GridLayoutManager.java revision 3a23ad69eef2b92be38f9704e064600066b7dfe9
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.v7.widget.LinearSmoothScroller; 25import android.support.v7.widget.RecyclerView; 26import android.support.v7.widget.RecyclerView.Recycler; 27import android.support.v7.widget.RecyclerView.State; 28import android.support.v17.leanback.os.TraceHelper; 29 30import static android.support.v7.widget.RecyclerView.NO_ID; 31import static android.support.v7.widget.RecyclerView.NO_POSITION; 32import static android.support.v7.widget.RecyclerView.HORIZONTAL; 33import static android.support.v7.widget.RecyclerView.VERTICAL; 34 35import android.util.AttributeSet; 36import android.util.Log; 37import android.view.FocusFinder; 38import android.view.Gravity; 39import android.view.View; 40import android.view.ViewParent; 41import android.view.View.MeasureSpec; 42import android.view.ViewGroup.MarginLayoutParams; 43import android.view.ViewGroup; 44 45import java.io.PrintWriter; 46import java.io.StringWriter; 47import java.util.ArrayList; 48import java.util.List; 49 50final class GridLayoutManager extends RecyclerView.LayoutManager { 51 52 /* 53 * LayoutParams for {@link HorizontalGridView} and {@link VerticalGridView}. 54 * The class currently does two internal jobs: 55 * - Saves optical bounds insets. 56 * - Caches focus align view center. 57 */ 58 static class LayoutParams extends RecyclerView.LayoutParams { 59 60 // The view is saved only during animation. 61 private View mView; 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 73 public LayoutParams(Context c, AttributeSet attrs) { 74 super(c, attrs); 75 } 76 77 public LayoutParams(int width, int height) { 78 super(width, height); 79 } 80 81 public LayoutParams(MarginLayoutParams source) { 82 super(source); 83 } 84 85 public LayoutParams(ViewGroup.LayoutParams source) { 86 super(source); 87 } 88 89 public LayoutParams(RecyclerView.LayoutParams source) { 90 super(source); 91 } 92 93 public LayoutParams(LayoutParams source) { 94 super(source); 95 } 96 97 int getAlignX() { 98 return mAlignX; 99 } 100 101 int getAlignY() { 102 return mAlignY; 103 } 104 105 int getOpticalLeft(View view) { 106 return view.getLeft() + mLeftInset; 107 } 108 109 int getOpticalTop(View view) { 110 return view.getTop() + mTopInset; 111 } 112 113 int getOpticalRight(View view) { 114 return view.getRight() - mRightInset; 115 } 116 117 int getOpticalBottom(View view) { 118 return view.getBottom() - mBottomInset; 119 } 120 121 int getOpticalWidth(View view) { 122 return view.getWidth() - mLeftInset - mRightInset; 123 } 124 125 int getOpticalHeight(View view) { 126 return view.getHeight() - mTopInset - mBottomInset; 127 } 128 129 int getOpticalLeftInset() { 130 return mLeftInset; 131 } 132 133 int getOpticalRightInset() { 134 return mRightInset; 135 } 136 137 int getOpticalTopInset() { 138 return mTopInset; 139 } 140 141 int getOpticalBottomInset() { 142 return mBottomInset; 143 } 144 145 void setAlignX(int alignX) { 146 mAlignX = alignX; 147 } 148 149 void setAlignY(int alignY) { 150 mAlignY = alignY; 151 } 152 153 void setOpticalInsets(int leftInset, int topInset, int rightInset, int bottomInset) { 154 mLeftInset = leftInset; 155 mTopInset = topInset; 156 mRightInset = rightInset; 157 mBottomInset = bottomInset; 158 } 159 160 private void invalidateItemDecoration() { 161 ViewParent parent = mView.getParent(); 162 if (parent instanceof RecyclerView) { 163 // TODO: we only need invalidate parent if it has ItemDecoration 164 ((RecyclerView) parent).invalidate(); 165 } 166 } 167 } 168 169 private static final String TAG = "GridLayoutManager"; 170 private static final boolean DEBUG = false; 171 private static final boolean TRACE = false; 172 173 private String getTag() { 174 return TAG + ":" + mBaseGridView.getId(); 175 } 176 177 private final BaseGridView mBaseGridView; 178 179 /** 180 * Note on conventions in the presence of RTL layout directions: 181 * Many properties and method names reference entities related to the 182 * beginnings and ends of things. In the presence of RTL flows, 183 * it may not be clear whether this is intended to reference a 184 * quantity that changes direction in RTL cases, or a quantity that 185 * does not. Here are the conventions in use: 186 * 187 * start/end: coordinate quantities - do reverse 188 * (optical) left/right: coordinate quantities - do not reverse 189 * low/high: coordinate quantities - do not reverse 190 * min/max: coordinate quantities - do not reverse 191 * scroll offset - coordinate quantities - do not reverse 192 * first/last: positional indices - do not reverse 193 * front/end: positional indices - do not reverse 194 * prepend/append: related to positional indices - do not reverse 195 * 196 * Note that although quantities do not reverse in RTL flows, their 197 * relationship does. In LTR flows, the first positional index is 198 * leftmost; in RTL flows, it is rightmost. Thus, anywhere that 199 * positional quantities are mapped onto coordinate quantities, 200 * the flow must be checked and the logic reversed. 201 */ 202 203 /** 204 * The orientation of a "row". 205 */ 206 private int mOrientation = HORIZONTAL; 207 208 private RecyclerView.State mState; 209 private RecyclerView.Recycler mRecycler; 210 211 private boolean mInLayout = false; 212 private boolean mInSelection = false; 213 214 private OnChildSelectedListener mChildSelectedListener = null; 215 216 /** 217 * The focused position, it's not the currently visually aligned position 218 * but it is the final position that we intend to focus on. If there are 219 * multiple setSelection() called, mFocusPosition saves last value. 220 */ 221 private int mFocusPosition = NO_POSITION; 222 223 /** 224 * The offset to be applied to mFocusPosition, due to adapter change, on the next 225 * layout. Set to Integer.MIN_VALUE means item was removed. 226 * TODO: This is somewhat duplication of RecyclerView getOldPosition() which is 227 * unfortunately cleared after prelayout. 228 */ 229 private int mFocusPositionOffset = 0; 230 231 /** 232 * Force a full layout under certain situations. E.g. Rows change, jump to invisible child. 233 */ 234 private boolean mForceFullLayout; 235 236 /** 237 * True if layout is enabled. 238 */ 239 private boolean mLayoutEnabled = true; 240 241 /** 242 * override child visibility 243 */ 244 private int mChildVisibility = -1; 245 246 /** 247 * The scroll offsets of the viewport relative to the entire view. 248 */ 249 private int mScrollOffsetPrimary; 250 private int mScrollOffsetSecondary; 251 252 /** 253 * User-specified row height/column width. Can be WRAP_CONTENT. 254 */ 255 private int mRowSizeSecondaryRequested; 256 257 /** 258 * The fixed size of each grid item in the secondary direction. This corresponds to 259 * the row height, equal for all rows. Grid items may have variable length 260 * in the primary direction. 261 */ 262 private int mFixedRowSizeSecondary; 263 264 /** 265 * Tracks the secondary size of each row. 266 */ 267 private int[] mRowSizeSecondary; 268 269 /** 270 * Flag controlling whether the current/next layout should 271 * be updating the secondary size of rows. 272 */ 273 private boolean mRowSecondarySizeRefresh; 274 275 /** 276 * The maximum measured size of the view. 277 */ 278 private int mMaxSizeSecondary; 279 280 /** 281 * Margin between items. 282 */ 283 private int mHorizontalMargin; 284 /** 285 * Margin between items vertically. 286 */ 287 private int mVerticalMargin; 288 /** 289 * Margin in main direction. 290 */ 291 private int mMarginPrimary; 292 /** 293 * Margin in second direction. 294 */ 295 private int mMarginSecondary; 296 /** 297 * How to position child in secondary direction. 298 */ 299 private int mGravity = Gravity.START | Gravity.TOP; 300 /** 301 * The number of rows in the grid. 302 */ 303 private int mNumRows; 304 /** 305 * Number of rows requested, can be 0 to be determined by parent size and 306 * rowHeight. 307 */ 308 private int mNumRowsRequested = 1; 309 310 /** 311 * Saves grid information of each view. 312 */ 313 private Grid mGrid; 314 315 /** 316 * Focus Scroll strategy. 317 */ 318 private int mFocusScrollStrategy = BaseGridView.FOCUS_SCROLL_ALIGNED; 319 /** 320 * Defines how item view is aligned in the window. 321 */ 322 private final WindowAlignment mWindowAlignment = new WindowAlignment(); 323 324 /** 325 * Defines how item view is aligned. 326 */ 327 private final ItemAlignment mItemAlignment = new ItemAlignment(); 328 329 /** 330 * Dimensions of the view, width or height depending on orientation. 331 */ 332 private int mSizePrimary; 333 334 /** 335 * Allow DPAD key to navigate out at the front of the View (where position = 0), 336 * default is false. 337 */ 338 private boolean mFocusOutFront; 339 340 /** 341 * Allow DPAD key to navigate out at the end of the view, default is false. 342 */ 343 private boolean mFocusOutEnd; 344 345 /** 346 * True if focus search is disabled. 347 */ 348 private boolean mFocusSearchDisabled; 349 350 /** 351 * True if prune child, might be disabled during transition. 352 */ 353 private boolean mPruneChild = true; 354 355 /** 356 * True if scroll content, might be disabled during transition. 357 */ 358 private boolean mScrollEnabled = true; 359 360 /** 361 * Temporary variable: an int array of length=2. 362 */ 363 private static int[] sTwoInts = new int[2]; 364 365 /** 366 * Set to true for RTL layout in horizontal orientation 367 */ 368 private boolean mReverseFlowPrimary = false; 369 370 /** 371 * Set to true for RTL layout in vertical orientation 372 */ 373 private boolean mReverseFlowSecondary = false; 374 375 /** 376 * Temporaries used for measuring. 377 */ 378 private int[] mMeasuredDimension = new int[2]; 379 380 final ViewsStateBundle mChildrenStates = new ViewsStateBundle(); 381 382 public GridLayoutManager(BaseGridView baseGridView) { 383 mBaseGridView = baseGridView; 384 } 385 386 public void setOrientation(int orientation) { 387 if (orientation != HORIZONTAL && orientation != VERTICAL) { 388 if (DEBUG) Log.v(getTag(), "invalid orientation: " + orientation); 389 return; 390 } 391 392 mOrientation = orientation; 393 mWindowAlignment.setOrientation(orientation); 394 mItemAlignment.setOrientation(orientation); 395 mForceFullLayout = true; 396 } 397 398 public void onRtlPropertiesChanged(int layoutDirection) { 399 if (mOrientation == HORIZONTAL) { 400 mReverseFlowPrimary = layoutDirection == View.LAYOUT_DIRECTION_RTL; 401 mReverseFlowSecondary = false; 402 } else { 403 mReverseFlowSecondary = layoutDirection == View.LAYOUT_DIRECTION_RTL; 404 mReverseFlowPrimary = false; 405 } 406 mWindowAlignment.horizontal.setReversedFlow(layoutDirection == View.LAYOUT_DIRECTION_RTL); 407 } 408 409 public int getFocusScrollStrategy() { 410 return mFocusScrollStrategy; 411 } 412 413 public void setFocusScrollStrategy(int focusScrollStrategy) { 414 mFocusScrollStrategy = focusScrollStrategy; 415 } 416 417 public void setWindowAlignment(int windowAlignment) { 418 mWindowAlignment.mainAxis().setWindowAlignment(windowAlignment); 419 } 420 421 public int getWindowAlignment() { 422 return mWindowAlignment.mainAxis().getWindowAlignment(); 423 } 424 425 public void setWindowAlignmentOffset(int alignmentOffset) { 426 mWindowAlignment.mainAxis().setWindowAlignmentOffset(alignmentOffset); 427 } 428 429 public int getWindowAlignmentOffset() { 430 return mWindowAlignment.mainAxis().getWindowAlignmentOffset(); 431 } 432 433 public void setWindowAlignmentOffsetPercent(float offsetPercent) { 434 mWindowAlignment.mainAxis().setWindowAlignmentOffsetPercent(offsetPercent); 435 } 436 437 public float getWindowAlignmentOffsetPercent() { 438 return mWindowAlignment.mainAxis().getWindowAlignmentOffsetPercent(); 439 } 440 441 public void setItemAlignmentOffset(int alignmentOffset) { 442 mItemAlignment.mainAxis().setItemAlignmentOffset(alignmentOffset); 443 updateChildAlignments(); 444 } 445 446 public int getItemAlignmentOffset() { 447 return mItemAlignment.mainAxis().getItemAlignmentOffset(); 448 } 449 450 public void setItemAlignmentOffsetWithPadding(boolean withPadding) { 451 mItemAlignment.mainAxis().setItemAlignmentOffsetWithPadding(withPadding); 452 updateChildAlignments(); 453 } 454 455 public boolean isItemAlignmentOffsetWithPadding() { 456 return mItemAlignment.mainAxis().isItemAlignmentOffsetWithPadding(); 457 } 458 459 public void setItemAlignmentOffsetPercent(float offsetPercent) { 460 mItemAlignment.mainAxis().setItemAlignmentOffsetPercent(offsetPercent); 461 updateChildAlignments(); 462 } 463 464 public float getItemAlignmentOffsetPercent() { 465 return mItemAlignment.mainAxis().getItemAlignmentOffsetPercent(); 466 } 467 468 public void setItemAlignmentViewId(int viewId) { 469 mItemAlignment.mainAxis().setItemAlignmentViewId(viewId); 470 updateChildAlignments(); 471 } 472 473 public int getItemAlignmentViewId() { 474 return mItemAlignment.mainAxis().getItemAlignmentViewId(); 475 } 476 477 public void setFocusOutAllowed(boolean throughFront, boolean throughEnd) { 478 mFocusOutFront = throughFront; 479 mFocusOutEnd = throughEnd; 480 } 481 482 public void setNumRows(int numRows) { 483 if (numRows < 0) throw new IllegalArgumentException(); 484 mNumRowsRequested = numRows; 485 mForceFullLayout = true; 486 } 487 488 /** 489 * Set the row height. May be WRAP_CONTENT, or a size in pixels. 490 */ 491 public void setRowHeight(int height) { 492 if (height >= 0 || height == ViewGroup.LayoutParams.WRAP_CONTENT) { 493 mRowSizeSecondaryRequested = height; 494 } else { 495 throw new IllegalArgumentException("Invalid row height: " + height); 496 } 497 } 498 499 public void setItemMargin(int margin) { 500 mVerticalMargin = mHorizontalMargin = margin; 501 mMarginPrimary = mMarginSecondary = margin; 502 } 503 504 public void setVerticalMargin(int margin) { 505 if (mOrientation == HORIZONTAL) { 506 mMarginSecondary = mVerticalMargin = margin; 507 } else { 508 mMarginPrimary = mVerticalMargin = margin; 509 } 510 } 511 512 public void setHorizontalMargin(int margin) { 513 if (mOrientation == HORIZONTAL) { 514 mMarginPrimary = mHorizontalMargin = margin; 515 } else { 516 mMarginSecondary = mHorizontalMargin = margin; 517 } 518 } 519 520 public int getVerticalMargin() { 521 return mVerticalMargin; 522 } 523 524 public int getHorizontalMargin() { 525 return mHorizontalMargin; 526 } 527 528 public void setGravity(int gravity) { 529 mGravity = gravity; 530 } 531 532 protected boolean hasDoneFirstLayout() { 533 return mGrid != null; 534 } 535 536 public void setOnChildSelectedListener(OnChildSelectedListener listener) { 537 mChildSelectedListener = listener; 538 } 539 540 private int getPositionByView(View view) { 541 if (view == null) { 542 return NO_POSITION; 543 } 544 LayoutParams params = (LayoutParams) view.getLayoutParams(); 545 if (params == null || params.isItemRemoved()) { 546 // when item is removed, the position value can be any value. 547 return NO_POSITION; 548 } 549 return params.getViewPosition(); 550 } 551 552 private int getPositionByIndex(int index) { 553 return getPositionByView(getChildAt(index)); 554 } 555 556 private void dispatchChildSelected() { 557 if (mChildSelectedListener == null) { 558 return; 559 } 560 561 if (TRACE) TraceHelper.beginSection("onChildSelected"); 562 View view = mFocusPosition == NO_POSITION ? null : findViewByPosition(mFocusPosition); 563 if (view != null) { 564 RecyclerView.ViewHolder vh = mBaseGridView.getChildViewHolder(view); 565 mChildSelectedListener.onChildSelected(mBaseGridView, view, mFocusPosition, 566 vh == null? NO_ID: vh.getItemId()); 567 } else { 568 mChildSelectedListener.onChildSelected(mBaseGridView, null, NO_POSITION, NO_ID); 569 } 570 if (TRACE) TraceHelper.endSection(); 571 572 // Children may request layout when a child selection event occurs (such as a change of 573 // padding on the current and previously selected rows). 574 // If in layout, a child requesting layout may have been laid out before the selection 575 // callback. 576 // If it was not, the child will be laid out after the selection callback. 577 // If so, the layout request will be honoured though the view system will emit a double- 578 // layout warning. 579 // If not in layout, we may be scrolling in which case the child layout request will be 580 // eaten by recyclerview. Post a requestLayout. 581 if (!mInLayout && !mBaseGridView.isLayoutRequested()) { 582 int childCount = getChildCount(); 583 for (int i = 0; i < childCount; i++) { 584 if (getChildAt(i).isLayoutRequested()) { 585 forceRequestLayout(); 586 break; 587 } 588 } 589 } 590 } 591 592 @Override 593 public boolean canScrollHorizontally() { 594 // We can scroll horizontally if we have horizontal orientation, or if 595 // we are vertical and have more than one column. 596 return mOrientation == HORIZONTAL || mNumRows > 1; 597 } 598 599 @Override 600 public boolean canScrollVertically() { 601 // We can scroll vertically if we have vertical orientation, or if we 602 // are horizontal and have more than one row. 603 return mOrientation == VERTICAL || mNumRows > 1; 604 } 605 606 @Override 607 public RecyclerView.LayoutParams generateDefaultLayoutParams() { 608 return new LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, 609 ViewGroup.LayoutParams.WRAP_CONTENT); 610 } 611 612 @Override 613 public RecyclerView.LayoutParams generateLayoutParams(Context context, AttributeSet attrs) { 614 return new LayoutParams(context, attrs); 615 } 616 617 @Override 618 public RecyclerView.LayoutParams generateLayoutParams(ViewGroup.LayoutParams lp) { 619 if (lp instanceof LayoutParams) { 620 return new LayoutParams((LayoutParams) lp); 621 } else if (lp instanceof RecyclerView.LayoutParams) { 622 return new LayoutParams((RecyclerView.LayoutParams) lp); 623 } else if (lp instanceof MarginLayoutParams) { 624 return new LayoutParams((MarginLayoutParams) lp); 625 } else { 626 return new LayoutParams(lp); 627 } 628 } 629 630 protected View getViewForPosition(int position) { 631 return mRecycler.getViewForPosition(position); 632 } 633 634 final int getOpticalLeft(View v) { 635 return ((LayoutParams) v.getLayoutParams()).getOpticalLeft(v); 636 } 637 638 final int getOpticalRight(View v) { 639 return ((LayoutParams) v.getLayoutParams()).getOpticalRight(v); 640 } 641 642 final int getOpticalTop(View v) { 643 return ((LayoutParams) v.getLayoutParams()).getOpticalTop(v); 644 } 645 646 final int getOpticalBottom(View v) { 647 return ((LayoutParams) v.getLayoutParams()).getOpticalBottom(v); 648 } 649 650 private int getViewMin(View v) { 651 return (mOrientation == HORIZONTAL) ? getOpticalLeft(v) : getOpticalTop(v); 652 } 653 654 private int getViewMax(View v) { 655 return (mOrientation == HORIZONTAL) ? getOpticalRight(v) : getOpticalBottom(v); 656 } 657 658 private int getViewCenter(View view) { 659 return (mOrientation == HORIZONTAL) ? getViewCenterX(view) : getViewCenterY(view); 660 } 661 662 private int getViewCenterSecondary(View view) { 663 return (mOrientation == HORIZONTAL) ? getViewCenterY(view) : getViewCenterX(view); 664 } 665 666 private int getViewCenterX(View v) { 667 LayoutParams p = (LayoutParams) v.getLayoutParams(); 668 return p.getOpticalLeft(v) + p.getAlignX(); 669 } 670 671 private int getViewCenterY(View v) { 672 LayoutParams p = (LayoutParams) v.getLayoutParams(); 673 return p.getOpticalTop(v) + p.getAlignY(); 674 } 675 676 /** 677 * Save Recycler and State for convenience. Must be paired with leaveContext(). 678 */ 679 private void saveContext(Recycler recycler, State state) { 680 if (mRecycler != null || mState != null) { 681 Log.e(TAG, "Recycler information was not released, bug!"); 682 } 683 mRecycler = recycler; 684 mState = state; 685 } 686 687 /** 688 * Discard saved Recycler and State. 689 */ 690 private void leaveContext() { 691 mRecycler = null; 692 mState = null; 693 } 694 695 /** 696 * Re-initialize data structures for a data change or handling invisible 697 * selection. The method tries its best to preserve position information so 698 * that staggered grid looks same before and after re-initialize. 699 * @return true if can fastRelayout() 700 */ 701 private boolean layoutInit() { 702 if (!mState.didStructureChange() && !mForceFullLayout && mGrid != null) { 703 updateScrollController(); 704 updateScrollSecondAxis(); 705 mGrid.setMargin(mMarginPrimary); 706 return true; 707 } else { 708 mForceFullLayout = false; 709 boolean focusViewWasInTree = mGrid != null && mFocusPosition >= 0 710 && mFocusPosition >= mGrid.getFirstVisibleIndex() 711 && mFocusPosition <= mGrid.getLastVisibleIndex(); 712 int firstVisibleIndex = focusViewWasInTree ? mGrid.getFirstVisibleIndex() : 0; 713 final int newItemCount = mState.getItemCount(); 714 if (newItemCount == 0) { 715 mFocusPosition = NO_POSITION; 716 } else if (mFocusPosition >= newItemCount) { 717 mFocusPosition = newItemCount - 1; 718 } else if (mFocusPosition == NO_POSITION && newItemCount > 0) { 719 // if focus position is never set before, initialize it to 0 720 mFocusPosition = 0; 721 } 722 723 if (mGrid == null || mNumRows != mGrid.getNumRows() || 724 mReverseFlowPrimary != mGrid.isReversedFlow()) { 725 mGrid = Grid.createStaggeredMultipleRows(mNumRows); 726 mGrid.setProvider(mGridProvider); 727 mGrid.setReversedFlow(mReverseFlowPrimary); 728 } 729 initScrollController(); 730 updateScrollSecondAxis(); 731 mGrid.setMargin(mMarginPrimary); 732 detachAndScrapAttachedViews(mRecycler); 733 mGrid.resetVisibleIndex(); 734 if (mFocusPosition == NO_POSITION) { 735 mBaseGridView.clearFocus(); 736 } 737 mWindowAlignment.mainAxis().invalidateScrollMin(); 738 mWindowAlignment.mainAxis().invalidateScrollMax(); 739 if (focusViewWasInTree && firstVisibleIndex <= mFocusPosition) { 740 // if focusView was in tree, we will add item from first visible item 741 mGrid.setStart(firstVisibleIndex); 742 } else { 743 // if focusView was not in tree, it's probably because focus position jumped 744 // far away from visible range, so use mFocusPosition as start 745 mGrid.setStart(mFocusPosition); 746 } 747 return false; 748 } 749 } 750 751 private int getRowSizeSecondary(int rowIndex) { 752 if (mFixedRowSizeSecondary != 0) { 753 return mFixedRowSizeSecondary; 754 } 755 if (mRowSizeSecondary == null) { 756 return 0; 757 } 758 return mRowSizeSecondary[rowIndex]; 759 } 760 761 private int getRowStartSecondary(int rowIndex) { 762 int start = 0; 763 // Iterate from left to right, which is a different index traversal 764 // in RTL flow 765 if (mReverseFlowSecondary) { 766 for (int i = mNumRows-1; i > rowIndex; i--) { 767 start += getRowSizeSecondary(i) + mMarginSecondary; 768 } 769 } else { 770 for (int i = 0; i < rowIndex; i++) { 771 start += getRowSizeSecondary(i) + mMarginSecondary; 772 } 773 } 774 return start; 775 } 776 777 private int getSizeSecondary() { 778 int rightmostIndex = mReverseFlowSecondary ? 0 : mNumRows - 1; 779 return getRowStartSecondary(rightmostIndex) + getRowSizeSecondary(rightmostIndex); 780 } 781 782 private void measureScrapChild(int position, int widthSpec, int heightSpec, 783 int[] measuredDimension) { 784 View view = mRecycler.getViewForPosition(position); 785 if (view != null) { 786 LayoutParams p = (LayoutParams) view.getLayoutParams(); 787 int childWidthSpec = ViewGroup.getChildMeasureSpec(widthSpec, 788 getPaddingLeft() + getPaddingRight(), p.width); 789 int childHeightSpec = ViewGroup.getChildMeasureSpec(heightSpec, 790 getPaddingTop() + getPaddingBottom(), p.height); 791 view.measure(childWidthSpec, childHeightSpec); 792 measuredDimension[0] = view.getMeasuredWidth(); 793 measuredDimension[1] = view.getMeasuredHeight(); 794 mRecycler.recycleView(view); 795 } 796 } 797 798 private boolean processRowSizeSecondary(boolean measure) { 799 if (mFixedRowSizeSecondary != 0) { 800 return false; 801 } 802 803 if (TRACE) TraceHelper.beginSection("processRowSizeSecondary"); 804 CircularIntArray[] rows = mGrid == null ? null : mGrid.getItemPositionsInRows(); 805 boolean changed = false; 806 int scrapChildWidth = -1; 807 int scrapChildHeight = -1; 808 809 for (int rowIndex = 0; rowIndex < mNumRows; rowIndex++) { 810 CircularIntArray row = rows == null ? null : rows[rowIndex]; 811 final int rowItemsPairCount = row == null ? 0 : row.size(); 812 int rowSize = -1; 813 for (int rowItemPairIndex = 0; rowItemPairIndex < rowItemsPairCount; 814 rowItemPairIndex += 2) { 815 final int rowIndexStart = row.get(rowItemPairIndex); 816 final int rowIndexEnd = row.get(rowItemPairIndex + 1); 817 for (int i = rowIndexStart; i <= rowIndexEnd; i++) { 818 final View view = findViewByPosition(i); 819 if (view == null) { 820 continue; 821 } 822 if (measure && view.isLayoutRequested()) { 823 measureChild(view); 824 } 825 final int secondarySize = mOrientation == HORIZONTAL ? 826 view.getMeasuredHeight() : view.getMeasuredWidth(); 827 if (secondarySize > rowSize) { 828 rowSize = secondarySize; 829 } 830 } 831 } 832 833 final int itemCount = mState.getItemCount(); 834 if (measure && rowSize < 0 && itemCount > 0) { 835 if (scrapChildWidth < 0 && scrapChildHeight < 0) { 836 int position; 837 if (mFocusPosition == NO_POSITION) { 838 position = 0; 839 } else if (mFocusPosition >= itemCount) { 840 position = itemCount - 1; 841 } else { 842 position = mFocusPosition; 843 } 844 measureScrapChild(position, 845 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 846 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 847 mMeasuredDimension); 848 scrapChildWidth = mMeasuredDimension[0]; 849 scrapChildHeight = mMeasuredDimension[1]; 850 if (DEBUG) Log.v(TAG, "measured scrap child: " + scrapChildWidth + 851 " " + scrapChildHeight); 852 } 853 rowSize = mOrientation == HORIZONTAL ? scrapChildHeight : scrapChildWidth; 854 } 855 if (rowSize < 0) { 856 rowSize = 0; 857 } 858 if (mRowSizeSecondary[rowIndex] != rowSize) { 859 if (DEBUG) Log.v(getTag(), "row size secondary changed: " + mRowSizeSecondary[rowIndex] + 860 ", " + rowSize); 861 mRowSizeSecondary[rowIndex] = rowSize; 862 changed = true; 863 } 864 } 865 866 if (TRACE) TraceHelper.endSection(); 867 return changed; 868 } 869 870 /** 871 * Checks if we need to update row secondary sizes. 872 */ 873 private void updateRowSecondarySizeRefresh() { 874 mRowSecondarySizeRefresh = processRowSizeSecondary(false); 875 if (mRowSecondarySizeRefresh) { 876 if (DEBUG) Log.v(getTag(), "mRowSecondarySizeRefresh now set"); 877 forceRequestLayout(); 878 } 879 } 880 881 private void forceRequestLayout() { 882 if (DEBUG) Log.v(getTag(), "forceRequestLayout"); 883 // RecyclerView prevents us from requesting layout in many cases 884 // (during layout, during scroll, etc.) 885 // For secondary row size wrap_content support we currently need a 886 // second layout pass to update the measured size after having measured 887 // and added child views in layoutChildren. 888 // Force the second layout by posting a delayed runnable. 889 // TODO: investigate allowing a second layout pass, 890 // or move child add/measure logic to the measure phase. 891 ViewCompat.postOnAnimation(mBaseGridView, mRequestLayoutRunnable); 892 } 893 894 private final Runnable mRequestLayoutRunnable = new Runnable() { 895 @Override 896 public void run() { 897 if (DEBUG) Log.v(getTag(), "request Layout from runnable"); 898 requestLayout(); 899 } 900 }; 901 902 @Override 903 public void onMeasure(Recycler recycler, State state, int widthSpec, int heightSpec) { 904 saveContext(recycler, state); 905 906 int sizePrimary, sizeSecondary, modeSecondary, paddingSecondary; 907 int measuredSizeSecondary; 908 if (mOrientation == HORIZONTAL) { 909 sizePrimary = MeasureSpec.getSize(widthSpec); 910 sizeSecondary = MeasureSpec.getSize(heightSpec); 911 modeSecondary = MeasureSpec.getMode(heightSpec); 912 paddingSecondary = getPaddingTop() + getPaddingBottom(); 913 } else { 914 sizeSecondary = MeasureSpec.getSize(widthSpec); 915 sizePrimary = MeasureSpec.getSize(heightSpec); 916 modeSecondary = MeasureSpec.getMode(widthSpec); 917 paddingSecondary = getPaddingLeft() + getPaddingRight(); 918 } 919 if (DEBUG) Log.v(getTag(), "onMeasure widthSpec " + Integer.toHexString(widthSpec) + 920 " heightSpec " + Integer.toHexString(heightSpec) + 921 " modeSecondary " + Integer.toHexString(modeSecondary) + 922 " sizeSecondary " + sizeSecondary + " " + this); 923 924 mMaxSizeSecondary = sizeSecondary; 925 926 if (mRowSizeSecondaryRequested == ViewGroup.LayoutParams.WRAP_CONTENT) { 927 mNumRows = mNumRowsRequested == 0 ? 1 : mNumRowsRequested; 928 mFixedRowSizeSecondary = 0; 929 930 if (mRowSizeSecondary == null || mRowSizeSecondary.length != mNumRows) { 931 mRowSizeSecondary = new int[mNumRows]; 932 } 933 934 // Measure all current children and update cached row heights 935 processRowSizeSecondary(true); 936 937 switch (modeSecondary) { 938 case MeasureSpec.UNSPECIFIED: 939 measuredSizeSecondary = getSizeSecondary() + paddingSecondary; 940 break; 941 case MeasureSpec.AT_MOST: 942 measuredSizeSecondary = Math.min(getSizeSecondary() + paddingSecondary, 943 mMaxSizeSecondary); 944 break; 945 case MeasureSpec.EXACTLY: 946 measuredSizeSecondary = mMaxSizeSecondary; 947 break; 948 default: 949 throw new IllegalStateException("wrong spec"); 950 } 951 952 } else { 953 switch (modeSecondary) { 954 case MeasureSpec.UNSPECIFIED: 955 if (mRowSizeSecondaryRequested == 0) { 956 if (mOrientation == HORIZONTAL) { 957 throw new IllegalStateException("Must specify rowHeight or view height"); 958 } else { 959 throw new IllegalStateException("Must specify columnWidth or view width"); 960 } 961 } 962 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 963 mNumRows = mNumRowsRequested == 0 ? 1 : mNumRowsRequested; 964 measuredSizeSecondary = mFixedRowSizeSecondary * mNumRows + mMarginSecondary 965 * (mNumRows - 1) + paddingSecondary; 966 break; 967 case MeasureSpec.AT_MOST: 968 case MeasureSpec.EXACTLY: 969 if (mNumRowsRequested == 0 && mRowSizeSecondaryRequested == 0) { 970 mNumRows = 1; 971 mFixedRowSizeSecondary = sizeSecondary - paddingSecondary; 972 } else if (mNumRowsRequested == 0) { 973 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 974 mNumRows = (sizeSecondary + mMarginSecondary) 975 / (mRowSizeSecondaryRequested + mMarginSecondary); 976 } else if (mRowSizeSecondaryRequested == 0) { 977 mNumRows = mNumRowsRequested; 978 mFixedRowSizeSecondary = (sizeSecondary - paddingSecondary - mMarginSecondary 979 * (mNumRows - 1)) / mNumRows; 980 } else { 981 mNumRows = mNumRowsRequested; 982 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 983 } 984 measuredSizeSecondary = sizeSecondary; 985 if (modeSecondary == MeasureSpec.AT_MOST) { 986 int childrenSize = mFixedRowSizeSecondary * mNumRows + mMarginSecondary 987 * (mNumRows - 1) + paddingSecondary; 988 if (childrenSize < measuredSizeSecondary) { 989 measuredSizeSecondary = childrenSize; 990 } 991 } 992 break; 993 default: 994 throw new IllegalStateException("wrong spec"); 995 } 996 } 997 if (mOrientation == HORIZONTAL) { 998 setMeasuredDimension(sizePrimary, measuredSizeSecondary); 999 } else { 1000 setMeasuredDimension(measuredSizeSecondary, sizePrimary); 1001 } 1002 if (DEBUG) { 1003 Log.v(getTag(), "onMeasure sizePrimary " + sizePrimary + 1004 " measuredSizeSecondary " + measuredSizeSecondary + 1005 " mFixedRowSizeSecondary " + mFixedRowSizeSecondary + 1006 " mNumRows " + mNumRows); 1007 } 1008 leaveContext(); 1009 } 1010 1011 private void measureChild(View child) { 1012 if (TRACE) TraceHelper.beginSection("measureChild"); 1013 final ViewGroup.LayoutParams lp = child.getLayoutParams(); 1014 final int secondarySpec = (mRowSizeSecondaryRequested == ViewGroup.LayoutParams.WRAP_CONTENT) ? 1015 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED) : 1016 MeasureSpec.makeMeasureSpec(mFixedRowSizeSecondary, MeasureSpec.EXACTLY); 1017 int widthSpec, heightSpec; 1018 1019 if (mOrientation == HORIZONTAL) { 1020 widthSpec = ViewGroup.getChildMeasureSpec( 1021 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 1022 0, lp.width); 1023 heightSpec = ViewGroup.getChildMeasureSpec(secondarySpec, 0, lp.height); 1024 } else { 1025 heightSpec = ViewGroup.getChildMeasureSpec( 1026 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 1027 0, lp.height); 1028 widthSpec = ViewGroup.getChildMeasureSpec(secondarySpec, 0, lp.width); 1029 } 1030 child.measure(widthSpec, heightSpec); 1031 if (DEBUG) Log.v(getTag(), "measureChild secondarySpec " + Integer.toHexString(secondarySpec) + 1032 " widthSpec " + Integer.toHexString(widthSpec) + 1033 " heightSpec " + Integer.toHexString(heightSpec) + 1034 " measuredWidth " + child.getMeasuredWidth() + 1035 " measuredHeight " + child.getMeasuredHeight()); 1036 if (DEBUG) Log.v(getTag(), "child lp width " + lp.width + " height " + lp.height); 1037 if (TRACE) TraceHelper.endSection(); 1038 } 1039 1040 private Grid.Provider mGridProvider = new Grid.Provider() { 1041 1042 @Override 1043 public int getCount() { 1044 return mState.getItemCount(); 1045 } 1046 1047 @Override 1048 public int createItem(int index, boolean append, Object[] item) { 1049 if (TRACE) TraceHelper.beginSection("createItem"); 1050 if (TRACE) TraceHelper.beginSection("getview"); 1051 View v = getViewForPosition(index); 1052 if (TRACE) TraceHelper.endSection(); 1053 // See recyclerView docs: we don't need re-add scraped view if it was removed. 1054 if (!((RecyclerView.LayoutParams) v.getLayoutParams()).isItemRemoved()) { 1055 if (TRACE) TraceHelper.beginSection("addView"); 1056 if (append) { 1057 addView(v); 1058 } else { 1059 addView(v, 0); 1060 } 1061 if (TRACE) TraceHelper.endSection(); 1062 if (mChildVisibility != -1) { 1063 v.setVisibility(mChildVisibility); 1064 } 1065 1066 // View is added first or it won't be found by dispatchChildSelected. 1067 if (mInLayout && index == mFocusPosition) { 1068 dispatchChildSelected(); 1069 } 1070 measureChild(v); 1071 } 1072 item[0] = v; 1073 return mOrientation == HORIZONTAL ? v.getMeasuredWidth() : v.getMeasuredHeight(); 1074 } 1075 1076 @Override 1077 public void addItem(Object item, int index, int length, int rowIndex, int edge) { 1078 View v = (View) item; 1079 int start, end; 1080 if (edge == Integer.MIN_VALUE || edge == Integer.MAX_VALUE) { 1081 edge = !mGrid.isReversedFlow() ? mWindowAlignment.mainAxis().getPaddingLow() 1082 : mWindowAlignment.mainAxis().getSize() 1083 - mWindowAlignment.mainAxis().getPaddingHigh(); 1084 } 1085 boolean edgeIsMin = !mGrid.isReversedFlow(); 1086 if (edgeIsMin) { 1087 start = edge; 1088 end = edge + length; 1089 } else { 1090 start = edge - length; 1091 end = edge; 1092 } 1093 int startSecondary = getRowStartSecondary(rowIndex) - mScrollOffsetSecondary; 1094 mChildrenStates.loadView(v, index); 1095 layoutChild(rowIndex, v, start, end, startSecondary); 1096 if (DEBUG) { 1097 Log.d(getTag(), "addView " + index + " " + v); 1098 } 1099 if (TRACE) TraceHelper.endSection(); 1100 1101 if (index == mGrid.getFirstVisibleIndex()) { 1102 if (!mGrid.isReversedFlow()) { 1103 updateScrollMin(); 1104 } else { 1105 updateScrollMax(); 1106 } 1107 } 1108 if (index == mGrid.getLastVisibleIndex()) { 1109 if (!mGrid.isReversedFlow()) { 1110 updateScrollMax(); 1111 } else { 1112 updateScrollMin(); 1113 } 1114 } 1115 } 1116 1117 @Override 1118 public void removeItem(int index) { 1119 if (TRACE) TraceHelper.beginSection("removeItem"); 1120 View v = findViewByPosition(index); 1121 if (mInLayout) { 1122 detachAndScrapView(v, mRecycler); 1123 } else { 1124 removeAndRecycleView(v, mRecycler); 1125 } 1126 if (TRACE) TraceHelper.endSection(); 1127 } 1128 1129 @Override 1130 public int getEdge(int index) { 1131 if (mReverseFlowPrimary) { 1132 return getViewMax(findViewByPosition(index)); 1133 } else { 1134 return getViewMin(findViewByPosition(index)); 1135 } 1136 } 1137 1138 @Override 1139 public int getSize(int index) { 1140 final View v = findViewByPosition(index); 1141 return mOrientation == HORIZONTAL ? v.getMeasuredWidth() : v.getMeasuredHeight(); 1142 } 1143 }; 1144 1145 private void layoutChild(int rowIndex, View v, int start, int end, int startSecondary) { 1146 if (TRACE) TraceHelper.beginSection("layoutChild"); 1147 int sizeSecondary = mOrientation == HORIZONTAL ? v.getMeasuredHeight() 1148 : v.getMeasuredWidth(); 1149 if (mFixedRowSizeSecondary > 0) { 1150 sizeSecondary = Math.min(sizeSecondary, mFixedRowSizeSecondary); 1151 } 1152 final int verticalGravity = mGravity & Gravity.VERTICAL_GRAVITY_MASK; 1153 final int horizontalGravity = (mReverseFlowPrimary || mReverseFlowSecondary) ? 1154 Gravity.getAbsoluteGravity(mGravity & Gravity.RELATIVE_HORIZONTAL_GRAVITY_MASK, View.LAYOUT_DIRECTION_RTL) : 1155 mGravity & Gravity.HORIZONTAL_GRAVITY_MASK; 1156 if (mOrientation == HORIZONTAL && verticalGravity == Gravity.TOP 1157 || mOrientation == VERTICAL && horizontalGravity == Gravity.LEFT) { 1158 // do nothing 1159 } else if (mOrientation == HORIZONTAL && verticalGravity == Gravity.BOTTOM 1160 || mOrientation == VERTICAL && horizontalGravity == Gravity.RIGHT) { 1161 startSecondary += getRowSizeSecondary(rowIndex) - sizeSecondary; 1162 } else if (mOrientation == HORIZONTAL && verticalGravity == Gravity.CENTER_VERTICAL 1163 || mOrientation == VERTICAL && horizontalGravity == Gravity.CENTER_HORIZONTAL) { 1164 startSecondary += (getRowSizeSecondary(rowIndex) - sizeSecondary) / 2; 1165 } 1166 int left, top, right, bottom; 1167 if (mOrientation == HORIZONTAL) { 1168 left = start; 1169 top = startSecondary; 1170 right = end; 1171 bottom = startSecondary + sizeSecondary; 1172 } else { 1173 top = start; 1174 left = startSecondary; 1175 bottom = end; 1176 right = startSecondary + sizeSecondary; 1177 } 1178 v.layout(left, top, right, bottom); 1179 updateChildOpticalInsets(v, left, top, right, bottom); 1180 updateChildAlignments(v); 1181 if (TRACE) TraceHelper.endSection(); 1182 } 1183 1184 private void updateChildOpticalInsets(View v, int left, int top, int right, int bottom) { 1185 LayoutParams p = (LayoutParams) v.getLayoutParams(); 1186 p.setOpticalInsets(left - v.getLeft(), top - v.getTop(), 1187 v.getRight() - right, v.getBottom() - bottom); 1188 } 1189 1190 private void updateChildAlignments(View v) { 1191 LayoutParams p = (LayoutParams) v.getLayoutParams(); 1192 p.setAlignX(mItemAlignment.horizontal.getAlignmentPosition(v)); 1193 p.setAlignY(mItemAlignment.vertical.getAlignmentPosition(v)); 1194 } 1195 1196 private void updateChildAlignments() { 1197 for (int i = 0, c = getChildCount(); i < c; i++) { 1198 updateChildAlignments(getChildAt(i)); 1199 } 1200 } 1201 1202 private void removeInvisibleViewsAtEnd() { 1203 if (mPruneChild) { 1204 mGrid.removeInvisibleItemsAtEnd(mFocusPosition, 1205 mReverseFlowPrimary ? 0 : mSizePrimary); 1206 } 1207 } 1208 1209 private void removeInvisibleViewsAtFront() { 1210 if (mPruneChild) { 1211 mGrid.removeInvisibleItemsAtFront(mFocusPosition, 1212 mReverseFlowPrimary ? mSizePrimary : 0); 1213 } 1214 } 1215 1216 private boolean appendOneColumnVisibleItems() { 1217 return mGrid.appendOneColumnVisibleItems(); 1218 } 1219 1220 private boolean prependOneColumnVisibleItems() { 1221 return mGrid.prependOneColumnVisibleItems(); 1222 } 1223 1224 private void appendVisibleItems() { 1225 mGrid.appendVisibleItems(mReverseFlowPrimary ? 0 : mSizePrimary); 1226 } 1227 1228 private void prependVisibleItems() { 1229 mGrid.prependVisibleItems(mReverseFlowPrimary ? mSizePrimary : 0); 1230 } 1231 1232 /** 1233 * Fast layout when there is no structure change, adapter change, etc. 1234 * It will layout all views was layout requested or updated, until hit a view 1235 * with different size, then it break and detachAndScrap all views after that. 1236 */ 1237 private void fastRelayout() { 1238 boolean invalidateAfter = false; 1239 final int childCount = getChildCount(); 1240 int position = -1; 1241 for (int index = 0; index < childCount; index++) { 1242 View view = getChildAt(index); 1243 position = getPositionByIndex(index); 1244 Grid.Location location = mGrid.getLocation(position); 1245 if (location == null) { 1246 if (DEBUG) Log.w(getTag(), "fastRelayout(): no Location at " + position); 1247 invalidateAfter = true; 1248 break; 1249 } 1250 1251 int startSecondary = getRowStartSecondary(location.row) - mScrollOffsetSecondary; 1252 int primarySize, end; 1253 int start = getViewMin(view); 1254 int oldPrimarySize = (mOrientation == HORIZONTAL) ? 1255 view.getMeasuredWidth() : 1256 view.getMeasuredHeight(); 1257 1258 LayoutParams lp = (LayoutParams) view.getLayoutParams(); 1259 if (lp.viewNeedsUpdate()) { 1260 int viewIndex = mBaseGridView.indexOfChild(view); 1261 detachAndScrapView(view, mRecycler); 1262 view = getViewForPosition(position); 1263 addView(view, viewIndex); 1264 } 1265 1266 if (view.isLayoutRequested()) { 1267 measureChild(view); 1268 } 1269 if (mOrientation == HORIZONTAL) { 1270 primarySize = view.getMeasuredWidth(); 1271 end = start + primarySize; 1272 } else { 1273 primarySize = view.getMeasuredHeight(); 1274 end = start + primarySize; 1275 } 1276 layoutChild(location.row, view, start, end, startSecondary); 1277 if (oldPrimarySize != primarySize) { 1278 // size changed invalidate remaining Locations 1279 if (DEBUG) Log.d(getTag(), "fastRelayout: view size changed at " + position); 1280 invalidateAfter = true; 1281 break; 1282 } 1283 } 1284 if (invalidateAfter) { 1285 final int savedLastPos = mGrid.getLastVisibleIndex(); 1286 mGrid.invalidateItemsAfter(position); 1287 if (mPruneChild) { 1288 // in regular prune child mode, we just append items up to edge limit 1289 appendVisibleItems(); 1290 } else { 1291 // prune disabled(e.g. in RowsFragment transition): append all removed items 1292 while (mGrid.appendOneColumnVisibleItems() 1293 && mGrid.getLastVisibleIndex() < savedLastPos); 1294 } 1295 } 1296 updateScrollMin(); 1297 updateScrollMax(); 1298 updateScrollSecondAxis(); 1299 } 1300 1301 public void removeAndRecycleAllViews(RecyclerView.Recycler recycler) { 1302 if (TRACE) TraceHelper.beginSection("removeAndRecycleAllViews"); 1303 if (DEBUG) Log.v(TAG, "removeAndRecycleAllViews " + getChildCount()); 1304 for (int i = getChildCount() - 1; i >= 0; i--) { 1305 removeAndRecycleViewAt(i, recycler); 1306 } 1307 if (TRACE) TraceHelper.endSection(); 1308 } 1309 1310 // Lays out items based on the current scroll position 1311 @Override 1312 public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state) { 1313 if (DEBUG) { 1314 Log.v(getTag(), "layoutChildren start numRows " + mNumRows + " mScrollOffsetSecondary " 1315 + mScrollOffsetSecondary + " mScrollOffsetPrimary " + mScrollOffsetPrimary 1316 + " inPreLayout " + state.isPreLayout() 1317 + " didStructureChange " + state.didStructureChange() 1318 + " mForceFullLayout " + mForceFullLayout); 1319 Log.v(getTag(), "width " + getWidth() + " height " + getHeight()); 1320 } 1321 1322 if (mNumRows == 0) { 1323 // haven't done measure yet 1324 return; 1325 } 1326 final int itemCount = state.getItemCount(); 1327 if (itemCount < 0) { 1328 return; 1329 } 1330 1331 if (!mLayoutEnabled) { 1332 discardLayoutInfo(); 1333 removeAndRecycleAllViews(recycler); 1334 return; 1335 } 1336 mInLayout = true; 1337 1338 final boolean scrollToFocus = !isSmoothScrolling() 1339 && mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED; 1340 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE) { 1341 mFocusPosition = mFocusPosition + mFocusPositionOffset; 1342 mFocusPositionOffset = 0; 1343 } 1344 saveContext(recycler, state); 1345 1346 // Track the old focus view so we can adjust our system scroll position 1347 // so that any scroll animations happening now will remain valid. 1348 // We must use same delta in Pre Layout (if prelayout exists) and second layout. 1349 // So we cache the deltas in PreLayout and use it in second layout. 1350 int delta = 0, deltaSecondary = 0; 1351 if (mFocusPosition != NO_POSITION && scrollToFocus 1352 && mBaseGridView.getScrollState() != RecyclerView.SCROLL_STATE_IDLE) { 1353 // FIXME: we should get the remaining scroll animation offset from RecyclerView 1354 View focusView = findViewByPosition(mFocusPosition); 1355 if (focusView != null) { 1356 delta = mWindowAlignment.mainAxis().getSystemScrollPos(mScrollOffsetPrimary 1357 + getViewCenter(focusView), false, false) - mScrollOffsetPrimary; 1358 deltaSecondary = mWindowAlignment.secondAxis().getSystemScrollPos( 1359 mScrollOffsetSecondary + getViewCenterSecondary(focusView), 1360 false, false) - mScrollOffsetSecondary; 1361 } 1362 } 1363 1364 boolean hadFocus = mBaseGridView.hasFocus(); 1365 int savedFocusPos = mFocusPosition; 1366 boolean fastRelayout; 1367 if (fastRelayout = layoutInit()) { 1368 fastRelayout(); 1369 View focusView = findViewByPosition(mFocusPosition); 1370 if (scrollToFocus) { 1371 scrollToView(focusView, false); 1372 } 1373 if (focusView != null && hadFocus) { 1374 focusView.requestFocus(); 1375 } 1376 } else { 1377 if (mFocusPosition != NO_POSITION) { 1378 // appends items till focus position. 1379 while (appendOneColumnVisibleItems() 1380 && findViewByPosition(mFocusPosition) == null) ; 1381 } 1382 // multiple rounds: scrollToView of first round may drag first/last child into 1383 // "visible window" and we update scrollMin/scrollMax then run second scrollToView 1384 int oldFirstVisible; 1385 int oldLastVisible; 1386 do { 1387 updateScrollMin(); 1388 updateScrollMax(); 1389 oldFirstVisible = mGrid.getFirstVisibleIndex(); 1390 oldLastVisible = mGrid.getLastVisibleIndex(); 1391 View focusView = findViewByPosition(mFocusPosition); 1392 // we need force to initialize the child view's position 1393 scrollToView(focusView, false); 1394 if (focusView != null && hadFocus) { 1395 focusView.requestFocus(); 1396 } 1397 appendVisibleItems(); 1398 prependVisibleItems(); 1399 removeInvisibleViewsAtFront(); 1400 removeInvisibleViewsAtEnd(); 1401 } while (mGrid.getFirstVisibleIndex() != oldFirstVisible || 1402 mGrid.getLastVisibleIndex() != oldLastVisible); 1403 } 1404 1405 if (scrollToFocus) { 1406 scrollDirectionPrimary(-delta); 1407 scrollDirectionSecondary(-deltaSecondary); 1408 } 1409 appendVisibleItems(); 1410 prependVisibleItems(); 1411 removeInvisibleViewsAtFront(); 1412 removeInvisibleViewsAtEnd(); 1413 1414 if (DEBUG) { 1415 StringWriter sw = new StringWriter(); 1416 PrintWriter pw = new PrintWriter(sw); 1417 mGrid.debugPrint(pw); 1418 Log.d(getTag(), sw.toString()); 1419 } 1420 1421 if (mRowSecondarySizeRefresh) { 1422 mRowSecondarySizeRefresh = false; 1423 } else { 1424 updateRowSecondarySizeRefresh(); 1425 } 1426 1427 if (fastRelayout && mFocusPosition != savedFocusPos) { 1428 dispatchChildSelected(); 1429 } 1430 1431 mInLayout = false; 1432 leaveContext(); 1433 if (DEBUG) Log.v(getTag(), "layoutChildren end"); 1434 } 1435 1436 private void offsetChildrenSecondary(int increment) { 1437 final int childCount = getChildCount(); 1438 if (mOrientation == HORIZONTAL) { 1439 for (int i = 0; i < childCount; i++) { 1440 getChildAt(i).offsetTopAndBottom(increment); 1441 } 1442 } else { 1443 for (int i = 0; i < childCount; i++) { 1444 getChildAt(i).offsetLeftAndRight(increment); 1445 } 1446 } 1447 } 1448 1449 private void offsetChildrenPrimary(int increment) { 1450 final int childCount = getChildCount(); 1451 if (mOrientation == VERTICAL) { 1452 for (int i = 0; i < childCount; i++) { 1453 getChildAt(i).offsetTopAndBottom(increment); 1454 } 1455 } else { 1456 for (int i = 0; i < childCount; i++) { 1457 getChildAt(i).offsetLeftAndRight(increment); 1458 } 1459 } 1460 } 1461 1462 @Override 1463 public int scrollHorizontallyBy(int dx, Recycler recycler, RecyclerView.State state) { 1464 if (DEBUG) Log.v(getTag(), "scrollHorizontallyBy " + dx); 1465 if (!mLayoutEnabled || !hasDoneFirstLayout()) { 1466 return 0; 1467 } 1468 saveContext(recycler, state); 1469 int result; 1470 if (mOrientation == HORIZONTAL) { 1471 result = scrollDirectionPrimary(dx); 1472 } else { 1473 result = scrollDirectionSecondary(dx); 1474 } 1475 leaveContext(); 1476 return result; 1477 } 1478 1479 @Override 1480 public int scrollVerticallyBy(int dy, Recycler recycler, RecyclerView.State state) { 1481 if (DEBUG) Log.v(getTag(), "scrollVerticallyBy " + dy); 1482 if (!mLayoutEnabled || !hasDoneFirstLayout()) { 1483 return 0; 1484 } 1485 saveContext(recycler, state); 1486 int result; 1487 if (mOrientation == VERTICAL) { 1488 result = scrollDirectionPrimary(dy); 1489 } else { 1490 result = scrollDirectionSecondary(dy); 1491 } 1492 leaveContext(); 1493 return result; 1494 } 1495 1496 // scroll in main direction may add/prune views 1497 private int scrollDirectionPrimary(int da) { 1498 if (TRACE) TraceHelper.beginSection("scrollPrimary"); 1499 boolean isMaxUnknown = false, isMinUnknown = false; 1500 int minScroll = 0, maxScroll = 0; 1501 if (da > 0) { 1502 isMaxUnknown = mWindowAlignment.mainAxis().isMaxUnknown(); 1503 if (!isMaxUnknown) { 1504 maxScroll = mWindowAlignment.mainAxis().getMaxScroll(); 1505 if (mScrollOffsetPrimary + da > maxScroll) { 1506 da = maxScroll - mScrollOffsetPrimary; 1507 } 1508 } 1509 } else if (da < 0) { 1510 isMinUnknown = mWindowAlignment.mainAxis().isMinUnknown(); 1511 if (!isMinUnknown) { 1512 minScroll = mWindowAlignment.mainAxis().getMinScroll(); 1513 if (mScrollOffsetPrimary + da < minScroll) { 1514 da = minScroll - mScrollOffsetPrimary; 1515 } 1516 } 1517 } 1518 if (da == 0) { 1519 if (TRACE) TraceHelper.endSection(); 1520 return 0; 1521 } 1522 offsetChildrenPrimary(-da); 1523 mScrollOffsetPrimary += da; 1524 if (mInLayout) { 1525 if (TRACE) TraceHelper.endSection(); 1526 return da; 1527 } 1528 1529 int childCount = getChildCount(); 1530 boolean updated; 1531 1532 if (mReverseFlowPrimary ? da > 0 : da < 0) { 1533 prependVisibleItems(); 1534 } else { 1535 appendVisibleItems(); 1536 } 1537 updated = getChildCount() > childCount; 1538 childCount = getChildCount(); 1539 1540 if (TRACE) TraceHelper.beginSection("remove"); 1541 if (mReverseFlowPrimary ? da > 0 : da < 0) { 1542 removeInvisibleViewsAtEnd(); 1543 } else { 1544 removeInvisibleViewsAtFront(); 1545 } 1546 if (TRACE) TraceHelper.endSection(); 1547 updated |= getChildCount() < childCount; 1548 if (updated) { 1549 updateRowSecondarySizeRefresh(); 1550 } 1551 1552 mBaseGridView.invalidate(); 1553 if (TRACE) TraceHelper.endSection(); 1554 return da; 1555 } 1556 1557 // scroll in second direction will not add/prune views 1558 private int scrollDirectionSecondary(int dy) { 1559 if (dy == 0) { 1560 return 0; 1561 } 1562 offsetChildrenSecondary(-dy); 1563 mScrollOffsetSecondary += dy; 1564 mBaseGridView.invalidate(); 1565 return dy; 1566 } 1567 1568 private void updateScrollMax() { 1569 int highVisiblePos = (!mReverseFlowPrimary) ? mGrid.getLastVisibleIndex() 1570 : mGrid.getFirstVisibleIndex(); 1571 int highMaxPos = (!mReverseFlowPrimary) ? mState.getItemCount() - 1 : 0; 1572 if (highVisiblePos < 0) { 1573 return; 1574 } 1575 final boolean highAvailable = highVisiblePos == highMaxPos; 1576 final boolean maxUnknown = mWindowAlignment.mainAxis().isMaxUnknown(); 1577 if (!highAvailable && maxUnknown) { 1578 return; 1579 } 1580 int maxEdge = mGrid.findRowMax(true, sTwoInts) + mScrollOffsetPrimary; 1581 int rowIndex = sTwoInts[0]; 1582 int pos = sTwoInts[1]; 1583 int savedMaxEdge = mWindowAlignment.mainAxis().getMaxEdge(); 1584 mWindowAlignment.mainAxis().setMaxEdge(maxEdge); 1585 int maxScroll = getPrimarySystemScrollPosition(findViewByPosition(pos)); 1586 mWindowAlignment.mainAxis().setMaxEdge(savedMaxEdge); 1587 1588 if (highAvailable) { 1589 mWindowAlignment.mainAxis().setMaxEdge(maxEdge); 1590 mWindowAlignment.mainAxis().setMaxScroll(maxScroll); 1591 if (DEBUG) Log.v(getTag(), "updating scroll maxEdge to " + maxEdge + 1592 " scrollMax to " + maxScroll); 1593 } else { 1594 // the maxScroll for currently last visible item is larger, 1595 // so we must invalidate the max scroll value. 1596 if (maxScroll > mWindowAlignment.mainAxis().getMaxScroll()) { 1597 mWindowAlignment.mainAxis().invalidateScrollMax(); 1598 if (DEBUG) Log.v(getTag(), "Invalidate scrollMax since it should be " 1599 + "greater than " + maxScroll); 1600 } 1601 } 1602 } 1603 1604 private void updateScrollMin() { 1605 int lowVisiblePos = (!mReverseFlowPrimary) ? mGrid.getFirstVisibleIndex() 1606 : mGrid.getLastVisibleIndex(); 1607 int lowMinPos = (!mReverseFlowPrimary) ? 0 : mState.getItemCount() - 1; 1608 if (lowVisiblePos < 0) { 1609 return; 1610 } 1611 final boolean lowAvailable = lowVisiblePos == lowMinPos; 1612 final boolean minUnknown = mWindowAlignment.mainAxis().isMinUnknown(); 1613 if (!lowAvailable && minUnknown) { 1614 return; 1615 } 1616 int minEdge = mGrid.findRowMin(false, sTwoInts) + mScrollOffsetPrimary; 1617 int rowIndex = sTwoInts[0]; 1618 int pos = sTwoInts[1]; 1619 int savedMinEdge = mWindowAlignment.mainAxis().getMinEdge(); 1620 mWindowAlignment.mainAxis().setMinEdge(minEdge); 1621 int minScroll = getPrimarySystemScrollPosition(findViewByPosition(pos)); 1622 mWindowAlignment.mainAxis().setMinEdge(savedMinEdge); 1623 1624 if (lowAvailable) { 1625 mWindowAlignment.mainAxis().setMinEdge(minEdge); 1626 mWindowAlignment.mainAxis().setMinScroll(minScroll); 1627 if (DEBUG) Log.v(getTag(), "updating scroll minEdge to " + minEdge + 1628 " scrollMin to " + minScroll); 1629 } else { 1630 // the minScroll for currently first visible item is smaller, 1631 // so we must invalidate the min scroll value. 1632 if (minScroll < mWindowAlignment.mainAxis().getMinScroll()) { 1633 mWindowAlignment.mainAxis().invalidateScrollMin(); 1634 if (DEBUG) Log.v(getTag(), "Invalidate scrollMin, since it should be " 1635 + "less than " + minScroll); 1636 } 1637 } 1638 } 1639 1640 private void updateScrollSecondAxis() { 1641 mWindowAlignment.secondAxis().setMinEdge(0); 1642 mWindowAlignment.secondAxis().setMaxEdge(getSizeSecondary()); 1643 } 1644 1645 private void initScrollController() { 1646 mWindowAlignment.reset(); 1647 mWindowAlignment.horizontal.setSize(getWidth()); 1648 mWindowAlignment.vertical.setSize(getHeight()); 1649 mWindowAlignment.horizontal.setPadding(getPaddingLeft(), getPaddingRight()); 1650 mWindowAlignment.vertical.setPadding(getPaddingTop(), getPaddingBottom()); 1651 mSizePrimary = mWindowAlignment.mainAxis().getSize(); 1652 mScrollOffsetPrimary = -mWindowAlignment.mainAxis().getPaddingLow(); 1653 mScrollOffsetSecondary = -mWindowAlignment.secondAxis().getPaddingLow(); 1654 1655 if (DEBUG) { 1656 Log.v(getTag(), "initScrollController mSizePrimary " + mSizePrimary 1657 + " mWindowAlignment " + mWindowAlignment 1658 + " mScrollOffsetPrimary " + mScrollOffsetPrimary); 1659 } 1660 } 1661 1662 private void updateScrollController() { 1663 // mScrollOffsetPrimary and mScrollOffsetSecondary includes the padding. 1664 // e.g. when topPadding is 16 for horizontal grid view, the initial 1665 // mScrollOffsetSecondary is -16. fastRelayout() put views based on offsets(not padding), 1666 // when padding changes to 20, we also need update mScrollOffsetSecondary to -20 before 1667 // fastRelayout() is performed 1668 int paddingPrimaryDiff, paddingSecondaryDiff; 1669 if (mOrientation == HORIZONTAL) { 1670 paddingPrimaryDiff = getPaddingLeft() - mWindowAlignment.horizontal.getPaddingLow(); 1671 paddingSecondaryDiff = getPaddingTop() - mWindowAlignment.vertical.getPaddingLow(); 1672 } else { 1673 paddingPrimaryDiff = getPaddingTop() - mWindowAlignment.vertical.getPaddingLow(); 1674 paddingSecondaryDiff = getPaddingLeft() - mWindowAlignment.horizontal.getPaddingLow(); 1675 } 1676 mScrollOffsetPrimary -= paddingPrimaryDiff; 1677 mScrollOffsetSecondary -= paddingSecondaryDiff; 1678 1679 mWindowAlignment.horizontal.setSize(getWidth()); 1680 mWindowAlignment.vertical.setSize(getHeight()); 1681 mWindowAlignment.horizontal.setPadding(getPaddingLeft(), getPaddingRight()); 1682 mWindowAlignment.vertical.setPadding(getPaddingTop(), getPaddingBottom()); 1683 mSizePrimary = mWindowAlignment.mainAxis().getSize(); 1684 1685 if (DEBUG) { 1686 Log.v(getTag(), "updateScrollController mSizePrimary " + mSizePrimary 1687 + " mWindowAlignment " + mWindowAlignment 1688 + " mScrollOffsetPrimary " + mScrollOffsetPrimary); 1689 } 1690 } 1691 1692 public void setSelection(RecyclerView parent, int position) { 1693 setSelection(parent, position, false); 1694 } 1695 1696 public void setSelectionSmooth(RecyclerView parent, int position) { 1697 setSelection(parent, position, true); 1698 } 1699 1700 public int getSelection() { 1701 return mFocusPosition; 1702 } 1703 1704 public void setSelection(RecyclerView parent, int position, boolean smooth) { 1705 if (mFocusPosition != position && position != NO_POSITION) { 1706 scrollToSelection(parent, position, smooth); 1707 } 1708 } 1709 1710 private void scrollToSelection(RecyclerView parent, int position, boolean smooth) { 1711 if (TRACE) TraceHelper.beginSection("scrollToSelection"); 1712 View view = findViewByPosition(position); 1713 if (view != null) { 1714 mInSelection = true; 1715 scrollToView(view, smooth); 1716 mInSelection = false; 1717 } else { 1718 mFocusPosition = position; 1719 mFocusPositionOffset = 0; 1720 if (!mLayoutEnabled) { 1721 return; 1722 } 1723 if (smooth) { 1724 if (!hasDoneFirstLayout()) { 1725 Log.w(getTag(), "setSelectionSmooth should " + 1726 "not be called before first layout pass"); 1727 return; 1728 } 1729 LinearSmoothScroller linearSmoothScroller = 1730 new LinearSmoothScroller(parent.getContext()) { 1731 @Override 1732 public PointF computeScrollVectorForPosition(int targetPosition) { 1733 if (getChildCount() == 0) { 1734 return null; 1735 } 1736 final int firstChildPos = getPosition(getChildAt(0)); 1737 // TODO We should be able to deduce direction from bounds of current and target focus, 1738 // rather than making assumptions about positions and directionality 1739 final boolean isStart = mReverseFlowPrimary ? targetPosition > firstChildPos : targetPosition < firstChildPos; 1740 final int direction = isStart ? -1 : 1; 1741 if (mOrientation == HORIZONTAL) { 1742 return new PointF(direction, 0); 1743 } else { 1744 return new PointF(0, direction); 1745 } 1746 } 1747 1748 @Override 1749 protected void onStop() { 1750 // onTargetFound() may not be called if we hit the "wall" first. 1751 View targetView = findViewByPosition(getTargetPosition()); 1752 if (hasFocus() && targetView != null) { 1753 targetView.requestFocus(); 1754 } 1755 dispatchChildSelected(); 1756 super.onStop(); 1757 } 1758 1759 @Override 1760 protected void onTargetFound(View targetView, 1761 RecyclerView.State state, Action action) { 1762 if (getScrollPosition(targetView, sTwoInts)) { 1763 int dx, dy; 1764 if (mOrientation == HORIZONTAL) { 1765 dx = sTwoInts[0]; 1766 dy = sTwoInts[1]; 1767 } else { 1768 dx = sTwoInts[1]; 1769 dy = sTwoInts[0]; 1770 } 1771 final int distance = (int) Math.sqrt(dx * dx + dy * dy); 1772 final int time = calculateTimeForDeceleration(distance); 1773 action.update(dx, dy, time, mDecelerateInterpolator); 1774 } 1775 } 1776 }; 1777 linearSmoothScroller.setTargetPosition(position); 1778 startSmoothScroll(linearSmoothScroller); 1779 } else { 1780 mForceFullLayout = true; 1781 parent.requestLayout(); 1782 } 1783 } 1784 if (TRACE) TraceHelper.endSection(); 1785 } 1786 1787 @Override 1788 public void onItemsAdded(RecyclerView recyclerView, int positionStart, int itemCount) { 1789 if (DEBUG) Log.v(getTag(), "onItemsAdded positionStart " 1790 + positionStart + " itemCount " + itemCount); 1791 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE) { 1792 int pos = mFocusPosition + mFocusPositionOffset; 1793 if (positionStart <= pos) { 1794 mFocusPositionOffset += itemCount; 1795 } 1796 } 1797 mChildrenStates.clear(); 1798 } 1799 1800 @Override 1801 public void onItemsChanged(RecyclerView recyclerView) { 1802 if (DEBUG) Log.v(getTag(), "onItemsChanged"); 1803 mFocusPositionOffset = 0; 1804 mChildrenStates.clear(); 1805 } 1806 1807 @Override 1808 public void onItemsRemoved(RecyclerView recyclerView, int positionStart, int itemCount) { 1809 if (DEBUG) Log.v(getTag(), "onItemsRemoved positionStart " 1810 + positionStart + " itemCount " + itemCount); 1811 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE) { 1812 int pos = mFocusPosition + mFocusPositionOffset; 1813 if (positionStart <= pos) { 1814 if (positionStart + itemCount > pos) { 1815 // stop updating offset after the focus item was removed 1816 mFocusPositionOffset = Integer.MIN_VALUE; 1817 } else { 1818 mFocusPositionOffset -= itemCount; 1819 } 1820 } 1821 } 1822 mChildrenStates.clear(); 1823 } 1824 1825 @Override 1826 public void onItemsMoved(RecyclerView recyclerView, int fromPosition, int toPosition, 1827 int itemCount) { 1828 if (DEBUG) Log.v(getTag(), "onItemsMoved fromPosition " 1829 + fromPosition + " toPosition " + toPosition); 1830 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE) { 1831 int pos = mFocusPosition + mFocusPositionOffset; 1832 if (fromPosition <= pos && pos < fromPosition + itemCount) { 1833 // moved items include focused position 1834 mFocusPositionOffset += toPosition - fromPosition; 1835 } else if (fromPosition < pos && toPosition > pos - itemCount) { 1836 // move items before focus position to after focused position 1837 mFocusPositionOffset -= itemCount; 1838 } else if (fromPosition > pos && toPosition < pos) { 1839 // move items after focus position to before focused position 1840 mFocusPositionOffset += itemCount; 1841 } 1842 } 1843 mChildrenStates.clear(); 1844 } 1845 1846 @Override 1847 public void onItemsUpdated(RecyclerView recyclerView, int positionStart, int itemCount) { 1848 if (DEBUG) Log.v(getTag(), "onItemsUpdated positionStart " 1849 + positionStart + " itemCount " + itemCount); 1850 for (int i = positionStart, end = positionStart + itemCount; i < end; i++) { 1851 mChildrenStates.remove(i); 1852 } 1853 } 1854 1855 @Override 1856 public boolean onRequestChildFocus(RecyclerView parent, View child, View focused) { 1857 if (mFocusSearchDisabled) { 1858 return true; 1859 } 1860 if (getPositionByView(child) == NO_POSITION) { 1861 // This shouldn't happen, but in case it does be sure not to attempt a 1862 // scroll to a view whose item has been removed. 1863 return true; 1864 } 1865 if (!mInLayout && !mInSelection) { 1866 scrollToView(child, true); 1867 } 1868 return true; 1869 } 1870 1871 @Override 1872 public boolean requestChildRectangleOnScreen(RecyclerView parent, View view, Rect rect, 1873 boolean immediate) { 1874 if (DEBUG) Log.v(getTag(), "requestChildRectangleOnScreen " + view + " " + rect); 1875 return false; 1876 } 1877 1878 int getScrollOffsetX() { 1879 return mOrientation == HORIZONTAL ? mScrollOffsetPrimary : mScrollOffsetSecondary; 1880 } 1881 1882 int getScrollOffsetY() { 1883 return mOrientation == HORIZONTAL ? mScrollOffsetSecondary : mScrollOffsetPrimary; 1884 } 1885 1886 public void getViewSelectedOffsets(View view, int[] offsets) { 1887 if (mOrientation == HORIZONTAL) { 1888 offsets[0] = getPrimarySystemScrollPosition(view) - mScrollOffsetPrimary; 1889 offsets[1] = getSecondarySystemScrollPosition(view) - mScrollOffsetSecondary; 1890 } else { 1891 offsets[1] = getPrimarySystemScrollPosition(view) - mScrollOffsetPrimary; 1892 offsets[0] = getSecondarySystemScrollPosition(view) - mScrollOffsetSecondary; 1893 } 1894 } 1895 1896 private int getPrimarySystemScrollPosition(View view) { 1897 final int viewCenterPrimary = mScrollOffsetPrimary + getViewCenter(view); 1898 final int viewMin = getViewMin(view); 1899 final int viewMax = getViewMax(view); 1900 // TODO: change to use State object in onRequestChildFocus() 1901 boolean isMin, isMax; 1902 if (!mReverseFlowPrimary) { 1903 isMin = mGrid.getFirstVisibleIndex() == 0; 1904 isMax = mGrid.getLastVisibleIndex() == (mState == null ? 1905 getItemCount() : mState.getItemCount()) - 1; 1906 } else { 1907 isMax = mGrid.getFirstVisibleIndex() == 0; 1908 isMin = mGrid.getLastVisibleIndex() == (mState == null ? 1909 getItemCount() : mState.getItemCount()) - 1; 1910 } 1911 for (int i = getChildCount() - 1; (isMin || isMax) && i >= 0; i--) { 1912 View v = getChildAt(i); 1913 if (v == view || v == null) { 1914 continue; 1915 } 1916 if (isMin && getViewMin(v) < viewMin) { 1917 isMin = false; 1918 } 1919 if (isMax && getViewMax(v) > viewMax) { 1920 isMax = false; 1921 } 1922 } 1923 return mWindowAlignment.mainAxis().getSystemScrollPos(viewCenterPrimary, isMin, isMax); 1924 } 1925 1926 private int getSecondarySystemScrollPosition(View view) { 1927 int viewCenterSecondary = mScrollOffsetSecondary + getViewCenterSecondary(view); 1928 int pos = getPositionByView(view); 1929 Grid.Location location = mGrid.getLocation(pos); 1930 final int row = location.row; 1931 final boolean isMin, isMax; 1932 if (!mReverseFlowSecondary) { 1933 isMin = row == 0; 1934 isMax = row == mGrid.getNumRows() - 1; 1935 } else { 1936 isMax = row == 0; 1937 isMin = row == mGrid.getNumRows() - 1; 1938 } 1939 return mWindowAlignment.secondAxis().getSystemScrollPos(viewCenterSecondary, isMin, isMax); 1940 } 1941 1942 /** 1943 * Scroll to a given child view and change mFocusPosition. 1944 */ 1945 private void scrollToView(View view, boolean smooth) { 1946 int newFocusPosition = getPositionByView(view); 1947 if (newFocusPosition != mFocusPosition) { 1948 mFocusPosition = newFocusPosition; 1949 mFocusPositionOffset = 0; 1950 if (!mInLayout) { 1951 dispatchChildSelected(); 1952 } 1953 } 1954 if (mBaseGridView.isChildrenDrawingOrderEnabledInternal()) { 1955 mBaseGridView.invalidate(); 1956 } 1957 if (view == null) { 1958 return; 1959 } 1960 if (!view.hasFocus() && mBaseGridView.hasFocus()) { 1961 // transfer focus to the child if it does not have focus yet (e.g. triggered 1962 // by setSelection()) 1963 view.requestFocus(); 1964 } 1965 if (!mScrollEnabled && smooth) { 1966 return; 1967 } 1968 if (getScrollPosition(view, sTwoInts)) { 1969 scrollGrid(sTwoInts[0], sTwoInts[1], smooth); 1970 } 1971 } 1972 1973 private boolean getScrollPosition(View view, int[] deltas) { 1974 switch (mFocusScrollStrategy) { 1975 case BaseGridView.FOCUS_SCROLL_ALIGNED: 1976 default: 1977 return getAlignedPosition(view, deltas); 1978 case BaseGridView.FOCUS_SCROLL_ITEM: 1979 case BaseGridView.FOCUS_SCROLL_PAGE: 1980 return getNoneAlignedPosition(view, deltas); 1981 } 1982 } 1983 1984 private boolean getNoneAlignedPosition(View view, int[] deltas) { 1985 int pos = getPositionByView(view); 1986 int viewMin = getViewMin(view); 1987 int viewMax = getViewMax(view); 1988 // we either align "firstView" to left/top padding edge 1989 // or align "lastView" to right/bottom padding edge 1990 View firstView = null; 1991 View lastView = null; 1992 int paddingLow = mWindowAlignment.mainAxis().getPaddingLow(); 1993 int clientSize = mWindowAlignment.mainAxis().getClientSize(); 1994 final int row = mGrid.getRowIndex(pos); 1995 if (viewMin < paddingLow) { 1996 // view enters low padding area: 1997 firstView = view; 1998 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_PAGE) { 1999 // scroll one "page" left/top, 2000 // align first visible item of the "page" at the low padding edge. 2001 while (prependOneColumnVisibleItems()) { 2002 CircularIntArray positions = 2003 mGrid.getItemPositionsInRows(mGrid.getFirstVisibleIndex(), pos)[row]; 2004 firstView = findViewByPosition(positions.get(0)); 2005 if (viewMax - getViewMin(firstView) > clientSize) { 2006 if (positions.size() > 2) { 2007 firstView = findViewByPosition(positions.get(2)); 2008 } 2009 break; 2010 } 2011 } 2012 } 2013 } else if (viewMax > clientSize + paddingLow) { 2014 // view enters high padding area: 2015 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_PAGE) { 2016 // scroll whole one page right/bottom, align view at the low padding edge. 2017 firstView = view; 2018 do { 2019 CircularIntArray positions = 2020 mGrid.getItemPositionsInRows(pos, mGrid.getLastVisibleIndex())[row]; 2021 lastView = findViewByPosition(positions.get(positions.size() - 1)); 2022 if (getViewMax(lastView) - viewMin > clientSize) { 2023 lastView = null; 2024 break; 2025 } 2026 } while (appendOneColumnVisibleItems()); 2027 if (lastView != null) { 2028 // however if we reached end, we should align last view. 2029 firstView = null; 2030 } 2031 } else { 2032 lastView = view; 2033 } 2034 } 2035 int scrollPrimary = 0; 2036 int scrollSecondary = 0; 2037 if (firstView != null) { 2038 scrollPrimary = getViewMin(firstView) - paddingLow; 2039 } else if (lastView != null) { 2040 scrollPrimary = getViewMax(lastView) - (paddingLow + clientSize); 2041 } 2042 View secondaryAlignedView; 2043 if (firstView != null) { 2044 secondaryAlignedView = firstView; 2045 } else if (lastView != null) { 2046 secondaryAlignedView = lastView; 2047 } else { 2048 secondaryAlignedView = view; 2049 } 2050 scrollSecondary = getSecondarySystemScrollPosition(secondaryAlignedView); 2051 scrollSecondary -= mScrollOffsetSecondary; 2052 if (scrollPrimary != 0 || scrollSecondary != 0) { 2053 deltas[0] = scrollPrimary; 2054 deltas[1] = scrollSecondary; 2055 return true; 2056 } 2057 return false; 2058 } 2059 2060 private boolean getAlignedPosition(View view, int[] deltas) { 2061 int scrollPrimary = getPrimarySystemScrollPosition(view); 2062 int scrollSecondary = getSecondarySystemScrollPosition(view); 2063 if (DEBUG) { 2064 Log.v(getTag(), "getAlignedPosition " + scrollPrimary + " " + scrollSecondary 2065 + " " + mWindowAlignment); 2066 Log.v(getTag(), "getAlignedPosition " + mScrollOffsetPrimary + " " + mScrollOffsetSecondary); 2067 } 2068 scrollPrimary -= mScrollOffsetPrimary; 2069 scrollSecondary -= mScrollOffsetSecondary; 2070 if (scrollPrimary != 0 || scrollSecondary != 0) { 2071 deltas[0] = scrollPrimary; 2072 deltas[1] = scrollSecondary; 2073 return true; 2074 } 2075 return false; 2076 } 2077 2078 private void scrollGrid(int scrollPrimary, int scrollSecondary, boolean smooth) { 2079 if (mInLayout) { 2080 scrollDirectionPrimary(scrollPrimary); 2081 scrollDirectionSecondary(scrollSecondary); 2082 } else { 2083 int scrollX; 2084 int scrollY; 2085 if (mOrientation == HORIZONTAL) { 2086 scrollX = scrollPrimary; 2087 scrollY = scrollSecondary; 2088 } else { 2089 scrollX = scrollSecondary; 2090 scrollY = scrollPrimary; 2091 } 2092 if (smooth) { 2093 mBaseGridView.smoothScrollBy(scrollX, scrollY); 2094 } else { 2095 mBaseGridView.scrollBy(scrollX, scrollY); 2096 } 2097 } 2098 } 2099 2100 public void setPruneChild(boolean pruneChild) { 2101 if (mPruneChild != pruneChild) { 2102 mPruneChild = pruneChild; 2103 if (mPruneChild) { 2104 requestLayout(); 2105 } 2106 } 2107 } 2108 2109 public boolean getPruneChild() { 2110 return mPruneChild; 2111 } 2112 2113 public void setScrollEnabled(boolean scrollEnabled) { 2114 if (mScrollEnabled != scrollEnabled) { 2115 mScrollEnabled = scrollEnabled; 2116 if (mScrollEnabled && mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED 2117 && mFocusPosition != NO_POSITION) { 2118 scrollToSelection(mBaseGridView, mFocusPosition, true); 2119 } 2120 } 2121 } 2122 2123 public boolean isScrollEnabled() { 2124 return mScrollEnabled; 2125 } 2126 2127 private int findImmediateChildIndex(View view) { 2128 while (view != null && view != mBaseGridView) { 2129 int index = mBaseGridView.indexOfChild(view); 2130 if (index >= 0) { 2131 return index; 2132 } 2133 view = (View) view.getParent(); 2134 } 2135 return NO_POSITION; 2136 } 2137 2138 void setFocusSearchDisabled(boolean disabled) { 2139 mFocusSearchDisabled = disabled; 2140 } 2141 2142 boolean isFocusSearchDisabled() { 2143 return mFocusSearchDisabled; 2144 } 2145 2146 @Override 2147 public View onInterceptFocusSearch(View focused, int direction) { 2148 if (mFocusSearchDisabled) { 2149 return focused; 2150 } 2151 return null; 2152 } 2153 2154 boolean hasPreviousViewInSameRow(int pos) { 2155 if (mGrid == null || pos == NO_POSITION || mGrid.getFirstVisibleIndex() < 0) { 2156 return false; 2157 } 2158 if (mGrid.getFirstVisibleIndex() > 0) { 2159 return true; 2160 } 2161 final int focusedRow = mGrid.getLocation(pos).row; 2162 for (int i = getChildCount() - 1; i >= 0; i--) { 2163 int position = getPositionByIndex(i); 2164 Grid.Location loc = mGrid.getLocation(position); 2165 if (loc != null && loc.row == focusedRow) { 2166 if (position < pos) { 2167 return true; 2168 } 2169 } 2170 } 2171 return false; 2172 } 2173 2174 @Override 2175 public boolean onAddFocusables(RecyclerView recyclerView, 2176 ArrayList<View> views, int direction, int focusableMode) { 2177 if (mFocusSearchDisabled) { 2178 return true; 2179 } 2180 // If this viewgroup or one of its children currently has focus then we 2181 // consider our children for focus searching in main direction on the same row. 2182 // If this viewgroup has no focus and using focus align, we want the system 2183 // to ignore our children and pass focus to the viewgroup, which will pass 2184 // focus on to its children appropriately. 2185 // If this viewgroup has no focus and not using focus align, we want to 2186 // consider the child that does not overlap with padding area. 2187 if (recyclerView.hasFocus()) { 2188 final int movement = getMovement(direction); 2189 if (movement != PREV_ITEM && movement != NEXT_ITEM) { 2190 // Move on secondary direction uses default addFocusables(). 2191 return false; 2192 } 2193 final View focused = recyclerView.findFocus(); 2194 final int focusedPos = getPositionByIndex(findImmediateChildIndex(focused)); 2195 // Add focusables of focused item. 2196 if (focusedPos != NO_POSITION) { 2197 findViewByPosition(focusedPos).addFocusables(views, direction, focusableMode); 2198 } 2199 final int focusedRow = mGrid != null && focusedPos != NO_POSITION ? 2200 mGrid.getLocation(focusedPos).row : NO_POSITION; 2201 // Add focusables of next neighbor of same row on the focus search direction. 2202 if (mGrid != null) { 2203 final int focusableCount = views.size(); 2204 for (int i = 0, count = getChildCount(); i < count; i++) { 2205 int index = movement == NEXT_ITEM ? i : count - 1 - i; 2206 final View child = getChildAt(index); 2207 if (child.getVisibility() != View.VISIBLE) { 2208 continue; 2209 } 2210 int position = getPositionByIndex(index); 2211 Grid.Location loc = mGrid.getLocation(position); 2212 if (focusedRow == NO_POSITION || (loc != null && loc.row == focusedRow)) { 2213 if (focusedPos == NO_POSITION || 2214 (movement == NEXT_ITEM && position > focusedPos) 2215 || (movement == PREV_ITEM && position < focusedPos)) { 2216 child.addFocusables(views, direction, focusableMode); 2217 if (views.size() > focusableCount) { 2218 break; 2219 } 2220 } 2221 } 2222 } 2223 } 2224 } else { 2225 if (mFocusScrollStrategy != BaseGridView.FOCUS_SCROLL_ALIGNED) { 2226 // adding views not overlapping padding area to avoid scrolling in gaining focus 2227 int left = mWindowAlignment.mainAxis().getPaddingLow(); 2228 int right = mWindowAlignment.mainAxis().getClientSize() + left; 2229 int focusableCount = views.size(); 2230 for (int i = 0, count = getChildCount(); i < count; i++) { 2231 View child = getChildAt(i); 2232 if (child.getVisibility() == View.VISIBLE) { 2233 if (getViewMin(child) >= left && getViewMax(child) <= right) { 2234 child.addFocusables(views, direction, focusableMode); 2235 } 2236 } 2237 } 2238 // if we cannot find any, then just add all children. 2239 if (views.size() == focusableCount) { 2240 for (int i = 0, count = getChildCount(); i < count; i++) { 2241 View child = getChildAt(i); 2242 if (child.getVisibility() == View.VISIBLE) { 2243 child.addFocusables(views, direction, focusableMode); 2244 } 2245 } 2246 if (views.size() != focusableCount) { 2247 return true; 2248 } 2249 } else { 2250 return true; 2251 } 2252 // if still cannot find any, fall through and add itself 2253 } 2254 if (recyclerView.isFocusable()) { 2255 views.add(recyclerView); 2256 } 2257 } 2258 return true; 2259 } 2260 2261 @Override 2262 public View onFocusSearchFailed(View focused, int direction, Recycler recycler, 2263 RecyclerView.State state) { 2264 if (DEBUG) Log.v(getTag(), "onFocusSearchFailed direction " + direction); 2265 2266 View view = null; 2267 int movement = getMovement(direction); 2268 final boolean isScroll = mBaseGridView.getScrollState() != RecyclerView.SCROLL_STATE_IDLE; 2269 if (mNumRows == 1) { 2270 // for simple row, use LinearSmoothScroller to smooth animation. 2271 // It will stay at a fixed cap speed in continuous scroll. 2272 if (movement == NEXT_ITEM) { 2273 int newPos = mFocusPosition + mNumRows; 2274 if (newPos < getItemCount() && mScrollEnabled) { 2275 setSelectionSmooth(mBaseGridView, newPos); 2276 view = focused; 2277 } else { 2278 if (isScroll || !mFocusOutEnd) { 2279 view = focused; 2280 } 2281 } 2282 } else if (movement == PREV_ITEM){ 2283 int newPos = mFocusPosition - mNumRows; 2284 if (newPos >= 0 && mScrollEnabled) { 2285 setSelectionSmooth(mBaseGridView, newPos); 2286 view = focused; 2287 } else { 2288 if (isScroll || !mFocusOutFront) { 2289 view = focused; 2290 } 2291 } 2292 } 2293 } else if (mNumRows > 1) { 2294 // for possible staggered grid, we need guarantee focus to same row/column. 2295 // TODO: we may also use LinearSmoothScroller. 2296 saveContext(recycler, state); 2297 final FocusFinder ff = FocusFinder.getInstance(); 2298 if (movement == NEXT_ITEM) { 2299 while (view == null && appendOneColumnVisibleItems()) { 2300 view = ff.findNextFocus(mBaseGridView, focused, direction); 2301 } 2302 } else if (movement == PREV_ITEM){ 2303 while (view == null && prependOneColumnVisibleItems()) { 2304 view = ff.findNextFocus(mBaseGridView, focused, direction); 2305 } 2306 } 2307 if (view == null) { 2308 // returning the same view to prevent focus lost when scrolling past the end of the list 2309 if (movement == PREV_ITEM) { 2310 view = mFocusOutFront && !isScroll ? null : focused; 2311 } else if (movement == NEXT_ITEM){ 2312 view = mFocusOutEnd && !isScroll ? null : focused; 2313 } 2314 } 2315 leaveContext(); 2316 } 2317 if (DEBUG) Log.v(getTag(), "returning view " + view); 2318 return view; 2319 } 2320 2321 boolean gridOnRequestFocusInDescendants(RecyclerView recyclerView, int direction, 2322 Rect previouslyFocusedRect) { 2323 switch (mFocusScrollStrategy) { 2324 case BaseGridView.FOCUS_SCROLL_ALIGNED: 2325 default: 2326 return gridOnRequestFocusInDescendantsAligned(recyclerView, 2327 direction, previouslyFocusedRect); 2328 case BaseGridView.FOCUS_SCROLL_PAGE: 2329 case BaseGridView.FOCUS_SCROLL_ITEM: 2330 return gridOnRequestFocusInDescendantsUnaligned(recyclerView, 2331 direction, previouslyFocusedRect); 2332 } 2333 } 2334 2335 private boolean gridOnRequestFocusInDescendantsAligned(RecyclerView recyclerView, 2336 int direction, Rect previouslyFocusedRect) { 2337 View view = findViewByPosition(mFocusPosition); 2338 if (view != null) { 2339 boolean result = view.requestFocus(direction, previouslyFocusedRect); 2340 if (!result && DEBUG) { 2341 Log.w(getTag(), "failed to request focus on " + view); 2342 } 2343 return result; 2344 } 2345 return false; 2346 } 2347 2348 private boolean gridOnRequestFocusInDescendantsUnaligned(RecyclerView recyclerView, 2349 int direction, Rect previouslyFocusedRect) { 2350 // focus to view not overlapping padding area to avoid scrolling in gaining focus 2351 int index; 2352 int increment; 2353 int end; 2354 int count = getChildCount(); 2355 if ((direction & View.FOCUS_FORWARD) != 0) { 2356 index = 0; 2357 increment = 1; 2358 end = count; 2359 } else { 2360 index = count - 1; 2361 increment = -1; 2362 end = -1; 2363 } 2364 int left = mWindowAlignment.mainAxis().getPaddingLow(); 2365 int right = mWindowAlignment.mainAxis().getClientSize() + left; 2366 for (int i = index; i != end; i += increment) { 2367 View child = getChildAt(i); 2368 if (child.getVisibility() == View.VISIBLE) { 2369 if (getViewMin(child) >= left && getViewMax(child) <= right) { 2370 if (child.requestFocus(direction, previouslyFocusedRect)) { 2371 return true; 2372 } 2373 } 2374 } 2375 } 2376 return false; 2377 } 2378 2379 private final static int PREV_ITEM = 0; 2380 private final static int NEXT_ITEM = 1; 2381 private final static int PREV_ROW = 2; 2382 private final static int NEXT_ROW = 3; 2383 2384 private int getMovement(int direction) { 2385 int movement = View.FOCUS_LEFT; 2386 2387 if (mOrientation == HORIZONTAL) { 2388 switch(direction) { 2389 case View.FOCUS_LEFT: 2390 movement = (!mReverseFlowPrimary) ? PREV_ITEM : NEXT_ITEM; 2391 break; 2392 case View.FOCUS_RIGHT: 2393 movement = (!mReverseFlowPrimary) ? NEXT_ITEM : PREV_ITEM; 2394 break; 2395 case View.FOCUS_UP: 2396 movement = PREV_ROW; 2397 break; 2398 case View.FOCUS_DOWN: 2399 movement = NEXT_ROW; 2400 break; 2401 } 2402 } else if (mOrientation == VERTICAL) { 2403 switch(direction) { 2404 case View.FOCUS_LEFT: 2405 movement = (!mReverseFlowPrimary) ? PREV_ROW : NEXT_ROW; 2406 break; 2407 case View.FOCUS_RIGHT: 2408 movement = (!mReverseFlowPrimary) ? NEXT_ROW : PREV_ROW; 2409 break; 2410 case View.FOCUS_UP: 2411 movement = PREV_ITEM; 2412 break; 2413 case View.FOCUS_DOWN: 2414 movement = NEXT_ITEM; 2415 break; 2416 } 2417 } 2418 2419 return movement; 2420 } 2421 2422 int getChildDrawingOrder(RecyclerView recyclerView, int childCount, int i) { 2423 View view = findViewByPosition(mFocusPosition); 2424 if (view == null) { 2425 return i; 2426 } 2427 int focusIndex = recyclerView.indexOfChild(view); 2428 // supposely 0 1 2 3 4 5 6 7 8 9, 4 is the center item 2429 // drawing order is 0 1 2 3 9 8 7 6 5 4 2430 if (i < focusIndex) { 2431 return i; 2432 } else if (i < childCount - 1) { 2433 return focusIndex + childCount - 1 - i; 2434 } else { 2435 return focusIndex; 2436 } 2437 } 2438 2439 @Override 2440 public void onAdapterChanged(RecyclerView.Adapter oldAdapter, 2441 RecyclerView.Adapter newAdapter) { 2442 if (DEBUG) Log.v(getTag(), "onAdapterChanged to " + newAdapter); 2443 if (oldAdapter != null) { 2444 discardLayoutInfo(); 2445 mFocusPosition = NO_POSITION; 2446 mFocusPositionOffset = 0; 2447 mChildrenStates.clear(); 2448 } 2449 super.onAdapterChanged(oldAdapter, newAdapter); 2450 } 2451 2452 private void discardLayoutInfo() { 2453 mGrid = null; 2454 mRowSizeSecondary = null; 2455 mRowSecondarySizeRefresh = false; 2456 } 2457 2458 public void setLayoutEnabled(boolean layoutEnabled) { 2459 if (mLayoutEnabled != layoutEnabled) { 2460 mLayoutEnabled = layoutEnabled; 2461 requestLayout(); 2462 } 2463 } 2464 2465 void setChildrenVisibility(int visiblity) { 2466 mChildVisibility = visiblity; 2467 if (mChildVisibility != -1) { 2468 int count = getChildCount(); 2469 for (int i= 0; i < count; i++) { 2470 getChildAt(i).setVisibility(mChildVisibility); 2471 } 2472 } 2473 } 2474 2475 final static class SavedState implements Parcelable { 2476 2477 int index; // index inside adapter of the current view 2478 Bundle childStates = Bundle.EMPTY; 2479 2480 @Override 2481 public void writeToParcel(Parcel out, int flags) { 2482 out.writeInt(index); 2483 out.writeBundle(childStates); 2484 } 2485 2486 @SuppressWarnings("hiding") 2487 public static final Parcelable.Creator<SavedState> CREATOR = 2488 new Parcelable.Creator<SavedState>() { 2489 @Override 2490 public SavedState createFromParcel(Parcel in) { 2491 return new SavedState(in); 2492 } 2493 2494 @Override 2495 public SavedState[] newArray(int size) { 2496 return new SavedState[size]; 2497 } 2498 }; 2499 2500 @Override 2501 public int describeContents() { 2502 return 0; 2503 } 2504 2505 SavedState(Parcel in) { 2506 index = in.readInt(); 2507 childStates = in.readBundle(GridLayoutManager.class.getClassLoader()); 2508 } 2509 2510 SavedState() { 2511 } 2512 } 2513 2514 @Override 2515 public Parcelable onSaveInstanceState() { 2516 if (DEBUG) Log.v(getTag(), "onSaveInstanceState getSelection() " + getSelection()); 2517 SavedState ss = new SavedState(); 2518 for (int i = 0, count = getChildCount(); i < count; i++) { 2519 View view = getChildAt(i); 2520 int position = getPositionByView(view); 2521 if (position != NO_POSITION) { 2522 mChildrenStates.saveOnScreenView(view, position); 2523 } 2524 } 2525 ss.index = getSelection(); 2526 ss.childStates = mChildrenStates.saveAsBundle(); 2527 return ss; 2528 } 2529 2530 void onChildDetachedFromWindow(RecyclerView.ViewHolder holder) { 2531 // FIXME: use getAdapterPosition() once RV can return position after view is detached. 2532 final int position = holder.getLayoutPosition(); 2533 if (position != NO_POSITION) { 2534 mChildrenStates.saveOffscreenView(holder.itemView, position); 2535 } 2536 } 2537 2538 @Override 2539 public void onRestoreInstanceState(Parcelable state) { 2540 if (!(state instanceof SavedState)) { 2541 return; 2542 } 2543 SavedState loadingState = (SavedState)state; 2544 mFocusPosition = loadingState.index; 2545 mFocusPositionOffset = 0; 2546 mChildrenStates.loadFromBundle(loadingState.childStates); 2547 mForceFullLayout = true; 2548 requestLayout(); 2549 if (DEBUG) Log.v(getTag(), "onRestoreInstanceState mFocusPosition " + mFocusPosition); 2550 } 2551} 2552