GridLayoutManager.java revision c88e63b62bf417df87d9c14daf35d7a7e1125115
1/* 2 * Copyright (C) 2014 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except 5 * in compliance with the License. You may obtain a copy of the License at 6 * 7 * http://www.apache.org/licenses/LICENSE-2.0 8 * 9 * Unless required by applicable law or agreed to in writing, software distributed under the License 10 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express 11 * or implied. See the License for the specific language governing permissions and limitations under 12 * the License. 13 */ 14package android.support.v17.leanback.widget; 15 16import android.content.Context; 17import android.graphics.PointF; 18import android.graphics.Rect; 19import android.os.Bundle; 20import android.os.Parcel; 21import android.os.Parcelable; 22import android.support.v4.util.CircularIntArray; 23import android.support.v4.view.ViewCompat; 24import android.support.v4.view.accessibility.AccessibilityEventCompat; 25import android.support.v4.view.accessibility.AccessibilityNodeInfoCompat; 26import android.support.v4.view.accessibility.AccessibilityRecordCompat; 27import android.support.v7.widget.LinearSmoothScroller; 28import android.support.v7.widget.RecyclerView; 29import android.support.v7.widget.RecyclerView.Recycler; 30import android.support.v7.widget.RecyclerView.State; 31import android.support.v17.leanback.os.TraceHelper; 32 33import static android.support.v7.widget.RecyclerView.NO_ID; 34import static android.support.v7.widget.RecyclerView.NO_POSITION; 35import static android.support.v7.widget.RecyclerView.HORIZONTAL; 36import static android.support.v7.widget.RecyclerView.VERTICAL; 37 38import android.util.AttributeSet; 39import android.util.Log; 40import android.view.FocusFinder; 41import android.view.Gravity; 42import android.view.View; 43import android.view.ViewParent; 44import android.view.View.MeasureSpec; 45import android.view.ViewGroup.MarginLayoutParams; 46import android.view.ViewGroup; 47 48import java.io.PrintWriter; 49import java.io.StringWriter; 50import java.util.ArrayList; 51import java.util.List; 52 53final class GridLayoutManager extends RecyclerView.LayoutManager { 54 55 /* 56 * LayoutParams for {@link HorizontalGridView} and {@link VerticalGridView}. 57 * The class currently does two internal jobs: 58 * - Saves optical bounds insets. 59 * - Caches focus align view center. 60 */ 61 final static class LayoutParams extends RecyclerView.LayoutParams { 62 63 // For placement 64 private int mLeftInset; 65 private int mTopInset; 66 private int mRightInset; 67 private int mBottomInset; 68 69 // For alignment 70 private int mAlignX; 71 private int mAlignY; 72 private int[] mAlignMultiple; 73 private ItemAlignmentFacet mAlignmentFacet; 74 75 public LayoutParams(Context c, AttributeSet attrs) { 76 super(c, attrs); 77 } 78 79 public LayoutParams(int width, int height) { 80 super(width, height); 81 } 82 83 public LayoutParams(MarginLayoutParams source) { 84 super(source); 85 } 86 87 public LayoutParams(ViewGroup.LayoutParams source) { 88 super(source); 89 } 90 91 public LayoutParams(RecyclerView.LayoutParams source) { 92 super(source); 93 } 94 95 public LayoutParams(LayoutParams source) { 96 super(source); 97 } 98 99 int getAlignX() { 100 return mAlignX; 101 } 102 103 int getAlignY() { 104 return mAlignY; 105 } 106 107 int getOpticalLeft(View view) { 108 return view.getLeft() + mLeftInset; 109 } 110 111 int getOpticalTop(View view) { 112 return view.getTop() + mTopInset; 113 } 114 115 int getOpticalRight(View view) { 116 return view.getRight() - mRightInset; 117 } 118 119 int getOpticalBottom(View view) { 120 return view.getBottom() - mBottomInset; 121 } 122 123 int getOpticalWidth(View view) { 124 return view.getWidth() - mLeftInset - mRightInset; 125 } 126 127 int getOpticalHeight(View view) { 128 return view.getHeight() - mTopInset - mBottomInset; 129 } 130 131 int getDecoratedOpticalLeftWithMargin(RecyclerView.LayoutManager lm, View view) { 132 return lm.getDecoratedLeft(view) + mLeftInset - leftMargin; 133 } 134 135 int getDecoratedOpticalTopWithMargin(RecyclerView.LayoutManager lm, View view) { 136 return lm.getDecoratedTop(view) + mTopInset - topMargin; 137 } 138 139 int getDecoratedOpticalRightWithMargin(RecyclerView.LayoutManager lm, View view) { 140 return lm.getDecoratedRight(view) - mRightInset + rightMargin; 141 } 142 143 int getDecoratedOpticalBottomWithMargin(RecyclerView.LayoutManager lm, View view) { 144 return lm.getDecoratedBottom(view) - mBottomInset + bottomMargin; 145 } 146 147 int getDecoratedOpticalWidthWithMargin(RecyclerView.LayoutManager lm, View view) { 148 return lm.getDecoratedRight(view) - lm.getDecoratedLeft(view) 149 - mLeftInset - mRightInset + leftMargin + rightMargin; 150 } 151 152 int getDecoratedOpticalHeightWithMargin(RecyclerView.LayoutManager lm, View view) { 153 return lm.getDecoratedBottom(view) - lm.getDecoratedTop(view) 154 - mTopInset - mBottomInset + topMargin + bottomMargin; 155 } 156 157 int getOpticalLeftInset() { 158 return mLeftInset; 159 } 160 161 int getOpticalRightInset() { 162 return mRightInset; 163 } 164 165 int getOpticalTopInset() { 166 return mTopInset; 167 } 168 169 int getOpticalBottomInset() { 170 return mBottomInset; 171 } 172 173 void setAlignX(int alignX) { 174 mAlignX = alignX; 175 } 176 177 void setAlignY(int alignY) { 178 mAlignY = alignY; 179 } 180 181 void setItemAlignmentFacet(ItemAlignmentFacet facet) { 182 mAlignmentFacet = facet; 183 } 184 185 ItemAlignmentFacet getItemAlignmentFacet() { 186 return mAlignmentFacet; 187 } 188 189 void calculateItemAlignments(int orientation, View view) { 190 ItemAlignmentFacet.ItemAlignmentDef[] defs = mAlignmentFacet.getAlignmentDefs(); 191 if (mAlignMultiple == null || mAlignMultiple.length != defs.length) { 192 mAlignMultiple = new int[defs.length]; 193 } 194 for (int i = 0; i < defs.length; i++) { 195 mAlignMultiple[i] = ItemAlignmentFacetHelper 196 .getAlignmentPosition(view, defs[i], orientation); 197 } 198 if (orientation == HORIZONTAL) { 199 mAlignX = mAlignMultiple[0]; 200 } else { 201 mAlignY = mAlignMultiple[0]; 202 } 203 } 204 205 int[] getAlignMultiple() { 206 return mAlignMultiple; 207 } 208 209 void setOpticalInsets(int leftInset, int topInset, int rightInset, int bottomInset) { 210 mLeftInset = leftInset; 211 mTopInset = topInset; 212 mRightInset = rightInset; 213 mBottomInset = bottomInset; 214 } 215 216 } 217 218 /** 219 * Base class which scrolls to selected view in onStop(). 220 */ 221 abstract class GridLinearSmoothScroller extends LinearSmoothScroller { 222 GridLinearSmoothScroller() { 223 super(mBaseGridView.getContext()); 224 } 225 226 @Override 227 protected void onStop() { 228 // onTargetFound() may not be called if we hit the "wall" first. 229 View targetView = findViewByPosition(getTargetPosition()); 230 if (hasFocus() && targetView != null) { 231 mInSelection = true; 232 targetView.requestFocus(); 233 mInSelection = false; 234 } 235 dispatchChildSelected(); 236 super.onStop(); 237 } 238 239 @Override 240 protected void onTargetFound(View targetView, 241 RecyclerView.State state, Action action) { 242 if (getScrollPosition(targetView, null, sTwoInts)) { 243 int dx, dy; 244 if (mOrientation == HORIZONTAL) { 245 dx = sTwoInts[0]; 246 dy = sTwoInts[1]; 247 } else { 248 dx = sTwoInts[1]; 249 dy = sTwoInts[0]; 250 } 251 final int distance = (int) Math.sqrt(dx * dx + dy * dy); 252 final int time = calculateTimeForDeceleration(distance); 253 action.update(dx, dy, time, mDecelerateInterpolator); 254 } 255 } 256 } 257 258 /** 259 * The SmoothScroller that remembers pending DPAD keys and consume pending keys 260 * during scroll. 261 */ 262 final class PendingMoveSmoothScroller extends GridLinearSmoothScroller { 263 // -2 is a target position that LinearSmoothScroller can never find until 264 // consumePendingMovesXXX() sets real targetPosition. 265 final static int TARGET_UNDEFINED = -2; 266 // whether the grid is staggered. 267 private final boolean mStaggeredGrid; 268 // Number of pending movements on primary direction, negative if PREV_ITEM. 269 private int mPendingMoves; 270 271 PendingMoveSmoothScroller(int initialPendingMoves, boolean staggeredGrid) { 272 mPendingMoves = initialPendingMoves; 273 mStaggeredGrid = staggeredGrid; 274 setTargetPosition(TARGET_UNDEFINED); 275 } 276 277 void increasePendingMoves() { 278 if (mPendingMoves < MAX_PENDING_MOVES) { 279 mPendingMoves++; 280 } 281 } 282 283 void decreasePendingMoves() { 284 if (mPendingMoves > -MAX_PENDING_MOVES) { 285 mPendingMoves--; 286 } 287 } 288 289 /** 290 * Called before laid out an item when non-staggered grid can handle pending movements 291 * by skipping "mNumRows" per movement; staggered grid will have to wait the item 292 * has been laid out in consumePendingMovesAfterLayout(). 293 */ 294 void consumePendingMovesBeforeLayout() { 295 if (mStaggeredGrid || mPendingMoves == 0) { 296 return; 297 } 298 View newSelected = null; 299 int startPos = mPendingMoves > 0 ? mFocusPosition + mNumRows : 300 mFocusPosition - mNumRows; 301 for (int pos = startPos; mPendingMoves != 0; 302 pos = mPendingMoves > 0 ? pos + mNumRows: pos - mNumRows) { 303 View v = findViewByPosition(pos); 304 if (v == null) { 305 break; 306 } 307 if (!canScrollTo(v)) { 308 continue; 309 } 310 newSelected = v; 311 mFocusPosition = pos; 312 mSubFocusPosition = 0; 313 if (mPendingMoves > 0) { 314 mPendingMoves--; 315 } else { 316 mPendingMoves++; 317 } 318 } 319 if (newSelected != null && hasFocus()) { 320 mInSelection = true; 321 newSelected.requestFocus(); 322 mInSelection = false; 323 } 324 } 325 326 /** 327 * Called after laid out an item. Staggered grid should find view on same 328 * Row and consume pending movements. 329 */ 330 void consumePendingMovesAfterLayout() { 331 if (mStaggeredGrid && mPendingMoves != 0) { 332 // consume pending moves, focus to item on the same row. 333 mPendingMoves = processSelectionMoves(true, mPendingMoves); 334 } 335 if (mPendingMoves == 0 || (mPendingMoves > 0 && hasCreatedLastItem()) 336 || (mPendingMoves < 0 && hasCreatedFirstItem())) { 337 setTargetPosition(mFocusPosition); 338 stop(); 339 } 340 } 341 342 @Override 343 protected void updateActionForInterimTarget(Action action) { 344 if (mPendingMoves == 0) { 345 return; 346 } 347 super.updateActionForInterimTarget(action); 348 } 349 350 @Override 351 public PointF computeScrollVectorForPosition(int targetPosition) { 352 if (mPendingMoves == 0) { 353 return null; 354 } 355 int direction = (mReverseFlowPrimary ? mPendingMoves > 0 : mPendingMoves < 0) ? 356 -1 : 1; 357 if (mOrientation == HORIZONTAL) { 358 return new PointF(direction, 0); 359 } else { 360 return new PointF(0, direction); 361 } 362 } 363 364 @Override 365 protected void onStop() { 366 super.onStop(); 367 // if we hit wall, need clear the remaining pending moves. 368 mPendingMoves = 0; 369 mPendingMoveSmoothScroller = null; 370 View v = findViewByPosition(getTargetPosition()); 371 if (v != null) scrollToView(v, true); 372 } 373 }; 374 375 private static final String TAG = "GridLayoutManager"; 376 private static final boolean DEBUG = false; 377 private static final boolean TRACE = false; 378 379 // maximum pending movement in one direction. 380 private final static int MAX_PENDING_MOVES = 10; 381 382 private String getTag() { 383 return TAG + ":" + mBaseGridView.getId(); 384 } 385 386 private final BaseGridView mBaseGridView; 387 388 /** 389 * Note on conventions in the presence of RTL layout directions: 390 * Many properties and method names reference entities related to the 391 * beginnings and ends of things. In the presence of RTL flows, 392 * it may not be clear whether this is intended to reference a 393 * quantity that changes direction in RTL cases, or a quantity that 394 * does not. Here are the conventions in use: 395 * 396 * start/end: coordinate quantities - do reverse 397 * (optical) left/right: coordinate quantities - do not reverse 398 * low/high: coordinate quantities - do not reverse 399 * min/max: coordinate quantities - do not reverse 400 * scroll offset - coordinate quantities - do not reverse 401 * first/last: positional indices - do not reverse 402 * front/end: positional indices - do not reverse 403 * prepend/append: related to positional indices - do not reverse 404 * 405 * Note that although quantities do not reverse in RTL flows, their 406 * relationship does. In LTR flows, the first positional index is 407 * leftmost; in RTL flows, it is rightmost. Thus, anywhere that 408 * positional quantities are mapped onto coordinate quantities, 409 * the flow must be checked and the logic reversed. 410 */ 411 412 /** 413 * The orientation of a "row". 414 */ 415 private int mOrientation = HORIZONTAL; 416 417 private RecyclerView.State mState; 418 private RecyclerView.Recycler mRecycler; 419 420 private static final Rect sTempRect = new Rect(); 421 422 private boolean mInLayout; 423 private boolean mInScroll; 424 private boolean mInFastRelayout; 425 /** 426 * During full layout pass, when GridView had focus: onLayoutChildren will 427 * skip non-focusable child and adjust mFocusPosition. 428 */ 429 private boolean mInLayoutSearchFocus; 430 private boolean mInSelection = false; 431 432 private OnChildSelectedListener mChildSelectedListener = null; 433 434 private OnChildViewHolderSelectedListener mChildViewHolderSelectedListener = null; 435 436 private OnChildLaidOutListener mChildLaidOutListener = null; 437 438 /** 439 * The focused position, it's not the currently visually aligned position 440 * but it is the final position that we intend to focus on. If there are 441 * multiple setSelection() called, mFocusPosition saves last value. 442 */ 443 private int mFocusPosition = NO_POSITION; 444 445 /** 446 * A view can have mutliple alignment position, this is the index of which 447 * alignment is used, by default is 0. 448 */ 449 private int mSubFocusPosition = 0; 450 451 /** 452 * LinearSmoothScroller that consume pending DPAD movements. 453 */ 454 private PendingMoveSmoothScroller mPendingMoveSmoothScroller; 455 456 /** 457 * The offset to be applied to mFocusPosition, due to adapter change, on the next 458 * layout. Set to Integer.MIN_VALUE means we should stop adding delta to mFocusPosition 459 * until next layout cycler. 460 * TODO: This is somewhat duplication of RecyclerView getOldPosition() which is 461 * unfortunately cleared after prelayout. 462 */ 463 private int mFocusPositionOffset = 0; 464 465 /** 466 * Extra pixels applied on primary direction. 467 */ 468 private int mPrimaryScrollExtra; 469 470 /** 471 * Force a full layout under certain situations. E.g. Rows change, jump to invisible child. 472 */ 473 private boolean mForceFullLayout; 474 475 /** 476 * True if layout is enabled. 477 */ 478 private boolean mLayoutEnabled = true; 479 480 /** 481 * override child visibility 482 */ 483 private int mChildVisibility = -1; 484 485 /** 486 * The scroll offsets of the viewport relative to the entire view. 487 */ 488 private int mScrollOffsetPrimary; 489 private int mScrollOffsetSecondary; 490 491 /** 492 * User-specified row height/column width. Can be WRAP_CONTENT. 493 */ 494 private int mRowSizeSecondaryRequested; 495 496 /** 497 * The fixed size of each grid item in the secondary direction. This corresponds to 498 * the row height, equal for all rows. Grid items may have variable length 499 * in the primary direction. 500 */ 501 private int mFixedRowSizeSecondary; 502 503 /** 504 * Tracks the secondary size of each row. 505 */ 506 private int[] mRowSizeSecondary; 507 508 /** 509 * Flag controlling whether the current/next layout should 510 * be updating the secondary size of rows. 511 */ 512 private boolean mRowSecondarySizeRefresh; 513 514 /** 515 * The maximum measured size of the view. 516 */ 517 private int mMaxSizeSecondary; 518 519 /** 520 * Margin between items. 521 */ 522 private int mHorizontalMargin; 523 /** 524 * Margin between items vertically. 525 */ 526 private int mVerticalMargin; 527 /** 528 * Margin in main direction. 529 */ 530 private int mMarginPrimary; 531 /** 532 * Margin in second direction. 533 */ 534 private int mMarginSecondary; 535 /** 536 * How to position child in secondary direction. 537 */ 538 private int mGravity = Gravity.START | Gravity.TOP; 539 /** 540 * The number of rows in the grid. 541 */ 542 private int mNumRows; 543 /** 544 * Number of rows requested, can be 0 to be determined by parent size and 545 * rowHeight. 546 */ 547 private int mNumRowsRequested = 1; 548 549 /** 550 * Saves grid information of each view. 551 */ 552 Grid mGrid; 553 554 /** 555 * Focus Scroll strategy. 556 */ 557 private int mFocusScrollStrategy = BaseGridView.FOCUS_SCROLL_ALIGNED; 558 /** 559 * Defines how item view is aligned in the window. 560 */ 561 private final WindowAlignment mWindowAlignment = new WindowAlignment(); 562 563 /** 564 * Defines how item view is aligned. 565 */ 566 private final ItemAlignment mItemAlignment = new ItemAlignment(); 567 568 /** 569 * Dimensions of the view, width or height depending on orientation. 570 */ 571 private int mSizePrimary; 572 573 /** 574 * Pixels of extra space for layout item (outside the widget) 575 */ 576 private int mExtraLayoutSpace; 577 578 /** 579 * Allow DPAD key to navigate out at the front of the View (where position = 0), 580 * default is false. 581 */ 582 private boolean mFocusOutFront; 583 584 /** 585 * Allow DPAD key to navigate out at the end of the view, default is false. 586 */ 587 private boolean mFocusOutEnd; 588 589 /** 590 * True if focus search is disabled. 591 */ 592 private boolean mFocusSearchDisabled; 593 594 /** 595 * True if prune child, might be disabled during transition. 596 */ 597 private boolean mPruneChild = true; 598 599 /** 600 * True if scroll content, might be disabled during transition. 601 */ 602 private boolean mScrollEnabled = true; 603 604 /** 605 * Temporary variable: an int array of length=2. 606 */ 607 private static int[] sTwoInts = new int[2]; 608 609 /** 610 * Set to true for RTL layout in horizontal orientation 611 */ 612 private boolean mReverseFlowPrimary = false; 613 614 /** 615 * Set to true for RTL layout in vertical orientation 616 */ 617 private boolean mReverseFlowSecondary = false; 618 619 /** 620 * Temporaries used for measuring. 621 */ 622 private int[] mMeasuredDimension = new int[2]; 623 624 final ViewsStateBundle mChildrenStates = new ViewsStateBundle(); 625 626 /** 627 * Optional interface implemented by Adapter. 628 */ 629 private FacetProviderAdapter mFacetProviderAdapter; 630 631 public GridLayoutManager(BaseGridView baseGridView) { 632 mBaseGridView = baseGridView; 633 } 634 635 public void setOrientation(int orientation) { 636 if (orientation != HORIZONTAL && orientation != VERTICAL) { 637 if (DEBUG) Log.v(getTag(), "invalid orientation: " + orientation); 638 return; 639 } 640 641 mOrientation = orientation; 642 mWindowAlignment.setOrientation(orientation); 643 mItemAlignment.setOrientation(orientation); 644 mForceFullLayout = true; 645 } 646 647 public void onRtlPropertiesChanged(int layoutDirection) { 648 if (mOrientation == HORIZONTAL) { 649 mReverseFlowPrimary = layoutDirection == View.LAYOUT_DIRECTION_RTL; 650 mReverseFlowSecondary = false; 651 } else { 652 mReverseFlowSecondary = layoutDirection == View.LAYOUT_DIRECTION_RTL; 653 mReverseFlowPrimary = false; 654 } 655 mWindowAlignment.horizontal.setReversedFlow(layoutDirection == View.LAYOUT_DIRECTION_RTL); 656 } 657 658 public int getFocusScrollStrategy() { 659 return mFocusScrollStrategy; 660 } 661 662 public void setFocusScrollStrategy(int focusScrollStrategy) { 663 mFocusScrollStrategy = focusScrollStrategy; 664 } 665 666 public void setWindowAlignment(int windowAlignment) { 667 mWindowAlignment.mainAxis().setWindowAlignment(windowAlignment); 668 } 669 670 public int getWindowAlignment() { 671 return mWindowAlignment.mainAxis().getWindowAlignment(); 672 } 673 674 public void setWindowAlignmentOffset(int alignmentOffset) { 675 mWindowAlignment.mainAxis().setWindowAlignmentOffset(alignmentOffset); 676 } 677 678 public int getWindowAlignmentOffset() { 679 return mWindowAlignment.mainAxis().getWindowAlignmentOffset(); 680 } 681 682 public void setWindowAlignmentOffsetPercent(float offsetPercent) { 683 mWindowAlignment.mainAxis().setWindowAlignmentOffsetPercent(offsetPercent); 684 } 685 686 public float getWindowAlignmentOffsetPercent() { 687 return mWindowAlignment.mainAxis().getWindowAlignmentOffsetPercent(); 688 } 689 690 public void setItemAlignmentOffset(int alignmentOffset) { 691 mItemAlignment.mainAxis().setItemAlignmentOffset(alignmentOffset); 692 updateChildAlignments(); 693 } 694 695 public int getItemAlignmentOffset() { 696 return mItemAlignment.mainAxis().getItemAlignmentOffset(); 697 } 698 699 public void setItemAlignmentOffsetWithPadding(boolean withPadding) { 700 mItemAlignment.mainAxis().setItemAlignmentOffsetWithPadding(withPadding); 701 updateChildAlignments(); 702 } 703 704 public boolean isItemAlignmentOffsetWithPadding() { 705 return mItemAlignment.mainAxis().isItemAlignmentOffsetWithPadding(); 706 } 707 708 public void setItemAlignmentOffsetPercent(float offsetPercent) { 709 mItemAlignment.mainAxis().setItemAlignmentOffsetPercent(offsetPercent); 710 updateChildAlignments(); 711 } 712 713 public float getItemAlignmentOffsetPercent() { 714 return mItemAlignment.mainAxis().getItemAlignmentOffsetPercent(); 715 } 716 717 public void setItemAlignmentViewId(int viewId) { 718 mItemAlignment.mainAxis().setItemAlignmentViewId(viewId); 719 updateChildAlignments(); 720 } 721 722 public int getItemAlignmentViewId() { 723 return mItemAlignment.mainAxis().getItemAlignmentViewId(); 724 } 725 726 public void setFocusOutAllowed(boolean throughFront, boolean throughEnd) { 727 mFocusOutFront = throughFront; 728 mFocusOutEnd = throughEnd; 729 } 730 731 public void setNumRows(int numRows) { 732 if (numRows < 0) throw new IllegalArgumentException(); 733 mNumRowsRequested = numRows; 734 } 735 736 /** 737 * Set the row height. May be WRAP_CONTENT, or a size in pixels. 738 */ 739 public void setRowHeight(int height) { 740 if (height >= 0 || height == ViewGroup.LayoutParams.WRAP_CONTENT) { 741 mRowSizeSecondaryRequested = height; 742 } else { 743 throw new IllegalArgumentException("Invalid row height: " + height); 744 } 745 } 746 747 public void setItemMargin(int margin) { 748 mVerticalMargin = mHorizontalMargin = margin; 749 mMarginPrimary = mMarginSecondary = margin; 750 } 751 752 public void setVerticalMargin(int margin) { 753 if (mOrientation == HORIZONTAL) { 754 mMarginSecondary = mVerticalMargin = margin; 755 } else { 756 mMarginPrimary = mVerticalMargin = margin; 757 } 758 } 759 760 public void setHorizontalMargin(int margin) { 761 if (mOrientation == HORIZONTAL) { 762 mMarginPrimary = mHorizontalMargin = margin; 763 } else { 764 mMarginSecondary = mHorizontalMargin = margin; 765 } 766 } 767 768 public int getVerticalMargin() { 769 return mVerticalMargin; 770 } 771 772 public int getHorizontalMargin() { 773 return mHorizontalMargin; 774 } 775 776 public void setGravity(int gravity) { 777 mGravity = gravity; 778 } 779 780 protected boolean hasDoneFirstLayout() { 781 return mGrid != null; 782 } 783 784 public void setOnChildSelectedListener(OnChildSelectedListener listener) { 785 mChildSelectedListener = listener; 786 } 787 788 public void setOnChildViewHolderSelectedListener(OnChildViewHolderSelectedListener listener) { 789 mChildViewHolderSelectedListener = listener; 790 } 791 792 void setOnChildLaidOutListener(OnChildLaidOutListener listener) { 793 mChildLaidOutListener = listener; 794 } 795 796 private int getPositionByView(View view) { 797 if (view == null) { 798 return NO_POSITION; 799 } 800 LayoutParams params = (LayoutParams) view.getLayoutParams(); 801 if (params == null || params.isItemRemoved()) { 802 // when item is removed, the position value can be any value. 803 return NO_POSITION; 804 } 805 return params.getViewPosition(); 806 } 807 808 private int getSubPositionByView(View view, View childView) { 809 if (view == null || childView == null) { 810 return 0; 811 } 812 final LayoutParams lp = (LayoutParams) view.getLayoutParams(); 813 final ItemAlignmentFacet facet = lp.getItemAlignmentFacet(); 814 if (facet != null) { 815 final ItemAlignmentFacet.ItemAlignmentDef[] defs = facet.getAlignmentDefs(); 816 if (defs.length > 1) { 817 while (childView != view) { 818 int id = childView.getId(); 819 if (id != View.NO_ID) { 820 for (int i = 1; i < defs.length; i++) { 821 if (defs[i].getItemAlignmentFocusViewId() == id) { 822 return i; 823 } 824 } 825 } 826 childView = (View) childView.getParent(); 827 } 828 } 829 } 830 return 0; 831 } 832 833 private int getPositionByIndex(int index) { 834 return getPositionByView(getChildAt(index)); 835 } 836 837 private void dispatchChildSelected() { 838 if (mChildSelectedListener == null && mChildViewHolderSelectedListener == null) { 839 return; 840 } 841 842 if (TRACE) TraceHelper.beginSection("onChildSelected"); 843 View view = mFocusPosition == NO_POSITION ? null : findViewByPosition(mFocusPosition); 844 if (view != null) { 845 RecyclerView.ViewHolder vh = mBaseGridView.getChildViewHolder(view); 846 if (mChildSelectedListener != null) { 847 mChildSelectedListener.onChildSelected(mBaseGridView, view, mFocusPosition, 848 vh == null? NO_ID: vh.getItemId()); 849 } 850 if (mChildViewHolderSelectedListener != null) { 851 mChildViewHolderSelectedListener.onChildViewHolderSelected(mBaseGridView, vh, 852 mFocusPosition, mSubFocusPosition); 853 } 854 } else { 855 if (mChildSelectedListener != null) { 856 mChildSelectedListener.onChildSelected(mBaseGridView, null, NO_POSITION, NO_ID); 857 } 858 if (mChildViewHolderSelectedListener != null) { 859 mChildViewHolderSelectedListener.onChildViewHolderSelected(mBaseGridView, null, 860 NO_POSITION, 0); 861 } 862 } 863 if (TRACE) TraceHelper.endSection(); 864 865 // Children may request layout when a child selection event occurs (such as a change of 866 // padding on the current and previously selected rows). 867 // If in layout, a child requesting layout may have been laid out before the selection 868 // callback. 869 // If it was not, the child will be laid out after the selection callback. 870 // If so, the layout request will be honoured though the view system will emit a double- 871 // layout warning. 872 // If not in layout, we may be scrolling in which case the child layout request will be 873 // eaten by recyclerview. Post a requestLayout. 874 if (!mInLayout && !mBaseGridView.isLayoutRequested()) { 875 int childCount = getChildCount(); 876 for (int i = 0; i < childCount; i++) { 877 if (getChildAt(i).isLayoutRequested()) { 878 forceRequestLayout(); 879 break; 880 } 881 } 882 } 883 } 884 885 @Override 886 public boolean canScrollHorizontally() { 887 // We can scroll horizontally if we have horizontal orientation, or if 888 // we are vertical and have more than one column. 889 return mOrientation == HORIZONTAL || mNumRows > 1; 890 } 891 892 @Override 893 public boolean canScrollVertically() { 894 // We can scroll vertically if we have vertical orientation, or if we 895 // are horizontal and have more than one row. 896 return mOrientation == VERTICAL || mNumRows > 1; 897 } 898 899 @Override 900 public RecyclerView.LayoutParams generateDefaultLayoutParams() { 901 return new LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, 902 ViewGroup.LayoutParams.WRAP_CONTENT); 903 } 904 905 @Override 906 public RecyclerView.LayoutParams generateLayoutParams(Context context, AttributeSet attrs) { 907 return new LayoutParams(context, attrs); 908 } 909 910 @Override 911 public RecyclerView.LayoutParams generateLayoutParams(ViewGroup.LayoutParams lp) { 912 if (lp instanceof LayoutParams) { 913 return new LayoutParams((LayoutParams) lp); 914 } else if (lp instanceof RecyclerView.LayoutParams) { 915 return new LayoutParams((RecyclerView.LayoutParams) lp); 916 } else if (lp instanceof MarginLayoutParams) { 917 return new LayoutParams((MarginLayoutParams) lp); 918 } else { 919 return new LayoutParams(lp); 920 } 921 } 922 923 protected View getViewForPosition(int position) { 924 return mRecycler.getViewForPosition(position); 925 } 926 927 final int getOpticalLeft(View v) { 928 return ((LayoutParams) v.getLayoutParams()).getOpticalLeft(v); 929 } 930 931 final int getOpticalRight(View v) { 932 return ((LayoutParams) v.getLayoutParams()).getOpticalRight(v); 933 } 934 935 final int getOpticalTop(View v) { 936 return ((LayoutParams) v.getLayoutParams()).getOpticalTop(v); 937 } 938 939 final int getOpticalBottom(View v) { 940 return ((LayoutParams) v.getLayoutParams()).getOpticalBottom(v); 941 } 942 943 private int getViewMin(View v) { 944 LayoutParams lp = (LayoutParams) v.getLayoutParams(); 945 return (mOrientation == HORIZONTAL) ? lp.getDecoratedOpticalLeftWithMargin(this, v) 946 : lp.getDecoratedOpticalTopWithMargin(this, v); 947 } 948 949 private int getViewMax(View v) { 950 LayoutParams lp = (LayoutParams) v.getLayoutParams(); 951 return (mOrientation == HORIZONTAL) ? lp.getDecoratedOpticalRightWithMargin(this, v) 952 : lp.getDecoratedOpticalBottomWithMargin(this, v); 953 } 954 955 private int getViewPrimarySize(View view) { 956 LayoutParams p = (LayoutParams) view.getLayoutParams(); 957 return mOrientation == HORIZONTAL ? p.getDecoratedOpticalWidthWithMargin(this, view) 958 : p.getDecoratedOpticalHeightWithMargin(this, view); 959 } 960 961 private int getViewCenter(View view) { 962 return (mOrientation == HORIZONTAL) ? getViewCenterX(view) : getViewCenterY(view); 963 } 964 965 private int getViewCenterSecondary(View view) { 966 return (mOrientation == HORIZONTAL) ? getViewCenterY(view) : getViewCenterX(view); 967 } 968 969 private int getViewCenterX(View v) { 970 LayoutParams p = (LayoutParams) v.getLayoutParams(); 971 return p.getOpticalLeft(v) + p.getAlignX(); 972 } 973 974 private int getViewCenterY(View v) { 975 LayoutParams p = (LayoutParams) v.getLayoutParams(); 976 return p.getOpticalTop(v) + p.getAlignY(); 977 } 978 979 /** 980 * Save Recycler and State for convenience. Must be paired with leaveContext(). 981 */ 982 private void saveContext(Recycler recycler, State state) { 983 if (mRecycler != null || mState != null) { 984 Log.e(TAG, "Recycler information was not released, bug!"); 985 } 986 mRecycler = recycler; 987 mState = state; 988 } 989 990 /** 991 * Discard saved Recycler and State. 992 */ 993 private void leaveContext() { 994 mRecycler = null; 995 mState = null; 996 } 997 998 /** 999 * Re-initialize data structures for a data change or handling invisible 1000 * selection. The method tries its best to preserve position information so 1001 * that staggered grid looks same before and after re-initialize. 1002 * @return true if can fastRelayout() 1003 */ 1004 private boolean layoutInit() { 1005 boolean focusViewWasInTree = mGrid != null && mFocusPosition >= 0 1006 && mFocusPosition >= mGrid.getFirstVisibleIndex() 1007 && mFocusPosition <= mGrid.getLastVisibleIndex(); 1008 final int newItemCount = mState.getItemCount(); 1009 if (newItemCount == 0) { 1010 mFocusPosition = NO_POSITION; 1011 mSubFocusPosition = 0; 1012 } else if (mFocusPosition >= newItemCount) { 1013 mFocusPosition = newItemCount - 1; 1014 mSubFocusPosition = 0; 1015 } else if (mFocusPosition == NO_POSITION && newItemCount > 0) { 1016 // if focus position is never set before, initialize it to 0 1017 mFocusPosition = 0; 1018 mSubFocusPosition = 0; 1019 } 1020 if (!mState.didStructureChange() && mGrid.getFirstVisibleIndex() >= 0 && 1021 !mForceFullLayout && mGrid != null && mGrid.getNumRows() == mNumRows) { 1022 updateScrollController(); 1023 updateScrollSecondAxis(); 1024 mGrid.setMargin(mMarginPrimary); 1025 if (!focusViewWasInTree && mFocusPosition != NO_POSITION) { 1026 mGrid.setStart(mFocusPosition); 1027 } 1028 return true; 1029 } else { 1030 mForceFullLayout = false; 1031 int firstVisibleIndex = focusViewWasInTree ? mGrid.getFirstVisibleIndex() : 0; 1032 1033 if (mGrid == null || mNumRows != mGrid.getNumRows() || 1034 mReverseFlowPrimary != mGrid.isReversedFlow()) { 1035 mGrid = Grid.createGrid(mNumRows); 1036 mGrid.setProvider(mGridProvider); 1037 mGrid.setReversedFlow(mReverseFlowPrimary); 1038 } 1039 initScrollController(); 1040 updateScrollSecondAxis(); 1041 mGrid.setMargin(mMarginPrimary); 1042 detachAndScrapAttachedViews(mRecycler); 1043 mGrid.resetVisibleIndex(); 1044 if (mFocusPosition == NO_POSITION) { 1045 mBaseGridView.clearFocus(); 1046 } 1047 mWindowAlignment.mainAxis().invalidateScrollMin(); 1048 mWindowAlignment.mainAxis().invalidateScrollMax(); 1049 if (focusViewWasInTree && firstVisibleIndex <= mFocusPosition) { 1050 // if focusView was in tree, we will add item from first visible item 1051 mGrid.setStart(firstVisibleIndex); 1052 } else { 1053 // if focusView was not in tree, it's probably because focus position jumped 1054 // far away from visible range, so use mFocusPosition as start 1055 mGrid.setStart(mFocusPosition); 1056 } 1057 return false; 1058 } 1059 } 1060 1061 private int getRowSizeSecondary(int rowIndex) { 1062 if (mFixedRowSizeSecondary != 0) { 1063 return mFixedRowSizeSecondary; 1064 } 1065 if (mRowSizeSecondary == null) { 1066 return 0; 1067 } 1068 return mRowSizeSecondary[rowIndex]; 1069 } 1070 1071 private int getRowStartSecondary(int rowIndex) { 1072 int start = 0; 1073 // Iterate from left to right, which is a different index traversal 1074 // in RTL flow 1075 if (mReverseFlowSecondary) { 1076 for (int i = mNumRows-1; i > rowIndex; i--) { 1077 start += getRowSizeSecondary(i) + mMarginSecondary; 1078 } 1079 } else { 1080 for (int i = 0; i < rowIndex; i++) { 1081 start += getRowSizeSecondary(i) + mMarginSecondary; 1082 } 1083 } 1084 return start; 1085 } 1086 1087 private int getSizeSecondary() { 1088 int rightmostIndex = mReverseFlowSecondary ? 0 : mNumRows - 1; 1089 return getRowStartSecondary(rightmostIndex) + getRowSizeSecondary(rightmostIndex); 1090 } 1091 1092 int getDecoratedMeasuredWidthWithMargin(View v) { 1093 final LayoutParams lp = (LayoutParams) v.getLayoutParams(); 1094 return getDecoratedMeasuredWidth(v) + lp.leftMargin + lp.rightMargin; 1095 } 1096 1097 int getDecoratedMeasuredHeightWithMargin(View v) { 1098 final LayoutParams lp = (LayoutParams) v.getLayoutParams(); 1099 return getDecoratedMeasuredHeight(v) + lp.topMargin + lp.bottomMargin; 1100 } 1101 1102 private void measureScrapChild(int position, int widthSpec, int heightSpec, 1103 int[] measuredDimension) { 1104 View view = mRecycler.getViewForPosition(position); 1105 if (view != null) { 1106 final LayoutParams p = (LayoutParams) view.getLayoutParams(); 1107 calculateItemDecorationsForChild(view, sTempRect); 1108 int widthUsed = p.leftMargin + p.rightMargin + sTempRect.left + sTempRect.right; 1109 int heightUsed = p.topMargin + p.bottomMargin + sTempRect.top + sTempRect.bottom; 1110 1111 int childWidthSpec = ViewGroup.getChildMeasureSpec(widthSpec, 1112 getPaddingLeft() + getPaddingRight() + widthUsed, p.width); 1113 int childHeightSpec = ViewGroup.getChildMeasureSpec(heightSpec, 1114 getPaddingTop() + getPaddingBottom() + heightUsed, p.height); 1115 view.measure(childWidthSpec, childHeightSpec); 1116 1117 measuredDimension[0] = getDecoratedMeasuredWidthWithMargin(view); 1118 measuredDimension[1] = getDecoratedMeasuredHeightWithMargin(view); 1119 mRecycler.recycleView(view); 1120 } 1121 } 1122 1123 private boolean processRowSizeSecondary(boolean measure) { 1124 if (mFixedRowSizeSecondary != 0 || mRowSizeSecondary == null) { 1125 return false; 1126 } 1127 1128 if (TRACE) TraceHelper.beginSection("processRowSizeSecondary"); 1129 CircularIntArray[] rows = mGrid == null ? null : mGrid.getItemPositionsInRows(); 1130 boolean changed = false; 1131 int scrapChildWidth = -1; 1132 int scrapChildHeight = -1; 1133 1134 for (int rowIndex = 0; rowIndex < mNumRows; rowIndex++) { 1135 CircularIntArray row = rows == null ? null : rows[rowIndex]; 1136 final int rowItemsPairCount = row == null ? 0 : row.size(); 1137 int rowSize = -1; 1138 for (int rowItemPairIndex = 0; rowItemPairIndex < rowItemsPairCount; 1139 rowItemPairIndex += 2) { 1140 final int rowIndexStart = row.get(rowItemPairIndex); 1141 final int rowIndexEnd = row.get(rowItemPairIndex + 1); 1142 for (int i = rowIndexStart; i <= rowIndexEnd; i++) { 1143 final View view = findViewByPosition(i); 1144 if (view == null) { 1145 continue; 1146 } 1147 if (measure && view.isLayoutRequested()) { 1148 measureChild(view); 1149 } 1150 final int secondarySize = mOrientation == HORIZONTAL ? 1151 getDecoratedMeasuredHeightWithMargin(view) 1152 : getDecoratedMeasuredWidthWithMargin(view); 1153 if (secondarySize > rowSize) { 1154 rowSize = secondarySize; 1155 } 1156 } 1157 } 1158 1159 final int itemCount = mState.getItemCount(); 1160 if (measure && rowSize < 0 && itemCount > 0) { 1161 if (scrapChildWidth < 0 && scrapChildHeight < 0) { 1162 int position; 1163 if (mFocusPosition == NO_POSITION) { 1164 position = 0; 1165 } else if (mFocusPosition >= itemCount) { 1166 position = itemCount - 1; 1167 } else { 1168 position = mFocusPosition; 1169 } 1170 measureScrapChild(position, 1171 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 1172 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 1173 mMeasuredDimension); 1174 scrapChildWidth = mMeasuredDimension[0]; 1175 scrapChildHeight = mMeasuredDimension[1]; 1176 if (DEBUG) Log.v(TAG, "measured scrap child: " + scrapChildWidth + 1177 " " + scrapChildHeight); 1178 } 1179 rowSize = mOrientation == HORIZONTAL ? scrapChildHeight : scrapChildWidth; 1180 } 1181 if (rowSize < 0) { 1182 rowSize = 0; 1183 } 1184 if (mRowSizeSecondary[rowIndex] != rowSize) { 1185 if (DEBUG) Log.v(getTag(), "row size secondary changed: " + mRowSizeSecondary[rowIndex] + 1186 ", " + rowSize); 1187 mRowSizeSecondary[rowIndex] = rowSize; 1188 changed = true; 1189 } 1190 } 1191 1192 if (TRACE) TraceHelper.endSection(); 1193 return changed; 1194 } 1195 1196 /** 1197 * Checks if we need to update row secondary sizes. 1198 */ 1199 private void updateRowSecondarySizeRefresh() { 1200 mRowSecondarySizeRefresh = processRowSizeSecondary(false); 1201 if (mRowSecondarySizeRefresh) { 1202 if (DEBUG) Log.v(getTag(), "mRowSecondarySizeRefresh now set"); 1203 forceRequestLayout(); 1204 } 1205 } 1206 1207 private void forceRequestLayout() { 1208 if (DEBUG) Log.v(getTag(), "forceRequestLayout"); 1209 // RecyclerView prevents us from requesting layout in many cases 1210 // (during layout, during scroll, etc.) 1211 // For secondary row size wrap_content support we currently need a 1212 // second layout pass to update the measured size after having measured 1213 // and added child views in layoutChildren. 1214 // Force the second layout by posting a delayed runnable. 1215 // TODO: investigate allowing a second layout pass, 1216 // or move child add/measure logic to the measure phase. 1217 ViewCompat.postOnAnimation(mBaseGridView, mRequestLayoutRunnable); 1218 } 1219 1220 private final Runnable mRequestLayoutRunnable = new Runnable() { 1221 @Override 1222 public void run() { 1223 if (DEBUG) Log.v(getTag(), "request Layout from runnable"); 1224 requestLayout(); 1225 } 1226 }; 1227 1228 @Override 1229 public void onMeasure(Recycler recycler, State state, int widthSpec, int heightSpec) { 1230 saveContext(recycler, state); 1231 1232 int sizePrimary, sizeSecondary, modeSecondary, paddingSecondary; 1233 int measuredSizeSecondary; 1234 if (mOrientation == HORIZONTAL) { 1235 sizePrimary = MeasureSpec.getSize(widthSpec); 1236 sizeSecondary = MeasureSpec.getSize(heightSpec); 1237 modeSecondary = MeasureSpec.getMode(heightSpec); 1238 paddingSecondary = getPaddingTop() + getPaddingBottom(); 1239 } else { 1240 sizeSecondary = MeasureSpec.getSize(widthSpec); 1241 sizePrimary = MeasureSpec.getSize(heightSpec); 1242 modeSecondary = MeasureSpec.getMode(widthSpec); 1243 paddingSecondary = getPaddingLeft() + getPaddingRight(); 1244 } 1245 if (DEBUG) Log.v(getTag(), "onMeasure widthSpec " + Integer.toHexString(widthSpec) + 1246 " heightSpec " + Integer.toHexString(heightSpec) + 1247 " modeSecondary " + Integer.toHexString(modeSecondary) + 1248 " sizeSecondary " + sizeSecondary + " " + this); 1249 1250 mMaxSizeSecondary = sizeSecondary; 1251 1252 if (mRowSizeSecondaryRequested == ViewGroup.LayoutParams.WRAP_CONTENT) { 1253 mNumRows = mNumRowsRequested == 0 ? 1 : mNumRowsRequested; 1254 mFixedRowSizeSecondary = 0; 1255 1256 if (mRowSizeSecondary == null || mRowSizeSecondary.length != mNumRows) { 1257 mRowSizeSecondary = new int[mNumRows]; 1258 } 1259 1260 // Measure all current children and update cached row heights 1261 processRowSizeSecondary(true); 1262 1263 switch (modeSecondary) { 1264 case MeasureSpec.UNSPECIFIED: 1265 measuredSizeSecondary = getSizeSecondary() + paddingSecondary; 1266 break; 1267 case MeasureSpec.AT_MOST: 1268 measuredSizeSecondary = Math.min(getSizeSecondary() + paddingSecondary, 1269 mMaxSizeSecondary); 1270 break; 1271 case MeasureSpec.EXACTLY: 1272 measuredSizeSecondary = mMaxSizeSecondary; 1273 break; 1274 default: 1275 throw new IllegalStateException("wrong spec"); 1276 } 1277 1278 } else { 1279 switch (modeSecondary) { 1280 case MeasureSpec.UNSPECIFIED: 1281 if (mRowSizeSecondaryRequested == 0) { 1282 if (mOrientation == HORIZONTAL) { 1283 throw new IllegalStateException("Must specify rowHeight or view height"); 1284 } else { 1285 throw new IllegalStateException("Must specify columnWidth or view width"); 1286 } 1287 } 1288 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 1289 mNumRows = mNumRowsRequested == 0 ? 1 : mNumRowsRequested; 1290 measuredSizeSecondary = mFixedRowSizeSecondary * mNumRows + mMarginSecondary 1291 * (mNumRows - 1) + paddingSecondary; 1292 break; 1293 case MeasureSpec.AT_MOST: 1294 case MeasureSpec.EXACTLY: 1295 if (mNumRowsRequested == 0 && mRowSizeSecondaryRequested == 0) { 1296 mNumRows = 1; 1297 mFixedRowSizeSecondary = sizeSecondary - paddingSecondary; 1298 } else if (mNumRowsRequested == 0) { 1299 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 1300 mNumRows = (sizeSecondary + mMarginSecondary) 1301 / (mRowSizeSecondaryRequested + mMarginSecondary); 1302 } else if (mRowSizeSecondaryRequested == 0) { 1303 mNumRows = mNumRowsRequested; 1304 mFixedRowSizeSecondary = (sizeSecondary - paddingSecondary - mMarginSecondary 1305 * (mNumRows - 1)) / mNumRows; 1306 } else { 1307 mNumRows = mNumRowsRequested; 1308 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 1309 } 1310 measuredSizeSecondary = sizeSecondary; 1311 if (modeSecondary == MeasureSpec.AT_MOST) { 1312 int childrenSize = mFixedRowSizeSecondary * mNumRows + mMarginSecondary 1313 * (mNumRows - 1) + paddingSecondary; 1314 if (childrenSize < measuredSizeSecondary) { 1315 measuredSizeSecondary = childrenSize; 1316 } 1317 } 1318 break; 1319 default: 1320 throw new IllegalStateException("wrong spec"); 1321 } 1322 } 1323 if (mOrientation == HORIZONTAL) { 1324 setMeasuredDimension(sizePrimary, measuredSizeSecondary); 1325 } else { 1326 setMeasuredDimension(measuredSizeSecondary, sizePrimary); 1327 } 1328 if (DEBUG) { 1329 Log.v(getTag(), "onMeasure sizePrimary " + sizePrimary + 1330 " measuredSizeSecondary " + measuredSizeSecondary + 1331 " mFixedRowSizeSecondary " + mFixedRowSizeSecondary + 1332 " mNumRows " + mNumRows); 1333 } 1334 leaveContext(); 1335 } 1336 1337 private void measureChild(View child) { 1338 if (TRACE) TraceHelper.beginSection("measureChild"); 1339 final LayoutParams lp = (LayoutParams) child.getLayoutParams(); 1340 calculateItemDecorationsForChild(child, sTempRect); 1341 int widthUsed = lp.leftMargin + lp.rightMargin + sTempRect.left + sTempRect.right; 1342 int heightUsed = lp.topMargin + lp.bottomMargin + sTempRect.top + sTempRect.bottom; 1343 1344 final int secondarySpec = (mRowSizeSecondaryRequested == ViewGroup.LayoutParams.WRAP_CONTENT) ? 1345 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED) : 1346 MeasureSpec.makeMeasureSpec(mFixedRowSizeSecondary, MeasureSpec.EXACTLY); 1347 int widthSpec, heightSpec; 1348 1349 if (mOrientation == HORIZONTAL) { 1350 widthSpec = ViewGroup.getChildMeasureSpec( 1351 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), widthUsed, lp.width); 1352 heightSpec = ViewGroup.getChildMeasureSpec(secondarySpec, heightUsed, lp.height); 1353 } else { 1354 heightSpec = ViewGroup.getChildMeasureSpec( 1355 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), heightUsed, lp.height); 1356 widthSpec = ViewGroup.getChildMeasureSpec(secondarySpec, widthUsed, lp.width); 1357 } 1358 child.measure(widthSpec, heightSpec); 1359 if (DEBUG) Log.v(getTag(), "measureChild secondarySpec " + Integer.toHexString(secondarySpec) + 1360 " widthSpec " + Integer.toHexString(widthSpec) + 1361 " heightSpec " + Integer.toHexString(heightSpec) + 1362 " measuredWidth " + child.getMeasuredWidth() + 1363 " measuredHeight " + child.getMeasuredHeight()); 1364 if (DEBUG) Log.v(getTag(), "child lp width " + lp.width + " height " + lp.height); 1365 if (TRACE) TraceHelper.endSection(); 1366 } 1367 1368 /** 1369 * Get facet from the ViewHolder or the viewType. 1370 */ 1371 private <E> E getFacet(RecyclerView.ViewHolder vh, Class<? extends E> facetClass) { 1372 E facet = null; 1373 if (vh instanceof FacetProvider) { 1374 facet = (E) ((FacetProvider) vh).getFacet(facetClass); 1375 } 1376 if (facet == null && mFacetProviderAdapter != null) { 1377 FacetProvider p = mFacetProviderAdapter.getFacetProvider(vh.getItemViewType()); 1378 if (p != null) { 1379 facet = (E) p.getFacet(facetClass); 1380 } 1381 } 1382 return facet; 1383 } 1384 1385 private Grid.Provider mGridProvider = new Grid.Provider() { 1386 1387 @Override 1388 public int getCount() { 1389 return mState.getItemCount(); 1390 } 1391 1392 @Override 1393 public int createItem(int index, boolean append, Object[] item) { 1394 if (TRACE) TraceHelper.beginSection("createItem"); 1395 if (TRACE) TraceHelper.beginSection("getview"); 1396 View v = getViewForPosition(index); 1397 if (TRACE) TraceHelper.endSection(); 1398 LayoutParams lp = (LayoutParams) v.getLayoutParams(); 1399 RecyclerView.ViewHolder vh = mBaseGridView.getChildViewHolder(v); 1400 lp.setItemAlignmentFacet((ItemAlignmentFacet)getFacet(vh, ItemAlignmentFacet.class)); 1401 // See recyclerView docs: we don't need re-add scraped view if it was removed. 1402 if (!lp.isItemRemoved()) { 1403 if (TRACE) TraceHelper.beginSection("addView"); 1404 if (append) { 1405 addView(v); 1406 } else { 1407 addView(v, 0); 1408 } 1409 if (TRACE) TraceHelper.endSection(); 1410 if (mChildVisibility != -1) { 1411 v.setVisibility(mChildVisibility); 1412 } 1413 1414 if (mPendingMoveSmoothScroller != null) { 1415 mPendingMoveSmoothScroller.consumePendingMovesBeforeLayout(); 1416 } 1417 int subindex = getSubPositionByView(v, v.findFocus()); 1418 if (!mInLayout) { 1419 // when we are appending item during scroll pass and the item's position 1420 // matches the mFocusPosition, we should signal a childSelected event. 1421 // However if we are still running PendingMoveSmoothScroller, we defer and 1422 // signal the event in PendingMoveSmoothScroller.onStop(). This can 1423 // avoid lots of childSelected events during a long smooth scrolling and 1424 // increase performance. 1425 if (index == mFocusPosition && subindex == mSubFocusPosition 1426 && mPendingMoveSmoothScroller == null) { 1427 dispatchChildSelected(); 1428 } 1429 } else if (!mInFastRelayout) { 1430 // fastRelayout will dispatch event at end of onLayoutChildren(). 1431 // For full layout, two situations here: 1432 // 1. mInLayoutSearchFocus is false, dispatchChildSelected() at mFocusPosition. 1433 // 2. mInLayoutSearchFocus is true: dispatchChildSelected() on first child 1434 // equal to or after mFocusPosition that can take focus. 1435 if (!mInLayoutSearchFocus && index == mFocusPosition 1436 && subindex == mSubFocusPosition) { 1437 dispatchChildSelected(); 1438 } else if (mInLayoutSearchFocus && index >= mFocusPosition 1439 && v.hasFocusable()) { 1440 mFocusPosition = index; 1441 mSubFocusPosition = subindex; 1442 mInLayoutSearchFocus = false; 1443 dispatchChildSelected(); 1444 } 1445 } 1446 measureChild(v); 1447 } 1448 item[0] = v; 1449 return mOrientation == HORIZONTAL ? getDecoratedMeasuredWidthWithMargin(v) 1450 : getDecoratedMeasuredHeightWithMargin(v); 1451 } 1452 1453 @Override 1454 public void addItem(Object item, int index, int length, int rowIndex, int edge) { 1455 View v = (View) item; 1456 int start, end; 1457 if (edge == Integer.MIN_VALUE || edge == Integer.MAX_VALUE) { 1458 edge = !mGrid.isReversedFlow() ? mWindowAlignment.mainAxis().getPaddingLow() 1459 : mWindowAlignment.mainAxis().getSize() 1460 - mWindowAlignment.mainAxis().getPaddingHigh(); 1461 } 1462 boolean edgeIsMin = !mGrid.isReversedFlow(); 1463 if (edgeIsMin) { 1464 start = edge; 1465 end = edge + length; 1466 } else { 1467 start = edge - length; 1468 end = edge; 1469 } 1470 int startSecondary = getRowStartSecondary(rowIndex) - mScrollOffsetSecondary; 1471 mChildrenStates.loadView(v, index); 1472 layoutChild(rowIndex, v, start, end, startSecondary); 1473 if (DEBUG) { 1474 Log.d(getTag(), "addView " + index + " " + v); 1475 } 1476 if (TRACE) TraceHelper.endSection(); 1477 1478 if (index == mGrid.getFirstVisibleIndex()) { 1479 if (!mGrid.isReversedFlow()) { 1480 updateScrollMin(); 1481 } else { 1482 updateScrollMax(); 1483 } 1484 } 1485 if (index == mGrid.getLastVisibleIndex()) { 1486 if (!mGrid.isReversedFlow()) { 1487 updateScrollMax(); 1488 } else { 1489 updateScrollMin(); 1490 } 1491 } 1492 if (!mInLayout && mPendingMoveSmoothScroller != null) { 1493 mPendingMoveSmoothScroller.consumePendingMovesAfterLayout(); 1494 } 1495 if (mChildLaidOutListener != null) { 1496 RecyclerView.ViewHolder vh = mBaseGridView.getChildViewHolder(v); 1497 mChildLaidOutListener.onChildLaidOut(mBaseGridView, v, index, 1498 vh == null ? NO_ID : vh.getItemId()); 1499 } 1500 } 1501 1502 @Override 1503 public void removeItem(int index) { 1504 if (TRACE) TraceHelper.beginSection("removeItem"); 1505 View v = findViewByPosition(index); 1506 if (mInLayout) { 1507 detachAndScrapView(v, mRecycler); 1508 } else { 1509 removeAndRecycleView(v, mRecycler); 1510 } 1511 if (TRACE) TraceHelper.endSection(); 1512 } 1513 1514 @Override 1515 public int getEdge(int index) { 1516 if (mReverseFlowPrimary) { 1517 return getViewMax(findViewByPosition(index)); 1518 } else { 1519 return getViewMin(findViewByPosition(index)); 1520 } 1521 } 1522 1523 @Override 1524 public int getSize(int index) { 1525 return getViewPrimarySize(findViewByPosition(index)); 1526 } 1527 }; 1528 1529 private void layoutChild(int rowIndex, View v, int start, int end, int startSecondary) { 1530 if (TRACE) TraceHelper.beginSection("layoutChild"); 1531 int sizeSecondary = mOrientation == HORIZONTAL ? getDecoratedMeasuredHeightWithMargin(v) 1532 : getDecoratedMeasuredWidthWithMargin(v); 1533 if (mFixedRowSizeSecondary > 0) { 1534 sizeSecondary = Math.min(sizeSecondary, mFixedRowSizeSecondary); 1535 } 1536 final int verticalGravity = mGravity & Gravity.VERTICAL_GRAVITY_MASK; 1537 final int horizontalGravity = (mReverseFlowPrimary || mReverseFlowSecondary) ? 1538 Gravity.getAbsoluteGravity(mGravity & Gravity.RELATIVE_HORIZONTAL_GRAVITY_MASK, View.LAYOUT_DIRECTION_RTL) : 1539 mGravity & Gravity.HORIZONTAL_GRAVITY_MASK; 1540 if (mOrientation == HORIZONTAL && verticalGravity == Gravity.TOP 1541 || mOrientation == VERTICAL && horizontalGravity == Gravity.LEFT) { 1542 // do nothing 1543 } else if (mOrientation == HORIZONTAL && verticalGravity == Gravity.BOTTOM 1544 || mOrientation == VERTICAL && horizontalGravity == Gravity.RIGHT) { 1545 startSecondary += getRowSizeSecondary(rowIndex) - sizeSecondary; 1546 } else if (mOrientation == HORIZONTAL && verticalGravity == Gravity.CENTER_VERTICAL 1547 || mOrientation == VERTICAL && horizontalGravity == Gravity.CENTER_HORIZONTAL) { 1548 startSecondary += (getRowSizeSecondary(rowIndex) - sizeSecondary) / 2; 1549 } 1550 int left, top, right, bottom; 1551 if (mOrientation == HORIZONTAL) { 1552 left = start; 1553 top = startSecondary; 1554 right = end; 1555 bottom = startSecondary + sizeSecondary; 1556 } else { 1557 top = start; 1558 left = startSecondary; 1559 bottom = end; 1560 right = startSecondary + sizeSecondary; 1561 } 1562 LayoutParams params = (LayoutParams) v.getLayoutParams(); 1563 layoutDecorated(v, left + params.leftMargin, top + params.topMargin, 1564 right - params.rightMargin, bottom - params.bottomMargin); 1565 updateChildOpticalInsets(v, left, top, right, bottom); 1566 updateChildAlignments(v); 1567 if (TRACE) TraceHelper.endSection(); 1568 } 1569 1570 private void updateChildOpticalInsets(View v, int left, int top, int right, int bottom) { 1571 LayoutParams p = (LayoutParams) v.getLayoutParams(); 1572 p.setOpticalInsets(left - v.getLeft(), top - v.getTop(), 1573 v.getRight() - right, v.getBottom() - bottom); 1574 } 1575 1576 private void updateChildAlignments(View v) { 1577 final LayoutParams p = (LayoutParams) v.getLayoutParams(); 1578 if (p.getItemAlignmentFacet() == null) { 1579 // Fallback to global settings on grid view 1580 p.setAlignX(mItemAlignment.horizontal.getAlignmentPosition(v)); 1581 p.setAlignY(mItemAlignment.vertical.getAlignmentPosition(v)); 1582 } else { 1583 // Use ItemAlignmentFacet defined on specific ViewHolder 1584 p.calculateItemAlignments(mOrientation, v); 1585 if (mOrientation == HORIZONTAL) { 1586 p.setAlignY(mItemAlignment.vertical.getAlignmentPosition(v)); 1587 } else { 1588 p.setAlignX(mItemAlignment.horizontal.getAlignmentPosition(v)); 1589 } 1590 } 1591 } 1592 1593 private void updateChildAlignments() { 1594 for (int i = 0, c = getChildCount(); i < c; i++) { 1595 updateChildAlignments(getChildAt(i)); 1596 } 1597 } 1598 1599 void setExtraLayoutSpace(int extraLayoutSpace) { 1600 if (mExtraLayoutSpace == extraLayoutSpace) { 1601 return; 1602 } else if (mExtraLayoutSpace < 0) { 1603 throw new IllegalArgumentException("ExtraLayoutSpace must >= 0"); 1604 } 1605 mExtraLayoutSpace = extraLayoutSpace; 1606 requestLayout(); 1607 } 1608 1609 int getExtraLayoutSpace() { 1610 return mExtraLayoutSpace; 1611 } 1612 1613 private void removeInvisibleViewsAtEnd() { 1614 if (mPruneChild) { 1615 mGrid.removeInvisibleItemsAtEnd(mFocusPosition, 1616 mReverseFlowPrimary ? -mExtraLayoutSpace : mSizePrimary + mExtraLayoutSpace); 1617 } 1618 } 1619 1620 private void removeInvisibleViewsAtFront() { 1621 if (mPruneChild) { 1622 mGrid.removeInvisibleItemsAtFront(mFocusPosition, 1623 mReverseFlowPrimary ? mSizePrimary + mExtraLayoutSpace: -mExtraLayoutSpace); 1624 } 1625 } 1626 1627 private boolean appendOneColumnVisibleItems() { 1628 return mGrid.appendOneColumnVisibleItems(); 1629 } 1630 1631 private boolean prependOneColumnVisibleItems() { 1632 return mGrid.prependOneColumnVisibleItems(); 1633 } 1634 1635 private void appendVisibleItems() { 1636 mGrid.appendVisibleItems(mReverseFlowPrimary ? -mExtraLayoutSpace 1637 : mSizePrimary + mExtraLayoutSpace); 1638 } 1639 1640 private void prependVisibleItems() { 1641 mGrid.prependVisibleItems(mReverseFlowPrimary ? mSizePrimary + mExtraLayoutSpace 1642 : -mExtraLayoutSpace); 1643 } 1644 1645 /** 1646 * Fast layout when there is no structure change, adapter change, etc. 1647 * It will layout all views was layout requested or updated, until hit a view 1648 * with different size, then it break and detachAndScrap all views after that. 1649 */ 1650 private void fastRelayout() { 1651 boolean invalidateAfter = false; 1652 final int childCount = getChildCount(); 1653 int position = -1; 1654 for (int index = 0; index < childCount; index++) { 1655 View view = getChildAt(index); 1656 position = getPositionByIndex(index); 1657 Grid.Location location = mGrid.getLocation(position); 1658 if (location == null) { 1659 if (DEBUG) Log.w(getTag(), "fastRelayout(): no Location at " + position); 1660 invalidateAfter = true; 1661 break; 1662 } 1663 1664 int startSecondary = getRowStartSecondary(location.row) - mScrollOffsetSecondary; 1665 int primarySize, end; 1666 int start = getViewMin(view); 1667 int oldPrimarySize = getViewPrimarySize(view); 1668 1669 LayoutParams lp = (LayoutParams) view.getLayoutParams(); 1670 if (lp.viewNeedsUpdate()) { 1671 int viewIndex = mBaseGridView.indexOfChild(view); 1672 detachAndScrapView(view, mRecycler); 1673 view = getViewForPosition(position); 1674 addView(view, viewIndex); 1675 } 1676 1677 if (view.isLayoutRequested()) { 1678 measureChild(view); 1679 } 1680 if (mOrientation == HORIZONTAL) { 1681 primarySize = getDecoratedMeasuredWidthWithMargin(view); 1682 end = start + primarySize; 1683 } else { 1684 primarySize = getDecoratedMeasuredHeightWithMargin(view); 1685 end = start + primarySize; 1686 } 1687 layoutChild(location.row, view, start, end, startSecondary); 1688 if (oldPrimarySize != primarySize) { 1689 // size changed invalidate remaining Locations 1690 if (DEBUG) Log.d(getTag(), "fastRelayout: view size changed at " + position); 1691 invalidateAfter = true; 1692 break; 1693 } 1694 } 1695 if (invalidateAfter) { 1696 final int savedLastPos = mGrid.getLastVisibleIndex(); 1697 mGrid.invalidateItemsAfter(position); 1698 if (mPruneChild) { 1699 // in regular prune child mode, we just append items up to edge limit 1700 appendVisibleItems(); 1701 if (mFocusPosition >= 0 && mFocusPosition <= savedLastPos) { 1702 // make sure add focus view back: the view might be outside edge limit 1703 // when there is delta in onLayoutChildren(). 1704 while (mGrid.getLastVisibleIndex() < mFocusPosition) { 1705 mGrid.appendOneColumnVisibleItems(); 1706 } 1707 } 1708 } else { 1709 // prune disabled(e.g. in RowsFragment transition): append all removed items 1710 while (mGrid.appendOneColumnVisibleItems() 1711 && mGrid.getLastVisibleIndex() < savedLastPos); 1712 } 1713 } 1714 updateScrollMin(); 1715 updateScrollMax(); 1716 updateScrollSecondAxis(); 1717 } 1718 1719 public void removeAndRecycleAllViews(RecyclerView.Recycler recycler) { 1720 if (TRACE) TraceHelper.beginSection("removeAndRecycleAllViews"); 1721 if (DEBUG) Log.v(TAG, "removeAndRecycleAllViews " + getChildCount()); 1722 for (int i = getChildCount() - 1; i >= 0; i--) { 1723 removeAndRecycleViewAt(i, recycler); 1724 } 1725 if (TRACE) TraceHelper.endSection(); 1726 } 1727 1728 // Lays out items based on the current scroll position 1729 @Override 1730 public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state) { 1731 if (DEBUG) { 1732 Log.v(getTag(), "layoutChildren start numRows " + mNumRows + " mScrollOffsetSecondary " 1733 + mScrollOffsetSecondary + " mScrollOffsetPrimary " + mScrollOffsetPrimary 1734 + " inPreLayout " + state.isPreLayout() 1735 + " didStructureChange " + state.didStructureChange() 1736 + " mForceFullLayout " + mForceFullLayout); 1737 Log.v(getTag(), "width " + getWidth() + " height " + getHeight()); 1738 } 1739 1740 if (mNumRows == 0) { 1741 // haven't done measure yet 1742 return; 1743 } 1744 final int itemCount = state.getItemCount(); 1745 if (itemCount < 0) { 1746 return; 1747 } 1748 1749 if (!mLayoutEnabled) { 1750 discardLayoutInfo(); 1751 removeAndRecycleAllViews(recycler); 1752 return; 1753 } 1754 mInLayout = true; 1755 1756 if (state.didStructureChange()) { 1757 // didStructureChange() == true means attached item has been removed/added. 1758 // scroll animation: we are unable to continue a scroll animation, 1759 // kill the scroll animation, and let ItemAnimation move the item to new position. 1760 // position smooth scroller: kill the animation and stop at final position. 1761 // pending smooth scroller: stop and scroll to current focus position. 1762 mBaseGridView.stopScroll(); 1763 } 1764 final boolean scrollToFocus = !isSmoothScrolling() 1765 && mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED; 1766 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE) { 1767 mFocusPosition = mFocusPosition + mFocusPositionOffset; 1768 mSubFocusPosition = 0; 1769 } 1770 mFocusPositionOffset = 0; 1771 saveContext(recycler, state); 1772 1773 // Track the old focus view so we can adjust our system scroll position 1774 // so that any scroll animations happening now will remain valid. 1775 // We must use same delta in Pre Layout (if prelayout exists) and second layout. 1776 // So we cache the deltas in PreLayout and use it in second layout. 1777 int delta = 0, deltaSecondary = 0; 1778 if (mFocusPosition != NO_POSITION && scrollToFocus 1779 && mBaseGridView.getScrollState() != RecyclerView.SCROLL_STATE_IDLE) { 1780 // FIXME: we should get the remaining scroll animation offset from RecyclerView 1781 View focusView = findViewByPosition(mFocusPosition); 1782 if (focusView != null) { 1783 if (getScrollPosition(focusView, focusView.findFocus(), sTwoInts)) { 1784 delta = sTwoInts[0]; 1785 deltaSecondary = sTwoInts[1]; 1786 } 1787 } 1788 } 1789 1790 boolean hadFocus = mBaseGridView.hasFocus(); 1791 int savedFocusPos = mFocusPosition; 1792 if (mInFastRelayout = layoutInit()) { 1793 fastRelayout(); 1794 // appends items till focus position. 1795 if (mFocusPosition != NO_POSITION) { 1796 View focusView = findViewByPosition(mFocusPosition); 1797 if (focusView != null) { 1798 if (scrollToFocus) { 1799 scrollToView(focusView, false); 1800 } 1801 if (hadFocus && !focusView.hasFocus()) { 1802 focusView.requestFocus(); 1803 } 1804 } 1805 } 1806 } else { 1807 mInLayoutSearchFocus = hadFocus; 1808 if (mFocusPosition != NO_POSITION) { 1809 // appends items till focus position. 1810 while (appendOneColumnVisibleItems() 1811 && findViewByPosition(mFocusPosition) == null) ; 1812 } 1813 // multiple rounds: scrollToView of first round may drag first/last child into 1814 // "visible window" and we update scrollMin/scrollMax then run second scrollToView 1815 int oldFirstVisible; 1816 int oldLastVisible; 1817 do { 1818 updateScrollMin(); 1819 updateScrollMax(); 1820 oldFirstVisible = mGrid.getFirstVisibleIndex(); 1821 oldLastVisible = mGrid.getLastVisibleIndex(); 1822 View focusView = findViewByPosition(mFocusPosition); 1823 // we need force to initialize the child view's position 1824 scrollToView(focusView, false); 1825 if (focusView != null && hadFocus && !focusView.hasFocus()) { 1826 focusView.requestFocus(); 1827 } 1828 appendVisibleItems(); 1829 prependVisibleItems(); 1830 removeInvisibleViewsAtFront(); 1831 removeInvisibleViewsAtEnd(); 1832 } while (mGrid.getFirstVisibleIndex() != oldFirstVisible || 1833 mGrid.getLastVisibleIndex() != oldLastVisible); 1834 } 1835 1836 if (scrollToFocus) { 1837 scrollDirectionPrimary(-delta); 1838 scrollDirectionSecondary(-deltaSecondary); 1839 } 1840 appendVisibleItems(); 1841 prependVisibleItems(); 1842 removeInvisibleViewsAtFront(); 1843 removeInvisibleViewsAtEnd(); 1844 1845 if (DEBUG) { 1846 StringWriter sw = new StringWriter(); 1847 PrintWriter pw = new PrintWriter(sw); 1848 mGrid.debugPrint(pw); 1849 Log.d(getTag(), sw.toString()); 1850 } 1851 1852 if (mRowSecondarySizeRefresh) { 1853 mRowSecondarySizeRefresh = false; 1854 } else { 1855 updateRowSecondarySizeRefresh(); 1856 } 1857 1858 // For fastRelayout, only dispatch event when focus position changes. 1859 if (mInFastRelayout && mFocusPosition != savedFocusPos) { 1860 dispatchChildSelected(); 1861 } else if (!mInFastRelayout && mInLayoutSearchFocus) { 1862 // For full layout we dispatchChildSelected() in createItem() unless searched all 1863 // children and found none is focusable then dispatchChildSelected() here. 1864 dispatchChildSelected(); 1865 } 1866 1867 mInLayout = false; 1868 leaveContext(); 1869 if (DEBUG) Log.v(getTag(), "layoutChildren end"); 1870 } 1871 1872 private void offsetChildrenSecondary(int increment) { 1873 final int childCount = getChildCount(); 1874 if (mOrientation == HORIZONTAL) { 1875 for (int i = 0; i < childCount; i++) { 1876 getChildAt(i).offsetTopAndBottom(increment); 1877 } 1878 } else { 1879 for (int i = 0; i < childCount; i++) { 1880 getChildAt(i).offsetLeftAndRight(increment); 1881 } 1882 } 1883 } 1884 1885 private void offsetChildrenPrimary(int increment) { 1886 final int childCount = getChildCount(); 1887 if (mOrientation == VERTICAL) { 1888 for (int i = 0; i < childCount; i++) { 1889 getChildAt(i).offsetTopAndBottom(increment); 1890 } 1891 } else { 1892 for (int i = 0; i < childCount; i++) { 1893 getChildAt(i).offsetLeftAndRight(increment); 1894 } 1895 } 1896 } 1897 1898 @Override 1899 public int scrollHorizontallyBy(int dx, Recycler recycler, RecyclerView.State state) { 1900 if (DEBUG) Log.v(getTag(), "scrollHorizontallyBy " + dx); 1901 if (!mLayoutEnabled || !hasDoneFirstLayout()) { 1902 return 0; 1903 } 1904 saveContext(recycler, state); 1905 mInScroll = true; 1906 int result; 1907 if (mOrientation == HORIZONTAL) { 1908 result = scrollDirectionPrimary(dx); 1909 } else { 1910 result = scrollDirectionSecondary(dx); 1911 } 1912 leaveContext(); 1913 mInScroll = false; 1914 return result; 1915 } 1916 1917 @Override 1918 public int scrollVerticallyBy(int dy, Recycler recycler, RecyclerView.State state) { 1919 if (DEBUG) Log.v(getTag(), "scrollVerticallyBy " + dy); 1920 if (!mLayoutEnabled || !hasDoneFirstLayout()) { 1921 return 0; 1922 } 1923 mInScroll = true; 1924 saveContext(recycler, state); 1925 int result; 1926 if (mOrientation == VERTICAL) { 1927 result = scrollDirectionPrimary(dy); 1928 } else { 1929 result = scrollDirectionSecondary(dy); 1930 } 1931 leaveContext(); 1932 mInScroll = false; 1933 return result; 1934 } 1935 1936 // scroll in main direction may add/prune views 1937 private int scrollDirectionPrimary(int da) { 1938 if (TRACE) TraceHelper.beginSection("scrollPrimary"); 1939 boolean isMaxUnknown = false, isMinUnknown = false; 1940 int minScroll = 0, maxScroll = 0; 1941 if (da > 0) { 1942 isMaxUnknown = mWindowAlignment.mainAxis().isMaxUnknown(); 1943 if (!isMaxUnknown) { 1944 maxScroll = mWindowAlignment.mainAxis().getMaxScroll(); 1945 if (mScrollOffsetPrimary + da > maxScroll) { 1946 da = maxScroll - mScrollOffsetPrimary; 1947 } 1948 } 1949 } else if (da < 0) { 1950 isMinUnknown = mWindowAlignment.mainAxis().isMinUnknown(); 1951 if (!isMinUnknown) { 1952 minScroll = mWindowAlignment.mainAxis().getMinScroll(); 1953 if (mScrollOffsetPrimary + da < minScroll) { 1954 da = minScroll - mScrollOffsetPrimary; 1955 } 1956 } 1957 } 1958 if (da == 0) { 1959 if (TRACE) TraceHelper.endSection(); 1960 return 0; 1961 } 1962 offsetChildrenPrimary(-da); 1963 mScrollOffsetPrimary += da; 1964 if (mInLayout) { 1965 if (TRACE) TraceHelper.endSection(); 1966 return da; 1967 } 1968 1969 int childCount = getChildCount(); 1970 boolean updated; 1971 1972 if (mReverseFlowPrimary ? da > 0 : da < 0) { 1973 prependVisibleItems(); 1974 } else { 1975 appendVisibleItems(); 1976 } 1977 updated = getChildCount() > childCount; 1978 childCount = getChildCount(); 1979 1980 if (TRACE) TraceHelper.beginSection("remove"); 1981 if (mReverseFlowPrimary ? da > 0 : da < 0) { 1982 removeInvisibleViewsAtEnd(); 1983 } else { 1984 removeInvisibleViewsAtFront(); 1985 } 1986 if (TRACE) TraceHelper.endSection(); 1987 updated |= getChildCount() < childCount; 1988 if (updated) { 1989 updateRowSecondarySizeRefresh(); 1990 } 1991 1992 mBaseGridView.invalidate(); 1993 if (TRACE) TraceHelper.endSection(); 1994 return da; 1995 } 1996 1997 // scroll in second direction will not add/prune views 1998 private int scrollDirectionSecondary(int dy) { 1999 if (dy == 0) { 2000 return 0; 2001 } 2002 offsetChildrenSecondary(-dy); 2003 mScrollOffsetSecondary += dy; 2004 mBaseGridView.invalidate(); 2005 return dy; 2006 } 2007 2008 private void updateScrollMax() { 2009 int highVisiblePos = (!mReverseFlowPrimary) ? mGrid.getLastVisibleIndex() 2010 : mGrid.getFirstVisibleIndex(); 2011 int highMaxPos = (!mReverseFlowPrimary) ? mState.getItemCount() - 1 : 0; 2012 if (highVisiblePos < 0) { 2013 return; 2014 } 2015 final boolean highAvailable = highVisiblePos == highMaxPos; 2016 final boolean maxUnknown = mWindowAlignment.mainAxis().isMaxUnknown(); 2017 if (!highAvailable && maxUnknown) { 2018 return; 2019 } 2020 int maxEdge = mGrid.findRowMax(true, sTwoInts) + mScrollOffsetPrimary; 2021 int rowIndex = sTwoInts[0]; 2022 int pos = sTwoInts[1]; 2023 int savedMaxEdge = mWindowAlignment.mainAxis().getMaxEdge(); 2024 mWindowAlignment.mainAxis().setMaxEdge(maxEdge); 2025 int maxScroll = getPrimarySystemScrollPositionOfChildMax(findViewByPosition(pos)); 2026 mWindowAlignment.mainAxis().setMaxEdge(savedMaxEdge); 2027 2028 if (highAvailable) { 2029 mWindowAlignment.mainAxis().setMaxEdge(maxEdge); 2030 mWindowAlignment.mainAxis().setMaxScroll(maxScroll); 2031 if (DEBUG) Log.v(getTag(), "updating scroll maxEdge to " + maxEdge + 2032 " scrollMax to " + maxScroll); 2033 } else { 2034 mWindowAlignment.mainAxis().invalidateScrollMax(); 2035 if (DEBUG) Log.v(getTag(), "Invalidate scrollMax since it should be " 2036 + "greater than " + maxScroll); 2037 } 2038 } 2039 2040 private void updateScrollMin() { 2041 int lowVisiblePos = (!mReverseFlowPrimary) ? mGrid.getFirstVisibleIndex() 2042 : mGrid.getLastVisibleIndex(); 2043 int lowMinPos = (!mReverseFlowPrimary) ? 0 : mState.getItemCount() - 1; 2044 if (lowVisiblePos < 0) { 2045 return; 2046 } 2047 final boolean lowAvailable = lowVisiblePos == lowMinPos; 2048 final boolean minUnknown = mWindowAlignment.mainAxis().isMinUnknown(); 2049 if (!lowAvailable && minUnknown) { 2050 return; 2051 } 2052 int minEdge = mGrid.findRowMin(false, sTwoInts) + mScrollOffsetPrimary; 2053 int rowIndex = sTwoInts[0]; 2054 int pos = sTwoInts[1]; 2055 int savedMinEdge = mWindowAlignment.mainAxis().getMinEdge(); 2056 mWindowAlignment.mainAxis().setMinEdge(minEdge); 2057 int minScroll = getPrimarySystemScrollPosition(findViewByPosition(pos)); 2058 mWindowAlignment.mainAxis().setMinEdge(savedMinEdge); 2059 2060 if (lowAvailable) { 2061 mWindowAlignment.mainAxis().setMinEdge(minEdge); 2062 mWindowAlignment.mainAxis().setMinScroll(minScroll); 2063 if (DEBUG) Log.v(getTag(), "updating scroll minEdge to " + minEdge + 2064 " scrollMin to " + minScroll); 2065 } else { 2066 mWindowAlignment.mainAxis().invalidateScrollMin(); 2067 if (DEBUG) Log.v(getTag(), "Invalidate scrollMin, since it should be " 2068 + "less than " + minScroll); 2069 } 2070 } 2071 2072 private void updateScrollSecondAxis() { 2073 mWindowAlignment.secondAxis().setMinEdge(0); 2074 mWindowAlignment.secondAxis().setMaxEdge(getSizeSecondary()); 2075 } 2076 2077 private void initScrollController() { 2078 mWindowAlignment.reset(); 2079 mWindowAlignment.horizontal.setSize(getWidth()); 2080 mWindowAlignment.vertical.setSize(getHeight()); 2081 mWindowAlignment.horizontal.setPadding(getPaddingLeft(), getPaddingRight()); 2082 mWindowAlignment.vertical.setPadding(getPaddingTop(), getPaddingBottom()); 2083 mSizePrimary = mWindowAlignment.mainAxis().getSize(); 2084 mScrollOffsetPrimary = -mWindowAlignment.mainAxis().getPaddingLow(); 2085 mScrollOffsetSecondary = -mWindowAlignment.secondAxis().getPaddingLow(); 2086 2087 if (DEBUG) { 2088 Log.v(getTag(), "initScrollController mSizePrimary " + mSizePrimary 2089 + " mWindowAlignment " + mWindowAlignment 2090 + " mScrollOffsetPrimary " + mScrollOffsetPrimary); 2091 } 2092 } 2093 2094 private void updateScrollController() { 2095 // mScrollOffsetPrimary and mScrollOffsetSecondary includes the padding. 2096 // e.g. when topPadding is 16 for horizontal grid view, the initial 2097 // mScrollOffsetSecondary is -16. fastRelayout() put views based on offsets(not padding), 2098 // when padding changes to 20, we also need update mScrollOffsetSecondary to -20 before 2099 // fastRelayout() is performed 2100 int paddingPrimaryDiff, paddingSecondaryDiff; 2101 if (mOrientation == HORIZONTAL) { 2102 paddingPrimaryDiff = getPaddingLeft() - mWindowAlignment.horizontal.getPaddingLow(); 2103 paddingSecondaryDiff = getPaddingTop() - mWindowAlignment.vertical.getPaddingLow(); 2104 } else { 2105 paddingPrimaryDiff = getPaddingTop() - mWindowAlignment.vertical.getPaddingLow(); 2106 paddingSecondaryDiff = getPaddingLeft() - mWindowAlignment.horizontal.getPaddingLow(); 2107 } 2108 mScrollOffsetPrimary -= paddingPrimaryDiff; 2109 mScrollOffsetSecondary -= paddingSecondaryDiff; 2110 2111 mWindowAlignment.horizontal.setSize(getWidth()); 2112 mWindowAlignment.vertical.setSize(getHeight()); 2113 mWindowAlignment.horizontal.setPadding(getPaddingLeft(), getPaddingRight()); 2114 mWindowAlignment.vertical.setPadding(getPaddingTop(), getPaddingBottom()); 2115 mSizePrimary = mWindowAlignment.mainAxis().getSize(); 2116 2117 if (DEBUG) { 2118 Log.v(getTag(), "updateScrollController mSizePrimary " + mSizePrimary 2119 + " mWindowAlignment " + mWindowAlignment 2120 + " mScrollOffsetPrimary " + mScrollOffsetPrimary); 2121 } 2122 } 2123 2124 public void setSelection(RecyclerView parent, int position, 2125 int primaryScrollExtra) { 2126 setSelection(parent, position, 0, false, primaryScrollExtra); 2127 } 2128 2129 public void setSelectionSmooth(RecyclerView parent, int position) { 2130 setSelection(parent, position, 0, true, 0); 2131 } 2132 2133 public void setSelectionWithSub(RecyclerView parent, int position, int subposition, 2134 int primaryScrollExtra) { 2135 setSelection(parent, position, subposition, false, primaryScrollExtra); 2136 } 2137 2138 public void setSelectionSmoothWithSub(RecyclerView parent, int position, int subposition) { 2139 setSelection(parent, position, subposition, true, 0); 2140 } 2141 2142 public int getSelection() { 2143 return mFocusPosition; 2144 } 2145 2146 public int getSubSelection() { 2147 return mSubFocusPosition; 2148 } 2149 2150 public void setSelection(RecyclerView parent, int position, int subposition, boolean smooth, 2151 int primaryScrollExtra) { 2152 if (mFocusPosition != position && position != NO_POSITION 2153 || subposition != mSubFocusPosition || primaryScrollExtra != mPrimaryScrollExtra) { 2154 scrollToSelection(parent, position, subposition, smooth, primaryScrollExtra); 2155 } 2156 } 2157 2158 private void scrollToSelection(RecyclerView parent, int position, int subposition, 2159 boolean smooth, int primaryScrollExtra) { 2160 if (TRACE) TraceHelper.beginSection("scrollToSelection"); 2161 mPrimaryScrollExtra = primaryScrollExtra; 2162 View view = findViewByPosition(position); 2163 if (view != null) { 2164 mInSelection = true; 2165 scrollToView(view, smooth); 2166 mInSelection = false; 2167 } else { 2168 mFocusPosition = position; 2169 mSubFocusPosition = subposition; 2170 mFocusPositionOffset = Integer.MIN_VALUE; 2171 if (!mLayoutEnabled) { 2172 return; 2173 } 2174 if (smooth) { 2175 if (!hasDoneFirstLayout()) { 2176 Log.w(getTag(), "setSelectionSmooth should " + 2177 "not be called before first layout pass"); 2178 return; 2179 } 2180 startPositionSmoothScroller(position); 2181 } else { 2182 mForceFullLayout = true; 2183 parent.requestLayout(); 2184 } 2185 } 2186 if (TRACE) TraceHelper.endSection(); 2187 } 2188 2189 void startPositionSmoothScroller(int position) { 2190 LinearSmoothScroller linearSmoothScroller = new GridLinearSmoothScroller() { 2191 @Override 2192 public PointF computeScrollVectorForPosition(int targetPosition) { 2193 if (getChildCount() == 0) { 2194 return null; 2195 } 2196 final int firstChildPos = getPosition(getChildAt(0)); 2197 // TODO We should be able to deduce direction from bounds of current and target 2198 // focus, rather than making assumptions about positions and directionality 2199 final boolean isStart = mReverseFlowPrimary ? targetPosition > firstChildPos 2200 : targetPosition < firstChildPos; 2201 final int direction = isStart ? -1 : 1; 2202 if (mOrientation == HORIZONTAL) { 2203 return new PointF(direction, 0); 2204 } else { 2205 return new PointF(0, direction); 2206 } 2207 } 2208 2209 }; 2210 linearSmoothScroller.setTargetPosition(position); 2211 startSmoothScroll(linearSmoothScroller); 2212 } 2213 2214 private void processPendingMovement(boolean forward) { 2215 if (forward ? hasCreatedLastItem() : hasCreatedFirstItem()) { 2216 return; 2217 } 2218 if (mPendingMoveSmoothScroller == null) { 2219 // Stop existing scroller and create a new PendingMoveSmoothScroller. 2220 mBaseGridView.stopScroll(); 2221 PendingMoveSmoothScroller linearSmoothScroller = new PendingMoveSmoothScroller( 2222 forward ? 1 : -1, mNumRows > 1); 2223 mFocusPositionOffset = 0; 2224 startSmoothScroll(linearSmoothScroller); 2225 if (linearSmoothScroller.isRunning()) { 2226 mPendingMoveSmoothScroller = linearSmoothScroller; 2227 } 2228 } else { 2229 if (forward) { 2230 mPendingMoveSmoothScroller.increasePendingMoves(); 2231 } else { 2232 mPendingMoveSmoothScroller.decreasePendingMoves(); 2233 } 2234 } 2235 } 2236 2237 @Override 2238 public void onItemsAdded(RecyclerView recyclerView, int positionStart, int itemCount) { 2239 if (DEBUG) Log.v(getTag(), "onItemsAdded positionStart " 2240 + positionStart + " itemCount " + itemCount); 2241 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE) { 2242 int pos = mFocusPosition + mFocusPositionOffset; 2243 if (positionStart <= pos) { 2244 mFocusPositionOffset += itemCount; 2245 } 2246 } 2247 mChildrenStates.clear(); 2248 } 2249 2250 @Override 2251 public void onItemsChanged(RecyclerView recyclerView) { 2252 if (DEBUG) Log.v(getTag(), "onItemsChanged"); 2253 mFocusPositionOffset = 0; 2254 mChildrenStates.clear(); 2255 } 2256 2257 @Override 2258 public void onItemsRemoved(RecyclerView recyclerView, int positionStart, int itemCount) { 2259 if (DEBUG) Log.v(getTag(), "onItemsRemoved positionStart " 2260 + positionStart + " itemCount " + itemCount); 2261 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE) { 2262 int pos = mFocusPosition + mFocusPositionOffset; 2263 if (positionStart <= pos) { 2264 if (positionStart + itemCount > pos) { 2265 // stop updating offset after the focus item was removed 2266 mFocusPositionOffset = Integer.MIN_VALUE; 2267 } else { 2268 mFocusPositionOffset -= itemCount; 2269 } 2270 } 2271 } 2272 mChildrenStates.clear(); 2273 } 2274 2275 @Override 2276 public void onItemsMoved(RecyclerView recyclerView, int fromPosition, int toPosition, 2277 int itemCount) { 2278 if (DEBUG) Log.v(getTag(), "onItemsMoved fromPosition " 2279 + fromPosition + " toPosition " + toPosition); 2280 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE) { 2281 int pos = mFocusPosition + mFocusPositionOffset; 2282 if (fromPosition <= pos && pos < fromPosition + itemCount) { 2283 // moved items include focused position 2284 mFocusPositionOffset += toPosition - fromPosition; 2285 } else if (fromPosition < pos && toPosition > pos - itemCount) { 2286 // move items before focus position to after focused position 2287 mFocusPositionOffset -= itemCount; 2288 } else if (fromPosition > pos && toPosition < pos) { 2289 // move items after focus position to before focused position 2290 mFocusPositionOffset += itemCount; 2291 } 2292 } 2293 mChildrenStates.clear(); 2294 } 2295 2296 @Override 2297 public void onItemsUpdated(RecyclerView recyclerView, int positionStart, int itemCount) { 2298 if (DEBUG) Log.v(getTag(), "onItemsUpdated positionStart " 2299 + positionStart + " itemCount " + itemCount); 2300 for (int i = positionStart, end = positionStart + itemCount; i < end; i++) { 2301 mChildrenStates.remove(i); 2302 } 2303 } 2304 2305 @Override 2306 public boolean onRequestChildFocus(RecyclerView parent, View child, View focused) { 2307 if (mFocusSearchDisabled) { 2308 return true; 2309 } 2310 if (getPositionByView(child) == NO_POSITION) { 2311 // This shouldn't happen, but in case it does be sure not to attempt a 2312 // scroll to a view whose item has been removed. 2313 return true; 2314 } 2315 if (!mInLayout && !mInSelection && !mInScroll) { 2316 scrollToView(child, focused, true); 2317 } 2318 return true; 2319 } 2320 2321 @Override 2322 public boolean requestChildRectangleOnScreen(RecyclerView parent, View view, Rect rect, 2323 boolean immediate) { 2324 if (DEBUG) Log.v(getTag(), "requestChildRectangleOnScreen " + view + " " + rect); 2325 return false; 2326 } 2327 2328 int getScrollOffsetX() { 2329 return mOrientation == HORIZONTAL ? mScrollOffsetPrimary : mScrollOffsetSecondary; 2330 } 2331 2332 int getScrollOffsetY() { 2333 return mOrientation == HORIZONTAL ? mScrollOffsetSecondary : mScrollOffsetPrimary; 2334 } 2335 2336 public void getViewSelectedOffsets(View view, int[] offsets) { 2337 if (mOrientation == HORIZONTAL) { 2338 offsets[0] = getPrimarySystemScrollPosition(view) - mScrollOffsetPrimary; 2339 offsets[1] = getSecondarySystemScrollPosition(view) - mScrollOffsetSecondary; 2340 } else { 2341 offsets[1] = getPrimarySystemScrollPosition(view) - mScrollOffsetPrimary; 2342 offsets[0] = getSecondarySystemScrollPosition(view) - mScrollOffsetSecondary; 2343 } 2344 } 2345 2346 private int getPrimarySystemScrollPosition(View view) { 2347 final int viewCenterPrimary = mScrollOffsetPrimary + getViewCenter(view); 2348 final int viewMin = getViewMin(view); 2349 final int viewMax = getViewMax(view); 2350 // TODO: change to use State object in onRequestChildFocus() 2351 boolean isMin, isMax; 2352 if (!mReverseFlowPrimary) { 2353 isMin = mGrid.getFirstVisibleIndex() == 0; 2354 isMax = mGrid.getLastVisibleIndex() == (mState == null ? 2355 getItemCount() : mState.getItemCount()) - 1; 2356 } else { 2357 isMax = mGrid.getFirstVisibleIndex() == 0; 2358 isMin = mGrid.getLastVisibleIndex() == (mState == null ? 2359 getItemCount() : mState.getItemCount()) - 1; 2360 } 2361 for (int i = getChildCount() - 1; (isMin || isMax) && i >= 0; i--) { 2362 View v = getChildAt(i); 2363 if (v == view || v == null) { 2364 continue; 2365 } 2366 if (isMin && getViewMin(v) < viewMin) { 2367 isMin = false; 2368 } 2369 if (isMax && getViewMax(v) > viewMax) { 2370 isMax = false; 2371 } 2372 } 2373 return mWindowAlignment.mainAxis().getSystemScrollPos(viewCenterPrimary, isMin, isMax); 2374 } 2375 2376 private int getPrimarySystemScrollPositionOfChildMax(View view) { 2377 int scrollPosition = getPrimarySystemScrollPosition(view); 2378 final LayoutParams lp = (LayoutParams) view.getLayoutParams(); 2379 int[] multipleAligns = lp.getAlignMultiple(); 2380 if (multipleAligns != null && multipleAligns.length > 0) { 2381 scrollPosition += multipleAligns[multipleAligns.length - 1] - multipleAligns[0]; 2382 } 2383 return scrollPosition; 2384 } 2385 2386 /** 2387 * Get adjusted primary position for a given childView (if there is multiple ItemAlignment defined 2388 * on the view). 2389 */ 2390 private int getAdjustedPrimaryScrollPosition(int scrollPrimary, View view, View childView) { 2391 int subindex = getSubPositionByView(view, childView); 2392 if (subindex != 0) { 2393 final LayoutParams lp = (LayoutParams) view.getLayoutParams(); 2394 scrollPrimary += lp.getAlignMultiple()[subindex] - lp.getAlignMultiple()[0]; 2395 } 2396 return scrollPrimary; 2397 } 2398 2399 private int getSecondarySystemScrollPosition(View view) { 2400 int viewCenterSecondary = mScrollOffsetSecondary + getViewCenterSecondary(view); 2401 int pos = getPositionByView(view); 2402 Grid.Location location = mGrid.getLocation(pos); 2403 final int row = location.row; 2404 final boolean isMin, isMax; 2405 if (!mReverseFlowSecondary) { 2406 isMin = row == 0; 2407 isMax = row == mGrid.getNumRows() - 1; 2408 } else { 2409 isMax = row == 0; 2410 isMin = row == mGrid.getNumRows() - 1; 2411 } 2412 return mWindowAlignment.secondAxis().getSystemScrollPos(viewCenterSecondary, isMin, isMax); 2413 } 2414 2415 /** 2416 * Scroll to a given child view and change mFocusPosition. 2417 */ 2418 private void scrollToView(View view, boolean smooth) { 2419 scrollToView(view, view == null ? null : view.findFocus(), smooth); 2420 } 2421 2422 /** 2423 * Scroll to a given child view and change mFocusPosition. 2424 */ 2425 private void scrollToView(View view, View childView, boolean smooth) { 2426 int newFocusPosition = getPositionByView(view); 2427 int newSubFocusPosition = getSubPositionByView(view, childView); 2428 if (newFocusPosition != mFocusPosition || newSubFocusPosition != mSubFocusPosition) { 2429 mFocusPosition = newFocusPosition; 2430 mSubFocusPosition = newSubFocusPosition; 2431 mFocusPositionOffset = 0; 2432 if (!mInLayout) { 2433 dispatchChildSelected(); 2434 } 2435 if (mBaseGridView.isChildrenDrawingOrderEnabledInternal()) { 2436 mBaseGridView.invalidate(); 2437 } 2438 } 2439 if (view == null) { 2440 return; 2441 } 2442 if (!view.hasFocus() && mBaseGridView.hasFocus()) { 2443 // transfer focus to the child if it does not have focus yet (e.g. triggered 2444 // by setSelection()) 2445 view.requestFocus(); 2446 } 2447 if (!mScrollEnabled && smooth) { 2448 return; 2449 } 2450 if (getScrollPosition(view, childView, sTwoInts)) { 2451 scrollGrid(sTwoInts[0], sTwoInts[1], smooth); 2452 } 2453 } 2454 2455 private boolean getScrollPosition(View view, View childView, int[] deltas) { 2456 switch (mFocusScrollStrategy) { 2457 case BaseGridView.FOCUS_SCROLL_ALIGNED: 2458 default: 2459 return getAlignedPosition(view, childView, deltas); 2460 case BaseGridView.FOCUS_SCROLL_ITEM: 2461 case BaseGridView.FOCUS_SCROLL_PAGE: 2462 return getNoneAlignedPosition(view, deltas); 2463 } 2464 } 2465 2466 private boolean getNoneAlignedPosition(View view, int[] deltas) { 2467 int pos = getPositionByView(view); 2468 int viewMin = getViewMin(view); 2469 int viewMax = getViewMax(view); 2470 // we either align "firstView" to left/top padding edge 2471 // or align "lastView" to right/bottom padding edge 2472 View firstView = null; 2473 View lastView = null; 2474 int paddingLow = mWindowAlignment.mainAxis().getPaddingLow(); 2475 int clientSize = mWindowAlignment.mainAxis().getClientSize(); 2476 final int row = mGrid.getRowIndex(pos); 2477 if (viewMin < paddingLow) { 2478 // view enters low padding area: 2479 firstView = view; 2480 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_PAGE) { 2481 // scroll one "page" left/top, 2482 // align first visible item of the "page" at the low padding edge. 2483 while (prependOneColumnVisibleItems()) { 2484 CircularIntArray positions = 2485 mGrid.getItemPositionsInRows(mGrid.getFirstVisibleIndex(), pos)[row]; 2486 firstView = findViewByPosition(positions.get(0)); 2487 if (viewMax - getViewMin(firstView) > clientSize) { 2488 if (positions.size() > 2) { 2489 firstView = findViewByPosition(positions.get(2)); 2490 } 2491 break; 2492 } 2493 } 2494 } 2495 } else if (viewMax > clientSize + paddingLow) { 2496 // view enters high padding area: 2497 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_PAGE) { 2498 // scroll whole one page right/bottom, align view at the low padding edge. 2499 firstView = view; 2500 do { 2501 CircularIntArray positions = 2502 mGrid.getItemPositionsInRows(pos, mGrid.getLastVisibleIndex())[row]; 2503 lastView = findViewByPosition(positions.get(positions.size() - 1)); 2504 if (getViewMax(lastView) - viewMin > clientSize) { 2505 lastView = null; 2506 break; 2507 } 2508 } while (appendOneColumnVisibleItems()); 2509 if (lastView != null) { 2510 // however if we reached end, we should align last view. 2511 firstView = null; 2512 } 2513 } else { 2514 lastView = view; 2515 } 2516 } 2517 int scrollPrimary = 0; 2518 int scrollSecondary = 0; 2519 if (firstView != null) { 2520 scrollPrimary = getViewMin(firstView) - paddingLow; 2521 } else if (lastView != null) { 2522 scrollPrimary = getViewMax(lastView) - (paddingLow + clientSize); 2523 } 2524 View secondaryAlignedView; 2525 if (firstView != null) { 2526 secondaryAlignedView = firstView; 2527 } else if (lastView != null) { 2528 secondaryAlignedView = lastView; 2529 } else { 2530 secondaryAlignedView = view; 2531 } 2532 scrollSecondary = getSecondarySystemScrollPosition(secondaryAlignedView); 2533 scrollSecondary -= mScrollOffsetSecondary; 2534 if (scrollPrimary != 0 || scrollSecondary != 0) { 2535 deltas[0] = scrollPrimary; 2536 deltas[1] = scrollSecondary; 2537 return true; 2538 } 2539 return false; 2540 } 2541 2542 private boolean getAlignedPosition(View view, View childView, int[] deltas) { 2543 int scrollPrimary = getPrimarySystemScrollPosition(view); 2544 if (childView != null) { 2545 scrollPrimary = getAdjustedPrimaryScrollPosition(scrollPrimary, view, childView); 2546 } 2547 int scrollSecondary = getSecondarySystemScrollPosition(view); 2548 if (DEBUG) { 2549 Log.v(getTag(), "getAlignedPosition " + scrollPrimary + " " + scrollSecondary 2550 + " " + mPrimaryScrollExtra + " " + mWindowAlignment); 2551 Log.v(getTag(), "getAlignedPosition " + mScrollOffsetPrimary + " " + mScrollOffsetSecondary); 2552 } 2553 scrollPrimary -= mScrollOffsetPrimary; 2554 scrollSecondary -= mScrollOffsetSecondary; 2555 scrollPrimary += mPrimaryScrollExtra; 2556 if (scrollPrimary != 0 || scrollSecondary != 0) { 2557 deltas[0] = scrollPrimary; 2558 deltas[1] = scrollSecondary; 2559 return true; 2560 } 2561 return false; 2562 } 2563 2564 private void scrollGrid(int scrollPrimary, int scrollSecondary, boolean smooth) { 2565 if (mInLayout) { 2566 scrollDirectionPrimary(scrollPrimary); 2567 scrollDirectionSecondary(scrollSecondary); 2568 } else { 2569 int scrollX; 2570 int scrollY; 2571 if (mOrientation == HORIZONTAL) { 2572 scrollX = scrollPrimary; 2573 scrollY = scrollSecondary; 2574 } else { 2575 scrollX = scrollSecondary; 2576 scrollY = scrollPrimary; 2577 } 2578 if (smooth) { 2579 mBaseGridView.smoothScrollBy(scrollX, scrollY); 2580 } else { 2581 mBaseGridView.scrollBy(scrollX, scrollY); 2582 } 2583 } 2584 } 2585 2586 public void setPruneChild(boolean pruneChild) { 2587 if (mPruneChild != pruneChild) { 2588 mPruneChild = pruneChild; 2589 if (mPruneChild) { 2590 requestLayout(); 2591 } 2592 } 2593 } 2594 2595 public boolean getPruneChild() { 2596 return mPruneChild; 2597 } 2598 2599 public void setScrollEnabled(boolean scrollEnabled) { 2600 if (mScrollEnabled != scrollEnabled) { 2601 mScrollEnabled = scrollEnabled; 2602 if (mScrollEnabled && mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED 2603 && mFocusPosition != NO_POSITION) { 2604 scrollToSelection(mBaseGridView, mFocusPosition, mSubFocusPosition, 2605 true, mPrimaryScrollExtra); 2606 } 2607 } 2608 } 2609 2610 public boolean isScrollEnabled() { 2611 return mScrollEnabled; 2612 } 2613 2614 private int findImmediateChildIndex(View view) { 2615 while (view != null && view != mBaseGridView) { 2616 int index = mBaseGridView.indexOfChild(view); 2617 if (index >= 0) { 2618 return index; 2619 } 2620 view = (View) view.getParent(); 2621 } 2622 return NO_POSITION; 2623 } 2624 2625 void onFocusChanged(boolean gainFocus, int direction, Rect previouslyFocusedRect) { 2626 if (gainFocus) { 2627 // if gridview.requestFocus() is called, select first focusable child. 2628 for (int i = mFocusPosition; ;i++) { 2629 View view = findViewByPosition(i); 2630 if (view == null) { 2631 break; 2632 } 2633 if (view.getVisibility() == View.VISIBLE && view.hasFocusable()) { 2634 view.requestFocus(); 2635 break; 2636 } 2637 } 2638 } 2639 } 2640 2641 void setFocusSearchDisabled(boolean disabled) { 2642 mFocusSearchDisabled = disabled; 2643 } 2644 2645 boolean isFocusSearchDisabled() { 2646 return mFocusSearchDisabled; 2647 } 2648 2649 @Override 2650 public View onInterceptFocusSearch(View focused, int direction) { 2651 if (mFocusSearchDisabled) { 2652 return focused; 2653 } 2654 return null; 2655 } 2656 2657 boolean hasPreviousViewInSameRow(int pos) { 2658 if (mGrid == null || pos == NO_POSITION || mGrid.getFirstVisibleIndex() < 0) { 2659 return false; 2660 } 2661 if (mGrid.getFirstVisibleIndex() > 0) { 2662 return true; 2663 } 2664 final int focusedRow = mGrid.getLocation(pos).row; 2665 for (int i = getChildCount() - 1; i >= 0; i--) { 2666 int position = getPositionByIndex(i); 2667 Grid.Location loc = mGrid.getLocation(position); 2668 if (loc != null && loc.row == focusedRow) { 2669 if (position < pos) { 2670 return true; 2671 } 2672 } 2673 } 2674 return false; 2675 } 2676 2677 @Override 2678 public boolean onAddFocusables(RecyclerView recyclerView, 2679 ArrayList<View> views, int direction, int focusableMode) { 2680 if (mFocusSearchDisabled) { 2681 return true; 2682 } 2683 // If this viewgroup or one of its children currently has focus then we 2684 // consider our children for focus searching in main direction on the same row. 2685 // If this viewgroup has no focus and using focus align, we want the system 2686 // to ignore our children and pass focus to the viewgroup, which will pass 2687 // focus on to its children appropriately. 2688 // If this viewgroup has no focus and not using focus align, we want to 2689 // consider the child that does not overlap with padding area. 2690 if (recyclerView.hasFocus()) { 2691 final int movement = getMovement(direction); 2692 if (movement != PREV_ITEM && movement != NEXT_ITEM) { 2693 // Move on secondary direction uses default addFocusables(). 2694 return false; 2695 } 2696 if (mPendingMoveSmoothScroller != null) { 2697 // don't find next focusable if has pending movement. 2698 return true; 2699 } 2700 final View focused = recyclerView.findFocus(); 2701 final int focusedPos = getPositionByIndex(findImmediateChildIndex(focused)); 2702 // Add focusables of focused item. 2703 if (focusedPos != NO_POSITION) { 2704 findViewByPosition(focusedPos).addFocusables(views, direction, focusableMode); 2705 } 2706 final int focusedRow = mGrid != null && focusedPos != NO_POSITION ? 2707 mGrid.getLocation(focusedPos).row : NO_POSITION; 2708 // Add focusables of next neighbor of same row on the focus search direction. 2709 if (mGrid != null) { 2710 final int focusableCount = views.size(); 2711 for (int i = 0, count = getChildCount(); i < count; i++) { 2712 int index = movement == NEXT_ITEM ? i : count - 1 - i; 2713 final View child = getChildAt(index); 2714 if (child.getVisibility() != View.VISIBLE || !child.hasFocusable()) { 2715 continue; 2716 } 2717 int position = getPositionByIndex(index); 2718 Grid.Location loc = mGrid.getLocation(position); 2719 if (focusedRow == NO_POSITION || (loc != null && loc.row == focusedRow)) { 2720 if (focusedPos == NO_POSITION || 2721 (movement == NEXT_ITEM && position > focusedPos) 2722 || (movement == PREV_ITEM && position < focusedPos)) { 2723 child.addFocusables(views, direction, focusableMode); 2724 if (views.size() > focusableCount) { 2725 break; 2726 } 2727 } 2728 } 2729 } 2730 } 2731 } else { 2732 if (mFocusScrollStrategy != BaseGridView.FOCUS_SCROLL_ALIGNED) { 2733 // adding views not overlapping padding area to avoid scrolling in gaining focus 2734 int left = mWindowAlignment.mainAxis().getPaddingLow(); 2735 int right = mWindowAlignment.mainAxis().getClientSize() + left; 2736 int focusableCount = views.size(); 2737 for (int i = 0, count = getChildCount(); i < count; i++) { 2738 View child = getChildAt(i); 2739 if (child.getVisibility() == View.VISIBLE) { 2740 if (getViewMin(child) >= left && getViewMax(child) <= right) { 2741 child.addFocusables(views, direction, focusableMode); 2742 } 2743 } 2744 } 2745 // if we cannot find any, then just add all children. 2746 if (views.size() == focusableCount) { 2747 for (int i = 0, count = getChildCount(); i < count; i++) { 2748 View child = getChildAt(i); 2749 if (child.getVisibility() == View.VISIBLE) { 2750 child.addFocusables(views, direction, focusableMode); 2751 } 2752 } 2753 if (views.size() != focusableCount) { 2754 return true; 2755 } 2756 } else { 2757 return true; 2758 } 2759 // if still cannot find any, fall through and add itself 2760 } 2761 if (recyclerView.isFocusable()) { 2762 views.add(recyclerView); 2763 } 2764 } 2765 return true; 2766 } 2767 2768 private boolean hasCreatedLastItem() { 2769 int count = mState.getItemCount(); 2770 return count == 0 || findViewByPosition(count - 1) != null; 2771 } 2772 2773 private boolean hasCreatedFirstItem() { 2774 int count = mState.getItemCount(); 2775 return count == 0 || findViewByPosition(0) != null; 2776 } 2777 2778 boolean canScrollTo(View view) { 2779 return view.getVisibility() == View.VISIBLE && (!hasFocus() || view.hasFocusable()); 2780 } 2781 2782 @Override 2783 public View onFocusSearchFailed(View focused, int direction, Recycler recycler, 2784 RecyclerView.State state) { 2785 if (DEBUG) Log.v(getTag(), "onFocusSearchFailed direction " + direction); 2786 2787 View view = null; 2788 int movement = getMovement(direction); 2789 final boolean isScroll = mBaseGridView.getScrollState() != RecyclerView.SCROLL_STATE_IDLE; 2790 saveContext(recycler, state); 2791 if (movement == NEXT_ITEM) { 2792 if (isScroll || !mFocusOutEnd) { 2793 view = focused; 2794 } 2795 if (mScrollEnabled && !hasCreatedLastItem()) { 2796 processPendingMovement(true); 2797 view = focused; 2798 } 2799 } else if (movement == PREV_ITEM) { 2800 if (isScroll || !mFocusOutFront) { 2801 view = focused; 2802 } 2803 if (mScrollEnabled && !hasCreatedFirstItem()) { 2804 processPendingMovement(false); 2805 view = focused; 2806 } 2807 } 2808 leaveContext(); 2809 if (DEBUG) Log.v(getTag(), "onFocusSearchFailed returning view " + view); 2810 return view; 2811 } 2812 2813 boolean gridOnRequestFocusInDescendants(RecyclerView recyclerView, int direction, 2814 Rect previouslyFocusedRect) { 2815 switch (mFocusScrollStrategy) { 2816 case BaseGridView.FOCUS_SCROLL_ALIGNED: 2817 default: 2818 return gridOnRequestFocusInDescendantsAligned(recyclerView, 2819 direction, previouslyFocusedRect); 2820 case BaseGridView.FOCUS_SCROLL_PAGE: 2821 case BaseGridView.FOCUS_SCROLL_ITEM: 2822 return gridOnRequestFocusInDescendantsUnaligned(recyclerView, 2823 direction, previouslyFocusedRect); 2824 } 2825 } 2826 2827 private boolean gridOnRequestFocusInDescendantsAligned(RecyclerView recyclerView, 2828 int direction, Rect previouslyFocusedRect) { 2829 View view = findViewByPosition(mFocusPosition); 2830 if (view != null) { 2831 boolean result = view.requestFocus(direction, previouslyFocusedRect); 2832 if (!result && DEBUG) { 2833 Log.w(getTag(), "failed to request focus on " + view); 2834 } 2835 return result; 2836 } 2837 return false; 2838 } 2839 2840 private boolean gridOnRequestFocusInDescendantsUnaligned(RecyclerView recyclerView, 2841 int direction, Rect previouslyFocusedRect) { 2842 // focus to view not overlapping padding area to avoid scrolling in gaining focus 2843 int index; 2844 int increment; 2845 int end; 2846 int count = getChildCount(); 2847 if ((direction & View.FOCUS_FORWARD) != 0) { 2848 index = 0; 2849 increment = 1; 2850 end = count; 2851 } else { 2852 index = count - 1; 2853 increment = -1; 2854 end = -1; 2855 } 2856 int left = mWindowAlignment.mainAxis().getPaddingLow(); 2857 int right = mWindowAlignment.mainAxis().getClientSize() + left; 2858 for (int i = index; i != end; i += increment) { 2859 View child = getChildAt(i); 2860 if (child.getVisibility() == View.VISIBLE) { 2861 if (getViewMin(child) >= left && getViewMax(child) <= right) { 2862 if (child.requestFocus(direction, previouslyFocusedRect)) { 2863 return true; 2864 } 2865 } 2866 } 2867 } 2868 return false; 2869 } 2870 2871 private final static int PREV_ITEM = 0; 2872 private final static int NEXT_ITEM = 1; 2873 private final static int PREV_ROW = 2; 2874 private final static int NEXT_ROW = 3; 2875 2876 private int getMovement(int direction) { 2877 int movement = View.FOCUS_LEFT; 2878 2879 if (mOrientation == HORIZONTAL) { 2880 switch(direction) { 2881 case View.FOCUS_LEFT: 2882 movement = (!mReverseFlowPrimary) ? PREV_ITEM : NEXT_ITEM; 2883 break; 2884 case View.FOCUS_RIGHT: 2885 movement = (!mReverseFlowPrimary) ? NEXT_ITEM : PREV_ITEM; 2886 break; 2887 case View.FOCUS_UP: 2888 movement = PREV_ROW; 2889 break; 2890 case View.FOCUS_DOWN: 2891 movement = NEXT_ROW; 2892 break; 2893 } 2894 } else if (mOrientation == VERTICAL) { 2895 switch(direction) { 2896 case View.FOCUS_LEFT: 2897 movement = (!mReverseFlowPrimary) ? PREV_ROW : NEXT_ROW; 2898 break; 2899 case View.FOCUS_RIGHT: 2900 movement = (!mReverseFlowPrimary) ? NEXT_ROW : PREV_ROW; 2901 break; 2902 case View.FOCUS_UP: 2903 movement = PREV_ITEM; 2904 break; 2905 case View.FOCUS_DOWN: 2906 movement = NEXT_ITEM; 2907 break; 2908 } 2909 } 2910 2911 return movement; 2912 } 2913 2914 int getChildDrawingOrder(RecyclerView recyclerView, int childCount, int i) { 2915 View view = findViewByPosition(mFocusPosition); 2916 if (view == null) { 2917 return i; 2918 } 2919 int focusIndex = recyclerView.indexOfChild(view); 2920 // supposely 0 1 2 3 4 5 6 7 8 9, 4 is the center item 2921 // drawing order is 0 1 2 3 9 8 7 6 5 4 2922 if (i < focusIndex) { 2923 return i; 2924 } else if (i < childCount - 1) { 2925 return focusIndex + childCount - 1 - i; 2926 } else { 2927 return focusIndex; 2928 } 2929 } 2930 2931 @Override 2932 public void onAdapterChanged(RecyclerView.Adapter oldAdapter, 2933 RecyclerView.Adapter newAdapter) { 2934 if (DEBUG) Log.v(getTag(), "onAdapterChanged to " + newAdapter); 2935 if (oldAdapter != null) { 2936 discardLayoutInfo(); 2937 mFocusPosition = NO_POSITION; 2938 mFocusPositionOffset = 0; 2939 mChildrenStates.clear(); 2940 } 2941 if (newAdapter instanceof FacetProviderAdapter) { 2942 mFacetProviderAdapter = (FacetProviderAdapter) newAdapter; 2943 } else { 2944 mFacetProviderAdapter = null; 2945 } 2946 super.onAdapterChanged(oldAdapter, newAdapter); 2947 } 2948 2949 private void discardLayoutInfo() { 2950 mGrid = null; 2951 mRowSizeSecondary = null; 2952 mRowSecondarySizeRefresh = false; 2953 } 2954 2955 public void setLayoutEnabled(boolean layoutEnabled) { 2956 if (mLayoutEnabled != layoutEnabled) { 2957 mLayoutEnabled = layoutEnabled; 2958 requestLayout(); 2959 } 2960 } 2961 2962 void setChildrenVisibility(int visiblity) { 2963 mChildVisibility = visiblity; 2964 if (mChildVisibility != -1) { 2965 int count = getChildCount(); 2966 for (int i= 0; i < count; i++) { 2967 getChildAt(i).setVisibility(mChildVisibility); 2968 } 2969 } 2970 } 2971 2972 final static class SavedState implements Parcelable { 2973 2974 int index; // index inside adapter of the current view 2975 Bundle childStates = Bundle.EMPTY; 2976 2977 @Override 2978 public void writeToParcel(Parcel out, int flags) { 2979 out.writeInt(index); 2980 out.writeBundle(childStates); 2981 } 2982 2983 @SuppressWarnings("hiding") 2984 public static final Parcelable.Creator<SavedState> CREATOR = 2985 new Parcelable.Creator<SavedState>() { 2986 @Override 2987 public SavedState createFromParcel(Parcel in) { 2988 return new SavedState(in); 2989 } 2990 2991 @Override 2992 public SavedState[] newArray(int size) { 2993 return new SavedState[size]; 2994 } 2995 }; 2996 2997 @Override 2998 public int describeContents() { 2999 return 0; 3000 } 3001 3002 SavedState(Parcel in) { 3003 index = in.readInt(); 3004 childStates = in.readBundle(GridLayoutManager.class.getClassLoader()); 3005 } 3006 3007 SavedState() { 3008 } 3009 } 3010 3011 @Override 3012 public Parcelable onSaveInstanceState() { 3013 if (DEBUG) Log.v(getTag(), "onSaveInstanceState getSelection() " + getSelection()); 3014 SavedState ss = new SavedState(); 3015 // save selected index 3016 ss.index = getSelection(); 3017 // save offscreen child (state when they are recycled) 3018 Bundle bundle = mChildrenStates.saveAsBundle(); 3019 // save views currently is on screen (TODO save cached views) 3020 for (int i = 0, count = getChildCount(); i < count; i++) { 3021 View view = getChildAt(i); 3022 int position = getPositionByView(view); 3023 if (position != NO_POSITION) { 3024 bundle = mChildrenStates.saveOnScreenView(bundle, view, position); 3025 } 3026 } 3027 ss.childStates = bundle; 3028 return ss; 3029 } 3030 3031 void onChildRecycled(RecyclerView.ViewHolder holder) { 3032 final int position = holder.getAdapterPosition(); 3033 if (position != NO_POSITION) { 3034 mChildrenStates.saveOffscreenView(holder.itemView, position); 3035 } 3036 } 3037 3038 @Override 3039 public void onRestoreInstanceState(Parcelable state) { 3040 if (!(state instanceof SavedState)) { 3041 return; 3042 } 3043 SavedState loadingState = (SavedState)state; 3044 mFocusPosition = loadingState.index; 3045 mFocusPositionOffset = 0; 3046 mChildrenStates.loadFromBundle(loadingState.childStates); 3047 mForceFullLayout = true; 3048 requestLayout(); 3049 if (DEBUG) Log.v(getTag(), "onRestoreInstanceState mFocusPosition " + mFocusPosition); 3050 } 3051 3052 @Override 3053 public int getRowCountForAccessibility(RecyclerView.Recycler recycler, 3054 RecyclerView.State state) { 3055 if (mOrientation == HORIZONTAL && mGrid != null) { 3056 return mGrid.getNumRows(); 3057 } 3058 return super.getRowCountForAccessibility(recycler, state); 3059 } 3060 3061 @Override 3062 public int getColumnCountForAccessibility(RecyclerView.Recycler recycler, 3063 RecyclerView.State state) { 3064 if (mOrientation == VERTICAL && mGrid != null) { 3065 return mGrid.getNumRows(); 3066 } 3067 return super.getColumnCountForAccessibility(recycler, state); 3068 } 3069 3070 @Override 3071 public void onInitializeAccessibilityNodeInfoForItem(RecyclerView.Recycler recycler, 3072 RecyclerView.State state, View host, AccessibilityNodeInfoCompat info) { 3073 ViewGroup.LayoutParams lp = host.getLayoutParams(); 3074 if (mGrid == null || !(lp instanceof LayoutParams)) { 3075 super.onInitializeAccessibilityNodeInfoForItem(recycler, state, host, info); 3076 return; 3077 } 3078 LayoutParams glp = (LayoutParams) lp; 3079 int position = glp.getViewLayoutPosition(); 3080 int rowIndex = mGrid.getRowIndex(position); 3081 int guessSpanIndex = position / mGrid.getNumRows(); 3082 if (mOrientation == HORIZONTAL) { 3083 info.setCollectionItemInfo(AccessibilityNodeInfoCompat.CollectionItemInfoCompat.obtain( 3084 rowIndex, 1, guessSpanIndex, 1, false, false)); 3085 } else { 3086 info.setCollectionItemInfo(AccessibilityNodeInfoCompat.CollectionItemInfoCompat.obtain( 3087 guessSpanIndex, 1, rowIndex, 1, false, false)); 3088 } 3089 } 3090 3091 /* 3092 * Leanback widget is different than the default implementation because the "scroll" is driven 3093 * by selection change. 3094 */ 3095 @Override 3096 public boolean performAccessibilityAction(Recycler recycler, State state, int action, 3097 Bundle args) { 3098 saveContext(recycler, state); 3099 switch (action) { 3100 case AccessibilityNodeInfoCompat.ACTION_SCROLL_BACKWARD: 3101 // try to focus all the way to the last visible item on the same row. 3102 processSelectionMoves(false, -mState.getItemCount()); 3103 break; 3104 case AccessibilityNodeInfoCompat.ACTION_SCROLL_FORWARD: 3105 processSelectionMoves(false, mState.getItemCount()); 3106 break; 3107 } 3108 leaveContext(); 3109 return true; 3110 } 3111 3112 /* 3113 * Move mFocusPosition multiple steps on the same row in main direction. 3114 * Stops when moves are all consumed or reach first/last visible item. 3115 * Returning remaining moves. 3116 */ 3117 private int processSelectionMoves(boolean preventScroll, int moves) { 3118 if (mGrid == null) { 3119 return moves; 3120 } 3121 int focusPosition = mFocusPosition; 3122 int focusedRow = focusPosition != NO_POSITION ? 3123 mGrid.getRowIndex(focusPosition) : NO_POSITION; 3124 View newSelected = null; 3125 for (int i = 0, count = getChildCount(); i < count && moves != 0; i++) { 3126 int index = moves > 0 ? i : count - 1 - i; 3127 final View child = getChildAt(index); 3128 if (!canScrollTo(child)) { 3129 continue; 3130 } 3131 int position = getPositionByIndex(index); 3132 int rowIndex = mGrid.getRowIndex(position); 3133 if (focusedRow == NO_POSITION) { 3134 focusPosition = position; 3135 newSelected = child; 3136 focusedRow = rowIndex; 3137 } else if (rowIndex == focusedRow) { 3138 if ((moves > 0 && position > focusPosition) 3139 || (moves < 0 && position < focusPosition)) { 3140 focusPosition = position; 3141 newSelected = child; 3142 if (moves > 0) { 3143 moves--; 3144 } else { 3145 moves++; 3146 } 3147 } 3148 } 3149 } 3150 if (newSelected != null) { 3151 if (preventScroll) { 3152 if (hasFocus()) { 3153 mInSelection = true; 3154 newSelected.requestFocus(); 3155 mInSelection = false; 3156 } 3157 mFocusPosition = focusPosition; 3158 mSubFocusPosition = 0; 3159 } else { 3160 scrollToView(newSelected, true); 3161 } 3162 } 3163 return moves; 3164 } 3165 3166 @Override 3167 public void onInitializeAccessibilityNodeInfo(Recycler recycler, State state, 3168 AccessibilityNodeInfoCompat info) { 3169 saveContext(recycler, state); 3170 if (mScrollEnabled && !hasCreatedFirstItem()) { 3171 info.addAction(AccessibilityNodeInfoCompat.ACTION_SCROLL_BACKWARD); 3172 info.setScrollable(true); 3173 } 3174 if (mScrollEnabled && !hasCreatedLastItem()) { 3175 info.addAction(AccessibilityNodeInfoCompat.ACTION_SCROLL_FORWARD); 3176 info.setScrollable(true); 3177 } 3178 final AccessibilityNodeInfoCompat.CollectionInfoCompat collectionInfo 3179 = AccessibilityNodeInfoCompat.CollectionInfoCompat 3180 .obtain(getRowCountForAccessibility(recycler, state), 3181 getColumnCountForAccessibility(recycler, state), 3182 isLayoutHierarchical(recycler, state), 3183 getSelectionModeForAccessibility(recycler, state)); 3184 info.setCollectionInfo(collectionInfo); 3185 leaveContext(); 3186 } 3187} 3188