GridLayoutManager.java revision 81a36a4dd93bf2f14c2eb88ae01464f85ddb0706
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 * The scroll offsets of the viewport relative to the entire view. 216 */ 217 private int mScrollOffsetPrimary; 218 private int mScrollOffsetSecondary; 219 220 /** 221 * User-specified row height/column width. Can be WRAP_CONTENT. 222 */ 223 private int mRowSizeSecondaryRequested; 224 225 /** 226 * The fixed size of each grid item in the secondary direction. This corresponds to 227 * the row height, equal for all rows. Grid items may have variable length 228 * in the primary direction. 229 */ 230 private int mFixedRowSizeSecondary; 231 232 /** 233 * Tracks the secondary size of each row. 234 */ 235 private int[] mRowSizeSecondary; 236 237 /** 238 * Flag controlling whether the current/next layout should 239 * be updating the secondary size of rows. 240 */ 241 private boolean mRowSecondarySizeRefresh; 242 243 /** 244 * The maximum measured size of the view. 245 */ 246 private int mMaxSizeSecondary; 247 248 /** 249 * Margin between items. 250 */ 251 private int mHorizontalMargin; 252 /** 253 * Margin between items vertically. 254 */ 255 private int mVerticalMargin; 256 /** 257 * Margin in main direction. 258 */ 259 private int mMarginPrimary; 260 /** 261 * Margin in second direction. 262 */ 263 private int mMarginSecondary; 264 /** 265 * How to position child in secondary direction. 266 */ 267 private int mGravity = Gravity.LEFT | Gravity.TOP; 268 /** 269 * The number of rows in the grid. 270 */ 271 private int mNumRows; 272 /** 273 * Number of rows requested, can be 0 to be determined by parent size and 274 * rowHeight. 275 */ 276 private int mNumRowsRequested = 1; 277 278 /** 279 * Tracking start/end position of each row for visible items. 280 */ 281 private StaggeredGrid.Row[] mRows; 282 283 /** 284 * Saves grid information of each view. 285 */ 286 private StaggeredGrid mGrid; 287 /** 288 * Position of first item (included) that has attached views. 289 */ 290 private int mFirstVisiblePos; 291 /** 292 * Position of last item (included) that has attached views. 293 */ 294 private int mLastVisiblePos; 295 296 /** 297 * Focus Scroll strategy. 298 */ 299 private int mFocusScrollStrategy = BaseGridView.FOCUS_SCROLL_ALIGNED; 300 /** 301 * Defines how item view is aligned in the window. 302 */ 303 private final WindowAlignment mWindowAlignment = new WindowAlignment(); 304 305 /** 306 * Defines how item view is aligned. 307 */ 308 private final ItemAlignment mItemAlignment = new ItemAlignment(); 309 310 /** 311 * Dimensions of the view, width or height depending on orientation. 312 */ 313 private int mSizePrimary; 314 315 /** 316 * Allow DPAD key to navigate out at the front of the View (where position = 0), 317 * default is false. 318 */ 319 private boolean mFocusOutFront; 320 321 /** 322 * Allow DPAD key to navigate out at the end of the view, default is false. 323 */ 324 private boolean mFocusOutEnd; 325 326 /** 327 * True if focus search is disabled. 328 */ 329 private boolean mFocusSearchDisabled; 330 331 /** 332 * True if prune child, might be disabled during transition. 333 */ 334 private boolean mPruneChild = true; 335 336 /** 337 * True if scroll content, might be disabled during transition. 338 */ 339 private boolean mScrollEnabled = true; 340 341 private int[] mTempDeltas = new int[2]; 342 343 /** 344 * Temporaries used for measuring. 345 */ 346 private int[] mMeasuredDimension = new int[2]; 347 348 SavedState mLoadingState; 349 final ViewsStateBundle mChildrenStates = new ViewsStateBundle( 350 ViewsStateBundle.SAVE_LIMITED_CHILD, ViewsStateBundle.DEFAULT_LIMIT); 351 352 public GridLayoutManager(BaseGridView baseGridView) { 353 mBaseGridView = baseGridView; 354 } 355 356 public void setOrientation(int orientation) { 357 if (orientation != HORIZONTAL && orientation != VERTICAL) { 358 if (DEBUG) Log.v(getTag(), "invalid orientation: " + orientation); 359 return; 360 } 361 362 mOrientation = orientation; 363 mWindowAlignment.setOrientation(orientation); 364 mItemAlignment.setOrientation(orientation); 365 mForceFullLayout = true; 366 } 367 368 public int getFocusScrollStrategy() { 369 return mFocusScrollStrategy; 370 } 371 372 public void setFocusScrollStrategy(int focusScrollStrategy) { 373 mFocusScrollStrategy = focusScrollStrategy; 374 } 375 376 public void setWindowAlignment(int windowAlignment) { 377 mWindowAlignment.mainAxis().setWindowAlignment(windowAlignment); 378 } 379 380 public int getWindowAlignment() { 381 return mWindowAlignment.mainAxis().getWindowAlignment(); 382 } 383 384 public void setWindowAlignmentOffset(int alignmentOffset) { 385 mWindowAlignment.mainAxis().setWindowAlignmentOffset(alignmentOffset); 386 } 387 388 public int getWindowAlignmentOffset() { 389 return mWindowAlignment.mainAxis().getWindowAlignmentOffset(); 390 } 391 392 public void setWindowAlignmentOffsetPercent(float offsetPercent) { 393 mWindowAlignment.mainAxis().setWindowAlignmentOffsetPercent(offsetPercent); 394 } 395 396 public float getWindowAlignmentOffsetPercent() { 397 return mWindowAlignment.mainAxis().getWindowAlignmentOffsetPercent(); 398 } 399 400 public void setItemAlignmentOffset(int alignmentOffset) { 401 mItemAlignment.mainAxis().setItemAlignmentOffset(alignmentOffset); 402 updateChildAlignments(); 403 } 404 405 public int getItemAlignmentOffset() { 406 return mItemAlignment.mainAxis().getItemAlignmentOffset(); 407 } 408 409 public void setItemAlignmentOffsetWithPadding(boolean withPadding) { 410 mItemAlignment.mainAxis().setItemAlignmentOffsetWithPadding(withPadding); 411 updateChildAlignments(); 412 } 413 414 public boolean isItemAlignmentOffsetWithPadding() { 415 return mItemAlignment.mainAxis().isItemAlignmentOffsetWithPadding(); 416 } 417 418 public void setItemAlignmentOffsetPercent(float offsetPercent) { 419 mItemAlignment.mainAxis().setItemAlignmentOffsetPercent(offsetPercent); 420 updateChildAlignments(); 421 } 422 423 public float getItemAlignmentOffsetPercent() { 424 return mItemAlignment.mainAxis().getItemAlignmentOffsetPercent(); 425 } 426 427 public void setItemAlignmentViewId(int viewId) { 428 mItemAlignment.mainAxis().setItemAlignmentViewId(viewId); 429 updateChildAlignments(); 430 } 431 432 public int getItemAlignmentViewId() { 433 return mItemAlignment.mainAxis().getItemAlignmentViewId(); 434 } 435 436 public void setFocusOutAllowed(boolean throughFront, boolean throughEnd) { 437 mFocusOutFront = throughFront; 438 mFocusOutEnd = throughEnd; 439 } 440 441 public void setNumRows(int numRows) { 442 if (numRows < 0) throw new IllegalArgumentException(); 443 mNumRowsRequested = numRows; 444 mForceFullLayout = true; 445 } 446 447 /** 448 * Set the row height. May be WRAP_CONTENT, or a size in pixels. 449 */ 450 public void setRowHeight(int height) { 451 if (height >= 0 || height == ViewGroup.LayoutParams.WRAP_CONTENT) { 452 mRowSizeSecondaryRequested = height; 453 } else { 454 throw new IllegalArgumentException("Invalid row height: " + height); 455 } 456 } 457 458 public void setItemMargin(int margin) { 459 mVerticalMargin = mHorizontalMargin = margin; 460 mMarginPrimary = mMarginSecondary = margin; 461 } 462 463 public void setVerticalMargin(int margin) { 464 if (mOrientation == HORIZONTAL) { 465 mMarginSecondary = mVerticalMargin = margin; 466 } else { 467 mMarginPrimary = mVerticalMargin = margin; 468 } 469 } 470 471 public void setHorizontalMargin(int margin) { 472 if (mOrientation == HORIZONTAL) { 473 mMarginPrimary = mHorizontalMargin = margin; 474 } else { 475 mMarginSecondary = mHorizontalMargin = margin; 476 } 477 } 478 479 public int getVerticalMargin() { 480 return mVerticalMargin; 481 } 482 483 public int getHorizontalMargin() { 484 return mHorizontalMargin; 485 } 486 487 public void setGravity(int gravity) { 488 mGravity = gravity; 489 } 490 491 protected boolean hasDoneFirstLayout() { 492 return mGrid != null; 493 } 494 495 public void setOnChildSelectedListener(OnChildSelectedListener listener) { 496 mChildSelectedListener = listener; 497 } 498 499 private int getPositionByView(View view) { 500 if (view == null) { 501 return NO_POSITION; 502 } 503 LayoutParams params = (LayoutParams) view.getLayoutParams(); 504 if (params == null || params.isItemRemoved()) { 505 // when item is removed, the position value can be any value. 506 return NO_POSITION; 507 } 508 return params.getViewPosition(); 509 } 510 511 private int getPositionByIndex(int index) { 512 return getPositionByView(getChildAt(index)); 513 } 514 515 private void dispatchChildSelected() { 516 if (mChildSelectedListener == null) { 517 return; 518 } 519 if (mFocusPosition != NO_POSITION) { 520 View view = findViewByPosition(mFocusPosition); 521 if (view != null) { 522 RecyclerView.ViewHolder vh = mBaseGridView.getChildViewHolder(view); 523 mChildSelectedListener.onChildSelected(mBaseGridView, view, mFocusPosition, 524 vh == null? NO_ID: vh.getItemId()); 525 return; 526 } 527 } 528 mChildSelectedListener.onChildSelected(mBaseGridView, null, NO_POSITION, NO_ID); 529 } 530 531 @Override 532 public boolean canScrollHorizontally() { 533 // We can scroll horizontally if we have horizontal orientation, or if 534 // we are vertical and have more than one column. 535 return mOrientation == HORIZONTAL || mNumRows > 1; 536 } 537 538 @Override 539 public boolean canScrollVertically() { 540 // We can scroll vertically if we have vertical orientation, or if we 541 // are horizontal and have more than one row. 542 return mOrientation == VERTICAL || mNumRows > 1; 543 } 544 545 @Override 546 public RecyclerView.LayoutParams generateDefaultLayoutParams() { 547 return new LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, 548 ViewGroup.LayoutParams.WRAP_CONTENT); 549 } 550 551 @Override 552 public RecyclerView.LayoutParams generateLayoutParams(Context context, AttributeSet attrs) { 553 return new LayoutParams(context, attrs); 554 } 555 556 @Override 557 public RecyclerView.LayoutParams generateLayoutParams(ViewGroup.LayoutParams lp) { 558 if (lp instanceof LayoutParams) { 559 return new LayoutParams((LayoutParams) lp); 560 } else if (lp instanceof RecyclerView.LayoutParams) { 561 return new LayoutParams((RecyclerView.LayoutParams) lp); 562 } else if (lp instanceof MarginLayoutParams) { 563 return new LayoutParams((MarginLayoutParams) lp); 564 } else { 565 return new LayoutParams(lp); 566 } 567 } 568 569 protected View getViewForPosition(int position) { 570 return mRecycler.getViewForPosition(position); 571 } 572 573 final int getOpticalLeft(View v) { 574 return ((LayoutParams) v.getLayoutParams()).getOpticalLeft(v); 575 } 576 577 final int getOpticalRight(View v) { 578 return ((LayoutParams) v.getLayoutParams()).getOpticalRight(v); 579 } 580 581 final int getOpticalTop(View v) { 582 return ((LayoutParams) v.getLayoutParams()).getOpticalTop(v); 583 } 584 585 final int getOpticalBottom(View v) { 586 return ((LayoutParams) v.getLayoutParams()).getOpticalBottom(v); 587 } 588 589 private int getViewMin(View v) { 590 return (mOrientation == HORIZONTAL) ? getOpticalLeft(v) : getOpticalTop(v); 591 } 592 593 private int getViewMax(View v) { 594 return (mOrientation == HORIZONTAL) ? getOpticalRight(v) : getOpticalBottom(v); 595 } 596 597 private int getViewCenter(View view) { 598 return (mOrientation == HORIZONTAL) ? getViewCenterX(view) : getViewCenterY(view); 599 } 600 601 private int getViewCenterSecondary(View view) { 602 return (mOrientation == HORIZONTAL) ? getViewCenterY(view) : getViewCenterX(view); 603 } 604 605 private int getViewCenterX(View v) { 606 LayoutParams p = (LayoutParams) v.getLayoutParams(); 607 return p.getOpticalLeft(v) + p.getAlignX(); 608 } 609 610 private int getViewCenterY(View v) { 611 LayoutParams p = (LayoutParams) v.getLayoutParams(); 612 return p.getOpticalTop(v) + p.getAlignY(); 613 } 614 615 /** 616 * Save Recycler and State for convenience. Must be paired with leaveContext(). 617 */ 618 private void saveContext(Recycler recycler, State state) { 619 if (mRecycler != null || mState != null) { 620 Log.e(TAG, "Recycler information was not released, bug!"); 621 } 622 mRecycler = recycler; 623 mState = state; 624 } 625 626 /** 627 * Discard saved Recycler and State. 628 */ 629 private void leaveContext() { 630 mRecycler = null; 631 mState = null; 632 } 633 634 /** 635 * Re-initialize data structures for a data change or handling invisible 636 * selection. The method tries its best to preserve position information so 637 * that staggered grid looks same before and after re-initialize. 638 * @param focusPosition The initial focusPosition that we would like to 639 * focus on. 640 * @return Actual position that can be focused on. 641 */ 642 private int init(int focusPosition) { 643 644 final int newItemCount = mState.getItemCount(); 645 646 if (focusPosition == NO_POSITION && newItemCount > 0) { 647 // if focus position is never set before, initialize it to 0 648 focusPosition = 0; 649 } 650 // If adapter has changed then caches are invalid; otherwise, 651 // we try to maintain each row's position if number of rows keeps the same 652 // and existing mGrid contains the focusPosition. 653 if (mRows != null && mNumRows == mRows.length && 654 mGrid != null && mGrid.getSize() > 0 && focusPosition >= 0 && 655 focusPosition >= mGrid.getFirstIndex() && 656 focusPosition <= mGrid.getLastIndex()) { 657 // strip mGrid to a subset (like a column) that contains focusPosition 658 mGrid.stripDownTo(focusPosition); 659 // make sure that remaining items do not exceed new adapter size 660 int firstIndex = mGrid.getFirstIndex(); 661 int lastIndex = mGrid.getLastIndex(); 662 if (DEBUG) { 663 Log .v(getTag(), "mGrid firstIndex " + firstIndex + " lastIndex " + lastIndex); 664 } 665 for (int i = lastIndex; i >=firstIndex; i--) { 666 if (i >= newItemCount) { 667 mGrid.removeLast(); 668 } 669 } 670 if (mGrid.getSize() == 0) { 671 focusPosition = newItemCount - 1; 672 // initialize row start locations 673 for (int i = 0; i < mNumRows; i++) { 674 mRows[i].low = 0; 675 mRows[i].high = 0; 676 } 677 if (DEBUG) Log.v(getTag(), "mGrid zero size"); 678 } else { 679 // initialize row start locations 680 for (int i = 0; i < mNumRows; i++) { 681 mRows[i].low = Integer.MAX_VALUE; 682 mRows[i].high = Integer.MIN_VALUE; 683 } 684 firstIndex = mGrid.getFirstIndex(); 685 lastIndex = mGrid.getLastIndex(); 686 if (focusPosition > lastIndex) { 687 focusPosition = mGrid.getLastIndex(); 688 } 689 if (DEBUG) { 690 Log.v(getTag(), "mGrid firstIndex " + firstIndex + " lastIndex " 691 + lastIndex + " focusPosition " + focusPosition); 692 } 693 // fill rows with minimal view positions of the subset 694 for (int i = firstIndex; i <= lastIndex; i++) { 695 View v = findViewByPosition(i); 696 if (v == null) { 697 continue; 698 } 699 int row = mGrid.getLocation(i).row; 700 int low = getViewMin(v) + mScrollOffsetPrimary; 701 if (low < mRows[row].low) { 702 mRows[row].low = mRows[row].high = low; 703 } 704 } 705 int firstItemRowPosition = mRows[mGrid.getLocation(firstIndex).row].low; 706 if (firstItemRowPosition == Integer.MAX_VALUE) { 707 firstItemRowPosition = 0; 708 } 709 if (mState.didStructureChange()) { 710 // if there is structure change, the removed item might be in the 711 // subset, so it is meaningless to maintain the low locations. 712 for (int i = 0; i < mNumRows; i++) { 713 mRows[i].low = firstItemRowPosition; 714 mRows[i].high = firstItemRowPosition; 715 } 716 } else { 717 // fill other rows that does not include the subset using first item 718 for (int i = 0; i < mNumRows; i++) { 719 if (mRows[i].low == Integer.MAX_VALUE) { 720 mRows[i].low = mRows[i].high = firstItemRowPosition; 721 } 722 } 723 } 724 } 725 726 // Same adapter, we can reuse any attached views 727 detachAndScrapAttachedViews(mRecycler); 728 729 } else { 730 // otherwise recreate data structure 731 mRows = new StaggeredGrid.Row[mNumRows]; 732 733 for (int i = 0; i < mNumRows; i++) { 734 mRows[i] = new StaggeredGrid.Row(); 735 } 736 mGrid = new StaggeredGridDefault(); 737 if (newItemCount == 0) { 738 focusPosition = NO_POSITION; 739 } else if (focusPosition >= newItemCount) { 740 focusPosition = newItemCount - 1; 741 } 742 743 // Adapter may have changed so remove all attached views permanently 744 removeAndRecycleAllViews(mRecycler); 745 746 mScrollOffsetPrimary = 0; 747 mScrollOffsetSecondary = 0; 748 mWindowAlignment.reset(); 749 } 750 751 mGrid.setProvider(mGridProvider); 752 // mGrid share the same Row array information 753 mGrid.setRows(mRows); 754 mFirstVisiblePos = mLastVisiblePos = NO_POSITION; 755 756 initScrollController(); 757 updateScrollSecondAxis(); 758 759 return focusPosition; 760 } 761 762 private int getRowSizeSecondary(int rowIndex) { 763 if (mFixedRowSizeSecondary != 0) { 764 return mFixedRowSizeSecondary; 765 } 766 if (mRowSizeSecondary == null) { 767 return 0; 768 } 769 return mRowSizeSecondary[rowIndex]; 770 } 771 772 private int getRowStartSecondary(int rowIndex) { 773 int start = 0; 774 for (int i = 0; i < rowIndex; i++) { 775 start += getRowSizeSecondary(i) + mMarginSecondary; 776 } 777 return start; 778 } 779 780 private int getSizeSecondary() { 781 return getRowStartSecondary(mNumRows - 1) + getRowSizeSecondary(mNumRows - 1); 782 } 783 784 private void measureScrapChild(int position, int widthSpec, int heightSpec, 785 int[] measuredDimension) { 786 View view = mRecycler.getViewForPosition(position); 787 if (view != null) { 788 LayoutParams p = (LayoutParams) view.getLayoutParams(); 789 int childWidthSpec = ViewGroup.getChildMeasureSpec(widthSpec, 790 getPaddingLeft() + getPaddingRight(), p.width); 791 int childHeightSpec = ViewGroup.getChildMeasureSpec(heightSpec, 792 getPaddingTop() + getPaddingBottom(), p.height); 793 view.measure(childWidthSpec, childHeightSpec); 794 measuredDimension[0] = view.getMeasuredWidth(); 795 measuredDimension[1] = view.getMeasuredHeight(); 796 mRecycler.recycleView(view); 797 } 798 } 799 800 private boolean processRowSizeSecondary(boolean measure) { 801 if (mFixedRowSizeSecondary != 0) { 802 return false; 803 } 804 805 List<Integer>[] rows = mGrid == null ? null : 806 mGrid.getItemPositionsInRows(mFirstVisiblePos, mLastVisiblePos); 807 boolean changed = false; 808 int scrapChildWidth = -1; 809 int scrapChildHeight = -1; 810 811 for (int rowIndex = 0; rowIndex < mNumRows; rowIndex++) { 812 final int rowItemCount = rows == null ? 0 : rows[rowIndex].size(); 813 if (DEBUG) Log.v(getTag(), "processRowSizeSecondary row " + rowIndex + 814 " rowItemCount " + rowItemCount); 815 816 int rowSize = -1; 817 for (int i = 0; i < rowItemCount; i++) { 818 final View view = findViewByPosition(rows[rowIndex].get(i)); 819 if (view == null) { 820 continue; 821 } 822 if (measure && view.isLayoutRequested()) { 823 measureChild(view); 824 } 825 final int secondarySize = mOrientation == HORIZONTAL ? 826 view.getMeasuredHeight() : view.getMeasuredWidth(); 827 if (secondarySize > rowSize) { 828 rowSize = secondarySize; 829 } 830 } 831 832 if (measure && rowSize < 0 && mState.getItemCount() > 0) { 833 if (scrapChildWidth < 0 && scrapChildHeight < 0) { 834 measureScrapChild(mFocusPosition == NO_POSITION ? 0 : mFocusPosition, 835 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 836 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 837 mMeasuredDimension); 838 scrapChildWidth = mMeasuredDimension[0]; 839 scrapChildHeight = mMeasuredDimension[1]; 840 if (DEBUG) Log.v(TAG, "measured scrap child: " + scrapChildWidth + 841 " " + scrapChildHeight); 842 } 843 rowSize = mOrientation == HORIZONTAL ? scrapChildHeight : scrapChildWidth; 844 } 845 846 if (rowSize < 0) { 847 rowSize = 0; 848 } 849 850 if (DEBUG) Log.v(getTag(), "row " + rowIndex + " rowItemCount " + rowItemCount + 851 " rowSize " + rowSize); 852 853 if (mRowSizeSecondary[rowIndex] != rowSize) { 854 if (DEBUG) Log.v(getTag(), "row size secondary changed: " + mRowSizeSecondary[rowIndex] + 855 ", " + rowSize); 856 857 mRowSizeSecondary[rowIndex] = rowSize; 858 changed = true; 859 } 860 } 861 862 return changed; 863 } 864 865 /** 866 * Checks if we need to update row secondary sizes. 867 */ 868 private void updateRowSecondarySizeRefresh() { 869 mRowSecondarySizeRefresh = processRowSizeSecondary(false); 870 if (mRowSecondarySizeRefresh) { 871 if (DEBUG) Log.v(getTag(), "mRowSecondarySizeRefresh now set"); 872 forceRequestLayout(); 873 } 874 } 875 876 private void forceRequestLayout() { 877 if (DEBUG) Log.v(getTag(), "forceRequestLayout"); 878 // RecyclerView prevents us from requesting layout in many cases 879 // (during layout, during scroll, etc.) 880 // For secondary row size wrap_content support we currently need a 881 // second layout pass to update the measured size after having measured 882 // and added child views in layoutChildren. 883 // Force the second layout by posting a delayed runnable. 884 // TODO: investigate allowing a second layout pass, 885 // or move child add/measure logic to the measure phase. 886 ViewCompat.postOnAnimation(mBaseGridView, mRequestLayoutRunnable); 887 } 888 889 private final Runnable mRequestLayoutRunnable = new Runnable() { 890 @Override 891 public void run() { 892 if (DEBUG) Log.v(getTag(), "request Layout from runnable"); 893 requestLayout(); 894 } 895 }; 896 897 @Override 898 public void onMeasure(Recycler recycler, State state, int widthSpec, int heightSpec) { 899 saveContext(recycler, state); 900 901 int sizePrimary, sizeSecondary, modeSecondary, paddingSecondary; 902 int measuredSizeSecondary; 903 if (mOrientation == HORIZONTAL) { 904 sizePrimary = MeasureSpec.getSize(widthSpec); 905 sizeSecondary = MeasureSpec.getSize(heightSpec); 906 modeSecondary = MeasureSpec.getMode(heightSpec); 907 paddingSecondary = getPaddingTop() + getPaddingBottom(); 908 } else { 909 sizeSecondary = MeasureSpec.getSize(widthSpec); 910 sizePrimary = MeasureSpec.getSize(heightSpec); 911 modeSecondary = MeasureSpec.getMode(widthSpec); 912 paddingSecondary = getPaddingLeft() + getPaddingRight(); 913 } 914 if (DEBUG) Log.v(getTag(), "onMeasure widthSpec " + Integer.toHexString(widthSpec) + 915 " heightSpec " + Integer.toHexString(heightSpec) + 916 " modeSecondary " + Integer.toHexString(modeSecondary) + 917 " sizeSecondary " + sizeSecondary + " " + this); 918 919 mMaxSizeSecondary = sizeSecondary; 920 921 if (mRowSizeSecondaryRequested == ViewGroup.LayoutParams.WRAP_CONTENT) { 922 mNumRows = mNumRowsRequested == 0 ? 1 : mNumRowsRequested; 923 mFixedRowSizeSecondary = 0; 924 925 if (mRowSizeSecondary == null || mRowSizeSecondary.length != mNumRows) { 926 mRowSizeSecondary = new int[mNumRows]; 927 } 928 929 // Measure all current children and update cached row heights 930 processRowSizeSecondary(true); 931 932 switch (modeSecondary) { 933 case MeasureSpec.UNSPECIFIED: 934 measuredSizeSecondary = getSizeSecondary() + paddingSecondary; 935 break; 936 case MeasureSpec.AT_MOST: 937 measuredSizeSecondary = Math.min(getSizeSecondary() + paddingSecondary, 938 mMaxSizeSecondary); 939 break; 940 case MeasureSpec.EXACTLY: 941 measuredSizeSecondary = mMaxSizeSecondary; 942 break; 943 default: 944 throw new IllegalStateException("wrong spec"); 945 } 946 947 } else { 948 switch (modeSecondary) { 949 case MeasureSpec.UNSPECIFIED: 950 if (mRowSizeSecondaryRequested == 0) { 951 if (mOrientation == HORIZONTAL) { 952 throw new IllegalStateException("Must specify rowHeight or view height"); 953 } else { 954 throw new IllegalStateException("Must specify columnWidth or view width"); 955 } 956 } 957 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 958 mNumRows = mNumRowsRequested == 0 ? 1 : mNumRowsRequested; 959 measuredSizeSecondary = mFixedRowSizeSecondary * mNumRows + mMarginSecondary 960 * (mNumRows - 1) + paddingSecondary; 961 break; 962 case MeasureSpec.AT_MOST: 963 case MeasureSpec.EXACTLY: 964 if (mNumRowsRequested == 0 && mRowSizeSecondaryRequested == 0) { 965 mNumRows = 1; 966 mFixedRowSizeSecondary = sizeSecondary - paddingSecondary; 967 } else if (mNumRowsRequested == 0) { 968 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 969 mNumRows = (sizeSecondary + mMarginSecondary) 970 / (mRowSizeSecondaryRequested + mMarginSecondary); 971 } else if (mRowSizeSecondaryRequested == 0) { 972 mNumRows = mNumRowsRequested; 973 mFixedRowSizeSecondary = (sizeSecondary - paddingSecondary - mMarginSecondary 974 * (mNumRows - 1)) / mNumRows; 975 } else { 976 mNumRows = mNumRowsRequested; 977 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 978 } 979 measuredSizeSecondary = sizeSecondary; 980 if (modeSecondary == MeasureSpec.AT_MOST) { 981 int childrenSize = mFixedRowSizeSecondary * mNumRows + mMarginSecondary 982 * (mNumRows - 1) + paddingSecondary; 983 if (childrenSize < measuredSizeSecondary) { 984 measuredSizeSecondary = childrenSize; 985 } 986 } 987 break; 988 default: 989 throw new IllegalStateException("wrong spec"); 990 } 991 } 992 if (mOrientation == HORIZONTAL) { 993 setMeasuredDimension(sizePrimary, measuredSizeSecondary); 994 } else { 995 setMeasuredDimension(measuredSizeSecondary, sizePrimary); 996 } 997 if (DEBUG) { 998 Log.v(getTag(), "onMeasure sizePrimary " + sizePrimary + 999 " measuredSizeSecondary " + measuredSizeSecondary + 1000 " mFixedRowSizeSecondary " + mFixedRowSizeSecondary + 1001 " mNumRows " + mNumRows); 1002 } 1003 1004 leaveContext(); 1005 } 1006 1007 private void measureChild(View child) { 1008 final ViewGroup.LayoutParams lp = child.getLayoutParams(); 1009 final int secondarySpec = (mRowSizeSecondaryRequested == ViewGroup.LayoutParams.WRAP_CONTENT) ? 1010 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED) : 1011 MeasureSpec.makeMeasureSpec(mFixedRowSizeSecondary, MeasureSpec.EXACTLY); 1012 int widthSpec, heightSpec; 1013 1014 if (mOrientation == HORIZONTAL) { 1015 widthSpec = ViewGroup.getChildMeasureSpec( 1016 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 1017 0, lp.width); 1018 heightSpec = ViewGroup.getChildMeasureSpec(secondarySpec, 0, lp.height); 1019 } else { 1020 heightSpec = ViewGroup.getChildMeasureSpec( 1021 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 1022 0, lp.height); 1023 widthSpec = ViewGroup.getChildMeasureSpec(secondarySpec, 0, lp.width); 1024 } 1025 1026 child.measure(widthSpec, heightSpec); 1027 1028 if (DEBUG) Log.v(getTag(), "measureChild secondarySpec " + Integer.toHexString(secondarySpec) + 1029 " widthSpec " + Integer.toHexString(widthSpec) + 1030 " heightSpec " + Integer.toHexString(heightSpec) + 1031 " measuredWidth " + child.getMeasuredWidth() + 1032 " measuredHeight " + child.getMeasuredHeight()); 1033 if (DEBUG) Log.v(getTag(), "child lp width " + lp.width + " height " + lp.height); 1034 } 1035 1036 private StaggeredGrid.Provider mGridProvider = new StaggeredGrid.Provider() { 1037 1038 @Override 1039 public int getCount() { 1040 return mState.getItemCount(); 1041 } 1042 1043 @Override 1044 public void createItem(int index, int rowIndex, boolean append) { 1045 View v = getViewForPosition(index); 1046 if (mFirstVisiblePos >= 0) { 1047 // when StaggeredGrid append or prepend item, we must guarantee 1048 // that sibling item has created views already. 1049 if (append && index != mLastVisiblePos + 1) { 1050 throw new RuntimeException(); 1051 } else if (!append && index != mFirstVisiblePos - 1) { 1052 throw new RuntimeException(); 1053 } 1054 } 1055 1056 // See recyclerView docs: we don't need re-add scraped view if it was removed. 1057 if (!((RecyclerView.LayoutParams) v.getLayoutParams()).isItemRemoved()) { 1058 if (append) { 1059 addView(v); 1060 } else { 1061 addView(v, 0); 1062 } 1063 measureChild(v); 1064 } 1065 1066 int length = mOrientation == HORIZONTAL ? v.getMeasuredWidth() : v.getMeasuredHeight(); 1067 int start, end; 1068 final boolean rowIsEmpty = mRows[rowIndex].high == mRows[rowIndex].low; 1069 if (append) { 1070 if (!rowIsEmpty) { 1071 // if there are existing item in the row, add margin between 1072 start = mRows[rowIndex].high + mMarginPrimary; 1073 } else { 1074 if (mLastVisiblePos >= 0) { 1075 int lastRow = mGrid.getLocation(mLastVisiblePos).row; 1076 // if the last visible item is not last row, align to beginning, 1077 // otherwise start a new column after. 1078 if (lastRow < mNumRows - 1) { 1079 start = mRows[lastRow].low; 1080 } else { 1081 start = mRows[lastRow].high + mMarginPrimary; 1082 } 1083 } else { 1084 start = 0; 1085 } 1086 mRows[rowIndex].low = start; 1087 } 1088 end = start + length; 1089 mRows[rowIndex].high = end; 1090 } else { 1091 if (!rowIsEmpty) { 1092 // if there are existing item in the row, add margin between 1093 end = mRows[rowIndex].low - mMarginPrimary; 1094 start = end - length; 1095 } else { 1096 if (mFirstVisiblePos >= 0) { 1097 int firstRow = mGrid.getLocation(mFirstVisiblePos).row; 1098 // if the first visible item is not first row, align to beginning, 1099 // otherwise start a new column before. 1100 if (firstRow > 0) { 1101 start = mRows[firstRow].low; 1102 end = start + length; 1103 } else { 1104 end = mRows[firstRow].low - mMarginPrimary; 1105 start = end - length; 1106 } 1107 } else { 1108 start = 0; 1109 end = length; 1110 } 1111 mRows[rowIndex].high = end; 1112 } 1113 mRows[rowIndex].low = start; 1114 } 1115 if (mFirstVisiblePos < 0) { 1116 mFirstVisiblePos = mLastVisiblePos = index; 1117 } else { 1118 if (append) { 1119 mLastVisiblePos++; 1120 } else { 1121 mFirstVisiblePos--; 1122 } 1123 } 1124 if (DEBUG) Log.v(getTag(), "start " + start + " end " + end); 1125 int startSecondary = getRowStartSecondary(rowIndex) - mScrollOffsetSecondary; 1126 layoutChild(rowIndex, v, start - mScrollOffsetPrimary, end - mScrollOffsetPrimary, 1127 startSecondary); 1128 if (DEBUG) { 1129 Log.d(getTag(), "addView " + index + " " + v); 1130 } 1131 if (index == mFirstVisiblePos) { 1132 updateScrollMin(); 1133 } 1134 if (index == mLastVisiblePos) { 1135 updateScrollMax(); 1136 } 1137 mChildrenStates.loadView(v, index); 1138 } 1139 }; 1140 1141 private void layoutChild(int rowIndex, View v, int start, int end, int startSecondary) { 1142 int sizeSecondary = mOrientation == HORIZONTAL ? v.getMeasuredHeight() 1143 : v.getMeasuredWidth(); 1144 if (mFixedRowSizeSecondary > 0) { 1145 sizeSecondary = Math.min(sizeSecondary, mFixedRowSizeSecondary); 1146 } 1147 final int verticalGravity = mGravity & Gravity.VERTICAL_GRAVITY_MASK; 1148 final int horizontalGravity = mGravity & Gravity.HORIZONTAL_GRAVITY_MASK; 1149 if (mOrientation == HORIZONTAL && verticalGravity == Gravity.TOP 1150 || mOrientation == VERTICAL && horizontalGravity == Gravity.LEFT) { 1151 // do nothing 1152 } else if (mOrientation == HORIZONTAL && verticalGravity == Gravity.BOTTOM 1153 || mOrientation == VERTICAL && horizontalGravity == Gravity.RIGHT) { 1154 startSecondary += getRowSizeSecondary(rowIndex) - sizeSecondary; 1155 } else if (mOrientation == HORIZONTAL && verticalGravity == Gravity.CENTER_VERTICAL 1156 || mOrientation == VERTICAL && horizontalGravity == Gravity.CENTER_HORIZONTAL) { 1157 startSecondary += (getRowSizeSecondary(rowIndex) - sizeSecondary) / 2; 1158 } 1159 int left, top, right, bottom; 1160 if (mOrientation == HORIZONTAL) { 1161 left = start; 1162 top = startSecondary; 1163 right = end; 1164 bottom = startSecondary + sizeSecondary; 1165 } else { 1166 top = start; 1167 left = startSecondary; 1168 bottom = end; 1169 right = startSecondary + sizeSecondary; 1170 } 1171 v.layout(left, top, right, bottom); 1172 updateChildOpticalInsets(v, left, top, right, bottom); 1173 updateChildAlignments(v); 1174 } 1175 1176 private void updateChildOpticalInsets(View v, int left, int top, int right, int bottom) { 1177 LayoutParams p = (LayoutParams) v.getLayoutParams(); 1178 p.setOpticalInsets(left - v.getLeft(), top - v.getTop(), 1179 v.getRight() - right, v.getBottom() - bottom); 1180 } 1181 1182 private void updateChildAlignments(View v) { 1183 LayoutParams p = (LayoutParams) v.getLayoutParams(); 1184 p.setAlignX(mItemAlignment.horizontal.getAlignmentPosition(v)); 1185 p.setAlignY(mItemAlignment.vertical.getAlignmentPosition(v)); 1186 } 1187 1188 private void updateChildAlignments() { 1189 for (int i = 0, c = getChildCount(); i < c; i++) { 1190 updateChildAlignments(getChildAt(i)); 1191 } 1192 } 1193 1194 private boolean needsAppendVisibleItem() { 1195 if (mLastVisiblePos < mFocusPosition) { 1196 return true; 1197 } 1198 int right = mScrollOffsetPrimary + mSizePrimary; 1199 for (int i = 0; i < mNumRows; i++) { 1200 if (mRows[i].low == mRows[i].high) { 1201 if (mRows[i].high < right) { 1202 return true; 1203 } 1204 } else if (mRows[i].high < right - mMarginPrimary) { 1205 return true; 1206 } 1207 } 1208 return false; 1209 } 1210 1211 private boolean needsPrependVisibleItem() { 1212 if (mFirstVisiblePos > mFocusPosition) { 1213 return true; 1214 } 1215 for (int i = 0; i < mNumRows; i++) { 1216 if (mRows[i].low == mRows[i].high) { 1217 if (mRows[i].low > mScrollOffsetPrimary) { 1218 return true; 1219 } 1220 } else if (mRows[i].low - mMarginPrimary > mScrollOffsetPrimary) { 1221 return true; 1222 } 1223 } 1224 return false; 1225 } 1226 1227 // Append one column if possible and return true if reach end. 1228 private boolean appendOneVisibleItem() { 1229 while (true) { 1230 if (mLastVisiblePos != NO_POSITION && mLastVisiblePos < mState.getItemCount() -1 && 1231 mLastVisiblePos < mGrid.getLastIndex()) { 1232 // append invisible view of saved location till last row 1233 final int index = mLastVisiblePos + 1; 1234 final int row = mGrid.getLocation(index).row; 1235 mGridProvider.createItem(index, row, true); 1236 if (row == mNumRows - 1) { 1237 return false; 1238 } 1239 } else if ((mLastVisiblePos == NO_POSITION && mState.getItemCount() > 0) || 1240 (mLastVisiblePos != NO_POSITION && 1241 mLastVisiblePos < mState.getItemCount() - 1)) { 1242 mGrid.appendItems(mScrollOffsetPrimary + mSizePrimary); 1243 return false; 1244 } else { 1245 return true; 1246 } 1247 } 1248 } 1249 1250 private void appendVisibleItems() { 1251 while (needsAppendVisibleItem()) { 1252 if (appendOneVisibleItem()) { 1253 break; 1254 } 1255 } 1256 } 1257 1258 // Prepend one column if possible and return true if reach end. 1259 private boolean prependOneVisibleItem() { 1260 while (true) { 1261 if (mFirstVisiblePos > 0) { 1262 if (mFirstVisiblePos > mGrid.getFirstIndex()) { 1263 // prepend invisible view of saved location till first row 1264 final int index = mFirstVisiblePos - 1; 1265 final int row = mGrid.getLocation(index).row; 1266 mGridProvider.createItem(index, row, false); 1267 if (row == 0) { 1268 return false; 1269 } 1270 } else { 1271 mGrid.prependItems(mScrollOffsetPrimary); 1272 return false; 1273 } 1274 } else { 1275 return true; 1276 } 1277 } 1278 } 1279 1280 private void prependVisibleItems() { 1281 while (needsPrependVisibleItem()) { 1282 if (prependOneVisibleItem()) { 1283 break; 1284 } 1285 } 1286 } 1287 1288 private void removeChildAt(int position) { 1289 View v = findViewByPosition(position); 1290 if (v != null) { 1291 if (DEBUG) { 1292 Log.d(getTag(), "removeAndRecycleViewAt " + position); 1293 } 1294 mChildrenStates.saveOffscreenView(v, position); 1295 removeAndRecycleView(v, mRecycler); 1296 } 1297 } 1298 1299 private void removeInvisibleViewsAtEnd() { 1300 if (!mPruneChild) { 1301 return; 1302 } 1303 boolean update = false; 1304 while(mLastVisiblePos > mFirstVisiblePos && mLastVisiblePos > mFocusPosition) { 1305 View view = findViewByPosition(mLastVisiblePos); 1306 if (getViewMin(view) > mSizePrimary) { 1307 removeChildAt(mLastVisiblePos); 1308 mLastVisiblePos--; 1309 update = true; 1310 } else { 1311 break; 1312 } 1313 } 1314 if (update) { 1315 updateRowsMinMax(); 1316 } 1317 } 1318 1319 private void removeInvisibleViewsAtFront() { 1320 if (!mPruneChild) { 1321 return; 1322 } 1323 boolean update = false; 1324 while(mLastVisiblePos > mFirstVisiblePos && mFirstVisiblePos < mFocusPosition) { 1325 View view = findViewByPosition(mFirstVisiblePos); 1326 if (getViewMax(view) < 0) { 1327 removeChildAt(mFirstVisiblePos); 1328 mFirstVisiblePos++; 1329 update = true; 1330 } else { 1331 break; 1332 } 1333 } 1334 if (update) { 1335 updateRowsMinMax(); 1336 } 1337 } 1338 1339 private void updateRowsMinMax() { 1340 if (mFirstVisiblePos < 0) { 1341 return; 1342 } 1343 for (int i = 0; i < mNumRows; i++) { 1344 mRows[i].low = Integer.MAX_VALUE; 1345 mRows[i].high = Integer.MIN_VALUE; 1346 } 1347 for (int i = mFirstVisiblePos; i <= mLastVisiblePos; i++) { 1348 View view = findViewByPosition(i); 1349 int row = mGrid.getLocation(i).row; 1350 int low = getViewMin(view) + mScrollOffsetPrimary; 1351 if (low < mRows[row].low) { 1352 mRows[row].low = low; 1353 } 1354 int high = getViewMax(view) + mScrollOffsetPrimary; 1355 if (high > mRows[row].high) { 1356 mRows[row].high = high; 1357 } 1358 } 1359 } 1360 1361 // Fast layout when there is no structure change, adapter change, etc. 1362 protected void fastRelayout(boolean scrollToFocus) { 1363 initScrollController(); 1364 1365 List<Integer>[] rows = mGrid.getItemPositionsInRows(mFirstVisiblePos, mLastVisiblePos); 1366 1367 // relayout and repositioning views on each row 1368 for (int i = 0; i < mNumRows; i++) { 1369 List<Integer> row = rows[i]; 1370 final int startSecondary = getRowStartSecondary(i) - mScrollOffsetSecondary; 1371 for (int j = 0, size = row.size(); j < size; j++) { 1372 final int position = row.get(j); 1373 final View view = findViewByPosition(position); 1374 int primaryDelta, start, end; 1375 1376 if (mOrientation == HORIZONTAL) { 1377 final int primarySize = view.getMeasuredWidth(); 1378 if (view.isLayoutRequested()) { 1379 measureChild(view); 1380 } 1381 start = getViewMin(view); 1382 end = start + view.getMeasuredWidth(); 1383 primaryDelta = view.getMeasuredWidth() - primarySize; 1384 if (primaryDelta != 0) { 1385 for (int k = j + 1; k < size; k++) { 1386 findViewByPosition(row.get(k)).offsetLeftAndRight(primaryDelta); 1387 } 1388 } 1389 } else { 1390 final int primarySize = view.getMeasuredHeight(); 1391 if (view.isLayoutRequested()) { 1392 measureChild(view); 1393 } 1394 start = getViewMin(view); 1395 end = start + view.getMeasuredHeight(); 1396 primaryDelta = view.getMeasuredHeight() - primarySize; 1397 if (primaryDelta != 0) { 1398 for (int k = j + 1; k < size; k++) { 1399 findViewByPosition(row.get(k)).offsetTopAndBottom(primaryDelta); 1400 } 1401 } 1402 } 1403 layoutChild(i, view, start, end, startSecondary); 1404 } 1405 } 1406 1407 updateRowsMinMax(); 1408 appendVisibleItems(); 1409 prependVisibleItems(); 1410 1411 updateRowsMinMax(); 1412 updateScrollMin(); 1413 updateScrollMax(); 1414 updateScrollSecondAxis(); 1415 1416 if (scrollToFocus) { 1417 View focusView = findViewByPosition(mFocusPosition == NO_POSITION ? 0 : mFocusPosition); 1418 scrollToView(focusView, false); 1419 } 1420 } 1421 1422 public void removeAndRecycleAllViews(RecyclerView.Recycler recycler) { 1423 if (DEBUG) Log.v(TAG, "removeAndRecycleAllViews " + getChildCount()); 1424 for (int i = getChildCount() - 1; i >= 0; i--) { 1425 removeAndRecycleViewAt(i, recycler); 1426 } 1427 } 1428 1429 // Lays out items based on the current scroll position 1430 @Override 1431 public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state) { 1432 if (DEBUG) { 1433 Log.v(getTag(), "layoutChildren start numRows " + mNumRows + " mScrollOffsetSecondary " 1434 + mScrollOffsetSecondary + " mScrollOffsetPrimary " + mScrollOffsetPrimary 1435 + " inPreLayout " + state.isPreLayout() 1436 + " didStructureChange " + state.didStructureChange() 1437 + " mForceFullLayout " + mForceFullLayout); 1438 Log.v(getTag(), "width " + getWidth() + " height " + getHeight()); 1439 } 1440 1441 if (mNumRows == 0) { 1442 // haven't done measure yet 1443 return; 1444 } 1445 final int itemCount = state.getItemCount(); 1446 if (itemCount < 0) { 1447 return; 1448 } 1449 1450 if (!mLayoutEnabled) { 1451 discardLayoutInfo(); 1452 removeAndRecycleAllViews(recycler); 1453 return; 1454 } 1455 mInLayout = true; 1456 1457 if (mLoadingState != null) { 1458 mFocusPosition = mLoadingState.index; 1459 mFocusPositionOffset = 0; 1460 mChildrenStates.getChildStates().putAll(mLoadingState.childStates); 1461 mLoadingState = null; 1462 } 1463 final boolean scrollToFocus = !isSmoothScrolling() 1464 && mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED; 1465 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE) { 1466 mFocusPosition = mFocusPosition + mFocusPositionOffset; 1467 mFocusPositionOffset = 0; 1468 } 1469 saveContext(recycler, state); 1470 // Track the old focus view so we can adjust our system scroll position 1471 // so that any scroll animations happening now will remain valid. 1472 // We must use same delta in Pre Layout (if prelayout exists) and second layout. 1473 // So we cache the deltas in PreLayout and use it in second layout. 1474 int delta = 0, deltaSecondary = 0; 1475 if (mFocusPosition != NO_POSITION && scrollToFocus) { 1476 // FIXME: we should get the remaining scroll animation offset from RecyclerView 1477 View focusView = findViewByPosition(mFocusPosition); 1478 if (focusView != null) { 1479 delta = mWindowAlignment.mainAxis().getSystemScrollPos(mScrollOffsetPrimary 1480 + getViewCenter(focusView), false, false) - mScrollOffsetPrimary; 1481 deltaSecondary = mWindowAlignment.secondAxis().getSystemScrollPos( 1482 mScrollOffsetSecondary + getViewCenterSecondary(focusView), 1483 false, false) - mScrollOffsetSecondary; 1484 } 1485 } 1486 1487 final boolean hasDoneFirstLayout = hasDoneFirstLayout(); 1488 int savedFocusPos = mFocusPosition; 1489 boolean fastRelayout = false; 1490 if (!mState.didStructureChange() && !mForceFullLayout && hasDoneFirstLayout) { 1491 fastRelayout = true; 1492 fastRelayout(scrollToFocus); 1493 } else { 1494 boolean hadFocus = mBaseGridView.hasFocus(); 1495 1496 int newFocusPosition = init(mFocusPosition); 1497 if (DEBUG) { 1498 Log.v(getTag(), "mFocusPosition " + mFocusPosition + " newFocusPosition " 1499 + newFocusPosition); 1500 } 1501 1502 // depending on result of init(), either recreating everything 1503 // or try to reuse the row start positions near mFocusPosition 1504 if (mGrid.getSize() == 0) { 1505 // this is a fresh creating all items, starting from 1506 // mFocusPosition with a estimated row index. 1507 mGrid.setStart(newFocusPosition, StaggeredGrid.START_DEFAULT); 1508 1509 // Can't track the old focus view 1510 delta = deltaSecondary = 0; 1511 1512 } else { 1513 // mGrid remembers Locations for the column that 1514 // contains mFocusePosition and also mRows remembers start 1515 // positions of each row. 1516 // Manually re-create child views for that column 1517 int firstIndex = mGrid.getFirstIndex(); 1518 int lastIndex = mGrid.getLastIndex(); 1519 for (int i = firstIndex; i <= lastIndex; i++) { 1520 mGridProvider.createItem(i, mGrid.getLocation(i).row, true); 1521 } 1522 } 1523 // add visible views at end until reach the end of window 1524 appendVisibleItems(); 1525 // add visible views at front until reach the start of window 1526 prependVisibleItems(); 1527 // multiple rounds: scrollToView of first round may drag first/last child into 1528 // "visible window" and we update scrollMin/scrollMax then run second scrollToView 1529 int oldFirstVisible; 1530 int oldLastVisible; 1531 do { 1532 updateScrollMin(); 1533 updateScrollMax(); 1534 oldFirstVisible = mFirstVisiblePos; 1535 oldLastVisible = mLastVisiblePos; 1536 View focusView = findViewByPosition(newFocusPosition); 1537 // we need force to initialize the child view's position 1538 scrollToView(focusView, false); 1539 if (focusView != null && hadFocus) { 1540 focusView.requestFocus(); 1541 } 1542 appendVisibleItems(); 1543 prependVisibleItems(); 1544 removeInvisibleViewsAtFront(); 1545 removeInvisibleViewsAtEnd(); 1546 } while (mFirstVisiblePos != oldFirstVisible || mLastVisiblePos != oldLastVisible); 1547 } 1548 mForceFullLayout = false; 1549 1550 if (scrollToFocus) { 1551 scrollDirectionPrimary(-delta); 1552 scrollDirectionSecondary(-deltaSecondary); 1553 } 1554 appendVisibleItems(); 1555 prependVisibleItems(); 1556 removeInvisibleViewsAtFront(); 1557 removeInvisibleViewsAtEnd(); 1558 1559 if (DEBUG) { 1560 StringWriter sw = new StringWriter(); 1561 PrintWriter pw = new PrintWriter(sw); 1562 mGrid.debugPrint(pw); 1563 Log.d(getTag(), sw.toString()); 1564 } 1565 1566 if (mRowSecondarySizeRefresh) { 1567 mRowSecondarySizeRefresh = false; 1568 } else { 1569 updateRowSecondarySizeRefresh(); 1570 } 1571 1572 if (!fastRelayout || mFocusPosition != savedFocusPos) { 1573 dispatchChildSelected(); 1574 } 1575 mInLayout = false; 1576 leaveContext(); 1577 if (DEBUG) Log.v(getTag(), "layoutChildren end"); 1578 } 1579 1580 private void offsetChildrenSecondary(int increment) { 1581 final int childCount = getChildCount(); 1582 if (mOrientation == HORIZONTAL) { 1583 for (int i = 0; i < childCount; i++) { 1584 getChildAt(i).offsetTopAndBottom(increment); 1585 } 1586 } else { 1587 for (int i = 0; i < childCount; i++) { 1588 getChildAt(i).offsetLeftAndRight(increment); 1589 } 1590 } 1591 } 1592 1593 private void offsetChildrenPrimary(int increment) { 1594 final int childCount = getChildCount(); 1595 if (mOrientation == VERTICAL) { 1596 for (int i = 0; i < childCount; i++) { 1597 getChildAt(i).offsetTopAndBottom(increment); 1598 } 1599 } else { 1600 for (int i = 0; i < childCount; i++) { 1601 getChildAt(i).offsetLeftAndRight(increment); 1602 } 1603 } 1604 } 1605 1606 @Override 1607 public int scrollHorizontallyBy(int dx, Recycler recycler, RecyclerView.State state) { 1608 if (DEBUG) Log.v(getTag(), "scrollHorizontallyBy " + dx); 1609 if (!mLayoutEnabled || !hasDoneFirstLayout()) { 1610 return 0; 1611 } 1612 saveContext(recycler, state); 1613 int result; 1614 if (mOrientation == HORIZONTAL) { 1615 result = scrollDirectionPrimary(dx); 1616 } else { 1617 result = scrollDirectionSecondary(dx); 1618 } 1619 leaveContext(); 1620 return result; 1621 } 1622 1623 @Override 1624 public int scrollVerticallyBy(int dy, Recycler recycler, RecyclerView.State state) { 1625 if (DEBUG) Log.v(getTag(), "scrollVerticallyBy " + dy); 1626 if (!mLayoutEnabled || !hasDoneFirstLayout()) { 1627 return 0; 1628 } 1629 saveContext(recycler, state); 1630 int result; 1631 if (mOrientation == VERTICAL) { 1632 result = scrollDirectionPrimary(dy); 1633 } else { 1634 result = scrollDirectionSecondary(dy); 1635 } 1636 leaveContext(); 1637 return result; 1638 } 1639 1640 // scroll in main direction may add/prune views 1641 private int scrollDirectionPrimary(int da) { 1642 if (da > 0) { 1643 if (!mWindowAlignment.mainAxis().isMaxUnknown()) { 1644 int maxScroll = mWindowAlignment.mainAxis().getMaxScroll(); 1645 if (mScrollOffsetPrimary + da > maxScroll) { 1646 da = maxScroll - mScrollOffsetPrimary; 1647 } 1648 } 1649 } else if (da < 0) { 1650 if (!mWindowAlignment.mainAxis().isMinUnknown()) { 1651 int minScroll = mWindowAlignment.mainAxis().getMinScroll(); 1652 if (mScrollOffsetPrimary + da < minScroll) { 1653 da = minScroll - mScrollOffsetPrimary; 1654 } 1655 } 1656 } 1657 if (da == 0) { 1658 return 0; 1659 } 1660 offsetChildrenPrimary(-da); 1661 mScrollOffsetPrimary += da; 1662 if (mInLayout) { 1663 return da; 1664 } 1665 1666 int childCount = getChildCount(); 1667 boolean updated; 1668 1669 if (da > 0) { 1670 appendVisibleItems(); 1671 } else if (da < 0) { 1672 prependVisibleItems(); 1673 } 1674 updated = getChildCount() > childCount; 1675 childCount = getChildCount(); 1676 1677 if (da > 0) { 1678 removeInvisibleViewsAtFront(); 1679 } else if (da < 0) { 1680 removeInvisibleViewsAtEnd(); 1681 } 1682 updated |= getChildCount() < childCount; 1683 1684 if (updated) { 1685 updateRowSecondarySizeRefresh(); 1686 } 1687 1688 mBaseGridView.invalidate(); 1689 return da; 1690 } 1691 1692 // scroll in second direction will not add/prune views 1693 private int scrollDirectionSecondary(int dy) { 1694 if (dy == 0) { 1695 return 0; 1696 } 1697 offsetChildrenSecondary(-dy); 1698 mScrollOffsetSecondary += dy; 1699 mBaseGridView.invalidate(); 1700 return dy; 1701 } 1702 1703 private void updateScrollMax() { 1704 if (mLastVisiblePos < 0) { 1705 return; 1706 } 1707 final boolean lastAvailable = mLastVisiblePos == mState.getItemCount() - 1; 1708 final boolean maxUnknown = mWindowAlignment.mainAxis().isMaxUnknown(); 1709 if (!lastAvailable && maxUnknown) { 1710 return; 1711 } 1712 int maxEdge = Integer.MIN_VALUE; 1713 int rowIndex = -1; 1714 for (int i = 0; i < mRows.length; i++) { 1715 if (mRows[i].high > maxEdge) { 1716 maxEdge = mRows[i].high; 1717 rowIndex = i; 1718 } 1719 } 1720 int maxScroll = Integer.MAX_VALUE; 1721 for (int i = mLastVisiblePos; i >= mFirstVisiblePos; i--) { 1722 StaggeredGrid.Location location = mGrid.getLocation(i); 1723 if (location != null && location.row == rowIndex) { 1724 int savedMaxEdge = mWindowAlignment.mainAxis().getMaxEdge(); 1725 mWindowAlignment.mainAxis().setMaxEdge(maxEdge); 1726 maxScroll = getPrimarySystemScrollPosition(findViewByPosition(i)); 1727 mWindowAlignment.mainAxis().setMaxEdge(savedMaxEdge); 1728 break; 1729 } 1730 } 1731 if (lastAvailable) { 1732 mWindowAlignment.mainAxis().setMaxEdge(maxEdge); 1733 mWindowAlignment.mainAxis().setMaxScroll(maxScroll); 1734 if (DEBUG) Log.v(getTag(), "updating scroll maxEdge to " + maxEdge + 1735 " scrollMax to " + maxScroll); 1736 } else { 1737 // the maxScroll for currently last visible item is larger, 1738 // so we must invalidate the max scroll value. 1739 if (maxScroll > mWindowAlignment.mainAxis().getMaxScroll()) { 1740 mWindowAlignment.mainAxis().invalidateScrollMax(); 1741 if (DEBUG) Log.v(getTag(), "Invalidate scrollMax since it should be " 1742 + "greater than " + maxScroll); 1743 } 1744 } 1745 } 1746 1747 private void updateScrollMin() { 1748 if (mFirstVisiblePos < 0) { 1749 return; 1750 } 1751 final boolean firstAvailable = mFirstVisiblePos == 0; 1752 final boolean minUnknown = mWindowAlignment.mainAxis().isMinUnknown(); 1753 if (!firstAvailable && minUnknown) { 1754 return; 1755 } 1756 int minEdge = Integer.MAX_VALUE; 1757 int rowIndex = -1; 1758 for (int i = 0; i < mRows.length; i++) { 1759 if (mRows[i].low < minEdge) { 1760 minEdge = mRows[i].low; 1761 rowIndex = i; 1762 } 1763 } 1764 int minScroll = Integer.MIN_VALUE; 1765 for (int i = mFirstVisiblePos; i <= mLastVisiblePos; i++) { 1766 StaggeredGrid.Location location = mGrid.getLocation(i); 1767 if (location != null && location.row == rowIndex) { 1768 int savedMinEdge = mWindowAlignment.mainAxis().getMinEdge(); 1769 mWindowAlignment.mainAxis().setMinEdge(minEdge); 1770 minScroll = getPrimarySystemScrollPosition(findViewByPosition(i)); 1771 mWindowAlignment.mainAxis().setMinEdge(savedMinEdge); 1772 break; 1773 } 1774 } 1775 if (firstAvailable) { 1776 mWindowAlignment.mainAxis().setMinEdge(minEdge); 1777 mWindowAlignment.mainAxis().setMinScroll(minScroll); 1778 if (DEBUG) Log.v(getTag(), "updating scroll minEdge to " + minEdge + 1779 " scrollMin to " + minScroll); 1780 } else { 1781 // the minScroll for currently first visible item is smaller, 1782 // so we must invalidate the min scroll value. 1783 if (minScroll < mWindowAlignment.mainAxis().getMinScroll()) { 1784 mWindowAlignment.mainAxis().invalidateScrollMin(); 1785 if (DEBUG) Log.v(getTag(), "Invalidate scrollMin, since it should be " 1786 + "less than " + minScroll); 1787 } 1788 } 1789 } 1790 1791 private void updateScrollSecondAxis() { 1792 mWindowAlignment.secondAxis().setMinEdge(0); 1793 mWindowAlignment.secondAxis().setMaxEdge(getSizeSecondary()); 1794 } 1795 1796 private void initScrollController() { 1797 // mScrollOffsetPrimary and mScrollOffsetSecondary includes the padding. 1798 // e.g. when topPadding is 16 for horizontal grid view, the initial 1799 // mScrollOffsetSecondary is -16. fastLayout() put views based on offsets(not padding), 1800 // when padding changes to 20, we also need update mScrollOffsetSecondary to -20 before 1801 // fastLayout() is performed 1802 int paddingPrimaryDiff, paddingSecondaryDiff; 1803 if (mOrientation == HORIZONTAL) { 1804 paddingPrimaryDiff = getPaddingLeft() - mWindowAlignment.horizontal.getPaddingLow(); 1805 paddingSecondaryDiff = getPaddingTop() - mWindowAlignment.vertical.getPaddingLow(); 1806 } else { 1807 paddingPrimaryDiff = getPaddingTop() - mWindowAlignment.vertical.getPaddingLow(); 1808 paddingSecondaryDiff = getPaddingLeft() - mWindowAlignment.horizontal.getPaddingLow(); 1809 } 1810 mScrollOffsetPrimary -= paddingPrimaryDiff; 1811 mScrollOffsetSecondary -= paddingSecondaryDiff; 1812 1813 mWindowAlignment.horizontal.setSize(getWidth()); 1814 mWindowAlignment.horizontal.setPadding(getPaddingLeft(), getPaddingRight()); 1815 mWindowAlignment.vertical.setSize(getHeight()); 1816 mWindowAlignment.vertical.setPadding(getPaddingTop(), getPaddingBottom()); 1817 mSizePrimary = mWindowAlignment.mainAxis().getSize(); 1818 1819 if (DEBUG) { 1820 Log.v(getTag(), "initScrollController mSizePrimary " + mSizePrimary 1821 + " mWindowAlignment " + mWindowAlignment); 1822 } 1823 } 1824 1825 public void setSelection(RecyclerView parent, int position) { 1826 setSelection(parent, position, false); 1827 } 1828 1829 public void setSelectionSmooth(RecyclerView parent, int position) { 1830 setSelection(parent, position, true); 1831 } 1832 1833 public int getSelection() { 1834 return mFocusPosition; 1835 } 1836 1837 public void setSelection(RecyclerView parent, int position, boolean smooth) { 1838 if (mFocusPosition == position) { 1839 return; 1840 } 1841 View view = findViewByPosition(position); 1842 if (view != null) { 1843 mInSelection = true; 1844 scrollToView(view, smooth); 1845 mInSelection = false; 1846 } else { 1847 mFocusPosition = position; 1848 mFocusPositionOffset = 0; 1849 if (!mLayoutEnabled) { 1850 return; 1851 } 1852 if (smooth) { 1853 if (!hasDoneFirstLayout()) { 1854 Log.w(getTag(), "setSelectionSmooth should " + 1855 "not be called before first layout pass"); 1856 return; 1857 } 1858 LinearSmoothScroller linearSmoothScroller = 1859 new LinearSmoothScroller(parent.getContext()) { 1860 @Override 1861 public PointF computeScrollVectorForPosition(int targetPosition) { 1862 if (getChildCount() == 0) { 1863 return null; 1864 } 1865 final int firstChildPos = getPosition(getChildAt(0)); 1866 final int direction = targetPosition < firstChildPos ? -1 : 1; 1867 if (mOrientation == HORIZONTAL) { 1868 return new PointF(direction, 0); 1869 } else { 1870 return new PointF(0, direction); 1871 } 1872 } 1873 @Override 1874 protected void onTargetFound(View targetView, 1875 RecyclerView.State state, Action action) { 1876 if (hasFocus()) { 1877 targetView.requestFocus(); 1878 } 1879 dispatchChildSelected(); 1880 if (getScrollPosition(targetView, mTempDeltas)) { 1881 int dx, dy; 1882 if (mOrientation == HORIZONTAL) { 1883 dx = mTempDeltas[0]; 1884 dy = mTempDeltas[1]; 1885 } else { 1886 dx = mTempDeltas[1]; 1887 dy = mTempDeltas[0]; 1888 } 1889 final int distance = (int) Math.sqrt(dx * dx + dy * dy); 1890 final int time = calculateTimeForDeceleration(distance); 1891 action.update(dx, dy, time, mDecelerateInterpolator); 1892 } 1893 } 1894 }; 1895 linearSmoothScroller.setTargetPosition(position); 1896 startSmoothScroll(linearSmoothScroller); 1897 } else { 1898 mForceFullLayout = true; 1899 parent.requestLayout(); 1900 } 1901 } 1902 } 1903 1904 @Override 1905 public void onItemsAdded(RecyclerView recyclerView, int positionStart, int itemCount) { 1906 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE) { 1907 int pos = mFocusPosition + mFocusPositionOffset; 1908 if (positionStart <= pos) { 1909 mFocusPositionOffset += itemCount; 1910 } 1911 } 1912 } 1913 1914 @Override 1915 public void onItemsChanged(RecyclerView recyclerView) { 1916 mFocusPositionOffset = 0; 1917 mChildrenStates.clear(); 1918 } 1919 1920 @Override 1921 public void onItemsRemoved(RecyclerView recyclerView, int positionStart, int itemCount) { 1922 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE) { 1923 int pos = mFocusPosition + mFocusPositionOffset; 1924 if (positionStart <= pos) { 1925 if (positionStart + itemCount > pos) { 1926 // stop updating offset after the focus item was removed 1927 mFocusPositionOffset = Integer.MIN_VALUE; 1928 } else { 1929 mFocusPositionOffset -= itemCount; 1930 } 1931 } 1932 } 1933 for (int i = 0; i < itemCount; i++) { 1934 mChildrenStates.remove(positionStart + i); 1935 } 1936 } 1937 1938 public void onItemsMoved(RecyclerView recyclerView, int fromPosition, int toPosition, 1939 int itemCount) { 1940 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE) { 1941 int pos = mFocusPosition + mFocusPositionOffset; 1942 if (fromPosition <= pos && pos < fromPosition + itemCount) { 1943 // moved items include focused position 1944 mFocusPositionOffset += toPosition - fromPosition; 1945 } else if (fromPosition < pos && toPosition > pos - itemCount) { 1946 // move items before focus position to after focused position 1947 mFocusPositionOffset -= itemCount; 1948 } else if (fromPosition > pos && toPosition < pos) { 1949 // move items after focus position to before focused position 1950 mFocusPositionOffset += itemCount; 1951 } 1952 } 1953 } 1954 1955 @Override 1956 public boolean onRequestChildFocus(RecyclerView parent, View child, View focused) { 1957 if (mFocusSearchDisabled) { 1958 return true; 1959 } 1960 if (!mInLayout && !mInSelection) { 1961 scrollToView(child, true); 1962 } 1963 return true; 1964 } 1965 1966 @Override 1967 public boolean requestChildRectangleOnScreen(RecyclerView parent, View view, Rect rect, 1968 boolean immediate) { 1969 if (DEBUG) Log.v(getTag(), "requestChildRectangleOnScreen " + view + " " + rect); 1970 return false; 1971 } 1972 1973 int getScrollOffsetX() { 1974 return mOrientation == HORIZONTAL ? mScrollOffsetPrimary : mScrollOffsetSecondary; 1975 } 1976 1977 int getScrollOffsetY() { 1978 return mOrientation == HORIZONTAL ? mScrollOffsetSecondary : mScrollOffsetPrimary; 1979 } 1980 1981 public void getViewSelectedOffsets(View view, int[] offsets) { 1982 if (mOrientation == HORIZONTAL) { 1983 offsets[0] = getPrimarySystemScrollPosition(view) - mScrollOffsetPrimary; 1984 offsets[1] = getSecondarySystemScrollPosition(view) - mScrollOffsetSecondary; 1985 } else { 1986 offsets[1] = getPrimarySystemScrollPosition(view) - mScrollOffsetPrimary; 1987 offsets[0] = getSecondarySystemScrollPosition(view) - mScrollOffsetSecondary; 1988 } 1989 } 1990 1991 private int getPrimarySystemScrollPosition(View view) { 1992 int viewCenterPrimary = mScrollOffsetPrimary + getViewCenter(view); 1993 int pos = getPositionByView(view); 1994 StaggeredGrid.Location location = mGrid.getLocation(pos); 1995 final int row = location.row; 1996 boolean isFirst = mFirstVisiblePos == 0; 1997 // TODO: change to use State object in onRequestChildFocus() 1998 boolean isLast = mLastVisiblePos == (mState == null ? 1999 getItemCount() : mState.getItemCount()) - 1; 2000 if (isFirst || isLast) { 2001 for (int i = getChildCount() - 1; i >= 0; i--) { 2002 int position = getPositionByIndex(i); 2003 StaggeredGrid.Location loc = mGrid.getLocation(position); 2004 if (loc != null && loc.row == row) { 2005 if (position < pos) { 2006 isFirst = false; 2007 } else if (position > pos) { 2008 isLast = false; 2009 } 2010 } 2011 } 2012 } 2013 return mWindowAlignment.mainAxis().getSystemScrollPos(viewCenterPrimary, isFirst, isLast); 2014 } 2015 2016 private int getSecondarySystemScrollPosition(View view) { 2017 int viewCenterSecondary = mScrollOffsetSecondary + getViewCenterSecondary(view); 2018 int pos = getPositionByView(view); 2019 StaggeredGrid.Location location = mGrid.getLocation(pos); 2020 final int row = location.row; 2021 boolean isFirst = row == 0; 2022 boolean isLast = row == mGrid.getNumRows() - 1; 2023 return mWindowAlignment.secondAxis().getSystemScrollPos(viewCenterSecondary, 2024 isFirst, isLast); 2025 } 2026 2027 /** 2028 * Scroll to a given child view and change mFocusPosition. 2029 */ 2030 private void scrollToView(View view, boolean smooth) { 2031 int newFocusPosition = getPositionByView(view); 2032 if (newFocusPosition != mFocusPosition) { 2033 mFocusPosition = newFocusPosition; 2034 mFocusPositionOffset = 0; 2035 if (!mInLayout) { 2036 dispatchChildSelected(); 2037 } 2038 } 2039 if (mBaseGridView.isChildrenDrawingOrderEnabledInternal()) { 2040 mBaseGridView.invalidate(); 2041 } 2042 if (view == null) { 2043 return; 2044 } 2045 if (!view.hasFocus() && mBaseGridView.hasFocus()) { 2046 // transfer focus to the child if it does not have focus yet (e.g. triggered 2047 // by setSelection()) 2048 view.requestFocus(); 2049 } 2050 if (!mScrollEnabled) { 2051 return; 2052 } 2053 if (getScrollPosition(view, mTempDeltas)) { 2054 scrollGrid(mTempDeltas[0], mTempDeltas[1], smooth); 2055 } 2056 } 2057 2058 private boolean getScrollPosition(View view, int[] deltas) { 2059 switch (mFocusScrollStrategy) { 2060 case BaseGridView.FOCUS_SCROLL_ALIGNED: 2061 default: 2062 return getAlignedPosition(view, deltas); 2063 case BaseGridView.FOCUS_SCROLL_ITEM: 2064 case BaseGridView.FOCUS_SCROLL_PAGE: 2065 return getNoneAlignedPosition(view, deltas); 2066 } 2067 } 2068 2069 private boolean getNoneAlignedPosition(View view, int[] deltas) { 2070 int pos = getPositionByView(view); 2071 int viewMin = getViewMin(view); 2072 int viewMax = getViewMax(view); 2073 // we either align "firstView" to left/top padding edge 2074 // or align "lastView" to right/bottom padding edge 2075 View firstView = null; 2076 View lastView = null; 2077 int paddingLow = mWindowAlignment.mainAxis().getPaddingLow(); 2078 int clientSize = mWindowAlignment.mainAxis().getClientSize(); 2079 final int row = mGrid.getLocation(pos).row; 2080 if (viewMin < paddingLow) { 2081 // view enters low padding area: 2082 firstView = view; 2083 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_PAGE) { 2084 // scroll one "page" left/top, 2085 // align first visible item of the "page" at the low padding edge. 2086 while (!prependOneVisibleItem()) { 2087 List<Integer> positions = 2088 mGrid.getItemPositionsInRows(mFirstVisiblePos, pos)[row]; 2089 firstView = findViewByPosition(positions.get(0)); 2090 if (viewMax - getViewMin(firstView) > clientSize) { 2091 if (positions.size() > 1) { 2092 firstView = findViewByPosition(positions.get(1)); 2093 } 2094 break; 2095 } 2096 } 2097 } 2098 } else if (viewMax > clientSize + paddingLow) { 2099 // view enters high padding area: 2100 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_PAGE) { 2101 // scroll whole one page right/bottom, align view at the low padding edge. 2102 firstView = view; 2103 do { 2104 List<Integer> positions = 2105 mGrid.getItemPositionsInRows(pos, mLastVisiblePos)[row]; 2106 lastView = findViewByPosition(positions.get(positions.size() - 1)); 2107 if (getViewMax(lastView) - viewMin > clientSize) { 2108 lastView = null; 2109 break; 2110 } 2111 } while (!appendOneVisibleItem()); 2112 if (lastView != null) { 2113 // however if we reached end, we should align last view. 2114 firstView = null; 2115 } 2116 } else { 2117 lastView = view; 2118 } 2119 } 2120 int scrollPrimary = 0; 2121 int scrollSecondary = 0; 2122 if (firstView != null) { 2123 scrollPrimary = getViewMin(firstView) - paddingLow; 2124 } else if (lastView != null) { 2125 scrollPrimary = getViewMax(lastView) - (paddingLow + clientSize); 2126 } 2127 View secondaryAlignedView; 2128 if (firstView != null) { 2129 secondaryAlignedView = firstView; 2130 } else if (lastView != null) { 2131 secondaryAlignedView = lastView; 2132 } else { 2133 secondaryAlignedView = view; 2134 } 2135 scrollSecondary = getSecondarySystemScrollPosition(secondaryAlignedView); 2136 scrollSecondary -= mScrollOffsetSecondary; 2137 if (scrollPrimary != 0 || scrollSecondary != 0) { 2138 deltas[0] = scrollPrimary; 2139 deltas[1] = scrollSecondary; 2140 return true; 2141 } 2142 return false; 2143 } 2144 2145 private boolean getAlignedPosition(View view, int[] deltas) { 2146 int scrollPrimary = getPrimarySystemScrollPosition(view); 2147 int scrollSecondary = getSecondarySystemScrollPosition(view); 2148 if (DEBUG) { 2149 Log.v(getTag(), "getAlignedPosition " + scrollPrimary + " " + scrollSecondary 2150 +" " + mWindowAlignment); 2151 } 2152 scrollPrimary -= mScrollOffsetPrimary; 2153 scrollSecondary -= mScrollOffsetSecondary; 2154 if (scrollPrimary != 0 || scrollSecondary != 0) { 2155 deltas[0] = scrollPrimary; 2156 deltas[1] = scrollSecondary; 2157 return true; 2158 } 2159 return false; 2160 } 2161 2162 private void scrollGrid(int scrollPrimary, int scrollSecondary, boolean smooth) { 2163 if (mInLayout) { 2164 scrollDirectionPrimary(scrollPrimary); 2165 scrollDirectionSecondary(scrollSecondary); 2166 } else { 2167 int scrollX; 2168 int scrollY; 2169 if (mOrientation == HORIZONTAL) { 2170 scrollX = scrollPrimary; 2171 scrollY = scrollSecondary; 2172 } else { 2173 scrollX = scrollSecondary; 2174 scrollY = scrollPrimary; 2175 } 2176 if (smooth) { 2177 mBaseGridView.smoothScrollBy(scrollX, scrollY); 2178 } else { 2179 mBaseGridView.scrollBy(scrollX, scrollY); 2180 } 2181 } 2182 } 2183 2184 public void setPruneChild(boolean pruneChild) { 2185 if (mPruneChild != pruneChild) { 2186 mPruneChild = pruneChild; 2187 if (mPruneChild) { 2188 requestLayout(); 2189 } 2190 } 2191 } 2192 2193 public boolean getPruneChild() { 2194 return mPruneChild; 2195 } 2196 2197 public void setScrollEnabled(boolean scrollEnabled) { 2198 if (mScrollEnabled != scrollEnabled) { 2199 mScrollEnabled = scrollEnabled; 2200 if (mScrollEnabled && mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED) { 2201 View focusView = findViewByPosition(mFocusPosition == NO_POSITION ? 0 : 2202 mFocusPosition); 2203 if (focusView != null) { 2204 scrollToView(focusView, true); 2205 } 2206 } 2207 } 2208 } 2209 2210 public boolean isScrollEnabled() { 2211 return mScrollEnabled; 2212 } 2213 2214 private int findImmediateChildIndex(View view) { 2215 while (view != null && view != mBaseGridView) { 2216 int index = mBaseGridView.indexOfChild(view); 2217 if (index >= 0) { 2218 return index; 2219 } 2220 view = (View) view.getParent(); 2221 } 2222 return NO_POSITION; 2223 } 2224 2225 void setFocusSearchDisabled(boolean disabled) { 2226 mFocusSearchDisabled = disabled; 2227 } 2228 2229 boolean isFocusSearchDisabled() { 2230 return mFocusSearchDisabled; 2231 } 2232 2233 @Override 2234 public View onInterceptFocusSearch(View focused, int direction) { 2235 if (mFocusSearchDisabled) { 2236 return focused; 2237 } 2238 return null; 2239 } 2240 2241 boolean hasPreviousViewInSameRow(int pos) { 2242 if (mGrid == null || pos == NO_POSITION) { 2243 return false; 2244 } 2245 if (mFirstVisiblePos > 0) { 2246 return true; 2247 } 2248 final int focusedRow = mGrid.getLocation(pos).row; 2249 for (int i = getChildCount() - 1; i >= 0; i--) { 2250 int position = getPositionByIndex(i); 2251 StaggeredGrid.Location loc = mGrid.getLocation(position); 2252 if (loc != null && loc.row == focusedRow) { 2253 if (position < pos) { 2254 return true; 2255 } 2256 } 2257 } 2258 return false; 2259 } 2260 2261 @Override 2262 public boolean onAddFocusables(RecyclerView recyclerView, 2263 ArrayList<View> views, int direction, int focusableMode) { 2264 if (mFocusSearchDisabled) { 2265 return true; 2266 } 2267 // If this viewgroup or one of its children currently has focus then we 2268 // consider our children for focus searching in main direction on the same row. 2269 // If this viewgroup has no focus and using focus align, we want the system 2270 // to ignore our children and pass focus to the viewgroup, which will pass 2271 // focus on to its children appropriately. 2272 // If this viewgroup has no focus and not using focus align, we want to 2273 // consider the child that does not overlap with padding area. 2274 if (recyclerView.hasFocus()) { 2275 final int movement = getMovement(direction); 2276 if (movement != PREV_ITEM && movement != NEXT_ITEM) { 2277 // Move on secondary direction uses default addFocusables(). 2278 return false; 2279 } 2280 final View focused = recyclerView.findFocus(); 2281 final int focusedPos = getPositionByIndex(findImmediateChildIndex(focused)); 2282 // Add focusables of focused item. 2283 if (focusedPos != NO_POSITION) { 2284 findViewByPosition(focusedPos).addFocusables(views, direction, focusableMode); 2285 } 2286 final int focusedRow = mGrid != null && focusedPos != NO_POSITION ? 2287 mGrid.getLocation(focusedPos).row : NO_POSITION; 2288 // Add focusables of next neighbor of same row on the focus search direction. 2289 if (mGrid != null) { 2290 final int focusableCount = views.size(); 2291 for (int i = 0, count = getChildCount(); i < count; i++) { 2292 int index = movement == NEXT_ITEM ? i : count - 1 - i; 2293 final View child = getChildAt(index); 2294 if (child.getVisibility() != View.VISIBLE) { 2295 continue; 2296 } 2297 int position = getPositionByIndex(index); 2298 StaggeredGrid.Location loc = mGrid.getLocation(position); 2299 if (focusedRow == NO_POSITION || (loc != null && loc.row == focusedRow)) { 2300 if (focusedPos == NO_POSITION || 2301 (movement == NEXT_ITEM && position > focusedPos) 2302 || (movement == PREV_ITEM && position < focusedPos)) { 2303 child.addFocusables(views, direction, focusableMode); 2304 if (views.size() > focusableCount) { 2305 break; 2306 } 2307 } 2308 } 2309 } 2310 } 2311 } else { 2312 if (mFocusScrollStrategy != BaseGridView.FOCUS_SCROLL_ALIGNED) { 2313 // adding views not overlapping padding area to avoid scrolling in gaining focus 2314 int left = mWindowAlignment.mainAxis().getPaddingLow(); 2315 int right = mWindowAlignment.mainAxis().getClientSize() + left; 2316 int focusableCount = views.size(); 2317 for (int i = 0, count = getChildCount(); i < count; i++) { 2318 View child = getChildAt(i); 2319 if (child.getVisibility() == View.VISIBLE) { 2320 if (getViewMin(child) >= left && getViewMax(child) <= right) { 2321 child.addFocusables(views, direction, focusableMode); 2322 } 2323 } 2324 } 2325 // if we cannot find any, then just add all children. 2326 if (views.size() == focusableCount) { 2327 for (int i = 0, count = getChildCount(); i < count; i++) { 2328 View child = getChildAt(i); 2329 if (child.getVisibility() == View.VISIBLE) { 2330 child.addFocusables(views, direction, focusableMode); 2331 } 2332 } 2333 if (views.size() != focusableCount) { 2334 return true; 2335 } 2336 } else { 2337 return true; 2338 } 2339 // if still cannot find any, fall through and add itself 2340 } 2341 if (recyclerView.isFocusable()) { 2342 views.add(recyclerView); 2343 } 2344 } 2345 return true; 2346 } 2347 2348 @Override 2349 public View onFocusSearchFailed(View focused, int direction, Recycler recycler, 2350 RecyclerView.State state) { 2351 if (DEBUG) Log.v(getTag(), "onFocusSearchFailed direction " + direction); 2352 2353 View view = null; 2354 int movement = getMovement(direction); 2355 if (mNumRows == 1) { 2356 // for simple row, use LinearSmoothScroller to smooth animation. 2357 // It will stay at a fixed cap speed in continuous scroll. 2358 if (movement == NEXT_ITEM) { 2359 int newPos = mFocusPosition + mNumRows; 2360 if (newPos < getItemCount()) { 2361 setSelectionSmooth(mBaseGridView, newPos); 2362 view = focused; 2363 } else { 2364 if (!mFocusOutEnd) { 2365 view = focused; 2366 } 2367 } 2368 } else if (movement == PREV_ITEM){ 2369 int newPos = mFocusPosition - mNumRows; 2370 if (newPos >= 0) { 2371 setSelectionSmooth(mBaseGridView, newPos); 2372 view = focused; 2373 } else { 2374 if (!mFocusOutFront) { 2375 view = focused; 2376 } 2377 } 2378 } 2379 } else if (mNumRows > 1) { 2380 // for possible staggered grid, we need guarantee focus to same row/column. 2381 // TODO: we may also use LinearSmoothScroller. 2382 saveContext(recycler, state); 2383 final FocusFinder ff = FocusFinder.getInstance(); 2384 if (movement == NEXT_ITEM) { 2385 while (view == null && !appendOneVisibleItem()) { 2386 view = ff.findNextFocus(mBaseGridView, focused, direction); 2387 } 2388 } else if (movement == PREV_ITEM){ 2389 while (view == null && !prependOneVisibleItem()) { 2390 view = ff.findNextFocus(mBaseGridView, focused, direction); 2391 } 2392 } 2393 if (view == null) { 2394 // returning the same view to prevent focus lost when scrolling past the end of the list 2395 if (movement == PREV_ITEM) { 2396 view = mFocusOutFront ? null : focused; 2397 } else if (movement == NEXT_ITEM){ 2398 view = mFocusOutEnd ? null : focused; 2399 } 2400 } 2401 leaveContext(); 2402 } 2403 if (DEBUG) Log.v(getTag(), "returning view " + view); 2404 return view; 2405 } 2406 2407 boolean gridOnRequestFocusInDescendants(RecyclerView recyclerView, int direction, 2408 Rect previouslyFocusedRect) { 2409 switch (mFocusScrollStrategy) { 2410 case BaseGridView.FOCUS_SCROLL_ALIGNED: 2411 default: 2412 return gridOnRequestFocusInDescendantsAligned(recyclerView, 2413 direction, previouslyFocusedRect); 2414 case BaseGridView.FOCUS_SCROLL_PAGE: 2415 case BaseGridView.FOCUS_SCROLL_ITEM: 2416 return gridOnRequestFocusInDescendantsUnaligned(recyclerView, 2417 direction, previouslyFocusedRect); 2418 } 2419 } 2420 2421 private boolean gridOnRequestFocusInDescendantsAligned(RecyclerView recyclerView, 2422 int direction, Rect previouslyFocusedRect) { 2423 View view = findViewByPosition(mFocusPosition); 2424 if (view != null) { 2425 boolean result = view.requestFocus(direction, previouslyFocusedRect); 2426 if (!result && DEBUG) { 2427 Log.w(getTag(), "failed to request focus on " + view); 2428 } 2429 return result; 2430 } 2431 return false; 2432 } 2433 2434 private boolean gridOnRequestFocusInDescendantsUnaligned(RecyclerView recyclerView, 2435 int direction, Rect previouslyFocusedRect) { 2436 // focus to view not overlapping padding area to avoid scrolling in gaining focus 2437 int index; 2438 int increment; 2439 int end; 2440 int count = getChildCount(); 2441 if ((direction & View.FOCUS_FORWARD) != 0) { 2442 index = 0; 2443 increment = 1; 2444 end = count; 2445 } else { 2446 index = count - 1; 2447 increment = -1; 2448 end = -1; 2449 } 2450 int left = mWindowAlignment.mainAxis().getPaddingLow(); 2451 int right = mWindowAlignment.mainAxis().getClientSize() + left; 2452 for (int i = index; i != end; i += increment) { 2453 View child = getChildAt(i); 2454 if (child.getVisibility() == View.VISIBLE) { 2455 if (getViewMin(child) >= left && getViewMax(child) <= right) { 2456 if (child.requestFocus(direction, previouslyFocusedRect)) { 2457 return true; 2458 } 2459 } 2460 } 2461 } 2462 return false; 2463 } 2464 2465 private final static int PREV_ITEM = 0; 2466 private final static int NEXT_ITEM = 1; 2467 private final static int PREV_ROW = 2; 2468 private final static int NEXT_ROW = 3; 2469 2470 private int getMovement(int direction) { 2471 int movement = View.FOCUS_LEFT; 2472 2473 if (mOrientation == HORIZONTAL) { 2474 switch(direction) { 2475 case View.FOCUS_LEFT: 2476 movement = PREV_ITEM; 2477 break; 2478 case View.FOCUS_RIGHT: 2479 movement = NEXT_ITEM; 2480 break; 2481 case View.FOCUS_UP: 2482 movement = PREV_ROW; 2483 break; 2484 case View.FOCUS_DOWN: 2485 movement = NEXT_ROW; 2486 break; 2487 } 2488 } else if (mOrientation == VERTICAL) { 2489 switch(direction) { 2490 case View.FOCUS_LEFT: 2491 movement = PREV_ROW; 2492 break; 2493 case View.FOCUS_RIGHT: 2494 movement = NEXT_ROW; 2495 break; 2496 case View.FOCUS_UP: 2497 movement = PREV_ITEM; 2498 break; 2499 case View.FOCUS_DOWN: 2500 movement = NEXT_ITEM; 2501 break; 2502 } 2503 } 2504 2505 return movement; 2506 } 2507 2508 int getChildDrawingOrder(RecyclerView recyclerView, int childCount, int i) { 2509 View view = findViewByPosition(mFocusPosition); 2510 if (view == null) { 2511 return i; 2512 } 2513 int focusIndex = recyclerView.indexOfChild(view); 2514 // supposely 0 1 2 3 4 5 6 7 8 9, 4 is the center item 2515 // drawing order is 0 1 2 3 9 8 7 6 5 4 2516 if (i < focusIndex) { 2517 return i; 2518 } else if (i < childCount - 1) { 2519 return focusIndex + childCount - 1 - i; 2520 } else { 2521 return focusIndex; 2522 } 2523 } 2524 2525 @Override 2526 public void onAdapterChanged(RecyclerView.Adapter oldAdapter, 2527 RecyclerView.Adapter newAdapter) { 2528 discardLayoutInfo(); 2529 mFocusPosition = NO_POSITION; 2530 mFocusPositionOffset = 0; 2531 mLoadingState = null; 2532 mChildrenStates.clear(); 2533 super.onAdapterChanged(oldAdapter, newAdapter); 2534 } 2535 2536 private void discardLayoutInfo() { 2537 mGrid = null; 2538 mRows = null; 2539 mRowSizeSecondary = null; 2540 mFirstVisiblePos = -1; 2541 mLastVisiblePos = -1; 2542 mRowSecondarySizeRefresh = false; 2543 } 2544 2545 public void setLayoutEnabled(boolean layoutEnabled) { 2546 if (mLayoutEnabled != layoutEnabled) { 2547 mLayoutEnabled = layoutEnabled; 2548 requestLayout(); 2549 } 2550 } 2551 2552 final static class SavedState implements Parcelable { 2553 2554 int index; // index inside adapter of the current view 2555 Bundle childStates = Bundle.EMPTY; 2556 2557 @Override 2558 public void writeToParcel(Parcel out, int flags) { 2559 out.writeInt(index); 2560 out.writeBundle(childStates); 2561 } 2562 2563 @SuppressWarnings("hiding") 2564 public static final Parcelable.Creator<SavedState> CREATOR = 2565 new Parcelable.Creator<SavedState>() { 2566 @Override 2567 public SavedState createFromParcel(Parcel in) { 2568 return new SavedState(in); 2569 } 2570 2571 @Override 2572 public SavedState[] newArray(int size) { 2573 return new SavedState[size]; 2574 } 2575 }; 2576 2577 @Override 2578 public int describeContents() { 2579 return 0; 2580 } 2581 2582 SavedState(Parcel in) { 2583 index = in.readInt(); 2584 childStates = in.readBundle(GridLayoutManager.class.getClassLoader()); 2585 } 2586 2587 SavedState() { 2588 } 2589 } 2590 2591 @Override 2592 public Parcelable onSaveInstanceState() { 2593 SavedState ss = new SavedState(); 2594 for (int i = 0, count = getChildCount(); i < count; i++) { 2595 View view = getChildAt(i); 2596 int position = getPositionByView(view); 2597 if (position != NO_POSITION) { 2598 mChildrenStates.saveOnScreenView(view, position); 2599 } 2600 } 2601 ss.index = getSelection(); 2602 ss.childStates = mChildrenStates.getChildStates(); 2603 return ss; 2604 } 2605 2606 @Override 2607 public void onRestoreInstanceState(Parcelable state) { 2608 if (!(state instanceof SavedState)) { 2609 return; 2610 } 2611 SavedState ss = (SavedState)state; 2612 mLoadingState = ss; 2613 mForceFullLayout = true; 2614 requestLayout(); 2615 } 2616} 2617