GridLayoutManager.java revision 49c83b12201dde5b93d4eca3d44478e0c967a2e6
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.v7.widget.LinearSmoothScroller; 20import android.support.v7.widget.RecyclerView; 21import android.support.v7.widget.RecyclerView.Recycler; 22import android.support.v7.widget.RecyclerView.State; 23 24import static android.support.v7.widget.RecyclerView.NO_ID; 25import static android.support.v7.widget.RecyclerView.NO_POSITION; 26import static android.support.v7.widget.RecyclerView.HORIZONTAL; 27import static android.support.v7.widget.RecyclerView.VERTICAL; 28 29import android.util.AttributeSet; 30import android.util.Log; 31import android.view.FocusFinder; 32import android.view.Gravity; 33import android.view.View; 34import android.view.ViewParent; 35import android.view.View.MeasureSpec; 36import android.view.ViewGroup.MarginLayoutParams; 37import android.view.ViewGroup; 38 39import java.io.PrintWriter; 40import java.io.StringWriter; 41import java.util.ArrayList; 42import java.util.List; 43 44final class GridLayoutManager extends RecyclerView.LayoutManager { 45 46 /* 47 * LayoutParams for {@link HorizontalGridView} and {@link VerticalGridView}. 48 * The class currently does two internal jobs: 49 * - Saves optical bounds insets. 50 * - Caches focus align view center. 51 */ 52 static class LayoutParams extends RecyclerView.LayoutParams { 53 54 // The view is saved only during animation. 55 private View mView; 56 57 // For placement 58 private int mLeftInset; 59 private int mTopInset; 60 private int mRighInset; 61 private int mBottomInset; 62 63 // For alignment 64 private int mAlignX; 65 private int mAlignY; 66 67 public LayoutParams(Context c, AttributeSet attrs) { 68 super(c, attrs); 69 } 70 71 public LayoutParams(int width, int height) { 72 super(width, height); 73 } 74 75 public LayoutParams(MarginLayoutParams source) { 76 super(source); 77 } 78 79 public LayoutParams(ViewGroup.LayoutParams source) { 80 super(source); 81 } 82 83 public LayoutParams(RecyclerView.LayoutParams source) { 84 super(source); 85 } 86 87 public LayoutParams(LayoutParams source) { 88 super(source); 89 } 90 91 int getAlignX() { 92 return mAlignX; 93 } 94 95 int getAlignY() { 96 return mAlignY; 97 } 98 99 int getOpticalLeft(View view) { 100 return view.getLeft() + mLeftInset; 101 } 102 103 int getOpticalTop(View view) { 104 return view.getTop() + mTopInset; 105 } 106 107 int getOpticalRight(View view) { 108 return view.getRight() - mRighInset; 109 } 110 111 int getOpticalBottom(View view) { 112 return view.getBottom() - mBottomInset; 113 } 114 115 int getOpticalWidth(View view) { 116 return view.getWidth() - mLeftInset - mRighInset; 117 } 118 119 int getOpticalHeight(View view) { 120 return view.getHeight() - mTopInset - mBottomInset; 121 } 122 123 int getOpticalLeftInset() { 124 return mLeftInset; 125 } 126 127 int getOpticalRightInset() { 128 return mRighInset; 129 } 130 131 int getOpticalTopInset() { 132 return mTopInset; 133 } 134 135 int getOpticalBottomInset() { 136 return mBottomInset; 137 } 138 139 void setAlignX(int alignX) { 140 mAlignX = alignX; 141 } 142 143 void setAlignY(int alignY) { 144 mAlignY = alignY; 145 } 146 147 void setOpticalInsets(int leftInset, int topInset, int rightInset, int bottomInset) { 148 mLeftInset = leftInset; 149 mTopInset = topInset; 150 mRighInset = rightInset; 151 mBottomInset = bottomInset; 152 } 153 154 private void invalidateItemDecoration() { 155 ViewParent parent = mView.getParent(); 156 if (parent instanceof RecyclerView) { 157 // TODO: we only need invalidate parent if it has ItemDecoration 158 ((RecyclerView) parent).invalidate(); 159 } 160 } 161 } 162 163 private static final String TAG = "GridLayoutManager"; 164 private static final boolean DEBUG = false; 165 166 private String getTag() { 167 return TAG + ":" + mBaseGridView.getId(); 168 } 169 170 private final BaseGridView mBaseGridView; 171 172 /** 173 * The orientation of a "row". 174 */ 175 private int mOrientation = HORIZONTAL; 176 177 private RecyclerView.State mState; 178 private RecyclerView.Recycler mRecycler; 179 180 private boolean mInLayout = false; 181 182 private OnChildSelectedListener mChildSelectedListener = null; 183 184 /** 185 * The focused position, it's not the currently visually aligned position 186 * but it is the final position that we intend to focus on. If there are 187 * multiple setSelection() called, mFocusPosition saves last value. 188 */ 189 private int mFocusPosition = NO_POSITION; 190 191 /** 192 * Force a full layout under certain situations. 193 */ 194 private boolean mForceFullLayout; 195 196 /** 197 * True if layout is enabled. 198 */ 199 private boolean mLayoutEnabled = true; 200 201 /** 202 * The scroll offsets of the viewport relative to the entire view. 203 */ 204 private int mScrollOffsetPrimary; 205 private int mScrollOffsetSecondary; 206 207 /** 208 * User-specified row height/column width. Can be WRAP_CONTENT. 209 */ 210 private int mRowSizeSecondaryRequested; 211 212 /** 213 * The fixed size of each grid item in the secondary direction. This corresponds to 214 * the row height, equal for all rows. Grid items may have variable length 215 * in the primary direction. 216 */ 217 private int mFixedRowSizeSecondary; 218 219 /** 220 * Tracks the secondary size of each row. 221 */ 222 private int[] mRowSizeSecondary; 223 224 /** 225 * Flag controlling whether the current/next layout should 226 * be updating the secondary size of rows. 227 */ 228 private boolean mRowSecondarySizeRefresh; 229 230 /** 231 * The maximum measured size of the view. 232 */ 233 private int mMaxSizeSecondary; 234 235 /** 236 * Margin between items. 237 */ 238 private int mHorizontalMargin; 239 /** 240 * Margin between items vertically. 241 */ 242 private int mVerticalMargin; 243 /** 244 * Margin in main direction. 245 */ 246 private int mMarginPrimary; 247 /** 248 * Margin in second direction. 249 */ 250 private int mMarginSecondary; 251 /** 252 * How to position child in secondary direction. 253 */ 254 private int mGravity = Gravity.LEFT | Gravity.TOP; 255 /** 256 * The number of rows in the grid. 257 */ 258 private int mNumRows; 259 /** 260 * Number of rows requested, can be 0 to be determined by parent size and 261 * rowHeight. 262 */ 263 private int mNumRowsRequested = 1; 264 265 /** 266 * Tracking start/end position of each row for visible items. 267 */ 268 private StaggeredGrid.Row[] mRows; 269 270 /** 271 * Saves grid information of each view. 272 */ 273 private StaggeredGrid mGrid; 274 /** 275 * Position of first item (included) that has attached views. 276 */ 277 private int mFirstVisiblePos; 278 /** 279 * Position of last item (included) that has attached views. 280 */ 281 private int mLastVisiblePos; 282 283 /** 284 * Focus Scroll strategy. 285 */ 286 private int mFocusScrollStrategy = BaseGridView.FOCUS_SCROLL_ALIGNED; 287 /** 288 * Defines how item view is aligned in the window. 289 */ 290 private final WindowAlignment mWindowAlignment = new WindowAlignment(); 291 292 /** 293 * Defines how item view is aligned. 294 */ 295 private final ItemAlignment mItemAlignment = new ItemAlignment(); 296 297 /** 298 * Dimensions of the view, width or height depending on orientation. 299 */ 300 private int mSizePrimary; 301 302 /** 303 * Allow DPAD key to navigate out at the front of the View (where position = 0), 304 * default is false. 305 */ 306 private boolean mFocusOutFront; 307 308 /** 309 * Allow DPAD key to navigate out at the end of the view, default is false. 310 */ 311 private boolean mFocusOutEnd; 312 313 /** 314 * True if focus search is disabled. 315 */ 316 private boolean mFocusSearchDisabled; 317 318 /** 319 * True if prune child, might be disabled during transition. 320 */ 321 private boolean mPruneChild = true; 322 323 private int[] mTempDeltas = new int[2]; 324 325 private boolean mUseDeltaInPreLayout; 326 327 private int mDeltaInPreLayout, mDeltaSecondaryInPreLayout; 328 329 /** 330 * Temporaries used for measuring. 331 */ 332 private int[] mMeasuredDimension = new int[2]; 333 334 public GridLayoutManager(BaseGridView baseGridView) { 335 mBaseGridView = baseGridView; 336 } 337 338 public void setOrientation(int orientation) { 339 if (orientation != HORIZONTAL && orientation != VERTICAL) { 340 if (DEBUG) Log.v(getTag(), "invalid orientation: " + orientation); 341 return; 342 } 343 344 mOrientation = orientation; 345 mWindowAlignment.setOrientation(orientation); 346 mItemAlignment.setOrientation(orientation); 347 mForceFullLayout = true; 348 } 349 350 public int getFocusScrollStrategy() { 351 return mFocusScrollStrategy; 352 } 353 354 public void setFocusScrollStrategy(int focusScrollStrategy) { 355 mFocusScrollStrategy = focusScrollStrategy; 356 } 357 358 public void setWindowAlignment(int windowAlignment) { 359 mWindowAlignment.mainAxis().setWindowAlignment(windowAlignment); 360 } 361 362 public int getWindowAlignment() { 363 return mWindowAlignment.mainAxis().getWindowAlignment(); 364 } 365 366 public void setWindowAlignmentOffset(int alignmentOffset) { 367 mWindowAlignment.mainAxis().setWindowAlignmentOffset(alignmentOffset); 368 } 369 370 public int getWindowAlignmentOffset() { 371 return mWindowAlignment.mainAxis().getWindowAlignmentOffset(); 372 } 373 374 public void setWindowAlignmentOffsetPercent(float offsetPercent) { 375 mWindowAlignment.mainAxis().setWindowAlignmentOffsetPercent(offsetPercent); 376 } 377 378 public float getWindowAlignmentOffsetPercent() { 379 return mWindowAlignment.mainAxis().getWindowAlignmentOffsetPercent(); 380 } 381 382 public void setItemAlignmentOffset(int alignmentOffset) { 383 mItemAlignment.mainAxis().setItemAlignmentOffset(alignmentOffset); 384 updateChildAlignments(); 385 } 386 387 public int getItemAlignmentOffset() { 388 return mItemAlignment.mainAxis().getItemAlignmentOffset(); 389 } 390 391 public void setItemAlignmentOffsetWithPadding(boolean withPadding) { 392 mItemAlignment.mainAxis().setItemAlignmentOffsetWithPadding(withPadding); 393 updateChildAlignments(); 394 } 395 396 public boolean isItemAlignmentOffsetWithPadding() { 397 return mItemAlignment.mainAxis().isItemAlignmentOffsetWithPadding(); 398 } 399 400 public void setItemAlignmentOffsetPercent(float offsetPercent) { 401 mItemAlignment.mainAxis().setItemAlignmentOffsetPercent(offsetPercent); 402 updateChildAlignments(); 403 } 404 405 public float getItemAlignmentOffsetPercent() { 406 return mItemAlignment.mainAxis().getItemAlignmentOffsetPercent(); 407 } 408 409 public void setItemAlignmentViewId(int viewId) { 410 mItemAlignment.mainAxis().setItemAlignmentViewId(viewId); 411 updateChildAlignments(); 412 } 413 414 public int getItemAlignmentViewId() { 415 return mItemAlignment.mainAxis().getItemAlignmentViewId(); 416 } 417 418 public void setFocusOutAllowed(boolean throughFront, boolean throughEnd) { 419 mFocusOutFront = throughFront; 420 mFocusOutEnd = throughEnd; 421 } 422 423 public void setNumRows(int numRows) { 424 if (numRows < 0) throw new IllegalArgumentException(); 425 mNumRowsRequested = numRows; 426 mForceFullLayout = true; 427 } 428 429 /** 430 * Set the row height. May be WRAP_CONTENT, or a size in pixels. 431 */ 432 public void setRowHeight(int height) { 433 if (height >= 0 || height == ViewGroup.LayoutParams.WRAP_CONTENT) { 434 mRowSizeSecondaryRequested = height; 435 } else { 436 throw new IllegalArgumentException("Invalid row height: " + height); 437 } 438 } 439 440 public void setItemMargin(int margin) { 441 mVerticalMargin = mHorizontalMargin = margin; 442 mMarginPrimary = mMarginSecondary = margin; 443 } 444 445 public void setVerticalMargin(int margin) { 446 if (mOrientation == HORIZONTAL) { 447 mMarginSecondary = mVerticalMargin = margin; 448 } else { 449 mMarginPrimary = mVerticalMargin = margin; 450 } 451 } 452 453 public void setHorizontalMargin(int margin) { 454 if (mOrientation == HORIZONTAL) { 455 mMarginPrimary = mHorizontalMargin = margin; 456 } else { 457 mMarginSecondary = mHorizontalMargin = margin; 458 } 459 } 460 461 public int getVerticalMargin() { 462 return mVerticalMargin; 463 } 464 465 public int getHorizontalMargin() { 466 return mHorizontalMargin; 467 } 468 469 public void setGravity(int gravity) { 470 mGravity = gravity; 471 } 472 473 protected boolean hasDoneFirstLayout() { 474 return mGrid != null; 475 } 476 477 public void setOnChildSelectedListener(OnChildSelectedListener listener) { 478 mChildSelectedListener = listener; 479 } 480 481 private int getPositionByView(View view) { 482 if (view == null) { 483 return NO_POSITION; 484 } 485 LayoutParams params = (LayoutParams) view.getLayoutParams(); 486 if (params == null || params.isItemRemoved()) { 487 // when item is removed, the position value can be any value. 488 return NO_POSITION; 489 } 490 return params.getViewPosition(); 491 } 492 493 private int getPositionByIndex(int index) { 494 return getPositionByView(getChildAt(index)); 495 } 496 497 private void dispatchChildSelected() { 498 if (mChildSelectedListener == null) { 499 return; 500 } 501 if (mFocusPosition != NO_POSITION) { 502 View view = findViewByPosition(mFocusPosition); 503 if (view != null) { 504 RecyclerView.ViewHolder vh = mBaseGridView.getChildViewHolder(view); 505 mChildSelectedListener.onChildSelected(mBaseGridView, view, mFocusPosition, 506 vh == null? NO_ID: vh.getItemId()); 507 return; 508 } 509 } 510 mChildSelectedListener.onChildSelected(mBaseGridView, null, NO_POSITION, NO_ID); 511 } 512 513 @Override 514 public boolean canScrollHorizontally() { 515 // We can scroll horizontally if we have horizontal orientation, or if 516 // we are vertical and have more than one column. 517 return mOrientation == HORIZONTAL || mNumRows > 1; 518 } 519 520 @Override 521 public boolean canScrollVertically() { 522 // We can scroll vertically if we have vertical orientation, or if we 523 // are horizontal and have more than one row. 524 return mOrientation == VERTICAL || mNumRows > 1; 525 } 526 527 @Override 528 public RecyclerView.LayoutParams generateDefaultLayoutParams() { 529 return new LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, 530 ViewGroup.LayoutParams.WRAP_CONTENT); 531 } 532 533 @Override 534 public RecyclerView.LayoutParams generateLayoutParams(Context context, AttributeSet attrs) { 535 return new LayoutParams(context, attrs); 536 } 537 538 @Override 539 public RecyclerView.LayoutParams generateLayoutParams(ViewGroup.LayoutParams lp) { 540 if (lp instanceof LayoutParams) { 541 return new LayoutParams((LayoutParams) lp); 542 } else if (lp instanceof RecyclerView.LayoutParams) { 543 return new LayoutParams((RecyclerView.LayoutParams) lp); 544 } else if (lp instanceof MarginLayoutParams) { 545 return new LayoutParams((MarginLayoutParams) lp); 546 } else { 547 return new LayoutParams(lp); 548 } 549 } 550 551 protected View getViewForPosition(int position) { 552 return mRecycler.getViewForPosition(position); 553 } 554 555 final int getOpticalLeft(View v) { 556 return ((LayoutParams) v.getLayoutParams()).getOpticalLeft(v); 557 } 558 559 final int getOpticalRight(View v) { 560 return ((LayoutParams) v.getLayoutParams()).getOpticalRight(v); 561 } 562 563 final int getOpticalTop(View v) { 564 return ((LayoutParams) v.getLayoutParams()).getOpticalTop(v); 565 } 566 567 final int getOpticalBottom(View v) { 568 return ((LayoutParams) v.getLayoutParams()).getOpticalBottom(v); 569 } 570 571 private int getViewMin(View v) { 572 return (mOrientation == HORIZONTAL) ? getOpticalLeft(v) : getOpticalTop(v); 573 } 574 575 private int getViewMax(View v) { 576 return (mOrientation == HORIZONTAL) ? getOpticalRight(v) : getOpticalBottom(v); 577 } 578 579 private int getViewCenter(View view) { 580 return (mOrientation == HORIZONTAL) ? getViewCenterX(view) : getViewCenterY(view); 581 } 582 583 private int getViewCenterSecondary(View view) { 584 return (mOrientation == HORIZONTAL) ? getViewCenterY(view) : getViewCenterX(view); 585 } 586 587 private int getViewCenterX(View v) { 588 LayoutParams p = (LayoutParams) v.getLayoutParams(); 589 return p.getOpticalLeft(v) + p.getAlignX(); 590 } 591 592 private int getViewCenterY(View v) { 593 LayoutParams p = (LayoutParams) v.getLayoutParams(); 594 return p.getOpticalTop(v) + p.getAlignY(); 595 } 596 597 /** 598 * Save Recycler and State for convenience. Must be paired with leaveContext(). 599 */ 600 private void saveContext(Recycler recycler, State state) { 601 if (mRecycler != null || mState != null) { 602 Log.e(TAG, "Recycler information was not released, bug!"); 603 } 604 mRecycler = recycler; 605 mState = state; 606 } 607 608 /** 609 * Discard saved Recycler and State. 610 */ 611 private void leaveContext() { 612 mRecycler = null; 613 mState = null; 614 } 615 616 /** 617 * Re-initialize data structures for a data change or handling invisible 618 * selection. The method tries its best to preserve position information so 619 * that staggered grid looks same before and after re-initialize. 620 * @param focusPosition The initial focusPosition that we would like to 621 * focus on. 622 * @return Actual position that can be focused on. 623 */ 624 private int init(int focusPosition) { 625 626 final int newItemCount = mState.getItemCount(); 627 628 if (focusPosition == NO_POSITION && newItemCount > 0) { 629 // if focus position is never set before, initialize it to 0 630 focusPosition = 0; 631 } 632 // If adapter has changed then caches are invalid; otherwise, 633 // we try to maintain each row's position if number of rows keeps the same 634 // and existing mGrid contains the focusPosition. 635 if (mRows != null && mNumRows == mRows.length && 636 mGrid != null && mGrid.getSize() > 0 && focusPosition >= 0 && 637 focusPosition >= mGrid.getFirstIndex() && 638 focusPosition <= mGrid.getLastIndex()) { 639 // strip mGrid to a subset (like a column) that contains focusPosition 640 mGrid.stripDownTo(focusPosition); 641 // make sure that remaining items do not exceed new adapter size 642 int firstIndex = mGrid.getFirstIndex(); 643 int lastIndex = mGrid.getLastIndex(); 644 if (DEBUG) { 645 Log .v(getTag(), "mGrid firstIndex " + firstIndex + " lastIndex " + lastIndex); 646 } 647 for (int i = lastIndex; i >=firstIndex; i--) { 648 if (i >= newItemCount) { 649 mGrid.removeLast(); 650 } 651 } 652 if (mGrid.getSize() == 0) { 653 focusPosition = newItemCount - 1; 654 // initialize row start locations 655 for (int i = 0; i < mNumRows; i++) { 656 mRows[i].low = 0; 657 mRows[i].high = 0; 658 } 659 if (DEBUG) Log.v(getTag(), "mGrid zero size"); 660 } else { 661 // initialize row start locations 662 for (int i = 0; i < mNumRows; i++) { 663 mRows[i].low = Integer.MAX_VALUE; 664 mRows[i].high = Integer.MIN_VALUE; 665 } 666 firstIndex = mGrid.getFirstIndex(); 667 lastIndex = mGrid.getLastIndex(); 668 if (focusPosition > lastIndex) { 669 focusPosition = mGrid.getLastIndex(); 670 } 671 if (DEBUG) { 672 Log.v(getTag(), "mGrid firstIndex " + firstIndex + " lastIndex " 673 + lastIndex + " focusPosition " + focusPosition); 674 } 675 // fill rows with minimal view positions of the subset 676 for (int i = firstIndex; i <= lastIndex; i++) { 677 View v = findViewByPosition(i); 678 if (v == null) { 679 continue; 680 } 681 int row = mGrid.getLocation(i).row; 682 int low = getViewMin(v) + mScrollOffsetPrimary; 683 if (low < mRows[row].low) { 684 mRows[row].low = mRows[row].high = low; 685 } 686 } 687 int firstItemRowPosition = mRows[mGrid.getLocation(firstIndex).row].low; 688 if (firstItemRowPosition == Integer.MAX_VALUE) { 689 firstItemRowPosition = 0; 690 } 691 if (mState.didStructureChange()) { 692 // if there is structure change, the removed item might be in the 693 // subset, so it is meaningless to maintain the low locations. 694 for (int i = 0; i < mNumRows; i++) { 695 mRows[i].low = firstItemRowPosition; 696 mRows[i].high = firstItemRowPosition; 697 } 698 } else { 699 // fill other rows that does not include the subset using first item 700 for (int i = 0; i < mNumRows; i++) { 701 if (mRows[i].low == Integer.MAX_VALUE) { 702 mRows[i].low = mRows[i].high = firstItemRowPosition; 703 } 704 } 705 } 706 } 707 708 // Same adapter, we can reuse any attached views 709 detachAndScrapAttachedViews(mRecycler); 710 711 } else { 712 // otherwise recreate data structure 713 mRows = new StaggeredGrid.Row[mNumRows]; 714 715 for (int i = 0; i < mNumRows; i++) { 716 mRows[i] = new StaggeredGrid.Row(); 717 } 718 mGrid = new StaggeredGridDefault(); 719 if (newItemCount == 0) { 720 focusPosition = NO_POSITION; 721 } else if (focusPosition >= newItemCount) { 722 focusPosition = newItemCount - 1; 723 } 724 725 // Adapter may have changed so remove all attached views permanently 726 removeAndRecycleAllViews(mRecycler); 727 728 mScrollOffsetPrimary = 0; 729 mScrollOffsetSecondary = 0; 730 mWindowAlignment.reset(); 731 } 732 733 mGrid.setProvider(mGridProvider); 734 // mGrid share the same Row array information 735 mGrid.setRows(mRows); 736 mFirstVisiblePos = mLastVisiblePos = NO_POSITION; 737 738 initScrollController(); 739 updateScrollSecondAxis(); 740 741 return focusPosition; 742 } 743 744 private int getRowSizeSecondary(int rowIndex) { 745 if (mFixedRowSizeSecondary != 0) { 746 return mFixedRowSizeSecondary; 747 } 748 if (mRowSizeSecondary == null) { 749 return 0; 750 } 751 return mRowSizeSecondary[rowIndex]; 752 } 753 754 private int getRowStartSecondary(int rowIndex) { 755 int start = 0; 756 for (int i = 0; i < rowIndex; i++) { 757 start += getRowSizeSecondary(i) + mMarginSecondary; 758 } 759 return start; 760 } 761 762 private int getSizeSecondary() { 763 return getRowStartSecondary(mNumRows - 1) + getRowSizeSecondary(mNumRows - 1); 764 } 765 766 private void measureScrapChild(int position, int widthSpec, int heightSpec, 767 int[] measuredDimension) { 768 View view = mRecycler.getViewForPosition(position); 769 if (view != null) { 770 LayoutParams p = (LayoutParams) view.getLayoutParams(); 771 int childWidthSpec = ViewGroup.getChildMeasureSpec(widthSpec, 772 getPaddingLeft() + getPaddingRight(), p.width); 773 int childHeightSpec = ViewGroup.getChildMeasureSpec(heightSpec, 774 getPaddingTop() + getPaddingBottom(), p.height); 775 view.measure(childWidthSpec, childHeightSpec); 776 measuredDimension[0] = view.getMeasuredWidth(); 777 measuredDimension[1] = view.getMeasuredHeight(); 778 mRecycler.recycleView(view); 779 } 780 } 781 782 private boolean processRowSizeSecondary(boolean measure) { 783 if (mFixedRowSizeSecondary != 0) { 784 return false; 785 } 786 787 if (mGrid == null) { 788 if (mState.getItemCount() > 0) { 789 measureScrapChild(mFocusPosition == NO_POSITION ? 0 : mFocusPosition, 790 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 791 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 792 mMeasuredDimension); 793 if (DEBUG) Log.v(TAG, "measured scrap child: " + mMeasuredDimension[0] + 794 " " + mMeasuredDimension[1]); 795 } else { 796 mMeasuredDimension[0] = mMeasuredDimension[1] = 0; 797 } 798 } 799 800 List<Integer>[] rows = mGrid == null ? null : 801 mGrid.getItemPositionsInRows(mFirstVisiblePos, mLastVisiblePos); 802 boolean changed = false; 803 804 for (int rowIndex = 0; rowIndex < mNumRows; rowIndex++) { 805 int rowSize = 0; 806 807 final int rowItemCount = rows == null ? 1 : rows[rowIndex].size(); 808 if (DEBUG) Log.v(getTag(), "processRowSizeSecondary row " + rowIndex + 809 " rowItemCount " + rowItemCount); 810 811 for (int i = 0; i < rowItemCount; i++) { 812 if (rows != null) { 813 final int position = rows[rowIndex].get(i); 814 final View view = findViewByPosition(position); 815 if (measure && view.isLayoutRequested()) { 816 measureChild(view); 817 } 818 mMeasuredDimension[0] = view.getMeasuredWidth(); 819 mMeasuredDimension[1] = view.getMeasuredHeight(); 820 } 821 final int secondarySize = mOrientation == HORIZONTAL ? 822 mMeasuredDimension[1] : mMeasuredDimension[0]; 823 if (secondarySize > rowSize) { 824 rowSize = secondarySize; 825 } 826 } 827 if (DEBUG) Log.v(getTag(), "row " + rowIndex + " rowItemCount " + rowItemCount + 828 " rowSize " + rowSize); 829 830 if (mRowSizeSecondary[rowIndex] != rowSize) { 831 if (DEBUG) Log.v(getTag(), "row size secondary changed: " + mRowSizeSecondary[rowIndex] + 832 ", " + rowSize); 833 834 mRowSizeSecondary[rowIndex] = rowSize; 835 changed = true; 836 } 837 } 838 839 return changed; 840 } 841 842 /** 843 * Checks if we need to update row secondary sizes. 844 */ 845 private void updateRowSecondarySizeRefresh() { 846 mRowSecondarySizeRefresh = processRowSizeSecondary(false); 847 if (mRowSecondarySizeRefresh) { 848 if (DEBUG) Log.v(getTag(), "mRowSecondarySizeRefresh now set"); 849 forceRequestLayout(); 850 } 851 } 852 853 private void forceRequestLayout() { 854 if (DEBUG) Log.v(getTag(), "forceRequestLayout"); 855 // RecyclerView prevents us from requesting layout in many cases 856 // (during layout, during scroll, etc.) 857 // For secondary row size wrap_content support we currently need a 858 // second layout pass to update the measured size after having measured 859 // and added child views in layoutChildren. 860 // Force the second layout by posting a delayed runnable. 861 // TODO: investigate allowing a second layout pass, 862 // or move child add/measure logic to the measure phase. 863 mBaseGridView.postOnAnimation(mRequestLayoutRunnable); 864 } 865 866 private final Runnable mRequestLayoutRunnable = new Runnable() { 867 @Override 868 public void run() { 869 if (DEBUG) Log.v(getTag(), "request Layout from runnable"); 870 requestLayout(); 871 } 872 }; 873 874 @Override 875 public void onMeasure(Recycler recycler, State state, int widthSpec, int heightSpec) { 876 saveContext(recycler, state); 877 878 int sizePrimary, sizeSecondary, modeSecondary, paddingSecondary; 879 int measuredSizeSecondary; 880 if (mOrientation == HORIZONTAL) { 881 sizePrimary = MeasureSpec.getSize(widthSpec); 882 sizeSecondary = MeasureSpec.getSize(heightSpec); 883 modeSecondary = MeasureSpec.getMode(heightSpec); 884 paddingSecondary = getPaddingTop() + getPaddingBottom(); 885 } else { 886 sizeSecondary = MeasureSpec.getSize(widthSpec); 887 sizePrimary = MeasureSpec.getSize(heightSpec); 888 modeSecondary = MeasureSpec.getMode(widthSpec); 889 paddingSecondary = getPaddingLeft() + getPaddingRight(); 890 } 891 if (DEBUG) Log.v(getTag(), "onMeasure widthSpec " + Integer.toHexString(widthSpec) + 892 " heightSpec " + Integer.toHexString(heightSpec) + 893 " modeSecondary " + Integer.toHexString(modeSecondary) + 894 " sizeSecondary " + sizeSecondary + " " + this); 895 896 mMaxSizeSecondary = sizeSecondary; 897 898 if (mRowSizeSecondaryRequested == ViewGroup.LayoutParams.WRAP_CONTENT) { 899 mNumRows = mNumRowsRequested == 0 ? 1 : mNumRowsRequested; 900 mFixedRowSizeSecondary = 0; 901 902 if (mRowSizeSecondary == null || mRowSizeSecondary.length != mNumRows) { 903 mRowSizeSecondary = new int[mNumRows]; 904 } 905 906 // Measure all current children and update cached row heights 907 processRowSizeSecondary(true); 908 909 switch (modeSecondary) { 910 case MeasureSpec.UNSPECIFIED: 911 measuredSizeSecondary = getSizeSecondary() + paddingSecondary; 912 break; 913 case MeasureSpec.AT_MOST: 914 measuredSizeSecondary = Math.min(getSizeSecondary() + paddingSecondary, 915 mMaxSizeSecondary); 916 break; 917 case MeasureSpec.EXACTLY: 918 measuredSizeSecondary = mMaxSizeSecondary; 919 break; 920 default: 921 throw new IllegalStateException("wrong spec"); 922 } 923 924 } else { 925 switch (modeSecondary) { 926 case MeasureSpec.UNSPECIFIED: 927 if (mRowSizeSecondaryRequested == 0) { 928 if (mOrientation == HORIZONTAL) { 929 throw new IllegalStateException("Must specify rowHeight or view height"); 930 } else { 931 throw new IllegalStateException("Must specify columnWidth or view width"); 932 } 933 } 934 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 935 mNumRows = mNumRowsRequested == 0 ? 1 : mNumRowsRequested; 936 measuredSizeSecondary = mFixedRowSizeSecondary * mNumRows + mMarginSecondary 937 * (mNumRows - 1) + paddingSecondary; 938 break; 939 case MeasureSpec.AT_MOST: 940 case MeasureSpec.EXACTLY: 941 if (mNumRowsRequested == 0 && mRowSizeSecondaryRequested == 0) { 942 mNumRows = 1; 943 mFixedRowSizeSecondary = sizeSecondary - paddingSecondary; 944 } else if (mNumRowsRequested == 0) { 945 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 946 mNumRows = (sizeSecondary + mMarginSecondary) 947 / (mRowSizeSecondaryRequested + mMarginSecondary); 948 } else if (mRowSizeSecondaryRequested == 0) { 949 mNumRows = mNumRowsRequested; 950 mFixedRowSizeSecondary = (sizeSecondary - paddingSecondary - mMarginSecondary 951 * (mNumRows - 1)) / mNumRows; 952 } else { 953 mNumRows = mNumRowsRequested; 954 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 955 } 956 measuredSizeSecondary = sizeSecondary; 957 if (modeSecondary == MeasureSpec.AT_MOST) { 958 int childrenSize = mFixedRowSizeSecondary * mNumRows + mMarginSecondary 959 * (mNumRows - 1) + paddingSecondary; 960 if (childrenSize < measuredSizeSecondary) { 961 measuredSizeSecondary = childrenSize; 962 } 963 } 964 break; 965 default: 966 throw new IllegalStateException("wrong spec"); 967 } 968 } 969 if (mOrientation == HORIZONTAL) { 970 setMeasuredDimension(sizePrimary, measuredSizeSecondary); 971 } else { 972 setMeasuredDimension(measuredSizeSecondary, sizePrimary); 973 } 974 if (DEBUG) { 975 Log.v(getTag(), "onMeasure sizePrimary " + sizePrimary + 976 " measuredSizeSecondary " + measuredSizeSecondary + 977 " mFixedRowSizeSecondary " + mFixedRowSizeSecondary + 978 " mNumRows " + mNumRows); 979 } 980 981 leaveContext(); 982 } 983 984 private void measureChild(View child) { 985 final ViewGroup.LayoutParams lp = child.getLayoutParams(); 986 final int secondarySpec = (mRowSizeSecondaryRequested == ViewGroup.LayoutParams.WRAP_CONTENT) ? 987 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED) : 988 MeasureSpec.makeMeasureSpec(mFixedRowSizeSecondary, MeasureSpec.EXACTLY); 989 int widthSpec, heightSpec; 990 991 if (mOrientation == HORIZONTAL) { 992 widthSpec = ViewGroup.getChildMeasureSpec( 993 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 994 0, lp.width); 995 heightSpec = ViewGroup.getChildMeasureSpec(secondarySpec, 0, lp.height); 996 } else { 997 heightSpec = ViewGroup.getChildMeasureSpec( 998 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 999 0, lp.height); 1000 widthSpec = ViewGroup.getChildMeasureSpec(secondarySpec, 0, lp.width); 1001 } 1002 1003 child.measure(widthSpec, heightSpec); 1004 1005 if (DEBUG) Log.v(getTag(), "measureChild secondarySpec " + Integer.toHexString(secondarySpec) + 1006 " widthSpec " + Integer.toHexString(widthSpec) + 1007 " heightSpec " + Integer.toHexString(heightSpec) + 1008 " measuredWidth " + child.getMeasuredWidth() + 1009 " measuredHeight " + child.getMeasuredHeight()); 1010 if (DEBUG) Log.v(getTag(), "child lp width " + lp.width + " height " + lp.height); 1011 } 1012 1013 private StaggeredGrid.Provider mGridProvider = new StaggeredGrid.Provider() { 1014 1015 @Override 1016 public int getCount() { 1017 return mState.getItemCount(); 1018 } 1019 1020 @Override 1021 public void createItem(int index, int rowIndex, boolean append) { 1022 View v = getViewForPosition(index); 1023 if (mFirstVisiblePos >= 0) { 1024 // when StaggeredGrid append or prepend item, we must guarantee 1025 // that sibling item has created views already. 1026 if (append && index != mLastVisiblePos + 1) { 1027 throw new RuntimeException(); 1028 } else if (!append && index != mFirstVisiblePos - 1) { 1029 throw new RuntimeException(); 1030 } 1031 } 1032 1033 // See recyclerView docs: we don't need re-add scraped view if it was removed. 1034 if (!((RecyclerView.LayoutParams) v.getLayoutParams()).isItemRemoved()) { 1035 if (append) { 1036 addView(v); 1037 } else { 1038 addView(v, 0); 1039 } 1040 measureChild(v); 1041 } 1042 1043 int length = mOrientation == HORIZONTAL ? v.getMeasuredWidth() : v.getMeasuredHeight(); 1044 int start, end; 1045 if (append) { 1046 start = mRows[rowIndex].high; 1047 if (start != mRows[rowIndex].low) { 1048 // if there are existing item in the row, add margin between 1049 start += mMarginPrimary; 1050 } else { 1051 final int lastRow = mRows.length - 1; 1052 if (lastRow != rowIndex && mRows[lastRow].high != mRows[lastRow].low) { 1053 // if there are existing item in the last row, insert 1054 // the new item after the last item of last row. 1055 start = mRows[lastRow].high + mMarginPrimary; 1056 } 1057 } 1058 end = start + length; 1059 mRows[rowIndex].high = end; 1060 } else { 1061 end = mRows[rowIndex].low; 1062 if (end != mRows[rowIndex].high) { 1063 end -= mMarginPrimary; 1064 } else if (0 != rowIndex && mRows[0].high != mRows[0].low) { 1065 // if there are existing item in the first row, insert 1066 // the new item before the first item of first row. 1067 end = mRows[0].low - mMarginPrimary; 1068 } 1069 start = end - length; 1070 mRows[rowIndex].low = start; 1071 } 1072 if (mFirstVisiblePos < 0) { 1073 mFirstVisiblePos = mLastVisiblePos = index; 1074 } else { 1075 if (append) { 1076 mLastVisiblePos++; 1077 } else { 1078 mFirstVisiblePos--; 1079 } 1080 } 1081 if (DEBUG) Log.v(getTag(), "start " + start + " end " + end); 1082 int startSecondary = getRowStartSecondary(rowIndex) - mScrollOffsetSecondary; 1083 layoutChild(rowIndex, v, start - mScrollOffsetPrimary, end - mScrollOffsetPrimary, 1084 startSecondary); 1085 if (DEBUG) { 1086 Log.d(getTag(), "addView " + index + " " + v); 1087 } 1088 if (index == mFirstVisiblePos) { 1089 updateScrollMin(); 1090 } 1091 if (index == mLastVisiblePos) { 1092 updateScrollMax(); 1093 } 1094 } 1095 }; 1096 1097 private void layoutChild(int rowIndex, View v, int start, int end, int startSecondary) { 1098 int sizeSecondary = mOrientation == HORIZONTAL ? v.getMeasuredHeight() 1099 : v.getMeasuredWidth(); 1100 if (mFixedRowSizeSecondary > 0) { 1101 sizeSecondary = Math.min(sizeSecondary, mFixedRowSizeSecondary); 1102 } 1103 final int verticalGravity = mGravity & Gravity.VERTICAL_GRAVITY_MASK; 1104 final int horizontalGravity = mGravity & Gravity.HORIZONTAL_GRAVITY_MASK; 1105 if (mOrientation == HORIZONTAL && verticalGravity == Gravity.TOP 1106 || mOrientation == VERTICAL && horizontalGravity == Gravity.LEFT) { 1107 // do nothing 1108 } else if (mOrientation == HORIZONTAL && verticalGravity == Gravity.BOTTOM 1109 || mOrientation == VERTICAL && horizontalGravity == Gravity.RIGHT) { 1110 startSecondary += getRowSizeSecondary(rowIndex) - sizeSecondary; 1111 } else if (mOrientation == HORIZONTAL && verticalGravity == Gravity.CENTER_VERTICAL 1112 || mOrientation == VERTICAL && horizontalGravity == Gravity.CENTER_HORIZONTAL) { 1113 startSecondary += (getRowSizeSecondary(rowIndex) - sizeSecondary) / 2; 1114 } 1115 int left, top, right, bottom; 1116 if (mOrientation == HORIZONTAL) { 1117 left = start; 1118 top = startSecondary; 1119 right = end; 1120 bottom = startSecondary + sizeSecondary; 1121 } else { 1122 top = start; 1123 left = startSecondary; 1124 bottom = end; 1125 right = startSecondary + sizeSecondary; 1126 } 1127 v.layout(left, top, right, bottom); 1128 updateChildOpticalInsets(v, left, top, right, bottom); 1129 updateChildAlignments(v); 1130 } 1131 1132 private void updateChildOpticalInsets(View v, int left, int top, int right, int bottom) { 1133 LayoutParams p = (LayoutParams) v.getLayoutParams(); 1134 p.setOpticalInsets(left - v.getLeft(), top - v.getTop(), 1135 v.getRight() - right, v.getBottom() - bottom); 1136 } 1137 1138 private void updateChildAlignments(View v) { 1139 LayoutParams p = (LayoutParams) v.getLayoutParams(); 1140 p.setAlignX(mItemAlignment.horizontal.getAlignmentPosition(v)); 1141 p.setAlignY(mItemAlignment.vertical.getAlignmentPosition(v)); 1142 } 1143 1144 private void updateChildAlignments() { 1145 for (int i = 0, c = getChildCount(); i < c; i++) { 1146 updateChildAlignments(getChildAt(i)); 1147 } 1148 } 1149 1150 private boolean needsAppendVisibleItem() { 1151 if (mLastVisiblePos < mFocusPosition) { 1152 return true; 1153 } 1154 int right = mScrollOffsetPrimary + mSizePrimary; 1155 for (int i = 0; i < mNumRows; i++) { 1156 if (mRows[i].low == mRows[i].high) { 1157 if (mRows[i].high < right) { 1158 return true; 1159 } 1160 } else if (mRows[i].high < right - mMarginPrimary) { 1161 return true; 1162 } 1163 } 1164 return false; 1165 } 1166 1167 private boolean needsPrependVisibleItem() { 1168 if (mFirstVisiblePos > mFocusPosition) { 1169 return true; 1170 } 1171 for (int i = 0; i < mNumRows; i++) { 1172 if (mRows[i].low == mRows[i].high) { 1173 if (mRows[i].low > mScrollOffsetPrimary) { 1174 return true; 1175 } 1176 } else if (mRows[i].low - mMarginPrimary > mScrollOffsetPrimary) { 1177 return true; 1178 } 1179 } 1180 return false; 1181 } 1182 1183 // Append one column if possible and return true if reach end. 1184 private boolean appendOneVisibleItem() { 1185 while (true) { 1186 if (mLastVisiblePos != NO_POSITION && mLastVisiblePos < mState.getItemCount() -1 && 1187 mLastVisiblePos < mGrid.getLastIndex()) { 1188 // append invisible view of saved location till last row 1189 final int index = mLastVisiblePos + 1; 1190 final int row = mGrid.getLocation(index).row; 1191 mGridProvider.createItem(index, row, true); 1192 if (row == mNumRows - 1) { 1193 return false; 1194 } 1195 } else if ((mLastVisiblePos == NO_POSITION && mState.getItemCount() > 0) || 1196 (mLastVisiblePos != NO_POSITION && 1197 mLastVisiblePos < mState.getItemCount() - 1)) { 1198 mGrid.appendItems(mScrollOffsetPrimary + mSizePrimary); 1199 return false; 1200 } else { 1201 return true; 1202 } 1203 } 1204 } 1205 1206 private void appendVisibleItems() { 1207 while (needsAppendVisibleItem()) { 1208 if (appendOneVisibleItem()) { 1209 break; 1210 } 1211 } 1212 } 1213 1214 // Prepend one column if possible and return true if reach end. 1215 private boolean prependOneVisibleItem() { 1216 while (true) { 1217 if (mFirstVisiblePos > 0) { 1218 if (mFirstVisiblePos > mGrid.getFirstIndex()) { 1219 // prepend invisible view of saved location till first row 1220 final int index = mFirstVisiblePos - 1; 1221 final int row = mGrid.getLocation(index).row; 1222 mGridProvider.createItem(index, row, false); 1223 if (row == 0) { 1224 return false; 1225 } 1226 } else { 1227 mGrid.prependItems(mScrollOffsetPrimary); 1228 return false; 1229 } 1230 } else { 1231 return true; 1232 } 1233 } 1234 } 1235 1236 private void prependVisibleItems() { 1237 while (needsPrependVisibleItem()) { 1238 if (prependOneVisibleItem()) { 1239 break; 1240 } 1241 } 1242 } 1243 1244 private void removeChildAt(int position) { 1245 View v = findViewByPosition(position); 1246 if (v != null) { 1247 if (DEBUG) { 1248 Log.d(getTag(), "removeAndRecycleViewAt " + position); 1249 } 1250 removeAndRecycleView(v, mRecycler); 1251 } 1252 } 1253 1254 private void removeInvisibleViewsAtEnd() { 1255 if (!mPruneChild) { 1256 return; 1257 } 1258 boolean update = false; 1259 while(mLastVisiblePos > mFirstVisiblePos && mLastVisiblePos > mFocusPosition) { 1260 View view = findViewByPosition(mLastVisiblePos); 1261 if (getViewMin(view) > mSizePrimary) { 1262 removeChildAt(mLastVisiblePos); 1263 mLastVisiblePos--; 1264 update = true; 1265 } else { 1266 break; 1267 } 1268 } 1269 if (update) { 1270 updateRowsMinMax(); 1271 } 1272 } 1273 1274 private void removeInvisibleViewsAtFront() { 1275 if (!mPruneChild) { 1276 return; 1277 } 1278 boolean update = false; 1279 while(mLastVisiblePos > mFirstVisiblePos && mFirstVisiblePos < mFocusPosition) { 1280 View view = findViewByPosition(mFirstVisiblePos); 1281 if (getViewMax(view) < 0) { 1282 removeChildAt(mFirstVisiblePos); 1283 mFirstVisiblePos++; 1284 update = true; 1285 } else { 1286 break; 1287 } 1288 } 1289 if (update) { 1290 updateRowsMinMax(); 1291 } 1292 } 1293 1294 private void updateRowsMinMax() { 1295 if (mFirstVisiblePos < 0) { 1296 return; 1297 } 1298 for (int i = 0; i < mNumRows; i++) { 1299 mRows[i].low = Integer.MAX_VALUE; 1300 mRows[i].high = Integer.MIN_VALUE; 1301 } 1302 for (int i = mFirstVisiblePos; i <= mLastVisiblePos; i++) { 1303 View view = findViewByPosition(i); 1304 int row = mGrid.getLocation(i).row; 1305 int low = getViewMin(view) + mScrollOffsetPrimary; 1306 if (low < mRows[row].low) { 1307 mRows[row].low = low; 1308 } 1309 int high = getViewMax(view) + mScrollOffsetPrimary; 1310 if (high > mRows[row].high) { 1311 mRows[row].high = high; 1312 } 1313 } 1314 } 1315 1316 // Fast layout when there is no structure change, adapter change, etc. 1317 protected void fastRelayout() { 1318 initScrollController(); 1319 1320 List<Integer>[] rows = mGrid.getItemPositionsInRows(mFirstVisiblePos, mLastVisiblePos); 1321 1322 // relayout and repositioning views on each row 1323 for (int i = 0; i < mNumRows; i++) { 1324 List<Integer> row = rows[i]; 1325 final int startSecondary = getRowStartSecondary(i) - mScrollOffsetSecondary; 1326 for (int j = 0, size = row.size(); j < size; j++) { 1327 final int position = row.get(j); 1328 final View view = findViewByPosition(position); 1329 int primaryDelta, start, end; 1330 1331 if (mOrientation == HORIZONTAL) { 1332 final int primarySize = view.getMeasuredWidth(); 1333 if (view.isLayoutRequested()) { 1334 measureChild(view); 1335 } 1336 start = getViewMin(view); 1337 end = start + view.getMeasuredWidth(); 1338 primaryDelta = view.getMeasuredWidth() - primarySize; 1339 if (primaryDelta != 0) { 1340 for (int k = j + 1; k < size; k++) { 1341 findViewByPosition(row.get(k)).offsetLeftAndRight(primaryDelta); 1342 } 1343 } 1344 } else { 1345 final int primarySize = view.getMeasuredHeight(); 1346 if (view.isLayoutRequested()) { 1347 measureChild(view); 1348 } 1349 start = getViewMin(view); 1350 end = start + view.getMeasuredHeight(); 1351 primaryDelta = view.getMeasuredHeight() - primarySize; 1352 if (primaryDelta != 0) { 1353 for (int k = j + 1; k < size; k++) { 1354 findViewByPosition(row.get(k)).offsetTopAndBottom(primaryDelta); 1355 } 1356 } 1357 } 1358 layoutChild(i, view, start, end, startSecondary); 1359 } 1360 } 1361 1362 updateRowsMinMax(); 1363 appendVisibleItems(); 1364 prependVisibleItems(); 1365 1366 updateRowsMinMax(); 1367 updateScrollMin(); 1368 updateScrollMax(); 1369 updateScrollSecondAxis(); 1370 1371 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED) { 1372 View focusView = findViewByPosition(mFocusPosition == NO_POSITION ? 0 : mFocusPosition); 1373 scrollToView(focusView, false); 1374 } 1375 } 1376 1377 public void removeAndRecycleAllViews(RecyclerView.Recycler recycler) { 1378 if (DEBUG) Log.v(TAG, "removeAndRecycleAllViews " + getChildCount()); 1379 for (int i = getChildCount() - 1; i >= 0; i--) { 1380 removeAndRecycleViewAt(i, recycler); 1381 } 1382 } 1383 1384 // Lays out items based on the current scroll position 1385 @Override 1386 public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state) { 1387 if (DEBUG) { 1388 Log.v(getTag(), "layoutChildren start numRows " + mNumRows + " mScrollOffsetSecondary " 1389 + mScrollOffsetSecondary + " mScrollOffsetPrimary " + mScrollOffsetPrimary 1390 + " inPreLayout " + state.isPreLayout() 1391 + " didStructureChange " + state.didStructureChange() 1392 + " mForceFullLayout " + mForceFullLayout); 1393 Log.v(getTag(), "width " + getWidth() + " height " + getHeight()); 1394 } 1395 1396 if (mNumRows == 0) { 1397 // haven't done measure yet 1398 return; 1399 } 1400 final int itemCount = state.getItemCount(); 1401 if (itemCount < 0) { 1402 return; 1403 } 1404 1405 if (!mLayoutEnabled) { 1406 discardLayoutInfo(); 1407 removeAndRecycleAllViews(recycler); 1408 return; 1409 } 1410 mInLayout = true; 1411 1412 saveContext(recycler, state); 1413 // Track the old focus view so we can adjust our system scroll position 1414 // so that any scroll animations happening now will remain valid. 1415 // We must use same delta in Pre Layout (if prelayout exists) and second layout. 1416 // So we cache the deltas in PreLayout and use it in second layout. 1417 int delta = 0, deltaSecondary = 0; 1418 if (!state.isPreLayout() && mUseDeltaInPreLayout) { 1419 delta = mDeltaInPreLayout; 1420 deltaSecondary = mDeltaSecondaryInPreLayout; 1421 } else { 1422 if (mFocusPosition != NO_POSITION 1423 && mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED) { 1424 // FIXME: we should get the remaining scroll animation offset from RecyclerView 1425 View focusView = findViewByPosition(mFocusPosition); 1426 if (focusView != null) { 1427 delta = mWindowAlignment.mainAxis().getSystemScrollPos(mScrollOffsetPrimary 1428 + getViewCenter(focusView), false, false) - mScrollOffsetPrimary; 1429 deltaSecondary = mWindowAlignment.secondAxis().getSystemScrollPos( 1430 mScrollOffsetSecondary + getViewCenterSecondary(focusView), 1431 false, false) - mScrollOffsetSecondary; 1432 if (mUseDeltaInPreLayout = state.isPreLayout()) { 1433 mDeltaInPreLayout = delta; 1434 mDeltaSecondaryInPreLayout = deltaSecondary; 1435 } 1436 } 1437 } 1438 } 1439 1440 final boolean hasDoneFirstLayout = hasDoneFirstLayout(); 1441 int savedFocusPos = mFocusPosition; 1442 boolean fastRelayout = false; 1443 if (!mState.didStructureChange() && !mForceFullLayout && hasDoneFirstLayout) { 1444 fastRelayout = true; 1445 fastRelayout(); 1446 } else { 1447 boolean hadFocus = mBaseGridView.hasFocus(); 1448 1449 int newFocusPosition = init(mFocusPosition); 1450 if (DEBUG) { 1451 Log.v(getTag(), "mFocusPosition " + mFocusPosition + " newFocusPosition " 1452 + newFocusPosition); 1453 } 1454 1455 // depending on result of init(), either recreating everything 1456 // or try to reuse the row start positions near mFocusPosition 1457 if (mGrid.getSize() == 0) { 1458 // this is a fresh creating all items, starting from 1459 // mFocusPosition with a estimated row index. 1460 mGrid.setStart(newFocusPosition, StaggeredGrid.START_DEFAULT); 1461 1462 // Can't track the old focus view 1463 delta = deltaSecondary = 0; 1464 1465 } else { 1466 // mGrid remembers Locations for the column that 1467 // contains mFocusePosition and also mRows remembers start 1468 // positions of each row. 1469 // Manually re-create child views for that column 1470 int firstIndex = mGrid.getFirstIndex(); 1471 int lastIndex = mGrid.getLastIndex(); 1472 for (int i = firstIndex; i <= lastIndex; i++) { 1473 mGridProvider.createItem(i, mGrid.getLocation(i).row, true); 1474 } 1475 } 1476 // add visible views at end until reach the end of window 1477 appendVisibleItems(); 1478 // add visible views at front until reach the start of window 1479 prependVisibleItems(); 1480 // multiple rounds: scrollToView of first round may drag first/last child into 1481 // "visible window" and we update scrollMin/scrollMax then run second scrollToView 1482 int oldFirstVisible; 1483 int oldLastVisible; 1484 do { 1485 oldFirstVisible = mFirstVisiblePos; 1486 oldLastVisible = mLastVisiblePos; 1487 View focusView = findViewByPosition(newFocusPosition); 1488 // we need force to initialize the child view's position 1489 scrollToView(focusView, false); 1490 if (focusView != null && hadFocus) { 1491 focusView.requestFocus(); 1492 } 1493 appendVisibleItems(); 1494 prependVisibleItems(); 1495 removeInvisibleViewsAtFront(); 1496 removeInvisibleViewsAtEnd(); 1497 } while (mFirstVisiblePos != oldFirstVisible || mLastVisiblePos != oldLastVisible); 1498 } 1499 mForceFullLayout = false; 1500 1501 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED) { 1502 scrollDirectionPrimary(-delta); 1503 scrollDirectionSecondary(-deltaSecondary); 1504 } 1505 appendVisibleItems(); 1506 prependVisibleItems(); 1507 removeInvisibleViewsAtFront(); 1508 removeInvisibleViewsAtEnd(); 1509 1510 if (DEBUG) { 1511 StringWriter sw = new StringWriter(); 1512 PrintWriter pw = new PrintWriter(sw); 1513 mGrid.debugPrint(pw); 1514 Log.d(getTag(), sw.toString()); 1515 } 1516 1517 if (mRowSecondarySizeRefresh) { 1518 mRowSecondarySizeRefresh = false; 1519 } else { 1520 updateRowSecondarySizeRefresh(); 1521 } 1522 1523 if (!state.isPreLayout()) { 1524 mUseDeltaInPreLayout = false; 1525 if (!fastRelayout || mFocusPosition != savedFocusPos) { 1526 dispatchChildSelected(); 1527 } 1528 } 1529 mInLayout = false; 1530 leaveContext(); 1531 if (DEBUG) Log.v(getTag(), "layoutChildren end"); 1532 } 1533 1534 private void offsetChildrenSecondary(int increment) { 1535 final int childCount = getChildCount(); 1536 if (mOrientation == HORIZONTAL) { 1537 for (int i = 0; i < childCount; i++) { 1538 getChildAt(i).offsetTopAndBottom(increment); 1539 } 1540 } else { 1541 for (int i = 0; i < childCount; i++) { 1542 getChildAt(i).offsetLeftAndRight(increment); 1543 } 1544 } 1545 } 1546 1547 private void offsetChildrenPrimary(int increment) { 1548 final int childCount = getChildCount(); 1549 if (mOrientation == VERTICAL) { 1550 for (int i = 0; i < childCount; i++) { 1551 getChildAt(i).offsetTopAndBottom(increment); 1552 } 1553 } else { 1554 for (int i = 0; i < childCount; i++) { 1555 getChildAt(i).offsetLeftAndRight(increment); 1556 } 1557 } 1558 } 1559 1560 @Override 1561 public int scrollHorizontallyBy(int dx, Recycler recycler, RecyclerView.State state) { 1562 if (DEBUG) Log.v(getTag(), "scrollHorizontallyBy " + dx); 1563 if (!mLayoutEnabled || !hasDoneFirstLayout()) { 1564 return 0; 1565 } 1566 saveContext(recycler, state); 1567 int result; 1568 if (mOrientation == HORIZONTAL) { 1569 result = scrollDirectionPrimary(dx); 1570 } else { 1571 result = scrollDirectionSecondary(dx); 1572 } 1573 leaveContext(); 1574 return result; 1575 } 1576 1577 @Override 1578 public int scrollVerticallyBy(int dy, Recycler recycler, RecyclerView.State state) { 1579 if (DEBUG) Log.v(getTag(), "scrollVerticallyBy " + dy); 1580 if (!mLayoutEnabled || !hasDoneFirstLayout()) { 1581 return 0; 1582 } 1583 saveContext(recycler, state); 1584 int result; 1585 if (mOrientation == VERTICAL) { 1586 result = scrollDirectionPrimary(dy); 1587 } else { 1588 result = scrollDirectionSecondary(dy); 1589 } 1590 leaveContext(); 1591 return result; 1592 } 1593 1594 // scroll in main direction may add/prune views 1595 private int scrollDirectionPrimary(int da) { 1596 if (da > 0) { 1597 if (!mWindowAlignment.mainAxis().isMaxUnknown()) { 1598 int maxScroll = mWindowAlignment.mainAxis().getMaxScroll(); 1599 if (mScrollOffsetPrimary + da > maxScroll) { 1600 da = maxScroll - mScrollOffsetPrimary; 1601 } 1602 } 1603 } else if (da < 0) { 1604 if (!mWindowAlignment.mainAxis().isMinUnknown()) { 1605 int minScroll = mWindowAlignment.mainAxis().getMinScroll(); 1606 if (mScrollOffsetPrimary + da < minScroll) { 1607 da = minScroll - mScrollOffsetPrimary; 1608 } 1609 } 1610 } 1611 if (da == 0) { 1612 return 0; 1613 } 1614 offsetChildrenPrimary(-da); 1615 mScrollOffsetPrimary += da; 1616 if (mInLayout) { 1617 return da; 1618 } 1619 1620 int childCount = getChildCount(); 1621 boolean updated; 1622 1623 if (da > 0) { 1624 appendVisibleItems(); 1625 } else if (da < 0) { 1626 prependVisibleItems(); 1627 } 1628 updated = getChildCount() > childCount; 1629 childCount = getChildCount(); 1630 1631 if (da > 0) { 1632 removeInvisibleViewsAtFront(); 1633 } else if (da < 0) { 1634 removeInvisibleViewsAtEnd(); 1635 } 1636 updated |= getChildCount() < childCount; 1637 1638 if (updated) { 1639 updateRowSecondarySizeRefresh(); 1640 } 1641 1642 mBaseGridView.invalidate(); 1643 return da; 1644 } 1645 1646 // scroll in second direction will not add/prune views 1647 private int scrollDirectionSecondary(int dy) { 1648 if (dy == 0) { 1649 return 0; 1650 } 1651 offsetChildrenSecondary(-dy); 1652 mScrollOffsetSecondary += dy; 1653 mBaseGridView.invalidate(); 1654 return dy; 1655 } 1656 1657 private void updateScrollMax() { 1658 if (mLastVisiblePos < 0) { 1659 return; 1660 } 1661 final boolean lastAvailable = mLastVisiblePos == mState.getItemCount() - 1; 1662 final boolean maxUnknown = mWindowAlignment.mainAxis().isMaxUnknown(); 1663 if (!lastAvailable && maxUnknown) { 1664 return; 1665 } 1666 int maxEdge = Integer.MIN_VALUE; 1667 int rowIndex = -1; 1668 for (int i = 0; i < mRows.length; i++) { 1669 if (mRows[i].high > maxEdge) { 1670 maxEdge = mRows[i].high; 1671 rowIndex = i; 1672 } 1673 } 1674 int maxScroll = Integer.MAX_VALUE; 1675 for (int i = mLastVisiblePos; i >= mFirstVisiblePos; i--) { 1676 StaggeredGrid.Location location = mGrid.getLocation(i); 1677 if (location != null && location.row == rowIndex) { 1678 int savedMaxEdge = mWindowAlignment.mainAxis().getMaxEdge(); 1679 mWindowAlignment.mainAxis().setMaxEdge(maxEdge); 1680 maxScroll = getPrimarySystemScrollPosition(findViewByPosition(i)); 1681 mWindowAlignment.mainAxis().setMaxEdge(savedMaxEdge); 1682 break; 1683 } 1684 } 1685 if (lastAvailable) { 1686 mWindowAlignment.mainAxis().setMaxEdge(maxEdge); 1687 mWindowAlignment.mainAxis().setMaxScroll(maxScroll); 1688 if (DEBUG) Log.v(getTag(), "updating scroll maxEdge to " + maxEdge + 1689 " scrollMax to " + maxScroll); 1690 } else { 1691 // the maxScroll for currently last visible item is larger, 1692 // so we must invalidate the max scroll value. 1693 if (maxScroll > mWindowAlignment.mainAxis().getMaxScroll()) { 1694 mWindowAlignment.mainAxis().invalidateScrollMax(); 1695 if (DEBUG) Log.v(getTag(), "Invalidate scrollMax since it should be " 1696 + "greater than " + maxScroll); 1697 } 1698 } 1699 } 1700 1701 private void updateScrollMin() { 1702 if (mFirstVisiblePos < 0) { 1703 return; 1704 } 1705 final boolean firstAvailable = mFirstVisiblePos == 0; 1706 final boolean minUnknown = mWindowAlignment.mainAxis().isMinUnknown(); 1707 if (!firstAvailable && minUnknown) { 1708 return; 1709 } 1710 int minEdge = Integer.MAX_VALUE; 1711 int rowIndex = -1; 1712 for (int i = 0; i < mRows.length; i++) { 1713 if (mRows[i].low < minEdge) { 1714 minEdge = mRows[i].low; 1715 rowIndex = i; 1716 } 1717 } 1718 int minScroll = Integer.MIN_VALUE; 1719 for (int i = mFirstVisiblePos; i <= mLastVisiblePos; i++) { 1720 StaggeredGrid.Location location = mGrid.getLocation(i); 1721 if (location != null && location.row == rowIndex) { 1722 int savedMinEdge = mWindowAlignment.mainAxis().getMinEdge(); 1723 mWindowAlignment.mainAxis().setMinEdge(minEdge); 1724 minScroll = getPrimarySystemScrollPosition(findViewByPosition(i)); 1725 mWindowAlignment.mainAxis().setMinEdge(savedMinEdge); 1726 break; 1727 } 1728 } 1729 if (firstAvailable) { 1730 mWindowAlignment.mainAxis().setMinEdge(minEdge); 1731 mWindowAlignment.mainAxis().setMinScroll(minScroll); 1732 if (DEBUG) Log.v(getTag(), "updating scroll minEdge to " + minEdge + 1733 " scrollMin to " + minScroll); 1734 } else { 1735 // the minScroll for currently first visible item is smaller, 1736 // so we must invalidate the min scroll value. 1737 if (minScroll < mWindowAlignment.mainAxis().getMinScroll()) { 1738 mWindowAlignment.mainAxis().invalidateScrollMin(); 1739 if (DEBUG) Log.v(getTag(), "Invalidate scrollMin, since it should be " 1740 + "less than " + minScroll); 1741 } 1742 } 1743 } 1744 1745 private void updateScrollSecondAxis() { 1746 mWindowAlignment.secondAxis().setMinEdge(0); 1747 mWindowAlignment.secondAxis().setMaxEdge(getSizeSecondary()); 1748 } 1749 1750 private void initScrollController() { 1751 mWindowAlignment.horizontal.setSize(getWidth()); 1752 mWindowAlignment.horizontal.setPadding(getPaddingLeft(), getPaddingRight()); 1753 mWindowAlignment.vertical.setSize(getHeight()); 1754 mWindowAlignment.vertical.setPadding(getPaddingTop(), getPaddingBottom()); 1755 mSizePrimary = mWindowAlignment.mainAxis().getSize(); 1756 1757 if (DEBUG) { 1758 Log.v(getTag(), "initScrollController mSizePrimary " + mSizePrimary 1759 + " mWindowAlignment " + mWindowAlignment); 1760 } 1761 } 1762 1763 public void setSelection(RecyclerView parent, int position) { 1764 setSelection(parent, position, false); 1765 } 1766 1767 public void setSelectionSmooth(RecyclerView parent, int position) { 1768 setSelection(parent, position, true); 1769 } 1770 1771 public int getSelection() { 1772 return mFocusPosition; 1773 } 1774 1775 public void setSelection(RecyclerView parent, int position, boolean smooth) { 1776 if (mFocusPosition == position) { 1777 return; 1778 } 1779 View view = findViewByPosition(position); 1780 if (view != null) { 1781 scrollToView(view, smooth); 1782 } else { 1783 mFocusPosition = position; 1784 if (!mLayoutEnabled) { 1785 return; 1786 } 1787 if (smooth) { 1788 if (!hasDoneFirstLayout()) { 1789 Log.w(getTag(), "setSelectionSmooth should " + 1790 "not be called before first layout pass"); 1791 return; 1792 } 1793 LinearSmoothScroller linearSmoothScroller = 1794 new LinearSmoothScroller(parent.getContext()) { 1795 @Override 1796 public PointF computeScrollVectorForPosition(int targetPosition) { 1797 if (getChildCount() == 0) { 1798 return null; 1799 } 1800 final int firstChildPos = getPosition(getChildAt(0)); 1801 final int direction = targetPosition < firstChildPos ? -1 : 1; 1802 if (mOrientation == HORIZONTAL) { 1803 return new PointF(direction, 0); 1804 } else { 1805 return new PointF(0, direction); 1806 } 1807 } 1808 @Override 1809 protected void onTargetFound(View targetView, 1810 RecyclerView.State state, Action action) { 1811 if (hasFocus()) { 1812 targetView.requestFocus(); 1813 } else { 1814 dispatchChildSelected(); 1815 } 1816 if (getScrollPosition(targetView, mTempDeltas)) { 1817 int dx, dy; 1818 if (mOrientation == HORIZONTAL) { 1819 dx = mTempDeltas[0]; 1820 dy = mTempDeltas[1]; 1821 } else { 1822 dx = mTempDeltas[1]; 1823 dy = mTempDeltas[0]; 1824 } 1825 final int distance = (int) Math.sqrt(dx * dx + dy * dy); 1826 final int time = calculateTimeForDeceleration(distance); 1827 action.update(dx, dy, time, mDecelerateInterpolator); 1828 } 1829 } 1830 }; 1831 linearSmoothScroller.setTargetPosition(position); 1832 startSmoothScroll(linearSmoothScroller); 1833 } else { 1834 mForceFullLayout = true; 1835 parent.requestLayout(); 1836 } 1837 } 1838 } 1839 1840 @Override 1841 public void onItemsAdded(RecyclerView recyclerView, int positionStart, int itemCount) { 1842 boolean needsLayout = false; 1843 if (itemCount != 0) { 1844 if (mFirstVisiblePos < 0) { 1845 needsLayout = true; 1846 } else if (!(positionStart > mLastVisiblePos + 1 || 1847 positionStart + itemCount < mFirstVisiblePos - 1)) { 1848 needsLayout = true; 1849 } 1850 } 1851 if (needsLayout) { 1852 recyclerView.requestLayout(); 1853 } 1854 } 1855 1856 @Override 1857 public boolean onRequestChildFocus(RecyclerView parent, View child, View focused) { 1858 if (mFocusSearchDisabled) { 1859 return true; 1860 } 1861 if (!mInLayout) { 1862 scrollToView(child, true); 1863 } 1864 return true; 1865 } 1866 1867 @Override 1868 public boolean requestChildRectangleOnScreen(RecyclerView parent, View view, Rect rect, 1869 boolean immediate) { 1870 if (DEBUG) Log.v(getTag(), "requestChildRectangleOnScreen " + view + " " + rect); 1871 return false; 1872 } 1873 1874 int getScrollOffsetX() { 1875 return mOrientation == HORIZONTAL ? mScrollOffsetPrimary : mScrollOffsetSecondary; 1876 } 1877 1878 int getScrollOffsetY() { 1879 return mOrientation == HORIZONTAL ? mScrollOffsetSecondary : mScrollOffsetPrimary; 1880 } 1881 1882 public void getViewSelectedOffsets(View view, int[] offsets) { 1883 if (mOrientation == HORIZONTAL) { 1884 offsets[0] = getPrimarySystemScrollPosition(view) - mScrollOffsetPrimary; 1885 offsets[1] = getSecondarySystemScrollPosition(view) - mScrollOffsetSecondary; 1886 } else { 1887 offsets[1] = getPrimarySystemScrollPosition(view) - mScrollOffsetPrimary; 1888 offsets[0] = getSecondarySystemScrollPosition(view) - mScrollOffsetSecondary; 1889 } 1890 } 1891 1892 private int getPrimarySystemScrollPosition(View view) { 1893 int viewCenterPrimary = mScrollOffsetPrimary + getViewCenter(view); 1894 int pos = getPositionByView(view); 1895 StaggeredGrid.Location location = mGrid.getLocation(pos); 1896 final int row = location.row; 1897 boolean isFirst = mFirstVisiblePos == 0; 1898 // TODO: change to use State object in onRequestChildFocus() 1899 boolean isLast = mLastVisiblePos == (mState == null ? 1900 getItemCount() : mState.getItemCount()) - 1; 1901 if (isFirst || isLast) { 1902 for (int i = getChildCount() - 1; i >= 0; i--) { 1903 int position = getPositionByIndex(i); 1904 StaggeredGrid.Location loc = mGrid.getLocation(position); 1905 if (loc != null && loc.row == row) { 1906 if (position < pos) { 1907 isFirst = false; 1908 } else if (position > pos) { 1909 isLast = false; 1910 } 1911 } 1912 } 1913 } 1914 return mWindowAlignment.mainAxis().getSystemScrollPos(viewCenterPrimary, isFirst, isLast); 1915 } 1916 1917 private int getSecondarySystemScrollPosition(View view) { 1918 int viewCenterSecondary = mScrollOffsetSecondary + getViewCenterSecondary(view); 1919 int pos = getPositionByView(view); 1920 StaggeredGrid.Location location = mGrid.getLocation(pos); 1921 final int row = location.row; 1922 boolean isFirst = row == 0; 1923 boolean isLast = row == mGrid.getNumRows() - 1; 1924 return mWindowAlignment.secondAxis().getSystemScrollPos(viewCenterSecondary, 1925 isFirst, isLast); 1926 } 1927 1928 /** 1929 * Scroll to a given child view and change mFocusPosition. 1930 */ 1931 private void scrollToView(View view, boolean smooth) { 1932 int newFocusPosition = getPositionByView(view); 1933 if (newFocusPosition != mFocusPosition) { 1934 mFocusPosition = newFocusPosition; 1935 if (!mInLayout) { 1936 dispatchChildSelected(); 1937 } 1938 } 1939 if (mBaseGridView.isChildrenDrawingOrderEnabledInternal()) { 1940 mBaseGridView.invalidate(); 1941 } 1942 if (view == null) { 1943 return; 1944 } 1945 if (!view.hasFocus() && mBaseGridView.hasFocus()) { 1946 // transfer focus to the child if it does not have focus yet (e.g. triggered 1947 // by setSelection()) 1948 view.requestFocus(); 1949 } 1950 if (getScrollPosition(view, mTempDeltas)) { 1951 scrollGrid(mTempDeltas[0], mTempDeltas[1], smooth); 1952 } 1953 } 1954 1955 private boolean getScrollPosition(View view, int[] deltas) { 1956 switch (mFocusScrollStrategy) { 1957 case BaseGridView.FOCUS_SCROLL_ALIGNED: 1958 default: 1959 return getAlignedPosition(view, deltas); 1960 case BaseGridView.FOCUS_SCROLL_ITEM: 1961 case BaseGridView.FOCUS_SCROLL_PAGE: 1962 return getNoneAlignedPosition(view, deltas); 1963 } 1964 } 1965 1966 private boolean getNoneAlignedPosition(View view, int[] deltas) { 1967 int pos = getPositionByView(view); 1968 int viewMin = getViewMin(view); 1969 int viewMax = getViewMax(view); 1970 // we either align "firstView" to left/top padding edge 1971 // or align "lastView" to right/bottom padding edge 1972 View firstView = null; 1973 View lastView = null; 1974 int paddingLow = mWindowAlignment.mainAxis().getPaddingLow(); 1975 int clientSize = mWindowAlignment.mainAxis().getClientSize(); 1976 final int row = mGrid.getLocation(pos).row; 1977 if (viewMin < paddingLow) { 1978 // view enters low padding area: 1979 firstView = view; 1980 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_PAGE) { 1981 // scroll one "page" left/top, 1982 // align first visible item of the "page" at the low padding edge. 1983 while (!prependOneVisibleItem()) { 1984 List<Integer> positions = 1985 mGrid.getItemPositionsInRows(mFirstVisiblePos, pos)[row]; 1986 firstView = findViewByPosition(positions.get(0)); 1987 if (viewMax - getViewMin(firstView) > clientSize) { 1988 if (positions.size() > 1) { 1989 firstView = findViewByPosition(positions.get(1)); 1990 } 1991 break; 1992 } 1993 } 1994 } 1995 } else if (viewMax > clientSize + paddingLow) { 1996 // view enters high padding area: 1997 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_PAGE) { 1998 // scroll whole one page right/bottom, align view at the low padding edge. 1999 firstView = view; 2000 do { 2001 List<Integer> positions = 2002 mGrid.getItemPositionsInRows(pos, mLastVisiblePos)[row]; 2003 lastView = findViewByPosition(positions.get(positions.size() - 1)); 2004 if (getViewMax(lastView) - viewMin > clientSize) { 2005 lastView = null; 2006 break; 2007 } 2008 } while (!appendOneVisibleItem()); 2009 if (lastView != null) { 2010 // however if we reached end, we should align last view. 2011 firstView = null; 2012 } 2013 } else { 2014 lastView = view; 2015 } 2016 } 2017 int scrollPrimary = 0; 2018 int scrollSecondary = 0; 2019 if (firstView != null) { 2020 scrollPrimary = getViewMin(firstView) - paddingLow; 2021 } else if (lastView != null) { 2022 scrollPrimary = getViewMax(lastView) - (paddingLow + clientSize); 2023 } 2024 View secondaryAlignedView; 2025 if (firstView != null) { 2026 secondaryAlignedView = firstView; 2027 } else if (lastView != null) { 2028 secondaryAlignedView = lastView; 2029 } else { 2030 secondaryAlignedView = view; 2031 } 2032 scrollSecondary = getSecondarySystemScrollPosition(secondaryAlignedView); 2033 scrollSecondary -= mScrollOffsetSecondary; 2034 if (scrollPrimary != 0 || scrollSecondary != 0) { 2035 deltas[0] = scrollPrimary; 2036 deltas[1] = scrollSecondary; 2037 return true; 2038 } 2039 return false; 2040 } 2041 2042 private boolean getAlignedPosition(View view, int[] deltas) { 2043 int scrollPrimary = getPrimarySystemScrollPosition(view); 2044 int scrollSecondary = getSecondarySystemScrollPosition(view); 2045 if (DEBUG) { 2046 Log.v(getTag(), "getAlignedPosition " + scrollPrimary + " " + scrollSecondary 2047 +" " + mWindowAlignment); 2048 } 2049 scrollPrimary -= mScrollOffsetPrimary; 2050 scrollSecondary -= mScrollOffsetSecondary; 2051 if (scrollPrimary != 0 || scrollSecondary != 0) { 2052 deltas[0] = scrollPrimary; 2053 deltas[1] = scrollSecondary; 2054 return true; 2055 } 2056 return false; 2057 } 2058 2059 private void scrollGrid(int scrollPrimary, int scrollSecondary, boolean smooth) { 2060 if (mInLayout) { 2061 scrollDirectionPrimary(scrollPrimary); 2062 scrollDirectionSecondary(scrollSecondary); 2063 } else { 2064 int scrollX; 2065 int scrollY; 2066 if (mOrientation == HORIZONTAL) { 2067 scrollX = scrollPrimary; 2068 scrollY = scrollSecondary; 2069 } else { 2070 scrollX = scrollSecondary; 2071 scrollY = scrollPrimary; 2072 } 2073 if (smooth) { 2074 mBaseGridView.smoothScrollBy(scrollX, scrollY); 2075 } else { 2076 mBaseGridView.scrollBy(scrollX, scrollY); 2077 } 2078 } 2079 } 2080 2081 public void setPruneChild(boolean pruneChild) { 2082 if (mPruneChild != pruneChild) { 2083 mPruneChild = pruneChild; 2084 if (mPruneChild) { 2085 requestLayout(); 2086 } 2087 } 2088 } 2089 2090 public boolean getPruneChild() { 2091 return mPruneChild; 2092 } 2093 2094 private int findImmediateChildIndex(View view) { 2095 while (view != null && view != mBaseGridView) { 2096 int index = mBaseGridView.indexOfChild(view); 2097 if (index >= 0) { 2098 return index; 2099 } 2100 view = (View) view.getParent(); 2101 } 2102 return NO_POSITION; 2103 } 2104 2105 void setFocusSearchDisabled(boolean disabled) { 2106 mFocusSearchDisabled = disabled; 2107 } 2108 2109 boolean isFocusSearchDisabled() { 2110 return mFocusSearchDisabled; 2111 } 2112 2113 @Override 2114 public View onInterceptFocusSearch(View focused, int direction) { 2115 if (mFocusSearchDisabled) { 2116 return focused; 2117 } 2118 return null; 2119 } 2120 2121 boolean hasPreviousViewInSameRow(int pos) { 2122 if (mGrid == null || pos == NO_POSITION) { 2123 return false; 2124 } 2125 if (mFirstVisiblePos > 0) { 2126 return true; 2127 } 2128 final int focusedRow = mGrid.getLocation(pos).row; 2129 for (int i = getChildCount() - 1; i >= 0; i--) { 2130 int position = getPositionByIndex(i); 2131 StaggeredGrid.Location loc = mGrid.getLocation(position); 2132 if (loc != null && loc.row == focusedRow) { 2133 if (position < pos) { 2134 return true; 2135 } 2136 } 2137 } 2138 return false; 2139 } 2140 2141 @Override 2142 public boolean onAddFocusables(RecyclerView recyclerView, 2143 ArrayList<View> views, int direction, int focusableMode) { 2144 if (mFocusSearchDisabled) { 2145 return true; 2146 } 2147 // If this viewgroup or one of its children currently has focus then we 2148 // consider our children for focus searching in main direction on the same row. 2149 // If this viewgroup has no focus and using focus align, we want the system 2150 // to ignore our children and pass focus to the viewgroup, which will pass 2151 // focus on to its children appropriately. 2152 // If this viewgroup has no focus and not using focus align, we want to 2153 // consider the child that does not overlap with padding area. 2154 if (recyclerView.hasFocus()) { 2155 final int movement = getMovement(direction); 2156 if (movement != PREV_ITEM && movement != NEXT_ITEM) { 2157 // Move on secondary direction uses default addFocusables(). 2158 return false; 2159 } 2160 final View focused = recyclerView.findFocus(); 2161 final int focusedPos = getPositionByIndex(findImmediateChildIndex(focused)); 2162 // Add focusables of focused item. 2163 if (focusedPos != NO_POSITION) { 2164 findViewByPosition(focusedPos).addFocusables(views, direction, focusableMode); 2165 } 2166 final int focusedRow = mGrid != null && focusedPos != NO_POSITION ? 2167 mGrid.getLocation(focusedPos).row : NO_POSITION; 2168 // Add focusables of next neighbor of same row on the focus search direction. 2169 if (mGrid != null) { 2170 final int focusableCount = views.size(); 2171 for (int i = 0, count = getChildCount(); i < count; i++) { 2172 int index = movement == NEXT_ITEM ? i : count - 1 - i; 2173 final View child = getChildAt(index); 2174 if (child.getVisibility() != View.VISIBLE) { 2175 continue; 2176 } 2177 int position = getPositionByIndex(index); 2178 StaggeredGrid.Location loc = mGrid.getLocation(position); 2179 if (focusedRow == NO_POSITION || (loc != null && loc.row == focusedRow)) { 2180 if (focusedPos == NO_POSITION || 2181 (movement == NEXT_ITEM && position > focusedPos) 2182 || (movement == PREV_ITEM && position < focusedPos)) { 2183 child.addFocusables(views, direction, focusableMode); 2184 if (views.size() > focusableCount) { 2185 break; 2186 } 2187 } 2188 } 2189 } 2190 } 2191 } else { 2192 if (mFocusScrollStrategy != BaseGridView.FOCUS_SCROLL_ALIGNED) { 2193 // adding views not overlapping padding area to avoid scrolling in gaining focus 2194 int left = mWindowAlignment.mainAxis().getPaddingLow(); 2195 int right = mWindowAlignment.mainAxis().getClientSize() + left; 2196 int focusableCount = views.size(); 2197 for (int i = 0, count = getChildCount(); i < count; i++) { 2198 View child = getChildAt(i); 2199 if (child.getVisibility() == View.VISIBLE) { 2200 if (getViewMin(child) >= left && getViewMax(child) <= right) { 2201 child.addFocusables(views, direction, focusableMode); 2202 } 2203 } 2204 } 2205 // if we cannot find any, then just add all children. 2206 if (views.size() == focusableCount) { 2207 for (int i = 0, count = getChildCount(); i < count; i++) { 2208 View child = getChildAt(i); 2209 if (child.getVisibility() == View.VISIBLE) { 2210 child.addFocusables(views, direction, focusableMode); 2211 } 2212 } 2213 if (views.size() != focusableCount) { 2214 return true; 2215 } 2216 } else { 2217 return true; 2218 } 2219 // if still cannot find any, fall through and add itself 2220 } 2221 if (recyclerView.isFocusable()) { 2222 views.add(recyclerView); 2223 } 2224 } 2225 return true; 2226 } 2227 2228 @Override 2229 public View onFocusSearchFailed(View focused, int direction, Recycler recycler, 2230 RecyclerView.State state) { 2231 if (DEBUG) Log.v(getTag(), "onFocusSearchFailed direction " + direction); 2232 2233 saveContext(recycler, state); 2234 View view = null; 2235 int movement = getMovement(direction); 2236 final FocusFinder ff = FocusFinder.getInstance(); 2237 if (movement == NEXT_ITEM) { 2238 while (view == null && !appendOneVisibleItem()) { 2239 view = ff.findNextFocus(mBaseGridView, focused, direction); 2240 } 2241 } else if (movement == PREV_ITEM){ 2242 while (view == null && !prependOneVisibleItem()) { 2243 view = ff.findNextFocus(mBaseGridView, focused, direction); 2244 } 2245 } 2246 if (view == null) { 2247 // returning the same view to prevent focus lost when scrolling past the end of the list 2248 if (movement == PREV_ITEM) { 2249 view = mFocusOutFront ? null : focused; 2250 } else if (movement == NEXT_ITEM){ 2251 view = mFocusOutEnd ? null : focused; 2252 } 2253 } 2254 leaveContext(); 2255 if (DEBUG) Log.v(getTag(), "returning view " + view); 2256 return view; 2257 } 2258 2259 boolean gridOnRequestFocusInDescendants(RecyclerView recyclerView, int direction, 2260 Rect previouslyFocusedRect) { 2261 switch (mFocusScrollStrategy) { 2262 case BaseGridView.FOCUS_SCROLL_ALIGNED: 2263 default: 2264 return gridOnRequestFocusInDescendantsAligned(recyclerView, 2265 direction, previouslyFocusedRect); 2266 case BaseGridView.FOCUS_SCROLL_PAGE: 2267 case BaseGridView.FOCUS_SCROLL_ITEM: 2268 return gridOnRequestFocusInDescendantsUnaligned(recyclerView, 2269 direction, previouslyFocusedRect); 2270 } 2271 } 2272 2273 private boolean gridOnRequestFocusInDescendantsAligned(RecyclerView recyclerView, 2274 int direction, Rect previouslyFocusedRect) { 2275 View view = findViewByPosition(mFocusPosition); 2276 if (view != null) { 2277 boolean result = view.requestFocus(direction, previouslyFocusedRect); 2278 if (!result && DEBUG) { 2279 Log.w(getTag(), "failed to request focus on " + view); 2280 } 2281 return result; 2282 } 2283 return false; 2284 } 2285 2286 private boolean gridOnRequestFocusInDescendantsUnaligned(RecyclerView recyclerView, 2287 int direction, Rect previouslyFocusedRect) { 2288 // focus to view not overlapping padding area to avoid scrolling in gaining focus 2289 int index; 2290 int increment; 2291 int end; 2292 int count = getChildCount(); 2293 if ((direction & View.FOCUS_FORWARD) != 0) { 2294 index = 0; 2295 increment = 1; 2296 end = count; 2297 } else { 2298 index = count - 1; 2299 increment = -1; 2300 end = -1; 2301 } 2302 int left = mWindowAlignment.mainAxis().getPaddingLow(); 2303 int right = mWindowAlignment.mainAxis().getClientSize() + left; 2304 for (int i = index; i != end; i += increment) { 2305 View child = getChildAt(i); 2306 if (child.getVisibility() == View.VISIBLE) { 2307 if (getViewMin(child) >= left && getViewMax(child) <= right) { 2308 if (child.requestFocus(direction, previouslyFocusedRect)) { 2309 return true; 2310 } 2311 } 2312 } 2313 } 2314 return false; 2315 } 2316 2317 private final static int PREV_ITEM = 0; 2318 private final static int NEXT_ITEM = 1; 2319 private final static int PREV_ROW = 2; 2320 private final static int NEXT_ROW = 3; 2321 2322 private int getMovement(int direction) { 2323 int movement = View.FOCUS_LEFT; 2324 2325 if (mOrientation == HORIZONTAL) { 2326 switch(direction) { 2327 case View.FOCUS_LEFT: 2328 movement = PREV_ITEM; 2329 break; 2330 case View.FOCUS_RIGHT: 2331 movement = NEXT_ITEM; 2332 break; 2333 case View.FOCUS_UP: 2334 movement = PREV_ROW; 2335 break; 2336 case View.FOCUS_DOWN: 2337 movement = NEXT_ROW; 2338 break; 2339 } 2340 } else if (mOrientation == VERTICAL) { 2341 switch(direction) { 2342 case View.FOCUS_LEFT: 2343 movement = PREV_ROW; 2344 break; 2345 case View.FOCUS_RIGHT: 2346 movement = NEXT_ROW; 2347 break; 2348 case View.FOCUS_UP: 2349 movement = PREV_ITEM; 2350 break; 2351 case View.FOCUS_DOWN: 2352 movement = NEXT_ITEM; 2353 break; 2354 } 2355 } 2356 2357 return movement; 2358 } 2359 2360 int getChildDrawingOrder(RecyclerView recyclerView, int childCount, int i) { 2361 View view = findViewByPosition(mFocusPosition); 2362 if (view == null) { 2363 return i; 2364 } 2365 int focusIndex = recyclerView.indexOfChild(view); 2366 // supposely 0 1 2 3 4 5 6 7 8 9, 4 is the center item 2367 // drawing order is 0 1 2 3 9 8 7 6 5 4 2368 if (i < focusIndex) { 2369 return i; 2370 } else if (i < childCount - 1) { 2371 return focusIndex + childCount - 1 - i; 2372 } else { 2373 return focusIndex; 2374 } 2375 } 2376 2377 @Override 2378 public void onAdapterChanged(RecyclerView.Adapter oldAdapter, 2379 RecyclerView.Adapter newAdapter) { 2380 discardLayoutInfo(); 2381 mFocusPosition = NO_POSITION; 2382 super.onAdapterChanged(oldAdapter, newAdapter); 2383 } 2384 2385 private void discardLayoutInfo() { 2386 mGrid = null; 2387 mRows = null; 2388 mRowSizeSecondary = null; 2389 mFirstVisiblePos = -1; 2390 mLastVisiblePos = -1; 2391 mRowSecondarySizeRefresh = false; 2392 } 2393 2394 public void setLayoutEnabled(boolean layoutEnabled) { 2395 if (mLayoutEnabled != layoutEnabled) { 2396 mLayoutEnabled = layoutEnabled; 2397 requestLayout(); 2398 } 2399 } 2400} 2401