GridLayoutManager.java revision 597f620c2503bb18aabf0b6fe4c0c84ab7b42cba
1/* 2 * Copyright (C) 2014 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except 5 * in compliance with the License. You may obtain a copy of the License at 6 * 7 * http://www.apache.org/licenses/LICENSE-2.0 8 * 9 * Unless required by applicable law or agreed to in writing, software distributed under the License 10 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express 11 * or implied. See the License for the specific language governing permissions and limitations under 12 * the License. 13 */ 14package android.support.v17.leanback.widget; 15 16import android.content.Context; 17import android.graphics.PointF; 18import android.graphics.Rect; 19import android.os.Bundle; 20import android.os.Parcel; 21import android.os.Parcelable; 22import android.support.v4.view.ViewCompat; 23import android.support.v7.widget.LinearSmoothScroller; 24import android.support.v7.widget.RecyclerView; 25import android.support.v7.widget.RecyclerView.Recycler; 26import android.support.v7.widget.RecyclerView.State; 27 28import static android.support.v7.widget.RecyclerView.NO_ID; 29import static android.support.v7.widget.RecyclerView.NO_POSITION; 30import static android.support.v7.widget.RecyclerView.HORIZONTAL; 31import static android.support.v7.widget.RecyclerView.VERTICAL; 32 33import android.util.AttributeSet; 34import android.util.Log; 35import android.view.FocusFinder; 36import android.view.Gravity; 37import android.view.View; 38import android.view.ViewParent; 39import android.view.View.MeasureSpec; 40import android.view.ViewGroup.MarginLayoutParams; 41import android.view.ViewGroup; 42 43import java.io.PrintWriter; 44import java.io.StringWriter; 45import java.util.ArrayList; 46import java.util.List; 47 48final class GridLayoutManager extends RecyclerView.LayoutManager { 49 50 /* 51 * LayoutParams for {@link HorizontalGridView} and {@link VerticalGridView}. 52 * The class currently does two internal jobs: 53 * - Saves optical bounds insets. 54 * - Caches focus align view center. 55 */ 56 static class LayoutParams extends RecyclerView.LayoutParams { 57 58 // The view is saved only during animation. 59 private View mView; 60 61 // For placement 62 private int mLeftInset; 63 private int mTopInset; 64 private int mRightInset; 65 private int mBottomInset; 66 67 // For alignment 68 private int mAlignX; 69 private int mAlignY; 70 71 public LayoutParams(Context c, AttributeSet attrs) { 72 super(c, attrs); 73 } 74 75 public LayoutParams(int width, int height) { 76 super(width, height); 77 } 78 79 public LayoutParams(MarginLayoutParams source) { 80 super(source); 81 } 82 83 public LayoutParams(ViewGroup.LayoutParams source) { 84 super(source); 85 } 86 87 public LayoutParams(RecyclerView.LayoutParams source) { 88 super(source); 89 } 90 91 public LayoutParams(LayoutParams source) { 92 super(source); 93 } 94 95 int getAlignX() { 96 return mAlignX; 97 } 98 99 int getAlignY() { 100 return mAlignY; 101 } 102 103 int getOpticalLeft(View view) { 104 return view.getLeft() + mLeftInset; 105 } 106 107 int getOpticalTop(View view) { 108 return view.getTop() + mTopInset; 109 } 110 111 int getOpticalRight(View view) { 112 return view.getRight() - mRightInset; 113 } 114 115 int getOpticalBottom(View view) { 116 return view.getBottom() - mBottomInset; 117 } 118 119 int getOpticalWidth(View view) { 120 return view.getWidth() - mLeftInset - mRightInset; 121 } 122 123 int getOpticalHeight(View view) { 124 return view.getHeight() - mTopInset - mBottomInset; 125 } 126 127 int getOpticalLeftInset() { 128 return mLeftInset; 129 } 130 131 int getOpticalRightInset() { 132 return mRightInset; 133 } 134 135 int getOpticalTopInset() { 136 return mTopInset; 137 } 138 139 int getOpticalBottomInset() { 140 return mBottomInset; 141 } 142 143 void setAlignX(int alignX) { 144 mAlignX = alignX; 145 } 146 147 void setAlignY(int alignY) { 148 mAlignY = alignY; 149 } 150 151 void setOpticalInsets(int leftInset, int topInset, int rightInset, int bottomInset) { 152 mLeftInset = leftInset; 153 mTopInset = topInset; 154 mRightInset = rightInset; 155 mBottomInset = bottomInset; 156 } 157 158 private void invalidateItemDecoration() { 159 ViewParent parent = mView.getParent(); 160 if (parent instanceof RecyclerView) { 161 // TODO: we only need invalidate parent if it has ItemDecoration 162 ((RecyclerView) parent).invalidate(); 163 } 164 } 165 } 166 167 private static final String TAG = "GridLayoutManager"; 168 private static final boolean DEBUG = false; 169 170 private String getTag() { 171 return TAG + ":" + mBaseGridView.getId(); 172 } 173 174 private final BaseGridView mBaseGridView; 175 176 /** 177 * Note on conventions in the presence of RTL layout directions: 178 * Many properties and method names reference entities related to the 179 * beginnings and ends of things. In the presence of RTL flows, 180 * it may not be clear whether this is intended to reference a 181 * quantity that changes direction in RTL cases, or a quantity that 182 * does not. Here are the conventions in use: 183 * 184 * start/end: coordinate quantities - do reverse 185 * (optical) left/right: coordinate quantities - do not reverse 186 * low/high: coordinate quantities - do not reverse 187 * min/max: coordinate quantities - do not reverse 188 * scroll offset - coordinate quantities - do not reverse 189 * first/last: positional indices - do not reverse 190 * front/end: positional indices - do not reverse 191 * prepend/append: related to positional indices - do not reverse 192 * 193 * Note that although quantities do not reverse in RTL flows, their 194 * relationship does. In LTR flows, the first positional index is 195 * leftmost; in RTL flows, it is rightmost. Thus, anywhere that 196 * positional quantities are mapped onto coordinate quantities, 197 * the flow must be checked and the logic reversed. 198 */ 199 200 /** 201 * The orientation of a "row". 202 */ 203 private int mOrientation = HORIZONTAL; 204 205 private RecyclerView.State mState; 206 private RecyclerView.Recycler mRecycler; 207 208 private boolean mInLayout = false; 209 private boolean mInSelection = false; 210 211 private OnChildSelectedListener mChildSelectedListener = null; 212 213 /** 214 * The focused position, it's not the currently visually aligned position 215 * but it is the final position that we intend to focus on. If there are 216 * multiple setSelection() called, mFocusPosition saves last value. 217 */ 218 private int mFocusPosition = NO_POSITION; 219 220 /** 221 * The offset to be applied to mFocusPosition, due to adapter change, on the next 222 * layout. Set to Integer.MIN_VALUE means item was removed. 223 * TODO: This is somewhat duplication of RecyclerView getOldPosition() which is 224 * unfortunately cleared after prelayout. 225 */ 226 private int mFocusPositionOffset = 0; 227 228 /** 229 * Force a full layout under certain situations. 230 */ 231 private boolean mForceFullLayout; 232 233 /** 234 * True if layout is enabled. 235 */ 236 private boolean mLayoutEnabled = true; 237 238 /** 239 * override child visibility 240 */ 241 private int mChildVisibility = -1; 242 243 /** 244 * The scroll offsets of the viewport relative to the entire view. 245 */ 246 private int mScrollOffsetPrimary; 247 private int mScrollOffsetSecondary; 248 249 /** 250 * User-specified row height/column width. Can be WRAP_CONTENT. 251 */ 252 private int mRowSizeSecondaryRequested; 253 254 /** 255 * The fixed size of each grid item in the secondary direction. This corresponds to 256 * the row height, equal for all rows. Grid items may have variable length 257 * in the primary direction. 258 */ 259 private int mFixedRowSizeSecondary; 260 261 /** 262 * Tracks the secondary size of each row. 263 */ 264 private int[] mRowSizeSecondary; 265 266 /** 267 * Flag controlling whether the current/next layout should 268 * be updating the secondary size of rows. 269 */ 270 private boolean mRowSecondarySizeRefresh; 271 272 /** 273 * The maximum measured size of the view. 274 */ 275 private int mMaxSizeSecondary; 276 277 /** 278 * Margin between items. 279 */ 280 private int mHorizontalMargin; 281 /** 282 * Margin between items vertically. 283 */ 284 private int mVerticalMargin; 285 /** 286 * Margin in main direction. 287 */ 288 private int mMarginPrimary; 289 /** 290 * Margin in second direction. 291 */ 292 private int mMarginSecondary; 293 /** 294 * How to position child in secondary direction. 295 */ 296 private int mGravity = Gravity.START | Gravity.TOP; 297 /** 298 * The number of rows in the grid. 299 */ 300 private int mNumRows; 301 /** 302 * Number of rows requested, can be 0 to be determined by parent size and 303 * rowHeight. 304 */ 305 private int mNumRowsRequested = 1; 306 307 /** 308 * Tracking start/end position of each row for visible items. 309 */ 310 private StaggeredGrid.Row[] mRows; 311 312 /** 313 * Saves grid information of each view. 314 */ 315 private StaggeredGrid mGrid; 316 /** 317 * Position of first item (included) that has attached views. 318 */ 319 private int mFirstVisiblePos; 320 /** 321 * Position of last item (included) that has attached views. 322 */ 323 private int mLastVisiblePos; 324 325 /** 326 * Focus Scroll strategy. 327 */ 328 private int mFocusScrollStrategy = BaseGridView.FOCUS_SCROLL_ALIGNED; 329 /** 330 * Defines how item view is aligned in the window. 331 */ 332 private final WindowAlignment mWindowAlignment = new WindowAlignment(); 333 334 /** 335 * Defines how item view is aligned. 336 */ 337 private final ItemAlignment mItemAlignment = new ItemAlignment(); 338 339 /** 340 * Dimensions of the view, width or height depending on orientation. 341 */ 342 private int mSizePrimary; 343 344 /** 345 * Allow DPAD key to navigate out at the front of the View (where position = 0), 346 * default is false. 347 */ 348 private boolean mFocusOutFront; 349 350 /** 351 * Allow DPAD key to navigate out at the end of the view, default is false. 352 */ 353 private boolean mFocusOutEnd; 354 355 /** 356 * True if focus search is disabled. 357 */ 358 private boolean mFocusSearchDisabled; 359 360 /** 361 * True if prune child, might be disabled during transition. 362 */ 363 private boolean mPruneChild = true; 364 365 /** 366 * True if scroll content, might be disabled during transition. 367 */ 368 private boolean mScrollEnabled = true; 369 370 private int[] mTempDeltas = new int[2]; 371 372 /** 373 * Set to true for RTL layout in horizontal orientation 374 */ 375 private boolean mReverseFlowPrimary = false; 376 377 /** 378 * Set to true for RTL layout in vertical orientation 379 */ 380 private boolean mReverseFlowSecondary = false; 381 382 /** 383 * Temporaries used for measuring. 384 */ 385 private int[] mMeasuredDimension = new int[2]; 386 387 final ViewsStateBundle mChildrenStates = new ViewsStateBundle(); 388 389 public GridLayoutManager(BaseGridView baseGridView) { 390 mBaseGridView = baseGridView; 391 } 392 393 public void setOrientation(int orientation) { 394 if (orientation != HORIZONTAL && orientation != VERTICAL) { 395 if (DEBUG) Log.v(getTag(), "invalid orientation: " + orientation); 396 return; 397 } 398 399 mOrientation = orientation; 400 mWindowAlignment.setOrientation(orientation); 401 mItemAlignment.setOrientation(orientation); 402 mForceFullLayout = true; 403 } 404 405 public void onRtlPropertiesChanged(int layoutDirection) { 406 if (mOrientation == HORIZONTAL) { 407 mReverseFlowPrimary = layoutDirection == View.LAYOUT_DIRECTION_RTL; 408 mReverseFlowSecondary = false; 409 } else { 410 mReverseFlowSecondary = layoutDirection == View.LAYOUT_DIRECTION_RTL; 411 mReverseFlowPrimary = false; 412 } 413 mWindowAlignment.horizontal.setReversedFlow(layoutDirection == View.LAYOUT_DIRECTION_RTL); 414 } 415 416 public int getFocusScrollStrategy() { 417 return mFocusScrollStrategy; 418 } 419 420 public void setFocusScrollStrategy(int focusScrollStrategy) { 421 mFocusScrollStrategy = focusScrollStrategy; 422 } 423 424 public void setWindowAlignment(int windowAlignment) { 425 mWindowAlignment.mainAxis().setWindowAlignment(windowAlignment); 426 } 427 428 public int getWindowAlignment() { 429 return mWindowAlignment.mainAxis().getWindowAlignment(); 430 } 431 432 public void setWindowAlignmentOffset(int alignmentOffset) { 433 mWindowAlignment.mainAxis().setWindowAlignmentOffset(alignmentOffset); 434 } 435 436 public int getWindowAlignmentOffset() { 437 return mWindowAlignment.mainAxis().getWindowAlignmentOffset(); 438 } 439 440 public void setWindowAlignmentOffsetPercent(float offsetPercent) { 441 mWindowAlignment.mainAxis().setWindowAlignmentOffsetPercent(offsetPercent); 442 } 443 444 public float getWindowAlignmentOffsetPercent() { 445 return mWindowAlignment.mainAxis().getWindowAlignmentOffsetPercent(); 446 } 447 448 public void setItemAlignmentOffset(int alignmentOffset) { 449 mItemAlignment.mainAxis().setItemAlignmentOffset(alignmentOffset); 450 updateChildAlignments(); 451 } 452 453 public int getItemAlignmentOffset() { 454 return mItemAlignment.mainAxis().getItemAlignmentOffset(); 455 } 456 457 public void setItemAlignmentOffsetWithPadding(boolean withPadding) { 458 mItemAlignment.mainAxis().setItemAlignmentOffsetWithPadding(withPadding); 459 updateChildAlignments(); 460 } 461 462 public boolean isItemAlignmentOffsetWithPadding() { 463 return mItemAlignment.mainAxis().isItemAlignmentOffsetWithPadding(); 464 } 465 466 public void setItemAlignmentOffsetPercent(float offsetPercent) { 467 mItemAlignment.mainAxis().setItemAlignmentOffsetPercent(offsetPercent); 468 updateChildAlignments(); 469 } 470 471 public float getItemAlignmentOffsetPercent() { 472 return mItemAlignment.mainAxis().getItemAlignmentOffsetPercent(); 473 } 474 475 public void setItemAlignmentViewId(int viewId) { 476 mItemAlignment.mainAxis().setItemAlignmentViewId(viewId); 477 updateChildAlignments(); 478 } 479 480 public int getItemAlignmentViewId() { 481 return mItemAlignment.mainAxis().getItemAlignmentViewId(); 482 } 483 484 public void setFocusOutAllowed(boolean throughFront, boolean throughEnd) { 485 mFocusOutFront = throughFront; 486 mFocusOutEnd = throughEnd; 487 } 488 489 public void setNumRows(int numRows) { 490 if (numRows < 0) throw new IllegalArgumentException(); 491 mNumRowsRequested = numRows; 492 mForceFullLayout = true; 493 } 494 495 /** 496 * Set the row height. May be WRAP_CONTENT, or a size in pixels. 497 */ 498 public void setRowHeight(int height) { 499 if (height >= 0 || height == ViewGroup.LayoutParams.WRAP_CONTENT) { 500 mRowSizeSecondaryRequested = height; 501 } else { 502 throw new IllegalArgumentException("Invalid row height: " + height); 503 } 504 } 505 506 public void setItemMargin(int margin) { 507 mVerticalMargin = mHorizontalMargin = margin; 508 mMarginPrimary = mMarginSecondary = margin; 509 } 510 511 public void setVerticalMargin(int margin) { 512 if (mOrientation == HORIZONTAL) { 513 mMarginSecondary = mVerticalMargin = margin; 514 } else { 515 mMarginPrimary = mVerticalMargin = margin; 516 } 517 } 518 519 public void setHorizontalMargin(int margin) { 520 if (mOrientation == HORIZONTAL) { 521 mMarginPrimary = mHorizontalMargin = margin; 522 } else { 523 mMarginSecondary = mHorizontalMargin = margin; 524 } 525 } 526 527 public int getVerticalMargin() { 528 return mVerticalMargin; 529 } 530 531 public int getHorizontalMargin() { 532 return mHorizontalMargin; 533 } 534 535 public void setGravity(int gravity) { 536 mGravity = gravity; 537 } 538 539 protected boolean hasDoneFirstLayout() { 540 return mGrid != null; 541 } 542 543 public void setOnChildSelectedListener(OnChildSelectedListener listener) { 544 mChildSelectedListener = listener; 545 } 546 547 private int getPositionByView(View view) { 548 if (view == null) { 549 return NO_POSITION; 550 } 551 LayoutParams params = (LayoutParams) view.getLayoutParams(); 552 if (params == null || params.isItemRemoved()) { 553 // when item is removed, the position value can be any value. 554 return NO_POSITION; 555 } 556 return params.getViewPosition(); 557 } 558 559 private int getPositionByIndex(int index) { 560 return getPositionByView(getChildAt(index)); 561 } 562 563 private void dispatchChildSelected() { 564 if (mChildSelectedListener == null) { 565 return; 566 } 567 568 View view = mFocusPosition == NO_POSITION ? null : findViewByPosition(mFocusPosition); 569 if (view != null) { 570 RecyclerView.ViewHolder vh = mBaseGridView.getChildViewHolder(view); 571 mChildSelectedListener.onChildSelected(mBaseGridView, view, mFocusPosition, 572 vh == null? NO_ID: vh.getItemId()); 573 } else { 574 mChildSelectedListener.onChildSelected(mBaseGridView, null, NO_POSITION, NO_ID); 575 } 576 577 // Children may request layout when a child selection event occurs (such as a change of 578 // padding on the current and previously selected rows). 579 // If in layout, a child requesting layout may have been laid out before the selection 580 // callback. 581 // If it was not, the child will be laid out after the selection callback. 582 // If so, the layout request will be honoured though the view system will emit a double- 583 // layout warning. 584 // If not in layout, we may be scrolling in which case the child layout request will be 585 // eaten by recyclerview. Post a requestLayout. 586 if (!mInLayout && !mBaseGridView.isLayoutRequested()) { 587 int childCount = getChildCount(); 588 for (int i = 0; i < childCount; i++) { 589 if (getChildAt(i).isLayoutRequested()) { 590 forceRequestLayout(); 591 break; 592 } 593 } 594 } 595 } 596 597 @Override 598 public boolean canScrollHorizontally() { 599 // We can scroll horizontally if we have horizontal orientation, or if 600 // we are vertical and have more than one column. 601 return mOrientation == HORIZONTAL || mNumRows > 1; 602 } 603 604 @Override 605 public boolean canScrollVertically() { 606 // We can scroll vertically if we have vertical orientation, or if we 607 // are horizontal and have more than one row. 608 return mOrientation == VERTICAL || mNumRows > 1; 609 } 610 611 @Override 612 public RecyclerView.LayoutParams generateDefaultLayoutParams() { 613 return new LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, 614 ViewGroup.LayoutParams.WRAP_CONTENT); 615 } 616 617 @Override 618 public RecyclerView.LayoutParams generateLayoutParams(Context context, AttributeSet attrs) { 619 return new LayoutParams(context, attrs); 620 } 621 622 @Override 623 public RecyclerView.LayoutParams generateLayoutParams(ViewGroup.LayoutParams lp) { 624 if (lp instanceof LayoutParams) { 625 return new LayoutParams((LayoutParams) lp); 626 } else if (lp instanceof RecyclerView.LayoutParams) { 627 return new LayoutParams((RecyclerView.LayoutParams) lp); 628 } else if (lp instanceof MarginLayoutParams) { 629 return new LayoutParams((MarginLayoutParams) lp); 630 } else { 631 return new LayoutParams(lp); 632 } 633 } 634 635 protected View getViewForPosition(int position) { 636 return mRecycler.getViewForPosition(position); 637 } 638 639 final int getOpticalLeft(View v) { 640 return ((LayoutParams) v.getLayoutParams()).getOpticalLeft(v); 641 } 642 643 final int getOpticalRight(View v) { 644 return ((LayoutParams) v.getLayoutParams()).getOpticalRight(v); 645 } 646 647 final int getOpticalTop(View v) { 648 return ((LayoutParams) v.getLayoutParams()).getOpticalTop(v); 649 } 650 651 final int getOpticalBottom(View v) { 652 return ((LayoutParams) v.getLayoutParams()).getOpticalBottom(v); 653 } 654 655 private int getViewMin(View v) { 656 return (mOrientation == HORIZONTAL) ? getOpticalLeft(v) : getOpticalTop(v); 657 } 658 659 private int getViewMax(View v) { 660 return (mOrientation == HORIZONTAL) ? getOpticalRight(v) : getOpticalBottom(v); 661 } 662 663 private int getViewCenter(View view) { 664 return (mOrientation == HORIZONTAL) ? getViewCenterX(view) : getViewCenterY(view); 665 } 666 667 private int getViewCenterSecondary(View view) { 668 return (mOrientation == HORIZONTAL) ? getViewCenterY(view) : getViewCenterX(view); 669 } 670 671 private int getViewCenterX(View v) { 672 LayoutParams p = (LayoutParams) v.getLayoutParams(); 673 return p.getOpticalLeft(v) + p.getAlignX(); 674 } 675 676 private int getViewCenterY(View v) { 677 LayoutParams p = (LayoutParams) v.getLayoutParams(); 678 return p.getOpticalTop(v) + p.getAlignY(); 679 } 680 681 /** 682 * Save Recycler and State for convenience. Must be paired with leaveContext(). 683 */ 684 private void saveContext(Recycler recycler, State state) { 685 if (mRecycler != null || mState != null) { 686 Log.e(TAG, "Recycler information was not released, bug!"); 687 } 688 mRecycler = recycler; 689 mState = state; 690 } 691 692 /** 693 * Discard saved Recycler and State. 694 */ 695 private void leaveContext() { 696 mRecycler = null; 697 mState = null; 698 } 699 700 /** 701 * Re-initialize data structures for a data change or handling invisible 702 * selection. The method tries its best to preserve position information so 703 * that staggered grid looks same before and after re-initialize. 704 * @param focusPosition The initial focusPosition that we would like to 705 * focus on. 706 * @return Actual position that can be focused on. 707 */ 708 private int init(int focusPosition) { 709 710 final int newItemCount = mState.getItemCount(); 711 712 // Force the re-init path in the following conditional 713 if (newItemCount == 0) { 714 focusPosition = NO_POSITION; 715 } else if (focusPosition == NO_POSITION && newItemCount > 0) { 716 // if focus position is never set before, initialize it to 0 717 focusPosition = 0; 718 } 719 720 // If adapter has changed then caches are invalid; otherwise, 721 // we try to maintain each row's position if number of rows keeps the same 722 // and existing mGrid contains the focusPosition. 723 if (mRows != null && mNumRows == mRows.length && 724 mGrid != null && mGrid.getSize() > 0 && focusPosition >= 0 && 725 focusPosition >= mGrid.getFirstIndex() && 726 focusPosition <= mGrid.getLastIndex()) { 727 // strip mGrid to a subset (like a column) that contains focusPosition 728 mGrid.stripDownTo(focusPosition); 729 // make sure that remaining items do not exceed new adapter size 730 int firstIndex = mGrid.getFirstIndex(); 731 int lastIndex = mGrid.getLastIndex(); 732 if (DEBUG) { 733 Log .v(getTag(), "mGrid firstIndex " + firstIndex + " lastIndex " + lastIndex); 734 } 735 for (int i = lastIndex; i >=firstIndex; i--) { 736 if (i >= newItemCount) { 737 mGrid.removeLast(); 738 } 739 } 740 if (mGrid.getSize() == 0) { 741 focusPosition = newItemCount - 1; 742 // initialize row start locations 743 for (int i = 0; i < mNumRows; i++) { 744 mRows[i].low = 0; 745 mRows[i].high = 0; 746 } 747 if (DEBUG) Log.v(getTag(), "mGrid zero size"); 748 } else { 749 // initialize row start locations 750 for (int i = 0; i < mNumRows; i++) { 751 mRows[i].low = Integer.MAX_VALUE; 752 mRows[i].high = Integer.MIN_VALUE; 753 } 754 firstIndex = mGrid.getFirstIndex(); 755 lastIndex = mGrid.getLastIndex(); 756 if (focusPosition > lastIndex) { 757 focusPosition = mGrid.getLastIndex(); 758 } 759 if (DEBUG) { 760 Log.v(getTag(), "mGrid firstIndex " + firstIndex + " lastIndex " 761 + lastIndex + " focusPosition " + focusPosition); 762 } 763 // fill rows with minimal view positions of the subset 764 for (int i = firstIndex; i <= lastIndex; i++) { 765 View v = findViewByPosition(i); 766 if (v == null) { 767 continue; 768 } 769 int row = mGrid.getLocation(i).row; 770 int low = getViewMin(v) + mScrollOffsetPrimary; 771 if (low < mRows[row].low) { 772 mRows[row].low = mRows[row].high = low; 773 } 774 } 775 int firstItemRowPosition = mRows[mGrid.getLocation(firstIndex).row].low; 776 if (firstItemRowPosition == Integer.MAX_VALUE) { 777 firstItemRowPosition = 0; 778 } 779 if (mState.didStructureChange()) { 780 // if there is structure change, the removed item might be in the 781 // subset, so it is meaningless to maintain the low locations. 782 for (int i = 0; i < mNumRows; i++) { 783 mRows[i].low = firstItemRowPosition; 784 mRows[i].high = firstItemRowPosition; 785 } 786 } else { 787 // fill other rows that does not include the subset using first item 788 for (int i = 0; i < mNumRows; i++) { 789 if (mRows[i].low == Integer.MAX_VALUE) { 790 mRows[i].low = mRows[i].high = firstItemRowPosition; 791 } 792 } 793 } 794 } 795 796 // Same adapter, we can reuse any attached views 797 detachAndScrapAttachedViews(mRecycler); 798 799 } else { 800 // otherwise recreate data structure 801 mRows = new StaggeredGrid.Row[mNumRows]; 802 803 for (int i = 0; i < mNumRows; i++) { 804 mRows[i] = new StaggeredGrid.Row(); 805 } 806 mGrid = new StaggeredGridDefault(); 807 mGrid.setReversedFlow(mOrientation == HORIZONTAL && mReverseFlowPrimary); 808 if (newItemCount == 0) { 809 focusPosition = NO_POSITION; 810 } else if (focusPosition >= newItemCount) { 811 focusPosition = newItemCount - 1; 812 } 813 814 // Adapter may have changed so remove all attached views permanently 815 removeAndRecycleAllViews(mRecycler); 816 817 mScrollOffsetPrimary = 0; 818 mScrollOffsetSecondary = 0; 819 mWindowAlignment.reset(); 820 } 821 822 mGrid.setProvider(mGridProvider); 823 // mGrid share the same Row array information 824 mGrid.setRows(mRows); 825 mFirstVisiblePos = mLastVisiblePos = NO_POSITION; 826 827 initScrollController(); 828 updateScrollSecondAxis(); 829 830 return focusPosition; 831 } 832 833 private int getRowSizeSecondary(int rowIndex) { 834 if (mFixedRowSizeSecondary != 0) { 835 return mFixedRowSizeSecondary; 836 } 837 if (mRowSizeSecondary == null) { 838 return 0; 839 } 840 return mRowSizeSecondary[rowIndex]; 841 } 842 843 private int getRowStartSecondary(int rowIndex) { 844 int start = 0; 845 // Iterate from left to right, which is a different index traversal 846 // in RTL flow 847 if (mReverseFlowSecondary) { 848 for (int i = mNumRows-1; i > rowIndex; i--) { 849 start += getRowSizeSecondary(i) + mMarginSecondary; 850 } 851 } else { 852 for (int i = 0; i < rowIndex; i++) { 853 start += getRowSizeSecondary(i) + mMarginSecondary; 854 } 855 } 856 return start; 857 } 858 859 private int getSizeSecondary() { 860 int rightmostIndex = mReverseFlowSecondary ? 0 : mNumRows - 1; 861 return getRowStartSecondary(rightmostIndex) + getRowSizeSecondary(rightmostIndex); 862 } 863 864 private void measureScrapChild(int position, int widthSpec, int heightSpec, 865 int[] measuredDimension) { 866 View view = mRecycler.getViewForPosition(position); 867 if (view != null) { 868 LayoutParams p = (LayoutParams) view.getLayoutParams(); 869 int childWidthSpec = ViewGroup.getChildMeasureSpec(widthSpec, 870 getPaddingLeft() + getPaddingRight(), p.width); 871 int childHeightSpec = ViewGroup.getChildMeasureSpec(heightSpec, 872 getPaddingTop() + getPaddingBottom(), p.height); 873 view.measure(childWidthSpec, childHeightSpec); 874 measuredDimension[0] = view.getMeasuredWidth(); 875 measuredDimension[1] = view.getMeasuredHeight(); 876 mRecycler.recycleView(view); 877 } 878 } 879 880 private boolean processRowSizeSecondary(boolean measure) { 881 if (mFixedRowSizeSecondary != 0) { 882 return false; 883 } 884 885 List<Integer>[] rows = mGrid == null ? null : 886 mGrid.getItemPositionsInRows(mFirstVisiblePos, mLastVisiblePos); 887 boolean changed = false; 888 int scrapChildWidth = -1; 889 int scrapChildHeight = -1; 890 891 for (int rowIndex = 0; rowIndex < mNumRows; rowIndex++) { 892 final int rowItemCount = rows == null ? 0 : rows[rowIndex].size(); 893 if (DEBUG) Log.v(getTag(), "processRowSizeSecondary row " + rowIndex + 894 " rowItemCount " + rowItemCount); 895 896 int rowSize = -1; 897 for (int i = 0; i < rowItemCount; i++) { 898 final View view = findViewByPosition(rows[rowIndex].get(i)); 899 if (view == null) { 900 continue; 901 } 902 if (measure && view.isLayoutRequested()) { 903 measureChild(view); 904 } 905 final int secondarySize = mOrientation == HORIZONTAL ? 906 view.getMeasuredHeight() : view.getMeasuredWidth(); 907 if (secondarySize > rowSize) { 908 rowSize = secondarySize; 909 } 910 } 911 912 final int itemCount = mState.getItemCount(); 913 if (measure && rowSize < 0 && itemCount > 0) { 914 if (scrapChildWidth < 0 && scrapChildHeight < 0) { 915 int position; 916 if (mFocusPosition == NO_POSITION) { 917 position = 0; 918 } else if (mFocusPosition >= itemCount) { 919 position = itemCount - 1; 920 } else { 921 position = mFocusPosition; 922 } 923 measureScrapChild(position, 924 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 925 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 926 mMeasuredDimension); 927 scrapChildWidth = mMeasuredDimension[0]; 928 scrapChildHeight = mMeasuredDimension[1]; 929 if (DEBUG) Log.v(TAG, "measured scrap child: " + scrapChildWidth + 930 " " + scrapChildHeight); 931 } 932 rowSize = mOrientation == HORIZONTAL ? scrapChildHeight : scrapChildWidth; 933 } 934 935 if (rowSize < 0) { 936 rowSize = 0; 937 } 938 939 if (DEBUG) Log.v(getTag(), "row " + rowIndex + " rowItemCount " + rowItemCount + 940 " rowSize " + rowSize); 941 942 if (mRowSizeSecondary[rowIndex] != rowSize) { 943 if (DEBUG) Log.v(getTag(), "row size secondary changed: " + mRowSizeSecondary[rowIndex] + 944 ", " + rowSize); 945 946 mRowSizeSecondary[rowIndex] = rowSize; 947 changed = true; 948 } 949 } 950 951 return changed; 952 } 953 954 /** 955 * Checks if we need to update row secondary sizes. 956 */ 957 private void updateRowSecondarySizeRefresh() { 958 mRowSecondarySizeRefresh = processRowSizeSecondary(false); 959 if (mRowSecondarySizeRefresh) { 960 if (DEBUG) Log.v(getTag(), "mRowSecondarySizeRefresh now set"); 961 forceRequestLayout(); 962 } 963 } 964 965 private void forceRequestLayout() { 966 if (DEBUG) Log.v(getTag(), "forceRequestLayout"); 967 // RecyclerView prevents us from requesting layout in many cases 968 // (during layout, during scroll, etc.) 969 // For secondary row size wrap_content support we currently need a 970 // second layout pass to update the measured size after having measured 971 // and added child views in layoutChildren. 972 // Force the second layout by posting a delayed runnable. 973 // TODO: investigate allowing a second layout pass, 974 // or move child add/measure logic to the measure phase. 975 ViewCompat.postOnAnimation(mBaseGridView, mRequestLayoutRunnable); 976 } 977 978 private final Runnable mRequestLayoutRunnable = new Runnable() { 979 @Override 980 public void run() { 981 if (DEBUG) Log.v(getTag(), "request Layout from runnable"); 982 requestLayout(); 983 } 984 }; 985 986 @Override 987 public void onMeasure(Recycler recycler, State state, int widthSpec, int heightSpec) { 988 saveContext(recycler, state); 989 990 int sizePrimary, sizeSecondary, modeSecondary, paddingSecondary; 991 int measuredSizeSecondary; 992 if (mOrientation == HORIZONTAL) { 993 sizePrimary = MeasureSpec.getSize(widthSpec); 994 sizeSecondary = MeasureSpec.getSize(heightSpec); 995 modeSecondary = MeasureSpec.getMode(heightSpec); 996 paddingSecondary = getPaddingTop() + getPaddingBottom(); 997 } else { 998 sizeSecondary = MeasureSpec.getSize(widthSpec); 999 sizePrimary = MeasureSpec.getSize(heightSpec); 1000 modeSecondary = MeasureSpec.getMode(widthSpec); 1001 paddingSecondary = getPaddingLeft() + getPaddingRight(); 1002 } 1003 if (DEBUG) Log.v(getTag(), "onMeasure widthSpec " + Integer.toHexString(widthSpec) + 1004 " heightSpec " + Integer.toHexString(heightSpec) + 1005 " modeSecondary " + Integer.toHexString(modeSecondary) + 1006 " sizeSecondary " + sizeSecondary + " " + this); 1007 1008 mMaxSizeSecondary = sizeSecondary; 1009 1010 if (mRowSizeSecondaryRequested == ViewGroup.LayoutParams.WRAP_CONTENT) { 1011 mNumRows = mNumRowsRequested == 0 ? 1 : mNumRowsRequested; 1012 mFixedRowSizeSecondary = 0; 1013 1014 if (mRowSizeSecondary == null || mRowSizeSecondary.length != mNumRows) { 1015 mRowSizeSecondary = new int[mNumRows]; 1016 } 1017 1018 // Measure all current children and update cached row heights 1019 processRowSizeSecondary(true); 1020 1021 switch (modeSecondary) { 1022 case MeasureSpec.UNSPECIFIED: 1023 measuredSizeSecondary = getSizeSecondary() + paddingSecondary; 1024 break; 1025 case MeasureSpec.AT_MOST: 1026 measuredSizeSecondary = Math.min(getSizeSecondary() + paddingSecondary, 1027 mMaxSizeSecondary); 1028 break; 1029 case MeasureSpec.EXACTLY: 1030 measuredSizeSecondary = mMaxSizeSecondary; 1031 break; 1032 default: 1033 throw new IllegalStateException("wrong spec"); 1034 } 1035 1036 } else { 1037 switch (modeSecondary) { 1038 case MeasureSpec.UNSPECIFIED: 1039 if (mRowSizeSecondaryRequested == 0) { 1040 if (mOrientation == HORIZONTAL) { 1041 throw new IllegalStateException("Must specify rowHeight or view height"); 1042 } else { 1043 throw new IllegalStateException("Must specify columnWidth or view width"); 1044 } 1045 } 1046 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 1047 mNumRows = mNumRowsRequested == 0 ? 1 : mNumRowsRequested; 1048 measuredSizeSecondary = mFixedRowSizeSecondary * mNumRows + mMarginSecondary 1049 * (mNumRows - 1) + paddingSecondary; 1050 break; 1051 case MeasureSpec.AT_MOST: 1052 case MeasureSpec.EXACTLY: 1053 if (mNumRowsRequested == 0 && mRowSizeSecondaryRequested == 0) { 1054 mNumRows = 1; 1055 mFixedRowSizeSecondary = sizeSecondary - paddingSecondary; 1056 } else if (mNumRowsRequested == 0) { 1057 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 1058 mNumRows = (sizeSecondary + mMarginSecondary) 1059 / (mRowSizeSecondaryRequested + mMarginSecondary); 1060 } else if (mRowSizeSecondaryRequested == 0) { 1061 mNumRows = mNumRowsRequested; 1062 mFixedRowSizeSecondary = (sizeSecondary - paddingSecondary - mMarginSecondary 1063 * (mNumRows - 1)) / mNumRows; 1064 } else { 1065 mNumRows = mNumRowsRequested; 1066 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 1067 } 1068 measuredSizeSecondary = sizeSecondary; 1069 if (modeSecondary == MeasureSpec.AT_MOST) { 1070 int childrenSize = mFixedRowSizeSecondary * mNumRows + mMarginSecondary 1071 * (mNumRows - 1) + paddingSecondary; 1072 if (childrenSize < measuredSizeSecondary) { 1073 measuredSizeSecondary = childrenSize; 1074 } 1075 } 1076 break; 1077 default: 1078 throw new IllegalStateException("wrong spec"); 1079 } 1080 } 1081 if (mOrientation == HORIZONTAL) { 1082 setMeasuredDimension(sizePrimary, measuredSizeSecondary); 1083 } else { 1084 setMeasuredDimension(measuredSizeSecondary, sizePrimary); 1085 } 1086 if (DEBUG) { 1087 Log.v(getTag(), "onMeasure sizePrimary " + sizePrimary + 1088 " measuredSizeSecondary " + measuredSizeSecondary + 1089 " mFixedRowSizeSecondary " + mFixedRowSizeSecondary + 1090 " mNumRows " + mNumRows); 1091 } 1092 1093 leaveContext(); 1094 } 1095 1096 private void measureChild(View child) { 1097 final ViewGroup.LayoutParams lp = child.getLayoutParams(); 1098 final int secondarySpec = (mRowSizeSecondaryRequested == ViewGroup.LayoutParams.WRAP_CONTENT) ? 1099 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED) : 1100 MeasureSpec.makeMeasureSpec(mFixedRowSizeSecondary, MeasureSpec.EXACTLY); 1101 int widthSpec, heightSpec; 1102 1103 if (mOrientation == HORIZONTAL) { 1104 widthSpec = ViewGroup.getChildMeasureSpec( 1105 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 1106 0, lp.width); 1107 heightSpec = ViewGroup.getChildMeasureSpec(secondarySpec, 0, lp.height); 1108 } else { 1109 heightSpec = ViewGroup.getChildMeasureSpec( 1110 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 1111 0, lp.height); 1112 widthSpec = ViewGroup.getChildMeasureSpec(secondarySpec, 0, lp.width); 1113 } 1114 1115 child.measure(widthSpec, heightSpec); 1116 1117 if (DEBUG) Log.v(getTag(), "measureChild secondarySpec " + Integer.toHexString(secondarySpec) + 1118 " widthSpec " + Integer.toHexString(widthSpec) + 1119 " heightSpec " + Integer.toHexString(heightSpec) + 1120 " measuredWidth " + child.getMeasuredWidth() + 1121 " measuredHeight " + child.getMeasuredHeight()); 1122 if (DEBUG) Log.v(getTag(), "child lp width " + lp.width + " height " + lp.height); 1123 } 1124 1125 private StaggeredGrid.Provider mGridProvider = new StaggeredGrid.Provider() { 1126 1127 @Override 1128 public int getCount() { 1129 return mState.getItemCount(); 1130 } 1131 1132 @Override 1133 public void createItem(int index, int rowIndex, boolean append) { 1134 View v = getViewForPosition(index); 1135 if (mFirstVisiblePos >= 0) { 1136 // when StaggeredGrid append or prepend item, we must guarantee 1137 // that sibling item has created views already. 1138 if (append && index != mLastVisiblePos + 1) { 1139 throw new RuntimeException(); 1140 } else if (!append && index != mFirstVisiblePos - 1) { 1141 throw new RuntimeException(); 1142 } 1143 } 1144 1145 // See recyclerView docs: we don't need re-add scraped view if it was removed. 1146 if (!((RecyclerView.LayoutParams) v.getLayoutParams()).isItemRemoved()) { 1147 if (append) { 1148 addView(v); 1149 } else { 1150 addView(v, 0); 1151 } 1152 if (mChildVisibility != -1) { 1153 v.setVisibility(mChildVisibility); 1154 } 1155 1156 // View is added first or it won't be found by dispatchChildSelected. 1157 if (mInLayout && index == mFocusPosition) { 1158 dispatchChildSelected(); 1159 } 1160 1161 measureChild(v); 1162 } 1163 1164 int length = mOrientation == HORIZONTAL ? v.getMeasuredWidth() : v.getMeasuredHeight(); 1165 int start, end; 1166 final boolean rowIsEmpty = mRows[rowIndex].high == mRows[rowIndex].low; 1167 boolean addHigh = (!mReverseFlowPrimary) ? append : !append; 1168 int lowVisiblePos = (!mReverseFlowPrimary) ? mFirstVisiblePos : mLastVisiblePos; 1169 int highVisiblePos = (!mReverseFlowPrimary) ? mLastVisiblePos : mFirstVisiblePos; 1170 if (addHigh) { 1171 if (!rowIsEmpty) { 1172 // if there are existing item in the row, add margin between 1173 start = mRows[rowIndex].high + mMarginPrimary; 1174 } else { 1175 if (lowVisiblePos >= 0) { 1176 int rowOfLowPos = mGrid.getLocation(lowVisiblePos).row; 1177 // If row is after row of lowest position, 1178 // start a new column after the first row. 1179 if (rowIndex < rowOfLowPos) { 1180 mRows[rowIndex].low = mRows[rowOfLowPos].high + mMarginPrimary; 1181 } 1182 } 1183 start = mRows[rowIndex].low; 1184 } 1185 end = start + length; 1186 mRows[rowIndex].high = end; 1187 } else { 1188 if (!rowIsEmpty) { 1189 // if there are existing item in the row, add margin between 1190 end = mRows[rowIndex].low - mMarginPrimary; 1191 } else { 1192 if (highVisiblePos >= 0) { 1193 int rowOfHighPos = mGrid.getLocation(highVisiblePos).row; 1194 if (mOrientation == HORIZONTAL ? 1195 rowIndex < rowOfHighPos : rowIndex > rowOfHighPos) { 1196 mRows[rowIndex].high = mRows[rowOfHighPos].low - mMarginPrimary; 1197 } 1198 } 1199 end = mRows[rowIndex].high; 1200 } 1201 start = end - length; 1202 mRows[rowIndex].low = start; 1203 } 1204 if (mFirstVisiblePos < 0) { 1205 mFirstVisiblePos = mLastVisiblePos = index; 1206 } else { 1207 if (append) { 1208 mLastVisiblePos++; 1209 } else { 1210 mFirstVisiblePos--; 1211 } 1212 } 1213 if (DEBUG) Log.v(getTag(), "start " + start + " end " + end); 1214 int startSecondary = getRowStartSecondary(rowIndex) - mScrollOffsetSecondary; 1215 mChildrenStates.loadView(v, index); 1216 layoutChild(rowIndex, v, start - mScrollOffsetPrimary, end - mScrollOffsetPrimary, 1217 startSecondary); 1218 if (DEBUG) { 1219 Log.d(getTag(), "addView " + index + " " + v); 1220 } 1221 if (index == mFirstVisiblePos) { 1222 if (!mReverseFlowPrimary) { 1223 updateScrollMin(); 1224 } else { 1225 updateScrollMax(); 1226 } 1227 } 1228 if (index == mLastVisiblePos) { 1229 if (!mReverseFlowPrimary) { 1230 updateScrollMax(); 1231 } else { 1232 updateScrollMin(); 1233 } 1234 } 1235 } 1236 }; 1237 1238 private void layoutChild(int rowIndex, View v, int start, int end, int startSecondary) { 1239 int sizeSecondary = mOrientation == HORIZONTAL ? v.getMeasuredHeight() 1240 : v.getMeasuredWidth(); 1241 if (mFixedRowSizeSecondary > 0) { 1242 sizeSecondary = Math.min(sizeSecondary, mFixedRowSizeSecondary); 1243 } 1244 final int verticalGravity = mGravity & Gravity.VERTICAL_GRAVITY_MASK; 1245 final int horizontalGravity = (mReverseFlowPrimary || mReverseFlowSecondary) ? 1246 Gravity.getAbsoluteGravity(mGravity & Gravity.RELATIVE_HORIZONTAL_GRAVITY_MASK, View.LAYOUT_DIRECTION_RTL) : 1247 mGravity & Gravity.HORIZONTAL_GRAVITY_MASK; 1248 if (mOrientation == HORIZONTAL && verticalGravity == Gravity.TOP 1249 || mOrientation == VERTICAL && horizontalGravity == Gravity.LEFT) { 1250 // do nothing 1251 } else if (mOrientation == HORIZONTAL && verticalGravity == Gravity.BOTTOM 1252 || mOrientation == VERTICAL && horizontalGravity == Gravity.RIGHT) { 1253 startSecondary += getRowSizeSecondary(rowIndex) - sizeSecondary; 1254 } else if (mOrientation == HORIZONTAL && verticalGravity == Gravity.CENTER_VERTICAL 1255 || mOrientation == VERTICAL && horizontalGravity == Gravity.CENTER_HORIZONTAL) { 1256 startSecondary += (getRowSizeSecondary(rowIndex) - sizeSecondary) / 2; 1257 } 1258 int left, top, right, bottom; 1259 if (mOrientation == HORIZONTAL) { 1260 left = start; 1261 top = startSecondary; 1262 right = end; 1263 bottom = startSecondary + sizeSecondary; 1264 } else { 1265 top = start; 1266 left = startSecondary; 1267 bottom = end; 1268 right = startSecondary + sizeSecondary; 1269 } 1270 v.layout(left, top, right, bottom); 1271 updateChildOpticalInsets(v, left, top, right, bottom); 1272 updateChildAlignments(v); 1273 } 1274 1275 private void updateChildOpticalInsets(View v, int left, int top, int right, int bottom) { 1276 LayoutParams p = (LayoutParams) v.getLayoutParams(); 1277 p.setOpticalInsets(left - v.getLeft(), top - v.getTop(), 1278 v.getRight() - right, v.getBottom() - bottom); 1279 } 1280 1281 private void updateChildAlignments(View v) { 1282 LayoutParams p = (LayoutParams) v.getLayoutParams(); 1283 p.setAlignX(mItemAlignment.horizontal.getAlignmentPosition(v)); 1284 p.setAlignY(mItemAlignment.vertical.getAlignmentPosition(v)); 1285 } 1286 1287 private void updateChildAlignments() { 1288 for (int i = 0, c = getChildCount(); i < c; i++) { 1289 updateChildAlignments(getChildAt(i)); 1290 } 1291 } 1292 1293 private boolean needsAppendVisibleItem() { 1294 if (mLastVisiblePos < mFocusPosition) { 1295 return true; 1296 } 1297 if (mReverseFlowPrimary) { 1298 for (int i = 0; i < mNumRows; i++) { 1299 if (mRows[i].low == mRows[i].high) { 1300 if (mRows[i].low > mScrollOffsetPrimary) { 1301 return true; 1302 } 1303 } else if (mRows[i].low - mMarginPrimary > mScrollOffsetPrimary) { 1304 return true; 1305 } 1306 } 1307 } else { 1308 int right = mScrollOffsetPrimary + mSizePrimary; 1309 for (int i = 0; i < mNumRows; i++) { 1310 if (mRows[i].low == mRows[i].high) { 1311 if (mRows[i].high < right) { 1312 return true; 1313 } 1314 } else if (mRows[i].high < right - mMarginPrimary) { 1315 return true; 1316 } 1317 } 1318 } 1319 return false; 1320 } 1321 1322 private boolean needsPrependVisibleItem() { 1323 if (mFirstVisiblePos > mFocusPosition) { 1324 return true; 1325 } 1326 if (mReverseFlowPrimary) { 1327 int right = mScrollOffsetPrimary + mSizePrimary; 1328 for (int i = 0; i < mNumRows; i++) { 1329 if (mRows[i].low == mRows[i].high) { 1330 if (mRows[i].high < right) { 1331 return true; 1332 } 1333 } else if (mRows[i].high < right - mMarginPrimary) { 1334 return true; 1335 } 1336 } 1337 } else { 1338 for (int i = 0; i < mNumRows; i++) { 1339 if (mRows[i].low == mRows[i].high) { 1340 if (mRows[i].low > mScrollOffsetPrimary) { 1341 return true; 1342 } 1343 } else if (mRows[i].low - mMarginPrimary > mScrollOffsetPrimary) { 1344 return true; 1345 } 1346 } 1347 } 1348 return false; 1349 } 1350 1351 // Append one column if possible and return true if reach end. 1352 private boolean appendOneVisibleItem() { 1353 while (true) { 1354 if (mLastVisiblePos != NO_POSITION && mLastVisiblePos < mState.getItemCount() -1 && 1355 mLastVisiblePos < mGrid.getLastIndex()) { 1356 // append invisible view of saved location till last row 1357 final int index = mLastVisiblePos + 1; 1358 final int row = mGrid.getLocation(index).row; 1359 mGridProvider.createItem(index, row, true); 1360 if (row == mNumRows - 1) { 1361 return false; 1362 } 1363 } else if ((mLastVisiblePos == NO_POSITION && mState.getItemCount() > 0) || 1364 (mLastVisiblePos != NO_POSITION && 1365 mLastVisiblePos < mState.getItemCount() - 1)) { 1366 if (mReverseFlowPrimary) { 1367 mGrid.appendItems(mScrollOffsetPrimary); 1368 } else { 1369 mGrid.appendItems(mScrollOffsetPrimary + mSizePrimary); 1370 } 1371 return false; 1372 } else { 1373 return true; 1374 } 1375 } 1376 } 1377 1378 private void appendVisibleItems() { 1379 while (needsAppendVisibleItem()) { 1380 if (appendOneVisibleItem()) { 1381 break; 1382 } 1383 } 1384 } 1385 1386 // Prepend one column if possible and return true if reach end. 1387 private boolean prependOneVisibleItem() { 1388 while (true) { 1389 if (mFirstVisiblePos > 0) { 1390 if (mFirstVisiblePos > mGrid.getFirstIndex()) { 1391 // prepend invisible view of saved location till first row 1392 final int index = mFirstVisiblePos - 1; 1393 final int row = mGrid.getLocation(index).row; 1394 mGridProvider.createItem(index, row, false); 1395 if (row == 0) { 1396 return false; 1397 } 1398 } else { 1399 if (mReverseFlowPrimary) { 1400 mGrid.prependItems(mScrollOffsetPrimary + mSizePrimary); 1401 } else { 1402 mGrid.prependItems(mScrollOffsetPrimary); 1403 } 1404 return false; 1405 } 1406 } else { 1407 return true; 1408 } 1409 } 1410 } 1411 1412 private void prependVisibleItems() { 1413 while (needsPrependVisibleItem()) { 1414 if (prependOneVisibleItem()) { 1415 break; 1416 } 1417 } 1418 } 1419 1420 private void removeChildAt(int position) { 1421 View v = findViewByPosition(position); 1422 if (v != null) { 1423 if (DEBUG) { 1424 Log.d(getTag(), "removeAndRecycleViewAt " + position + " " + v); 1425 } 1426 mChildrenStates.saveOffscreenView(v, position); 1427 removeAndRecycleView(v, mRecycler); 1428 } 1429 } 1430 1431 private void removeInvisibleViewsAtEnd() { 1432 if (!mPruneChild) { 1433 return; 1434 } 1435 boolean update = false; 1436 while(mLastVisiblePos > mFirstVisiblePos && mLastVisiblePos > mFocusPosition) { 1437 View view = findViewByPosition(mLastVisiblePos); 1438 boolean offEnd = (!mReverseFlowPrimary) ? getViewMin(view) > mSizePrimary : 1439 getViewMax(view) < 0; 1440 if (offEnd) { 1441 removeChildAt(mLastVisiblePos); 1442 mLastVisiblePos--; 1443 update = true; 1444 } else { 1445 break; 1446 } 1447 } 1448 if (update) { 1449 updateRowsMinMax(); 1450 } 1451 } 1452 1453 private void removeInvisibleViewsAtFront() { 1454 if (!mPruneChild) { 1455 return; 1456 } 1457 boolean update = false; 1458 while(mLastVisiblePos > mFirstVisiblePos && mFirstVisiblePos < mFocusPosition) { 1459 View view = findViewByPosition(mFirstVisiblePos); 1460 boolean offFront = (!mReverseFlowPrimary) ? getViewMax(view) < 0: 1461 getViewMin(view) > mSizePrimary; 1462 if (offFront) { 1463 removeChildAt(mFirstVisiblePos); 1464 mFirstVisiblePos++; 1465 update = true; 1466 } else { 1467 break; 1468 } 1469 } 1470 if (update) { 1471 updateRowsMinMax(); 1472 } 1473 } 1474 1475 private void updateRowsMinMax() { 1476 if (mFirstVisiblePos < 0) { 1477 return; 1478 } 1479 for (int i = 0; i < mNumRows; i++) { 1480 mRows[i].low = Integer.MAX_VALUE; 1481 mRows[i].high = Integer.MIN_VALUE; 1482 } 1483 for (int i = mFirstVisiblePos; i <= mLastVisiblePos; i++) { 1484 View view = findViewByPosition(i); 1485 int row = mGrid.getLocation(i).row; 1486 int low = getViewMin(view) + mScrollOffsetPrimary; 1487 if (low < mRows[row].low) { 1488 mRows[row].low = low; 1489 } 1490 int high = getViewMax(view) + mScrollOffsetPrimary; 1491 if (high > mRows[row].high) { 1492 mRows[row].high = high; 1493 } 1494 } 1495 } 1496 1497 // Fast layout when there is no structure change, adapter change, etc. 1498 protected void fastRelayout(boolean scrollToFocus) { 1499 initScrollController(); 1500 1501 List<Integer>[] rows = mGrid.getItemPositionsInRows(mFirstVisiblePos, mLastVisiblePos); 1502 1503 // relayout and repositioning views on each row 1504 for (int i = 0; i < mNumRows; i++) { 1505 List<Integer> row = rows[i]; 1506 final int startSecondary = getRowStartSecondary(i) - mScrollOffsetSecondary; 1507 for (int j = 0, size = row.size(); j < size; j++) { 1508 final int position = row.get(j); 1509 View view = findViewByPosition(position); 1510 int primaryDelta, end; 1511 1512 int start = getViewMin(view); 1513 int oldPrimarySize = (mOrientation == HORIZONTAL) ? 1514 view.getMeasuredWidth() : 1515 view.getMeasuredHeight(); 1516 1517 LayoutParams lp = (LayoutParams) view.getLayoutParams(); 1518 if (lp.viewNeedsUpdate()) { 1519 int index = mBaseGridView.indexOfChild(view); 1520 detachAndScrapView(view, mRecycler); 1521 view = getViewForPosition(position); 1522 addView(view, index); 1523 } 1524 1525 if (view.isLayoutRequested()) { 1526 measureChild(view); 1527 } 1528 1529 if (mOrientation == HORIZONTAL) { 1530 end = start + view.getMeasuredWidth(); 1531 primaryDelta = view.getMeasuredWidth() - oldPrimarySize; 1532 if (primaryDelta != 0) { 1533 for (int k = j + 1; k < size; k++) { 1534 findViewByPosition(row.get(k)).offsetLeftAndRight(primaryDelta); 1535 } 1536 } 1537 } else { 1538 end = start + view.getMeasuredHeight(); 1539 primaryDelta = view.getMeasuredHeight() - oldPrimarySize; 1540 if (primaryDelta != 0) { 1541 for (int k = j + 1; k < size; k++) { 1542 findViewByPosition(row.get(k)).offsetTopAndBottom(primaryDelta); 1543 } 1544 } 1545 } 1546 layoutChild(i, view, start, end, startSecondary); 1547 } 1548 } 1549 1550 updateRowsMinMax(); 1551 appendVisibleItems(); 1552 prependVisibleItems(); 1553 1554 updateRowsMinMax(); 1555 updateScrollMin(); 1556 updateScrollMax(); 1557 updateScrollSecondAxis(); 1558 1559 if (scrollToFocus) { 1560 View focusView = findViewByPosition(mFocusPosition == NO_POSITION ? 0 : mFocusPosition); 1561 scrollToView(focusView, false); 1562 } 1563 } 1564 1565 public void removeAndRecycleAllViews(RecyclerView.Recycler recycler) { 1566 if (DEBUG) Log.v(TAG, "removeAndRecycleAllViews " + getChildCount()); 1567 for (int i = getChildCount() - 1; i >= 0; i--) { 1568 removeAndRecycleViewAt(i, recycler); 1569 } 1570 } 1571 1572 // Lays out items based on the current scroll position 1573 @Override 1574 public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state) { 1575 if (DEBUG) { 1576 Log.v(getTag(), "layoutChildren start numRows " + mNumRows + " mScrollOffsetSecondary " 1577 + mScrollOffsetSecondary + " mScrollOffsetPrimary " + mScrollOffsetPrimary 1578 + " inPreLayout " + state.isPreLayout() 1579 + " didStructureChange " + state.didStructureChange() 1580 + " mForceFullLayout " + mForceFullLayout); 1581 Log.v(getTag(), "width " + getWidth() + " height " + getHeight()); 1582 } 1583 1584 if (mNumRows == 0) { 1585 // haven't done measure yet 1586 return; 1587 } 1588 final int itemCount = state.getItemCount(); 1589 if (itemCount < 0) { 1590 return; 1591 } 1592 1593 if (!mLayoutEnabled) { 1594 discardLayoutInfo(); 1595 removeAndRecycleAllViews(recycler); 1596 return; 1597 } 1598 mInLayout = true; 1599 1600 final boolean scrollToFocus = !isSmoothScrolling() 1601 && mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED; 1602 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE) { 1603 mFocusPosition = mFocusPosition + mFocusPositionOffset; 1604 mFocusPositionOffset = 0; 1605 } 1606 saveContext(recycler, state); 1607 1608 // Track the old focus view so we can adjust our system scroll position 1609 // so that any scroll animations happening now will remain valid. 1610 // We must use same delta in Pre Layout (if prelayout exists) and second layout. 1611 // So we cache the deltas in PreLayout and use it in second layout. 1612 int delta = 0, deltaSecondary = 0; 1613 if (mFocusPosition != NO_POSITION && scrollToFocus 1614 && mBaseGridView.getScrollState() != RecyclerView.SCROLL_STATE_IDLE) { 1615 // FIXME: we should get the remaining scroll animation offset from RecyclerView 1616 View focusView = findViewByPosition(mFocusPosition); 1617 if (focusView != null) { 1618 delta = mWindowAlignment.mainAxis().getSystemScrollPos(mScrollOffsetPrimary 1619 + getViewCenter(focusView), false, false) - mScrollOffsetPrimary; 1620 deltaSecondary = mWindowAlignment.secondAxis().getSystemScrollPos( 1621 mScrollOffsetSecondary + getViewCenterSecondary(focusView), 1622 false, false) - mScrollOffsetSecondary; 1623 } 1624 } 1625 1626 final boolean hasDoneFirstLayout = hasDoneFirstLayout(); 1627 int savedFocusPos = mFocusPosition; 1628 boolean fastRelayout = false; 1629 if (!mState.didStructureChange() && !mForceFullLayout && hasDoneFirstLayout) { 1630 fastRelayout = true; 1631 fastRelayout(scrollToFocus); 1632 } else { 1633 boolean hadFocus = mBaseGridView.hasFocus(); 1634 1635 mFocusPosition = init(mFocusPosition); 1636 if (mFocusPosition != savedFocusPos) { 1637 if (DEBUG) Log.v(getTag(), "savedFocusPos " + savedFocusPos + 1638 " mFocusPosition " + mFocusPosition); 1639 } 1640 if (mFocusPosition == NO_POSITION) { 1641 mBaseGridView.clearFocus(); 1642 } 1643 1644 mWindowAlignment.mainAxis().invalidateScrollMin(); 1645 mWindowAlignment.mainAxis().invalidateScrollMax(); 1646 // depending on result of init(), either recreating everything 1647 // or try to reuse the row start positions near mFocusPosition 1648 if (mGrid.getSize() == 0) { 1649 // this is a fresh creating all items, starting from 1650 // mFocusPosition with a estimated row index. 1651 mGrid.setStart(mFocusPosition, StaggeredGrid.START_DEFAULT); 1652 1653 // Can't track the old focus view 1654 delta = deltaSecondary = 0; 1655 1656 } else { 1657 // mGrid remembers Locations for the column that 1658 // contains mFocusePosition and also mRows remembers start 1659 // positions of each row. 1660 // Manually re-create child views for that column 1661 int firstIndex = mGrid.getFirstIndex(); 1662 int lastIndex = mGrid.getLastIndex(); 1663 for (int i = firstIndex; i <= lastIndex; i++) { 1664 mGridProvider.createItem(i, mGrid.getLocation(i).row, true); 1665 } 1666 } 1667 1668 // add visible views at end until reach the end of window 1669 appendVisibleItems(); 1670 // add visible views at front until reach the start of window 1671 prependVisibleItems(); 1672 // multiple rounds: scrollToView of first round may drag first/last child into 1673 // "visible window" and we update scrollMin/scrollMax then run second scrollToView 1674 int oldFirstVisible; 1675 int oldLastVisible; 1676 do { 1677 updateScrollMin(); 1678 updateScrollMax(); 1679 oldFirstVisible = mFirstVisiblePos; 1680 oldLastVisible = mLastVisiblePos; 1681 View focusView = findViewByPosition(mFocusPosition); 1682 // we need force to initialize the child view's position 1683 scrollToView(focusView, false); 1684 if (focusView != null && hadFocus) { 1685 focusView.requestFocus(); 1686 } 1687 appendVisibleItems(); 1688 prependVisibleItems(); 1689 removeInvisibleViewsAtFront(); 1690 removeInvisibleViewsAtEnd(); 1691 } while (mFirstVisiblePos != oldFirstVisible || mLastVisiblePos != oldLastVisible); 1692 } 1693 mForceFullLayout = false; 1694 1695 if (scrollToFocus) { 1696 scrollDirectionPrimary(-delta); 1697 scrollDirectionSecondary(-deltaSecondary); 1698 } 1699 appendVisibleItems(); 1700 prependVisibleItems(); 1701 removeInvisibleViewsAtFront(); 1702 removeInvisibleViewsAtEnd(); 1703 1704 if (DEBUG) { 1705 StringWriter sw = new StringWriter(); 1706 PrintWriter pw = new PrintWriter(sw); 1707 mGrid.debugPrint(pw); 1708 Log.d(getTag(), sw.toString()); 1709 } 1710 1711 if (mRowSecondarySizeRefresh) { 1712 mRowSecondarySizeRefresh = false; 1713 } else { 1714 updateRowSecondarySizeRefresh(); 1715 } 1716 1717 if (fastRelayout && mFocusPosition != savedFocusPos) { 1718 dispatchChildSelected(); 1719 } 1720 1721 mInLayout = false; 1722 leaveContext(); 1723 if (DEBUG) Log.v(getTag(), "layoutChildren end"); 1724 } 1725 1726 private void offsetChildrenSecondary(int increment) { 1727 final int childCount = getChildCount(); 1728 if (mOrientation == HORIZONTAL) { 1729 for (int i = 0; i < childCount; i++) { 1730 getChildAt(i).offsetTopAndBottom(increment); 1731 } 1732 } else { 1733 for (int i = 0; i < childCount; i++) { 1734 getChildAt(i).offsetLeftAndRight(increment); 1735 } 1736 } 1737 } 1738 1739 private void offsetChildrenPrimary(int increment) { 1740 final int childCount = getChildCount(); 1741 if (mOrientation == VERTICAL) { 1742 for (int i = 0; i < childCount; i++) { 1743 getChildAt(i).offsetTopAndBottom(increment); 1744 } 1745 } else { 1746 for (int i = 0; i < childCount; i++) { 1747 getChildAt(i).offsetLeftAndRight(increment); 1748 } 1749 } 1750 } 1751 1752 @Override 1753 public int scrollHorizontallyBy(int dx, Recycler recycler, RecyclerView.State state) { 1754 if (DEBUG) Log.v(getTag(), "scrollHorizontallyBy " + dx); 1755 if (!mLayoutEnabled || !hasDoneFirstLayout()) { 1756 return 0; 1757 } 1758 saveContext(recycler, state); 1759 int result; 1760 if (mOrientation == HORIZONTAL) { 1761 result = scrollDirectionPrimary(dx); 1762 } else { 1763 result = scrollDirectionSecondary(dx); 1764 } 1765 leaveContext(); 1766 return result; 1767 } 1768 1769 @Override 1770 public int scrollVerticallyBy(int dy, Recycler recycler, RecyclerView.State state) { 1771 if (DEBUG) Log.v(getTag(), "scrollVerticallyBy " + dy); 1772 if (!mLayoutEnabled || !hasDoneFirstLayout()) { 1773 return 0; 1774 } 1775 saveContext(recycler, state); 1776 int result; 1777 if (mOrientation == VERTICAL) { 1778 result = scrollDirectionPrimary(dy); 1779 } else { 1780 result = scrollDirectionSecondary(dy); 1781 } 1782 leaveContext(); 1783 return result; 1784 } 1785 1786 // scroll in main direction may add/prune views 1787 private int scrollDirectionPrimary(int da) { 1788 boolean isMaxUnknown = false, isMinUnknown = false; 1789 int minScroll = 0, maxScroll = 0; 1790 if (da > 0) { 1791 isMaxUnknown = mWindowAlignment.mainAxis().isMaxUnknown(); 1792 if (!isMaxUnknown) { 1793 maxScroll = mWindowAlignment.mainAxis().getMaxScroll(); 1794 if (mScrollOffsetPrimary + da > maxScroll) { 1795 da = maxScroll - mScrollOffsetPrimary; 1796 } 1797 } 1798 } else if (da < 0) { 1799 isMinUnknown = mWindowAlignment.mainAxis().isMinUnknown(); 1800 if (!isMinUnknown) { 1801 minScroll = mWindowAlignment.mainAxis().getMinScroll(); 1802 if (mScrollOffsetPrimary + da < minScroll) { 1803 da = minScroll - mScrollOffsetPrimary; 1804 } 1805 } 1806 } 1807 if (da == 0) { 1808 return 0; 1809 } 1810 offsetChildrenPrimary(-da); 1811 mScrollOffsetPrimary += da; 1812 if (mInLayout) { 1813 return da; 1814 } 1815 1816 int childCount = getChildCount(); 1817 boolean updated; 1818 1819 if (da > 0) { 1820 if (mReverseFlowPrimary) { 1821 prependVisibleItems(); 1822 } else { 1823 appendVisibleItems(); 1824 } 1825 } else if (da < 0) { 1826 if (mReverseFlowPrimary) { 1827 appendVisibleItems(); 1828 } else { 1829 prependVisibleItems(); 1830 } 1831 } 1832 updated = getChildCount() > childCount; 1833 childCount = getChildCount(); 1834 1835 if (da > 0) { 1836 if (mReverseFlowPrimary) { 1837 removeInvisibleViewsAtEnd(); 1838 } else { 1839 removeInvisibleViewsAtFront(); 1840 } 1841 } else if (da < 0) { 1842 if (mReverseFlowPrimary) { 1843 removeInvisibleViewsAtFront(); 1844 } else { 1845 removeInvisibleViewsAtEnd(); 1846 } 1847 } 1848 updated |= getChildCount() < childCount; 1849 1850 if (updated) { 1851 updateRowSecondarySizeRefresh(); 1852 } 1853 1854 mBaseGridView.invalidate(); 1855 return da; 1856 } 1857 1858 // scroll in second direction will not add/prune views 1859 private int scrollDirectionSecondary(int dy) { 1860 if (dy == 0) { 1861 return 0; 1862 } 1863 offsetChildrenSecondary(-dy); 1864 mScrollOffsetSecondary += dy; 1865 mBaseGridView.invalidate(); 1866 return dy; 1867 } 1868 1869 private void updateScrollMax() { 1870 int highVisiblePos = (!mReverseFlowPrimary) ? mLastVisiblePos : mFirstVisiblePos; 1871 int highMaxPos = (!mReverseFlowPrimary) ? mState.getItemCount() - 1 : 0; 1872 if (highVisiblePos < 0) { 1873 return; 1874 } 1875 final boolean highAvailable = highVisiblePos == highMaxPos; 1876 final boolean maxUnknown = mWindowAlignment.mainAxis().isMaxUnknown(); 1877 if (!highAvailable && maxUnknown) { 1878 return; 1879 } 1880 int maxEdge = Integer.MIN_VALUE; 1881 int rowIndex = -1; 1882 for (int i = 0; i < mRows.length; i++) { 1883 if (mRows[i].high > maxEdge) { 1884 maxEdge = mRows[i].high; 1885 rowIndex = i; 1886 } 1887 } 1888 int maxScroll = Integer.MAX_VALUE; 1889 for (int i = mFirstVisiblePos; i <= mLastVisiblePos; i++) { 1890 int pos = mReverseFlowPrimary ? i : mLastVisiblePos-i+mFirstVisiblePos; 1891 StaggeredGrid.Location location = mGrid.getLocation(pos); 1892 if (location != null && location.row == rowIndex) { 1893 int savedMaxEdge = mWindowAlignment.mainAxis().getMaxEdge(); 1894 mWindowAlignment.mainAxis().setMaxEdge(maxEdge); 1895 maxScroll = getPrimarySystemScrollPosition(findViewByPosition(pos)); 1896 mWindowAlignment.mainAxis().setMaxEdge(savedMaxEdge); 1897 break; 1898 } 1899 } 1900 if (highAvailable) { 1901 mWindowAlignment.mainAxis().setMaxEdge(maxEdge); 1902 mWindowAlignment.mainAxis().setMaxScroll(maxScroll); 1903 if (DEBUG) Log.v(getTag(), "updating scroll maxEdge to " + maxEdge + 1904 " scrollMax to " + maxScroll); 1905 } else { 1906 // the maxScroll for currently last visible item is larger, 1907 // so we must invalidate the max scroll value. 1908 if (maxScroll > mWindowAlignment.mainAxis().getMaxScroll()) { 1909 mWindowAlignment.mainAxis().invalidateScrollMax(); 1910 if (DEBUG) Log.v(getTag(), "Invalidate scrollMax since it should be " 1911 + "greater than " + maxScroll); 1912 } 1913 } 1914 } 1915 1916 private void updateScrollMin() { 1917 int lowVisiblePos = (!mReverseFlowPrimary) ? mFirstVisiblePos : mLastVisiblePos; 1918 int lowMinPos = (!mReverseFlowPrimary) ? 0 : mState.getItemCount() - 1; 1919 if (lowVisiblePos < 0) { 1920 return; 1921 } 1922 final boolean lowAvailable = lowVisiblePos == lowMinPos; 1923 final boolean minUnknown = mWindowAlignment.mainAxis().isMinUnknown(); 1924 if (!lowAvailable && minUnknown) { 1925 return; 1926 } 1927 int minEdge = Integer.MAX_VALUE; 1928 int rowIndex = -1; 1929 for (int i = 0; i < mRows.length; i++) { 1930 if (mRows[i].low < minEdge) { 1931 minEdge = mRows[i].low; 1932 rowIndex = i; 1933 } 1934 } 1935 int minScroll = Integer.MIN_VALUE; 1936 for (int i = mFirstVisiblePos; i <= mLastVisiblePos; i++) { 1937 int pos = mReverseFlowPrimary ? mLastVisiblePos-i+mFirstVisiblePos : i; 1938 StaggeredGrid.Location location = mGrid.getLocation(pos); 1939 if (location != null && location.row == rowIndex) { 1940 int savedMinEdge = mWindowAlignment.mainAxis().getMinEdge(); 1941 mWindowAlignment.mainAxis().setMinEdge(minEdge); 1942 minScroll = getPrimarySystemScrollPosition(findViewByPosition(pos)); 1943 mWindowAlignment.mainAxis().setMinEdge(savedMinEdge); 1944 break; 1945 } 1946 } 1947 if (lowAvailable) { 1948 mWindowAlignment.mainAxis().setMinEdge(minEdge); 1949 mWindowAlignment.mainAxis().setMinScroll(minScroll); 1950 if (DEBUG) Log.v(getTag(), "updating scroll minEdge to " + minEdge + 1951 " scrollMin to " + minScroll); 1952 } else { 1953 // the minScroll for currently first visible item is smaller, 1954 // so we must invalidate the min scroll value. 1955 if (minScroll < mWindowAlignment.mainAxis().getMinScroll()) { 1956 mWindowAlignment.mainAxis().invalidateScrollMin(); 1957 if (DEBUG) Log.v(getTag(), "Invalidate scrollMin, since it should be " 1958 + "less than " + minScroll); 1959 } 1960 } 1961 } 1962 1963 private void updateScrollSecondAxis() { 1964 mWindowAlignment.secondAxis().setMinEdge(0); 1965 mWindowAlignment.secondAxis().setMaxEdge(getSizeSecondary()); 1966 } 1967 1968 private void initScrollController() { 1969 // mScrollOffsetPrimary and mScrollOffsetSecondary includes the padding. 1970 // e.g. when topPadding is 16 for horizontal grid view, the initial 1971 // mScrollOffsetSecondary is -16. fastLayout() put views based on offsets(not padding), 1972 // when padding changes to 20, we also need update mScrollOffsetSecondary to -20 before 1973 // fastLayout() is performed 1974 int paddingPrimaryDiff, paddingSecondaryDiff; 1975 if (mOrientation == HORIZONTAL) { 1976 paddingPrimaryDiff = getPaddingLeft() - mWindowAlignment.horizontal.getPaddingLow(); 1977 paddingSecondaryDiff = getPaddingTop() - mWindowAlignment.vertical.getPaddingLow(); 1978 } else { 1979 paddingPrimaryDiff = getPaddingTop() - mWindowAlignment.vertical.getPaddingLow(); 1980 paddingSecondaryDiff = getPaddingLeft() - mWindowAlignment.horizontal.getPaddingLow(); 1981 } 1982 mScrollOffsetPrimary -= paddingPrimaryDiff; 1983 mScrollOffsetSecondary -= paddingSecondaryDiff; 1984 1985 mWindowAlignment.horizontal.setSize(getWidth()); 1986 mWindowAlignment.vertical.setSize(getHeight()); 1987 mWindowAlignment.horizontal.setPadding(getPaddingLeft(), getPaddingRight()); 1988 mWindowAlignment.vertical.setPadding(getPaddingTop(), getPaddingBottom()); 1989 mSizePrimary = mWindowAlignment.mainAxis().getSize(); 1990 1991 if (DEBUG) { 1992 Log.v(getTag(), "initScrollController mSizePrimary " + mSizePrimary 1993 + " mWindowAlignment " + mWindowAlignment); 1994 } 1995 } 1996 1997 public void setSelection(RecyclerView parent, int position) { 1998 setSelection(parent, position, false); 1999 } 2000 2001 public void setSelectionSmooth(RecyclerView parent, int position) { 2002 setSelection(parent, position, true); 2003 } 2004 2005 public int getSelection() { 2006 return mFocusPosition; 2007 } 2008 2009 public void setSelection(RecyclerView parent, int position, boolean smooth) { 2010 if (mFocusPosition != position && position != NO_POSITION) { 2011 scrollToSelection(parent, position, smooth); 2012 } 2013 } 2014 2015 private void scrollToSelection(RecyclerView parent, int position, boolean smooth) { 2016 View view = findViewByPosition(position); 2017 if (view != null) { 2018 mInSelection = true; 2019 scrollToView(view, smooth); 2020 mInSelection = false; 2021 } else { 2022 mFocusPosition = position; 2023 mFocusPositionOffset = 0; 2024 if (!mLayoutEnabled) { 2025 return; 2026 } 2027 if (smooth) { 2028 if (!hasDoneFirstLayout()) { 2029 Log.w(getTag(), "setSelectionSmooth should " + 2030 "not be called before first layout pass"); 2031 return; 2032 } 2033 LinearSmoothScroller linearSmoothScroller = 2034 new LinearSmoothScroller(parent.getContext()) { 2035 @Override 2036 public PointF computeScrollVectorForPosition(int targetPosition) { 2037 if (getChildCount() == 0) { 2038 return null; 2039 } 2040 final int firstChildPos = getPosition(getChildAt(0)); 2041 // TODO We should be able to deduce direction from bounds of current and target focus, 2042 // rather than making assumptions about positions and directionality 2043 final boolean isStart = mReverseFlowPrimary ? targetPosition > firstChildPos : targetPosition < firstChildPos; 2044 final int direction = isStart ? -1 : 1; 2045 if (mOrientation == HORIZONTAL) { 2046 return new PointF(direction, 0); 2047 } else { 2048 return new PointF(0, direction); 2049 } 2050 } 2051 @Override 2052 protected void onTargetFound(View targetView, 2053 RecyclerView.State state, Action action) { 2054 if (hasFocus()) { 2055 targetView.requestFocus(); 2056 } 2057 dispatchChildSelected(); 2058 if (getScrollPosition(targetView, mTempDeltas)) { 2059 int dx, dy; 2060 if (mOrientation == HORIZONTAL) { 2061 dx = mTempDeltas[0]; 2062 dy = mTempDeltas[1]; 2063 } else { 2064 dx = mTempDeltas[1]; 2065 dy = mTempDeltas[0]; 2066 } 2067 final int distance = (int) Math.sqrt(dx * dx + dy * dy); 2068 final int time = calculateTimeForDeceleration(distance); 2069 action.update(dx, dy, time, mDecelerateInterpolator); 2070 } 2071 } 2072 }; 2073 linearSmoothScroller.setTargetPosition(position); 2074 startSmoothScroll(linearSmoothScroller); 2075 } else { 2076 mForceFullLayout = true; 2077 parent.requestLayout(); 2078 } 2079 } 2080 } 2081 2082 @Override 2083 public void onItemsAdded(RecyclerView recyclerView, int positionStart, int itemCount) { 2084 if (DEBUG) Log.v(getTag(), "onItemsAdded positionStart " 2085 + positionStart + " itemCount " + itemCount); 2086 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE 2087 && getChildAt(mFocusPosition) != null) { 2088 int pos = mFocusPosition + mFocusPositionOffset; 2089 if (positionStart <= pos) { 2090 mFocusPositionOffset += itemCount; 2091 } 2092 } 2093 mChildrenStates.clear(); 2094 } 2095 2096 @Override 2097 public void onItemsChanged(RecyclerView recyclerView) { 2098 if (DEBUG) Log.v(getTag(), "onItemsChanged"); 2099 mFocusPositionOffset = 0; 2100 mChildrenStates.clear(); 2101 } 2102 2103 @Override 2104 public void onItemsRemoved(RecyclerView recyclerView, int positionStart, int itemCount) { 2105 if (DEBUG) Log.v(getTag(), "onItemsRemoved positionStart " 2106 + positionStart + " itemCount " + itemCount); 2107 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE 2108 && getChildAt(mFocusPosition) != null) { 2109 int pos = mFocusPosition + mFocusPositionOffset; 2110 if (positionStart <= pos) { 2111 if (positionStart + itemCount > pos) { 2112 // stop updating offset after the focus item was removed 2113 mFocusPositionOffset = Integer.MIN_VALUE; 2114 } else { 2115 mFocusPositionOffset -= itemCount; 2116 } 2117 } 2118 } 2119 mChildrenStates.clear(); 2120 } 2121 2122 @Override 2123 public void onItemsMoved(RecyclerView recyclerView, int fromPosition, int toPosition, 2124 int itemCount) { 2125 if (DEBUG) Log.v(getTag(), "onItemsMoved fromPosition " 2126 + fromPosition + " toPosition " + toPosition); 2127 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE 2128 && getChildAt(mFocusPosition) != null) { 2129 int pos = mFocusPosition + mFocusPositionOffset; 2130 if (fromPosition <= pos && pos < fromPosition + itemCount) { 2131 // moved items include focused position 2132 mFocusPositionOffset += toPosition - fromPosition; 2133 } else if (fromPosition < pos && toPosition > pos - itemCount) { 2134 // move items before focus position to after focused position 2135 mFocusPositionOffset -= itemCount; 2136 } else if (fromPosition > pos && toPosition < pos) { 2137 // move items after focus position to before focused position 2138 mFocusPositionOffset += itemCount; 2139 } 2140 } 2141 mChildrenStates.clear(); 2142 } 2143 2144 @Override 2145 public void onItemsUpdated(RecyclerView recyclerView, int positionStart, int itemCount) { 2146 if (DEBUG) Log.v(getTag(), "onItemsUpdated positionStart " 2147 + positionStart + " itemCount " + itemCount); 2148 for (int i = positionStart, end = positionStart + itemCount; i < end; i++) { 2149 mChildrenStates.remove(i); 2150 } 2151 } 2152 2153 @Override 2154 public boolean onRequestChildFocus(RecyclerView parent, View child, View focused) { 2155 if (mFocusSearchDisabled) { 2156 return true; 2157 } 2158 if (getPositionByView(child) == NO_POSITION) { 2159 // This shouldn't happen, but in case it does be sure not to attempt a 2160 // scroll to a view whose item has been removed. 2161 return true; 2162 } 2163 if (!mInLayout && !mInSelection) { 2164 scrollToView(child, true); 2165 } 2166 return true; 2167 } 2168 2169 @Override 2170 public boolean requestChildRectangleOnScreen(RecyclerView parent, View view, Rect rect, 2171 boolean immediate) { 2172 if (DEBUG) Log.v(getTag(), "requestChildRectangleOnScreen " + view + " " + rect); 2173 return false; 2174 } 2175 2176 int getScrollOffsetX() { 2177 return mOrientation == HORIZONTAL ? mScrollOffsetPrimary : mScrollOffsetSecondary; 2178 } 2179 2180 int getScrollOffsetY() { 2181 return mOrientation == HORIZONTAL ? mScrollOffsetSecondary : mScrollOffsetPrimary; 2182 } 2183 2184 public void getViewSelectedOffsets(View view, int[] offsets) { 2185 if (mOrientation == HORIZONTAL) { 2186 offsets[0] = getPrimarySystemScrollPosition(view) - mScrollOffsetPrimary; 2187 offsets[1] = getSecondarySystemScrollPosition(view) - mScrollOffsetSecondary; 2188 } else { 2189 offsets[1] = getPrimarySystemScrollPosition(view) - mScrollOffsetPrimary; 2190 offsets[0] = getSecondarySystemScrollPosition(view) - mScrollOffsetSecondary; 2191 } 2192 } 2193 2194 private int getPrimarySystemScrollPosition(View view) { 2195 final int viewCenterPrimary = mScrollOffsetPrimary + getViewCenter(view); 2196 final int viewMin = getViewMin(view); 2197 final int viewMax = getViewMax(view); 2198 // TODO: change to use State object in onRequestChildFocus() 2199 boolean isMin, isMax; 2200 if (!mReverseFlowPrimary) { 2201 isMin = mFirstVisiblePos == 0; 2202 isMax = mLastVisiblePos == (mState == null ? 2203 getItemCount() : mState.getItemCount()) - 1; 2204 } else { 2205 isMax = mFirstVisiblePos == 0; 2206 isMin = mLastVisiblePos == (mState == null ? 2207 getItemCount() : mState.getItemCount()) - 1; 2208 } 2209 for (int i = getChildCount() - 1; (isMin || isMax) && i >= 0; i--) { 2210 View v = getChildAt(i); 2211 if (v == view || v == null) { 2212 continue; 2213 } 2214 if (isMin && getViewMin(v) < viewMin) { 2215 isMin = false; 2216 } 2217 if (isMax && getViewMax(v) > viewMax) { 2218 isMax = false; 2219 } 2220 } 2221 return mWindowAlignment.mainAxis().getSystemScrollPos(viewCenterPrimary, isMin, isMax); 2222 } 2223 2224 private int getSecondarySystemScrollPosition(View view) { 2225 int viewCenterSecondary = mScrollOffsetSecondary + getViewCenterSecondary(view); 2226 int pos = getPositionByView(view); 2227 StaggeredGrid.Location location = mGrid.getLocation(pos); 2228 final int row = location.row; 2229 final boolean isMin, isMax; 2230 if (!mReverseFlowSecondary) { 2231 isMin = row == 0; 2232 isMax = row == mGrid.getNumRows() - 1; 2233 } else { 2234 isMax = row == 0; 2235 isMin = row == mGrid.getNumRows() - 1; 2236 } 2237 return mWindowAlignment.secondAxis().getSystemScrollPos(viewCenterSecondary, isMin, isMax); 2238 } 2239 2240 /** 2241 * Scroll to a given child view and change mFocusPosition. 2242 */ 2243 private void scrollToView(View view, boolean smooth) { 2244 int newFocusPosition = getPositionByView(view); 2245 if (newFocusPosition != mFocusPosition) { 2246 mFocusPosition = newFocusPosition; 2247 mFocusPositionOffset = 0; 2248 if (!mInLayout) { 2249 dispatchChildSelected(); 2250 } 2251 } 2252 if (mBaseGridView.isChildrenDrawingOrderEnabledInternal()) { 2253 mBaseGridView.invalidate(); 2254 } 2255 if (view == null) { 2256 return; 2257 } 2258 if (!view.hasFocus() && mBaseGridView.hasFocus()) { 2259 // transfer focus to the child if it does not have focus yet (e.g. triggered 2260 // by setSelection()) 2261 view.requestFocus(); 2262 } 2263 if (!mScrollEnabled) { 2264 return; 2265 } 2266 if (getScrollPosition(view, mTempDeltas)) { 2267 scrollGrid(mTempDeltas[0], mTempDeltas[1], smooth); 2268 } 2269 } 2270 2271 private boolean getScrollPosition(View view, int[] deltas) { 2272 switch (mFocusScrollStrategy) { 2273 case BaseGridView.FOCUS_SCROLL_ALIGNED: 2274 default: 2275 return getAlignedPosition(view, deltas); 2276 case BaseGridView.FOCUS_SCROLL_ITEM: 2277 case BaseGridView.FOCUS_SCROLL_PAGE: 2278 return getNoneAlignedPosition(view, deltas); 2279 } 2280 } 2281 2282 private boolean getNoneAlignedPosition(View view, int[] deltas) { 2283 int pos = getPositionByView(view); 2284 int viewMin = getViewMin(view); 2285 int viewMax = getViewMax(view); 2286 // we either align "firstView" to left/top padding edge 2287 // or align "lastView" to right/bottom padding edge 2288 View firstView = null; 2289 View lastView = null; 2290 int paddingLow = mWindowAlignment.mainAxis().getPaddingLow(); 2291 int clientSize = mWindowAlignment.mainAxis().getClientSize(); 2292 final int row = mGrid.getLocation(pos).row; 2293 if (viewMin < paddingLow) { 2294 // view enters low padding area: 2295 firstView = view; 2296 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_PAGE) { 2297 // scroll one "page" left/top, 2298 // align first visible item of the "page" at the low padding edge. 2299 while (!prependOneVisibleItem()) { 2300 List<Integer> positions = 2301 mGrid.getItemPositionsInRows(mFirstVisiblePos, pos)[row]; 2302 firstView = findViewByPosition(positions.get(0)); 2303 if (viewMax - getViewMin(firstView) > clientSize) { 2304 if (positions.size() > 1) { 2305 firstView = findViewByPosition(positions.get(1)); 2306 } 2307 break; 2308 } 2309 } 2310 } 2311 } else if (viewMax > clientSize + paddingLow) { 2312 // view enters high padding area: 2313 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_PAGE) { 2314 // scroll whole one page right/bottom, align view at the low padding edge. 2315 firstView = view; 2316 do { 2317 List<Integer> positions = 2318 mGrid.getItemPositionsInRows(pos, mLastVisiblePos)[row]; 2319 lastView = findViewByPosition(positions.get(positions.size() - 1)); 2320 if (getViewMax(lastView) - viewMin > clientSize) { 2321 lastView = null; 2322 break; 2323 } 2324 } while (!appendOneVisibleItem()); 2325 if (lastView != null) { 2326 // however if we reached end, we should align last view. 2327 firstView = null; 2328 } 2329 } else { 2330 lastView = view; 2331 } 2332 } 2333 int scrollPrimary = 0; 2334 int scrollSecondary = 0; 2335 if (firstView != null) { 2336 scrollPrimary = getViewMin(firstView) - paddingLow; 2337 } else if (lastView != null) { 2338 scrollPrimary = getViewMax(lastView) - (paddingLow + clientSize); 2339 } 2340 View secondaryAlignedView; 2341 if (firstView != null) { 2342 secondaryAlignedView = firstView; 2343 } else if (lastView != null) { 2344 secondaryAlignedView = lastView; 2345 } else { 2346 secondaryAlignedView = view; 2347 } 2348 scrollSecondary = getSecondarySystemScrollPosition(secondaryAlignedView); 2349 scrollSecondary -= mScrollOffsetSecondary; 2350 if (scrollPrimary != 0 || scrollSecondary != 0) { 2351 deltas[0] = scrollPrimary; 2352 deltas[1] = scrollSecondary; 2353 return true; 2354 } 2355 return false; 2356 } 2357 2358 private boolean getAlignedPosition(View view, int[] deltas) { 2359 int scrollPrimary = getPrimarySystemScrollPosition(view); 2360 int scrollSecondary = getSecondarySystemScrollPosition(view); 2361 if (DEBUG) { 2362 Log.v(getTag(), "getAlignedPosition " + scrollPrimary + " " + scrollSecondary 2363 + " " + mWindowAlignment); 2364 Log.v(getTag(), "getAlignedPosition " + mScrollOffsetPrimary + " " + mScrollOffsetSecondary); 2365 } 2366 scrollPrimary -= mScrollOffsetPrimary; 2367 scrollSecondary -= mScrollOffsetSecondary; 2368 if (scrollPrimary != 0 || scrollSecondary != 0) { 2369 deltas[0] = scrollPrimary; 2370 deltas[1] = scrollSecondary; 2371 return true; 2372 } 2373 return false; 2374 } 2375 2376 private void scrollGrid(int scrollPrimary, int scrollSecondary, boolean smooth) { 2377 if (mInLayout) { 2378 scrollDirectionPrimary(scrollPrimary); 2379 scrollDirectionSecondary(scrollSecondary); 2380 } else { 2381 int scrollX; 2382 int scrollY; 2383 if (mOrientation == HORIZONTAL) { 2384 scrollX = scrollPrimary; 2385 scrollY = scrollSecondary; 2386 } else { 2387 scrollX = scrollSecondary; 2388 scrollY = scrollPrimary; 2389 } 2390 if (smooth) { 2391 mBaseGridView.smoothScrollBy(scrollX, scrollY); 2392 } else { 2393 mBaseGridView.scrollBy(scrollX, scrollY); 2394 } 2395 } 2396 } 2397 2398 public void setPruneChild(boolean pruneChild) { 2399 if (mPruneChild != pruneChild) { 2400 mPruneChild = pruneChild; 2401 if (mPruneChild) { 2402 requestLayout(); 2403 } 2404 } 2405 } 2406 2407 public boolean getPruneChild() { 2408 return mPruneChild; 2409 } 2410 2411 public void setScrollEnabled(boolean scrollEnabled) { 2412 if (mScrollEnabled != scrollEnabled) { 2413 mScrollEnabled = scrollEnabled; 2414 if (mScrollEnabled && mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED 2415 && mFocusPosition != NO_POSITION) { 2416 scrollToSelection(mBaseGridView, mFocusPosition, true); 2417 } 2418 } 2419 } 2420 2421 public boolean isScrollEnabled() { 2422 return mScrollEnabled; 2423 } 2424 2425 private int findImmediateChildIndex(View view) { 2426 while (view != null && view != mBaseGridView) { 2427 int index = mBaseGridView.indexOfChild(view); 2428 if (index >= 0) { 2429 return index; 2430 } 2431 view = (View) view.getParent(); 2432 } 2433 return NO_POSITION; 2434 } 2435 2436 void setFocusSearchDisabled(boolean disabled) { 2437 mFocusSearchDisabled = disabled; 2438 } 2439 2440 boolean isFocusSearchDisabled() { 2441 return mFocusSearchDisabled; 2442 } 2443 2444 @Override 2445 public View onInterceptFocusSearch(View focused, int direction) { 2446 if (mFocusSearchDisabled) { 2447 return focused; 2448 } 2449 return null; 2450 } 2451 2452 boolean hasPreviousViewInSameRow(int pos) { 2453 if (mGrid == null || pos == NO_POSITION) { 2454 return false; 2455 } 2456 if (mFirstVisiblePos > 0) { 2457 return true; 2458 } 2459 final int focusedRow = mGrid.getLocation(pos).row; 2460 for (int i = getChildCount() - 1; i >= 0; i--) { 2461 int position = getPositionByIndex(i); 2462 StaggeredGrid.Location loc = mGrid.getLocation(position); 2463 if (loc != null && loc.row == focusedRow) { 2464 if (position < pos) { 2465 return true; 2466 } 2467 } 2468 } 2469 return false; 2470 } 2471 2472 @Override 2473 public boolean onAddFocusables(RecyclerView recyclerView, 2474 ArrayList<View> views, int direction, int focusableMode) { 2475 if (mFocusSearchDisabled) { 2476 return true; 2477 } 2478 // If this viewgroup or one of its children currently has focus then we 2479 // consider our children for focus searching in main direction on the same row. 2480 // If this viewgroup has no focus and using focus align, we want the system 2481 // to ignore our children and pass focus to the viewgroup, which will pass 2482 // focus on to its children appropriately. 2483 // If this viewgroup has no focus and not using focus align, we want to 2484 // consider the child that does not overlap with padding area. 2485 if (recyclerView.hasFocus()) { 2486 final int movement = getMovement(direction); 2487 if (movement != PREV_ITEM && movement != NEXT_ITEM) { 2488 // Move on secondary direction uses default addFocusables(). 2489 return false; 2490 } 2491 final View focused = recyclerView.findFocus(); 2492 final int focusedPos = getPositionByIndex(findImmediateChildIndex(focused)); 2493 // Add focusables of focused item. 2494 if (focusedPos != NO_POSITION) { 2495 findViewByPosition(focusedPos).addFocusables(views, direction, focusableMode); 2496 } 2497 final int focusedRow = mGrid != null && focusedPos != NO_POSITION ? 2498 mGrid.getLocation(focusedPos).row : NO_POSITION; 2499 // Add focusables of next neighbor of same row on the focus search direction. 2500 if (mGrid != null) { 2501 final int focusableCount = views.size(); 2502 for (int i = 0, count = getChildCount(); i < count; i++) { 2503 int index = movement == NEXT_ITEM ? i : count - 1 - i; 2504 final View child = getChildAt(index); 2505 if (child.getVisibility() != View.VISIBLE) { 2506 continue; 2507 } 2508 int position = getPositionByIndex(index); 2509 StaggeredGrid.Location loc = mGrid.getLocation(position); 2510 if (focusedRow == NO_POSITION || (loc != null && loc.row == focusedRow)) { 2511 if (focusedPos == NO_POSITION || 2512 (movement == NEXT_ITEM && position > focusedPos) 2513 || (movement == PREV_ITEM && position < focusedPos)) { 2514 child.addFocusables(views, direction, focusableMode); 2515 if (views.size() > focusableCount) { 2516 break; 2517 } 2518 } 2519 } 2520 } 2521 } 2522 } else { 2523 if (mFocusScrollStrategy != BaseGridView.FOCUS_SCROLL_ALIGNED) { 2524 // adding views not overlapping padding area to avoid scrolling in gaining focus 2525 int left = mWindowAlignment.mainAxis().getPaddingLow(); 2526 int right = mWindowAlignment.mainAxis().getClientSize() + left; 2527 int focusableCount = views.size(); 2528 for (int i = 0, count = getChildCount(); i < count; i++) { 2529 View child = getChildAt(i); 2530 if (child.getVisibility() == View.VISIBLE) { 2531 if (getViewMin(child) >= left && getViewMax(child) <= right) { 2532 child.addFocusables(views, direction, focusableMode); 2533 } 2534 } 2535 } 2536 // if we cannot find any, then just add all children. 2537 if (views.size() == focusableCount) { 2538 for (int i = 0, count = getChildCount(); i < count; i++) { 2539 View child = getChildAt(i); 2540 if (child.getVisibility() == View.VISIBLE) { 2541 child.addFocusables(views, direction, focusableMode); 2542 } 2543 } 2544 if (views.size() != focusableCount) { 2545 return true; 2546 } 2547 } else { 2548 return true; 2549 } 2550 // if still cannot find any, fall through and add itself 2551 } 2552 if (recyclerView.isFocusable()) { 2553 views.add(recyclerView); 2554 } 2555 } 2556 return true; 2557 } 2558 2559 @Override 2560 public View onFocusSearchFailed(View focused, int direction, Recycler recycler, 2561 RecyclerView.State state) { 2562 if (DEBUG) Log.v(getTag(), "onFocusSearchFailed direction " + direction); 2563 2564 View view = null; 2565 int movement = getMovement(direction); 2566 final boolean isScroll = mBaseGridView.getScrollState() != RecyclerView.SCROLL_STATE_IDLE; 2567 if (mNumRows == 1) { 2568 // for simple row, use LinearSmoothScroller to smooth animation. 2569 // It will stay at a fixed cap speed in continuous scroll. 2570 if (movement == NEXT_ITEM) { 2571 int newPos = mFocusPosition + mNumRows; 2572 if (newPos < getItemCount() && mScrollEnabled) { 2573 setSelectionSmooth(mBaseGridView, newPos); 2574 view = focused; 2575 } else { 2576 if (isScroll || !mFocusOutEnd) { 2577 view = focused; 2578 } 2579 } 2580 } else if (movement == PREV_ITEM){ 2581 int newPos = mFocusPosition - mNumRows; 2582 if (newPos >= 0 && mScrollEnabled) { 2583 setSelectionSmooth(mBaseGridView, newPos); 2584 view = focused; 2585 } else { 2586 if (isScroll || !mFocusOutFront) { 2587 view = focused; 2588 } 2589 } 2590 } 2591 } else if (mNumRows > 1) { 2592 // for possible staggered grid, we need guarantee focus to same row/column. 2593 // TODO: we may also use LinearSmoothScroller. 2594 saveContext(recycler, state); 2595 final FocusFinder ff = FocusFinder.getInstance(); 2596 if (movement == NEXT_ITEM) { 2597 while (view == null && !appendOneVisibleItem()) { 2598 view = ff.findNextFocus(mBaseGridView, focused, direction); 2599 } 2600 } else if (movement == PREV_ITEM){ 2601 while (view == null && !prependOneVisibleItem()) { 2602 view = ff.findNextFocus(mBaseGridView, focused, direction); 2603 } 2604 } 2605 if (view == null) { 2606 // returning the same view to prevent focus lost when scrolling past the end of the list 2607 if (movement == PREV_ITEM) { 2608 view = mFocusOutFront && !isScroll ? null : focused; 2609 } else if (movement == NEXT_ITEM){ 2610 view = mFocusOutEnd && !isScroll ? null : focused; 2611 } 2612 } 2613 leaveContext(); 2614 } 2615 if (DEBUG) Log.v(getTag(), "returning view " + view); 2616 return view; 2617 } 2618 2619 boolean gridOnRequestFocusInDescendants(RecyclerView recyclerView, int direction, 2620 Rect previouslyFocusedRect) { 2621 switch (mFocusScrollStrategy) { 2622 case BaseGridView.FOCUS_SCROLL_ALIGNED: 2623 default: 2624 return gridOnRequestFocusInDescendantsAligned(recyclerView, 2625 direction, previouslyFocusedRect); 2626 case BaseGridView.FOCUS_SCROLL_PAGE: 2627 case BaseGridView.FOCUS_SCROLL_ITEM: 2628 return gridOnRequestFocusInDescendantsUnaligned(recyclerView, 2629 direction, previouslyFocusedRect); 2630 } 2631 } 2632 2633 private boolean gridOnRequestFocusInDescendantsAligned(RecyclerView recyclerView, 2634 int direction, Rect previouslyFocusedRect) { 2635 View view = findViewByPosition(mFocusPosition); 2636 if (view != null) { 2637 boolean result = view.requestFocus(direction, previouslyFocusedRect); 2638 if (!result && DEBUG) { 2639 Log.w(getTag(), "failed to request focus on " + view); 2640 } 2641 return result; 2642 } 2643 return false; 2644 } 2645 2646 private boolean gridOnRequestFocusInDescendantsUnaligned(RecyclerView recyclerView, 2647 int direction, Rect previouslyFocusedRect) { 2648 // focus to view not overlapping padding area to avoid scrolling in gaining focus 2649 int index; 2650 int increment; 2651 int end; 2652 int count = getChildCount(); 2653 if ((direction & View.FOCUS_FORWARD) != 0) { 2654 index = 0; 2655 increment = 1; 2656 end = count; 2657 } else { 2658 index = count - 1; 2659 increment = -1; 2660 end = -1; 2661 } 2662 int left = mWindowAlignment.mainAxis().getPaddingLow(); 2663 int right = mWindowAlignment.mainAxis().getClientSize() + left; 2664 for (int i = index; i != end; i += increment) { 2665 View child = getChildAt(i); 2666 if (child.getVisibility() == View.VISIBLE) { 2667 if (getViewMin(child) >= left && getViewMax(child) <= right) { 2668 if (child.requestFocus(direction, previouslyFocusedRect)) { 2669 return true; 2670 } 2671 } 2672 } 2673 } 2674 return false; 2675 } 2676 2677 private final static int PREV_ITEM = 0; 2678 private final static int NEXT_ITEM = 1; 2679 private final static int PREV_ROW = 2; 2680 private final static int NEXT_ROW = 3; 2681 2682 private int getMovement(int direction) { 2683 int movement = View.FOCUS_LEFT; 2684 2685 if (mOrientation == HORIZONTAL) { 2686 switch(direction) { 2687 case View.FOCUS_LEFT: 2688 movement = (!mReverseFlowPrimary) ? PREV_ITEM : NEXT_ITEM; 2689 break; 2690 case View.FOCUS_RIGHT: 2691 movement = (!mReverseFlowPrimary) ? NEXT_ITEM : PREV_ITEM; 2692 break; 2693 case View.FOCUS_UP: 2694 movement = PREV_ROW; 2695 break; 2696 case View.FOCUS_DOWN: 2697 movement = NEXT_ROW; 2698 break; 2699 } 2700 } else if (mOrientation == VERTICAL) { 2701 switch(direction) { 2702 case View.FOCUS_LEFT: 2703 movement = (!mReverseFlowPrimary) ? PREV_ROW : NEXT_ROW; 2704 break; 2705 case View.FOCUS_RIGHT: 2706 movement = (!mReverseFlowPrimary) ? NEXT_ROW : PREV_ROW; 2707 break; 2708 case View.FOCUS_UP: 2709 movement = PREV_ITEM; 2710 break; 2711 case View.FOCUS_DOWN: 2712 movement = NEXT_ITEM; 2713 break; 2714 } 2715 } 2716 2717 return movement; 2718 } 2719 2720 int getChildDrawingOrder(RecyclerView recyclerView, int childCount, int i) { 2721 View view = findViewByPosition(mFocusPosition); 2722 if (view == null) { 2723 return i; 2724 } 2725 int focusIndex = recyclerView.indexOfChild(view); 2726 // supposely 0 1 2 3 4 5 6 7 8 9, 4 is the center item 2727 // drawing order is 0 1 2 3 9 8 7 6 5 4 2728 if (i < focusIndex) { 2729 return i; 2730 } else if (i < childCount - 1) { 2731 return focusIndex + childCount - 1 - i; 2732 } else { 2733 return focusIndex; 2734 } 2735 } 2736 2737 @Override 2738 public void onAdapterChanged(RecyclerView.Adapter oldAdapter, 2739 RecyclerView.Adapter newAdapter) { 2740 if (DEBUG) Log.v(getTag(), "onAdapterChanged to " + newAdapter); 2741 if (oldAdapter != null) { 2742 discardLayoutInfo(); 2743 mFocusPosition = NO_POSITION; 2744 mFocusPositionOffset = 0; 2745 mChildrenStates.clear(); 2746 } 2747 super.onAdapterChanged(oldAdapter, newAdapter); 2748 } 2749 2750 private void discardLayoutInfo() { 2751 mGrid = null; 2752 mRows = null; 2753 mRowSizeSecondary = null; 2754 mFirstVisiblePos = -1; 2755 mLastVisiblePos = -1; 2756 mRowSecondarySizeRefresh = false; 2757 } 2758 2759 public void setLayoutEnabled(boolean layoutEnabled) { 2760 if (mLayoutEnabled != layoutEnabled) { 2761 mLayoutEnabled = layoutEnabled; 2762 requestLayout(); 2763 } 2764 } 2765 2766 void setChildrenVisibility(int visiblity) { 2767 mChildVisibility = visiblity; 2768 if (mChildVisibility != -1) { 2769 int count = getChildCount(); 2770 for (int i= 0; i < count; i++) { 2771 getChildAt(i).setVisibility(mChildVisibility); 2772 } 2773 } 2774 } 2775 2776 final static class SavedState implements Parcelable { 2777 2778 int index; // index inside adapter of the current view 2779 Bundle childStates = Bundle.EMPTY; 2780 2781 @Override 2782 public void writeToParcel(Parcel out, int flags) { 2783 out.writeInt(index); 2784 out.writeBundle(childStates); 2785 } 2786 2787 @SuppressWarnings("hiding") 2788 public static final Parcelable.Creator<SavedState> CREATOR = 2789 new Parcelable.Creator<SavedState>() { 2790 @Override 2791 public SavedState createFromParcel(Parcel in) { 2792 return new SavedState(in); 2793 } 2794 2795 @Override 2796 public SavedState[] newArray(int size) { 2797 return new SavedState[size]; 2798 } 2799 }; 2800 2801 @Override 2802 public int describeContents() { 2803 return 0; 2804 } 2805 2806 SavedState(Parcel in) { 2807 index = in.readInt(); 2808 childStates = in.readBundle(GridLayoutManager.class.getClassLoader()); 2809 } 2810 2811 SavedState() { 2812 } 2813 } 2814 2815 @Override 2816 public Parcelable onSaveInstanceState() { 2817 if (DEBUG) Log.v(getTag(), "onSaveInstanceState getSelection() " + getSelection()); 2818 SavedState ss = new SavedState(); 2819 for (int i = 0, count = getChildCount(); i < count; i++) { 2820 View view = getChildAt(i); 2821 int position = getPositionByView(view); 2822 if (position != NO_POSITION) { 2823 mChildrenStates.saveOnScreenView(view, position); 2824 } 2825 } 2826 ss.index = getSelection(); 2827 ss.childStates = mChildrenStates.saveAsBundle(); 2828 return ss; 2829 } 2830 2831 @Override 2832 public void onRestoreInstanceState(Parcelable state) { 2833 if (!(state instanceof SavedState)) { 2834 return; 2835 } 2836 SavedState loadingState = (SavedState)state; 2837 mFocusPosition = loadingState.index; 2838 mFocusPositionOffset = 0; 2839 mChildrenStates.loadFromBundle(loadingState.childStates); 2840 mForceFullLayout = true; 2841 requestLayout(); 2842 if (DEBUG) Log.v(getTag(), "onRestoreInstanceState mFocusPosition " + mFocusPosition); 2843 } 2844} 2845