GridLayoutManager.java revision 2986af93ba272bdc69d414bdcf5fcf0901c8ee97
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 /** 347 * Percent of overreach. 348 */ 349 private float mPrimaryOverReach = 1f; 350 351 private int[] mTempDeltas = new int[2]; 352 353 /** 354 * Temporaries used for measuring. 355 */ 356 private int[] mMeasuredDimension = new int[2]; 357 358 final ViewsStateBundle mChildrenStates = new ViewsStateBundle(); 359 360 public GridLayoutManager(BaseGridView baseGridView) { 361 mBaseGridView = baseGridView; 362 } 363 364 public void setOrientation(int orientation) { 365 if (orientation != HORIZONTAL && orientation != VERTICAL) { 366 if (DEBUG) Log.v(getTag(), "invalid orientation: " + orientation); 367 return; 368 } 369 370 mOrientation = orientation; 371 mWindowAlignment.setOrientation(orientation); 372 mItemAlignment.setOrientation(orientation); 373 mForceFullLayout = true; 374 } 375 376 public int getFocusScrollStrategy() { 377 return mFocusScrollStrategy; 378 } 379 380 public void setFocusScrollStrategy(int focusScrollStrategy) { 381 mFocusScrollStrategy = focusScrollStrategy; 382 } 383 384 public void setWindowAlignment(int windowAlignment) { 385 mWindowAlignment.mainAxis().setWindowAlignment(windowAlignment); 386 } 387 388 public int getWindowAlignment() { 389 return mWindowAlignment.mainAxis().getWindowAlignment(); 390 } 391 392 public void setWindowAlignmentOffset(int alignmentOffset) { 393 mWindowAlignment.mainAxis().setWindowAlignmentOffset(alignmentOffset); 394 } 395 396 public int getWindowAlignmentOffset() { 397 return mWindowAlignment.mainAxis().getWindowAlignmentOffset(); 398 } 399 400 public void setWindowAlignmentOffsetPercent(float offsetPercent) { 401 mWindowAlignment.mainAxis().setWindowAlignmentOffsetPercent(offsetPercent); 402 } 403 404 public float getWindowAlignmentOffsetPercent() { 405 return mWindowAlignment.mainAxis().getWindowAlignmentOffsetPercent(); 406 } 407 408 public void setItemAlignmentOffset(int alignmentOffset) { 409 mItemAlignment.mainAxis().setItemAlignmentOffset(alignmentOffset); 410 updateChildAlignments(); 411 } 412 413 public int getItemAlignmentOffset() { 414 return mItemAlignment.mainAxis().getItemAlignmentOffset(); 415 } 416 417 public void setItemAlignmentOffsetWithPadding(boolean withPadding) { 418 mItemAlignment.mainAxis().setItemAlignmentOffsetWithPadding(withPadding); 419 updateChildAlignments(); 420 } 421 422 public boolean isItemAlignmentOffsetWithPadding() { 423 return mItemAlignment.mainAxis().isItemAlignmentOffsetWithPadding(); 424 } 425 426 public void setItemAlignmentOffsetPercent(float offsetPercent) { 427 mItemAlignment.mainAxis().setItemAlignmentOffsetPercent(offsetPercent); 428 updateChildAlignments(); 429 } 430 431 public float getItemAlignmentOffsetPercent() { 432 return mItemAlignment.mainAxis().getItemAlignmentOffsetPercent(); 433 } 434 435 public void setItemAlignmentViewId(int viewId) { 436 mItemAlignment.mainAxis().setItemAlignmentViewId(viewId); 437 updateChildAlignments(); 438 } 439 440 public int getItemAlignmentViewId() { 441 return mItemAlignment.mainAxis().getItemAlignmentViewId(); 442 } 443 444 public void setFocusOutAllowed(boolean throughFront, boolean throughEnd) { 445 mFocusOutFront = throughFront; 446 mFocusOutEnd = throughEnd; 447 } 448 449 public void setNumRows(int numRows) { 450 if (numRows < 0) throw new IllegalArgumentException(); 451 mNumRowsRequested = numRows; 452 mForceFullLayout = true; 453 } 454 455 /** 456 * Set the row height. May be WRAP_CONTENT, or a size in pixels. 457 */ 458 public void setRowHeight(int height) { 459 if (height >= 0 || height == ViewGroup.LayoutParams.WRAP_CONTENT) { 460 mRowSizeSecondaryRequested = height; 461 } else { 462 throw new IllegalArgumentException("Invalid row height: " + height); 463 } 464 } 465 466 public void setItemMargin(int margin) { 467 mVerticalMargin = mHorizontalMargin = margin; 468 mMarginPrimary = mMarginSecondary = margin; 469 } 470 471 public void setVerticalMargin(int margin) { 472 if (mOrientation == HORIZONTAL) { 473 mMarginSecondary = mVerticalMargin = margin; 474 } else { 475 mMarginPrimary = mVerticalMargin = margin; 476 } 477 } 478 479 public void setHorizontalMargin(int margin) { 480 if (mOrientation == HORIZONTAL) { 481 mMarginPrimary = mHorizontalMargin = margin; 482 } else { 483 mMarginSecondary = mHorizontalMargin = margin; 484 } 485 } 486 487 public int getVerticalMargin() { 488 return mVerticalMargin; 489 } 490 491 public int getHorizontalMargin() { 492 return mHorizontalMargin; 493 } 494 495 public void setGravity(int gravity) { 496 mGravity = gravity; 497 } 498 499 protected boolean hasDoneFirstLayout() { 500 return mGrid != null; 501 } 502 503 public void setOnChildSelectedListener(OnChildSelectedListener listener) { 504 mChildSelectedListener = listener; 505 } 506 507 public void setPrimaryOverReach(float fraction) { 508 if (fraction != mPrimaryOverReach) { 509 if (DEBUG) Log.v(getTag(), "setPrimaryOverReach " + fraction); 510 mPrimaryOverReach = fraction; 511 requestLayout(); 512 } 513 } 514 515 private int getPositionByView(View view) { 516 if (view == null) { 517 return NO_POSITION; 518 } 519 LayoutParams params = (LayoutParams) view.getLayoutParams(); 520 if (params == null || params.isItemRemoved()) { 521 // when item is removed, the position value can be any value. 522 return NO_POSITION; 523 } 524 return params.getViewPosition(); 525 } 526 527 private int getPositionByIndex(int index) { 528 return getPositionByView(getChildAt(index)); 529 } 530 531 private void dispatchChildSelected() { 532 if (mChildSelectedListener == null) { 533 return; 534 } 535 if (mFocusPosition != NO_POSITION) { 536 View view = findViewByPosition(mFocusPosition); 537 if (view != null) { 538 RecyclerView.ViewHolder vh = mBaseGridView.getChildViewHolder(view); 539 mChildSelectedListener.onChildSelected(mBaseGridView, view, mFocusPosition, 540 vh == null? NO_ID: vh.getItemId()); 541 return; 542 } 543 } 544 mChildSelectedListener.onChildSelected(mBaseGridView, null, NO_POSITION, NO_ID); 545 } 546 547 @Override 548 public boolean canScrollHorizontally() { 549 // We can scroll horizontally if we have horizontal orientation, or if 550 // we are vertical and have more than one column. 551 return mOrientation == HORIZONTAL || mNumRows > 1; 552 } 553 554 @Override 555 public boolean canScrollVertically() { 556 // We can scroll vertically if we have vertical orientation, or if we 557 // are horizontal and have more than one row. 558 return mOrientation == VERTICAL || mNumRows > 1; 559 } 560 561 @Override 562 public RecyclerView.LayoutParams generateDefaultLayoutParams() { 563 return new LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, 564 ViewGroup.LayoutParams.WRAP_CONTENT); 565 } 566 567 @Override 568 public RecyclerView.LayoutParams generateLayoutParams(Context context, AttributeSet attrs) { 569 return new LayoutParams(context, attrs); 570 } 571 572 @Override 573 public RecyclerView.LayoutParams generateLayoutParams(ViewGroup.LayoutParams lp) { 574 if (lp instanceof LayoutParams) { 575 return new LayoutParams((LayoutParams) lp); 576 } else if (lp instanceof RecyclerView.LayoutParams) { 577 return new LayoutParams((RecyclerView.LayoutParams) lp); 578 } else if (lp instanceof MarginLayoutParams) { 579 return new LayoutParams((MarginLayoutParams) lp); 580 } else { 581 return new LayoutParams(lp); 582 } 583 } 584 585 protected View getViewForPosition(int position) { 586 return mRecycler.getViewForPosition(position); 587 } 588 589 final int getOpticalLeft(View v) { 590 return ((LayoutParams) v.getLayoutParams()).getOpticalLeft(v); 591 } 592 593 final int getOpticalRight(View v) { 594 return ((LayoutParams) v.getLayoutParams()).getOpticalRight(v); 595 } 596 597 final int getOpticalTop(View v) { 598 return ((LayoutParams) v.getLayoutParams()).getOpticalTop(v); 599 } 600 601 final int getOpticalBottom(View v) { 602 return ((LayoutParams) v.getLayoutParams()).getOpticalBottom(v); 603 } 604 605 private int getViewMin(View v) { 606 return (mOrientation == HORIZONTAL) ? getOpticalLeft(v) : getOpticalTop(v); 607 } 608 609 private int getViewMax(View v) { 610 return (mOrientation == HORIZONTAL) ? getOpticalRight(v) : getOpticalBottom(v); 611 } 612 613 private int getViewCenter(View view) { 614 return (mOrientation == HORIZONTAL) ? getViewCenterX(view) : getViewCenterY(view); 615 } 616 617 private int getViewCenterSecondary(View view) { 618 return (mOrientation == HORIZONTAL) ? getViewCenterY(view) : getViewCenterX(view); 619 } 620 621 private int getViewCenterX(View v) { 622 LayoutParams p = (LayoutParams) v.getLayoutParams(); 623 return p.getOpticalLeft(v) + p.getAlignX(); 624 } 625 626 private int getViewCenterY(View v) { 627 LayoutParams p = (LayoutParams) v.getLayoutParams(); 628 return p.getOpticalTop(v) + p.getAlignY(); 629 } 630 631 /** 632 * Save Recycler and State for convenience. Must be paired with leaveContext(). 633 */ 634 private void saveContext(Recycler recycler, State state) { 635 if (mRecycler != null || mState != null) { 636 Log.e(TAG, "Recycler information was not released, bug!"); 637 } 638 mRecycler = recycler; 639 mState = state; 640 } 641 642 /** 643 * Discard saved Recycler and State. 644 */ 645 private void leaveContext() { 646 mRecycler = null; 647 mState = null; 648 } 649 650 /** 651 * Re-initialize data structures for a data change or handling invisible 652 * selection. The method tries its best to preserve position information so 653 * that staggered grid looks same before and after re-initialize. 654 * @param focusPosition The initial focusPosition that we would like to 655 * focus on. 656 * @return Actual position that can be focused on. 657 */ 658 private int init(int focusPosition) { 659 660 final int newItemCount = mState.getItemCount(); 661 662 if (focusPosition == NO_POSITION && newItemCount > 0) { 663 // if focus position is never set before, initialize it to 0 664 focusPosition = 0; 665 } 666 // If adapter has changed then caches are invalid; otherwise, 667 // we try to maintain each row's position if number of rows keeps the same 668 // and existing mGrid contains the focusPosition. 669 if (mRows != null && mNumRows == mRows.length && 670 mGrid != null && mGrid.getSize() > 0 && focusPosition >= 0 && 671 focusPosition >= mGrid.getFirstIndex() && 672 focusPosition <= mGrid.getLastIndex()) { 673 // strip mGrid to a subset (like a column) that contains focusPosition 674 mGrid.stripDownTo(focusPosition); 675 // make sure that remaining items do not exceed new adapter size 676 int firstIndex = mGrid.getFirstIndex(); 677 int lastIndex = mGrid.getLastIndex(); 678 if (DEBUG) { 679 Log .v(getTag(), "mGrid firstIndex " + firstIndex + " lastIndex " + lastIndex); 680 } 681 for (int i = lastIndex; i >=firstIndex; i--) { 682 if (i >= newItemCount) { 683 mGrid.removeLast(); 684 } 685 } 686 if (mGrid.getSize() == 0) { 687 focusPosition = newItemCount - 1; 688 // initialize row start locations 689 for (int i = 0; i < mNumRows; i++) { 690 mRows[i].low = 0; 691 mRows[i].high = 0; 692 } 693 if (DEBUG) Log.v(getTag(), "mGrid zero size"); 694 } else { 695 // initialize row start locations 696 for (int i = 0; i < mNumRows; i++) { 697 mRows[i].low = Integer.MAX_VALUE; 698 mRows[i].high = Integer.MIN_VALUE; 699 } 700 firstIndex = mGrid.getFirstIndex(); 701 lastIndex = mGrid.getLastIndex(); 702 if (focusPosition > lastIndex) { 703 focusPosition = mGrid.getLastIndex(); 704 } 705 if (DEBUG) { 706 Log.v(getTag(), "mGrid firstIndex " + firstIndex + " lastIndex " 707 + lastIndex + " focusPosition " + focusPosition); 708 } 709 // fill rows with minimal view positions of the subset 710 for (int i = firstIndex; i <= lastIndex; i++) { 711 View v = findViewByPosition(i); 712 if (v == null) { 713 continue; 714 } 715 int row = mGrid.getLocation(i).row; 716 int low = getViewMin(v) + mScrollOffsetPrimary; 717 if (low < mRows[row].low) { 718 mRows[row].low = mRows[row].high = low; 719 } 720 } 721 int firstItemRowPosition = mRows[mGrid.getLocation(firstIndex).row].low; 722 if (firstItemRowPosition == Integer.MAX_VALUE) { 723 firstItemRowPosition = 0; 724 } 725 if (mState.didStructureChange()) { 726 // if there is structure change, the removed item might be in the 727 // subset, so it is meaningless to maintain the low locations. 728 for (int i = 0; i < mNumRows; i++) { 729 mRows[i].low = firstItemRowPosition; 730 mRows[i].high = firstItemRowPosition; 731 } 732 } else { 733 // fill other rows that does not include the subset using first item 734 for (int i = 0; i < mNumRows; i++) { 735 if (mRows[i].low == Integer.MAX_VALUE) { 736 mRows[i].low = mRows[i].high = firstItemRowPosition; 737 } 738 } 739 } 740 } 741 742 // Same adapter, we can reuse any attached views 743 detachAndScrapAttachedViews(mRecycler); 744 745 } else { 746 // otherwise recreate data structure 747 mRows = new StaggeredGrid.Row[mNumRows]; 748 749 for (int i = 0; i < mNumRows; i++) { 750 mRows[i] = new StaggeredGrid.Row(); 751 } 752 mGrid = new StaggeredGridDefault(); 753 if (newItemCount == 0) { 754 focusPosition = NO_POSITION; 755 } else if (focusPosition >= newItemCount) { 756 focusPosition = newItemCount - 1; 757 } 758 759 // Adapter may have changed so remove all attached views permanently 760 removeAndRecycleAllViews(mRecycler); 761 762 mScrollOffsetPrimary = 0; 763 mScrollOffsetSecondary = 0; 764 mWindowAlignment.reset(); 765 } 766 767 mGrid.setProvider(mGridProvider); 768 // mGrid share the same Row array information 769 mGrid.setRows(mRows); 770 mFirstVisiblePos = mLastVisiblePos = NO_POSITION; 771 772 initScrollController(); 773 updateScrollSecondAxis(); 774 775 return focusPosition; 776 } 777 778 private int getRowSizeSecondary(int rowIndex) { 779 if (mFixedRowSizeSecondary != 0) { 780 return mFixedRowSizeSecondary; 781 } 782 if (mRowSizeSecondary == null) { 783 return 0; 784 } 785 return mRowSizeSecondary[rowIndex]; 786 } 787 788 private int getRowStartSecondary(int rowIndex) { 789 int start = 0; 790 for (int i = 0; i < rowIndex; i++) { 791 start += getRowSizeSecondary(i) + mMarginSecondary; 792 } 793 return start; 794 } 795 796 private int getSizeSecondary() { 797 return getRowStartSecondary(mNumRows - 1) + getRowSizeSecondary(mNumRows - 1); 798 } 799 800 private void measureScrapChild(int position, int widthSpec, int heightSpec, 801 int[] measuredDimension) { 802 View view = mRecycler.getViewForPosition(position); 803 if (view != null) { 804 LayoutParams p = (LayoutParams) view.getLayoutParams(); 805 int childWidthSpec = ViewGroup.getChildMeasureSpec(widthSpec, 806 getPaddingLeft() + getPaddingRight(), p.width); 807 int childHeightSpec = ViewGroup.getChildMeasureSpec(heightSpec, 808 getPaddingTop() + getPaddingBottom(), p.height); 809 view.measure(childWidthSpec, childHeightSpec); 810 measuredDimension[0] = view.getMeasuredWidth(); 811 measuredDimension[1] = view.getMeasuredHeight(); 812 mRecycler.recycleView(view); 813 } 814 } 815 816 private boolean processRowSizeSecondary(boolean measure) { 817 if (mFixedRowSizeSecondary != 0) { 818 return false; 819 } 820 821 List<Integer>[] rows = mGrid == null ? null : 822 mGrid.getItemPositionsInRows(mFirstVisiblePos, mLastVisiblePos); 823 boolean changed = false; 824 int scrapChildWidth = -1; 825 int scrapChildHeight = -1; 826 827 for (int rowIndex = 0; rowIndex < mNumRows; rowIndex++) { 828 final int rowItemCount = rows == null ? 0 : rows[rowIndex].size(); 829 if (DEBUG) Log.v(getTag(), "processRowSizeSecondary row " + rowIndex + 830 " rowItemCount " + rowItemCount); 831 832 int rowSize = -1; 833 for (int i = 0; i < rowItemCount; i++) { 834 final View view = findViewByPosition(rows[rowIndex].get(i)); 835 if (view == null) { 836 continue; 837 } 838 if (measure && view.isLayoutRequested()) { 839 measureChild(view); 840 } 841 final int secondarySize = mOrientation == HORIZONTAL ? 842 view.getMeasuredHeight() : view.getMeasuredWidth(); 843 if (secondarySize > rowSize) { 844 rowSize = secondarySize; 845 } 846 } 847 848 final int itemCount = mState.getItemCount(); 849 if (measure && rowSize < 0 && itemCount > 0) { 850 if (scrapChildWidth < 0 && scrapChildHeight < 0) { 851 int position; 852 if (mFocusPosition == NO_POSITION) { 853 position = 0; 854 } else if (mFocusPosition >= itemCount) { 855 position = itemCount - 1; 856 } else { 857 position = mFocusPosition; 858 } 859 measureScrapChild(position, 860 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 861 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 862 mMeasuredDimension); 863 scrapChildWidth = mMeasuredDimension[0]; 864 scrapChildHeight = mMeasuredDimension[1]; 865 if (DEBUG) Log.v(TAG, "measured scrap child: " + scrapChildWidth + 866 " " + scrapChildHeight); 867 } 868 rowSize = mOrientation == HORIZONTAL ? scrapChildHeight : scrapChildWidth; 869 } 870 871 if (rowSize < 0) { 872 rowSize = 0; 873 } 874 875 if (DEBUG) Log.v(getTag(), "row " + rowIndex + " rowItemCount " + rowItemCount + 876 " rowSize " + rowSize); 877 878 if (mRowSizeSecondary[rowIndex] != rowSize) { 879 if (DEBUG) Log.v(getTag(), "row size secondary changed: " + mRowSizeSecondary[rowIndex] + 880 ", " + rowSize); 881 882 mRowSizeSecondary[rowIndex] = rowSize; 883 changed = true; 884 } 885 } 886 887 return changed; 888 } 889 890 /** 891 * Checks if we need to update row secondary sizes. 892 */ 893 private void updateRowSecondarySizeRefresh() { 894 mRowSecondarySizeRefresh = processRowSizeSecondary(false); 895 if (mRowSecondarySizeRefresh) { 896 if (DEBUG) Log.v(getTag(), "mRowSecondarySizeRefresh now set"); 897 forceRequestLayout(); 898 } 899 } 900 901 private void forceRequestLayout() { 902 if (DEBUG) Log.v(getTag(), "forceRequestLayout"); 903 // RecyclerView prevents us from requesting layout in many cases 904 // (during layout, during scroll, etc.) 905 // For secondary row size wrap_content support we currently need a 906 // second layout pass to update the measured size after having measured 907 // and added child views in layoutChildren. 908 // Force the second layout by posting a delayed runnable. 909 // TODO: investigate allowing a second layout pass, 910 // or move child add/measure logic to the measure phase. 911 ViewCompat.postOnAnimation(mBaseGridView, mRequestLayoutRunnable); 912 } 913 914 private final Runnable mRequestLayoutRunnable = new Runnable() { 915 @Override 916 public void run() { 917 if (DEBUG) Log.v(getTag(), "request Layout from runnable"); 918 requestLayout(); 919 } 920 }; 921 922 @Override 923 public void onMeasure(Recycler recycler, State state, int widthSpec, int heightSpec) { 924 saveContext(recycler, state); 925 926 int sizePrimary, sizeSecondary, modeSecondary, paddingSecondary; 927 int measuredSizeSecondary; 928 if (mOrientation == HORIZONTAL) { 929 sizePrimary = MeasureSpec.getSize(widthSpec); 930 sizeSecondary = MeasureSpec.getSize(heightSpec); 931 modeSecondary = MeasureSpec.getMode(heightSpec); 932 paddingSecondary = getPaddingTop() + getPaddingBottom(); 933 } else { 934 sizeSecondary = MeasureSpec.getSize(widthSpec); 935 sizePrimary = MeasureSpec.getSize(heightSpec); 936 modeSecondary = MeasureSpec.getMode(widthSpec); 937 paddingSecondary = getPaddingLeft() + getPaddingRight(); 938 } 939 if (DEBUG) Log.v(getTag(), "onMeasure widthSpec " + Integer.toHexString(widthSpec) + 940 " heightSpec " + Integer.toHexString(heightSpec) + 941 " modeSecondary " + Integer.toHexString(modeSecondary) + 942 " sizeSecondary " + sizeSecondary + " " + this); 943 944 mMaxSizeSecondary = sizeSecondary; 945 946 if (mRowSizeSecondaryRequested == ViewGroup.LayoutParams.WRAP_CONTENT) { 947 mNumRows = mNumRowsRequested == 0 ? 1 : mNumRowsRequested; 948 mFixedRowSizeSecondary = 0; 949 950 if (mRowSizeSecondary == null || mRowSizeSecondary.length != mNumRows) { 951 mRowSizeSecondary = new int[mNumRows]; 952 } 953 954 // Measure all current children and update cached row heights 955 processRowSizeSecondary(true); 956 957 switch (modeSecondary) { 958 case MeasureSpec.UNSPECIFIED: 959 measuredSizeSecondary = getSizeSecondary() + paddingSecondary; 960 break; 961 case MeasureSpec.AT_MOST: 962 measuredSizeSecondary = Math.min(getSizeSecondary() + paddingSecondary, 963 mMaxSizeSecondary); 964 break; 965 case MeasureSpec.EXACTLY: 966 measuredSizeSecondary = mMaxSizeSecondary; 967 break; 968 default: 969 throw new IllegalStateException("wrong spec"); 970 } 971 972 } else { 973 switch (modeSecondary) { 974 case MeasureSpec.UNSPECIFIED: 975 if (mRowSizeSecondaryRequested == 0) { 976 if (mOrientation == HORIZONTAL) { 977 throw new IllegalStateException("Must specify rowHeight or view height"); 978 } else { 979 throw new IllegalStateException("Must specify columnWidth or view width"); 980 } 981 } 982 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 983 mNumRows = mNumRowsRequested == 0 ? 1 : mNumRowsRequested; 984 measuredSizeSecondary = mFixedRowSizeSecondary * mNumRows + mMarginSecondary 985 * (mNumRows - 1) + paddingSecondary; 986 break; 987 case MeasureSpec.AT_MOST: 988 case MeasureSpec.EXACTLY: 989 if (mNumRowsRequested == 0 && mRowSizeSecondaryRequested == 0) { 990 mNumRows = 1; 991 mFixedRowSizeSecondary = sizeSecondary - paddingSecondary; 992 } else if (mNumRowsRequested == 0) { 993 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 994 mNumRows = (sizeSecondary + mMarginSecondary) 995 / (mRowSizeSecondaryRequested + mMarginSecondary); 996 } else if (mRowSizeSecondaryRequested == 0) { 997 mNumRows = mNumRowsRequested; 998 mFixedRowSizeSecondary = (sizeSecondary - paddingSecondary - mMarginSecondary 999 * (mNumRows - 1)) / mNumRows; 1000 } else { 1001 mNumRows = mNumRowsRequested; 1002 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 1003 } 1004 measuredSizeSecondary = sizeSecondary; 1005 if (modeSecondary == MeasureSpec.AT_MOST) { 1006 int childrenSize = mFixedRowSizeSecondary * mNumRows + mMarginSecondary 1007 * (mNumRows - 1) + paddingSecondary; 1008 if (childrenSize < measuredSizeSecondary) { 1009 measuredSizeSecondary = childrenSize; 1010 } 1011 } 1012 break; 1013 default: 1014 throw new IllegalStateException("wrong spec"); 1015 } 1016 } 1017 if (mOrientation == HORIZONTAL) { 1018 setMeasuredDimension(sizePrimary, measuredSizeSecondary); 1019 } else { 1020 setMeasuredDimension(measuredSizeSecondary, sizePrimary); 1021 } 1022 if (DEBUG) { 1023 Log.v(getTag(), "onMeasure sizePrimary " + sizePrimary + 1024 " measuredSizeSecondary " + measuredSizeSecondary + 1025 " mFixedRowSizeSecondary " + mFixedRowSizeSecondary + 1026 " mNumRows " + mNumRows); 1027 } 1028 1029 leaveContext(); 1030 } 1031 1032 private void measureChild(View child) { 1033 final ViewGroup.LayoutParams lp = child.getLayoutParams(); 1034 final int secondarySpec = (mRowSizeSecondaryRequested == ViewGroup.LayoutParams.WRAP_CONTENT) ? 1035 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED) : 1036 MeasureSpec.makeMeasureSpec(mFixedRowSizeSecondary, MeasureSpec.EXACTLY); 1037 int widthSpec, heightSpec; 1038 1039 if (mOrientation == HORIZONTAL) { 1040 widthSpec = ViewGroup.getChildMeasureSpec( 1041 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 1042 0, lp.width); 1043 heightSpec = ViewGroup.getChildMeasureSpec(secondarySpec, 0, lp.height); 1044 } else { 1045 heightSpec = ViewGroup.getChildMeasureSpec( 1046 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 1047 0, lp.height); 1048 widthSpec = ViewGroup.getChildMeasureSpec(secondarySpec, 0, lp.width); 1049 } 1050 1051 child.measure(widthSpec, heightSpec); 1052 1053 if (DEBUG) Log.v(getTag(), "measureChild secondarySpec " + Integer.toHexString(secondarySpec) + 1054 " widthSpec " + Integer.toHexString(widthSpec) + 1055 " heightSpec " + Integer.toHexString(heightSpec) + 1056 " measuredWidth " + child.getMeasuredWidth() + 1057 " measuredHeight " + child.getMeasuredHeight()); 1058 if (DEBUG) Log.v(getTag(), "child lp width " + lp.width + " height " + lp.height); 1059 } 1060 1061 private StaggeredGrid.Provider mGridProvider = new StaggeredGrid.Provider() { 1062 1063 @Override 1064 public int getCount() { 1065 return mState.getItemCount(); 1066 } 1067 1068 @Override 1069 public void createItem(int index, int rowIndex, boolean append) { 1070 View v = getViewForPosition(index); 1071 if (mFirstVisiblePos >= 0) { 1072 // when StaggeredGrid append or prepend item, we must guarantee 1073 // that sibling item has created views already. 1074 if (append && index != mLastVisiblePos + 1) { 1075 throw new RuntimeException(); 1076 } else if (!append && index != mFirstVisiblePos - 1) { 1077 throw new RuntimeException(); 1078 } 1079 } 1080 1081 // See recyclerView docs: we don't need re-add scraped view if it was removed. 1082 if (!((RecyclerView.LayoutParams) v.getLayoutParams()).isItemRemoved()) { 1083 if (append) { 1084 addView(v); 1085 } else { 1086 addView(v, 0); 1087 } 1088 if (mChildVisibility != -1) { 1089 v.setVisibility(mChildVisibility); 1090 } 1091 1092 // View is added first or it won't be found by dispatchChildSelected. 1093 if (mInLayout && index == mFocusPosition) { 1094 dispatchChildSelected(); 1095 } 1096 1097 measureChild(v); 1098 } 1099 1100 int length = mOrientation == HORIZONTAL ? v.getMeasuredWidth() : v.getMeasuredHeight(); 1101 int start, end; 1102 final boolean rowIsEmpty = mRows[rowIndex].high == mRows[rowIndex].low; 1103 if (append) { 1104 if (!rowIsEmpty) { 1105 // if there are existing item in the row, add margin between 1106 start = mRows[rowIndex].high + mMarginPrimary; 1107 } else { 1108 if (mLastVisiblePos >= 0) { 1109 int lastRow = mGrid.getLocation(mLastVisiblePos).row; 1110 // if the last visible item is not last row, align to beginning, 1111 // otherwise start a new column after. 1112 if (lastRow < mNumRows - 1) { 1113 start = mRows[lastRow].low; 1114 } else { 1115 start = mRows[lastRow].high + mMarginPrimary; 1116 } 1117 } else { 1118 start = 0; 1119 } 1120 mRows[rowIndex].low = start; 1121 } 1122 end = start + length; 1123 mRows[rowIndex].high = end; 1124 } else { 1125 if (!rowIsEmpty) { 1126 // if there are existing item in the row, add margin between 1127 end = mRows[rowIndex].low - mMarginPrimary; 1128 start = end - length; 1129 } else { 1130 if (mFirstVisiblePos >= 0) { 1131 int firstRow = mGrid.getLocation(mFirstVisiblePos).row; 1132 // if the first visible item is not first row, align to beginning, 1133 // otherwise start a new column before. 1134 if (firstRow > 0) { 1135 start = mRows[firstRow].low; 1136 end = start + length; 1137 } else { 1138 end = mRows[firstRow].low - mMarginPrimary; 1139 start = end - length; 1140 } 1141 } else { 1142 start = 0; 1143 end = length; 1144 } 1145 mRows[rowIndex].high = end; 1146 } 1147 mRows[rowIndex].low = start; 1148 } 1149 if (mFirstVisiblePos < 0) { 1150 mFirstVisiblePos = mLastVisiblePos = index; 1151 } else { 1152 if (append) { 1153 mLastVisiblePos++; 1154 } else { 1155 mFirstVisiblePos--; 1156 } 1157 } 1158 if (DEBUG) Log.v(getTag(), "start " + start + " end " + end); 1159 int startSecondary = getRowStartSecondary(rowIndex) - mScrollOffsetSecondary; 1160 mChildrenStates.loadView(v, index); 1161 layoutChild(rowIndex, v, start - mScrollOffsetPrimary, end - mScrollOffsetPrimary, 1162 startSecondary); 1163 if (DEBUG) { 1164 Log.d(getTag(), "addView " + index + " " + v); 1165 } 1166 if (index == mFirstVisiblePos) { 1167 updateScrollMin(); 1168 } 1169 if (index == mLastVisiblePos) { 1170 updateScrollMax(); 1171 } 1172 } 1173 }; 1174 1175 private void layoutChild(int rowIndex, View v, int start, int end, int startSecondary) { 1176 int sizeSecondary = mOrientation == HORIZONTAL ? v.getMeasuredHeight() 1177 : v.getMeasuredWidth(); 1178 if (mFixedRowSizeSecondary > 0) { 1179 sizeSecondary = Math.min(sizeSecondary, mFixedRowSizeSecondary); 1180 } 1181 final int verticalGravity = mGravity & Gravity.VERTICAL_GRAVITY_MASK; 1182 final int horizontalGravity = mGravity & Gravity.HORIZONTAL_GRAVITY_MASK; 1183 if (mOrientation == HORIZONTAL && verticalGravity == Gravity.TOP 1184 || mOrientation == VERTICAL && horizontalGravity == Gravity.LEFT) { 1185 // do nothing 1186 } else if (mOrientation == HORIZONTAL && verticalGravity == Gravity.BOTTOM 1187 || mOrientation == VERTICAL && horizontalGravity == Gravity.RIGHT) { 1188 startSecondary += getRowSizeSecondary(rowIndex) - sizeSecondary; 1189 } else if (mOrientation == HORIZONTAL && verticalGravity == Gravity.CENTER_VERTICAL 1190 || mOrientation == VERTICAL && horizontalGravity == Gravity.CENTER_HORIZONTAL) { 1191 startSecondary += (getRowSizeSecondary(rowIndex) - sizeSecondary) / 2; 1192 } 1193 int left, top, right, bottom; 1194 if (mOrientation == HORIZONTAL) { 1195 left = start; 1196 top = startSecondary; 1197 right = end; 1198 bottom = startSecondary + sizeSecondary; 1199 } else { 1200 top = start; 1201 left = startSecondary; 1202 bottom = end; 1203 right = startSecondary + sizeSecondary; 1204 } 1205 v.layout(left, top, right, bottom); 1206 updateChildOpticalInsets(v, left, top, right, bottom); 1207 updateChildAlignments(v); 1208 } 1209 1210 private void updateChildOpticalInsets(View v, int left, int top, int right, int bottom) { 1211 LayoutParams p = (LayoutParams) v.getLayoutParams(); 1212 p.setOpticalInsets(left - v.getLeft(), top - v.getTop(), 1213 v.getRight() - right, v.getBottom() - bottom); 1214 } 1215 1216 private void updateChildAlignments(View v) { 1217 LayoutParams p = (LayoutParams) v.getLayoutParams(); 1218 p.setAlignX(mItemAlignment.horizontal.getAlignmentPosition(v)); 1219 p.setAlignY(mItemAlignment.vertical.getAlignmentPosition(v)); 1220 } 1221 1222 private void updateChildAlignments() { 1223 for (int i = 0, c = getChildCount(); i < c; i++) { 1224 updateChildAlignments(getChildAt(i)); 1225 } 1226 } 1227 1228 private boolean needsAppendVisibleItem() { 1229 if (mLastVisiblePos < mFocusPosition) { 1230 return true; 1231 } 1232 int right = mScrollOffsetPrimary + mSizePrimary; 1233 for (int i = 0; i < mNumRows; i++) { 1234 if (mRows[i].low == mRows[i].high) { 1235 if (mRows[i].high < right) { 1236 return true; 1237 } 1238 } else if (mRows[i].high < right - mMarginPrimary) { 1239 return true; 1240 } 1241 } 1242 return false; 1243 } 1244 1245 private boolean needsPrependVisibleItem() { 1246 if (mFirstVisiblePos > mFocusPosition) { 1247 return true; 1248 } 1249 for (int i = 0; i < mNumRows; i++) { 1250 if (mRows[i].low == mRows[i].high) { 1251 if (mRows[i].low > mScrollOffsetPrimary) { 1252 return true; 1253 } 1254 } else if (mRows[i].low - mMarginPrimary > mScrollOffsetPrimary) { 1255 return true; 1256 } 1257 } 1258 return false; 1259 } 1260 1261 // Append one column if possible and return true if reach end. 1262 private boolean appendOneVisibleItem() { 1263 while (true) { 1264 if (mLastVisiblePos != NO_POSITION && mLastVisiblePos < mState.getItemCount() -1 && 1265 mLastVisiblePos < mGrid.getLastIndex()) { 1266 // append invisible view of saved location till last row 1267 final int index = mLastVisiblePos + 1; 1268 final int row = mGrid.getLocation(index).row; 1269 mGridProvider.createItem(index, row, true); 1270 if (row == mNumRows - 1) { 1271 return false; 1272 } 1273 } else if ((mLastVisiblePos == NO_POSITION && mState.getItemCount() > 0) || 1274 (mLastVisiblePos != NO_POSITION && 1275 mLastVisiblePos < mState.getItemCount() - 1)) { 1276 mGrid.appendItems(mScrollOffsetPrimary + mSizePrimary); 1277 return false; 1278 } else { 1279 return true; 1280 } 1281 } 1282 } 1283 1284 private void appendVisibleItems() { 1285 while (needsAppendVisibleItem()) { 1286 if (appendOneVisibleItem()) { 1287 break; 1288 } 1289 } 1290 } 1291 1292 // Prepend one column if possible and return true if reach end. 1293 private boolean prependOneVisibleItem() { 1294 while (true) { 1295 if (mFirstVisiblePos > 0) { 1296 if (mFirstVisiblePos > mGrid.getFirstIndex()) { 1297 // prepend invisible view of saved location till first row 1298 final int index = mFirstVisiblePos - 1; 1299 final int row = mGrid.getLocation(index).row; 1300 mGridProvider.createItem(index, row, false); 1301 if (row == 0) { 1302 return false; 1303 } 1304 } else { 1305 mGrid.prependItems(mScrollOffsetPrimary); 1306 return false; 1307 } 1308 } else { 1309 return true; 1310 } 1311 } 1312 } 1313 1314 private void prependVisibleItems() { 1315 while (needsPrependVisibleItem()) { 1316 if (prependOneVisibleItem()) { 1317 break; 1318 } 1319 } 1320 } 1321 1322 private void removeChildAt(int position) { 1323 View v = findViewByPosition(position); 1324 if (v != null) { 1325 if (DEBUG) { 1326 Log.d(getTag(), "removeAndRecycleViewAt " + position + " " + v); 1327 } 1328 mChildrenStates.saveOffscreenView(v, position); 1329 removeAndRecycleView(v, mRecycler); 1330 } 1331 } 1332 1333 private void removeInvisibleViewsAtEnd() { 1334 if (!mPruneChild) { 1335 return; 1336 } 1337 boolean update = false; 1338 while(mLastVisiblePos > mFirstVisiblePos && mLastVisiblePos > mFocusPosition) { 1339 View view = findViewByPosition(mLastVisiblePos); 1340 if (getViewMin(view) > mSizePrimary) { 1341 removeChildAt(mLastVisiblePos); 1342 mLastVisiblePos--; 1343 update = true; 1344 } else { 1345 break; 1346 } 1347 } 1348 if (update) { 1349 updateRowsMinMax(); 1350 } 1351 } 1352 1353 private void removeInvisibleViewsAtFront() { 1354 if (!mPruneChild) { 1355 return; 1356 } 1357 boolean update = false; 1358 while(mLastVisiblePos > mFirstVisiblePos && mFirstVisiblePos < mFocusPosition) { 1359 View view = findViewByPosition(mFirstVisiblePos); 1360 if (getViewMax(view) < 0) { 1361 removeChildAt(mFirstVisiblePos); 1362 mFirstVisiblePos++; 1363 update = true; 1364 } else { 1365 break; 1366 } 1367 } 1368 if (update) { 1369 updateRowsMinMax(); 1370 } 1371 } 1372 1373 private void updateRowsMinMax() { 1374 if (mFirstVisiblePos < 0) { 1375 return; 1376 } 1377 for (int i = 0; i < mNumRows; i++) { 1378 mRows[i].low = Integer.MAX_VALUE; 1379 mRows[i].high = Integer.MIN_VALUE; 1380 } 1381 for (int i = mFirstVisiblePos; i <= mLastVisiblePos; i++) { 1382 View view = findViewByPosition(i); 1383 int row = mGrid.getLocation(i).row; 1384 int low = getViewMin(view) + mScrollOffsetPrimary; 1385 if (low < mRows[row].low) { 1386 mRows[row].low = low; 1387 } 1388 int high = getViewMax(view) + mScrollOffsetPrimary; 1389 if (high > mRows[row].high) { 1390 mRows[row].high = high; 1391 } 1392 } 1393 } 1394 1395 // Fast layout when there is no structure change, adapter change, etc. 1396 protected void fastRelayout(boolean scrollToFocus) { 1397 initScrollController(); 1398 1399 List<Integer>[] rows = mGrid.getItemPositionsInRows(mFirstVisiblePos, mLastVisiblePos); 1400 1401 // relayout and repositioning views on each row 1402 for (int i = 0; i < mNumRows; i++) { 1403 List<Integer> row = rows[i]; 1404 final int startSecondary = getRowStartSecondary(i) - mScrollOffsetSecondary; 1405 for (int j = 0, size = row.size(); j < size; j++) { 1406 final int position = row.get(j); 1407 View view = findViewByPosition(position); 1408 int primaryDelta, end; 1409 1410 int start = getViewMin(view); 1411 int oldPrimarySize = (mOrientation == HORIZONTAL) ? 1412 view.getMeasuredWidth() : 1413 view.getMeasuredHeight(); 1414 1415 LayoutParams lp = (LayoutParams) view.getLayoutParams(); 1416 if (lp.viewNeedsUpdate()) { 1417 int index = mBaseGridView.indexOfChild(view); 1418 detachAndScrapView(view, mRecycler); 1419 view = getViewForPosition(position); 1420 addView(view, index); 1421 } 1422 1423 if (view.isLayoutRequested()) { 1424 measureChild(view); 1425 } 1426 1427 if (mOrientation == HORIZONTAL) { 1428 end = start + view.getMeasuredWidth(); 1429 primaryDelta = view.getMeasuredWidth() - oldPrimarySize; 1430 if (primaryDelta != 0) { 1431 for (int k = j + 1; k < size; k++) { 1432 findViewByPosition(row.get(k)).offsetLeftAndRight(primaryDelta); 1433 } 1434 } 1435 } else { 1436 end = start + view.getMeasuredHeight(); 1437 primaryDelta = view.getMeasuredHeight() - oldPrimarySize; 1438 if (primaryDelta != 0) { 1439 for (int k = j + 1; k < size; k++) { 1440 findViewByPosition(row.get(k)).offsetTopAndBottom(primaryDelta); 1441 } 1442 } 1443 } 1444 layoutChild(i, view, start, end, startSecondary); 1445 } 1446 } 1447 1448 updateRowsMinMax(); 1449 appendVisibleItems(); 1450 prependVisibleItems(); 1451 1452 updateRowsMinMax(); 1453 updateScrollMin(); 1454 updateScrollMax(); 1455 updateScrollSecondAxis(); 1456 1457 if (scrollToFocus) { 1458 View focusView = findViewByPosition(mFocusPosition == NO_POSITION ? 0 : mFocusPosition); 1459 scrollToView(focusView, false); 1460 } 1461 } 1462 1463 public void removeAndRecycleAllViews(RecyclerView.Recycler recycler) { 1464 if (DEBUG) Log.v(TAG, "removeAndRecycleAllViews " + getChildCount()); 1465 for (int i = getChildCount() - 1; i >= 0; i--) { 1466 removeAndRecycleViewAt(i, recycler); 1467 } 1468 } 1469 1470 // Lays out items based on the current scroll position 1471 @Override 1472 public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state) { 1473 if (DEBUG) { 1474 Log.v(getTag(), "layoutChildren start numRows " + mNumRows + " mScrollOffsetSecondary " 1475 + mScrollOffsetSecondary + " mScrollOffsetPrimary " + mScrollOffsetPrimary 1476 + " inPreLayout " + state.isPreLayout() 1477 + " didStructureChange " + state.didStructureChange() 1478 + " mForceFullLayout " + mForceFullLayout); 1479 Log.v(getTag(), "width " + getWidth() + " height " + getHeight()); 1480 } 1481 1482 if (mNumRows == 0) { 1483 // haven't done measure yet 1484 return; 1485 } 1486 final int itemCount = state.getItemCount(); 1487 if (itemCount < 0) { 1488 return; 1489 } 1490 1491 if (!mLayoutEnabled) { 1492 discardLayoutInfo(); 1493 removeAndRecycleAllViews(recycler); 1494 return; 1495 } 1496 mInLayout = true; 1497 1498 final boolean scrollToFocus = !isSmoothScrolling() 1499 && mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED; 1500 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE) { 1501 mFocusPosition = mFocusPosition + mFocusPositionOffset; 1502 mFocusPositionOffset = 0; 1503 } 1504 saveContext(recycler, state); 1505 // Track the old focus view so we can adjust our system scroll position 1506 // so that any scroll animations happening now will remain valid. 1507 // We must use same delta in Pre Layout (if prelayout exists) and second layout. 1508 // So we cache the deltas in PreLayout and use it in second layout. 1509 int delta = 0, deltaSecondary = 0; 1510 if (mFocusPosition != NO_POSITION && scrollToFocus) { 1511 // FIXME: we should get the remaining scroll animation offset from RecyclerView 1512 View focusView = findViewByPosition(mFocusPosition); 1513 if (focusView != null) { 1514 delta = mWindowAlignment.mainAxis().getSystemScrollPos(mScrollOffsetPrimary 1515 + getViewCenter(focusView), false, false) - mScrollOffsetPrimary; 1516 deltaSecondary = mWindowAlignment.secondAxis().getSystemScrollPos( 1517 mScrollOffsetSecondary + getViewCenterSecondary(focusView), 1518 false, false) - mScrollOffsetSecondary; 1519 } 1520 } 1521 1522 final boolean hasDoneFirstLayout = hasDoneFirstLayout(); 1523 int savedFocusPos = mFocusPosition; 1524 boolean fastRelayout = false; 1525 if (!mState.didStructureChange() && !mForceFullLayout && hasDoneFirstLayout) { 1526 fastRelayout = true; 1527 fastRelayout(scrollToFocus); 1528 } else { 1529 boolean hadFocus = mBaseGridView.hasFocus(); 1530 1531 mFocusPosition = init(mFocusPosition); 1532 if (mFocusPosition != savedFocusPos) { 1533 if (DEBUG) Log.v(getTag(), "savedFocusPos " + savedFocusPos + 1534 " mFocusPosition " + mFocusPosition); 1535 } 1536 1537 mWindowAlignment.mainAxis().invalidateScrollMin(); 1538 mWindowAlignment.mainAxis().invalidateScrollMax(); 1539 // depending on result of init(), either recreating everything 1540 // or try to reuse the row start positions near mFocusPosition 1541 if (mGrid.getSize() == 0) { 1542 // this is a fresh creating all items, starting from 1543 // mFocusPosition with a estimated row index. 1544 mGrid.setStart(mFocusPosition, StaggeredGrid.START_DEFAULT); 1545 1546 // Can't track the old focus view 1547 delta = deltaSecondary = 0; 1548 1549 } else { 1550 // mGrid remembers Locations for the column that 1551 // contains mFocusePosition and also mRows remembers start 1552 // positions of each row. 1553 // Manually re-create child views for that column 1554 int firstIndex = mGrid.getFirstIndex(); 1555 int lastIndex = mGrid.getLastIndex(); 1556 for (int i = firstIndex; i <= lastIndex; i++) { 1557 mGridProvider.createItem(i, mGrid.getLocation(i).row, true); 1558 } 1559 } 1560 1561 // add visible views at end until reach the end of window 1562 appendVisibleItems(); 1563 // add visible views at front until reach the start of window 1564 prependVisibleItems(); 1565 // multiple rounds: scrollToView of first round may drag first/last child into 1566 // "visible window" and we update scrollMin/scrollMax then run second scrollToView 1567 int oldFirstVisible; 1568 int oldLastVisible; 1569 do { 1570 updateScrollMin(); 1571 updateScrollMax(); 1572 oldFirstVisible = mFirstVisiblePos; 1573 oldLastVisible = mLastVisiblePos; 1574 View focusView = findViewByPosition(mFocusPosition); 1575 // we need force to initialize the child view's position 1576 scrollToView(focusView, false); 1577 if (focusView != null && hadFocus) { 1578 focusView.requestFocus(); 1579 } 1580 appendVisibleItems(); 1581 prependVisibleItems(); 1582 removeInvisibleViewsAtFront(); 1583 removeInvisibleViewsAtEnd(); 1584 } while (mFirstVisiblePos != oldFirstVisible || mLastVisiblePos != oldLastVisible); 1585 } 1586 mForceFullLayout = false; 1587 1588 if (scrollToFocus) { 1589 scrollDirectionPrimary(-delta); 1590 scrollDirectionSecondary(-deltaSecondary); 1591 } 1592 appendVisibleItems(); 1593 prependVisibleItems(); 1594 removeInvisibleViewsAtFront(); 1595 removeInvisibleViewsAtEnd(); 1596 1597 if (DEBUG) { 1598 StringWriter sw = new StringWriter(); 1599 PrintWriter pw = new PrintWriter(sw); 1600 mGrid.debugPrint(pw); 1601 Log.d(getTag(), sw.toString()); 1602 } 1603 1604 if (mRowSecondarySizeRefresh) { 1605 mRowSecondarySizeRefresh = false; 1606 } else { 1607 updateRowSecondarySizeRefresh(); 1608 } 1609 1610 if (fastRelayout && mFocusPosition != savedFocusPos) { 1611 dispatchChildSelected(); 1612 } 1613 mInLayout = false; 1614 leaveContext(); 1615 if (DEBUG) Log.v(getTag(), "layoutChildren end"); 1616 } 1617 1618 private void offsetChildrenSecondary(int increment) { 1619 final int childCount = getChildCount(); 1620 if (mOrientation == HORIZONTAL) { 1621 for (int i = 0; i < childCount; i++) { 1622 getChildAt(i).offsetTopAndBottom(increment); 1623 } 1624 } else { 1625 for (int i = 0; i < childCount; i++) { 1626 getChildAt(i).offsetLeftAndRight(increment); 1627 } 1628 } 1629 } 1630 1631 private void offsetChildrenPrimary(int increment) { 1632 final int childCount = getChildCount(); 1633 if (mOrientation == VERTICAL) { 1634 for (int i = 0; i < childCount; i++) { 1635 getChildAt(i).offsetTopAndBottom(increment); 1636 } 1637 } else { 1638 for (int i = 0; i < childCount; i++) { 1639 getChildAt(i).offsetLeftAndRight(increment); 1640 } 1641 } 1642 } 1643 1644 @Override 1645 public int scrollHorizontallyBy(int dx, Recycler recycler, RecyclerView.State state) { 1646 if (DEBUG) Log.v(getTag(), "scrollHorizontallyBy " + dx); 1647 if (!mLayoutEnabled || !hasDoneFirstLayout()) { 1648 return 0; 1649 } 1650 saveContext(recycler, state); 1651 int result; 1652 if (mOrientation == HORIZONTAL) { 1653 result = scrollDirectionPrimary(dx); 1654 } else { 1655 result = scrollDirectionSecondary(dx); 1656 } 1657 leaveContext(); 1658 return result; 1659 } 1660 1661 @Override 1662 public int scrollVerticallyBy(int dy, Recycler recycler, RecyclerView.State state) { 1663 if (DEBUG) Log.v(getTag(), "scrollVerticallyBy " + dy); 1664 if (!mLayoutEnabled || !hasDoneFirstLayout()) { 1665 return 0; 1666 } 1667 saveContext(recycler, state); 1668 int result; 1669 if (mOrientation == VERTICAL) { 1670 result = scrollDirectionPrimary(dy); 1671 } else { 1672 result = scrollDirectionSecondary(dy); 1673 } 1674 leaveContext(); 1675 return result; 1676 } 1677 1678 // scroll in main direction may add/prune views 1679 private int scrollDirectionPrimary(int da) { 1680 if (da > 0) { 1681 if (!mWindowAlignment.mainAxis().isMaxUnknown()) { 1682 int maxScroll = mWindowAlignment.mainAxis().getMaxScroll(); 1683 if (mScrollOffsetPrimary + da > maxScroll) { 1684 da = maxScroll - mScrollOffsetPrimary; 1685 } 1686 } 1687 } else if (da < 0) { 1688 if (!mWindowAlignment.mainAxis().isMinUnknown()) { 1689 int minScroll = mWindowAlignment.mainAxis().getMinScroll(); 1690 if (mScrollOffsetPrimary + da < minScroll) { 1691 da = minScroll - mScrollOffsetPrimary; 1692 } 1693 } 1694 } 1695 if (da == 0) { 1696 return 0; 1697 } 1698 offsetChildrenPrimary(-da); 1699 mScrollOffsetPrimary += da; 1700 if (mInLayout) { 1701 return da; 1702 } 1703 1704 int childCount = getChildCount(); 1705 boolean updated; 1706 1707 if (da > 0) { 1708 appendVisibleItems(); 1709 } else if (da < 0) { 1710 prependVisibleItems(); 1711 } 1712 updated = getChildCount() > childCount; 1713 childCount = getChildCount(); 1714 1715 if (da > 0) { 1716 removeInvisibleViewsAtFront(); 1717 } else if (da < 0) { 1718 removeInvisibleViewsAtEnd(); 1719 } 1720 updated |= getChildCount() < childCount; 1721 1722 if (updated) { 1723 updateRowSecondarySizeRefresh(); 1724 } 1725 1726 mBaseGridView.invalidate(); 1727 return da; 1728 } 1729 1730 // scroll in second direction will not add/prune views 1731 private int scrollDirectionSecondary(int dy) { 1732 if (dy == 0) { 1733 return 0; 1734 } 1735 offsetChildrenSecondary(-dy); 1736 mScrollOffsetSecondary += dy; 1737 mBaseGridView.invalidate(); 1738 return dy; 1739 } 1740 1741 private void updateScrollMax() { 1742 if (mLastVisiblePos < 0) { 1743 return; 1744 } 1745 final boolean lastAvailable = mLastVisiblePos == mState.getItemCount() - 1; 1746 final boolean maxUnknown = mWindowAlignment.mainAxis().isMaxUnknown(); 1747 if (!lastAvailable && maxUnknown) { 1748 return; 1749 } 1750 int maxEdge = Integer.MIN_VALUE; 1751 int rowIndex = -1; 1752 for (int i = 0; i < mRows.length; i++) { 1753 if (mRows[i].high > maxEdge) { 1754 maxEdge = mRows[i].high; 1755 rowIndex = i; 1756 } 1757 } 1758 int maxScroll = Integer.MAX_VALUE; 1759 for (int i = mLastVisiblePos; i >= mFirstVisiblePos; i--) { 1760 StaggeredGrid.Location location = mGrid.getLocation(i); 1761 if (location != null && location.row == rowIndex) { 1762 int savedMaxEdge = mWindowAlignment.mainAxis().getMaxEdge(); 1763 mWindowAlignment.mainAxis().setMaxEdge(maxEdge); 1764 maxScroll = getPrimarySystemScrollPosition(findViewByPosition(i)); 1765 mWindowAlignment.mainAxis().setMaxEdge(savedMaxEdge); 1766 break; 1767 } 1768 } 1769 if (lastAvailable) { 1770 mWindowAlignment.mainAxis().setMaxEdge(maxEdge); 1771 mWindowAlignment.mainAxis().setMaxScroll(maxScroll); 1772 if (DEBUG) Log.v(getTag(), "updating scroll maxEdge to " + maxEdge + 1773 " scrollMax to " + maxScroll); 1774 } else { 1775 // the maxScroll for currently last visible item is larger, 1776 // so we must invalidate the max scroll value. 1777 if (maxScroll > mWindowAlignment.mainAxis().getMaxScroll()) { 1778 mWindowAlignment.mainAxis().invalidateScrollMax(); 1779 if (DEBUG) Log.v(getTag(), "Invalidate scrollMax since it should be " 1780 + "greater than " + maxScroll); 1781 } 1782 } 1783 } 1784 1785 private void updateScrollMin() { 1786 if (mFirstVisiblePos < 0) { 1787 return; 1788 } 1789 final boolean firstAvailable = mFirstVisiblePos == 0; 1790 final boolean minUnknown = mWindowAlignment.mainAxis().isMinUnknown(); 1791 if (!firstAvailable && minUnknown) { 1792 return; 1793 } 1794 int minEdge = Integer.MAX_VALUE; 1795 int rowIndex = -1; 1796 for (int i = 0; i < mRows.length; i++) { 1797 if (mRows[i].low < minEdge) { 1798 minEdge = mRows[i].low; 1799 rowIndex = i; 1800 } 1801 } 1802 int minScroll = Integer.MIN_VALUE; 1803 for (int i = mFirstVisiblePos; i <= mLastVisiblePos; i++) { 1804 StaggeredGrid.Location location = mGrid.getLocation(i); 1805 if (location != null && location.row == rowIndex) { 1806 int savedMinEdge = mWindowAlignment.mainAxis().getMinEdge(); 1807 mWindowAlignment.mainAxis().setMinEdge(minEdge); 1808 minScroll = getPrimarySystemScrollPosition(findViewByPosition(i)); 1809 mWindowAlignment.mainAxis().setMinEdge(savedMinEdge); 1810 break; 1811 } 1812 } 1813 if (firstAvailable) { 1814 mWindowAlignment.mainAxis().setMinEdge(minEdge); 1815 mWindowAlignment.mainAxis().setMinScroll(minScroll); 1816 if (DEBUG) Log.v(getTag(), "updating scroll minEdge to " + minEdge + 1817 " scrollMin to " + minScroll); 1818 } else { 1819 // the minScroll for currently first visible item is smaller, 1820 // so we must invalidate the min scroll value. 1821 if (minScroll < mWindowAlignment.mainAxis().getMinScroll()) { 1822 mWindowAlignment.mainAxis().invalidateScrollMin(); 1823 if (DEBUG) Log.v(getTag(), "Invalidate scrollMin, since it should be " 1824 + "less than " + minScroll); 1825 } 1826 } 1827 } 1828 1829 private void updateScrollSecondAxis() { 1830 mWindowAlignment.secondAxis().setMinEdge(0); 1831 mWindowAlignment.secondAxis().setMaxEdge(getSizeSecondary()); 1832 } 1833 1834 private void initScrollController() { 1835 // mScrollOffsetPrimary and mScrollOffsetSecondary includes the padding. 1836 // e.g. when topPadding is 16 for horizontal grid view, the initial 1837 // mScrollOffsetSecondary is -16. fastLayout() put views based on offsets(not padding), 1838 // when padding changes to 20, we also need update mScrollOffsetSecondary to -20 before 1839 // fastLayout() is performed 1840 int paddingPrimaryDiff, paddingSecondaryDiff; 1841 if (mOrientation == HORIZONTAL) { 1842 paddingPrimaryDiff = getPaddingLeft() - mWindowAlignment.horizontal.getPaddingLow(); 1843 paddingSecondaryDiff = getPaddingTop() - mWindowAlignment.vertical.getPaddingLow(); 1844 } else { 1845 paddingPrimaryDiff = getPaddingTop() - mWindowAlignment.vertical.getPaddingLow(); 1846 paddingSecondaryDiff = getPaddingLeft() - mWindowAlignment.horizontal.getPaddingLow(); 1847 } 1848 mScrollOffsetPrimary -= paddingPrimaryDiff; 1849 mScrollOffsetSecondary -= paddingSecondaryDiff; 1850 1851 if (mOrientation == HORIZONTAL) { 1852 mWindowAlignment.horizontal.setSize((int)(getWidth() * mPrimaryOverReach + 0.5f)); 1853 mWindowAlignment.vertical.setSize(getHeight()); 1854 } else { 1855 mWindowAlignment.horizontal.setSize(getWidth()); 1856 mWindowAlignment.vertical.setSize((int) (getHeight() * mPrimaryOverReach + 0.5f)); 1857 } 1858 mWindowAlignment.horizontal.setPadding(getPaddingLeft(), getPaddingRight()); 1859 mWindowAlignment.vertical.setPadding(getPaddingTop(), getPaddingBottom()); 1860 mSizePrimary = mWindowAlignment.mainAxis().getSize(); 1861 1862 if (DEBUG) { 1863 Log.v(getTag(), "initScrollController mSizePrimary " + mSizePrimary 1864 + " mWindowAlignment " + mWindowAlignment); 1865 } 1866 } 1867 1868 public void setSelection(RecyclerView parent, int position) { 1869 setSelection(parent, position, false); 1870 } 1871 1872 public void setSelectionSmooth(RecyclerView parent, int position) { 1873 setSelection(parent, position, true); 1874 } 1875 1876 public int getSelection() { 1877 return mFocusPosition; 1878 } 1879 1880 public void setSelection(RecyclerView parent, int position, boolean smooth) { 1881 if (mFocusPosition == position) { 1882 return; 1883 } 1884 View view = findViewByPosition(position); 1885 if (view != null) { 1886 mInSelection = true; 1887 scrollToView(view, smooth); 1888 mInSelection = false; 1889 } else { 1890 mFocusPosition = position; 1891 mFocusPositionOffset = 0; 1892 if (!mLayoutEnabled) { 1893 return; 1894 } 1895 if (smooth) { 1896 if (!hasDoneFirstLayout()) { 1897 Log.w(getTag(), "setSelectionSmooth should " + 1898 "not be called before first layout pass"); 1899 return; 1900 } 1901 LinearSmoothScroller linearSmoothScroller = 1902 new LinearSmoothScroller(parent.getContext()) { 1903 @Override 1904 public PointF computeScrollVectorForPosition(int targetPosition) { 1905 if (getChildCount() == 0) { 1906 return null; 1907 } 1908 final int firstChildPos = getPosition(getChildAt(0)); 1909 final int direction = targetPosition < firstChildPos ? -1 : 1; 1910 if (mOrientation == HORIZONTAL) { 1911 return new PointF(direction, 0); 1912 } else { 1913 return new PointF(0, direction); 1914 } 1915 } 1916 @Override 1917 protected void onTargetFound(View targetView, 1918 RecyclerView.State state, Action action) { 1919 if (hasFocus()) { 1920 targetView.requestFocus(); 1921 } 1922 dispatchChildSelected(); 1923 if (getScrollPosition(targetView, mTempDeltas)) { 1924 int dx, dy; 1925 if (mOrientation == HORIZONTAL) { 1926 dx = mTempDeltas[0]; 1927 dy = mTempDeltas[1]; 1928 } else { 1929 dx = mTempDeltas[1]; 1930 dy = mTempDeltas[0]; 1931 } 1932 final int distance = (int) Math.sqrt(dx * dx + dy * dy); 1933 final int time = calculateTimeForDeceleration(distance); 1934 action.update(dx, dy, time, mDecelerateInterpolator); 1935 } 1936 } 1937 }; 1938 linearSmoothScroller.setTargetPosition(position); 1939 startSmoothScroll(linearSmoothScroller); 1940 } else { 1941 mForceFullLayout = true; 1942 parent.requestLayout(); 1943 } 1944 } 1945 } 1946 1947 @Override 1948 public void onItemsAdded(RecyclerView recyclerView, int positionStart, int itemCount) { 1949 if (DEBUG) Log.v(getTag(), "onItemsAdded positionStart " 1950 + positionStart + " itemCount " + itemCount); 1951 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE 1952 && getChildAt(mFocusPosition) != null) { 1953 int pos = mFocusPosition + mFocusPositionOffset; 1954 if (positionStart <= pos) { 1955 mFocusPositionOffset += itemCount; 1956 } 1957 } 1958 mChildrenStates.clear(); 1959 } 1960 1961 @Override 1962 public void onItemsChanged(RecyclerView recyclerView) { 1963 if (DEBUG) Log.v(getTag(), "onItemsChanged"); 1964 mFocusPositionOffset = 0; 1965 mChildrenStates.clear(); 1966 } 1967 1968 @Override 1969 public void onItemsRemoved(RecyclerView recyclerView, int positionStart, int itemCount) { 1970 if (DEBUG) Log.v(getTag(), "onItemsAdded positionStart " 1971 + positionStart + " itemCount " + itemCount); 1972 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE 1973 && getChildAt(mFocusPosition) != null) { 1974 int pos = mFocusPosition + mFocusPositionOffset; 1975 if (positionStart <= pos) { 1976 if (positionStart + itemCount > pos) { 1977 // stop updating offset after the focus item was removed 1978 mFocusPositionOffset = Integer.MIN_VALUE; 1979 } else { 1980 mFocusPositionOffset -= itemCount; 1981 } 1982 } 1983 } 1984 mChildrenStates.clear(); 1985 } 1986 1987 @Override 1988 public void onItemsMoved(RecyclerView recyclerView, int fromPosition, int toPosition, 1989 int itemCount) { 1990 if (DEBUG) Log.v(getTag(), "onItemsAdded fromPosition " 1991 + fromPosition + " toPosition " + toPosition); 1992 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE 1993 && getChildAt(mFocusPosition) != null) { 1994 int pos = mFocusPosition + mFocusPositionOffset; 1995 if (fromPosition <= pos && pos < fromPosition + itemCount) { 1996 // moved items include focused position 1997 mFocusPositionOffset += toPosition - fromPosition; 1998 } else if (fromPosition < pos && toPosition > pos - itemCount) { 1999 // move items before focus position to after focused position 2000 mFocusPositionOffset -= itemCount; 2001 } else if (fromPosition > pos && toPosition < pos) { 2002 // move items after focus position to before focused position 2003 mFocusPositionOffset += itemCount; 2004 } 2005 } 2006 mChildrenStates.clear(); 2007 } 2008 2009 @Override 2010 public void onItemsUpdated(RecyclerView recyclerView, int positionStart, int itemCount) { 2011 for (int i = positionStart, end = positionStart + itemCount; i < end; i++) { 2012 mChildrenStates.remove(i); 2013 } 2014 } 2015 2016 @Override 2017 public boolean onRequestChildFocus(RecyclerView parent, View child, View focused) { 2018 if (mFocusSearchDisabled) { 2019 return true; 2020 } 2021 if (!mInLayout && !mInSelection) { 2022 scrollToView(child, true); 2023 } 2024 return true; 2025 } 2026 2027 @Override 2028 public boolean requestChildRectangleOnScreen(RecyclerView parent, View view, Rect rect, 2029 boolean immediate) { 2030 if (DEBUG) Log.v(getTag(), "requestChildRectangleOnScreen " + view + " " + rect); 2031 return false; 2032 } 2033 2034 int getScrollOffsetX() { 2035 return mOrientation == HORIZONTAL ? mScrollOffsetPrimary : mScrollOffsetSecondary; 2036 } 2037 2038 int getScrollOffsetY() { 2039 return mOrientation == HORIZONTAL ? mScrollOffsetSecondary : mScrollOffsetPrimary; 2040 } 2041 2042 public void getViewSelectedOffsets(View view, int[] offsets) { 2043 if (mOrientation == HORIZONTAL) { 2044 offsets[0] = getPrimarySystemScrollPosition(view) - mScrollOffsetPrimary; 2045 offsets[1] = getSecondarySystemScrollPosition(view) - mScrollOffsetSecondary; 2046 } else { 2047 offsets[1] = getPrimarySystemScrollPosition(view) - mScrollOffsetPrimary; 2048 offsets[0] = getSecondarySystemScrollPosition(view) - mScrollOffsetSecondary; 2049 } 2050 } 2051 2052 private int getPrimarySystemScrollPosition(View view) { 2053 int viewCenterPrimary = mScrollOffsetPrimary + getViewCenter(view); 2054 int pos = getPositionByView(view); 2055 StaggeredGrid.Location location = mGrid.getLocation(pos); 2056 final int row = location.row; 2057 boolean isFirst = mFirstVisiblePos == 0; 2058 // TODO: change to use State object in onRequestChildFocus() 2059 boolean isLast = mLastVisiblePos == (mState == null ? 2060 getItemCount() : mState.getItemCount()) - 1; 2061 if (isFirst || isLast) { 2062 for (int i = getChildCount() - 1; i >= 0; i--) { 2063 int position = getPositionByIndex(i); 2064 StaggeredGrid.Location loc = mGrid.getLocation(position); 2065 if (loc != null && loc.row == row) { 2066 if (position < pos) { 2067 isFirst = false; 2068 } else if (position > pos) { 2069 isLast = false; 2070 } 2071 } 2072 } 2073 } 2074 return mWindowAlignment.mainAxis().getSystemScrollPos(viewCenterPrimary, isFirst, isLast); 2075 } 2076 2077 private int getSecondarySystemScrollPosition(View view) { 2078 int viewCenterSecondary = mScrollOffsetSecondary + getViewCenterSecondary(view); 2079 int pos = getPositionByView(view); 2080 StaggeredGrid.Location location = mGrid.getLocation(pos); 2081 final int row = location.row; 2082 boolean isFirst = row == 0; 2083 boolean isLast = row == mGrid.getNumRows() - 1; 2084 return mWindowAlignment.secondAxis().getSystemScrollPos(viewCenterSecondary, 2085 isFirst, isLast); 2086 } 2087 2088 /** 2089 * Scroll to a given child view and change mFocusPosition. 2090 */ 2091 private void scrollToView(View view, boolean smooth) { 2092 int newFocusPosition = getPositionByView(view); 2093 if (newFocusPosition != mFocusPosition) { 2094 mFocusPosition = newFocusPosition; 2095 mFocusPositionOffset = 0; 2096 if (!mInLayout) { 2097 dispatchChildSelected(); 2098 } 2099 } 2100 if (mBaseGridView.isChildrenDrawingOrderEnabledInternal()) { 2101 mBaseGridView.invalidate(); 2102 } 2103 if (view == null) { 2104 return; 2105 } 2106 if (!view.hasFocus() && mBaseGridView.hasFocus()) { 2107 // transfer focus to the child if it does not have focus yet (e.g. triggered 2108 // by setSelection()) 2109 view.requestFocus(); 2110 } 2111 if (!mScrollEnabled) { 2112 return; 2113 } 2114 if (getScrollPosition(view, mTempDeltas)) { 2115 scrollGrid(mTempDeltas[0], mTempDeltas[1], smooth); 2116 } 2117 } 2118 2119 private boolean getScrollPosition(View view, int[] deltas) { 2120 switch (mFocusScrollStrategy) { 2121 case BaseGridView.FOCUS_SCROLL_ALIGNED: 2122 default: 2123 return getAlignedPosition(view, deltas); 2124 case BaseGridView.FOCUS_SCROLL_ITEM: 2125 case BaseGridView.FOCUS_SCROLL_PAGE: 2126 return getNoneAlignedPosition(view, deltas); 2127 } 2128 } 2129 2130 private boolean getNoneAlignedPosition(View view, int[] deltas) { 2131 int pos = getPositionByView(view); 2132 int viewMin = getViewMin(view); 2133 int viewMax = getViewMax(view); 2134 // we either align "firstView" to left/top padding edge 2135 // or align "lastView" to right/bottom padding edge 2136 View firstView = null; 2137 View lastView = null; 2138 int paddingLow = mWindowAlignment.mainAxis().getPaddingLow(); 2139 int clientSize = mWindowAlignment.mainAxis().getClientSize(); 2140 final int row = mGrid.getLocation(pos).row; 2141 if (viewMin < paddingLow) { 2142 // view enters low padding area: 2143 firstView = view; 2144 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_PAGE) { 2145 // scroll one "page" left/top, 2146 // align first visible item of the "page" at the low padding edge. 2147 while (!prependOneVisibleItem()) { 2148 List<Integer> positions = 2149 mGrid.getItemPositionsInRows(mFirstVisiblePos, pos)[row]; 2150 firstView = findViewByPosition(positions.get(0)); 2151 if (viewMax - getViewMin(firstView) > clientSize) { 2152 if (positions.size() > 1) { 2153 firstView = findViewByPosition(positions.get(1)); 2154 } 2155 break; 2156 } 2157 } 2158 } 2159 } else if (viewMax > clientSize + paddingLow) { 2160 // view enters high padding area: 2161 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_PAGE) { 2162 // scroll whole one page right/bottom, align view at the low padding edge. 2163 firstView = view; 2164 do { 2165 List<Integer> positions = 2166 mGrid.getItemPositionsInRows(pos, mLastVisiblePos)[row]; 2167 lastView = findViewByPosition(positions.get(positions.size() - 1)); 2168 if (getViewMax(lastView) - viewMin > clientSize) { 2169 lastView = null; 2170 break; 2171 } 2172 } while (!appendOneVisibleItem()); 2173 if (lastView != null) { 2174 // however if we reached end, we should align last view. 2175 firstView = null; 2176 } 2177 } else { 2178 lastView = view; 2179 } 2180 } 2181 int scrollPrimary = 0; 2182 int scrollSecondary = 0; 2183 if (firstView != null) { 2184 scrollPrimary = getViewMin(firstView) - paddingLow; 2185 } else if (lastView != null) { 2186 scrollPrimary = getViewMax(lastView) - (paddingLow + clientSize); 2187 } 2188 View secondaryAlignedView; 2189 if (firstView != null) { 2190 secondaryAlignedView = firstView; 2191 } else if (lastView != null) { 2192 secondaryAlignedView = lastView; 2193 } else { 2194 secondaryAlignedView = view; 2195 } 2196 scrollSecondary = getSecondarySystemScrollPosition(secondaryAlignedView); 2197 scrollSecondary -= mScrollOffsetSecondary; 2198 if (scrollPrimary != 0 || scrollSecondary != 0) { 2199 deltas[0] = scrollPrimary; 2200 deltas[1] = scrollSecondary; 2201 return true; 2202 } 2203 return false; 2204 } 2205 2206 private boolean getAlignedPosition(View view, int[] deltas) { 2207 int scrollPrimary = getPrimarySystemScrollPosition(view); 2208 int scrollSecondary = getSecondarySystemScrollPosition(view); 2209 if (DEBUG) { 2210 Log.v(getTag(), "getAlignedPosition " + scrollPrimary + " " + scrollSecondary 2211 +" " + mWindowAlignment); 2212 } 2213 scrollPrimary -= mScrollOffsetPrimary; 2214 scrollSecondary -= mScrollOffsetSecondary; 2215 if (scrollPrimary != 0 || scrollSecondary != 0) { 2216 deltas[0] = scrollPrimary; 2217 deltas[1] = scrollSecondary; 2218 return true; 2219 } 2220 return false; 2221 } 2222 2223 private void scrollGrid(int scrollPrimary, int scrollSecondary, boolean smooth) { 2224 if (mInLayout) { 2225 scrollDirectionPrimary(scrollPrimary); 2226 scrollDirectionSecondary(scrollSecondary); 2227 } else { 2228 int scrollX; 2229 int scrollY; 2230 if (mOrientation == HORIZONTAL) { 2231 scrollX = scrollPrimary; 2232 scrollY = scrollSecondary; 2233 } else { 2234 scrollX = scrollSecondary; 2235 scrollY = scrollPrimary; 2236 } 2237 if (smooth) { 2238 mBaseGridView.smoothScrollBy(scrollX, scrollY); 2239 } else { 2240 mBaseGridView.scrollBy(scrollX, scrollY); 2241 } 2242 } 2243 } 2244 2245 public void setPruneChild(boolean pruneChild) { 2246 if (mPruneChild != pruneChild) { 2247 mPruneChild = pruneChild; 2248 if (mPruneChild) { 2249 requestLayout(); 2250 } 2251 } 2252 } 2253 2254 public boolean getPruneChild() { 2255 return mPruneChild; 2256 } 2257 2258 public void setScrollEnabled(boolean scrollEnabled) { 2259 if (mScrollEnabled != scrollEnabled) { 2260 mScrollEnabled = scrollEnabled; 2261 if (mScrollEnabled && mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED) { 2262 View focusView = findViewByPosition(mFocusPosition == NO_POSITION ? 0 : 2263 mFocusPosition); 2264 if (focusView != null) { 2265 scrollToView(focusView, true); 2266 } 2267 } 2268 } 2269 } 2270 2271 public boolean isScrollEnabled() { 2272 return mScrollEnabled; 2273 } 2274 2275 private int findImmediateChildIndex(View view) { 2276 while (view != null && view != mBaseGridView) { 2277 int index = mBaseGridView.indexOfChild(view); 2278 if (index >= 0) { 2279 return index; 2280 } 2281 view = (View) view.getParent(); 2282 } 2283 return NO_POSITION; 2284 } 2285 2286 void setFocusSearchDisabled(boolean disabled) { 2287 mFocusSearchDisabled = disabled; 2288 } 2289 2290 boolean isFocusSearchDisabled() { 2291 return mFocusSearchDisabled; 2292 } 2293 2294 @Override 2295 public View onInterceptFocusSearch(View focused, int direction) { 2296 if (mFocusSearchDisabled) { 2297 return focused; 2298 } 2299 return null; 2300 } 2301 2302 boolean hasPreviousViewInSameRow(int pos) { 2303 if (mGrid == null || pos == NO_POSITION) { 2304 return false; 2305 } 2306 if (mFirstVisiblePos > 0) { 2307 return true; 2308 } 2309 final int focusedRow = mGrid.getLocation(pos).row; 2310 for (int i = getChildCount() - 1; i >= 0; i--) { 2311 int position = getPositionByIndex(i); 2312 StaggeredGrid.Location loc = mGrid.getLocation(position); 2313 if (loc != null && loc.row == focusedRow) { 2314 if (position < pos) { 2315 return true; 2316 } 2317 } 2318 } 2319 return false; 2320 } 2321 2322 @Override 2323 public boolean onAddFocusables(RecyclerView recyclerView, 2324 ArrayList<View> views, int direction, int focusableMode) { 2325 if (mFocusSearchDisabled) { 2326 return true; 2327 } 2328 // If this viewgroup or one of its children currently has focus then we 2329 // consider our children for focus searching in main direction on the same row. 2330 // If this viewgroup has no focus and using focus align, we want the system 2331 // to ignore our children and pass focus to the viewgroup, which will pass 2332 // focus on to its children appropriately. 2333 // If this viewgroup has no focus and not using focus align, we want to 2334 // consider the child that does not overlap with padding area. 2335 if (recyclerView.hasFocus()) { 2336 final int movement = getMovement(direction); 2337 if (movement != PREV_ITEM && movement != NEXT_ITEM) { 2338 // Move on secondary direction uses default addFocusables(). 2339 return false; 2340 } 2341 final View focused = recyclerView.findFocus(); 2342 final int focusedPos = getPositionByIndex(findImmediateChildIndex(focused)); 2343 // Add focusables of focused item. 2344 if (focusedPos != NO_POSITION) { 2345 findViewByPosition(focusedPos).addFocusables(views, direction, focusableMode); 2346 } 2347 final int focusedRow = mGrid != null && focusedPos != NO_POSITION ? 2348 mGrid.getLocation(focusedPos).row : NO_POSITION; 2349 // Add focusables of next neighbor of same row on the focus search direction. 2350 if (mGrid != null) { 2351 final int focusableCount = views.size(); 2352 for (int i = 0, count = getChildCount(); i < count; i++) { 2353 int index = movement == NEXT_ITEM ? i : count - 1 - i; 2354 final View child = getChildAt(index); 2355 if (child.getVisibility() != View.VISIBLE) { 2356 continue; 2357 } 2358 int position = getPositionByIndex(index); 2359 StaggeredGrid.Location loc = mGrid.getLocation(position); 2360 if (focusedRow == NO_POSITION || (loc != null && loc.row == focusedRow)) { 2361 if (focusedPos == NO_POSITION || 2362 (movement == NEXT_ITEM && position > focusedPos) 2363 || (movement == PREV_ITEM && position < focusedPos)) { 2364 child.addFocusables(views, direction, focusableMode); 2365 if (views.size() > focusableCount) { 2366 break; 2367 } 2368 } 2369 } 2370 } 2371 } 2372 } else { 2373 if (mFocusScrollStrategy != BaseGridView.FOCUS_SCROLL_ALIGNED) { 2374 // adding views not overlapping padding area to avoid scrolling in gaining focus 2375 int left = mWindowAlignment.mainAxis().getPaddingLow(); 2376 int right = mWindowAlignment.mainAxis().getClientSize() + left; 2377 int focusableCount = views.size(); 2378 for (int i = 0, count = getChildCount(); i < count; i++) { 2379 View child = getChildAt(i); 2380 if (child.getVisibility() == View.VISIBLE) { 2381 if (getViewMin(child) >= left && getViewMax(child) <= right) { 2382 child.addFocusables(views, direction, focusableMode); 2383 } 2384 } 2385 } 2386 // if we cannot find any, then just add all children. 2387 if (views.size() == focusableCount) { 2388 for (int i = 0, count = getChildCount(); i < count; i++) { 2389 View child = getChildAt(i); 2390 if (child.getVisibility() == View.VISIBLE) { 2391 child.addFocusables(views, direction, focusableMode); 2392 } 2393 } 2394 if (views.size() != focusableCount) { 2395 return true; 2396 } 2397 } else { 2398 return true; 2399 } 2400 // if still cannot find any, fall through and add itself 2401 } 2402 if (recyclerView.isFocusable()) { 2403 views.add(recyclerView); 2404 } 2405 } 2406 return true; 2407 } 2408 2409 @Override 2410 public View onFocusSearchFailed(View focused, int direction, Recycler recycler, 2411 RecyclerView.State state) { 2412 if (DEBUG) Log.v(getTag(), "onFocusSearchFailed direction " + direction); 2413 2414 View view = null; 2415 int movement = getMovement(direction); 2416 if (mNumRows == 1) { 2417 // for simple row, use LinearSmoothScroller to smooth animation. 2418 // It will stay at a fixed cap speed in continuous scroll. 2419 if (movement == NEXT_ITEM) { 2420 int newPos = mFocusPosition + mNumRows; 2421 if (newPos < getItemCount()) { 2422 setSelectionSmooth(mBaseGridView, newPos); 2423 view = focused; 2424 } else { 2425 if (!mFocusOutEnd) { 2426 view = focused; 2427 } 2428 } 2429 } else if (movement == PREV_ITEM){ 2430 int newPos = mFocusPosition - mNumRows; 2431 if (newPos >= 0) { 2432 setSelectionSmooth(mBaseGridView, newPos); 2433 view = focused; 2434 } else { 2435 if (!mFocusOutFront) { 2436 view = focused; 2437 } 2438 } 2439 } 2440 } else if (mNumRows > 1) { 2441 // for possible staggered grid, we need guarantee focus to same row/column. 2442 // TODO: we may also use LinearSmoothScroller. 2443 saveContext(recycler, state); 2444 final FocusFinder ff = FocusFinder.getInstance(); 2445 if (movement == NEXT_ITEM) { 2446 while (view == null && !appendOneVisibleItem()) { 2447 view = ff.findNextFocus(mBaseGridView, focused, direction); 2448 } 2449 } else if (movement == PREV_ITEM){ 2450 while (view == null && !prependOneVisibleItem()) { 2451 view = ff.findNextFocus(mBaseGridView, focused, direction); 2452 } 2453 } 2454 if (view == null) { 2455 // returning the same view to prevent focus lost when scrolling past the end of the list 2456 if (movement == PREV_ITEM) { 2457 view = mFocusOutFront ? null : focused; 2458 } else if (movement == NEXT_ITEM){ 2459 view = mFocusOutEnd ? null : focused; 2460 } 2461 } 2462 leaveContext(); 2463 } 2464 if (DEBUG) Log.v(getTag(), "returning view " + view); 2465 return view; 2466 } 2467 2468 boolean gridOnRequestFocusInDescendants(RecyclerView recyclerView, int direction, 2469 Rect previouslyFocusedRect) { 2470 switch (mFocusScrollStrategy) { 2471 case BaseGridView.FOCUS_SCROLL_ALIGNED: 2472 default: 2473 return gridOnRequestFocusInDescendantsAligned(recyclerView, 2474 direction, previouslyFocusedRect); 2475 case BaseGridView.FOCUS_SCROLL_PAGE: 2476 case BaseGridView.FOCUS_SCROLL_ITEM: 2477 return gridOnRequestFocusInDescendantsUnaligned(recyclerView, 2478 direction, previouslyFocusedRect); 2479 } 2480 } 2481 2482 private boolean gridOnRequestFocusInDescendantsAligned(RecyclerView recyclerView, 2483 int direction, Rect previouslyFocusedRect) { 2484 View view = findViewByPosition(mFocusPosition); 2485 if (view != null) { 2486 boolean result = view.requestFocus(direction, previouslyFocusedRect); 2487 if (!result && DEBUG) { 2488 Log.w(getTag(), "failed to request focus on " + view); 2489 } 2490 return result; 2491 } 2492 return false; 2493 } 2494 2495 private boolean gridOnRequestFocusInDescendantsUnaligned(RecyclerView recyclerView, 2496 int direction, Rect previouslyFocusedRect) { 2497 // focus to view not overlapping padding area to avoid scrolling in gaining focus 2498 int index; 2499 int increment; 2500 int end; 2501 int count = getChildCount(); 2502 if ((direction & View.FOCUS_FORWARD) != 0) { 2503 index = 0; 2504 increment = 1; 2505 end = count; 2506 } else { 2507 index = count - 1; 2508 increment = -1; 2509 end = -1; 2510 } 2511 int left = mWindowAlignment.mainAxis().getPaddingLow(); 2512 int right = mWindowAlignment.mainAxis().getClientSize() + left; 2513 for (int i = index; i != end; i += increment) { 2514 View child = getChildAt(i); 2515 if (child.getVisibility() == View.VISIBLE) { 2516 if (getViewMin(child) >= left && getViewMax(child) <= right) { 2517 if (child.requestFocus(direction, previouslyFocusedRect)) { 2518 return true; 2519 } 2520 } 2521 } 2522 } 2523 return false; 2524 } 2525 2526 private final static int PREV_ITEM = 0; 2527 private final static int NEXT_ITEM = 1; 2528 private final static int PREV_ROW = 2; 2529 private final static int NEXT_ROW = 3; 2530 2531 private int getMovement(int direction) { 2532 int movement = View.FOCUS_LEFT; 2533 2534 if (mOrientation == HORIZONTAL) { 2535 switch(direction) { 2536 case View.FOCUS_LEFT: 2537 movement = PREV_ITEM; 2538 break; 2539 case View.FOCUS_RIGHT: 2540 movement = NEXT_ITEM; 2541 break; 2542 case View.FOCUS_UP: 2543 movement = PREV_ROW; 2544 break; 2545 case View.FOCUS_DOWN: 2546 movement = NEXT_ROW; 2547 break; 2548 } 2549 } else if (mOrientation == VERTICAL) { 2550 switch(direction) { 2551 case View.FOCUS_LEFT: 2552 movement = PREV_ROW; 2553 break; 2554 case View.FOCUS_RIGHT: 2555 movement = NEXT_ROW; 2556 break; 2557 case View.FOCUS_UP: 2558 movement = PREV_ITEM; 2559 break; 2560 case View.FOCUS_DOWN: 2561 movement = NEXT_ITEM; 2562 break; 2563 } 2564 } 2565 2566 return movement; 2567 } 2568 2569 int getChildDrawingOrder(RecyclerView recyclerView, int childCount, int i) { 2570 View view = findViewByPosition(mFocusPosition); 2571 if (view == null) { 2572 return i; 2573 } 2574 int focusIndex = recyclerView.indexOfChild(view); 2575 // supposely 0 1 2 3 4 5 6 7 8 9, 4 is the center item 2576 // drawing order is 0 1 2 3 9 8 7 6 5 4 2577 if (i < focusIndex) { 2578 return i; 2579 } else if (i < childCount - 1) { 2580 return focusIndex + childCount - 1 - i; 2581 } else { 2582 return focusIndex; 2583 } 2584 } 2585 2586 @Override 2587 public void onAdapterChanged(RecyclerView.Adapter oldAdapter, 2588 RecyclerView.Adapter newAdapter) { 2589 if (DEBUG) Log.v(getTag(), "onAdapterChanged to " + newAdapter); 2590 if (oldAdapter != null) { 2591 discardLayoutInfo(); 2592 mFocusPosition = NO_POSITION; 2593 mFocusPositionOffset = 0; 2594 mChildrenStates.clear(); 2595 } 2596 super.onAdapterChanged(oldAdapter, newAdapter); 2597 } 2598 2599 private void discardLayoutInfo() { 2600 mGrid = null; 2601 mRows = null; 2602 mRowSizeSecondary = null; 2603 mFirstVisiblePos = -1; 2604 mLastVisiblePos = -1; 2605 mRowSecondarySizeRefresh = false; 2606 } 2607 2608 public void setLayoutEnabled(boolean layoutEnabled) { 2609 if (mLayoutEnabled != layoutEnabled) { 2610 mLayoutEnabled = layoutEnabled; 2611 requestLayout(); 2612 } 2613 } 2614 2615 void setChildrenVisibility(int visiblity) { 2616 mChildVisibility = visiblity; 2617 if (mChildVisibility != -1) { 2618 int count = getChildCount(); 2619 for (int i= 0; i < count; i++) { 2620 getChildAt(i).setVisibility(mChildVisibility); 2621 } 2622 } 2623 } 2624 2625 final static class SavedState implements Parcelable { 2626 2627 int index; // index inside adapter of the current view 2628 Bundle childStates = Bundle.EMPTY; 2629 2630 @Override 2631 public void writeToParcel(Parcel out, int flags) { 2632 out.writeInt(index); 2633 out.writeBundle(childStates); 2634 } 2635 2636 @SuppressWarnings("hiding") 2637 public static final Parcelable.Creator<SavedState> CREATOR = 2638 new Parcelable.Creator<SavedState>() { 2639 @Override 2640 public SavedState createFromParcel(Parcel in) { 2641 return new SavedState(in); 2642 } 2643 2644 @Override 2645 public SavedState[] newArray(int size) { 2646 return new SavedState[size]; 2647 } 2648 }; 2649 2650 @Override 2651 public int describeContents() { 2652 return 0; 2653 } 2654 2655 SavedState(Parcel in) { 2656 index = in.readInt(); 2657 childStates = in.readBundle(GridLayoutManager.class.getClassLoader()); 2658 } 2659 2660 SavedState() { 2661 } 2662 } 2663 2664 @Override 2665 public Parcelable onSaveInstanceState() { 2666 if (DEBUG) Log.v(getTag(), "onSaveInstanceState getSelection() " + getSelection()); 2667 SavedState ss = new SavedState(); 2668 for (int i = 0, count = getChildCount(); i < count; i++) { 2669 View view = getChildAt(i); 2670 int position = getPositionByView(view); 2671 if (position != NO_POSITION) { 2672 mChildrenStates.saveOnScreenView(view, position); 2673 } 2674 } 2675 ss.index = getSelection(); 2676 ss.childStates = mChildrenStates.saveAsBundle(); 2677 return ss; 2678 } 2679 2680 @Override 2681 public void onRestoreInstanceState(Parcelable state) { 2682 if (!(state instanceof SavedState)) { 2683 return; 2684 } 2685 SavedState loadingState = (SavedState)state; 2686 mFocusPosition = loadingState.index; 2687 mFocusPositionOffset = 0; 2688 mChildrenStates.loadFromBundle(loadingState.childStates); 2689 mForceFullLayout = true; 2690 requestLayout(); 2691 if (DEBUG) Log.v(getTag(), "onRestoreInstanceState mFocusPosition " + mFocusPosition); 2692 } 2693} 2694