GridLayoutManager.java revision e692c096892075c6ac5cf509f118df6b618edecc
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.support.v4.view.ViewCompat; 20import android.support.v7.widget.LinearSmoothScroller; 21import android.support.v7.widget.RecyclerView; 22import android.support.v7.widget.RecyclerView.Recycler; 23import android.support.v7.widget.RecyclerView.State; 24 25import static android.support.v7.widget.RecyclerView.NO_ID; 26import static android.support.v7.widget.RecyclerView.NO_POSITION; 27import static android.support.v7.widget.RecyclerView.HORIZONTAL; 28import static android.support.v7.widget.RecyclerView.VERTICAL; 29 30import android.util.AttributeSet; 31import android.util.Log; 32import android.view.FocusFinder; 33import android.view.Gravity; 34import android.view.View; 35import android.view.ViewParent; 36import android.view.View.MeasureSpec; 37import android.view.ViewGroup.MarginLayoutParams; 38import android.view.ViewGroup; 39 40import java.io.PrintWriter; 41import java.io.StringWriter; 42import java.util.ArrayList; 43import java.util.List; 44 45final class GridLayoutManager extends RecyclerView.LayoutManager { 46 47 /* 48 * LayoutParams for {@link HorizontalGridView} and {@link VerticalGridView}. 49 * The class currently does two internal jobs: 50 * - Saves optical bounds insets. 51 * - Caches focus align view center. 52 */ 53 static class LayoutParams extends RecyclerView.LayoutParams { 54 55 // The view is saved only during animation. 56 private View mView; 57 58 // For placement 59 private int mLeftInset; 60 private int mTopInset; 61 private int mRighInset; 62 private int mBottomInset; 63 64 // For alignment 65 private int mAlignX; 66 private int mAlignY; 67 68 public LayoutParams(Context c, AttributeSet attrs) { 69 super(c, attrs); 70 } 71 72 public LayoutParams(int width, int height) { 73 super(width, height); 74 } 75 76 public LayoutParams(MarginLayoutParams source) { 77 super(source); 78 } 79 80 public LayoutParams(ViewGroup.LayoutParams source) { 81 super(source); 82 } 83 84 public LayoutParams(RecyclerView.LayoutParams source) { 85 super(source); 86 } 87 88 public LayoutParams(LayoutParams source) { 89 super(source); 90 } 91 92 int getAlignX() { 93 return mAlignX; 94 } 95 96 int getAlignY() { 97 return mAlignY; 98 } 99 100 int getOpticalLeft(View view) { 101 return view.getLeft() + mLeftInset; 102 } 103 104 int getOpticalTop(View view) { 105 return view.getTop() + mTopInset; 106 } 107 108 int getOpticalRight(View view) { 109 return view.getRight() - mRighInset; 110 } 111 112 int getOpticalBottom(View view) { 113 return view.getBottom() - mBottomInset; 114 } 115 116 int getOpticalWidth(View view) { 117 return view.getWidth() - mLeftInset - mRighInset; 118 } 119 120 int getOpticalHeight(View view) { 121 return view.getHeight() - mTopInset - mBottomInset; 122 } 123 124 int getOpticalLeftInset() { 125 return mLeftInset; 126 } 127 128 int getOpticalRightInset() { 129 return mRighInset; 130 } 131 132 int getOpticalTopInset() { 133 return mTopInset; 134 } 135 136 int getOpticalBottomInset() { 137 return mBottomInset; 138 } 139 140 void setAlignX(int alignX) { 141 mAlignX = alignX; 142 } 143 144 void setAlignY(int alignY) { 145 mAlignY = alignY; 146 } 147 148 void setOpticalInsets(int leftInset, int topInset, int rightInset, int bottomInset) { 149 mLeftInset = leftInset; 150 mTopInset = topInset; 151 mRighInset = rightInset; 152 mBottomInset = bottomInset; 153 } 154 155 private void invalidateItemDecoration() { 156 ViewParent parent = mView.getParent(); 157 if (parent instanceof RecyclerView) { 158 // TODO: we only need invalidate parent if it has ItemDecoration 159 ((RecyclerView) parent).invalidate(); 160 } 161 } 162 } 163 164 private static final String TAG = "GridLayoutManager"; 165 private static final boolean DEBUG = false; 166 167 private String getTag() { 168 return TAG + ":" + mBaseGridView.getId(); 169 } 170 171 private final BaseGridView mBaseGridView; 172 173 /** 174 * The orientation of a "row". 175 */ 176 private int mOrientation = HORIZONTAL; 177 178 private RecyclerView.State mState; 179 private RecyclerView.Recycler mRecycler; 180 181 private boolean mInLayout = false; 182 183 private OnChildSelectedListener mChildSelectedListener = null; 184 185 /** 186 * The focused position, it's not the currently visually aligned position 187 * but it is the final position that we intend to focus on. If there are 188 * multiple setSelection() called, mFocusPosition saves last value. 189 */ 190 private int mFocusPosition = NO_POSITION; 191 192 /** 193 * The offset to be applied to mFocusPosition, due to adapter change, on the next 194 * layout. Set to Integer.MIN_VALUE means item was removed. 195 * TODO: This is somewhat duplication of RecyclerView getOldPosition() which is 196 * unfortunately cleared after prelayout. 197 */ 198 private int mFocusPositionOffset = 0; 199 200 /** 201 * Force a full layout under certain situations. 202 */ 203 private boolean mForceFullLayout; 204 205 /** 206 * True if layout is enabled. 207 */ 208 private boolean mLayoutEnabled = true; 209 210 /** 211 * The scroll offsets of the viewport relative to the entire view. 212 */ 213 private int mScrollOffsetPrimary; 214 private int mScrollOffsetSecondary; 215 216 /** 217 * User-specified row height/column width. Can be WRAP_CONTENT. 218 */ 219 private int mRowSizeSecondaryRequested; 220 221 /** 222 * The fixed size of each grid item in the secondary direction. This corresponds to 223 * the row height, equal for all rows. Grid items may have variable length 224 * in the primary direction. 225 */ 226 private int mFixedRowSizeSecondary; 227 228 /** 229 * Tracks the secondary size of each row. 230 */ 231 private int[] mRowSizeSecondary; 232 233 /** 234 * Flag controlling whether the current/next layout should 235 * be updating the secondary size of rows. 236 */ 237 private boolean mRowSecondarySizeRefresh; 238 239 /** 240 * The maximum measured size of the view. 241 */ 242 private int mMaxSizeSecondary; 243 244 /** 245 * Margin between items. 246 */ 247 private int mHorizontalMargin; 248 /** 249 * Margin between items vertically. 250 */ 251 private int mVerticalMargin; 252 /** 253 * Margin in main direction. 254 */ 255 private int mMarginPrimary; 256 /** 257 * Margin in second direction. 258 */ 259 private int mMarginSecondary; 260 /** 261 * How to position child in secondary direction. 262 */ 263 private int mGravity = Gravity.LEFT | Gravity.TOP; 264 /** 265 * The number of rows in the grid. 266 */ 267 private int mNumRows; 268 /** 269 * Number of rows requested, can be 0 to be determined by parent size and 270 * rowHeight. 271 */ 272 private int mNumRowsRequested = 1; 273 274 /** 275 * Tracking start/end position of each row for visible items. 276 */ 277 private StaggeredGrid.Row[] mRows; 278 279 /** 280 * Saves grid information of each view. 281 */ 282 private StaggeredGrid mGrid; 283 /** 284 * Position of first item (included) that has attached views. 285 */ 286 private int mFirstVisiblePos; 287 /** 288 * Position of last item (included) that has attached views. 289 */ 290 private int mLastVisiblePos; 291 292 /** 293 * Focus Scroll strategy. 294 */ 295 private int mFocusScrollStrategy = BaseGridView.FOCUS_SCROLL_ALIGNED; 296 /** 297 * Defines how item view is aligned in the window. 298 */ 299 private final WindowAlignment mWindowAlignment = new WindowAlignment(); 300 301 /** 302 * Defines how item view is aligned. 303 */ 304 private final ItemAlignment mItemAlignment = new ItemAlignment(); 305 306 /** 307 * Dimensions of the view, width or height depending on orientation. 308 */ 309 private int mSizePrimary; 310 311 /** 312 * Allow DPAD key to navigate out at the front of the View (where position = 0), 313 * default is false. 314 */ 315 private boolean mFocusOutFront; 316 317 /** 318 * Allow DPAD key to navigate out at the end of the view, default is false. 319 */ 320 private boolean mFocusOutEnd; 321 322 /** 323 * True if focus search is disabled. 324 */ 325 private boolean mFocusSearchDisabled; 326 327 /** 328 * True if prune child, might be disabled during transition. 329 */ 330 private boolean mPruneChild = true; 331 332 /** 333 * True if scroll content, might be disabled during transition. 334 */ 335 private boolean mScrollEnabled = true; 336 337 private int[] mTempDeltas = new int[2]; 338 339 /** 340 * Temporaries used for measuring. 341 */ 342 private int[] mMeasuredDimension = new int[2]; 343 344 public GridLayoutManager(BaseGridView baseGridView) { 345 mBaseGridView = baseGridView; 346 } 347 348 public void setOrientation(int orientation) { 349 if (orientation != HORIZONTAL && orientation != VERTICAL) { 350 if (DEBUG) Log.v(getTag(), "invalid orientation: " + orientation); 351 return; 352 } 353 354 mOrientation = orientation; 355 mWindowAlignment.setOrientation(orientation); 356 mItemAlignment.setOrientation(orientation); 357 mForceFullLayout = true; 358 } 359 360 public int getFocusScrollStrategy() { 361 return mFocusScrollStrategy; 362 } 363 364 public void setFocusScrollStrategy(int focusScrollStrategy) { 365 mFocusScrollStrategy = focusScrollStrategy; 366 } 367 368 public void setWindowAlignment(int windowAlignment) { 369 mWindowAlignment.mainAxis().setWindowAlignment(windowAlignment); 370 } 371 372 public int getWindowAlignment() { 373 return mWindowAlignment.mainAxis().getWindowAlignment(); 374 } 375 376 public void setWindowAlignmentOffset(int alignmentOffset) { 377 mWindowAlignment.mainAxis().setWindowAlignmentOffset(alignmentOffset); 378 } 379 380 public int getWindowAlignmentOffset() { 381 return mWindowAlignment.mainAxis().getWindowAlignmentOffset(); 382 } 383 384 public void setWindowAlignmentOffsetPercent(float offsetPercent) { 385 mWindowAlignment.mainAxis().setWindowAlignmentOffsetPercent(offsetPercent); 386 } 387 388 public float getWindowAlignmentOffsetPercent() { 389 return mWindowAlignment.mainAxis().getWindowAlignmentOffsetPercent(); 390 } 391 392 public void setItemAlignmentOffset(int alignmentOffset) { 393 mItemAlignment.mainAxis().setItemAlignmentOffset(alignmentOffset); 394 updateChildAlignments(); 395 } 396 397 public int getItemAlignmentOffset() { 398 return mItemAlignment.mainAxis().getItemAlignmentOffset(); 399 } 400 401 public void setItemAlignmentOffsetWithPadding(boolean withPadding) { 402 mItemAlignment.mainAxis().setItemAlignmentOffsetWithPadding(withPadding); 403 updateChildAlignments(); 404 } 405 406 public boolean isItemAlignmentOffsetWithPadding() { 407 return mItemAlignment.mainAxis().isItemAlignmentOffsetWithPadding(); 408 } 409 410 public void setItemAlignmentOffsetPercent(float offsetPercent) { 411 mItemAlignment.mainAxis().setItemAlignmentOffsetPercent(offsetPercent); 412 updateChildAlignments(); 413 } 414 415 public float getItemAlignmentOffsetPercent() { 416 return mItemAlignment.mainAxis().getItemAlignmentOffsetPercent(); 417 } 418 419 public void setItemAlignmentViewId(int viewId) { 420 mItemAlignment.mainAxis().setItemAlignmentViewId(viewId); 421 updateChildAlignments(); 422 } 423 424 public int getItemAlignmentViewId() { 425 return mItemAlignment.mainAxis().getItemAlignmentViewId(); 426 } 427 428 public void setFocusOutAllowed(boolean throughFront, boolean throughEnd) { 429 mFocusOutFront = throughFront; 430 mFocusOutEnd = throughEnd; 431 } 432 433 public void setNumRows(int numRows) { 434 if (numRows < 0) throw new IllegalArgumentException(); 435 mNumRowsRequested = numRows; 436 mForceFullLayout = true; 437 } 438 439 /** 440 * Set the row height. May be WRAP_CONTENT, or a size in pixels. 441 */ 442 public void setRowHeight(int height) { 443 if (height >= 0 || height == ViewGroup.LayoutParams.WRAP_CONTENT) { 444 mRowSizeSecondaryRequested = height; 445 } else { 446 throw new IllegalArgumentException("Invalid row height: " + height); 447 } 448 } 449 450 public void setItemMargin(int margin) { 451 mVerticalMargin = mHorizontalMargin = margin; 452 mMarginPrimary = mMarginSecondary = margin; 453 } 454 455 public void setVerticalMargin(int margin) { 456 if (mOrientation == HORIZONTAL) { 457 mMarginSecondary = mVerticalMargin = margin; 458 } else { 459 mMarginPrimary = mVerticalMargin = margin; 460 } 461 } 462 463 public void setHorizontalMargin(int margin) { 464 if (mOrientation == HORIZONTAL) { 465 mMarginPrimary = mHorizontalMargin = margin; 466 } else { 467 mMarginSecondary = mHorizontalMargin = margin; 468 } 469 } 470 471 public int getVerticalMargin() { 472 return mVerticalMargin; 473 } 474 475 public int getHorizontalMargin() { 476 return mHorizontalMargin; 477 } 478 479 public void setGravity(int gravity) { 480 mGravity = gravity; 481 } 482 483 protected boolean hasDoneFirstLayout() { 484 return mGrid != null; 485 } 486 487 public void setOnChildSelectedListener(OnChildSelectedListener listener) { 488 mChildSelectedListener = listener; 489 } 490 491 private int getPositionByView(View view) { 492 if (view == null) { 493 return NO_POSITION; 494 } 495 LayoutParams params = (LayoutParams) view.getLayoutParams(); 496 if (params == null || params.isItemRemoved()) { 497 // when item is removed, the position value can be any value. 498 return NO_POSITION; 499 } 500 return params.getViewPosition(); 501 } 502 503 private int getPositionByIndex(int index) { 504 return getPositionByView(getChildAt(index)); 505 } 506 507 private void dispatchChildSelected() { 508 if (mChildSelectedListener == null) { 509 return; 510 } 511 if (mFocusPosition != NO_POSITION) { 512 View view = findViewByPosition(mFocusPosition); 513 if (view != null) { 514 RecyclerView.ViewHolder vh = mBaseGridView.getChildViewHolder(view); 515 mChildSelectedListener.onChildSelected(mBaseGridView, view, mFocusPosition, 516 vh == null? NO_ID: vh.getItemId()); 517 return; 518 } 519 } 520 mChildSelectedListener.onChildSelected(mBaseGridView, null, NO_POSITION, NO_ID); 521 } 522 523 @Override 524 public boolean canScrollHorizontally() { 525 // We can scroll horizontally if we have horizontal orientation, or if 526 // we are vertical and have more than one column. 527 return mOrientation == HORIZONTAL || mNumRows > 1; 528 } 529 530 @Override 531 public boolean canScrollVertically() { 532 // We can scroll vertically if we have vertical orientation, or if we 533 // are horizontal and have more than one row. 534 return mOrientation == VERTICAL || mNumRows > 1; 535 } 536 537 @Override 538 public RecyclerView.LayoutParams generateDefaultLayoutParams() { 539 return new LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, 540 ViewGroup.LayoutParams.WRAP_CONTENT); 541 } 542 543 @Override 544 public RecyclerView.LayoutParams generateLayoutParams(Context context, AttributeSet attrs) { 545 return new LayoutParams(context, attrs); 546 } 547 548 @Override 549 public RecyclerView.LayoutParams generateLayoutParams(ViewGroup.LayoutParams lp) { 550 if (lp instanceof LayoutParams) { 551 return new LayoutParams((LayoutParams) lp); 552 } else if (lp instanceof RecyclerView.LayoutParams) { 553 return new LayoutParams((RecyclerView.LayoutParams) lp); 554 } else if (lp instanceof MarginLayoutParams) { 555 return new LayoutParams((MarginLayoutParams) lp); 556 } else { 557 return new LayoutParams(lp); 558 } 559 } 560 561 protected View getViewForPosition(int position) { 562 return mRecycler.getViewForPosition(position); 563 } 564 565 final int getOpticalLeft(View v) { 566 return ((LayoutParams) v.getLayoutParams()).getOpticalLeft(v); 567 } 568 569 final int getOpticalRight(View v) { 570 return ((LayoutParams) v.getLayoutParams()).getOpticalRight(v); 571 } 572 573 final int getOpticalTop(View v) { 574 return ((LayoutParams) v.getLayoutParams()).getOpticalTop(v); 575 } 576 577 final int getOpticalBottom(View v) { 578 return ((LayoutParams) v.getLayoutParams()).getOpticalBottom(v); 579 } 580 581 private int getViewMin(View v) { 582 return (mOrientation == HORIZONTAL) ? getOpticalLeft(v) : getOpticalTop(v); 583 } 584 585 private int getViewMax(View v) { 586 return (mOrientation == HORIZONTAL) ? getOpticalRight(v) : getOpticalBottom(v); 587 } 588 589 private int getViewCenter(View view) { 590 return (mOrientation == HORIZONTAL) ? getViewCenterX(view) : getViewCenterY(view); 591 } 592 593 private int getViewCenterSecondary(View view) { 594 return (mOrientation == HORIZONTAL) ? getViewCenterY(view) : getViewCenterX(view); 595 } 596 597 private int getViewCenterX(View v) { 598 LayoutParams p = (LayoutParams) v.getLayoutParams(); 599 return p.getOpticalLeft(v) + p.getAlignX(); 600 } 601 602 private int getViewCenterY(View v) { 603 LayoutParams p = (LayoutParams) v.getLayoutParams(); 604 return p.getOpticalTop(v) + p.getAlignY(); 605 } 606 607 /** 608 * Save Recycler and State for convenience. Must be paired with leaveContext(). 609 */ 610 private void saveContext(Recycler recycler, State state) { 611 if (mRecycler != null || mState != null) { 612 Log.e(TAG, "Recycler information was not released, bug!"); 613 } 614 mRecycler = recycler; 615 mState = state; 616 } 617 618 /** 619 * Discard saved Recycler and State. 620 */ 621 private void leaveContext() { 622 mRecycler = null; 623 mState = null; 624 } 625 626 /** 627 * Re-initialize data structures for a data change or handling invisible 628 * selection. The method tries its best to preserve position information so 629 * that staggered grid looks same before and after re-initialize. 630 * @param focusPosition The initial focusPosition that we would like to 631 * focus on. 632 * @return Actual position that can be focused on. 633 */ 634 private int init(int focusPosition) { 635 636 final int newItemCount = mState.getItemCount(); 637 638 if (focusPosition == NO_POSITION && newItemCount > 0) { 639 // if focus position is never set before, initialize it to 0 640 focusPosition = 0; 641 } 642 // If adapter has changed then caches are invalid; otherwise, 643 // we try to maintain each row's position if number of rows keeps the same 644 // and existing mGrid contains the focusPosition. 645 if (mRows != null && mNumRows == mRows.length && 646 mGrid != null && mGrid.getSize() > 0 && focusPosition >= 0 && 647 focusPosition >= mGrid.getFirstIndex() && 648 focusPosition <= mGrid.getLastIndex()) { 649 // strip mGrid to a subset (like a column) that contains focusPosition 650 mGrid.stripDownTo(focusPosition); 651 // make sure that remaining items do not exceed new adapter size 652 int firstIndex = mGrid.getFirstIndex(); 653 int lastIndex = mGrid.getLastIndex(); 654 if (DEBUG) { 655 Log .v(getTag(), "mGrid firstIndex " + firstIndex + " lastIndex " + lastIndex); 656 } 657 for (int i = lastIndex; i >=firstIndex; i--) { 658 if (i >= newItemCount) { 659 mGrid.removeLast(); 660 } 661 } 662 if (mGrid.getSize() == 0) { 663 focusPosition = newItemCount - 1; 664 // initialize row start locations 665 for (int i = 0; i < mNumRows; i++) { 666 mRows[i].low = 0; 667 mRows[i].high = 0; 668 } 669 if (DEBUG) Log.v(getTag(), "mGrid zero size"); 670 } else { 671 // initialize row start locations 672 for (int i = 0; i < mNumRows; i++) { 673 mRows[i].low = Integer.MAX_VALUE; 674 mRows[i].high = Integer.MIN_VALUE; 675 } 676 firstIndex = mGrid.getFirstIndex(); 677 lastIndex = mGrid.getLastIndex(); 678 if (focusPosition > lastIndex) { 679 focusPosition = mGrid.getLastIndex(); 680 } 681 if (DEBUG) { 682 Log.v(getTag(), "mGrid firstIndex " + firstIndex + " lastIndex " 683 + lastIndex + " focusPosition " + focusPosition); 684 } 685 // fill rows with minimal view positions of the subset 686 for (int i = firstIndex; i <= lastIndex; i++) { 687 View v = findViewByPosition(i); 688 if (v == null) { 689 continue; 690 } 691 int row = mGrid.getLocation(i).row; 692 int low = getViewMin(v) + mScrollOffsetPrimary; 693 if (low < mRows[row].low) { 694 mRows[row].low = mRows[row].high = low; 695 } 696 } 697 int firstItemRowPosition = mRows[mGrid.getLocation(firstIndex).row].low; 698 if (firstItemRowPosition == Integer.MAX_VALUE) { 699 firstItemRowPosition = 0; 700 } 701 if (mState.didStructureChange()) { 702 // if there is structure change, the removed item might be in the 703 // subset, so it is meaningless to maintain the low locations. 704 for (int i = 0; i < mNumRows; i++) { 705 mRows[i].low = firstItemRowPosition; 706 mRows[i].high = firstItemRowPosition; 707 } 708 } else { 709 // fill other rows that does not include the subset using first item 710 for (int i = 0; i < mNumRows; i++) { 711 if (mRows[i].low == Integer.MAX_VALUE) { 712 mRows[i].low = mRows[i].high = firstItemRowPosition; 713 } 714 } 715 } 716 } 717 718 // Same adapter, we can reuse any attached views 719 detachAndScrapAttachedViews(mRecycler); 720 721 } else { 722 // otherwise recreate data structure 723 mRows = new StaggeredGrid.Row[mNumRows]; 724 725 for (int i = 0; i < mNumRows; i++) { 726 mRows[i] = new StaggeredGrid.Row(); 727 } 728 mGrid = new StaggeredGridDefault(); 729 if (newItemCount == 0) { 730 focusPosition = NO_POSITION; 731 } else if (focusPosition >= newItemCount) { 732 focusPosition = newItemCount - 1; 733 } 734 735 // Adapter may have changed so remove all attached views permanently 736 removeAndRecycleAllViews(mRecycler); 737 738 mScrollOffsetPrimary = 0; 739 mScrollOffsetSecondary = 0; 740 mWindowAlignment.reset(); 741 } 742 743 mGrid.setProvider(mGridProvider); 744 // mGrid share the same Row array information 745 mGrid.setRows(mRows); 746 mFirstVisiblePos = mLastVisiblePos = NO_POSITION; 747 748 initScrollController(); 749 updateScrollSecondAxis(); 750 751 return focusPosition; 752 } 753 754 private int getRowSizeSecondary(int rowIndex) { 755 if (mFixedRowSizeSecondary != 0) { 756 return mFixedRowSizeSecondary; 757 } 758 if (mRowSizeSecondary == null) { 759 return 0; 760 } 761 return mRowSizeSecondary[rowIndex]; 762 } 763 764 private int getRowStartSecondary(int rowIndex) { 765 int start = 0; 766 for (int i = 0; i < rowIndex; i++) { 767 start += getRowSizeSecondary(i) + mMarginSecondary; 768 } 769 return start; 770 } 771 772 private int getSizeSecondary() { 773 return getRowStartSecondary(mNumRows - 1) + getRowSizeSecondary(mNumRows - 1); 774 } 775 776 private void measureScrapChild(int position, int widthSpec, int heightSpec, 777 int[] measuredDimension) { 778 View view = mRecycler.getViewForPosition(position); 779 if (view != null) { 780 LayoutParams p = (LayoutParams) view.getLayoutParams(); 781 int childWidthSpec = ViewGroup.getChildMeasureSpec(widthSpec, 782 getPaddingLeft() + getPaddingRight(), p.width); 783 int childHeightSpec = ViewGroup.getChildMeasureSpec(heightSpec, 784 getPaddingTop() + getPaddingBottom(), p.height); 785 view.measure(childWidthSpec, childHeightSpec); 786 measuredDimension[0] = view.getMeasuredWidth(); 787 measuredDimension[1] = view.getMeasuredHeight(); 788 mRecycler.recycleView(view); 789 } 790 } 791 792 private boolean processRowSizeSecondary(boolean measure) { 793 if (mFixedRowSizeSecondary != 0) { 794 return false; 795 } 796 797 List<Integer>[] rows = mGrid == null ? null : 798 mGrid.getItemPositionsInRows(mFirstVisiblePos, mLastVisiblePos); 799 boolean changed = false; 800 int scrapChildWidth = -1; 801 int scrapChildHeight = -1; 802 803 for (int rowIndex = 0; rowIndex < mNumRows; rowIndex++) { 804 final int rowItemCount = rows == null ? 0 : rows[rowIndex].size(); 805 if (DEBUG) Log.v(getTag(), "processRowSizeSecondary row " + rowIndex + 806 " rowItemCount " + rowItemCount); 807 808 int rowSize = -1; 809 for (int i = 0; i < rowItemCount; i++) { 810 final View view = findViewByPosition(rows[rowIndex].get(i)); 811 if (view == null) { 812 continue; 813 } 814 if (measure && view.isLayoutRequested()) { 815 measureChild(view); 816 } 817 final int secondarySize = mOrientation == HORIZONTAL ? 818 view.getMeasuredHeight() : view.getMeasuredWidth(); 819 if (secondarySize > rowSize) { 820 rowSize = secondarySize; 821 } 822 } 823 824 if (measure && rowSize < 0 && mState.getItemCount() > 0) { 825 if (scrapChildWidth < 0 && scrapChildHeight < 0) { 826 measureScrapChild(mFocusPosition == NO_POSITION ? 0 : mFocusPosition, 827 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 828 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 829 mMeasuredDimension); 830 scrapChildWidth = mMeasuredDimension[0]; 831 scrapChildHeight = mMeasuredDimension[1]; 832 if (DEBUG) Log.v(TAG, "measured scrap child: " + scrapChildWidth + 833 " " + scrapChildHeight); 834 } 835 rowSize = mOrientation == HORIZONTAL ? scrapChildHeight : scrapChildWidth; 836 } 837 838 if (rowSize < 0) { 839 rowSize = 0; 840 } 841 842 if (DEBUG) Log.v(getTag(), "row " + rowIndex + " rowItemCount " + rowItemCount + 843 " rowSize " + rowSize); 844 845 if (mRowSizeSecondary[rowIndex] != rowSize) { 846 if (DEBUG) Log.v(getTag(), "row size secondary changed: " + mRowSizeSecondary[rowIndex] + 847 ", " + rowSize); 848 849 mRowSizeSecondary[rowIndex] = rowSize; 850 changed = true; 851 } 852 } 853 854 return changed; 855 } 856 857 /** 858 * Checks if we need to update row secondary sizes. 859 */ 860 private void updateRowSecondarySizeRefresh() { 861 mRowSecondarySizeRefresh = processRowSizeSecondary(false); 862 if (mRowSecondarySizeRefresh) { 863 if (DEBUG) Log.v(getTag(), "mRowSecondarySizeRefresh now set"); 864 forceRequestLayout(); 865 } 866 } 867 868 private void forceRequestLayout() { 869 if (DEBUG) Log.v(getTag(), "forceRequestLayout"); 870 // RecyclerView prevents us from requesting layout in many cases 871 // (during layout, during scroll, etc.) 872 // For secondary row size wrap_content support we currently need a 873 // second layout pass to update the measured size after having measured 874 // and added child views in layoutChildren. 875 // Force the second layout by posting a delayed runnable. 876 // TODO: investigate allowing a second layout pass, 877 // or move child add/measure logic to the measure phase. 878 ViewCompat.postOnAnimation(mBaseGridView, mRequestLayoutRunnable); 879 } 880 881 private final Runnable mRequestLayoutRunnable = new Runnable() { 882 @Override 883 public void run() { 884 if (DEBUG) Log.v(getTag(), "request Layout from runnable"); 885 requestLayout(); 886 } 887 }; 888 889 @Override 890 public void onMeasure(Recycler recycler, State state, int widthSpec, int heightSpec) { 891 saveContext(recycler, state); 892 893 int sizePrimary, sizeSecondary, modeSecondary, paddingSecondary; 894 int measuredSizeSecondary; 895 if (mOrientation == HORIZONTAL) { 896 sizePrimary = MeasureSpec.getSize(widthSpec); 897 sizeSecondary = MeasureSpec.getSize(heightSpec); 898 modeSecondary = MeasureSpec.getMode(heightSpec); 899 paddingSecondary = getPaddingTop() + getPaddingBottom(); 900 } else { 901 sizeSecondary = MeasureSpec.getSize(widthSpec); 902 sizePrimary = MeasureSpec.getSize(heightSpec); 903 modeSecondary = MeasureSpec.getMode(widthSpec); 904 paddingSecondary = getPaddingLeft() + getPaddingRight(); 905 } 906 if (DEBUG) Log.v(getTag(), "onMeasure widthSpec " + Integer.toHexString(widthSpec) + 907 " heightSpec " + Integer.toHexString(heightSpec) + 908 " modeSecondary " + Integer.toHexString(modeSecondary) + 909 " sizeSecondary " + sizeSecondary + " " + this); 910 911 mMaxSizeSecondary = sizeSecondary; 912 913 if (mRowSizeSecondaryRequested == ViewGroup.LayoutParams.WRAP_CONTENT) { 914 mNumRows = mNumRowsRequested == 0 ? 1 : mNumRowsRequested; 915 mFixedRowSizeSecondary = 0; 916 917 if (mRowSizeSecondary == null || mRowSizeSecondary.length != mNumRows) { 918 mRowSizeSecondary = new int[mNumRows]; 919 } 920 921 // Measure all current children and update cached row heights 922 processRowSizeSecondary(true); 923 924 switch (modeSecondary) { 925 case MeasureSpec.UNSPECIFIED: 926 measuredSizeSecondary = getSizeSecondary() + paddingSecondary; 927 break; 928 case MeasureSpec.AT_MOST: 929 measuredSizeSecondary = Math.min(getSizeSecondary() + paddingSecondary, 930 mMaxSizeSecondary); 931 break; 932 case MeasureSpec.EXACTLY: 933 measuredSizeSecondary = mMaxSizeSecondary; 934 break; 935 default: 936 throw new IllegalStateException("wrong spec"); 937 } 938 939 } else { 940 switch (modeSecondary) { 941 case MeasureSpec.UNSPECIFIED: 942 if (mRowSizeSecondaryRequested == 0) { 943 if (mOrientation == HORIZONTAL) { 944 throw new IllegalStateException("Must specify rowHeight or view height"); 945 } else { 946 throw new IllegalStateException("Must specify columnWidth or view width"); 947 } 948 } 949 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 950 mNumRows = mNumRowsRequested == 0 ? 1 : mNumRowsRequested; 951 measuredSizeSecondary = mFixedRowSizeSecondary * mNumRows + mMarginSecondary 952 * (mNumRows - 1) + paddingSecondary; 953 break; 954 case MeasureSpec.AT_MOST: 955 case MeasureSpec.EXACTLY: 956 if (mNumRowsRequested == 0 && mRowSizeSecondaryRequested == 0) { 957 mNumRows = 1; 958 mFixedRowSizeSecondary = sizeSecondary - paddingSecondary; 959 } else if (mNumRowsRequested == 0) { 960 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 961 mNumRows = (sizeSecondary + mMarginSecondary) 962 / (mRowSizeSecondaryRequested + mMarginSecondary); 963 } else if (mRowSizeSecondaryRequested == 0) { 964 mNumRows = mNumRowsRequested; 965 mFixedRowSizeSecondary = (sizeSecondary - paddingSecondary - mMarginSecondary 966 * (mNumRows - 1)) / mNumRows; 967 } else { 968 mNumRows = mNumRowsRequested; 969 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 970 } 971 measuredSizeSecondary = sizeSecondary; 972 if (modeSecondary == MeasureSpec.AT_MOST) { 973 int childrenSize = mFixedRowSizeSecondary * mNumRows + mMarginSecondary 974 * (mNumRows - 1) + paddingSecondary; 975 if (childrenSize < measuredSizeSecondary) { 976 measuredSizeSecondary = childrenSize; 977 } 978 } 979 break; 980 default: 981 throw new IllegalStateException("wrong spec"); 982 } 983 } 984 if (mOrientation == HORIZONTAL) { 985 setMeasuredDimension(sizePrimary, measuredSizeSecondary); 986 } else { 987 setMeasuredDimension(measuredSizeSecondary, sizePrimary); 988 } 989 if (DEBUG) { 990 Log.v(getTag(), "onMeasure sizePrimary " + sizePrimary + 991 " measuredSizeSecondary " + measuredSizeSecondary + 992 " mFixedRowSizeSecondary " + mFixedRowSizeSecondary + 993 " mNumRows " + mNumRows); 994 } 995 996 leaveContext(); 997 } 998 999 private void measureChild(View child) { 1000 final ViewGroup.LayoutParams lp = child.getLayoutParams(); 1001 final int secondarySpec = (mRowSizeSecondaryRequested == ViewGroup.LayoutParams.WRAP_CONTENT) ? 1002 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED) : 1003 MeasureSpec.makeMeasureSpec(mFixedRowSizeSecondary, MeasureSpec.EXACTLY); 1004 int widthSpec, heightSpec; 1005 1006 if (mOrientation == HORIZONTAL) { 1007 widthSpec = ViewGroup.getChildMeasureSpec( 1008 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 1009 0, lp.width); 1010 heightSpec = ViewGroup.getChildMeasureSpec(secondarySpec, 0, lp.height); 1011 } else { 1012 heightSpec = ViewGroup.getChildMeasureSpec( 1013 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 1014 0, lp.height); 1015 widthSpec = ViewGroup.getChildMeasureSpec(secondarySpec, 0, lp.width); 1016 } 1017 1018 child.measure(widthSpec, heightSpec); 1019 1020 if (DEBUG) Log.v(getTag(), "measureChild secondarySpec " + Integer.toHexString(secondarySpec) + 1021 " widthSpec " + Integer.toHexString(widthSpec) + 1022 " heightSpec " + Integer.toHexString(heightSpec) + 1023 " measuredWidth " + child.getMeasuredWidth() + 1024 " measuredHeight " + child.getMeasuredHeight()); 1025 if (DEBUG) Log.v(getTag(), "child lp width " + lp.width + " height " + lp.height); 1026 } 1027 1028 private StaggeredGrid.Provider mGridProvider = new StaggeredGrid.Provider() { 1029 1030 @Override 1031 public int getCount() { 1032 return mState.getItemCount(); 1033 } 1034 1035 @Override 1036 public void createItem(int index, int rowIndex, boolean append) { 1037 View v = getViewForPosition(index); 1038 if (mFirstVisiblePos >= 0) { 1039 // when StaggeredGrid append or prepend item, we must guarantee 1040 // that sibling item has created views already. 1041 if (append && index != mLastVisiblePos + 1) { 1042 throw new RuntimeException(); 1043 } else if (!append && index != mFirstVisiblePos - 1) { 1044 throw new RuntimeException(); 1045 } 1046 } 1047 1048 // See recyclerView docs: we don't need re-add scraped view if it was removed. 1049 if (!((RecyclerView.LayoutParams) v.getLayoutParams()).isItemRemoved()) { 1050 if (append) { 1051 addView(v); 1052 } else { 1053 addView(v, 0); 1054 } 1055 measureChild(v); 1056 } 1057 1058 int length = mOrientation == HORIZONTAL ? v.getMeasuredWidth() : v.getMeasuredHeight(); 1059 int start, end; 1060 if (append) { 1061 start = mRows[rowIndex].high; 1062 if (start != mRows[rowIndex].low) { 1063 // if there are existing item in the row, add margin between 1064 start += mMarginPrimary; 1065 } else { 1066 final int lastRow = mRows.length - 1; 1067 if (lastRow != rowIndex && mRows[lastRow].high != mRows[lastRow].low) { 1068 // if there are existing item in the last row, insert 1069 // the new item after the last item of last row. 1070 start = mRows[lastRow].high + mMarginPrimary; 1071 } 1072 } 1073 end = start + length; 1074 mRows[rowIndex].high = end; 1075 } else { 1076 end = mRows[rowIndex].low; 1077 if (end != mRows[rowIndex].high) { 1078 end -= mMarginPrimary; 1079 } else if (0 != rowIndex && mRows[0].high != mRows[0].low) { 1080 // if there are existing item in the first row, insert 1081 // the new item before the first item of first row. 1082 end = mRows[0].low - mMarginPrimary; 1083 } 1084 start = end - length; 1085 mRows[rowIndex].low = start; 1086 } 1087 if (mFirstVisiblePos < 0) { 1088 mFirstVisiblePos = mLastVisiblePos = index; 1089 } else { 1090 if (append) { 1091 mLastVisiblePos++; 1092 } else { 1093 mFirstVisiblePos--; 1094 } 1095 } 1096 if (DEBUG) Log.v(getTag(), "start " + start + " end " + end); 1097 int startSecondary = getRowStartSecondary(rowIndex) - mScrollOffsetSecondary; 1098 layoutChild(rowIndex, v, start - mScrollOffsetPrimary, end - mScrollOffsetPrimary, 1099 startSecondary); 1100 if (DEBUG) { 1101 Log.d(getTag(), "addView " + index + " " + v); 1102 } 1103 if (index == mFirstVisiblePos) { 1104 updateScrollMin(); 1105 } 1106 if (index == mLastVisiblePos) { 1107 updateScrollMax(); 1108 } 1109 } 1110 }; 1111 1112 private void layoutChild(int rowIndex, View v, int start, int end, int startSecondary) { 1113 int sizeSecondary = mOrientation == HORIZONTAL ? v.getMeasuredHeight() 1114 : v.getMeasuredWidth(); 1115 if (mFixedRowSizeSecondary > 0) { 1116 sizeSecondary = Math.min(sizeSecondary, mFixedRowSizeSecondary); 1117 } 1118 final int verticalGravity = mGravity & Gravity.VERTICAL_GRAVITY_MASK; 1119 final int horizontalGravity = mGravity & Gravity.HORIZONTAL_GRAVITY_MASK; 1120 if (mOrientation == HORIZONTAL && verticalGravity == Gravity.TOP 1121 || mOrientation == VERTICAL && horizontalGravity == Gravity.LEFT) { 1122 // do nothing 1123 } else if (mOrientation == HORIZONTAL && verticalGravity == Gravity.BOTTOM 1124 || mOrientation == VERTICAL && horizontalGravity == Gravity.RIGHT) { 1125 startSecondary += getRowSizeSecondary(rowIndex) - sizeSecondary; 1126 } else if (mOrientation == HORIZONTAL && verticalGravity == Gravity.CENTER_VERTICAL 1127 || mOrientation == VERTICAL && horizontalGravity == Gravity.CENTER_HORIZONTAL) { 1128 startSecondary += (getRowSizeSecondary(rowIndex) - sizeSecondary) / 2; 1129 } 1130 int left, top, right, bottom; 1131 if (mOrientation == HORIZONTAL) { 1132 left = start; 1133 top = startSecondary; 1134 right = end; 1135 bottom = startSecondary + sizeSecondary; 1136 } else { 1137 top = start; 1138 left = startSecondary; 1139 bottom = end; 1140 right = startSecondary + sizeSecondary; 1141 } 1142 v.layout(left, top, right, bottom); 1143 updateChildOpticalInsets(v, left, top, right, bottom); 1144 updateChildAlignments(v); 1145 } 1146 1147 private void updateChildOpticalInsets(View v, int left, int top, int right, int bottom) { 1148 LayoutParams p = (LayoutParams) v.getLayoutParams(); 1149 p.setOpticalInsets(left - v.getLeft(), top - v.getTop(), 1150 v.getRight() - right, v.getBottom() - bottom); 1151 } 1152 1153 private void updateChildAlignments(View v) { 1154 LayoutParams p = (LayoutParams) v.getLayoutParams(); 1155 p.setAlignX(mItemAlignment.horizontal.getAlignmentPosition(v)); 1156 p.setAlignY(mItemAlignment.vertical.getAlignmentPosition(v)); 1157 } 1158 1159 private void updateChildAlignments() { 1160 for (int i = 0, c = getChildCount(); i < c; i++) { 1161 updateChildAlignments(getChildAt(i)); 1162 } 1163 } 1164 1165 private boolean needsAppendVisibleItem() { 1166 if (mLastVisiblePos < mFocusPosition) { 1167 return true; 1168 } 1169 int right = mScrollOffsetPrimary + mSizePrimary; 1170 for (int i = 0; i < mNumRows; i++) { 1171 if (mRows[i].low == mRows[i].high) { 1172 if (mRows[i].high < right) { 1173 return true; 1174 } 1175 } else if (mRows[i].high < right - mMarginPrimary) { 1176 return true; 1177 } 1178 } 1179 return false; 1180 } 1181 1182 private boolean needsPrependVisibleItem() { 1183 if (mFirstVisiblePos > mFocusPosition) { 1184 return true; 1185 } 1186 for (int i = 0; i < mNumRows; i++) { 1187 if (mRows[i].low == mRows[i].high) { 1188 if (mRows[i].low > mScrollOffsetPrimary) { 1189 return true; 1190 } 1191 } else if (mRows[i].low - mMarginPrimary > mScrollOffsetPrimary) { 1192 return true; 1193 } 1194 } 1195 return false; 1196 } 1197 1198 // Append one column if possible and return true if reach end. 1199 private boolean appendOneVisibleItem() { 1200 while (true) { 1201 if (mLastVisiblePos != NO_POSITION && mLastVisiblePos < mState.getItemCount() -1 && 1202 mLastVisiblePos < mGrid.getLastIndex()) { 1203 // append invisible view of saved location till last row 1204 final int index = mLastVisiblePos + 1; 1205 final int row = mGrid.getLocation(index).row; 1206 mGridProvider.createItem(index, row, true); 1207 if (row == mNumRows - 1) { 1208 return false; 1209 } 1210 } else if ((mLastVisiblePos == NO_POSITION && mState.getItemCount() > 0) || 1211 (mLastVisiblePos != NO_POSITION && 1212 mLastVisiblePos < mState.getItemCount() - 1)) { 1213 mGrid.appendItems(mScrollOffsetPrimary + mSizePrimary); 1214 return false; 1215 } else { 1216 return true; 1217 } 1218 } 1219 } 1220 1221 private void appendVisibleItems() { 1222 while (needsAppendVisibleItem()) { 1223 if (appendOneVisibleItem()) { 1224 break; 1225 } 1226 } 1227 } 1228 1229 // Prepend one column if possible and return true if reach end. 1230 private boolean prependOneVisibleItem() { 1231 while (true) { 1232 if (mFirstVisiblePos > 0) { 1233 if (mFirstVisiblePos > mGrid.getFirstIndex()) { 1234 // prepend invisible view of saved location till first row 1235 final int index = mFirstVisiblePos - 1; 1236 final int row = mGrid.getLocation(index).row; 1237 mGridProvider.createItem(index, row, false); 1238 if (row == 0) { 1239 return false; 1240 } 1241 } else { 1242 mGrid.prependItems(mScrollOffsetPrimary); 1243 return false; 1244 } 1245 } else { 1246 return true; 1247 } 1248 } 1249 } 1250 1251 private void prependVisibleItems() { 1252 while (needsPrependVisibleItem()) { 1253 if (prependOneVisibleItem()) { 1254 break; 1255 } 1256 } 1257 } 1258 1259 private void removeChildAt(int position) { 1260 View v = findViewByPosition(position); 1261 if (v != null) { 1262 if (DEBUG) { 1263 Log.d(getTag(), "removeAndRecycleViewAt " + position); 1264 } 1265 removeAndRecycleView(v, mRecycler); 1266 } 1267 } 1268 1269 private void removeInvisibleViewsAtEnd() { 1270 if (!mPruneChild) { 1271 return; 1272 } 1273 boolean update = false; 1274 while(mLastVisiblePos > mFirstVisiblePos && mLastVisiblePos > mFocusPosition) { 1275 View view = findViewByPosition(mLastVisiblePos); 1276 if (getViewMin(view) > mSizePrimary) { 1277 removeChildAt(mLastVisiblePos); 1278 mLastVisiblePos--; 1279 update = true; 1280 } else { 1281 break; 1282 } 1283 } 1284 if (update) { 1285 updateRowsMinMax(); 1286 } 1287 } 1288 1289 private void removeInvisibleViewsAtFront() { 1290 if (!mPruneChild) { 1291 return; 1292 } 1293 boolean update = false; 1294 while(mLastVisiblePos > mFirstVisiblePos && mFirstVisiblePos < mFocusPosition) { 1295 View view = findViewByPosition(mFirstVisiblePos); 1296 if (getViewMax(view) < 0) { 1297 removeChildAt(mFirstVisiblePos); 1298 mFirstVisiblePos++; 1299 update = true; 1300 } else { 1301 break; 1302 } 1303 } 1304 if (update) { 1305 updateRowsMinMax(); 1306 } 1307 } 1308 1309 private void updateRowsMinMax() { 1310 if (mFirstVisiblePos < 0) { 1311 return; 1312 } 1313 for (int i = 0; i < mNumRows; i++) { 1314 mRows[i].low = Integer.MAX_VALUE; 1315 mRows[i].high = Integer.MIN_VALUE; 1316 } 1317 for (int i = mFirstVisiblePos; i <= mLastVisiblePos; i++) { 1318 View view = findViewByPosition(i); 1319 int row = mGrid.getLocation(i).row; 1320 int low = getViewMin(view) + mScrollOffsetPrimary; 1321 if (low < mRows[row].low) { 1322 mRows[row].low = low; 1323 } 1324 int high = getViewMax(view) + mScrollOffsetPrimary; 1325 if (high > mRows[row].high) { 1326 mRows[row].high = high; 1327 } 1328 } 1329 } 1330 1331 // Fast layout when there is no structure change, adapter change, etc. 1332 protected void fastRelayout(boolean scrollToFocus) { 1333 initScrollController(); 1334 1335 List<Integer>[] rows = mGrid.getItemPositionsInRows(mFirstVisiblePos, mLastVisiblePos); 1336 1337 // relayout and repositioning views on each row 1338 for (int i = 0; i < mNumRows; i++) { 1339 List<Integer> row = rows[i]; 1340 final int startSecondary = getRowStartSecondary(i) - mScrollOffsetSecondary; 1341 for (int j = 0, size = row.size(); j < size; j++) { 1342 final int position = row.get(j); 1343 final View view = findViewByPosition(position); 1344 int primaryDelta, start, end; 1345 1346 if (mOrientation == HORIZONTAL) { 1347 final int primarySize = view.getMeasuredWidth(); 1348 if (view.isLayoutRequested()) { 1349 measureChild(view); 1350 } 1351 start = getViewMin(view); 1352 end = start + view.getMeasuredWidth(); 1353 primaryDelta = view.getMeasuredWidth() - primarySize; 1354 if (primaryDelta != 0) { 1355 for (int k = j + 1; k < size; k++) { 1356 findViewByPosition(row.get(k)).offsetLeftAndRight(primaryDelta); 1357 } 1358 } 1359 } else { 1360 final int primarySize = view.getMeasuredHeight(); 1361 if (view.isLayoutRequested()) { 1362 measureChild(view); 1363 } 1364 start = getViewMin(view); 1365 end = start + view.getMeasuredHeight(); 1366 primaryDelta = view.getMeasuredHeight() - primarySize; 1367 if (primaryDelta != 0) { 1368 for (int k = j + 1; k < size; k++) { 1369 findViewByPosition(row.get(k)).offsetTopAndBottom(primaryDelta); 1370 } 1371 } 1372 } 1373 layoutChild(i, view, start, end, startSecondary); 1374 } 1375 } 1376 1377 updateRowsMinMax(); 1378 appendVisibleItems(); 1379 prependVisibleItems(); 1380 1381 updateRowsMinMax(); 1382 updateScrollMin(); 1383 updateScrollMax(); 1384 updateScrollSecondAxis(); 1385 1386 if (scrollToFocus) { 1387 View focusView = findViewByPosition(mFocusPosition == NO_POSITION ? 0 : mFocusPosition); 1388 scrollToView(focusView, false); 1389 } 1390 } 1391 1392 public void removeAndRecycleAllViews(RecyclerView.Recycler recycler) { 1393 if (DEBUG) Log.v(TAG, "removeAndRecycleAllViews " + getChildCount()); 1394 for (int i = getChildCount() - 1; i >= 0; i--) { 1395 removeAndRecycleViewAt(i, recycler); 1396 } 1397 } 1398 1399 // Lays out items based on the current scroll position 1400 @Override 1401 public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state) { 1402 if (DEBUG) { 1403 Log.v(getTag(), "layoutChildren start numRows " + mNumRows + " mScrollOffsetSecondary " 1404 + mScrollOffsetSecondary + " mScrollOffsetPrimary " + mScrollOffsetPrimary 1405 + " inPreLayout " + state.isPreLayout() 1406 + " didStructureChange " + state.didStructureChange() 1407 + " mForceFullLayout " + mForceFullLayout); 1408 Log.v(getTag(), "width " + getWidth() + " height " + getHeight()); 1409 } 1410 1411 if (mNumRows == 0) { 1412 // haven't done measure yet 1413 return; 1414 } 1415 final int itemCount = state.getItemCount(); 1416 if (itemCount < 0) { 1417 return; 1418 } 1419 1420 if (!mLayoutEnabled) { 1421 discardLayoutInfo(); 1422 removeAndRecycleAllViews(recycler); 1423 return; 1424 } 1425 mInLayout = true; 1426 1427 final boolean scrollToFocus = !isSmoothScrolling() 1428 && mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED; 1429 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE) { 1430 mFocusPosition = mFocusPosition + mFocusPositionOffset; 1431 mFocusPositionOffset = 0; 1432 } 1433 saveContext(recycler, state); 1434 // Track the old focus view so we can adjust our system scroll position 1435 // so that any scroll animations happening now will remain valid. 1436 // We must use same delta in Pre Layout (if prelayout exists) and second layout. 1437 // So we cache the deltas in PreLayout and use it in second layout. 1438 int delta = 0, deltaSecondary = 0; 1439 if (mFocusPosition != NO_POSITION && scrollToFocus) { 1440 // FIXME: we should get the remaining scroll animation offset from RecyclerView 1441 View focusView = findViewByPosition(mFocusPosition); 1442 if (focusView != null) { 1443 delta = mWindowAlignment.mainAxis().getSystemScrollPos(mScrollOffsetPrimary 1444 + getViewCenter(focusView), false, false) - mScrollOffsetPrimary; 1445 deltaSecondary = mWindowAlignment.secondAxis().getSystemScrollPos( 1446 mScrollOffsetSecondary + getViewCenterSecondary(focusView), 1447 false, false) - mScrollOffsetSecondary; 1448 } 1449 } 1450 1451 final boolean hasDoneFirstLayout = hasDoneFirstLayout(); 1452 int savedFocusPos = mFocusPosition; 1453 boolean fastRelayout = false; 1454 if (!mState.didStructureChange() && !mForceFullLayout && hasDoneFirstLayout) { 1455 fastRelayout = true; 1456 fastRelayout(scrollToFocus); 1457 } else { 1458 boolean hadFocus = mBaseGridView.hasFocus(); 1459 1460 int newFocusPosition = init(mFocusPosition); 1461 if (DEBUG) { 1462 Log.v(getTag(), "mFocusPosition " + mFocusPosition + " newFocusPosition " 1463 + newFocusPosition); 1464 } 1465 1466 // depending on result of init(), either recreating everything 1467 // or try to reuse the row start positions near mFocusPosition 1468 if (mGrid.getSize() == 0) { 1469 // this is a fresh creating all items, starting from 1470 // mFocusPosition with a estimated row index. 1471 mGrid.setStart(newFocusPosition, StaggeredGrid.START_DEFAULT); 1472 1473 // Can't track the old focus view 1474 delta = deltaSecondary = 0; 1475 1476 } else { 1477 // mGrid remembers Locations for the column that 1478 // contains mFocusePosition and also mRows remembers start 1479 // positions of each row. 1480 // Manually re-create child views for that column 1481 int firstIndex = mGrid.getFirstIndex(); 1482 int lastIndex = mGrid.getLastIndex(); 1483 for (int i = firstIndex; i <= lastIndex; i++) { 1484 mGridProvider.createItem(i, mGrid.getLocation(i).row, true); 1485 } 1486 } 1487 // add visible views at end until reach the end of window 1488 appendVisibleItems(); 1489 // add visible views at front until reach the start of window 1490 prependVisibleItems(); 1491 // multiple rounds: scrollToView of first round may drag first/last child into 1492 // "visible window" and we update scrollMin/scrollMax then run second scrollToView 1493 int oldFirstVisible; 1494 int oldLastVisible; 1495 do { 1496 updateScrollMin(); 1497 updateScrollMax(); 1498 oldFirstVisible = mFirstVisiblePos; 1499 oldLastVisible = mLastVisiblePos; 1500 View focusView = findViewByPosition(newFocusPosition); 1501 // we need force to initialize the child view's position 1502 scrollToView(focusView, false); 1503 if (focusView != null && hadFocus) { 1504 focusView.requestFocus(); 1505 } 1506 appendVisibleItems(); 1507 prependVisibleItems(); 1508 removeInvisibleViewsAtFront(); 1509 removeInvisibleViewsAtEnd(); 1510 } while (mFirstVisiblePos != oldFirstVisible || mLastVisiblePos != oldLastVisible); 1511 } 1512 mForceFullLayout = false; 1513 1514 if (scrollToFocus) { 1515 scrollDirectionPrimary(-delta); 1516 scrollDirectionSecondary(-deltaSecondary); 1517 } 1518 appendVisibleItems(); 1519 prependVisibleItems(); 1520 removeInvisibleViewsAtFront(); 1521 removeInvisibleViewsAtEnd(); 1522 1523 if (DEBUG) { 1524 StringWriter sw = new StringWriter(); 1525 PrintWriter pw = new PrintWriter(sw); 1526 mGrid.debugPrint(pw); 1527 Log.d(getTag(), sw.toString()); 1528 } 1529 1530 if (mRowSecondarySizeRefresh) { 1531 mRowSecondarySizeRefresh = false; 1532 } else { 1533 updateRowSecondarySizeRefresh(); 1534 } 1535 1536 if (!fastRelayout || mFocusPosition != savedFocusPos) { 1537 dispatchChildSelected(); 1538 } 1539 mInLayout = false; 1540 leaveContext(); 1541 if (DEBUG) Log.v(getTag(), "layoutChildren end"); 1542 } 1543 1544 private void offsetChildrenSecondary(int increment) { 1545 final int childCount = getChildCount(); 1546 if (mOrientation == HORIZONTAL) { 1547 for (int i = 0; i < childCount; i++) { 1548 getChildAt(i).offsetTopAndBottom(increment); 1549 } 1550 } else { 1551 for (int i = 0; i < childCount; i++) { 1552 getChildAt(i).offsetLeftAndRight(increment); 1553 } 1554 } 1555 } 1556 1557 private void offsetChildrenPrimary(int increment) { 1558 final int childCount = getChildCount(); 1559 if (mOrientation == VERTICAL) { 1560 for (int i = 0; i < childCount; i++) { 1561 getChildAt(i).offsetTopAndBottom(increment); 1562 } 1563 } else { 1564 for (int i = 0; i < childCount; i++) { 1565 getChildAt(i).offsetLeftAndRight(increment); 1566 } 1567 } 1568 } 1569 1570 @Override 1571 public int scrollHorizontallyBy(int dx, Recycler recycler, RecyclerView.State state) { 1572 if (DEBUG) Log.v(getTag(), "scrollHorizontallyBy " + dx); 1573 if (!mLayoutEnabled || !hasDoneFirstLayout()) { 1574 return 0; 1575 } 1576 saveContext(recycler, state); 1577 int result; 1578 if (mOrientation == HORIZONTAL) { 1579 result = scrollDirectionPrimary(dx); 1580 } else { 1581 result = scrollDirectionSecondary(dx); 1582 } 1583 leaveContext(); 1584 return result; 1585 } 1586 1587 @Override 1588 public int scrollVerticallyBy(int dy, Recycler recycler, RecyclerView.State state) { 1589 if (DEBUG) Log.v(getTag(), "scrollVerticallyBy " + dy); 1590 if (!mLayoutEnabled || !hasDoneFirstLayout()) { 1591 return 0; 1592 } 1593 saveContext(recycler, state); 1594 int result; 1595 if (mOrientation == VERTICAL) { 1596 result = scrollDirectionPrimary(dy); 1597 } else { 1598 result = scrollDirectionSecondary(dy); 1599 } 1600 leaveContext(); 1601 return result; 1602 } 1603 1604 // scroll in main direction may add/prune views 1605 private int scrollDirectionPrimary(int da) { 1606 if (da > 0) { 1607 if (!mWindowAlignment.mainAxis().isMaxUnknown()) { 1608 int maxScroll = mWindowAlignment.mainAxis().getMaxScroll(); 1609 if (mScrollOffsetPrimary + da > maxScroll) { 1610 da = maxScroll - mScrollOffsetPrimary; 1611 } 1612 } 1613 } else if (da < 0) { 1614 if (!mWindowAlignment.mainAxis().isMinUnknown()) { 1615 int minScroll = mWindowAlignment.mainAxis().getMinScroll(); 1616 if (mScrollOffsetPrimary + da < minScroll) { 1617 da = minScroll - mScrollOffsetPrimary; 1618 } 1619 } 1620 } 1621 if (da == 0) { 1622 return 0; 1623 } 1624 offsetChildrenPrimary(-da); 1625 mScrollOffsetPrimary += da; 1626 if (mInLayout) { 1627 return da; 1628 } 1629 1630 int childCount = getChildCount(); 1631 boolean updated; 1632 1633 if (da > 0) { 1634 appendVisibleItems(); 1635 } else if (da < 0) { 1636 prependVisibleItems(); 1637 } 1638 updated = getChildCount() > childCount; 1639 childCount = getChildCount(); 1640 1641 if (da > 0) { 1642 removeInvisibleViewsAtFront(); 1643 } else if (da < 0) { 1644 removeInvisibleViewsAtEnd(); 1645 } 1646 updated |= getChildCount() < childCount; 1647 1648 if (updated) { 1649 updateRowSecondarySizeRefresh(); 1650 } 1651 1652 mBaseGridView.invalidate(); 1653 return da; 1654 } 1655 1656 // scroll in second direction will not add/prune views 1657 private int scrollDirectionSecondary(int dy) { 1658 if (dy == 0) { 1659 return 0; 1660 } 1661 offsetChildrenSecondary(-dy); 1662 mScrollOffsetSecondary += dy; 1663 mBaseGridView.invalidate(); 1664 return dy; 1665 } 1666 1667 private void updateScrollMax() { 1668 if (mLastVisiblePos < 0) { 1669 return; 1670 } 1671 final boolean lastAvailable = mLastVisiblePos == mState.getItemCount() - 1; 1672 final boolean maxUnknown = mWindowAlignment.mainAxis().isMaxUnknown(); 1673 if (!lastAvailable && maxUnknown) { 1674 return; 1675 } 1676 int maxEdge = Integer.MIN_VALUE; 1677 int rowIndex = -1; 1678 for (int i = 0; i < mRows.length; i++) { 1679 if (mRows[i].high > maxEdge) { 1680 maxEdge = mRows[i].high; 1681 rowIndex = i; 1682 } 1683 } 1684 int maxScroll = Integer.MAX_VALUE; 1685 for (int i = mLastVisiblePos; i >= mFirstVisiblePos; i--) { 1686 StaggeredGrid.Location location = mGrid.getLocation(i); 1687 if (location != null && location.row == rowIndex) { 1688 int savedMaxEdge = mWindowAlignment.mainAxis().getMaxEdge(); 1689 mWindowAlignment.mainAxis().setMaxEdge(maxEdge); 1690 maxScroll = getPrimarySystemScrollPosition(findViewByPosition(i)); 1691 mWindowAlignment.mainAxis().setMaxEdge(savedMaxEdge); 1692 break; 1693 } 1694 } 1695 if (lastAvailable) { 1696 mWindowAlignment.mainAxis().setMaxEdge(maxEdge); 1697 mWindowAlignment.mainAxis().setMaxScroll(maxScroll); 1698 if (DEBUG) Log.v(getTag(), "updating scroll maxEdge to " + maxEdge + 1699 " scrollMax to " + maxScroll); 1700 } else { 1701 // the maxScroll for currently last visible item is larger, 1702 // so we must invalidate the max scroll value. 1703 if (maxScroll > mWindowAlignment.mainAxis().getMaxScroll()) { 1704 mWindowAlignment.mainAxis().invalidateScrollMax(); 1705 if (DEBUG) Log.v(getTag(), "Invalidate scrollMax since it should be " 1706 + "greater than " + maxScroll); 1707 } 1708 } 1709 } 1710 1711 private void updateScrollMin() { 1712 if (mFirstVisiblePos < 0) { 1713 return; 1714 } 1715 final boolean firstAvailable = mFirstVisiblePos == 0; 1716 final boolean minUnknown = mWindowAlignment.mainAxis().isMinUnknown(); 1717 if (!firstAvailable && minUnknown) { 1718 return; 1719 } 1720 int minEdge = Integer.MAX_VALUE; 1721 int rowIndex = -1; 1722 for (int i = 0; i < mRows.length; i++) { 1723 if (mRows[i].low < minEdge) { 1724 minEdge = mRows[i].low; 1725 rowIndex = i; 1726 } 1727 } 1728 int minScroll = Integer.MIN_VALUE; 1729 for (int i = mFirstVisiblePos; i <= mLastVisiblePos; i++) { 1730 StaggeredGrid.Location location = mGrid.getLocation(i); 1731 if (location != null && location.row == rowIndex) { 1732 int savedMinEdge = mWindowAlignment.mainAxis().getMinEdge(); 1733 mWindowAlignment.mainAxis().setMinEdge(minEdge); 1734 minScroll = getPrimarySystemScrollPosition(findViewByPosition(i)); 1735 mWindowAlignment.mainAxis().setMinEdge(savedMinEdge); 1736 break; 1737 } 1738 } 1739 if (firstAvailable) { 1740 mWindowAlignment.mainAxis().setMinEdge(minEdge); 1741 mWindowAlignment.mainAxis().setMinScroll(minScroll); 1742 if (DEBUG) Log.v(getTag(), "updating scroll minEdge to " + minEdge + 1743 " scrollMin to " + minScroll); 1744 } else { 1745 // the minScroll for currently first visible item is smaller, 1746 // so we must invalidate the min scroll value. 1747 if (minScroll < mWindowAlignment.mainAxis().getMinScroll()) { 1748 mWindowAlignment.mainAxis().invalidateScrollMin(); 1749 if (DEBUG) Log.v(getTag(), "Invalidate scrollMin, since it should be " 1750 + "less than " + minScroll); 1751 } 1752 } 1753 } 1754 1755 private void updateScrollSecondAxis() { 1756 mWindowAlignment.secondAxis().setMinEdge(0); 1757 mWindowAlignment.secondAxis().setMaxEdge(getSizeSecondary()); 1758 } 1759 1760 private void initScrollController() { 1761 // mScrollOffsetPrimary and mScrollOffsetSecondary includes the padding. 1762 // e.g. when topPadding is 16 for horizontal grid view, the initial 1763 // mScrollOffsetSecondary is -16. fastLayout() put views based on offsets(not padding), 1764 // when padding changes to 20, we also need update mScrollOffsetSecondary to -20 before 1765 // fastLayout() is performed 1766 int paddingPrimaryDiff, paddingSecondaryDiff; 1767 if (mOrientation == HORIZONTAL) { 1768 paddingPrimaryDiff = getPaddingLeft() - mWindowAlignment.horizontal.getPaddingLow(); 1769 paddingSecondaryDiff = getPaddingTop() - mWindowAlignment.vertical.getPaddingLow(); 1770 } else { 1771 paddingPrimaryDiff = getPaddingTop() - mWindowAlignment.vertical.getPaddingLow(); 1772 paddingSecondaryDiff = getPaddingLeft() - mWindowAlignment.horizontal.getPaddingLow(); 1773 } 1774 mScrollOffsetPrimary -= paddingPrimaryDiff; 1775 mScrollOffsetSecondary -= paddingSecondaryDiff; 1776 1777 mWindowAlignment.horizontal.setSize(getWidth()); 1778 mWindowAlignment.horizontal.setPadding(getPaddingLeft(), getPaddingRight()); 1779 mWindowAlignment.vertical.setSize(getHeight()); 1780 mWindowAlignment.vertical.setPadding(getPaddingTop(), getPaddingBottom()); 1781 mSizePrimary = mWindowAlignment.mainAxis().getSize(); 1782 1783 if (DEBUG) { 1784 Log.v(getTag(), "initScrollController mSizePrimary " + mSizePrimary 1785 + " mWindowAlignment " + mWindowAlignment); 1786 } 1787 } 1788 1789 public void setSelection(RecyclerView parent, int position) { 1790 setSelection(parent, position, false); 1791 } 1792 1793 public void setSelectionSmooth(RecyclerView parent, int position) { 1794 setSelection(parent, position, true); 1795 } 1796 1797 public int getSelection() { 1798 return mFocusPosition; 1799 } 1800 1801 public void setSelection(RecyclerView parent, int position, boolean smooth) { 1802 if (mFocusPosition == position) { 1803 return; 1804 } 1805 View view = findViewByPosition(position); 1806 if (view != null) { 1807 scrollToView(view, smooth); 1808 } else { 1809 mFocusPosition = position; 1810 mFocusPositionOffset = 0; 1811 if (!mLayoutEnabled) { 1812 return; 1813 } 1814 if (smooth) { 1815 if (!hasDoneFirstLayout()) { 1816 Log.w(getTag(), "setSelectionSmooth should " + 1817 "not be called before first layout pass"); 1818 return; 1819 } 1820 LinearSmoothScroller linearSmoothScroller = 1821 new LinearSmoothScroller(parent.getContext()) { 1822 @Override 1823 public PointF computeScrollVectorForPosition(int targetPosition) { 1824 if (getChildCount() == 0) { 1825 return null; 1826 } 1827 final int firstChildPos = getPosition(getChildAt(0)); 1828 final int direction = targetPosition < firstChildPos ? -1 : 1; 1829 if (mOrientation == HORIZONTAL) { 1830 return new PointF(direction, 0); 1831 } else { 1832 return new PointF(0, direction); 1833 } 1834 } 1835 @Override 1836 protected void onTargetFound(View targetView, 1837 RecyclerView.State state, Action action) { 1838 if (hasFocus()) { 1839 targetView.requestFocus(); 1840 } 1841 dispatchChildSelected(); 1842 if (getScrollPosition(targetView, mTempDeltas)) { 1843 int dx, dy; 1844 if (mOrientation == HORIZONTAL) { 1845 dx = mTempDeltas[0]; 1846 dy = mTempDeltas[1]; 1847 } else { 1848 dx = mTempDeltas[1]; 1849 dy = mTempDeltas[0]; 1850 } 1851 final int distance = (int) Math.sqrt(dx * dx + dy * dy); 1852 final int time = calculateTimeForDeceleration(distance); 1853 action.update(dx, dy, time, mDecelerateInterpolator); 1854 } 1855 } 1856 }; 1857 linearSmoothScroller.setTargetPosition(position); 1858 startSmoothScroll(linearSmoothScroller); 1859 } else { 1860 mForceFullLayout = true; 1861 parent.requestLayout(); 1862 } 1863 } 1864 } 1865 1866 @Override 1867 public void onItemsAdded(RecyclerView recyclerView, int positionStart, int itemCount) { 1868 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE) { 1869 int pos = mFocusPosition + mFocusPositionOffset; 1870 if (positionStart <= pos) { 1871 mFocusPositionOffset += itemCount; 1872 } 1873 } 1874 } 1875 1876 @Override 1877 public void onItemsChanged(RecyclerView recyclerView) { 1878 mFocusPositionOffset = 0; 1879 } 1880 1881 @Override 1882 public void onItemsRemoved(RecyclerView recyclerView, int positionStart, int itemCount) { 1883 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE) { 1884 int pos = mFocusPosition + mFocusPositionOffset; 1885 if (positionStart <= pos) { 1886 if (positionStart + itemCount > pos) { 1887 // stop updating offset after the focus item was removed 1888 mFocusPositionOffset = Integer.MIN_VALUE; 1889 } else { 1890 mFocusPositionOffset -= itemCount; 1891 } 1892 } 1893 } 1894 } 1895 1896 public void onItemsMoved(RecyclerView recyclerView, int fromPosition, int toPosition, 1897 int itemCount) { 1898 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE) { 1899 int pos = mFocusPosition + mFocusPositionOffset; 1900 if (fromPosition <= pos && pos < fromPosition + itemCount) { 1901 // moved items include focused position 1902 mFocusPositionOffset += toPosition - fromPosition; 1903 } else if (fromPosition < pos && toPosition > pos - itemCount) { 1904 // move items before focus position to after focused position 1905 mFocusPositionOffset -= itemCount; 1906 } else if (fromPosition > pos && toPosition < pos) { 1907 // move items after focus position to before focused position 1908 mFocusPositionOffset += itemCount; 1909 } 1910 } 1911 } 1912 1913 @Override 1914 public boolean onRequestChildFocus(RecyclerView parent, View child, View focused) { 1915 if (mFocusSearchDisabled) { 1916 return true; 1917 } 1918 if (!mInLayout) { 1919 scrollToView(child, true); 1920 } 1921 return true; 1922 } 1923 1924 @Override 1925 public boolean requestChildRectangleOnScreen(RecyclerView parent, View view, Rect rect, 1926 boolean immediate) { 1927 if (DEBUG) Log.v(getTag(), "requestChildRectangleOnScreen " + view + " " + rect); 1928 return false; 1929 } 1930 1931 int getScrollOffsetX() { 1932 return mOrientation == HORIZONTAL ? mScrollOffsetPrimary : mScrollOffsetSecondary; 1933 } 1934 1935 int getScrollOffsetY() { 1936 return mOrientation == HORIZONTAL ? mScrollOffsetSecondary : mScrollOffsetPrimary; 1937 } 1938 1939 public void getViewSelectedOffsets(View view, int[] offsets) { 1940 if (mOrientation == HORIZONTAL) { 1941 offsets[0] = getPrimarySystemScrollPosition(view) - mScrollOffsetPrimary; 1942 offsets[1] = getSecondarySystemScrollPosition(view) - mScrollOffsetSecondary; 1943 } else { 1944 offsets[1] = getPrimarySystemScrollPosition(view) - mScrollOffsetPrimary; 1945 offsets[0] = getSecondarySystemScrollPosition(view) - mScrollOffsetSecondary; 1946 } 1947 } 1948 1949 private int getPrimarySystemScrollPosition(View view) { 1950 int viewCenterPrimary = mScrollOffsetPrimary + getViewCenter(view); 1951 int pos = getPositionByView(view); 1952 StaggeredGrid.Location location = mGrid.getLocation(pos); 1953 final int row = location.row; 1954 boolean isFirst = mFirstVisiblePos == 0; 1955 // TODO: change to use State object in onRequestChildFocus() 1956 boolean isLast = mLastVisiblePos == (mState == null ? 1957 getItemCount() : mState.getItemCount()) - 1; 1958 if (isFirst || isLast) { 1959 for (int i = getChildCount() - 1; i >= 0; i--) { 1960 int position = getPositionByIndex(i); 1961 StaggeredGrid.Location loc = mGrid.getLocation(position); 1962 if (loc != null && loc.row == row) { 1963 if (position < pos) { 1964 isFirst = false; 1965 } else if (position > pos) { 1966 isLast = false; 1967 } 1968 } 1969 } 1970 } 1971 return mWindowAlignment.mainAxis().getSystemScrollPos(viewCenterPrimary, isFirst, isLast); 1972 } 1973 1974 private int getSecondarySystemScrollPosition(View view) { 1975 int viewCenterSecondary = mScrollOffsetSecondary + getViewCenterSecondary(view); 1976 int pos = getPositionByView(view); 1977 StaggeredGrid.Location location = mGrid.getLocation(pos); 1978 final int row = location.row; 1979 boolean isFirst = row == 0; 1980 boolean isLast = row == mGrid.getNumRows() - 1; 1981 return mWindowAlignment.secondAxis().getSystemScrollPos(viewCenterSecondary, 1982 isFirst, isLast); 1983 } 1984 1985 /** 1986 * Scroll to a given child view and change mFocusPosition. 1987 */ 1988 private void scrollToView(View view, boolean smooth) { 1989 int newFocusPosition = getPositionByView(view); 1990 if (newFocusPosition != mFocusPosition) { 1991 mFocusPosition = newFocusPosition; 1992 mFocusPositionOffset = 0; 1993 if (!mInLayout) { 1994 dispatchChildSelected(); 1995 } 1996 } 1997 if (mBaseGridView.isChildrenDrawingOrderEnabledInternal()) { 1998 mBaseGridView.invalidate(); 1999 } 2000 if (view == null) { 2001 return; 2002 } 2003 if (!view.hasFocus() && mBaseGridView.hasFocus()) { 2004 // transfer focus to the child if it does not have focus yet (e.g. triggered 2005 // by setSelection()) 2006 view.requestFocus(); 2007 } 2008 if (!mScrollEnabled) { 2009 return; 2010 } 2011 if (getScrollPosition(view, mTempDeltas)) { 2012 scrollGrid(mTempDeltas[0], mTempDeltas[1], smooth); 2013 } 2014 } 2015 2016 private boolean getScrollPosition(View view, int[] deltas) { 2017 switch (mFocusScrollStrategy) { 2018 case BaseGridView.FOCUS_SCROLL_ALIGNED: 2019 default: 2020 return getAlignedPosition(view, deltas); 2021 case BaseGridView.FOCUS_SCROLL_ITEM: 2022 case BaseGridView.FOCUS_SCROLL_PAGE: 2023 return getNoneAlignedPosition(view, deltas); 2024 } 2025 } 2026 2027 private boolean getNoneAlignedPosition(View view, int[] deltas) { 2028 int pos = getPositionByView(view); 2029 int viewMin = getViewMin(view); 2030 int viewMax = getViewMax(view); 2031 // we either align "firstView" to left/top padding edge 2032 // or align "lastView" to right/bottom padding edge 2033 View firstView = null; 2034 View lastView = null; 2035 int paddingLow = mWindowAlignment.mainAxis().getPaddingLow(); 2036 int clientSize = mWindowAlignment.mainAxis().getClientSize(); 2037 final int row = mGrid.getLocation(pos).row; 2038 if (viewMin < paddingLow) { 2039 // view enters low padding area: 2040 firstView = view; 2041 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_PAGE) { 2042 // scroll one "page" left/top, 2043 // align first visible item of the "page" at the low padding edge. 2044 while (!prependOneVisibleItem()) { 2045 List<Integer> positions = 2046 mGrid.getItemPositionsInRows(mFirstVisiblePos, pos)[row]; 2047 firstView = findViewByPosition(positions.get(0)); 2048 if (viewMax - getViewMin(firstView) > clientSize) { 2049 if (positions.size() > 1) { 2050 firstView = findViewByPosition(positions.get(1)); 2051 } 2052 break; 2053 } 2054 } 2055 } 2056 } else if (viewMax > clientSize + paddingLow) { 2057 // view enters high padding area: 2058 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_PAGE) { 2059 // scroll whole one page right/bottom, align view at the low padding edge. 2060 firstView = view; 2061 do { 2062 List<Integer> positions = 2063 mGrid.getItemPositionsInRows(pos, mLastVisiblePos)[row]; 2064 lastView = findViewByPosition(positions.get(positions.size() - 1)); 2065 if (getViewMax(lastView) - viewMin > clientSize) { 2066 lastView = null; 2067 break; 2068 } 2069 } while (!appendOneVisibleItem()); 2070 if (lastView != null) { 2071 // however if we reached end, we should align last view. 2072 firstView = null; 2073 } 2074 } else { 2075 lastView = view; 2076 } 2077 } 2078 int scrollPrimary = 0; 2079 int scrollSecondary = 0; 2080 if (firstView != null) { 2081 scrollPrimary = getViewMin(firstView) - paddingLow; 2082 } else if (lastView != null) { 2083 scrollPrimary = getViewMax(lastView) - (paddingLow + clientSize); 2084 } 2085 View secondaryAlignedView; 2086 if (firstView != null) { 2087 secondaryAlignedView = firstView; 2088 } else if (lastView != null) { 2089 secondaryAlignedView = lastView; 2090 } else { 2091 secondaryAlignedView = view; 2092 } 2093 scrollSecondary = getSecondarySystemScrollPosition(secondaryAlignedView); 2094 scrollSecondary -= mScrollOffsetSecondary; 2095 if (scrollPrimary != 0 || scrollSecondary != 0) { 2096 deltas[0] = scrollPrimary; 2097 deltas[1] = scrollSecondary; 2098 return true; 2099 } 2100 return false; 2101 } 2102 2103 private boolean getAlignedPosition(View view, int[] deltas) { 2104 int scrollPrimary = getPrimarySystemScrollPosition(view); 2105 int scrollSecondary = getSecondarySystemScrollPosition(view); 2106 if (DEBUG) { 2107 Log.v(getTag(), "getAlignedPosition " + scrollPrimary + " " + scrollSecondary 2108 +" " + mWindowAlignment); 2109 } 2110 scrollPrimary -= mScrollOffsetPrimary; 2111 scrollSecondary -= mScrollOffsetSecondary; 2112 if (scrollPrimary != 0 || scrollSecondary != 0) { 2113 deltas[0] = scrollPrimary; 2114 deltas[1] = scrollSecondary; 2115 return true; 2116 } 2117 return false; 2118 } 2119 2120 private void scrollGrid(int scrollPrimary, int scrollSecondary, boolean smooth) { 2121 if (mInLayout) { 2122 scrollDirectionPrimary(scrollPrimary); 2123 scrollDirectionSecondary(scrollSecondary); 2124 } else { 2125 int scrollX; 2126 int scrollY; 2127 if (mOrientation == HORIZONTAL) { 2128 scrollX = scrollPrimary; 2129 scrollY = scrollSecondary; 2130 } else { 2131 scrollX = scrollSecondary; 2132 scrollY = scrollPrimary; 2133 } 2134 if (smooth) { 2135 mBaseGridView.smoothScrollBy(scrollX, scrollY); 2136 } else { 2137 mBaseGridView.scrollBy(scrollX, scrollY); 2138 } 2139 } 2140 } 2141 2142 public void setPruneChild(boolean pruneChild) { 2143 if (mPruneChild != pruneChild) { 2144 mPruneChild = pruneChild; 2145 if (mPruneChild) { 2146 requestLayout(); 2147 } 2148 } 2149 } 2150 2151 public boolean getPruneChild() { 2152 return mPruneChild; 2153 } 2154 2155 public void setScrollEnabled(boolean scrollEnabled) { 2156 if (mScrollEnabled != scrollEnabled) { 2157 mScrollEnabled = scrollEnabled; 2158 if (mScrollEnabled && mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED) { 2159 View focusView = findViewByPosition(mFocusPosition == NO_POSITION ? 0 : 2160 mFocusPosition); 2161 if (focusView != null) { 2162 scrollToView(focusView, true); 2163 } 2164 } 2165 } 2166 } 2167 2168 public boolean isScrollEnabled() { 2169 return mScrollEnabled; 2170 } 2171 2172 private int findImmediateChildIndex(View view) { 2173 while (view != null && view != mBaseGridView) { 2174 int index = mBaseGridView.indexOfChild(view); 2175 if (index >= 0) { 2176 return index; 2177 } 2178 view = (View) view.getParent(); 2179 } 2180 return NO_POSITION; 2181 } 2182 2183 void setFocusSearchDisabled(boolean disabled) { 2184 mFocusSearchDisabled = disabled; 2185 } 2186 2187 boolean isFocusSearchDisabled() { 2188 return mFocusSearchDisabled; 2189 } 2190 2191 @Override 2192 public View onInterceptFocusSearch(View focused, int direction) { 2193 if (mFocusSearchDisabled) { 2194 return focused; 2195 } 2196 return null; 2197 } 2198 2199 boolean hasPreviousViewInSameRow(int pos) { 2200 if (mGrid == null || pos == NO_POSITION) { 2201 return false; 2202 } 2203 if (mFirstVisiblePos > 0) { 2204 return true; 2205 } 2206 final int focusedRow = mGrid.getLocation(pos).row; 2207 for (int i = getChildCount() - 1; i >= 0; i--) { 2208 int position = getPositionByIndex(i); 2209 StaggeredGrid.Location loc = mGrid.getLocation(position); 2210 if (loc != null && loc.row == focusedRow) { 2211 if (position < pos) { 2212 return true; 2213 } 2214 } 2215 } 2216 return false; 2217 } 2218 2219 @Override 2220 public boolean onAddFocusables(RecyclerView recyclerView, 2221 ArrayList<View> views, int direction, int focusableMode) { 2222 if (mFocusSearchDisabled) { 2223 return true; 2224 } 2225 // If this viewgroup or one of its children currently has focus then we 2226 // consider our children for focus searching in main direction on the same row. 2227 // If this viewgroup has no focus and using focus align, we want the system 2228 // to ignore our children and pass focus to the viewgroup, which will pass 2229 // focus on to its children appropriately. 2230 // If this viewgroup has no focus and not using focus align, we want to 2231 // consider the child that does not overlap with padding area. 2232 if (recyclerView.hasFocus()) { 2233 final int movement = getMovement(direction); 2234 if (movement != PREV_ITEM && movement != NEXT_ITEM) { 2235 // Move on secondary direction uses default addFocusables(). 2236 return false; 2237 } 2238 final View focused = recyclerView.findFocus(); 2239 final int focusedPos = getPositionByIndex(findImmediateChildIndex(focused)); 2240 // Add focusables of focused item. 2241 if (focusedPos != NO_POSITION) { 2242 findViewByPosition(focusedPos).addFocusables(views, direction, focusableMode); 2243 } 2244 final int focusedRow = mGrid != null && focusedPos != NO_POSITION ? 2245 mGrid.getLocation(focusedPos).row : NO_POSITION; 2246 // Add focusables of next neighbor of same row on the focus search direction. 2247 if (mGrid != null) { 2248 final int focusableCount = views.size(); 2249 for (int i = 0, count = getChildCount(); i < count; i++) { 2250 int index = movement == NEXT_ITEM ? i : count - 1 - i; 2251 final View child = getChildAt(index); 2252 if (child.getVisibility() != View.VISIBLE) { 2253 continue; 2254 } 2255 int position = getPositionByIndex(index); 2256 StaggeredGrid.Location loc = mGrid.getLocation(position); 2257 if (focusedRow == NO_POSITION || (loc != null && loc.row == focusedRow)) { 2258 if (focusedPos == NO_POSITION || 2259 (movement == NEXT_ITEM && position > focusedPos) 2260 || (movement == PREV_ITEM && position < focusedPos)) { 2261 child.addFocusables(views, direction, focusableMode); 2262 if (views.size() > focusableCount) { 2263 break; 2264 } 2265 } 2266 } 2267 } 2268 } 2269 } else { 2270 if (mFocusScrollStrategy != BaseGridView.FOCUS_SCROLL_ALIGNED) { 2271 // adding views not overlapping padding area to avoid scrolling in gaining focus 2272 int left = mWindowAlignment.mainAxis().getPaddingLow(); 2273 int right = mWindowAlignment.mainAxis().getClientSize() + left; 2274 int focusableCount = views.size(); 2275 for (int i = 0, count = getChildCount(); i < count; i++) { 2276 View child = getChildAt(i); 2277 if (child.getVisibility() == View.VISIBLE) { 2278 if (getViewMin(child) >= left && getViewMax(child) <= right) { 2279 child.addFocusables(views, direction, focusableMode); 2280 } 2281 } 2282 } 2283 // if we cannot find any, then just add all children. 2284 if (views.size() == focusableCount) { 2285 for (int i = 0, count = getChildCount(); i < count; i++) { 2286 View child = getChildAt(i); 2287 if (child.getVisibility() == View.VISIBLE) { 2288 child.addFocusables(views, direction, focusableMode); 2289 } 2290 } 2291 if (views.size() != focusableCount) { 2292 return true; 2293 } 2294 } else { 2295 return true; 2296 } 2297 // if still cannot find any, fall through and add itself 2298 } 2299 if (recyclerView.isFocusable()) { 2300 views.add(recyclerView); 2301 } 2302 } 2303 return true; 2304 } 2305 2306 @Override 2307 public View onFocusSearchFailed(View focused, int direction, Recycler recycler, 2308 RecyclerView.State state) { 2309 if (DEBUG) Log.v(getTag(), "onFocusSearchFailed direction " + direction); 2310 2311 View view = null; 2312 int movement = getMovement(direction); 2313 if (mNumRows == 1) { 2314 // for simple row, use LinearSmoothScroller to smooth animation. 2315 // It will stay at a fixed cap speed in continuous scroll. 2316 if (movement == NEXT_ITEM) { 2317 int newPos = mFocusPosition + mNumRows; 2318 if (newPos < getItemCount()) { 2319 setSelectionSmooth(mBaseGridView, newPos); 2320 view = focused; 2321 } else { 2322 if (!mFocusOutEnd) { 2323 view = focused; 2324 } 2325 } 2326 } else if (movement == PREV_ITEM){ 2327 int newPos = mFocusPosition - mNumRows; 2328 if (newPos >= 0) { 2329 setSelectionSmooth(mBaseGridView, newPos); 2330 view = focused; 2331 } else { 2332 if (!mFocusOutFront) { 2333 view = focused; 2334 } 2335 } 2336 } 2337 } else if (mNumRows > 1) { 2338 // for possible staggered grid, we need guarantee focus to same row/column. 2339 // TODO: we may also use LinearSmoothScroller. 2340 saveContext(recycler, state); 2341 final FocusFinder ff = FocusFinder.getInstance(); 2342 if (movement == NEXT_ITEM) { 2343 while (view == null && !appendOneVisibleItem()) { 2344 view = ff.findNextFocus(mBaseGridView, focused, direction); 2345 } 2346 } else if (movement == PREV_ITEM){ 2347 while (view == null && !prependOneVisibleItem()) { 2348 view = ff.findNextFocus(mBaseGridView, focused, direction); 2349 } 2350 } 2351 if (view == null) { 2352 // returning the same view to prevent focus lost when scrolling past the end of the list 2353 if (movement == PREV_ITEM) { 2354 view = mFocusOutFront ? null : focused; 2355 } else if (movement == NEXT_ITEM){ 2356 view = mFocusOutEnd ? null : focused; 2357 } 2358 } 2359 leaveContext(); 2360 } 2361 if (DEBUG) Log.v(getTag(), "returning view " + view); 2362 return view; 2363 } 2364 2365 boolean gridOnRequestFocusInDescendants(RecyclerView recyclerView, int direction, 2366 Rect previouslyFocusedRect) { 2367 switch (mFocusScrollStrategy) { 2368 case BaseGridView.FOCUS_SCROLL_ALIGNED: 2369 default: 2370 return gridOnRequestFocusInDescendantsAligned(recyclerView, 2371 direction, previouslyFocusedRect); 2372 case BaseGridView.FOCUS_SCROLL_PAGE: 2373 case BaseGridView.FOCUS_SCROLL_ITEM: 2374 return gridOnRequestFocusInDescendantsUnaligned(recyclerView, 2375 direction, previouslyFocusedRect); 2376 } 2377 } 2378 2379 private boolean gridOnRequestFocusInDescendantsAligned(RecyclerView recyclerView, 2380 int direction, Rect previouslyFocusedRect) { 2381 View view = findViewByPosition(mFocusPosition); 2382 if (view != null) { 2383 boolean result = view.requestFocus(direction, previouslyFocusedRect); 2384 if (!result && DEBUG) { 2385 Log.w(getTag(), "failed to request focus on " + view); 2386 } 2387 return result; 2388 } 2389 return false; 2390 } 2391 2392 private boolean gridOnRequestFocusInDescendantsUnaligned(RecyclerView recyclerView, 2393 int direction, Rect previouslyFocusedRect) { 2394 // focus to view not overlapping padding area to avoid scrolling in gaining focus 2395 int index; 2396 int increment; 2397 int end; 2398 int count = getChildCount(); 2399 if ((direction & View.FOCUS_FORWARD) != 0) { 2400 index = 0; 2401 increment = 1; 2402 end = count; 2403 } else { 2404 index = count - 1; 2405 increment = -1; 2406 end = -1; 2407 } 2408 int left = mWindowAlignment.mainAxis().getPaddingLow(); 2409 int right = mWindowAlignment.mainAxis().getClientSize() + left; 2410 for (int i = index; i != end; i += increment) { 2411 View child = getChildAt(i); 2412 if (child.getVisibility() == View.VISIBLE) { 2413 if (getViewMin(child) >= left && getViewMax(child) <= right) { 2414 if (child.requestFocus(direction, previouslyFocusedRect)) { 2415 return true; 2416 } 2417 } 2418 } 2419 } 2420 return false; 2421 } 2422 2423 private final static int PREV_ITEM = 0; 2424 private final static int NEXT_ITEM = 1; 2425 private final static int PREV_ROW = 2; 2426 private final static int NEXT_ROW = 3; 2427 2428 private int getMovement(int direction) { 2429 int movement = View.FOCUS_LEFT; 2430 2431 if (mOrientation == HORIZONTAL) { 2432 switch(direction) { 2433 case View.FOCUS_LEFT: 2434 movement = PREV_ITEM; 2435 break; 2436 case View.FOCUS_RIGHT: 2437 movement = NEXT_ITEM; 2438 break; 2439 case View.FOCUS_UP: 2440 movement = PREV_ROW; 2441 break; 2442 case View.FOCUS_DOWN: 2443 movement = NEXT_ROW; 2444 break; 2445 } 2446 } else if (mOrientation == VERTICAL) { 2447 switch(direction) { 2448 case View.FOCUS_LEFT: 2449 movement = PREV_ROW; 2450 break; 2451 case View.FOCUS_RIGHT: 2452 movement = NEXT_ROW; 2453 break; 2454 case View.FOCUS_UP: 2455 movement = PREV_ITEM; 2456 break; 2457 case View.FOCUS_DOWN: 2458 movement = NEXT_ITEM; 2459 break; 2460 } 2461 } 2462 2463 return movement; 2464 } 2465 2466 int getChildDrawingOrder(RecyclerView recyclerView, int childCount, int i) { 2467 View view = findViewByPosition(mFocusPosition); 2468 if (view == null) { 2469 return i; 2470 } 2471 int focusIndex = recyclerView.indexOfChild(view); 2472 // supposely 0 1 2 3 4 5 6 7 8 9, 4 is the center item 2473 // drawing order is 0 1 2 3 9 8 7 6 5 4 2474 if (i < focusIndex) { 2475 return i; 2476 } else if (i < childCount - 1) { 2477 return focusIndex + childCount - 1 - i; 2478 } else { 2479 return focusIndex; 2480 } 2481 } 2482 2483 @Override 2484 public void onAdapterChanged(RecyclerView.Adapter oldAdapter, 2485 RecyclerView.Adapter newAdapter) { 2486 discardLayoutInfo(); 2487 mFocusPosition = NO_POSITION; 2488 mFocusPositionOffset = 0; 2489 super.onAdapterChanged(oldAdapter, newAdapter); 2490 } 2491 2492 private void discardLayoutInfo() { 2493 mGrid = null; 2494 mRows = null; 2495 mRowSizeSecondary = null; 2496 mFirstVisiblePos = -1; 2497 mLastVisiblePos = -1; 2498 mRowSecondarySizeRefresh = false; 2499 } 2500 2501 public void setLayoutEnabled(boolean layoutEnabled) { 2502 if (mLayoutEnabled != layoutEnabled) { 2503 mLayoutEnabled = layoutEnabled; 2504 requestLayout(); 2505 } 2506 } 2507} 2508