GridLayoutManager.java revision d633c87b6565c6068a5c5beb5a1ef91a493acea8
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 1493 // Track the old focus view so we can adjust our system scroll position 1494 // so that any scroll animations happening now will remain valid. 1495 // We must use same delta in Pre Layout (if prelayout exists) and second layout. 1496 // So we cache the deltas in PreLayout and use it in second layout. 1497 int delta = 0, deltaSecondary = 0; 1498 if (mFocusPosition != NO_POSITION && scrollToFocus 1499 && mBaseGridView.getScrollState() != RecyclerView.SCROLL_STATE_IDLE) { 1500 // FIXME: we should get the remaining scroll animation offset from RecyclerView 1501 View focusView = findViewByPosition(mFocusPosition); 1502 if (focusView != null) { 1503 delta = mWindowAlignment.mainAxis().getSystemScrollPos(mScrollOffsetPrimary 1504 + getViewCenter(focusView), false, false) - mScrollOffsetPrimary; 1505 deltaSecondary = mWindowAlignment.secondAxis().getSystemScrollPos( 1506 mScrollOffsetSecondary + getViewCenterSecondary(focusView), 1507 false, false) - mScrollOffsetSecondary; 1508 } 1509 } 1510 1511 final boolean hasDoneFirstLayout = hasDoneFirstLayout(); 1512 int savedFocusPos = mFocusPosition; 1513 boolean fastRelayout = false; 1514 if (!mState.didStructureChange() && !mForceFullLayout && hasDoneFirstLayout) { 1515 fastRelayout = true; 1516 fastRelayout(scrollToFocus); 1517 } else { 1518 boolean hadFocus = mBaseGridView.hasFocus(); 1519 1520 mFocusPosition = init(mFocusPosition); 1521 if (mFocusPosition != savedFocusPos) { 1522 if (DEBUG) Log.v(getTag(), "savedFocusPos " + savedFocusPos + 1523 " mFocusPosition " + mFocusPosition); 1524 } 1525 if (mFocusPosition == NO_POSITION) { 1526 mBaseGridView.clearFocus(); 1527 } 1528 1529 mWindowAlignment.mainAxis().invalidateScrollMin(); 1530 mWindowAlignment.mainAxis().invalidateScrollMax(); 1531 // depending on result of init(), either recreating everything 1532 // or try to reuse the row start positions near mFocusPosition 1533 if (mGrid.getSize() == 0) { 1534 // this is a fresh creating all items, starting from 1535 // mFocusPosition with a estimated row index. 1536 mGrid.setStart(mFocusPosition, StaggeredGrid.START_DEFAULT); 1537 1538 // Can't track the old focus view 1539 delta = deltaSecondary = 0; 1540 1541 } else { 1542 // mGrid remembers Locations for the column that 1543 // contains mFocusePosition and also mRows remembers start 1544 // positions of each row. 1545 // Manually re-create child views for that column 1546 int firstIndex = mGrid.getFirstIndex(); 1547 int lastIndex = mGrid.getLastIndex(); 1548 for (int i = firstIndex; i <= lastIndex; i++) { 1549 mGridProvider.createItem(i, mGrid.getLocation(i).row, true); 1550 } 1551 } 1552 1553 // add visible views at end until reach the end of window 1554 appendVisibleItems(); 1555 // add visible views at front until reach the start of window 1556 prependVisibleItems(); 1557 // multiple rounds: scrollToView of first round may drag first/last child into 1558 // "visible window" and we update scrollMin/scrollMax then run second scrollToView 1559 int oldFirstVisible; 1560 int oldLastVisible; 1561 do { 1562 updateScrollMin(); 1563 updateScrollMax(); 1564 oldFirstVisible = mFirstVisiblePos; 1565 oldLastVisible = mLastVisiblePos; 1566 View focusView = findViewByPosition(mFocusPosition); 1567 // we need force to initialize the child view's position 1568 scrollToView(focusView, false); 1569 if (focusView != null && hadFocus) { 1570 focusView.requestFocus(); 1571 } 1572 appendVisibleItems(); 1573 prependVisibleItems(); 1574 removeInvisibleViewsAtFront(); 1575 removeInvisibleViewsAtEnd(); 1576 } while (mFirstVisiblePos != oldFirstVisible || mLastVisiblePos != oldLastVisible); 1577 } 1578 mForceFullLayout = false; 1579 1580 if (scrollToFocus) { 1581 scrollDirectionPrimary(-delta); 1582 scrollDirectionSecondary(-deltaSecondary); 1583 } 1584 appendVisibleItems(); 1585 prependVisibleItems(); 1586 removeInvisibleViewsAtFront(); 1587 removeInvisibleViewsAtEnd(); 1588 1589 if (DEBUG) { 1590 StringWriter sw = new StringWriter(); 1591 PrintWriter pw = new PrintWriter(sw); 1592 mGrid.debugPrint(pw); 1593 Log.d(getTag(), sw.toString()); 1594 } 1595 1596 if (mRowSecondarySizeRefresh) { 1597 mRowSecondarySizeRefresh = false; 1598 } else { 1599 updateRowSecondarySizeRefresh(); 1600 } 1601 1602 if (fastRelayout && mFocusPosition != savedFocusPos) { 1603 dispatchChildSelected(); 1604 } 1605 mInLayout = false; 1606 leaveContext(); 1607 if (DEBUG) Log.v(getTag(), "layoutChildren end"); 1608 } 1609 1610 private void offsetChildrenSecondary(int increment) { 1611 final int childCount = getChildCount(); 1612 if (mOrientation == HORIZONTAL) { 1613 for (int i = 0; i < childCount; i++) { 1614 getChildAt(i).offsetTopAndBottom(increment); 1615 } 1616 } else { 1617 for (int i = 0; i < childCount; i++) { 1618 getChildAt(i).offsetLeftAndRight(increment); 1619 } 1620 } 1621 } 1622 1623 private void offsetChildrenPrimary(int increment) { 1624 final int childCount = getChildCount(); 1625 if (mOrientation == VERTICAL) { 1626 for (int i = 0; i < childCount; i++) { 1627 getChildAt(i).offsetTopAndBottom(increment); 1628 } 1629 } else { 1630 for (int i = 0; i < childCount; i++) { 1631 getChildAt(i).offsetLeftAndRight(increment); 1632 } 1633 } 1634 } 1635 1636 @Override 1637 public int scrollHorizontallyBy(int dx, Recycler recycler, RecyclerView.State state) { 1638 if (DEBUG) Log.v(getTag(), "scrollHorizontallyBy " + dx); 1639 if (!mLayoutEnabled || !hasDoneFirstLayout()) { 1640 return 0; 1641 } 1642 saveContext(recycler, state); 1643 int result; 1644 if (mOrientation == HORIZONTAL) { 1645 result = scrollDirectionPrimary(dx); 1646 } else { 1647 result = scrollDirectionSecondary(dx); 1648 } 1649 leaveContext(); 1650 return result; 1651 } 1652 1653 @Override 1654 public int scrollVerticallyBy(int dy, Recycler recycler, RecyclerView.State state) { 1655 if (DEBUG) Log.v(getTag(), "scrollVerticallyBy " + dy); 1656 if (!mLayoutEnabled || !hasDoneFirstLayout()) { 1657 return 0; 1658 } 1659 saveContext(recycler, state); 1660 int result; 1661 if (mOrientation == VERTICAL) { 1662 result = scrollDirectionPrimary(dy); 1663 } else { 1664 result = scrollDirectionSecondary(dy); 1665 } 1666 leaveContext(); 1667 return result; 1668 } 1669 1670 // scroll in main direction may add/prune views 1671 private int scrollDirectionPrimary(int da) { 1672 if (da > 0) { 1673 if (!mWindowAlignment.mainAxis().isMaxUnknown()) { 1674 int maxScroll = mWindowAlignment.mainAxis().getMaxScroll(); 1675 if (mScrollOffsetPrimary + da > maxScroll) { 1676 da = maxScroll - mScrollOffsetPrimary; 1677 } 1678 } 1679 } else if (da < 0) { 1680 if (!mWindowAlignment.mainAxis().isMinUnknown()) { 1681 int minScroll = mWindowAlignment.mainAxis().getMinScroll(); 1682 if (mScrollOffsetPrimary + da < minScroll) { 1683 da = minScroll - mScrollOffsetPrimary; 1684 } 1685 } 1686 } 1687 if (da == 0) { 1688 return 0; 1689 } 1690 offsetChildrenPrimary(-da); 1691 mScrollOffsetPrimary += da; 1692 if (mInLayout) { 1693 return da; 1694 } 1695 1696 int childCount = getChildCount(); 1697 boolean updated; 1698 1699 if (da > 0) { 1700 appendVisibleItems(); 1701 } else if (da < 0) { 1702 prependVisibleItems(); 1703 } 1704 updated = getChildCount() > childCount; 1705 childCount = getChildCount(); 1706 1707 if (da > 0) { 1708 removeInvisibleViewsAtFront(); 1709 } else if (da < 0) { 1710 removeInvisibleViewsAtEnd(); 1711 } 1712 updated |= getChildCount() < childCount; 1713 1714 if (updated) { 1715 updateRowSecondarySizeRefresh(); 1716 } 1717 1718 mBaseGridView.invalidate(); 1719 return da; 1720 } 1721 1722 // scroll in second direction will not add/prune views 1723 private int scrollDirectionSecondary(int dy) { 1724 if (dy == 0) { 1725 return 0; 1726 } 1727 offsetChildrenSecondary(-dy); 1728 mScrollOffsetSecondary += dy; 1729 mBaseGridView.invalidate(); 1730 return dy; 1731 } 1732 1733 private void updateScrollMax() { 1734 if (mLastVisiblePos < 0) { 1735 return; 1736 } 1737 final boolean lastAvailable = mLastVisiblePos == mState.getItemCount() - 1; 1738 final boolean maxUnknown = mWindowAlignment.mainAxis().isMaxUnknown(); 1739 if (!lastAvailable && maxUnknown) { 1740 return; 1741 } 1742 int maxEdge = Integer.MIN_VALUE; 1743 int rowIndex = -1; 1744 for (int i = 0; i < mRows.length; i++) { 1745 if (mRows[i].high > maxEdge) { 1746 maxEdge = mRows[i].high; 1747 rowIndex = i; 1748 } 1749 } 1750 int maxScroll = Integer.MAX_VALUE; 1751 for (int i = mLastVisiblePos; i >= mFirstVisiblePos; i--) { 1752 StaggeredGrid.Location location = mGrid.getLocation(i); 1753 if (location != null && location.row == rowIndex) { 1754 int savedMaxEdge = mWindowAlignment.mainAxis().getMaxEdge(); 1755 mWindowAlignment.mainAxis().setMaxEdge(maxEdge); 1756 maxScroll = getPrimarySystemScrollPosition(findViewByPosition(i)); 1757 mWindowAlignment.mainAxis().setMaxEdge(savedMaxEdge); 1758 break; 1759 } 1760 } 1761 if (lastAvailable) { 1762 mWindowAlignment.mainAxis().setMaxEdge(maxEdge); 1763 mWindowAlignment.mainAxis().setMaxScroll(maxScroll); 1764 if (DEBUG) Log.v(getTag(), "updating scroll maxEdge to " + maxEdge + 1765 " scrollMax to " + maxScroll); 1766 } else { 1767 // the maxScroll for currently last visible item is larger, 1768 // so we must invalidate the max scroll value. 1769 if (maxScroll > mWindowAlignment.mainAxis().getMaxScroll()) { 1770 mWindowAlignment.mainAxis().invalidateScrollMax(); 1771 if (DEBUG) Log.v(getTag(), "Invalidate scrollMax since it should be " 1772 + "greater than " + maxScroll); 1773 } 1774 } 1775 } 1776 1777 private void updateScrollMin() { 1778 if (mFirstVisiblePos < 0) { 1779 return; 1780 } 1781 final boolean firstAvailable = mFirstVisiblePos == 0; 1782 final boolean minUnknown = mWindowAlignment.mainAxis().isMinUnknown(); 1783 if (!firstAvailable && minUnknown) { 1784 return; 1785 } 1786 int minEdge = Integer.MAX_VALUE; 1787 int rowIndex = -1; 1788 for (int i = 0; i < mRows.length; i++) { 1789 if (mRows[i].low < minEdge) { 1790 minEdge = mRows[i].low; 1791 rowIndex = i; 1792 } 1793 } 1794 int minScroll = Integer.MIN_VALUE; 1795 for (int i = mFirstVisiblePos; i <= mLastVisiblePos; i++) { 1796 StaggeredGrid.Location location = mGrid.getLocation(i); 1797 if (location != null && location.row == rowIndex) { 1798 int savedMinEdge = mWindowAlignment.mainAxis().getMinEdge(); 1799 mWindowAlignment.mainAxis().setMinEdge(minEdge); 1800 minScroll = getPrimarySystemScrollPosition(findViewByPosition(i)); 1801 mWindowAlignment.mainAxis().setMinEdge(savedMinEdge); 1802 break; 1803 } 1804 } 1805 if (firstAvailable) { 1806 mWindowAlignment.mainAxis().setMinEdge(minEdge); 1807 mWindowAlignment.mainAxis().setMinScroll(minScroll); 1808 if (DEBUG) Log.v(getTag(), "updating scroll minEdge to " + minEdge + 1809 " scrollMin to " + minScroll); 1810 } else { 1811 // the minScroll for currently first visible item is smaller, 1812 // so we must invalidate the min scroll value. 1813 if (minScroll < mWindowAlignment.mainAxis().getMinScroll()) { 1814 mWindowAlignment.mainAxis().invalidateScrollMin(); 1815 if (DEBUG) Log.v(getTag(), "Invalidate scrollMin, since it should be " 1816 + "less than " + minScroll); 1817 } 1818 } 1819 } 1820 1821 private void updateScrollSecondAxis() { 1822 mWindowAlignment.secondAxis().setMinEdge(0); 1823 mWindowAlignment.secondAxis().setMaxEdge(getSizeSecondary()); 1824 } 1825 1826 private void initScrollController() { 1827 // mScrollOffsetPrimary and mScrollOffsetSecondary includes the padding. 1828 // e.g. when topPadding is 16 for horizontal grid view, the initial 1829 // mScrollOffsetSecondary is -16. fastLayout() put views based on offsets(not padding), 1830 // when padding changes to 20, we also need update mScrollOffsetSecondary to -20 before 1831 // fastLayout() is performed 1832 int paddingPrimaryDiff, paddingSecondaryDiff; 1833 if (mOrientation == HORIZONTAL) { 1834 paddingPrimaryDiff = getPaddingLeft() - mWindowAlignment.horizontal.getPaddingLow(); 1835 paddingSecondaryDiff = getPaddingTop() - mWindowAlignment.vertical.getPaddingLow(); 1836 } else { 1837 paddingPrimaryDiff = getPaddingTop() - mWindowAlignment.vertical.getPaddingLow(); 1838 paddingSecondaryDiff = getPaddingLeft() - mWindowAlignment.horizontal.getPaddingLow(); 1839 } 1840 mScrollOffsetPrimary -= paddingPrimaryDiff; 1841 mScrollOffsetSecondary -= paddingSecondaryDiff; 1842 1843 mWindowAlignment.horizontal.setSize(getWidth()); 1844 mWindowAlignment.vertical.setSize(getHeight()); 1845 mWindowAlignment.horizontal.setPadding(getPaddingLeft(), getPaddingRight()); 1846 mWindowAlignment.vertical.setPadding(getPaddingTop(), getPaddingBottom()); 1847 mSizePrimary = mWindowAlignment.mainAxis().getSize(); 1848 1849 if (DEBUG) { 1850 Log.v(getTag(), "initScrollController mSizePrimary " + mSizePrimary 1851 + " mWindowAlignment " + mWindowAlignment); 1852 } 1853 } 1854 1855 public void setSelection(RecyclerView parent, int position) { 1856 setSelection(parent, position, false); 1857 } 1858 1859 public void setSelectionSmooth(RecyclerView parent, int position) { 1860 setSelection(parent, position, true); 1861 } 1862 1863 public int getSelection() { 1864 return mFocusPosition; 1865 } 1866 1867 public void setSelection(RecyclerView parent, int position, boolean smooth) { 1868 if (mFocusPosition != position) { 1869 scrollToSelection(parent, position, smooth); 1870 } 1871 } 1872 1873 private void scrollToSelection(RecyclerView parent, int position, boolean smooth) { 1874 View view = findViewByPosition(position); 1875 if (view != null) { 1876 mInSelection = true; 1877 scrollToView(view, smooth); 1878 mInSelection = false; 1879 } else { 1880 mFocusPosition = position; 1881 mFocusPositionOffset = 0; 1882 if (!mLayoutEnabled) { 1883 return; 1884 } 1885 if (smooth) { 1886 if (!hasDoneFirstLayout()) { 1887 Log.w(getTag(), "setSelectionSmooth should " + 1888 "not be called before first layout pass"); 1889 return; 1890 } 1891 LinearSmoothScroller linearSmoothScroller = 1892 new LinearSmoothScroller(parent.getContext()) { 1893 @Override 1894 public PointF computeScrollVectorForPosition(int targetPosition) { 1895 if (getChildCount() == 0) { 1896 return null; 1897 } 1898 final int firstChildPos = getPosition(getChildAt(0)); 1899 final int direction = targetPosition < firstChildPos ? -1 : 1; 1900 if (mOrientation == HORIZONTAL) { 1901 return new PointF(direction, 0); 1902 } else { 1903 return new PointF(0, direction); 1904 } 1905 } 1906 @Override 1907 protected void onTargetFound(View targetView, 1908 RecyclerView.State state, Action action) { 1909 if (hasFocus()) { 1910 targetView.requestFocus(); 1911 } 1912 dispatchChildSelected(); 1913 if (getScrollPosition(targetView, mTempDeltas)) { 1914 int dx, dy; 1915 if (mOrientation == HORIZONTAL) { 1916 dx = mTempDeltas[0]; 1917 dy = mTempDeltas[1]; 1918 } else { 1919 dx = mTempDeltas[1]; 1920 dy = mTempDeltas[0]; 1921 } 1922 final int distance = (int) Math.sqrt(dx * dx + dy * dy); 1923 final int time = calculateTimeForDeceleration(distance); 1924 action.update(dx, dy, time, mDecelerateInterpolator); 1925 } 1926 } 1927 }; 1928 linearSmoothScroller.setTargetPosition(position); 1929 startSmoothScroll(linearSmoothScroller); 1930 } else { 1931 mForceFullLayout = true; 1932 parent.requestLayout(); 1933 } 1934 } 1935 } 1936 1937 @Override 1938 public void onItemsAdded(RecyclerView recyclerView, int positionStart, int itemCount) { 1939 if (DEBUG) Log.v(getTag(), "onItemsAdded positionStart " 1940 + positionStart + " itemCount " + itemCount); 1941 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE 1942 && getChildAt(mFocusPosition) != null) { 1943 int pos = mFocusPosition + mFocusPositionOffset; 1944 if (positionStart <= pos) { 1945 mFocusPositionOffset += itemCount; 1946 } 1947 } 1948 mChildrenStates.clear(); 1949 } 1950 1951 @Override 1952 public void onItemsChanged(RecyclerView recyclerView) { 1953 if (DEBUG) Log.v(getTag(), "onItemsChanged"); 1954 mFocusPositionOffset = 0; 1955 mChildrenStates.clear(); 1956 } 1957 1958 @Override 1959 public void onItemsRemoved(RecyclerView recyclerView, int positionStart, int itemCount) { 1960 if (DEBUG) Log.v(getTag(), "onItemsAdded positionStart " 1961 + positionStart + " itemCount " + itemCount); 1962 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE 1963 && getChildAt(mFocusPosition) != null) { 1964 int pos = mFocusPosition + mFocusPositionOffset; 1965 if (positionStart <= pos) { 1966 if (positionStart + itemCount > pos) { 1967 // stop updating offset after the focus item was removed 1968 mFocusPositionOffset = Integer.MIN_VALUE; 1969 } else { 1970 mFocusPositionOffset -= itemCount; 1971 } 1972 } 1973 } 1974 mChildrenStates.clear(); 1975 } 1976 1977 @Override 1978 public void onItemsMoved(RecyclerView recyclerView, int fromPosition, int toPosition, 1979 int itemCount) { 1980 if (DEBUG) Log.v(getTag(), "onItemsAdded fromPosition " 1981 + fromPosition + " toPosition " + toPosition); 1982 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE 1983 && getChildAt(mFocusPosition) != null) { 1984 int pos = mFocusPosition + mFocusPositionOffset; 1985 if (fromPosition <= pos && pos < fromPosition + itemCount) { 1986 // moved items include focused position 1987 mFocusPositionOffset += toPosition - fromPosition; 1988 } else if (fromPosition < pos && toPosition > pos - itemCount) { 1989 // move items before focus position to after focused position 1990 mFocusPositionOffset -= itemCount; 1991 } else if (fromPosition > pos && toPosition < pos) { 1992 // move items after focus position to before focused position 1993 mFocusPositionOffset += itemCount; 1994 } 1995 } 1996 mChildrenStates.clear(); 1997 } 1998 1999 @Override 2000 public void onItemsUpdated(RecyclerView recyclerView, int positionStart, int itemCount) { 2001 for (int i = positionStart, end = positionStart + itemCount; i < end; i++) { 2002 mChildrenStates.remove(i); 2003 } 2004 } 2005 2006 @Override 2007 public boolean onRequestChildFocus(RecyclerView parent, View child, View focused) { 2008 if (mFocusSearchDisabled) { 2009 return true; 2010 } 2011 if (getPositionByView(child) == NO_POSITION) { 2012 // This shouldn't happen, but in case it does be sure not to attempt a 2013 // scroll to a view whose item has been removed. 2014 return true; 2015 } 2016 if (!mInLayout && !mInSelection) { 2017 scrollToView(child, true); 2018 } 2019 return true; 2020 } 2021 2022 @Override 2023 public boolean requestChildRectangleOnScreen(RecyclerView parent, View view, Rect rect, 2024 boolean immediate) { 2025 if (DEBUG) Log.v(getTag(), "requestChildRectangleOnScreen " + view + " " + rect); 2026 return false; 2027 } 2028 2029 int getScrollOffsetX() { 2030 return mOrientation == HORIZONTAL ? mScrollOffsetPrimary : mScrollOffsetSecondary; 2031 } 2032 2033 int getScrollOffsetY() { 2034 return mOrientation == HORIZONTAL ? mScrollOffsetSecondary : mScrollOffsetPrimary; 2035 } 2036 2037 public void getViewSelectedOffsets(View view, int[] offsets) { 2038 if (mOrientation == HORIZONTAL) { 2039 offsets[0] = getPrimarySystemScrollPosition(view) - mScrollOffsetPrimary; 2040 offsets[1] = getSecondarySystemScrollPosition(view) - mScrollOffsetSecondary; 2041 } else { 2042 offsets[1] = getPrimarySystemScrollPosition(view) - mScrollOffsetPrimary; 2043 offsets[0] = getSecondarySystemScrollPosition(view) - mScrollOffsetSecondary; 2044 } 2045 } 2046 2047 private int getPrimarySystemScrollPosition(View view) { 2048 int viewCenterPrimary = mScrollOffsetPrimary + getViewCenter(view); 2049 int pos = getPositionByView(view); 2050 StaggeredGrid.Location location = mGrid.getLocation(pos); 2051 final int row = location.row; 2052 boolean isFirst = mFirstVisiblePos == 0; 2053 // TODO: change to use State object in onRequestChildFocus() 2054 boolean isLast = mLastVisiblePos == (mState == null ? 2055 getItemCount() : mState.getItemCount()) - 1; 2056 if (isFirst || isLast) { 2057 for (int i = getChildCount() - 1; i >= 0; i--) { 2058 int position = getPositionByIndex(i); 2059 StaggeredGrid.Location loc = mGrid.getLocation(position); 2060 if (loc != null && loc.row == row) { 2061 if (position < pos) { 2062 isFirst = false; 2063 } else if (position > pos) { 2064 isLast = false; 2065 } 2066 } 2067 } 2068 } 2069 return mWindowAlignment.mainAxis().getSystemScrollPos(viewCenterPrimary, isFirst, isLast); 2070 } 2071 2072 private int getSecondarySystemScrollPosition(View view) { 2073 int viewCenterSecondary = mScrollOffsetSecondary + getViewCenterSecondary(view); 2074 int pos = getPositionByView(view); 2075 StaggeredGrid.Location location = mGrid.getLocation(pos); 2076 final int row = location.row; 2077 boolean isFirst = row == 0; 2078 boolean isLast = row == mGrid.getNumRows() - 1; 2079 return mWindowAlignment.secondAxis().getSystemScrollPos(viewCenterSecondary, 2080 isFirst, isLast); 2081 } 2082 2083 /** 2084 * Scroll to a given child view and change mFocusPosition. 2085 */ 2086 private void scrollToView(View view, boolean smooth) { 2087 int newFocusPosition = getPositionByView(view); 2088 if (newFocusPosition != mFocusPosition) { 2089 mFocusPosition = newFocusPosition; 2090 mFocusPositionOffset = 0; 2091 if (!mInLayout) { 2092 dispatchChildSelected(); 2093 } 2094 } 2095 if (mBaseGridView.isChildrenDrawingOrderEnabledInternal()) { 2096 mBaseGridView.invalidate(); 2097 } 2098 if (view == null) { 2099 return; 2100 } 2101 if (!view.hasFocus() && mBaseGridView.hasFocus()) { 2102 // transfer focus to the child if it does not have focus yet (e.g. triggered 2103 // by setSelection()) 2104 view.requestFocus(); 2105 } 2106 if (!mScrollEnabled) { 2107 return; 2108 } 2109 if (getScrollPosition(view, mTempDeltas)) { 2110 scrollGrid(mTempDeltas[0], mTempDeltas[1], smooth); 2111 } 2112 } 2113 2114 private boolean getScrollPosition(View view, int[] deltas) { 2115 switch (mFocusScrollStrategy) { 2116 case BaseGridView.FOCUS_SCROLL_ALIGNED: 2117 default: 2118 return getAlignedPosition(view, deltas); 2119 case BaseGridView.FOCUS_SCROLL_ITEM: 2120 case BaseGridView.FOCUS_SCROLL_PAGE: 2121 return getNoneAlignedPosition(view, deltas); 2122 } 2123 } 2124 2125 private boolean getNoneAlignedPosition(View view, int[] deltas) { 2126 int pos = getPositionByView(view); 2127 int viewMin = getViewMin(view); 2128 int viewMax = getViewMax(view); 2129 // we either align "firstView" to left/top padding edge 2130 // or align "lastView" to right/bottom padding edge 2131 View firstView = null; 2132 View lastView = null; 2133 int paddingLow = mWindowAlignment.mainAxis().getPaddingLow(); 2134 int clientSize = mWindowAlignment.mainAxis().getClientSize(); 2135 final int row = mGrid.getLocation(pos).row; 2136 if (viewMin < paddingLow) { 2137 // view enters low padding area: 2138 firstView = view; 2139 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_PAGE) { 2140 // scroll one "page" left/top, 2141 // align first visible item of the "page" at the low padding edge. 2142 while (!prependOneVisibleItem()) { 2143 List<Integer> positions = 2144 mGrid.getItemPositionsInRows(mFirstVisiblePos, pos)[row]; 2145 firstView = findViewByPosition(positions.get(0)); 2146 if (viewMax - getViewMin(firstView) > clientSize) { 2147 if (positions.size() > 1) { 2148 firstView = findViewByPosition(positions.get(1)); 2149 } 2150 break; 2151 } 2152 } 2153 } 2154 } else if (viewMax > clientSize + paddingLow) { 2155 // view enters high padding area: 2156 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_PAGE) { 2157 // scroll whole one page right/bottom, align view at the low padding edge. 2158 firstView = view; 2159 do { 2160 List<Integer> positions = 2161 mGrid.getItemPositionsInRows(pos, mLastVisiblePos)[row]; 2162 lastView = findViewByPosition(positions.get(positions.size() - 1)); 2163 if (getViewMax(lastView) - viewMin > clientSize) { 2164 lastView = null; 2165 break; 2166 } 2167 } while (!appendOneVisibleItem()); 2168 if (lastView != null) { 2169 // however if we reached end, we should align last view. 2170 firstView = null; 2171 } 2172 } else { 2173 lastView = view; 2174 } 2175 } 2176 int scrollPrimary = 0; 2177 int scrollSecondary = 0; 2178 if (firstView != null) { 2179 scrollPrimary = getViewMin(firstView) - paddingLow; 2180 } else if (lastView != null) { 2181 scrollPrimary = getViewMax(lastView) - (paddingLow + clientSize); 2182 } 2183 View secondaryAlignedView; 2184 if (firstView != null) { 2185 secondaryAlignedView = firstView; 2186 } else if (lastView != null) { 2187 secondaryAlignedView = lastView; 2188 } else { 2189 secondaryAlignedView = view; 2190 } 2191 scrollSecondary = getSecondarySystemScrollPosition(secondaryAlignedView); 2192 scrollSecondary -= mScrollOffsetSecondary; 2193 if (scrollPrimary != 0 || scrollSecondary != 0) { 2194 deltas[0] = scrollPrimary; 2195 deltas[1] = scrollSecondary; 2196 return true; 2197 } 2198 return false; 2199 } 2200 2201 private boolean getAlignedPosition(View view, int[] deltas) { 2202 int scrollPrimary = getPrimarySystemScrollPosition(view); 2203 int scrollSecondary = getSecondarySystemScrollPosition(view); 2204 if (DEBUG) { 2205 Log.v(getTag(), "getAlignedPosition " + scrollPrimary + " " + scrollSecondary 2206 +" " + mWindowAlignment); 2207 } 2208 scrollPrimary -= mScrollOffsetPrimary; 2209 scrollSecondary -= mScrollOffsetSecondary; 2210 if (scrollPrimary != 0 || scrollSecondary != 0) { 2211 deltas[0] = scrollPrimary; 2212 deltas[1] = scrollSecondary; 2213 return true; 2214 } 2215 return false; 2216 } 2217 2218 private void scrollGrid(int scrollPrimary, int scrollSecondary, boolean smooth) { 2219 if (mInLayout) { 2220 scrollDirectionPrimary(scrollPrimary); 2221 scrollDirectionSecondary(scrollSecondary); 2222 } else { 2223 int scrollX; 2224 int scrollY; 2225 if (mOrientation == HORIZONTAL) { 2226 scrollX = scrollPrimary; 2227 scrollY = scrollSecondary; 2228 } else { 2229 scrollX = scrollSecondary; 2230 scrollY = scrollPrimary; 2231 } 2232 if (smooth) { 2233 mBaseGridView.smoothScrollBy(scrollX, scrollY); 2234 } else { 2235 mBaseGridView.scrollBy(scrollX, scrollY); 2236 } 2237 } 2238 } 2239 2240 public void setPruneChild(boolean pruneChild) { 2241 if (mPruneChild != pruneChild) { 2242 mPruneChild = pruneChild; 2243 if (mPruneChild) { 2244 requestLayout(); 2245 } 2246 } 2247 } 2248 2249 public boolean getPruneChild() { 2250 return mPruneChild; 2251 } 2252 2253 public void setScrollEnabled(boolean scrollEnabled) { 2254 if (mScrollEnabled != scrollEnabled) { 2255 mScrollEnabled = scrollEnabled; 2256 if (mScrollEnabled && mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED) { 2257 scrollToSelection(mBaseGridView, mFocusPosition, true); 2258 } 2259 } 2260 } 2261 2262 public boolean isScrollEnabled() { 2263 return mScrollEnabled; 2264 } 2265 2266 private int findImmediateChildIndex(View view) { 2267 while (view != null && view != mBaseGridView) { 2268 int index = mBaseGridView.indexOfChild(view); 2269 if (index >= 0) { 2270 return index; 2271 } 2272 view = (View) view.getParent(); 2273 } 2274 return NO_POSITION; 2275 } 2276 2277 void setFocusSearchDisabled(boolean disabled) { 2278 mFocusSearchDisabled = disabled; 2279 } 2280 2281 boolean isFocusSearchDisabled() { 2282 return mFocusSearchDisabled; 2283 } 2284 2285 @Override 2286 public View onInterceptFocusSearch(View focused, int direction) { 2287 if (mFocusSearchDisabled) { 2288 return focused; 2289 } 2290 return null; 2291 } 2292 2293 boolean hasPreviousViewInSameRow(int pos) { 2294 if (mGrid == null || pos == NO_POSITION) { 2295 return false; 2296 } 2297 if (mFirstVisiblePos > 0) { 2298 return true; 2299 } 2300 final int focusedRow = mGrid.getLocation(pos).row; 2301 for (int i = getChildCount() - 1; i >= 0; i--) { 2302 int position = getPositionByIndex(i); 2303 StaggeredGrid.Location loc = mGrid.getLocation(position); 2304 if (loc != null && loc.row == focusedRow) { 2305 if (position < pos) { 2306 return true; 2307 } 2308 } 2309 } 2310 return false; 2311 } 2312 2313 @Override 2314 public boolean onAddFocusables(RecyclerView recyclerView, 2315 ArrayList<View> views, int direction, int focusableMode) { 2316 if (mFocusSearchDisabled) { 2317 return true; 2318 } 2319 // If this viewgroup or one of its children currently has focus then we 2320 // consider our children for focus searching in main direction on the same row. 2321 // If this viewgroup has no focus and using focus align, we want the system 2322 // to ignore our children and pass focus to the viewgroup, which will pass 2323 // focus on to its children appropriately. 2324 // If this viewgroup has no focus and not using focus align, we want to 2325 // consider the child that does not overlap with padding area. 2326 if (recyclerView.hasFocus()) { 2327 final int movement = getMovement(direction); 2328 if (movement != PREV_ITEM && movement != NEXT_ITEM) { 2329 // Move on secondary direction uses default addFocusables(). 2330 return false; 2331 } 2332 final View focused = recyclerView.findFocus(); 2333 final int focusedPos = getPositionByIndex(findImmediateChildIndex(focused)); 2334 // Add focusables of focused item. 2335 if (focusedPos != NO_POSITION) { 2336 findViewByPosition(focusedPos).addFocusables(views, direction, focusableMode); 2337 } 2338 final int focusedRow = mGrid != null && focusedPos != NO_POSITION ? 2339 mGrid.getLocation(focusedPos).row : NO_POSITION; 2340 // Add focusables of next neighbor of same row on the focus search direction. 2341 if (mGrid != null) { 2342 final int focusableCount = views.size(); 2343 for (int i = 0, count = getChildCount(); i < count; i++) { 2344 int index = movement == NEXT_ITEM ? i : count - 1 - i; 2345 final View child = getChildAt(index); 2346 if (child.getVisibility() != View.VISIBLE) { 2347 continue; 2348 } 2349 int position = getPositionByIndex(index); 2350 StaggeredGrid.Location loc = mGrid.getLocation(position); 2351 if (focusedRow == NO_POSITION || (loc != null && loc.row == focusedRow)) { 2352 if (focusedPos == NO_POSITION || 2353 (movement == NEXT_ITEM && position > focusedPos) 2354 || (movement == PREV_ITEM && position < focusedPos)) { 2355 child.addFocusables(views, direction, focusableMode); 2356 if (views.size() > focusableCount) { 2357 break; 2358 } 2359 } 2360 } 2361 } 2362 } 2363 } else { 2364 if (mFocusScrollStrategy != BaseGridView.FOCUS_SCROLL_ALIGNED) { 2365 // adding views not overlapping padding area to avoid scrolling in gaining focus 2366 int left = mWindowAlignment.mainAxis().getPaddingLow(); 2367 int right = mWindowAlignment.mainAxis().getClientSize() + left; 2368 int focusableCount = views.size(); 2369 for (int i = 0, count = getChildCount(); i < count; i++) { 2370 View child = getChildAt(i); 2371 if (child.getVisibility() == View.VISIBLE) { 2372 if (getViewMin(child) >= left && getViewMax(child) <= right) { 2373 child.addFocusables(views, direction, focusableMode); 2374 } 2375 } 2376 } 2377 // if we cannot find any, then just add all children. 2378 if (views.size() == focusableCount) { 2379 for (int i = 0, count = getChildCount(); i < count; i++) { 2380 View child = getChildAt(i); 2381 if (child.getVisibility() == View.VISIBLE) { 2382 child.addFocusables(views, direction, focusableMode); 2383 } 2384 } 2385 if (views.size() != focusableCount) { 2386 return true; 2387 } 2388 } else { 2389 return true; 2390 } 2391 // if still cannot find any, fall through and add itself 2392 } 2393 if (recyclerView.isFocusable()) { 2394 views.add(recyclerView); 2395 } 2396 } 2397 return true; 2398 } 2399 2400 @Override 2401 public View onFocusSearchFailed(View focused, int direction, Recycler recycler, 2402 RecyclerView.State state) { 2403 if (DEBUG) Log.v(getTag(), "onFocusSearchFailed direction " + direction); 2404 2405 View view = null; 2406 int movement = getMovement(direction); 2407 final boolean isScroll = mBaseGridView.getScrollState() != RecyclerView.SCROLL_STATE_IDLE; 2408 if (mNumRows == 1) { 2409 // for simple row, use LinearSmoothScroller to smooth animation. 2410 // It will stay at a fixed cap speed in continuous scroll. 2411 if (movement == NEXT_ITEM) { 2412 int newPos = mFocusPosition + mNumRows; 2413 if (newPos < getItemCount() && mScrollEnabled) { 2414 setSelectionSmooth(mBaseGridView, newPos); 2415 view = focused; 2416 } else { 2417 if (isScroll || !mFocusOutEnd) { 2418 view = focused; 2419 } 2420 } 2421 } else if (movement == PREV_ITEM){ 2422 int newPos = mFocusPosition - mNumRows; 2423 if (newPos >= 0 && mScrollEnabled) { 2424 setSelectionSmooth(mBaseGridView, newPos); 2425 view = focused; 2426 } else { 2427 if (isScroll || !mFocusOutFront) { 2428 view = focused; 2429 } 2430 } 2431 } 2432 } else if (mNumRows > 1) { 2433 // for possible staggered grid, we need guarantee focus to same row/column. 2434 // TODO: we may also use LinearSmoothScroller. 2435 saveContext(recycler, state); 2436 final FocusFinder ff = FocusFinder.getInstance(); 2437 if (movement == NEXT_ITEM) { 2438 while (view == null && !appendOneVisibleItem()) { 2439 view = ff.findNextFocus(mBaseGridView, focused, direction); 2440 } 2441 } else if (movement == PREV_ITEM){ 2442 while (view == null && !prependOneVisibleItem()) { 2443 view = ff.findNextFocus(mBaseGridView, focused, direction); 2444 } 2445 } 2446 if (view == null) { 2447 // returning the same view to prevent focus lost when scrolling past the end of the list 2448 if (movement == PREV_ITEM) { 2449 view = mFocusOutFront && !isScroll ? null : focused; 2450 } else if (movement == NEXT_ITEM){ 2451 view = mFocusOutEnd && !isScroll ? null : focused; 2452 } 2453 } 2454 leaveContext(); 2455 } 2456 if (DEBUG) Log.v(getTag(), "returning view " + view); 2457 return view; 2458 } 2459 2460 boolean gridOnRequestFocusInDescendants(RecyclerView recyclerView, int direction, 2461 Rect previouslyFocusedRect) { 2462 switch (mFocusScrollStrategy) { 2463 case BaseGridView.FOCUS_SCROLL_ALIGNED: 2464 default: 2465 return gridOnRequestFocusInDescendantsAligned(recyclerView, 2466 direction, previouslyFocusedRect); 2467 case BaseGridView.FOCUS_SCROLL_PAGE: 2468 case BaseGridView.FOCUS_SCROLL_ITEM: 2469 return gridOnRequestFocusInDescendantsUnaligned(recyclerView, 2470 direction, previouslyFocusedRect); 2471 } 2472 } 2473 2474 private boolean gridOnRequestFocusInDescendantsAligned(RecyclerView recyclerView, 2475 int direction, Rect previouslyFocusedRect) { 2476 View view = findViewByPosition(mFocusPosition); 2477 if (view != null) { 2478 boolean result = view.requestFocus(direction, previouslyFocusedRect); 2479 if (!result && DEBUG) { 2480 Log.w(getTag(), "failed to request focus on " + view); 2481 } 2482 return result; 2483 } 2484 return false; 2485 } 2486 2487 private boolean gridOnRequestFocusInDescendantsUnaligned(RecyclerView recyclerView, 2488 int direction, Rect previouslyFocusedRect) { 2489 // focus to view not overlapping padding area to avoid scrolling in gaining focus 2490 int index; 2491 int increment; 2492 int end; 2493 int count = getChildCount(); 2494 if ((direction & View.FOCUS_FORWARD) != 0) { 2495 index = 0; 2496 increment = 1; 2497 end = count; 2498 } else { 2499 index = count - 1; 2500 increment = -1; 2501 end = -1; 2502 } 2503 int left = mWindowAlignment.mainAxis().getPaddingLow(); 2504 int right = mWindowAlignment.mainAxis().getClientSize() + left; 2505 for (int i = index; i != end; i += increment) { 2506 View child = getChildAt(i); 2507 if (child.getVisibility() == View.VISIBLE) { 2508 if (getViewMin(child) >= left && getViewMax(child) <= right) { 2509 if (child.requestFocus(direction, previouslyFocusedRect)) { 2510 return true; 2511 } 2512 } 2513 } 2514 } 2515 return false; 2516 } 2517 2518 private final static int PREV_ITEM = 0; 2519 private final static int NEXT_ITEM = 1; 2520 private final static int PREV_ROW = 2; 2521 private final static int NEXT_ROW = 3; 2522 2523 private int getMovement(int direction) { 2524 int movement = View.FOCUS_LEFT; 2525 2526 if (mOrientation == HORIZONTAL) { 2527 switch(direction) { 2528 case View.FOCUS_LEFT: 2529 movement = PREV_ITEM; 2530 break; 2531 case View.FOCUS_RIGHT: 2532 movement = NEXT_ITEM; 2533 break; 2534 case View.FOCUS_UP: 2535 movement = PREV_ROW; 2536 break; 2537 case View.FOCUS_DOWN: 2538 movement = NEXT_ROW; 2539 break; 2540 } 2541 } else if (mOrientation == VERTICAL) { 2542 switch(direction) { 2543 case View.FOCUS_LEFT: 2544 movement = PREV_ROW; 2545 break; 2546 case View.FOCUS_RIGHT: 2547 movement = NEXT_ROW; 2548 break; 2549 case View.FOCUS_UP: 2550 movement = PREV_ITEM; 2551 break; 2552 case View.FOCUS_DOWN: 2553 movement = NEXT_ITEM; 2554 break; 2555 } 2556 } 2557 2558 return movement; 2559 } 2560 2561 int getChildDrawingOrder(RecyclerView recyclerView, int childCount, int i) { 2562 View view = findViewByPosition(mFocusPosition); 2563 if (view == null) { 2564 return i; 2565 } 2566 int focusIndex = recyclerView.indexOfChild(view); 2567 // supposely 0 1 2 3 4 5 6 7 8 9, 4 is the center item 2568 // drawing order is 0 1 2 3 9 8 7 6 5 4 2569 if (i < focusIndex) { 2570 return i; 2571 } else if (i < childCount - 1) { 2572 return focusIndex + childCount - 1 - i; 2573 } else { 2574 return focusIndex; 2575 } 2576 } 2577 2578 @Override 2579 public void onAdapterChanged(RecyclerView.Adapter oldAdapter, 2580 RecyclerView.Adapter newAdapter) { 2581 if (DEBUG) Log.v(getTag(), "onAdapterChanged to " + newAdapter); 2582 if (oldAdapter != null) { 2583 discardLayoutInfo(); 2584 mFocusPosition = NO_POSITION; 2585 mFocusPositionOffset = 0; 2586 mChildrenStates.clear(); 2587 } 2588 super.onAdapterChanged(oldAdapter, newAdapter); 2589 } 2590 2591 private void discardLayoutInfo() { 2592 mGrid = null; 2593 mRows = null; 2594 mRowSizeSecondary = null; 2595 mFirstVisiblePos = -1; 2596 mLastVisiblePos = -1; 2597 mRowSecondarySizeRefresh = false; 2598 } 2599 2600 public void setLayoutEnabled(boolean layoutEnabled) { 2601 if (mLayoutEnabled != layoutEnabled) { 2602 mLayoutEnabled = layoutEnabled; 2603 requestLayout(); 2604 } 2605 } 2606 2607 void setChildrenVisibility(int visiblity) { 2608 mChildVisibility = visiblity; 2609 if (mChildVisibility != -1) { 2610 int count = getChildCount(); 2611 for (int i= 0; i < count; i++) { 2612 getChildAt(i).setVisibility(mChildVisibility); 2613 } 2614 } 2615 } 2616 2617 final static class SavedState implements Parcelable { 2618 2619 int index; // index inside adapter of the current view 2620 Bundle childStates = Bundle.EMPTY; 2621 2622 @Override 2623 public void writeToParcel(Parcel out, int flags) { 2624 out.writeInt(index); 2625 out.writeBundle(childStates); 2626 } 2627 2628 @SuppressWarnings("hiding") 2629 public static final Parcelable.Creator<SavedState> CREATOR = 2630 new Parcelable.Creator<SavedState>() { 2631 @Override 2632 public SavedState createFromParcel(Parcel in) { 2633 return new SavedState(in); 2634 } 2635 2636 @Override 2637 public SavedState[] newArray(int size) { 2638 return new SavedState[size]; 2639 } 2640 }; 2641 2642 @Override 2643 public int describeContents() { 2644 return 0; 2645 } 2646 2647 SavedState(Parcel in) { 2648 index = in.readInt(); 2649 childStates = in.readBundle(GridLayoutManager.class.getClassLoader()); 2650 } 2651 2652 SavedState() { 2653 } 2654 } 2655 2656 @Override 2657 public Parcelable onSaveInstanceState() { 2658 if (DEBUG) Log.v(getTag(), "onSaveInstanceState getSelection() " + getSelection()); 2659 SavedState ss = new SavedState(); 2660 for (int i = 0, count = getChildCount(); i < count; i++) { 2661 View view = getChildAt(i); 2662 int position = getPositionByView(view); 2663 if (position != NO_POSITION) { 2664 mChildrenStates.saveOnScreenView(view, position); 2665 } 2666 } 2667 ss.index = getSelection(); 2668 ss.childStates = mChildrenStates.saveAsBundle(); 2669 return ss; 2670 } 2671 2672 @Override 2673 public void onRestoreInstanceState(Parcelable state) { 2674 if (!(state instanceof SavedState)) { 2675 return; 2676 } 2677 SavedState loadingState = (SavedState)state; 2678 mFocusPosition = loadingState.index; 2679 mFocusPositionOffset = 0; 2680 mChildrenStates.loadFromBundle(loadingState.childStates); 2681 mForceFullLayout = true; 2682 requestLayout(); 2683 if (DEBUG) Log.v(getTag(), "onRestoreInstanceState mFocusPosition " + mFocusPosition); 2684 } 2685} 2686