GridLayoutManager.java revision 2024f694e8ae778eefb3f6b6cdc245a67975436c
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.view.ViewCompat; 23import android.support.v7.widget.LinearSmoothScroller; 24import android.support.v7.widget.RecyclerView; 25import android.support.v7.widget.RecyclerView.Recycler; 26import android.support.v7.widget.RecyclerView.State; 27 28import static android.support.v7.widget.RecyclerView.NO_ID; 29import static android.support.v7.widget.RecyclerView.NO_POSITION; 30import static android.support.v7.widget.RecyclerView.HORIZONTAL; 31import static android.support.v7.widget.RecyclerView.VERTICAL; 32 33import android.util.AttributeSet; 34import android.util.Log; 35import android.view.FocusFinder; 36import android.view.Gravity; 37import android.view.View; 38import android.view.ViewParent; 39import android.view.View.MeasureSpec; 40import android.view.ViewGroup.MarginLayoutParams; 41import android.view.ViewGroup; 42 43import java.io.PrintWriter; 44import java.io.StringWriter; 45import java.util.ArrayList; 46import java.util.List; 47 48final class GridLayoutManager extends RecyclerView.LayoutManager { 49 50 /* 51 * LayoutParams for {@link HorizontalGridView} and {@link VerticalGridView}. 52 * The class currently does two internal jobs: 53 * - Saves optical bounds insets. 54 * - Caches focus align view center. 55 */ 56 static class LayoutParams extends RecyclerView.LayoutParams { 57 58 // The view is saved only during animation. 59 private View mView; 60 61 // For placement 62 private int mLeftInset; 63 private int mTopInset; 64 private int mRighInset; 65 private int mBottomInset; 66 67 // For alignment 68 private int mAlignX; 69 private int mAlignY; 70 71 public LayoutParams(Context c, AttributeSet attrs) { 72 super(c, attrs); 73 } 74 75 public LayoutParams(int width, int height) { 76 super(width, height); 77 } 78 79 public LayoutParams(MarginLayoutParams source) { 80 super(source); 81 } 82 83 public LayoutParams(ViewGroup.LayoutParams source) { 84 super(source); 85 } 86 87 public LayoutParams(RecyclerView.LayoutParams source) { 88 super(source); 89 } 90 91 public LayoutParams(LayoutParams source) { 92 super(source); 93 } 94 95 int getAlignX() { 96 return mAlignX; 97 } 98 99 int getAlignY() { 100 return mAlignY; 101 } 102 103 int getOpticalLeft(View view) { 104 return view.getLeft() + mLeftInset; 105 } 106 107 int getOpticalTop(View view) { 108 return view.getTop() + mTopInset; 109 } 110 111 int getOpticalRight(View view) { 112 return view.getRight() - mRighInset; 113 } 114 115 int getOpticalBottom(View view) { 116 return view.getBottom() - mBottomInset; 117 } 118 119 int getOpticalWidth(View view) { 120 return view.getWidth() - mLeftInset - mRighInset; 121 } 122 123 int getOpticalHeight(View view) { 124 return view.getHeight() - mTopInset - mBottomInset; 125 } 126 127 int getOpticalLeftInset() { 128 return mLeftInset; 129 } 130 131 int getOpticalRightInset() { 132 return mRighInset; 133 } 134 135 int getOpticalTopInset() { 136 return mTopInset; 137 } 138 139 int getOpticalBottomInset() { 140 return mBottomInset; 141 } 142 143 void setAlignX(int alignX) { 144 mAlignX = alignX; 145 } 146 147 void setAlignY(int alignY) { 148 mAlignY = alignY; 149 } 150 151 void setOpticalInsets(int leftInset, int topInset, int rightInset, int bottomInset) { 152 mLeftInset = leftInset; 153 mTopInset = topInset; 154 mRighInset = rightInset; 155 mBottomInset = bottomInset; 156 } 157 158 private void invalidateItemDecoration() { 159 ViewParent parent = mView.getParent(); 160 if (parent instanceof RecyclerView) { 161 // TODO: we only need invalidate parent if it has ItemDecoration 162 ((RecyclerView) parent).invalidate(); 163 } 164 } 165 } 166 167 private static final String TAG = "GridLayoutManager"; 168 private static final boolean DEBUG = false; 169 170 private String getTag() { 171 return TAG + ":" + mBaseGridView.getId(); 172 } 173 174 private final BaseGridView mBaseGridView; 175 176 /** 177 * The orientation of a "row". 178 */ 179 private int mOrientation = HORIZONTAL; 180 181 private RecyclerView.State mState; 182 private RecyclerView.Recycler mRecycler; 183 184 private boolean mInLayout = false; 185 private boolean mInSelection = false; 186 187 private OnChildSelectedListener mChildSelectedListener = null; 188 189 /** 190 * The focused position, it's not the currently visually aligned position 191 * but it is the final position that we intend to focus on. If there are 192 * multiple setSelection() called, mFocusPosition saves last value. 193 */ 194 private int mFocusPosition = NO_POSITION; 195 196 /** 197 * The offset to be applied to mFocusPosition, due to adapter change, on the next 198 * layout. Set to Integer.MIN_VALUE means item was removed. 199 * TODO: This is somewhat duplication of RecyclerView getOldPosition() which is 200 * unfortunately cleared after prelayout. 201 */ 202 private int mFocusPositionOffset = 0; 203 204 /** 205 * Force a full layout under certain situations. 206 */ 207 private boolean mForceFullLayout; 208 209 /** 210 * True if layout is enabled. 211 */ 212 private boolean mLayoutEnabled = true; 213 214 /** 215 * override child visibility 216 */ 217 private int mChildVisibility = -1; 218 219 /** 220 * The scroll offsets of the viewport relative to the entire view. 221 */ 222 private int mScrollOffsetPrimary; 223 private int mScrollOffsetSecondary; 224 225 /** 226 * User-specified row height/column width. Can be WRAP_CONTENT. 227 */ 228 private int mRowSizeSecondaryRequested; 229 230 /** 231 * The fixed size of each grid item in the secondary direction. This corresponds to 232 * the row height, equal for all rows. Grid items may have variable length 233 * in the primary direction. 234 */ 235 private int mFixedRowSizeSecondary; 236 237 /** 238 * Tracks the secondary size of each row. 239 */ 240 private int[] mRowSizeSecondary; 241 242 /** 243 * Flag controlling whether the current/next layout should 244 * be updating the secondary size of rows. 245 */ 246 private boolean mRowSecondarySizeRefresh; 247 248 /** 249 * The maximum measured size of the view. 250 */ 251 private int mMaxSizeSecondary; 252 253 /** 254 * Margin between items. 255 */ 256 private int mHorizontalMargin; 257 /** 258 * Margin between items vertically. 259 */ 260 private int mVerticalMargin; 261 /** 262 * Margin in main direction. 263 */ 264 private int mMarginPrimary; 265 /** 266 * Margin in second direction. 267 */ 268 private int mMarginSecondary; 269 /** 270 * How to position child in secondary direction. 271 */ 272 private int mGravity = Gravity.LEFT | Gravity.TOP; 273 /** 274 * The number of rows in the grid. 275 */ 276 private int mNumRows; 277 /** 278 * Number of rows requested, can be 0 to be determined by parent size and 279 * rowHeight. 280 */ 281 private int mNumRowsRequested = 1; 282 283 /** 284 * Tracking start/end position of each row for visible items. 285 */ 286 private StaggeredGrid.Row[] mRows; 287 288 /** 289 * Saves grid information of each view. 290 */ 291 private StaggeredGrid mGrid; 292 /** 293 * Position of first item (included) that has attached views. 294 */ 295 private int mFirstVisiblePos; 296 /** 297 * Position of last item (included) that has attached views. 298 */ 299 private int mLastVisiblePos; 300 301 /** 302 * Focus Scroll strategy. 303 */ 304 private int mFocusScrollStrategy = BaseGridView.FOCUS_SCROLL_ALIGNED; 305 /** 306 * Defines how item view is aligned in the window. 307 */ 308 private final WindowAlignment mWindowAlignment = new WindowAlignment(); 309 310 /** 311 * Defines how item view is aligned. 312 */ 313 private final ItemAlignment mItemAlignment = new ItemAlignment(); 314 315 /** 316 * Dimensions of the view, width or height depending on orientation. 317 */ 318 private int mSizePrimary; 319 320 /** 321 * Allow DPAD key to navigate out at the front of the View (where position = 0), 322 * default is false. 323 */ 324 private boolean mFocusOutFront; 325 326 /** 327 * Allow DPAD key to navigate out at the end of the view, default is false. 328 */ 329 private boolean mFocusOutEnd; 330 331 /** 332 * True if focus search is disabled. 333 */ 334 private boolean mFocusSearchDisabled; 335 336 /** 337 * True if prune child, might be disabled during transition. 338 */ 339 private boolean mPruneChild = true; 340 341 /** 342 * True if scroll content, might be disabled during transition. 343 */ 344 private boolean mScrollEnabled = true; 345 346 private int[] mTempDeltas = new int[2]; 347 348 /** 349 * Temporaries used for measuring. 350 */ 351 private int[] mMeasuredDimension = new int[2]; 352 353 final ViewsStateBundle mChildrenStates = new ViewsStateBundle(); 354 355 public GridLayoutManager(BaseGridView baseGridView) { 356 mBaseGridView = baseGridView; 357 } 358 359 public void setOrientation(int orientation) { 360 if (orientation != HORIZONTAL && orientation != VERTICAL) { 361 if (DEBUG) Log.v(getTag(), "invalid orientation: " + orientation); 362 return; 363 } 364 365 mOrientation = orientation; 366 mWindowAlignment.setOrientation(orientation); 367 mItemAlignment.setOrientation(orientation); 368 mForceFullLayout = true; 369 } 370 371 public int getFocusScrollStrategy() { 372 return mFocusScrollStrategy; 373 } 374 375 public void setFocusScrollStrategy(int focusScrollStrategy) { 376 mFocusScrollStrategy = focusScrollStrategy; 377 } 378 379 public void setWindowAlignment(int windowAlignment) { 380 mWindowAlignment.mainAxis().setWindowAlignment(windowAlignment); 381 } 382 383 public int getWindowAlignment() { 384 return mWindowAlignment.mainAxis().getWindowAlignment(); 385 } 386 387 public void setWindowAlignmentOffset(int alignmentOffset) { 388 mWindowAlignment.mainAxis().setWindowAlignmentOffset(alignmentOffset); 389 } 390 391 public int getWindowAlignmentOffset() { 392 return mWindowAlignment.mainAxis().getWindowAlignmentOffset(); 393 } 394 395 public void setWindowAlignmentOffsetPercent(float offsetPercent) { 396 mWindowAlignment.mainAxis().setWindowAlignmentOffsetPercent(offsetPercent); 397 } 398 399 public float getWindowAlignmentOffsetPercent() { 400 return mWindowAlignment.mainAxis().getWindowAlignmentOffsetPercent(); 401 } 402 403 public void setItemAlignmentOffset(int alignmentOffset) { 404 mItemAlignment.mainAxis().setItemAlignmentOffset(alignmentOffset); 405 updateChildAlignments(); 406 } 407 408 public int getItemAlignmentOffset() { 409 return mItemAlignment.mainAxis().getItemAlignmentOffset(); 410 } 411 412 public void setItemAlignmentOffsetWithPadding(boolean withPadding) { 413 mItemAlignment.mainAxis().setItemAlignmentOffsetWithPadding(withPadding); 414 updateChildAlignments(); 415 } 416 417 public boolean isItemAlignmentOffsetWithPadding() { 418 return mItemAlignment.mainAxis().isItemAlignmentOffsetWithPadding(); 419 } 420 421 public void setItemAlignmentOffsetPercent(float offsetPercent) { 422 mItemAlignment.mainAxis().setItemAlignmentOffsetPercent(offsetPercent); 423 updateChildAlignments(); 424 } 425 426 public float getItemAlignmentOffsetPercent() { 427 return mItemAlignment.mainAxis().getItemAlignmentOffsetPercent(); 428 } 429 430 public void setItemAlignmentViewId(int viewId) { 431 mItemAlignment.mainAxis().setItemAlignmentViewId(viewId); 432 updateChildAlignments(); 433 } 434 435 public int getItemAlignmentViewId() { 436 return mItemAlignment.mainAxis().getItemAlignmentViewId(); 437 } 438 439 public void setFocusOutAllowed(boolean throughFront, boolean throughEnd) { 440 mFocusOutFront = throughFront; 441 mFocusOutEnd = throughEnd; 442 } 443 444 public void setNumRows(int numRows) { 445 if (numRows < 0) throw new IllegalArgumentException(); 446 mNumRowsRequested = numRows; 447 mForceFullLayout = true; 448 } 449 450 /** 451 * Set the row height. May be WRAP_CONTENT, or a size in pixels. 452 */ 453 public void setRowHeight(int height) { 454 if (height >= 0 || height == ViewGroup.LayoutParams.WRAP_CONTENT) { 455 mRowSizeSecondaryRequested = height; 456 } else { 457 throw new IllegalArgumentException("Invalid row height: " + height); 458 } 459 } 460 461 public void setItemMargin(int margin) { 462 mVerticalMargin = mHorizontalMargin = margin; 463 mMarginPrimary = mMarginSecondary = margin; 464 } 465 466 public void setVerticalMargin(int margin) { 467 if (mOrientation == HORIZONTAL) { 468 mMarginSecondary = mVerticalMargin = margin; 469 } else { 470 mMarginPrimary = mVerticalMargin = margin; 471 } 472 } 473 474 public void setHorizontalMargin(int margin) { 475 if (mOrientation == HORIZONTAL) { 476 mMarginPrimary = mHorizontalMargin = margin; 477 } else { 478 mMarginSecondary = mHorizontalMargin = margin; 479 } 480 } 481 482 public int getVerticalMargin() { 483 return mVerticalMargin; 484 } 485 486 public int getHorizontalMargin() { 487 return mHorizontalMargin; 488 } 489 490 public void setGravity(int gravity) { 491 mGravity = gravity; 492 } 493 494 protected boolean hasDoneFirstLayout() { 495 return mGrid != null; 496 } 497 498 public void setOnChildSelectedListener(OnChildSelectedListener listener) { 499 mChildSelectedListener = listener; 500 } 501 502 private int getPositionByView(View view) { 503 if (view == null) { 504 return NO_POSITION; 505 } 506 LayoutParams params = (LayoutParams) view.getLayoutParams(); 507 if (params == null || params.isItemRemoved()) { 508 // when item is removed, the position value can be any value. 509 return NO_POSITION; 510 } 511 return params.getViewPosition(); 512 } 513 514 private int getPositionByIndex(int index) { 515 return getPositionByView(getChildAt(index)); 516 } 517 518 private void dispatchChildSelected() { 519 if (mChildSelectedListener == null) { 520 return; 521 } 522 if (mFocusPosition != NO_POSITION) { 523 View view = findViewByPosition(mFocusPosition); 524 if (view != null) { 525 RecyclerView.ViewHolder vh = mBaseGridView.getChildViewHolder(view); 526 mChildSelectedListener.onChildSelected(mBaseGridView, view, mFocusPosition, 527 vh == null? NO_ID: vh.getItemId()); 528 return; 529 } 530 } 531 mChildSelectedListener.onChildSelected(mBaseGridView, null, NO_POSITION, NO_ID); 532 } 533 534 @Override 535 public boolean canScrollHorizontally() { 536 // We can scroll horizontally if we have horizontal orientation, or if 537 // we are vertical and have more than one column. 538 return mOrientation == HORIZONTAL || mNumRows > 1; 539 } 540 541 @Override 542 public boolean canScrollVertically() { 543 // We can scroll vertically if we have vertical orientation, or if we 544 // are horizontal and have more than one row. 545 return mOrientation == VERTICAL || mNumRows > 1; 546 } 547 548 @Override 549 public RecyclerView.LayoutParams generateDefaultLayoutParams() { 550 return new LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, 551 ViewGroup.LayoutParams.WRAP_CONTENT); 552 } 553 554 @Override 555 public RecyclerView.LayoutParams generateLayoutParams(Context context, AttributeSet attrs) { 556 return new LayoutParams(context, attrs); 557 } 558 559 @Override 560 public RecyclerView.LayoutParams generateLayoutParams(ViewGroup.LayoutParams lp) { 561 if (lp instanceof LayoutParams) { 562 return new LayoutParams((LayoutParams) lp); 563 } else if (lp instanceof RecyclerView.LayoutParams) { 564 return new LayoutParams((RecyclerView.LayoutParams) lp); 565 } else if (lp instanceof MarginLayoutParams) { 566 return new LayoutParams((MarginLayoutParams) lp); 567 } else { 568 return new LayoutParams(lp); 569 } 570 } 571 572 protected View getViewForPosition(int position) { 573 return mRecycler.getViewForPosition(position); 574 } 575 576 final int getOpticalLeft(View v) { 577 return ((LayoutParams) v.getLayoutParams()).getOpticalLeft(v); 578 } 579 580 final int getOpticalRight(View v) { 581 return ((LayoutParams) v.getLayoutParams()).getOpticalRight(v); 582 } 583 584 final int getOpticalTop(View v) { 585 return ((LayoutParams) v.getLayoutParams()).getOpticalTop(v); 586 } 587 588 final int getOpticalBottom(View v) { 589 return ((LayoutParams) v.getLayoutParams()).getOpticalBottom(v); 590 } 591 592 private int getViewMin(View v) { 593 return (mOrientation == HORIZONTAL) ? getOpticalLeft(v) : getOpticalTop(v); 594 } 595 596 private int getViewMax(View v) { 597 return (mOrientation == HORIZONTAL) ? getOpticalRight(v) : getOpticalBottom(v); 598 } 599 600 private int getViewCenter(View view) { 601 return (mOrientation == HORIZONTAL) ? getViewCenterX(view) : getViewCenterY(view); 602 } 603 604 private int getViewCenterSecondary(View view) { 605 return (mOrientation == HORIZONTAL) ? getViewCenterY(view) : getViewCenterX(view); 606 } 607 608 private int getViewCenterX(View v) { 609 LayoutParams p = (LayoutParams) v.getLayoutParams(); 610 return p.getOpticalLeft(v) + p.getAlignX(); 611 } 612 613 private int getViewCenterY(View v) { 614 LayoutParams p = (LayoutParams) v.getLayoutParams(); 615 return p.getOpticalTop(v) + p.getAlignY(); 616 } 617 618 /** 619 * Save Recycler and State for convenience. Must be paired with leaveContext(). 620 */ 621 private void saveContext(Recycler recycler, State state) { 622 if (mRecycler != null || mState != null) { 623 Log.e(TAG, "Recycler information was not released, bug!"); 624 } 625 mRecycler = recycler; 626 mState = state; 627 } 628 629 /** 630 * Discard saved Recycler and State. 631 */ 632 private void leaveContext() { 633 mRecycler = null; 634 mState = null; 635 } 636 637 /** 638 * Re-initialize data structures for a data change or handling invisible 639 * selection. The method tries its best to preserve position information so 640 * that staggered grid looks same before and after re-initialize. 641 * @param focusPosition The initial focusPosition that we would like to 642 * focus on. 643 * @return Actual position that can be focused on. 644 */ 645 private int init(int focusPosition) { 646 647 final int newItemCount = mState.getItemCount(); 648 649 if (focusPosition == NO_POSITION && newItemCount > 0) { 650 // if focus position is never set before, initialize it to 0 651 focusPosition = 0; 652 } 653 // If adapter has changed then caches are invalid; otherwise, 654 // we try to maintain each row's position if number of rows keeps the same 655 // and existing mGrid contains the focusPosition. 656 if (mRows != null && mNumRows == mRows.length && 657 mGrid != null && mGrid.getSize() > 0 && focusPosition >= 0 && 658 focusPosition >= mGrid.getFirstIndex() && 659 focusPosition <= mGrid.getLastIndex()) { 660 // strip mGrid to a subset (like a column) that contains focusPosition 661 mGrid.stripDownTo(focusPosition); 662 // make sure that remaining items do not exceed new adapter size 663 int firstIndex = mGrid.getFirstIndex(); 664 int lastIndex = mGrid.getLastIndex(); 665 if (DEBUG) { 666 Log .v(getTag(), "mGrid firstIndex " + firstIndex + " lastIndex " + lastIndex); 667 } 668 for (int i = lastIndex; i >=firstIndex; i--) { 669 if (i >= newItemCount) { 670 mGrid.removeLast(); 671 } 672 } 673 if (mGrid.getSize() == 0) { 674 focusPosition = newItemCount - 1; 675 // initialize row start locations 676 for (int i = 0; i < mNumRows; i++) { 677 mRows[i].low = 0; 678 mRows[i].high = 0; 679 } 680 if (DEBUG) Log.v(getTag(), "mGrid zero size"); 681 } else { 682 // initialize row start locations 683 for (int i = 0; i < mNumRows; i++) { 684 mRows[i].low = Integer.MAX_VALUE; 685 mRows[i].high = Integer.MIN_VALUE; 686 } 687 firstIndex = mGrid.getFirstIndex(); 688 lastIndex = mGrid.getLastIndex(); 689 if (focusPosition > lastIndex) { 690 focusPosition = mGrid.getLastIndex(); 691 } 692 if (DEBUG) { 693 Log.v(getTag(), "mGrid firstIndex " + firstIndex + " lastIndex " 694 + lastIndex + " focusPosition " + focusPosition); 695 } 696 // fill rows with minimal view positions of the subset 697 for (int i = firstIndex; i <= lastIndex; i++) { 698 View v = findViewByPosition(i); 699 if (v == null) { 700 continue; 701 } 702 int row = mGrid.getLocation(i).row; 703 int low = getViewMin(v) + mScrollOffsetPrimary; 704 if (low < mRows[row].low) { 705 mRows[row].low = mRows[row].high = low; 706 } 707 } 708 int firstItemRowPosition = mRows[mGrid.getLocation(firstIndex).row].low; 709 if (firstItemRowPosition == Integer.MAX_VALUE) { 710 firstItemRowPosition = 0; 711 } 712 if (mState.didStructureChange()) { 713 // if there is structure change, the removed item might be in the 714 // subset, so it is meaningless to maintain the low locations. 715 for (int i = 0; i < mNumRows; i++) { 716 mRows[i].low = firstItemRowPosition; 717 mRows[i].high = firstItemRowPosition; 718 } 719 } else { 720 // fill other rows that does not include the subset using first item 721 for (int i = 0; i < mNumRows; i++) { 722 if (mRows[i].low == Integer.MAX_VALUE) { 723 mRows[i].low = mRows[i].high = firstItemRowPosition; 724 } 725 } 726 } 727 } 728 729 // Same adapter, we can reuse any attached views 730 detachAndScrapAttachedViews(mRecycler); 731 732 } else { 733 // otherwise recreate data structure 734 mRows = new StaggeredGrid.Row[mNumRows]; 735 736 for (int i = 0; i < mNumRows; i++) { 737 mRows[i] = new StaggeredGrid.Row(); 738 } 739 mGrid = new StaggeredGridDefault(); 740 if (newItemCount == 0) { 741 focusPosition = NO_POSITION; 742 } else if (focusPosition >= newItemCount) { 743 focusPosition = newItemCount - 1; 744 } 745 746 // Adapter may have changed so remove all attached views permanently 747 removeAndRecycleAllViews(mRecycler); 748 749 mScrollOffsetPrimary = 0; 750 mScrollOffsetSecondary = 0; 751 mWindowAlignment.reset(); 752 } 753 754 mGrid.setProvider(mGridProvider); 755 // mGrid share the same Row array information 756 mGrid.setRows(mRows); 757 mFirstVisiblePos = mLastVisiblePos = NO_POSITION; 758 759 initScrollController(); 760 updateScrollSecondAxis(); 761 762 return focusPosition; 763 } 764 765 private int getRowSizeSecondary(int rowIndex) { 766 if (mFixedRowSizeSecondary != 0) { 767 return mFixedRowSizeSecondary; 768 } 769 if (mRowSizeSecondary == null) { 770 return 0; 771 } 772 return mRowSizeSecondary[rowIndex]; 773 } 774 775 private int getRowStartSecondary(int rowIndex) { 776 int start = 0; 777 for (int i = 0; i < rowIndex; i++) { 778 start += getRowSizeSecondary(i) + mMarginSecondary; 779 } 780 return start; 781 } 782 783 private int getSizeSecondary() { 784 return getRowStartSecondary(mNumRows - 1) + getRowSizeSecondary(mNumRows - 1); 785 } 786 787 private void measureScrapChild(int position, int widthSpec, int heightSpec, 788 int[] measuredDimension) { 789 View view = mRecycler.getViewForPosition(position); 790 if (view != null) { 791 LayoutParams p = (LayoutParams) view.getLayoutParams(); 792 int childWidthSpec = ViewGroup.getChildMeasureSpec(widthSpec, 793 getPaddingLeft() + getPaddingRight(), p.width); 794 int childHeightSpec = ViewGroup.getChildMeasureSpec(heightSpec, 795 getPaddingTop() + getPaddingBottom(), p.height); 796 view.measure(childWidthSpec, childHeightSpec); 797 measuredDimension[0] = view.getMeasuredWidth(); 798 measuredDimension[1] = view.getMeasuredHeight(); 799 mRecycler.recycleView(view); 800 } 801 } 802 803 private boolean processRowSizeSecondary(boolean measure) { 804 if (mFixedRowSizeSecondary != 0) { 805 return false; 806 } 807 808 List<Integer>[] rows = mGrid == null ? null : 809 mGrid.getItemPositionsInRows(mFirstVisiblePos, mLastVisiblePos); 810 boolean changed = false; 811 int scrapChildWidth = -1; 812 int scrapChildHeight = -1; 813 814 for (int rowIndex = 0; rowIndex < mNumRows; rowIndex++) { 815 final int rowItemCount = rows == null ? 0 : rows[rowIndex].size(); 816 if (DEBUG) Log.v(getTag(), "processRowSizeSecondary row " + rowIndex + 817 " rowItemCount " + rowItemCount); 818 819 int rowSize = -1; 820 for (int i = 0; i < rowItemCount; i++) { 821 final View view = findViewByPosition(rows[rowIndex].get(i)); 822 if (view == null) { 823 continue; 824 } 825 if (measure && view.isLayoutRequested()) { 826 measureChild(view); 827 } 828 final int secondarySize = mOrientation == HORIZONTAL ? 829 view.getMeasuredHeight() : view.getMeasuredWidth(); 830 if (secondarySize > rowSize) { 831 rowSize = secondarySize; 832 } 833 } 834 835 if (measure && rowSize < 0 && mState.getItemCount() > 0) { 836 if (scrapChildWidth < 0 && scrapChildHeight < 0) { 837 measureScrapChild(mFocusPosition == NO_POSITION ? 0 : mFocusPosition, 838 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 839 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 840 mMeasuredDimension); 841 scrapChildWidth = mMeasuredDimension[0]; 842 scrapChildHeight = mMeasuredDimension[1]; 843 if (DEBUG) Log.v(TAG, "measured scrap child: " + scrapChildWidth + 844 " " + scrapChildHeight); 845 } 846 rowSize = mOrientation == HORIZONTAL ? scrapChildHeight : scrapChildWidth; 847 } 848 849 if (rowSize < 0) { 850 rowSize = 0; 851 } 852 853 if (DEBUG) Log.v(getTag(), "row " + rowIndex + " rowItemCount " + rowItemCount + 854 " rowSize " + rowSize); 855 856 if (mRowSizeSecondary[rowIndex] != rowSize) { 857 if (DEBUG) Log.v(getTag(), "row size secondary changed: " + mRowSizeSecondary[rowIndex] + 858 ", " + rowSize); 859 860 mRowSizeSecondary[rowIndex] = rowSize; 861 changed = true; 862 } 863 } 864 865 return changed; 866 } 867 868 /** 869 * Checks if we need to update row secondary sizes. 870 */ 871 private void updateRowSecondarySizeRefresh() { 872 mRowSecondarySizeRefresh = processRowSizeSecondary(false); 873 if (mRowSecondarySizeRefresh) { 874 if (DEBUG) Log.v(getTag(), "mRowSecondarySizeRefresh now set"); 875 forceRequestLayout(); 876 } 877 } 878 879 private void forceRequestLayout() { 880 if (DEBUG) Log.v(getTag(), "forceRequestLayout"); 881 // RecyclerView prevents us from requesting layout in many cases 882 // (during layout, during scroll, etc.) 883 // For secondary row size wrap_content support we currently need a 884 // second layout pass to update the measured size after having measured 885 // and added child views in layoutChildren. 886 // Force the second layout by posting a delayed runnable. 887 // TODO: investigate allowing a second layout pass, 888 // or move child add/measure logic to the measure phase. 889 ViewCompat.postOnAnimation(mBaseGridView, mRequestLayoutRunnable); 890 } 891 892 private final Runnable mRequestLayoutRunnable = new Runnable() { 893 @Override 894 public void run() { 895 if (DEBUG) Log.v(getTag(), "request Layout from runnable"); 896 requestLayout(); 897 } 898 }; 899 900 @Override 901 public void onMeasure(Recycler recycler, State state, int widthSpec, int heightSpec) { 902 saveContext(recycler, state); 903 904 int sizePrimary, sizeSecondary, modeSecondary, paddingSecondary; 905 int measuredSizeSecondary; 906 if (mOrientation == HORIZONTAL) { 907 sizePrimary = MeasureSpec.getSize(widthSpec); 908 sizeSecondary = MeasureSpec.getSize(heightSpec); 909 modeSecondary = MeasureSpec.getMode(heightSpec); 910 paddingSecondary = getPaddingTop() + getPaddingBottom(); 911 } else { 912 sizeSecondary = MeasureSpec.getSize(widthSpec); 913 sizePrimary = MeasureSpec.getSize(heightSpec); 914 modeSecondary = MeasureSpec.getMode(widthSpec); 915 paddingSecondary = getPaddingLeft() + getPaddingRight(); 916 } 917 if (DEBUG) Log.v(getTag(), "onMeasure widthSpec " + Integer.toHexString(widthSpec) + 918 " heightSpec " + Integer.toHexString(heightSpec) + 919 " modeSecondary " + Integer.toHexString(modeSecondary) + 920 " sizeSecondary " + sizeSecondary + " " + this); 921 922 mMaxSizeSecondary = sizeSecondary; 923 924 if (mRowSizeSecondaryRequested == ViewGroup.LayoutParams.WRAP_CONTENT) { 925 mNumRows = mNumRowsRequested == 0 ? 1 : mNumRowsRequested; 926 mFixedRowSizeSecondary = 0; 927 928 if (mRowSizeSecondary == null || mRowSizeSecondary.length != mNumRows) { 929 mRowSizeSecondary = new int[mNumRows]; 930 } 931 932 // Measure all current children and update cached row heights 933 processRowSizeSecondary(true); 934 935 switch (modeSecondary) { 936 case MeasureSpec.UNSPECIFIED: 937 measuredSizeSecondary = getSizeSecondary() + paddingSecondary; 938 break; 939 case MeasureSpec.AT_MOST: 940 measuredSizeSecondary = Math.min(getSizeSecondary() + paddingSecondary, 941 mMaxSizeSecondary); 942 break; 943 case MeasureSpec.EXACTLY: 944 measuredSizeSecondary = mMaxSizeSecondary; 945 break; 946 default: 947 throw new IllegalStateException("wrong spec"); 948 } 949 950 } else { 951 switch (modeSecondary) { 952 case MeasureSpec.UNSPECIFIED: 953 if (mRowSizeSecondaryRequested == 0) { 954 if (mOrientation == HORIZONTAL) { 955 throw new IllegalStateException("Must specify rowHeight or view height"); 956 } else { 957 throw new IllegalStateException("Must specify columnWidth or view width"); 958 } 959 } 960 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 961 mNumRows = mNumRowsRequested == 0 ? 1 : mNumRowsRequested; 962 measuredSizeSecondary = mFixedRowSizeSecondary * mNumRows + mMarginSecondary 963 * (mNumRows - 1) + paddingSecondary; 964 break; 965 case MeasureSpec.AT_MOST: 966 case MeasureSpec.EXACTLY: 967 if (mNumRowsRequested == 0 && mRowSizeSecondaryRequested == 0) { 968 mNumRows = 1; 969 mFixedRowSizeSecondary = sizeSecondary - paddingSecondary; 970 } else if (mNumRowsRequested == 0) { 971 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 972 mNumRows = (sizeSecondary + mMarginSecondary) 973 / (mRowSizeSecondaryRequested + mMarginSecondary); 974 } else if (mRowSizeSecondaryRequested == 0) { 975 mNumRows = mNumRowsRequested; 976 mFixedRowSizeSecondary = (sizeSecondary - paddingSecondary - mMarginSecondary 977 * (mNumRows - 1)) / mNumRows; 978 } else { 979 mNumRows = mNumRowsRequested; 980 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 981 } 982 measuredSizeSecondary = sizeSecondary; 983 if (modeSecondary == MeasureSpec.AT_MOST) { 984 int childrenSize = mFixedRowSizeSecondary * mNumRows + mMarginSecondary 985 * (mNumRows - 1) + paddingSecondary; 986 if (childrenSize < measuredSizeSecondary) { 987 measuredSizeSecondary = childrenSize; 988 } 989 } 990 break; 991 default: 992 throw new IllegalStateException("wrong spec"); 993 } 994 } 995 if (mOrientation == HORIZONTAL) { 996 setMeasuredDimension(sizePrimary, measuredSizeSecondary); 997 } else { 998 setMeasuredDimension(measuredSizeSecondary, sizePrimary); 999 } 1000 if (DEBUG) { 1001 Log.v(getTag(), "onMeasure sizePrimary " + sizePrimary + 1002 " measuredSizeSecondary " + measuredSizeSecondary + 1003 " mFixedRowSizeSecondary " + mFixedRowSizeSecondary + 1004 " mNumRows " + mNumRows); 1005 } 1006 1007 leaveContext(); 1008 } 1009 1010 private void measureChild(View child) { 1011 final ViewGroup.LayoutParams lp = child.getLayoutParams(); 1012 final int secondarySpec = (mRowSizeSecondaryRequested == ViewGroup.LayoutParams.WRAP_CONTENT) ? 1013 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED) : 1014 MeasureSpec.makeMeasureSpec(mFixedRowSizeSecondary, MeasureSpec.EXACTLY); 1015 int widthSpec, heightSpec; 1016 1017 if (mOrientation == HORIZONTAL) { 1018 widthSpec = ViewGroup.getChildMeasureSpec( 1019 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 1020 0, lp.width); 1021 heightSpec = ViewGroup.getChildMeasureSpec(secondarySpec, 0, lp.height); 1022 } else { 1023 heightSpec = ViewGroup.getChildMeasureSpec( 1024 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 1025 0, lp.height); 1026 widthSpec = ViewGroup.getChildMeasureSpec(secondarySpec, 0, lp.width); 1027 } 1028 1029 child.measure(widthSpec, heightSpec); 1030 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 } 1038 1039 private StaggeredGrid.Provider mGridProvider = new StaggeredGrid.Provider() { 1040 1041 @Override 1042 public int getCount() { 1043 return mState.getItemCount(); 1044 } 1045 1046 @Override 1047 public void createItem(int index, int rowIndex, boolean append) { 1048 View v = getViewForPosition(index); 1049 if (mFirstVisiblePos >= 0) { 1050 // when StaggeredGrid append or prepend item, we must guarantee 1051 // that sibling item has created views already. 1052 if (append && index != mLastVisiblePos + 1) { 1053 throw new RuntimeException(); 1054 } else if (!append && index != mFirstVisiblePos - 1) { 1055 throw new RuntimeException(); 1056 } 1057 } 1058 1059 // See recyclerView docs: we don't need re-add scraped view if it was removed. 1060 if (!((RecyclerView.LayoutParams) v.getLayoutParams()).isItemRemoved()) { 1061 if (append) { 1062 addView(v); 1063 } else { 1064 addView(v, 0); 1065 } 1066 if (mChildVisibility != -1) { 1067 v.setVisibility(mChildVisibility); 1068 } 1069 1070 // View is added first or it won't be found by dispatchChildSelected. 1071 if (mInLayout && index == mFocusPosition) { 1072 dispatchChildSelected(); 1073 } 1074 1075 measureChild(v); 1076 } 1077 1078 int length = mOrientation == HORIZONTAL ? v.getMeasuredWidth() : v.getMeasuredHeight(); 1079 int start, end; 1080 final boolean rowIsEmpty = mRows[rowIndex].high == mRows[rowIndex].low; 1081 if (append) { 1082 if (!rowIsEmpty) { 1083 // if there are existing item in the row, add margin between 1084 start = mRows[rowIndex].high + mMarginPrimary; 1085 } else { 1086 if (mLastVisiblePos >= 0) { 1087 int lastRow = mGrid.getLocation(mLastVisiblePos).row; 1088 // if the last visible item is not last row, align to beginning, 1089 // otherwise start a new column after. 1090 if (lastRow < mNumRows - 1) { 1091 start = mRows[lastRow].low; 1092 } else { 1093 start = mRows[lastRow].high + mMarginPrimary; 1094 } 1095 } else { 1096 start = 0; 1097 } 1098 mRows[rowIndex].low = start; 1099 } 1100 end = start + length; 1101 mRows[rowIndex].high = end; 1102 } else { 1103 if (!rowIsEmpty) { 1104 // if there are existing item in the row, add margin between 1105 end = mRows[rowIndex].low - mMarginPrimary; 1106 start = end - length; 1107 } else { 1108 if (mFirstVisiblePos >= 0) { 1109 int firstRow = mGrid.getLocation(mFirstVisiblePos).row; 1110 // if the first visible item is not first row, align to beginning, 1111 // otherwise start a new column before. 1112 if (firstRow > 0) { 1113 start = mRows[firstRow].low; 1114 end = start + length; 1115 } else { 1116 end = mRows[firstRow].low - mMarginPrimary; 1117 start = end - length; 1118 } 1119 } else { 1120 start = 0; 1121 end = length; 1122 } 1123 mRows[rowIndex].high = end; 1124 } 1125 mRows[rowIndex].low = start; 1126 } 1127 if (mFirstVisiblePos < 0) { 1128 mFirstVisiblePos = mLastVisiblePos = index; 1129 } else { 1130 if (append) { 1131 mLastVisiblePos++; 1132 } else { 1133 mFirstVisiblePos--; 1134 } 1135 } 1136 if (DEBUG) Log.v(getTag(), "start " + start + " end " + end); 1137 int startSecondary = getRowStartSecondary(rowIndex) - mScrollOffsetSecondary; 1138 mChildrenStates.loadView(v, index); 1139 layoutChild(rowIndex, v, start - mScrollOffsetPrimary, end - mScrollOffsetPrimary, 1140 startSecondary); 1141 if (DEBUG) { 1142 Log.d(getTag(), "addView " + index + " " + v); 1143 } 1144 if (index == mFirstVisiblePos) { 1145 updateScrollMin(); 1146 } 1147 if (index == mLastVisiblePos) { 1148 updateScrollMax(); 1149 } 1150 } 1151 }; 1152 1153 private void layoutChild(int rowIndex, View v, int start, int end, int startSecondary) { 1154 int sizeSecondary = mOrientation == HORIZONTAL ? v.getMeasuredHeight() 1155 : v.getMeasuredWidth(); 1156 if (mFixedRowSizeSecondary > 0) { 1157 sizeSecondary = Math.min(sizeSecondary, mFixedRowSizeSecondary); 1158 } 1159 final int verticalGravity = mGravity & Gravity.VERTICAL_GRAVITY_MASK; 1160 final int horizontalGravity = mGravity & Gravity.HORIZONTAL_GRAVITY_MASK; 1161 if (mOrientation == HORIZONTAL && verticalGravity == Gravity.TOP 1162 || mOrientation == VERTICAL && horizontalGravity == Gravity.LEFT) { 1163 // do nothing 1164 } else if (mOrientation == HORIZONTAL && verticalGravity == Gravity.BOTTOM 1165 || mOrientation == VERTICAL && horizontalGravity == Gravity.RIGHT) { 1166 startSecondary += getRowSizeSecondary(rowIndex) - sizeSecondary; 1167 } else if (mOrientation == HORIZONTAL && verticalGravity == Gravity.CENTER_VERTICAL 1168 || mOrientation == VERTICAL && horizontalGravity == Gravity.CENTER_HORIZONTAL) { 1169 startSecondary += (getRowSizeSecondary(rowIndex) - sizeSecondary) / 2; 1170 } 1171 int left, top, right, bottom; 1172 if (mOrientation == HORIZONTAL) { 1173 left = start; 1174 top = startSecondary; 1175 right = end; 1176 bottom = startSecondary + sizeSecondary; 1177 } else { 1178 top = start; 1179 left = startSecondary; 1180 bottom = end; 1181 right = startSecondary + sizeSecondary; 1182 } 1183 v.layout(left, top, right, bottom); 1184 updateChildOpticalInsets(v, left, top, right, bottom); 1185 updateChildAlignments(v); 1186 } 1187 1188 private void updateChildOpticalInsets(View v, int left, int top, int right, int bottom) { 1189 LayoutParams p = (LayoutParams) v.getLayoutParams(); 1190 p.setOpticalInsets(left - v.getLeft(), top - v.getTop(), 1191 v.getRight() - right, v.getBottom() - bottom); 1192 } 1193 1194 private void updateChildAlignments(View v) { 1195 LayoutParams p = (LayoutParams) v.getLayoutParams(); 1196 p.setAlignX(mItemAlignment.horizontal.getAlignmentPosition(v)); 1197 p.setAlignY(mItemAlignment.vertical.getAlignmentPosition(v)); 1198 } 1199 1200 private void updateChildAlignments() { 1201 for (int i = 0, c = getChildCount(); i < c; i++) { 1202 updateChildAlignments(getChildAt(i)); 1203 } 1204 } 1205 1206 private boolean needsAppendVisibleItem() { 1207 if (mLastVisiblePos < mFocusPosition) { 1208 return true; 1209 } 1210 int right = mScrollOffsetPrimary + mSizePrimary; 1211 for (int i = 0; i < mNumRows; i++) { 1212 if (mRows[i].low == mRows[i].high) { 1213 if (mRows[i].high < right) { 1214 return true; 1215 } 1216 } else if (mRows[i].high < right - mMarginPrimary) { 1217 return true; 1218 } 1219 } 1220 return false; 1221 } 1222 1223 private boolean needsPrependVisibleItem() { 1224 if (mFirstVisiblePos > mFocusPosition) { 1225 return true; 1226 } 1227 for (int i = 0; i < mNumRows; i++) { 1228 if (mRows[i].low == mRows[i].high) { 1229 if (mRows[i].low > mScrollOffsetPrimary) { 1230 return true; 1231 } 1232 } else if (mRows[i].low - mMarginPrimary > mScrollOffsetPrimary) { 1233 return true; 1234 } 1235 } 1236 return false; 1237 } 1238 1239 // Append one column if possible and return true if reach end. 1240 private boolean appendOneVisibleItem() { 1241 while (true) { 1242 if (mLastVisiblePos != NO_POSITION && mLastVisiblePos < mState.getItemCount() -1 && 1243 mLastVisiblePos < mGrid.getLastIndex()) { 1244 // append invisible view of saved location till last row 1245 final int index = mLastVisiblePos + 1; 1246 final int row = mGrid.getLocation(index).row; 1247 mGridProvider.createItem(index, row, true); 1248 if (row == mNumRows - 1) { 1249 return false; 1250 } 1251 } else if ((mLastVisiblePos == NO_POSITION && mState.getItemCount() > 0) || 1252 (mLastVisiblePos != NO_POSITION && 1253 mLastVisiblePos < mState.getItemCount() - 1)) { 1254 mGrid.appendItems(mScrollOffsetPrimary + mSizePrimary); 1255 return false; 1256 } else { 1257 return true; 1258 } 1259 } 1260 } 1261 1262 private void appendVisibleItems() { 1263 while (needsAppendVisibleItem()) { 1264 if (appendOneVisibleItem()) { 1265 break; 1266 } 1267 } 1268 } 1269 1270 // Prepend one column if possible and return true if reach end. 1271 private boolean prependOneVisibleItem() { 1272 while (true) { 1273 if (mFirstVisiblePos > 0) { 1274 if (mFirstVisiblePos > mGrid.getFirstIndex()) { 1275 // prepend invisible view of saved location till first row 1276 final int index = mFirstVisiblePos - 1; 1277 final int row = mGrid.getLocation(index).row; 1278 mGridProvider.createItem(index, row, false); 1279 if (row == 0) { 1280 return false; 1281 } 1282 } else { 1283 mGrid.prependItems(mScrollOffsetPrimary); 1284 return false; 1285 } 1286 } else { 1287 return true; 1288 } 1289 } 1290 } 1291 1292 private void prependVisibleItems() { 1293 while (needsPrependVisibleItem()) { 1294 if (prependOneVisibleItem()) { 1295 break; 1296 } 1297 } 1298 } 1299 1300 private void removeChildAt(int position) { 1301 View v = findViewByPosition(position); 1302 if (v != null) { 1303 if (DEBUG) { 1304 Log.d(getTag(), "removeAndRecycleViewAt " + position); 1305 } 1306 mChildrenStates.saveOffscreenView(v, position); 1307 removeAndRecycleView(v, mRecycler); 1308 } 1309 } 1310 1311 private void removeInvisibleViewsAtEnd() { 1312 if (!mPruneChild) { 1313 return; 1314 } 1315 boolean update = false; 1316 while(mLastVisiblePos > mFirstVisiblePos && mLastVisiblePos > mFocusPosition) { 1317 View view = findViewByPosition(mLastVisiblePos); 1318 if (getViewMin(view) > mSizePrimary) { 1319 removeChildAt(mLastVisiblePos); 1320 mLastVisiblePos--; 1321 update = true; 1322 } else { 1323 break; 1324 } 1325 } 1326 if (update) { 1327 updateRowsMinMax(); 1328 } 1329 } 1330 1331 private void removeInvisibleViewsAtFront() { 1332 if (!mPruneChild) { 1333 return; 1334 } 1335 boolean update = false; 1336 while(mLastVisiblePos > mFirstVisiblePos && mFirstVisiblePos < mFocusPosition) { 1337 View view = findViewByPosition(mFirstVisiblePos); 1338 if (getViewMax(view) < 0) { 1339 removeChildAt(mFirstVisiblePos); 1340 mFirstVisiblePos++; 1341 update = true; 1342 } else { 1343 break; 1344 } 1345 } 1346 if (update) { 1347 updateRowsMinMax(); 1348 } 1349 } 1350 1351 private void updateRowsMinMax() { 1352 if (mFirstVisiblePos < 0) { 1353 return; 1354 } 1355 for (int i = 0; i < mNumRows; i++) { 1356 mRows[i].low = Integer.MAX_VALUE; 1357 mRows[i].high = Integer.MIN_VALUE; 1358 } 1359 for (int i = mFirstVisiblePos; i <= mLastVisiblePos; i++) { 1360 View view = findViewByPosition(i); 1361 int row = mGrid.getLocation(i).row; 1362 int low = getViewMin(view) + mScrollOffsetPrimary; 1363 if (low < mRows[row].low) { 1364 mRows[row].low = low; 1365 } 1366 int high = getViewMax(view) + mScrollOffsetPrimary; 1367 if (high > mRows[row].high) { 1368 mRows[row].high = high; 1369 } 1370 } 1371 } 1372 1373 // Fast layout when there is no structure change, adapter change, etc. 1374 protected void fastRelayout(boolean scrollToFocus) { 1375 initScrollController(); 1376 1377 List<Integer>[] rows = mGrid.getItemPositionsInRows(mFirstVisiblePos, mLastVisiblePos); 1378 1379 // relayout and repositioning views on each row 1380 for (int i = 0; i < mNumRows; i++) { 1381 List<Integer> row = rows[i]; 1382 final int startSecondary = getRowStartSecondary(i) - mScrollOffsetSecondary; 1383 for (int j = 0, size = row.size(); j < size; j++) { 1384 final int position = row.get(j); 1385 final View view = findViewByPosition(position); 1386 int primaryDelta, start, end; 1387 1388 if (mOrientation == HORIZONTAL) { 1389 final int primarySize = view.getMeasuredWidth(); 1390 if (view.isLayoutRequested()) { 1391 measureChild(view); 1392 } 1393 start = getViewMin(view); 1394 end = start + view.getMeasuredWidth(); 1395 primaryDelta = view.getMeasuredWidth() - primarySize; 1396 if (primaryDelta != 0) { 1397 for (int k = j + 1; k < size; k++) { 1398 findViewByPosition(row.get(k)).offsetLeftAndRight(primaryDelta); 1399 } 1400 } 1401 } else { 1402 final int primarySize = view.getMeasuredHeight(); 1403 if (view.isLayoutRequested()) { 1404 measureChild(view); 1405 } 1406 start = getViewMin(view); 1407 end = start + view.getMeasuredHeight(); 1408 primaryDelta = view.getMeasuredHeight() - primarySize; 1409 if (primaryDelta != 0) { 1410 for (int k = j + 1; k < size; k++) { 1411 findViewByPosition(row.get(k)).offsetTopAndBottom(primaryDelta); 1412 } 1413 } 1414 } 1415 layoutChild(i, view, start, end, startSecondary); 1416 } 1417 } 1418 1419 updateRowsMinMax(); 1420 appendVisibleItems(); 1421 prependVisibleItems(); 1422 1423 updateRowsMinMax(); 1424 updateScrollMin(); 1425 updateScrollMax(); 1426 updateScrollSecondAxis(); 1427 1428 if (scrollToFocus) { 1429 View focusView = findViewByPosition(mFocusPosition == NO_POSITION ? 0 : mFocusPosition); 1430 scrollToView(focusView, false); 1431 } 1432 } 1433 1434 public void removeAndRecycleAllViews(RecyclerView.Recycler recycler) { 1435 if (DEBUG) Log.v(TAG, "removeAndRecycleAllViews " + getChildCount()); 1436 for (int i = getChildCount() - 1; i >= 0; i--) { 1437 removeAndRecycleViewAt(i, recycler); 1438 } 1439 } 1440 1441 // Lays out items based on the current scroll position 1442 @Override 1443 public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state) { 1444 if (DEBUG) { 1445 Log.v(getTag(), "layoutChildren start numRows " + mNumRows + " mScrollOffsetSecondary " 1446 + mScrollOffsetSecondary + " mScrollOffsetPrimary " + mScrollOffsetPrimary 1447 + " inPreLayout " + state.isPreLayout() 1448 + " didStructureChange " + state.didStructureChange() 1449 + " mForceFullLayout " + mForceFullLayout); 1450 Log.v(getTag(), "width " + getWidth() + " height " + getHeight()); 1451 } 1452 1453 if (mNumRows == 0) { 1454 // haven't done measure yet 1455 return; 1456 } 1457 final int itemCount = state.getItemCount(); 1458 if (itemCount < 0) { 1459 return; 1460 } 1461 1462 if (!mLayoutEnabled) { 1463 discardLayoutInfo(); 1464 removeAndRecycleAllViews(recycler); 1465 return; 1466 } 1467 mInLayout = true; 1468 1469 final boolean scrollToFocus = !isSmoothScrolling() 1470 && mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED; 1471 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE) { 1472 mFocusPosition = mFocusPosition + mFocusPositionOffset; 1473 mFocusPositionOffset = 0; 1474 } 1475 saveContext(recycler, state); 1476 // Track the old focus view so we can adjust our system scroll position 1477 // so that any scroll animations happening now will remain valid. 1478 // We must use same delta in Pre Layout (if prelayout exists) and second layout. 1479 // So we cache the deltas in PreLayout and use it in second layout. 1480 int delta = 0, deltaSecondary = 0; 1481 if (mFocusPosition != NO_POSITION && scrollToFocus) { 1482 // FIXME: we should get the remaining scroll animation offset from RecyclerView 1483 View focusView = findViewByPosition(mFocusPosition); 1484 if (focusView != null) { 1485 delta = mWindowAlignment.mainAxis().getSystemScrollPos(mScrollOffsetPrimary 1486 + getViewCenter(focusView), false, false) - mScrollOffsetPrimary; 1487 deltaSecondary = mWindowAlignment.secondAxis().getSystemScrollPos( 1488 mScrollOffsetSecondary + getViewCenterSecondary(focusView), 1489 false, false) - mScrollOffsetSecondary; 1490 } 1491 } 1492 1493 final boolean hasDoneFirstLayout = hasDoneFirstLayout(); 1494 int savedFocusPos = mFocusPosition; 1495 boolean fastRelayout = false; 1496 if (!mState.didStructureChange() && !mForceFullLayout && hasDoneFirstLayout) { 1497 fastRelayout = true; 1498 fastRelayout(scrollToFocus); 1499 } else { 1500 boolean hadFocus = mBaseGridView.hasFocus(); 1501 1502 mFocusPosition = init(mFocusPosition); 1503 if (mFocusPosition != savedFocusPos) { 1504 if (DEBUG) Log.v(getTag(), "savedFocusPos " + savedFocusPos + 1505 " mFocusPosition " + mFocusPosition); 1506 } 1507 1508 mWindowAlignment.mainAxis().invalidateScrollMin(); 1509 mWindowAlignment.mainAxis().invalidateScrollMax(); 1510 // depending on result of init(), either recreating everything 1511 // or try to reuse the row start positions near mFocusPosition 1512 if (mGrid.getSize() == 0) { 1513 // this is a fresh creating all items, starting from 1514 // mFocusPosition with a estimated row index. 1515 mGrid.setStart(mFocusPosition, StaggeredGrid.START_DEFAULT); 1516 1517 // Can't track the old focus view 1518 delta = deltaSecondary = 0; 1519 1520 } else { 1521 // mGrid remembers Locations for the column that 1522 // contains mFocusePosition and also mRows remembers start 1523 // positions of each row. 1524 // Manually re-create child views for that column 1525 int firstIndex = mGrid.getFirstIndex(); 1526 int lastIndex = mGrid.getLastIndex(); 1527 for (int i = firstIndex; i <= lastIndex; i++) { 1528 mGridProvider.createItem(i, mGrid.getLocation(i).row, true); 1529 } 1530 } 1531 1532 // add visible views at end until reach the end of window 1533 appendVisibleItems(); 1534 // add visible views at front until reach the start of window 1535 prependVisibleItems(); 1536 // multiple rounds: scrollToView of first round may drag first/last child into 1537 // "visible window" and we update scrollMin/scrollMax then run second scrollToView 1538 int oldFirstVisible; 1539 int oldLastVisible; 1540 do { 1541 updateScrollMin(); 1542 updateScrollMax(); 1543 oldFirstVisible = mFirstVisiblePos; 1544 oldLastVisible = mLastVisiblePos; 1545 View focusView = findViewByPosition(mFocusPosition); 1546 // we need force to initialize the child view's position 1547 scrollToView(focusView, false); 1548 if (focusView != null && hadFocus) { 1549 focusView.requestFocus(); 1550 } 1551 appendVisibleItems(); 1552 prependVisibleItems(); 1553 removeInvisibleViewsAtFront(); 1554 removeInvisibleViewsAtEnd(); 1555 } while (mFirstVisiblePos != oldFirstVisible || mLastVisiblePos != oldLastVisible); 1556 } 1557 mForceFullLayout = false; 1558 1559 if (scrollToFocus) { 1560 scrollDirectionPrimary(-delta); 1561 scrollDirectionSecondary(-deltaSecondary); 1562 } 1563 appendVisibleItems(); 1564 prependVisibleItems(); 1565 removeInvisibleViewsAtFront(); 1566 removeInvisibleViewsAtEnd(); 1567 1568 if (DEBUG) { 1569 StringWriter sw = new StringWriter(); 1570 PrintWriter pw = new PrintWriter(sw); 1571 mGrid.debugPrint(pw); 1572 Log.d(getTag(), sw.toString()); 1573 } 1574 1575 if (mRowSecondarySizeRefresh) { 1576 mRowSecondarySizeRefresh = false; 1577 } else { 1578 updateRowSecondarySizeRefresh(); 1579 } 1580 1581 if (fastRelayout && mFocusPosition != savedFocusPos) { 1582 dispatchChildSelected(); 1583 } 1584 mInLayout = false; 1585 leaveContext(); 1586 if (DEBUG) Log.v(getTag(), "layoutChildren end"); 1587 } 1588 1589 private void offsetChildrenSecondary(int increment) { 1590 final int childCount = getChildCount(); 1591 if (mOrientation == HORIZONTAL) { 1592 for (int i = 0; i < childCount; i++) { 1593 getChildAt(i).offsetTopAndBottom(increment); 1594 } 1595 } else { 1596 for (int i = 0; i < childCount; i++) { 1597 getChildAt(i).offsetLeftAndRight(increment); 1598 } 1599 } 1600 } 1601 1602 private void offsetChildrenPrimary(int increment) { 1603 final int childCount = getChildCount(); 1604 if (mOrientation == VERTICAL) { 1605 for (int i = 0; i < childCount; i++) { 1606 getChildAt(i).offsetTopAndBottom(increment); 1607 } 1608 } else { 1609 for (int i = 0; i < childCount; i++) { 1610 getChildAt(i).offsetLeftAndRight(increment); 1611 } 1612 } 1613 } 1614 1615 @Override 1616 public int scrollHorizontallyBy(int dx, Recycler recycler, RecyclerView.State state) { 1617 if (DEBUG) Log.v(getTag(), "scrollHorizontallyBy " + dx); 1618 if (!mLayoutEnabled || !hasDoneFirstLayout()) { 1619 return 0; 1620 } 1621 saveContext(recycler, state); 1622 int result; 1623 if (mOrientation == HORIZONTAL) { 1624 result = scrollDirectionPrimary(dx); 1625 } else { 1626 result = scrollDirectionSecondary(dx); 1627 } 1628 leaveContext(); 1629 return result; 1630 } 1631 1632 @Override 1633 public int scrollVerticallyBy(int dy, Recycler recycler, RecyclerView.State state) { 1634 if (DEBUG) Log.v(getTag(), "scrollVerticallyBy " + dy); 1635 if (!mLayoutEnabled || !hasDoneFirstLayout()) { 1636 return 0; 1637 } 1638 saveContext(recycler, state); 1639 int result; 1640 if (mOrientation == VERTICAL) { 1641 result = scrollDirectionPrimary(dy); 1642 } else { 1643 result = scrollDirectionSecondary(dy); 1644 } 1645 leaveContext(); 1646 return result; 1647 } 1648 1649 // scroll in main direction may add/prune views 1650 private int scrollDirectionPrimary(int da) { 1651 if (da > 0) { 1652 if (!mWindowAlignment.mainAxis().isMaxUnknown()) { 1653 int maxScroll = mWindowAlignment.mainAxis().getMaxScroll(); 1654 if (mScrollOffsetPrimary + da > maxScroll) { 1655 da = maxScroll - mScrollOffsetPrimary; 1656 } 1657 } 1658 } else if (da < 0) { 1659 if (!mWindowAlignment.mainAxis().isMinUnknown()) { 1660 int minScroll = mWindowAlignment.mainAxis().getMinScroll(); 1661 if (mScrollOffsetPrimary + da < minScroll) { 1662 da = minScroll - mScrollOffsetPrimary; 1663 } 1664 } 1665 } 1666 if (da == 0) { 1667 return 0; 1668 } 1669 offsetChildrenPrimary(-da); 1670 mScrollOffsetPrimary += da; 1671 if (mInLayout) { 1672 return da; 1673 } 1674 1675 int childCount = getChildCount(); 1676 boolean updated; 1677 1678 if (da > 0) { 1679 appendVisibleItems(); 1680 } else if (da < 0) { 1681 prependVisibleItems(); 1682 } 1683 updated = getChildCount() > childCount; 1684 childCount = getChildCount(); 1685 1686 if (da > 0) { 1687 removeInvisibleViewsAtFront(); 1688 } else if (da < 0) { 1689 removeInvisibleViewsAtEnd(); 1690 } 1691 updated |= getChildCount() < childCount; 1692 1693 if (updated) { 1694 updateRowSecondarySizeRefresh(); 1695 } 1696 1697 mBaseGridView.invalidate(); 1698 return da; 1699 } 1700 1701 // scroll in second direction will not add/prune views 1702 private int scrollDirectionSecondary(int dy) { 1703 if (dy == 0) { 1704 return 0; 1705 } 1706 offsetChildrenSecondary(-dy); 1707 mScrollOffsetSecondary += dy; 1708 mBaseGridView.invalidate(); 1709 return dy; 1710 } 1711 1712 private void updateScrollMax() { 1713 if (mLastVisiblePos < 0) { 1714 return; 1715 } 1716 final boolean lastAvailable = mLastVisiblePos == mState.getItemCount() - 1; 1717 final boolean maxUnknown = mWindowAlignment.mainAxis().isMaxUnknown(); 1718 if (!lastAvailable && maxUnknown) { 1719 return; 1720 } 1721 int maxEdge = Integer.MIN_VALUE; 1722 int rowIndex = -1; 1723 for (int i = 0; i < mRows.length; i++) { 1724 if (mRows[i].high > maxEdge) { 1725 maxEdge = mRows[i].high; 1726 rowIndex = i; 1727 } 1728 } 1729 int maxScroll = Integer.MAX_VALUE; 1730 for (int i = mLastVisiblePos; i >= mFirstVisiblePos; i--) { 1731 StaggeredGrid.Location location = mGrid.getLocation(i); 1732 if (location != null && location.row == rowIndex) { 1733 int savedMaxEdge = mWindowAlignment.mainAxis().getMaxEdge(); 1734 mWindowAlignment.mainAxis().setMaxEdge(maxEdge); 1735 maxScroll = getPrimarySystemScrollPosition(findViewByPosition(i)); 1736 mWindowAlignment.mainAxis().setMaxEdge(savedMaxEdge); 1737 break; 1738 } 1739 } 1740 if (lastAvailable) { 1741 mWindowAlignment.mainAxis().setMaxEdge(maxEdge); 1742 mWindowAlignment.mainAxis().setMaxScroll(maxScroll); 1743 if (DEBUG) Log.v(getTag(), "updating scroll maxEdge to " + maxEdge + 1744 " scrollMax to " + maxScroll); 1745 } else { 1746 // the maxScroll for currently last visible item is larger, 1747 // so we must invalidate the max scroll value. 1748 if (maxScroll > mWindowAlignment.mainAxis().getMaxScroll()) { 1749 mWindowAlignment.mainAxis().invalidateScrollMax(); 1750 if (DEBUG) Log.v(getTag(), "Invalidate scrollMax since it should be " 1751 + "greater than " + maxScroll); 1752 } 1753 } 1754 } 1755 1756 private void updateScrollMin() { 1757 if (mFirstVisiblePos < 0) { 1758 return; 1759 } 1760 final boolean firstAvailable = mFirstVisiblePos == 0; 1761 final boolean minUnknown = mWindowAlignment.mainAxis().isMinUnknown(); 1762 if (!firstAvailable && minUnknown) { 1763 return; 1764 } 1765 int minEdge = Integer.MAX_VALUE; 1766 int rowIndex = -1; 1767 for (int i = 0; i < mRows.length; i++) { 1768 if (mRows[i].low < minEdge) { 1769 minEdge = mRows[i].low; 1770 rowIndex = i; 1771 } 1772 } 1773 int minScroll = Integer.MIN_VALUE; 1774 for (int i = mFirstVisiblePos; i <= mLastVisiblePos; i++) { 1775 StaggeredGrid.Location location = mGrid.getLocation(i); 1776 if (location != null && location.row == rowIndex) { 1777 int savedMinEdge = mWindowAlignment.mainAxis().getMinEdge(); 1778 mWindowAlignment.mainAxis().setMinEdge(minEdge); 1779 minScroll = getPrimarySystemScrollPosition(findViewByPosition(i)); 1780 mWindowAlignment.mainAxis().setMinEdge(savedMinEdge); 1781 break; 1782 } 1783 } 1784 if (firstAvailable) { 1785 mWindowAlignment.mainAxis().setMinEdge(minEdge); 1786 mWindowAlignment.mainAxis().setMinScroll(minScroll); 1787 if (DEBUG) Log.v(getTag(), "updating scroll minEdge to " + minEdge + 1788 " scrollMin to " + minScroll); 1789 } else { 1790 // the minScroll for currently first visible item is smaller, 1791 // so we must invalidate the min scroll value. 1792 if (minScroll < mWindowAlignment.mainAxis().getMinScroll()) { 1793 mWindowAlignment.mainAxis().invalidateScrollMin(); 1794 if (DEBUG) Log.v(getTag(), "Invalidate scrollMin, since it should be " 1795 + "less than " + minScroll); 1796 } 1797 } 1798 } 1799 1800 private void updateScrollSecondAxis() { 1801 mWindowAlignment.secondAxis().setMinEdge(0); 1802 mWindowAlignment.secondAxis().setMaxEdge(getSizeSecondary()); 1803 } 1804 1805 private void initScrollController() { 1806 // mScrollOffsetPrimary and mScrollOffsetSecondary includes the padding. 1807 // e.g. when topPadding is 16 for horizontal grid view, the initial 1808 // mScrollOffsetSecondary is -16. fastLayout() put views based on offsets(not padding), 1809 // when padding changes to 20, we also need update mScrollOffsetSecondary to -20 before 1810 // fastLayout() is performed 1811 int paddingPrimaryDiff, paddingSecondaryDiff; 1812 if (mOrientation == HORIZONTAL) { 1813 paddingPrimaryDiff = getPaddingLeft() - mWindowAlignment.horizontal.getPaddingLow(); 1814 paddingSecondaryDiff = getPaddingTop() - mWindowAlignment.vertical.getPaddingLow(); 1815 } else { 1816 paddingPrimaryDiff = getPaddingTop() - mWindowAlignment.vertical.getPaddingLow(); 1817 paddingSecondaryDiff = getPaddingLeft() - mWindowAlignment.horizontal.getPaddingLow(); 1818 } 1819 mScrollOffsetPrimary -= paddingPrimaryDiff; 1820 mScrollOffsetSecondary -= paddingSecondaryDiff; 1821 1822 mWindowAlignment.horizontal.setSize(getWidth()); 1823 mWindowAlignment.horizontal.setPadding(getPaddingLeft(), getPaddingRight()); 1824 mWindowAlignment.vertical.setSize(getHeight()); 1825 mWindowAlignment.vertical.setPadding(getPaddingTop(), getPaddingBottom()); 1826 mSizePrimary = mWindowAlignment.mainAxis().getSize(); 1827 1828 if (DEBUG) { 1829 Log.v(getTag(), "initScrollController mSizePrimary " + mSizePrimary 1830 + " mWindowAlignment " + mWindowAlignment); 1831 } 1832 } 1833 1834 public void setSelection(RecyclerView parent, int position) { 1835 setSelection(parent, position, false); 1836 } 1837 1838 public void setSelectionSmooth(RecyclerView parent, int position) { 1839 setSelection(parent, position, true); 1840 } 1841 1842 public int getSelection() { 1843 return mFocusPosition; 1844 } 1845 1846 public void setSelection(RecyclerView parent, int position, boolean smooth) { 1847 if (mFocusPosition == position) { 1848 return; 1849 } 1850 View view = findViewByPosition(position); 1851 if (view != null) { 1852 mInSelection = true; 1853 scrollToView(view, smooth); 1854 mInSelection = false; 1855 } else { 1856 mFocusPosition = position; 1857 mFocusPositionOffset = 0; 1858 if (!mLayoutEnabled) { 1859 return; 1860 } 1861 if (smooth) { 1862 if (!hasDoneFirstLayout()) { 1863 Log.w(getTag(), "setSelectionSmooth should " + 1864 "not be called before first layout pass"); 1865 return; 1866 } 1867 LinearSmoothScroller linearSmoothScroller = 1868 new LinearSmoothScroller(parent.getContext()) { 1869 @Override 1870 public PointF computeScrollVectorForPosition(int targetPosition) { 1871 if (getChildCount() == 0) { 1872 return null; 1873 } 1874 final int firstChildPos = getPosition(getChildAt(0)); 1875 final int direction = targetPosition < firstChildPos ? -1 : 1; 1876 if (mOrientation == HORIZONTAL) { 1877 return new PointF(direction, 0); 1878 } else { 1879 return new PointF(0, direction); 1880 } 1881 } 1882 @Override 1883 protected void onTargetFound(View targetView, 1884 RecyclerView.State state, Action action) { 1885 if (hasFocus()) { 1886 targetView.requestFocus(); 1887 } 1888 dispatchChildSelected(); 1889 if (getScrollPosition(targetView, mTempDeltas)) { 1890 int dx, dy; 1891 if (mOrientation == HORIZONTAL) { 1892 dx = mTempDeltas[0]; 1893 dy = mTempDeltas[1]; 1894 } else { 1895 dx = mTempDeltas[1]; 1896 dy = mTempDeltas[0]; 1897 } 1898 final int distance = (int) Math.sqrt(dx * dx + dy * dy); 1899 final int time = calculateTimeForDeceleration(distance); 1900 action.update(dx, dy, time, mDecelerateInterpolator); 1901 } 1902 } 1903 }; 1904 linearSmoothScroller.setTargetPosition(position); 1905 startSmoothScroll(linearSmoothScroller); 1906 } else { 1907 mForceFullLayout = true; 1908 parent.requestLayout(); 1909 } 1910 } 1911 } 1912 1913 @Override 1914 public void onItemsAdded(RecyclerView recyclerView, int positionStart, int itemCount) { 1915 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE 1916 && getChildAt(mFocusPosition) != null) { 1917 int pos = mFocusPosition + mFocusPositionOffset; 1918 if (positionStart <= pos) { 1919 mFocusPositionOffset += itemCount; 1920 } 1921 } 1922 mChildrenStates.clear(); 1923 } 1924 1925 @Override 1926 public void onItemsChanged(RecyclerView recyclerView) { 1927 mFocusPositionOffset = 0; 1928 mChildrenStates.clear(); 1929 } 1930 1931 @Override 1932 public void onItemsRemoved(RecyclerView recyclerView, int positionStart, int itemCount) { 1933 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE 1934 && getChildAt(mFocusPosition) != null) { 1935 int pos = mFocusPosition + mFocusPositionOffset; 1936 if (positionStart <= pos) { 1937 if (positionStart + itemCount > pos) { 1938 // stop updating offset after the focus item was removed 1939 mFocusPositionOffset = Integer.MIN_VALUE; 1940 } else { 1941 mFocusPositionOffset -= itemCount; 1942 } 1943 } 1944 } 1945 mChildrenStates.clear(); 1946 } 1947 1948 @Override 1949 public void onItemsMoved(RecyclerView recyclerView, int fromPosition, int toPosition, 1950 int itemCount) { 1951 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE 1952 && getChildAt(mFocusPosition) != null) { 1953 int pos = mFocusPosition + mFocusPositionOffset; 1954 if (fromPosition <= pos && pos < fromPosition + itemCount) { 1955 // moved items include focused position 1956 mFocusPositionOffset += toPosition - fromPosition; 1957 } else if (fromPosition < pos && toPosition > pos - itemCount) { 1958 // move items before focus position to after focused position 1959 mFocusPositionOffset -= itemCount; 1960 } else if (fromPosition > pos && toPosition < pos) { 1961 // move items after focus position to before focused position 1962 mFocusPositionOffset += itemCount; 1963 } 1964 } 1965 mChildrenStates.clear(); 1966 } 1967 1968 @Override 1969 public void onItemsUpdated(RecyclerView recyclerView, int positionStart, int itemCount) { 1970 for (int i = positionStart, end = positionStart + itemCount; i < end; i++) { 1971 mChildrenStates.remove(i); 1972 } 1973 } 1974 1975 @Override 1976 public boolean onRequestChildFocus(RecyclerView parent, View child, View focused) { 1977 if (mFocusSearchDisabled) { 1978 return true; 1979 } 1980 if (!mInLayout && !mInSelection) { 1981 scrollToView(child, true); 1982 } 1983 return true; 1984 } 1985 1986 @Override 1987 public boolean requestChildRectangleOnScreen(RecyclerView parent, View view, Rect rect, 1988 boolean immediate) { 1989 if (DEBUG) Log.v(getTag(), "requestChildRectangleOnScreen " + view + " " + rect); 1990 return false; 1991 } 1992 1993 int getScrollOffsetX() { 1994 return mOrientation == HORIZONTAL ? mScrollOffsetPrimary : mScrollOffsetSecondary; 1995 } 1996 1997 int getScrollOffsetY() { 1998 return mOrientation == HORIZONTAL ? mScrollOffsetSecondary : mScrollOffsetPrimary; 1999 } 2000 2001 public void getViewSelectedOffsets(View view, int[] offsets) { 2002 if (mOrientation == HORIZONTAL) { 2003 offsets[0] = getPrimarySystemScrollPosition(view) - mScrollOffsetPrimary; 2004 offsets[1] = getSecondarySystemScrollPosition(view) - mScrollOffsetSecondary; 2005 } else { 2006 offsets[1] = getPrimarySystemScrollPosition(view) - mScrollOffsetPrimary; 2007 offsets[0] = getSecondarySystemScrollPosition(view) - mScrollOffsetSecondary; 2008 } 2009 } 2010 2011 private int getPrimarySystemScrollPosition(View view) { 2012 int viewCenterPrimary = mScrollOffsetPrimary + getViewCenter(view); 2013 int pos = getPositionByView(view); 2014 StaggeredGrid.Location location = mGrid.getLocation(pos); 2015 final int row = location.row; 2016 boolean isFirst = mFirstVisiblePos == 0; 2017 // TODO: change to use State object in onRequestChildFocus() 2018 boolean isLast = mLastVisiblePos == (mState == null ? 2019 getItemCount() : mState.getItemCount()) - 1; 2020 if (isFirst || isLast) { 2021 for (int i = getChildCount() - 1; i >= 0; i--) { 2022 int position = getPositionByIndex(i); 2023 StaggeredGrid.Location loc = mGrid.getLocation(position); 2024 if (loc != null && loc.row == row) { 2025 if (position < pos) { 2026 isFirst = false; 2027 } else if (position > pos) { 2028 isLast = false; 2029 } 2030 } 2031 } 2032 } 2033 return mWindowAlignment.mainAxis().getSystemScrollPos(viewCenterPrimary, isFirst, isLast); 2034 } 2035 2036 private int getSecondarySystemScrollPosition(View view) { 2037 int viewCenterSecondary = mScrollOffsetSecondary + getViewCenterSecondary(view); 2038 int pos = getPositionByView(view); 2039 StaggeredGrid.Location location = mGrid.getLocation(pos); 2040 final int row = location.row; 2041 boolean isFirst = row == 0; 2042 boolean isLast = row == mGrid.getNumRows() - 1; 2043 return mWindowAlignment.secondAxis().getSystemScrollPos(viewCenterSecondary, 2044 isFirst, isLast); 2045 } 2046 2047 /** 2048 * Scroll to a given child view and change mFocusPosition. 2049 */ 2050 private void scrollToView(View view, boolean smooth) { 2051 int newFocusPosition = getPositionByView(view); 2052 if (newFocusPosition != mFocusPosition) { 2053 mFocusPosition = newFocusPosition; 2054 mFocusPositionOffset = 0; 2055 if (!mInLayout) { 2056 dispatchChildSelected(); 2057 } 2058 } 2059 if (mBaseGridView.isChildrenDrawingOrderEnabledInternal()) { 2060 mBaseGridView.invalidate(); 2061 } 2062 if (view == null) { 2063 return; 2064 } 2065 if (!view.hasFocus() && mBaseGridView.hasFocus()) { 2066 // transfer focus to the child if it does not have focus yet (e.g. triggered 2067 // by setSelection()) 2068 view.requestFocus(); 2069 } 2070 if (!mScrollEnabled) { 2071 return; 2072 } 2073 if (getScrollPosition(view, mTempDeltas)) { 2074 scrollGrid(mTempDeltas[0], mTempDeltas[1], smooth); 2075 } 2076 } 2077 2078 private boolean getScrollPosition(View view, int[] deltas) { 2079 switch (mFocusScrollStrategy) { 2080 case BaseGridView.FOCUS_SCROLL_ALIGNED: 2081 default: 2082 return getAlignedPosition(view, deltas); 2083 case BaseGridView.FOCUS_SCROLL_ITEM: 2084 case BaseGridView.FOCUS_SCROLL_PAGE: 2085 return getNoneAlignedPosition(view, deltas); 2086 } 2087 } 2088 2089 private boolean getNoneAlignedPosition(View view, int[] deltas) { 2090 int pos = getPositionByView(view); 2091 int viewMin = getViewMin(view); 2092 int viewMax = getViewMax(view); 2093 // we either align "firstView" to left/top padding edge 2094 // or align "lastView" to right/bottom padding edge 2095 View firstView = null; 2096 View lastView = null; 2097 int paddingLow = mWindowAlignment.mainAxis().getPaddingLow(); 2098 int clientSize = mWindowAlignment.mainAxis().getClientSize(); 2099 final int row = mGrid.getLocation(pos).row; 2100 if (viewMin < paddingLow) { 2101 // view enters low padding area: 2102 firstView = view; 2103 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_PAGE) { 2104 // scroll one "page" left/top, 2105 // align first visible item of the "page" at the low padding edge. 2106 while (!prependOneVisibleItem()) { 2107 List<Integer> positions = 2108 mGrid.getItemPositionsInRows(mFirstVisiblePos, pos)[row]; 2109 firstView = findViewByPosition(positions.get(0)); 2110 if (viewMax - getViewMin(firstView) > clientSize) { 2111 if (positions.size() > 1) { 2112 firstView = findViewByPosition(positions.get(1)); 2113 } 2114 break; 2115 } 2116 } 2117 } 2118 } else if (viewMax > clientSize + paddingLow) { 2119 // view enters high padding area: 2120 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_PAGE) { 2121 // scroll whole one page right/bottom, align view at the low padding edge. 2122 firstView = view; 2123 do { 2124 List<Integer> positions = 2125 mGrid.getItemPositionsInRows(pos, mLastVisiblePos)[row]; 2126 lastView = findViewByPosition(positions.get(positions.size() - 1)); 2127 if (getViewMax(lastView) - viewMin > clientSize) { 2128 lastView = null; 2129 break; 2130 } 2131 } while (!appendOneVisibleItem()); 2132 if (lastView != null) { 2133 // however if we reached end, we should align last view. 2134 firstView = null; 2135 } 2136 } else { 2137 lastView = view; 2138 } 2139 } 2140 int scrollPrimary = 0; 2141 int scrollSecondary = 0; 2142 if (firstView != null) { 2143 scrollPrimary = getViewMin(firstView) - paddingLow; 2144 } else if (lastView != null) { 2145 scrollPrimary = getViewMax(lastView) - (paddingLow + clientSize); 2146 } 2147 View secondaryAlignedView; 2148 if (firstView != null) { 2149 secondaryAlignedView = firstView; 2150 } else if (lastView != null) { 2151 secondaryAlignedView = lastView; 2152 } else { 2153 secondaryAlignedView = view; 2154 } 2155 scrollSecondary = getSecondarySystemScrollPosition(secondaryAlignedView); 2156 scrollSecondary -= mScrollOffsetSecondary; 2157 if (scrollPrimary != 0 || scrollSecondary != 0) { 2158 deltas[0] = scrollPrimary; 2159 deltas[1] = scrollSecondary; 2160 return true; 2161 } 2162 return false; 2163 } 2164 2165 private boolean getAlignedPosition(View view, int[] deltas) { 2166 int scrollPrimary = getPrimarySystemScrollPosition(view); 2167 int scrollSecondary = getSecondarySystemScrollPosition(view); 2168 if (DEBUG) { 2169 Log.v(getTag(), "getAlignedPosition " + scrollPrimary + " " + scrollSecondary 2170 +" " + mWindowAlignment); 2171 } 2172 scrollPrimary -= mScrollOffsetPrimary; 2173 scrollSecondary -= mScrollOffsetSecondary; 2174 if (scrollPrimary != 0 || scrollSecondary != 0) { 2175 deltas[0] = scrollPrimary; 2176 deltas[1] = scrollSecondary; 2177 return true; 2178 } 2179 return false; 2180 } 2181 2182 private void scrollGrid(int scrollPrimary, int scrollSecondary, boolean smooth) { 2183 if (mInLayout) { 2184 scrollDirectionPrimary(scrollPrimary); 2185 scrollDirectionSecondary(scrollSecondary); 2186 } else { 2187 int scrollX; 2188 int scrollY; 2189 if (mOrientation == HORIZONTAL) { 2190 scrollX = scrollPrimary; 2191 scrollY = scrollSecondary; 2192 } else { 2193 scrollX = scrollSecondary; 2194 scrollY = scrollPrimary; 2195 } 2196 if (smooth) { 2197 mBaseGridView.smoothScrollBy(scrollX, scrollY); 2198 } else { 2199 mBaseGridView.scrollBy(scrollX, scrollY); 2200 } 2201 } 2202 } 2203 2204 public void setPruneChild(boolean pruneChild) { 2205 if (mPruneChild != pruneChild) { 2206 mPruneChild = pruneChild; 2207 if (mPruneChild) { 2208 requestLayout(); 2209 } 2210 } 2211 } 2212 2213 public boolean getPruneChild() { 2214 return mPruneChild; 2215 } 2216 2217 public void setScrollEnabled(boolean scrollEnabled) { 2218 if (mScrollEnabled != scrollEnabled) { 2219 mScrollEnabled = scrollEnabled; 2220 if (mScrollEnabled && mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED) { 2221 View focusView = findViewByPosition(mFocusPosition == NO_POSITION ? 0 : 2222 mFocusPosition); 2223 if (focusView != null) { 2224 scrollToView(focusView, true); 2225 } 2226 } 2227 } 2228 } 2229 2230 public boolean isScrollEnabled() { 2231 return mScrollEnabled; 2232 } 2233 2234 private int findImmediateChildIndex(View view) { 2235 while (view != null && view != mBaseGridView) { 2236 int index = mBaseGridView.indexOfChild(view); 2237 if (index >= 0) { 2238 return index; 2239 } 2240 view = (View) view.getParent(); 2241 } 2242 return NO_POSITION; 2243 } 2244 2245 void setFocusSearchDisabled(boolean disabled) { 2246 mFocusSearchDisabled = disabled; 2247 } 2248 2249 boolean isFocusSearchDisabled() { 2250 return mFocusSearchDisabled; 2251 } 2252 2253 @Override 2254 public View onInterceptFocusSearch(View focused, int direction) { 2255 if (mFocusSearchDisabled) { 2256 return focused; 2257 } 2258 return null; 2259 } 2260 2261 boolean hasPreviousViewInSameRow(int pos) { 2262 if (mGrid == null || pos == NO_POSITION) { 2263 return false; 2264 } 2265 if (mFirstVisiblePos > 0) { 2266 return true; 2267 } 2268 final int focusedRow = mGrid.getLocation(pos).row; 2269 for (int i = getChildCount() - 1; i >= 0; i--) { 2270 int position = getPositionByIndex(i); 2271 StaggeredGrid.Location loc = mGrid.getLocation(position); 2272 if (loc != null && loc.row == focusedRow) { 2273 if (position < pos) { 2274 return true; 2275 } 2276 } 2277 } 2278 return false; 2279 } 2280 2281 @Override 2282 public boolean onAddFocusables(RecyclerView recyclerView, 2283 ArrayList<View> views, int direction, int focusableMode) { 2284 if (mFocusSearchDisabled) { 2285 return true; 2286 } 2287 // If this viewgroup or one of its children currently has focus then we 2288 // consider our children for focus searching in main direction on the same row. 2289 // If this viewgroup has no focus and using focus align, we want the system 2290 // to ignore our children and pass focus to the viewgroup, which will pass 2291 // focus on to its children appropriately. 2292 // If this viewgroup has no focus and not using focus align, we want to 2293 // consider the child that does not overlap with padding area. 2294 if (recyclerView.hasFocus()) { 2295 final int movement = getMovement(direction); 2296 if (movement != PREV_ITEM && movement != NEXT_ITEM) { 2297 // Move on secondary direction uses default addFocusables(). 2298 return false; 2299 } 2300 final View focused = recyclerView.findFocus(); 2301 final int focusedPos = getPositionByIndex(findImmediateChildIndex(focused)); 2302 // Add focusables of focused item. 2303 if (focusedPos != NO_POSITION) { 2304 findViewByPosition(focusedPos).addFocusables(views, direction, focusableMode); 2305 } 2306 final int focusedRow = mGrid != null && focusedPos != NO_POSITION ? 2307 mGrid.getLocation(focusedPos).row : NO_POSITION; 2308 // Add focusables of next neighbor of same row on the focus search direction. 2309 if (mGrid != null) { 2310 final int focusableCount = views.size(); 2311 for (int i = 0, count = getChildCount(); i < count; i++) { 2312 int index = movement == NEXT_ITEM ? i : count - 1 - i; 2313 final View child = getChildAt(index); 2314 if (child.getVisibility() != View.VISIBLE) { 2315 continue; 2316 } 2317 int position = getPositionByIndex(index); 2318 StaggeredGrid.Location loc = mGrid.getLocation(position); 2319 if (focusedRow == NO_POSITION || (loc != null && loc.row == focusedRow)) { 2320 if (focusedPos == NO_POSITION || 2321 (movement == NEXT_ITEM && position > focusedPos) 2322 || (movement == PREV_ITEM && position < focusedPos)) { 2323 child.addFocusables(views, direction, focusableMode); 2324 if (views.size() > focusableCount) { 2325 break; 2326 } 2327 } 2328 } 2329 } 2330 } 2331 } else { 2332 if (mFocusScrollStrategy != BaseGridView.FOCUS_SCROLL_ALIGNED) { 2333 // adding views not overlapping padding area to avoid scrolling in gaining focus 2334 int left = mWindowAlignment.mainAxis().getPaddingLow(); 2335 int right = mWindowAlignment.mainAxis().getClientSize() + left; 2336 int focusableCount = views.size(); 2337 for (int i = 0, count = getChildCount(); i < count; i++) { 2338 View child = getChildAt(i); 2339 if (child.getVisibility() == View.VISIBLE) { 2340 if (getViewMin(child) >= left && getViewMax(child) <= right) { 2341 child.addFocusables(views, direction, focusableMode); 2342 } 2343 } 2344 } 2345 // if we cannot find any, then just add all children. 2346 if (views.size() == focusableCount) { 2347 for (int i = 0, count = getChildCount(); i < count; i++) { 2348 View child = getChildAt(i); 2349 if (child.getVisibility() == View.VISIBLE) { 2350 child.addFocusables(views, direction, focusableMode); 2351 } 2352 } 2353 if (views.size() != focusableCount) { 2354 return true; 2355 } 2356 } else { 2357 return true; 2358 } 2359 // if still cannot find any, fall through and add itself 2360 } 2361 if (recyclerView.isFocusable()) { 2362 views.add(recyclerView); 2363 } 2364 } 2365 return true; 2366 } 2367 2368 @Override 2369 public View onFocusSearchFailed(View focused, int direction, Recycler recycler, 2370 RecyclerView.State state) { 2371 if (DEBUG) Log.v(getTag(), "onFocusSearchFailed direction " + direction); 2372 2373 View view = null; 2374 int movement = getMovement(direction); 2375 if (mNumRows == 1) { 2376 // for simple row, use LinearSmoothScroller to smooth animation. 2377 // It will stay at a fixed cap speed in continuous scroll. 2378 if (movement == NEXT_ITEM) { 2379 int newPos = mFocusPosition + mNumRows; 2380 if (newPos < getItemCount()) { 2381 setSelectionSmooth(mBaseGridView, newPos); 2382 view = focused; 2383 } else { 2384 if (!mFocusOutEnd) { 2385 view = focused; 2386 } 2387 } 2388 } else if (movement == PREV_ITEM){ 2389 int newPos = mFocusPosition - mNumRows; 2390 if (newPos >= 0) { 2391 setSelectionSmooth(mBaseGridView, newPos); 2392 view = focused; 2393 } else { 2394 if (!mFocusOutFront) { 2395 view = focused; 2396 } 2397 } 2398 } 2399 } else if (mNumRows > 1) { 2400 // for possible staggered grid, we need guarantee focus to same row/column. 2401 // TODO: we may also use LinearSmoothScroller. 2402 saveContext(recycler, state); 2403 final FocusFinder ff = FocusFinder.getInstance(); 2404 if (movement == NEXT_ITEM) { 2405 while (view == null && !appendOneVisibleItem()) { 2406 view = ff.findNextFocus(mBaseGridView, focused, direction); 2407 } 2408 } else if (movement == PREV_ITEM){ 2409 while (view == null && !prependOneVisibleItem()) { 2410 view = ff.findNextFocus(mBaseGridView, focused, direction); 2411 } 2412 } 2413 if (view == null) { 2414 // returning the same view to prevent focus lost when scrolling past the end of the list 2415 if (movement == PREV_ITEM) { 2416 view = mFocusOutFront ? null : focused; 2417 } else if (movement == NEXT_ITEM){ 2418 view = mFocusOutEnd ? null : focused; 2419 } 2420 } 2421 leaveContext(); 2422 } 2423 if (DEBUG) Log.v(getTag(), "returning view " + view); 2424 return view; 2425 } 2426 2427 boolean gridOnRequestFocusInDescendants(RecyclerView recyclerView, int direction, 2428 Rect previouslyFocusedRect) { 2429 switch (mFocusScrollStrategy) { 2430 case BaseGridView.FOCUS_SCROLL_ALIGNED: 2431 default: 2432 return gridOnRequestFocusInDescendantsAligned(recyclerView, 2433 direction, previouslyFocusedRect); 2434 case BaseGridView.FOCUS_SCROLL_PAGE: 2435 case BaseGridView.FOCUS_SCROLL_ITEM: 2436 return gridOnRequestFocusInDescendantsUnaligned(recyclerView, 2437 direction, previouslyFocusedRect); 2438 } 2439 } 2440 2441 private boolean gridOnRequestFocusInDescendantsAligned(RecyclerView recyclerView, 2442 int direction, Rect previouslyFocusedRect) { 2443 View view = findViewByPosition(mFocusPosition); 2444 if (view != null) { 2445 boolean result = view.requestFocus(direction, previouslyFocusedRect); 2446 if (!result && DEBUG) { 2447 Log.w(getTag(), "failed to request focus on " + view); 2448 } 2449 return result; 2450 } 2451 return false; 2452 } 2453 2454 private boolean gridOnRequestFocusInDescendantsUnaligned(RecyclerView recyclerView, 2455 int direction, Rect previouslyFocusedRect) { 2456 // focus to view not overlapping padding area to avoid scrolling in gaining focus 2457 int index; 2458 int increment; 2459 int end; 2460 int count = getChildCount(); 2461 if ((direction & View.FOCUS_FORWARD) != 0) { 2462 index = 0; 2463 increment = 1; 2464 end = count; 2465 } else { 2466 index = count - 1; 2467 increment = -1; 2468 end = -1; 2469 } 2470 int left = mWindowAlignment.mainAxis().getPaddingLow(); 2471 int right = mWindowAlignment.mainAxis().getClientSize() + left; 2472 for (int i = index; i != end; i += increment) { 2473 View child = getChildAt(i); 2474 if (child.getVisibility() == View.VISIBLE) { 2475 if (getViewMin(child) >= left && getViewMax(child) <= right) { 2476 if (child.requestFocus(direction, previouslyFocusedRect)) { 2477 return true; 2478 } 2479 } 2480 } 2481 } 2482 return false; 2483 } 2484 2485 private final static int PREV_ITEM = 0; 2486 private final static int NEXT_ITEM = 1; 2487 private final static int PREV_ROW = 2; 2488 private final static int NEXT_ROW = 3; 2489 2490 private int getMovement(int direction) { 2491 int movement = View.FOCUS_LEFT; 2492 2493 if (mOrientation == HORIZONTAL) { 2494 switch(direction) { 2495 case View.FOCUS_LEFT: 2496 movement = PREV_ITEM; 2497 break; 2498 case View.FOCUS_RIGHT: 2499 movement = NEXT_ITEM; 2500 break; 2501 case View.FOCUS_UP: 2502 movement = PREV_ROW; 2503 break; 2504 case View.FOCUS_DOWN: 2505 movement = NEXT_ROW; 2506 break; 2507 } 2508 } else if (mOrientation == VERTICAL) { 2509 switch(direction) { 2510 case View.FOCUS_LEFT: 2511 movement = PREV_ROW; 2512 break; 2513 case View.FOCUS_RIGHT: 2514 movement = NEXT_ROW; 2515 break; 2516 case View.FOCUS_UP: 2517 movement = PREV_ITEM; 2518 break; 2519 case View.FOCUS_DOWN: 2520 movement = NEXT_ITEM; 2521 break; 2522 } 2523 } 2524 2525 return movement; 2526 } 2527 2528 int getChildDrawingOrder(RecyclerView recyclerView, int childCount, int i) { 2529 View view = findViewByPosition(mFocusPosition); 2530 if (view == null) { 2531 return i; 2532 } 2533 int focusIndex = recyclerView.indexOfChild(view); 2534 // supposely 0 1 2 3 4 5 6 7 8 9, 4 is the center item 2535 // drawing order is 0 1 2 3 9 8 7 6 5 4 2536 if (i < focusIndex) { 2537 return i; 2538 } else if (i < childCount - 1) { 2539 return focusIndex + childCount - 1 - i; 2540 } else { 2541 return focusIndex; 2542 } 2543 } 2544 2545 @Override 2546 public void onAdapterChanged(RecyclerView.Adapter oldAdapter, 2547 RecyclerView.Adapter newAdapter) { 2548 discardLayoutInfo(); 2549 mFocusPosition = NO_POSITION; 2550 mFocusPositionOffset = 0; 2551 mChildrenStates.clear(); 2552 super.onAdapterChanged(oldAdapter, newAdapter); 2553 } 2554 2555 private void discardLayoutInfo() { 2556 mGrid = null; 2557 mRows = null; 2558 mRowSizeSecondary = null; 2559 mFirstVisiblePos = -1; 2560 mLastVisiblePos = -1; 2561 mRowSecondarySizeRefresh = false; 2562 } 2563 2564 public void setLayoutEnabled(boolean layoutEnabled) { 2565 if (mLayoutEnabled != layoutEnabled) { 2566 mLayoutEnabled = layoutEnabled; 2567 requestLayout(); 2568 } 2569 } 2570 2571 void setChildrenVisibility(int visiblity) { 2572 mChildVisibility = visiblity; 2573 if (mChildVisibility != -1) { 2574 int count = getChildCount(); 2575 for (int i= 0; i < count; i++) { 2576 getChildAt(i).setVisibility(mChildVisibility); 2577 } 2578 } 2579 } 2580 2581 final static class SavedState implements Parcelable { 2582 2583 int index; // index inside adapter of the current view 2584 Bundle childStates = Bundle.EMPTY; 2585 2586 @Override 2587 public void writeToParcel(Parcel out, int flags) { 2588 out.writeInt(index); 2589 out.writeBundle(childStates); 2590 } 2591 2592 @SuppressWarnings("hiding") 2593 public static final Parcelable.Creator<SavedState> CREATOR = 2594 new Parcelable.Creator<SavedState>() { 2595 @Override 2596 public SavedState createFromParcel(Parcel in) { 2597 return new SavedState(in); 2598 } 2599 2600 @Override 2601 public SavedState[] newArray(int size) { 2602 return new SavedState[size]; 2603 } 2604 }; 2605 2606 @Override 2607 public int describeContents() { 2608 return 0; 2609 } 2610 2611 SavedState(Parcel in) { 2612 index = in.readInt(); 2613 childStates = in.readBundle(GridLayoutManager.class.getClassLoader()); 2614 } 2615 2616 SavedState() { 2617 } 2618 } 2619 2620 @Override 2621 public Parcelable onSaveInstanceState() { 2622 SavedState ss = new SavedState(); 2623 for (int i = 0, count = getChildCount(); i < count; i++) { 2624 View view = getChildAt(i); 2625 int position = getPositionByView(view); 2626 if (position != NO_POSITION) { 2627 mChildrenStates.saveOnScreenView(view, position); 2628 } 2629 } 2630 ss.index = getSelection(); 2631 ss.childStates = mChildrenStates.saveAsBundle(); 2632 return ss; 2633 } 2634 2635 @Override 2636 public void onRestoreInstanceState(Parcelable state) { 2637 if (!(state instanceof SavedState)) { 2638 return; 2639 } 2640 SavedState loadingState = (SavedState)state; 2641 mFocusPosition = loadingState.index; 2642 mFocusPositionOffset = 0; 2643 mChildrenStates.loadFromBundle(loadingState.childStates); 2644 mForceFullLayout = true; 2645 requestLayout(); 2646 } 2647} 2648