GridLayoutManager.java revision 77b17ebed6d1f8488b150b25e2b6754971480cae
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.util.CircularIntArray; 23import android.support.v4.view.ViewCompat; 24import android.support.v7.widget.LinearSmoothScroller; 25import android.support.v7.widget.RecyclerView; 26import android.support.v7.widget.RecyclerView.Recycler; 27import android.support.v7.widget.RecyclerView.State; 28import android.support.v17.leanback.os.TraceHelper; 29 30import static android.support.v7.widget.RecyclerView.NO_ID; 31import static android.support.v7.widget.RecyclerView.NO_POSITION; 32import static android.support.v7.widget.RecyclerView.HORIZONTAL; 33import static android.support.v7.widget.RecyclerView.VERTICAL; 34 35import android.util.AttributeSet; 36import android.util.Log; 37import android.view.FocusFinder; 38import android.view.Gravity; 39import android.view.View; 40import android.view.ViewParent; 41import android.view.View.MeasureSpec; 42import android.view.ViewGroup.MarginLayoutParams; 43import android.view.ViewGroup; 44 45import java.io.PrintWriter; 46import java.io.StringWriter; 47import java.util.ArrayList; 48import java.util.List; 49 50final class GridLayoutManager extends RecyclerView.LayoutManager { 51 52 /* 53 * LayoutParams for {@link HorizontalGridView} and {@link VerticalGridView}. 54 * The class currently does two internal jobs: 55 * - Saves optical bounds insets. 56 * - Caches focus align view center. 57 */ 58 static class LayoutParams extends RecyclerView.LayoutParams { 59 60 // The view is saved only during animation. 61 private View mView; 62 63 // For placement 64 private int mLeftInset; 65 private int mTopInset; 66 private int mRightInset; 67 private int mBottomInset; 68 69 // For alignment 70 private int mAlignX; 71 private int mAlignY; 72 73 public LayoutParams(Context c, AttributeSet attrs) { 74 super(c, attrs); 75 } 76 77 public LayoutParams(int width, int height) { 78 super(width, height); 79 } 80 81 public LayoutParams(MarginLayoutParams source) { 82 super(source); 83 } 84 85 public LayoutParams(ViewGroup.LayoutParams source) { 86 super(source); 87 } 88 89 public LayoutParams(RecyclerView.LayoutParams source) { 90 super(source); 91 } 92 93 public LayoutParams(LayoutParams source) { 94 super(source); 95 } 96 97 int getAlignX() { 98 return mAlignX; 99 } 100 101 int getAlignY() { 102 return mAlignY; 103 } 104 105 int getOpticalLeft(View view) { 106 return view.getLeft() + mLeftInset; 107 } 108 109 int getOpticalTop(View view) { 110 return view.getTop() + mTopInset; 111 } 112 113 int getOpticalRight(View view) { 114 return view.getRight() - mRightInset; 115 } 116 117 int getOpticalBottom(View view) { 118 return view.getBottom() - mBottomInset; 119 } 120 121 int getOpticalWidth(View view) { 122 return view.getWidth() - mLeftInset - mRightInset; 123 } 124 125 int getOpticalHeight(View view) { 126 return view.getHeight() - mTopInset - mBottomInset; 127 } 128 129 int getOpticalLeftInset() { 130 return mLeftInset; 131 } 132 133 int getOpticalRightInset() { 134 return mRightInset; 135 } 136 137 int getOpticalTopInset() { 138 return mTopInset; 139 } 140 141 int getOpticalBottomInset() { 142 return mBottomInset; 143 } 144 145 void setAlignX(int alignX) { 146 mAlignX = alignX; 147 } 148 149 void setAlignY(int alignY) { 150 mAlignY = alignY; 151 } 152 153 void setOpticalInsets(int leftInset, int topInset, int rightInset, int bottomInset) { 154 mLeftInset = leftInset; 155 mTopInset = topInset; 156 mRightInset = rightInset; 157 mBottomInset = bottomInset; 158 } 159 160 private void invalidateItemDecoration() { 161 ViewParent parent = mView.getParent(); 162 if (parent instanceof RecyclerView) { 163 // TODO: we only need invalidate parent if it has ItemDecoration 164 ((RecyclerView) parent).invalidate(); 165 } 166 } 167 } 168 169 /** 170 * Base class which scrolls to selected view in onStop(). 171 */ 172 abstract class GridLinearSmoothScroller extends LinearSmoothScroller { 173 GridLinearSmoothScroller() { 174 super(mBaseGridView.getContext()); 175 } 176 177 @Override 178 protected void onStop() { 179 // onTargetFound() may not be called if we hit the "wall" first. 180 View targetView = findViewByPosition(getTargetPosition()); 181 if (hasFocus() && targetView != null) { 182 mInSelection = true; 183 targetView.requestFocus(); 184 mInSelection = false; 185 } 186 if (needsDispatchChildSelectedOnStop()) { 187 dispatchChildSelected(); 188 } 189 super.onStop(); 190 } 191 192 boolean needsDispatchChildSelectedOnStop() { 193 return true; 194 } 195 196 @Override 197 protected void onTargetFound(View targetView, 198 RecyclerView.State state, Action action) { 199 if (getScrollPosition(targetView, sTwoInts)) { 200 int dx, dy; 201 if (mOrientation == HORIZONTAL) { 202 dx = sTwoInts[0]; 203 dy = sTwoInts[1]; 204 } else { 205 dx = sTwoInts[1]; 206 dy = sTwoInts[0]; 207 } 208 final int distance = (int) Math.sqrt(dx * dx + dy * dy); 209 final int time = calculateTimeForDeceleration(distance); 210 action.update(dx, dy, time, mDecelerateInterpolator); 211 } 212 } 213 } 214 215 /** 216 * The SmoothScroller that remembers pending DPAD keys and consume pending keys 217 * during scroll. 218 */ 219 final class PendingMoveSmoothScroller extends GridLinearSmoothScroller { 220 // -2 is a target position that LinearSmoothScroller can never find until 221 // consumePendingMovesXXX() sets real targetPosition. 222 final static int TARGET_UNDEFINED = -2; 223 // whether the grid is staggered. 224 private final boolean mStaggeredGrid; 225 // Number of pending movements on primary direction, negative if PREV_ITEM. 226 private int mPendingMoves; 227 228 PendingMoveSmoothScroller(int initialPendingMoves, boolean staggeredGrid) { 229 mPendingMoves = initialPendingMoves; 230 mStaggeredGrid = staggeredGrid; 231 setTargetPosition(TARGET_UNDEFINED); 232 } 233 234 void increasePendingMoves() { 235 if (mPendingMoves < MAX_PENDING_MOVES) { 236 mPendingMoves++; 237 if (mPendingMoves == 0) { 238 dispatchChildSelected(); 239 } 240 } 241 } 242 243 void decreasePendingMoves() { 244 if (mPendingMoves > -MAX_PENDING_MOVES) { 245 mPendingMoves--; 246 if (mPendingMoves == 0) { 247 dispatchChildSelected(); 248 } 249 } 250 } 251 252 /** 253 * Called before laid out an item when non-staggered grid can handle pending movements 254 * by skipping "mNumRows" per movement; staggered grid will have to wait the item 255 * has been laid out in consumePendingMovesAfterLayout(). 256 */ 257 void consumePendingMovesBeforeLayout() { 258 if (mStaggeredGrid || mPendingMoves == 0) { 259 return; 260 } 261 View newSelected = null; 262 int startPos = mPendingMoves > 0 ? mFocusPosition + mNumRows : 263 mFocusPosition - mNumRows; 264 for (int pos = startPos; mPendingMoves != 0; 265 pos = mPendingMoves > 0 ? pos + mNumRows: pos - mNumRows) { 266 View v = findViewByPosition(pos); 267 if (v == null) { 268 break; 269 } 270 if (!canScrollTo(v)) { 271 continue; 272 } 273 newSelected = v; 274 mFocusPosition = pos; 275 if (mPendingMoves > 0) { 276 mPendingMoves--; 277 } else { 278 mPendingMoves++; 279 } 280 } 281 if (newSelected != null && hasFocus()) { 282 mInSelection = true; 283 newSelected.requestFocus(); 284 mInSelection = false; 285 } 286 } 287 288 /** 289 * Called after laid out an item. Staggered grid should find view on same 290 * Row and consume pending movements. 291 */ 292 void consumePendingMovesAfterLayout() { 293 if (mStaggeredGrid && mPendingMoves != 0) { 294 // consume pending moves, focus to item on the same row. 295 final int focusedRow = mGrid != null && mFocusPosition != NO_POSITION ? 296 mGrid.getLocation(mFocusPosition).row : NO_POSITION; 297 View newSelected = null; 298 for (int i = 0, count = getChildCount(); i < count && mPendingMoves != 0; i++) { 299 int index = mPendingMoves > 0 ? i : count - 1 - i; 300 final View child = getChildAt(index); 301 if (!canScrollTo(child)) { 302 continue; 303 } 304 int position = getPositionByIndex(index); 305 Grid.Location loc = mGrid.getLocation(position); 306 if (focusedRow == NO_POSITION || (loc != null && loc.row == focusedRow)) { 307 if (mFocusPosition == NO_POSITION) { 308 mFocusPosition = position; 309 newSelected = child; 310 } else if ((mPendingMoves > 0 && position > mFocusPosition) 311 || (mPendingMoves < 0 && position < mFocusPosition)) { 312 mFocusPosition = position; 313 if (mPendingMoves > 0) { 314 mPendingMoves--; 315 } else { 316 mPendingMoves++; 317 } 318 newSelected = child; 319 } 320 } 321 } 322 if (newSelected != null && hasFocus()) { 323 mInSelection = true; 324 newSelected.requestFocus(); 325 mInSelection = false; 326 } 327 } 328 if (mPendingMoves == 0 || (mPendingMoves > 0 && hasCreatedLastItem()) 329 || (mPendingMoves < 0 && hasCreatedFirstItem())) { 330 setTargetPosition(mFocusPosition); 331 stop(); 332 } 333 } 334 335 @Override 336 protected void updateActionForInterimTarget(Action action) { 337 if (mPendingMoves == 0) { 338 return; 339 } 340 super.updateActionForInterimTarget(action); 341 } 342 343 @Override 344 public PointF computeScrollVectorForPosition(int targetPosition) { 345 if (mPendingMoves == 0) { 346 return null; 347 } 348 int direction = (mReverseFlowPrimary ? mPendingMoves > 0 : mPendingMoves < 0) ? 349 -1 : 1; 350 if (mOrientation == HORIZONTAL) { 351 return new PointF(direction, 0); 352 } else { 353 return new PointF(0, direction); 354 } 355 } 356 357 @Override 358 boolean needsDispatchChildSelectedOnStop() { 359 return mPendingMoves != 0; 360 } 361 362 @Override 363 protected void onStop() { 364 super.onStop(); 365 // if we hit wall, need clear the remaining pending moves. 366 mPendingMoves = 0; 367 mPendingMoveSmoothScroller = null; 368 View v = findViewByPosition(getTargetPosition()); 369 if (v != null) scrollToView(v, true); 370 } 371 }; 372 373 private static final String TAG = "GridLayoutManager"; 374 private static final boolean DEBUG = false; 375 private static final boolean TRACE = false; 376 377 // maximum pending movement in one direction. 378 private final static int MAX_PENDING_MOVES = 10; 379 380 private String getTag() { 381 return TAG + ":" + mBaseGridView.getId(); 382 } 383 384 private final BaseGridView mBaseGridView; 385 386 /** 387 * Note on conventions in the presence of RTL layout directions: 388 * Many properties and method names reference entities related to the 389 * beginnings and ends of things. In the presence of RTL flows, 390 * it may not be clear whether this is intended to reference a 391 * quantity that changes direction in RTL cases, or a quantity that 392 * does not. Here are the conventions in use: 393 * 394 * start/end: coordinate quantities - do reverse 395 * (optical) left/right: coordinate quantities - do not reverse 396 * low/high: coordinate quantities - do not reverse 397 * min/max: coordinate quantities - do not reverse 398 * scroll offset - coordinate quantities - do not reverse 399 * first/last: positional indices - do not reverse 400 * front/end: positional indices - do not reverse 401 * prepend/append: related to positional indices - do not reverse 402 * 403 * Note that although quantities do not reverse in RTL flows, their 404 * relationship does. In LTR flows, the first positional index is 405 * leftmost; in RTL flows, it is rightmost. Thus, anywhere that 406 * positional quantities are mapped onto coordinate quantities, 407 * the flow must be checked and the logic reversed. 408 */ 409 410 /** 411 * The orientation of a "row". 412 */ 413 private int mOrientation = HORIZONTAL; 414 415 private RecyclerView.State mState; 416 private RecyclerView.Recycler mRecycler; 417 418 private boolean mInLayout = false; 419 private boolean mInFastRelayout; 420 private boolean mInSelection = false; 421 422 private OnChildSelectedListener mChildSelectedListener = null; 423 424 private OnChildLaidOutListener mChildLaidOutListener = null; 425 426 /** 427 * The focused position, it's not the currently visually aligned position 428 * but it is the final position that we intend to focus on. If there are 429 * multiple setSelection() called, mFocusPosition saves last value. 430 */ 431 private int mFocusPosition = NO_POSITION; 432 433 /** 434 * LinearSmoothScroller that consume pending DPAD movements. 435 */ 436 private PendingMoveSmoothScroller mPendingMoveSmoothScroller; 437 438 /** 439 * The offset to be applied to mFocusPosition, due to adapter change, on the next 440 * layout. Set to Integer.MIN_VALUE means item was removed. 441 * TODO: This is somewhat duplication of RecyclerView getOldPosition() which is 442 * unfortunately cleared after prelayout. 443 */ 444 private int mFocusPositionOffset = 0; 445 446 /** 447 * Force a full layout under certain situations. E.g. Rows change, jump to invisible child. 448 */ 449 private boolean mForceFullLayout; 450 451 /** 452 * True if layout is enabled. 453 */ 454 private boolean mLayoutEnabled = true; 455 456 /** 457 * override child visibility 458 */ 459 private int mChildVisibility = -1; 460 461 /** 462 * The scroll offsets of the viewport relative to the entire view. 463 */ 464 private int mScrollOffsetPrimary; 465 private int mScrollOffsetSecondary; 466 467 /** 468 * User-specified row height/column width. Can be WRAP_CONTENT. 469 */ 470 private int mRowSizeSecondaryRequested; 471 472 /** 473 * The fixed size of each grid item in the secondary direction. This corresponds to 474 * the row height, equal for all rows. Grid items may have variable length 475 * in the primary direction. 476 */ 477 private int mFixedRowSizeSecondary; 478 479 /** 480 * Tracks the secondary size of each row. 481 */ 482 private int[] mRowSizeSecondary; 483 484 /** 485 * Flag controlling whether the current/next layout should 486 * be updating the secondary size of rows. 487 */ 488 private boolean mRowSecondarySizeRefresh; 489 490 /** 491 * The maximum measured size of the view. 492 */ 493 private int mMaxSizeSecondary; 494 495 /** 496 * Margin between items. 497 */ 498 private int mHorizontalMargin; 499 /** 500 * Margin between items vertically. 501 */ 502 private int mVerticalMargin; 503 /** 504 * Margin in main direction. 505 */ 506 private int mMarginPrimary; 507 /** 508 * Margin in second direction. 509 */ 510 private int mMarginSecondary; 511 /** 512 * How to position child in secondary direction. 513 */ 514 private int mGravity = Gravity.START | Gravity.TOP; 515 /** 516 * The number of rows in the grid. 517 */ 518 private int mNumRows; 519 /** 520 * Number of rows requested, can be 0 to be determined by parent size and 521 * rowHeight. 522 */ 523 private int mNumRowsRequested = 1; 524 525 /** 526 * Saves grid information of each view. 527 */ 528 Grid mGrid; 529 530 /** 531 * Focus Scroll strategy. 532 */ 533 private int mFocusScrollStrategy = BaseGridView.FOCUS_SCROLL_ALIGNED; 534 /** 535 * Defines how item view is aligned in the window. 536 */ 537 private final WindowAlignment mWindowAlignment = new WindowAlignment(); 538 539 /** 540 * Defines how item view is aligned. 541 */ 542 private final ItemAlignment mItemAlignment = new ItemAlignment(); 543 544 /** 545 * Dimensions of the view, width or height depending on orientation. 546 */ 547 private int mSizePrimary; 548 549 /** 550 * Allow DPAD key to navigate out at the front of the View (where position = 0), 551 * default is false. 552 */ 553 private boolean mFocusOutFront; 554 555 /** 556 * Allow DPAD key to navigate out at the end of the view, default is false. 557 */ 558 private boolean mFocusOutEnd; 559 560 /** 561 * True if focus search is disabled. 562 */ 563 private boolean mFocusSearchDisabled; 564 565 /** 566 * True if prune child, might be disabled during transition. 567 */ 568 private boolean mPruneChild = true; 569 570 /** 571 * True if scroll content, might be disabled during transition. 572 */ 573 private boolean mScrollEnabled = true; 574 575 /** 576 * Temporary variable: an int array of length=2. 577 */ 578 private static int[] sTwoInts = new int[2]; 579 580 /** 581 * Set to true for RTL layout in horizontal orientation 582 */ 583 private boolean mReverseFlowPrimary = false; 584 585 /** 586 * Set to true for RTL layout in vertical orientation 587 */ 588 private boolean mReverseFlowSecondary = false; 589 590 /** 591 * Temporaries used for measuring. 592 */ 593 private int[] mMeasuredDimension = new int[2]; 594 595 final ViewsStateBundle mChildrenStates = new ViewsStateBundle(); 596 597 public GridLayoutManager(BaseGridView baseGridView) { 598 mBaseGridView = baseGridView; 599 } 600 601 public void setOrientation(int orientation) { 602 if (orientation != HORIZONTAL && orientation != VERTICAL) { 603 if (DEBUG) Log.v(getTag(), "invalid orientation: " + orientation); 604 return; 605 } 606 607 mOrientation = orientation; 608 mWindowAlignment.setOrientation(orientation); 609 mItemAlignment.setOrientation(orientation); 610 mForceFullLayout = true; 611 } 612 613 public void onRtlPropertiesChanged(int layoutDirection) { 614 if (mOrientation == HORIZONTAL) { 615 mReverseFlowPrimary = layoutDirection == View.LAYOUT_DIRECTION_RTL; 616 mReverseFlowSecondary = false; 617 } else { 618 mReverseFlowSecondary = layoutDirection == View.LAYOUT_DIRECTION_RTL; 619 mReverseFlowPrimary = false; 620 } 621 mWindowAlignment.horizontal.setReversedFlow(layoutDirection == View.LAYOUT_DIRECTION_RTL); 622 } 623 624 public int getFocusScrollStrategy() { 625 return mFocusScrollStrategy; 626 } 627 628 public void setFocusScrollStrategy(int focusScrollStrategy) { 629 mFocusScrollStrategy = focusScrollStrategy; 630 } 631 632 public void setWindowAlignment(int windowAlignment) { 633 mWindowAlignment.mainAxis().setWindowAlignment(windowAlignment); 634 } 635 636 public int getWindowAlignment() { 637 return mWindowAlignment.mainAxis().getWindowAlignment(); 638 } 639 640 public void setWindowAlignmentOffset(int alignmentOffset) { 641 mWindowAlignment.mainAxis().setWindowAlignmentOffset(alignmentOffset); 642 } 643 644 public int getWindowAlignmentOffset() { 645 return mWindowAlignment.mainAxis().getWindowAlignmentOffset(); 646 } 647 648 public void setWindowAlignmentOffsetPercent(float offsetPercent) { 649 mWindowAlignment.mainAxis().setWindowAlignmentOffsetPercent(offsetPercent); 650 } 651 652 public float getWindowAlignmentOffsetPercent() { 653 return mWindowAlignment.mainAxis().getWindowAlignmentOffsetPercent(); 654 } 655 656 public void setItemAlignmentOffset(int alignmentOffset) { 657 mItemAlignment.mainAxis().setItemAlignmentOffset(alignmentOffset); 658 updateChildAlignments(); 659 } 660 661 public int getItemAlignmentOffset() { 662 return mItemAlignment.mainAxis().getItemAlignmentOffset(); 663 } 664 665 public void setItemAlignmentOffsetWithPadding(boolean withPadding) { 666 mItemAlignment.mainAxis().setItemAlignmentOffsetWithPadding(withPadding); 667 updateChildAlignments(); 668 } 669 670 public boolean isItemAlignmentOffsetWithPadding() { 671 return mItemAlignment.mainAxis().isItemAlignmentOffsetWithPadding(); 672 } 673 674 public void setItemAlignmentOffsetPercent(float offsetPercent) { 675 mItemAlignment.mainAxis().setItemAlignmentOffsetPercent(offsetPercent); 676 updateChildAlignments(); 677 } 678 679 public float getItemAlignmentOffsetPercent() { 680 return mItemAlignment.mainAxis().getItemAlignmentOffsetPercent(); 681 } 682 683 public void setItemAlignmentViewId(int viewId) { 684 mItemAlignment.mainAxis().setItemAlignmentViewId(viewId); 685 updateChildAlignments(); 686 } 687 688 public int getItemAlignmentViewId() { 689 return mItemAlignment.mainAxis().getItemAlignmentViewId(); 690 } 691 692 public void setFocusOutAllowed(boolean throughFront, boolean throughEnd) { 693 mFocusOutFront = throughFront; 694 mFocusOutEnd = throughEnd; 695 } 696 697 public void setNumRows(int numRows) { 698 if (numRows < 0) throw new IllegalArgumentException(); 699 mNumRowsRequested = numRows; 700 mForceFullLayout = true; 701 } 702 703 /** 704 * Set the row height. May be WRAP_CONTENT, or a size in pixels. 705 */ 706 public void setRowHeight(int height) { 707 if (height >= 0 || height == ViewGroup.LayoutParams.WRAP_CONTENT) { 708 mRowSizeSecondaryRequested = height; 709 } else { 710 throw new IllegalArgumentException("Invalid row height: " + height); 711 } 712 } 713 714 public void setItemMargin(int margin) { 715 mVerticalMargin = mHorizontalMargin = margin; 716 mMarginPrimary = mMarginSecondary = margin; 717 } 718 719 public void setVerticalMargin(int margin) { 720 if (mOrientation == HORIZONTAL) { 721 mMarginSecondary = mVerticalMargin = margin; 722 } else { 723 mMarginPrimary = mVerticalMargin = margin; 724 } 725 } 726 727 public void setHorizontalMargin(int margin) { 728 if (mOrientation == HORIZONTAL) { 729 mMarginPrimary = mHorizontalMargin = margin; 730 } else { 731 mMarginSecondary = mHorizontalMargin = margin; 732 } 733 } 734 735 public int getVerticalMargin() { 736 return mVerticalMargin; 737 } 738 739 public int getHorizontalMargin() { 740 return mHorizontalMargin; 741 } 742 743 public void setGravity(int gravity) { 744 mGravity = gravity; 745 } 746 747 protected boolean hasDoneFirstLayout() { 748 return mGrid != null; 749 } 750 751 public void setOnChildSelectedListener(OnChildSelectedListener listener) { 752 mChildSelectedListener = listener; 753 } 754 755 void setOnChildLaidOutListener(OnChildLaidOutListener listener) { 756 mChildLaidOutListener = listener; 757 } 758 759 private int getPositionByView(View view) { 760 if (view == null) { 761 return NO_POSITION; 762 } 763 LayoutParams params = (LayoutParams) view.getLayoutParams(); 764 if (params == null || params.isItemRemoved()) { 765 // when item is removed, the position value can be any value. 766 return NO_POSITION; 767 } 768 return params.getViewPosition(); 769 } 770 771 private int getPositionByIndex(int index) { 772 return getPositionByView(getChildAt(index)); 773 } 774 775 private void dispatchChildSelected() { 776 if (mChildSelectedListener == null) { 777 return; 778 } 779 780 if (TRACE) TraceHelper.beginSection("onChildSelected"); 781 View view = mFocusPosition == NO_POSITION ? null : findViewByPosition(mFocusPosition); 782 if (view != null) { 783 RecyclerView.ViewHolder vh = mBaseGridView.getChildViewHolder(view); 784 mChildSelectedListener.onChildSelected(mBaseGridView, view, mFocusPosition, 785 vh == null? NO_ID: vh.getItemId()); 786 } else { 787 mChildSelectedListener.onChildSelected(mBaseGridView, null, NO_POSITION, NO_ID); 788 } 789 if (TRACE) TraceHelper.endSection(); 790 791 // Children may request layout when a child selection event occurs (such as a change of 792 // padding on the current and previously selected rows). 793 // If in layout, a child requesting layout may have been laid out before the selection 794 // callback. 795 // If it was not, the child will be laid out after the selection callback. 796 // If so, the layout request will be honoured though the view system will emit a double- 797 // layout warning. 798 // If not in layout, we may be scrolling in which case the child layout request will be 799 // eaten by recyclerview. Post a requestLayout. 800 if (!mInLayout && !mBaseGridView.isLayoutRequested()) { 801 int childCount = getChildCount(); 802 for (int i = 0; i < childCount; i++) { 803 if (getChildAt(i).isLayoutRequested()) { 804 forceRequestLayout(); 805 break; 806 } 807 } 808 } 809 } 810 811 @Override 812 public boolean canScrollHorizontally() { 813 // We can scroll horizontally if we have horizontal orientation, or if 814 // we are vertical and have more than one column. 815 return mOrientation == HORIZONTAL || mNumRows > 1; 816 } 817 818 @Override 819 public boolean canScrollVertically() { 820 // We can scroll vertically if we have vertical orientation, or if we 821 // are horizontal and have more than one row. 822 return mOrientation == VERTICAL || mNumRows > 1; 823 } 824 825 @Override 826 public RecyclerView.LayoutParams generateDefaultLayoutParams() { 827 return new LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, 828 ViewGroup.LayoutParams.WRAP_CONTENT); 829 } 830 831 @Override 832 public RecyclerView.LayoutParams generateLayoutParams(Context context, AttributeSet attrs) { 833 return new LayoutParams(context, attrs); 834 } 835 836 @Override 837 public RecyclerView.LayoutParams generateLayoutParams(ViewGroup.LayoutParams lp) { 838 if (lp instanceof LayoutParams) { 839 return new LayoutParams((LayoutParams) lp); 840 } else if (lp instanceof RecyclerView.LayoutParams) { 841 return new LayoutParams((RecyclerView.LayoutParams) lp); 842 } else if (lp instanceof MarginLayoutParams) { 843 return new LayoutParams((MarginLayoutParams) lp); 844 } else { 845 return new LayoutParams(lp); 846 } 847 } 848 849 protected View getViewForPosition(int position) { 850 return mRecycler.getViewForPosition(position); 851 } 852 853 final int getOpticalLeft(View v) { 854 return ((LayoutParams) v.getLayoutParams()).getOpticalLeft(v); 855 } 856 857 final int getOpticalRight(View v) { 858 return ((LayoutParams) v.getLayoutParams()).getOpticalRight(v); 859 } 860 861 final int getOpticalTop(View v) { 862 return ((LayoutParams) v.getLayoutParams()).getOpticalTop(v); 863 } 864 865 final int getOpticalBottom(View v) { 866 return ((LayoutParams) v.getLayoutParams()).getOpticalBottom(v); 867 } 868 869 private int getViewMin(View v) { 870 return (mOrientation == HORIZONTAL) ? getOpticalLeft(v) : getOpticalTop(v); 871 } 872 873 private int getViewMax(View v) { 874 return (mOrientation == HORIZONTAL) ? getOpticalRight(v) : getOpticalBottom(v); 875 } 876 877 private int getViewCenter(View view) { 878 return (mOrientation == HORIZONTAL) ? getViewCenterX(view) : getViewCenterY(view); 879 } 880 881 private int getViewCenterSecondary(View view) { 882 return (mOrientation == HORIZONTAL) ? getViewCenterY(view) : getViewCenterX(view); 883 } 884 885 private int getViewCenterX(View v) { 886 LayoutParams p = (LayoutParams) v.getLayoutParams(); 887 return p.getOpticalLeft(v) + p.getAlignX(); 888 } 889 890 private int getViewCenterY(View v) { 891 LayoutParams p = (LayoutParams) v.getLayoutParams(); 892 return p.getOpticalTop(v) + p.getAlignY(); 893 } 894 895 /** 896 * Save Recycler and State for convenience. Must be paired with leaveContext(). 897 */ 898 private void saveContext(Recycler recycler, State state) { 899 if (mRecycler != null || mState != null) { 900 Log.e(TAG, "Recycler information was not released, bug!"); 901 } 902 mRecycler = recycler; 903 mState = state; 904 } 905 906 /** 907 * Discard saved Recycler and State. 908 */ 909 private void leaveContext() { 910 mRecycler = null; 911 mState = null; 912 } 913 914 /** 915 * Re-initialize data structures for a data change or handling invisible 916 * selection. The method tries its best to preserve position information so 917 * that staggered grid looks same before and after re-initialize. 918 * @return true if can fastRelayout() 919 */ 920 private boolean layoutInit() { 921 if (!mState.didStructureChange() && !mForceFullLayout && mGrid != null) { 922 updateScrollController(); 923 updateScrollSecondAxis(); 924 mGrid.setMargin(mMarginPrimary); 925 return true; 926 } else { 927 mForceFullLayout = false; 928 boolean focusViewWasInTree = mGrid != null && mFocusPosition >= 0 929 && mFocusPosition >= mGrid.getFirstVisibleIndex() 930 && mFocusPosition <= mGrid.getLastVisibleIndex(); 931 int firstVisibleIndex = focusViewWasInTree ? mGrid.getFirstVisibleIndex() : 0; 932 final int newItemCount = mState.getItemCount(); 933 if (newItemCount == 0) { 934 mFocusPosition = NO_POSITION; 935 } else if (mFocusPosition >= newItemCount) { 936 mFocusPosition = newItemCount - 1; 937 } else if (mFocusPosition == NO_POSITION && newItemCount > 0) { 938 // if focus position is never set before, initialize it to 0 939 mFocusPosition = 0; 940 } 941 942 if (mGrid == null || mNumRows != mGrid.getNumRows() || 943 mReverseFlowPrimary != mGrid.isReversedFlow()) { 944 mGrid = Grid.createStaggeredMultipleRows(mNumRows); 945 mGrid.setProvider(mGridProvider); 946 mGrid.setReversedFlow(mReverseFlowPrimary); 947 } 948 initScrollController(); 949 updateScrollSecondAxis(); 950 mGrid.setMargin(mMarginPrimary); 951 detachAndScrapAttachedViews(mRecycler); 952 mGrid.resetVisibleIndex(); 953 if (mFocusPosition == NO_POSITION) { 954 mBaseGridView.clearFocus(); 955 } 956 mWindowAlignment.mainAxis().invalidateScrollMin(); 957 mWindowAlignment.mainAxis().invalidateScrollMax(); 958 if (focusViewWasInTree && firstVisibleIndex <= mFocusPosition) { 959 // if focusView was in tree, we will add item from first visible item 960 mGrid.setStart(firstVisibleIndex); 961 } else { 962 // if focusView was not in tree, it's probably because focus position jumped 963 // far away from visible range, so use mFocusPosition as start 964 mGrid.setStart(mFocusPosition); 965 } 966 return false; 967 } 968 } 969 970 private int getRowSizeSecondary(int rowIndex) { 971 if (mFixedRowSizeSecondary != 0) { 972 return mFixedRowSizeSecondary; 973 } 974 if (mRowSizeSecondary == null) { 975 return 0; 976 } 977 return mRowSizeSecondary[rowIndex]; 978 } 979 980 private int getRowStartSecondary(int rowIndex) { 981 int start = 0; 982 // Iterate from left to right, which is a different index traversal 983 // in RTL flow 984 if (mReverseFlowSecondary) { 985 for (int i = mNumRows-1; i > rowIndex; i--) { 986 start += getRowSizeSecondary(i) + mMarginSecondary; 987 } 988 } else { 989 for (int i = 0; i < rowIndex; i++) { 990 start += getRowSizeSecondary(i) + mMarginSecondary; 991 } 992 } 993 return start; 994 } 995 996 private int getSizeSecondary() { 997 int rightmostIndex = mReverseFlowSecondary ? 0 : mNumRows - 1; 998 return getRowStartSecondary(rightmostIndex) + getRowSizeSecondary(rightmostIndex); 999 } 1000 1001 private void measureScrapChild(int position, int widthSpec, int heightSpec, 1002 int[] measuredDimension) { 1003 View view = mRecycler.getViewForPosition(position); 1004 if (view != null) { 1005 LayoutParams p = (LayoutParams) view.getLayoutParams(); 1006 int childWidthSpec = ViewGroup.getChildMeasureSpec(widthSpec, 1007 getPaddingLeft() + getPaddingRight(), p.width); 1008 int childHeightSpec = ViewGroup.getChildMeasureSpec(heightSpec, 1009 getPaddingTop() + getPaddingBottom(), p.height); 1010 view.measure(childWidthSpec, childHeightSpec); 1011 measuredDimension[0] = view.getMeasuredWidth(); 1012 measuredDimension[1] = view.getMeasuredHeight(); 1013 mRecycler.recycleView(view); 1014 } 1015 } 1016 1017 private boolean processRowSizeSecondary(boolean measure) { 1018 if (mFixedRowSizeSecondary != 0) { 1019 return false; 1020 } 1021 1022 if (TRACE) TraceHelper.beginSection("processRowSizeSecondary"); 1023 CircularIntArray[] rows = mGrid == null ? null : mGrid.getItemPositionsInRows(); 1024 boolean changed = false; 1025 int scrapChildWidth = -1; 1026 int scrapChildHeight = -1; 1027 1028 for (int rowIndex = 0; rowIndex < mNumRows; rowIndex++) { 1029 CircularIntArray row = rows == null ? null : rows[rowIndex]; 1030 final int rowItemsPairCount = row == null ? 0 : row.size(); 1031 int rowSize = -1; 1032 for (int rowItemPairIndex = 0; rowItemPairIndex < rowItemsPairCount; 1033 rowItemPairIndex += 2) { 1034 final int rowIndexStart = row.get(rowItemPairIndex); 1035 final int rowIndexEnd = row.get(rowItemPairIndex + 1); 1036 for (int i = rowIndexStart; i <= rowIndexEnd; i++) { 1037 final View view = findViewByPosition(i); 1038 if (view == null) { 1039 continue; 1040 } 1041 if (measure && view.isLayoutRequested()) { 1042 measureChild(view); 1043 } 1044 final int secondarySize = mOrientation == HORIZONTAL ? 1045 view.getMeasuredHeight() : view.getMeasuredWidth(); 1046 if (secondarySize > rowSize) { 1047 rowSize = secondarySize; 1048 } 1049 } 1050 } 1051 1052 final int itemCount = mState.getItemCount(); 1053 if (measure && rowSize < 0 && itemCount > 0) { 1054 if (scrapChildWidth < 0 && scrapChildHeight < 0) { 1055 int position; 1056 if (mFocusPosition == NO_POSITION) { 1057 position = 0; 1058 } else if (mFocusPosition >= itemCount) { 1059 position = itemCount - 1; 1060 } else { 1061 position = mFocusPosition; 1062 } 1063 measureScrapChild(position, 1064 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 1065 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 1066 mMeasuredDimension); 1067 scrapChildWidth = mMeasuredDimension[0]; 1068 scrapChildHeight = mMeasuredDimension[1]; 1069 if (DEBUG) Log.v(TAG, "measured scrap child: " + scrapChildWidth + 1070 " " + scrapChildHeight); 1071 } 1072 rowSize = mOrientation == HORIZONTAL ? scrapChildHeight : scrapChildWidth; 1073 } 1074 if (rowSize < 0) { 1075 rowSize = 0; 1076 } 1077 if (mRowSizeSecondary[rowIndex] != rowSize) { 1078 if (DEBUG) Log.v(getTag(), "row size secondary changed: " + mRowSizeSecondary[rowIndex] + 1079 ", " + rowSize); 1080 mRowSizeSecondary[rowIndex] = rowSize; 1081 changed = true; 1082 } 1083 } 1084 1085 if (TRACE) TraceHelper.endSection(); 1086 return changed; 1087 } 1088 1089 /** 1090 * Checks if we need to update row secondary sizes. 1091 */ 1092 private void updateRowSecondarySizeRefresh() { 1093 mRowSecondarySizeRefresh = processRowSizeSecondary(false); 1094 if (mRowSecondarySizeRefresh) { 1095 if (DEBUG) Log.v(getTag(), "mRowSecondarySizeRefresh now set"); 1096 forceRequestLayout(); 1097 } 1098 } 1099 1100 private void forceRequestLayout() { 1101 if (DEBUG) Log.v(getTag(), "forceRequestLayout"); 1102 // RecyclerView prevents us from requesting layout in many cases 1103 // (during layout, during scroll, etc.) 1104 // For secondary row size wrap_content support we currently need a 1105 // second layout pass to update the measured size after having measured 1106 // and added child views in layoutChildren. 1107 // Force the second layout by posting a delayed runnable. 1108 // TODO: investigate allowing a second layout pass, 1109 // or move child add/measure logic to the measure phase. 1110 ViewCompat.postOnAnimation(mBaseGridView, mRequestLayoutRunnable); 1111 } 1112 1113 private final Runnable mRequestLayoutRunnable = new Runnable() { 1114 @Override 1115 public void run() { 1116 if (DEBUG) Log.v(getTag(), "request Layout from runnable"); 1117 requestLayout(); 1118 } 1119 }; 1120 1121 @Override 1122 public void onMeasure(Recycler recycler, State state, int widthSpec, int heightSpec) { 1123 saveContext(recycler, state); 1124 1125 int sizePrimary, sizeSecondary, modeSecondary, paddingSecondary; 1126 int measuredSizeSecondary; 1127 if (mOrientation == HORIZONTAL) { 1128 sizePrimary = MeasureSpec.getSize(widthSpec); 1129 sizeSecondary = MeasureSpec.getSize(heightSpec); 1130 modeSecondary = MeasureSpec.getMode(heightSpec); 1131 paddingSecondary = getPaddingTop() + getPaddingBottom(); 1132 } else { 1133 sizeSecondary = MeasureSpec.getSize(widthSpec); 1134 sizePrimary = MeasureSpec.getSize(heightSpec); 1135 modeSecondary = MeasureSpec.getMode(widthSpec); 1136 paddingSecondary = getPaddingLeft() + getPaddingRight(); 1137 } 1138 if (DEBUG) Log.v(getTag(), "onMeasure widthSpec " + Integer.toHexString(widthSpec) + 1139 " heightSpec " + Integer.toHexString(heightSpec) + 1140 " modeSecondary " + Integer.toHexString(modeSecondary) + 1141 " sizeSecondary " + sizeSecondary + " " + this); 1142 1143 mMaxSizeSecondary = sizeSecondary; 1144 1145 if (mRowSizeSecondaryRequested == ViewGroup.LayoutParams.WRAP_CONTENT) { 1146 mNumRows = mNumRowsRequested == 0 ? 1 : mNumRowsRequested; 1147 mFixedRowSizeSecondary = 0; 1148 1149 if (mRowSizeSecondary == null || mRowSizeSecondary.length != mNumRows) { 1150 mRowSizeSecondary = new int[mNumRows]; 1151 } 1152 1153 // Measure all current children and update cached row heights 1154 processRowSizeSecondary(true); 1155 1156 switch (modeSecondary) { 1157 case MeasureSpec.UNSPECIFIED: 1158 measuredSizeSecondary = getSizeSecondary() + paddingSecondary; 1159 break; 1160 case MeasureSpec.AT_MOST: 1161 measuredSizeSecondary = Math.min(getSizeSecondary() + paddingSecondary, 1162 mMaxSizeSecondary); 1163 break; 1164 case MeasureSpec.EXACTLY: 1165 measuredSizeSecondary = mMaxSizeSecondary; 1166 break; 1167 default: 1168 throw new IllegalStateException("wrong spec"); 1169 } 1170 1171 } else { 1172 switch (modeSecondary) { 1173 case MeasureSpec.UNSPECIFIED: 1174 if (mRowSizeSecondaryRequested == 0) { 1175 if (mOrientation == HORIZONTAL) { 1176 throw new IllegalStateException("Must specify rowHeight or view height"); 1177 } else { 1178 throw new IllegalStateException("Must specify columnWidth or view width"); 1179 } 1180 } 1181 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 1182 mNumRows = mNumRowsRequested == 0 ? 1 : mNumRowsRequested; 1183 measuredSizeSecondary = mFixedRowSizeSecondary * mNumRows + mMarginSecondary 1184 * (mNumRows - 1) + paddingSecondary; 1185 break; 1186 case MeasureSpec.AT_MOST: 1187 case MeasureSpec.EXACTLY: 1188 if (mNumRowsRequested == 0 && mRowSizeSecondaryRequested == 0) { 1189 mNumRows = 1; 1190 mFixedRowSizeSecondary = sizeSecondary - paddingSecondary; 1191 } else if (mNumRowsRequested == 0) { 1192 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 1193 mNumRows = (sizeSecondary + mMarginSecondary) 1194 / (mRowSizeSecondaryRequested + mMarginSecondary); 1195 } else if (mRowSizeSecondaryRequested == 0) { 1196 mNumRows = mNumRowsRequested; 1197 mFixedRowSizeSecondary = (sizeSecondary - paddingSecondary - mMarginSecondary 1198 * (mNumRows - 1)) / mNumRows; 1199 } else { 1200 mNumRows = mNumRowsRequested; 1201 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 1202 } 1203 measuredSizeSecondary = sizeSecondary; 1204 if (modeSecondary == MeasureSpec.AT_MOST) { 1205 int childrenSize = mFixedRowSizeSecondary * mNumRows + mMarginSecondary 1206 * (mNumRows - 1) + paddingSecondary; 1207 if (childrenSize < measuredSizeSecondary) { 1208 measuredSizeSecondary = childrenSize; 1209 } 1210 } 1211 break; 1212 default: 1213 throw new IllegalStateException("wrong spec"); 1214 } 1215 } 1216 if (mOrientation == HORIZONTAL) { 1217 setMeasuredDimension(sizePrimary, measuredSizeSecondary); 1218 } else { 1219 setMeasuredDimension(measuredSizeSecondary, sizePrimary); 1220 } 1221 if (DEBUG) { 1222 Log.v(getTag(), "onMeasure sizePrimary " + sizePrimary + 1223 " measuredSizeSecondary " + measuredSizeSecondary + 1224 " mFixedRowSizeSecondary " + mFixedRowSizeSecondary + 1225 " mNumRows " + mNumRows); 1226 } 1227 leaveContext(); 1228 } 1229 1230 private void measureChild(View child) { 1231 if (TRACE) TraceHelper.beginSection("measureChild"); 1232 final ViewGroup.LayoutParams lp = child.getLayoutParams(); 1233 final int secondarySpec = (mRowSizeSecondaryRequested == ViewGroup.LayoutParams.WRAP_CONTENT) ? 1234 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED) : 1235 MeasureSpec.makeMeasureSpec(mFixedRowSizeSecondary, MeasureSpec.EXACTLY); 1236 int widthSpec, heightSpec; 1237 1238 if (mOrientation == HORIZONTAL) { 1239 widthSpec = ViewGroup.getChildMeasureSpec( 1240 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 1241 0, lp.width); 1242 heightSpec = ViewGroup.getChildMeasureSpec(secondarySpec, 0, lp.height); 1243 } else { 1244 heightSpec = ViewGroup.getChildMeasureSpec( 1245 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 1246 0, lp.height); 1247 widthSpec = ViewGroup.getChildMeasureSpec(secondarySpec, 0, lp.width); 1248 } 1249 child.measure(widthSpec, heightSpec); 1250 if (DEBUG) Log.v(getTag(), "measureChild secondarySpec " + Integer.toHexString(secondarySpec) + 1251 " widthSpec " + Integer.toHexString(widthSpec) + 1252 " heightSpec " + Integer.toHexString(heightSpec) + 1253 " measuredWidth " + child.getMeasuredWidth() + 1254 " measuredHeight " + child.getMeasuredHeight()); 1255 if (DEBUG) Log.v(getTag(), "child lp width " + lp.width + " height " + lp.height); 1256 if (TRACE) TraceHelper.endSection(); 1257 } 1258 1259 private Grid.Provider mGridProvider = new Grid.Provider() { 1260 1261 @Override 1262 public int getCount() { 1263 return mState.getItemCount(); 1264 } 1265 1266 @Override 1267 public int createItem(int index, boolean append, Object[] item) { 1268 if (TRACE) TraceHelper.beginSection("createItem"); 1269 if (TRACE) TraceHelper.beginSection("getview"); 1270 View v = getViewForPosition(index); 1271 if (TRACE) TraceHelper.endSection(); 1272 // See recyclerView docs: we don't need re-add scraped view if it was removed. 1273 if (!((RecyclerView.LayoutParams) v.getLayoutParams()).isItemRemoved()) { 1274 if (TRACE) TraceHelper.beginSection("addView"); 1275 if (append) { 1276 addView(v); 1277 } else { 1278 addView(v, 0); 1279 } 1280 if (TRACE) TraceHelper.endSection(); 1281 if (mChildVisibility != -1) { 1282 v.setVisibility(mChildVisibility); 1283 } 1284 1285 if (mPendingMoveSmoothScroller != null) { 1286 mPendingMoveSmoothScroller.consumePendingMovesBeforeLayout(); 1287 } 1288 if (!mInLayout) { 1289 // when we are appending item during scroll pass and the item's position 1290 // matches the mFocusPosition, we should signal a childSelected event. 1291 // However if we are still running PendingMoveSmoothScroller, we defer and 1292 // signal the event in PendingMoveSmoothScroller.onStop(). This can 1293 // avoid lots of childSelected events during a long smooth scrolling and 1294 // increase performance. 1295 if (index == mFocusPosition && (mPendingMoveSmoothScroller == null 1296 || mPendingMoveSmoothScroller.mPendingMoves == 0)) { 1297 dispatchChildSelected(); 1298 } 1299 } else { 1300 // during layout pass, we notify change for non fastRelayout case. 1301 // fastRelayout will dispatch event at end of onLayoutChildren() 1302 if (!mInFastRelayout && index == mFocusPosition) { 1303 dispatchChildSelected(); 1304 } 1305 } 1306 measureChild(v); 1307 } 1308 item[0] = v; 1309 return mOrientation == HORIZONTAL ? v.getMeasuredWidth() : v.getMeasuredHeight(); 1310 } 1311 1312 @Override 1313 public void addItem(Object item, int index, int length, int rowIndex, int edge) { 1314 View v = (View) item; 1315 int start, end; 1316 if (edge == Integer.MIN_VALUE || edge == Integer.MAX_VALUE) { 1317 edge = !mGrid.isReversedFlow() ? mWindowAlignment.mainAxis().getPaddingLow() 1318 : mWindowAlignment.mainAxis().getSize() 1319 - mWindowAlignment.mainAxis().getPaddingHigh(); 1320 } 1321 boolean edgeIsMin = !mGrid.isReversedFlow(); 1322 if (edgeIsMin) { 1323 start = edge; 1324 end = edge + length; 1325 } else { 1326 start = edge - length; 1327 end = edge; 1328 } 1329 int startSecondary = getRowStartSecondary(rowIndex) - mScrollOffsetSecondary; 1330 mChildrenStates.loadView(v, index); 1331 layoutChild(rowIndex, v, start, end, startSecondary); 1332 if (DEBUG) { 1333 Log.d(getTag(), "addView " + index + " " + v); 1334 } 1335 if (TRACE) TraceHelper.endSection(); 1336 1337 if (index == mGrid.getFirstVisibleIndex()) { 1338 if (!mGrid.isReversedFlow()) { 1339 updateScrollMin(); 1340 } else { 1341 updateScrollMax(); 1342 } 1343 } 1344 if (index == mGrid.getLastVisibleIndex()) { 1345 if (!mGrid.isReversedFlow()) { 1346 updateScrollMax(); 1347 } else { 1348 updateScrollMin(); 1349 } 1350 } 1351 if (!mInLayout && mPendingMoveSmoothScroller != null) { 1352 mPendingMoveSmoothScroller.consumePendingMovesAfterLayout(); 1353 } 1354 if (mChildLaidOutListener != null) { 1355 RecyclerView.ViewHolder vh = mBaseGridView.getChildViewHolder(v); 1356 mChildLaidOutListener.onChildLaidOut(mBaseGridView, v, index, 1357 vh == null ? NO_ID : vh.getItemId()); 1358 } 1359 } 1360 1361 @Override 1362 public void removeItem(int index) { 1363 if (TRACE) TraceHelper.beginSection("removeItem"); 1364 View v = findViewByPosition(index); 1365 if (mInLayout) { 1366 detachAndScrapView(v, mRecycler); 1367 } else { 1368 removeAndRecycleView(v, mRecycler); 1369 } 1370 if (TRACE) TraceHelper.endSection(); 1371 } 1372 1373 @Override 1374 public int getEdge(int index) { 1375 if (mReverseFlowPrimary) { 1376 return getViewMax(findViewByPosition(index)); 1377 } else { 1378 return getViewMin(findViewByPosition(index)); 1379 } 1380 } 1381 1382 @Override 1383 public int getSize(int index) { 1384 final View v = findViewByPosition(index); 1385 return mOrientation == HORIZONTAL ? v.getMeasuredWidth() : v.getMeasuredHeight(); 1386 } 1387 }; 1388 1389 private void layoutChild(int rowIndex, View v, int start, int end, int startSecondary) { 1390 if (TRACE) TraceHelper.beginSection("layoutChild"); 1391 int sizeSecondary = mOrientation == HORIZONTAL ? v.getMeasuredHeight() 1392 : v.getMeasuredWidth(); 1393 if (mFixedRowSizeSecondary > 0) { 1394 sizeSecondary = Math.min(sizeSecondary, mFixedRowSizeSecondary); 1395 } 1396 final int verticalGravity = mGravity & Gravity.VERTICAL_GRAVITY_MASK; 1397 final int horizontalGravity = (mReverseFlowPrimary || mReverseFlowSecondary) ? 1398 Gravity.getAbsoluteGravity(mGravity & Gravity.RELATIVE_HORIZONTAL_GRAVITY_MASK, View.LAYOUT_DIRECTION_RTL) : 1399 mGravity & Gravity.HORIZONTAL_GRAVITY_MASK; 1400 if (mOrientation == HORIZONTAL && verticalGravity == Gravity.TOP 1401 || mOrientation == VERTICAL && horizontalGravity == Gravity.LEFT) { 1402 // do nothing 1403 } else if (mOrientation == HORIZONTAL && verticalGravity == Gravity.BOTTOM 1404 || mOrientation == VERTICAL && horizontalGravity == Gravity.RIGHT) { 1405 startSecondary += getRowSizeSecondary(rowIndex) - sizeSecondary; 1406 } else if (mOrientation == HORIZONTAL && verticalGravity == Gravity.CENTER_VERTICAL 1407 || mOrientation == VERTICAL && horizontalGravity == Gravity.CENTER_HORIZONTAL) { 1408 startSecondary += (getRowSizeSecondary(rowIndex) - sizeSecondary) / 2; 1409 } 1410 int left, top, right, bottom; 1411 if (mOrientation == HORIZONTAL) { 1412 left = start; 1413 top = startSecondary; 1414 right = end; 1415 bottom = startSecondary + sizeSecondary; 1416 } else { 1417 top = start; 1418 left = startSecondary; 1419 bottom = end; 1420 right = startSecondary + sizeSecondary; 1421 } 1422 v.layout(left, top, right, bottom); 1423 updateChildOpticalInsets(v, left, top, right, bottom); 1424 updateChildAlignments(v); 1425 if (TRACE) TraceHelper.endSection(); 1426 } 1427 1428 private void updateChildOpticalInsets(View v, int left, int top, int right, int bottom) { 1429 LayoutParams p = (LayoutParams) v.getLayoutParams(); 1430 p.setOpticalInsets(left - v.getLeft(), top - v.getTop(), 1431 v.getRight() - right, v.getBottom() - bottom); 1432 } 1433 1434 private void updateChildAlignments(View v) { 1435 LayoutParams p = (LayoutParams) v.getLayoutParams(); 1436 p.setAlignX(mItemAlignment.horizontal.getAlignmentPosition(v)); 1437 p.setAlignY(mItemAlignment.vertical.getAlignmentPosition(v)); 1438 } 1439 1440 private void updateChildAlignments() { 1441 for (int i = 0, c = getChildCount(); i < c; i++) { 1442 updateChildAlignments(getChildAt(i)); 1443 } 1444 } 1445 1446 private void removeInvisibleViewsAtEnd() { 1447 if (mPruneChild) { 1448 mGrid.removeInvisibleItemsAtEnd(mFocusPosition, 1449 mReverseFlowPrimary ? 0 : mSizePrimary); 1450 } 1451 } 1452 1453 private void removeInvisibleViewsAtFront() { 1454 if (mPruneChild) { 1455 mGrid.removeInvisibleItemsAtFront(mFocusPosition, 1456 mReverseFlowPrimary ? mSizePrimary : 0); 1457 } 1458 } 1459 1460 private boolean appendOneColumnVisibleItems() { 1461 return mGrid.appendOneColumnVisibleItems(); 1462 } 1463 1464 private boolean prependOneColumnVisibleItems() { 1465 return mGrid.prependOneColumnVisibleItems(); 1466 } 1467 1468 private void appendVisibleItems() { 1469 mGrid.appendVisibleItems(mReverseFlowPrimary ? 0 : mSizePrimary); 1470 } 1471 1472 private void prependVisibleItems() { 1473 mGrid.prependVisibleItems(mReverseFlowPrimary ? mSizePrimary : 0); 1474 } 1475 1476 /** 1477 * Fast layout when there is no structure change, adapter change, etc. 1478 * It will layout all views was layout requested or updated, until hit a view 1479 * with different size, then it break and detachAndScrap all views after that. 1480 */ 1481 private void fastRelayout() { 1482 boolean invalidateAfter = false; 1483 final int childCount = getChildCount(); 1484 int position = -1; 1485 for (int index = 0; index < childCount; index++) { 1486 View view = getChildAt(index); 1487 position = getPositionByIndex(index); 1488 Grid.Location location = mGrid.getLocation(position); 1489 if (location == null) { 1490 if (DEBUG) Log.w(getTag(), "fastRelayout(): no Location at " + position); 1491 invalidateAfter = true; 1492 break; 1493 } 1494 1495 int startSecondary = getRowStartSecondary(location.row) - mScrollOffsetSecondary; 1496 int primarySize, end; 1497 int start = getViewMin(view); 1498 int oldPrimarySize = (mOrientation == HORIZONTAL) ? 1499 view.getMeasuredWidth() : 1500 view.getMeasuredHeight(); 1501 1502 LayoutParams lp = (LayoutParams) view.getLayoutParams(); 1503 if (lp.viewNeedsUpdate()) { 1504 int viewIndex = mBaseGridView.indexOfChild(view); 1505 detachAndScrapView(view, mRecycler); 1506 view = getViewForPosition(position); 1507 addView(view, viewIndex); 1508 } 1509 1510 if (view.isLayoutRequested()) { 1511 measureChild(view); 1512 } 1513 if (mOrientation == HORIZONTAL) { 1514 primarySize = view.getMeasuredWidth(); 1515 end = start + primarySize; 1516 } else { 1517 primarySize = view.getMeasuredHeight(); 1518 end = start + primarySize; 1519 } 1520 layoutChild(location.row, view, start, end, startSecondary); 1521 if (oldPrimarySize != primarySize) { 1522 // size changed invalidate remaining Locations 1523 if (DEBUG) Log.d(getTag(), "fastRelayout: view size changed at " + position); 1524 invalidateAfter = true; 1525 break; 1526 } 1527 } 1528 if (invalidateAfter) { 1529 final int savedLastPos = mGrid.getLastVisibleIndex(); 1530 mGrid.invalidateItemsAfter(position); 1531 if (mPruneChild) { 1532 // in regular prune child mode, we just append items up to edge limit 1533 appendVisibleItems(); 1534 } else { 1535 // prune disabled(e.g. in RowsFragment transition): append all removed items 1536 while (mGrid.appendOneColumnVisibleItems() 1537 && mGrid.getLastVisibleIndex() < savedLastPos); 1538 } 1539 } 1540 updateScrollMin(); 1541 updateScrollMax(); 1542 updateScrollSecondAxis(); 1543 } 1544 1545 public void removeAndRecycleAllViews(RecyclerView.Recycler recycler) { 1546 if (TRACE) TraceHelper.beginSection("removeAndRecycleAllViews"); 1547 if (DEBUG) Log.v(TAG, "removeAndRecycleAllViews " + getChildCount()); 1548 for (int i = getChildCount() - 1; i >= 0; i--) { 1549 removeAndRecycleViewAt(i, recycler); 1550 } 1551 if (TRACE) TraceHelper.endSection(); 1552 } 1553 1554 // Lays out items based on the current scroll position 1555 @Override 1556 public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state) { 1557 if (DEBUG) { 1558 Log.v(getTag(), "layoutChildren start numRows " + mNumRows + " mScrollOffsetSecondary " 1559 + mScrollOffsetSecondary + " mScrollOffsetPrimary " + mScrollOffsetPrimary 1560 + " inPreLayout " + state.isPreLayout() 1561 + " didStructureChange " + state.didStructureChange() 1562 + " mForceFullLayout " + mForceFullLayout); 1563 Log.v(getTag(), "width " + getWidth() + " height " + getHeight()); 1564 } 1565 1566 if (mNumRows == 0) { 1567 // haven't done measure yet 1568 return; 1569 } 1570 final int itemCount = state.getItemCount(); 1571 if (itemCount < 0) { 1572 return; 1573 } 1574 1575 if (!mLayoutEnabled) { 1576 discardLayoutInfo(); 1577 removeAndRecycleAllViews(recycler); 1578 return; 1579 } 1580 mInLayout = true; 1581 1582 final boolean scrollToFocus = !isSmoothScrolling() 1583 && mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED; 1584 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE) { 1585 mFocusPosition = mFocusPosition + mFocusPositionOffset; 1586 mFocusPositionOffset = 0; 1587 } 1588 saveContext(recycler, state); 1589 1590 // Track the old focus view so we can adjust our system scroll position 1591 // so that any scroll animations happening now will remain valid. 1592 // We must use same delta in Pre Layout (if prelayout exists) and second layout. 1593 // So we cache the deltas in PreLayout and use it in second layout. 1594 int delta = 0, deltaSecondary = 0; 1595 if (mFocusPosition != NO_POSITION && scrollToFocus 1596 && mBaseGridView.getScrollState() != RecyclerView.SCROLL_STATE_IDLE) { 1597 // FIXME: we should get the remaining scroll animation offset from RecyclerView 1598 View focusView = findViewByPosition(mFocusPosition); 1599 if (focusView != null) { 1600 delta = mWindowAlignment.mainAxis().getSystemScrollPos(mScrollOffsetPrimary 1601 + getViewCenter(focusView), false, false) - mScrollOffsetPrimary; 1602 deltaSecondary = mWindowAlignment.secondAxis().getSystemScrollPos( 1603 mScrollOffsetSecondary + getViewCenterSecondary(focusView), 1604 false, false) - mScrollOffsetSecondary; 1605 } 1606 } 1607 1608 boolean hadFocus = mBaseGridView.hasFocus(); 1609 int savedFocusPos = mFocusPosition; 1610 if (mInFastRelayout = layoutInit()) { 1611 fastRelayout(); 1612 View focusView = findViewByPosition(mFocusPosition); 1613 if (scrollToFocus) { 1614 scrollToView(focusView, false); 1615 } 1616 if (focusView != null && hadFocus) { 1617 focusView.requestFocus(); 1618 } 1619 } else { 1620 if (mFocusPosition != NO_POSITION) { 1621 // appends items till focus position. 1622 while (appendOneColumnVisibleItems() 1623 && findViewByPosition(mFocusPosition) == null) ; 1624 } 1625 // multiple rounds: scrollToView of first round may drag first/last child into 1626 // "visible window" and we update scrollMin/scrollMax then run second scrollToView 1627 int oldFirstVisible; 1628 int oldLastVisible; 1629 do { 1630 updateScrollMin(); 1631 updateScrollMax(); 1632 oldFirstVisible = mGrid.getFirstVisibleIndex(); 1633 oldLastVisible = mGrid.getLastVisibleIndex(); 1634 View focusView = findViewByPosition(mFocusPosition); 1635 // we need force to initialize the child view's position 1636 scrollToView(focusView, false); 1637 if (focusView != null && hadFocus) { 1638 focusView.requestFocus(); 1639 } 1640 appendVisibleItems(); 1641 prependVisibleItems(); 1642 removeInvisibleViewsAtFront(); 1643 removeInvisibleViewsAtEnd(); 1644 } while (mGrid.getFirstVisibleIndex() != oldFirstVisible || 1645 mGrid.getLastVisibleIndex() != oldLastVisible); 1646 } 1647 1648 if (scrollToFocus) { 1649 scrollDirectionPrimary(-delta); 1650 scrollDirectionSecondary(-deltaSecondary); 1651 } 1652 appendVisibleItems(); 1653 prependVisibleItems(); 1654 removeInvisibleViewsAtFront(); 1655 removeInvisibleViewsAtEnd(); 1656 1657 if (DEBUG) { 1658 StringWriter sw = new StringWriter(); 1659 PrintWriter pw = new PrintWriter(sw); 1660 mGrid.debugPrint(pw); 1661 Log.d(getTag(), sw.toString()); 1662 } 1663 1664 if (mRowSecondarySizeRefresh) { 1665 mRowSecondarySizeRefresh = false; 1666 } else { 1667 updateRowSecondarySizeRefresh(); 1668 } 1669 1670 // For non fastRelayout we notify selection change in createItem(). 1671 // For fastRelayout, only dispatch event when focus position changes. 1672 if (mInFastRelayout && mFocusPosition != savedFocusPos) { 1673 dispatchChildSelected(); 1674 } 1675 1676 mInLayout = false; 1677 leaveContext(); 1678 if (DEBUG) Log.v(getTag(), "layoutChildren end"); 1679 } 1680 1681 private void offsetChildrenSecondary(int increment) { 1682 final int childCount = getChildCount(); 1683 if (mOrientation == HORIZONTAL) { 1684 for (int i = 0; i < childCount; i++) { 1685 getChildAt(i).offsetTopAndBottom(increment); 1686 } 1687 } else { 1688 for (int i = 0; i < childCount; i++) { 1689 getChildAt(i).offsetLeftAndRight(increment); 1690 } 1691 } 1692 } 1693 1694 private void offsetChildrenPrimary(int increment) { 1695 final int childCount = getChildCount(); 1696 if (mOrientation == VERTICAL) { 1697 for (int i = 0; i < childCount; i++) { 1698 getChildAt(i).offsetTopAndBottom(increment); 1699 } 1700 } else { 1701 for (int i = 0; i < childCount; i++) { 1702 getChildAt(i).offsetLeftAndRight(increment); 1703 } 1704 } 1705 } 1706 1707 @Override 1708 public int scrollHorizontallyBy(int dx, Recycler recycler, RecyclerView.State state) { 1709 if (DEBUG) Log.v(getTag(), "scrollHorizontallyBy " + dx); 1710 if (!mLayoutEnabled || !hasDoneFirstLayout()) { 1711 return 0; 1712 } 1713 saveContext(recycler, state); 1714 int result; 1715 if (mOrientation == HORIZONTAL) { 1716 result = scrollDirectionPrimary(dx); 1717 } else { 1718 result = scrollDirectionSecondary(dx); 1719 } 1720 leaveContext(); 1721 return result; 1722 } 1723 1724 @Override 1725 public int scrollVerticallyBy(int dy, Recycler recycler, RecyclerView.State state) { 1726 if (DEBUG) Log.v(getTag(), "scrollVerticallyBy " + dy); 1727 if (!mLayoutEnabled || !hasDoneFirstLayout()) { 1728 return 0; 1729 } 1730 saveContext(recycler, state); 1731 int result; 1732 if (mOrientation == VERTICAL) { 1733 result = scrollDirectionPrimary(dy); 1734 } else { 1735 result = scrollDirectionSecondary(dy); 1736 } 1737 leaveContext(); 1738 return result; 1739 } 1740 1741 // scroll in main direction may add/prune views 1742 private int scrollDirectionPrimary(int da) { 1743 if (TRACE) TraceHelper.beginSection("scrollPrimary"); 1744 boolean isMaxUnknown = false, isMinUnknown = false; 1745 int minScroll = 0, maxScroll = 0; 1746 if (da > 0) { 1747 isMaxUnknown = mWindowAlignment.mainAxis().isMaxUnknown(); 1748 if (!isMaxUnknown) { 1749 maxScroll = mWindowAlignment.mainAxis().getMaxScroll(); 1750 if (mScrollOffsetPrimary + da > maxScroll) { 1751 da = maxScroll - mScrollOffsetPrimary; 1752 } 1753 } 1754 } else if (da < 0) { 1755 isMinUnknown = mWindowAlignment.mainAxis().isMinUnknown(); 1756 if (!isMinUnknown) { 1757 minScroll = mWindowAlignment.mainAxis().getMinScroll(); 1758 if (mScrollOffsetPrimary + da < minScroll) { 1759 da = minScroll - mScrollOffsetPrimary; 1760 } 1761 } 1762 } 1763 if (da == 0) { 1764 if (TRACE) TraceHelper.endSection(); 1765 return 0; 1766 } 1767 offsetChildrenPrimary(-da); 1768 mScrollOffsetPrimary += da; 1769 if (mInLayout) { 1770 if (TRACE) TraceHelper.endSection(); 1771 return da; 1772 } 1773 1774 int childCount = getChildCount(); 1775 boolean updated; 1776 1777 if (mReverseFlowPrimary ? da > 0 : da < 0) { 1778 prependVisibleItems(); 1779 } else { 1780 appendVisibleItems(); 1781 } 1782 updated = getChildCount() > childCount; 1783 childCount = getChildCount(); 1784 1785 if (TRACE) TraceHelper.beginSection("remove"); 1786 if (mReverseFlowPrimary ? da > 0 : da < 0) { 1787 removeInvisibleViewsAtEnd(); 1788 } else { 1789 removeInvisibleViewsAtFront(); 1790 } 1791 if (TRACE) TraceHelper.endSection(); 1792 updated |= getChildCount() < childCount; 1793 if (updated) { 1794 updateRowSecondarySizeRefresh(); 1795 } 1796 1797 mBaseGridView.invalidate(); 1798 if (TRACE) TraceHelper.endSection(); 1799 return da; 1800 } 1801 1802 // scroll in second direction will not add/prune views 1803 private int scrollDirectionSecondary(int dy) { 1804 if (dy == 0) { 1805 return 0; 1806 } 1807 offsetChildrenSecondary(-dy); 1808 mScrollOffsetSecondary += dy; 1809 mBaseGridView.invalidate(); 1810 return dy; 1811 } 1812 1813 private void updateScrollMax() { 1814 int highVisiblePos = (!mReverseFlowPrimary) ? mGrid.getLastVisibleIndex() 1815 : mGrid.getFirstVisibleIndex(); 1816 int highMaxPos = (!mReverseFlowPrimary) ? mState.getItemCount() - 1 : 0; 1817 if (highVisiblePos < 0) { 1818 return; 1819 } 1820 final boolean highAvailable = highVisiblePos == highMaxPos; 1821 final boolean maxUnknown = mWindowAlignment.mainAxis().isMaxUnknown(); 1822 if (!highAvailable && maxUnknown) { 1823 return; 1824 } 1825 int maxEdge = mGrid.findRowMax(true, sTwoInts) + mScrollOffsetPrimary; 1826 int rowIndex = sTwoInts[0]; 1827 int pos = sTwoInts[1]; 1828 int savedMaxEdge = mWindowAlignment.mainAxis().getMaxEdge(); 1829 mWindowAlignment.mainAxis().setMaxEdge(maxEdge); 1830 int maxScroll = getPrimarySystemScrollPosition(findViewByPosition(pos)); 1831 mWindowAlignment.mainAxis().setMaxEdge(savedMaxEdge); 1832 1833 if (highAvailable) { 1834 mWindowAlignment.mainAxis().setMaxEdge(maxEdge); 1835 mWindowAlignment.mainAxis().setMaxScroll(maxScroll); 1836 if (DEBUG) Log.v(getTag(), "updating scroll maxEdge to " + maxEdge + 1837 " scrollMax to " + maxScroll); 1838 } else { 1839 // the maxScroll for currently last visible item is larger, 1840 // so we must invalidate the max scroll value. 1841 if (maxScroll > mWindowAlignment.mainAxis().getMaxScroll()) { 1842 mWindowAlignment.mainAxis().invalidateScrollMax(); 1843 if (DEBUG) Log.v(getTag(), "Invalidate scrollMax since it should be " 1844 + "greater than " + maxScroll); 1845 } 1846 } 1847 } 1848 1849 private void updateScrollMin() { 1850 int lowVisiblePos = (!mReverseFlowPrimary) ? mGrid.getFirstVisibleIndex() 1851 : mGrid.getLastVisibleIndex(); 1852 int lowMinPos = (!mReverseFlowPrimary) ? 0 : mState.getItemCount() - 1; 1853 if (lowVisiblePos < 0) { 1854 return; 1855 } 1856 final boolean lowAvailable = lowVisiblePos == lowMinPos; 1857 final boolean minUnknown = mWindowAlignment.mainAxis().isMinUnknown(); 1858 if (!lowAvailable && minUnknown) { 1859 return; 1860 } 1861 int minEdge = mGrid.findRowMin(false, sTwoInts) + mScrollOffsetPrimary; 1862 int rowIndex = sTwoInts[0]; 1863 int pos = sTwoInts[1]; 1864 int savedMinEdge = mWindowAlignment.mainAxis().getMinEdge(); 1865 mWindowAlignment.mainAxis().setMinEdge(minEdge); 1866 int minScroll = getPrimarySystemScrollPosition(findViewByPosition(pos)); 1867 mWindowAlignment.mainAxis().setMinEdge(savedMinEdge); 1868 1869 if (lowAvailable) { 1870 mWindowAlignment.mainAxis().setMinEdge(minEdge); 1871 mWindowAlignment.mainAxis().setMinScroll(minScroll); 1872 if (DEBUG) Log.v(getTag(), "updating scroll minEdge to " + minEdge + 1873 " scrollMin to " + minScroll); 1874 } else { 1875 // the minScroll for currently first visible item is smaller, 1876 // so we must invalidate the min scroll value. 1877 if (minScroll < mWindowAlignment.mainAxis().getMinScroll()) { 1878 mWindowAlignment.mainAxis().invalidateScrollMin(); 1879 if (DEBUG) Log.v(getTag(), "Invalidate scrollMin, since it should be " 1880 + "less than " + minScroll); 1881 } 1882 } 1883 } 1884 1885 private void updateScrollSecondAxis() { 1886 mWindowAlignment.secondAxis().setMinEdge(0); 1887 mWindowAlignment.secondAxis().setMaxEdge(getSizeSecondary()); 1888 } 1889 1890 private void initScrollController() { 1891 mWindowAlignment.reset(); 1892 mWindowAlignment.horizontal.setSize(getWidth()); 1893 mWindowAlignment.vertical.setSize(getHeight()); 1894 mWindowAlignment.horizontal.setPadding(getPaddingLeft(), getPaddingRight()); 1895 mWindowAlignment.vertical.setPadding(getPaddingTop(), getPaddingBottom()); 1896 mSizePrimary = mWindowAlignment.mainAxis().getSize(); 1897 mScrollOffsetPrimary = -mWindowAlignment.mainAxis().getPaddingLow(); 1898 mScrollOffsetSecondary = -mWindowAlignment.secondAxis().getPaddingLow(); 1899 1900 if (DEBUG) { 1901 Log.v(getTag(), "initScrollController mSizePrimary " + mSizePrimary 1902 + " mWindowAlignment " + mWindowAlignment 1903 + " mScrollOffsetPrimary " + mScrollOffsetPrimary); 1904 } 1905 } 1906 1907 private void updateScrollController() { 1908 // mScrollOffsetPrimary and mScrollOffsetSecondary includes the padding. 1909 // e.g. when topPadding is 16 for horizontal grid view, the initial 1910 // mScrollOffsetSecondary is -16. fastRelayout() put views based on offsets(not padding), 1911 // when padding changes to 20, we also need update mScrollOffsetSecondary to -20 before 1912 // fastRelayout() is performed 1913 int paddingPrimaryDiff, paddingSecondaryDiff; 1914 if (mOrientation == HORIZONTAL) { 1915 paddingPrimaryDiff = getPaddingLeft() - mWindowAlignment.horizontal.getPaddingLow(); 1916 paddingSecondaryDiff = getPaddingTop() - mWindowAlignment.vertical.getPaddingLow(); 1917 } else { 1918 paddingPrimaryDiff = getPaddingTop() - mWindowAlignment.vertical.getPaddingLow(); 1919 paddingSecondaryDiff = getPaddingLeft() - mWindowAlignment.horizontal.getPaddingLow(); 1920 } 1921 mScrollOffsetPrimary -= paddingPrimaryDiff; 1922 mScrollOffsetSecondary -= paddingSecondaryDiff; 1923 1924 mWindowAlignment.horizontal.setSize(getWidth()); 1925 mWindowAlignment.vertical.setSize(getHeight()); 1926 mWindowAlignment.horizontal.setPadding(getPaddingLeft(), getPaddingRight()); 1927 mWindowAlignment.vertical.setPadding(getPaddingTop(), getPaddingBottom()); 1928 mSizePrimary = mWindowAlignment.mainAxis().getSize(); 1929 1930 if (DEBUG) { 1931 Log.v(getTag(), "updateScrollController mSizePrimary " + mSizePrimary 1932 + " mWindowAlignment " + mWindowAlignment 1933 + " mScrollOffsetPrimary " + mScrollOffsetPrimary); 1934 } 1935 } 1936 1937 public void setSelection(RecyclerView parent, int position) { 1938 setSelection(parent, position, false); 1939 } 1940 1941 public void setSelectionSmooth(RecyclerView parent, int position) { 1942 setSelection(parent, position, true); 1943 } 1944 1945 public int getSelection() { 1946 return mFocusPosition; 1947 } 1948 1949 public void setSelection(RecyclerView parent, int position, boolean smooth) { 1950 if (mFocusPosition != position && position != NO_POSITION) { 1951 scrollToSelection(parent, position, smooth); 1952 } 1953 } 1954 1955 private void scrollToSelection(RecyclerView parent, int position, boolean smooth) { 1956 if (TRACE) TraceHelper.beginSection("scrollToSelection"); 1957 View view = findViewByPosition(position); 1958 if (view != null) { 1959 mInSelection = true; 1960 scrollToView(view, smooth); 1961 mInSelection = false; 1962 } else { 1963 mFocusPosition = position; 1964 mFocusPositionOffset = 0; 1965 if (!mLayoutEnabled) { 1966 return; 1967 } 1968 if (smooth) { 1969 if (!hasDoneFirstLayout()) { 1970 Log.w(getTag(), "setSelectionSmooth should " + 1971 "not be called before first layout pass"); 1972 return; 1973 } 1974 startPositionSmoothScroller(position); 1975 } else { 1976 mForceFullLayout = true; 1977 parent.requestLayout(); 1978 } 1979 } 1980 if (TRACE) TraceHelper.endSection(); 1981 } 1982 1983 void startPositionSmoothScroller(int position) { 1984 LinearSmoothScroller linearSmoothScroller = new GridLinearSmoothScroller() { 1985 @Override 1986 public PointF computeScrollVectorForPosition(int targetPosition) { 1987 if (getChildCount() == 0) { 1988 return null; 1989 } 1990 final int firstChildPos = getPosition(getChildAt(0)); 1991 // TODO We should be able to deduce direction from bounds of current and target 1992 // focus, rather than making assumptions about positions and directionality 1993 final boolean isStart = mReverseFlowPrimary ? targetPosition > firstChildPos 1994 : targetPosition < firstChildPos; 1995 final int direction = isStart ? -1 : 1; 1996 if (mOrientation == HORIZONTAL) { 1997 return new PointF(direction, 0); 1998 } else { 1999 return new PointF(0, direction); 2000 } 2001 } 2002 2003 }; 2004 linearSmoothScroller.setTargetPosition(position); 2005 startSmoothScroll(linearSmoothScroller); 2006 } 2007 2008 private void processPendingMovement(boolean forward) { 2009 if (forward ? hasCreatedLastItem() : hasCreatedFirstItem()) { 2010 return; 2011 } 2012 if (mPendingMoveSmoothScroller == null) { 2013 // Stop existing scroller and create a new PendingMoveSmoothScroller. 2014 mBaseGridView.stopScroll(); 2015 PendingMoveSmoothScroller linearSmoothScroller = new PendingMoveSmoothScroller( 2016 forward ? 1 : -1, mNumRows > 1); 2017 mFocusPositionOffset = 0; 2018 startSmoothScroll(linearSmoothScroller); 2019 if (linearSmoothScroller.isRunning()) { 2020 mPendingMoveSmoothScroller = linearSmoothScroller; 2021 } 2022 } else { 2023 if (forward) { 2024 mPendingMoveSmoothScroller.increasePendingMoves(); 2025 } else { 2026 mPendingMoveSmoothScroller.decreasePendingMoves(); 2027 } 2028 } 2029 } 2030 2031 @Override 2032 public void onItemsAdded(RecyclerView recyclerView, int positionStart, int itemCount) { 2033 if (DEBUG) Log.v(getTag(), "onItemsAdded positionStart " 2034 + positionStart + " itemCount " + itemCount); 2035 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE) { 2036 int pos = mFocusPosition + mFocusPositionOffset; 2037 if (positionStart <= pos) { 2038 mFocusPositionOffset += itemCount; 2039 } 2040 } 2041 mChildrenStates.clear(); 2042 } 2043 2044 @Override 2045 public void onItemsChanged(RecyclerView recyclerView) { 2046 if (DEBUG) Log.v(getTag(), "onItemsChanged"); 2047 mFocusPositionOffset = 0; 2048 mChildrenStates.clear(); 2049 } 2050 2051 @Override 2052 public void onItemsRemoved(RecyclerView recyclerView, int positionStart, int itemCount) { 2053 if (DEBUG) Log.v(getTag(), "onItemsRemoved positionStart " 2054 + positionStart + " itemCount " + itemCount); 2055 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE) { 2056 int pos = mFocusPosition + mFocusPositionOffset; 2057 if (positionStart <= pos) { 2058 if (positionStart + itemCount > pos) { 2059 // stop updating offset after the focus item was removed 2060 mFocusPositionOffset = Integer.MIN_VALUE; 2061 } else { 2062 mFocusPositionOffset -= itemCount; 2063 } 2064 } 2065 } 2066 mChildrenStates.clear(); 2067 } 2068 2069 @Override 2070 public void onItemsMoved(RecyclerView recyclerView, int fromPosition, int toPosition, 2071 int itemCount) { 2072 if (DEBUG) Log.v(getTag(), "onItemsMoved fromPosition " 2073 + fromPosition + " toPosition " + toPosition); 2074 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE) { 2075 int pos = mFocusPosition + mFocusPositionOffset; 2076 if (fromPosition <= pos && pos < fromPosition + itemCount) { 2077 // moved items include focused position 2078 mFocusPositionOffset += toPosition - fromPosition; 2079 } else if (fromPosition < pos && toPosition > pos - itemCount) { 2080 // move items before focus position to after focused position 2081 mFocusPositionOffset -= itemCount; 2082 } else if (fromPosition > pos && toPosition < pos) { 2083 // move items after focus position to before focused position 2084 mFocusPositionOffset += itemCount; 2085 } 2086 } 2087 mChildrenStates.clear(); 2088 } 2089 2090 @Override 2091 public void onItemsUpdated(RecyclerView recyclerView, int positionStart, int itemCount) { 2092 if (DEBUG) Log.v(getTag(), "onItemsUpdated positionStart " 2093 + positionStart + " itemCount " + itemCount); 2094 for (int i = positionStart, end = positionStart + itemCount; i < end; i++) { 2095 mChildrenStates.remove(i); 2096 } 2097 } 2098 2099 @Override 2100 public boolean onRequestChildFocus(RecyclerView parent, View child, View focused) { 2101 if (mFocusSearchDisabled) { 2102 return true; 2103 } 2104 if (getPositionByView(child) == NO_POSITION) { 2105 // This shouldn't happen, but in case it does be sure not to attempt a 2106 // scroll to a view whose item has been removed. 2107 return true; 2108 } 2109 if (!mInLayout && !mInSelection) { 2110 scrollToView(child, true); 2111 } 2112 return true; 2113 } 2114 2115 @Override 2116 public boolean requestChildRectangleOnScreen(RecyclerView parent, View view, Rect rect, 2117 boolean immediate) { 2118 if (DEBUG) Log.v(getTag(), "requestChildRectangleOnScreen " + view + " " + rect); 2119 return false; 2120 } 2121 2122 int getScrollOffsetX() { 2123 return mOrientation == HORIZONTAL ? mScrollOffsetPrimary : mScrollOffsetSecondary; 2124 } 2125 2126 int getScrollOffsetY() { 2127 return mOrientation == HORIZONTAL ? mScrollOffsetSecondary : mScrollOffsetPrimary; 2128 } 2129 2130 public void getViewSelectedOffsets(View view, int[] offsets) { 2131 if (mOrientation == HORIZONTAL) { 2132 offsets[0] = getPrimarySystemScrollPosition(view) - mScrollOffsetPrimary; 2133 offsets[1] = getSecondarySystemScrollPosition(view) - mScrollOffsetSecondary; 2134 } else { 2135 offsets[1] = getPrimarySystemScrollPosition(view) - mScrollOffsetPrimary; 2136 offsets[0] = getSecondarySystemScrollPosition(view) - mScrollOffsetSecondary; 2137 } 2138 } 2139 2140 private int getPrimarySystemScrollPosition(View view) { 2141 final int viewCenterPrimary = mScrollOffsetPrimary + getViewCenter(view); 2142 final int viewMin = getViewMin(view); 2143 final int viewMax = getViewMax(view); 2144 // TODO: change to use State object in onRequestChildFocus() 2145 boolean isMin, isMax; 2146 if (!mReverseFlowPrimary) { 2147 isMin = mGrid.getFirstVisibleIndex() == 0; 2148 isMax = mGrid.getLastVisibleIndex() == (mState == null ? 2149 getItemCount() : mState.getItemCount()) - 1; 2150 } else { 2151 isMax = mGrid.getFirstVisibleIndex() == 0; 2152 isMin = mGrid.getLastVisibleIndex() == (mState == null ? 2153 getItemCount() : mState.getItemCount()) - 1; 2154 } 2155 for (int i = getChildCount() - 1; (isMin || isMax) && i >= 0; i--) { 2156 View v = getChildAt(i); 2157 if (v == view || v == null) { 2158 continue; 2159 } 2160 if (isMin && getViewMin(v) < viewMin) { 2161 isMin = false; 2162 } 2163 if (isMax && getViewMax(v) > viewMax) { 2164 isMax = false; 2165 } 2166 } 2167 return mWindowAlignment.mainAxis().getSystemScrollPos(viewCenterPrimary, isMin, isMax); 2168 } 2169 2170 private int getSecondarySystemScrollPosition(View view) { 2171 int viewCenterSecondary = mScrollOffsetSecondary + getViewCenterSecondary(view); 2172 int pos = getPositionByView(view); 2173 Grid.Location location = mGrid.getLocation(pos); 2174 final int row = location.row; 2175 final boolean isMin, isMax; 2176 if (!mReverseFlowSecondary) { 2177 isMin = row == 0; 2178 isMax = row == mGrid.getNumRows() - 1; 2179 } else { 2180 isMax = row == 0; 2181 isMin = row == mGrid.getNumRows() - 1; 2182 } 2183 return mWindowAlignment.secondAxis().getSystemScrollPos(viewCenterSecondary, isMin, isMax); 2184 } 2185 2186 /** 2187 * Scroll to a given child view and change mFocusPosition. 2188 */ 2189 private void scrollToView(View view, boolean smooth) { 2190 int newFocusPosition = getPositionByView(view); 2191 if (newFocusPosition != mFocusPosition) { 2192 mFocusPosition = newFocusPosition; 2193 mFocusPositionOffset = 0; 2194 if (!mInLayout) { 2195 dispatchChildSelected(); 2196 } 2197 if (mBaseGridView.isChildrenDrawingOrderEnabledInternal()) { 2198 mBaseGridView.invalidate(); 2199 } 2200 } 2201 if (view == null) { 2202 return; 2203 } 2204 if (!view.hasFocus() && mBaseGridView.hasFocus()) { 2205 // transfer focus to the child if it does not have focus yet (e.g. triggered 2206 // by setSelection()) 2207 view.requestFocus(); 2208 } 2209 if (!mScrollEnabled && smooth) { 2210 return; 2211 } 2212 if (getScrollPosition(view, sTwoInts)) { 2213 scrollGrid(sTwoInts[0], sTwoInts[1], smooth); 2214 } 2215 } 2216 2217 private boolean getScrollPosition(View view, int[] deltas) { 2218 switch (mFocusScrollStrategy) { 2219 case BaseGridView.FOCUS_SCROLL_ALIGNED: 2220 default: 2221 return getAlignedPosition(view, deltas); 2222 case BaseGridView.FOCUS_SCROLL_ITEM: 2223 case BaseGridView.FOCUS_SCROLL_PAGE: 2224 return getNoneAlignedPosition(view, deltas); 2225 } 2226 } 2227 2228 private boolean getNoneAlignedPosition(View view, int[] deltas) { 2229 int pos = getPositionByView(view); 2230 int viewMin = getViewMin(view); 2231 int viewMax = getViewMax(view); 2232 // we either align "firstView" to left/top padding edge 2233 // or align "lastView" to right/bottom padding edge 2234 View firstView = null; 2235 View lastView = null; 2236 int paddingLow = mWindowAlignment.mainAxis().getPaddingLow(); 2237 int clientSize = mWindowAlignment.mainAxis().getClientSize(); 2238 final int row = mGrid.getRowIndex(pos); 2239 if (viewMin < paddingLow) { 2240 // view enters low padding area: 2241 firstView = view; 2242 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_PAGE) { 2243 // scroll one "page" left/top, 2244 // align first visible item of the "page" at the low padding edge. 2245 while (prependOneColumnVisibleItems()) { 2246 CircularIntArray positions = 2247 mGrid.getItemPositionsInRows(mGrid.getFirstVisibleIndex(), pos)[row]; 2248 firstView = findViewByPosition(positions.get(0)); 2249 if (viewMax - getViewMin(firstView) > clientSize) { 2250 if (positions.size() > 2) { 2251 firstView = findViewByPosition(positions.get(2)); 2252 } 2253 break; 2254 } 2255 } 2256 } 2257 } else if (viewMax > clientSize + paddingLow) { 2258 // view enters high padding area: 2259 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_PAGE) { 2260 // scroll whole one page right/bottom, align view at the low padding edge. 2261 firstView = view; 2262 do { 2263 CircularIntArray positions = 2264 mGrid.getItemPositionsInRows(pos, mGrid.getLastVisibleIndex())[row]; 2265 lastView = findViewByPosition(positions.get(positions.size() - 1)); 2266 if (getViewMax(lastView) - viewMin > clientSize) { 2267 lastView = null; 2268 break; 2269 } 2270 } while (appendOneColumnVisibleItems()); 2271 if (lastView != null) { 2272 // however if we reached end, we should align last view. 2273 firstView = null; 2274 } 2275 } else { 2276 lastView = view; 2277 } 2278 } 2279 int scrollPrimary = 0; 2280 int scrollSecondary = 0; 2281 if (firstView != null) { 2282 scrollPrimary = getViewMin(firstView) - paddingLow; 2283 } else if (lastView != null) { 2284 scrollPrimary = getViewMax(lastView) - (paddingLow + clientSize); 2285 } 2286 View secondaryAlignedView; 2287 if (firstView != null) { 2288 secondaryAlignedView = firstView; 2289 } else if (lastView != null) { 2290 secondaryAlignedView = lastView; 2291 } else { 2292 secondaryAlignedView = view; 2293 } 2294 scrollSecondary = getSecondarySystemScrollPosition(secondaryAlignedView); 2295 scrollSecondary -= mScrollOffsetSecondary; 2296 if (scrollPrimary != 0 || scrollSecondary != 0) { 2297 deltas[0] = scrollPrimary; 2298 deltas[1] = scrollSecondary; 2299 return true; 2300 } 2301 return false; 2302 } 2303 2304 private boolean getAlignedPosition(View view, int[] deltas) { 2305 int scrollPrimary = getPrimarySystemScrollPosition(view); 2306 int scrollSecondary = getSecondarySystemScrollPosition(view); 2307 if (DEBUG) { 2308 Log.v(getTag(), "getAlignedPosition " + scrollPrimary + " " + scrollSecondary 2309 + " " + mWindowAlignment); 2310 Log.v(getTag(), "getAlignedPosition " + mScrollOffsetPrimary + " " + mScrollOffsetSecondary); 2311 } 2312 scrollPrimary -= mScrollOffsetPrimary; 2313 scrollSecondary -= mScrollOffsetSecondary; 2314 if (scrollPrimary != 0 || scrollSecondary != 0) { 2315 deltas[0] = scrollPrimary; 2316 deltas[1] = scrollSecondary; 2317 return true; 2318 } 2319 return false; 2320 } 2321 2322 private void scrollGrid(int scrollPrimary, int scrollSecondary, boolean smooth) { 2323 if (mInLayout) { 2324 scrollDirectionPrimary(scrollPrimary); 2325 scrollDirectionSecondary(scrollSecondary); 2326 } else { 2327 int scrollX; 2328 int scrollY; 2329 if (mOrientation == HORIZONTAL) { 2330 scrollX = scrollPrimary; 2331 scrollY = scrollSecondary; 2332 } else { 2333 scrollX = scrollSecondary; 2334 scrollY = scrollPrimary; 2335 } 2336 if (smooth) { 2337 mBaseGridView.smoothScrollBy(scrollX, scrollY); 2338 } else { 2339 mBaseGridView.scrollBy(scrollX, scrollY); 2340 } 2341 } 2342 } 2343 2344 public void setPruneChild(boolean pruneChild) { 2345 if (mPruneChild != pruneChild) { 2346 mPruneChild = pruneChild; 2347 if (mPruneChild) { 2348 requestLayout(); 2349 } 2350 } 2351 } 2352 2353 public boolean getPruneChild() { 2354 return mPruneChild; 2355 } 2356 2357 public void setScrollEnabled(boolean scrollEnabled) { 2358 if (mScrollEnabled != scrollEnabled) { 2359 mScrollEnabled = scrollEnabled; 2360 if (mScrollEnabled && mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED 2361 && mFocusPosition != NO_POSITION) { 2362 scrollToSelection(mBaseGridView, mFocusPosition, true); 2363 } 2364 } 2365 } 2366 2367 public boolean isScrollEnabled() { 2368 return mScrollEnabled; 2369 } 2370 2371 private int findImmediateChildIndex(View view) { 2372 while (view != null && view != mBaseGridView) { 2373 int index = mBaseGridView.indexOfChild(view); 2374 if (index >= 0) { 2375 return index; 2376 } 2377 view = (View) view.getParent(); 2378 } 2379 return NO_POSITION; 2380 } 2381 2382 void setFocusSearchDisabled(boolean disabled) { 2383 mFocusSearchDisabled = disabled; 2384 } 2385 2386 boolean isFocusSearchDisabled() { 2387 return mFocusSearchDisabled; 2388 } 2389 2390 @Override 2391 public View onInterceptFocusSearch(View focused, int direction) { 2392 if (mFocusSearchDisabled) { 2393 return focused; 2394 } 2395 return null; 2396 } 2397 2398 boolean hasPreviousViewInSameRow(int pos) { 2399 if (mGrid == null || pos == NO_POSITION || mGrid.getFirstVisibleIndex() < 0) { 2400 return false; 2401 } 2402 if (mGrid.getFirstVisibleIndex() > 0) { 2403 return true; 2404 } 2405 final int focusedRow = mGrid.getLocation(pos).row; 2406 for (int i = getChildCount() - 1; i >= 0; i--) { 2407 int position = getPositionByIndex(i); 2408 Grid.Location loc = mGrid.getLocation(position); 2409 if (loc != null && loc.row == focusedRow) { 2410 if (position < pos) { 2411 return true; 2412 } 2413 } 2414 } 2415 return false; 2416 } 2417 2418 @Override 2419 public boolean onAddFocusables(RecyclerView recyclerView, 2420 ArrayList<View> views, int direction, int focusableMode) { 2421 if (mFocusSearchDisabled) { 2422 return true; 2423 } 2424 // If this viewgroup or one of its children currently has focus then we 2425 // consider our children for focus searching in main direction on the same row. 2426 // If this viewgroup has no focus and using focus align, we want the system 2427 // to ignore our children and pass focus to the viewgroup, which will pass 2428 // focus on to its children appropriately. 2429 // If this viewgroup has no focus and not using focus align, we want to 2430 // consider the child that does not overlap with padding area. 2431 if (recyclerView.hasFocus()) { 2432 final int movement = getMovement(direction); 2433 if (movement != PREV_ITEM && movement != NEXT_ITEM) { 2434 // Move on secondary direction uses default addFocusables(). 2435 return false; 2436 } 2437 if (mPendingMoveSmoothScroller != null) { 2438 // don't find next focusable if has pending movement. 2439 return true; 2440 } 2441 final View focused = recyclerView.findFocus(); 2442 final int focusedPos = getPositionByIndex(findImmediateChildIndex(focused)); 2443 // Add focusables of focused item. 2444 if (focusedPos != NO_POSITION) { 2445 findViewByPosition(focusedPos).addFocusables(views, direction, focusableMode); 2446 } 2447 final int focusedRow = mGrid != null && focusedPos != NO_POSITION ? 2448 mGrid.getLocation(focusedPos).row : NO_POSITION; 2449 // Add focusables of next neighbor of same row on the focus search direction. 2450 if (mGrid != null) { 2451 final int focusableCount = views.size(); 2452 for (int i = 0, count = getChildCount(); i < count; i++) { 2453 int index = movement == NEXT_ITEM ? i : count - 1 - i; 2454 final View child = getChildAt(index); 2455 if (child.getVisibility() != View.VISIBLE || !child.hasFocusable()) { 2456 continue; 2457 } 2458 int position = getPositionByIndex(index); 2459 Grid.Location loc = mGrid.getLocation(position); 2460 if (focusedRow == NO_POSITION || (loc != null && loc.row == focusedRow)) { 2461 if (focusedPos == NO_POSITION || 2462 (movement == NEXT_ITEM && position > focusedPos) 2463 || (movement == PREV_ITEM && position < focusedPos)) { 2464 child.addFocusables(views, direction, focusableMode); 2465 if (views.size() > focusableCount) { 2466 break; 2467 } 2468 } 2469 } 2470 } 2471 } 2472 } else { 2473 if (mFocusScrollStrategy != BaseGridView.FOCUS_SCROLL_ALIGNED) { 2474 // adding views not overlapping padding area to avoid scrolling in gaining focus 2475 int left = mWindowAlignment.mainAxis().getPaddingLow(); 2476 int right = mWindowAlignment.mainAxis().getClientSize() + left; 2477 int focusableCount = views.size(); 2478 for (int i = 0, count = getChildCount(); i < count; i++) { 2479 View child = getChildAt(i); 2480 if (child.getVisibility() == View.VISIBLE) { 2481 if (getViewMin(child) >= left && getViewMax(child) <= right) { 2482 child.addFocusables(views, direction, focusableMode); 2483 } 2484 } 2485 } 2486 // if we cannot find any, then just add all children. 2487 if (views.size() == focusableCount) { 2488 for (int i = 0, count = getChildCount(); i < count; i++) { 2489 View child = getChildAt(i); 2490 if (child.getVisibility() == View.VISIBLE) { 2491 child.addFocusables(views, direction, focusableMode); 2492 } 2493 } 2494 if (views.size() != focusableCount) { 2495 return true; 2496 } 2497 } else { 2498 return true; 2499 } 2500 // if still cannot find any, fall through and add itself 2501 } 2502 if (recyclerView.isFocusable()) { 2503 views.add(recyclerView); 2504 } 2505 } 2506 return true; 2507 } 2508 2509 private boolean hasCreatedLastItem() { 2510 int count = mState.getItemCount(); 2511 return count == 0 || findViewByPosition(count - 1) != null; 2512 } 2513 2514 private boolean hasCreatedFirstItem() { 2515 int count = mState.getItemCount(); 2516 return count == 0 || findViewByPosition(0) != null; 2517 } 2518 2519 boolean canScrollTo(View view) { 2520 return view.getVisibility() == View.VISIBLE && (!hasFocus() || view.hasFocusable()); 2521 } 2522 2523 @Override 2524 public View onFocusSearchFailed(View focused, int direction, Recycler recycler, 2525 RecyclerView.State state) { 2526 if (DEBUG) Log.v(getTag(), "onFocusSearchFailed direction " + direction); 2527 2528 View view = null; 2529 int movement = getMovement(direction); 2530 final boolean isScroll = mBaseGridView.getScrollState() != RecyclerView.SCROLL_STATE_IDLE; 2531 saveContext(recycler, state); 2532 if (movement == NEXT_ITEM) { 2533 if (isScroll || !mFocusOutEnd) { 2534 view = focused; 2535 } 2536 if (mScrollEnabled && !hasCreatedLastItem()) { 2537 processPendingMovement(true); 2538 view = focused; 2539 } 2540 } else if (movement == PREV_ITEM) { 2541 if (isScroll || !mFocusOutFront) { 2542 view = focused; 2543 } 2544 if (mScrollEnabled && !hasCreatedFirstItem()) { 2545 processPendingMovement(false); 2546 view = focused; 2547 } 2548 } 2549 leaveContext(); 2550 if (DEBUG) Log.v(getTag(), "onFocusSearchFailed returning view " + view); 2551 return view; 2552 } 2553 2554 boolean gridOnRequestFocusInDescendants(RecyclerView recyclerView, int direction, 2555 Rect previouslyFocusedRect) { 2556 switch (mFocusScrollStrategy) { 2557 case BaseGridView.FOCUS_SCROLL_ALIGNED: 2558 default: 2559 return gridOnRequestFocusInDescendantsAligned(recyclerView, 2560 direction, previouslyFocusedRect); 2561 case BaseGridView.FOCUS_SCROLL_PAGE: 2562 case BaseGridView.FOCUS_SCROLL_ITEM: 2563 return gridOnRequestFocusInDescendantsUnaligned(recyclerView, 2564 direction, previouslyFocusedRect); 2565 } 2566 } 2567 2568 private boolean gridOnRequestFocusInDescendantsAligned(RecyclerView recyclerView, 2569 int direction, Rect previouslyFocusedRect) { 2570 View view = findViewByPosition(mFocusPosition); 2571 if (view != null) { 2572 boolean result = view.requestFocus(direction, previouslyFocusedRect); 2573 if (!result && DEBUG) { 2574 Log.w(getTag(), "failed to request focus on " + view); 2575 } 2576 return result; 2577 } 2578 return false; 2579 } 2580 2581 private boolean gridOnRequestFocusInDescendantsUnaligned(RecyclerView recyclerView, 2582 int direction, Rect previouslyFocusedRect) { 2583 // focus to view not overlapping padding area to avoid scrolling in gaining focus 2584 int index; 2585 int increment; 2586 int end; 2587 int count = getChildCount(); 2588 if ((direction & View.FOCUS_FORWARD) != 0) { 2589 index = 0; 2590 increment = 1; 2591 end = count; 2592 } else { 2593 index = count - 1; 2594 increment = -1; 2595 end = -1; 2596 } 2597 int left = mWindowAlignment.mainAxis().getPaddingLow(); 2598 int right = mWindowAlignment.mainAxis().getClientSize() + left; 2599 for (int i = index; i != end; i += increment) { 2600 View child = getChildAt(i); 2601 if (child.getVisibility() == View.VISIBLE) { 2602 if (getViewMin(child) >= left && getViewMax(child) <= right) { 2603 if (child.requestFocus(direction, previouslyFocusedRect)) { 2604 return true; 2605 } 2606 } 2607 } 2608 } 2609 return false; 2610 } 2611 2612 private final static int PREV_ITEM = 0; 2613 private final static int NEXT_ITEM = 1; 2614 private final static int PREV_ROW = 2; 2615 private final static int NEXT_ROW = 3; 2616 2617 private int getMovement(int direction) { 2618 int movement = View.FOCUS_LEFT; 2619 2620 if (mOrientation == HORIZONTAL) { 2621 switch(direction) { 2622 case View.FOCUS_LEFT: 2623 movement = (!mReverseFlowPrimary) ? PREV_ITEM : NEXT_ITEM; 2624 break; 2625 case View.FOCUS_RIGHT: 2626 movement = (!mReverseFlowPrimary) ? NEXT_ITEM : PREV_ITEM; 2627 break; 2628 case View.FOCUS_UP: 2629 movement = PREV_ROW; 2630 break; 2631 case View.FOCUS_DOWN: 2632 movement = NEXT_ROW; 2633 break; 2634 } 2635 } else if (mOrientation == VERTICAL) { 2636 switch(direction) { 2637 case View.FOCUS_LEFT: 2638 movement = (!mReverseFlowPrimary) ? PREV_ROW : NEXT_ROW; 2639 break; 2640 case View.FOCUS_RIGHT: 2641 movement = (!mReverseFlowPrimary) ? NEXT_ROW : PREV_ROW; 2642 break; 2643 case View.FOCUS_UP: 2644 movement = PREV_ITEM; 2645 break; 2646 case View.FOCUS_DOWN: 2647 movement = NEXT_ITEM; 2648 break; 2649 } 2650 } 2651 2652 return movement; 2653 } 2654 2655 int getChildDrawingOrder(RecyclerView recyclerView, int childCount, int i) { 2656 View view = findViewByPosition(mFocusPosition); 2657 if (view == null) { 2658 return i; 2659 } 2660 int focusIndex = recyclerView.indexOfChild(view); 2661 // supposely 0 1 2 3 4 5 6 7 8 9, 4 is the center item 2662 // drawing order is 0 1 2 3 9 8 7 6 5 4 2663 if (i < focusIndex) { 2664 return i; 2665 } else if (i < childCount - 1) { 2666 return focusIndex + childCount - 1 - i; 2667 } else { 2668 return focusIndex; 2669 } 2670 } 2671 2672 @Override 2673 public void onAdapterChanged(RecyclerView.Adapter oldAdapter, 2674 RecyclerView.Adapter newAdapter) { 2675 if (DEBUG) Log.v(getTag(), "onAdapterChanged to " + newAdapter); 2676 if (oldAdapter != null) { 2677 discardLayoutInfo(); 2678 mFocusPosition = NO_POSITION; 2679 mFocusPositionOffset = 0; 2680 mChildrenStates.clear(); 2681 } 2682 super.onAdapterChanged(oldAdapter, newAdapter); 2683 } 2684 2685 private void discardLayoutInfo() { 2686 mGrid = null; 2687 mRowSizeSecondary = null; 2688 mRowSecondarySizeRefresh = false; 2689 } 2690 2691 public void setLayoutEnabled(boolean layoutEnabled) { 2692 if (mLayoutEnabled != layoutEnabled) { 2693 mLayoutEnabled = layoutEnabled; 2694 requestLayout(); 2695 } 2696 } 2697 2698 void setChildrenVisibility(int visiblity) { 2699 mChildVisibility = visiblity; 2700 if (mChildVisibility != -1) { 2701 int count = getChildCount(); 2702 for (int i= 0; i < count; i++) { 2703 getChildAt(i).setVisibility(mChildVisibility); 2704 } 2705 } 2706 } 2707 2708 final static class SavedState implements Parcelable { 2709 2710 int index; // index inside adapter of the current view 2711 Bundle childStates = Bundle.EMPTY; 2712 2713 @Override 2714 public void writeToParcel(Parcel out, int flags) { 2715 out.writeInt(index); 2716 out.writeBundle(childStates); 2717 } 2718 2719 @SuppressWarnings("hiding") 2720 public static final Parcelable.Creator<SavedState> CREATOR = 2721 new Parcelable.Creator<SavedState>() { 2722 @Override 2723 public SavedState createFromParcel(Parcel in) { 2724 return new SavedState(in); 2725 } 2726 2727 @Override 2728 public SavedState[] newArray(int size) { 2729 return new SavedState[size]; 2730 } 2731 }; 2732 2733 @Override 2734 public int describeContents() { 2735 return 0; 2736 } 2737 2738 SavedState(Parcel in) { 2739 index = in.readInt(); 2740 childStates = in.readBundle(GridLayoutManager.class.getClassLoader()); 2741 } 2742 2743 SavedState() { 2744 } 2745 } 2746 2747 @Override 2748 public Parcelable onSaveInstanceState() { 2749 if (DEBUG) Log.v(getTag(), "onSaveInstanceState getSelection() " + getSelection()); 2750 SavedState ss = new SavedState(); 2751 for (int i = 0, count = getChildCount(); i < count; i++) { 2752 View view = getChildAt(i); 2753 int position = getPositionByView(view); 2754 if (position != NO_POSITION) { 2755 mChildrenStates.saveOnScreenView(view, position); 2756 } 2757 } 2758 ss.index = getSelection(); 2759 ss.childStates = mChildrenStates.saveAsBundle(); 2760 return ss; 2761 } 2762 2763 void onChildRecycled(RecyclerView.ViewHolder holder) { 2764 final int position = holder.getAdapterPosition(); 2765 if (position != NO_POSITION) { 2766 mChildrenStates.saveOffscreenView(holder.itemView, position); 2767 } 2768 } 2769 2770 @Override 2771 public void onRestoreInstanceState(Parcelable state) { 2772 if (!(state instanceof SavedState)) { 2773 return; 2774 } 2775 SavedState loadingState = (SavedState)state; 2776 mFocusPosition = loadingState.index; 2777 mFocusPositionOffset = 0; 2778 mChildrenStates.loadFromBundle(loadingState.childStates); 2779 mForceFullLayout = true; 2780 requestLayout(); 2781 if (DEBUG) Log.v(getTag(), "onRestoreInstanceState mFocusPosition " + mFocusPosition); 2782 } 2783} 2784