GridLayoutManager.java revision d1911befd5509ac5ba188559eab193291bedb4ed
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 if (measure && rowSize < 0 && mState.getItemCount() > 0) { 849 if (scrapChildWidth < 0 && scrapChildHeight < 0) { 850 measureScrapChild(mFocusPosition == NO_POSITION ? 0 : mFocusPosition, 851 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 852 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 853 mMeasuredDimension); 854 scrapChildWidth = mMeasuredDimension[0]; 855 scrapChildHeight = mMeasuredDimension[1]; 856 if (DEBUG) Log.v(TAG, "measured scrap child: " + scrapChildWidth + 857 " " + scrapChildHeight); 858 } 859 rowSize = mOrientation == HORIZONTAL ? scrapChildHeight : scrapChildWidth; 860 } 861 862 if (rowSize < 0) { 863 rowSize = 0; 864 } 865 866 if (DEBUG) Log.v(getTag(), "row " + rowIndex + " rowItemCount " + rowItemCount + 867 " rowSize " + rowSize); 868 869 if (mRowSizeSecondary[rowIndex] != rowSize) { 870 if (DEBUG) Log.v(getTag(), "row size secondary changed: " + mRowSizeSecondary[rowIndex] + 871 ", " + rowSize); 872 873 mRowSizeSecondary[rowIndex] = rowSize; 874 changed = true; 875 } 876 } 877 878 return changed; 879 } 880 881 /** 882 * Checks if we need to update row secondary sizes. 883 */ 884 private void updateRowSecondarySizeRefresh() { 885 mRowSecondarySizeRefresh = processRowSizeSecondary(false); 886 if (mRowSecondarySizeRefresh) { 887 if (DEBUG) Log.v(getTag(), "mRowSecondarySizeRefresh now set"); 888 forceRequestLayout(); 889 } 890 } 891 892 private void forceRequestLayout() { 893 if (DEBUG) Log.v(getTag(), "forceRequestLayout"); 894 // RecyclerView prevents us from requesting layout in many cases 895 // (during layout, during scroll, etc.) 896 // For secondary row size wrap_content support we currently need a 897 // second layout pass to update the measured size after having measured 898 // and added child views in layoutChildren. 899 // Force the second layout by posting a delayed runnable. 900 // TODO: investigate allowing a second layout pass, 901 // or move child add/measure logic to the measure phase. 902 ViewCompat.postOnAnimation(mBaseGridView, mRequestLayoutRunnable); 903 } 904 905 private final Runnable mRequestLayoutRunnable = new Runnable() { 906 @Override 907 public void run() { 908 if (DEBUG) Log.v(getTag(), "request Layout from runnable"); 909 requestLayout(); 910 } 911 }; 912 913 @Override 914 public void onMeasure(Recycler recycler, State state, int widthSpec, int heightSpec) { 915 saveContext(recycler, state); 916 917 int sizePrimary, sizeSecondary, modeSecondary, paddingSecondary; 918 int measuredSizeSecondary; 919 if (mOrientation == HORIZONTAL) { 920 sizePrimary = MeasureSpec.getSize(widthSpec); 921 sizeSecondary = MeasureSpec.getSize(heightSpec); 922 modeSecondary = MeasureSpec.getMode(heightSpec); 923 paddingSecondary = getPaddingTop() + getPaddingBottom(); 924 } else { 925 sizeSecondary = MeasureSpec.getSize(widthSpec); 926 sizePrimary = MeasureSpec.getSize(heightSpec); 927 modeSecondary = MeasureSpec.getMode(widthSpec); 928 paddingSecondary = getPaddingLeft() + getPaddingRight(); 929 } 930 if (DEBUG) Log.v(getTag(), "onMeasure widthSpec " + Integer.toHexString(widthSpec) + 931 " heightSpec " + Integer.toHexString(heightSpec) + 932 " modeSecondary " + Integer.toHexString(modeSecondary) + 933 " sizeSecondary " + sizeSecondary + " " + this); 934 935 mMaxSizeSecondary = sizeSecondary; 936 937 if (mRowSizeSecondaryRequested == ViewGroup.LayoutParams.WRAP_CONTENT) { 938 mNumRows = mNumRowsRequested == 0 ? 1 : mNumRowsRequested; 939 mFixedRowSizeSecondary = 0; 940 941 if (mRowSizeSecondary == null || mRowSizeSecondary.length != mNumRows) { 942 mRowSizeSecondary = new int[mNumRows]; 943 } 944 945 // Measure all current children and update cached row heights 946 processRowSizeSecondary(true); 947 948 switch (modeSecondary) { 949 case MeasureSpec.UNSPECIFIED: 950 measuredSizeSecondary = getSizeSecondary() + paddingSecondary; 951 break; 952 case MeasureSpec.AT_MOST: 953 measuredSizeSecondary = Math.min(getSizeSecondary() + paddingSecondary, 954 mMaxSizeSecondary); 955 break; 956 case MeasureSpec.EXACTLY: 957 measuredSizeSecondary = mMaxSizeSecondary; 958 break; 959 default: 960 throw new IllegalStateException("wrong spec"); 961 } 962 963 } else { 964 switch (modeSecondary) { 965 case MeasureSpec.UNSPECIFIED: 966 if (mRowSizeSecondaryRequested == 0) { 967 if (mOrientation == HORIZONTAL) { 968 throw new IllegalStateException("Must specify rowHeight or view height"); 969 } else { 970 throw new IllegalStateException("Must specify columnWidth or view width"); 971 } 972 } 973 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 974 mNumRows = mNumRowsRequested == 0 ? 1 : mNumRowsRequested; 975 measuredSizeSecondary = mFixedRowSizeSecondary * mNumRows + mMarginSecondary 976 * (mNumRows - 1) + paddingSecondary; 977 break; 978 case MeasureSpec.AT_MOST: 979 case MeasureSpec.EXACTLY: 980 if (mNumRowsRequested == 0 && mRowSizeSecondaryRequested == 0) { 981 mNumRows = 1; 982 mFixedRowSizeSecondary = sizeSecondary - paddingSecondary; 983 } else if (mNumRowsRequested == 0) { 984 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 985 mNumRows = (sizeSecondary + mMarginSecondary) 986 / (mRowSizeSecondaryRequested + mMarginSecondary); 987 } else if (mRowSizeSecondaryRequested == 0) { 988 mNumRows = mNumRowsRequested; 989 mFixedRowSizeSecondary = (sizeSecondary - paddingSecondary - mMarginSecondary 990 * (mNumRows - 1)) / mNumRows; 991 } else { 992 mNumRows = mNumRowsRequested; 993 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 994 } 995 measuredSizeSecondary = sizeSecondary; 996 if (modeSecondary == MeasureSpec.AT_MOST) { 997 int childrenSize = mFixedRowSizeSecondary * mNumRows + mMarginSecondary 998 * (mNumRows - 1) + paddingSecondary; 999 if (childrenSize < measuredSizeSecondary) { 1000 measuredSizeSecondary = childrenSize; 1001 } 1002 } 1003 break; 1004 default: 1005 throw new IllegalStateException("wrong spec"); 1006 } 1007 } 1008 if (mOrientation == HORIZONTAL) { 1009 setMeasuredDimension(sizePrimary, measuredSizeSecondary); 1010 } else { 1011 setMeasuredDimension(measuredSizeSecondary, sizePrimary); 1012 } 1013 if (DEBUG) { 1014 Log.v(getTag(), "onMeasure sizePrimary " + sizePrimary + 1015 " measuredSizeSecondary " + measuredSizeSecondary + 1016 " mFixedRowSizeSecondary " + mFixedRowSizeSecondary + 1017 " mNumRows " + mNumRows); 1018 } 1019 1020 leaveContext(); 1021 } 1022 1023 private void measureChild(View child) { 1024 final ViewGroup.LayoutParams lp = child.getLayoutParams(); 1025 final int secondarySpec = (mRowSizeSecondaryRequested == ViewGroup.LayoutParams.WRAP_CONTENT) ? 1026 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED) : 1027 MeasureSpec.makeMeasureSpec(mFixedRowSizeSecondary, MeasureSpec.EXACTLY); 1028 int widthSpec, heightSpec; 1029 1030 if (mOrientation == HORIZONTAL) { 1031 widthSpec = ViewGroup.getChildMeasureSpec( 1032 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 1033 0, lp.width); 1034 heightSpec = ViewGroup.getChildMeasureSpec(secondarySpec, 0, lp.height); 1035 } else { 1036 heightSpec = ViewGroup.getChildMeasureSpec( 1037 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 1038 0, lp.height); 1039 widthSpec = ViewGroup.getChildMeasureSpec(secondarySpec, 0, lp.width); 1040 } 1041 1042 child.measure(widthSpec, heightSpec); 1043 1044 if (DEBUG) Log.v(getTag(), "measureChild secondarySpec " + Integer.toHexString(secondarySpec) + 1045 " widthSpec " + Integer.toHexString(widthSpec) + 1046 " heightSpec " + Integer.toHexString(heightSpec) + 1047 " measuredWidth " + child.getMeasuredWidth() + 1048 " measuredHeight " + child.getMeasuredHeight()); 1049 if (DEBUG) Log.v(getTag(), "child lp width " + lp.width + " height " + lp.height); 1050 } 1051 1052 private StaggeredGrid.Provider mGridProvider = new StaggeredGrid.Provider() { 1053 1054 @Override 1055 public int getCount() { 1056 return mState.getItemCount(); 1057 } 1058 1059 @Override 1060 public void createItem(int index, int rowIndex, boolean append) { 1061 View v = getViewForPosition(index); 1062 if (mFirstVisiblePos >= 0) { 1063 // when StaggeredGrid append or prepend item, we must guarantee 1064 // that sibling item has created views already. 1065 if (append && index != mLastVisiblePos + 1) { 1066 throw new RuntimeException(); 1067 } else if (!append && index != mFirstVisiblePos - 1) { 1068 throw new RuntimeException(); 1069 } 1070 } 1071 1072 // See recyclerView docs: we don't need re-add scraped view if it was removed. 1073 if (!((RecyclerView.LayoutParams) v.getLayoutParams()).isItemRemoved()) { 1074 if (append) { 1075 addView(v); 1076 } else { 1077 addView(v, 0); 1078 } 1079 if (mChildVisibility != -1) { 1080 v.setVisibility(mChildVisibility); 1081 } 1082 1083 // View is added first or it won't be found by dispatchChildSelected. 1084 if (mInLayout && index == mFocusPosition) { 1085 dispatchChildSelected(); 1086 } 1087 1088 measureChild(v); 1089 } 1090 1091 int length = mOrientation == HORIZONTAL ? v.getMeasuredWidth() : v.getMeasuredHeight(); 1092 int start, end; 1093 final boolean rowIsEmpty = mRows[rowIndex].high == mRows[rowIndex].low; 1094 if (append) { 1095 if (!rowIsEmpty) { 1096 // if there are existing item in the row, add margin between 1097 start = mRows[rowIndex].high + mMarginPrimary; 1098 } else { 1099 if (mLastVisiblePos >= 0) { 1100 int lastRow = mGrid.getLocation(mLastVisiblePos).row; 1101 // if the last visible item is not last row, align to beginning, 1102 // otherwise start a new column after. 1103 if (lastRow < mNumRows - 1) { 1104 start = mRows[lastRow].low; 1105 } else { 1106 start = mRows[lastRow].high + mMarginPrimary; 1107 } 1108 } else { 1109 start = 0; 1110 } 1111 mRows[rowIndex].low = start; 1112 } 1113 end = start + length; 1114 mRows[rowIndex].high = end; 1115 } else { 1116 if (!rowIsEmpty) { 1117 // if there are existing item in the row, add margin between 1118 end = mRows[rowIndex].low - mMarginPrimary; 1119 start = end - length; 1120 } else { 1121 if (mFirstVisiblePos >= 0) { 1122 int firstRow = mGrid.getLocation(mFirstVisiblePos).row; 1123 // if the first visible item is not first row, align to beginning, 1124 // otherwise start a new column before. 1125 if (firstRow > 0) { 1126 start = mRows[firstRow].low; 1127 end = start + length; 1128 } else { 1129 end = mRows[firstRow].low - mMarginPrimary; 1130 start = end - length; 1131 } 1132 } else { 1133 start = 0; 1134 end = length; 1135 } 1136 mRows[rowIndex].high = end; 1137 } 1138 mRows[rowIndex].low = start; 1139 } 1140 if (mFirstVisiblePos < 0) { 1141 mFirstVisiblePos = mLastVisiblePos = index; 1142 } else { 1143 if (append) { 1144 mLastVisiblePos++; 1145 } else { 1146 mFirstVisiblePos--; 1147 } 1148 } 1149 if (DEBUG) Log.v(getTag(), "start " + start + " end " + end); 1150 int startSecondary = getRowStartSecondary(rowIndex) - mScrollOffsetSecondary; 1151 mChildrenStates.loadView(v, index); 1152 layoutChild(rowIndex, v, start - mScrollOffsetPrimary, end - mScrollOffsetPrimary, 1153 startSecondary); 1154 if (DEBUG) { 1155 Log.d(getTag(), "addView " + index + " " + v); 1156 } 1157 if (index == mFirstVisiblePos) { 1158 updateScrollMin(); 1159 } 1160 if (index == mLastVisiblePos) { 1161 updateScrollMax(); 1162 } 1163 } 1164 }; 1165 1166 private void layoutChild(int rowIndex, View v, int start, int end, int startSecondary) { 1167 int sizeSecondary = mOrientation == HORIZONTAL ? v.getMeasuredHeight() 1168 : v.getMeasuredWidth(); 1169 if (mFixedRowSizeSecondary > 0) { 1170 sizeSecondary = Math.min(sizeSecondary, mFixedRowSizeSecondary); 1171 } 1172 final int verticalGravity = mGravity & Gravity.VERTICAL_GRAVITY_MASK; 1173 final int horizontalGravity = mGravity & Gravity.HORIZONTAL_GRAVITY_MASK; 1174 if (mOrientation == HORIZONTAL && verticalGravity == Gravity.TOP 1175 || mOrientation == VERTICAL && horizontalGravity == Gravity.LEFT) { 1176 // do nothing 1177 } else if (mOrientation == HORIZONTAL && verticalGravity == Gravity.BOTTOM 1178 || mOrientation == VERTICAL && horizontalGravity == Gravity.RIGHT) { 1179 startSecondary += getRowSizeSecondary(rowIndex) - sizeSecondary; 1180 } else if (mOrientation == HORIZONTAL && verticalGravity == Gravity.CENTER_VERTICAL 1181 || mOrientation == VERTICAL && horizontalGravity == Gravity.CENTER_HORIZONTAL) { 1182 startSecondary += (getRowSizeSecondary(rowIndex) - sizeSecondary) / 2; 1183 } 1184 int left, top, right, bottom; 1185 if (mOrientation == HORIZONTAL) { 1186 left = start; 1187 top = startSecondary; 1188 right = end; 1189 bottom = startSecondary + sizeSecondary; 1190 } else { 1191 top = start; 1192 left = startSecondary; 1193 bottom = end; 1194 right = startSecondary + sizeSecondary; 1195 } 1196 v.layout(left, top, right, bottom); 1197 updateChildOpticalInsets(v, left, top, right, bottom); 1198 updateChildAlignments(v); 1199 } 1200 1201 private void updateChildOpticalInsets(View v, int left, int top, int right, int bottom) { 1202 LayoutParams p = (LayoutParams) v.getLayoutParams(); 1203 p.setOpticalInsets(left - v.getLeft(), top - v.getTop(), 1204 v.getRight() - right, v.getBottom() - bottom); 1205 } 1206 1207 private void updateChildAlignments(View v) { 1208 LayoutParams p = (LayoutParams) v.getLayoutParams(); 1209 p.setAlignX(mItemAlignment.horizontal.getAlignmentPosition(v)); 1210 p.setAlignY(mItemAlignment.vertical.getAlignmentPosition(v)); 1211 } 1212 1213 private void updateChildAlignments() { 1214 for (int i = 0, c = getChildCount(); i < c; i++) { 1215 updateChildAlignments(getChildAt(i)); 1216 } 1217 } 1218 1219 private boolean needsAppendVisibleItem() { 1220 if (mLastVisiblePos < mFocusPosition) { 1221 return true; 1222 } 1223 int right = mScrollOffsetPrimary + mSizePrimary; 1224 for (int i = 0; i < mNumRows; i++) { 1225 if (mRows[i].low == mRows[i].high) { 1226 if (mRows[i].high < right) { 1227 return true; 1228 } 1229 } else if (mRows[i].high < right - mMarginPrimary) { 1230 return true; 1231 } 1232 } 1233 return false; 1234 } 1235 1236 private boolean needsPrependVisibleItem() { 1237 if (mFirstVisiblePos > mFocusPosition) { 1238 return true; 1239 } 1240 for (int i = 0; i < mNumRows; i++) { 1241 if (mRows[i].low == mRows[i].high) { 1242 if (mRows[i].low > mScrollOffsetPrimary) { 1243 return true; 1244 } 1245 } else if (mRows[i].low - mMarginPrimary > mScrollOffsetPrimary) { 1246 return true; 1247 } 1248 } 1249 return false; 1250 } 1251 1252 // Append one column if possible and return true if reach end. 1253 private boolean appendOneVisibleItem() { 1254 while (true) { 1255 if (mLastVisiblePos != NO_POSITION && mLastVisiblePos < mState.getItemCount() -1 && 1256 mLastVisiblePos < mGrid.getLastIndex()) { 1257 // append invisible view of saved location till last row 1258 final int index = mLastVisiblePos + 1; 1259 final int row = mGrid.getLocation(index).row; 1260 mGridProvider.createItem(index, row, true); 1261 if (row == mNumRows - 1) { 1262 return false; 1263 } 1264 } else if ((mLastVisiblePos == NO_POSITION && mState.getItemCount() > 0) || 1265 (mLastVisiblePos != NO_POSITION && 1266 mLastVisiblePos < mState.getItemCount() - 1)) { 1267 mGrid.appendItems(mScrollOffsetPrimary + mSizePrimary); 1268 return false; 1269 } else { 1270 return true; 1271 } 1272 } 1273 } 1274 1275 private void appendVisibleItems() { 1276 while (needsAppendVisibleItem()) { 1277 if (appendOneVisibleItem()) { 1278 break; 1279 } 1280 } 1281 } 1282 1283 // Prepend one column if possible and return true if reach end. 1284 private boolean prependOneVisibleItem() { 1285 while (true) { 1286 if (mFirstVisiblePos > 0) { 1287 if (mFirstVisiblePos > mGrid.getFirstIndex()) { 1288 // prepend invisible view of saved location till first row 1289 final int index = mFirstVisiblePos - 1; 1290 final int row = mGrid.getLocation(index).row; 1291 mGridProvider.createItem(index, row, false); 1292 if (row == 0) { 1293 return false; 1294 } 1295 } else { 1296 mGrid.prependItems(mScrollOffsetPrimary); 1297 return false; 1298 } 1299 } else { 1300 return true; 1301 } 1302 } 1303 } 1304 1305 private void prependVisibleItems() { 1306 while (needsPrependVisibleItem()) { 1307 if (prependOneVisibleItem()) { 1308 break; 1309 } 1310 } 1311 } 1312 1313 private void removeChildAt(int position) { 1314 View v = findViewByPosition(position); 1315 if (v != null) { 1316 if (DEBUG) { 1317 Log.d(getTag(), "removeAndRecycleViewAt " + position + " " + v); 1318 } 1319 mChildrenStates.saveOffscreenView(v, position); 1320 removeAndRecycleView(v, mRecycler); 1321 } 1322 } 1323 1324 private void removeInvisibleViewsAtEnd() { 1325 if (!mPruneChild) { 1326 return; 1327 } 1328 boolean update = false; 1329 while(mLastVisiblePos > mFirstVisiblePos && mLastVisiblePos > mFocusPosition) { 1330 View view = findViewByPosition(mLastVisiblePos); 1331 if (getViewMin(view) > mSizePrimary) { 1332 removeChildAt(mLastVisiblePos); 1333 mLastVisiblePos--; 1334 update = true; 1335 } else { 1336 break; 1337 } 1338 } 1339 if (update) { 1340 updateRowsMinMax(); 1341 } 1342 } 1343 1344 private void removeInvisibleViewsAtFront() { 1345 if (!mPruneChild) { 1346 return; 1347 } 1348 boolean update = false; 1349 while(mLastVisiblePos > mFirstVisiblePos && mFirstVisiblePos < mFocusPosition) { 1350 View view = findViewByPosition(mFirstVisiblePos); 1351 if (getViewMax(view) < 0) { 1352 removeChildAt(mFirstVisiblePos); 1353 mFirstVisiblePos++; 1354 update = true; 1355 } else { 1356 break; 1357 } 1358 } 1359 if (update) { 1360 updateRowsMinMax(); 1361 } 1362 } 1363 1364 private void updateRowsMinMax() { 1365 if (mFirstVisiblePos < 0) { 1366 return; 1367 } 1368 for (int i = 0; i < mNumRows; i++) { 1369 mRows[i].low = Integer.MAX_VALUE; 1370 mRows[i].high = Integer.MIN_VALUE; 1371 } 1372 for (int i = mFirstVisiblePos; i <= mLastVisiblePos; i++) { 1373 View view = findViewByPosition(i); 1374 int row = mGrid.getLocation(i).row; 1375 int low = getViewMin(view) + mScrollOffsetPrimary; 1376 if (low < mRows[row].low) { 1377 mRows[row].low = low; 1378 } 1379 int high = getViewMax(view) + mScrollOffsetPrimary; 1380 if (high > mRows[row].high) { 1381 mRows[row].high = high; 1382 } 1383 } 1384 } 1385 1386 // Fast layout when there is no structure change, adapter change, etc. 1387 protected void fastRelayout(boolean scrollToFocus) { 1388 initScrollController(); 1389 1390 List<Integer>[] rows = mGrid.getItemPositionsInRows(mFirstVisiblePos, mLastVisiblePos); 1391 1392 // relayout and repositioning views on each row 1393 for (int i = 0; i < mNumRows; i++) { 1394 List<Integer> row = rows[i]; 1395 final int startSecondary = getRowStartSecondary(i) - mScrollOffsetSecondary; 1396 for (int j = 0, size = row.size(); j < size; j++) { 1397 final int position = row.get(j); 1398 View view = findViewByPosition(position); 1399 int primaryDelta, end; 1400 1401 int start = getViewMin(view); 1402 int oldPrimarySize = (mOrientation == HORIZONTAL) ? 1403 view.getMeasuredWidth() : 1404 view.getMeasuredHeight(); 1405 1406 LayoutParams lp = (LayoutParams) view.getLayoutParams(); 1407 if (lp.viewNeedsUpdate()) { 1408 int index = mBaseGridView.indexOfChild(view); 1409 detachAndScrapView(view, mRecycler); 1410 view = getViewForPosition(position); 1411 addView(view, index); 1412 } 1413 1414 if (view.isLayoutRequested()) { 1415 measureChild(view); 1416 } 1417 1418 if (mOrientation == HORIZONTAL) { 1419 end = start + view.getMeasuredWidth(); 1420 primaryDelta = view.getMeasuredWidth() - oldPrimarySize; 1421 if (primaryDelta != 0) { 1422 for (int k = j + 1; k < size; k++) { 1423 findViewByPosition(row.get(k)).offsetLeftAndRight(primaryDelta); 1424 } 1425 } 1426 } else { 1427 end = start + view.getMeasuredHeight(); 1428 primaryDelta = view.getMeasuredHeight() - oldPrimarySize; 1429 if (primaryDelta != 0) { 1430 for (int k = j + 1; k < size; k++) { 1431 findViewByPosition(row.get(k)).offsetTopAndBottom(primaryDelta); 1432 } 1433 } 1434 } 1435 layoutChild(i, view, start, end, startSecondary); 1436 } 1437 } 1438 1439 updateRowsMinMax(); 1440 appendVisibleItems(); 1441 prependVisibleItems(); 1442 1443 updateRowsMinMax(); 1444 updateScrollMin(); 1445 updateScrollMax(); 1446 updateScrollSecondAxis(); 1447 1448 if (scrollToFocus) { 1449 View focusView = findViewByPosition(mFocusPosition == NO_POSITION ? 0 : mFocusPosition); 1450 scrollToView(focusView, false); 1451 } 1452 } 1453 1454 public void removeAndRecycleAllViews(RecyclerView.Recycler recycler) { 1455 if (DEBUG) Log.v(TAG, "removeAndRecycleAllViews " + getChildCount()); 1456 for (int i = getChildCount() - 1; i >= 0; i--) { 1457 removeAndRecycleViewAt(i, recycler); 1458 } 1459 } 1460 1461 // Lays out items based on the current scroll position 1462 @Override 1463 public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state) { 1464 if (DEBUG) { 1465 Log.v(getTag(), "layoutChildren start numRows " + mNumRows + " mScrollOffsetSecondary " 1466 + mScrollOffsetSecondary + " mScrollOffsetPrimary " + mScrollOffsetPrimary 1467 + " inPreLayout " + state.isPreLayout() 1468 + " didStructureChange " + state.didStructureChange() 1469 + " mForceFullLayout " + mForceFullLayout); 1470 Log.v(getTag(), "width " + getWidth() + " height " + getHeight()); 1471 } 1472 1473 if (mNumRows == 0) { 1474 // haven't done measure yet 1475 return; 1476 } 1477 final int itemCount = state.getItemCount(); 1478 if (itemCount < 0) { 1479 return; 1480 } 1481 1482 if (!mLayoutEnabled) { 1483 discardLayoutInfo(); 1484 removeAndRecycleAllViews(recycler); 1485 return; 1486 } 1487 mInLayout = true; 1488 1489 final boolean scrollToFocus = !isSmoothScrolling() 1490 && mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED; 1491 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE) { 1492 mFocusPosition = mFocusPosition + mFocusPositionOffset; 1493 mFocusPositionOffset = 0; 1494 } 1495 saveContext(recycler, state); 1496 // Track the old focus view so we can adjust our system scroll position 1497 // so that any scroll animations happening now will remain valid. 1498 // We must use same delta in Pre Layout (if prelayout exists) and second layout. 1499 // So we cache the deltas in PreLayout and use it in second layout. 1500 int delta = 0, deltaSecondary = 0; 1501 if (mFocusPosition != NO_POSITION && scrollToFocus) { 1502 // FIXME: we should get the remaining scroll animation offset from RecyclerView 1503 View focusView = findViewByPosition(mFocusPosition); 1504 if (focusView != null) { 1505 delta = mWindowAlignment.mainAxis().getSystemScrollPos(mScrollOffsetPrimary 1506 + getViewCenter(focusView), false, false) - mScrollOffsetPrimary; 1507 deltaSecondary = mWindowAlignment.secondAxis().getSystemScrollPos( 1508 mScrollOffsetSecondary + getViewCenterSecondary(focusView), 1509 false, false) - mScrollOffsetSecondary; 1510 } 1511 } 1512 1513 final boolean hasDoneFirstLayout = hasDoneFirstLayout(); 1514 int savedFocusPos = mFocusPosition; 1515 boolean fastRelayout = false; 1516 if (!mState.didStructureChange() && !mForceFullLayout && hasDoneFirstLayout) { 1517 fastRelayout = true; 1518 fastRelayout(scrollToFocus); 1519 } else { 1520 boolean hadFocus = mBaseGridView.hasFocus(); 1521 1522 mFocusPosition = init(mFocusPosition); 1523 if (mFocusPosition != savedFocusPos) { 1524 if (DEBUG) Log.v(getTag(), "savedFocusPos " + savedFocusPos + 1525 " mFocusPosition " + mFocusPosition); 1526 } 1527 1528 mWindowAlignment.mainAxis().invalidateScrollMin(); 1529 mWindowAlignment.mainAxis().invalidateScrollMax(); 1530 // depending on result of init(), either recreating everything 1531 // or try to reuse the row start positions near mFocusPosition 1532 if (mGrid.getSize() == 0) { 1533 // this is a fresh creating all items, starting from 1534 // mFocusPosition with a estimated row index. 1535 mGrid.setStart(mFocusPosition, StaggeredGrid.START_DEFAULT); 1536 1537 // Can't track the old focus view 1538 delta = deltaSecondary = 0; 1539 1540 } else { 1541 // mGrid remembers Locations for the column that 1542 // contains mFocusePosition and also mRows remembers start 1543 // positions of each row. 1544 // Manually re-create child views for that column 1545 int firstIndex = mGrid.getFirstIndex(); 1546 int lastIndex = mGrid.getLastIndex(); 1547 for (int i = firstIndex; i <= lastIndex; i++) { 1548 mGridProvider.createItem(i, mGrid.getLocation(i).row, true); 1549 } 1550 } 1551 1552 // add visible views at end until reach the end of window 1553 appendVisibleItems(); 1554 // add visible views at front until reach the start of window 1555 prependVisibleItems(); 1556 // multiple rounds: scrollToView of first round may drag first/last child into 1557 // "visible window" and we update scrollMin/scrollMax then run second scrollToView 1558 int oldFirstVisible; 1559 int oldLastVisible; 1560 do { 1561 updateScrollMin(); 1562 updateScrollMax(); 1563 oldFirstVisible = mFirstVisiblePos; 1564 oldLastVisible = mLastVisiblePos; 1565 View focusView = findViewByPosition(mFocusPosition); 1566 // we need force to initialize the child view's position 1567 scrollToView(focusView, false); 1568 if (focusView != null && hadFocus) { 1569 focusView.requestFocus(); 1570 } 1571 appendVisibleItems(); 1572 prependVisibleItems(); 1573 removeInvisibleViewsAtFront(); 1574 removeInvisibleViewsAtEnd(); 1575 } while (mFirstVisiblePos != oldFirstVisible || mLastVisiblePos != oldLastVisible); 1576 } 1577 mForceFullLayout = false; 1578 1579 if (scrollToFocus) { 1580 scrollDirectionPrimary(-delta); 1581 scrollDirectionSecondary(-deltaSecondary); 1582 } 1583 appendVisibleItems(); 1584 prependVisibleItems(); 1585 removeInvisibleViewsAtFront(); 1586 removeInvisibleViewsAtEnd(); 1587 1588 if (DEBUG) { 1589 StringWriter sw = new StringWriter(); 1590 PrintWriter pw = new PrintWriter(sw); 1591 mGrid.debugPrint(pw); 1592 Log.d(getTag(), sw.toString()); 1593 } 1594 1595 if (mRowSecondarySizeRefresh) { 1596 mRowSecondarySizeRefresh = false; 1597 } else { 1598 updateRowSecondarySizeRefresh(); 1599 } 1600 1601 if (fastRelayout && mFocusPosition != savedFocusPos) { 1602 dispatchChildSelected(); 1603 } 1604 mInLayout = false; 1605 leaveContext(); 1606 if (DEBUG) Log.v(getTag(), "layoutChildren end"); 1607 } 1608 1609 private void offsetChildrenSecondary(int increment) { 1610 final int childCount = getChildCount(); 1611 if (mOrientation == HORIZONTAL) { 1612 for (int i = 0; i < childCount; i++) { 1613 getChildAt(i).offsetTopAndBottom(increment); 1614 } 1615 } else { 1616 for (int i = 0; i < childCount; i++) { 1617 getChildAt(i).offsetLeftAndRight(increment); 1618 } 1619 } 1620 } 1621 1622 private void offsetChildrenPrimary(int increment) { 1623 final int childCount = getChildCount(); 1624 if (mOrientation == VERTICAL) { 1625 for (int i = 0; i < childCount; i++) { 1626 getChildAt(i).offsetTopAndBottom(increment); 1627 } 1628 } else { 1629 for (int i = 0; i < childCount; i++) { 1630 getChildAt(i).offsetLeftAndRight(increment); 1631 } 1632 } 1633 } 1634 1635 @Override 1636 public int scrollHorizontallyBy(int dx, Recycler recycler, RecyclerView.State state) { 1637 if (DEBUG) Log.v(getTag(), "scrollHorizontallyBy " + dx); 1638 if (!mLayoutEnabled || !hasDoneFirstLayout()) { 1639 return 0; 1640 } 1641 saveContext(recycler, state); 1642 int result; 1643 if (mOrientation == HORIZONTAL) { 1644 result = scrollDirectionPrimary(dx); 1645 } else { 1646 result = scrollDirectionSecondary(dx); 1647 } 1648 leaveContext(); 1649 return result; 1650 } 1651 1652 @Override 1653 public int scrollVerticallyBy(int dy, Recycler recycler, RecyclerView.State state) { 1654 if (DEBUG) Log.v(getTag(), "scrollVerticallyBy " + dy); 1655 if (!mLayoutEnabled || !hasDoneFirstLayout()) { 1656 return 0; 1657 } 1658 saveContext(recycler, state); 1659 int result; 1660 if (mOrientation == VERTICAL) { 1661 result = scrollDirectionPrimary(dy); 1662 } else { 1663 result = scrollDirectionSecondary(dy); 1664 } 1665 leaveContext(); 1666 return result; 1667 } 1668 1669 // scroll in main direction may add/prune views 1670 private int scrollDirectionPrimary(int da) { 1671 if (da > 0) { 1672 if (!mWindowAlignment.mainAxis().isMaxUnknown()) { 1673 int maxScroll = mWindowAlignment.mainAxis().getMaxScroll(); 1674 if (mScrollOffsetPrimary + da > maxScroll) { 1675 da = maxScroll - mScrollOffsetPrimary; 1676 } 1677 } 1678 } else if (da < 0) { 1679 if (!mWindowAlignment.mainAxis().isMinUnknown()) { 1680 int minScroll = mWindowAlignment.mainAxis().getMinScroll(); 1681 if (mScrollOffsetPrimary + da < minScroll) { 1682 da = minScroll - mScrollOffsetPrimary; 1683 } 1684 } 1685 } 1686 if (da == 0) { 1687 return 0; 1688 } 1689 offsetChildrenPrimary(-da); 1690 mScrollOffsetPrimary += da; 1691 if (mInLayout) { 1692 return da; 1693 } 1694 1695 int childCount = getChildCount(); 1696 boolean updated; 1697 1698 if (da > 0) { 1699 appendVisibleItems(); 1700 } else if (da < 0) { 1701 prependVisibleItems(); 1702 } 1703 updated = getChildCount() > childCount; 1704 childCount = getChildCount(); 1705 1706 if (da > 0) { 1707 removeInvisibleViewsAtFront(); 1708 } else if (da < 0) { 1709 removeInvisibleViewsAtEnd(); 1710 } 1711 updated |= getChildCount() < childCount; 1712 1713 if (updated) { 1714 updateRowSecondarySizeRefresh(); 1715 } 1716 1717 mBaseGridView.invalidate(); 1718 return da; 1719 } 1720 1721 // scroll in second direction will not add/prune views 1722 private int scrollDirectionSecondary(int dy) { 1723 if (dy == 0) { 1724 return 0; 1725 } 1726 offsetChildrenSecondary(-dy); 1727 mScrollOffsetSecondary += dy; 1728 mBaseGridView.invalidate(); 1729 return dy; 1730 } 1731 1732 private void updateScrollMax() { 1733 if (mLastVisiblePos < 0) { 1734 return; 1735 } 1736 final boolean lastAvailable = mLastVisiblePos == mState.getItemCount() - 1; 1737 final boolean maxUnknown = mWindowAlignment.mainAxis().isMaxUnknown(); 1738 if (!lastAvailable && maxUnknown) { 1739 return; 1740 } 1741 int maxEdge = Integer.MIN_VALUE; 1742 int rowIndex = -1; 1743 for (int i = 0; i < mRows.length; i++) { 1744 if (mRows[i].high > maxEdge) { 1745 maxEdge = mRows[i].high; 1746 rowIndex = i; 1747 } 1748 } 1749 int maxScroll = Integer.MAX_VALUE; 1750 for (int i = mLastVisiblePos; i >= mFirstVisiblePos; i--) { 1751 StaggeredGrid.Location location = mGrid.getLocation(i); 1752 if (location != null && location.row == rowIndex) { 1753 int savedMaxEdge = mWindowAlignment.mainAxis().getMaxEdge(); 1754 mWindowAlignment.mainAxis().setMaxEdge(maxEdge); 1755 maxScroll = getPrimarySystemScrollPosition(findViewByPosition(i)); 1756 mWindowAlignment.mainAxis().setMaxEdge(savedMaxEdge); 1757 break; 1758 } 1759 } 1760 if (lastAvailable) { 1761 mWindowAlignment.mainAxis().setMaxEdge(maxEdge); 1762 mWindowAlignment.mainAxis().setMaxScroll(maxScroll); 1763 if (DEBUG) Log.v(getTag(), "updating scroll maxEdge to " + maxEdge + 1764 " scrollMax to " + maxScroll); 1765 } else { 1766 // the maxScroll for currently last visible item is larger, 1767 // so we must invalidate the max scroll value. 1768 if (maxScroll > mWindowAlignment.mainAxis().getMaxScroll()) { 1769 mWindowAlignment.mainAxis().invalidateScrollMax(); 1770 if (DEBUG) Log.v(getTag(), "Invalidate scrollMax since it should be " 1771 + "greater than " + maxScroll); 1772 } 1773 } 1774 } 1775 1776 private void updateScrollMin() { 1777 if (mFirstVisiblePos < 0) { 1778 return; 1779 } 1780 final boolean firstAvailable = mFirstVisiblePos == 0; 1781 final boolean minUnknown = mWindowAlignment.mainAxis().isMinUnknown(); 1782 if (!firstAvailable && minUnknown) { 1783 return; 1784 } 1785 int minEdge = Integer.MAX_VALUE; 1786 int rowIndex = -1; 1787 for (int i = 0; i < mRows.length; i++) { 1788 if (mRows[i].low < minEdge) { 1789 minEdge = mRows[i].low; 1790 rowIndex = i; 1791 } 1792 } 1793 int minScroll = Integer.MIN_VALUE; 1794 for (int i = mFirstVisiblePos; i <= mLastVisiblePos; i++) { 1795 StaggeredGrid.Location location = mGrid.getLocation(i); 1796 if (location != null && location.row == rowIndex) { 1797 int savedMinEdge = mWindowAlignment.mainAxis().getMinEdge(); 1798 mWindowAlignment.mainAxis().setMinEdge(minEdge); 1799 minScroll = getPrimarySystemScrollPosition(findViewByPosition(i)); 1800 mWindowAlignment.mainAxis().setMinEdge(savedMinEdge); 1801 break; 1802 } 1803 } 1804 if (firstAvailable) { 1805 mWindowAlignment.mainAxis().setMinEdge(minEdge); 1806 mWindowAlignment.mainAxis().setMinScroll(minScroll); 1807 if (DEBUG) Log.v(getTag(), "updating scroll minEdge to " + minEdge + 1808 " scrollMin to " + minScroll); 1809 } else { 1810 // the minScroll for currently first visible item is smaller, 1811 // so we must invalidate the min scroll value. 1812 if (minScroll < mWindowAlignment.mainAxis().getMinScroll()) { 1813 mWindowAlignment.mainAxis().invalidateScrollMin(); 1814 if (DEBUG) Log.v(getTag(), "Invalidate scrollMin, since it should be " 1815 + "less than " + minScroll); 1816 } 1817 } 1818 } 1819 1820 private void updateScrollSecondAxis() { 1821 mWindowAlignment.secondAxis().setMinEdge(0); 1822 mWindowAlignment.secondAxis().setMaxEdge(getSizeSecondary()); 1823 } 1824 1825 private void initScrollController() { 1826 // mScrollOffsetPrimary and mScrollOffsetSecondary includes the padding. 1827 // e.g. when topPadding is 16 for horizontal grid view, the initial 1828 // mScrollOffsetSecondary is -16. fastLayout() put views based on offsets(not padding), 1829 // when padding changes to 20, we also need update mScrollOffsetSecondary to -20 before 1830 // fastLayout() is performed 1831 int paddingPrimaryDiff, paddingSecondaryDiff; 1832 if (mOrientation == HORIZONTAL) { 1833 paddingPrimaryDiff = getPaddingLeft() - mWindowAlignment.horizontal.getPaddingLow(); 1834 paddingSecondaryDiff = getPaddingTop() - mWindowAlignment.vertical.getPaddingLow(); 1835 } else { 1836 paddingPrimaryDiff = getPaddingTop() - mWindowAlignment.vertical.getPaddingLow(); 1837 paddingSecondaryDiff = getPaddingLeft() - mWindowAlignment.horizontal.getPaddingLow(); 1838 } 1839 mScrollOffsetPrimary -= paddingPrimaryDiff; 1840 mScrollOffsetSecondary -= paddingSecondaryDiff; 1841 1842 if (mOrientation == HORIZONTAL) { 1843 mWindowAlignment.horizontal.setSize((int)(getWidth() * mPrimaryOverReach + 0.5f)); 1844 mWindowAlignment.vertical.setSize(getHeight()); 1845 } else { 1846 mWindowAlignment.horizontal.setSize(getWidth()); 1847 mWindowAlignment.vertical.setSize((int) (getHeight() * mPrimaryOverReach + 0.5f)); 1848 } 1849 mWindowAlignment.horizontal.setPadding(getPaddingLeft(), getPaddingRight()); 1850 mWindowAlignment.vertical.setPadding(getPaddingTop(), getPaddingBottom()); 1851 mSizePrimary = mWindowAlignment.mainAxis().getSize(); 1852 1853 if (DEBUG) { 1854 Log.v(getTag(), "initScrollController mSizePrimary " + mSizePrimary 1855 + " mWindowAlignment " + mWindowAlignment); 1856 } 1857 } 1858 1859 public void setSelection(RecyclerView parent, int position) { 1860 setSelection(parent, position, false); 1861 } 1862 1863 public void setSelectionSmooth(RecyclerView parent, int position) { 1864 setSelection(parent, position, true); 1865 } 1866 1867 public int getSelection() { 1868 return mFocusPosition; 1869 } 1870 1871 public void setSelection(RecyclerView parent, int position, boolean smooth) { 1872 if (mFocusPosition != position) { 1873 scrollToSelection(parent, position, smooth); 1874 } 1875 } 1876 1877 private void scrollToSelection(RecyclerView parent, int position, boolean smooth) { 1878 View view = findViewByPosition(position); 1879 if (view != null) { 1880 mInSelection = true; 1881 scrollToView(view, smooth); 1882 mInSelection = false; 1883 } else { 1884 mFocusPosition = position; 1885 mFocusPositionOffset = 0; 1886 if (!mLayoutEnabled) { 1887 return; 1888 } 1889 if (smooth) { 1890 if (!hasDoneFirstLayout()) { 1891 Log.w(getTag(), "setSelectionSmooth should " + 1892 "not be called before first layout pass"); 1893 return; 1894 } 1895 LinearSmoothScroller linearSmoothScroller = 1896 new LinearSmoothScroller(parent.getContext()) { 1897 @Override 1898 public PointF computeScrollVectorForPosition(int targetPosition) { 1899 if (getChildCount() == 0) { 1900 return null; 1901 } 1902 final int firstChildPos = getPosition(getChildAt(0)); 1903 final int direction = targetPosition < firstChildPos ? -1 : 1; 1904 if (mOrientation == HORIZONTAL) { 1905 return new PointF(direction, 0); 1906 } else { 1907 return new PointF(0, direction); 1908 } 1909 } 1910 @Override 1911 protected void onTargetFound(View targetView, 1912 RecyclerView.State state, Action action) { 1913 if (hasFocus()) { 1914 targetView.requestFocus(); 1915 } 1916 dispatchChildSelected(); 1917 if (getScrollPosition(targetView, mTempDeltas)) { 1918 int dx, dy; 1919 if (mOrientation == HORIZONTAL) { 1920 dx = mTempDeltas[0]; 1921 dy = mTempDeltas[1]; 1922 } else { 1923 dx = mTempDeltas[1]; 1924 dy = mTempDeltas[0]; 1925 } 1926 final int distance = (int) Math.sqrt(dx * dx + dy * dy); 1927 final int time = calculateTimeForDeceleration(distance); 1928 action.update(dx, dy, time, mDecelerateInterpolator); 1929 } 1930 } 1931 }; 1932 linearSmoothScroller.setTargetPosition(position); 1933 startSmoothScroll(linearSmoothScroller); 1934 } else { 1935 mForceFullLayout = true; 1936 parent.requestLayout(); 1937 } 1938 } 1939 } 1940 1941 @Override 1942 public void onItemsAdded(RecyclerView recyclerView, int positionStart, int itemCount) { 1943 if (DEBUG) Log.v(getTag(), "onItemsAdded positionStart " 1944 + positionStart + " itemCount " + itemCount); 1945 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE 1946 && getChildAt(mFocusPosition) != null) { 1947 int pos = mFocusPosition + mFocusPositionOffset; 1948 if (positionStart <= pos) { 1949 mFocusPositionOffset += itemCount; 1950 } 1951 } 1952 mChildrenStates.clear(); 1953 } 1954 1955 @Override 1956 public void onItemsChanged(RecyclerView recyclerView) { 1957 if (DEBUG) Log.v(getTag(), "onItemsChanged"); 1958 mFocusPositionOffset = 0; 1959 mChildrenStates.clear(); 1960 } 1961 1962 @Override 1963 public void onItemsRemoved(RecyclerView recyclerView, int positionStart, int itemCount) { 1964 if (DEBUG) Log.v(getTag(), "onItemsAdded positionStart " 1965 + positionStart + " itemCount " + itemCount); 1966 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE 1967 && getChildAt(mFocusPosition) != null) { 1968 int pos = mFocusPosition + mFocusPositionOffset; 1969 if (positionStart <= pos) { 1970 if (positionStart + itemCount > pos) { 1971 // stop updating offset after the focus item was removed 1972 mFocusPositionOffset = Integer.MIN_VALUE; 1973 } else { 1974 mFocusPositionOffset -= itemCount; 1975 } 1976 } 1977 } 1978 mChildrenStates.clear(); 1979 } 1980 1981 @Override 1982 public void onItemsMoved(RecyclerView recyclerView, int fromPosition, int toPosition, 1983 int itemCount) { 1984 if (DEBUG) Log.v(getTag(), "onItemsAdded fromPosition " 1985 + fromPosition + " toPosition " + toPosition); 1986 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE 1987 && getChildAt(mFocusPosition) != null) { 1988 int pos = mFocusPosition + mFocusPositionOffset; 1989 if (fromPosition <= pos && pos < fromPosition + itemCount) { 1990 // moved items include focused position 1991 mFocusPositionOffset += toPosition - fromPosition; 1992 } else if (fromPosition < pos && toPosition > pos - itemCount) { 1993 // move items before focus position to after focused position 1994 mFocusPositionOffset -= itemCount; 1995 } else if (fromPosition > pos && toPosition < pos) { 1996 // move items after focus position to before focused position 1997 mFocusPositionOffset += itemCount; 1998 } 1999 } 2000 mChildrenStates.clear(); 2001 } 2002 2003 @Override 2004 public void onItemsUpdated(RecyclerView recyclerView, int positionStart, int itemCount) { 2005 for (int i = positionStart, end = positionStart + itemCount; i < end; i++) { 2006 mChildrenStates.remove(i); 2007 } 2008 } 2009 2010 @Override 2011 public boolean onRequestChildFocus(RecyclerView parent, View child, View focused) { 2012 if (mFocusSearchDisabled) { 2013 return true; 2014 } 2015 if (!mInLayout && !mInSelection) { 2016 scrollToView(child, true); 2017 } 2018 return true; 2019 } 2020 2021 @Override 2022 public boolean requestChildRectangleOnScreen(RecyclerView parent, View view, Rect rect, 2023 boolean immediate) { 2024 if (DEBUG) Log.v(getTag(), "requestChildRectangleOnScreen " + view + " " + rect); 2025 return false; 2026 } 2027 2028 int getScrollOffsetX() { 2029 return mOrientation == HORIZONTAL ? mScrollOffsetPrimary : mScrollOffsetSecondary; 2030 } 2031 2032 int getScrollOffsetY() { 2033 return mOrientation == HORIZONTAL ? mScrollOffsetSecondary : mScrollOffsetPrimary; 2034 } 2035 2036 public void getViewSelectedOffsets(View view, int[] offsets) { 2037 if (mOrientation == HORIZONTAL) { 2038 offsets[0] = getPrimarySystemScrollPosition(view) - mScrollOffsetPrimary; 2039 offsets[1] = getSecondarySystemScrollPosition(view) - mScrollOffsetSecondary; 2040 } else { 2041 offsets[1] = getPrimarySystemScrollPosition(view) - mScrollOffsetPrimary; 2042 offsets[0] = getSecondarySystemScrollPosition(view) - mScrollOffsetSecondary; 2043 } 2044 } 2045 2046 private int getPrimarySystemScrollPosition(View view) { 2047 int viewCenterPrimary = mScrollOffsetPrimary + getViewCenter(view); 2048 int pos = getPositionByView(view); 2049 StaggeredGrid.Location location = mGrid.getLocation(pos); 2050 final int row = location.row; 2051 boolean isFirst = mFirstVisiblePos == 0; 2052 // TODO: change to use State object in onRequestChildFocus() 2053 boolean isLast = mLastVisiblePos == (mState == null ? 2054 getItemCount() : mState.getItemCount()) - 1; 2055 if (isFirst || isLast) { 2056 for (int i = getChildCount() - 1; i >= 0; i--) { 2057 int position = getPositionByIndex(i); 2058 StaggeredGrid.Location loc = mGrid.getLocation(position); 2059 if (loc != null && loc.row == row) { 2060 if (position < pos) { 2061 isFirst = false; 2062 } else if (position > pos) { 2063 isLast = false; 2064 } 2065 } 2066 } 2067 } 2068 return mWindowAlignment.mainAxis().getSystemScrollPos(viewCenterPrimary, isFirst, isLast); 2069 } 2070 2071 private int getSecondarySystemScrollPosition(View view) { 2072 int viewCenterSecondary = mScrollOffsetSecondary + getViewCenterSecondary(view); 2073 int pos = getPositionByView(view); 2074 StaggeredGrid.Location location = mGrid.getLocation(pos); 2075 final int row = location.row; 2076 boolean isFirst = row == 0; 2077 boolean isLast = row == mGrid.getNumRows() - 1; 2078 return mWindowAlignment.secondAxis().getSystemScrollPos(viewCenterSecondary, 2079 isFirst, isLast); 2080 } 2081 2082 /** 2083 * Scroll to a given child view and change mFocusPosition. 2084 */ 2085 private void scrollToView(View view, boolean smooth) { 2086 int newFocusPosition = getPositionByView(view); 2087 if (newFocusPosition != mFocusPosition) { 2088 mFocusPosition = newFocusPosition; 2089 mFocusPositionOffset = 0; 2090 if (!mInLayout) { 2091 dispatchChildSelected(); 2092 } 2093 } 2094 if (mBaseGridView.isChildrenDrawingOrderEnabledInternal()) { 2095 mBaseGridView.invalidate(); 2096 } 2097 if (view == null) { 2098 return; 2099 } 2100 if (!view.hasFocus() && mBaseGridView.hasFocus()) { 2101 // transfer focus to the child if it does not have focus yet (e.g. triggered 2102 // by setSelection()) 2103 view.requestFocus(); 2104 } 2105 if (!mScrollEnabled) { 2106 return; 2107 } 2108 if (getScrollPosition(view, mTempDeltas)) { 2109 scrollGrid(mTempDeltas[0], mTempDeltas[1], smooth); 2110 } 2111 } 2112 2113 private boolean getScrollPosition(View view, int[] deltas) { 2114 switch (mFocusScrollStrategy) { 2115 case BaseGridView.FOCUS_SCROLL_ALIGNED: 2116 default: 2117 return getAlignedPosition(view, deltas); 2118 case BaseGridView.FOCUS_SCROLL_ITEM: 2119 case BaseGridView.FOCUS_SCROLL_PAGE: 2120 return getNoneAlignedPosition(view, deltas); 2121 } 2122 } 2123 2124 private boolean getNoneAlignedPosition(View view, int[] deltas) { 2125 int pos = getPositionByView(view); 2126 int viewMin = getViewMin(view); 2127 int viewMax = getViewMax(view); 2128 // we either align "firstView" to left/top padding edge 2129 // or align "lastView" to right/bottom padding edge 2130 View firstView = null; 2131 View lastView = null; 2132 int paddingLow = mWindowAlignment.mainAxis().getPaddingLow(); 2133 int clientSize = mWindowAlignment.mainAxis().getClientSize(); 2134 final int row = mGrid.getLocation(pos).row; 2135 if (viewMin < paddingLow) { 2136 // view enters low padding area: 2137 firstView = view; 2138 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_PAGE) { 2139 // scroll one "page" left/top, 2140 // align first visible item of the "page" at the low padding edge. 2141 while (!prependOneVisibleItem()) { 2142 List<Integer> positions = 2143 mGrid.getItemPositionsInRows(mFirstVisiblePos, pos)[row]; 2144 firstView = findViewByPosition(positions.get(0)); 2145 if (viewMax - getViewMin(firstView) > clientSize) { 2146 if (positions.size() > 1) { 2147 firstView = findViewByPosition(positions.get(1)); 2148 } 2149 break; 2150 } 2151 } 2152 } 2153 } else if (viewMax > clientSize + paddingLow) { 2154 // view enters high padding area: 2155 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_PAGE) { 2156 // scroll whole one page right/bottom, align view at the low padding edge. 2157 firstView = view; 2158 do { 2159 List<Integer> positions = 2160 mGrid.getItemPositionsInRows(pos, mLastVisiblePos)[row]; 2161 lastView = findViewByPosition(positions.get(positions.size() - 1)); 2162 if (getViewMax(lastView) - viewMin > clientSize) { 2163 lastView = null; 2164 break; 2165 } 2166 } while (!appendOneVisibleItem()); 2167 if (lastView != null) { 2168 // however if we reached end, we should align last view. 2169 firstView = null; 2170 } 2171 } else { 2172 lastView = view; 2173 } 2174 } 2175 int scrollPrimary = 0; 2176 int scrollSecondary = 0; 2177 if (firstView != null) { 2178 scrollPrimary = getViewMin(firstView) - paddingLow; 2179 } else if (lastView != null) { 2180 scrollPrimary = getViewMax(lastView) - (paddingLow + clientSize); 2181 } 2182 View secondaryAlignedView; 2183 if (firstView != null) { 2184 secondaryAlignedView = firstView; 2185 } else if (lastView != null) { 2186 secondaryAlignedView = lastView; 2187 } else { 2188 secondaryAlignedView = view; 2189 } 2190 scrollSecondary = getSecondarySystemScrollPosition(secondaryAlignedView); 2191 scrollSecondary -= mScrollOffsetSecondary; 2192 if (scrollPrimary != 0 || scrollSecondary != 0) { 2193 deltas[0] = scrollPrimary; 2194 deltas[1] = scrollSecondary; 2195 return true; 2196 } 2197 return false; 2198 } 2199 2200 private boolean getAlignedPosition(View view, int[] deltas) { 2201 int scrollPrimary = getPrimarySystemScrollPosition(view); 2202 int scrollSecondary = getSecondarySystemScrollPosition(view); 2203 if (DEBUG) { 2204 Log.v(getTag(), "getAlignedPosition " + scrollPrimary + " " + scrollSecondary 2205 +" " + mWindowAlignment); 2206 } 2207 scrollPrimary -= mScrollOffsetPrimary; 2208 scrollSecondary -= mScrollOffsetSecondary; 2209 if (scrollPrimary != 0 || scrollSecondary != 0) { 2210 deltas[0] = scrollPrimary; 2211 deltas[1] = scrollSecondary; 2212 return true; 2213 } 2214 return false; 2215 } 2216 2217 private void scrollGrid(int scrollPrimary, int scrollSecondary, boolean smooth) { 2218 if (mInLayout) { 2219 scrollDirectionPrimary(scrollPrimary); 2220 scrollDirectionSecondary(scrollSecondary); 2221 } else { 2222 int scrollX; 2223 int scrollY; 2224 if (mOrientation == HORIZONTAL) { 2225 scrollX = scrollPrimary; 2226 scrollY = scrollSecondary; 2227 } else { 2228 scrollX = scrollSecondary; 2229 scrollY = scrollPrimary; 2230 } 2231 if (smooth) { 2232 mBaseGridView.smoothScrollBy(scrollX, scrollY); 2233 } else { 2234 mBaseGridView.scrollBy(scrollX, scrollY); 2235 } 2236 } 2237 } 2238 2239 public void setPruneChild(boolean pruneChild) { 2240 if (mPruneChild != pruneChild) { 2241 mPruneChild = pruneChild; 2242 if (mPruneChild) { 2243 requestLayout(); 2244 } 2245 } 2246 } 2247 2248 public boolean getPruneChild() { 2249 return mPruneChild; 2250 } 2251 2252 public void setScrollEnabled(boolean scrollEnabled) { 2253 if (mScrollEnabled != scrollEnabled) { 2254 mScrollEnabled = scrollEnabled; 2255 if (mScrollEnabled && mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED) { 2256 scrollToSelection(mBaseGridView, mFocusPosition, true); 2257 } 2258 } 2259 } 2260 2261 public boolean isScrollEnabled() { 2262 return mScrollEnabled; 2263 } 2264 2265 private int findImmediateChildIndex(View view) { 2266 while (view != null && view != mBaseGridView) { 2267 int index = mBaseGridView.indexOfChild(view); 2268 if (index >= 0) { 2269 return index; 2270 } 2271 view = (View) view.getParent(); 2272 } 2273 return NO_POSITION; 2274 } 2275 2276 void setFocusSearchDisabled(boolean disabled) { 2277 mFocusSearchDisabled = disabled; 2278 } 2279 2280 boolean isFocusSearchDisabled() { 2281 return mFocusSearchDisabled; 2282 } 2283 2284 @Override 2285 public View onInterceptFocusSearch(View focused, int direction) { 2286 if (mFocusSearchDisabled) { 2287 return focused; 2288 } 2289 return null; 2290 } 2291 2292 boolean hasPreviousViewInSameRow(int pos) { 2293 if (mGrid == null || pos == NO_POSITION) { 2294 return false; 2295 } 2296 if (mFirstVisiblePos > 0) { 2297 return true; 2298 } 2299 final int focusedRow = mGrid.getLocation(pos).row; 2300 for (int i = getChildCount() - 1; i >= 0; i--) { 2301 int position = getPositionByIndex(i); 2302 StaggeredGrid.Location loc = mGrid.getLocation(position); 2303 if (loc != null && loc.row == focusedRow) { 2304 if (position < pos) { 2305 return true; 2306 } 2307 } 2308 } 2309 return false; 2310 } 2311 2312 @Override 2313 public boolean onAddFocusables(RecyclerView recyclerView, 2314 ArrayList<View> views, int direction, int focusableMode) { 2315 if (mFocusSearchDisabled) { 2316 return true; 2317 } 2318 // If this viewgroup or one of its children currently has focus then we 2319 // consider our children for focus searching in main direction on the same row. 2320 // If this viewgroup has no focus and using focus align, we want the system 2321 // to ignore our children and pass focus to the viewgroup, which will pass 2322 // focus on to its children appropriately. 2323 // If this viewgroup has no focus and not using focus align, we want to 2324 // consider the child that does not overlap with padding area. 2325 if (recyclerView.hasFocus()) { 2326 final int movement = getMovement(direction); 2327 if (movement != PREV_ITEM && movement != NEXT_ITEM) { 2328 // Move on secondary direction uses default addFocusables(). 2329 return false; 2330 } 2331 final View focused = recyclerView.findFocus(); 2332 final int focusedPos = getPositionByIndex(findImmediateChildIndex(focused)); 2333 // Add focusables of focused item. 2334 if (focusedPos != NO_POSITION) { 2335 findViewByPosition(focusedPos).addFocusables(views, direction, focusableMode); 2336 } 2337 final int focusedRow = mGrid != null && focusedPos != NO_POSITION ? 2338 mGrid.getLocation(focusedPos).row : NO_POSITION; 2339 // Add focusables of next neighbor of same row on the focus search direction. 2340 if (mGrid != null) { 2341 final int focusableCount = views.size(); 2342 for (int i = 0, count = getChildCount(); i < count; i++) { 2343 int index = movement == NEXT_ITEM ? i : count - 1 - i; 2344 final View child = getChildAt(index); 2345 if (child.getVisibility() != View.VISIBLE) { 2346 continue; 2347 } 2348 int position = getPositionByIndex(index); 2349 StaggeredGrid.Location loc = mGrid.getLocation(position); 2350 if (focusedRow == NO_POSITION || (loc != null && loc.row == focusedRow)) { 2351 if (focusedPos == NO_POSITION || 2352 (movement == NEXT_ITEM && position > focusedPos) 2353 || (movement == PREV_ITEM && position < focusedPos)) { 2354 child.addFocusables(views, direction, focusableMode); 2355 if (views.size() > focusableCount) { 2356 break; 2357 } 2358 } 2359 } 2360 } 2361 } 2362 } else { 2363 if (mFocusScrollStrategy != BaseGridView.FOCUS_SCROLL_ALIGNED) { 2364 // adding views not overlapping padding area to avoid scrolling in gaining focus 2365 int left = mWindowAlignment.mainAxis().getPaddingLow(); 2366 int right = mWindowAlignment.mainAxis().getClientSize() + left; 2367 int focusableCount = views.size(); 2368 for (int i = 0, count = getChildCount(); i < count; i++) { 2369 View child = getChildAt(i); 2370 if (child.getVisibility() == View.VISIBLE) { 2371 if (getViewMin(child) >= left && getViewMax(child) <= right) { 2372 child.addFocusables(views, direction, focusableMode); 2373 } 2374 } 2375 } 2376 // if we cannot find any, then just add all children. 2377 if (views.size() == focusableCount) { 2378 for (int i = 0, count = getChildCount(); i < count; i++) { 2379 View child = getChildAt(i); 2380 if (child.getVisibility() == View.VISIBLE) { 2381 child.addFocusables(views, direction, focusableMode); 2382 } 2383 } 2384 if (views.size() != focusableCount) { 2385 return true; 2386 } 2387 } else { 2388 return true; 2389 } 2390 // if still cannot find any, fall through and add itself 2391 } 2392 if (recyclerView.isFocusable()) { 2393 views.add(recyclerView); 2394 } 2395 } 2396 return true; 2397 } 2398 2399 @Override 2400 public View onFocusSearchFailed(View focused, int direction, Recycler recycler, 2401 RecyclerView.State state) { 2402 if (DEBUG) Log.v(getTag(), "onFocusSearchFailed direction " + direction); 2403 2404 View view = null; 2405 int movement = getMovement(direction); 2406 final boolean isScroll = mBaseGridView.getScrollState() != RecyclerView.SCROLL_STATE_IDLE; 2407 if (mNumRows == 1) { 2408 // for simple row, use LinearSmoothScroller to smooth animation. 2409 // It will stay at a fixed cap speed in continuous scroll. 2410 if (movement == NEXT_ITEM) { 2411 int newPos = mFocusPosition + mNumRows; 2412 if (newPos < getItemCount() && mScrollEnabled) { 2413 setSelectionSmooth(mBaseGridView, newPos); 2414 view = focused; 2415 } else { 2416 if (isScroll || !mFocusOutEnd) { 2417 view = focused; 2418 } 2419 } 2420 } else if (movement == PREV_ITEM){ 2421 int newPos = mFocusPosition - mNumRows; 2422 if (newPos >= 0 && mScrollEnabled) { 2423 setSelectionSmooth(mBaseGridView, newPos); 2424 view = focused; 2425 } else { 2426 if (isScroll || !mFocusOutFront) { 2427 view = focused; 2428 } 2429 } 2430 } 2431 } else if (mNumRows > 1) { 2432 // for possible staggered grid, we need guarantee focus to same row/column. 2433 // TODO: we may also use LinearSmoothScroller. 2434 saveContext(recycler, state); 2435 final FocusFinder ff = FocusFinder.getInstance(); 2436 if (movement == NEXT_ITEM) { 2437 while (view == null && !appendOneVisibleItem()) { 2438 view = ff.findNextFocus(mBaseGridView, focused, direction); 2439 } 2440 } else if (movement == PREV_ITEM){ 2441 while (view == null && !prependOneVisibleItem()) { 2442 view = ff.findNextFocus(mBaseGridView, focused, direction); 2443 } 2444 } 2445 if (view == null) { 2446 // returning the same view to prevent focus lost when scrolling past the end of the list 2447 if (movement == PREV_ITEM) { 2448 view = mFocusOutFront && !isScroll ? null : focused; 2449 } else if (movement == NEXT_ITEM){ 2450 view = mFocusOutEnd && !isScroll ? null : focused; 2451 } 2452 } 2453 leaveContext(); 2454 } 2455 if (DEBUG) Log.v(getTag(), "returning view " + view); 2456 return view; 2457 } 2458 2459 boolean gridOnRequestFocusInDescendants(RecyclerView recyclerView, int direction, 2460 Rect previouslyFocusedRect) { 2461 switch (mFocusScrollStrategy) { 2462 case BaseGridView.FOCUS_SCROLL_ALIGNED: 2463 default: 2464 return gridOnRequestFocusInDescendantsAligned(recyclerView, 2465 direction, previouslyFocusedRect); 2466 case BaseGridView.FOCUS_SCROLL_PAGE: 2467 case BaseGridView.FOCUS_SCROLL_ITEM: 2468 return gridOnRequestFocusInDescendantsUnaligned(recyclerView, 2469 direction, previouslyFocusedRect); 2470 } 2471 } 2472 2473 private boolean gridOnRequestFocusInDescendantsAligned(RecyclerView recyclerView, 2474 int direction, Rect previouslyFocusedRect) { 2475 View view = findViewByPosition(mFocusPosition); 2476 if (view != null) { 2477 boolean result = view.requestFocus(direction, previouslyFocusedRect); 2478 if (!result && DEBUG) { 2479 Log.w(getTag(), "failed to request focus on " + view); 2480 } 2481 return result; 2482 } 2483 return false; 2484 } 2485 2486 private boolean gridOnRequestFocusInDescendantsUnaligned(RecyclerView recyclerView, 2487 int direction, Rect previouslyFocusedRect) { 2488 // focus to view not overlapping padding area to avoid scrolling in gaining focus 2489 int index; 2490 int increment; 2491 int end; 2492 int count = getChildCount(); 2493 if ((direction & View.FOCUS_FORWARD) != 0) { 2494 index = 0; 2495 increment = 1; 2496 end = count; 2497 } else { 2498 index = count - 1; 2499 increment = -1; 2500 end = -1; 2501 } 2502 int left = mWindowAlignment.mainAxis().getPaddingLow(); 2503 int right = mWindowAlignment.mainAxis().getClientSize() + left; 2504 for (int i = index; i != end; i += increment) { 2505 View child = getChildAt(i); 2506 if (child.getVisibility() == View.VISIBLE) { 2507 if (getViewMin(child) >= left && getViewMax(child) <= right) { 2508 if (child.requestFocus(direction, previouslyFocusedRect)) { 2509 return true; 2510 } 2511 } 2512 } 2513 } 2514 return false; 2515 } 2516 2517 private final static int PREV_ITEM = 0; 2518 private final static int NEXT_ITEM = 1; 2519 private final static int PREV_ROW = 2; 2520 private final static int NEXT_ROW = 3; 2521 2522 private int getMovement(int direction) { 2523 int movement = View.FOCUS_LEFT; 2524 2525 if (mOrientation == HORIZONTAL) { 2526 switch(direction) { 2527 case View.FOCUS_LEFT: 2528 movement = PREV_ITEM; 2529 break; 2530 case View.FOCUS_RIGHT: 2531 movement = NEXT_ITEM; 2532 break; 2533 case View.FOCUS_UP: 2534 movement = PREV_ROW; 2535 break; 2536 case View.FOCUS_DOWN: 2537 movement = NEXT_ROW; 2538 break; 2539 } 2540 } else if (mOrientation == VERTICAL) { 2541 switch(direction) { 2542 case View.FOCUS_LEFT: 2543 movement = PREV_ROW; 2544 break; 2545 case View.FOCUS_RIGHT: 2546 movement = NEXT_ROW; 2547 break; 2548 case View.FOCUS_UP: 2549 movement = PREV_ITEM; 2550 break; 2551 case View.FOCUS_DOWN: 2552 movement = NEXT_ITEM; 2553 break; 2554 } 2555 } 2556 2557 return movement; 2558 } 2559 2560 int getChildDrawingOrder(RecyclerView recyclerView, int childCount, int i) { 2561 View view = findViewByPosition(mFocusPosition); 2562 if (view == null) { 2563 return i; 2564 } 2565 int focusIndex = recyclerView.indexOfChild(view); 2566 // supposely 0 1 2 3 4 5 6 7 8 9, 4 is the center item 2567 // drawing order is 0 1 2 3 9 8 7 6 5 4 2568 if (i < focusIndex) { 2569 return i; 2570 } else if (i < childCount - 1) { 2571 return focusIndex + childCount - 1 - i; 2572 } else { 2573 return focusIndex; 2574 } 2575 } 2576 2577 @Override 2578 public void onAdapterChanged(RecyclerView.Adapter oldAdapter, 2579 RecyclerView.Adapter newAdapter) { 2580 if (DEBUG) Log.v(getTag(), "onAdapterChanged to " + newAdapter); 2581 if (oldAdapter != null) { 2582 discardLayoutInfo(); 2583 mFocusPosition = NO_POSITION; 2584 mFocusPositionOffset = 0; 2585 mChildrenStates.clear(); 2586 } 2587 super.onAdapterChanged(oldAdapter, newAdapter); 2588 } 2589 2590 private void discardLayoutInfo() { 2591 mGrid = null; 2592 mRows = null; 2593 mRowSizeSecondary = null; 2594 mFirstVisiblePos = -1; 2595 mLastVisiblePos = -1; 2596 mRowSecondarySizeRefresh = false; 2597 } 2598 2599 public void setLayoutEnabled(boolean layoutEnabled) { 2600 if (mLayoutEnabled != layoutEnabled) { 2601 mLayoutEnabled = layoutEnabled; 2602 requestLayout(); 2603 } 2604 } 2605 2606 void setChildrenVisibility(int visiblity) { 2607 mChildVisibility = visiblity; 2608 if (mChildVisibility != -1) { 2609 int count = getChildCount(); 2610 for (int i= 0; i < count; i++) { 2611 getChildAt(i).setVisibility(mChildVisibility); 2612 } 2613 } 2614 } 2615 2616 final static class SavedState implements Parcelable { 2617 2618 int index; // index inside adapter of the current view 2619 Bundle childStates = Bundle.EMPTY; 2620 2621 @Override 2622 public void writeToParcel(Parcel out, int flags) { 2623 out.writeInt(index); 2624 out.writeBundle(childStates); 2625 } 2626 2627 @SuppressWarnings("hiding") 2628 public static final Parcelable.Creator<SavedState> CREATOR = 2629 new Parcelable.Creator<SavedState>() { 2630 @Override 2631 public SavedState createFromParcel(Parcel in) { 2632 return new SavedState(in); 2633 } 2634 2635 @Override 2636 public SavedState[] newArray(int size) { 2637 return new SavedState[size]; 2638 } 2639 }; 2640 2641 @Override 2642 public int describeContents() { 2643 return 0; 2644 } 2645 2646 SavedState(Parcel in) { 2647 index = in.readInt(); 2648 childStates = in.readBundle(GridLayoutManager.class.getClassLoader()); 2649 } 2650 2651 SavedState() { 2652 } 2653 } 2654 2655 @Override 2656 public Parcelable onSaveInstanceState() { 2657 if (DEBUG) Log.v(getTag(), "onSaveInstanceState getSelection() " + getSelection()); 2658 SavedState ss = new SavedState(); 2659 for (int i = 0, count = getChildCount(); i < count; i++) { 2660 View view = getChildAt(i); 2661 int position = getPositionByView(view); 2662 if (position != NO_POSITION) { 2663 mChildrenStates.saveOnScreenView(view, position); 2664 } 2665 } 2666 ss.index = getSelection(); 2667 ss.childStates = mChildrenStates.saveAsBundle(); 2668 return ss; 2669 } 2670 2671 @Override 2672 public void onRestoreInstanceState(Parcelable state) { 2673 if (!(state instanceof SavedState)) { 2674 return; 2675 } 2676 SavedState loadingState = (SavedState)state; 2677 mFocusPosition = loadingState.index; 2678 mFocusPositionOffset = 0; 2679 mChildrenStates.loadFromBundle(loadingState.childStates); 2680 mForceFullLayout = true; 2681 requestLayout(); 2682 if (DEBUG) Log.v(getTag(), "onRestoreInstanceState mFocusPosition " + mFocusPosition); 2683 } 2684} 2685