GridLayoutManager.java revision b33714d135e006cf3bdba09788c27d4791b8632e
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 final ViewsStateBundle mChildrenStates = new ViewsStateBundle(); 349 350 public GridLayoutManager(BaseGridView baseGridView) { 351 mBaseGridView = baseGridView; 352 } 353 354 public void setOrientation(int orientation) { 355 if (orientation != HORIZONTAL && orientation != VERTICAL) { 356 if (DEBUG) Log.v(getTag(), "invalid orientation: " + orientation); 357 return; 358 } 359 360 mOrientation = orientation; 361 mWindowAlignment.setOrientation(orientation); 362 mItemAlignment.setOrientation(orientation); 363 mForceFullLayout = true; 364 } 365 366 public int getFocusScrollStrategy() { 367 return mFocusScrollStrategy; 368 } 369 370 public void setFocusScrollStrategy(int focusScrollStrategy) { 371 mFocusScrollStrategy = focusScrollStrategy; 372 } 373 374 public void setWindowAlignment(int windowAlignment) { 375 mWindowAlignment.mainAxis().setWindowAlignment(windowAlignment); 376 } 377 378 public int getWindowAlignment() { 379 return mWindowAlignment.mainAxis().getWindowAlignment(); 380 } 381 382 public void setWindowAlignmentOffset(int alignmentOffset) { 383 mWindowAlignment.mainAxis().setWindowAlignmentOffset(alignmentOffset); 384 } 385 386 public int getWindowAlignmentOffset() { 387 return mWindowAlignment.mainAxis().getWindowAlignmentOffset(); 388 } 389 390 public void setWindowAlignmentOffsetPercent(float offsetPercent) { 391 mWindowAlignment.mainAxis().setWindowAlignmentOffsetPercent(offsetPercent); 392 } 393 394 public float getWindowAlignmentOffsetPercent() { 395 return mWindowAlignment.mainAxis().getWindowAlignmentOffsetPercent(); 396 } 397 398 public void setItemAlignmentOffset(int alignmentOffset) { 399 mItemAlignment.mainAxis().setItemAlignmentOffset(alignmentOffset); 400 updateChildAlignments(); 401 } 402 403 public int getItemAlignmentOffset() { 404 return mItemAlignment.mainAxis().getItemAlignmentOffset(); 405 } 406 407 public void setItemAlignmentOffsetWithPadding(boolean withPadding) { 408 mItemAlignment.mainAxis().setItemAlignmentOffsetWithPadding(withPadding); 409 updateChildAlignments(); 410 } 411 412 public boolean isItemAlignmentOffsetWithPadding() { 413 return mItemAlignment.mainAxis().isItemAlignmentOffsetWithPadding(); 414 } 415 416 public void setItemAlignmentOffsetPercent(float offsetPercent) { 417 mItemAlignment.mainAxis().setItemAlignmentOffsetPercent(offsetPercent); 418 updateChildAlignments(); 419 } 420 421 public float getItemAlignmentOffsetPercent() { 422 return mItemAlignment.mainAxis().getItemAlignmentOffsetPercent(); 423 } 424 425 public void setItemAlignmentViewId(int viewId) { 426 mItemAlignment.mainAxis().setItemAlignmentViewId(viewId); 427 updateChildAlignments(); 428 } 429 430 public int getItemAlignmentViewId() { 431 return mItemAlignment.mainAxis().getItemAlignmentViewId(); 432 } 433 434 public void setFocusOutAllowed(boolean throughFront, boolean throughEnd) { 435 mFocusOutFront = throughFront; 436 mFocusOutEnd = throughEnd; 437 } 438 439 public void setNumRows(int numRows) { 440 if (numRows < 0) throw new IllegalArgumentException(); 441 mNumRowsRequested = numRows; 442 mForceFullLayout = true; 443 } 444 445 /** 446 * Set the row height. May be WRAP_CONTENT, or a size in pixels. 447 */ 448 public void setRowHeight(int height) { 449 if (height >= 0 || height == ViewGroup.LayoutParams.WRAP_CONTENT) { 450 mRowSizeSecondaryRequested = height; 451 } else { 452 throw new IllegalArgumentException("Invalid row height: " + height); 453 } 454 } 455 456 public void setItemMargin(int margin) { 457 mVerticalMargin = mHorizontalMargin = margin; 458 mMarginPrimary = mMarginSecondary = margin; 459 } 460 461 public void setVerticalMargin(int margin) { 462 if (mOrientation == HORIZONTAL) { 463 mMarginSecondary = mVerticalMargin = margin; 464 } else { 465 mMarginPrimary = mVerticalMargin = margin; 466 } 467 } 468 469 public void setHorizontalMargin(int margin) { 470 if (mOrientation == HORIZONTAL) { 471 mMarginPrimary = mHorizontalMargin = margin; 472 } else { 473 mMarginSecondary = mHorizontalMargin = margin; 474 } 475 } 476 477 public int getVerticalMargin() { 478 return mVerticalMargin; 479 } 480 481 public int getHorizontalMargin() { 482 return mHorizontalMargin; 483 } 484 485 public void setGravity(int gravity) { 486 mGravity = gravity; 487 } 488 489 protected boolean hasDoneFirstLayout() { 490 return mGrid != null; 491 } 492 493 public void setOnChildSelectedListener(OnChildSelectedListener listener) { 494 mChildSelectedListener = listener; 495 } 496 497 private int getPositionByView(View view) { 498 if (view == null) { 499 return NO_POSITION; 500 } 501 LayoutParams params = (LayoutParams) view.getLayoutParams(); 502 if (params == null || params.isItemRemoved()) { 503 // when item is removed, the position value can be any value. 504 return NO_POSITION; 505 } 506 return params.getViewPosition(); 507 } 508 509 private int getPositionByIndex(int index) { 510 return getPositionByView(getChildAt(index)); 511 } 512 513 private void dispatchChildSelected() { 514 if (mChildSelectedListener == null) { 515 return; 516 } 517 if (mFocusPosition != NO_POSITION) { 518 View view = findViewByPosition(mFocusPosition); 519 if (view != null) { 520 RecyclerView.ViewHolder vh = mBaseGridView.getChildViewHolder(view); 521 mChildSelectedListener.onChildSelected(mBaseGridView, view, mFocusPosition, 522 vh == null? NO_ID: vh.getItemId()); 523 return; 524 } 525 } 526 mChildSelectedListener.onChildSelected(mBaseGridView, null, NO_POSITION, NO_ID); 527 } 528 529 @Override 530 public boolean canScrollHorizontally() { 531 // We can scroll horizontally if we have horizontal orientation, or if 532 // we are vertical and have more than one column. 533 return mOrientation == HORIZONTAL || mNumRows > 1; 534 } 535 536 @Override 537 public boolean canScrollVertically() { 538 // We can scroll vertically if we have vertical orientation, or if we 539 // are horizontal and have more than one row. 540 return mOrientation == VERTICAL || mNumRows > 1; 541 } 542 543 @Override 544 public RecyclerView.LayoutParams generateDefaultLayoutParams() { 545 return new LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, 546 ViewGroup.LayoutParams.WRAP_CONTENT); 547 } 548 549 @Override 550 public RecyclerView.LayoutParams generateLayoutParams(Context context, AttributeSet attrs) { 551 return new LayoutParams(context, attrs); 552 } 553 554 @Override 555 public RecyclerView.LayoutParams generateLayoutParams(ViewGroup.LayoutParams lp) { 556 if (lp instanceof LayoutParams) { 557 return new LayoutParams((LayoutParams) lp); 558 } else if (lp instanceof RecyclerView.LayoutParams) { 559 return new LayoutParams((RecyclerView.LayoutParams) lp); 560 } else if (lp instanceof MarginLayoutParams) { 561 return new LayoutParams((MarginLayoutParams) lp); 562 } else { 563 return new LayoutParams(lp); 564 } 565 } 566 567 protected View getViewForPosition(int position) { 568 return mRecycler.getViewForPosition(position); 569 } 570 571 final int getOpticalLeft(View v) { 572 return ((LayoutParams) v.getLayoutParams()).getOpticalLeft(v); 573 } 574 575 final int getOpticalRight(View v) { 576 return ((LayoutParams) v.getLayoutParams()).getOpticalRight(v); 577 } 578 579 final int getOpticalTop(View v) { 580 return ((LayoutParams) v.getLayoutParams()).getOpticalTop(v); 581 } 582 583 final int getOpticalBottom(View v) { 584 return ((LayoutParams) v.getLayoutParams()).getOpticalBottom(v); 585 } 586 587 private int getViewMin(View v) { 588 return (mOrientation == HORIZONTAL) ? getOpticalLeft(v) : getOpticalTop(v); 589 } 590 591 private int getViewMax(View v) { 592 return (mOrientation == HORIZONTAL) ? getOpticalRight(v) : getOpticalBottom(v); 593 } 594 595 private int getViewCenter(View view) { 596 return (mOrientation == HORIZONTAL) ? getViewCenterX(view) : getViewCenterY(view); 597 } 598 599 private int getViewCenterSecondary(View view) { 600 return (mOrientation == HORIZONTAL) ? getViewCenterY(view) : getViewCenterX(view); 601 } 602 603 private int getViewCenterX(View v) { 604 LayoutParams p = (LayoutParams) v.getLayoutParams(); 605 return p.getOpticalLeft(v) + p.getAlignX(); 606 } 607 608 private int getViewCenterY(View v) { 609 LayoutParams p = (LayoutParams) v.getLayoutParams(); 610 return p.getOpticalTop(v) + p.getAlignY(); 611 } 612 613 /** 614 * Save Recycler and State for convenience. Must be paired with leaveContext(). 615 */ 616 private void saveContext(Recycler recycler, State state) { 617 if (mRecycler != null || mState != null) { 618 Log.e(TAG, "Recycler information was not released, bug!"); 619 } 620 mRecycler = recycler; 621 mState = state; 622 } 623 624 /** 625 * Discard saved Recycler and State. 626 */ 627 private void leaveContext() { 628 mRecycler = null; 629 mState = null; 630 } 631 632 /** 633 * Re-initialize data structures for a data change or handling invisible 634 * selection. The method tries its best to preserve position information so 635 * that staggered grid looks same before and after re-initialize. 636 * @param focusPosition The initial focusPosition that we would like to 637 * focus on. 638 * @return Actual position that can be focused on. 639 */ 640 private int init(int focusPosition) { 641 642 final int newItemCount = mState.getItemCount(); 643 644 if (focusPosition == NO_POSITION && newItemCount > 0) { 645 // if focus position is never set before, initialize it to 0 646 focusPosition = 0; 647 } 648 // If adapter has changed then caches are invalid; otherwise, 649 // we try to maintain each row's position if number of rows keeps the same 650 // and existing mGrid contains the focusPosition. 651 if (mRows != null && mNumRows == mRows.length && 652 mGrid != null && mGrid.getSize() > 0 && focusPosition >= 0 && 653 focusPosition >= mGrid.getFirstIndex() && 654 focusPosition <= mGrid.getLastIndex()) { 655 // strip mGrid to a subset (like a column) that contains focusPosition 656 mGrid.stripDownTo(focusPosition); 657 // make sure that remaining items do not exceed new adapter size 658 int firstIndex = mGrid.getFirstIndex(); 659 int lastIndex = mGrid.getLastIndex(); 660 if (DEBUG) { 661 Log .v(getTag(), "mGrid firstIndex " + firstIndex + " lastIndex " + lastIndex); 662 } 663 for (int i = lastIndex; i >=firstIndex; i--) { 664 if (i >= newItemCount) { 665 mGrid.removeLast(); 666 } 667 } 668 if (mGrid.getSize() == 0) { 669 focusPosition = newItemCount - 1; 670 // initialize row start locations 671 for (int i = 0; i < mNumRows; i++) { 672 mRows[i].low = 0; 673 mRows[i].high = 0; 674 } 675 if (DEBUG) Log.v(getTag(), "mGrid zero size"); 676 } else { 677 // initialize row start locations 678 for (int i = 0; i < mNumRows; i++) { 679 mRows[i].low = Integer.MAX_VALUE; 680 mRows[i].high = Integer.MIN_VALUE; 681 } 682 firstIndex = mGrid.getFirstIndex(); 683 lastIndex = mGrid.getLastIndex(); 684 if (focusPosition > lastIndex) { 685 focusPosition = mGrid.getLastIndex(); 686 } 687 if (DEBUG) { 688 Log.v(getTag(), "mGrid firstIndex " + firstIndex + " lastIndex " 689 + lastIndex + " focusPosition " + focusPosition); 690 } 691 // fill rows with minimal view positions of the subset 692 for (int i = firstIndex; i <= lastIndex; i++) { 693 View v = findViewByPosition(i); 694 if (v == null) { 695 continue; 696 } 697 int row = mGrid.getLocation(i).row; 698 int low = getViewMin(v) + mScrollOffsetPrimary; 699 if (low < mRows[row].low) { 700 mRows[row].low = mRows[row].high = low; 701 } 702 } 703 int firstItemRowPosition = mRows[mGrid.getLocation(firstIndex).row].low; 704 if (firstItemRowPosition == Integer.MAX_VALUE) { 705 firstItemRowPosition = 0; 706 } 707 if (mState.didStructureChange()) { 708 // if there is structure change, the removed item might be in the 709 // subset, so it is meaningless to maintain the low locations. 710 for (int i = 0; i < mNumRows; i++) { 711 mRows[i].low = firstItemRowPosition; 712 mRows[i].high = firstItemRowPosition; 713 } 714 } else { 715 // fill other rows that does not include the subset using first item 716 for (int i = 0; i < mNumRows; i++) { 717 if (mRows[i].low == Integer.MAX_VALUE) { 718 mRows[i].low = mRows[i].high = firstItemRowPosition; 719 } 720 } 721 } 722 } 723 724 // Same adapter, we can reuse any attached views 725 detachAndScrapAttachedViews(mRecycler); 726 727 } else { 728 // otherwise recreate data structure 729 mRows = new StaggeredGrid.Row[mNumRows]; 730 731 for (int i = 0; i < mNumRows; i++) { 732 mRows[i] = new StaggeredGrid.Row(); 733 } 734 mGrid = new StaggeredGridDefault(); 735 if (newItemCount == 0) { 736 focusPosition = NO_POSITION; 737 } else if (focusPosition >= newItemCount) { 738 focusPosition = newItemCount - 1; 739 } 740 741 // Adapter may have changed so remove all attached views permanently 742 removeAndRecycleAllViews(mRecycler); 743 744 mScrollOffsetPrimary = 0; 745 mScrollOffsetSecondary = 0; 746 mWindowAlignment.reset(); 747 } 748 749 mGrid.setProvider(mGridProvider); 750 // mGrid share the same Row array information 751 mGrid.setRows(mRows); 752 mFirstVisiblePos = mLastVisiblePos = NO_POSITION; 753 754 initScrollController(); 755 updateScrollSecondAxis(); 756 757 return focusPosition; 758 } 759 760 private int getRowSizeSecondary(int rowIndex) { 761 if (mFixedRowSizeSecondary != 0) { 762 return mFixedRowSizeSecondary; 763 } 764 if (mRowSizeSecondary == null) { 765 return 0; 766 } 767 return mRowSizeSecondary[rowIndex]; 768 } 769 770 private int getRowStartSecondary(int rowIndex) { 771 int start = 0; 772 for (int i = 0; i < rowIndex; i++) { 773 start += getRowSizeSecondary(i) + mMarginSecondary; 774 } 775 return start; 776 } 777 778 private int getSizeSecondary() { 779 return getRowStartSecondary(mNumRows - 1) + getRowSizeSecondary(mNumRows - 1); 780 } 781 782 private void measureScrapChild(int position, int widthSpec, int heightSpec, 783 int[] measuredDimension) { 784 View view = mRecycler.getViewForPosition(position); 785 if (view != null) { 786 LayoutParams p = (LayoutParams) view.getLayoutParams(); 787 int childWidthSpec = ViewGroup.getChildMeasureSpec(widthSpec, 788 getPaddingLeft() + getPaddingRight(), p.width); 789 int childHeightSpec = ViewGroup.getChildMeasureSpec(heightSpec, 790 getPaddingTop() + getPaddingBottom(), p.height); 791 view.measure(childWidthSpec, childHeightSpec); 792 measuredDimension[0] = view.getMeasuredWidth(); 793 measuredDimension[1] = view.getMeasuredHeight(); 794 mRecycler.recycleView(view); 795 } 796 } 797 798 private boolean processRowSizeSecondary(boolean measure) { 799 if (mFixedRowSizeSecondary != 0) { 800 return false; 801 } 802 803 List<Integer>[] rows = mGrid == null ? null : 804 mGrid.getItemPositionsInRows(mFirstVisiblePos, mLastVisiblePos); 805 boolean changed = false; 806 int scrapChildWidth = -1; 807 int scrapChildHeight = -1; 808 809 for (int rowIndex = 0; rowIndex < mNumRows; rowIndex++) { 810 final int rowItemCount = rows == null ? 0 : rows[rowIndex].size(); 811 if (DEBUG) Log.v(getTag(), "processRowSizeSecondary row " + rowIndex + 812 " rowItemCount " + rowItemCount); 813 814 int rowSize = -1; 815 for (int i = 0; i < rowItemCount; i++) { 816 final View view = findViewByPosition(rows[rowIndex].get(i)); 817 if (view == null) { 818 continue; 819 } 820 if (measure && view.isLayoutRequested()) { 821 measureChild(view); 822 } 823 final int secondarySize = mOrientation == HORIZONTAL ? 824 view.getMeasuredHeight() : view.getMeasuredWidth(); 825 if (secondarySize > rowSize) { 826 rowSize = secondarySize; 827 } 828 } 829 830 if (measure && rowSize < 0 && mState.getItemCount() > 0) { 831 if (scrapChildWidth < 0 && scrapChildHeight < 0) { 832 measureScrapChild(mFocusPosition == NO_POSITION ? 0 : mFocusPosition, 833 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 834 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 835 mMeasuredDimension); 836 scrapChildWidth = mMeasuredDimension[0]; 837 scrapChildHeight = mMeasuredDimension[1]; 838 if (DEBUG) Log.v(TAG, "measured scrap child: " + scrapChildWidth + 839 " " + scrapChildHeight); 840 } 841 rowSize = mOrientation == HORIZONTAL ? scrapChildHeight : scrapChildWidth; 842 } 843 844 if (rowSize < 0) { 845 rowSize = 0; 846 } 847 848 if (DEBUG) Log.v(getTag(), "row " + rowIndex + " rowItemCount " + rowItemCount + 849 " rowSize " + rowSize); 850 851 if (mRowSizeSecondary[rowIndex] != rowSize) { 852 if (DEBUG) Log.v(getTag(), "row size secondary changed: " + mRowSizeSecondary[rowIndex] + 853 ", " + rowSize); 854 855 mRowSizeSecondary[rowIndex] = rowSize; 856 changed = true; 857 } 858 } 859 860 return changed; 861 } 862 863 /** 864 * Checks if we need to update row secondary sizes. 865 */ 866 private void updateRowSecondarySizeRefresh() { 867 mRowSecondarySizeRefresh = processRowSizeSecondary(false); 868 if (mRowSecondarySizeRefresh) { 869 if (DEBUG) Log.v(getTag(), "mRowSecondarySizeRefresh now set"); 870 forceRequestLayout(); 871 } 872 } 873 874 private void forceRequestLayout() { 875 if (DEBUG) Log.v(getTag(), "forceRequestLayout"); 876 // RecyclerView prevents us from requesting layout in many cases 877 // (during layout, during scroll, etc.) 878 // For secondary row size wrap_content support we currently need a 879 // second layout pass to update the measured size after having measured 880 // and added child views in layoutChildren. 881 // Force the second layout by posting a delayed runnable. 882 // TODO: investigate allowing a second layout pass, 883 // or move child add/measure logic to the measure phase. 884 ViewCompat.postOnAnimation(mBaseGridView, mRequestLayoutRunnable); 885 } 886 887 private final Runnable mRequestLayoutRunnable = new Runnable() { 888 @Override 889 public void run() { 890 if (DEBUG) Log.v(getTag(), "request Layout from runnable"); 891 requestLayout(); 892 } 893 }; 894 895 @Override 896 public void onMeasure(Recycler recycler, State state, int widthSpec, int heightSpec) { 897 saveContext(recycler, state); 898 899 int sizePrimary, sizeSecondary, modeSecondary, paddingSecondary; 900 int measuredSizeSecondary; 901 if (mOrientation == HORIZONTAL) { 902 sizePrimary = MeasureSpec.getSize(widthSpec); 903 sizeSecondary = MeasureSpec.getSize(heightSpec); 904 modeSecondary = MeasureSpec.getMode(heightSpec); 905 paddingSecondary = getPaddingTop() + getPaddingBottom(); 906 } else { 907 sizeSecondary = MeasureSpec.getSize(widthSpec); 908 sizePrimary = MeasureSpec.getSize(heightSpec); 909 modeSecondary = MeasureSpec.getMode(widthSpec); 910 paddingSecondary = getPaddingLeft() + getPaddingRight(); 911 } 912 if (DEBUG) Log.v(getTag(), "onMeasure widthSpec " + Integer.toHexString(widthSpec) + 913 " heightSpec " + Integer.toHexString(heightSpec) + 914 " modeSecondary " + Integer.toHexString(modeSecondary) + 915 " sizeSecondary " + sizeSecondary + " " + this); 916 917 mMaxSizeSecondary = sizeSecondary; 918 919 if (mRowSizeSecondaryRequested == ViewGroup.LayoutParams.WRAP_CONTENT) { 920 mNumRows = mNumRowsRequested == 0 ? 1 : mNumRowsRequested; 921 mFixedRowSizeSecondary = 0; 922 923 if (mRowSizeSecondary == null || mRowSizeSecondary.length != mNumRows) { 924 mRowSizeSecondary = new int[mNumRows]; 925 } 926 927 // Measure all current children and update cached row heights 928 processRowSizeSecondary(true); 929 930 switch (modeSecondary) { 931 case MeasureSpec.UNSPECIFIED: 932 measuredSizeSecondary = getSizeSecondary() + paddingSecondary; 933 break; 934 case MeasureSpec.AT_MOST: 935 measuredSizeSecondary = Math.min(getSizeSecondary() + paddingSecondary, 936 mMaxSizeSecondary); 937 break; 938 case MeasureSpec.EXACTLY: 939 measuredSizeSecondary = mMaxSizeSecondary; 940 break; 941 default: 942 throw new IllegalStateException("wrong spec"); 943 } 944 945 } else { 946 switch (modeSecondary) { 947 case MeasureSpec.UNSPECIFIED: 948 if (mRowSizeSecondaryRequested == 0) { 949 if (mOrientation == HORIZONTAL) { 950 throw new IllegalStateException("Must specify rowHeight or view height"); 951 } else { 952 throw new IllegalStateException("Must specify columnWidth or view width"); 953 } 954 } 955 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 956 mNumRows = mNumRowsRequested == 0 ? 1 : mNumRowsRequested; 957 measuredSizeSecondary = mFixedRowSizeSecondary * mNumRows + mMarginSecondary 958 * (mNumRows - 1) + paddingSecondary; 959 break; 960 case MeasureSpec.AT_MOST: 961 case MeasureSpec.EXACTLY: 962 if (mNumRowsRequested == 0 && mRowSizeSecondaryRequested == 0) { 963 mNumRows = 1; 964 mFixedRowSizeSecondary = sizeSecondary - paddingSecondary; 965 } else if (mNumRowsRequested == 0) { 966 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 967 mNumRows = (sizeSecondary + mMarginSecondary) 968 / (mRowSizeSecondaryRequested + mMarginSecondary); 969 } else if (mRowSizeSecondaryRequested == 0) { 970 mNumRows = mNumRowsRequested; 971 mFixedRowSizeSecondary = (sizeSecondary - paddingSecondary - mMarginSecondary 972 * (mNumRows - 1)) / mNumRows; 973 } else { 974 mNumRows = mNumRowsRequested; 975 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 976 } 977 measuredSizeSecondary = sizeSecondary; 978 if (modeSecondary == MeasureSpec.AT_MOST) { 979 int childrenSize = mFixedRowSizeSecondary * mNumRows + mMarginSecondary 980 * (mNumRows - 1) + paddingSecondary; 981 if (childrenSize < measuredSizeSecondary) { 982 measuredSizeSecondary = childrenSize; 983 } 984 } 985 break; 986 default: 987 throw new IllegalStateException("wrong spec"); 988 } 989 } 990 if (mOrientation == HORIZONTAL) { 991 setMeasuredDimension(sizePrimary, measuredSizeSecondary); 992 } else { 993 setMeasuredDimension(measuredSizeSecondary, sizePrimary); 994 } 995 if (DEBUG) { 996 Log.v(getTag(), "onMeasure sizePrimary " + sizePrimary + 997 " measuredSizeSecondary " + measuredSizeSecondary + 998 " mFixedRowSizeSecondary " + mFixedRowSizeSecondary + 999 " mNumRows " + mNumRows); 1000 } 1001 1002 leaveContext(); 1003 } 1004 1005 private void measureChild(View child) { 1006 final ViewGroup.LayoutParams lp = child.getLayoutParams(); 1007 final int secondarySpec = (mRowSizeSecondaryRequested == ViewGroup.LayoutParams.WRAP_CONTENT) ? 1008 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED) : 1009 MeasureSpec.makeMeasureSpec(mFixedRowSizeSecondary, MeasureSpec.EXACTLY); 1010 int widthSpec, heightSpec; 1011 1012 if (mOrientation == HORIZONTAL) { 1013 widthSpec = ViewGroup.getChildMeasureSpec( 1014 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 1015 0, lp.width); 1016 heightSpec = ViewGroup.getChildMeasureSpec(secondarySpec, 0, lp.height); 1017 } else { 1018 heightSpec = ViewGroup.getChildMeasureSpec( 1019 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 1020 0, lp.height); 1021 widthSpec = ViewGroup.getChildMeasureSpec(secondarySpec, 0, lp.width); 1022 } 1023 1024 child.measure(widthSpec, heightSpec); 1025 1026 if (DEBUG) Log.v(getTag(), "measureChild secondarySpec " + Integer.toHexString(secondarySpec) + 1027 " widthSpec " + Integer.toHexString(widthSpec) + 1028 " heightSpec " + Integer.toHexString(heightSpec) + 1029 " measuredWidth " + child.getMeasuredWidth() + 1030 " measuredHeight " + child.getMeasuredHeight()); 1031 if (DEBUG) Log.v(getTag(), "child lp width " + lp.width + " height " + lp.height); 1032 } 1033 1034 private StaggeredGrid.Provider mGridProvider = new StaggeredGrid.Provider() { 1035 1036 @Override 1037 public int getCount() { 1038 return mState.getItemCount(); 1039 } 1040 1041 @Override 1042 public void createItem(int index, int rowIndex, boolean append) { 1043 View v = getViewForPosition(index); 1044 if (mFirstVisiblePos >= 0) { 1045 // when StaggeredGrid append or prepend item, we must guarantee 1046 // that sibling item has created views already. 1047 if (append && index != mLastVisiblePos + 1) { 1048 throw new RuntimeException(); 1049 } else if (!append && index != mFirstVisiblePos - 1) { 1050 throw new RuntimeException(); 1051 } 1052 } 1053 1054 // See recyclerView docs: we don't need re-add scraped view if it was removed. 1055 if (!((RecyclerView.LayoutParams) v.getLayoutParams()).isItemRemoved()) { 1056 if (append) { 1057 addView(v); 1058 } else { 1059 addView(v, 0); 1060 } 1061 1062 // View is added first or it won't be found by dispatchChildSelected. 1063 if (mInLayout && index == mFocusPosition) { 1064 dispatchChildSelected(); 1065 } 1066 1067 measureChild(v); 1068 } 1069 1070 int length = mOrientation == HORIZONTAL ? v.getMeasuredWidth() : v.getMeasuredHeight(); 1071 int start, end; 1072 final boolean rowIsEmpty = mRows[rowIndex].high == mRows[rowIndex].low; 1073 if (append) { 1074 if (!rowIsEmpty) { 1075 // if there are existing item in the row, add margin between 1076 start = mRows[rowIndex].high + mMarginPrimary; 1077 } else { 1078 if (mLastVisiblePos >= 0) { 1079 int lastRow = mGrid.getLocation(mLastVisiblePos).row; 1080 // if the last visible item is not last row, align to beginning, 1081 // otherwise start a new column after. 1082 if (lastRow < mNumRows - 1) { 1083 start = mRows[lastRow].low; 1084 } else { 1085 start = mRows[lastRow].high + mMarginPrimary; 1086 } 1087 } else { 1088 start = 0; 1089 } 1090 mRows[rowIndex].low = start; 1091 } 1092 end = start + length; 1093 mRows[rowIndex].high = end; 1094 } else { 1095 if (!rowIsEmpty) { 1096 // if there are existing item in the row, add margin between 1097 end = mRows[rowIndex].low - mMarginPrimary; 1098 start = end - length; 1099 } else { 1100 if (mFirstVisiblePos >= 0) { 1101 int firstRow = mGrid.getLocation(mFirstVisiblePos).row; 1102 // if the first visible item is not first row, align to beginning, 1103 // otherwise start a new column before. 1104 if (firstRow > 0) { 1105 start = mRows[firstRow].low; 1106 end = start + length; 1107 } else { 1108 end = mRows[firstRow].low - mMarginPrimary; 1109 start = end - length; 1110 } 1111 } else { 1112 start = 0; 1113 end = length; 1114 } 1115 mRows[rowIndex].high = end; 1116 } 1117 mRows[rowIndex].low = start; 1118 } 1119 if (mFirstVisiblePos < 0) { 1120 mFirstVisiblePos = mLastVisiblePos = index; 1121 } else { 1122 if (append) { 1123 mLastVisiblePos++; 1124 } else { 1125 mFirstVisiblePos--; 1126 } 1127 } 1128 if (DEBUG) Log.v(getTag(), "start " + start + " end " + end); 1129 int startSecondary = getRowStartSecondary(rowIndex) - mScrollOffsetSecondary; 1130 mChildrenStates.loadView(v, index); 1131 layoutChild(rowIndex, v, start - mScrollOffsetPrimary, end - mScrollOffsetPrimary, 1132 startSecondary); 1133 if (DEBUG) { 1134 Log.d(getTag(), "addView " + index + " " + v); 1135 } 1136 if (index == mFirstVisiblePos) { 1137 updateScrollMin(); 1138 } 1139 if (index == mLastVisiblePos) { 1140 updateScrollMax(); 1141 } 1142 } 1143 }; 1144 1145 private void layoutChild(int rowIndex, View v, int start, int end, int startSecondary) { 1146 int sizeSecondary = mOrientation == HORIZONTAL ? v.getMeasuredHeight() 1147 : v.getMeasuredWidth(); 1148 if (mFixedRowSizeSecondary > 0) { 1149 sizeSecondary = Math.min(sizeSecondary, mFixedRowSizeSecondary); 1150 } 1151 final int verticalGravity = mGravity & Gravity.VERTICAL_GRAVITY_MASK; 1152 final int horizontalGravity = mGravity & Gravity.HORIZONTAL_GRAVITY_MASK; 1153 if (mOrientation == HORIZONTAL && verticalGravity == Gravity.TOP 1154 || mOrientation == VERTICAL && horizontalGravity == Gravity.LEFT) { 1155 // do nothing 1156 } else if (mOrientation == HORIZONTAL && verticalGravity == Gravity.BOTTOM 1157 || mOrientation == VERTICAL && horizontalGravity == Gravity.RIGHT) { 1158 startSecondary += getRowSizeSecondary(rowIndex) - sizeSecondary; 1159 } else if (mOrientation == HORIZONTAL && verticalGravity == Gravity.CENTER_VERTICAL 1160 || mOrientation == VERTICAL && horizontalGravity == Gravity.CENTER_HORIZONTAL) { 1161 startSecondary += (getRowSizeSecondary(rowIndex) - sizeSecondary) / 2; 1162 } 1163 int left, top, right, bottom; 1164 if (mOrientation == HORIZONTAL) { 1165 left = start; 1166 top = startSecondary; 1167 right = end; 1168 bottom = startSecondary + sizeSecondary; 1169 } else { 1170 top = start; 1171 left = startSecondary; 1172 bottom = end; 1173 right = startSecondary + sizeSecondary; 1174 } 1175 v.layout(left, top, right, bottom); 1176 updateChildOpticalInsets(v, left, top, right, bottom); 1177 updateChildAlignments(v); 1178 } 1179 1180 private void updateChildOpticalInsets(View v, int left, int top, int right, int bottom) { 1181 LayoutParams p = (LayoutParams) v.getLayoutParams(); 1182 p.setOpticalInsets(left - v.getLeft(), top - v.getTop(), 1183 v.getRight() - right, v.getBottom() - bottom); 1184 } 1185 1186 private void updateChildAlignments(View v) { 1187 LayoutParams p = (LayoutParams) v.getLayoutParams(); 1188 p.setAlignX(mItemAlignment.horizontal.getAlignmentPosition(v)); 1189 p.setAlignY(mItemAlignment.vertical.getAlignmentPosition(v)); 1190 } 1191 1192 private void updateChildAlignments() { 1193 for (int i = 0, c = getChildCount(); i < c; i++) { 1194 updateChildAlignments(getChildAt(i)); 1195 } 1196 } 1197 1198 private boolean needsAppendVisibleItem() { 1199 if (mLastVisiblePos < mFocusPosition) { 1200 return true; 1201 } 1202 int right = mScrollOffsetPrimary + mSizePrimary; 1203 for (int i = 0; i < mNumRows; i++) { 1204 if (mRows[i].low == mRows[i].high) { 1205 if (mRows[i].high < right) { 1206 return true; 1207 } 1208 } else if (mRows[i].high < right - mMarginPrimary) { 1209 return true; 1210 } 1211 } 1212 return false; 1213 } 1214 1215 private boolean needsPrependVisibleItem() { 1216 if (mFirstVisiblePos > mFocusPosition) { 1217 return true; 1218 } 1219 for (int i = 0; i < mNumRows; i++) { 1220 if (mRows[i].low == mRows[i].high) { 1221 if (mRows[i].low > mScrollOffsetPrimary) { 1222 return true; 1223 } 1224 } else if (mRows[i].low - mMarginPrimary > mScrollOffsetPrimary) { 1225 return true; 1226 } 1227 } 1228 return false; 1229 } 1230 1231 // Append one column if possible and return true if reach end. 1232 private boolean appendOneVisibleItem() { 1233 while (true) { 1234 if (mLastVisiblePos != NO_POSITION && mLastVisiblePos < mState.getItemCount() -1 && 1235 mLastVisiblePos < mGrid.getLastIndex()) { 1236 // append invisible view of saved location till last row 1237 final int index = mLastVisiblePos + 1; 1238 final int row = mGrid.getLocation(index).row; 1239 mGridProvider.createItem(index, row, true); 1240 if (row == mNumRows - 1) { 1241 return false; 1242 } 1243 } else if ((mLastVisiblePos == NO_POSITION && mState.getItemCount() > 0) || 1244 (mLastVisiblePos != NO_POSITION && 1245 mLastVisiblePos < mState.getItemCount() - 1)) { 1246 mGrid.appendItems(mScrollOffsetPrimary + mSizePrimary); 1247 return false; 1248 } else { 1249 return true; 1250 } 1251 } 1252 } 1253 1254 private void appendVisibleItems() { 1255 while (needsAppendVisibleItem()) { 1256 if (appendOneVisibleItem()) { 1257 break; 1258 } 1259 } 1260 } 1261 1262 // Prepend one column if possible and return true if reach end. 1263 private boolean prependOneVisibleItem() { 1264 while (true) { 1265 if (mFirstVisiblePos > 0) { 1266 if (mFirstVisiblePos > mGrid.getFirstIndex()) { 1267 // prepend invisible view of saved location till first row 1268 final int index = mFirstVisiblePos - 1; 1269 final int row = mGrid.getLocation(index).row; 1270 mGridProvider.createItem(index, row, false); 1271 if (row == 0) { 1272 return false; 1273 } 1274 } else { 1275 mGrid.prependItems(mScrollOffsetPrimary); 1276 return false; 1277 } 1278 } else { 1279 return true; 1280 } 1281 } 1282 } 1283 1284 private void prependVisibleItems() { 1285 while (needsPrependVisibleItem()) { 1286 if (prependOneVisibleItem()) { 1287 break; 1288 } 1289 } 1290 } 1291 1292 private void removeChildAt(int position) { 1293 View v = findViewByPosition(position); 1294 if (v != null) { 1295 if (DEBUG) { 1296 Log.d(getTag(), "removeAndRecycleViewAt " + position); 1297 } 1298 mChildrenStates.saveOffscreenView(v, position); 1299 removeAndRecycleView(v, mRecycler); 1300 } 1301 } 1302 1303 private void removeInvisibleViewsAtEnd() { 1304 if (!mPruneChild) { 1305 return; 1306 } 1307 boolean update = false; 1308 while(mLastVisiblePos > mFirstVisiblePos && mLastVisiblePos > mFocusPosition) { 1309 View view = findViewByPosition(mLastVisiblePos); 1310 if (getViewMin(view) > mSizePrimary) { 1311 removeChildAt(mLastVisiblePos); 1312 mLastVisiblePos--; 1313 update = true; 1314 } else { 1315 break; 1316 } 1317 } 1318 if (update) { 1319 updateRowsMinMax(); 1320 } 1321 } 1322 1323 private void removeInvisibleViewsAtFront() { 1324 if (!mPruneChild) { 1325 return; 1326 } 1327 boolean update = false; 1328 while(mLastVisiblePos > mFirstVisiblePos && mFirstVisiblePos < mFocusPosition) { 1329 View view = findViewByPosition(mFirstVisiblePos); 1330 if (getViewMax(view) < 0) { 1331 removeChildAt(mFirstVisiblePos); 1332 mFirstVisiblePos++; 1333 update = true; 1334 } else { 1335 break; 1336 } 1337 } 1338 if (update) { 1339 updateRowsMinMax(); 1340 } 1341 } 1342 1343 private void updateRowsMinMax() { 1344 if (mFirstVisiblePos < 0) { 1345 return; 1346 } 1347 for (int i = 0; i < mNumRows; i++) { 1348 mRows[i].low = Integer.MAX_VALUE; 1349 mRows[i].high = Integer.MIN_VALUE; 1350 } 1351 for (int i = mFirstVisiblePos; i <= mLastVisiblePos; i++) { 1352 View view = findViewByPosition(i); 1353 int row = mGrid.getLocation(i).row; 1354 int low = getViewMin(view) + mScrollOffsetPrimary; 1355 if (low < mRows[row].low) { 1356 mRows[row].low = low; 1357 } 1358 int high = getViewMax(view) + mScrollOffsetPrimary; 1359 if (high > mRows[row].high) { 1360 mRows[row].high = high; 1361 } 1362 } 1363 } 1364 1365 // Fast layout when there is no structure change, adapter change, etc. 1366 protected void fastRelayout(boolean scrollToFocus) { 1367 initScrollController(); 1368 1369 List<Integer>[] rows = mGrid.getItemPositionsInRows(mFirstVisiblePos, mLastVisiblePos); 1370 1371 // relayout and repositioning views on each row 1372 for (int i = 0; i < mNumRows; i++) { 1373 List<Integer> row = rows[i]; 1374 final int startSecondary = getRowStartSecondary(i) - mScrollOffsetSecondary; 1375 for (int j = 0, size = row.size(); j < size; j++) { 1376 final int position = row.get(j); 1377 final View view = findViewByPosition(position); 1378 int primaryDelta, start, end; 1379 1380 if (mOrientation == HORIZONTAL) { 1381 final int primarySize = view.getMeasuredWidth(); 1382 if (view.isLayoutRequested()) { 1383 measureChild(view); 1384 } 1385 start = getViewMin(view); 1386 end = start + view.getMeasuredWidth(); 1387 primaryDelta = view.getMeasuredWidth() - primarySize; 1388 if (primaryDelta != 0) { 1389 for (int k = j + 1; k < size; k++) { 1390 findViewByPosition(row.get(k)).offsetLeftAndRight(primaryDelta); 1391 } 1392 } 1393 } else { 1394 final int primarySize = view.getMeasuredHeight(); 1395 if (view.isLayoutRequested()) { 1396 measureChild(view); 1397 } 1398 start = getViewMin(view); 1399 end = start + view.getMeasuredHeight(); 1400 primaryDelta = view.getMeasuredHeight() - primarySize; 1401 if (primaryDelta != 0) { 1402 for (int k = j + 1; k < size; k++) { 1403 findViewByPosition(row.get(k)).offsetTopAndBottom(primaryDelta); 1404 } 1405 } 1406 } 1407 layoutChild(i, view, start, end, startSecondary); 1408 } 1409 } 1410 1411 updateRowsMinMax(); 1412 appendVisibleItems(); 1413 prependVisibleItems(); 1414 1415 updateRowsMinMax(); 1416 updateScrollMin(); 1417 updateScrollMax(); 1418 updateScrollSecondAxis(); 1419 1420 if (scrollToFocus) { 1421 View focusView = findViewByPosition(mFocusPosition == NO_POSITION ? 0 : mFocusPosition); 1422 scrollToView(focusView, false); 1423 } 1424 } 1425 1426 public void removeAndRecycleAllViews(RecyclerView.Recycler recycler) { 1427 if (DEBUG) Log.v(TAG, "removeAndRecycleAllViews " + getChildCount()); 1428 for (int i = getChildCount() - 1; i >= 0; i--) { 1429 removeAndRecycleViewAt(i, recycler); 1430 } 1431 } 1432 1433 // Lays out items based on the current scroll position 1434 @Override 1435 public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state) { 1436 if (DEBUG) { 1437 Log.v(getTag(), "layoutChildren start numRows " + mNumRows + " mScrollOffsetSecondary " 1438 + mScrollOffsetSecondary + " mScrollOffsetPrimary " + mScrollOffsetPrimary 1439 + " inPreLayout " + state.isPreLayout() 1440 + " didStructureChange " + state.didStructureChange() 1441 + " mForceFullLayout " + mForceFullLayout); 1442 Log.v(getTag(), "width " + getWidth() + " height " + getHeight()); 1443 } 1444 1445 if (mNumRows == 0) { 1446 // haven't done measure yet 1447 return; 1448 } 1449 final int itemCount = state.getItemCount(); 1450 if (itemCount < 0) { 1451 return; 1452 } 1453 1454 if (!mLayoutEnabled) { 1455 discardLayoutInfo(); 1456 removeAndRecycleAllViews(recycler); 1457 return; 1458 } 1459 mInLayout = true; 1460 1461 final boolean scrollToFocus = !isSmoothScrolling() 1462 && mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED; 1463 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE) { 1464 mFocusPosition = mFocusPosition + mFocusPositionOffset; 1465 mFocusPositionOffset = 0; 1466 } 1467 saveContext(recycler, state); 1468 // Track the old focus view so we can adjust our system scroll position 1469 // so that any scroll animations happening now will remain valid. 1470 // We must use same delta in Pre Layout (if prelayout exists) and second layout. 1471 // So we cache the deltas in PreLayout and use it in second layout. 1472 int delta = 0, deltaSecondary = 0; 1473 if (mFocusPosition != NO_POSITION && scrollToFocus) { 1474 // FIXME: we should get the remaining scroll animation offset from RecyclerView 1475 View focusView = findViewByPosition(mFocusPosition); 1476 if (focusView != null) { 1477 delta = mWindowAlignment.mainAxis().getSystemScrollPos(mScrollOffsetPrimary 1478 + getViewCenter(focusView), false, false) - mScrollOffsetPrimary; 1479 deltaSecondary = mWindowAlignment.secondAxis().getSystemScrollPos( 1480 mScrollOffsetSecondary + getViewCenterSecondary(focusView), 1481 false, false) - mScrollOffsetSecondary; 1482 } 1483 } 1484 1485 final boolean hasDoneFirstLayout = hasDoneFirstLayout(); 1486 int savedFocusPos = mFocusPosition; 1487 boolean fastRelayout = false; 1488 if (!mState.didStructureChange() && !mForceFullLayout && hasDoneFirstLayout) { 1489 fastRelayout = true; 1490 fastRelayout(scrollToFocus); 1491 } else { 1492 boolean hadFocus = mBaseGridView.hasFocus(); 1493 1494 mFocusPosition = init(mFocusPosition); 1495 if (mFocusPosition != savedFocusPos) { 1496 if (DEBUG) Log.v(getTag(), "savedFocusPos " + savedFocusPos + 1497 " mFocusPosition " + mFocusPosition); 1498 } 1499 1500 mWindowAlignment.mainAxis().invalidateScrollMin(); 1501 mWindowAlignment.mainAxis().invalidateScrollMax(); 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(mFocusPosition, 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 1524 // add visible views at end until reach the end of window 1525 appendVisibleItems(); 1526 // add visible views at front until reach the start of window 1527 prependVisibleItems(); 1528 // multiple rounds: scrollToView of first round may drag first/last child into 1529 // "visible window" and we update scrollMin/scrollMax then run second scrollToView 1530 int oldFirstVisible; 1531 int oldLastVisible; 1532 do { 1533 updateScrollMin(); 1534 updateScrollMax(); 1535 oldFirstVisible = mFirstVisiblePos; 1536 oldLastVisible = mLastVisiblePos; 1537 View focusView = findViewByPosition(mFocusPosition); 1538 // we need force to initialize the child view's position 1539 scrollToView(focusView, false); 1540 if (focusView != null && hadFocus) { 1541 focusView.requestFocus(); 1542 } 1543 appendVisibleItems(); 1544 prependVisibleItems(); 1545 removeInvisibleViewsAtFront(); 1546 removeInvisibleViewsAtEnd(); 1547 } while (mFirstVisiblePos != oldFirstVisible || mLastVisiblePos != oldLastVisible); 1548 } 1549 mForceFullLayout = false; 1550 1551 if (scrollToFocus) { 1552 scrollDirectionPrimary(-delta); 1553 scrollDirectionSecondary(-deltaSecondary); 1554 } 1555 appendVisibleItems(); 1556 prependVisibleItems(); 1557 removeInvisibleViewsAtFront(); 1558 removeInvisibleViewsAtEnd(); 1559 1560 if (DEBUG) { 1561 StringWriter sw = new StringWriter(); 1562 PrintWriter pw = new PrintWriter(sw); 1563 mGrid.debugPrint(pw); 1564 Log.d(getTag(), sw.toString()); 1565 } 1566 1567 if (mRowSecondarySizeRefresh) { 1568 mRowSecondarySizeRefresh = false; 1569 } else { 1570 updateRowSecondarySizeRefresh(); 1571 } 1572 1573 if (fastRelayout && mFocusPosition != savedFocusPos) { 1574 dispatchChildSelected(); 1575 } 1576 mInLayout = false; 1577 leaveContext(); 1578 if (DEBUG) Log.v(getTag(), "layoutChildren end"); 1579 } 1580 1581 private void offsetChildrenSecondary(int increment) { 1582 final int childCount = getChildCount(); 1583 if (mOrientation == HORIZONTAL) { 1584 for (int i = 0; i < childCount; i++) { 1585 getChildAt(i).offsetTopAndBottom(increment); 1586 } 1587 } else { 1588 for (int i = 0; i < childCount; i++) { 1589 getChildAt(i).offsetLeftAndRight(increment); 1590 } 1591 } 1592 } 1593 1594 private void offsetChildrenPrimary(int increment) { 1595 final int childCount = getChildCount(); 1596 if (mOrientation == VERTICAL) { 1597 for (int i = 0; i < childCount; i++) { 1598 getChildAt(i).offsetTopAndBottom(increment); 1599 } 1600 } else { 1601 for (int i = 0; i < childCount; i++) { 1602 getChildAt(i).offsetLeftAndRight(increment); 1603 } 1604 } 1605 } 1606 1607 @Override 1608 public int scrollHorizontallyBy(int dx, Recycler recycler, RecyclerView.State state) { 1609 if (DEBUG) Log.v(getTag(), "scrollHorizontallyBy " + dx); 1610 if (!mLayoutEnabled || !hasDoneFirstLayout()) { 1611 return 0; 1612 } 1613 saveContext(recycler, state); 1614 int result; 1615 if (mOrientation == HORIZONTAL) { 1616 result = scrollDirectionPrimary(dx); 1617 } else { 1618 result = scrollDirectionSecondary(dx); 1619 } 1620 leaveContext(); 1621 return result; 1622 } 1623 1624 @Override 1625 public int scrollVerticallyBy(int dy, Recycler recycler, RecyclerView.State state) { 1626 if (DEBUG) Log.v(getTag(), "scrollVerticallyBy " + dy); 1627 if (!mLayoutEnabled || !hasDoneFirstLayout()) { 1628 return 0; 1629 } 1630 saveContext(recycler, state); 1631 int result; 1632 if (mOrientation == VERTICAL) { 1633 result = scrollDirectionPrimary(dy); 1634 } else { 1635 result = scrollDirectionSecondary(dy); 1636 } 1637 leaveContext(); 1638 return result; 1639 } 1640 1641 // scroll in main direction may add/prune views 1642 private int scrollDirectionPrimary(int da) { 1643 if (da > 0) { 1644 if (!mWindowAlignment.mainAxis().isMaxUnknown()) { 1645 int maxScroll = mWindowAlignment.mainAxis().getMaxScroll(); 1646 if (mScrollOffsetPrimary + da > maxScroll) { 1647 da = maxScroll - mScrollOffsetPrimary; 1648 } 1649 } 1650 } else if (da < 0) { 1651 if (!mWindowAlignment.mainAxis().isMinUnknown()) { 1652 int minScroll = mWindowAlignment.mainAxis().getMinScroll(); 1653 if (mScrollOffsetPrimary + da < minScroll) { 1654 da = minScroll - mScrollOffsetPrimary; 1655 } 1656 } 1657 } 1658 if (da == 0) { 1659 return 0; 1660 } 1661 offsetChildrenPrimary(-da); 1662 mScrollOffsetPrimary += da; 1663 if (mInLayout) { 1664 return da; 1665 } 1666 1667 int childCount = getChildCount(); 1668 boolean updated; 1669 1670 if (da > 0) { 1671 appendVisibleItems(); 1672 } else if (da < 0) { 1673 prependVisibleItems(); 1674 } 1675 updated = getChildCount() > childCount; 1676 childCount = getChildCount(); 1677 1678 if (da > 0) { 1679 removeInvisibleViewsAtFront(); 1680 } else if (da < 0) { 1681 removeInvisibleViewsAtEnd(); 1682 } 1683 updated |= getChildCount() < childCount; 1684 1685 if (updated) { 1686 updateRowSecondarySizeRefresh(); 1687 } 1688 1689 mBaseGridView.invalidate(); 1690 return da; 1691 } 1692 1693 // scroll in second direction will not add/prune views 1694 private int scrollDirectionSecondary(int dy) { 1695 if (dy == 0) { 1696 return 0; 1697 } 1698 offsetChildrenSecondary(-dy); 1699 mScrollOffsetSecondary += dy; 1700 mBaseGridView.invalidate(); 1701 return dy; 1702 } 1703 1704 private void updateScrollMax() { 1705 if (mLastVisiblePos < 0) { 1706 return; 1707 } 1708 final boolean lastAvailable = mLastVisiblePos == mState.getItemCount() - 1; 1709 final boolean maxUnknown = mWindowAlignment.mainAxis().isMaxUnknown(); 1710 if (!lastAvailable && maxUnknown) { 1711 return; 1712 } 1713 int maxEdge = Integer.MIN_VALUE; 1714 int rowIndex = -1; 1715 for (int i = 0; i < mRows.length; i++) { 1716 if (mRows[i].high > maxEdge) { 1717 maxEdge = mRows[i].high; 1718 rowIndex = i; 1719 } 1720 } 1721 int maxScroll = Integer.MAX_VALUE; 1722 for (int i = mLastVisiblePos; i >= mFirstVisiblePos; i--) { 1723 StaggeredGrid.Location location = mGrid.getLocation(i); 1724 if (location != null && location.row == rowIndex) { 1725 int savedMaxEdge = mWindowAlignment.mainAxis().getMaxEdge(); 1726 mWindowAlignment.mainAxis().setMaxEdge(maxEdge); 1727 maxScroll = getPrimarySystemScrollPosition(findViewByPosition(i)); 1728 mWindowAlignment.mainAxis().setMaxEdge(savedMaxEdge); 1729 break; 1730 } 1731 } 1732 if (lastAvailable) { 1733 mWindowAlignment.mainAxis().setMaxEdge(maxEdge); 1734 mWindowAlignment.mainAxis().setMaxScroll(maxScroll); 1735 if (DEBUG) Log.v(getTag(), "updating scroll maxEdge to " + maxEdge + 1736 " scrollMax to " + maxScroll); 1737 } else { 1738 // the maxScroll for currently last visible item is larger, 1739 // so we must invalidate the max scroll value. 1740 if (maxScroll > mWindowAlignment.mainAxis().getMaxScroll()) { 1741 mWindowAlignment.mainAxis().invalidateScrollMax(); 1742 if (DEBUG) Log.v(getTag(), "Invalidate scrollMax since it should be " 1743 + "greater than " + maxScroll); 1744 } 1745 } 1746 } 1747 1748 private void updateScrollMin() { 1749 if (mFirstVisiblePos < 0) { 1750 return; 1751 } 1752 final boolean firstAvailable = mFirstVisiblePos == 0; 1753 final boolean minUnknown = mWindowAlignment.mainAxis().isMinUnknown(); 1754 if (!firstAvailable && minUnknown) { 1755 return; 1756 } 1757 int minEdge = Integer.MAX_VALUE; 1758 int rowIndex = -1; 1759 for (int i = 0; i < mRows.length; i++) { 1760 if (mRows[i].low < minEdge) { 1761 minEdge = mRows[i].low; 1762 rowIndex = i; 1763 } 1764 } 1765 int minScroll = Integer.MIN_VALUE; 1766 for (int i = mFirstVisiblePos; i <= mLastVisiblePos; i++) { 1767 StaggeredGrid.Location location = mGrid.getLocation(i); 1768 if (location != null && location.row == rowIndex) { 1769 int savedMinEdge = mWindowAlignment.mainAxis().getMinEdge(); 1770 mWindowAlignment.mainAxis().setMinEdge(minEdge); 1771 minScroll = getPrimarySystemScrollPosition(findViewByPosition(i)); 1772 mWindowAlignment.mainAxis().setMinEdge(savedMinEdge); 1773 break; 1774 } 1775 } 1776 if (firstAvailable) { 1777 mWindowAlignment.mainAxis().setMinEdge(minEdge); 1778 mWindowAlignment.mainAxis().setMinScroll(minScroll); 1779 if (DEBUG) Log.v(getTag(), "updating scroll minEdge to " + minEdge + 1780 " scrollMin to " + minScroll); 1781 } else { 1782 // the minScroll for currently first visible item is smaller, 1783 // so we must invalidate the min scroll value. 1784 if (minScroll < mWindowAlignment.mainAxis().getMinScroll()) { 1785 mWindowAlignment.mainAxis().invalidateScrollMin(); 1786 if (DEBUG) Log.v(getTag(), "Invalidate scrollMin, since it should be " 1787 + "less than " + minScroll); 1788 } 1789 } 1790 } 1791 1792 private void updateScrollSecondAxis() { 1793 mWindowAlignment.secondAxis().setMinEdge(0); 1794 mWindowAlignment.secondAxis().setMaxEdge(getSizeSecondary()); 1795 } 1796 1797 private void initScrollController() { 1798 // mScrollOffsetPrimary and mScrollOffsetSecondary includes the padding. 1799 // e.g. when topPadding is 16 for horizontal grid view, the initial 1800 // mScrollOffsetSecondary is -16. fastLayout() put views based on offsets(not padding), 1801 // when padding changes to 20, we also need update mScrollOffsetSecondary to -20 before 1802 // fastLayout() is performed 1803 int paddingPrimaryDiff, paddingSecondaryDiff; 1804 if (mOrientation == HORIZONTAL) { 1805 paddingPrimaryDiff = getPaddingLeft() - mWindowAlignment.horizontal.getPaddingLow(); 1806 paddingSecondaryDiff = getPaddingTop() - mWindowAlignment.vertical.getPaddingLow(); 1807 } else { 1808 paddingPrimaryDiff = getPaddingTop() - mWindowAlignment.vertical.getPaddingLow(); 1809 paddingSecondaryDiff = getPaddingLeft() - mWindowAlignment.horizontal.getPaddingLow(); 1810 } 1811 mScrollOffsetPrimary -= paddingPrimaryDiff; 1812 mScrollOffsetSecondary -= paddingSecondaryDiff; 1813 1814 mWindowAlignment.horizontal.setSize(getWidth()); 1815 mWindowAlignment.horizontal.setPadding(getPaddingLeft(), getPaddingRight()); 1816 mWindowAlignment.vertical.setSize(getHeight()); 1817 mWindowAlignment.vertical.setPadding(getPaddingTop(), getPaddingBottom()); 1818 mSizePrimary = mWindowAlignment.mainAxis().getSize(); 1819 1820 if (DEBUG) { 1821 Log.v(getTag(), "initScrollController mSizePrimary " + mSizePrimary 1822 + " mWindowAlignment " + mWindowAlignment); 1823 } 1824 } 1825 1826 public void setSelection(RecyclerView parent, int position) { 1827 setSelection(parent, position, false); 1828 } 1829 1830 public void setSelectionSmooth(RecyclerView parent, int position) { 1831 setSelection(parent, position, true); 1832 } 1833 1834 public int getSelection() { 1835 return mFocusPosition; 1836 } 1837 1838 public void setSelection(RecyclerView parent, int position, boolean smooth) { 1839 if (mFocusPosition == position) { 1840 return; 1841 } 1842 View view = findViewByPosition(position); 1843 if (view != null) { 1844 mInSelection = true; 1845 scrollToView(view, smooth); 1846 mInSelection = false; 1847 } else { 1848 mFocusPosition = position; 1849 mFocusPositionOffset = 0; 1850 if (!mLayoutEnabled) { 1851 return; 1852 } 1853 if (smooth) { 1854 if (!hasDoneFirstLayout()) { 1855 Log.w(getTag(), "setSelectionSmooth should " + 1856 "not be called before first layout pass"); 1857 return; 1858 } 1859 LinearSmoothScroller linearSmoothScroller = 1860 new LinearSmoothScroller(parent.getContext()) { 1861 @Override 1862 public PointF computeScrollVectorForPosition(int targetPosition) { 1863 if (getChildCount() == 0) { 1864 return null; 1865 } 1866 final int firstChildPos = getPosition(getChildAt(0)); 1867 final int direction = targetPosition < firstChildPos ? -1 : 1; 1868 if (mOrientation == HORIZONTAL) { 1869 return new PointF(direction, 0); 1870 } else { 1871 return new PointF(0, direction); 1872 } 1873 } 1874 @Override 1875 protected void onTargetFound(View targetView, 1876 RecyclerView.State state, Action action) { 1877 if (hasFocus()) { 1878 targetView.requestFocus(); 1879 } 1880 dispatchChildSelected(); 1881 if (getScrollPosition(targetView, mTempDeltas)) { 1882 int dx, dy; 1883 if (mOrientation == HORIZONTAL) { 1884 dx = mTempDeltas[0]; 1885 dy = mTempDeltas[1]; 1886 } else { 1887 dx = mTempDeltas[1]; 1888 dy = mTempDeltas[0]; 1889 } 1890 final int distance = (int) Math.sqrt(dx * dx + dy * dy); 1891 final int time = calculateTimeForDeceleration(distance); 1892 action.update(dx, dy, time, mDecelerateInterpolator); 1893 } 1894 } 1895 }; 1896 linearSmoothScroller.setTargetPosition(position); 1897 startSmoothScroll(linearSmoothScroller); 1898 } else { 1899 mForceFullLayout = true; 1900 parent.requestLayout(); 1901 } 1902 } 1903 } 1904 1905 @Override 1906 public void onItemsAdded(RecyclerView recyclerView, int positionStart, int itemCount) { 1907 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE 1908 && getChildAt(mFocusPosition) != null) { 1909 int pos = mFocusPosition + mFocusPositionOffset; 1910 if (positionStart <= pos) { 1911 mFocusPositionOffset += itemCount; 1912 } 1913 } 1914 mChildrenStates.clear(); 1915 } 1916 1917 @Override 1918 public void onItemsChanged(RecyclerView recyclerView) { 1919 mFocusPositionOffset = 0; 1920 mChildrenStates.clear(); 1921 } 1922 1923 @Override 1924 public void onItemsRemoved(RecyclerView recyclerView, int positionStart, int itemCount) { 1925 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE 1926 && getChildAt(mFocusPosition) != null) { 1927 int pos = mFocusPosition + mFocusPositionOffset; 1928 if (positionStart <= pos) { 1929 if (positionStart + itemCount > pos) { 1930 // stop updating offset after the focus item was removed 1931 mFocusPositionOffset = Integer.MIN_VALUE; 1932 } else { 1933 mFocusPositionOffset -= itemCount; 1934 } 1935 } 1936 } 1937 mChildrenStates.clear(); 1938 } 1939 1940 @Override 1941 public void onItemsMoved(RecyclerView recyclerView, int fromPosition, int toPosition, 1942 int itemCount) { 1943 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE 1944 && getChildAt(mFocusPosition) != null) { 1945 int pos = mFocusPosition + mFocusPositionOffset; 1946 if (fromPosition <= pos && pos < fromPosition + itemCount) { 1947 // moved items include focused position 1948 mFocusPositionOffset += toPosition - fromPosition; 1949 } else if (fromPosition < pos && toPosition > pos - itemCount) { 1950 // move items before focus position to after focused position 1951 mFocusPositionOffset -= itemCount; 1952 } else if (fromPosition > pos && toPosition < pos) { 1953 // move items after focus position to before focused position 1954 mFocusPositionOffset += itemCount; 1955 } 1956 } 1957 mChildrenStates.clear(); 1958 } 1959 1960 @Override 1961 public void onItemsUpdated(RecyclerView recyclerView, int positionStart, int itemCount) { 1962 for (int i = positionStart, end = positionStart + itemCount; i < end; i++) { 1963 mChildrenStates.remove(i); 1964 } 1965 } 1966 1967 @Override 1968 public boolean onRequestChildFocus(RecyclerView parent, View child, View focused) { 1969 if (mFocusSearchDisabled) { 1970 return true; 1971 } 1972 if (!mInLayout && !mInSelection) { 1973 scrollToView(child, true); 1974 } 1975 return true; 1976 } 1977 1978 @Override 1979 public boolean requestChildRectangleOnScreen(RecyclerView parent, View view, Rect rect, 1980 boolean immediate) { 1981 if (DEBUG) Log.v(getTag(), "requestChildRectangleOnScreen " + view + " " + rect); 1982 return false; 1983 } 1984 1985 int getScrollOffsetX() { 1986 return mOrientation == HORIZONTAL ? mScrollOffsetPrimary : mScrollOffsetSecondary; 1987 } 1988 1989 int getScrollOffsetY() { 1990 return mOrientation == HORIZONTAL ? mScrollOffsetSecondary : mScrollOffsetPrimary; 1991 } 1992 1993 public void getViewSelectedOffsets(View view, int[] offsets) { 1994 if (mOrientation == HORIZONTAL) { 1995 offsets[0] = getPrimarySystemScrollPosition(view) - mScrollOffsetPrimary; 1996 offsets[1] = getSecondarySystemScrollPosition(view) - mScrollOffsetSecondary; 1997 } else { 1998 offsets[1] = getPrimarySystemScrollPosition(view) - mScrollOffsetPrimary; 1999 offsets[0] = getSecondarySystemScrollPosition(view) - mScrollOffsetSecondary; 2000 } 2001 } 2002 2003 private int getPrimarySystemScrollPosition(View view) { 2004 int viewCenterPrimary = mScrollOffsetPrimary + getViewCenter(view); 2005 int pos = getPositionByView(view); 2006 StaggeredGrid.Location location = mGrid.getLocation(pos); 2007 final int row = location.row; 2008 boolean isFirst = mFirstVisiblePos == 0; 2009 // TODO: change to use State object in onRequestChildFocus() 2010 boolean isLast = mLastVisiblePos == (mState == null ? 2011 getItemCount() : mState.getItemCount()) - 1; 2012 if (isFirst || isLast) { 2013 for (int i = getChildCount() - 1; i >= 0; i--) { 2014 int position = getPositionByIndex(i); 2015 StaggeredGrid.Location loc = mGrid.getLocation(position); 2016 if (loc != null && loc.row == row) { 2017 if (position < pos) { 2018 isFirst = false; 2019 } else if (position > pos) { 2020 isLast = false; 2021 } 2022 } 2023 } 2024 } 2025 return mWindowAlignment.mainAxis().getSystemScrollPos(viewCenterPrimary, isFirst, isLast); 2026 } 2027 2028 private int getSecondarySystemScrollPosition(View view) { 2029 int viewCenterSecondary = mScrollOffsetSecondary + getViewCenterSecondary(view); 2030 int pos = getPositionByView(view); 2031 StaggeredGrid.Location location = mGrid.getLocation(pos); 2032 final int row = location.row; 2033 boolean isFirst = row == 0; 2034 boolean isLast = row == mGrid.getNumRows() - 1; 2035 return mWindowAlignment.secondAxis().getSystemScrollPos(viewCenterSecondary, 2036 isFirst, isLast); 2037 } 2038 2039 /** 2040 * Scroll to a given child view and change mFocusPosition. 2041 */ 2042 private void scrollToView(View view, boolean smooth) { 2043 int newFocusPosition = getPositionByView(view); 2044 if (newFocusPosition != mFocusPosition) { 2045 mFocusPosition = newFocusPosition; 2046 mFocusPositionOffset = 0; 2047 if (!mInLayout) { 2048 dispatchChildSelected(); 2049 } 2050 } 2051 if (mBaseGridView.isChildrenDrawingOrderEnabledInternal()) { 2052 mBaseGridView.invalidate(); 2053 } 2054 if (view == null) { 2055 return; 2056 } 2057 if (!view.hasFocus() && mBaseGridView.hasFocus()) { 2058 // transfer focus to the child if it does not have focus yet (e.g. triggered 2059 // by setSelection()) 2060 view.requestFocus(); 2061 } 2062 if (!mScrollEnabled) { 2063 return; 2064 } 2065 if (getScrollPosition(view, mTempDeltas)) { 2066 scrollGrid(mTempDeltas[0], mTempDeltas[1], smooth); 2067 } 2068 } 2069 2070 private boolean getScrollPosition(View view, int[] deltas) { 2071 switch (mFocusScrollStrategy) { 2072 case BaseGridView.FOCUS_SCROLL_ALIGNED: 2073 default: 2074 return getAlignedPosition(view, deltas); 2075 case BaseGridView.FOCUS_SCROLL_ITEM: 2076 case BaseGridView.FOCUS_SCROLL_PAGE: 2077 return getNoneAlignedPosition(view, deltas); 2078 } 2079 } 2080 2081 private boolean getNoneAlignedPosition(View view, int[] deltas) { 2082 int pos = getPositionByView(view); 2083 int viewMin = getViewMin(view); 2084 int viewMax = getViewMax(view); 2085 // we either align "firstView" to left/top padding edge 2086 // or align "lastView" to right/bottom padding edge 2087 View firstView = null; 2088 View lastView = null; 2089 int paddingLow = mWindowAlignment.mainAxis().getPaddingLow(); 2090 int clientSize = mWindowAlignment.mainAxis().getClientSize(); 2091 final int row = mGrid.getLocation(pos).row; 2092 if (viewMin < paddingLow) { 2093 // view enters low padding area: 2094 firstView = view; 2095 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_PAGE) { 2096 // scroll one "page" left/top, 2097 // align first visible item of the "page" at the low padding edge. 2098 while (!prependOneVisibleItem()) { 2099 List<Integer> positions = 2100 mGrid.getItemPositionsInRows(mFirstVisiblePos, pos)[row]; 2101 firstView = findViewByPosition(positions.get(0)); 2102 if (viewMax - getViewMin(firstView) > clientSize) { 2103 if (positions.size() > 1) { 2104 firstView = findViewByPosition(positions.get(1)); 2105 } 2106 break; 2107 } 2108 } 2109 } 2110 } else if (viewMax > clientSize + paddingLow) { 2111 // view enters high padding area: 2112 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_PAGE) { 2113 // scroll whole one page right/bottom, align view at the low padding edge. 2114 firstView = view; 2115 do { 2116 List<Integer> positions = 2117 mGrid.getItemPositionsInRows(pos, mLastVisiblePos)[row]; 2118 lastView = findViewByPosition(positions.get(positions.size() - 1)); 2119 if (getViewMax(lastView) - viewMin > clientSize) { 2120 lastView = null; 2121 break; 2122 } 2123 } while (!appendOneVisibleItem()); 2124 if (lastView != null) { 2125 // however if we reached end, we should align last view. 2126 firstView = null; 2127 } 2128 } else { 2129 lastView = view; 2130 } 2131 } 2132 int scrollPrimary = 0; 2133 int scrollSecondary = 0; 2134 if (firstView != null) { 2135 scrollPrimary = getViewMin(firstView) - paddingLow; 2136 } else if (lastView != null) { 2137 scrollPrimary = getViewMax(lastView) - (paddingLow + clientSize); 2138 } 2139 View secondaryAlignedView; 2140 if (firstView != null) { 2141 secondaryAlignedView = firstView; 2142 } else if (lastView != null) { 2143 secondaryAlignedView = lastView; 2144 } else { 2145 secondaryAlignedView = view; 2146 } 2147 scrollSecondary = getSecondarySystemScrollPosition(secondaryAlignedView); 2148 scrollSecondary -= mScrollOffsetSecondary; 2149 if (scrollPrimary != 0 || scrollSecondary != 0) { 2150 deltas[0] = scrollPrimary; 2151 deltas[1] = scrollSecondary; 2152 return true; 2153 } 2154 return false; 2155 } 2156 2157 private boolean getAlignedPosition(View view, int[] deltas) { 2158 int scrollPrimary = getPrimarySystemScrollPosition(view); 2159 int scrollSecondary = getSecondarySystemScrollPosition(view); 2160 if (DEBUG) { 2161 Log.v(getTag(), "getAlignedPosition " + scrollPrimary + " " + scrollSecondary 2162 +" " + mWindowAlignment); 2163 } 2164 scrollPrimary -= mScrollOffsetPrimary; 2165 scrollSecondary -= mScrollOffsetSecondary; 2166 if (scrollPrimary != 0 || scrollSecondary != 0) { 2167 deltas[0] = scrollPrimary; 2168 deltas[1] = scrollSecondary; 2169 return true; 2170 } 2171 return false; 2172 } 2173 2174 private void scrollGrid(int scrollPrimary, int scrollSecondary, boolean smooth) { 2175 if (mInLayout) { 2176 scrollDirectionPrimary(scrollPrimary); 2177 scrollDirectionSecondary(scrollSecondary); 2178 } else { 2179 int scrollX; 2180 int scrollY; 2181 if (mOrientation == HORIZONTAL) { 2182 scrollX = scrollPrimary; 2183 scrollY = scrollSecondary; 2184 } else { 2185 scrollX = scrollSecondary; 2186 scrollY = scrollPrimary; 2187 } 2188 if (smooth) { 2189 mBaseGridView.smoothScrollBy(scrollX, scrollY); 2190 } else { 2191 mBaseGridView.scrollBy(scrollX, scrollY); 2192 } 2193 } 2194 } 2195 2196 public void setPruneChild(boolean pruneChild) { 2197 if (mPruneChild != pruneChild) { 2198 mPruneChild = pruneChild; 2199 if (mPruneChild) { 2200 requestLayout(); 2201 } 2202 } 2203 } 2204 2205 public boolean getPruneChild() { 2206 return mPruneChild; 2207 } 2208 2209 public void setScrollEnabled(boolean scrollEnabled) { 2210 if (mScrollEnabled != scrollEnabled) { 2211 mScrollEnabled = scrollEnabled; 2212 if (mScrollEnabled && mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED) { 2213 View focusView = findViewByPosition(mFocusPosition == NO_POSITION ? 0 : 2214 mFocusPosition); 2215 if (focusView != null) { 2216 scrollToView(focusView, true); 2217 } 2218 } 2219 } 2220 } 2221 2222 public boolean isScrollEnabled() { 2223 return mScrollEnabled; 2224 } 2225 2226 private int findImmediateChildIndex(View view) { 2227 while (view != null && view != mBaseGridView) { 2228 int index = mBaseGridView.indexOfChild(view); 2229 if (index >= 0) { 2230 return index; 2231 } 2232 view = (View) view.getParent(); 2233 } 2234 return NO_POSITION; 2235 } 2236 2237 void setFocusSearchDisabled(boolean disabled) { 2238 mFocusSearchDisabled = disabled; 2239 } 2240 2241 boolean isFocusSearchDisabled() { 2242 return mFocusSearchDisabled; 2243 } 2244 2245 @Override 2246 public View onInterceptFocusSearch(View focused, int direction) { 2247 if (mFocusSearchDisabled) { 2248 return focused; 2249 } 2250 return null; 2251 } 2252 2253 boolean hasPreviousViewInSameRow(int pos) { 2254 if (mGrid == null || pos == NO_POSITION) { 2255 return false; 2256 } 2257 if (mFirstVisiblePos > 0) { 2258 return true; 2259 } 2260 final int focusedRow = mGrid.getLocation(pos).row; 2261 for (int i = getChildCount() - 1; i >= 0; i--) { 2262 int position = getPositionByIndex(i); 2263 StaggeredGrid.Location loc = mGrid.getLocation(position); 2264 if (loc != null && loc.row == focusedRow) { 2265 if (position < pos) { 2266 return true; 2267 } 2268 } 2269 } 2270 return false; 2271 } 2272 2273 @Override 2274 public boolean onAddFocusables(RecyclerView recyclerView, 2275 ArrayList<View> views, int direction, int focusableMode) { 2276 if (mFocusSearchDisabled) { 2277 return true; 2278 } 2279 // If this viewgroup or one of its children currently has focus then we 2280 // consider our children for focus searching in main direction on the same row. 2281 // If this viewgroup has no focus and using focus align, we want the system 2282 // to ignore our children and pass focus to the viewgroup, which will pass 2283 // focus on to its children appropriately. 2284 // If this viewgroup has no focus and not using focus align, we want to 2285 // consider the child that does not overlap with padding area. 2286 if (recyclerView.hasFocus()) { 2287 final int movement = getMovement(direction); 2288 if (movement != PREV_ITEM && movement != NEXT_ITEM) { 2289 // Move on secondary direction uses default addFocusables(). 2290 return false; 2291 } 2292 final View focused = recyclerView.findFocus(); 2293 final int focusedPos = getPositionByIndex(findImmediateChildIndex(focused)); 2294 // Add focusables of focused item. 2295 if (focusedPos != NO_POSITION) { 2296 findViewByPosition(focusedPos).addFocusables(views, direction, focusableMode); 2297 } 2298 final int focusedRow = mGrid != null && focusedPos != NO_POSITION ? 2299 mGrid.getLocation(focusedPos).row : NO_POSITION; 2300 // Add focusables of next neighbor of same row on the focus search direction. 2301 if (mGrid != null) { 2302 final int focusableCount = views.size(); 2303 for (int i = 0, count = getChildCount(); i < count; i++) { 2304 int index = movement == NEXT_ITEM ? i : count - 1 - i; 2305 final View child = getChildAt(index); 2306 if (child.getVisibility() != View.VISIBLE) { 2307 continue; 2308 } 2309 int position = getPositionByIndex(index); 2310 StaggeredGrid.Location loc = mGrid.getLocation(position); 2311 if (focusedRow == NO_POSITION || (loc != null && loc.row == focusedRow)) { 2312 if (focusedPos == NO_POSITION || 2313 (movement == NEXT_ITEM && position > focusedPos) 2314 || (movement == PREV_ITEM && position < focusedPos)) { 2315 child.addFocusables(views, direction, focusableMode); 2316 if (views.size() > focusableCount) { 2317 break; 2318 } 2319 } 2320 } 2321 } 2322 } 2323 } else { 2324 if (mFocusScrollStrategy != BaseGridView.FOCUS_SCROLL_ALIGNED) { 2325 // adding views not overlapping padding area to avoid scrolling in gaining focus 2326 int left = mWindowAlignment.mainAxis().getPaddingLow(); 2327 int right = mWindowAlignment.mainAxis().getClientSize() + left; 2328 int focusableCount = views.size(); 2329 for (int i = 0, count = getChildCount(); i < count; i++) { 2330 View child = getChildAt(i); 2331 if (child.getVisibility() == View.VISIBLE) { 2332 if (getViewMin(child) >= left && getViewMax(child) <= right) { 2333 child.addFocusables(views, direction, focusableMode); 2334 } 2335 } 2336 } 2337 // if we cannot find any, then just add all children. 2338 if (views.size() == focusableCount) { 2339 for (int i = 0, count = getChildCount(); i < count; i++) { 2340 View child = getChildAt(i); 2341 if (child.getVisibility() == View.VISIBLE) { 2342 child.addFocusables(views, direction, focusableMode); 2343 } 2344 } 2345 if (views.size() != focusableCount) { 2346 return true; 2347 } 2348 } else { 2349 return true; 2350 } 2351 // if still cannot find any, fall through and add itself 2352 } 2353 if (recyclerView.isFocusable()) { 2354 views.add(recyclerView); 2355 } 2356 } 2357 return true; 2358 } 2359 2360 @Override 2361 public View onFocusSearchFailed(View focused, int direction, Recycler recycler, 2362 RecyclerView.State state) { 2363 if (DEBUG) Log.v(getTag(), "onFocusSearchFailed direction " + direction); 2364 2365 View view = null; 2366 int movement = getMovement(direction); 2367 if (mNumRows == 1) { 2368 // for simple row, use LinearSmoothScroller to smooth animation. 2369 // It will stay at a fixed cap speed in continuous scroll. 2370 if (movement == NEXT_ITEM) { 2371 int newPos = mFocusPosition + mNumRows; 2372 if (newPos < getItemCount()) { 2373 setSelectionSmooth(mBaseGridView, newPos); 2374 view = focused; 2375 } else { 2376 if (!mFocusOutEnd) { 2377 view = focused; 2378 } 2379 } 2380 } else if (movement == PREV_ITEM){ 2381 int newPos = mFocusPosition - mNumRows; 2382 if (newPos >= 0) { 2383 setSelectionSmooth(mBaseGridView, newPos); 2384 view = focused; 2385 } else { 2386 if (!mFocusOutFront) { 2387 view = focused; 2388 } 2389 } 2390 } 2391 } else if (mNumRows > 1) { 2392 // for possible staggered grid, we need guarantee focus to same row/column. 2393 // TODO: we may also use LinearSmoothScroller. 2394 saveContext(recycler, state); 2395 final FocusFinder ff = FocusFinder.getInstance(); 2396 if (movement == NEXT_ITEM) { 2397 while (view == null && !appendOneVisibleItem()) { 2398 view = ff.findNextFocus(mBaseGridView, focused, direction); 2399 } 2400 } else if (movement == PREV_ITEM){ 2401 while (view == null && !prependOneVisibleItem()) { 2402 view = ff.findNextFocus(mBaseGridView, focused, direction); 2403 } 2404 } 2405 if (view == null) { 2406 // returning the same view to prevent focus lost when scrolling past the end of the list 2407 if (movement == PREV_ITEM) { 2408 view = mFocusOutFront ? null : focused; 2409 } else if (movement == NEXT_ITEM){ 2410 view = mFocusOutEnd ? null : focused; 2411 } 2412 } 2413 leaveContext(); 2414 } 2415 if (DEBUG) Log.v(getTag(), "returning view " + view); 2416 return view; 2417 } 2418 2419 boolean gridOnRequestFocusInDescendants(RecyclerView recyclerView, int direction, 2420 Rect previouslyFocusedRect) { 2421 switch (mFocusScrollStrategy) { 2422 case BaseGridView.FOCUS_SCROLL_ALIGNED: 2423 default: 2424 return gridOnRequestFocusInDescendantsAligned(recyclerView, 2425 direction, previouslyFocusedRect); 2426 case BaseGridView.FOCUS_SCROLL_PAGE: 2427 case BaseGridView.FOCUS_SCROLL_ITEM: 2428 return gridOnRequestFocusInDescendantsUnaligned(recyclerView, 2429 direction, previouslyFocusedRect); 2430 } 2431 } 2432 2433 private boolean gridOnRequestFocusInDescendantsAligned(RecyclerView recyclerView, 2434 int direction, Rect previouslyFocusedRect) { 2435 View view = findViewByPosition(mFocusPosition); 2436 if (view != null) { 2437 boolean result = view.requestFocus(direction, previouslyFocusedRect); 2438 if (!result && DEBUG) { 2439 Log.w(getTag(), "failed to request focus on " + view); 2440 } 2441 return result; 2442 } 2443 return false; 2444 } 2445 2446 private boolean gridOnRequestFocusInDescendantsUnaligned(RecyclerView recyclerView, 2447 int direction, Rect previouslyFocusedRect) { 2448 // focus to view not overlapping padding area to avoid scrolling in gaining focus 2449 int index; 2450 int increment; 2451 int end; 2452 int count = getChildCount(); 2453 if ((direction & View.FOCUS_FORWARD) != 0) { 2454 index = 0; 2455 increment = 1; 2456 end = count; 2457 } else { 2458 index = count - 1; 2459 increment = -1; 2460 end = -1; 2461 } 2462 int left = mWindowAlignment.mainAxis().getPaddingLow(); 2463 int right = mWindowAlignment.mainAxis().getClientSize() + left; 2464 for (int i = index; i != end; i += increment) { 2465 View child = getChildAt(i); 2466 if (child.getVisibility() == View.VISIBLE) { 2467 if (getViewMin(child) >= left && getViewMax(child) <= right) { 2468 if (child.requestFocus(direction, previouslyFocusedRect)) { 2469 return true; 2470 } 2471 } 2472 } 2473 } 2474 return false; 2475 } 2476 2477 private final static int PREV_ITEM = 0; 2478 private final static int NEXT_ITEM = 1; 2479 private final static int PREV_ROW = 2; 2480 private final static int NEXT_ROW = 3; 2481 2482 private int getMovement(int direction) { 2483 int movement = View.FOCUS_LEFT; 2484 2485 if (mOrientation == HORIZONTAL) { 2486 switch(direction) { 2487 case View.FOCUS_LEFT: 2488 movement = PREV_ITEM; 2489 break; 2490 case View.FOCUS_RIGHT: 2491 movement = NEXT_ITEM; 2492 break; 2493 case View.FOCUS_UP: 2494 movement = PREV_ROW; 2495 break; 2496 case View.FOCUS_DOWN: 2497 movement = NEXT_ROW; 2498 break; 2499 } 2500 } else if (mOrientation == VERTICAL) { 2501 switch(direction) { 2502 case View.FOCUS_LEFT: 2503 movement = PREV_ROW; 2504 break; 2505 case View.FOCUS_RIGHT: 2506 movement = NEXT_ROW; 2507 break; 2508 case View.FOCUS_UP: 2509 movement = PREV_ITEM; 2510 break; 2511 case View.FOCUS_DOWN: 2512 movement = NEXT_ITEM; 2513 break; 2514 } 2515 } 2516 2517 return movement; 2518 } 2519 2520 int getChildDrawingOrder(RecyclerView recyclerView, int childCount, int i) { 2521 View view = findViewByPosition(mFocusPosition); 2522 if (view == null) { 2523 return i; 2524 } 2525 int focusIndex = recyclerView.indexOfChild(view); 2526 // supposely 0 1 2 3 4 5 6 7 8 9, 4 is the center item 2527 // drawing order is 0 1 2 3 9 8 7 6 5 4 2528 if (i < focusIndex) { 2529 return i; 2530 } else if (i < childCount - 1) { 2531 return focusIndex + childCount - 1 - i; 2532 } else { 2533 return focusIndex; 2534 } 2535 } 2536 2537 @Override 2538 public void onAdapterChanged(RecyclerView.Adapter oldAdapter, 2539 RecyclerView.Adapter newAdapter) { 2540 discardLayoutInfo(); 2541 mFocusPosition = NO_POSITION; 2542 mFocusPositionOffset = 0; 2543 mChildrenStates.clear(); 2544 super.onAdapterChanged(oldAdapter, newAdapter); 2545 } 2546 2547 private void discardLayoutInfo() { 2548 mGrid = null; 2549 mRows = null; 2550 mRowSizeSecondary = null; 2551 mFirstVisiblePos = -1; 2552 mLastVisiblePos = -1; 2553 mRowSecondarySizeRefresh = false; 2554 } 2555 2556 public void setLayoutEnabled(boolean layoutEnabled) { 2557 if (mLayoutEnabled != layoutEnabled) { 2558 mLayoutEnabled = layoutEnabled; 2559 requestLayout(); 2560 } 2561 } 2562 2563 final static class SavedState implements Parcelable { 2564 2565 int index; // index inside adapter of the current view 2566 Bundle childStates = Bundle.EMPTY; 2567 2568 @Override 2569 public void writeToParcel(Parcel out, int flags) { 2570 out.writeInt(index); 2571 out.writeBundle(childStates); 2572 } 2573 2574 @SuppressWarnings("hiding") 2575 public static final Parcelable.Creator<SavedState> CREATOR = 2576 new Parcelable.Creator<SavedState>() { 2577 @Override 2578 public SavedState createFromParcel(Parcel in) { 2579 return new SavedState(in); 2580 } 2581 2582 @Override 2583 public SavedState[] newArray(int size) { 2584 return new SavedState[size]; 2585 } 2586 }; 2587 2588 @Override 2589 public int describeContents() { 2590 return 0; 2591 } 2592 2593 SavedState(Parcel in) { 2594 index = in.readInt(); 2595 childStates = in.readBundle(GridLayoutManager.class.getClassLoader()); 2596 } 2597 2598 SavedState() { 2599 } 2600 } 2601 2602 @Override 2603 public Parcelable onSaveInstanceState() { 2604 SavedState ss = new SavedState(); 2605 for (int i = 0, count = getChildCount(); i < count; i++) { 2606 View view = getChildAt(i); 2607 int position = getPositionByView(view); 2608 if (position != NO_POSITION) { 2609 mChildrenStates.saveOnScreenView(view, position); 2610 } 2611 } 2612 ss.index = getSelection(); 2613 ss.childStates = mChildrenStates.saveAsBundle(); 2614 return ss; 2615 } 2616 2617 @Override 2618 public void onRestoreInstanceState(Parcelable state) { 2619 if (!(state instanceof SavedState)) { 2620 return; 2621 } 2622 SavedState loadingState = (SavedState)state; 2623 mFocusPosition = loadingState.index; 2624 mFocusPositionOffset = 0; 2625 mChildrenStates.loadFromBundle(loadingState.childStates); 2626 mForceFullLayout = true; 2627 requestLayout(); 2628 } 2629} 2630