GridLayoutManager.java revision 4200ae975bfd7e4dc2e5c2d838c070470fcb3e2a
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.animation.TimeAnimator; 17import android.content.Context; 18import android.graphics.PointF; 19import android.graphics.Rect; 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; 39import android.view.animation.DecelerateInterpolator; 40import android.view.animation.Interpolator; 41 42import java.io.PrintWriter; 43import java.io.StringWriter; 44import java.util.ArrayList; 45import java.util.List; 46 47final class GridLayoutManager extends RecyclerView.LayoutManager { 48 49 /* 50 * LayoutParams for {@link HorizontalGridView} and {@link VerticalGridView}. 51 * The class currently does two internal jobs: 52 * - Saves optical bounds insets. 53 * - Caches focus align view center. 54 */ 55 static class LayoutParams extends RecyclerView.LayoutParams { 56 57 // The view is saved only during animation. 58 private View mView; 59 60 // For placement 61 private int mLeftInset; 62 private int mTopInset; 63 private int mRighInset; 64 private int mBottomInset; 65 66 // For alignment 67 private int mAlignX; 68 private int mAlignY; 69 70 public LayoutParams(Context c, AttributeSet attrs) { 71 super(c, attrs); 72 } 73 74 public LayoutParams(int width, int height) { 75 super(width, height); 76 } 77 78 public LayoutParams(MarginLayoutParams source) { 79 super(source); 80 } 81 82 public LayoutParams(ViewGroup.LayoutParams source) { 83 super(source); 84 } 85 86 public LayoutParams(RecyclerView.LayoutParams source) { 87 super(source); 88 } 89 90 public LayoutParams(LayoutParams source) { 91 super(source); 92 } 93 94 int getAlignX() { 95 return mAlignX; 96 } 97 98 int getAlignY() { 99 return mAlignY; 100 } 101 102 int getOpticalLeft(View view) { 103 return view.getLeft() + mLeftInset; 104 } 105 106 int getOpticalTop(View view) { 107 return view.getTop() + mTopInset; 108 } 109 110 int getOpticalRight(View view) { 111 return view.getRight() - mRighInset; 112 } 113 114 int getOpticalBottom(View view) { 115 return view.getBottom() - mBottomInset; 116 } 117 118 int getOpticalWidth(View view) { 119 return view.getWidth() - mLeftInset - mRighInset; 120 } 121 122 int getOpticalHeight(View view) { 123 return view.getHeight() - mTopInset - mBottomInset; 124 } 125 126 int getOpticalLeftInset() { 127 return mLeftInset; 128 } 129 130 int getOpticalRightInset() { 131 return mRighInset; 132 } 133 134 int getOpticalTopInset() { 135 return mTopInset; 136 } 137 138 int getOpticalBottomInset() { 139 return mBottomInset; 140 } 141 142 void setAlignX(int alignX) { 143 mAlignX = alignX; 144 } 145 146 void setAlignY(int alignY) { 147 mAlignY = alignY; 148 } 149 150 void setOpticalInsets(int leftInset, int topInset, int rightInset, int bottomInset) { 151 mLeftInset = leftInset; 152 mTopInset = topInset; 153 mRighInset = rightInset; 154 mBottomInset = bottomInset; 155 } 156 157 private void invalidateItemDecoration() { 158 ViewParent parent = mView.getParent(); 159 if (parent instanceof RecyclerView) { 160 // TODO: we only need invalidate parent if it has ItemDecoration 161 ((RecyclerView) parent).invalidate(); 162 } 163 } 164 } 165 166 private static final String TAG = "GridLayoutManager"; 167 private static final boolean DEBUG = false; 168 169 private static final Interpolator sDefaultAnimationChildLayoutInterpolator 170 = new DecelerateInterpolator(); 171 172 private static final long DEFAULT_CHILD_ANIMATION_DURATION_MS = 250; 173 174 private String getTag() { 175 return TAG + ":" + mBaseGridView.getId(); 176 } 177 178 private final BaseGridView mBaseGridView; 179 180 /** 181 * The orientation of a "row". 182 */ 183 private int mOrientation = HORIZONTAL; 184 185 private RecyclerView.State mState; 186 private RecyclerView.Recycler mRecycler; 187 188 private boolean mInLayout = false; 189 190 private OnChildSelectedListener mChildSelectedListener = null; 191 192 /** 193 * The focused position, it's not the currently visually aligned position 194 * but it is the final position that we intend to focus on. If there are 195 * multiple setSelection() called, mFocusPosition saves last value. 196 */ 197 private int mFocusPosition = NO_POSITION; 198 199 /** 200 * Force a full layout under certain situations. 201 */ 202 private boolean mForceFullLayout; 203 204 /** 205 * True if layout is enabled. 206 */ 207 private boolean mLayoutEnabled = true; 208 209 /** 210 * The scroll offsets of the viewport relative to the entire view. 211 */ 212 private int mScrollOffsetPrimary; 213 private int mScrollOffsetSecondary; 214 215 /** 216 * User-specified row height/column width. Can be WRAP_CONTENT. 217 */ 218 private int mRowSizeSecondaryRequested; 219 220 /** 221 * The fixed size of each grid item in the secondary direction. This corresponds to 222 * the row height, equal for all rows. Grid items may have variable length 223 * in the primary direction. 224 */ 225 private int mFixedRowSizeSecondary; 226 227 /** 228 * Tracks the secondary size of each row. 229 */ 230 private int[] mRowSizeSecondary; 231 232 /** 233 * Flag controlling whether the current/next layout should 234 * be updating the secondary size of rows. 235 */ 236 private boolean mRowSecondarySizeRefresh; 237 238 /** 239 * The maximum measured size of the view. 240 */ 241 private int mMaxSizeSecondary; 242 243 /** 244 * Margin between items. 245 */ 246 private int mHorizontalMargin; 247 /** 248 * Margin between items vertically. 249 */ 250 private int mVerticalMargin; 251 /** 252 * Margin in main direction. 253 */ 254 private int mMarginPrimary; 255 /** 256 * Margin in second direction. 257 */ 258 private int mMarginSecondary; 259 /** 260 * How to position child in secondary direction. 261 */ 262 private int mGravity = Gravity.LEFT | Gravity.TOP; 263 /** 264 * The number of rows in the grid. 265 */ 266 private int mNumRows; 267 /** 268 * Number of rows requested, can be 0 to be determined by parent size and 269 * rowHeight. 270 */ 271 private int mNumRowsRequested = 1; 272 273 /** 274 * Tracking start/end position of each row for visible items. 275 */ 276 private StaggeredGrid.Row[] mRows; 277 278 /** 279 * Saves grid information of each view. 280 */ 281 private StaggeredGrid mGrid; 282 /** 283 * Position of first item (included) that has attached views. 284 */ 285 private int mFirstVisiblePos; 286 /** 287 * Position of last item (included) that has attached views. 288 */ 289 private int mLastVisiblePos; 290 291 /** 292 * Focus Scroll strategy. 293 */ 294 private int mFocusScrollStrategy = BaseGridView.FOCUS_SCROLL_ALIGNED; 295 /** 296 * Defines how item view is aligned in the window. 297 */ 298 private final WindowAlignment mWindowAlignment = new WindowAlignment(); 299 300 /** 301 * Defines how item view is aligned. 302 */ 303 private final ItemAlignment mItemAlignment = new ItemAlignment(); 304 305 /** 306 * Dimensions of the view, width or height depending on orientation. 307 */ 308 private int mSizePrimary; 309 310 /** 311 * Allow DPAD key to navigate out at the front of the View (where position = 0), 312 * default is false. 313 */ 314 private boolean mFocusOutFront; 315 316 /** 317 * Allow DPAD key to navigate out at the end of the view, default is false. 318 */ 319 private boolean mFocusOutEnd; 320 321 /** 322 * True if focus search is disabled. 323 */ 324 private boolean mFocusSearchDisabled; 325 326 /** 327 * Animate layout changes from a child resizing or adding/removing a child. 328 */ 329 private boolean mAnimateChildLayout = true; 330 331 /** 332 * True if prune child, might be disabled during transition. 333 */ 334 private boolean mPruneChild = true; 335 336 private int[] mTempDeltas = new int[2]; 337 338 private boolean mUseDeltaInPreLayout; 339 340 private int mDeltaInPreLayout, mDeltaSecondaryInPreLayout; 341 342 public GridLayoutManager(BaseGridView baseGridView) { 343 mBaseGridView = baseGridView; 344 } 345 346 public void setOrientation(int orientation) { 347 if (orientation != HORIZONTAL && orientation != VERTICAL) { 348 if (DEBUG) Log.v(getTag(), "invalid orientation: " + orientation); 349 return; 350 } 351 352 mOrientation = orientation; 353 mWindowAlignment.setOrientation(orientation); 354 mItemAlignment.setOrientation(orientation); 355 mForceFullLayout = true; 356 } 357 358 public int getFocusScrollStrategy() { 359 return mFocusScrollStrategy; 360 } 361 362 public void setFocusScrollStrategy(int focusScrollStrategy) { 363 mFocusScrollStrategy = focusScrollStrategy; 364 } 365 366 public void setWindowAlignment(int windowAlignment) { 367 mWindowAlignment.mainAxis().setWindowAlignment(windowAlignment); 368 } 369 370 public int getWindowAlignment() { 371 return mWindowAlignment.mainAxis().getWindowAlignment(); 372 } 373 374 public void setWindowAlignmentOffset(int alignmentOffset) { 375 mWindowAlignment.mainAxis().setWindowAlignmentOffset(alignmentOffset); 376 } 377 378 public int getWindowAlignmentOffset() { 379 return mWindowAlignment.mainAxis().getWindowAlignmentOffset(); 380 } 381 382 public void setWindowAlignmentOffsetPercent(float offsetPercent) { 383 mWindowAlignment.mainAxis().setWindowAlignmentOffsetPercent(offsetPercent); 384 } 385 386 public float getWindowAlignmentOffsetPercent() { 387 return mWindowAlignment.mainAxis().getWindowAlignmentOffsetPercent(); 388 } 389 390 public void setItemAlignmentOffset(int alignmentOffset) { 391 mItemAlignment.mainAxis().setItemAlignmentOffset(alignmentOffset); 392 updateChildAlignments(); 393 } 394 395 public int getItemAlignmentOffset() { 396 return mItemAlignment.mainAxis().getItemAlignmentOffset(); 397 } 398 399 public void setItemAlignmentOffsetWithPadding(boolean withPadding) { 400 mItemAlignment.mainAxis().setItemAlignmentOffsetWithPadding(withPadding); 401 updateChildAlignments(); 402 } 403 404 public boolean isItemAlignmentOffsetWithPadding() { 405 return mItemAlignment.mainAxis().isItemAlignmentOffsetWithPadding(); 406 } 407 408 public void setItemAlignmentOffsetPercent(float offsetPercent) { 409 mItemAlignment.mainAxis().setItemAlignmentOffsetPercent(offsetPercent); 410 updateChildAlignments(); 411 } 412 413 public float getItemAlignmentOffsetPercent() { 414 return mItemAlignment.mainAxis().getItemAlignmentOffsetPercent(); 415 } 416 417 public void setItemAlignmentViewId(int viewId) { 418 mItemAlignment.mainAxis().setItemAlignmentViewId(viewId); 419 updateChildAlignments(); 420 } 421 422 public int getItemAlignmentViewId() { 423 return mItemAlignment.mainAxis().getItemAlignmentViewId(); 424 } 425 426 public void setFocusOutAllowed(boolean throughFront, boolean throughEnd) { 427 mFocusOutFront = throughFront; 428 mFocusOutEnd = throughEnd; 429 } 430 431 public void setNumRows(int numRows) { 432 if (numRows < 0) throw new IllegalArgumentException(); 433 mNumRowsRequested = numRows; 434 mForceFullLayout = true; 435 } 436 437 /** 438 * Set the row height. May be WRAP_CONTENT, or a size in pixels. 439 */ 440 public void setRowHeight(int height) { 441 if (height >= 0 || height == ViewGroup.LayoutParams.WRAP_CONTENT) { 442 mRowSizeSecondaryRequested = height; 443 } else { 444 throw new IllegalArgumentException("Invalid row height: " + height); 445 } 446 } 447 448 public void setItemMargin(int margin) { 449 mVerticalMargin = mHorizontalMargin = margin; 450 mMarginPrimary = mMarginSecondary = margin; 451 } 452 453 public void setVerticalMargin(int margin) { 454 if (mOrientation == HORIZONTAL) { 455 mMarginSecondary = mVerticalMargin = margin; 456 } else { 457 mMarginPrimary = mVerticalMargin = margin; 458 } 459 } 460 461 public void setHorizontalMargin(int margin) { 462 if (mOrientation == HORIZONTAL) { 463 mMarginPrimary = mHorizontalMargin = margin; 464 } else { 465 mMarginSecondary = mHorizontalMargin = margin; 466 } 467 } 468 469 public int getVerticalMargin() { 470 return mVerticalMargin; 471 } 472 473 public int getHorizontalMargin() { 474 return mHorizontalMargin; 475 } 476 477 public void setGravity(int gravity) { 478 mGravity = gravity; 479 } 480 481 protected boolean hasDoneFirstLayout() { 482 return mGrid != null; 483 } 484 485 public void setOnChildSelectedListener(OnChildSelectedListener listener) { 486 mChildSelectedListener = listener; 487 } 488 489 private int getPositionByView(View view) { 490 if (view == null) { 491 return NO_POSITION; 492 } 493 RecyclerView.ViewHolder vh = mBaseGridView.getChildViewHolder(view); 494 if (vh == null) { 495 return NO_POSITION; 496 } 497 return vh.getPosition(); 498 } 499 500 private int getPositionByIndex(int index) { 501 return getPositionByView(getChildAt(index)); 502 } 503 504 private void dispatchChildSelected() { 505 if (mChildSelectedListener == null) { 506 return; 507 } 508 if (mFocusPosition != NO_POSITION) { 509 View view = findViewByPosition(mFocusPosition); 510 if (view != null) { 511 RecyclerView.ViewHolder vh = mBaseGridView.getChildViewHolder(view); 512 mChildSelectedListener.onChildSelected(mBaseGridView, view, mFocusPosition, 513 vh == null? NO_ID: vh.getItemId()); 514 return; 515 } 516 } 517 mChildSelectedListener.onChildSelected(mBaseGridView, null, NO_POSITION, NO_ID); 518 } 519 520 @Override 521 public boolean canScrollHorizontally() { 522 // We can scroll horizontally if we have horizontal orientation, or if 523 // we are vertical and have more than one column. 524 return mOrientation == HORIZONTAL || mNumRows > 1; 525 } 526 527 @Override 528 public boolean canScrollVertically() { 529 // We can scroll vertically if we have vertical orientation, or if we 530 // are horizontal and have more than one row. 531 return mOrientation == VERTICAL || mNumRows > 1; 532 } 533 534 @Override 535 public RecyclerView.LayoutParams generateDefaultLayoutParams() { 536 return new LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, 537 ViewGroup.LayoutParams.WRAP_CONTENT); 538 } 539 540 @Override 541 public RecyclerView.LayoutParams generateLayoutParams(Context context, AttributeSet attrs) { 542 return new LayoutParams(context, attrs); 543 } 544 545 @Override 546 public RecyclerView.LayoutParams generateLayoutParams(ViewGroup.LayoutParams lp) { 547 if (lp instanceof LayoutParams) { 548 return new LayoutParams((LayoutParams) lp); 549 } else if (lp instanceof RecyclerView.LayoutParams) { 550 return new LayoutParams((RecyclerView.LayoutParams) lp); 551 } else if (lp instanceof MarginLayoutParams) { 552 return new LayoutParams((MarginLayoutParams) lp); 553 } else { 554 return new LayoutParams(lp); 555 } 556 } 557 558 protected View getViewForPosition(int position) { 559 return mRecycler.getViewForPosition(position); 560 } 561 562 final int getOpticalLeft(View v) { 563 return ((LayoutParams) v.getLayoutParams()).getOpticalLeft(v); 564 } 565 566 final int getOpticalRight(View v) { 567 return ((LayoutParams) v.getLayoutParams()).getOpticalRight(v); 568 } 569 570 final int getOpticalTop(View v) { 571 return ((LayoutParams) v.getLayoutParams()).getOpticalTop(v); 572 } 573 574 final int getOpticalBottom(View v) { 575 return ((LayoutParams) v.getLayoutParams()).getOpticalBottom(v); 576 } 577 578 private int getViewMin(View v) { 579 return (mOrientation == HORIZONTAL) ? getOpticalLeft(v) : getOpticalTop(v); 580 } 581 582 private int getViewMax(View v) { 583 return (mOrientation == HORIZONTAL) ? getOpticalRight(v) : getOpticalBottom(v); 584 } 585 586 private int getViewCenter(View view) { 587 return (mOrientation == HORIZONTAL) ? getViewCenterX(view) : getViewCenterY(view); 588 } 589 590 private int getViewCenterSecondary(View view) { 591 return (mOrientation == HORIZONTAL) ? getViewCenterY(view) : getViewCenterX(view); 592 } 593 594 private int getViewCenterX(View v) { 595 LayoutParams p = (LayoutParams) v.getLayoutParams(); 596 return p.getOpticalLeft(v) + p.getAlignX(); 597 } 598 599 private int getViewCenterY(View v) { 600 LayoutParams p = (LayoutParams) v.getLayoutParams(); 601 return p.getOpticalTop(v) + p.getAlignY(); 602 } 603 604 /** 605 * Save Recycler and State for convenience. Must be paired with leaveContext(). 606 */ 607 private void saveContext(Recycler recycler, State state) { 608 if (mRecycler != null || mState != null) { 609 Log.e(TAG, "Recycler information was not released, bug!"); 610 } 611 mRecycler = recycler; 612 mState = state; 613 } 614 615 /** 616 * Discard saved Recycler and State. 617 */ 618 private void leaveContext() { 619 mRecycler = null; 620 mState = null; 621 } 622 623 /** 624 * Re-initialize data structures for a data change or handling invisible 625 * selection. The method tries its best to preserve position information so 626 * that staggered grid looks same before and after re-initialize. 627 * @param focusPosition The initial focusPosition that we would like to 628 * focus on. 629 * @return Actual position that can be focused on. 630 */ 631 private int init(int focusPosition) { 632 633 final int newItemCount = mState.getItemCount(); 634 635 if (focusPosition == NO_POSITION && newItemCount > 0) { 636 // if focus position is never set before, initialize it to 0 637 focusPosition = 0; 638 } 639 // If adapter has changed then caches are invalid; otherwise, 640 // we try to maintain each row's position if number of rows keeps the same 641 // and existing mGrid contains the focusPosition. 642 if (mRows != null && mNumRows == mRows.length && 643 mGrid != null && mGrid.getSize() > 0 && focusPosition >= 0 && 644 focusPosition >= mGrid.getFirstIndex() && 645 focusPosition <= mGrid.getLastIndex()) { 646 // strip mGrid to a subset (like a column) that contains focusPosition 647 mGrid.stripDownTo(focusPosition); 648 // make sure that remaining items do not exceed new adapter size 649 int firstIndex = mGrid.getFirstIndex(); 650 int lastIndex = mGrid.getLastIndex(); 651 if (DEBUG) { 652 Log .v(getTag(), "mGrid firstIndex " + firstIndex + " lastIndex " + lastIndex); 653 } 654 for (int i = lastIndex; i >=firstIndex; i--) { 655 if (i >= newItemCount) { 656 mGrid.removeLast(); 657 } 658 } 659 if (mGrid.getSize() == 0) { 660 focusPosition = newItemCount - 1; 661 // initialize row start locations 662 for (int i = 0; i < mNumRows; i++) { 663 mRows[i].low = 0; 664 mRows[i].high = 0; 665 } 666 if (DEBUG) Log.v(getTag(), "mGrid zero size"); 667 } else { 668 // initialize row start locations 669 for (int i = 0; i < mNumRows; i++) { 670 mRows[i].low = Integer.MAX_VALUE; 671 mRows[i].high = Integer.MIN_VALUE; 672 } 673 firstIndex = mGrid.getFirstIndex(); 674 lastIndex = mGrid.getLastIndex(); 675 if (focusPosition > lastIndex) { 676 focusPosition = mGrid.getLastIndex(); 677 } 678 if (DEBUG) { 679 Log.v(getTag(), "mGrid firstIndex " + firstIndex + " lastIndex " 680 + lastIndex + " focusPosition " + focusPosition); 681 } 682 // fill rows with minimal view positions of the subset 683 for (int i = firstIndex; i <= lastIndex; i++) { 684 View v = findViewByPosition(i); 685 if (v == null) { 686 continue; 687 } 688 int row = mGrid.getLocation(i).row; 689 int low = getViewMin(v) + mScrollOffsetPrimary; 690 if (low < mRows[row].low) { 691 mRows[row].low = mRows[row].high = low; 692 } 693 } 694 int firstItemRowPosition = mRows[mGrid.getLocation(firstIndex).row].low; 695 if (firstItemRowPosition == Integer.MAX_VALUE) { 696 firstItemRowPosition = 0; 697 } 698 if (mState.didStructureChange()) { 699 // if there is structure change, the removed item might be in the 700 // subset, so it is meaningless to maintain the low locations. 701 for (int i = 0; i < mNumRows; i++) { 702 mRows[i].low = firstItemRowPosition; 703 mRows[i].high = firstItemRowPosition; 704 } 705 } else { 706 // fill other rows that does not include the subset using first item 707 for (int i = 0; i < mNumRows; i++) { 708 if (mRows[i].low == Integer.MAX_VALUE) { 709 mRows[i].low = mRows[i].high = firstItemRowPosition; 710 } 711 } 712 } 713 } 714 715 // Same adapter, we can reuse any attached views 716 detachAndScrapAttachedViews(mRecycler); 717 718 } else { 719 // otherwise recreate data structure 720 mRows = new StaggeredGrid.Row[mNumRows]; 721 mRowSizeSecondary = new int[mNumRows]; 722 723 for (int i = 0; i < mNumRows; i++) { 724 mRows[i] = new StaggeredGrid.Row(); 725 } 726 mGrid = new StaggeredGridDefault(); 727 if (newItemCount == 0) { 728 focusPosition = NO_POSITION; 729 } else if (focusPosition >= newItemCount) { 730 focusPosition = newItemCount - 1; 731 } 732 733 // Adapter may have changed so remove all attached views permanently 734 removeAllViews(); 735 736 mScrollOffsetPrimary = 0; 737 mScrollOffsetSecondary = 0; 738 mWindowAlignment.reset(); 739 } 740 741 mGrid.setProvider(mGridProvider); 742 // mGrid share the same Row array information 743 mGrid.setRows(mRows); 744 mFirstVisiblePos = mLastVisiblePos = NO_POSITION; 745 746 initScrollController(); 747 updateScrollSecondAxis(); 748 749 return focusPosition; 750 } 751 752 private int getRowSizeSecondary(int rowIndex) { 753 if (mFixedRowSizeSecondary != 0) { 754 return mFixedRowSizeSecondary; 755 } 756 if (mRowSizeSecondary == null) { 757 return 0; 758 } 759 return mRowSizeSecondary[rowIndex]; 760 } 761 762 private int getRowStartSecondary(int rowIndex) { 763 int start = 0; 764 for (int i = 0; i < rowIndex; i++) { 765 start += getRowSizeSecondary(i) + mMarginSecondary; 766 } 767 return start; 768 } 769 770 private int getSizeSecondary() { 771 return getRowStartSecondary(mNumRows - 1) + getRowSizeSecondary(mNumRows - 1); 772 } 773 774 private boolean processRowSizeSecondary(boolean measure) { 775 if (mFixedRowSizeSecondary != 0) { 776 return false; 777 } 778 779 List<Integer>[] rows = mGrid.getItemPositionsInRows(mFirstVisiblePos, mLastVisiblePos); 780 boolean changed = false; 781 782 for (int rowIndex = 0; rowIndex < mNumRows; rowIndex++) { 783 int rowSize = 0; 784 785 final int rowItemCount = rows[rowIndex].size(); 786 if (DEBUG) Log.v(getTag(), "processRowSizeSecondary row " + rowIndex + 787 " rowItemCount " + rowItemCount); 788 789 for (int i = 0; i < rowItemCount; i++) { 790 final int position = rows[rowIndex].get(i); 791 final View view = findViewByPosition(position); 792 if (measure && view.isLayoutRequested()) { 793 measureChild(view, rowIndex); 794 } 795 // If this view isn't visible, we ignore it. 796 if (getOpticalRight(view) < 0 || getOpticalLeft(view) > getWidth() || 797 getOpticalBottom(view) < 0 || getOpticalTop(view) > getHeight()) { 798 continue; 799 } 800 final int secondarySize = mOrientation == HORIZONTAL ? 801 view.getMeasuredHeight() : view.getMeasuredWidth(); 802 if (secondarySize > rowSize) { 803 rowSize = secondarySize; 804 } 805 } 806 if (DEBUG) Log.v(getTag(), "row " + rowIndex + " rowItemCount " + rowItemCount + 807 " rowSize " + rowSize); 808 809 if (mRowSizeSecondary[rowIndex] != rowSize) { 810 if (DEBUG) Log.v(getTag(), "row size secondary changed: " + mRowSizeSecondary[rowIndex] + 811 ", " + rowSize); 812 813 mRowSizeSecondary[rowIndex] = rowSize; 814 changed = true; 815 } 816 } 817 818 return changed; 819 } 820 821 /** 822 * Checks if we need to update row secondary sizes. 823 */ 824 private void updateRowSecondarySizeRefresh() { 825 mRowSecondarySizeRefresh = processRowSizeSecondary(false); 826 if (mRowSecondarySizeRefresh) { 827 if (DEBUG) Log.v(getTag(), "mRowSecondarySizeRefresh now set"); 828 forceRequestLayout(); 829 } 830 } 831 832 private void forceRequestLayout() { 833 if (DEBUG) Log.v(getTag(), "forceRequestLayout"); 834 // RecyclerView prevents us from requesting layout in many cases 835 // (during layout, during scroll, etc.) 836 // For secondary row size wrap_content support we currently need a 837 // second layout pass to update the measured size after having measured 838 // and added child views in layoutChildren. 839 // Force the second layout by posting a delayed runnable. 840 // TODO: investigate allowing a second layout pass, 841 // or move child add/measure logic to the measure phase. 842 mBaseGridView.getHandler().post(new Runnable() { 843 @Override 844 public void run() { 845 if (DEBUG) Log.v(getTag(), "request Layout from runnable"); 846 requestLayout(); 847 } 848 }); 849 } 850 851 @Override 852 public void onMeasure(int widthSpec, int heightSpec) { 853 int sizePrimary, sizeSecondary, modeSecondary, paddingSecondary; 854 int measuredSizeSecondary; 855 if (mOrientation == HORIZONTAL) { 856 sizePrimary = MeasureSpec.getSize(widthSpec); 857 sizeSecondary = MeasureSpec.getSize(heightSpec); 858 modeSecondary = MeasureSpec.getMode(heightSpec); 859 paddingSecondary = getPaddingTop() + getPaddingBottom(); 860 } else { 861 sizeSecondary = MeasureSpec.getSize(widthSpec); 862 sizePrimary = MeasureSpec.getSize(heightSpec); 863 modeSecondary = MeasureSpec.getMode(widthSpec); 864 paddingSecondary = getPaddingLeft() + getPaddingRight(); 865 } 866 if (DEBUG) Log.v(getTag(), "onMeasure widthSpec " + Integer.toHexString(widthSpec) + 867 " heightSpec " + Integer.toHexString(heightSpec) + 868 " modeSecondary " + Integer.toHexString(modeSecondary) + 869 " sizeSecondary " + sizeSecondary + " " + this); 870 871 mMaxSizeSecondary = sizeSecondary; 872 873 if (mRowSizeSecondaryRequested == ViewGroup.LayoutParams.WRAP_CONTENT) { 874 mNumRows = mNumRowsRequested == 0 ? 1 : mNumRowsRequested; 875 mFixedRowSizeSecondary = 0; 876 877 // Measure all current children and update cached row heights 878 if (mGrid != null) { 879 processRowSizeSecondary(true); 880 } 881 882 switch (modeSecondary) { 883 case MeasureSpec.UNSPECIFIED: 884 measuredSizeSecondary = getSizeSecondary() + paddingSecondary; 885 break; 886 case MeasureSpec.AT_MOST: 887 measuredSizeSecondary = Math.min(getSizeSecondary() + paddingSecondary, 888 mMaxSizeSecondary); 889 break; 890 case MeasureSpec.EXACTLY: 891 measuredSizeSecondary = mMaxSizeSecondary; 892 break; 893 default: 894 throw new IllegalStateException("wrong spec"); 895 } 896 897 } else { 898 switch (modeSecondary) { 899 case MeasureSpec.UNSPECIFIED: 900 if (mRowSizeSecondaryRequested == 0) { 901 if (mOrientation == HORIZONTAL) { 902 throw new IllegalStateException("Must specify rowHeight or view height"); 903 } else { 904 throw new IllegalStateException("Must specify columnWidth or view width"); 905 } 906 } 907 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 908 mNumRows = mNumRowsRequested == 0 ? 1 : mNumRowsRequested; 909 measuredSizeSecondary = mFixedRowSizeSecondary * mNumRows + mMarginSecondary 910 * (mNumRows - 1) + paddingSecondary; 911 break; 912 case MeasureSpec.AT_MOST: 913 case MeasureSpec.EXACTLY: 914 if (mNumRowsRequested == 0 && mRowSizeSecondaryRequested == 0) { 915 mNumRows = 1; 916 mFixedRowSizeSecondary = sizeSecondary - paddingSecondary; 917 } else if (mNumRowsRequested == 0) { 918 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 919 mNumRows = (sizeSecondary + mMarginSecondary) 920 / (mRowSizeSecondaryRequested + mMarginSecondary); 921 } else if (mRowSizeSecondaryRequested == 0) { 922 mNumRows = mNumRowsRequested; 923 mFixedRowSizeSecondary = (sizeSecondary - paddingSecondary - mMarginSecondary 924 * (mNumRows - 1)) / mNumRows; 925 } else { 926 mNumRows = mNumRowsRequested; 927 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 928 } 929 measuredSizeSecondary = sizeSecondary; 930 if (modeSecondary == MeasureSpec.AT_MOST) { 931 int childrenSize = mFixedRowSizeSecondary * mNumRows + mMarginSecondary 932 * (mNumRows - 1) + paddingSecondary; 933 if (childrenSize < measuredSizeSecondary) { 934 measuredSizeSecondary = childrenSize; 935 } 936 } 937 break; 938 default: 939 throw new IllegalStateException("wrong spec"); 940 } 941 } 942 if (mOrientation == HORIZONTAL) { 943 setMeasuredDimension(sizePrimary, measuredSizeSecondary); 944 } else { 945 setMeasuredDimension(measuredSizeSecondary, sizePrimary); 946 } 947 if (DEBUG) { 948 Log.v(getTag(), "onMeasure sizePrimary " + sizePrimary + 949 " measuredSizeSecondary " + measuredSizeSecondary + 950 " mFixedRowSizeSecondary " + mFixedRowSizeSecondary + 951 " mNumRows " + mNumRows); 952 } 953 } 954 955 private void measureChild(View child, int rowIndex) { 956 final ViewGroup.LayoutParams lp = child.getLayoutParams(); 957 final int secondarySpec = (mRowSizeSecondaryRequested == ViewGroup.LayoutParams.WRAP_CONTENT) ? 958 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED) : 959 MeasureSpec.makeMeasureSpec(mFixedRowSizeSecondary, MeasureSpec.EXACTLY); 960 int widthSpec, heightSpec; 961 962 if (mOrientation == HORIZONTAL) { 963 widthSpec = ViewGroup.getChildMeasureSpec( 964 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 965 0, lp.width); 966 heightSpec = ViewGroup.getChildMeasureSpec(secondarySpec, 0, lp.height); 967 } else { 968 heightSpec = ViewGroup.getChildMeasureSpec( 969 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 970 0, lp.height); 971 widthSpec = ViewGroup.getChildMeasureSpec(secondarySpec, 0, lp.width); 972 } 973 974 child.measure(widthSpec, heightSpec); 975 976 if (DEBUG) Log.v(getTag(), "measureChild secondarySpec " + Integer.toHexString(secondarySpec) + 977 " widthSpec " + Integer.toHexString(widthSpec) + 978 " heightSpec " + Integer.toHexString(heightSpec) + 979 " measuredWidth " + child.getMeasuredWidth() + 980 " measuredHeight " + child.getMeasuredHeight()); 981 if (DEBUG) Log.v(getTag(), "child lp width " + lp.width + " height " + lp.height); 982 } 983 984 private StaggeredGrid.Provider mGridProvider = new StaggeredGrid.Provider() { 985 986 @Override 987 public int getCount() { 988 return mState.getItemCount(); 989 } 990 991 @Override 992 public void createItem(int index, int rowIndex, boolean append) { 993 View v = getViewForPosition(index); 994 if (mFirstVisiblePos >= 0) { 995 // when StaggeredGrid append or prepend item, we must guarantee 996 // that sibling item has created views already. 997 if (append && index != mLastVisiblePos + 1) { 998 throw new RuntimeException(); 999 } else if (!append && index != mFirstVisiblePos - 1) { 1000 throw new RuntimeException(); 1001 } 1002 } 1003 1004 // See recyclerView docs: we don't need re-add scraped view if it was removed. 1005 if (!((RecyclerView.LayoutParams) v.getLayoutParams()).isItemRemoved()) { 1006 if (append) { 1007 addView(v); 1008 } else { 1009 addView(v, 0); 1010 } 1011 measureChild(v, rowIndex); 1012 } 1013 1014 int length = mOrientation == HORIZONTAL ? v.getMeasuredWidth() : v.getMeasuredHeight(); 1015 int start, end; 1016 if (append) { 1017 start = mRows[rowIndex].high; 1018 if (start != mRows[rowIndex].low) { 1019 // if there are existing item in the row, add margin between 1020 start += mMarginPrimary; 1021 } else { 1022 final int lastRow = mRows.length - 1; 1023 if (lastRow != rowIndex && mRows[lastRow].high != mRows[lastRow].low) { 1024 // if there are existing item in the last row, insert 1025 // the new item after the last item of last row. 1026 start = mRows[lastRow].high + mMarginPrimary; 1027 } 1028 } 1029 end = start + length; 1030 mRows[rowIndex].high = end; 1031 } else { 1032 end = mRows[rowIndex].low; 1033 if (end != mRows[rowIndex].high) { 1034 end -= mMarginPrimary; 1035 } else if (0 != rowIndex && mRows[0].high != mRows[0].low) { 1036 // if there are existing item in the first row, insert 1037 // the new item before the first item of first row. 1038 end = mRows[0].low - mMarginPrimary; 1039 } 1040 start = end - length; 1041 mRows[rowIndex].low = start; 1042 } 1043 if (mFirstVisiblePos < 0) { 1044 mFirstVisiblePos = mLastVisiblePos = index; 1045 } else { 1046 if (append) { 1047 mLastVisiblePos++; 1048 } else { 1049 mFirstVisiblePos--; 1050 } 1051 } 1052 if (DEBUG) Log.v(getTag(), "start " + start + " end " + end); 1053 int startSecondary = getRowStartSecondary(rowIndex) - mScrollOffsetSecondary; 1054 layoutChild(rowIndex, v, start - mScrollOffsetPrimary, end - mScrollOffsetPrimary, 1055 startSecondary); 1056 if (DEBUG) { 1057 Log.d(getTag(), "addView " + index + " " + v); 1058 } 1059 updateScrollMin(); 1060 updateScrollMax(); 1061 } 1062 }; 1063 1064 private void layoutChild(int rowIndex, View v, int start, int end, int startSecondary) { 1065 int sizeSecondary = mOrientation == HORIZONTAL ? v.getMeasuredHeight() 1066 : v.getMeasuredWidth(); 1067 if (mFixedRowSizeSecondary > 0) { 1068 sizeSecondary = Math.min(sizeSecondary, mFixedRowSizeSecondary); 1069 } 1070 final int verticalGravity = mGravity & Gravity.VERTICAL_GRAVITY_MASK; 1071 final int horizontalGravity = mGravity & Gravity.HORIZONTAL_GRAVITY_MASK; 1072 if (mOrientation == HORIZONTAL && verticalGravity == Gravity.TOP 1073 || mOrientation == VERTICAL && horizontalGravity == Gravity.LEFT) { 1074 // do nothing 1075 } else if (mOrientation == HORIZONTAL && verticalGravity == Gravity.BOTTOM 1076 || mOrientation == VERTICAL && horizontalGravity == Gravity.RIGHT) { 1077 startSecondary += getRowSizeSecondary(rowIndex) - sizeSecondary; 1078 } else if (mOrientation == HORIZONTAL && verticalGravity == Gravity.CENTER_VERTICAL 1079 || mOrientation == VERTICAL && horizontalGravity == Gravity.CENTER_HORIZONTAL) { 1080 startSecondary += (getRowSizeSecondary(rowIndex) - sizeSecondary) / 2; 1081 } 1082 int left, top, right, bottom; 1083 if (mOrientation == HORIZONTAL) { 1084 left = start; 1085 top = startSecondary; 1086 right = end; 1087 bottom = startSecondary + sizeSecondary; 1088 } else { 1089 top = start; 1090 left = startSecondary; 1091 bottom = end; 1092 right = startSecondary + sizeSecondary; 1093 } 1094 v.layout(left, top, right, bottom); 1095 updateChildOpticalInsets(v, left, top, right, bottom); 1096 updateChildAlignments(v); 1097 } 1098 1099 private void updateChildOpticalInsets(View v, int left, int top, int right, int bottom) { 1100 LayoutParams p = (LayoutParams) v.getLayoutParams(); 1101 p.setOpticalInsets(left - v.getLeft(), top - v.getTop(), 1102 v.getRight() - right, v.getBottom() - bottom); 1103 } 1104 1105 private void updateChildAlignments(View v) { 1106 LayoutParams p = (LayoutParams) v.getLayoutParams(); 1107 p.setAlignX(mItemAlignment.horizontal.getAlignmentPosition(v)); 1108 p.setAlignY(mItemAlignment.vertical.getAlignmentPosition(v)); 1109 } 1110 1111 private void updateChildAlignments() { 1112 for (int i = 0, c = getChildCount(); i < c; i++) { 1113 updateChildAlignments(getChildAt(i)); 1114 } 1115 } 1116 1117 private boolean needsAppendVisibleItem() { 1118 if (mLastVisiblePos < mFocusPosition) { 1119 return true; 1120 } 1121 int right = mScrollOffsetPrimary + mSizePrimary; 1122 for (int i = 0; i < mNumRows; i++) { 1123 if (mRows[i].low == mRows[i].high) { 1124 if (mRows[i].high < right) { 1125 return true; 1126 } 1127 } else if (mRows[i].high < right - mMarginPrimary) { 1128 return true; 1129 } 1130 } 1131 return false; 1132 } 1133 1134 private boolean needsPrependVisibleItem() { 1135 if (mFirstVisiblePos > mFocusPosition) { 1136 return true; 1137 } 1138 for (int i = 0; i < mNumRows; i++) { 1139 if (mRows[i].low == mRows[i].high) { 1140 if (mRows[i].low > mScrollOffsetPrimary) { 1141 return true; 1142 } 1143 } else if (mRows[i].low - mMarginPrimary > mScrollOffsetPrimary) { 1144 return true; 1145 } 1146 } 1147 return false; 1148 } 1149 1150 // Append one column if possible and return true if reach end. 1151 private boolean appendOneVisibleItem() { 1152 while (true) { 1153 if (mLastVisiblePos != NO_POSITION && mLastVisiblePos < mState.getItemCount() -1 && 1154 mLastVisiblePos < mGrid.getLastIndex()) { 1155 // append invisible view of saved location till last row 1156 final int index = mLastVisiblePos + 1; 1157 final int row = mGrid.getLocation(index).row; 1158 mGridProvider.createItem(index, row, true); 1159 if (row == mNumRows - 1) { 1160 return false; 1161 } 1162 } else if ((mLastVisiblePos == NO_POSITION && mState.getItemCount() > 0) || 1163 (mLastVisiblePos != NO_POSITION && 1164 mLastVisiblePos < mState.getItemCount() - 1)) { 1165 mGrid.appendItems(mScrollOffsetPrimary + mSizePrimary); 1166 return false; 1167 } else { 1168 return true; 1169 } 1170 } 1171 } 1172 1173 private void appendVisibleItems() { 1174 while (needsAppendVisibleItem()) { 1175 if (appendOneVisibleItem()) { 1176 break; 1177 } 1178 } 1179 } 1180 1181 // Prepend one column if possible and return true if reach end. 1182 private boolean prependOneVisibleItem() { 1183 while (true) { 1184 if (mFirstVisiblePos > 0) { 1185 if (mFirstVisiblePos > mGrid.getFirstIndex()) { 1186 // prepend invisible view of saved location till first row 1187 final int index = mFirstVisiblePos - 1; 1188 final int row = mGrid.getLocation(index).row; 1189 mGridProvider.createItem(index, row, false); 1190 if (row == 0) { 1191 return false; 1192 } 1193 } else { 1194 mGrid.prependItems(mScrollOffsetPrimary); 1195 return false; 1196 } 1197 } else { 1198 return true; 1199 } 1200 } 1201 } 1202 1203 private void prependVisibleItems() { 1204 while (needsPrependVisibleItem()) { 1205 if (prependOneVisibleItem()) { 1206 break; 1207 } 1208 } 1209 } 1210 1211 private void removeChildAt(int position) { 1212 View v = findViewByPosition(position); 1213 if (v != null) { 1214 if (DEBUG) { 1215 Log.d(getTag(), "removeAndRecycleViewAt " + position); 1216 } 1217 removeAndRecycleView(v, mRecycler); 1218 } 1219 } 1220 1221 private void removeInvisibleViewsAtEnd() { 1222 if (!mPruneChild) { 1223 return; 1224 } 1225 boolean update = false; 1226 while(mLastVisiblePos > mFirstVisiblePos && mLastVisiblePos > mFocusPosition) { 1227 View view = findViewByPosition(mLastVisiblePos); 1228 if (getViewMin(view) > mSizePrimary) { 1229 removeChildAt(mLastVisiblePos); 1230 mLastVisiblePos--; 1231 update = true; 1232 } else { 1233 break; 1234 } 1235 } 1236 if (update) { 1237 updateRowsMinMax(); 1238 } 1239 } 1240 1241 private void removeInvisibleViewsAtFront() { 1242 if (!mPruneChild) { 1243 return; 1244 } 1245 boolean update = false; 1246 while(mLastVisiblePos > mFirstVisiblePos && mFirstVisiblePos < mFocusPosition) { 1247 View view = findViewByPosition(mFirstVisiblePos); 1248 if (getViewMax(view) < 0) { 1249 removeChildAt(mFirstVisiblePos); 1250 mFirstVisiblePos++; 1251 update = true; 1252 } else { 1253 break; 1254 } 1255 } 1256 if (update) { 1257 updateRowsMinMax(); 1258 } 1259 } 1260 1261 private void updateRowsMinMax() { 1262 if (mFirstVisiblePos < 0) { 1263 return; 1264 } 1265 for (int i = 0; i < mNumRows; i++) { 1266 mRows[i].low = Integer.MAX_VALUE; 1267 mRows[i].high = Integer.MIN_VALUE; 1268 } 1269 for (int i = mFirstVisiblePos; i <= mLastVisiblePos; i++) { 1270 View view = findViewByPosition(i); 1271 int row = mGrid.getLocation(i).row; 1272 int low = getViewMin(view) + mScrollOffsetPrimary; 1273 if (low < mRows[row].low) { 1274 mRows[row].low = low; 1275 } 1276 int high = getViewMax(view) + mScrollOffsetPrimary; 1277 if (high > mRows[row].high) { 1278 mRows[row].high = high; 1279 } 1280 } 1281 } 1282 1283 // Fast layout when there is no structure change, adapter change, etc. 1284 protected void fastRelayout() { 1285 initScrollController(); 1286 1287 List<Integer>[] rows = mGrid.getItemPositionsInRows(mFirstVisiblePos, mLastVisiblePos); 1288 1289 // relayout and repositioning views on each row 1290 for (int i = 0; i < mNumRows; i++) { 1291 List<Integer> row = rows[i]; 1292 final int startSecondary = getRowStartSecondary(i) - mScrollOffsetSecondary; 1293 for (int j = 0, size = row.size(); j < size; j++) { 1294 final int position = row.get(j); 1295 final View view = findViewByPosition(position); 1296 int primaryDelta, start, end; 1297 1298 if (mOrientation == HORIZONTAL) { 1299 final int primarySize = view.getMeasuredWidth(); 1300 if (view.isLayoutRequested()) { 1301 measureChild(view, i); 1302 } 1303 start = getViewMin(view); 1304 end = start + view.getMeasuredWidth(); 1305 primaryDelta = view.getMeasuredWidth() - primarySize; 1306 if (primaryDelta != 0) { 1307 for (int k = j + 1; k < size; k++) { 1308 findViewByPosition(row.get(k)).offsetLeftAndRight(primaryDelta); 1309 } 1310 } 1311 } else { 1312 final int primarySize = view.getMeasuredHeight(); 1313 if (view.isLayoutRequested()) { 1314 measureChild(view, i); 1315 } 1316 start = getViewMin(view); 1317 end = start + view.getMeasuredHeight(); 1318 primaryDelta = view.getMeasuredHeight() - primarySize; 1319 if (primaryDelta != 0) { 1320 for (int k = j + 1; k < size; k++) { 1321 findViewByPosition(row.get(k)).offsetTopAndBottom(primaryDelta); 1322 } 1323 } 1324 } 1325 layoutChild(i, view, start, end, startSecondary); 1326 } 1327 } 1328 1329 updateRowsMinMax(); 1330 appendVisibleItems(); 1331 prependVisibleItems(); 1332 1333 updateRowsMinMax(); 1334 updateScrollMin(); 1335 updateScrollMax(); 1336 updateScrollSecondAxis(); 1337 1338 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED) { 1339 View focusView = findViewByPosition(mFocusPosition == NO_POSITION ? 0 : mFocusPosition); 1340 scrollToView(focusView, false); 1341 } 1342 } 1343 1344 @Override 1345 public boolean supportsItemAnimations() { 1346 return mAnimateChildLayout; 1347 } 1348 1349 // Lays out items based on the current scroll position 1350 @Override 1351 public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state) { 1352 if (DEBUG) { 1353 Log.v(getTag(), "layoutChildren start numRows " + mNumRows + " mScrollOffsetSecondary " 1354 + mScrollOffsetSecondary + " mScrollOffsetPrimary " + mScrollOffsetPrimary 1355 + " inPreLayout " + state.isPreLayout() 1356 + " didStructureChange " + state.didStructureChange() 1357 + " mForceFullLayout " + mForceFullLayout); 1358 Log.v(getTag(), "width " + getWidth() + " height " + getHeight()); 1359 } 1360 1361 if (mNumRows == 0) { 1362 // haven't done measure yet 1363 return; 1364 } 1365 final int itemCount = state.getItemCount(); 1366 if (itemCount < 0) { 1367 return; 1368 } 1369 1370 if (!mLayoutEnabled) { 1371 discardLayoutInfo(); 1372 removeAllViews(); 1373 return; 1374 } 1375 mInLayout = true; 1376 1377 saveContext(recycler, state); 1378 // Track the old focus view so we can adjust our system scroll position 1379 // so that any scroll animations happening now will remain valid. 1380 // We must use same delta in Pre Layout (if prelayout exists) and second layout. 1381 // So we cache the deltas in PreLayout and use it in second layout. 1382 int delta = 0, deltaSecondary = 0; 1383 if (!state.isPreLayout() && mUseDeltaInPreLayout) { 1384 delta = mDeltaInPreLayout; 1385 deltaSecondary = mDeltaSecondaryInPreLayout; 1386 } else { 1387 if (mFocusPosition != NO_POSITION 1388 && mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED) { 1389 View focusView = findViewByPosition(mFocusPosition); 1390 if (focusView != null) { 1391 delta = mWindowAlignment.mainAxis().getSystemScrollPos( 1392 getViewCenter(focusView) + mScrollOffsetPrimary) - mScrollOffsetPrimary; 1393 deltaSecondary = 1394 mWindowAlignment.secondAxis().getSystemScrollPos( 1395 getViewCenterSecondary(focusView) + mScrollOffsetSecondary) 1396 - mScrollOffsetSecondary; 1397 if (mUseDeltaInPreLayout = state.isPreLayout()) { 1398 mDeltaInPreLayout = delta; 1399 mDeltaSecondaryInPreLayout = deltaSecondary; 1400 } 1401 } 1402 } 1403 } 1404 1405 final boolean hasDoneFirstLayout = hasDoneFirstLayout(); 1406 if (!mState.didStructureChange() && !mForceFullLayout && hasDoneFirstLayout) { 1407 fastRelayout(); 1408 } else { 1409 boolean hadFocus = mBaseGridView.hasFocus(); 1410 1411 int newFocusPosition = init(mFocusPosition); 1412 if (DEBUG) { 1413 Log.v(getTag(), "mFocusPosition " + mFocusPosition + " newFocusPosition " 1414 + newFocusPosition); 1415 } 1416 1417 // depending on result of init(), either recreating everything 1418 // or try to reuse the row start positions near mFocusPosition 1419 if (mGrid.getSize() == 0) { 1420 // this is a fresh creating all items, starting from 1421 // mFocusPosition with a estimated row index. 1422 mGrid.setStart(newFocusPosition, StaggeredGrid.START_DEFAULT); 1423 1424 // Can't track the old focus view 1425 delta = deltaSecondary = 0; 1426 1427 } else { 1428 // mGrid remembers Locations for the column that 1429 // contains mFocusePosition and also mRows remembers start 1430 // positions of each row. 1431 // Manually re-create child views for that column 1432 int firstIndex = mGrid.getFirstIndex(); 1433 int lastIndex = mGrid.getLastIndex(); 1434 for (int i = firstIndex; i <= lastIndex; i++) { 1435 mGridProvider.createItem(i, mGrid.getLocation(i).row, true); 1436 } 1437 } 1438 // add visible views at end until reach the end of window 1439 appendVisibleItems(); 1440 // add visible views at front until reach the start of window 1441 prependVisibleItems(); 1442 // multiple rounds: scrollToView of first round may drag first/last child into 1443 // "visible window" and we update scrollMin/scrollMax then run second scrollToView 1444 int oldFirstVisible; 1445 int oldLastVisible; 1446 do { 1447 oldFirstVisible = mFirstVisiblePos; 1448 oldLastVisible = mLastVisiblePos; 1449 View focusView = findViewByPosition(newFocusPosition); 1450 // we need force to initialize the child view's position 1451 scrollToView(focusView, false); 1452 if (focusView != null && hadFocus) { 1453 focusView.requestFocus(); 1454 } 1455 appendVisibleItems(); 1456 prependVisibleItems(); 1457 removeInvisibleViewsAtFront(); 1458 removeInvisibleViewsAtEnd(); 1459 } while (mFirstVisiblePos != oldFirstVisible || mLastVisiblePos != oldLastVisible); 1460 } 1461 mForceFullLayout = false; 1462 1463 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED) { 1464 scrollDirectionPrimary(-delta); 1465 scrollDirectionSecondary(-deltaSecondary); 1466 } 1467 appendVisibleItems(); 1468 prependVisibleItems(); 1469 removeInvisibleViewsAtFront(); 1470 removeInvisibleViewsAtEnd(); 1471 1472 if (DEBUG) { 1473 StringWriter sw = new StringWriter(); 1474 PrintWriter pw = new PrintWriter(sw); 1475 mGrid.debugPrint(pw); 1476 Log.d(getTag(), sw.toString()); 1477 } 1478 1479 if (mRowSecondarySizeRefresh) { 1480 mRowSecondarySizeRefresh = false; 1481 } else { 1482 updateRowSecondarySizeRefresh(); 1483 } 1484 1485 if (!state.isPreLayout()) { 1486 mUseDeltaInPreLayout = false; 1487 if (!hasDoneFirstLayout) { 1488 dispatchChildSelected(); 1489 } 1490 } 1491 mInLayout = false; 1492 leaveContext(); 1493 if (DEBUG) Log.v(getTag(), "layoutChildren end"); 1494 } 1495 1496 private void offsetChildrenSecondary(int increment) { 1497 final int childCount = getChildCount(); 1498 if (mOrientation == HORIZONTAL) { 1499 for (int i = 0; i < childCount; i++) { 1500 getChildAt(i).offsetTopAndBottom(increment); 1501 } 1502 } else { 1503 for (int i = 0; i < childCount; i++) { 1504 getChildAt(i).offsetLeftAndRight(increment); 1505 } 1506 } 1507 mScrollOffsetSecondary -= increment; 1508 } 1509 1510 private void offsetChildrenPrimary(int increment) { 1511 final int childCount = getChildCount(); 1512 if (mOrientation == VERTICAL) { 1513 for (int i = 0; i < childCount; i++) { 1514 getChildAt(i).offsetTopAndBottom(increment); 1515 } 1516 } else { 1517 for (int i = 0; i < childCount; i++) { 1518 getChildAt(i).offsetLeftAndRight(increment); 1519 } 1520 } 1521 mScrollOffsetPrimary -= increment; 1522 } 1523 1524 @Override 1525 public int scrollHorizontallyBy(int dx, Recycler recycler, RecyclerView.State state) { 1526 if (DEBUG) Log.v(getTag(), "scrollHorizontallyBy " + dx); 1527 if (!mLayoutEnabled) { 1528 return 0; 1529 } 1530 saveContext(recycler, state); 1531 int result; 1532 if (mOrientation == HORIZONTAL) { 1533 result = scrollDirectionPrimary(dx); 1534 } else { 1535 result = scrollDirectionSecondary(dx); 1536 } 1537 leaveContext(); 1538 return result; 1539 } 1540 1541 @Override 1542 public int scrollVerticallyBy(int dy, Recycler recycler, RecyclerView.State state) { 1543 if (DEBUG) Log.v(getTag(), "scrollVerticallyBy " + dy); 1544 if (!mLayoutEnabled) { 1545 return 0; 1546 } 1547 saveContext(recycler, state); 1548 int result; 1549 if (mOrientation == VERTICAL) { 1550 result = scrollDirectionPrimary(dy); 1551 } else { 1552 result = scrollDirectionSecondary(dy); 1553 } 1554 leaveContext(); 1555 return result; 1556 } 1557 1558 // scroll in main direction may add/prune views 1559 private int scrollDirectionPrimary(int da) { 1560 if (da == 0) { 1561 return 0; 1562 } 1563 offsetChildrenPrimary(-da); 1564 if (mInLayout) { 1565 return da; 1566 } 1567 1568 int childCount = getChildCount(); 1569 boolean updated; 1570 1571 if (da > 0) { 1572 appendVisibleItems(); 1573 } else if (da < 0) { 1574 prependVisibleItems(); 1575 } 1576 updated = getChildCount() > childCount; 1577 childCount = getChildCount(); 1578 1579 if (da > 0) { 1580 removeInvisibleViewsAtFront(); 1581 } else if (da < 0) { 1582 removeInvisibleViewsAtEnd(); 1583 } 1584 updated |= getChildCount() < childCount; 1585 1586 if (updated) { 1587 updateRowSecondarySizeRefresh(); 1588 } 1589 1590 mBaseGridView.invalidate(); 1591 return da; 1592 } 1593 1594 // scroll in second direction will not add/prune views 1595 private int scrollDirectionSecondary(int dy) { 1596 if (dy == 0) { 1597 return 0; 1598 } 1599 offsetChildrenSecondary(-dy); 1600 mBaseGridView.invalidate(); 1601 return dy; 1602 } 1603 1604 private void updateScrollMax() { 1605 if (mLastVisiblePos >= 0 && mLastVisiblePos == mState.getItemCount() - 1) { 1606 int maxEdge = Integer.MIN_VALUE; 1607 for (int i = 0; i < mRows.length; i++) { 1608 if (mRows[i].high > maxEdge) { 1609 maxEdge = mRows[i].high; 1610 } 1611 } 1612 mWindowAlignment.mainAxis().setMaxEdge(maxEdge); 1613 if (DEBUG) Log.v(getTag(), "updating scroll maxEdge to " + maxEdge); 1614 } 1615 } 1616 1617 private void updateScrollMin() { 1618 if (mFirstVisiblePos == 0) { 1619 int minEdge = Integer.MAX_VALUE; 1620 for (int i = 0; i < mRows.length; i++) { 1621 if (mRows[i].low < minEdge) { 1622 minEdge = mRows[i].low; 1623 } 1624 } 1625 mWindowAlignment.mainAxis().setMinEdge(minEdge); 1626 if (DEBUG) Log.v(getTag(), "updating scroll minEdge to " + minEdge); 1627 } 1628 } 1629 1630 private void updateScrollSecondAxis() { 1631 mWindowAlignment.secondAxis().setMinEdge(0); 1632 mWindowAlignment.secondAxis().setMaxEdge(getSizeSecondary()); 1633 } 1634 1635 private void initScrollController() { 1636 mWindowAlignment.horizontal.setSize(getWidth()); 1637 mWindowAlignment.horizontal.setPadding(getPaddingLeft(), getPaddingRight()); 1638 mWindowAlignment.vertical.setSize(getHeight()); 1639 mWindowAlignment.vertical.setPadding(getPaddingTop(), getPaddingBottom()); 1640 mSizePrimary = mWindowAlignment.mainAxis().getSize(); 1641 mWindowAlignment.mainAxis().invalidateScrollMin(); 1642 mWindowAlignment.mainAxis().invalidateScrollMax(); 1643 1644 if (DEBUG) { 1645 Log.v(getTag(), "initScrollController mSizePrimary " + mSizePrimary 1646 + " mWindowAlignment " + mWindowAlignment); 1647 } 1648 } 1649 1650 public void setSelection(RecyclerView parent, int position) { 1651 setSelection(parent, position, false); 1652 } 1653 1654 public void setSelectionSmooth(RecyclerView parent, int position) { 1655 setSelection(parent, position, true); 1656 } 1657 1658 public int getSelection() { 1659 return mFocusPosition; 1660 } 1661 1662 public void setSelection(RecyclerView parent, int position, boolean smooth) { 1663 if (mFocusPosition == position) { 1664 return; 1665 } 1666 View view = findViewByPosition(position); 1667 if (view != null) { 1668 scrollToView(view, smooth); 1669 } else { 1670 mFocusPosition = position; 1671 if (!mLayoutEnabled) { 1672 return; 1673 } 1674 if (smooth) { 1675 if (!hasDoneFirstLayout()) { 1676 Log.w(getTag(), "setSelectionSmooth should " + 1677 "not be called before first layout pass"); 1678 return; 1679 } 1680 LinearSmoothScroller linearSmoothScroller = 1681 new LinearSmoothScroller(parent.getContext()) { 1682 @Override 1683 public PointF computeScrollVectorForPosition(int targetPosition) { 1684 if (getChildCount() == 0) { 1685 return null; 1686 } 1687 final int firstChildPos = getPosition(getChildAt(0)); 1688 final int direction = targetPosition < firstChildPos ? -1 : 1; 1689 if (mOrientation == HORIZONTAL) { 1690 return new PointF(direction, 0); 1691 } else { 1692 return new PointF(0, direction); 1693 } 1694 } 1695 @Override 1696 protected void onTargetFound(View targetView, 1697 RecyclerView.State state, Action action) { 1698 if (hasFocus()) { 1699 targetView.requestFocus(); 1700 } 1701 if (updateScrollPosition(targetView, false, mTempDeltas)) { 1702 int dx, dy; 1703 if (mOrientation == HORIZONTAL) { 1704 dx = mTempDeltas[0]; 1705 dy = mTempDeltas[1]; 1706 } else { 1707 dx = mTempDeltas[1]; 1708 dy = mTempDeltas[0]; 1709 } 1710 final int distance = (int) Math.sqrt(dx * dx + dy * dy); 1711 final int time = calculateTimeForDeceleration(distance); 1712 action.update(dx, dy, time, mDecelerateInterpolator); 1713 } 1714 } 1715 }; 1716 linearSmoothScroller.setTargetPosition(position); 1717 startSmoothScroll(linearSmoothScroller); 1718 } else { 1719 mForceFullLayout = true; 1720 parent.requestLayout(); 1721 } 1722 } 1723 } 1724 1725 @Override 1726 public void onItemsAdded(RecyclerView recyclerView, int positionStart, int itemCount) { 1727 boolean needsLayout = false; 1728 if (itemCount != 0) { 1729 if (mFirstVisiblePos < 0) { 1730 needsLayout = true; 1731 } else if (!(positionStart > mLastVisiblePos + 1 || 1732 positionStart + itemCount < mFirstVisiblePos - 1)) { 1733 needsLayout = true; 1734 } 1735 } 1736 if (needsLayout) { 1737 recyclerView.requestLayout(); 1738 } 1739 } 1740 1741 @Override 1742 public boolean onRequestChildFocus(RecyclerView parent, View child, View focused) { 1743 if (mFocusSearchDisabled) { 1744 return true; 1745 } 1746 if (!mInLayout) { 1747 scrollToView(child, true); 1748 } 1749 return true; 1750 } 1751 1752 @Override 1753 public boolean requestChildRectangleOnScreen(RecyclerView parent, View view, Rect rect, 1754 boolean immediate) { 1755 if (DEBUG) Log.v(getTag(), "requestChildRectangleOnScreen " + view + " " + rect); 1756 return false; 1757 } 1758 1759 int getScrollOffsetX() { 1760 return mOrientation == HORIZONTAL ? mScrollOffsetPrimary : mScrollOffsetSecondary; 1761 } 1762 1763 int getScrollOffsetY() { 1764 return mOrientation == HORIZONTAL ? mScrollOffsetSecondary : mScrollOffsetPrimary; 1765 } 1766 1767 public void getViewSelectedOffsets(View view, int[] offsets) { 1768 int scrollOffsetX = getScrollOffsetX(); 1769 int scrollOffsetY = getScrollOffsetY(); 1770 int viewCenterX = scrollOffsetX + getViewCenterX(view); 1771 int viewCenterY = scrollOffsetY + getViewCenterY(view); 1772 offsets[0] = mWindowAlignment.horizontal.getSystemScrollPos(viewCenterX) - scrollOffsetX; 1773 offsets[1] = mWindowAlignment.vertical.getSystemScrollPos(viewCenterY) - scrollOffsetY; 1774 } 1775 1776 /** 1777 * Scroll to a given child view and change mFocusPosition. 1778 */ 1779 private void scrollToView(View view, boolean smooth) { 1780 int newFocusPosition = getPositionByView(view); 1781 if (mInLayout || newFocusPosition != mFocusPosition) { 1782 mFocusPosition = newFocusPosition; 1783 dispatchChildSelected(); 1784 } 1785 if (mBaseGridView.isChildrenDrawingOrderEnabledInternal()) { 1786 mBaseGridView.invalidate(); 1787 } 1788 if (view == null) { 1789 return; 1790 } 1791 if (!view.hasFocus() && mBaseGridView.hasFocus()) { 1792 // transfer focus to the child if it does not have focus yet (e.g. triggered 1793 // by setSelection()) 1794 view.requestFocus(); 1795 } 1796 if (updateScrollPosition(view, mInLayout, mTempDeltas)) { 1797 scrollGrid(mTempDeltas[0], mTempDeltas[1], smooth); 1798 } 1799 } 1800 1801 private boolean updateScrollPosition(View view, boolean force, int[] deltas) { 1802 switch (mFocusScrollStrategy) { 1803 case BaseGridView.FOCUS_SCROLL_ALIGNED: 1804 default: 1805 return updateAlignedPosition(view, force, deltas); 1806 case BaseGridView.FOCUS_SCROLL_ITEM: 1807 case BaseGridView.FOCUS_SCROLL_PAGE: 1808 return updateNoneAlignedPosition(view, deltas); 1809 } 1810 } 1811 1812 private boolean updateNoneAlignedPosition(View view, int[] deltas) { 1813 int pos = getPositionByView(view); 1814 int viewMin = getViewMin(view); 1815 int viewMax = getViewMax(view); 1816 // we either align "firstView" to left/top padding edge 1817 // or align "lastView" to right/bottom padding edge 1818 View firstView = null; 1819 View lastView = null; 1820 int paddingLow = mWindowAlignment.mainAxis().getPaddingLow(); 1821 int clientSize = mWindowAlignment.mainAxis().getClientSize(); 1822 final int row = mGrid.getLocation(pos).row; 1823 if (viewMin < paddingLow) { 1824 // view enters low padding area: 1825 firstView = view; 1826 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_PAGE) { 1827 // scroll one "page" left/top, 1828 // align first visible item of the "page" at the low padding edge. 1829 while (!prependOneVisibleItem()) { 1830 List<Integer> positions = 1831 mGrid.getItemPositionsInRows(mFirstVisiblePos, pos)[row]; 1832 firstView = findViewByPosition(positions.get(0)); 1833 if (viewMax - getViewMin(firstView) > clientSize) { 1834 if (positions.size() > 1) { 1835 firstView = findViewByPosition(positions.get(1)); 1836 } 1837 break; 1838 } 1839 } 1840 } 1841 } else if (viewMax > clientSize + paddingLow) { 1842 // view enters high padding area: 1843 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_PAGE) { 1844 // scroll whole one page right/bottom, align view at the low padding edge. 1845 firstView = view; 1846 do { 1847 List<Integer> positions = 1848 mGrid.getItemPositionsInRows(pos, mLastVisiblePos)[row]; 1849 lastView = findViewByPosition(positions.get(positions.size() - 1)); 1850 if (getViewMax(lastView) - viewMin > clientSize) { 1851 lastView = null; 1852 break; 1853 } 1854 } while (!appendOneVisibleItem()); 1855 if (lastView != null) { 1856 // however if we reached end, we should align last view. 1857 firstView = null; 1858 } 1859 } else { 1860 lastView = view; 1861 } 1862 } 1863 int scrollPrimary = 0; 1864 int scrollSecondary = 0; 1865 if (firstView != null) { 1866 scrollPrimary = getViewMin(firstView) - paddingLow; 1867 } else if (lastView != null) { 1868 scrollPrimary = getViewMax(lastView) - (paddingLow + clientSize); 1869 } 1870 View secondaryAlignedView; 1871 if (firstView != null) { 1872 secondaryAlignedView = firstView; 1873 } else if (lastView != null) { 1874 secondaryAlignedView = lastView; 1875 } else { 1876 secondaryAlignedView = view; 1877 } 1878 int viewCenterSecondary = mScrollOffsetSecondary + 1879 getViewCenterSecondary(secondaryAlignedView); 1880 mWindowAlignment.secondAxis().updateScrollCenter(viewCenterSecondary); 1881 scrollSecondary = mWindowAlignment.secondAxis().getSystemScrollPos(); 1882 scrollSecondary -= mScrollOffsetSecondary; 1883 if (scrollPrimary != 0 || scrollSecondary != 0) { 1884 deltas[0] = scrollPrimary; 1885 deltas[1] = scrollSecondary; 1886 return true; 1887 } 1888 return false; 1889 } 1890 1891 private boolean updateAlignedPosition(View view, boolean force, int[] deltas) { 1892 int viewCenterPrimary = mScrollOffsetPrimary + getViewCenter(view); 1893 int viewCenterSecondary = mScrollOffsetSecondary + getViewCenterSecondary(view); 1894 1895 if (force || viewCenterPrimary != mWindowAlignment.mainAxis().getScrollCenter() 1896 || viewCenterSecondary != mWindowAlignment.secondAxis().getScrollCenter()) { 1897 mWindowAlignment.mainAxis().updateScrollCenter(viewCenterPrimary); 1898 mWindowAlignment.secondAxis().updateScrollCenter(viewCenterSecondary); 1899 int scrollPrimary = mWindowAlignment.mainAxis().getSystemScrollPos(); 1900 int scrollSecondary = mWindowAlignment.secondAxis().getSystemScrollPos(); 1901 if (DEBUG) { 1902 Log.v(getTag(), "updateAlignedPosition " + scrollPrimary + " " + scrollSecondary 1903 +" " + mWindowAlignment); 1904 } 1905 scrollPrimary -= mScrollOffsetPrimary; 1906 scrollSecondary -= mScrollOffsetSecondary; 1907 deltas[0] = scrollPrimary; 1908 deltas[1] = scrollSecondary; 1909 return true; 1910 } 1911 return false; 1912 } 1913 1914 private void scrollGrid(int scrollPrimary, int scrollSecondary, boolean smooth) { 1915 if (mInLayout) { 1916 scrollDirectionPrimary(scrollPrimary); 1917 scrollDirectionSecondary(scrollSecondary); 1918 } else { 1919 int scrollX; 1920 int scrollY; 1921 if (mOrientation == HORIZONTAL) { 1922 scrollX = scrollPrimary; 1923 scrollY = scrollSecondary; 1924 } else { 1925 scrollX = scrollSecondary; 1926 scrollY = scrollPrimary; 1927 } 1928 if (smooth) { 1929 mBaseGridView.smoothScrollBy(scrollX, scrollY); 1930 } else { 1931 mBaseGridView.scrollBy(scrollX, scrollY); 1932 } 1933 } 1934 } 1935 1936 public void setAnimateChildLayout(boolean animateChildLayout) { 1937 mAnimateChildLayout = animateChildLayout; 1938 } 1939 1940 public boolean isChildLayoutAnimated() { 1941 return mAnimateChildLayout; 1942 } 1943 1944 public void setPruneChild(boolean pruneChild) { 1945 if (mPruneChild != pruneChild) { 1946 mPruneChild = pruneChild; 1947 if (mPruneChild) { 1948 requestLayout(); 1949 } 1950 } 1951 } 1952 1953 public boolean getPruneChild() { 1954 return mPruneChild; 1955 } 1956 1957 private int findImmediateChildIndex(View view) { 1958 while (view != null && view != mBaseGridView) { 1959 int index = mBaseGridView.indexOfChild(view); 1960 if (index >= 0) { 1961 return index; 1962 } 1963 view = (View) view.getParent(); 1964 } 1965 return NO_POSITION; 1966 } 1967 1968 void setFocusSearchDisabled(boolean disabled) { 1969 mFocusSearchDisabled = disabled; 1970 } 1971 1972 boolean isFocusSearchDisabled() { 1973 return mFocusSearchDisabled; 1974 } 1975 1976 @Override 1977 public View onInterceptFocusSearch(View focused, int direction) { 1978 if (mFocusSearchDisabled) { 1979 return focused; 1980 } 1981 return null; 1982 } 1983 1984 boolean hasNextViewInSameRow(int pos) { 1985 if (mGrid == null || pos == NO_POSITION) { 1986 return false; 1987 } 1988 final int focusedRow = mGrid.getLocation(pos).row; 1989 for (int i = 0, count = getChildCount(); i < count; i++) { 1990 int position = getPositionByIndex(i); 1991 StaggeredGrid.Location loc = mGrid.getLocation(position); 1992 if (loc != null && loc.row == focusedRow) { 1993 if (position > pos) { 1994 return true; 1995 } 1996 } 1997 } 1998 return false; 1999 } 2000 2001 boolean hasPreviousViewInSameRow(int pos) { 2002 if (mGrid == null || pos == NO_POSITION) { 2003 return false; 2004 } 2005 final int focusedRow = mGrid.getLocation(pos).row; 2006 for (int i = getChildCount() - 1; i >= 0; i--) { 2007 int position = getPositionByIndex(i); 2008 StaggeredGrid.Location loc = mGrid.getLocation(position); 2009 if (loc != null && loc.row == focusedRow) { 2010 if (position < pos) { 2011 return true; 2012 } 2013 } 2014 } 2015 return false; 2016 } 2017 2018 @Override 2019 public boolean onAddFocusables(RecyclerView recyclerView, 2020 ArrayList<View> views, int direction, int focusableMode) { 2021 if (mFocusSearchDisabled) { 2022 return true; 2023 } 2024 // If this viewgroup or one of its children currently has focus then we 2025 // consider our children for focus searching in main direction on the same row. 2026 // If this viewgroup has no focus and using focus align, we want the system 2027 // to ignore our children and pass focus to the viewgroup, which will pass 2028 // focus on to its children appropriately. 2029 // If this viewgroup has no focus and not using focus align, we want to 2030 // consider the child that does not overlap with padding area. 2031 if (recyclerView.hasFocus()) { 2032 final int movement = getMovement(direction); 2033 if (movement != PREV_ITEM && movement != NEXT_ITEM) { 2034 // Move on secondary direction uses default addFocusables(). 2035 return false; 2036 } 2037 final View focused = recyclerView.findFocus(); 2038 final int focusedPos = getPositionByIndex(findImmediateChildIndex(focused)); 2039 // Add focusables of focused item. 2040 if (focusedPos != NO_POSITION) { 2041 findViewByPosition(focusedPos).addFocusables(views, direction, focusableMode); 2042 } 2043 final int focusedRow = mGrid != null && focusedPos != NO_POSITION ? 2044 mGrid.getLocation(focusedPos).row : NO_POSITION; 2045 // Add focusables of next neighbor of same row on the focus search direction. 2046 if (mGrid != null) { 2047 final int focusableCount = views.size(); 2048 for (int i = 0, count = getChildCount(); i < count; i++) { 2049 int index = movement == NEXT_ITEM ? i : count - 1 - i; 2050 final View child = getChildAt(index); 2051 if (child.getVisibility() != View.VISIBLE) { 2052 continue; 2053 } 2054 int position = getPositionByIndex(index); 2055 StaggeredGrid.Location loc = mGrid.getLocation(position); 2056 if (focusedRow == NO_POSITION || (loc != null && loc.row == focusedRow)) { 2057 if (focusedPos == NO_POSITION || 2058 (movement == NEXT_ITEM && position > focusedPos) 2059 || (movement == PREV_ITEM && position < focusedPos)) { 2060 child.addFocusables(views, direction, focusableMode); 2061 if (views.size() > focusableCount) { 2062 break; 2063 } 2064 } 2065 } 2066 } 2067 } 2068 } else { 2069 if (mFocusScrollStrategy != BaseGridView.FOCUS_SCROLL_ALIGNED) { 2070 // adding views not overlapping padding area to avoid scrolling in gaining focus 2071 int left = mWindowAlignment.mainAxis().getPaddingLow(); 2072 int right = mWindowAlignment.mainAxis().getClientSize() + left; 2073 int focusableCount = views.size(); 2074 for (int i = 0, count = getChildCount(); i < count; i++) { 2075 View child = getChildAt(i); 2076 if (child.getVisibility() == View.VISIBLE) { 2077 if (getViewMin(child) >= left && getViewMax(child) <= right) { 2078 child.addFocusables(views, direction, focusableMode); 2079 } 2080 } 2081 } 2082 // if we cannot find any, then just add all children. 2083 if (views.size() == focusableCount) { 2084 for (int i = 0, count = getChildCount(); i < count; i++) { 2085 View child = getChildAt(i); 2086 if (child.getVisibility() == View.VISIBLE) { 2087 child.addFocusables(views, direction, focusableMode); 2088 } 2089 } 2090 if (views.size() != focusableCount) { 2091 return true; 2092 } 2093 } else { 2094 return true; 2095 } 2096 // if still cannot find any, fall through and add itself 2097 } 2098 if (recyclerView.isFocusable()) { 2099 views.add(recyclerView); 2100 } 2101 } 2102 return true; 2103 } 2104 2105 @Override 2106 public View onFocusSearchFailed(View focused, int direction, Recycler recycler, 2107 RecyclerView.State state) { 2108 if (DEBUG) Log.v(getTag(), "onFocusSearchFailed direction " + direction); 2109 2110 saveContext(recycler, state); 2111 View view = null; 2112 int movement = getMovement(direction); 2113 final FocusFinder ff = FocusFinder.getInstance(); 2114 if (movement == NEXT_ITEM) { 2115 while (view == null && !appendOneVisibleItem()) { 2116 view = ff.findNextFocus(mBaseGridView, focused, direction); 2117 } 2118 } else if (movement == PREV_ITEM){ 2119 while (view == null && !prependOneVisibleItem()) { 2120 view = ff.findNextFocus(mBaseGridView, focused, direction); 2121 } 2122 } 2123 if (view == null) { 2124 // returning the same view to prevent focus lost when scrolling past the end of the list 2125 if (movement == PREV_ITEM) { 2126 view = mFocusOutFront ? null : focused; 2127 } else if (movement == NEXT_ITEM){ 2128 view = mFocusOutEnd ? null : focused; 2129 } 2130 } 2131 leaveContext(); 2132 if (DEBUG) Log.v(getTag(), "returning view " + view); 2133 return view; 2134 } 2135 2136 boolean gridOnRequestFocusInDescendants(RecyclerView recyclerView, int direction, 2137 Rect previouslyFocusedRect) { 2138 switch (mFocusScrollStrategy) { 2139 case BaseGridView.FOCUS_SCROLL_ALIGNED: 2140 default: 2141 return gridOnRequestFocusInDescendantsAligned(recyclerView, 2142 direction, previouslyFocusedRect); 2143 case BaseGridView.FOCUS_SCROLL_PAGE: 2144 case BaseGridView.FOCUS_SCROLL_ITEM: 2145 return gridOnRequestFocusInDescendantsUnaligned(recyclerView, 2146 direction, previouslyFocusedRect); 2147 } 2148 } 2149 2150 private boolean gridOnRequestFocusInDescendantsAligned(RecyclerView recyclerView, 2151 int direction, Rect previouslyFocusedRect) { 2152 View view = findViewByPosition(mFocusPosition); 2153 if (view != null) { 2154 boolean result = view.requestFocus(direction, previouslyFocusedRect); 2155 if (!result && DEBUG) { 2156 Log.w(getTag(), "failed to request focus on " + view); 2157 } 2158 return result; 2159 } 2160 return false; 2161 } 2162 2163 private boolean gridOnRequestFocusInDescendantsUnaligned(RecyclerView recyclerView, 2164 int direction, Rect previouslyFocusedRect) { 2165 // focus to view not overlapping padding area to avoid scrolling in gaining focus 2166 int index; 2167 int increment; 2168 int end; 2169 int count = getChildCount(); 2170 if ((direction & View.FOCUS_FORWARD) != 0) { 2171 index = 0; 2172 increment = 1; 2173 end = count; 2174 } else { 2175 index = count - 1; 2176 increment = -1; 2177 end = -1; 2178 } 2179 int left = mWindowAlignment.mainAxis().getPaddingLow(); 2180 int right = mWindowAlignment.mainAxis().getClientSize() + left; 2181 for (int i = index; i != end; i += increment) { 2182 View child = getChildAt(i); 2183 if (child.getVisibility() == View.VISIBLE) { 2184 if (getViewMin(child) >= left && getViewMax(child) <= right) { 2185 if (child.requestFocus(direction, previouslyFocusedRect)) { 2186 return true; 2187 } 2188 } 2189 } 2190 } 2191 return false; 2192 } 2193 2194 private final static int PREV_ITEM = 0; 2195 private final static int NEXT_ITEM = 1; 2196 private final static int PREV_ROW = 2; 2197 private final static int NEXT_ROW = 3; 2198 2199 private int getMovement(int direction) { 2200 int movement = View.FOCUS_LEFT; 2201 2202 if (mOrientation == HORIZONTAL) { 2203 switch(direction) { 2204 case View.FOCUS_LEFT: 2205 movement = PREV_ITEM; 2206 break; 2207 case View.FOCUS_RIGHT: 2208 movement = NEXT_ITEM; 2209 break; 2210 case View.FOCUS_UP: 2211 movement = PREV_ROW; 2212 break; 2213 case View.FOCUS_DOWN: 2214 movement = NEXT_ROW; 2215 break; 2216 } 2217 } else if (mOrientation == VERTICAL) { 2218 switch(direction) { 2219 case View.FOCUS_LEFT: 2220 movement = PREV_ROW; 2221 break; 2222 case View.FOCUS_RIGHT: 2223 movement = NEXT_ROW; 2224 break; 2225 case View.FOCUS_UP: 2226 movement = PREV_ITEM; 2227 break; 2228 case View.FOCUS_DOWN: 2229 movement = NEXT_ITEM; 2230 break; 2231 } 2232 } 2233 2234 return movement; 2235 } 2236 2237 int getChildDrawingOrder(RecyclerView recyclerView, int childCount, int i) { 2238 View view = findViewByPosition(mFocusPosition); 2239 if (view == null) { 2240 return i; 2241 } 2242 int focusIndex = recyclerView.indexOfChild(view); 2243 // supposely 0 1 2 3 4 5 6 7 8 9, 4 is the center item 2244 // drawing order is 0 1 2 3 9 8 7 6 5 4 2245 if (i < focusIndex) { 2246 return i; 2247 } else if (i < childCount - 1) { 2248 return focusIndex + childCount - 1 - i; 2249 } else { 2250 return focusIndex; 2251 } 2252 } 2253 2254 @Override 2255 public void onAdapterChanged(RecyclerView.Adapter oldAdapter, 2256 RecyclerView.Adapter newAdapter) { 2257 discardLayoutInfo(); 2258 super.onAdapterChanged(oldAdapter, newAdapter); 2259 } 2260 2261 private void discardLayoutInfo() { 2262 mGrid = null; 2263 mRows = null; 2264 mRowSizeSecondary = null; 2265 mFirstVisiblePos = -1; 2266 mLastVisiblePos = -1; 2267 mRowSecondarySizeRefresh = false; 2268 } 2269 2270 public void setLayoutEnabled(boolean layoutEnabled) { 2271 if (mLayoutEnabled != layoutEnabled) { 2272 mLayoutEnabled = layoutEnabled; 2273 requestLayout(); 2274 } 2275 } 2276} 2277