GridLayoutManager.java revision 3f23b01f1e22f971e2105557137927822e7419f1
1/* 2 * Copyright (C) 2014 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except 5 * in compliance with the License. You may obtain a copy of the License at 6 * 7 * http://www.apache.org/licenses/LICENSE-2.0 8 * 9 * Unless required by applicable law or agreed to in writing, software distributed under the License 10 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express 11 * or implied. See the License for the specific language governing permissions and limitations under 12 * the License. 13 */ 14package android.support.v17.leanback.widget; 15 16import android.content.Context; 17import android.graphics.PointF; 18import android.graphics.Rect; 19import android.os.Bundle; 20import android.os.Parcel; 21import android.os.Parcelable; 22import android.support.v4.view.ViewCompat; 23import android.support.v7.widget.LinearSmoothScroller; 24import android.support.v7.widget.RecyclerView; 25import android.support.v7.widget.RecyclerView.Recycler; 26import android.support.v7.widget.RecyclerView.State; 27 28import static android.support.v7.widget.RecyclerView.NO_ID; 29import static android.support.v7.widget.RecyclerView.NO_POSITION; 30import static android.support.v7.widget.RecyclerView.HORIZONTAL; 31import static android.support.v7.widget.RecyclerView.VERTICAL; 32 33import android.util.AttributeSet; 34import android.util.Log; 35import android.view.FocusFinder; 36import android.view.Gravity; 37import android.view.View; 38import android.view.ViewParent; 39import android.view.View.MeasureSpec; 40import android.view.ViewGroup.MarginLayoutParams; 41import android.view.ViewGroup; 42 43import java.io.PrintWriter; 44import java.io.StringWriter; 45import java.util.ArrayList; 46import java.util.List; 47 48final class GridLayoutManager extends RecyclerView.LayoutManager { 49 50 /* 51 * LayoutParams for {@link HorizontalGridView} and {@link VerticalGridView}. 52 * The class currently does two internal jobs: 53 * - Saves optical bounds insets. 54 * - Caches focus align view center. 55 */ 56 static class LayoutParams extends RecyclerView.LayoutParams { 57 58 // The view is saved only during animation. 59 private View mView; 60 61 // For placement 62 private int mLeftInset; 63 private int mTopInset; 64 private int mRightInset; 65 private int mBottomInset; 66 67 // For alignment 68 private int mAlignX; 69 private int mAlignY; 70 71 public LayoutParams(Context c, AttributeSet attrs) { 72 super(c, attrs); 73 } 74 75 public LayoutParams(int width, int height) { 76 super(width, height); 77 } 78 79 public LayoutParams(MarginLayoutParams source) { 80 super(source); 81 } 82 83 public LayoutParams(ViewGroup.LayoutParams source) { 84 super(source); 85 } 86 87 public LayoutParams(RecyclerView.LayoutParams source) { 88 super(source); 89 } 90 91 public LayoutParams(LayoutParams source) { 92 super(source); 93 } 94 95 int getAlignX() { 96 return mAlignX; 97 } 98 99 int getAlignY() { 100 return mAlignY; 101 } 102 103 int getOpticalLeft(View view) { 104 return view.getLeft() + mLeftInset; 105 } 106 107 int getOpticalTop(View view) { 108 return view.getTop() + mTopInset; 109 } 110 111 int getOpticalRight(View view) { 112 return view.getRight() - mRightInset; 113 } 114 115 int getOpticalBottom(View view) { 116 return view.getBottom() - mBottomInset; 117 } 118 119 int getOpticalWidth(View view) { 120 return view.getWidth() - mLeftInset - mRightInset; 121 } 122 123 int getOpticalHeight(View view) { 124 return view.getHeight() - mTopInset - mBottomInset; 125 } 126 127 int getOpticalLeftInset() { 128 return mLeftInset; 129 } 130 131 int getOpticalRightInset() { 132 return mRightInset; 133 } 134 135 int getOpticalTopInset() { 136 return mTopInset; 137 } 138 139 int getOpticalBottomInset() { 140 return mBottomInset; 141 } 142 143 void setAlignX(int alignX) { 144 mAlignX = alignX; 145 } 146 147 void setAlignY(int alignY) { 148 mAlignY = alignY; 149 } 150 151 void setOpticalInsets(int leftInset, int topInset, int rightInset, int bottomInset) { 152 mLeftInset = leftInset; 153 mTopInset = topInset; 154 mRightInset = rightInset; 155 mBottomInset = bottomInset; 156 } 157 158 private void invalidateItemDecoration() { 159 ViewParent parent = mView.getParent(); 160 if (parent instanceof RecyclerView) { 161 // TODO: we only need invalidate parent if it has ItemDecoration 162 ((RecyclerView) parent).invalidate(); 163 } 164 } 165 } 166 167 private static final String TAG = "GridLayoutManager"; 168 private static final boolean DEBUG = false; 169 170 private String getTag() { 171 return TAG + ":" + mBaseGridView.getId(); 172 } 173 174 private final BaseGridView mBaseGridView; 175 176 /** 177 * Note on conventions in the presence of RTL layout directions: 178 * Many properties and method names reference entities related to the 179 * beginnings and ends of things. In the presence of RTL flows, 180 * it may not be clear whether this is intended to reference a 181 * quantity that changes direction in RTL cases, or a quantity that 182 * does not. Here are the conventions in use: 183 * 184 * start/end: coordinate quantities - do reverse 185 * (optical) left/right: coordinate quantities - do not reverse 186 * low/high: coordinate quantities - do not reverse 187 * min/max: coordinate quantities - do not reverse 188 * scroll offset - coordinate quantities - do not reverse 189 * first/last: positional indices - do not reverse 190 * front/end: positional indices - do not reverse 191 * prepend/append: related to positional indices - do not reverse 192 * 193 * Note that although quantities do not reverse in RTL flows, their 194 * relationship does. In LTR flows, the first positional index is 195 * leftmost; in RTL flows, it is rightmost. Thus, anywhere that 196 * positional quantities are mapped onto coordinate quantities, 197 * the flow must be checked and the logic reversed. 198 */ 199 200 /** 201 * The orientation of a "row". 202 */ 203 private int mOrientation = HORIZONTAL; 204 205 private RecyclerView.State mState; 206 private RecyclerView.Recycler mRecycler; 207 208 private boolean mInLayout = false; 209 private boolean mInSelection = false; 210 211 private OnChildSelectedListener mChildSelectedListener = null; 212 213 /** 214 * The focused position, it's not the currently visually aligned position 215 * but it is the final position that we intend to focus on. If there are 216 * multiple setSelection() called, mFocusPosition saves last value. 217 */ 218 private int mFocusPosition = NO_POSITION; 219 220 /** 221 * The offset to be applied to mFocusPosition, due to adapter change, on the next 222 * layout. Set to Integer.MIN_VALUE means item was removed. 223 * TODO: This is somewhat duplication of RecyclerView getOldPosition() which is 224 * unfortunately cleared after prelayout. 225 */ 226 private int mFocusPositionOffset = 0; 227 228 /** 229 * Force a full layout under certain situations. 230 */ 231 private boolean mForceFullLayout; 232 233 /** 234 * True if layout is enabled. 235 */ 236 private boolean mLayoutEnabled = true; 237 238 /** 239 * override child visibility 240 */ 241 private int mChildVisibility = -1; 242 243 /** 244 * The scroll offsets of the viewport relative to the entire view. 245 */ 246 private int mScrollOffsetPrimary; 247 private int mScrollOffsetSecondary; 248 249 /** 250 * User-specified row height/column width. Can be WRAP_CONTENT. 251 */ 252 private int mRowSizeSecondaryRequested; 253 254 /** 255 * The fixed size of each grid item in the secondary direction. This corresponds to 256 * the row height, equal for all rows. Grid items may have variable length 257 * in the primary direction. 258 */ 259 private int mFixedRowSizeSecondary; 260 261 /** 262 * Tracks the secondary size of each row. 263 */ 264 private int[] mRowSizeSecondary; 265 266 /** 267 * Flag controlling whether the current/next layout should 268 * be updating the secondary size of rows. 269 */ 270 private boolean mRowSecondarySizeRefresh; 271 272 /** 273 * The maximum measured size of the view. 274 */ 275 private int mMaxSizeSecondary; 276 277 /** 278 * Margin between items. 279 */ 280 private int mHorizontalMargin; 281 /** 282 * Margin between items vertically. 283 */ 284 private int mVerticalMargin; 285 /** 286 * Margin in main direction. 287 */ 288 private int mMarginPrimary; 289 /** 290 * Margin in second direction. 291 */ 292 private int mMarginSecondary; 293 /** 294 * How to position child in secondary direction. 295 */ 296 private int mGravity = Gravity.START | Gravity.TOP; 297 /** 298 * The number of rows in the grid. 299 */ 300 private int mNumRows; 301 /** 302 * Number of rows requested, can be 0 to be determined by parent size and 303 * rowHeight. 304 */ 305 private int mNumRowsRequested = 1; 306 307 /** 308 * Tracking start/end position of each row for visible items. 309 */ 310 private StaggeredGrid.Row[] mRows; 311 312 /** 313 * Saves grid information of each view. 314 */ 315 private StaggeredGrid mGrid; 316 /** 317 * Position of first item (included) that has attached views. 318 */ 319 private int mFirstVisiblePos; 320 /** 321 * Position of last item (included) that has attached views. 322 */ 323 private int mLastVisiblePos; 324 325 /** 326 * Focus Scroll strategy. 327 */ 328 private int mFocusScrollStrategy = BaseGridView.FOCUS_SCROLL_ALIGNED; 329 /** 330 * Defines how item view is aligned in the window. 331 */ 332 private final WindowAlignment mWindowAlignment = new WindowAlignment(); 333 334 /** 335 * Defines how item view is aligned. 336 */ 337 private final ItemAlignment mItemAlignment = new ItemAlignment(); 338 339 /** 340 * Dimensions of the view, width or height depending on orientation. 341 */ 342 private int mSizePrimary; 343 344 /** 345 * Allow DPAD key to navigate out at the front of the View (where position = 0), 346 * default is false. 347 */ 348 private boolean mFocusOutFront; 349 350 /** 351 * Allow DPAD key to navigate out at the end of the view, default is false. 352 */ 353 private boolean mFocusOutEnd; 354 355 /** 356 * True if focus search is disabled. 357 */ 358 private boolean mFocusSearchDisabled; 359 360 /** 361 * True if prune child, might be disabled during transition. 362 */ 363 private boolean mPruneChild = true; 364 365 /** 366 * True if scroll content, might be disabled during transition. 367 */ 368 private boolean mScrollEnabled = true; 369 370 private int[] mTempDeltas = new int[2]; 371 372 /** 373 * Set to true for RTL layout in horizontal orientation 374 */ 375 private boolean mReverseFlowPrimary = false; 376 377 /** 378 * Set to true for RTL layout in vertical orientation 379 */ 380 private boolean mReverseFlowSecondary = false; 381 382 /** 383 * Temporaries used for measuring. 384 */ 385 private int[] mMeasuredDimension = new int[2]; 386 387 final ViewsStateBundle mChildrenStates = new ViewsStateBundle(); 388 389 public GridLayoutManager(BaseGridView baseGridView) { 390 mBaseGridView = baseGridView; 391 } 392 393 public void setOrientation(int orientation) { 394 if (orientation != HORIZONTAL && orientation != VERTICAL) { 395 if (DEBUG) Log.v(getTag(), "invalid orientation: " + orientation); 396 return; 397 } 398 399 mOrientation = orientation; 400 mWindowAlignment.setOrientation(orientation); 401 mItemAlignment.setOrientation(orientation); 402 mForceFullLayout = true; 403 } 404 405 public void onRtlPropertiesChanged(int layoutDirection) { 406 if (mOrientation == HORIZONTAL) { 407 mReverseFlowPrimary = layoutDirection == View.LAYOUT_DIRECTION_RTL; 408 mReverseFlowSecondary = false; 409 } else { 410 mReverseFlowSecondary = layoutDirection == View.LAYOUT_DIRECTION_RTL; 411 mReverseFlowPrimary = false; 412 } 413 mWindowAlignment.horizontal.setReversedFlow(layoutDirection == View.LAYOUT_DIRECTION_RTL); 414 } 415 416 public int getFocusScrollStrategy() { 417 return mFocusScrollStrategy; 418 } 419 420 public void setFocusScrollStrategy(int focusScrollStrategy) { 421 mFocusScrollStrategy = focusScrollStrategy; 422 } 423 424 public void setWindowAlignment(int windowAlignment) { 425 mWindowAlignment.mainAxis().setWindowAlignment(windowAlignment); 426 } 427 428 public int getWindowAlignment() { 429 return mWindowAlignment.mainAxis().getWindowAlignment(); 430 } 431 432 public void setWindowAlignmentOffset(int alignmentOffset) { 433 mWindowAlignment.mainAxis().setWindowAlignmentOffset(alignmentOffset); 434 } 435 436 public int getWindowAlignmentOffset() { 437 return mWindowAlignment.mainAxis().getWindowAlignmentOffset(); 438 } 439 440 public void setWindowAlignmentOffsetPercent(float offsetPercent) { 441 mWindowAlignment.mainAxis().setWindowAlignmentOffsetPercent(offsetPercent); 442 } 443 444 public float getWindowAlignmentOffsetPercent() { 445 return mWindowAlignment.mainAxis().getWindowAlignmentOffsetPercent(); 446 } 447 448 public void setItemAlignmentOffset(int alignmentOffset) { 449 mItemAlignment.mainAxis().setItemAlignmentOffset(alignmentOffset); 450 updateChildAlignments(); 451 } 452 453 public int getItemAlignmentOffset() { 454 return mItemAlignment.mainAxis().getItemAlignmentOffset(); 455 } 456 457 public void setItemAlignmentOffsetWithPadding(boolean withPadding) { 458 mItemAlignment.mainAxis().setItemAlignmentOffsetWithPadding(withPadding); 459 updateChildAlignments(); 460 } 461 462 public boolean isItemAlignmentOffsetWithPadding() { 463 return mItemAlignment.mainAxis().isItemAlignmentOffsetWithPadding(); 464 } 465 466 public void setItemAlignmentOffsetPercent(float offsetPercent) { 467 mItemAlignment.mainAxis().setItemAlignmentOffsetPercent(offsetPercent); 468 updateChildAlignments(); 469 } 470 471 public float getItemAlignmentOffsetPercent() { 472 return mItemAlignment.mainAxis().getItemAlignmentOffsetPercent(); 473 } 474 475 public void setItemAlignmentViewId(int viewId) { 476 mItemAlignment.mainAxis().setItemAlignmentViewId(viewId); 477 updateChildAlignments(); 478 } 479 480 public int getItemAlignmentViewId() { 481 return mItemAlignment.mainAxis().getItemAlignmentViewId(); 482 } 483 484 public void setFocusOutAllowed(boolean throughFront, boolean throughEnd) { 485 mFocusOutFront = throughFront; 486 mFocusOutEnd = throughEnd; 487 } 488 489 public void setNumRows(int numRows) { 490 if (numRows < 0) throw new IllegalArgumentException(); 491 mNumRowsRequested = numRows; 492 mForceFullLayout = true; 493 } 494 495 /** 496 * Set the row height. May be WRAP_CONTENT, or a size in pixels. 497 */ 498 public void setRowHeight(int height) { 499 if (height >= 0 || height == ViewGroup.LayoutParams.WRAP_CONTENT) { 500 mRowSizeSecondaryRequested = height; 501 } else { 502 throw new IllegalArgumentException("Invalid row height: " + height); 503 } 504 } 505 506 public void setItemMargin(int margin) { 507 mVerticalMargin = mHorizontalMargin = margin; 508 mMarginPrimary = mMarginSecondary = margin; 509 } 510 511 public void setVerticalMargin(int margin) { 512 if (mOrientation == HORIZONTAL) { 513 mMarginSecondary = mVerticalMargin = margin; 514 } else { 515 mMarginPrimary = mVerticalMargin = margin; 516 } 517 } 518 519 public void setHorizontalMargin(int margin) { 520 if (mOrientation == HORIZONTAL) { 521 mMarginPrimary = mHorizontalMargin = margin; 522 } else { 523 mMarginSecondary = mHorizontalMargin = margin; 524 } 525 } 526 527 public int getVerticalMargin() { 528 return mVerticalMargin; 529 } 530 531 public int getHorizontalMargin() { 532 return mHorizontalMargin; 533 } 534 535 public void setGravity(int gravity) { 536 mGravity = gravity; 537 } 538 539 protected boolean hasDoneFirstLayout() { 540 return mGrid != null; 541 } 542 543 public void setOnChildSelectedListener(OnChildSelectedListener listener) { 544 mChildSelectedListener = listener; 545 } 546 547 private int getPositionByView(View view) { 548 if (view == null) { 549 return NO_POSITION; 550 } 551 LayoutParams params = (LayoutParams) view.getLayoutParams(); 552 if (params == null || params.isItemRemoved()) { 553 // when item is removed, the position value can be any value. 554 return NO_POSITION; 555 } 556 return params.getViewPosition(); 557 } 558 559 private int getPositionByIndex(int index) { 560 return getPositionByView(getChildAt(index)); 561 } 562 563 private void dispatchChildSelected() { 564 if (mChildSelectedListener == null) { 565 return; 566 } 567 if (mFocusPosition != NO_POSITION) { 568 View view = findViewByPosition(mFocusPosition); 569 if (view != null) { 570 RecyclerView.ViewHolder vh = mBaseGridView.getChildViewHolder(view); 571 mChildSelectedListener.onChildSelected(mBaseGridView, view, mFocusPosition, 572 vh == null? NO_ID: vh.getItemId()); 573 return; 574 } 575 } 576 mChildSelectedListener.onChildSelected(mBaseGridView, null, NO_POSITION, NO_ID); 577 } 578 579 @Override 580 public boolean canScrollHorizontally() { 581 // We can scroll horizontally if we have horizontal orientation, or if 582 // we are vertical and have more than one column. 583 return mOrientation == HORIZONTAL || mNumRows > 1; 584 } 585 586 @Override 587 public boolean canScrollVertically() { 588 // We can scroll vertically if we have vertical orientation, or if we 589 // are horizontal and have more than one row. 590 return mOrientation == VERTICAL || mNumRows > 1; 591 } 592 593 @Override 594 public RecyclerView.LayoutParams generateDefaultLayoutParams() { 595 return new LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, 596 ViewGroup.LayoutParams.WRAP_CONTENT); 597 } 598 599 @Override 600 public RecyclerView.LayoutParams generateLayoutParams(Context context, AttributeSet attrs) { 601 return new LayoutParams(context, attrs); 602 } 603 604 @Override 605 public RecyclerView.LayoutParams generateLayoutParams(ViewGroup.LayoutParams lp) { 606 if (lp instanceof LayoutParams) { 607 return new LayoutParams((LayoutParams) lp); 608 } else if (lp instanceof RecyclerView.LayoutParams) { 609 return new LayoutParams((RecyclerView.LayoutParams) lp); 610 } else if (lp instanceof MarginLayoutParams) { 611 return new LayoutParams((MarginLayoutParams) lp); 612 } else { 613 return new LayoutParams(lp); 614 } 615 } 616 617 protected View getViewForPosition(int position) { 618 return mRecycler.getViewForPosition(position); 619 } 620 621 final int getOpticalLeft(View v) { 622 return ((LayoutParams) v.getLayoutParams()).getOpticalLeft(v); 623 } 624 625 final int getOpticalRight(View v) { 626 return ((LayoutParams) v.getLayoutParams()).getOpticalRight(v); 627 } 628 629 final int getOpticalTop(View v) { 630 return ((LayoutParams) v.getLayoutParams()).getOpticalTop(v); 631 } 632 633 final int getOpticalBottom(View v) { 634 return ((LayoutParams) v.getLayoutParams()).getOpticalBottom(v); 635 } 636 637 private int getViewMin(View v) { 638 return (mOrientation == HORIZONTAL) ? getOpticalLeft(v) : getOpticalTop(v); 639 } 640 641 private int getViewMax(View v) { 642 return (mOrientation == HORIZONTAL) ? getOpticalRight(v) : getOpticalBottom(v); 643 } 644 645 private int getViewCenter(View view) { 646 return (mOrientation == HORIZONTAL) ? getViewCenterX(view) : getViewCenterY(view); 647 } 648 649 private int getViewCenterSecondary(View view) { 650 return (mOrientation == HORIZONTAL) ? getViewCenterY(view) : getViewCenterX(view); 651 } 652 653 private int getViewCenterX(View v) { 654 LayoutParams p = (LayoutParams) v.getLayoutParams(); 655 return p.getOpticalLeft(v) + p.getAlignX(); 656 } 657 658 private int getViewCenterY(View v) { 659 LayoutParams p = (LayoutParams) v.getLayoutParams(); 660 return p.getOpticalTop(v) + p.getAlignY(); 661 } 662 663 /** 664 * Save Recycler and State for convenience. Must be paired with leaveContext(). 665 */ 666 private void saveContext(Recycler recycler, State state) { 667 if (mRecycler != null || mState != null) { 668 Log.e(TAG, "Recycler information was not released, bug!"); 669 } 670 mRecycler = recycler; 671 mState = state; 672 } 673 674 /** 675 * Discard saved Recycler and State. 676 */ 677 private void leaveContext() { 678 mRecycler = null; 679 mState = null; 680 } 681 682 /** 683 * Re-initialize data structures for a data change or handling invisible 684 * selection. The method tries its best to preserve position information so 685 * that staggered grid looks same before and after re-initialize. 686 * @param focusPosition The initial focusPosition that we would like to 687 * focus on. 688 * @return Actual position that can be focused on. 689 */ 690 private int init(int focusPosition) { 691 692 final int newItemCount = mState.getItemCount(); 693 694 // Force the re-init path in the following conditional 695 if (newItemCount == 0) { 696 focusPosition = NO_POSITION; 697 } else if (focusPosition == NO_POSITION && newItemCount > 0) { 698 // if focus position is never set before, initialize it to 0 699 focusPosition = 0; 700 } 701 702 // If adapter has changed then caches are invalid; otherwise, 703 // we try to maintain each row's position if number of rows keeps the same 704 // and existing mGrid contains the focusPosition. 705 if (mRows != null && mNumRows == mRows.length && 706 mGrid != null && mGrid.getSize() > 0 && focusPosition >= 0 && 707 focusPosition >= mGrid.getFirstIndex() && 708 focusPosition <= mGrid.getLastIndex()) { 709 // strip mGrid to a subset (like a column) that contains focusPosition 710 mGrid.stripDownTo(focusPosition); 711 // make sure that remaining items do not exceed new adapter size 712 int firstIndex = mGrid.getFirstIndex(); 713 int lastIndex = mGrid.getLastIndex(); 714 if (DEBUG) { 715 Log .v(getTag(), "mGrid firstIndex " + firstIndex + " lastIndex " + lastIndex); 716 } 717 for (int i = lastIndex; i >=firstIndex; i--) { 718 if (i >= newItemCount) { 719 mGrid.removeLast(); 720 } 721 } 722 if (mGrid.getSize() == 0) { 723 focusPosition = newItemCount - 1; 724 // initialize row start locations 725 for (int i = 0; i < mNumRows; i++) { 726 mRows[i].low = 0; 727 mRows[i].high = 0; 728 } 729 if (DEBUG) Log.v(getTag(), "mGrid zero size"); 730 } else { 731 // initialize row start locations 732 for (int i = 0; i < mNumRows; i++) { 733 mRows[i].low = Integer.MAX_VALUE; 734 mRows[i].high = Integer.MIN_VALUE; 735 } 736 firstIndex = mGrid.getFirstIndex(); 737 lastIndex = mGrid.getLastIndex(); 738 if (focusPosition > lastIndex) { 739 focusPosition = mGrid.getLastIndex(); 740 } 741 if (DEBUG) { 742 Log.v(getTag(), "mGrid firstIndex " + firstIndex + " lastIndex " 743 + lastIndex + " focusPosition " + focusPosition); 744 } 745 // fill rows with minimal view positions of the subset 746 for (int i = firstIndex; i <= lastIndex; i++) { 747 View v = findViewByPosition(i); 748 if (v == null) { 749 continue; 750 } 751 int row = mGrid.getLocation(i).row; 752 int low = getViewMin(v) + mScrollOffsetPrimary; 753 if (low < mRows[row].low) { 754 mRows[row].low = mRows[row].high = low; 755 } 756 } 757 int firstItemRowPosition = mRows[mGrid.getLocation(firstIndex).row].low; 758 if (firstItemRowPosition == Integer.MAX_VALUE) { 759 firstItemRowPosition = 0; 760 } 761 if (mState.didStructureChange()) { 762 // if there is structure change, the removed item might be in the 763 // subset, so it is meaningless to maintain the low locations. 764 for (int i = 0; i < mNumRows; i++) { 765 mRows[i].low = firstItemRowPosition; 766 mRows[i].high = firstItemRowPosition; 767 } 768 } else { 769 // fill other rows that does not include the subset using first item 770 for (int i = 0; i < mNumRows; i++) { 771 if (mRows[i].low == Integer.MAX_VALUE) { 772 mRows[i].low = mRows[i].high = firstItemRowPosition; 773 } 774 } 775 } 776 } 777 778 // Same adapter, we can reuse any attached views 779 detachAndScrapAttachedViews(mRecycler); 780 updateScrollController(); 781 782 } else { 783 // otherwise recreate data structure 784 mRows = new StaggeredGrid.Row[mNumRows]; 785 786 for (int i = 0; i < mNumRows; i++) { 787 mRows[i] = new StaggeredGrid.Row(); 788 } 789 mGrid = new StaggeredGridDefault(); 790 mGrid.setReversedFlow(mOrientation == HORIZONTAL && mReverseFlowPrimary); 791 if (newItemCount == 0) { 792 focusPosition = NO_POSITION; 793 } else if (focusPosition >= newItemCount) { 794 focusPosition = newItemCount - 1; 795 } 796 797 // Adapter may have changed so remove all attached views permanently 798 removeAndRecycleAllViews(mRecycler); 799 800 initScrollController(); 801 } 802 803 mGrid.setProvider(mGridProvider); 804 // mGrid share the same Row array information 805 mGrid.setRows(mRows); 806 mFirstVisiblePos = mLastVisiblePos = NO_POSITION; 807 808 updateScrollSecondAxis(); 809 810 return focusPosition; 811 } 812 813 private int getRowSizeSecondary(int rowIndex) { 814 if (mFixedRowSizeSecondary != 0) { 815 return mFixedRowSizeSecondary; 816 } 817 if (mRowSizeSecondary == null) { 818 return 0; 819 } 820 return mRowSizeSecondary[rowIndex]; 821 } 822 823 private int getRowStartSecondary(int rowIndex) { 824 int start = 0; 825 // Iterate from left to right, which is a different index traversal 826 // in RTL flow 827 if (mReverseFlowSecondary) { 828 for (int i = mNumRows-1; i > rowIndex; i--) { 829 start += getRowSizeSecondary(i) + mMarginSecondary; 830 } 831 } else { 832 for (int i = 0; i < rowIndex; i++) { 833 start += getRowSizeSecondary(i) + mMarginSecondary; 834 } 835 } 836 return start; 837 } 838 839 private int getSizeSecondary() { 840 int rightmostIndex = mReverseFlowSecondary ? 0 : mNumRows - 1; 841 return getRowStartSecondary(rightmostIndex) + getRowSizeSecondary(rightmostIndex); 842 } 843 844 private void measureScrapChild(int position, int widthSpec, int heightSpec, 845 int[] measuredDimension) { 846 View view = mRecycler.getViewForPosition(position); 847 if (view != null) { 848 LayoutParams p = (LayoutParams) view.getLayoutParams(); 849 int childWidthSpec = ViewGroup.getChildMeasureSpec(widthSpec, 850 getPaddingLeft() + getPaddingRight(), p.width); 851 int childHeightSpec = ViewGroup.getChildMeasureSpec(heightSpec, 852 getPaddingTop() + getPaddingBottom(), p.height); 853 view.measure(childWidthSpec, childHeightSpec); 854 measuredDimension[0] = view.getMeasuredWidth(); 855 measuredDimension[1] = view.getMeasuredHeight(); 856 mRecycler.recycleView(view); 857 } 858 } 859 860 private boolean processRowSizeSecondary(boolean measure) { 861 if (mFixedRowSizeSecondary != 0) { 862 return false; 863 } 864 865 List<Integer>[] rows = mGrid == null ? null : 866 mGrid.getItemPositionsInRows(mFirstVisiblePos, mLastVisiblePos); 867 boolean changed = false; 868 int scrapChildWidth = -1; 869 int scrapChildHeight = -1; 870 871 for (int rowIndex = 0; rowIndex < mNumRows; rowIndex++) { 872 final int rowItemCount = rows == null ? 0 : rows[rowIndex].size(); 873 if (DEBUG) Log.v(getTag(), "processRowSizeSecondary row " + rowIndex + 874 " rowItemCount " + rowItemCount); 875 876 int rowSize = -1; 877 for (int i = 0; i < rowItemCount; i++) { 878 final View view = findViewByPosition(rows[rowIndex].get(i)); 879 if (view == null) { 880 continue; 881 } 882 if (measure && view.isLayoutRequested()) { 883 measureChild(view); 884 } 885 final int secondarySize = mOrientation == HORIZONTAL ? 886 view.getMeasuredHeight() : view.getMeasuredWidth(); 887 if (secondarySize > rowSize) { 888 rowSize = secondarySize; 889 } 890 } 891 892 final int itemCount = mState.getItemCount(); 893 if (measure && rowSize < 0 && itemCount > 0) { 894 if (scrapChildWidth < 0 && scrapChildHeight < 0) { 895 int position; 896 if (mFocusPosition == NO_POSITION) { 897 position = 0; 898 } else if (mFocusPosition >= itemCount) { 899 position = itemCount - 1; 900 } else { 901 position = mFocusPosition; 902 } 903 measureScrapChild(position, 904 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 905 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 906 mMeasuredDimension); 907 scrapChildWidth = mMeasuredDimension[0]; 908 scrapChildHeight = mMeasuredDimension[1]; 909 if (DEBUG) Log.v(TAG, "measured scrap child: " + scrapChildWidth + 910 " " + scrapChildHeight); 911 } 912 rowSize = mOrientation == HORIZONTAL ? scrapChildHeight : scrapChildWidth; 913 } 914 915 if (rowSize < 0) { 916 rowSize = 0; 917 } 918 919 if (DEBUG) Log.v(getTag(), "row " + rowIndex + " rowItemCount " + rowItemCount + 920 " rowSize " + rowSize); 921 922 if (mRowSizeSecondary[rowIndex] != rowSize) { 923 if (DEBUG) Log.v(getTag(), "row size secondary changed: " + mRowSizeSecondary[rowIndex] + 924 ", " + rowSize); 925 926 mRowSizeSecondary[rowIndex] = rowSize; 927 changed = true; 928 } 929 } 930 931 return changed; 932 } 933 934 /** 935 * Checks if we need to update row secondary sizes. 936 */ 937 private void updateRowSecondarySizeRefresh() { 938 mRowSecondarySizeRefresh = processRowSizeSecondary(false); 939 if (mRowSecondarySizeRefresh) { 940 if (DEBUG) Log.v(getTag(), "mRowSecondarySizeRefresh now set"); 941 forceRequestLayout(); 942 } 943 } 944 945 private void forceRequestLayout() { 946 if (DEBUG) Log.v(getTag(), "forceRequestLayout"); 947 // RecyclerView prevents us from requesting layout in many cases 948 // (during layout, during scroll, etc.) 949 // For secondary row size wrap_content support we currently need a 950 // second layout pass to update the measured size after having measured 951 // and added child views in layoutChildren. 952 // Force the second layout by posting a delayed runnable. 953 // TODO: investigate allowing a second layout pass, 954 // or move child add/measure logic to the measure phase. 955 ViewCompat.postOnAnimation(mBaseGridView, mRequestLayoutRunnable); 956 } 957 958 private final Runnable mRequestLayoutRunnable = new Runnable() { 959 @Override 960 public void run() { 961 if (DEBUG) Log.v(getTag(), "request Layout from runnable"); 962 requestLayout(); 963 } 964 }; 965 966 @Override 967 public void onMeasure(Recycler recycler, State state, int widthSpec, int heightSpec) { 968 saveContext(recycler, state); 969 970 int sizePrimary, sizeSecondary, modeSecondary, paddingSecondary; 971 int measuredSizeSecondary; 972 if (mOrientation == HORIZONTAL) { 973 sizePrimary = MeasureSpec.getSize(widthSpec); 974 sizeSecondary = MeasureSpec.getSize(heightSpec); 975 modeSecondary = MeasureSpec.getMode(heightSpec); 976 paddingSecondary = getPaddingTop() + getPaddingBottom(); 977 } else { 978 sizeSecondary = MeasureSpec.getSize(widthSpec); 979 sizePrimary = MeasureSpec.getSize(heightSpec); 980 modeSecondary = MeasureSpec.getMode(widthSpec); 981 paddingSecondary = getPaddingLeft() + getPaddingRight(); 982 } 983 if (DEBUG) Log.v(getTag(), "onMeasure widthSpec " + Integer.toHexString(widthSpec) + 984 " heightSpec " + Integer.toHexString(heightSpec) + 985 " modeSecondary " + Integer.toHexString(modeSecondary) + 986 " sizeSecondary " + sizeSecondary + " " + this); 987 988 mMaxSizeSecondary = sizeSecondary; 989 990 if (mRowSizeSecondaryRequested == ViewGroup.LayoutParams.WRAP_CONTENT) { 991 mNumRows = mNumRowsRequested == 0 ? 1 : mNumRowsRequested; 992 mFixedRowSizeSecondary = 0; 993 994 if (mRowSizeSecondary == null || mRowSizeSecondary.length != mNumRows) { 995 mRowSizeSecondary = new int[mNumRows]; 996 } 997 998 // Measure all current children and update cached row heights 999 processRowSizeSecondary(true); 1000 1001 switch (modeSecondary) { 1002 case MeasureSpec.UNSPECIFIED: 1003 measuredSizeSecondary = getSizeSecondary() + paddingSecondary; 1004 break; 1005 case MeasureSpec.AT_MOST: 1006 measuredSizeSecondary = Math.min(getSizeSecondary() + paddingSecondary, 1007 mMaxSizeSecondary); 1008 break; 1009 case MeasureSpec.EXACTLY: 1010 measuredSizeSecondary = mMaxSizeSecondary; 1011 break; 1012 default: 1013 throw new IllegalStateException("wrong spec"); 1014 } 1015 1016 } else { 1017 switch (modeSecondary) { 1018 case MeasureSpec.UNSPECIFIED: 1019 if (mRowSizeSecondaryRequested == 0) { 1020 if (mOrientation == HORIZONTAL) { 1021 throw new IllegalStateException("Must specify rowHeight or view height"); 1022 } else { 1023 throw new IllegalStateException("Must specify columnWidth or view width"); 1024 } 1025 } 1026 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 1027 mNumRows = mNumRowsRequested == 0 ? 1 : mNumRowsRequested; 1028 measuredSizeSecondary = mFixedRowSizeSecondary * mNumRows + mMarginSecondary 1029 * (mNumRows - 1) + paddingSecondary; 1030 break; 1031 case MeasureSpec.AT_MOST: 1032 case MeasureSpec.EXACTLY: 1033 if (mNumRowsRequested == 0 && mRowSizeSecondaryRequested == 0) { 1034 mNumRows = 1; 1035 mFixedRowSizeSecondary = sizeSecondary - paddingSecondary; 1036 } else if (mNumRowsRequested == 0) { 1037 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 1038 mNumRows = (sizeSecondary + mMarginSecondary) 1039 / (mRowSizeSecondaryRequested + mMarginSecondary); 1040 } else if (mRowSizeSecondaryRequested == 0) { 1041 mNumRows = mNumRowsRequested; 1042 mFixedRowSizeSecondary = (sizeSecondary - paddingSecondary - mMarginSecondary 1043 * (mNumRows - 1)) / mNumRows; 1044 } else { 1045 mNumRows = mNumRowsRequested; 1046 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 1047 } 1048 measuredSizeSecondary = sizeSecondary; 1049 if (modeSecondary == MeasureSpec.AT_MOST) { 1050 int childrenSize = mFixedRowSizeSecondary * mNumRows + mMarginSecondary 1051 * (mNumRows - 1) + paddingSecondary; 1052 if (childrenSize < measuredSizeSecondary) { 1053 measuredSizeSecondary = childrenSize; 1054 } 1055 } 1056 break; 1057 default: 1058 throw new IllegalStateException("wrong spec"); 1059 } 1060 } 1061 if (mOrientation == HORIZONTAL) { 1062 setMeasuredDimension(sizePrimary, measuredSizeSecondary); 1063 } else { 1064 setMeasuredDimension(measuredSizeSecondary, sizePrimary); 1065 } 1066 if (DEBUG) { 1067 Log.v(getTag(), "onMeasure sizePrimary " + sizePrimary + 1068 " measuredSizeSecondary " + measuredSizeSecondary + 1069 " mFixedRowSizeSecondary " + mFixedRowSizeSecondary + 1070 " mNumRows " + mNumRows); 1071 } 1072 1073 leaveContext(); 1074 } 1075 1076 private void measureChild(View child) { 1077 final ViewGroup.LayoutParams lp = child.getLayoutParams(); 1078 final int secondarySpec = (mRowSizeSecondaryRequested == ViewGroup.LayoutParams.WRAP_CONTENT) ? 1079 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED) : 1080 MeasureSpec.makeMeasureSpec(mFixedRowSizeSecondary, MeasureSpec.EXACTLY); 1081 int widthSpec, heightSpec; 1082 1083 if (mOrientation == HORIZONTAL) { 1084 widthSpec = ViewGroup.getChildMeasureSpec( 1085 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 1086 0, lp.width); 1087 heightSpec = ViewGroup.getChildMeasureSpec(secondarySpec, 0, lp.height); 1088 } else { 1089 heightSpec = ViewGroup.getChildMeasureSpec( 1090 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 1091 0, lp.height); 1092 widthSpec = ViewGroup.getChildMeasureSpec(secondarySpec, 0, lp.width); 1093 } 1094 1095 child.measure(widthSpec, heightSpec); 1096 1097 if (DEBUG) Log.v(getTag(), "measureChild secondarySpec " + Integer.toHexString(secondarySpec) + 1098 " widthSpec " + Integer.toHexString(widthSpec) + 1099 " heightSpec " + Integer.toHexString(heightSpec) + 1100 " measuredWidth " + child.getMeasuredWidth() + 1101 " measuredHeight " + child.getMeasuredHeight()); 1102 if (DEBUG) Log.v(getTag(), "child lp width " + lp.width + " height " + lp.height); 1103 } 1104 1105 private StaggeredGrid.Provider mGridProvider = new StaggeredGrid.Provider() { 1106 1107 @Override 1108 public int getCount() { 1109 return mState.getItemCount(); 1110 } 1111 1112 @Override 1113 public void createItem(int index, int rowIndex, boolean append) { 1114 View v = getViewForPosition(index); 1115 if (mFirstVisiblePos >= 0) { 1116 // when StaggeredGrid append or prepend item, we must guarantee 1117 // that sibling item has created views already. 1118 if (append && index != mLastVisiblePos + 1) { 1119 throw new RuntimeException(); 1120 } else if (!append && index != mFirstVisiblePos - 1) { 1121 throw new RuntimeException(); 1122 } 1123 } 1124 1125 // See recyclerView docs: we don't need re-add scraped view if it was removed. 1126 if (!((RecyclerView.LayoutParams) v.getLayoutParams()).isItemRemoved()) { 1127 if (append) { 1128 addView(v); 1129 } else { 1130 addView(v, 0); 1131 } 1132 if (mChildVisibility != -1) { 1133 v.setVisibility(mChildVisibility); 1134 } 1135 1136 // View is added first or it won't be found by dispatchChildSelected. 1137 if (mInLayout && index == mFocusPosition) { 1138 dispatchChildSelected(); 1139 } 1140 1141 measureChild(v); 1142 } 1143 1144 int length = mOrientation == HORIZONTAL ? v.getMeasuredWidth() : v.getMeasuredHeight(); 1145 int start, end; 1146 final boolean rowIsEmpty = mRows[rowIndex].high == mRows[rowIndex].low; 1147 boolean addHigh = (!mReverseFlowPrimary) ? append : !append; 1148 int lowVisiblePos = (!mReverseFlowPrimary) ? mFirstVisiblePos : mLastVisiblePos; 1149 int highVisiblePos = (!mReverseFlowPrimary) ? mLastVisiblePos : mFirstVisiblePos; 1150 if (addHigh) { 1151 if (!rowIsEmpty) { 1152 // if there are existing item in the row, add margin between 1153 start = mRows[rowIndex].high + mMarginPrimary; 1154 } else { 1155 if (lowVisiblePos >= 0) { 1156 int rowOfLowPos = mGrid.getLocation(lowVisiblePos).row; 1157 // If row is after row of lowest position, 1158 // start a new column after the first row. 1159 if (rowIndex < rowOfLowPos) { 1160 mRows[rowIndex].low = mRows[rowOfLowPos].high + mMarginPrimary; 1161 } 1162 } 1163 start = mRows[rowIndex].low; 1164 } 1165 end = start + length; 1166 mRows[rowIndex].high = end; 1167 } else { 1168 if (!rowIsEmpty) { 1169 // if there are existing item in the row, add margin between 1170 end = mRows[rowIndex].low - mMarginPrimary; 1171 } else { 1172 if (highVisiblePos >= 0) { 1173 int rowOfHighPos = mGrid.getLocation(highVisiblePos).row; 1174 if (mOrientation == HORIZONTAL ? 1175 rowIndex < rowOfHighPos : rowIndex > rowOfHighPos) { 1176 mRows[rowIndex].high = mRows[rowOfHighPos].low - mMarginPrimary; 1177 } 1178 } 1179 end = mRows[rowIndex].high; 1180 } 1181 start = end - length; 1182 mRows[rowIndex].low = start; 1183 } 1184 if (mFirstVisiblePos < 0) { 1185 mFirstVisiblePos = mLastVisiblePos = index; 1186 } else { 1187 if (append) { 1188 mLastVisiblePos++; 1189 } else { 1190 mFirstVisiblePos--; 1191 } 1192 } 1193 if (DEBUG) Log.v(getTag(), "start " + start + " end " + end); 1194 int startSecondary = getRowStartSecondary(rowIndex) - mScrollOffsetSecondary; 1195 mChildrenStates.loadView(v, index); 1196 layoutChild(rowIndex, v, start - mScrollOffsetPrimary, end - mScrollOffsetPrimary, 1197 startSecondary); 1198 if (DEBUG) { 1199 Log.d(getTag(), "addView " + index + " " + v); 1200 } 1201 if (index == mFirstVisiblePos) { 1202 if (!mReverseFlowPrimary) { 1203 updateScrollMin(); 1204 } else { 1205 updateScrollMax(); 1206 } 1207 } 1208 if (index == mLastVisiblePos) { 1209 if (!mReverseFlowPrimary) { 1210 updateScrollMax(); 1211 } else { 1212 updateScrollMin(); 1213 } 1214 } 1215 } 1216 }; 1217 1218 private void layoutChild(int rowIndex, View v, int start, int end, int startSecondary) { 1219 int sizeSecondary = mOrientation == HORIZONTAL ? v.getMeasuredHeight() 1220 : v.getMeasuredWidth(); 1221 if (mFixedRowSizeSecondary > 0) { 1222 sizeSecondary = Math.min(sizeSecondary, mFixedRowSizeSecondary); 1223 } 1224 final int verticalGravity = mGravity & Gravity.VERTICAL_GRAVITY_MASK; 1225 final int horizontalGravity = (mReverseFlowPrimary || mReverseFlowSecondary) ? 1226 Gravity.getAbsoluteGravity(mGravity & Gravity.RELATIVE_HORIZONTAL_GRAVITY_MASK, View.LAYOUT_DIRECTION_RTL) : 1227 mGravity & Gravity.HORIZONTAL_GRAVITY_MASK; 1228 if (mOrientation == HORIZONTAL && verticalGravity == Gravity.TOP 1229 || mOrientation == VERTICAL && horizontalGravity == Gravity.LEFT) { 1230 // do nothing 1231 } else if (mOrientation == HORIZONTAL && verticalGravity == Gravity.BOTTOM 1232 || mOrientation == VERTICAL && horizontalGravity == Gravity.RIGHT) { 1233 startSecondary += getRowSizeSecondary(rowIndex) - sizeSecondary; 1234 } else if (mOrientation == HORIZONTAL && verticalGravity == Gravity.CENTER_VERTICAL 1235 || mOrientation == VERTICAL && horizontalGravity == Gravity.CENTER_HORIZONTAL) { 1236 startSecondary += (getRowSizeSecondary(rowIndex) - sizeSecondary) / 2; 1237 } 1238 int left, top, right, bottom; 1239 if (mOrientation == HORIZONTAL) { 1240 left = start; 1241 top = startSecondary; 1242 right = end; 1243 bottom = startSecondary + sizeSecondary; 1244 } else { 1245 top = start; 1246 left = startSecondary; 1247 bottom = end; 1248 right = startSecondary + sizeSecondary; 1249 } 1250 v.layout(left, top, right, bottom); 1251 updateChildOpticalInsets(v, left, top, right, bottom); 1252 updateChildAlignments(v); 1253 } 1254 1255 private void updateChildOpticalInsets(View v, int left, int top, int right, int bottom) { 1256 LayoutParams p = (LayoutParams) v.getLayoutParams(); 1257 p.setOpticalInsets(left - v.getLeft(), top - v.getTop(), 1258 v.getRight() - right, v.getBottom() - bottom); 1259 } 1260 1261 private void updateChildAlignments(View v) { 1262 LayoutParams p = (LayoutParams) v.getLayoutParams(); 1263 p.setAlignX(mItemAlignment.horizontal.getAlignmentPosition(v)); 1264 p.setAlignY(mItemAlignment.vertical.getAlignmentPosition(v)); 1265 } 1266 1267 private void updateChildAlignments() { 1268 for (int i = 0, c = getChildCount(); i < c; i++) { 1269 updateChildAlignments(getChildAt(i)); 1270 } 1271 } 1272 1273 private boolean needsAppendVisibleItem() { 1274 if (mLastVisiblePos < mFocusPosition) { 1275 return true; 1276 } 1277 if (mReverseFlowPrimary) { 1278 for (int i = 0; i < mNumRows; i++) { 1279 if (mRows[i].low == mRows[i].high) { 1280 if (mRows[i].low > mScrollOffsetPrimary) { 1281 return true; 1282 } 1283 } else if (mRows[i].low - mMarginPrimary > mScrollOffsetPrimary) { 1284 return true; 1285 } 1286 } 1287 } else { 1288 int right = mScrollOffsetPrimary + mSizePrimary; 1289 for (int i = 0; i < mNumRows; i++) { 1290 if (mRows[i].low == mRows[i].high) { 1291 if (mRows[i].high < right) { 1292 return true; 1293 } 1294 } else if (mRows[i].high < right - mMarginPrimary) { 1295 return true; 1296 } 1297 } 1298 } 1299 return false; 1300 } 1301 1302 private boolean needsPrependVisibleItem() { 1303 if (mFirstVisiblePos > mFocusPosition) { 1304 return true; 1305 } 1306 if (mReverseFlowPrimary) { 1307 int right = mScrollOffsetPrimary + mSizePrimary; 1308 for (int i = 0; i < mNumRows; i++) { 1309 if (mRows[i].low == mRows[i].high) { 1310 if (mRows[i].high < right) { 1311 return true; 1312 } 1313 } else if (mRows[i].high < right - mMarginPrimary) { 1314 return true; 1315 } 1316 } 1317 } else { 1318 for (int i = 0; i < mNumRows; i++) { 1319 if (mRows[i].low == mRows[i].high) { 1320 if (mRows[i].low > mScrollOffsetPrimary) { 1321 return true; 1322 } 1323 } else if (mRows[i].low - mMarginPrimary > mScrollOffsetPrimary) { 1324 return true; 1325 } 1326 } 1327 } 1328 return false; 1329 } 1330 1331 // Append one column if possible and return true if reach end. 1332 private boolean appendOneVisibleItem() { 1333 while (true) { 1334 if (mLastVisiblePos != NO_POSITION && mLastVisiblePos < mState.getItemCount() -1 && 1335 mLastVisiblePos < mGrid.getLastIndex()) { 1336 // append invisible view of saved location till last row 1337 final int index = mLastVisiblePos + 1; 1338 final int row = mGrid.getLocation(index).row; 1339 mGridProvider.createItem(index, row, true); 1340 if (row == mNumRows - 1) { 1341 return false; 1342 } 1343 } else if ((mLastVisiblePos == NO_POSITION && mState.getItemCount() > 0) || 1344 (mLastVisiblePos != NO_POSITION && 1345 mLastVisiblePos < mState.getItemCount() - 1)) { 1346 if (mReverseFlowPrimary) { 1347 mGrid.appendItems(mScrollOffsetPrimary); 1348 } else { 1349 mGrid.appendItems(mScrollOffsetPrimary + mSizePrimary); 1350 } 1351 return false; 1352 } else { 1353 return true; 1354 } 1355 } 1356 } 1357 1358 private void appendVisibleItems() { 1359 while (needsAppendVisibleItem()) { 1360 if (appendOneVisibleItem()) { 1361 break; 1362 } 1363 } 1364 } 1365 1366 // Prepend one column if possible and return true if reach end. 1367 private boolean prependOneVisibleItem() { 1368 while (true) { 1369 if (mFirstVisiblePos > 0) { 1370 if (mFirstVisiblePos > mGrid.getFirstIndex()) { 1371 // prepend invisible view of saved location till first row 1372 final int index = mFirstVisiblePos - 1; 1373 final int row = mGrid.getLocation(index).row; 1374 mGridProvider.createItem(index, row, false); 1375 if (row == 0) { 1376 return false; 1377 } 1378 } else { 1379 if (mReverseFlowPrimary) { 1380 mGrid.prependItems(mScrollOffsetPrimary + mSizePrimary); 1381 } else { 1382 mGrid.prependItems(mScrollOffsetPrimary); 1383 } 1384 return false; 1385 } 1386 } else { 1387 return true; 1388 } 1389 } 1390 } 1391 1392 private void prependVisibleItems() { 1393 while (needsPrependVisibleItem()) { 1394 if (prependOneVisibleItem()) { 1395 break; 1396 } 1397 } 1398 } 1399 1400 private void removeChildAt(int position) { 1401 View v = findViewByPosition(position); 1402 if (v != null) { 1403 if (DEBUG) { 1404 Log.d(getTag(), "removeAndRecycleViewAt " + position + " " + v); 1405 } 1406 mChildrenStates.saveOffscreenView(v, position); 1407 removeAndRecycleView(v, mRecycler); 1408 } 1409 } 1410 1411 private void removeInvisibleViewsAtEnd() { 1412 if (!mPruneChild) { 1413 return; 1414 } 1415 boolean update = false; 1416 while(mLastVisiblePos > mFirstVisiblePos && mLastVisiblePos > mFocusPosition) { 1417 View view = findViewByPosition(mLastVisiblePos); 1418 boolean offEnd = (!mReverseFlowPrimary) ? getViewMin(view) > mSizePrimary : 1419 getViewMax(view) < 0; 1420 if (offEnd) { 1421 removeChildAt(mLastVisiblePos); 1422 mLastVisiblePos--; 1423 update = true; 1424 } else { 1425 break; 1426 } 1427 } 1428 if (update) { 1429 updateRowsMinMax(); 1430 } 1431 } 1432 1433 private void removeInvisibleViewsAtFront() { 1434 if (!mPruneChild) { 1435 return; 1436 } 1437 boolean update = false; 1438 while(mLastVisiblePos > mFirstVisiblePos && mFirstVisiblePos < mFocusPosition) { 1439 View view = findViewByPosition(mFirstVisiblePos); 1440 boolean offFront = (!mReverseFlowPrimary) ? getViewMax(view) < 0: 1441 getViewMin(view) > mSizePrimary; 1442 if (offFront) { 1443 removeChildAt(mFirstVisiblePos); 1444 mFirstVisiblePos++; 1445 update = true; 1446 } else { 1447 break; 1448 } 1449 } 1450 if (update) { 1451 updateRowsMinMax(); 1452 } 1453 } 1454 1455 private void updateRowsMinMax() { 1456 if (mFirstVisiblePos < 0) { 1457 return; 1458 } 1459 for (int i = 0; i < mNumRows; i++) { 1460 mRows[i].low = Integer.MAX_VALUE; 1461 mRows[i].high = Integer.MIN_VALUE; 1462 } 1463 for (int i = mFirstVisiblePos; i <= mLastVisiblePos; i++) { 1464 View view = findViewByPosition(i); 1465 int row = mGrid.getLocation(i).row; 1466 int low = getViewMin(view) + mScrollOffsetPrimary; 1467 if (low < mRows[row].low) { 1468 mRows[row].low = low; 1469 } 1470 int high = getViewMax(view) + mScrollOffsetPrimary; 1471 if (high > mRows[row].high) { 1472 mRows[row].high = high; 1473 } 1474 } 1475 } 1476 1477 // Fast layout when there is no structure change, adapter change, etc. 1478 protected void fastRelayout(boolean scrollToFocus) { 1479 updateScrollController(); 1480 1481 List<Integer>[] rows = mGrid.getItemPositionsInRows(mFirstVisiblePos, mLastVisiblePos); 1482 1483 // relayout and repositioning views on each row 1484 for (int i = 0; i < mNumRows; i++) { 1485 List<Integer> row = rows[i]; 1486 final int startSecondary = getRowStartSecondary(i) - mScrollOffsetSecondary; 1487 for (int j = 0, size = row.size(); j < size; j++) { 1488 final int position = row.get(j); 1489 View view = findViewByPosition(position); 1490 int primaryDelta, end; 1491 1492 int start = getViewMin(view); 1493 int oldPrimarySize = (mOrientation == HORIZONTAL) ? 1494 view.getMeasuredWidth() : 1495 view.getMeasuredHeight(); 1496 1497 LayoutParams lp = (LayoutParams) view.getLayoutParams(); 1498 if (lp.viewNeedsUpdate()) { 1499 int index = mBaseGridView.indexOfChild(view); 1500 detachAndScrapView(view, mRecycler); 1501 view = getViewForPosition(position); 1502 addView(view, index); 1503 } 1504 1505 if (view.isLayoutRequested()) { 1506 measureChild(view); 1507 } 1508 1509 if (mOrientation == HORIZONTAL) { 1510 end = start + view.getMeasuredWidth(); 1511 primaryDelta = view.getMeasuredWidth() - oldPrimarySize; 1512 if (primaryDelta != 0) { 1513 for (int k = j + 1; k < size; k++) { 1514 findViewByPosition(row.get(k)).offsetLeftAndRight(primaryDelta); 1515 } 1516 } 1517 } else { 1518 end = start + view.getMeasuredHeight(); 1519 primaryDelta = view.getMeasuredHeight() - oldPrimarySize; 1520 if (primaryDelta != 0) { 1521 for (int k = j + 1; k < size; k++) { 1522 findViewByPosition(row.get(k)).offsetTopAndBottom(primaryDelta); 1523 } 1524 } 1525 } 1526 layoutChild(i, view, start, end, startSecondary); 1527 } 1528 } 1529 1530 updateRowsMinMax(); 1531 appendVisibleItems(); 1532 prependVisibleItems(); 1533 1534 updateRowsMinMax(); 1535 updateScrollMin(); 1536 updateScrollMax(); 1537 updateScrollSecondAxis(); 1538 1539 if (scrollToFocus) { 1540 View focusView = findViewByPosition(mFocusPosition == NO_POSITION ? 0 : mFocusPosition); 1541 scrollToView(focusView, false); 1542 } 1543 } 1544 1545 public void removeAndRecycleAllViews(RecyclerView.Recycler recycler) { 1546 if (DEBUG) Log.v(TAG, "removeAndRecycleAllViews " + getChildCount()); 1547 for (int i = getChildCount() - 1; i >= 0; i--) { 1548 removeAndRecycleViewAt(i, recycler); 1549 } 1550 } 1551 1552 // Lays out items based on the current scroll position 1553 @Override 1554 public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state) { 1555 if (DEBUG) { 1556 Log.v(getTag(), "layoutChildren start numRows " + mNumRows + " mScrollOffsetSecondary " 1557 + mScrollOffsetSecondary + " mScrollOffsetPrimary " + mScrollOffsetPrimary 1558 + " inPreLayout " + state.isPreLayout() 1559 + " didStructureChange " + state.didStructureChange() 1560 + " mForceFullLayout " + mForceFullLayout); 1561 Log.v(getTag(), "width " + getWidth() + " height " + getHeight()); 1562 } 1563 1564 if (mNumRows == 0) { 1565 // haven't done measure yet 1566 return; 1567 } 1568 final int itemCount = state.getItemCount(); 1569 if (itemCount < 0) { 1570 return; 1571 } 1572 1573 if (!mLayoutEnabled) { 1574 discardLayoutInfo(); 1575 removeAndRecycleAllViews(recycler); 1576 return; 1577 } 1578 mInLayout = true; 1579 1580 final boolean scrollToFocus = !isSmoothScrolling() 1581 && mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED; 1582 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE) { 1583 mFocusPosition = mFocusPosition + mFocusPositionOffset; 1584 mFocusPositionOffset = 0; 1585 } 1586 saveContext(recycler, state); 1587 1588 // Track the old focus view so we can adjust our system scroll position 1589 // so that any scroll animations happening now will remain valid. 1590 // We must use same delta in Pre Layout (if prelayout exists) and second layout. 1591 // So we cache the deltas in PreLayout and use it in second layout. 1592 int delta = 0, deltaSecondary = 0; 1593 if (mFocusPosition != NO_POSITION && scrollToFocus 1594 && mBaseGridView.getScrollState() != RecyclerView.SCROLL_STATE_IDLE) { 1595 // FIXME: we should get the remaining scroll animation offset from RecyclerView 1596 View focusView = findViewByPosition(mFocusPosition); 1597 if (focusView != null) { 1598 delta = mWindowAlignment.mainAxis().getSystemScrollPos(mScrollOffsetPrimary 1599 + getViewCenter(focusView), false, false) - mScrollOffsetPrimary; 1600 deltaSecondary = mWindowAlignment.secondAxis().getSystemScrollPos( 1601 mScrollOffsetSecondary + getViewCenterSecondary(focusView), 1602 false, false) - mScrollOffsetSecondary; 1603 } 1604 } 1605 1606 final boolean hasDoneFirstLayout = hasDoneFirstLayout(); 1607 int savedFocusPos = mFocusPosition; 1608 boolean fastRelayout = false; 1609 if (!mState.didStructureChange() && !mForceFullLayout && hasDoneFirstLayout) { 1610 fastRelayout = true; 1611 fastRelayout(scrollToFocus); 1612 } else { 1613 boolean hadFocus = mBaseGridView.hasFocus(); 1614 1615 mFocusPosition = init(mFocusPosition); 1616 if (mFocusPosition != savedFocusPos) { 1617 if (DEBUG) Log.v(getTag(), "savedFocusPos " + savedFocusPos + 1618 " mFocusPosition " + mFocusPosition); 1619 } 1620 if (mFocusPosition == NO_POSITION) { 1621 mBaseGridView.clearFocus(); 1622 } 1623 1624 mWindowAlignment.mainAxis().invalidateScrollMin(); 1625 mWindowAlignment.mainAxis().invalidateScrollMax(); 1626 // depending on result of init(), either recreating everything 1627 // or try to reuse the row start positions near mFocusPosition 1628 if (mGrid.getSize() == 0) { 1629 // this is a fresh creating all items, starting from 1630 // mFocusPosition with a estimated row index. 1631 mGrid.setStart(mFocusPosition, StaggeredGrid.START_DEFAULT); 1632 1633 // Can't track the old focus view 1634 delta = deltaSecondary = 0; 1635 1636 } else { 1637 // mGrid remembers Locations for the column that 1638 // contains mFocusePosition and also mRows remembers start 1639 // positions of each row. 1640 // Manually re-create child views for that column 1641 int firstIndex = mGrid.getFirstIndex(); 1642 int lastIndex = mGrid.getLastIndex(); 1643 for (int i = firstIndex; i <= lastIndex; i++) { 1644 mGridProvider.createItem(i, mGrid.getLocation(i).row, true); 1645 } 1646 } 1647 1648 // add visible views at end until reach the end of window 1649 appendVisibleItems(); 1650 // add visible views at front until reach the start of window 1651 prependVisibleItems(); 1652 // multiple rounds: scrollToView of first round may drag first/last child into 1653 // "visible window" and we update scrollMin/scrollMax then run second scrollToView 1654 int oldFirstVisible; 1655 int oldLastVisible; 1656 do { 1657 updateScrollMin(); 1658 updateScrollMax(); 1659 oldFirstVisible = mFirstVisiblePos; 1660 oldLastVisible = mLastVisiblePos; 1661 View focusView = findViewByPosition(mFocusPosition); 1662 // we need force to initialize the child view's position 1663 scrollToView(focusView, false); 1664 if (focusView != null && hadFocus) { 1665 focusView.requestFocus(); 1666 } 1667 appendVisibleItems(); 1668 prependVisibleItems(); 1669 removeInvisibleViewsAtFront(); 1670 removeInvisibleViewsAtEnd(); 1671 } while (mFirstVisiblePos != oldFirstVisible || mLastVisiblePos != oldLastVisible); 1672 } 1673 mForceFullLayout = false; 1674 1675 if (scrollToFocus) { 1676 scrollDirectionPrimary(-delta); 1677 scrollDirectionSecondary(-deltaSecondary); 1678 } 1679 appendVisibleItems(); 1680 prependVisibleItems(); 1681 removeInvisibleViewsAtFront(); 1682 removeInvisibleViewsAtEnd(); 1683 1684 if (DEBUG) { 1685 StringWriter sw = new StringWriter(); 1686 PrintWriter pw = new PrintWriter(sw); 1687 mGrid.debugPrint(pw); 1688 Log.d(getTag(), sw.toString()); 1689 } 1690 1691 if (mRowSecondarySizeRefresh) { 1692 mRowSecondarySizeRefresh = false; 1693 } else { 1694 updateRowSecondarySizeRefresh(); 1695 } 1696 1697 if (fastRelayout && mFocusPosition != savedFocusPos) { 1698 dispatchChildSelected(); 1699 } 1700 mInLayout = false; 1701 leaveContext(); 1702 if (DEBUG) Log.v(getTag(), "layoutChildren end"); 1703 } 1704 1705 private void offsetChildrenSecondary(int increment) { 1706 final int childCount = getChildCount(); 1707 if (mOrientation == HORIZONTAL) { 1708 for (int i = 0; i < childCount; i++) { 1709 getChildAt(i).offsetTopAndBottom(increment); 1710 } 1711 } else { 1712 for (int i = 0; i < childCount; i++) { 1713 getChildAt(i).offsetLeftAndRight(increment); 1714 } 1715 } 1716 } 1717 1718 private void offsetChildrenPrimary(int increment) { 1719 final int childCount = getChildCount(); 1720 if (mOrientation == VERTICAL) { 1721 for (int i = 0; i < childCount; i++) { 1722 getChildAt(i).offsetTopAndBottom(increment); 1723 } 1724 } else { 1725 for (int i = 0; i < childCount; i++) { 1726 getChildAt(i).offsetLeftAndRight(increment); 1727 } 1728 } 1729 } 1730 1731 @Override 1732 public int scrollHorizontallyBy(int dx, Recycler recycler, RecyclerView.State state) { 1733 if (DEBUG) Log.v(getTag(), "scrollHorizontallyBy " + dx); 1734 if (!mLayoutEnabled || !hasDoneFirstLayout()) { 1735 return 0; 1736 } 1737 saveContext(recycler, state); 1738 int result; 1739 if (mOrientation == HORIZONTAL) { 1740 result = scrollDirectionPrimary(dx); 1741 } else { 1742 result = scrollDirectionSecondary(dx); 1743 } 1744 leaveContext(); 1745 return result; 1746 } 1747 1748 @Override 1749 public int scrollVerticallyBy(int dy, Recycler recycler, RecyclerView.State state) { 1750 if (DEBUG) Log.v(getTag(), "scrollVerticallyBy " + dy); 1751 if (!mLayoutEnabled || !hasDoneFirstLayout()) { 1752 return 0; 1753 } 1754 saveContext(recycler, state); 1755 int result; 1756 if (mOrientation == VERTICAL) { 1757 result = scrollDirectionPrimary(dy); 1758 } else { 1759 result = scrollDirectionSecondary(dy); 1760 } 1761 leaveContext(); 1762 return result; 1763 } 1764 1765 // scroll in main direction may add/prune views 1766 private int scrollDirectionPrimary(int da) { 1767 boolean isMaxUnknown = false, isMinUnknown = false; 1768 int minScroll = 0, maxScroll = 0; 1769 if (da > 0) { 1770 isMaxUnknown = mWindowAlignment.mainAxis().isMaxUnknown(); 1771 if (!isMaxUnknown) { 1772 maxScroll = mWindowAlignment.mainAxis().getMaxScroll(); 1773 if (mScrollOffsetPrimary + da > maxScroll) { 1774 da = maxScroll - mScrollOffsetPrimary; 1775 } 1776 } 1777 } else if (da < 0) { 1778 isMinUnknown = mWindowAlignment.mainAxis().isMinUnknown(); 1779 if (!isMinUnknown) { 1780 minScroll = mWindowAlignment.mainAxis().getMinScroll(); 1781 if (mScrollOffsetPrimary + da < minScroll) { 1782 da = minScroll - mScrollOffsetPrimary; 1783 } 1784 } 1785 } 1786 if (da == 0) { 1787 return 0; 1788 } 1789 offsetChildrenPrimary(-da); 1790 mScrollOffsetPrimary += da; 1791 if (mInLayout) { 1792 return da; 1793 } 1794 1795 int childCount = getChildCount(); 1796 boolean updated; 1797 1798 if (da > 0) { 1799 if (mReverseFlowPrimary) { 1800 prependVisibleItems(); 1801 } else { 1802 appendVisibleItems(); 1803 } 1804 } else if (da < 0) { 1805 if (mReverseFlowPrimary) { 1806 appendVisibleItems(); 1807 } else { 1808 prependVisibleItems(); 1809 } 1810 } 1811 updated = getChildCount() > childCount; 1812 childCount = getChildCount(); 1813 1814 if (da > 0) { 1815 if (mReverseFlowPrimary) { 1816 removeInvisibleViewsAtEnd(); 1817 } else { 1818 removeInvisibleViewsAtFront(); 1819 } 1820 } else if (da < 0) { 1821 if (mReverseFlowPrimary) { 1822 removeInvisibleViewsAtFront(); 1823 } else { 1824 removeInvisibleViewsAtEnd(); 1825 } 1826 } 1827 updated |= getChildCount() < childCount; 1828 1829 if (updated) { 1830 updateRowSecondarySizeRefresh(); 1831 } 1832 1833 mBaseGridView.invalidate(); 1834 return da; 1835 } 1836 1837 // scroll in second direction will not add/prune views 1838 private int scrollDirectionSecondary(int dy) { 1839 if (dy == 0) { 1840 return 0; 1841 } 1842 offsetChildrenSecondary(-dy); 1843 mScrollOffsetSecondary += dy; 1844 mBaseGridView.invalidate(); 1845 return dy; 1846 } 1847 1848 private void updateScrollMax() { 1849 int highVisiblePos = (!mReverseFlowPrimary) ? mLastVisiblePos : mFirstVisiblePos; 1850 int highMaxPos = (!mReverseFlowPrimary) ? mState.getItemCount() - 1 : 0; 1851 if (highVisiblePos < 0) { 1852 return; 1853 } 1854 final boolean highAvailable = highVisiblePos == highMaxPos; 1855 final boolean maxUnknown = mWindowAlignment.mainAxis().isMaxUnknown(); 1856 if (!highAvailable && maxUnknown) { 1857 return; 1858 } 1859 int maxEdge = Integer.MIN_VALUE; 1860 int rowIndex = -1; 1861 for (int i = 0; i < mRows.length; i++) { 1862 if (mRows[i].high > maxEdge) { 1863 maxEdge = mRows[i].high; 1864 rowIndex = i; 1865 } 1866 } 1867 int maxScroll = Integer.MAX_VALUE; 1868 for (int i = mFirstVisiblePos; i <= mLastVisiblePos; i++) { 1869 int pos = mReverseFlowPrimary ? i : mLastVisiblePos-i+mFirstVisiblePos; 1870 StaggeredGrid.Location location = mGrid.getLocation(pos); 1871 if (location != null && location.row == rowIndex) { 1872 int savedMaxEdge = mWindowAlignment.mainAxis().getMaxEdge(); 1873 mWindowAlignment.mainAxis().setMaxEdge(maxEdge); 1874 maxScroll = getPrimarySystemScrollPosition(findViewByPosition(pos)); 1875 mWindowAlignment.mainAxis().setMaxEdge(savedMaxEdge); 1876 break; 1877 } 1878 } 1879 if (highAvailable) { 1880 mWindowAlignment.mainAxis().setMaxEdge(maxEdge); 1881 mWindowAlignment.mainAxis().setMaxScroll(maxScroll); 1882 if (DEBUG) Log.v(getTag(), "updating scroll maxEdge to " + maxEdge + 1883 " scrollMax to " + maxScroll); 1884 } else { 1885 // the maxScroll for currently last visible item is larger, 1886 // so we must invalidate the max scroll value. 1887 if (maxScroll > mWindowAlignment.mainAxis().getMaxScroll()) { 1888 mWindowAlignment.mainAxis().invalidateScrollMax(); 1889 if (DEBUG) Log.v(getTag(), "Invalidate scrollMax since it should be " 1890 + "greater than " + maxScroll); 1891 } 1892 } 1893 } 1894 1895 private void updateScrollMin() { 1896 int lowVisiblePos = (!mReverseFlowPrimary) ? mFirstVisiblePos : mLastVisiblePos; 1897 int lowMinPos = (!mReverseFlowPrimary) ? 0 : mState.getItemCount() - 1; 1898 if (lowVisiblePos < 0) { 1899 return; 1900 } 1901 final boolean lowAvailable = lowVisiblePos == lowMinPos; 1902 final boolean minUnknown = mWindowAlignment.mainAxis().isMinUnknown(); 1903 if (!lowAvailable && minUnknown) { 1904 return; 1905 } 1906 int minEdge = Integer.MAX_VALUE; 1907 int rowIndex = -1; 1908 for (int i = 0; i < mRows.length; i++) { 1909 if (mRows[i].low < minEdge) { 1910 minEdge = mRows[i].low; 1911 rowIndex = i; 1912 } 1913 } 1914 int minScroll = Integer.MIN_VALUE; 1915 for (int i = mFirstVisiblePos; i <= mLastVisiblePos; i++) { 1916 int pos = mReverseFlowPrimary ? mLastVisiblePos-i+mFirstVisiblePos : i; 1917 StaggeredGrid.Location location = mGrid.getLocation(pos); 1918 if (location != null && location.row == rowIndex) { 1919 int savedMinEdge = mWindowAlignment.mainAxis().getMinEdge(); 1920 mWindowAlignment.mainAxis().setMinEdge(minEdge); 1921 minScroll = getPrimarySystemScrollPosition(findViewByPosition(pos)); 1922 mWindowAlignment.mainAxis().setMinEdge(savedMinEdge); 1923 break; 1924 } 1925 } 1926 if (lowAvailable) { 1927 mWindowAlignment.mainAxis().setMinEdge(minEdge); 1928 mWindowAlignment.mainAxis().setMinScroll(minScroll); 1929 if (DEBUG) Log.v(getTag(), "updating scroll minEdge to " + minEdge + 1930 " scrollMin to " + minScroll); 1931 } else { 1932 // the minScroll for currently first visible item is smaller, 1933 // so we must invalidate the min scroll value. 1934 if (minScroll < mWindowAlignment.mainAxis().getMinScroll()) { 1935 mWindowAlignment.mainAxis().invalidateScrollMin(); 1936 if (DEBUG) Log.v(getTag(), "Invalidate scrollMin, since it should be " 1937 + "less than " + minScroll); 1938 } 1939 } 1940 } 1941 1942 private void updateScrollSecondAxis() { 1943 mWindowAlignment.secondAxis().setMinEdge(0); 1944 mWindowAlignment.secondAxis().setMaxEdge(getSizeSecondary()); 1945 } 1946 1947 private void initScrollController() { 1948 mWindowAlignment.reset(); 1949 mWindowAlignment.horizontal.setSize(getWidth()); 1950 mWindowAlignment.vertical.setSize(getHeight()); 1951 mWindowAlignment.horizontal.setPadding(getPaddingLeft(), getPaddingRight()); 1952 mWindowAlignment.vertical.setPadding(getPaddingTop(), getPaddingBottom()); 1953 mSizePrimary = mWindowAlignment.mainAxis().getSize(); 1954 mScrollOffsetPrimary = -mWindowAlignment.mainAxis().getPaddingLow(); 1955 mScrollOffsetSecondary = -mWindowAlignment.secondAxis().getPaddingLow(); 1956 1957 if (DEBUG) { 1958 Log.v(getTag(), "initScrollController mSizePrimary " + mSizePrimary 1959 + " mWindowAlignment " + mWindowAlignment 1960 + " mScrollOffsetPrimary " + mScrollOffsetPrimary); 1961 } 1962 } 1963 1964 private void updateScrollController() { 1965 // mScrollOffsetPrimary and mScrollOffsetSecondary includes the padding. 1966 // e.g. when topPadding is 16 for horizontal grid view, the initial 1967 // mScrollOffsetSecondary is -16. fastLayout() put views based on offsets(not padding), 1968 // when padding changes to 20, we also need update mScrollOffsetSecondary to -20 before 1969 // fastLayout() is performed 1970 int paddingPrimaryDiff, paddingSecondaryDiff; 1971 if (mOrientation == HORIZONTAL) { 1972 paddingPrimaryDiff = getPaddingLeft() - mWindowAlignment.horizontal.getPaddingLow(); 1973 paddingSecondaryDiff = getPaddingTop() - mWindowAlignment.vertical.getPaddingLow(); 1974 } else { 1975 paddingPrimaryDiff = getPaddingTop() - mWindowAlignment.vertical.getPaddingLow(); 1976 paddingSecondaryDiff = getPaddingLeft() - mWindowAlignment.horizontal.getPaddingLow(); 1977 } 1978 mScrollOffsetPrimary -= paddingPrimaryDiff; 1979 mScrollOffsetSecondary -= paddingSecondaryDiff; 1980 1981 mWindowAlignment.horizontal.setSize(getWidth()); 1982 mWindowAlignment.vertical.setSize(getHeight()); 1983 mWindowAlignment.horizontal.setPadding(getPaddingLeft(), getPaddingRight()); 1984 mWindowAlignment.vertical.setPadding(getPaddingTop(), getPaddingBottom()); 1985 mSizePrimary = mWindowAlignment.mainAxis().getSize(); 1986 1987 if (DEBUG) { 1988 Log.v(getTag(), "updateScrollController mSizePrimary " + mSizePrimary 1989 + " mWindowAlignment " + mWindowAlignment 1990 + " mScrollOffsetPrimary " + mScrollOffsetPrimary); 1991 } 1992 } 1993 1994 public void setSelection(RecyclerView parent, int position) { 1995 setSelection(parent, position, false); 1996 } 1997 1998 public void setSelectionSmooth(RecyclerView parent, int position) { 1999 setSelection(parent, position, true); 2000 } 2001 2002 public int getSelection() { 2003 return mFocusPosition; 2004 } 2005 2006 public void setSelection(RecyclerView parent, int position, boolean smooth) { 2007 if (mFocusPosition != position && position != NO_POSITION) { 2008 scrollToSelection(parent, position, smooth); 2009 } 2010 } 2011 2012 private void scrollToSelection(RecyclerView parent, int position, boolean smooth) { 2013 View view = findViewByPosition(position); 2014 if (view != null) { 2015 mInSelection = true; 2016 scrollToView(view, smooth); 2017 mInSelection = false; 2018 } else { 2019 mFocusPosition = position; 2020 mFocusPositionOffset = 0; 2021 if (!mLayoutEnabled) { 2022 return; 2023 } 2024 if (smooth) { 2025 if (!hasDoneFirstLayout()) { 2026 Log.w(getTag(), "setSelectionSmooth should " + 2027 "not be called before first layout pass"); 2028 return; 2029 } 2030 LinearSmoothScroller linearSmoothScroller = 2031 new LinearSmoothScroller(parent.getContext()) { 2032 @Override 2033 public PointF computeScrollVectorForPosition(int targetPosition) { 2034 if (getChildCount() == 0) { 2035 return null; 2036 } 2037 final int firstChildPos = getPosition(getChildAt(0)); 2038 // TODO We should be able to deduce direction from bounds of current and target focus, 2039 // rather than making assumptions about positions and directionality 2040 final boolean isStart = mReverseFlowPrimary ? targetPosition > firstChildPos : targetPosition < firstChildPos; 2041 final int direction = isStart ? -1 : 1; 2042 if (mOrientation == HORIZONTAL) { 2043 return new PointF(direction, 0); 2044 } else { 2045 return new PointF(0, direction); 2046 } 2047 } 2048 @Override 2049 protected void onTargetFound(View targetView, 2050 RecyclerView.State state, Action action) { 2051 if (hasFocus()) { 2052 targetView.requestFocus(); 2053 } 2054 dispatchChildSelected(); 2055 if (getScrollPosition(targetView, mTempDeltas)) { 2056 int dx, dy; 2057 if (mOrientation == HORIZONTAL) { 2058 dx = mTempDeltas[0]; 2059 dy = mTempDeltas[1]; 2060 } else { 2061 dx = mTempDeltas[1]; 2062 dy = mTempDeltas[0]; 2063 } 2064 final int distance = (int) Math.sqrt(dx * dx + dy * dy); 2065 final int time = calculateTimeForDeceleration(distance); 2066 action.update(dx, dy, time, mDecelerateInterpolator); 2067 } 2068 } 2069 }; 2070 linearSmoothScroller.setTargetPosition(position); 2071 startSmoothScroll(linearSmoothScroller); 2072 } else { 2073 mForceFullLayout = true; 2074 parent.requestLayout(); 2075 } 2076 } 2077 } 2078 2079 @Override 2080 public void onItemsAdded(RecyclerView recyclerView, int positionStart, int itemCount) { 2081 if (DEBUG) Log.v(getTag(), "onItemsAdded positionStart " 2082 + positionStart + " itemCount " + itemCount); 2083 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE 2084 && getChildAt(mFocusPosition) != null) { 2085 int pos = mFocusPosition + mFocusPositionOffset; 2086 if (positionStart <= pos) { 2087 mFocusPositionOffset += itemCount; 2088 } 2089 } 2090 mChildrenStates.clear(); 2091 } 2092 2093 @Override 2094 public void onItemsChanged(RecyclerView recyclerView) { 2095 if (DEBUG) Log.v(getTag(), "onItemsChanged"); 2096 mFocusPositionOffset = 0; 2097 mChildrenStates.clear(); 2098 } 2099 2100 @Override 2101 public void onItemsRemoved(RecyclerView recyclerView, int positionStart, int itemCount) { 2102 if (DEBUG) Log.v(getTag(), "onItemsRemoved positionStart " 2103 + positionStart + " itemCount " + itemCount); 2104 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE 2105 && getChildAt(mFocusPosition) != null) { 2106 int pos = mFocusPosition + mFocusPositionOffset; 2107 if (positionStart <= pos) { 2108 if (positionStart + itemCount > pos) { 2109 // stop updating offset after the focus item was removed 2110 mFocusPositionOffset = Integer.MIN_VALUE; 2111 } else { 2112 mFocusPositionOffset -= itemCount; 2113 } 2114 } 2115 } 2116 mChildrenStates.clear(); 2117 } 2118 2119 @Override 2120 public void onItemsMoved(RecyclerView recyclerView, int fromPosition, int toPosition, 2121 int itemCount) { 2122 if (DEBUG) Log.v(getTag(), "onItemsMoved fromPosition " 2123 + fromPosition + " toPosition " + toPosition); 2124 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE 2125 && getChildAt(mFocusPosition) != null) { 2126 int pos = mFocusPosition + mFocusPositionOffset; 2127 if (fromPosition <= pos && pos < fromPosition + itemCount) { 2128 // moved items include focused position 2129 mFocusPositionOffset += toPosition - fromPosition; 2130 } else if (fromPosition < pos && toPosition > pos - itemCount) { 2131 // move items before focus position to after focused position 2132 mFocusPositionOffset -= itemCount; 2133 } else if (fromPosition > pos && toPosition < pos) { 2134 // move items after focus position to before focused position 2135 mFocusPositionOffset += itemCount; 2136 } 2137 } 2138 mChildrenStates.clear(); 2139 } 2140 2141 @Override 2142 public void onItemsUpdated(RecyclerView recyclerView, int positionStart, int itemCount) { 2143 if (DEBUG) Log.v(getTag(), "onItemsUpdated positionStart " 2144 + positionStart + " itemCount " + itemCount); 2145 for (int i = positionStart, end = positionStart + itemCount; i < end; i++) { 2146 mChildrenStates.remove(i); 2147 } 2148 } 2149 2150 @Override 2151 public boolean onRequestChildFocus(RecyclerView parent, View child, View focused) { 2152 if (mFocusSearchDisabled) { 2153 return true; 2154 } 2155 if (getPositionByView(child) == NO_POSITION) { 2156 // This shouldn't happen, but in case it does be sure not to attempt a 2157 // scroll to a view whose item has been removed. 2158 return true; 2159 } 2160 if (!mInLayout && !mInSelection) { 2161 scrollToView(child, true); 2162 } 2163 return true; 2164 } 2165 2166 @Override 2167 public boolean requestChildRectangleOnScreen(RecyclerView parent, View view, Rect rect, 2168 boolean immediate) { 2169 if (DEBUG) Log.v(getTag(), "requestChildRectangleOnScreen " + view + " " + rect); 2170 return false; 2171 } 2172 2173 int getScrollOffsetX() { 2174 return mOrientation == HORIZONTAL ? mScrollOffsetPrimary : mScrollOffsetSecondary; 2175 } 2176 2177 int getScrollOffsetY() { 2178 return mOrientation == HORIZONTAL ? mScrollOffsetSecondary : mScrollOffsetPrimary; 2179 } 2180 2181 public void getViewSelectedOffsets(View view, int[] offsets) { 2182 if (mOrientation == HORIZONTAL) { 2183 offsets[0] = getPrimarySystemScrollPosition(view) - mScrollOffsetPrimary; 2184 offsets[1] = getSecondarySystemScrollPosition(view) - mScrollOffsetSecondary; 2185 } else { 2186 offsets[1] = getPrimarySystemScrollPosition(view) - mScrollOffsetPrimary; 2187 offsets[0] = getSecondarySystemScrollPosition(view) - mScrollOffsetSecondary; 2188 } 2189 } 2190 2191 private int getPrimarySystemScrollPosition(View view) { 2192 final int viewCenterPrimary = mScrollOffsetPrimary + getViewCenter(view); 2193 final int viewMin = getViewMin(view); 2194 final int viewMax = getViewMax(view); 2195 // TODO: change to use State object in onRequestChildFocus() 2196 boolean isMin, isMax; 2197 if (!mReverseFlowPrimary) { 2198 isMin = mFirstVisiblePos == 0; 2199 isMax = mLastVisiblePos == (mState == null ? 2200 getItemCount() : mState.getItemCount()) - 1; 2201 } else { 2202 isMax = mFirstVisiblePos == 0; 2203 isMin = mLastVisiblePos == (mState == null ? 2204 getItemCount() : mState.getItemCount()) - 1; 2205 } 2206 for (int i = getChildCount() - 1; (isMin || isMax) && i >= 0; i--) { 2207 View v = getChildAt(i); 2208 if (v == view || v == null) { 2209 continue; 2210 } 2211 if (isMin && getViewMin(v) < viewMin) { 2212 isMin = false; 2213 } 2214 if (isMax && getViewMax(v) > viewMax) { 2215 isMax = false; 2216 } 2217 } 2218 return mWindowAlignment.mainAxis().getSystemScrollPos(viewCenterPrimary, isMin, isMax); 2219 } 2220 2221 private int getSecondarySystemScrollPosition(View view) { 2222 int viewCenterSecondary = mScrollOffsetSecondary + getViewCenterSecondary(view); 2223 int pos = getPositionByView(view); 2224 StaggeredGrid.Location location = mGrid.getLocation(pos); 2225 final int row = location.row; 2226 final boolean isMin, isMax; 2227 if (!mReverseFlowSecondary) { 2228 isMin = row == 0; 2229 isMax = row == mGrid.getNumRows() - 1; 2230 } else { 2231 isMax = row == 0; 2232 isMin = row == mGrid.getNumRows() - 1; 2233 } 2234 return mWindowAlignment.secondAxis().getSystemScrollPos(viewCenterSecondary, isMin, isMax); 2235 } 2236 2237 /** 2238 * Scroll to a given child view and change mFocusPosition. 2239 */ 2240 private void scrollToView(View view, boolean smooth) { 2241 int newFocusPosition = getPositionByView(view); 2242 if (newFocusPosition != mFocusPosition) { 2243 mFocusPosition = newFocusPosition; 2244 mFocusPositionOffset = 0; 2245 if (!mInLayout) { 2246 dispatchChildSelected(); 2247 } 2248 } 2249 if (mBaseGridView.isChildrenDrawingOrderEnabledInternal()) { 2250 mBaseGridView.invalidate(); 2251 } 2252 if (view == null) { 2253 return; 2254 } 2255 if (!view.hasFocus() && mBaseGridView.hasFocus()) { 2256 // transfer focus to the child if it does not have focus yet (e.g. triggered 2257 // by setSelection()) 2258 view.requestFocus(); 2259 } 2260 if (!mScrollEnabled) { 2261 return; 2262 } 2263 if (getScrollPosition(view, mTempDeltas)) { 2264 scrollGrid(mTempDeltas[0], mTempDeltas[1], smooth); 2265 } 2266 } 2267 2268 private boolean getScrollPosition(View view, int[] deltas) { 2269 switch (mFocusScrollStrategy) { 2270 case BaseGridView.FOCUS_SCROLL_ALIGNED: 2271 default: 2272 return getAlignedPosition(view, deltas); 2273 case BaseGridView.FOCUS_SCROLL_ITEM: 2274 case BaseGridView.FOCUS_SCROLL_PAGE: 2275 return getNoneAlignedPosition(view, deltas); 2276 } 2277 } 2278 2279 private boolean getNoneAlignedPosition(View view, int[] deltas) { 2280 int pos = getPositionByView(view); 2281 int viewMin = getViewMin(view); 2282 int viewMax = getViewMax(view); 2283 // we either align "firstView" to left/top padding edge 2284 // or align "lastView" to right/bottom padding edge 2285 View firstView = null; 2286 View lastView = null; 2287 int paddingLow = mWindowAlignment.mainAxis().getPaddingLow(); 2288 int clientSize = mWindowAlignment.mainAxis().getClientSize(); 2289 final int row = mGrid.getLocation(pos).row; 2290 if (viewMin < paddingLow) { 2291 // view enters low padding area: 2292 firstView = view; 2293 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_PAGE) { 2294 // scroll one "page" left/top, 2295 // align first visible item of the "page" at the low padding edge. 2296 while (!prependOneVisibleItem()) { 2297 List<Integer> positions = 2298 mGrid.getItemPositionsInRows(mFirstVisiblePos, pos)[row]; 2299 firstView = findViewByPosition(positions.get(0)); 2300 if (viewMax - getViewMin(firstView) > clientSize) { 2301 if (positions.size() > 1) { 2302 firstView = findViewByPosition(positions.get(1)); 2303 } 2304 break; 2305 } 2306 } 2307 } 2308 } else if (viewMax > clientSize + paddingLow) { 2309 // view enters high padding area: 2310 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_PAGE) { 2311 // scroll whole one page right/bottom, align view at the low padding edge. 2312 firstView = view; 2313 do { 2314 List<Integer> positions = 2315 mGrid.getItemPositionsInRows(pos, mLastVisiblePos)[row]; 2316 lastView = findViewByPosition(positions.get(positions.size() - 1)); 2317 if (getViewMax(lastView) - viewMin > clientSize) { 2318 lastView = null; 2319 break; 2320 } 2321 } while (!appendOneVisibleItem()); 2322 if (lastView != null) { 2323 // however if we reached end, we should align last view. 2324 firstView = null; 2325 } 2326 } else { 2327 lastView = view; 2328 } 2329 } 2330 int scrollPrimary = 0; 2331 int scrollSecondary = 0; 2332 if (firstView != null) { 2333 scrollPrimary = getViewMin(firstView) - paddingLow; 2334 } else if (lastView != null) { 2335 scrollPrimary = getViewMax(lastView) - (paddingLow + clientSize); 2336 } 2337 View secondaryAlignedView; 2338 if (firstView != null) { 2339 secondaryAlignedView = firstView; 2340 } else if (lastView != null) { 2341 secondaryAlignedView = lastView; 2342 } else { 2343 secondaryAlignedView = view; 2344 } 2345 scrollSecondary = getSecondarySystemScrollPosition(secondaryAlignedView); 2346 scrollSecondary -= mScrollOffsetSecondary; 2347 if (scrollPrimary != 0 || scrollSecondary != 0) { 2348 deltas[0] = scrollPrimary; 2349 deltas[1] = scrollSecondary; 2350 return true; 2351 } 2352 return false; 2353 } 2354 2355 private boolean getAlignedPosition(View view, int[] deltas) { 2356 int scrollPrimary = getPrimarySystemScrollPosition(view); 2357 int scrollSecondary = getSecondarySystemScrollPosition(view); 2358 if (DEBUG) { 2359 Log.v(getTag(), "getAlignedPosition " + scrollPrimary + " " + scrollSecondary 2360 + " " + mWindowAlignment); 2361 Log.v(getTag(), "getAlignedPosition " + mScrollOffsetPrimary + " " + mScrollOffsetSecondary); 2362 } 2363 scrollPrimary -= mScrollOffsetPrimary; 2364 scrollSecondary -= mScrollOffsetSecondary; 2365 if (scrollPrimary != 0 || scrollSecondary != 0) { 2366 deltas[0] = scrollPrimary; 2367 deltas[1] = scrollSecondary; 2368 return true; 2369 } 2370 return false; 2371 } 2372 2373 private void scrollGrid(int scrollPrimary, int scrollSecondary, boolean smooth) { 2374 if (mInLayout) { 2375 scrollDirectionPrimary(scrollPrimary); 2376 scrollDirectionSecondary(scrollSecondary); 2377 } else { 2378 int scrollX; 2379 int scrollY; 2380 if (mOrientation == HORIZONTAL) { 2381 scrollX = scrollPrimary; 2382 scrollY = scrollSecondary; 2383 } else { 2384 scrollX = scrollSecondary; 2385 scrollY = scrollPrimary; 2386 } 2387 if (smooth) { 2388 mBaseGridView.smoothScrollBy(scrollX, scrollY); 2389 } else { 2390 mBaseGridView.scrollBy(scrollX, scrollY); 2391 } 2392 } 2393 } 2394 2395 public void setPruneChild(boolean pruneChild) { 2396 if (mPruneChild != pruneChild) { 2397 mPruneChild = pruneChild; 2398 if (mPruneChild) { 2399 requestLayout(); 2400 } 2401 } 2402 } 2403 2404 public boolean getPruneChild() { 2405 return mPruneChild; 2406 } 2407 2408 public void setScrollEnabled(boolean scrollEnabled) { 2409 if (mScrollEnabled != scrollEnabled) { 2410 mScrollEnabled = scrollEnabled; 2411 if (mScrollEnabled && mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED 2412 && mFocusPosition != NO_POSITION) { 2413 scrollToSelection(mBaseGridView, mFocusPosition, true); 2414 } 2415 } 2416 } 2417 2418 public boolean isScrollEnabled() { 2419 return mScrollEnabled; 2420 } 2421 2422 private int findImmediateChildIndex(View view) { 2423 while (view != null && view != mBaseGridView) { 2424 int index = mBaseGridView.indexOfChild(view); 2425 if (index >= 0) { 2426 return index; 2427 } 2428 view = (View) view.getParent(); 2429 } 2430 return NO_POSITION; 2431 } 2432 2433 void setFocusSearchDisabled(boolean disabled) { 2434 mFocusSearchDisabled = disabled; 2435 } 2436 2437 boolean isFocusSearchDisabled() { 2438 return mFocusSearchDisabled; 2439 } 2440 2441 @Override 2442 public View onInterceptFocusSearch(View focused, int direction) { 2443 if (mFocusSearchDisabled) { 2444 return focused; 2445 } 2446 return null; 2447 } 2448 2449 boolean hasPreviousViewInSameRow(int pos) { 2450 if (mGrid == null || pos == NO_POSITION) { 2451 return false; 2452 } 2453 if (mFirstVisiblePos > 0) { 2454 return true; 2455 } 2456 final int focusedRow = mGrid.getLocation(pos).row; 2457 for (int i = getChildCount() - 1; i >= 0; i--) { 2458 int position = getPositionByIndex(i); 2459 StaggeredGrid.Location loc = mGrid.getLocation(position); 2460 if (loc != null && loc.row == focusedRow) { 2461 if (position < pos) { 2462 return true; 2463 } 2464 } 2465 } 2466 return false; 2467 } 2468 2469 @Override 2470 public boolean onAddFocusables(RecyclerView recyclerView, 2471 ArrayList<View> views, int direction, int focusableMode) { 2472 if (mFocusSearchDisabled) { 2473 return true; 2474 } 2475 // If this viewgroup or one of its children currently has focus then we 2476 // consider our children for focus searching in main direction on the same row. 2477 // If this viewgroup has no focus and using focus align, we want the system 2478 // to ignore our children and pass focus to the viewgroup, which will pass 2479 // focus on to its children appropriately. 2480 // If this viewgroup has no focus and not using focus align, we want to 2481 // consider the child that does not overlap with padding area. 2482 if (recyclerView.hasFocus()) { 2483 final int movement = getMovement(direction); 2484 if (movement != PREV_ITEM && movement != NEXT_ITEM) { 2485 // Move on secondary direction uses default addFocusables(). 2486 return false; 2487 } 2488 final View focused = recyclerView.findFocus(); 2489 final int focusedPos = getPositionByIndex(findImmediateChildIndex(focused)); 2490 // Add focusables of focused item. 2491 if (focusedPos != NO_POSITION) { 2492 findViewByPosition(focusedPos).addFocusables(views, direction, focusableMode); 2493 } 2494 final int focusedRow = mGrid != null && focusedPos != NO_POSITION ? 2495 mGrid.getLocation(focusedPos).row : NO_POSITION; 2496 // Add focusables of next neighbor of same row on the focus search direction. 2497 if (mGrid != null) { 2498 final int focusableCount = views.size(); 2499 for (int i = 0, count = getChildCount(); i < count; i++) { 2500 int index = movement == NEXT_ITEM ? i : count - 1 - i; 2501 final View child = getChildAt(index); 2502 if (child.getVisibility() != View.VISIBLE) { 2503 continue; 2504 } 2505 int position = getPositionByIndex(index); 2506 StaggeredGrid.Location loc = mGrid.getLocation(position); 2507 if (focusedRow == NO_POSITION || (loc != null && loc.row == focusedRow)) { 2508 if (focusedPos == NO_POSITION || 2509 (movement == NEXT_ITEM && position > focusedPos) 2510 || (movement == PREV_ITEM && position < focusedPos)) { 2511 child.addFocusables(views, direction, focusableMode); 2512 if (views.size() > focusableCount) { 2513 break; 2514 } 2515 } 2516 } 2517 } 2518 } 2519 } else { 2520 if (mFocusScrollStrategy != BaseGridView.FOCUS_SCROLL_ALIGNED) { 2521 // adding views not overlapping padding area to avoid scrolling in gaining focus 2522 int left = mWindowAlignment.mainAxis().getPaddingLow(); 2523 int right = mWindowAlignment.mainAxis().getClientSize() + left; 2524 int focusableCount = views.size(); 2525 for (int i = 0, count = getChildCount(); i < count; i++) { 2526 View child = getChildAt(i); 2527 if (child.getVisibility() == View.VISIBLE) { 2528 if (getViewMin(child) >= left && getViewMax(child) <= right) { 2529 child.addFocusables(views, direction, focusableMode); 2530 } 2531 } 2532 } 2533 // if we cannot find any, then just add all children. 2534 if (views.size() == focusableCount) { 2535 for (int i = 0, count = getChildCount(); i < count; i++) { 2536 View child = getChildAt(i); 2537 if (child.getVisibility() == View.VISIBLE) { 2538 child.addFocusables(views, direction, focusableMode); 2539 } 2540 } 2541 if (views.size() != focusableCount) { 2542 return true; 2543 } 2544 } else { 2545 return true; 2546 } 2547 // if still cannot find any, fall through and add itself 2548 } 2549 if (recyclerView.isFocusable()) { 2550 views.add(recyclerView); 2551 } 2552 } 2553 return true; 2554 } 2555 2556 @Override 2557 public View onFocusSearchFailed(View focused, int direction, Recycler recycler, 2558 RecyclerView.State state) { 2559 if (DEBUG) Log.v(getTag(), "onFocusSearchFailed direction " + direction); 2560 2561 View view = null; 2562 int movement = getMovement(direction); 2563 final boolean isScroll = mBaseGridView.getScrollState() != RecyclerView.SCROLL_STATE_IDLE; 2564 if (mNumRows == 1) { 2565 // for simple row, use LinearSmoothScroller to smooth animation. 2566 // It will stay at a fixed cap speed in continuous scroll. 2567 if (movement == NEXT_ITEM) { 2568 int newPos = mFocusPosition + mNumRows; 2569 if (newPos < getItemCount() && mScrollEnabled) { 2570 setSelectionSmooth(mBaseGridView, newPos); 2571 view = focused; 2572 } else { 2573 if (isScroll || !mFocusOutEnd) { 2574 view = focused; 2575 } 2576 } 2577 } else if (movement == PREV_ITEM){ 2578 int newPos = mFocusPosition - mNumRows; 2579 if (newPos >= 0 && mScrollEnabled) { 2580 setSelectionSmooth(mBaseGridView, newPos); 2581 view = focused; 2582 } else { 2583 if (isScroll || !mFocusOutFront) { 2584 view = focused; 2585 } 2586 } 2587 } 2588 } else if (mNumRows > 1) { 2589 // for possible staggered grid, we need guarantee focus to same row/column. 2590 // TODO: we may also use LinearSmoothScroller. 2591 saveContext(recycler, state); 2592 final FocusFinder ff = FocusFinder.getInstance(); 2593 if (movement == NEXT_ITEM) { 2594 while (view == null && !appendOneVisibleItem()) { 2595 view = ff.findNextFocus(mBaseGridView, focused, direction); 2596 } 2597 } else if (movement == PREV_ITEM){ 2598 while (view == null && !prependOneVisibleItem()) { 2599 view = ff.findNextFocus(mBaseGridView, focused, direction); 2600 } 2601 } 2602 if (view == null) { 2603 // returning the same view to prevent focus lost when scrolling past the end of the list 2604 if (movement == PREV_ITEM) { 2605 view = mFocusOutFront && !isScroll ? null : focused; 2606 } else if (movement == NEXT_ITEM){ 2607 view = mFocusOutEnd && !isScroll ? null : focused; 2608 } 2609 } 2610 leaveContext(); 2611 } 2612 if (DEBUG) Log.v(getTag(), "returning view " + view); 2613 return view; 2614 } 2615 2616 boolean gridOnRequestFocusInDescendants(RecyclerView recyclerView, int direction, 2617 Rect previouslyFocusedRect) { 2618 switch (mFocusScrollStrategy) { 2619 case BaseGridView.FOCUS_SCROLL_ALIGNED: 2620 default: 2621 return gridOnRequestFocusInDescendantsAligned(recyclerView, 2622 direction, previouslyFocusedRect); 2623 case BaseGridView.FOCUS_SCROLL_PAGE: 2624 case BaseGridView.FOCUS_SCROLL_ITEM: 2625 return gridOnRequestFocusInDescendantsUnaligned(recyclerView, 2626 direction, previouslyFocusedRect); 2627 } 2628 } 2629 2630 private boolean gridOnRequestFocusInDescendantsAligned(RecyclerView recyclerView, 2631 int direction, Rect previouslyFocusedRect) { 2632 View view = findViewByPosition(mFocusPosition); 2633 if (view != null) { 2634 boolean result = view.requestFocus(direction, previouslyFocusedRect); 2635 if (!result && DEBUG) { 2636 Log.w(getTag(), "failed to request focus on " + view); 2637 } 2638 return result; 2639 } 2640 return false; 2641 } 2642 2643 private boolean gridOnRequestFocusInDescendantsUnaligned(RecyclerView recyclerView, 2644 int direction, Rect previouslyFocusedRect) { 2645 // focus to view not overlapping padding area to avoid scrolling in gaining focus 2646 int index; 2647 int increment; 2648 int end; 2649 int count = getChildCount(); 2650 if ((direction & View.FOCUS_FORWARD) != 0) { 2651 index = 0; 2652 increment = 1; 2653 end = count; 2654 } else { 2655 index = count - 1; 2656 increment = -1; 2657 end = -1; 2658 } 2659 int left = mWindowAlignment.mainAxis().getPaddingLow(); 2660 int right = mWindowAlignment.mainAxis().getClientSize() + left; 2661 for (int i = index; i != end; i += increment) { 2662 View child = getChildAt(i); 2663 if (child.getVisibility() == View.VISIBLE) { 2664 if (getViewMin(child) >= left && getViewMax(child) <= right) { 2665 if (child.requestFocus(direction, previouslyFocusedRect)) { 2666 return true; 2667 } 2668 } 2669 } 2670 } 2671 return false; 2672 } 2673 2674 private final static int PREV_ITEM = 0; 2675 private final static int NEXT_ITEM = 1; 2676 private final static int PREV_ROW = 2; 2677 private final static int NEXT_ROW = 3; 2678 2679 private int getMovement(int direction) { 2680 int movement = View.FOCUS_LEFT; 2681 2682 if (mOrientation == HORIZONTAL) { 2683 switch(direction) { 2684 case View.FOCUS_LEFT: 2685 movement = (!mReverseFlowPrimary) ? PREV_ITEM : NEXT_ITEM; 2686 break; 2687 case View.FOCUS_RIGHT: 2688 movement = (!mReverseFlowPrimary) ? NEXT_ITEM : PREV_ITEM; 2689 break; 2690 case View.FOCUS_UP: 2691 movement = PREV_ROW; 2692 break; 2693 case View.FOCUS_DOWN: 2694 movement = NEXT_ROW; 2695 break; 2696 } 2697 } else if (mOrientation == VERTICAL) { 2698 switch(direction) { 2699 case View.FOCUS_LEFT: 2700 movement = (!mReverseFlowPrimary) ? PREV_ROW : NEXT_ROW; 2701 break; 2702 case View.FOCUS_RIGHT: 2703 movement = (!mReverseFlowPrimary) ? NEXT_ROW : PREV_ROW; 2704 break; 2705 case View.FOCUS_UP: 2706 movement = PREV_ITEM; 2707 break; 2708 case View.FOCUS_DOWN: 2709 movement = NEXT_ITEM; 2710 break; 2711 } 2712 } 2713 2714 return movement; 2715 } 2716 2717 int getChildDrawingOrder(RecyclerView recyclerView, int childCount, int i) { 2718 View view = findViewByPosition(mFocusPosition); 2719 if (view == null) { 2720 return i; 2721 } 2722 int focusIndex = recyclerView.indexOfChild(view); 2723 // supposely 0 1 2 3 4 5 6 7 8 9, 4 is the center item 2724 // drawing order is 0 1 2 3 9 8 7 6 5 4 2725 if (i < focusIndex) { 2726 return i; 2727 } else if (i < childCount - 1) { 2728 return focusIndex + childCount - 1 - i; 2729 } else { 2730 return focusIndex; 2731 } 2732 } 2733 2734 @Override 2735 public void onAdapterChanged(RecyclerView.Adapter oldAdapter, 2736 RecyclerView.Adapter newAdapter) { 2737 if (DEBUG) Log.v(getTag(), "onAdapterChanged to " + newAdapter); 2738 if (oldAdapter != null) { 2739 discardLayoutInfo(); 2740 mFocusPosition = NO_POSITION; 2741 mFocusPositionOffset = 0; 2742 mChildrenStates.clear(); 2743 } 2744 super.onAdapterChanged(oldAdapter, newAdapter); 2745 } 2746 2747 private void discardLayoutInfo() { 2748 mGrid = null; 2749 mRows = null; 2750 mRowSizeSecondary = null; 2751 mFirstVisiblePos = -1; 2752 mLastVisiblePos = -1; 2753 mRowSecondarySizeRefresh = false; 2754 } 2755 2756 public void setLayoutEnabled(boolean layoutEnabled) { 2757 if (mLayoutEnabled != layoutEnabled) { 2758 mLayoutEnabled = layoutEnabled; 2759 requestLayout(); 2760 } 2761 } 2762 2763 void setChildrenVisibility(int visiblity) { 2764 mChildVisibility = visiblity; 2765 if (mChildVisibility != -1) { 2766 int count = getChildCount(); 2767 for (int i= 0; i < count; i++) { 2768 getChildAt(i).setVisibility(mChildVisibility); 2769 } 2770 } 2771 } 2772 2773 final static class SavedState implements Parcelable { 2774 2775 int index; // index inside adapter of the current view 2776 Bundle childStates = Bundle.EMPTY; 2777 2778 @Override 2779 public void writeToParcel(Parcel out, int flags) { 2780 out.writeInt(index); 2781 out.writeBundle(childStates); 2782 } 2783 2784 @SuppressWarnings("hiding") 2785 public static final Parcelable.Creator<SavedState> CREATOR = 2786 new Parcelable.Creator<SavedState>() { 2787 @Override 2788 public SavedState createFromParcel(Parcel in) { 2789 return new SavedState(in); 2790 } 2791 2792 @Override 2793 public SavedState[] newArray(int size) { 2794 return new SavedState[size]; 2795 } 2796 }; 2797 2798 @Override 2799 public int describeContents() { 2800 return 0; 2801 } 2802 2803 SavedState(Parcel in) { 2804 index = in.readInt(); 2805 childStates = in.readBundle(GridLayoutManager.class.getClassLoader()); 2806 } 2807 2808 SavedState() { 2809 } 2810 } 2811 2812 @Override 2813 public Parcelable onSaveInstanceState() { 2814 if (DEBUG) Log.v(getTag(), "onSaveInstanceState getSelection() " + getSelection()); 2815 SavedState ss = new SavedState(); 2816 for (int i = 0, count = getChildCount(); i < count; i++) { 2817 View view = getChildAt(i); 2818 int position = getPositionByView(view); 2819 if (position != NO_POSITION) { 2820 mChildrenStates.saveOnScreenView(view, position); 2821 } 2822 } 2823 ss.index = getSelection(); 2824 ss.childStates = mChildrenStates.saveAsBundle(); 2825 return ss; 2826 } 2827 2828 @Override 2829 public void onRestoreInstanceState(Parcelable state) { 2830 if (!(state instanceof SavedState)) { 2831 return; 2832 } 2833 SavedState loadingState = (SavedState)state; 2834 mFocusPosition = loadingState.index; 2835 mFocusPositionOffset = 0; 2836 mChildrenStates.loadFromBundle(loadingState.childStates); 2837 mForceFullLayout = true; 2838 requestLayout(); 2839 if (DEBUG) Log.v(getTag(), "onRestoreInstanceState mFocusPosition " + mFocusPosition); 2840 } 2841} 2842