GridLayoutManager.java revision b008e4b45faf7c1ece57e48a3517520d65e3b8ca
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 final int itemCount = mState.getItemCount(); 836 if (measure && rowSize < 0 && itemCount > 0) { 837 if (scrapChildWidth < 0 && scrapChildHeight < 0) { 838 int position; 839 if (mFocusPosition == NO_POSITION) { 840 position = 0; 841 } else if (mFocusPosition >= itemCount) { 842 position = itemCount - 1; 843 } else { 844 position = mFocusPosition; 845 } 846 measureScrapChild(position, 847 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 848 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 849 mMeasuredDimension); 850 scrapChildWidth = mMeasuredDimension[0]; 851 scrapChildHeight = mMeasuredDimension[1]; 852 if (DEBUG) Log.v(TAG, "measured scrap child: " + scrapChildWidth + 853 " " + scrapChildHeight); 854 } 855 rowSize = mOrientation == HORIZONTAL ? scrapChildHeight : scrapChildWidth; 856 } 857 858 if (rowSize < 0) { 859 rowSize = 0; 860 } 861 862 if (DEBUG) Log.v(getTag(), "row " + rowIndex + " rowItemCount " + rowItemCount + 863 " rowSize " + rowSize); 864 865 if (mRowSizeSecondary[rowIndex] != rowSize) { 866 if (DEBUG) Log.v(getTag(), "row size secondary changed: " + mRowSizeSecondary[rowIndex] + 867 ", " + rowSize); 868 869 mRowSizeSecondary[rowIndex] = rowSize; 870 changed = true; 871 } 872 } 873 874 return changed; 875 } 876 877 /** 878 * Checks if we need to update row secondary sizes. 879 */ 880 private void updateRowSecondarySizeRefresh() { 881 mRowSecondarySizeRefresh = processRowSizeSecondary(false); 882 if (mRowSecondarySizeRefresh) { 883 if (DEBUG) Log.v(getTag(), "mRowSecondarySizeRefresh now set"); 884 forceRequestLayout(); 885 } 886 } 887 888 private void forceRequestLayout() { 889 if (DEBUG) Log.v(getTag(), "forceRequestLayout"); 890 // RecyclerView prevents us from requesting layout in many cases 891 // (during layout, during scroll, etc.) 892 // For secondary row size wrap_content support we currently need a 893 // second layout pass to update the measured size after having measured 894 // and added child views in layoutChildren. 895 // Force the second layout by posting a delayed runnable. 896 // TODO: investigate allowing a second layout pass, 897 // or move child add/measure logic to the measure phase. 898 ViewCompat.postOnAnimation(mBaseGridView, mRequestLayoutRunnable); 899 } 900 901 private final Runnable mRequestLayoutRunnable = new Runnable() { 902 @Override 903 public void run() { 904 if (DEBUG) Log.v(getTag(), "request Layout from runnable"); 905 requestLayout(); 906 } 907 }; 908 909 @Override 910 public void onMeasure(Recycler recycler, State state, int widthSpec, int heightSpec) { 911 saveContext(recycler, state); 912 913 int sizePrimary, sizeSecondary, modeSecondary, paddingSecondary; 914 int measuredSizeSecondary; 915 if (mOrientation == HORIZONTAL) { 916 sizePrimary = MeasureSpec.getSize(widthSpec); 917 sizeSecondary = MeasureSpec.getSize(heightSpec); 918 modeSecondary = MeasureSpec.getMode(heightSpec); 919 paddingSecondary = getPaddingTop() + getPaddingBottom(); 920 } else { 921 sizeSecondary = MeasureSpec.getSize(widthSpec); 922 sizePrimary = MeasureSpec.getSize(heightSpec); 923 modeSecondary = MeasureSpec.getMode(widthSpec); 924 paddingSecondary = getPaddingLeft() + getPaddingRight(); 925 } 926 if (DEBUG) Log.v(getTag(), "onMeasure widthSpec " + Integer.toHexString(widthSpec) + 927 " heightSpec " + Integer.toHexString(heightSpec) + 928 " modeSecondary " + Integer.toHexString(modeSecondary) + 929 " sizeSecondary " + sizeSecondary + " " + this); 930 931 mMaxSizeSecondary = sizeSecondary; 932 933 if (mRowSizeSecondaryRequested == ViewGroup.LayoutParams.WRAP_CONTENT) { 934 mNumRows = mNumRowsRequested == 0 ? 1 : mNumRowsRequested; 935 mFixedRowSizeSecondary = 0; 936 937 if (mRowSizeSecondary == null || mRowSizeSecondary.length != mNumRows) { 938 mRowSizeSecondary = new int[mNumRows]; 939 } 940 941 // Measure all current children and update cached row heights 942 processRowSizeSecondary(true); 943 944 switch (modeSecondary) { 945 case MeasureSpec.UNSPECIFIED: 946 measuredSizeSecondary = getSizeSecondary() + paddingSecondary; 947 break; 948 case MeasureSpec.AT_MOST: 949 measuredSizeSecondary = Math.min(getSizeSecondary() + paddingSecondary, 950 mMaxSizeSecondary); 951 break; 952 case MeasureSpec.EXACTLY: 953 measuredSizeSecondary = mMaxSizeSecondary; 954 break; 955 default: 956 throw new IllegalStateException("wrong spec"); 957 } 958 959 } else { 960 switch (modeSecondary) { 961 case MeasureSpec.UNSPECIFIED: 962 if (mRowSizeSecondaryRequested == 0) { 963 if (mOrientation == HORIZONTAL) { 964 throw new IllegalStateException("Must specify rowHeight or view height"); 965 } else { 966 throw new IllegalStateException("Must specify columnWidth or view width"); 967 } 968 } 969 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 970 mNumRows = mNumRowsRequested == 0 ? 1 : mNumRowsRequested; 971 measuredSizeSecondary = mFixedRowSizeSecondary * mNumRows + mMarginSecondary 972 * (mNumRows - 1) + paddingSecondary; 973 break; 974 case MeasureSpec.AT_MOST: 975 case MeasureSpec.EXACTLY: 976 if (mNumRowsRequested == 0 && mRowSizeSecondaryRequested == 0) { 977 mNumRows = 1; 978 mFixedRowSizeSecondary = sizeSecondary - paddingSecondary; 979 } else if (mNumRowsRequested == 0) { 980 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 981 mNumRows = (sizeSecondary + mMarginSecondary) 982 / (mRowSizeSecondaryRequested + mMarginSecondary); 983 } else if (mRowSizeSecondaryRequested == 0) { 984 mNumRows = mNumRowsRequested; 985 mFixedRowSizeSecondary = (sizeSecondary - paddingSecondary - mMarginSecondary 986 * (mNumRows - 1)) / mNumRows; 987 } else { 988 mNumRows = mNumRowsRequested; 989 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 990 } 991 measuredSizeSecondary = sizeSecondary; 992 if (modeSecondary == MeasureSpec.AT_MOST) { 993 int childrenSize = mFixedRowSizeSecondary * mNumRows + mMarginSecondary 994 * (mNumRows - 1) + paddingSecondary; 995 if (childrenSize < measuredSizeSecondary) { 996 measuredSizeSecondary = childrenSize; 997 } 998 } 999 break; 1000 default: 1001 throw new IllegalStateException("wrong spec"); 1002 } 1003 } 1004 if (mOrientation == HORIZONTAL) { 1005 setMeasuredDimension(sizePrimary, measuredSizeSecondary); 1006 } else { 1007 setMeasuredDimension(measuredSizeSecondary, sizePrimary); 1008 } 1009 if (DEBUG) { 1010 Log.v(getTag(), "onMeasure sizePrimary " + sizePrimary + 1011 " measuredSizeSecondary " + measuredSizeSecondary + 1012 " mFixedRowSizeSecondary " + mFixedRowSizeSecondary + 1013 " mNumRows " + mNumRows); 1014 } 1015 1016 leaveContext(); 1017 } 1018 1019 private void measureChild(View child) { 1020 final ViewGroup.LayoutParams lp = child.getLayoutParams(); 1021 final int secondarySpec = (mRowSizeSecondaryRequested == ViewGroup.LayoutParams.WRAP_CONTENT) ? 1022 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED) : 1023 MeasureSpec.makeMeasureSpec(mFixedRowSizeSecondary, MeasureSpec.EXACTLY); 1024 int widthSpec, heightSpec; 1025 1026 if (mOrientation == HORIZONTAL) { 1027 widthSpec = ViewGroup.getChildMeasureSpec( 1028 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 1029 0, lp.width); 1030 heightSpec = ViewGroup.getChildMeasureSpec(secondarySpec, 0, lp.height); 1031 } else { 1032 heightSpec = ViewGroup.getChildMeasureSpec( 1033 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 1034 0, lp.height); 1035 widthSpec = ViewGroup.getChildMeasureSpec(secondarySpec, 0, lp.width); 1036 } 1037 1038 child.measure(widthSpec, heightSpec); 1039 1040 if (DEBUG) Log.v(getTag(), "measureChild secondarySpec " + Integer.toHexString(secondarySpec) + 1041 " widthSpec " + Integer.toHexString(widthSpec) + 1042 " heightSpec " + Integer.toHexString(heightSpec) + 1043 " measuredWidth " + child.getMeasuredWidth() + 1044 " measuredHeight " + child.getMeasuredHeight()); 1045 if (DEBUG) Log.v(getTag(), "child lp width " + lp.width + " height " + lp.height); 1046 } 1047 1048 private StaggeredGrid.Provider mGridProvider = new StaggeredGrid.Provider() { 1049 1050 @Override 1051 public int getCount() { 1052 return mState.getItemCount(); 1053 } 1054 1055 @Override 1056 public void createItem(int index, int rowIndex, boolean append) { 1057 View v = getViewForPosition(index); 1058 if (mFirstVisiblePos >= 0) { 1059 // when StaggeredGrid append or prepend item, we must guarantee 1060 // that sibling item has created views already. 1061 if (append && index != mLastVisiblePos + 1) { 1062 throw new RuntimeException(); 1063 } else if (!append && index != mFirstVisiblePos - 1) { 1064 throw new RuntimeException(); 1065 } 1066 } 1067 1068 // See recyclerView docs: we don't need re-add scraped view if it was removed. 1069 if (!((RecyclerView.LayoutParams) v.getLayoutParams()).isItemRemoved()) { 1070 if (append) { 1071 addView(v); 1072 } else { 1073 addView(v, 0); 1074 } 1075 if (mChildVisibility != -1) { 1076 v.setVisibility(mChildVisibility); 1077 } 1078 1079 // View is added first or it won't be found by dispatchChildSelected. 1080 if (mInLayout && index == mFocusPosition) { 1081 dispatchChildSelected(); 1082 } 1083 1084 measureChild(v); 1085 } 1086 1087 int length = mOrientation == HORIZONTAL ? v.getMeasuredWidth() : v.getMeasuredHeight(); 1088 int start, end; 1089 final boolean rowIsEmpty = mRows[rowIndex].high == mRows[rowIndex].low; 1090 if (append) { 1091 if (!rowIsEmpty) { 1092 // if there are existing item in the row, add margin between 1093 start = mRows[rowIndex].high + mMarginPrimary; 1094 } else { 1095 if (mLastVisiblePos >= 0) { 1096 int lastRow = mGrid.getLocation(mLastVisiblePos).row; 1097 // if the last visible item is not last row, align to beginning, 1098 // otherwise start a new column after. 1099 if (lastRow < mNumRows - 1) { 1100 start = mRows[lastRow].low; 1101 } else { 1102 start = mRows[lastRow].high + mMarginPrimary; 1103 } 1104 } else { 1105 start = 0; 1106 } 1107 mRows[rowIndex].low = start; 1108 } 1109 end = start + length; 1110 mRows[rowIndex].high = end; 1111 } else { 1112 if (!rowIsEmpty) { 1113 // if there are existing item in the row, add margin between 1114 end = mRows[rowIndex].low - mMarginPrimary; 1115 start = end - length; 1116 } else { 1117 if (mFirstVisiblePos >= 0) { 1118 int firstRow = mGrid.getLocation(mFirstVisiblePos).row; 1119 // if the first visible item is not first row, align to beginning, 1120 // otherwise start a new column before. 1121 if (firstRow > 0) { 1122 start = mRows[firstRow].low; 1123 end = start + length; 1124 } else { 1125 end = mRows[firstRow].low - mMarginPrimary; 1126 start = end - length; 1127 } 1128 } else { 1129 start = 0; 1130 end = length; 1131 } 1132 mRows[rowIndex].high = end; 1133 } 1134 mRows[rowIndex].low = start; 1135 } 1136 if (mFirstVisiblePos < 0) { 1137 mFirstVisiblePos = mLastVisiblePos = index; 1138 } else { 1139 if (append) { 1140 mLastVisiblePos++; 1141 } else { 1142 mFirstVisiblePos--; 1143 } 1144 } 1145 if (DEBUG) Log.v(getTag(), "start " + start + " end " + end); 1146 int startSecondary = getRowStartSecondary(rowIndex) - mScrollOffsetSecondary; 1147 mChildrenStates.loadView(v, index); 1148 layoutChild(rowIndex, v, start - mScrollOffsetPrimary, end - mScrollOffsetPrimary, 1149 startSecondary); 1150 if (DEBUG) { 1151 Log.d(getTag(), "addView " + index + " " + v); 1152 } 1153 if (index == mFirstVisiblePos) { 1154 updateScrollMin(); 1155 } 1156 if (index == mLastVisiblePos) { 1157 updateScrollMax(); 1158 } 1159 } 1160 }; 1161 1162 private void layoutChild(int rowIndex, View v, int start, int end, int startSecondary) { 1163 int sizeSecondary = mOrientation == HORIZONTAL ? v.getMeasuredHeight() 1164 : v.getMeasuredWidth(); 1165 if (mFixedRowSizeSecondary > 0) { 1166 sizeSecondary = Math.min(sizeSecondary, mFixedRowSizeSecondary); 1167 } 1168 final int verticalGravity = mGravity & Gravity.VERTICAL_GRAVITY_MASK; 1169 final int horizontalGravity = mGravity & Gravity.HORIZONTAL_GRAVITY_MASK; 1170 if (mOrientation == HORIZONTAL && verticalGravity == Gravity.TOP 1171 || mOrientation == VERTICAL && horizontalGravity == Gravity.LEFT) { 1172 // do nothing 1173 } else if (mOrientation == HORIZONTAL && verticalGravity == Gravity.BOTTOM 1174 || mOrientation == VERTICAL && horizontalGravity == Gravity.RIGHT) { 1175 startSecondary += getRowSizeSecondary(rowIndex) - sizeSecondary; 1176 } else if (mOrientation == HORIZONTAL && verticalGravity == Gravity.CENTER_VERTICAL 1177 || mOrientation == VERTICAL && horizontalGravity == Gravity.CENTER_HORIZONTAL) { 1178 startSecondary += (getRowSizeSecondary(rowIndex) - sizeSecondary) / 2; 1179 } 1180 int left, top, right, bottom; 1181 if (mOrientation == HORIZONTAL) { 1182 left = start; 1183 top = startSecondary; 1184 right = end; 1185 bottom = startSecondary + sizeSecondary; 1186 } else { 1187 top = start; 1188 left = startSecondary; 1189 bottom = end; 1190 right = startSecondary + sizeSecondary; 1191 } 1192 v.layout(left, top, right, bottom); 1193 updateChildOpticalInsets(v, left, top, right, bottom); 1194 updateChildAlignments(v); 1195 } 1196 1197 private void updateChildOpticalInsets(View v, int left, int top, int right, int bottom) { 1198 LayoutParams p = (LayoutParams) v.getLayoutParams(); 1199 p.setOpticalInsets(left - v.getLeft(), top - v.getTop(), 1200 v.getRight() - right, v.getBottom() - bottom); 1201 } 1202 1203 private void updateChildAlignments(View v) { 1204 LayoutParams p = (LayoutParams) v.getLayoutParams(); 1205 p.setAlignX(mItemAlignment.horizontal.getAlignmentPosition(v)); 1206 p.setAlignY(mItemAlignment.vertical.getAlignmentPosition(v)); 1207 } 1208 1209 private void updateChildAlignments() { 1210 for (int i = 0, c = getChildCount(); i < c; i++) { 1211 updateChildAlignments(getChildAt(i)); 1212 } 1213 } 1214 1215 private boolean needsAppendVisibleItem() { 1216 if (mLastVisiblePos < mFocusPosition) { 1217 return true; 1218 } 1219 int right = mScrollOffsetPrimary + mSizePrimary; 1220 for (int i = 0; i < mNumRows; i++) { 1221 if (mRows[i].low == mRows[i].high) { 1222 if (mRows[i].high < right) { 1223 return true; 1224 } 1225 } else if (mRows[i].high < right - mMarginPrimary) { 1226 return true; 1227 } 1228 } 1229 return false; 1230 } 1231 1232 private boolean needsPrependVisibleItem() { 1233 if (mFirstVisiblePos > mFocusPosition) { 1234 return true; 1235 } 1236 for (int i = 0; i < mNumRows; i++) { 1237 if (mRows[i].low == mRows[i].high) { 1238 if (mRows[i].low > mScrollOffsetPrimary) { 1239 return true; 1240 } 1241 } else if (mRows[i].low - mMarginPrimary > mScrollOffsetPrimary) { 1242 return true; 1243 } 1244 } 1245 return false; 1246 } 1247 1248 // Append one column if possible and return true if reach end. 1249 private boolean appendOneVisibleItem() { 1250 while (true) { 1251 if (mLastVisiblePos != NO_POSITION && mLastVisiblePos < mState.getItemCount() -1 && 1252 mLastVisiblePos < mGrid.getLastIndex()) { 1253 // append invisible view of saved location till last row 1254 final int index = mLastVisiblePos + 1; 1255 final int row = mGrid.getLocation(index).row; 1256 mGridProvider.createItem(index, row, true); 1257 if (row == mNumRows - 1) { 1258 return false; 1259 } 1260 } else if ((mLastVisiblePos == NO_POSITION && mState.getItemCount() > 0) || 1261 (mLastVisiblePos != NO_POSITION && 1262 mLastVisiblePos < mState.getItemCount() - 1)) { 1263 mGrid.appendItems(mScrollOffsetPrimary + mSizePrimary); 1264 return false; 1265 } else { 1266 return true; 1267 } 1268 } 1269 } 1270 1271 private void appendVisibleItems() { 1272 while (needsAppendVisibleItem()) { 1273 if (appendOneVisibleItem()) { 1274 break; 1275 } 1276 } 1277 } 1278 1279 // Prepend one column if possible and return true if reach end. 1280 private boolean prependOneVisibleItem() { 1281 while (true) { 1282 if (mFirstVisiblePos > 0) { 1283 if (mFirstVisiblePos > mGrid.getFirstIndex()) { 1284 // prepend invisible view of saved location till first row 1285 final int index = mFirstVisiblePos - 1; 1286 final int row = mGrid.getLocation(index).row; 1287 mGridProvider.createItem(index, row, false); 1288 if (row == 0) { 1289 return false; 1290 } 1291 } else { 1292 mGrid.prependItems(mScrollOffsetPrimary); 1293 return false; 1294 } 1295 } else { 1296 return true; 1297 } 1298 } 1299 } 1300 1301 private void prependVisibleItems() { 1302 while (needsPrependVisibleItem()) { 1303 if (prependOneVisibleItem()) { 1304 break; 1305 } 1306 } 1307 } 1308 1309 private void removeChildAt(int position) { 1310 View v = findViewByPosition(position); 1311 if (v != null) { 1312 if (DEBUG) { 1313 Log.d(getTag(), "removeAndRecycleViewAt " + position + " " + v); 1314 } 1315 mChildrenStates.saveOffscreenView(v, position); 1316 removeAndRecycleView(v, mRecycler); 1317 } 1318 } 1319 1320 private void removeInvisibleViewsAtEnd() { 1321 if (!mPruneChild) { 1322 return; 1323 } 1324 boolean update = false; 1325 while(mLastVisiblePos > mFirstVisiblePos && mLastVisiblePos > mFocusPosition) { 1326 View view = findViewByPosition(mLastVisiblePos); 1327 if (getViewMin(view) > mSizePrimary) { 1328 removeChildAt(mLastVisiblePos); 1329 mLastVisiblePos--; 1330 update = true; 1331 } else { 1332 break; 1333 } 1334 } 1335 if (update) { 1336 updateRowsMinMax(); 1337 } 1338 } 1339 1340 private void removeInvisibleViewsAtFront() { 1341 if (!mPruneChild) { 1342 return; 1343 } 1344 boolean update = false; 1345 while(mLastVisiblePos > mFirstVisiblePos && mFirstVisiblePos < mFocusPosition) { 1346 View view = findViewByPosition(mFirstVisiblePos); 1347 if (getViewMax(view) < 0) { 1348 removeChildAt(mFirstVisiblePos); 1349 mFirstVisiblePos++; 1350 update = true; 1351 } else { 1352 break; 1353 } 1354 } 1355 if (update) { 1356 updateRowsMinMax(); 1357 } 1358 } 1359 1360 private void updateRowsMinMax() { 1361 if (mFirstVisiblePos < 0) { 1362 return; 1363 } 1364 for (int i = 0; i < mNumRows; i++) { 1365 mRows[i].low = Integer.MAX_VALUE; 1366 mRows[i].high = Integer.MIN_VALUE; 1367 } 1368 for (int i = mFirstVisiblePos; i <= mLastVisiblePos; i++) { 1369 View view = findViewByPosition(i); 1370 int row = mGrid.getLocation(i).row; 1371 int low = getViewMin(view) + mScrollOffsetPrimary; 1372 if (low < mRows[row].low) { 1373 mRows[row].low = low; 1374 } 1375 int high = getViewMax(view) + mScrollOffsetPrimary; 1376 if (high > mRows[row].high) { 1377 mRows[row].high = high; 1378 } 1379 } 1380 } 1381 1382 // Fast layout when there is no structure change, adapter change, etc. 1383 protected void fastRelayout(boolean scrollToFocus) { 1384 initScrollController(); 1385 1386 List<Integer>[] rows = mGrid.getItemPositionsInRows(mFirstVisiblePos, mLastVisiblePos); 1387 1388 // relayout and repositioning views on each row 1389 for (int i = 0; i < mNumRows; i++) { 1390 List<Integer> row = rows[i]; 1391 final int startSecondary = getRowStartSecondary(i) - mScrollOffsetSecondary; 1392 for (int j = 0, size = row.size(); j < size; j++) { 1393 final int position = row.get(j); 1394 View view = findViewByPosition(position); 1395 int primaryDelta, end; 1396 1397 int start = getViewMin(view); 1398 int oldPrimarySize = (mOrientation == HORIZONTAL) ? 1399 view.getMeasuredWidth() : 1400 view.getMeasuredHeight(); 1401 1402 LayoutParams lp = (LayoutParams) view.getLayoutParams(); 1403 if (lp.viewNeedsUpdate()) { 1404 int index = mBaseGridView.indexOfChild(view); 1405 detachAndScrapView(view, mRecycler); 1406 view = getViewForPosition(position); 1407 addView(view, index); 1408 } 1409 1410 if (view.isLayoutRequested()) { 1411 measureChild(view); 1412 } 1413 1414 if (mOrientation == HORIZONTAL) { 1415 end = start + view.getMeasuredWidth(); 1416 primaryDelta = view.getMeasuredWidth() - oldPrimarySize; 1417 if (primaryDelta != 0) { 1418 for (int k = j + 1; k < size; k++) { 1419 findViewByPosition(row.get(k)).offsetLeftAndRight(primaryDelta); 1420 } 1421 } 1422 } else { 1423 end = start + view.getMeasuredHeight(); 1424 primaryDelta = view.getMeasuredHeight() - oldPrimarySize; 1425 if (primaryDelta != 0) { 1426 for (int k = j + 1; k < size; k++) { 1427 findViewByPosition(row.get(k)).offsetTopAndBottom(primaryDelta); 1428 } 1429 } 1430 } 1431 layoutChild(i, view, start, end, startSecondary); 1432 } 1433 } 1434 1435 updateRowsMinMax(); 1436 appendVisibleItems(); 1437 prependVisibleItems(); 1438 1439 updateRowsMinMax(); 1440 updateScrollMin(); 1441 updateScrollMax(); 1442 updateScrollSecondAxis(); 1443 1444 if (scrollToFocus) { 1445 View focusView = findViewByPosition(mFocusPosition == NO_POSITION ? 0 : mFocusPosition); 1446 scrollToView(focusView, false); 1447 } 1448 } 1449 1450 public void removeAndRecycleAllViews(RecyclerView.Recycler recycler) { 1451 if (DEBUG) Log.v(TAG, "removeAndRecycleAllViews " + getChildCount()); 1452 for (int i = getChildCount() - 1; i >= 0; i--) { 1453 removeAndRecycleViewAt(i, recycler); 1454 } 1455 } 1456 1457 // Lays out items based on the current scroll position 1458 @Override 1459 public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state) { 1460 if (DEBUG) { 1461 Log.v(getTag(), "layoutChildren start numRows " + mNumRows + " mScrollOffsetSecondary " 1462 + mScrollOffsetSecondary + " mScrollOffsetPrimary " + mScrollOffsetPrimary 1463 + " inPreLayout " + state.isPreLayout() 1464 + " didStructureChange " + state.didStructureChange() 1465 + " mForceFullLayout " + mForceFullLayout); 1466 Log.v(getTag(), "width " + getWidth() + " height " + getHeight()); 1467 } 1468 1469 if (mNumRows == 0) { 1470 // haven't done measure yet 1471 return; 1472 } 1473 final int itemCount = state.getItemCount(); 1474 if (itemCount < 0) { 1475 return; 1476 } 1477 1478 if (!mLayoutEnabled) { 1479 discardLayoutInfo(); 1480 removeAndRecycleAllViews(recycler); 1481 return; 1482 } 1483 mInLayout = true; 1484 1485 final boolean scrollToFocus = !isSmoothScrolling() 1486 && mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED; 1487 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE) { 1488 mFocusPosition = mFocusPosition + mFocusPositionOffset; 1489 mFocusPositionOffset = 0; 1490 } 1491 saveContext(recycler, state); 1492 // Track the old focus view so we can adjust our system scroll position 1493 // so that any scroll animations happening now will remain valid. 1494 // We must use same delta in Pre Layout (if prelayout exists) and second layout. 1495 // So we cache the deltas in PreLayout and use it in second layout. 1496 int delta = 0, deltaSecondary = 0; 1497 if (mFocusPosition != NO_POSITION && scrollToFocus 1498 && mBaseGridView.getScrollState() != RecyclerView.SCROLL_STATE_IDLE) { 1499 // FIXME: we should get the remaining scroll animation offset from RecyclerView 1500 View focusView = findViewByPosition(mFocusPosition); 1501 if (focusView != null) { 1502 delta = mWindowAlignment.mainAxis().getSystemScrollPos(mScrollOffsetPrimary 1503 + getViewCenter(focusView), false, false) - mScrollOffsetPrimary; 1504 deltaSecondary = mWindowAlignment.secondAxis().getSystemScrollPos( 1505 mScrollOffsetSecondary + getViewCenterSecondary(focusView), 1506 false, false) - mScrollOffsetSecondary; 1507 } 1508 } 1509 1510 final boolean hasDoneFirstLayout = hasDoneFirstLayout(); 1511 int savedFocusPos = mFocusPosition; 1512 boolean fastRelayout = false; 1513 if (!mState.didStructureChange() && !mForceFullLayout && hasDoneFirstLayout) { 1514 fastRelayout = true; 1515 fastRelayout(scrollToFocus); 1516 } else { 1517 boolean hadFocus = mBaseGridView.hasFocus(); 1518 1519 mFocusPosition = init(mFocusPosition); 1520 if (mFocusPosition != savedFocusPos) { 1521 if (DEBUG) Log.v(getTag(), "savedFocusPos " + savedFocusPos + 1522 " mFocusPosition " + mFocusPosition); 1523 } 1524 1525 mWindowAlignment.mainAxis().invalidateScrollMin(); 1526 mWindowAlignment.mainAxis().invalidateScrollMax(); 1527 // depending on result of init(), either recreating everything 1528 // or try to reuse the row start positions near mFocusPosition 1529 if (mGrid.getSize() == 0) { 1530 // this is a fresh creating all items, starting from 1531 // mFocusPosition with a estimated row index. 1532 mGrid.setStart(mFocusPosition, StaggeredGrid.START_DEFAULT); 1533 1534 // Can't track the old focus view 1535 delta = deltaSecondary = 0; 1536 1537 } else { 1538 // mGrid remembers Locations for the column that 1539 // contains mFocusePosition and also mRows remembers start 1540 // positions of each row. 1541 // Manually re-create child views for that column 1542 int firstIndex = mGrid.getFirstIndex(); 1543 int lastIndex = mGrid.getLastIndex(); 1544 for (int i = firstIndex; i <= lastIndex; i++) { 1545 mGridProvider.createItem(i, mGrid.getLocation(i).row, true); 1546 } 1547 } 1548 1549 // add visible views at end until reach the end of window 1550 appendVisibleItems(); 1551 // add visible views at front until reach the start of window 1552 prependVisibleItems(); 1553 // multiple rounds: scrollToView of first round may drag first/last child into 1554 // "visible window" and we update scrollMin/scrollMax then run second scrollToView 1555 int oldFirstVisible; 1556 int oldLastVisible; 1557 do { 1558 updateScrollMin(); 1559 updateScrollMax(); 1560 oldFirstVisible = mFirstVisiblePos; 1561 oldLastVisible = mLastVisiblePos; 1562 View focusView = findViewByPosition(mFocusPosition); 1563 // we need force to initialize the child view's position 1564 scrollToView(focusView, false); 1565 if (focusView != null && hadFocus) { 1566 focusView.requestFocus(); 1567 } 1568 appendVisibleItems(); 1569 prependVisibleItems(); 1570 removeInvisibleViewsAtFront(); 1571 removeInvisibleViewsAtEnd(); 1572 } while (mFirstVisiblePos != oldFirstVisible || mLastVisiblePos != oldLastVisible); 1573 } 1574 mForceFullLayout = false; 1575 1576 if (scrollToFocus) { 1577 scrollDirectionPrimary(-delta); 1578 scrollDirectionSecondary(-deltaSecondary); 1579 } 1580 appendVisibleItems(); 1581 prependVisibleItems(); 1582 removeInvisibleViewsAtFront(); 1583 removeInvisibleViewsAtEnd(); 1584 1585 if (DEBUG) { 1586 StringWriter sw = new StringWriter(); 1587 PrintWriter pw = new PrintWriter(sw); 1588 mGrid.debugPrint(pw); 1589 Log.d(getTag(), sw.toString()); 1590 } 1591 1592 if (mRowSecondarySizeRefresh) { 1593 mRowSecondarySizeRefresh = false; 1594 } else { 1595 updateRowSecondarySizeRefresh(); 1596 } 1597 1598 if (fastRelayout && mFocusPosition != savedFocusPos) { 1599 dispatchChildSelected(); 1600 } 1601 mInLayout = false; 1602 leaveContext(); 1603 if (DEBUG) Log.v(getTag(), "layoutChildren end"); 1604 } 1605 1606 private void offsetChildrenSecondary(int increment) { 1607 final int childCount = getChildCount(); 1608 if (mOrientation == HORIZONTAL) { 1609 for (int i = 0; i < childCount; i++) { 1610 getChildAt(i).offsetTopAndBottom(increment); 1611 } 1612 } else { 1613 for (int i = 0; i < childCount; i++) { 1614 getChildAt(i).offsetLeftAndRight(increment); 1615 } 1616 } 1617 } 1618 1619 private void offsetChildrenPrimary(int increment) { 1620 final int childCount = getChildCount(); 1621 if (mOrientation == VERTICAL) { 1622 for (int i = 0; i < childCount; i++) { 1623 getChildAt(i).offsetTopAndBottom(increment); 1624 } 1625 } else { 1626 for (int i = 0; i < childCount; i++) { 1627 getChildAt(i).offsetLeftAndRight(increment); 1628 } 1629 } 1630 } 1631 1632 @Override 1633 public int scrollHorizontallyBy(int dx, Recycler recycler, RecyclerView.State state) { 1634 if (DEBUG) Log.v(getTag(), "scrollHorizontallyBy " + dx); 1635 if (!mLayoutEnabled || !hasDoneFirstLayout()) { 1636 return 0; 1637 } 1638 saveContext(recycler, state); 1639 int result; 1640 if (mOrientation == HORIZONTAL) { 1641 result = scrollDirectionPrimary(dx); 1642 } else { 1643 result = scrollDirectionSecondary(dx); 1644 } 1645 leaveContext(); 1646 return result; 1647 } 1648 1649 @Override 1650 public int scrollVerticallyBy(int dy, Recycler recycler, RecyclerView.State state) { 1651 if (DEBUG) Log.v(getTag(), "scrollVerticallyBy " + dy); 1652 if (!mLayoutEnabled || !hasDoneFirstLayout()) { 1653 return 0; 1654 } 1655 saveContext(recycler, state); 1656 int result; 1657 if (mOrientation == VERTICAL) { 1658 result = scrollDirectionPrimary(dy); 1659 } else { 1660 result = scrollDirectionSecondary(dy); 1661 } 1662 leaveContext(); 1663 return result; 1664 } 1665 1666 // scroll in main direction may add/prune views 1667 private int scrollDirectionPrimary(int da) { 1668 if (da > 0) { 1669 if (!mWindowAlignment.mainAxis().isMaxUnknown()) { 1670 int maxScroll = mWindowAlignment.mainAxis().getMaxScroll(); 1671 if (mScrollOffsetPrimary + da > maxScroll) { 1672 da = maxScroll - mScrollOffsetPrimary; 1673 } 1674 } 1675 } else if (da < 0) { 1676 if (!mWindowAlignment.mainAxis().isMinUnknown()) { 1677 int minScroll = mWindowAlignment.mainAxis().getMinScroll(); 1678 if (mScrollOffsetPrimary + da < minScroll) { 1679 da = minScroll - mScrollOffsetPrimary; 1680 } 1681 } 1682 } 1683 if (da == 0) { 1684 return 0; 1685 } 1686 offsetChildrenPrimary(-da); 1687 mScrollOffsetPrimary += da; 1688 if (mInLayout) { 1689 return da; 1690 } 1691 1692 int childCount = getChildCount(); 1693 boolean updated; 1694 1695 if (da > 0) { 1696 appendVisibleItems(); 1697 } else if (da < 0) { 1698 prependVisibleItems(); 1699 } 1700 updated = getChildCount() > childCount; 1701 childCount = getChildCount(); 1702 1703 if (da > 0) { 1704 removeInvisibleViewsAtFront(); 1705 } else if (da < 0) { 1706 removeInvisibleViewsAtEnd(); 1707 } 1708 updated |= getChildCount() < childCount; 1709 1710 if (updated) { 1711 updateRowSecondarySizeRefresh(); 1712 } 1713 1714 mBaseGridView.invalidate(); 1715 return da; 1716 } 1717 1718 // scroll in second direction will not add/prune views 1719 private int scrollDirectionSecondary(int dy) { 1720 if (dy == 0) { 1721 return 0; 1722 } 1723 offsetChildrenSecondary(-dy); 1724 mScrollOffsetSecondary += dy; 1725 mBaseGridView.invalidate(); 1726 return dy; 1727 } 1728 1729 private void updateScrollMax() { 1730 if (mLastVisiblePos < 0) { 1731 return; 1732 } 1733 final boolean lastAvailable = mLastVisiblePos == mState.getItemCount() - 1; 1734 final boolean maxUnknown = mWindowAlignment.mainAxis().isMaxUnknown(); 1735 if (!lastAvailable && maxUnknown) { 1736 return; 1737 } 1738 int maxEdge = Integer.MIN_VALUE; 1739 int rowIndex = -1; 1740 for (int i = 0; i < mRows.length; i++) { 1741 if (mRows[i].high > maxEdge) { 1742 maxEdge = mRows[i].high; 1743 rowIndex = i; 1744 } 1745 } 1746 int maxScroll = Integer.MAX_VALUE; 1747 for (int i = mLastVisiblePos; i >= mFirstVisiblePos; i--) { 1748 StaggeredGrid.Location location = mGrid.getLocation(i); 1749 if (location != null && location.row == rowIndex) { 1750 int savedMaxEdge = mWindowAlignment.mainAxis().getMaxEdge(); 1751 mWindowAlignment.mainAxis().setMaxEdge(maxEdge); 1752 maxScroll = getPrimarySystemScrollPosition(findViewByPosition(i)); 1753 mWindowAlignment.mainAxis().setMaxEdge(savedMaxEdge); 1754 break; 1755 } 1756 } 1757 if (lastAvailable) { 1758 mWindowAlignment.mainAxis().setMaxEdge(maxEdge); 1759 mWindowAlignment.mainAxis().setMaxScroll(maxScroll); 1760 if (DEBUG) Log.v(getTag(), "updating scroll maxEdge to " + maxEdge + 1761 " scrollMax to " + maxScroll); 1762 } else { 1763 // the maxScroll for currently last visible item is larger, 1764 // so we must invalidate the max scroll value. 1765 if (maxScroll > mWindowAlignment.mainAxis().getMaxScroll()) { 1766 mWindowAlignment.mainAxis().invalidateScrollMax(); 1767 if (DEBUG) Log.v(getTag(), "Invalidate scrollMax since it should be " 1768 + "greater than " + maxScroll); 1769 } 1770 } 1771 } 1772 1773 private void updateScrollMin() { 1774 if (mFirstVisiblePos < 0) { 1775 return; 1776 } 1777 final boolean firstAvailable = mFirstVisiblePos == 0; 1778 final boolean minUnknown = mWindowAlignment.mainAxis().isMinUnknown(); 1779 if (!firstAvailable && minUnknown) { 1780 return; 1781 } 1782 int minEdge = Integer.MAX_VALUE; 1783 int rowIndex = -1; 1784 for (int i = 0; i < mRows.length; i++) { 1785 if (mRows[i].low < minEdge) { 1786 minEdge = mRows[i].low; 1787 rowIndex = i; 1788 } 1789 } 1790 int minScroll = Integer.MIN_VALUE; 1791 for (int i = mFirstVisiblePos; i <= mLastVisiblePos; i++) { 1792 StaggeredGrid.Location location = mGrid.getLocation(i); 1793 if (location != null && location.row == rowIndex) { 1794 int savedMinEdge = mWindowAlignment.mainAxis().getMinEdge(); 1795 mWindowAlignment.mainAxis().setMinEdge(minEdge); 1796 minScroll = getPrimarySystemScrollPosition(findViewByPosition(i)); 1797 mWindowAlignment.mainAxis().setMinEdge(savedMinEdge); 1798 break; 1799 } 1800 } 1801 if (firstAvailable) { 1802 mWindowAlignment.mainAxis().setMinEdge(minEdge); 1803 mWindowAlignment.mainAxis().setMinScroll(minScroll); 1804 if (DEBUG) Log.v(getTag(), "updating scroll minEdge to " + minEdge + 1805 " scrollMin to " + minScroll); 1806 } else { 1807 // the minScroll for currently first visible item is smaller, 1808 // so we must invalidate the min scroll value. 1809 if (minScroll < mWindowAlignment.mainAxis().getMinScroll()) { 1810 mWindowAlignment.mainAxis().invalidateScrollMin(); 1811 if (DEBUG) Log.v(getTag(), "Invalidate scrollMin, since it should be " 1812 + "less than " + minScroll); 1813 } 1814 } 1815 } 1816 1817 private void updateScrollSecondAxis() { 1818 mWindowAlignment.secondAxis().setMinEdge(0); 1819 mWindowAlignment.secondAxis().setMaxEdge(getSizeSecondary()); 1820 } 1821 1822 private void initScrollController() { 1823 // mScrollOffsetPrimary and mScrollOffsetSecondary includes the padding. 1824 // e.g. when topPadding is 16 for horizontal grid view, the initial 1825 // mScrollOffsetSecondary is -16. fastLayout() put views based on offsets(not padding), 1826 // when padding changes to 20, we also need update mScrollOffsetSecondary to -20 before 1827 // fastLayout() is performed 1828 int paddingPrimaryDiff, paddingSecondaryDiff; 1829 if (mOrientation == HORIZONTAL) { 1830 paddingPrimaryDiff = getPaddingLeft() - mWindowAlignment.horizontal.getPaddingLow(); 1831 paddingSecondaryDiff = getPaddingTop() - mWindowAlignment.vertical.getPaddingLow(); 1832 } else { 1833 paddingPrimaryDiff = getPaddingTop() - mWindowAlignment.vertical.getPaddingLow(); 1834 paddingSecondaryDiff = getPaddingLeft() - mWindowAlignment.horizontal.getPaddingLow(); 1835 } 1836 mScrollOffsetPrimary -= paddingPrimaryDiff; 1837 mScrollOffsetSecondary -= paddingSecondaryDiff; 1838 1839 mWindowAlignment.horizontal.setSize(getWidth()); 1840 mWindowAlignment.vertical.setSize(getHeight()); 1841 mWindowAlignment.horizontal.setPadding(getPaddingLeft(), getPaddingRight()); 1842 mWindowAlignment.vertical.setPadding(getPaddingTop(), getPaddingBottom()); 1843 mSizePrimary = mWindowAlignment.mainAxis().getSize(); 1844 1845 if (DEBUG) { 1846 Log.v(getTag(), "initScrollController mSizePrimary " + mSizePrimary 1847 + " mWindowAlignment " + mWindowAlignment); 1848 } 1849 } 1850 1851 public void setSelection(RecyclerView parent, int position) { 1852 setSelection(parent, position, false); 1853 } 1854 1855 public void setSelectionSmooth(RecyclerView parent, int position) { 1856 setSelection(parent, position, true); 1857 } 1858 1859 public int getSelection() { 1860 return mFocusPosition; 1861 } 1862 1863 public void setSelection(RecyclerView parent, int position, boolean smooth) { 1864 if (mFocusPosition != position && position != NO_POSITION) { 1865 scrollToSelection(parent, position, smooth); 1866 } 1867 } 1868 1869 private void scrollToSelection(RecyclerView parent, int position, boolean smooth) { 1870 View view = findViewByPosition(position); 1871 if (view != null) { 1872 mInSelection = true; 1873 scrollToView(view, smooth); 1874 mInSelection = false; 1875 } else { 1876 mFocusPosition = position; 1877 mFocusPositionOffset = 0; 1878 if (!mLayoutEnabled) { 1879 return; 1880 } 1881 if (smooth) { 1882 if (!hasDoneFirstLayout()) { 1883 Log.w(getTag(), "setSelectionSmooth should " + 1884 "not be called before first layout pass"); 1885 return; 1886 } 1887 LinearSmoothScroller linearSmoothScroller = 1888 new LinearSmoothScroller(parent.getContext()) { 1889 @Override 1890 public PointF computeScrollVectorForPosition(int targetPosition) { 1891 if (getChildCount() == 0) { 1892 return null; 1893 } 1894 final int firstChildPos = getPosition(getChildAt(0)); 1895 final int direction = targetPosition < firstChildPos ? -1 : 1; 1896 if (mOrientation == HORIZONTAL) { 1897 return new PointF(direction, 0); 1898 } else { 1899 return new PointF(0, direction); 1900 } 1901 } 1902 @Override 1903 protected void onTargetFound(View targetView, 1904 RecyclerView.State state, Action action) { 1905 if (hasFocus()) { 1906 targetView.requestFocus(); 1907 } 1908 dispatchChildSelected(); 1909 if (getScrollPosition(targetView, mTempDeltas)) { 1910 int dx, dy; 1911 if (mOrientation == HORIZONTAL) { 1912 dx = mTempDeltas[0]; 1913 dy = mTempDeltas[1]; 1914 } else { 1915 dx = mTempDeltas[1]; 1916 dy = mTempDeltas[0]; 1917 } 1918 final int distance = (int) Math.sqrt(dx * dx + dy * dy); 1919 final int time = calculateTimeForDeceleration(distance); 1920 action.update(dx, dy, time, mDecelerateInterpolator); 1921 } 1922 } 1923 }; 1924 linearSmoothScroller.setTargetPosition(position); 1925 startSmoothScroll(linearSmoothScroller); 1926 } else { 1927 mForceFullLayout = true; 1928 parent.requestLayout(); 1929 } 1930 } 1931 } 1932 1933 @Override 1934 public void onItemsAdded(RecyclerView recyclerView, int positionStart, int itemCount) { 1935 if (DEBUG) Log.v(getTag(), "onItemsAdded positionStart " 1936 + positionStart + " itemCount " + itemCount); 1937 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE 1938 && getChildAt(mFocusPosition) != null) { 1939 int pos = mFocusPosition + mFocusPositionOffset; 1940 if (positionStart <= pos) { 1941 mFocusPositionOffset += itemCount; 1942 } 1943 } 1944 mChildrenStates.clear(); 1945 } 1946 1947 @Override 1948 public void onItemsChanged(RecyclerView recyclerView) { 1949 if (DEBUG) Log.v(getTag(), "onItemsChanged"); 1950 mFocusPositionOffset = 0; 1951 mChildrenStates.clear(); 1952 } 1953 1954 @Override 1955 public void onItemsRemoved(RecyclerView recyclerView, int positionStart, int itemCount) { 1956 if (DEBUG) Log.v(getTag(), "onItemsAdded positionStart " 1957 + positionStart + " itemCount " + itemCount); 1958 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE 1959 && getChildAt(mFocusPosition) != null) { 1960 int pos = mFocusPosition + mFocusPositionOffset; 1961 if (positionStart <= pos) { 1962 if (positionStart + itemCount > pos) { 1963 // stop updating offset after the focus item was removed 1964 mFocusPositionOffset = Integer.MIN_VALUE; 1965 } else { 1966 mFocusPositionOffset -= itemCount; 1967 } 1968 } 1969 } 1970 mChildrenStates.clear(); 1971 } 1972 1973 @Override 1974 public void onItemsMoved(RecyclerView recyclerView, int fromPosition, int toPosition, 1975 int itemCount) { 1976 if (DEBUG) Log.v(getTag(), "onItemsAdded fromPosition " 1977 + fromPosition + " toPosition " + toPosition); 1978 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE 1979 && getChildAt(mFocusPosition) != null) { 1980 int pos = mFocusPosition + mFocusPositionOffset; 1981 if (fromPosition <= pos && pos < fromPosition + itemCount) { 1982 // moved items include focused position 1983 mFocusPositionOffset += toPosition - fromPosition; 1984 } else if (fromPosition < pos && toPosition > pos - itemCount) { 1985 // move items before focus position to after focused position 1986 mFocusPositionOffset -= itemCount; 1987 } else if (fromPosition > pos && toPosition < pos) { 1988 // move items after focus position to before focused position 1989 mFocusPositionOffset += itemCount; 1990 } 1991 } 1992 mChildrenStates.clear(); 1993 } 1994 1995 @Override 1996 public void onItemsUpdated(RecyclerView recyclerView, int positionStart, int itemCount) { 1997 for (int i = positionStart, end = positionStart + itemCount; i < end; i++) { 1998 mChildrenStates.remove(i); 1999 } 2000 } 2001 2002 @Override 2003 public boolean onRequestChildFocus(RecyclerView parent, View child, View focused) { 2004 if (mFocusSearchDisabled) { 2005 return true; 2006 } 2007 if (!mInLayout && !mInSelection) { 2008 scrollToView(child, true); 2009 } 2010 return true; 2011 } 2012 2013 @Override 2014 public boolean requestChildRectangleOnScreen(RecyclerView parent, View view, Rect rect, 2015 boolean immediate) { 2016 if (DEBUG) Log.v(getTag(), "requestChildRectangleOnScreen " + view + " " + rect); 2017 return false; 2018 } 2019 2020 int getScrollOffsetX() { 2021 return mOrientation == HORIZONTAL ? mScrollOffsetPrimary : mScrollOffsetSecondary; 2022 } 2023 2024 int getScrollOffsetY() { 2025 return mOrientation == HORIZONTAL ? mScrollOffsetSecondary : mScrollOffsetPrimary; 2026 } 2027 2028 public void getViewSelectedOffsets(View view, int[] offsets) { 2029 if (mOrientation == HORIZONTAL) { 2030 offsets[0] = getPrimarySystemScrollPosition(view) - mScrollOffsetPrimary; 2031 offsets[1] = getSecondarySystemScrollPosition(view) - mScrollOffsetSecondary; 2032 } else { 2033 offsets[1] = getPrimarySystemScrollPosition(view) - mScrollOffsetPrimary; 2034 offsets[0] = getSecondarySystemScrollPosition(view) - mScrollOffsetSecondary; 2035 } 2036 } 2037 2038 private int getPrimarySystemScrollPosition(View view) { 2039 int viewCenterPrimary = mScrollOffsetPrimary + getViewCenter(view); 2040 int pos = getPositionByView(view); 2041 StaggeredGrid.Location location = mGrid.getLocation(pos); 2042 final int row = location.row; 2043 boolean isFirst = mFirstVisiblePos == 0; 2044 // TODO: change to use State object in onRequestChildFocus() 2045 boolean isLast = mLastVisiblePos == (mState == null ? 2046 getItemCount() : mState.getItemCount()) - 1; 2047 if (isFirst || isLast) { 2048 for (int i = getChildCount() - 1; i >= 0; i--) { 2049 int position = getPositionByIndex(i); 2050 StaggeredGrid.Location loc = mGrid.getLocation(position); 2051 if (loc != null && loc.row == row) { 2052 if (position < pos) { 2053 isFirst = false; 2054 } else if (position > pos) { 2055 isLast = false; 2056 } 2057 } 2058 } 2059 } 2060 return mWindowAlignment.mainAxis().getSystemScrollPos(viewCenterPrimary, isFirst, isLast); 2061 } 2062 2063 private int getSecondarySystemScrollPosition(View view) { 2064 int viewCenterSecondary = mScrollOffsetSecondary + getViewCenterSecondary(view); 2065 int pos = getPositionByView(view); 2066 StaggeredGrid.Location location = mGrid.getLocation(pos); 2067 final int row = location.row; 2068 boolean isFirst = row == 0; 2069 boolean isLast = row == mGrid.getNumRows() - 1; 2070 return mWindowAlignment.secondAxis().getSystemScrollPos(viewCenterSecondary, 2071 isFirst, isLast); 2072 } 2073 2074 /** 2075 * Scroll to a given child view and change mFocusPosition. 2076 */ 2077 private void scrollToView(View view, boolean smooth) { 2078 int newFocusPosition = getPositionByView(view); 2079 if (newFocusPosition != mFocusPosition) { 2080 mFocusPosition = newFocusPosition; 2081 mFocusPositionOffset = 0; 2082 if (!mInLayout) { 2083 dispatchChildSelected(); 2084 } 2085 } 2086 if (mBaseGridView.isChildrenDrawingOrderEnabledInternal()) { 2087 mBaseGridView.invalidate(); 2088 } 2089 if (view == null) { 2090 return; 2091 } 2092 if (!view.hasFocus() && mBaseGridView.hasFocus()) { 2093 // transfer focus to the child if it does not have focus yet (e.g. triggered 2094 // by setSelection()) 2095 view.requestFocus(); 2096 } 2097 if (!mScrollEnabled) { 2098 return; 2099 } 2100 if (getScrollPosition(view, mTempDeltas)) { 2101 scrollGrid(mTempDeltas[0], mTempDeltas[1], smooth); 2102 } 2103 } 2104 2105 private boolean getScrollPosition(View view, int[] deltas) { 2106 switch (mFocusScrollStrategy) { 2107 case BaseGridView.FOCUS_SCROLL_ALIGNED: 2108 default: 2109 return getAlignedPosition(view, deltas); 2110 case BaseGridView.FOCUS_SCROLL_ITEM: 2111 case BaseGridView.FOCUS_SCROLL_PAGE: 2112 return getNoneAlignedPosition(view, deltas); 2113 } 2114 } 2115 2116 private boolean getNoneAlignedPosition(View view, int[] deltas) { 2117 int pos = getPositionByView(view); 2118 int viewMin = getViewMin(view); 2119 int viewMax = getViewMax(view); 2120 // we either align "firstView" to left/top padding edge 2121 // or align "lastView" to right/bottom padding edge 2122 View firstView = null; 2123 View lastView = null; 2124 int paddingLow = mWindowAlignment.mainAxis().getPaddingLow(); 2125 int clientSize = mWindowAlignment.mainAxis().getClientSize(); 2126 final int row = mGrid.getLocation(pos).row; 2127 if (viewMin < paddingLow) { 2128 // view enters low padding area: 2129 firstView = view; 2130 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_PAGE) { 2131 // scroll one "page" left/top, 2132 // align first visible item of the "page" at the low padding edge. 2133 while (!prependOneVisibleItem()) { 2134 List<Integer> positions = 2135 mGrid.getItemPositionsInRows(mFirstVisiblePos, pos)[row]; 2136 firstView = findViewByPosition(positions.get(0)); 2137 if (viewMax - getViewMin(firstView) > clientSize) { 2138 if (positions.size() > 1) { 2139 firstView = findViewByPosition(positions.get(1)); 2140 } 2141 break; 2142 } 2143 } 2144 } 2145 } else if (viewMax > clientSize + paddingLow) { 2146 // view enters high padding area: 2147 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_PAGE) { 2148 // scroll whole one page right/bottom, align view at the low padding edge. 2149 firstView = view; 2150 do { 2151 List<Integer> positions = 2152 mGrid.getItemPositionsInRows(pos, mLastVisiblePos)[row]; 2153 lastView = findViewByPosition(positions.get(positions.size() - 1)); 2154 if (getViewMax(lastView) - viewMin > clientSize) { 2155 lastView = null; 2156 break; 2157 } 2158 } while (!appendOneVisibleItem()); 2159 if (lastView != null) { 2160 // however if we reached end, we should align last view. 2161 firstView = null; 2162 } 2163 } else { 2164 lastView = view; 2165 } 2166 } 2167 int scrollPrimary = 0; 2168 int scrollSecondary = 0; 2169 if (firstView != null) { 2170 scrollPrimary = getViewMin(firstView) - paddingLow; 2171 } else if (lastView != null) { 2172 scrollPrimary = getViewMax(lastView) - (paddingLow + clientSize); 2173 } 2174 View secondaryAlignedView; 2175 if (firstView != null) { 2176 secondaryAlignedView = firstView; 2177 } else if (lastView != null) { 2178 secondaryAlignedView = lastView; 2179 } else { 2180 secondaryAlignedView = view; 2181 } 2182 scrollSecondary = getSecondarySystemScrollPosition(secondaryAlignedView); 2183 scrollSecondary -= mScrollOffsetSecondary; 2184 if (scrollPrimary != 0 || scrollSecondary != 0) { 2185 deltas[0] = scrollPrimary; 2186 deltas[1] = scrollSecondary; 2187 return true; 2188 } 2189 return false; 2190 } 2191 2192 private boolean getAlignedPosition(View view, int[] deltas) { 2193 int scrollPrimary = getPrimarySystemScrollPosition(view); 2194 int scrollSecondary = getSecondarySystemScrollPosition(view); 2195 if (DEBUG) { 2196 Log.v(getTag(), "getAlignedPosition " + scrollPrimary + " " + scrollSecondary 2197 +" " + mWindowAlignment); 2198 } 2199 scrollPrimary -= mScrollOffsetPrimary; 2200 scrollSecondary -= mScrollOffsetSecondary; 2201 if (scrollPrimary != 0 || scrollSecondary != 0) { 2202 deltas[0] = scrollPrimary; 2203 deltas[1] = scrollSecondary; 2204 return true; 2205 } 2206 return false; 2207 } 2208 2209 private void scrollGrid(int scrollPrimary, int scrollSecondary, boolean smooth) { 2210 if (mInLayout) { 2211 scrollDirectionPrimary(scrollPrimary); 2212 scrollDirectionSecondary(scrollSecondary); 2213 } else { 2214 int scrollX; 2215 int scrollY; 2216 if (mOrientation == HORIZONTAL) { 2217 scrollX = scrollPrimary; 2218 scrollY = scrollSecondary; 2219 } else { 2220 scrollX = scrollSecondary; 2221 scrollY = scrollPrimary; 2222 } 2223 if (smooth) { 2224 mBaseGridView.smoothScrollBy(scrollX, scrollY); 2225 } else { 2226 mBaseGridView.scrollBy(scrollX, scrollY); 2227 } 2228 } 2229 } 2230 2231 public void setPruneChild(boolean pruneChild) { 2232 if (mPruneChild != pruneChild) { 2233 mPruneChild = pruneChild; 2234 if (mPruneChild) { 2235 requestLayout(); 2236 } 2237 } 2238 } 2239 2240 public boolean getPruneChild() { 2241 return mPruneChild; 2242 } 2243 2244 public void setScrollEnabled(boolean scrollEnabled) { 2245 if (mScrollEnabled != scrollEnabled) { 2246 mScrollEnabled = scrollEnabled; 2247 if (mScrollEnabled && mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED 2248 && mFocusPosition != NO_POSITION) { 2249 scrollToSelection(mBaseGridView, mFocusPosition, true); 2250 } 2251 } 2252 } 2253 2254 public boolean isScrollEnabled() { 2255 return mScrollEnabled; 2256 } 2257 2258 private int findImmediateChildIndex(View view) { 2259 while (view != null && view != mBaseGridView) { 2260 int index = mBaseGridView.indexOfChild(view); 2261 if (index >= 0) { 2262 return index; 2263 } 2264 view = (View) view.getParent(); 2265 } 2266 return NO_POSITION; 2267 } 2268 2269 void setFocusSearchDisabled(boolean disabled) { 2270 mFocusSearchDisabled = disabled; 2271 } 2272 2273 boolean isFocusSearchDisabled() { 2274 return mFocusSearchDisabled; 2275 } 2276 2277 @Override 2278 public View onInterceptFocusSearch(View focused, int direction) { 2279 if (mFocusSearchDisabled) { 2280 return focused; 2281 } 2282 return null; 2283 } 2284 2285 boolean hasPreviousViewInSameRow(int pos) { 2286 if (mGrid == null || pos == NO_POSITION) { 2287 return false; 2288 } 2289 if (mFirstVisiblePos > 0) { 2290 return true; 2291 } 2292 final int focusedRow = mGrid.getLocation(pos).row; 2293 for (int i = getChildCount() - 1; i >= 0; i--) { 2294 int position = getPositionByIndex(i); 2295 StaggeredGrid.Location loc = mGrid.getLocation(position); 2296 if (loc != null && loc.row == focusedRow) { 2297 if (position < pos) { 2298 return true; 2299 } 2300 } 2301 } 2302 return false; 2303 } 2304 2305 @Override 2306 public boolean onAddFocusables(RecyclerView recyclerView, 2307 ArrayList<View> views, int direction, int focusableMode) { 2308 if (mFocusSearchDisabled) { 2309 return true; 2310 } 2311 // If this viewgroup or one of its children currently has focus then we 2312 // consider our children for focus searching in main direction on the same row. 2313 // If this viewgroup has no focus and using focus align, we want the system 2314 // to ignore our children and pass focus to the viewgroup, which will pass 2315 // focus on to its children appropriately. 2316 // If this viewgroup has no focus and not using focus align, we want to 2317 // consider the child that does not overlap with padding area. 2318 if (recyclerView.hasFocus()) { 2319 final int movement = getMovement(direction); 2320 if (movement != PREV_ITEM && movement != NEXT_ITEM) { 2321 // Move on secondary direction uses default addFocusables(). 2322 return false; 2323 } 2324 final View focused = recyclerView.findFocus(); 2325 final int focusedPos = getPositionByIndex(findImmediateChildIndex(focused)); 2326 // Add focusables of focused item. 2327 if (focusedPos != NO_POSITION) { 2328 findViewByPosition(focusedPos).addFocusables(views, direction, focusableMode); 2329 } 2330 final int focusedRow = mGrid != null && focusedPos != NO_POSITION ? 2331 mGrid.getLocation(focusedPos).row : NO_POSITION; 2332 // Add focusables of next neighbor of same row on the focus search direction. 2333 if (mGrid != null) { 2334 final int focusableCount = views.size(); 2335 for (int i = 0, count = getChildCount(); i < count; i++) { 2336 int index = movement == NEXT_ITEM ? i : count - 1 - i; 2337 final View child = getChildAt(index); 2338 if (child.getVisibility() != View.VISIBLE) { 2339 continue; 2340 } 2341 int position = getPositionByIndex(index); 2342 StaggeredGrid.Location loc = mGrid.getLocation(position); 2343 if (focusedRow == NO_POSITION || (loc != null && loc.row == focusedRow)) { 2344 if (focusedPos == NO_POSITION || 2345 (movement == NEXT_ITEM && position > focusedPos) 2346 || (movement == PREV_ITEM && position < focusedPos)) { 2347 child.addFocusables(views, direction, focusableMode); 2348 if (views.size() > focusableCount) { 2349 break; 2350 } 2351 } 2352 } 2353 } 2354 } 2355 } else { 2356 if (mFocusScrollStrategy != BaseGridView.FOCUS_SCROLL_ALIGNED) { 2357 // adding views not overlapping padding area to avoid scrolling in gaining focus 2358 int left = mWindowAlignment.mainAxis().getPaddingLow(); 2359 int right = mWindowAlignment.mainAxis().getClientSize() + left; 2360 int focusableCount = views.size(); 2361 for (int i = 0, count = getChildCount(); i < count; i++) { 2362 View child = getChildAt(i); 2363 if (child.getVisibility() == View.VISIBLE) { 2364 if (getViewMin(child) >= left && getViewMax(child) <= right) { 2365 child.addFocusables(views, direction, focusableMode); 2366 } 2367 } 2368 } 2369 // if we cannot find any, then just add all children. 2370 if (views.size() == focusableCount) { 2371 for (int i = 0, count = getChildCount(); i < count; i++) { 2372 View child = getChildAt(i); 2373 if (child.getVisibility() == View.VISIBLE) { 2374 child.addFocusables(views, direction, focusableMode); 2375 } 2376 } 2377 if (views.size() != focusableCount) { 2378 return true; 2379 } 2380 } else { 2381 return true; 2382 } 2383 // if still cannot find any, fall through and add itself 2384 } 2385 if (recyclerView.isFocusable()) { 2386 views.add(recyclerView); 2387 } 2388 } 2389 return true; 2390 } 2391 2392 @Override 2393 public View onFocusSearchFailed(View focused, int direction, Recycler recycler, 2394 RecyclerView.State state) { 2395 if (DEBUG) Log.v(getTag(), "onFocusSearchFailed direction " + direction); 2396 2397 View view = null; 2398 int movement = getMovement(direction); 2399 final boolean isScroll = mBaseGridView.getScrollState() != RecyclerView.SCROLL_STATE_IDLE; 2400 if (mNumRows == 1) { 2401 // for simple row, use LinearSmoothScroller to smooth animation. 2402 // It will stay at a fixed cap speed in continuous scroll. 2403 if (movement == NEXT_ITEM) { 2404 int newPos = mFocusPosition + mNumRows; 2405 if (newPos < getItemCount() && mScrollEnabled) { 2406 setSelectionSmooth(mBaseGridView, newPos); 2407 view = focused; 2408 } else { 2409 if (isScroll || !mFocusOutEnd) { 2410 view = focused; 2411 } 2412 } 2413 } else if (movement == PREV_ITEM){ 2414 int newPos = mFocusPosition - mNumRows; 2415 if (newPos >= 0 && mScrollEnabled) { 2416 setSelectionSmooth(mBaseGridView, newPos); 2417 view = focused; 2418 } else { 2419 if (isScroll || !mFocusOutFront) { 2420 view = focused; 2421 } 2422 } 2423 } 2424 } else if (mNumRows > 1) { 2425 // for possible staggered grid, we need guarantee focus to same row/column. 2426 // TODO: we may also use LinearSmoothScroller. 2427 saveContext(recycler, state); 2428 final FocusFinder ff = FocusFinder.getInstance(); 2429 if (movement == NEXT_ITEM) { 2430 while (view == null && !appendOneVisibleItem()) { 2431 view = ff.findNextFocus(mBaseGridView, focused, direction); 2432 } 2433 } else if (movement == PREV_ITEM){ 2434 while (view == null && !prependOneVisibleItem()) { 2435 view = ff.findNextFocus(mBaseGridView, focused, direction); 2436 } 2437 } 2438 if (view == null) { 2439 // returning the same view to prevent focus lost when scrolling past the end of the list 2440 if (movement == PREV_ITEM) { 2441 view = mFocusOutFront && !isScroll ? null : focused; 2442 } else if (movement == NEXT_ITEM){ 2443 view = mFocusOutEnd && !isScroll ? null : focused; 2444 } 2445 } 2446 leaveContext(); 2447 } 2448 if (DEBUG) Log.v(getTag(), "returning view " + view); 2449 return view; 2450 } 2451 2452 boolean gridOnRequestFocusInDescendants(RecyclerView recyclerView, int direction, 2453 Rect previouslyFocusedRect) { 2454 switch (mFocusScrollStrategy) { 2455 case BaseGridView.FOCUS_SCROLL_ALIGNED: 2456 default: 2457 return gridOnRequestFocusInDescendantsAligned(recyclerView, 2458 direction, previouslyFocusedRect); 2459 case BaseGridView.FOCUS_SCROLL_PAGE: 2460 case BaseGridView.FOCUS_SCROLL_ITEM: 2461 return gridOnRequestFocusInDescendantsUnaligned(recyclerView, 2462 direction, previouslyFocusedRect); 2463 } 2464 } 2465 2466 private boolean gridOnRequestFocusInDescendantsAligned(RecyclerView recyclerView, 2467 int direction, Rect previouslyFocusedRect) { 2468 View view = findViewByPosition(mFocusPosition); 2469 if (view != null) { 2470 boolean result = view.requestFocus(direction, previouslyFocusedRect); 2471 if (!result && DEBUG) { 2472 Log.w(getTag(), "failed to request focus on " + view); 2473 } 2474 return result; 2475 } 2476 return false; 2477 } 2478 2479 private boolean gridOnRequestFocusInDescendantsUnaligned(RecyclerView recyclerView, 2480 int direction, Rect previouslyFocusedRect) { 2481 // focus to view not overlapping padding area to avoid scrolling in gaining focus 2482 int index; 2483 int increment; 2484 int end; 2485 int count = getChildCount(); 2486 if ((direction & View.FOCUS_FORWARD) != 0) { 2487 index = 0; 2488 increment = 1; 2489 end = count; 2490 } else { 2491 index = count - 1; 2492 increment = -1; 2493 end = -1; 2494 } 2495 int left = mWindowAlignment.mainAxis().getPaddingLow(); 2496 int right = mWindowAlignment.mainAxis().getClientSize() + left; 2497 for (int i = index; i != end; i += increment) { 2498 View child = getChildAt(i); 2499 if (child.getVisibility() == View.VISIBLE) { 2500 if (getViewMin(child) >= left && getViewMax(child) <= right) { 2501 if (child.requestFocus(direction, previouslyFocusedRect)) { 2502 return true; 2503 } 2504 } 2505 } 2506 } 2507 return false; 2508 } 2509 2510 private final static int PREV_ITEM = 0; 2511 private final static int NEXT_ITEM = 1; 2512 private final static int PREV_ROW = 2; 2513 private final static int NEXT_ROW = 3; 2514 2515 private int getMovement(int direction) { 2516 int movement = View.FOCUS_LEFT; 2517 2518 if (mOrientation == HORIZONTAL) { 2519 switch(direction) { 2520 case View.FOCUS_LEFT: 2521 movement = PREV_ITEM; 2522 break; 2523 case View.FOCUS_RIGHT: 2524 movement = NEXT_ITEM; 2525 break; 2526 case View.FOCUS_UP: 2527 movement = PREV_ROW; 2528 break; 2529 case View.FOCUS_DOWN: 2530 movement = NEXT_ROW; 2531 break; 2532 } 2533 } else if (mOrientation == VERTICAL) { 2534 switch(direction) { 2535 case View.FOCUS_LEFT: 2536 movement = PREV_ROW; 2537 break; 2538 case View.FOCUS_RIGHT: 2539 movement = NEXT_ROW; 2540 break; 2541 case View.FOCUS_UP: 2542 movement = PREV_ITEM; 2543 break; 2544 case View.FOCUS_DOWN: 2545 movement = NEXT_ITEM; 2546 break; 2547 } 2548 } 2549 2550 return movement; 2551 } 2552 2553 int getChildDrawingOrder(RecyclerView recyclerView, int childCount, int i) { 2554 View view = findViewByPosition(mFocusPosition); 2555 if (view == null) { 2556 return i; 2557 } 2558 int focusIndex = recyclerView.indexOfChild(view); 2559 // supposely 0 1 2 3 4 5 6 7 8 9, 4 is the center item 2560 // drawing order is 0 1 2 3 9 8 7 6 5 4 2561 if (i < focusIndex) { 2562 return i; 2563 } else if (i < childCount - 1) { 2564 return focusIndex + childCount - 1 - i; 2565 } else { 2566 return focusIndex; 2567 } 2568 } 2569 2570 @Override 2571 public void onAdapterChanged(RecyclerView.Adapter oldAdapter, 2572 RecyclerView.Adapter newAdapter) { 2573 if (DEBUG) Log.v(getTag(), "onAdapterChanged to " + newAdapter); 2574 if (oldAdapter != null) { 2575 discardLayoutInfo(); 2576 mFocusPosition = NO_POSITION; 2577 mFocusPositionOffset = 0; 2578 mChildrenStates.clear(); 2579 } 2580 super.onAdapterChanged(oldAdapter, newAdapter); 2581 } 2582 2583 private void discardLayoutInfo() { 2584 mGrid = null; 2585 mRows = null; 2586 mRowSizeSecondary = null; 2587 mFirstVisiblePos = -1; 2588 mLastVisiblePos = -1; 2589 mRowSecondarySizeRefresh = false; 2590 } 2591 2592 public void setLayoutEnabled(boolean layoutEnabled) { 2593 if (mLayoutEnabled != layoutEnabled) { 2594 mLayoutEnabled = layoutEnabled; 2595 requestLayout(); 2596 } 2597 } 2598 2599 void setChildrenVisibility(int visiblity) { 2600 mChildVisibility = visiblity; 2601 if (mChildVisibility != -1) { 2602 int count = getChildCount(); 2603 for (int i= 0; i < count; i++) { 2604 getChildAt(i).setVisibility(mChildVisibility); 2605 } 2606 } 2607 } 2608 2609 final static class SavedState implements Parcelable { 2610 2611 int index; // index inside adapter of the current view 2612 Bundle childStates = Bundle.EMPTY; 2613 2614 @Override 2615 public void writeToParcel(Parcel out, int flags) { 2616 out.writeInt(index); 2617 out.writeBundle(childStates); 2618 } 2619 2620 @SuppressWarnings("hiding") 2621 public static final Parcelable.Creator<SavedState> CREATOR = 2622 new Parcelable.Creator<SavedState>() { 2623 @Override 2624 public SavedState createFromParcel(Parcel in) { 2625 return new SavedState(in); 2626 } 2627 2628 @Override 2629 public SavedState[] newArray(int size) { 2630 return new SavedState[size]; 2631 } 2632 }; 2633 2634 @Override 2635 public int describeContents() { 2636 return 0; 2637 } 2638 2639 SavedState(Parcel in) { 2640 index = in.readInt(); 2641 childStates = in.readBundle(GridLayoutManager.class.getClassLoader()); 2642 } 2643 2644 SavedState() { 2645 } 2646 } 2647 2648 @Override 2649 public Parcelable onSaveInstanceState() { 2650 if (DEBUG) Log.v(getTag(), "onSaveInstanceState getSelection() " + getSelection()); 2651 SavedState ss = new SavedState(); 2652 for (int i = 0, count = getChildCount(); i < count; i++) { 2653 View view = getChildAt(i); 2654 int position = getPositionByView(view); 2655 if (position != NO_POSITION) { 2656 mChildrenStates.saveOnScreenView(view, position); 2657 } 2658 } 2659 ss.index = getSelection(); 2660 ss.childStates = mChildrenStates.saveAsBundle(); 2661 return ss; 2662 } 2663 2664 @Override 2665 public void onRestoreInstanceState(Parcelable state) { 2666 if (!(state instanceof SavedState)) { 2667 return; 2668 } 2669 SavedState loadingState = (SavedState)state; 2670 mFocusPosition = loadingState.index; 2671 mFocusPositionOffset = 0; 2672 mChildrenStates.loadFromBundle(loadingState.childStates); 2673 mForceFullLayout = true; 2674 requestLayout(); 2675 if (DEBUG) Log.v(getTag(), "onRestoreInstanceState mFocusPosition " + mFocusPosition); 2676 } 2677} 2678