847 1848 if (!isInTouchMode()) { 1849 position = lookForSelectablePosition(position, true); 1850 if (position >= 0) { 1851 setNextSelectedPositionInt(position); 1852 } 1853 } else { 1854 mResurrectToPosition = position; 1855 } 1856 1857 if (position >= 0) { 1858 mLayoutMode = LAYOUT_SPECIFIC; 1859 mSpecificTop = mListPadding.top + y; 1860 1861 if (mNeedSync) { 1862 mSyncPosition = position; 1863 mSyncRowId = mAdapter.getItemId(position); 1864 } 1865 1866 requestLayout(); 1867 } 1868 } 1869 1870 /** 1871 * Makes the item at the supplied position selected. 1872 * 1873 * @param position the position of the item to select 1874 */ 1875 @Override 1876 void setSelectionInt(int position) { 1877 setNextSelectedPositionInt(position); 1878 boolean awakeScrollbars = false; 1879 1880 final int selectedPosition = mSelectedPosition; 1881 1882 if (selectedPosition >= 0) { 1883 if (position == selectedPosition - 1) { 1884 awakeScrollbars = true; 1885 } else if (position == selectedPosition + 1) { 1886 awakeScrollbars = true; 1887 } 1888 } 1889 1890 layoutChildren(); 1891 1892 if (awakeScrollbars) { 1893 awakenScrollBars(); 1894 } 1895 } 1896 1897 /** 1898 * Find a position that can be selected (i.e., is not a separator). 1899 * 1900 * @param position The starting position to look at. 1901 * @param lookDown Whether to look down for other positions. 1902 * @return The next selectable position starting at position and then searching either up or 1903 * down. Returns {@link #INVALID_POSITION} if nothing can be found. 1904 */ 1905 @Override 1906 int lookForSelectablePosition(int position, boolean lookDown) { 1907 final ListAdapter adapter = mAdapter; 1908 if (adapter == null || isInTouchMode()) { 1909 return INVALID_POSITION; 1910 } 1911 1912 final int count = adapter.getCount(); 1913 if (!mAreAllItemsSelectable) { 1914 if (lookDown) { 1915 position = Math.max(0, position); 1916 while (position < count && !adapter.isEnabled(position)) { 1917 position++; 1918 } 1919 } else { 1920 position = Math.min(position, count - 1); 1921 while (position >= 0 && !adapter.isEnabled(position)) { 1922 position--; 1923 } 1924 } 1925 1926 if (position < 0 || position >= count) { 1927 return INVALID_POSITION; 1928 } 1929 return position; 1930 } else { 1931 if (position < 0 || position >= count) { 1932 return INVALID_POSITION; 1933 } 1934 return position; 1935 } 1936 } 1937 1938 @Override 1939 public boolean dispatchPopulateAccessibilityEvent(AccessibilityEvent event) { 1940 boolean populated = super.dispatchPopulateAccessibilityEvent(event); 1941 1942 // If the item count is less than 15 then subtract disabled items from the count and 1943 // position. Otherwise ignore disabled items. 1944 if (!populated) { 1945 int itemCount = 0; 1946 int currentItemIndex = getSelectedItemPosition(); 1947 1948 ListAdapter adapter = getAdapter(); 1949 if (adapter != null) { 1950 final int count = adapter.getCount(); 1951 if (count < 15) { 1952 for (int i = 0; i < count; i++) { 1953 if (adapter.isEnabled(i)) { 1954 itemCount++; 1955 } else if (i <= currentItemIndex) { 1956 currentItemIndex--; 1957 } 1958 } 1959 } else { 1960 itemCount = count; 1961 } 1962 } 1963 1964 event.setItemCount(itemCount); 1965 event.setCurrentItemIndex(currentItemIndex); 1966 } 1967 1968 return populated; 1969 } 1970 1971 /** 1972 * setSelectionAfterHeaderView set the selection to be the first list item 1973 * after the header views. 1974 */ 1975 public void setSelectionAfterHeaderView() { 1976 final int count = mHeaderViewInfos.size(); 1977 if (count > 0) { 1978 mNextSelectedPosition = 0; 1979 return; 1980 } 1981 1982 if (mAdapter != null) { 1983 setSelection(count); 1984 } else { 1985 mNextSelectedPosition = count; 1986 mLayoutMode = LAYOUT_SET_SELECTION; 1987 } 1988 1989 } 1990 1991 @Override 1992 public boolean dispatchKeyEvent(KeyEvent event) { 1993 // Dispatch in the normal way 1994 boolean handled = super.dispatchKeyEvent(event); 1995 if (!handled) { 1996 // If we didn't handle it... 1997 View focused = getFocusedChild(); 1998 if (focused != null && event.getAction() == KeyEvent.ACTION_DOWN) { 1999 // ... and our focused child didn't handle it 2000 // ... give it to ourselves so we can scroll if necessary 2001 handled = onKeyDown(event.getKeyCode(), event); 2002 } 2003 } 2004 return handled; 2005 } 2006 2007 @Override 2008 public boolean onKeyDown(int keyCode, KeyEvent event) { 2009 return commonKey(keyCode, 1, event); 2010 } 2011 2012 @Override 2013 public boolean onKeyMultiple(int keyCode, int repeatCount, KeyEvent event) { 2014 return commonKey(keyCode, repeatCount, event); 2015 } 2016 2017 @Override 2018 public boolean onKeyUp(int keyCode, KeyEvent event) { 2019 return commonKey(keyCode, 1, event); 2020 } 2021 2022 private boolean commonKey(int keyCode, int count, KeyEvent event) { 2023 if (mAdapter == null) { 2024 return false; 2025 } 2026 2027 if (mDataChanged) { 2028 layoutChildren(); 2029 } 2030 2031 boolean handled = false; 2032 int action = event.getAction(); 2033 2034 if (action != KeyEvent.ACTION_UP) { 2035 if (mSelectedPosition < 0) { 2036 switch (keyCode) { 2037 case KeyEvent.KEYCODE_DPAD_UP: 2038 case KeyEvent.KEYCODE_DPAD_DOWN: 2039 case KeyEvent.KEYCODE_DPAD_CENTER: 2040 case KeyEvent.KEYCODE_ENTER: 2041 case KeyEvent.KEYCODE_SPACE: 2042 if (resurrectSelection()) { 2043 return true; 2044 } 2045 } 2046 } 2047 switch (keyCode) { 2048 case KeyEvent.KEYCODE_DPAD_UP: 2049 if (!event.isAltPressed()) { 2050 while (count > 0) { 2051 handled = arrowScroll(FOCUS_UP); 2052 count--; 2053 } 2054 } else { 2055 handled = fullScroll(FOCUS_UP); 2056 } 2057 break; 2058 2059 case KeyEvent.KEYCODE_DPAD_DOWN: 2060 if (!event.isAltPressed()) { 2061 while (count > 0) { 2062 handled = arrowScroll(FOCUS_DOWN); 2063 count--; 2064 } 2065 } else { 2066 handled = fullScroll(FOCUS_DOWN); 2067 } 2068 break; 2069 2070 case KeyEvent.KEYCODE_DPAD_LEFT: 2071 handled = handleHorizontalFocusWithinListItem(View.FOCUS_LEFT); 2072 break; 2073 case KeyEvent.KEYCODE_DPAD_RIGHT: 2074 handled = handleHorizontalFocusWithinListItem(View.FOCUS_RIGHT); 2075 break; 2076 2077 case KeyEvent.KEYCODE_DPAD_CENTER: 2078 case KeyEvent.KEYCODE_ENTER: 2079 if (mItemCount > 0 && event.getRepeatCount() == 0) { 2080 keyPressed(); 2081 } 2082 handled = true; 2083 break; 2084 2085 case KeyEvent.KEYCODE_SPACE: 2086 if (mPopup == null || !mPopup.isShowing()) { 2087 if (!event.isShiftPressed()) { 2088 pageScroll(FOCUS_DOWN); 2089 } else { 2090 pageScroll(FOCUS_UP); 2091 } 2092 handled = true; 2093 } 2094 break; 2095 } 2096 } 2097 2098 if (!handled) { 2099 handled = sendToTextFilter(keyCode, count, event); 2100 } 2101 2102 if (handled) { 2103 return true; 2104 } else { 2105 switch (action) { 2106 case KeyEvent.ACTION_DOWN: 2107 return super.onKeyDown(keyCode, event); 2108 2109 case KeyEvent.ACTION_UP: 2110 return super.onKeyUp(keyCode, event); 2111 2112 case KeyEvent.ACTION_MULTIPLE: 2113 return super.onKeyMultiple(keyCode, count, event); 2114 2115 default: // shouldn't happen 2116 return false; 2117 } 2118 } 2119 } 2120 2121 /** 2122 * Scrolls up or down by the number of items currently present on screen. 2123 * 2124 * @param direction either {@link View#FOCUS_UP} or {@link View#FOCUS_DOWN} 2125 * @return whether selection was moved 2126 */ 2127 boolean pageScroll(int direction) { 2128 int nextPage = -1; 2129 boolean down = false; 2130 2131 if (direction == FOCUS_UP) { 2132 nextPage = Math.max(0, mSelectedPosition - getChildCount() - 1); 2133 } else if (direction == FOCUS_DOWN) { 2134 nextPage = Math.min(mItemCount - 1, mSelectedPosition + getChildCount() - 1); 2135 down = true; 2136 } 2137 2138 if (nextPage >= 0) { 2139 int position = lookForSelectablePosition(nextPage, down); 2140 if (position >= 0) { 2141 mLayoutMode = LAYOUT_SPECIFIC; 2142 mSpecificTop = mPaddingTop + getVerticalFadingEdgeLength(); 2143 2144 if (down && position > mItemCount - getChildCount()) { 2145 mLayoutMode = LAYOUT_FORCE_BOTTOM; 2146 } 2147 2148 if (!down && position < getChildCount()) { 2149 mLayoutMode = LAYOUT_FORCE_TOP; 2150 } 2151 2152 setSelectionInt(position); 2153 invokeOnItemScrollListener(); 2154 if (!awakenScrollBars()) { 2155 invalidate(); 2156 } 2157 2158 return true; 2159 } 2160 } 2161 2162 return false; 2163 } 2164 2165 /** 2166 * Go to the last or first item if possible (not worrying about panning across or navigating 2167 * within the internal focus of the currently selected item.) 2168 * 2169 * @param direction either {@link View#FOCUS_UP} or {@link View#FOCUS_DOWN} 2170 * 2171 * @return whether selection was moved 2172 */ 2173 boolean fullScroll(int direction) { 2174 boolean moved = false; 2175 if (direction == FOCUS_UP) { 2176 if (mSelectedPosition != 0) { 2177 int position = lookForSelectablePosition(0, true); 2178 if (position >= 0) { 2179 mLayoutMode = LAYOUT_FORCE_TOP; 2180 setSelectionInt(position); 2181 invokeOnItemScrollListener(); 2182 } 2183 moved = true; 2184 } 2185 } else if (direction == FOCUS_DOWN) { 2186 if (mSelectedPosition < mItemCount - 1) { 2187 int position = lookForSelectablePosition(mItemCount - 1, true); 2188 if (position >= 0) { 2189 mLayoutMode = LAYOUT_FORCE_BOTTOM; 2190 setSelectionInt(position); 2191 invokeOnItemScrollListener(); 2192 } 2193 moved = true; 2194 } 2195 } 2196 2197 if (moved && !awakenScrollBars()) { 2198 awakenScrollBars(); 2199 invalidate(); 2200 } 2201 2202 return moved; 2203 } 2204 2205 /** 2206 * To avoid horizontal focus searches changing the selected item, we 2207 * manually focus search within the selected item (as applicable), and 2208 * prevent focus from jumping to something within another item. 2209 * @param direction one of {View.FOCUS_LEFT, View.FOCUS_RIGHT} 2210 * @return Whether this consumes the key event. 2211 */ 2212 private boolean handleHorizontalFocusWithinListItem(int direction) { 2213 if (direction != View.FOCUS_LEFT && direction != View.FOCUS_RIGHT) { 2214 throw new IllegalArgumentException("direction must be one of" 2215 + " {View.FOCUS_LEFT, View.FOCUS_RIGHT}"); 2216 } 2217 2218 final int numChildren = getChildCount(); 2219 if (mItemsCanFocus && numChildren > 0 && mSelectedPosition != INVALID_POSITION) { 2220 final View selectedView = getSelectedView(); 2221 if (selectedView != null && selectedView.hasFocus() && 2222 selectedView instanceof ViewGroup) { 2223 2224 final View currentFocus = selectedView.findFocus(); 2225 final View nextFocus = FocusFinder.getInstance().findNextFocus( 2226 (ViewGroup) selectedView, currentFocus, direction); 2227 if (nextFocus != null) { 2228 // do the math to get interesting rect in next focus' coordinates 2229 currentFocus.getFocusedRect(mTempRect); 2230 offsetDescendantRectToMyCoords(currentFocus, mTempRect); 2231 offsetRectIntoDescendantCoords(nextFocus, mTempRect); 2232 if (nextFocus.requestFocus(direction, mTempRect)) { 2233 return true; 2234 } 2235 } 2236 // we are blocking the key from being handled (by returning true) 2237 // if the global result is going to be some other view within this 2238 // list. this is to acheive the overall goal of having 2239 // horizontal d-pad navigation remain in the current item. 2240 final View globalNextFocus = FocusFinder.getInstance().findNextFocus( 2241 (ViewGroup) getRootView(), currentFocus, direction); 2242 if (globalNextFocus != null) { 2243 return isViewAncestorOf(globalNextFocus, this); 2244 } 2245 } 2246 } 2247 return false; 2248 } 2249 2250 /** 2251 * Scrolls to the next or previous item if possible. 2252 * 2253 * @param direction either {@link View#FOCUS_UP} or {@link View#FOCUS_DOWN} 2254 * 2255 * @return whether selection was moved 2256 */ 2257 boolean arrowScroll(int direction) { 2258 try { 2259 mInLayout = true; 2260 final boolean handled = arrowScrollImpl(direction); 2261 if (handled) { 2262 playSoundEffect(SoundEffectConstants.getContantForFocusDirection(direction)); 2263 } 2264 return handled; 2265 } finally { 2266 mInLayout = false; 2267 } 2268 } 2269 2270 /** 2271 * Handle an arrow scroll going up or down. Take into account whether items are selectable, 2272 * whether there are focusable items etc. 2273 * 2274 * @param direction Either {@link android.view.View#FOCUS_UP} or {@link android.view.View#FOCUS_DOWN}. 2275 * @return Whether any scrolling, selection or focus change occured. 2276 */ 2277 private boolean arrowScrollImpl(int direction) { 2278 if (getChildCount() <= 0) { 2279 return false; 2280 } 2281 2282 View selectedView = getSelectedView(); 2283 2284 int nextSelectedPosition = lookForSelectablePositionOnScreen(direction); 2285 int amountToScroll = amountToScroll(direction, nextSelectedPosition); 2286 2287 // if we are moving focus, we may OVERRIDE the default behavior 2288 final ArrowScrollFocusResult focusResult = mItemsCanFocus ? arrowScrollFocused(direction) : null; 2289 if (focusResult != null) { 2290 nextSelectedPosition = focusResult.getSelectedPosition(); 2291 amountToScroll = focusResult.getAmountToScroll(); 2292 } 2293 2294 boolean needToRedraw = focusResult != null; 2295 if (nextSelectedPosition != INVALID_POSITION) { 2296 handleNewSelectionChange(selectedView, direction, nextSelectedPosition, focusResult != null); 2297 setSelectedPositionInt(nextSelectedPosition); 2298 setNextSelectedPositionInt(nextSelectedPosition); 2299 selectedView = getSelectedView(); 2300 if (mItemsCanFocus && focusResult == null) { 2301 // there was no new view found to take focus, make sure we 2302 // don't leave focus with the old selection 2303 final View focused = getFocusedChild(); 2304 if (focused != null) { 2305 focused.clearFocus(); 2306 } 2307 } 2308 needToRedraw = true; 2309 checkSelectionChanged(); 2310 } 2311 2312 if (amountToScroll > 0) { 2313 scrollListItemsBy((direction == View.FOCUS_UP) ? amountToScroll : -amountToScroll); 2314 needToRedraw = true; 2315 } 2316 2317 // if we didn't find a new focusable, make sure any existing focused 2318 // item that was panned off screen gives up focus. 2319 if (mItemsCanFocus && (focusResult == null) 2320 && selectedView != null && selectedView.hasFocus()) { 2321 final View focused = selectedView.findFocus(); 2322 if (distanceToView(focused) > 0) { 2323 focused.clearFocus(); 2324 } 2325 } 2326 2327 // if the current selection is panned off, we need to remove the selection 2328 if (nextSelectedPosition == INVALID_POSITION && selectedView != null 2329 && !isViewAncestorOf(selectedView, this)) { 2330 selectedView = null; 2331 hideSelector(); 2332 2333 // but we don't want to set the ressurect position (that would make subsequent 2334 // unhandled key events bring back the item we just scrolled off!) 2335 mResurrectToPosition = INVALID_POSITION; 2336 } 2337 2338 if (needToRedraw) { 2339 if (selectedView != null) { 2340 positionSelector(selectedView); 2341 mSelectedTop = selectedView.getTop(); 2342 } 2343 if (!awakenScrollBars()) { 2344 invalidate(); 2345 } 2346 invokeOnItemScrollListener(); 2347 return true; 2348 } 2349 2350 return false; 2351 } 2352 2353 /** 2354 * When selection changes, it is possible that the previously selected or the 2355 * next selected item will change its size. If so, we need to offset some folks, 2356 * and re-layout the items as appropriate. 2357 * 2358 * @param selectedView The currently selected view (before changing selection). 2359 * should be <code>null</code> if there was no previous selection. 2360 * @param direction Either {@link android.view.View#FOCUS_UP} or 2361 * {@link android.view.View#FOCUS_DOWN}. 2362 * @param newSelectedPosition The position of the next selection. 2363 * @param newFocusAssigned whether new focus was assigned. This matters because 2364 * when something has focus, we don't want to show selection (ugh). 2365 */ 2366 private void handleNewSelectionChange(View selectedView, int direction, int newSelectedPosition, 2367 boolean newFocusAssigned) { 2368 if (newSelectedPosition == INVALID_POSITION) { 2369 throw new IllegalArgumentException("newSelectedPosition needs to be valid"); 2370 } 2371 2372 // whether or not we are moving down or up, we want to preserve the 2373 // top of whatever view is on top: 2374 // - moving down: the view that had selection 2375 // - moving up: the view that is getting selection 2376 View topView; 2377 View bottomView; 2378 int topViewIndex, bottomViewIndex; 2379 boolean topSelected = false; 2380 final int selectedIndex = mSelectedPosition - mFirstPosition; 2381 final int nextSelectedIndex = newSelectedPosition - mFirstPosition; 2382 if (direction == View.FOCUS_UP) { 2383 topViewIndex = nextSelectedIndex; 2384 bottomViewIndex = selectedIndex; 2385 topView = getChildAt(topViewIndex); 2386 bottomView = selectedView; 2387 topSelected = true; 2388 } else { 2389 topViewIndex = selectedIndex; 2390 bottomViewIndex = nextSelectedIndex; 2391 topView = selectedView; 2392 bottomView = getChildAt(bottomViewIndex); 2393 } 2394 2395 final int numChildren = getChildCount(); 2396 2397 // start with top view: is it changing size? 2398 if (topView != null) { 2399 topView.setSelected(!newFocusAssigned && topSelected); 2400 measureAndAdjustDown(topView, topViewIndex, numChildren); 2401 } 2402 2403 // is the bottom view changing size? 2404 if (bottomView != null) { 2405 bottomView.setSelected(!newFocusAssigned && !topSelected); 2406 measureAndAdjustDown(bottomView, bottomViewIndex, numChildren); 2407 } 2408 } 2409 2410 /** 2411 * Re-measure a child, and if its height changes, lay it out preserving its 2412 * top, and adjust the children below it appropriately. 2413 * @param child The child 2414 * @param childIndex The view group index of the child. 2415 * @param numChildren The number of children in the view group. 2416 */ 2417 private void measureAndAdjustDown(View child, int childIndex, int numChildren) { 2418 int oldHeight = child.getHeight(); 2419 measureItem(child); 2420 if (child.getMeasuredHeight() != oldHeight) { 2421 // lay out the view, preserving its top 2422 relayoutMeasuredItem(child); 2423 2424 // adjust views below appropriately 2425 final int heightDelta = child.getMeasuredHeight() - oldHeight; 2426 for (int i = childIndex + 1; i < numChildren; i++) { 2427 getChildAt(i).offsetTopAndBottom(heightDelta); 2428 } 2429 } 2430 } 2431 2432 /** 2433 * Measure a particular list child. 2434 * TODO: unify with setUpChild. 2435 * @param child The child. 2436 */ 2437 private void measureItem(View child) { 2438 ViewGroup.LayoutParams p = child.getLayoutParams(); 2439 if (p == null) { 2440 p = new ViewGroup.LayoutParams( 2441 ViewGroup.LayoutParams.MATCH_PARENT, 2442 ViewGroup.LayoutParams.WRAP_CONTENT); 2443 } 2444 2445 int childWidthSpec = ViewGroup.getChildMeasureSpec(mWidthMeasureSpec, 2446 mListPadding.left + mListPadding.right, p.width); 2447 int lpHeight = p.height; 2448 int childHeightSpec; 2449 if (lpHeight > 0) { 2450 childHeightSpec = MeasureSpec.makeMeasureSpec(lpHeight, MeasureSpec.EXACTLY); 2451 } else { 2452 childHeightSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED); 2453 } 2454 child.measure(childWidthSpec, childHeightSpec); 2455 } 2456 2457 /** 2458 * Layout a child that has been measured, preserving its top position. 2459 * TODO: unify with setUpChild. 2460 * @param child The child. 2461 */ 2462 private void relayoutMeasuredItem(View child) { 2463 final int w = child.getMeasuredWidth(); 2464 final int h = child.getMeasuredHeight(); 2465 final int childLeft = mListPadding.left; 2466 final int childRight = childLeft + w; 2467 final int childTop = child.getTop(); 2468 final int childBottom = childTop + h; 2469 child.layout(childLeft, childTop, childRight, childBottom); 2470 } 2471 2472 /** 2473 * @return The amount to preview next items when arrow srolling. 2474 */ 2475 private int getArrowScrollPreviewLength() { 2476 return Math.max(MIN_SCROLL_PREVIEW_PIXELS, getVerticalFadingEdgeLength()); 2477 } 2478 2479 /** 2480 * Determine how much we need to scroll in order to get the next selected view 2481 * visible, with a fading edge showing below as applicable. The amount is 2482 * capped at {@link #getMaxScrollAmount()} . 2483 * 2484 * @param direction either {@link android.view.View#FOCUS_UP} or 2485 * {@link android.view.View#FOCUS_DOWN}. 2486 * @param nextSelectedPosition The position of the next selection, or 2487 * {@link #INVALID_POSITION} if there is no next selectable position 2488 * @return The amount to scroll. Note: this is always positive! Direction 2489 * needs to be taken into account when actually scrolling. 2490 */ 2491 private int amountToScroll(int direction, int nextSelectedPosition) { 2492 final int listBottom = getHeight() - mListPadding.bottom; 2493 final int listTop = mListPadding.top; 2494 2495 final int numChildren = getChildCount(); 2496 2497 if (direction == View.FOCUS_DOWN) { 2498 int indexToMakeVisible = numChildren - 1; 2499 if (nextSelectedPosition != INVALID_POSITION) { 2500 indexToMakeVisible = nextSelectedPosition - mFirstPosition; 2501 } 2502 2503 final int positionToMakeVisible = mFirstPosition + indexToMakeVisible; 2504 final View viewToMakeVisible = getChildAt(indexToMakeVisible); 2505 2506 int goalBottom = listBottom; 2507 if (positionToMakeVisible < mItemCount - 1) { 2508 goalBottom -= getArrowScrollPreviewLength(); 2509 } 2510 2511 if (viewToMakeVisible.getBottom() <= goalBottom) { 2512 // item is fully visible. 2513 return 0; 2514 } 2515 2516 if (nextSelectedPosition != INVALID_POSITION 2517 && (goalBottom - viewToMakeVisible.getTop()) >= getMaxScrollAmount()) { 2518 // item already has enough of it visible, changing selection is good enough 2519 return 0; 2520 } 2521 2522 int amountToScroll = (viewToMakeVisible.getBottom() - goalBottom); 2523 2524 if ((mFirstPosition + numChildren) == mItemCount) { 2525 // last is last in list -> make sure we don't scroll past it 2526 final int max = getChildAt(numChildren - 1).getBottom() - listBottom; 2527 amountToScroll = Math.min(amountToScroll, max); 2528 } 2529 2530 return Math.min(amountToScroll, getMaxScrollAmount()); 2531 } else { 2532 int indexToMakeVisible = 0; 2533 if (nextSelectedPosition != INVALID_POSITION) { 2534 indexToMakeVisible = nextSelectedPosition - mFirstPosition; 2535 } 2536 final int positionToMakeVisible = mFirstPosition + indexToMakeVisible; 2537 final View viewToMakeVisible = getChildAt(indexToMakeVisible); 2538 int goalTop = listTop; 2539 if (positionToMakeVisible > 0) { 2540 goalTop += getArrowScrollPreviewLength(); 2541 } 2542 if (viewToMakeVisible.getTop() >= goalTop) { 2543 // item is fully visible. 2544 return 0; 2545 } 2546 2547 if (nextSelectedPosition != INVALID_POSITION && 2548 (viewToMakeVisible.getBottom() - goalTop) >= getMaxScrollAmount()) { 2549 // item already has enough of it visible, changing selection is good enough 2550 return 0; 2551 } 2552 2553 int amountToScroll = (goalTop - viewToMakeVisible.getTop()); 2554 if (mFirstPosition == 0) { 2555 // first is first in list -> make sure we don't scroll past it 2556 final int max = listTop - getChildAt(0).getTop(); 2557 amountToScroll = Math.min(amountToScroll, max); 2558 } 2559 return Math.min(amountToScroll, getMaxScrollAmount()); 2560 } 2561 } 2562 2563 /** 2564 * Holds results of focus aware arrow scrolling. 2565 */ 2566 static private class ArrowScrollFocusResult { 2567 private int mSelectedPosition; 2568 private int mAmountToScroll; 2569 2570 /** 2571 * How {@link android.widget.ListView#arrowScrollFocused} returns its values. 2572 */ 2573 void populate(int selectedPosition, int amountToScroll) { 2574 mSelectedPosition = selectedPosition; 2575 mAmountToScroll = amountToScroll; 2576 } 2577 2578 public int getSelectedPosition() { 2579 return mSelectedPosition; 2580 } 2581 2582 public int getAmountToScroll() { 2583 return mAmountToScroll; 2584 } 2585 } 2586 2587 /** 2588 * @param direction either {@link android.view.View#FOCUS_UP} or 2589 * {@link android.view.View#FOCUS_DOWN}. 2590 * @return The position of the next selectable position of the views that 2591 * are currently visible, taking into account the fact that there might 2592 * be no selection. Returns {@link #INVALID_POSITION} if there is no 2593 * selectable view on screen in the given direction. 2594 */ 2595 private int lookForSelectablePositionOnScreen(int direction) { 2596 final int firstPosition = mFirstPosition; 2597 if (direction == View.FOCUS_DOWN) { 2598 int startPos = (mSelectedPosition != INVALID_POSITION) ? 2599 mSelectedPosition + 1 : 2600 firstPosition; 2601 if (startPos >= mAdapter.getCount()) { 2602 return INVALID_POSITION; 2603 } 2604 if (startPos < firstPosition) { 2605 startPos = firstPosition; 2606 } 2607 2608 final int lastVisiblePos = getLastVisiblePosition(); 2609 final ListAdapter adapter = getAdapter(); 2610 for (int pos = startPos; pos <= lastVisiblePos; pos++) { 2611 if (adapter.isEnabled(pos) 2612 && getChildAt(pos - firstPosition).getVisibility() == View.VISIBLE) { 2613 return pos; 2614 } 2615 } 2616 } else { 2617 int last = firstPosition + getChildCount() - 1; 2618 int startPos = (mSelectedPosition != INVALID_POSITION) ? 2619 mSelectedPosition - 1 : 2620 firstPosition + getChildCount() - 1; 2621 if (startPos < 0) { 2622 return INVALID_POSITION; 2623 } 2624 if (startPos > last) { 2625 startPos = last; 2626 } 2627 2628 final ListAdapter adapter = getAdapter(); 2629 for (int pos = startPos; pos >= firstPosition; pos--) { 2630 if (adapter.isEnabled(pos) 2631 && getChildAt(pos - firstPosition).getVisibility() == View.VISIBLE) { 2632 return pos; 2633 } 2634 } 2635 } 2636 return INVALID_POSITION; 2637 } 2638 2639 /** 2640 * Do an arrow scroll based on focus searching. If a new view is 2641 * given focus, return the selection delta and amount to scroll via 2642 * an {@link ArrowScrollFocusResult}, otherwise, return null. 2643 * 2644 * @param direction either {@link android.view.View#FOCUS_UP} or 2645 * {@link android.view.View#FOCUS_DOWN}. 2646 * @return The result if focus has changed, or <code>null</code>. 2647 */ 2648 private ArrowScrollFocusResult arrowScrollFocused(final int direction) { 2649 final View selectedView = getSelectedView(); 2650 View newFocus; 2651 if (selectedView != null && selectedView.hasFocus()) { 2652 View oldFocus = selectedView.findFocus(); 2653 newFocus = FocusFinder.getInstance().findNextFocus(this, oldFocus, direction); 2654 } else { 2655 if (direction == View.FOCUS_DOWN) { 2656 final boolean topFadingEdgeShowing = (mFirstPosition > 0); 2657 final int listTop = mListPadding.top + 2658 (topFadingEdgeShowing ? getArrowScrollPreviewLength() : 0); 2659 final int ySearchPoint = 2660 (selectedView != null && selectedView.getTop() > listTop) ? 2661 selectedView.getTop() : 2662 listTop; 2663 mTempRect.set(0, ySearchPoint, 0, ySearchPoint); 2664 } else { 2665 final boolean bottomFadingEdgeShowing = 2666 (mFirstPosition + getChildCount() - 1) < mItemCount; 2667 final int listBottom = getHeight() - mListPadding.bottom - 2668 (bottomFadingEdgeShowing ? getArrowScrollPreviewLength() : 0); 2669 final int ySearchPoint = 2670 (selectedView != null && selectedView.getBottom() < listBottom) ? 2671 selectedView.getBottom() : 2672 listBottom; 2673 mTempRect.set(0, ySearchPoint, 0, ySearchPoint); 2674 } 2675 newFocus = FocusFinder.getInstance().findNextFocusFromRect(this, mTempRect, direction); 2676 } 2677 2678 if (newFocus != null) { 2679 final int positionOfNewFocus = positionOfNewFocus(newFocus); 2680 2681 // if the focus change is in a different new position, make sure 2682 // we aren't jumping over another selectable position 2683 if (mSelectedPosition != INVALID_POSITION && positionOfNewFocus != mSelectedPosition) { 2684 final int selectablePosition = lookForSelectablePositionOnScreen(direction); 2685 if (selectablePosition != INVALID_POSITION && 2686 ((direction == View.FOCUS_DOWN && selectablePosition < positionOfNewFocus) || 2687 (direction == View.FOCUS_UP && selectablePosition > positionOfNewFocus))) { 2688 return null; 2689 } 2690 } 2691 2692 int focusScroll = amountToScrollToNewFocus(direction, newFocus, positionOfNewFocus); 2693 2694 final int maxScrollAmount = getMaxScrollAmount(); 2695 if (focusScroll < maxScrollAmount) { 2696 // not moving too far, safe to give next view focus 2697 newFocus.requestFocus(direction); 2698 mArrowScrollFocusResult.populate(positionOfNewFocus, focusScroll); 2699 return mArrowScrollFocusResult; 2700 } else if (distanceToView(newFocus) < maxScrollAmount){ 2701 // Case to consider: 2702 // too far to get entire next focusable on screen, but by going 2703 // max scroll amount, we are getting it at least partially in view, 2704 // so give it focus and scroll the max ammount. 2705 newFocus.requestFocus(direction); 2706 mArrowScrollFocusResult.populate(positionOfNewFocus, maxScrollAmount); 2707 return mArrowScrollFocusResult; 2708 } 2709 } 2710 return null; 2711 } 2712 2713 /** 2714 * @param newFocus The view that would have focus. 2715 * @return the position that contains newFocus 2716 */ 2717 private int positionOfNewFocus(View newFocus) { 2718 final int numChildren = getChildCount(); 2719 for (int i = 0; i < numChildren; i++) { 2720 final View child = getChildAt(i); 2721 if (isViewAncestorOf(newFocus, child)) { 2722 return mFirstPosition + i; 2723 } 2724 } 2725 throw new IllegalArgumentException("newFocus is not a child of any of the" 2726 + " children of the list!"); 2727 } 2728 2729 /** 2730 * Return true if child is an ancestor of parent, (or equal to the parent). 2731 */ 2732 private boolean isViewAncestorOf(View child, View parent) { 2733 if (child == parent) { 2734 return true; 2735 } 2736 2737 final ViewParent theParent = child.getParent(); 2738 return (theParent instanceof ViewGroup) && isViewAncestorOf((View) theParent, parent); 2739 } 2740 2741 /** 2742 * Determine how much we need to scroll in order to get newFocus in view. 2743 * @param direction either {@link android.view.View#FOCUS_UP} or 2744 * {@link android.view.View#FOCUS_DOWN}. 2745 * @param newFocus The view that would take focus. 2746 * @param positionOfNewFocus The position of the list item containing newFocus 2747 * @return The amount to scroll. Note: this is always positive! Direction 2748 * needs to be taken into account when actually scrolling. 2749 */ 2750 private int amountToScrollToNewFocus(int direction, View newFocus, int positionOfNewFocus) { 2751 int amountToScroll = 0; 2752 newFocus.getDrawingRect(mTempRect); 2753 offsetDescendantRectToMyCoords(newFocus, mTempRect); 2754 if (direction == View.FOCUS_UP) { 2755 if (mTempRect.top < mListPadding.top) { 2756 amountToScroll = mListPadding.top - mTempRect.top; 2757 if (positionOfNewFocus > 0) { 2758 amountToScroll += getArrowScrollPreviewLength(); 2759 } 2760 } 2761 } else { 2762 final int listBottom = getHeight() - mListPadding.bottom; 2763 if (mTempRect.bottom > listBottom) { 2764 amountToScroll = mTempRect.bottom - listBottom; 2765 if (positionOfNewFocus < mItemCount - 1) { 2766 amountToScroll += getArrowScrollPreviewLength(); 2767 } 2768 } 2769 } 2770 return amountToScroll; 2771 } 2772 2773 /** 2774 * Determine the distance to the nearest edge of a view in a particular 2775 * direction. 2776 * 2777 * @param descendant A descendant of this list. 2778 * @return The distance, or 0 if the nearest edge is already on screen. 2779 */ 2780 private int distanceToView(View descendant) { 2781 int distance = 0; 2782 descendant.getDrawingRect(mTempRect); 2783 offsetDescendantRectToMyCoords(descendant, mTempRect); 2784 final int listBottom = mBottom - mTop - mListPadding.bottom; 2785 if (mTempRect.bottom < mListPadding.top) { 2786 distance = mListPadding.top - mTempRect.bottom; 2787 } else if (mTempRect.top > listBottom) { 2788 distance = mTempRect.top - listBottom; 2789 } 2790 return distance; 2791 } 2792 2793 2794 /** 2795 * Scroll the children by amount, adding a view at the end and removing 2796 * views that fall off as necessary. 2797 * 2798 * @param amount The amount (positive or negative) to scroll. 2799 */ 2800 private void scrollListItemsBy(int amount) { 2801 offsetChildrenTopAndBottom(amount); 2802 2803 final int listBottom = getHeight() - mListPadding.bottom; 2804 final int listTop = mListPadding.top; 2805 final AbsListView.RecycleBin recycleBin = mRecycler; 2806 2807 if (amount < 0) { 2808 // shifted items up 2809 2810 // may need to pan views into the bottom space 2811 int numChildren = getChildCount(); 2812 View last = getChildAt(numChildren - 1); 2813 while (last.getBottom() < listBottom) { 2814 final int lastVisiblePosition = mFirstPosition + numChildren - 1; 2815 if (lastVisiblePosition < mItemCount - 1) { 2816 last = addViewBelow(last, lastVisiblePosition); 2817 numChildren++; 2818 } else { 2819 break; 2820 } 2821 } 2822 2823 // may have brought in the last child of the list that is skinnier 2824 // than the fading edge, thereby leaving space at the end. need 2825 // to shift back 2826 if (last.getBottom() < listBottom) { 2827 offsetChildrenTopAndBottom(listBottom - last.getBottom()); 2828 } 2829 2830 // top views may be panned off screen 2831 View first = getChildAt(0); 2832 while (first.getBottom() < listTop) { 2833 AbsListView.LayoutParams layoutParams = (LayoutParams) first.getLayoutParams(); 2834 if (recycleBin.shouldRecycleViewType(layoutParams.viewType)) { 2835 detachViewFromParent(first); 2836 recycleBin.addScrapView(first); 2837 } else { 2838 removeViewInLayout(first); 2839 } 2840 first = getChildAt(0); 2841 mFirstPosition++; 2842 } 2843 } else { 2844 // shifted items down 2845 View first = getChildAt(0); 2846 2847 // may need to pan views into top 2848 while ((first.getTop() > listTop) && (mFirstPosition > 0)) { 2849 first = addViewAbove(first, mFirstPosition); 2850 mFirstPosition--; 2851 } 2852 2853 // may have brought the very first child of the list in too far and 2854 // need to shift it back 2855 if (first.getTop() > listTop) { 2856 offsetChildrenTopAndBottom(listTop - first.getTop()); 2857 } 2858 2859 int lastIndex = getChildCount() - 1; 2860 View last = getChildAt(lastIndex); 2861 2862 // bottom view may be panned off screen 2863 while (last.getTop() > listBottom) { 2864 AbsListView.LayoutParams layoutParams = (LayoutParams) last.getLayoutParams(); 2865 if (recycleBin.shouldRecycleViewType(layoutParams.viewType)) { 2866 detachViewFromParent(last); 2867 recycleBin.addScrapView(last); 2868 } else { 2869 removeViewInLayout(last); 2870 } 2871 last = getChildAt(--lastIndex); 2872 } 2873 } 2874 } 2875 2876 private View addViewAbove(View theView, int position) { 2877 int abovePosition = position - 1; 2878 View view = obtainView(abovePosition, mIsScrap); 2879 int edgeOfNewChild = theView.getTop() - mDividerHeight; 2880 setupChild(view, abovePosition, edgeOfNewChild, false, mListPadding.left, 2881 false, mIsScrap[0]); 2882 return view; 2883 } 2884 2885 private View addViewBelow(View theView, int position) { 2886 int belowPosition = position + 1; 2887 View view = obtainView(belowPosition, mIsScrap); 2888 int edgeOfNewChild = theView.getBottom() + mDividerHeight; 2889 setupChild(view, belowPosition, edgeOfNewChild, true, mListPadding.left, 2890 false, mIsScrap[0]); 2891 return view; 2892 } 2893 2894 /** 2895 * Indicates that the views created by the ListAdapter can contain focusable 2896 * items. 2897 * 2898 * @param itemsCanFocus true if items can get focus, false otherwise 2899 */ 2900 public void setItemsCanFocus(boolean itemsCanFocus) { 2901 mItemsCanFocus = itemsCanFocus; 2902 if (!itemsCanFocus) { 2903 setDescendantFocusability(ViewGroup.FOCUS_BLOCK_DESCENDANTS); 2904 } 2905 } 2906 2907 /** 2908 * @return Whether the views created by the ListAdapter can contain focusable 2909 * items. 2910 */ 2911 public boolean getItemsCanFocus() { 2912 return mItemsCanFocus; 2913 } 2914 2915 /** 2916 * @hide Pending API council approval. 2917 */ 2918 @Override 2919 public boolean isOpaque() { 2920 return (mCachingStarted && mIsCacheColorOpaque && mDividerIsOpaque && 2921 hasOpaqueScrollbars()) || super.isOpaque(); 2922 } 2923 2924 @Override 2925 public void setCacheColorHint(int color) { 2926 final boolean opaque = (color >>> 24) == 0xFF; 2927 mIsCacheColorOpaque = opaque; 2928 if (opaque) { 2929 if (mDividerPaint == null) { 2930 mDividerPaint = new Paint(); 2931 } 2932 mDividerPaint.setColor(color); 2933 } 2934 super.setCacheColorHint(color); 2935 } 2936 2937 @Override 2938 protected void dispatchDraw(Canvas canvas) { 2939 // Draw the dividers 2940 final int dividerHeight = mDividerHeight; 2941 2942 if (dividerHeight > 0 && mDivider != null) { 2943 // Only modify the top and bottom in the loop, we set the left and right here 2944 final Rect bounds = mTempRect; 2945 bounds.left = mPaddingLeft; 2946 bounds.right = mRight - mLeft - mPaddingRight; 2947 2948 final int count = getChildCount(); 2949 final int headerCount = mHeaderViewInfos.size(); 2950 final int footerLimit = mItemCount - mFooterViewInfos.size() - 1; 2951 final boolean headerDividers = mHeaderDividersEnabled; 2952 final boolean footerDividers = mFooterDividersEnabled; 2953 final int first = mFirstPosition; 2954 final boolean areAllItemsSelectable = mAreAllItemsSelectable; 2955 final ListAdapter adapter = mAdapter; 2956 // If the list is opaque *and* the background is not, we want to 2957 // fill a rect where the dividers would be for non-selectable items 2958 // If the list is opaque and the background is also opaque, we don't 2959 // need to draw anything since the background will do it for us 2960 final boolean fillForMissingDividers = isOpaque() && !super.isOpaque(); 2961 2962 if (fillForMissingDividers && mDividerPaint == null && mIsCacheColorOpaque) { 2963 mDividerPaint = new Paint(); 2964 mDividerPaint.setColor(getCacheColorHint()); 2965 } 2966 final Paint paint = mDividerPaint; 2967 2968 if (!mStackFromBottom) { 2969 int bottom; 2970 int listBottom = mBottom - mTop - mListPadding.bottom + mScrollY; 2971 2972 // Draw top divider for overscroll 2973 if (count > 0 && mScrollY < 0) { 2974 bounds.bottom = 0; 2975 bounds.top = -dividerHeight; 2976 drawDivider(canvas, bounds, -1); 2977 } 2978 2979 for (int i = 0; i < count; i++) { 2980 if ((headerDividers || first + i >= headerCount) && 2981 (footerDividers || first + i < footerLimit)) { 2982 View child = getChildAt(i); 2983 bottom = child.getBottom(); 2984 // Don't draw dividers next to items that are not enabled 2985 if (bottom < listBottom) { 2986 if ((areAllItemsSelectable || 2987 (adapter.isEnabled(first + i) && (i == count - 1 || 2988 adapter.isEnabled(first + i + 1))))) { 2989 bounds.top = bottom; 2990 bounds.bottom = bottom + dividerHeight; 2991 drawDivider(canvas, bounds, i); 2992 } else if (fillForMissingDividers) { 2993 bounds.top = bottom; 2994 bounds.bottom = bottom + dividerHeight; 2995 canvas.drawRect(bounds, paint); 2996 } 2997 } 2998 } 2999 } 3000 } else { 3001 int top; 3002 int listTop = mListPadding.top; 3003 3004 for (int i = 0; i < count; i++) { 3005 if ((headerDividers || first + i >= headerCount) && 3006 (footerDividers || first + i < footerLimit)) { 3007 View child = getChildAt(i); 3008 top = child.getTop(); 3009 // Don't draw dividers next to items that are not enabled 3010 if (top > listTop) { 3011 if ((areAllItemsSelectable || 3012 (adapter.isEnabled(first + i) && (i == count - 1 || 3013 adapter.isEnabled(first + i + 1))))) { 3014 bounds.top = top - dividerHeight; 3015 bounds.bottom = top; 3016 // Give the method the child ABOVE the divider, so we 3017 // subtract one from our child 3018 // position. Give -1 when there is no child above the 3019 // divider. 3020 drawDivider(canvas, bounds, i - 1); 3021 } else if (fillForMissingDividers) { 3022 bounds.top = top - dividerHeight; 3023 bounds.bottom = top; 3024 canvas.drawRect(bounds, paint); 3025 } 3026 } 3027 } 3028 } 3029 } 3030 } 3031 3032 // Draw the indicators (these should be drawn above the dividers) and children 3033 super.dispatchDraw(canvas); 3034 } 3035 3036 /** 3037 * Draws a divider for the given child in the given bounds. 3038 * 3039 * @param canvas The canvas to draw to. 3040 * @param bounds The bounds of the divider. 3041 * @param childIndex The index of child (of the View) above the divider. 3042 * This will be -1 if there is no child above the divider to be 3043 * drawn. 3044 */ 3045 void drawDivider(Canvas canvas, Rect bounds, int childIndex) { 3046 // This widget draws the same divider for all children 3047 final Drawable divider = mDivider; 3048 final boolean clipDivider = mClipDivider; 3049 3050 if (!clipDivider) { 3051 divider.setBounds(bounds); 3052 } else { 3053 canvas.save(); 3054 canvas.clipRect(bounds); 3055 } 3056 3057 divider.draw(canvas); 3058 3059 if (clipDivider) { 3060 canvas.restore(); 3061 } 3062 } 3063 3064 /** 3065 * Returns the drawable that will be drawn between each item in the list. 3066 * 3067 * @return the current drawable drawn between list elements 3068 */ 3069 public Drawable getDivider() { 3070 return mDivider; 3071 } 3072 3073 /** 3074 * Sets the drawable that will be drawn between each item in the list. If the drawable does 3075 * not have an intrinsic height, you should also call {@link #setDividerHeight(int)} 3076 * 3077 * @param divider The drawable to use. 3078 */ 3079 public void setDivider(Drawable divider) { 3080 if (divider != null) { 3081 mDividerHeight = divider.getIntrinsicHeight(); 3082 mClipDivider = divider instanceof ColorDrawable; 3083 } else { 3084 mDividerHeight = 0; 3085 mClipDivider = false; 3086 } 3087 mDivider = divider; 3088 mDividerIsOpaque = divider == null || divider.getOpacity() == PixelFormat.OPAQUE; 3089 requestLayoutIfNecessary(); 3090 } 3091 3092 /** 3093 * @return Returns the height of the divider that will be drawn between each item in the list. 3094 */ 3095 public int getDividerHeight() { 3096 return mDividerHeight; 3097 } 3098 3099 /** 3100 * Sets the height of the divider that will be drawn between each item in the list. Calling 3101 * this will override the intrinsic height as set by {@link #setDivider(Drawable)} 3102 * 3103 * @param height The new height of the divider in pixels. 3104 */ 3105 public void setDividerHeight(int height) { 3106 mDividerHeight = height; 3107 requestLayoutIfNecessary(); 3108 } 3109 3110 /** 3111 * Enables or disables the drawing of the divider for header views. 3112 * 3113 * @param headerDividersEnabled True to draw the headers, false otherwise. 3114 * 3115 * @see #setFooterDividersEnabled(boolean) 3116 * @see #addHeaderView(android.view.View) 3117 */ 3118 public void setHeaderDividersEnabled(boolean headerDividersEnabled) { 3119 mHeaderDividersEnabled = headerDividersEnabled; 3120 invalidate(); 3121 } 3122 3123 /** 3124 * Enables or disables the drawing of the divider for footer views. 3125 * 3126 * @param footerDividersEnabled True to draw the footers, false otherwise. 3127 * 3128 * @see #setHeaderDividersEnabled(boolean) 3129 * @see #addFooterView(android.view.View) 3130 */ 3131 public void setFooterDividersEnabled(boolean footerDividersEnabled) { 3132 mFooterDividersEnabled = footerDividersEnabled; 3133 invalidate(); 3134 } 3135 3136 @Override 3137 protected void onFocusChanged(boolean gainFocus, int direction, Rect previouslyFocusedRect) { 3138 super.onFocusChanged(gainFocus, direction, previouslyFocusedRect); 3139 3140 int closetChildIndex = -1; 3141 if (gainFocus && previouslyFocusedRect != null) { 3142 previouslyFocusedRect.offset(mScrollX, mScrollY); 3143 3144 final ListAdapter adapter = mAdapter; 3145 // Don't cache the result of getChildCount or mFirstPosition here, 3146 // it could change in layoutChildren. 3147 if (adapter.getCount() < getChildCount() + mFirstPosition) { 3148 mLayoutMode = LAYOUT_NORMAL; 3149 layoutChildren(); 3150 } 3151 3152 // figure out which item should be selected based on previously 3153 // focused rect 3154 Rect otherRect = mTempRect; 3155 int minDistance = Integer.MAX_VALUE; 3156 final int childCount = getChildCount(); 3157 final int firstPosition = mFirstPosition; 3158 3159 for (int i = 0; i < childCount; i++) { 3160 // only consider selectable views 3161 if (!adapter.isEnabled(firstPosition + i)) { 3162 continue; 3163 } 3164 3165 View other = getChildAt(i); 3166 other.getDrawingRect(otherRect); 3167 offsetDescendantRectToMyCoords(other, otherRect); 3168 int distance = getDistance(previouslyFocusedRect, otherRect, direction); 3169 3170 if (distance < minDistance) { 3171 minDistance = distance; 3172 closetChildIndex = i; 3173 } 3174 } 3175 } 3176 3177 if (closetChildIndex >= 0) { 3178 setSelection(closetChildIndex + mFirstPosition); 3179 } else { 3180 requestLayout(); 3181 } 3182 } 3183 3184 3185 /* 3186 * (non-Javadoc) 3187 * 3188 * Children specified in XML are assumed to be header views. After we have 3189 * parsed them move them out of the children list and into mHeaderViews. 3190 */ 3191 @Override 3192 protected void onFinishInflate() { 3193 super.onFinishInflate(); 3194 3195 int count = getChildCount(); 3196 if (count > 0) { 3197 for (int i = 0; i < count; ++i) { 3198 addHeaderView(getChildAt(i)); 3199 } 3200 removeAllViews(); 3201 } 3202 } 3203 3204 /* (non-Javadoc) 3205 * @see android.view.View#findViewById(int) 3206 * First look in our children, then in any header and footer views that may be scrolled off. 3207 */ 3208 @Override 3209 protected View findViewTraversal(int id) { 3210 View v; 3211 v = super.findViewTraversal(id); 3212 if (v == null) { 3213 v = findViewInHeadersOrFooters(mHeaderViewInfos, id); 3214 if (v != null) { 3215 return v; 3216 } 3217 v = findViewInHeadersOrFooters(mFooterViewInfos, id); 3218 if (v != null) { 3219 return v; 3220 } 3221 } 3222 return v; 3223 } 3224 3225 /* (non-Javadoc) 3226 * 3227 * Look in the passed in list of headers or footers for the view. 3228 */ 3229 View findViewInHeadersOrFooters(ArrayList<FixedViewInfo> where, int id) { 3230 if (where != null) { 3231 int len = where.size(); 3232 View v; 3233 3234 for (int i = 0; i < len; i++) { 3235 v = where.get(i).view; 3236 3237 if (!v.isRootNamespace()) { 3238 v = v.findViewById(id); 3239 3240 if (v != null) { 3241 return v; 3242 } 3243 } 3244 } 3245 } 3246 return null; 3247 } 3248 3249 /* (non-Javadoc) 3250 * @see android.view.View#findViewWithTag(String) 3251 * First look in our children, then in any header and footer views that may be scrolled off. 3252 */ 3253 @Override 3254 protected View findViewWithTagTraversal(Object tag) { 3255 View v; 3256 v = super.findViewWithTagTraversal(tag); 3257 if (v == null) { 3258 v = findViewTagInHeadersOrFooters(mHeaderViewInfos, tag); 3259 if (v != null) { 3260 return v; 3261 } 3262 3263 v = findViewTagInHeadersOrFooters(mFooterViewInfos, tag); 3264 if (v != null) { 3265 return v; 3266 } 3267 } 3268 return v; 3269 } 3270 3271 /* (non-Javadoc) 3272 * 3273 * Look in the passed in list of headers or footers for the view with the tag. 3274 */ 3275 View findViewTagInHeadersOrFooters(ArrayList<FixedViewInfo> where, Object tag) { 3276 if (where != null) { 3277 int len = where.size(); 3278 View v; 3279 3280 for (int i = 0; i < len; i++) { 3281 v = where.get(i).view; 3282 3283 if (!v.isRootNamespace()) { 3284 v = v.findViewWithTag(tag); 3285 3286 if (v != null) { 3287 return v; 3288 } 3289 } 3290 } 3291 } 3292 return null; 3293 } 3294 3295 @Override 3296 public boolean onTouchEvent(MotionEvent ev) { 3297 if (mItemsCanFocus && ev.getAction() == MotionEvent.ACTION_DOWN && ev.getEdgeFlags() != 0) { 3298 // Don't handle edge touches immediately -- they may actually belong to one of our 3299 // descendants. 3300 return false; 3301 } 3302 return super.onTouchEvent(ev); 3303 } 3304 3305 /** 3306 * @see #setChoiceMode(int) 3307 * 3308 * @return The current choice mode 3309 */ 3310 public int getChoiceMode() { 3311 return mChoiceMode; 3312 } 3313 3314 /** 3315 * Defines the choice behavior for the List. By default, Lists do not have any choice behavior 3316 * ({@link #CHOICE_MODE_NONE}). By setting the choiceMode to {@link #CHOICE_MODE_SINGLE}, the 3317 * List allows up to one item to be in a chosen state. By setting the choiceMode to 3318 * {@link #CHOICE_MODE_MULTIPLE}, the list allows any number of items to be chosen. 3319 * 3320 * @param choiceMode One of {@link #CHOICE_MODE_NONE}, {@link #CHOICE_MODE_SINGLE}, or 3321 * {@link #CHOICE_MODE_MULTIPLE} 3322 */ 3323 public void setChoiceMode(int choiceMode) { 3324 mChoiceMode = choiceMode; 3325 if (mChoiceMode != CHOICE_MODE_NONE) { 3326 if (mCheckStates == null) { 3327 mCheckStates = new SparseBooleanArray(); 3328 } 3329 if (mCheckedIdStates == null && mAdapter != null && mAdapter.hasStableIds()) { 3330 mCheckedIdStates = new LongSparseArray<Boolean>(); 3331 } 3332 } 3333 } 3334 3335 @Override 3336 public boolean performItemClick(View view, int position, long id) { 3337 boolean handled = false; 3338 3339 if (mChoiceMode != CHOICE_MODE_NONE) { 3340 handled = true; 3341 3342 if (mChoiceMode == CHOICE_MODE_MULTIPLE) { 3343 boolean newValue = !mCheckStates.get(position, false); 3344 mCheckStates.put(position, newValue); 3345 if (mCheckedIdStates != null && mAdapter.hasStableIds()) { 3346 if (newValue) { 3347 mCheckedIdStates.put(mAdapter.getItemId(position), Boolean.TRUE); 3348 } else { 3349 mCheckedIdStates.delete(mAdapter.getItemId(position)); 3350 } 3351 } 3352 } else { 3353 boolean newValue = !mCheckStates.get(position, false); 3354 if (newValue) { 3355 mCheckStates.clear(); 3356 mCheckStates.put(position, true); 3357 if (mCheckedIdStates != null && mAdapter.hasStableIds()) { 3358 mCheckedIdStates.clear(); 3359 mCheckedIdStates.put(mAdapter.getItemId(position), Boolean.TRUE); 3360 } 3361 } 3362 } 3363 3364 mDataChanged = true; 3365 rememberSyncState(); 3366 requestLayout(); 3367 } 3368 3369 handled |= super.performItemClick(view, position, id); 3370 3371 return handled; 3372 } 3373 3374 /** 3375 * Sets the checked state of the specified position. The is only valid if 3376 * the choice mode has been set to {@link #CHOICE_MODE_SINGLE} or 3377 * {@link #CHOICE_MODE_MULTIPLE}. 3378 * 3379 * @param position The item whose checked state is to be checked 3380 * @param value The new checked state for the item 3381 */ 3382 public void setItemChecked(int position, boolean value) { 3383 if (mChoiceMode == CHOICE_MODE_NONE) { 3384 return; 3385 } 3386 3387 if (mChoiceMode == CHOICE_MODE_MULTIPLE) { 3388 mCheckStates.put(position, value); 3389 if (mCheckedIdStates != null && mAdapter.hasStableIds()) { 3390 if (value) { 3391 mCheckedIdStates.put(mAdapter.getItemId(position), Boolean.TRUE); 3392 } else { 3393 mCheckedIdStates.delete(mAdapter.getItemId(position)); 3394 } 3395 } 3396 } else { 3397 boolean updateIds = mCheckedIdStates != null && mAdapter.hasStableIds(); 3398 // Clear all values if we're checking something, or unchecking the currently 3399 // selected item 3400 if (value || isItemChecked(position)) { 3401 mCheckStates.clear(); 3402 if (updateIds) { 3403 mCheckedIdStates.clear(); 3404 } 3405 } 3406 // this may end up selecting the value we just cleared but this way 3407 // we ensure length of mCheckStates is 1, a fact getCheckedItemPosition relies on 3408 if (value) { 3409 mCheckStates.put(position, true); 3410 if (updateIds) { 3411 mCheckedIdStates.put(mAdapter.getItemId(position), Boolean.TRUE); 3412 } 3413 } 3414 } 3415 3416 // Do not generate a data change while we are in the layout phase 3417 if (!mInLayout && !mBlockLayoutRequests) { 3418 mDataChanged = true; 3419 rememberSyncState(); 3420 requestLayout(); 3421 } 3422 } 3423 3424 /** 3425 * Returns the checked state of the specified position. The result is only 3426 * valid if the choice mode has been set to {@link #CHOICE_MODE_SINGLE} 3427 * or {@link #CHOICE_MODE_MULTIPLE}. 3428 * 3429 * @param position The item whose checked state to return 3430 * @return The item's checked state or <code>false</code> if choice mode 3431 * is invalid 3432 * 3433 * @see #setChoiceMode(int) 3434 */ 3435 public boolean isItemChecked(int position) { 3436 if (mChoiceMode != CHOICE_MODE_NONE && mCheckStates != null) { 3437 return mCheckStates.get(position); 3438 } 3439 3440 return false; 3441 } 3442 3443 /** 3444 * Returns the currently checked item. The result is only valid if the choice 3445 * mode has been set to {@link #CHOICE_MODE_SINGLE}. 3446 * 3447 * @return The position of the currently checked item or 3448 * {@link #INVALID_POSITION} if nothing is selected 3449 * 3450 * @see #setChoiceMode(int) 3451 */ 3452 public int getCheckedItemPosition() { 3453 if (mChoiceMode == CHOICE_MODE_SINGLE && mCheckStates != null && mCheckStates.size() == 1) { 3454 return mCheckStates.keyAt(0); 3455 } 3456 3457 return INVALID_POSITION; 3458 } 3459 3460 /** 3461 * Returns the set of checked items in the list. The result is only valid if 3462 * the choice mode has not been set to {@link #CHOICE_MODE_NONE}. 3463 * 3464 * @return A SparseBooleanArray which will return true for each call to 3465 * get(int position) where position is a position in the list, 3466 * or <code>null</code> if the choice mode is set to 3467 * {@link #CHOICE_MODE_NONE}. 3468 */ 3469 public SparseBooleanArray getCheckedItemPositions() { 3470 if (mChoiceMode != CHOICE_MODE_NONE) { 3471 return mCheckStates; 3472 } 3473 return null; 3474 } 3475 3476 /** 3477 * Returns the set of checked items ids. The result is only valid if the 3478 * choice mode has not been set to {@link #CHOICE_MODE_NONE}. 3479 * 3480 * @return A new array which contains the id of each checked item in the 3481 * list. 3482 * 3483 * @deprecated Use {@link #getCheckedItemIds()} instead. 3484 */ 3485 public long[] getCheckItemIds() { 3486 return getCheckedItemIds(); 3487 } 3488 3489 /** 3490 * Returns the set of checked items ids. The result is only valid if the 3491 * choice mode has not been set to {@link #CHOICE_MODE_NONE} and the adapter 3492 * has stable IDs. ({@link ListAdapter#hasStableIds()} == {@code true}) 3493 * 3494 * @return A new array which contains the id of each checked item in the 3495 * list. 3496 */ 3497 public long[] getCheckedItemIds() { 3498 if (mChoiceMode == CHOICE_MODE_NONE || mCheckedIdStates == null || mAdapter == null) { 3499 return new long[0]; 3500 } 3501 3502 final LongSparseArray<Boolean> idStates = mCheckedIdStates; 3503 final int count = idStates.size(); 3504 final long[] ids = new long[count]; 3505 3506 for (int i = 0; i < count; i++) { 3507 ids[i] = idStates.keyAt(i); 3508 } 3509 3510 return ids; 3511 } 3512 3513 /** 3514 * Clear any choices previously set 3515 */ 3516 public void clearChoices() { 3517 if (mCheckStates != null) { 3518 mCheckStates.clear(); 3519 } 3520 if (mCheckedIdStates != null) { 3521 mCheckedIdStates.clear(); 3522 } 3523 } 3524 3525 static class SavedState extends BaseSavedState { 3526 SparseBooleanArray checkState; 3527 LongSparseArray<Boolean> checkIdState; 3528 3529 /** 3530 * Constructor called from {@link ListView#onSaveInstanceState()} 3531 */ 3532 SavedState(Parcelable superState, SparseBooleanArray checkState, 3533 LongSparseArray<Boolean> checkIdState) { 3534 super(superState); 3535 this.checkState = checkState; 3536 this.checkIdState = checkIdState; 3537 } 3538 3539 /** 3540 * Constructor called from {@link #CREATOR} 3541 */ 3542 private SavedState(Parcel in) { 3543 super(in); 3544 checkState = in.readSparseBooleanArray(); 3545 long[] idState = in.createLongArray(); 3546 3547 if (idState.length > 0) { 3548 checkIdState = new LongSparseArray<Boolean>(); 3549 checkIdState.setValues(idState, Boolean.TRUE); 3550 } 3551 } 3552 3553 @Override 3554 public void writeToParcel(Parcel out, int flags) { 3555 super.writeToParcel(out, flags); 3556 out.writeSparseBooleanArray(checkState); 3557 out.writeLongArray(checkIdState != null ? checkIdState.getKeys() : new long[0]); 3558 } 3559 3560 @Override 3561 public String toString() { 3562 return "ListView.SavedState{" 3563 + Integer.toHexString(System.identityHashCode(this)) 3564 + " checkState=" + checkState + "}"; 3565 } 3566 3567 public static final Parcelable.Creator<SavedState> CREATOR 3568 = new Parcelable.Creator<SavedState>() { 3569 public SavedState createFromParcel(Parcel in) { 3570 return new SavedState(in); 3571 } 3572 3573 public SavedState[] newArray(int size) { 3574 return new SavedState[size]; 3575 } 3576 }; 3577 } 3578 3579 @Override 3580 public Parcelable onSaveInstanceState() { 3581 Parcelable superState = super.onSaveInstanceState(); 3582 return new SavedState(superState, mCheckStates, mCheckedIdStates); 3583 } 3584 3585 @Override 3586 public void onRestoreInstanceState(Parcelable state) { 3587 SavedState ss = (SavedState) state; 3588 3589 super.onRestoreInstanceState(ss.getSuperState()); 3590 3591 if (ss.checkState != null) { 3592 mCheckStates = ss.checkState; 3593 } 3594 3595 if (ss.checkIdState != null) { 3596 mCheckedIdStates = ss.checkIdState; 3597 } 3598 } 3599} 3600