GridLayoutManager.java revision dda08cebca092380021dc6277bb32c0e4da16fec
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; 27import android.support.v17.leanback.os.TraceHelper; 28 29import static android.support.v7.widget.RecyclerView.NO_ID; 30import static android.support.v7.widget.RecyclerView.NO_POSITION; 31import static android.support.v7.widget.RecyclerView.HORIZONTAL; 32import static android.support.v7.widget.RecyclerView.VERTICAL; 33 34import android.util.AttributeSet; 35import android.util.Log; 36import android.view.FocusFinder; 37import android.view.Gravity; 38import android.view.View; 39import android.view.ViewParent; 40import android.view.View.MeasureSpec; 41import android.view.ViewGroup.MarginLayoutParams; 42import android.view.ViewGroup; 43 44import java.io.PrintWriter; 45import java.io.StringWriter; 46import java.util.ArrayList; 47import java.util.List; 48 49final class GridLayoutManager extends RecyclerView.LayoutManager { 50 51 /* 52 * LayoutParams for {@link HorizontalGridView} and {@link VerticalGridView}. 53 * The class currently does two internal jobs: 54 * - Saves optical bounds insets. 55 * - Caches focus align view center. 56 */ 57 static class LayoutParams extends RecyclerView.LayoutParams { 58 59 // The view is saved only during animation. 60 private View mView; 61 62 // For placement 63 private int mLeftInset; 64 private int mTopInset; 65 private int mRightInset; 66 private int mBottomInset; 67 68 // For alignment 69 private int mAlignX; 70 private int mAlignY; 71 72 public LayoutParams(Context c, AttributeSet attrs) { 73 super(c, attrs); 74 } 75 76 public LayoutParams(int width, int height) { 77 super(width, height); 78 } 79 80 public LayoutParams(MarginLayoutParams source) { 81 super(source); 82 } 83 84 public LayoutParams(ViewGroup.LayoutParams source) { 85 super(source); 86 } 87 88 public LayoutParams(RecyclerView.LayoutParams source) { 89 super(source); 90 } 91 92 public LayoutParams(LayoutParams source) { 93 super(source); 94 } 95 96 int getAlignX() { 97 return mAlignX; 98 } 99 100 int getAlignY() { 101 return mAlignY; 102 } 103 104 int getOpticalLeft(View view) { 105 return view.getLeft() + mLeftInset; 106 } 107 108 int getOpticalTop(View view) { 109 return view.getTop() + mTopInset; 110 } 111 112 int getOpticalRight(View view) { 113 return view.getRight() - mRightInset; 114 } 115 116 int getOpticalBottom(View view) { 117 return view.getBottom() - mBottomInset; 118 } 119 120 int getOpticalWidth(View view) { 121 return view.getWidth() - mLeftInset - mRightInset; 122 } 123 124 int getOpticalHeight(View view) { 125 return view.getHeight() - mTopInset - mBottomInset; 126 } 127 128 int getOpticalLeftInset() { 129 return mLeftInset; 130 } 131 132 int getOpticalRightInset() { 133 return mRightInset; 134 } 135 136 int getOpticalTopInset() { 137 return mTopInset; 138 } 139 140 int getOpticalBottomInset() { 141 return mBottomInset; 142 } 143 144 void setAlignX(int alignX) { 145 mAlignX = alignX; 146 } 147 148 void setAlignY(int alignY) { 149 mAlignY = alignY; 150 } 151 152 void setOpticalInsets(int leftInset, int topInset, int rightInset, int bottomInset) { 153 mLeftInset = leftInset; 154 mTopInset = topInset; 155 mRightInset = rightInset; 156 mBottomInset = bottomInset; 157 } 158 159 private void invalidateItemDecoration() { 160 ViewParent parent = mView.getParent(); 161 if (parent instanceof RecyclerView) { 162 // TODO: we only need invalidate parent if it has ItemDecoration 163 ((RecyclerView) parent).invalidate(); 164 } 165 } 166 } 167 168 private static final String TAG = "GridLayoutManager"; 169 private static final boolean DEBUG = false; 170 private static final boolean TRACE = false; 171 172 private String getTag() { 173 return TAG + ":" + mBaseGridView.getId(); 174 } 175 176 private final BaseGridView mBaseGridView; 177 178 /** 179 * Note on conventions in the presence of RTL layout directions: 180 * Many properties and method names reference entities related to the 181 * beginnings and ends of things. In the presence of RTL flows, 182 * it may not be clear whether this is intended to reference a 183 * quantity that changes direction in RTL cases, or a quantity that 184 * does not. Here are the conventions in use: 185 * 186 * start/end: coordinate quantities - do reverse 187 * (optical) left/right: coordinate quantities - do not reverse 188 * low/high: coordinate quantities - do not reverse 189 * min/max: coordinate quantities - do not reverse 190 * scroll offset - coordinate quantities - do not reverse 191 * first/last: positional indices - do not reverse 192 * front/end: positional indices - do not reverse 193 * prepend/append: related to positional indices - do not reverse 194 * 195 * Note that although quantities do not reverse in RTL flows, their 196 * relationship does. In LTR flows, the first positional index is 197 * leftmost; in RTL flows, it is rightmost. Thus, anywhere that 198 * positional quantities are mapped onto coordinate quantities, 199 * the flow must be checked and the logic reversed. 200 */ 201 202 /** 203 * The orientation of a "row". 204 */ 205 private int mOrientation = HORIZONTAL; 206 207 private RecyclerView.State mState; 208 private RecyclerView.Recycler mRecycler; 209 210 private boolean mInLayout = false; 211 private boolean mInSelection = false; 212 213 private OnChildSelectedListener mChildSelectedListener = null; 214 215 /** 216 * The focused position, it's not the currently visually aligned position 217 * but it is the final position that we intend to focus on. If there are 218 * multiple setSelection() called, mFocusPosition saves last value. 219 */ 220 private int mFocusPosition = NO_POSITION; 221 222 /** 223 * The offset to be applied to mFocusPosition, due to adapter change, on the next 224 * layout. Set to Integer.MIN_VALUE means item was removed. 225 * TODO: This is somewhat duplication of RecyclerView getOldPosition() which is 226 * unfortunately cleared after prelayout. 227 */ 228 private int mFocusPositionOffset = 0; 229 230 /** 231 * Force a full layout under certain situations. 232 */ 233 private boolean mForceFullLayout; 234 235 /** 236 * True if layout is enabled. 237 */ 238 private boolean mLayoutEnabled = true; 239 240 /** 241 * override child visibility 242 */ 243 private int mChildVisibility = -1; 244 245 /** 246 * The scroll offsets of the viewport relative to the entire view. 247 */ 248 private int mScrollOffsetPrimary; 249 private int mScrollOffsetSecondary; 250 251 /** 252 * User-specified row height/column width. Can be WRAP_CONTENT. 253 */ 254 private int mRowSizeSecondaryRequested; 255 256 /** 257 * The fixed size of each grid item in the secondary direction. This corresponds to 258 * the row height, equal for all rows. Grid items may have variable length 259 * in the primary direction. 260 */ 261 private int mFixedRowSizeSecondary; 262 263 /** 264 * Tracks the secondary size of each row. 265 */ 266 private int[] mRowSizeSecondary; 267 268 /** 269 * Flag controlling whether the current/next layout should 270 * be updating the secondary size of rows. 271 */ 272 private boolean mRowSecondarySizeRefresh; 273 274 /** 275 * The maximum measured size of the view. 276 */ 277 private int mMaxSizeSecondary; 278 279 /** 280 * Margin between items. 281 */ 282 private int mHorizontalMargin; 283 /** 284 * Margin between items vertically. 285 */ 286 private int mVerticalMargin; 287 /** 288 * Margin in main direction. 289 */ 290 private int mMarginPrimary; 291 /** 292 * Margin in second direction. 293 */ 294 private int mMarginSecondary; 295 /** 296 * How to position child in secondary direction. 297 */ 298 private int mGravity = Gravity.START | Gravity.TOP; 299 /** 300 * The number of rows in the grid. 301 */ 302 private int mNumRows; 303 /** 304 * Number of rows requested, can be 0 to be determined by parent size and 305 * rowHeight. 306 */ 307 private int mNumRowsRequested = 1; 308 309 /** 310 * Tracking start/end position of each row for visible items. 311 */ 312 private StaggeredGrid.Row[] mRows; 313 314 /** 315 * Saves grid information of each view. 316 */ 317 private StaggeredGrid mGrid; 318 /** 319 * Position of first item (included) that has attached views. 320 */ 321 private int mFirstVisiblePos; 322 /** 323 * Position of last item (included) that has attached views. 324 */ 325 private int mLastVisiblePos; 326 327 /** 328 * Focus Scroll strategy. 329 */ 330 private int mFocusScrollStrategy = BaseGridView.FOCUS_SCROLL_ALIGNED; 331 /** 332 * Defines how item view is aligned in the window. 333 */ 334 private final WindowAlignment mWindowAlignment = new WindowAlignment(); 335 336 /** 337 * Defines how item view is aligned. 338 */ 339 private final ItemAlignment mItemAlignment = new ItemAlignment(); 340 341 /** 342 * Dimensions of the view, width or height depending on orientation. 343 */ 344 private int mSizePrimary; 345 346 /** 347 * Allow DPAD key to navigate out at the front of the View (where position = 0), 348 * default is false. 349 */ 350 private boolean mFocusOutFront; 351 352 /** 353 * Allow DPAD key to navigate out at the end of the view, default is false. 354 */ 355 private boolean mFocusOutEnd; 356 357 /** 358 * True if focus search is disabled. 359 */ 360 private boolean mFocusSearchDisabled; 361 362 /** 363 * True if prune child, might be disabled during transition. 364 */ 365 private boolean mPruneChild = true; 366 367 /** 368 * True if scroll content, might be disabled during transition. 369 */ 370 private boolean mScrollEnabled = true; 371 372 private int[] mTempDeltas = new int[2]; 373 374 /** 375 * Set to true for RTL layout in horizontal orientation 376 */ 377 private boolean mReverseFlowPrimary = false; 378 379 /** 380 * Set to true for RTL layout in vertical orientation 381 */ 382 private boolean mReverseFlowSecondary = false; 383 384 /** 385 * Temporaries used for measuring. 386 */ 387 private int[] mMeasuredDimension = new int[2]; 388 389 final ViewsStateBundle mChildrenStates = new ViewsStateBundle(); 390 391 public GridLayoutManager(BaseGridView baseGridView) { 392 mBaseGridView = baseGridView; 393 } 394 395 public void setOrientation(int orientation) { 396 if (orientation != HORIZONTAL && orientation != VERTICAL) { 397 if (DEBUG) Log.v(getTag(), "invalid orientation: " + orientation); 398 return; 399 } 400 401 mOrientation = orientation; 402 mWindowAlignment.setOrientation(orientation); 403 mItemAlignment.setOrientation(orientation); 404 mForceFullLayout = true; 405 } 406 407 public void onRtlPropertiesChanged(int layoutDirection) { 408 if (mOrientation == HORIZONTAL) { 409 mReverseFlowPrimary = layoutDirection == View.LAYOUT_DIRECTION_RTL; 410 mReverseFlowSecondary = false; 411 } else { 412 mReverseFlowSecondary = layoutDirection == View.LAYOUT_DIRECTION_RTL; 413 mReverseFlowPrimary = false; 414 } 415 mWindowAlignment.horizontal.setReversedFlow(layoutDirection == View.LAYOUT_DIRECTION_RTL); 416 } 417 418 public int getFocusScrollStrategy() { 419 return mFocusScrollStrategy; 420 } 421 422 public void setFocusScrollStrategy(int focusScrollStrategy) { 423 mFocusScrollStrategy = focusScrollStrategy; 424 } 425 426 public void setWindowAlignment(int windowAlignment) { 427 mWindowAlignment.mainAxis().setWindowAlignment(windowAlignment); 428 } 429 430 public int getWindowAlignment() { 431 return mWindowAlignment.mainAxis().getWindowAlignment(); 432 } 433 434 public void setWindowAlignmentOffset(int alignmentOffset) { 435 mWindowAlignment.mainAxis().setWindowAlignmentOffset(alignmentOffset); 436 } 437 438 public int getWindowAlignmentOffset() { 439 return mWindowAlignment.mainAxis().getWindowAlignmentOffset(); 440 } 441 442 public void setWindowAlignmentOffsetPercent(float offsetPercent) { 443 mWindowAlignment.mainAxis().setWindowAlignmentOffsetPercent(offsetPercent); 444 } 445 446 public float getWindowAlignmentOffsetPercent() { 447 return mWindowAlignment.mainAxis().getWindowAlignmentOffsetPercent(); 448 } 449 450 public void setItemAlignmentOffset(int alignmentOffset) { 451 mItemAlignment.mainAxis().setItemAlignmentOffset(alignmentOffset); 452 updateChildAlignments(); 453 } 454 455 public int getItemAlignmentOffset() { 456 return mItemAlignment.mainAxis().getItemAlignmentOffset(); 457 } 458 459 public void setItemAlignmentOffsetWithPadding(boolean withPadding) { 460 mItemAlignment.mainAxis().setItemAlignmentOffsetWithPadding(withPadding); 461 updateChildAlignments(); 462 } 463 464 public boolean isItemAlignmentOffsetWithPadding() { 465 return mItemAlignment.mainAxis().isItemAlignmentOffsetWithPadding(); 466 } 467 468 public void setItemAlignmentOffsetPercent(float offsetPercent) { 469 mItemAlignment.mainAxis().setItemAlignmentOffsetPercent(offsetPercent); 470 updateChildAlignments(); 471 } 472 473 public float getItemAlignmentOffsetPercent() { 474 return mItemAlignment.mainAxis().getItemAlignmentOffsetPercent(); 475 } 476 477 public void setItemAlignmentViewId(int viewId) { 478 mItemAlignment.mainAxis().setItemAlignmentViewId(viewId); 479 updateChildAlignments(); 480 } 481 482 public int getItemAlignmentViewId() { 483 return mItemAlignment.mainAxis().getItemAlignmentViewId(); 484 } 485 486 public void setFocusOutAllowed(boolean throughFront, boolean throughEnd) { 487 mFocusOutFront = throughFront; 488 mFocusOutEnd = throughEnd; 489 } 490 491 public void setNumRows(int numRows) { 492 if (numRows < 0) throw new IllegalArgumentException(); 493 mNumRowsRequested = numRows; 494 mForceFullLayout = true; 495 } 496 497 /** 498 * Set the row height. May be WRAP_CONTENT, or a size in pixels. 499 */ 500 public void setRowHeight(int height) { 501 if (height >= 0 || height == ViewGroup.LayoutParams.WRAP_CONTENT) { 502 mRowSizeSecondaryRequested = height; 503 } else { 504 throw new IllegalArgumentException("Invalid row height: " + height); 505 } 506 } 507 508 public void setItemMargin(int margin) { 509 mVerticalMargin = mHorizontalMargin = margin; 510 mMarginPrimary = mMarginSecondary = margin; 511 } 512 513 public void setVerticalMargin(int margin) { 514 if (mOrientation == HORIZONTAL) { 515 mMarginSecondary = mVerticalMargin = margin; 516 } else { 517 mMarginPrimary = mVerticalMargin = margin; 518 } 519 } 520 521 public void setHorizontalMargin(int margin) { 522 if (mOrientation == HORIZONTAL) { 523 mMarginPrimary = mHorizontalMargin = margin; 524 } else { 525 mMarginSecondary = mHorizontalMargin = margin; 526 } 527 } 528 529 public int getVerticalMargin() { 530 return mVerticalMargin; 531 } 532 533 public int getHorizontalMargin() { 534 return mHorizontalMargin; 535 } 536 537 public void setGravity(int gravity) { 538 mGravity = gravity; 539 } 540 541 protected boolean hasDoneFirstLayout() { 542 return mGrid != null; 543 } 544 545 public void setOnChildSelectedListener(OnChildSelectedListener listener) { 546 mChildSelectedListener = listener; 547 } 548 549 private int getPositionByView(View view) { 550 if (view == null) { 551 return NO_POSITION; 552 } 553 LayoutParams params = (LayoutParams) view.getLayoutParams(); 554 if (params == null || params.isItemRemoved()) { 555 // when item is removed, the position value can be any value. 556 return NO_POSITION; 557 } 558 return params.getViewPosition(); 559 } 560 561 private int getPositionByIndex(int index) { 562 return getPositionByView(getChildAt(index)); 563 } 564 565 private void dispatchChildSelected() { 566 if (mChildSelectedListener == null) { 567 return; 568 } 569 570 if (TRACE) TraceHelper.beginSection("onChildSelected"); 571 View view = mFocusPosition == NO_POSITION ? null : findViewByPosition(mFocusPosition); 572 if (view != null) { 573 RecyclerView.ViewHolder vh = mBaseGridView.getChildViewHolder(view); 574 mChildSelectedListener.onChildSelected(mBaseGridView, view, mFocusPosition, 575 vh == null? NO_ID: vh.getItemId()); 576 } else { 577 mChildSelectedListener.onChildSelected(mBaseGridView, null, NO_POSITION, NO_ID); 578 } 579 if (TRACE) TraceHelper.endSection(); 580 581 // Children may request layout when a child selection event occurs (such as a change of 582 // padding on the current and previously selected rows). 583 // If in layout, a child requesting layout may have been laid out before the selection 584 // callback. 585 // If it was not, the child will be laid out after the selection callback. 586 // If so, the layout request will be honoured though the view system will emit a double- 587 // layout warning. 588 // If not in layout, we may be scrolling in which case the child layout request will be 589 // eaten by recyclerview. Post a requestLayout. 590 if (!mInLayout && !mBaseGridView.isLayoutRequested()) { 591 int childCount = getChildCount(); 592 for (int i = 0; i < childCount; i++) { 593 if (getChildAt(i).isLayoutRequested()) { 594 forceRequestLayout(); 595 break; 596 } 597 } 598 } 599 } 600 601 @Override 602 public boolean canScrollHorizontally() { 603 // We can scroll horizontally if we have horizontal orientation, or if 604 // we are vertical and have more than one column. 605 return mOrientation == HORIZONTAL || mNumRows > 1; 606 } 607 608 @Override 609 public boolean canScrollVertically() { 610 // We can scroll vertically if we have vertical orientation, or if we 611 // are horizontal and have more than one row. 612 return mOrientation == VERTICAL || mNumRows > 1; 613 } 614 615 @Override 616 public RecyclerView.LayoutParams generateDefaultLayoutParams() { 617 return new LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, 618 ViewGroup.LayoutParams.WRAP_CONTENT); 619 } 620 621 @Override 622 public RecyclerView.LayoutParams generateLayoutParams(Context context, AttributeSet attrs) { 623 return new LayoutParams(context, attrs); 624 } 625 626 @Override 627 public RecyclerView.LayoutParams generateLayoutParams(ViewGroup.LayoutParams lp) { 628 if (lp instanceof LayoutParams) { 629 return new LayoutParams((LayoutParams) lp); 630 } else if (lp instanceof RecyclerView.LayoutParams) { 631 return new LayoutParams((RecyclerView.LayoutParams) lp); 632 } else if (lp instanceof MarginLayoutParams) { 633 return new LayoutParams((MarginLayoutParams) lp); 634 } else { 635 return new LayoutParams(lp); 636 } 637 } 638 639 protected View getViewForPosition(int position) { 640 return mRecycler.getViewForPosition(position); 641 } 642 643 final int getOpticalLeft(View v) { 644 return ((LayoutParams) v.getLayoutParams()).getOpticalLeft(v); 645 } 646 647 final int getOpticalRight(View v) { 648 return ((LayoutParams) v.getLayoutParams()).getOpticalRight(v); 649 } 650 651 final int getOpticalTop(View v) { 652 return ((LayoutParams) v.getLayoutParams()).getOpticalTop(v); 653 } 654 655 final int getOpticalBottom(View v) { 656 return ((LayoutParams) v.getLayoutParams()).getOpticalBottom(v); 657 } 658 659 private int getViewMin(View v) { 660 return (mOrientation == HORIZONTAL) ? getOpticalLeft(v) : getOpticalTop(v); 661 } 662 663 private int getViewMax(View v) { 664 return (mOrientation == HORIZONTAL) ? getOpticalRight(v) : getOpticalBottom(v); 665 } 666 667 private int getViewCenter(View view) { 668 return (mOrientation == HORIZONTAL) ? getViewCenterX(view) : getViewCenterY(view); 669 } 670 671 private int getViewCenterSecondary(View view) { 672 return (mOrientation == HORIZONTAL) ? getViewCenterY(view) : getViewCenterX(view); 673 } 674 675 private int getViewCenterX(View v) { 676 LayoutParams p = (LayoutParams) v.getLayoutParams(); 677 return p.getOpticalLeft(v) + p.getAlignX(); 678 } 679 680 private int getViewCenterY(View v) { 681 LayoutParams p = (LayoutParams) v.getLayoutParams(); 682 return p.getOpticalTop(v) + p.getAlignY(); 683 } 684 685 /** 686 * Save Recycler and State for convenience. Must be paired with leaveContext(). 687 */ 688 private void saveContext(Recycler recycler, State state) { 689 if (mRecycler != null || mState != null) { 690 Log.e(TAG, "Recycler information was not released, bug!"); 691 } 692 mRecycler = recycler; 693 mState = state; 694 } 695 696 /** 697 * Discard saved Recycler and State. 698 */ 699 private void leaveContext() { 700 mRecycler = null; 701 mState = null; 702 } 703 704 /** 705 * Re-initialize data structures for a data change or handling invisible 706 * selection. The method tries its best to preserve position information so 707 * that staggered grid looks same before and after re-initialize. 708 * @param focusPosition The initial focusPosition that we would like to 709 * focus on. 710 * @return Actual position that can be focused on. 711 */ 712 private int init(int focusPosition) { 713 714 final int newItemCount = mState.getItemCount(); 715 716 // Force the re-init path in the following conditional 717 if (newItemCount == 0) { 718 focusPosition = NO_POSITION; 719 } else if (focusPosition == NO_POSITION && newItemCount > 0) { 720 // if focus position is never set before, initialize it to 0 721 focusPosition = 0; 722 } 723 724 // If adapter has changed then caches are invalid; otherwise, 725 // we try to maintain each row's position if number of rows keeps the same 726 // and existing mGrid contains the focusPosition. 727 if (mRows != null && mNumRows == mRows.length && 728 mGrid != null && mGrid.getSize() > 0 && focusPosition >= 0 && 729 focusPosition >= mGrid.getFirstIndex() && 730 focusPosition <= mGrid.getLastIndex()) { 731 // strip mGrid to a subset (like a column) that contains focusPosition 732 mGrid.stripDownTo(focusPosition); 733 // make sure that remaining items do not exceed new adapter size 734 int firstIndex = mGrid.getFirstIndex(); 735 int lastIndex = mGrid.getLastIndex(); 736 if (DEBUG) { 737 Log .v(getTag(), "mGrid firstIndex " + firstIndex + " lastIndex " + lastIndex); 738 } 739 for (int i = lastIndex; i >=firstIndex; i--) { 740 if (i >= newItemCount) { 741 mGrid.removeLast(); 742 } 743 } 744 if (mGrid.getSize() == 0) { 745 focusPosition = newItemCount - 1; 746 // initialize row start locations 747 for (int i = 0; i < mNumRows; i++) { 748 mRows[i].low = 0; 749 mRows[i].high = 0; 750 } 751 if (DEBUG) Log.v(getTag(), "mGrid zero size"); 752 } else { 753 // initialize row start locations 754 for (int i = 0; i < mNumRows; i++) { 755 mRows[i].low = Integer.MAX_VALUE; 756 mRows[i].high = Integer.MIN_VALUE; 757 } 758 firstIndex = mGrid.getFirstIndex(); 759 lastIndex = mGrid.getLastIndex(); 760 if (focusPosition > lastIndex) { 761 focusPosition = mGrid.getLastIndex(); 762 } 763 if (DEBUG) { 764 Log.v(getTag(), "mGrid firstIndex " + firstIndex + " lastIndex " 765 + lastIndex + " focusPosition " + focusPosition); 766 } 767 // fill rows with minimal view positions of the subset 768 for (int i = firstIndex; i <= lastIndex; i++) { 769 View v = findViewByPosition(i); 770 if (v == null) { 771 continue; 772 } 773 int row = mGrid.getLocation(i).row; 774 int low = getViewMin(v) + mScrollOffsetPrimary; 775 if (low < mRows[row].low) { 776 mRows[row].low = mRows[row].high = low; 777 } 778 } 779 int firstItemRowPosition = mRows[mGrid.getLocation(firstIndex).row].low; 780 if (firstItemRowPosition == Integer.MAX_VALUE) { 781 firstItemRowPosition = 0; 782 } 783 if (mState.didStructureChange()) { 784 // if there is structure change, the removed item might be in the 785 // subset, so it is meaningless to maintain the low locations. 786 for (int i = 0; i < mNumRows; i++) { 787 mRows[i].low = firstItemRowPosition; 788 mRows[i].high = firstItemRowPosition; 789 } 790 } else { 791 // fill other rows that does not include the subset using first item 792 for (int i = 0; i < mNumRows; i++) { 793 if (mRows[i].low == Integer.MAX_VALUE) { 794 mRows[i].low = mRows[i].high = firstItemRowPosition; 795 } 796 } 797 } 798 } 799 800 // Same adapter, we can reuse any attached views 801 detachAndScrapAttachedViews(mRecycler); 802 updateScrollController(); 803 804 } else { 805 // otherwise recreate data structure 806 mRows = new StaggeredGrid.Row[mNumRows]; 807 808 for (int i = 0; i < mNumRows; i++) { 809 mRows[i] = new StaggeredGrid.Row(); 810 } 811 mGrid = new StaggeredGridDefault(); 812 mGrid.setReversedFlow(mOrientation == HORIZONTAL && mReverseFlowPrimary); 813 if (newItemCount == 0) { 814 focusPosition = NO_POSITION; 815 } else if (focusPosition >= newItemCount) { 816 focusPosition = newItemCount - 1; 817 } 818 819 // Adapter may have changed so remove all attached views permanently 820 removeAndRecycleAllViews(mRecycler); 821 822 initScrollController(); 823 } 824 825 mGrid.setProvider(mGridProvider); 826 // mGrid share the same Row array information 827 mGrid.setRows(mRows); 828 mFirstVisiblePos = mLastVisiblePos = NO_POSITION; 829 830 updateScrollSecondAxis(); 831 832 return focusPosition; 833 } 834 835 private int getRowSizeSecondary(int rowIndex) { 836 if (mFixedRowSizeSecondary != 0) { 837 return mFixedRowSizeSecondary; 838 } 839 if (mRowSizeSecondary == null) { 840 return 0; 841 } 842 return mRowSizeSecondary[rowIndex]; 843 } 844 845 private int getRowStartSecondary(int rowIndex) { 846 int start = 0; 847 // Iterate from left to right, which is a different index traversal 848 // in RTL flow 849 if (mReverseFlowSecondary) { 850 for (int i = mNumRows-1; i > rowIndex; i--) { 851 start += getRowSizeSecondary(i) + mMarginSecondary; 852 } 853 } else { 854 for (int i = 0; i < rowIndex; i++) { 855 start += getRowSizeSecondary(i) + mMarginSecondary; 856 } 857 } 858 return start; 859 } 860 861 private int getSizeSecondary() { 862 int rightmostIndex = mReverseFlowSecondary ? 0 : mNumRows - 1; 863 return getRowStartSecondary(rightmostIndex) + getRowSizeSecondary(rightmostIndex); 864 } 865 866 private void measureScrapChild(int position, int widthSpec, int heightSpec, 867 int[] measuredDimension) { 868 View view = mRecycler.getViewForPosition(position); 869 if (view != null) { 870 LayoutParams p = (LayoutParams) view.getLayoutParams(); 871 int childWidthSpec = ViewGroup.getChildMeasureSpec(widthSpec, 872 getPaddingLeft() + getPaddingRight(), p.width); 873 int childHeightSpec = ViewGroup.getChildMeasureSpec(heightSpec, 874 getPaddingTop() + getPaddingBottom(), p.height); 875 view.measure(childWidthSpec, childHeightSpec); 876 measuredDimension[0] = view.getMeasuredWidth(); 877 measuredDimension[1] = view.getMeasuredHeight(); 878 mRecycler.recycleView(view); 879 } 880 } 881 882 private boolean processRowSizeSecondary(boolean measure) { 883 if (mFixedRowSizeSecondary != 0) { 884 return false; 885 } 886 887 if (TRACE) TraceHelper.beginSection("processRowSizeSecondary"); 888 List<Integer>[] rows = mGrid == null ? null : 889 mGrid.getItemPositionsInRows(mFirstVisiblePos, mLastVisiblePos); 890 boolean changed = false; 891 int scrapChildWidth = -1; 892 int scrapChildHeight = -1; 893 894 for (int rowIndex = 0; rowIndex < mNumRows; rowIndex++) { 895 final int rowItemCount = rows == null ? 0 : rows[rowIndex].size(); 896 897 int rowSize = -1; 898 for (int i = 0; i < rowItemCount; i++) { 899 final View view = findViewByPosition(rows[rowIndex].get(i)); 900 if (view == null) { 901 continue; 902 } 903 if (measure && view.isLayoutRequested()) { 904 measureChild(view); 905 } 906 final int secondarySize = mOrientation == HORIZONTAL ? 907 view.getMeasuredHeight() : view.getMeasuredWidth(); 908 if (secondarySize > rowSize) { 909 rowSize = secondarySize; 910 } 911 } 912 913 final int itemCount = mState.getItemCount(); 914 if (measure && rowSize < 0 && itemCount > 0) { 915 if (scrapChildWidth < 0 && scrapChildHeight < 0) { 916 int position; 917 if (mFocusPosition == NO_POSITION) { 918 position = 0; 919 } else if (mFocusPosition >= itemCount) { 920 position = itemCount - 1; 921 } else { 922 position = mFocusPosition; 923 } 924 measureScrapChild(position, 925 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 926 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 927 mMeasuredDimension); 928 scrapChildWidth = mMeasuredDimension[0]; 929 scrapChildHeight = mMeasuredDimension[1]; 930 if (DEBUG) Log.v(TAG, "measured scrap child: " + scrapChildWidth + 931 " " + scrapChildHeight); 932 } 933 rowSize = mOrientation == HORIZONTAL ? scrapChildHeight : scrapChildWidth; 934 } 935 936 if (rowSize < 0) { 937 rowSize = 0; 938 } 939 940 if (DEBUG) Log.v(getTag(), "row " + rowIndex + " rowItemCount " + rowItemCount + 941 " rowSize " + rowSize); 942 943 if (mRowSizeSecondary[rowIndex] != rowSize) { 944 if (DEBUG) Log.v(getTag(), "row size secondary changed: " + mRowSizeSecondary[rowIndex] + 945 ", " + rowSize); 946 947 mRowSizeSecondary[rowIndex] = rowSize; 948 changed = true; 949 } 950 } 951 952 if (TRACE) TraceHelper.endSection(); 953 return changed; 954 } 955 956 /** 957 * Checks if we need to update row secondary sizes. 958 */ 959 private void updateRowSecondarySizeRefresh() { 960 mRowSecondarySizeRefresh = processRowSizeSecondary(false); 961 if (mRowSecondarySizeRefresh) { 962 if (DEBUG) Log.v(getTag(), "mRowSecondarySizeRefresh now set"); 963 forceRequestLayout(); 964 } 965 } 966 967 private void forceRequestLayout() { 968 if (DEBUG) Log.v(getTag(), "forceRequestLayout"); 969 // RecyclerView prevents us from requesting layout in many cases 970 // (during layout, during scroll, etc.) 971 // For secondary row size wrap_content support we currently need a 972 // second layout pass to update the measured size after having measured 973 // and added child views in layoutChildren. 974 // Force the second layout by posting a delayed runnable. 975 // TODO: investigate allowing a second layout pass, 976 // or move child add/measure logic to the measure phase. 977 ViewCompat.postOnAnimation(mBaseGridView, mRequestLayoutRunnable); 978 } 979 980 private final Runnable mRequestLayoutRunnable = new Runnable() { 981 @Override 982 public void run() { 983 if (DEBUG) Log.v(getTag(), "request Layout from runnable"); 984 requestLayout(); 985 } 986 }; 987 988 @Override 989 public void onMeasure(Recycler recycler, State state, int widthSpec, int heightSpec) { 990 saveContext(recycler, state); 991 992 int sizePrimary, sizeSecondary, modeSecondary, paddingSecondary; 993 int measuredSizeSecondary; 994 if (mOrientation == HORIZONTAL) { 995 sizePrimary = MeasureSpec.getSize(widthSpec); 996 sizeSecondary = MeasureSpec.getSize(heightSpec); 997 modeSecondary = MeasureSpec.getMode(heightSpec); 998 paddingSecondary = getPaddingTop() + getPaddingBottom(); 999 } else { 1000 sizeSecondary = MeasureSpec.getSize(widthSpec); 1001 sizePrimary = MeasureSpec.getSize(heightSpec); 1002 modeSecondary = MeasureSpec.getMode(widthSpec); 1003 paddingSecondary = getPaddingLeft() + getPaddingRight(); 1004 } 1005 if (DEBUG) Log.v(getTag(), "onMeasure widthSpec " + Integer.toHexString(widthSpec) + 1006 " heightSpec " + Integer.toHexString(heightSpec) + 1007 " modeSecondary " + Integer.toHexString(modeSecondary) + 1008 " sizeSecondary " + sizeSecondary + " " + this); 1009 1010 mMaxSizeSecondary = sizeSecondary; 1011 1012 if (mRowSizeSecondaryRequested == ViewGroup.LayoutParams.WRAP_CONTENT) { 1013 mNumRows = mNumRowsRequested == 0 ? 1 : mNumRowsRequested; 1014 mFixedRowSizeSecondary = 0; 1015 1016 if (mRowSizeSecondary == null || mRowSizeSecondary.length != mNumRows) { 1017 mRowSizeSecondary = new int[mNumRows]; 1018 } 1019 1020 // Measure all current children and update cached row heights 1021 processRowSizeSecondary(true); 1022 1023 switch (modeSecondary) { 1024 case MeasureSpec.UNSPECIFIED: 1025 measuredSizeSecondary = getSizeSecondary() + paddingSecondary; 1026 break; 1027 case MeasureSpec.AT_MOST: 1028 measuredSizeSecondary = Math.min(getSizeSecondary() + paddingSecondary, 1029 mMaxSizeSecondary); 1030 break; 1031 case MeasureSpec.EXACTLY: 1032 measuredSizeSecondary = mMaxSizeSecondary; 1033 break; 1034 default: 1035 throw new IllegalStateException("wrong spec"); 1036 } 1037 1038 } else { 1039 switch (modeSecondary) { 1040 case MeasureSpec.UNSPECIFIED: 1041 if (mRowSizeSecondaryRequested == 0) { 1042 if (mOrientation == HORIZONTAL) { 1043 throw new IllegalStateException("Must specify rowHeight or view height"); 1044 } else { 1045 throw new IllegalStateException("Must specify columnWidth or view width"); 1046 } 1047 } 1048 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 1049 mNumRows = mNumRowsRequested == 0 ? 1 : mNumRowsRequested; 1050 measuredSizeSecondary = mFixedRowSizeSecondary * mNumRows + mMarginSecondary 1051 * (mNumRows - 1) + paddingSecondary; 1052 break; 1053 case MeasureSpec.AT_MOST: 1054 case MeasureSpec.EXACTLY: 1055 if (mNumRowsRequested == 0 && mRowSizeSecondaryRequested == 0) { 1056 mNumRows = 1; 1057 mFixedRowSizeSecondary = sizeSecondary - paddingSecondary; 1058 } else if (mNumRowsRequested == 0) { 1059 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 1060 mNumRows = (sizeSecondary + mMarginSecondary) 1061 / (mRowSizeSecondaryRequested + mMarginSecondary); 1062 } else if (mRowSizeSecondaryRequested == 0) { 1063 mNumRows = mNumRowsRequested; 1064 mFixedRowSizeSecondary = (sizeSecondary - paddingSecondary - mMarginSecondary 1065 * (mNumRows - 1)) / mNumRows; 1066 } else { 1067 mNumRows = mNumRowsRequested; 1068 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 1069 } 1070 measuredSizeSecondary = sizeSecondary; 1071 if (modeSecondary == MeasureSpec.AT_MOST) { 1072 int childrenSize = mFixedRowSizeSecondary * mNumRows + mMarginSecondary 1073 * (mNumRows - 1) + paddingSecondary; 1074 if (childrenSize < measuredSizeSecondary) { 1075 measuredSizeSecondary = childrenSize; 1076 } 1077 } 1078 break; 1079 default: 1080 throw new IllegalStateException("wrong spec"); 1081 } 1082 } 1083 if (mOrientation == HORIZONTAL) { 1084 setMeasuredDimension(sizePrimary, measuredSizeSecondary); 1085 } else { 1086 setMeasuredDimension(measuredSizeSecondary, sizePrimary); 1087 } 1088 if (DEBUG) { 1089 Log.v(getTag(), "onMeasure sizePrimary " + sizePrimary + 1090 " measuredSizeSecondary " + measuredSizeSecondary + 1091 " mFixedRowSizeSecondary " + mFixedRowSizeSecondary + 1092 " mNumRows " + mNumRows); 1093 } 1094 1095 leaveContext(); 1096 } 1097 1098 private void measureChild(View child) { 1099 if (TRACE) TraceHelper.beginSection("measureChild"); 1100 final ViewGroup.LayoutParams lp = child.getLayoutParams(); 1101 final int secondarySpec = (mRowSizeSecondaryRequested == ViewGroup.LayoutParams.WRAP_CONTENT) ? 1102 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED) : 1103 MeasureSpec.makeMeasureSpec(mFixedRowSizeSecondary, MeasureSpec.EXACTLY); 1104 int widthSpec, heightSpec; 1105 1106 if (mOrientation == HORIZONTAL) { 1107 widthSpec = ViewGroup.getChildMeasureSpec( 1108 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 1109 0, lp.width); 1110 heightSpec = ViewGroup.getChildMeasureSpec(secondarySpec, 0, lp.height); 1111 } else { 1112 heightSpec = ViewGroup.getChildMeasureSpec( 1113 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 1114 0, lp.height); 1115 widthSpec = ViewGroup.getChildMeasureSpec(secondarySpec, 0, lp.width); 1116 } 1117 1118 child.measure(widthSpec, heightSpec); 1119 1120 if (DEBUG) Log.v(getTag(), "measureChild secondarySpec " + Integer.toHexString(secondarySpec) + 1121 " widthSpec " + Integer.toHexString(widthSpec) + 1122 " heightSpec " + Integer.toHexString(heightSpec) + 1123 " measuredWidth " + child.getMeasuredWidth() + 1124 " measuredHeight " + child.getMeasuredHeight()); 1125 if (DEBUG) Log.v(getTag(), "child lp width " + lp.width + " height " + lp.height); 1126 if (TRACE) TraceHelper.endSection(); 1127 } 1128 1129 private StaggeredGrid.Provider mGridProvider = new StaggeredGrid.Provider() { 1130 1131 @Override 1132 public int getCount() { 1133 return mState.getItemCount(); 1134 } 1135 1136 @Override 1137 public void createItem(int index, int rowIndex, boolean append) { 1138 if (TRACE) TraceHelper.beginSection("createItem"); 1139 if (TRACE) TraceHelper.beginSection("getview"); 1140 View v = getViewForPosition(index); 1141 if (TRACE) TraceHelper.endSection(); 1142 if (mFirstVisiblePos >= 0) { 1143 // when StaggeredGrid append or prepend item, we must guarantee 1144 // that sibling item has created views already. 1145 if (append && index != mLastVisiblePos + 1) { 1146 throw new RuntimeException(); 1147 } else if (!append && index != mFirstVisiblePos - 1) { 1148 throw new RuntimeException(); 1149 } 1150 } 1151 1152 // See recyclerView docs: we don't need re-add scraped view if it was removed. 1153 if (!((RecyclerView.LayoutParams) v.getLayoutParams()).isItemRemoved()) { 1154 if (TRACE) TraceHelper.beginSection("addView"); 1155 if (append) { 1156 addView(v); 1157 } else { 1158 addView(v, 0); 1159 } 1160 if (TRACE) TraceHelper.endSection(); 1161 if (mChildVisibility != -1) { 1162 v.setVisibility(mChildVisibility); 1163 } 1164 1165 // View is added first or it won't be found by dispatchChildSelected. 1166 if (mInLayout && index == mFocusPosition) { 1167 dispatchChildSelected(); 1168 } 1169 1170 measureChild(v); 1171 } 1172 1173 int length = mOrientation == HORIZONTAL ? v.getMeasuredWidth() : v.getMeasuredHeight(); 1174 int start, end; 1175 final boolean rowIsEmpty = mRows[rowIndex].high == mRows[rowIndex].low; 1176 boolean addHigh = (!mReverseFlowPrimary) ? append : !append; 1177 int lowVisiblePos = (!mReverseFlowPrimary) ? mFirstVisiblePos : mLastVisiblePos; 1178 int highVisiblePos = (!mReverseFlowPrimary) ? mLastVisiblePos : mFirstVisiblePos; 1179 if (addHigh) { 1180 if (!rowIsEmpty) { 1181 // if there are existing item in the row, add margin between 1182 start = mRows[rowIndex].high + mMarginPrimary; 1183 } else { 1184 if (lowVisiblePos >= 0) { 1185 int rowOfLowPos = mGrid.getLocation(lowVisiblePos).row; 1186 // If row is after row of lowest position, 1187 // start a new column after the first row. 1188 if (rowIndex < rowOfLowPos) { 1189 mRows[rowIndex].low = mRows[rowOfLowPos].high + mMarginPrimary; 1190 } 1191 } 1192 start = mRows[rowIndex].low; 1193 } 1194 end = start + length; 1195 mRows[rowIndex].high = end; 1196 } else { 1197 if (!rowIsEmpty) { 1198 // if there are existing item in the row, add margin between 1199 end = mRows[rowIndex].low - mMarginPrimary; 1200 } else { 1201 if (highVisiblePos >= 0) { 1202 int rowOfHighPos = mGrid.getLocation(highVisiblePos).row; 1203 if (mOrientation == HORIZONTAL ? 1204 rowIndex < rowOfHighPos : rowIndex > rowOfHighPos) { 1205 mRows[rowIndex].high = mRows[rowOfHighPos].low - mMarginPrimary; 1206 } 1207 } 1208 end = mRows[rowIndex].high; 1209 } 1210 start = end - length; 1211 mRows[rowIndex].low = start; 1212 } 1213 if (mFirstVisiblePos < 0) { 1214 mFirstVisiblePos = mLastVisiblePos = index; 1215 } else { 1216 if (append) { 1217 mLastVisiblePos++; 1218 } else { 1219 mFirstVisiblePos--; 1220 } 1221 } 1222 if (DEBUG) Log.v(getTag(), "start " + start + " end " + end); 1223 int startSecondary = getRowStartSecondary(rowIndex) - mScrollOffsetSecondary; 1224 mChildrenStates.loadView(v, index); 1225 layoutChild(rowIndex, v, start - mScrollOffsetPrimary, end - mScrollOffsetPrimary, 1226 startSecondary); 1227 if (DEBUG) { 1228 Log.d(getTag(), "addView " + index + " " + v); 1229 } 1230 if (index == mFirstVisiblePos) { 1231 if (!mReverseFlowPrimary) { 1232 updateScrollMin(); 1233 } else { 1234 updateScrollMax(); 1235 } 1236 } 1237 if (index == mLastVisiblePos) { 1238 if (!mReverseFlowPrimary) { 1239 updateScrollMax(); 1240 } else { 1241 updateScrollMin(); 1242 } 1243 } 1244 if (TRACE) TraceHelper.endSection(); 1245 } 1246 }; 1247 1248 private void layoutChild(int rowIndex, View v, int start, int end, int startSecondary) { 1249 if (TRACE) TraceHelper.beginSection("layoutChild"); 1250 int sizeSecondary = mOrientation == HORIZONTAL ? v.getMeasuredHeight() 1251 : v.getMeasuredWidth(); 1252 if (mFixedRowSizeSecondary > 0) { 1253 sizeSecondary = Math.min(sizeSecondary, mFixedRowSizeSecondary); 1254 } 1255 final int verticalGravity = mGravity & Gravity.VERTICAL_GRAVITY_MASK; 1256 final int horizontalGravity = (mReverseFlowPrimary || mReverseFlowSecondary) ? 1257 Gravity.getAbsoluteGravity(mGravity & Gravity.RELATIVE_HORIZONTAL_GRAVITY_MASK, View.LAYOUT_DIRECTION_RTL) : 1258 mGravity & Gravity.HORIZONTAL_GRAVITY_MASK; 1259 if (mOrientation == HORIZONTAL && verticalGravity == Gravity.TOP 1260 || mOrientation == VERTICAL && horizontalGravity == Gravity.LEFT) { 1261 // do nothing 1262 } else if (mOrientation == HORIZONTAL && verticalGravity == Gravity.BOTTOM 1263 || mOrientation == VERTICAL && horizontalGravity == Gravity.RIGHT) { 1264 startSecondary += getRowSizeSecondary(rowIndex) - sizeSecondary; 1265 } else if (mOrientation == HORIZONTAL && verticalGravity == Gravity.CENTER_VERTICAL 1266 || mOrientation == VERTICAL && horizontalGravity == Gravity.CENTER_HORIZONTAL) { 1267 startSecondary += (getRowSizeSecondary(rowIndex) - sizeSecondary) / 2; 1268 } 1269 int left, top, right, bottom; 1270 if (mOrientation == HORIZONTAL) { 1271 left = start; 1272 top = startSecondary; 1273 right = end; 1274 bottom = startSecondary + sizeSecondary; 1275 } else { 1276 top = start; 1277 left = startSecondary; 1278 bottom = end; 1279 right = startSecondary + sizeSecondary; 1280 } 1281 v.layout(left, top, right, bottom); 1282 updateChildOpticalInsets(v, left, top, right, bottom); 1283 updateChildAlignments(v); 1284 if (TRACE) TraceHelper.endSection(); 1285 } 1286 1287 private void updateChildOpticalInsets(View v, int left, int top, int right, int bottom) { 1288 LayoutParams p = (LayoutParams) v.getLayoutParams(); 1289 p.setOpticalInsets(left - v.getLeft(), top - v.getTop(), 1290 v.getRight() - right, v.getBottom() - bottom); 1291 } 1292 1293 private void updateChildAlignments(View v) { 1294 LayoutParams p = (LayoutParams) v.getLayoutParams(); 1295 p.setAlignX(mItemAlignment.horizontal.getAlignmentPosition(v)); 1296 p.setAlignY(mItemAlignment.vertical.getAlignmentPosition(v)); 1297 } 1298 1299 private void updateChildAlignments() { 1300 for (int i = 0, c = getChildCount(); i < c; i++) { 1301 updateChildAlignments(getChildAt(i)); 1302 } 1303 } 1304 1305 private boolean needsAppendVisibleItem() { 1306 if (mReverseFlowPrimary) { 1307 for (int i = 0; i < mNumRows; i++) { 1308 if (mRows[i].low == mRows[i].high) { 1309 if (mRows[i].low > mScrollOffsetPrimary) { 1310 return true; 1311 } 1312 } else if (mRows[i].low - mMarginPrimary > mScrollOffsetPrimary) { 1313 return true; 1314 } 1315 } 1316 } else { 1317 int right = mScrollOffsetPrimary + mSizePrimary; 1318 for (int i = 0; i < mNumRows; i++) { 1319 if (mRows[i].low == mRows[i].high) { 1320 if (mRows[i].high < right) { 1321 return true; 1322 } 1323 } else if (mRows[i].high < right - mMarginPrimary) { 1324 return true; 1325 } 1326 } 1327 } 1328 return false; 1329 } 1330 1331 private boolean needsPrependVisibleItem() { 1332 if (mReverseFlowPrimary) { 1333 int right = mScrollOffsetPrimary + mSizePrimary; 1334 for (int i = 0; i < mNumRows; i++) { 1335 if (mRows[i].low == mRows[i].high) { 1336 if (mRows[i].high < right) { 1337 return true; 1338 } 1339 } else if (mRows[i].high < right - mMarginPrimary) { 1340 return true; 1341 } 1342 } 1343 } else { 1344 for (int i = 0; i < mNumRows; i++) { 1345 if (mRows[i].low == mRows[i].high) { 1346 if (mRows[i].low > mScrollOffsetPrimary) { 1347 return true; 1348 } 1349 } else if (mRows[i].low - mMarginPrimary > mScrollOffsetPrimary) { 1350 return true; 1351 } 1352 } 1353 } 1354 return false; 1355 } 1356 1357 // Append one column if possible and return true if reach end. 1358 private boolean appendOneVisibleItem() { 1359 while (true) { 1360 if (mLastVisiblePos != NO_POSITION && mLastVisiblePos < mState.getItemCount() -1 && 1361 mLastVisiblePos < mGrid.getLastIndex()) { 1362 // append invisible view of saved location till last row 1363 final int index = mLastVisiblePos + 1; 1364 final int row = mGrid.getLocation(index).row; 1365 mGridProvider.createItem(index, row, true); 1366 if (row == mNumRows - 1) { 1367 return false; 1368 } 1369 } else if ((mLastVisiblePos == NO_POSITION && mState.getItemCount() > 0) || 1370 (mLastVisiblePos != NO_POSITION && 1371 mLastVisiblePos < mState.getItemCount() - 1)) { 1372 if (mReverseFlowPrimary) { 1373 mGrid.appendItems(mScrollOffsetPrimary); 1374 } else { 1375 mGrid.appendItems(mScrollOffsetPrimary + mSizePrimary); 1376 } 1377 return false; 1378 } else { 1379 return true; 1380 } 1381 } 1382 } 1383 1384 private void appendVisibleItems() { 1385 while (needsAppendVisibleItem()) { 1386 if (appendOneVisibleItem()) { 1387 break; 1388 } 1389 } 1390 } 1391 1392 // Prepend one column if possible and return true if reach end. 1393 private boolean prependOneVisibleItem() { 1394 while (true) { 1395 if (mFirstVisiblePos > 0) { 1396 if (mFirstVisiblePos > mGrid.getFirstIndex()) { 1397 // prepend invisible view of saved location till first row 1398 final int index = mFirstVisiblePos - 1; 1399 final int row = mGrid.getLocation(index).row; 1400 mGridProvider.createItem(index, row, false); 1401 if (row == 0) { 1402 return false; 1403 } 1404 } else { 1405 if (mReverseFlowPrimary) { 1406 mGrid.prependItems(mScrollOffsetPrimary + mSizePrimary); 1407 } else { 1408 mGrid.prependItems(mScrollOffsetPrimary); 1409 } 1410 return false; 1411 } 1412 } else { 1413 return true; 1414 } 1415 } 1416 } 1417 1418 private void prependVisibleItems() { 1419 while (needsPrependVisibleItem()) { 1420 if (prependOneVisibleItem()) { 1421 break; 1422 } 1423 } 1424 } 1425 1426 private void removeChildAt(int position) { 1427 if (TRACE) TraceHelper.beginSection("removeChildAt"); 1428 View v = findViewByPosition(position); 1429 if (v != null) { 1430 if (DEBUG) { 1431 Log.d(getTag(), "removeAndRecycleViewAt " + position + " " + v); 1432 } 1433 mChildrenStates.saveOffscreenView(v, position); 1434 removeAndRecycleView(v, mRecycler); 1435 } 1436 if (TRACE) TraceHelper.endSection(); 1437 } 1438 1439 private void removeInvisibleViewsAtEnd() { 1440 if (!mPruneChild) { 1441 return; 1442 } 1443 boolean update = false; 1444 while(mLastVisiblePos > mFirstVisiblePos && mLastVisiblePos > mFocusPosition) { 1445 View view = findViewByPosition(mLastVisiblePos); 1446 boolean offEnd = (!mReverseFlowPrimary) ? getViewMin(view) > mSizePrimary : 1447 getViewMax(view) < 0; 1448 if (offEnd) { 1449 removeChildAt(mLastVisiblePos); 1450 mLastVisiblePos--; 1451 update = true; 1452 } else { 1453 break; 1454 } 1455 } 1456 if (update) { 1457 updateRowsMinMax(); 1458 } 1459 } 1460 1461 private void removeInvisibleViewsAtFront() { 1462 if (!mPruneChild) { 1463 return; 1464 } 1465 boolean update = false; 1466 while(mLastVisiblePos > mFirstVisiblePos && mFirstVisiblePos < mFocusPosition) { 1467 View view = findViewByPosition(mFirstVisiblePos); 1468 boolean offFront = (!mReverseFlowPrimary) ? getViewMax(view) < 0: 1469 getViewMin(view) > mSizePrimary; 1470 if (offFront) { 1471 removeChildAt(mFirstVisiblePos); 1472 mFirstVisiblePos++; 1473 update = true; 1474 } else { 1475 break; 1476 } 1477 } 1478 if (update) { 1479 updateRowsMinMax(); 1480 } 1481 } 1482 1483 private void updateRowsMinMax() { 1484 if (mFirstVisiblePos < 0) { 1485 return; 1486 } 1487 for (int i = 0; i < mNumRows; i++) { 1488 mRows[i].low = Integer.MAX_VALUE; 1489 mRows[i].high = Integer.MIN_VALUE; 1490 } 1491 for (int i = mFirstVisiblePos; i <= mLastVisiblePos; i++) { 1492 View view = findViewByPosition(i); 1493 int row = mGrid.getLocation(i).row; 1494 int low = getViewMin(view) + mScrollOffsetPrimary; 1495 if (low < mRows[row].low) { 1496 mRows[row].low = low; 1497 } 1498 int high = getViewMax(view) + mScrollOffsetPrimary; 1499 if (high > mRows[row].high) { 1500 mRows[row].high = high; 1501 } 1502 } 1503 } 1504 1505 // Fast layout when there is no structure change, adapter change, etc. 1506 protected void fastRelayout(boolean scrollToFocus) { 1507 updateScrollController(); 1508 1509 List<Integer>[] rows = mGrid.getItemPositionsInRows(mFirstVisiblePos, mLastVisiblePos); 1510 1511 // relayout and repositioning views on each row 1512 for (int i = 0; i < mNumRows; i++) { 1513 List<Integer> row = rows[i]; 1514 final int startSecondary = getRowStartSecondary(i) - mScrollOffsetSecondary; 1515 for (int j = 0, size = row.size(); j < size; j++) { 1516 final int position = row.get(j); 1517 View view = findViewByPosition(position); 1518 int primaryDelta, end; 1519 1520 int start = getViewMin(view); 1521 int oldPrimarySize = (mOrientation == HORIZONTAL) ? 1522 view.getMeasuredWidth() : 1523 view.getMeasuredHeight(); 1524 1525 LayoutParams lp = (LayoutParams) view.getLayoutParams(); 1526 if (lp.viewNeedsUpdate()) { 1527 int index = mBaseGridView.indexOfChild(view); 1528 detachAndScrapView(view, mRecycler); 1529 view = getViewForPosition(position); 1530 addView(view, index); 1531 } 1532 1533 if (view.isLayoutRequested()) { 1534 measureChild(view); 1535 } 1536 1537 if (mOrientation == HORIZONTAL) { 1538 end = start + view.getMeasuredWidth(); 1539 primaryDelta = view.getMeasuredWidth() - oldPrimarySize; 1540 if (primaryDelta != 0) { 1541 for (int k = j + 1; k < size; k++) { 1542 findViewByPosition(row.get(k)).offsetLeftAndRight(primaryDelta); 1543 } 1544 } 1545 } else { 1546 end = start + view.getMeasuredHeight(); 1547 primaryDelta = view.getMeasuredHeight() - oldPrimarySize; 1548 if (primaryDelta != 0) { 1549 for (int k = j + 1; k < size; k++) { 1550 findViewByPosition(row.get(k)).offsetTopAndBottom(primaryDelta); 1551 } 1552 } 1553 } 1554 layoutChild(i, view, start, end, startSecondary); 1555 } 1556 } 1557 1558 updateRowsMinMax(); 1559 appendVisibleItems(); 1560 prependVisibleItems(); 1561 1562 updateRowsMinMax(); 1563 updateScrollMin(); 1564 updateScrollMax(); 1565 updateScrollSecondAxis(); 1566 1567 if (scrollToFocus) { 1568 View focusView = findViewByPosition(mFocusPosition == NO_POSITION ? 0 : mFocusPosition); 1569 scrollToView(focusView, false); 1570 } 1571 } 1572 1573 public void removeAndRecycleAllViews(RecyclerView.Recycler recycler) { 1574 if (TRACE) TraceHelper.beginSection("removeAndRecycleAllViews"); 1575 if (DEBUG) Log.v(TAG, "removeAndRecycleAllViews " + getChildCount()); 1576 for (int i = getChildCount() - 1; i >= 0; i--) { 1577 removeAndRecycleViewAt(i, recycler); 1578 } 1579 if (TRACE) TraceHelper.endSection(); 1580 } 1581 1582 // Lays out items based on the current scroll position 1583 @Override 1584 public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state) { 1585 if (DEBUG) { 1586 Log.v(getTag(), "layoutChildren start numRows " + mNumRows + " mScrollOffsetSecondary " 1587 + mScrollOffsetSecondary + " mScrollOffsetPrimary " + mScrollOffsetPrimary 1588 + " inPreLayout " + state.isPreLayout() 1589 + " didStructureChange " + state.didStructureChange() 1590 + " mForceFullLayout " + mForceFullLayout); 1591 Log.v(getTag(), "width " + getWidth() + " height " + getHeight()); 1592 } 1593 1594 if (mNumRows == 0) { 1595 // haven't done measure yet 1596 return; 1597 } 1598 final int itemCount = state.getItemCount(); 1599 if (itemCount < 0) { 1600 return; 1601 } 1602 1603 if (!mLayoutEnabled) { 1604 discardLayoutInfo(); 1605 removeAndRecycleAllViews(recycler); 1606 return; 1607 } 1608 mInLayout = true; 1609 1610 final boolean scrollToFocus = !isSmoothScrolling() 1611 && mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED; 1612 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE) { 1613 mFocusPosition = mFocusPosition + mFocusPositionOffset; 1614 mFocusPositionOffset = 0; 1615 } 1616 saveContext(recycler, state); 1617 1618 // Track the old focus view so we can adjust our system scroll position 1619 // so that any scroll animations happening now will remain valid. 1620 // We must use same delta in Pre Layout (if prelayout exists) and second layout. 1621 // So we cache the deltas in PreLayout and use it in second layout. 1622 int delta = 0, deltaSecondary = 0; 1623 if (mFocusPosition != NO_POSITION && scrollToFocus 1624 && mBaseGridView.getScrollState() != RecyclerView.SCROLL_STATE_IDLE) { 1625 // FIXME: we should get the remaining scroll animation offset from RecyclerView 1626 View focusView = findViewByPosition(mFocusPosition); 1627 if (focusView != null) { 1628 delta = mWindowAlignment.mainAxis().getSystemScrollPos(mScrollOffsetPrimary 1629 + getViewCenter(focusView), false, false) - mScrollOffsetPrimary; 1630 deltaSecondary = mWindowAlignment.secondAxis().getSystemScrollPos( 1631 mScrollOffsetSecondary + getViewCenterSecondary(focusView), 1632 false, false) - mScrollOffsetSecondary; 1633 } 1634 } 1635 1636 final boolean hasDoneFirstLayout = hasDoneFirstLayout(); 1637 int savedFocusPos = mFocusPosition; 1638 boolean fastRelayout = false; 1639 if (!mState.didStructureChange() && !mForceFullLayout && hasDoneFirstLayout) { 1640 fastRelayout = true; 1641 fastRelayout(scrollToFocus); 1642 } else { 1643 boolean hadFocus = mBaseGridView.hasFocus(); 1644 1645 mFocusPosition = init(mFocusPosition); 1646 if (mFocusPosition != savedFocusPos) { 1647 if (DEBUG) Log.v(getTag(), "savedFocusPos " + savedFocusPos + 1648 " mFocusPosition " + mFocusPosition); 1649 } 1650 if (mFocusPosition == NO_POSITION) { 1651 mBaseGridView.clearFocus(); 1652 } 1653 1654 mWindowAlignment.mainAxis().invalidateScrollMin(); 1655 mWindowAlignment.mainAxis().invalidateScrollMax(); 1656 // depending on result of init(), either recreating everything 1657 // or try to reuse the row start positions near mFocusPosition 1658 if (mGrid.getSize() == 0) { 1659 // this is a fresh creating all items, starting from 1660 // mFocusPosition with a estimated row index. 1661 mGrid.setStart(mFocusPosition, StaggeredGrid.START_DEFAULT); 1662 1663 // Can't track the old focus view 1664 delta = deltaSecondary = 0; 1665 1666 } else { 1667 // mGrid remembers Locations for the column that 1668 // contains mFocusePosition and also mRows remembers start 1669 // positions of each row. 1670 // Manually re-create child views for that column 1671 int firstIndex = mGrid.getFirstIndex(); 1672 int lastIndex = mGrid.getLastIndex(); 1673 for (int i = firstIndex; i <= lastIndex; i++) { 1674 mGridProvider.createItem(i, mGrid.getLocation(i).row, true); 1675 } 1676 } 1677 1678 // add visible views at end until reach the end of window 1679 appendVisibleItems(); 1680 // add visible views at front until reach the start of window 1681 prependVisibleItems(); 1682 // multiple rounds: scrollToView of first round may drag first/last child into 1683 // "visible window" and we update scrollMin/scrollMax then run second scrollToView 1684 int oldFirstVisible; 1685 int oldLastVisible; 1686 do { 1687 updateScrollMin(); 1688 updateScrollMax(); 1689 oldFirstVisible = mFirstVisiblePos; 1690 oldLastVisible = mLastVisiblePos; 1691 View focusView = findViewByPosition(mFocusPosition); 1692 // we need force to initialize the child view's position 1693 scrollToView(focusView, false); 1694 if (focusView != null && hadFocus) { 1695 focusView.requestFocus(); 1696 } 1697 appendVisibleItems(); 1698 prependVisibleItems(); 1699 removeInvisibleViewsAtFront(); 1700 removeInvisibleViewsAtEnd(); 1701 } while (mFirstVisiblePos != oldFirstVisible || mLastVisiblePos != oldLastVisible); 1702 } 1703 mForceFullLayout = false; 1704 1705 if (scrollToFocus) { 1706 scrollDirectionPrimary(-delta); 1707 scrollDirectionSecondary(-deltaSecondary); 1708 } 1709 appendVisibleItems(); 1710 prependVisibleItems(); 1711 removeInvisibleViewsAtFront(); 1712 removeInvisibleViewsAtEnd(); 1713 1714 if (DEBUG) { 1715 StringWriter sw = new StringWriter(); 1716 PrintWriter pw = new PrintWriter(sw); 1717 mGrid.debugPrint(pw); 1718 Log.d(getTag(), sw.toString()); 1719 } 1720 1721 if (mRowSecondarySizeRefresh) { 1722 mRowSecondarySizeRefresh = false; 1723 } else { 1724 updateRowSecondarySizeRefresh(); 1725 } 1726 1727 if (fastRelayout && mFocusPosition != savedFocusPos) { 1728 dispatchChildSelected(); 1729 } 1730 1731 mInLayout = false; 1732 leaveContext(); 1733 if (DEBUG) Log.v(getTag(), "layoutChildren end"); 1734 } 1735 1736 private void offsetChildrenSecondary(int increment) { 1737 final int childCount = getChildCount(); 1738 if (mOrientation == HORIZONTAL) { 1739 for (int i = 0; i < childCount; i++) { 1740 getChildAt(i).offsetTopAndBottom(increment); 1741 } 1742 } else { 1743 for (int i = 0; i < childCount; i++) { 1744 getChildAt(i).offsetLeftAndRight(increment); 1745 } 1746 } 1747 } 1748 1749 private void offsetChildrenPrimary(int increment) { 1750 final int childCount = getChildCount(); 1751 if (mOrientation == VERTICAL) { 1752 for (int i = 0; i < childCount; i++) { 1753 getChildAt(i).offsetTopAndBottom(increment); 1754 } 1755 } else { 1756 for (int i = 0; i < childCount; i++) { 1757 getChildAt(i).offsetLeftAndRight(increment); 1758 } 1759 } 1760 } 1761 1762 @Override 1763 public int scrollHorizontallyBy(int dx, Recycler recycler, RecyclerView.State state) { 1764 if (DEBUG) Log.v(getTag(), "scrollHorizontallyBy " + dx); 1765 if (!mLayoutEnabled || !hasDoneFirstLayout()) { 1766 return 0; 1767 } 1768 saveContext(recycler, state); 1769 int result; 1770 if (mOrientation == HORIZONTAL) { 1771 result = scrollDirectionPrimary(dx); 1772 } else { 1773 result = scrollDirectionSecondary(dx); 1774 } 1775 leaveContext(); 1776 return result; 1777 } 1778 1779 @Override 1780 public int scrollVerticallyBy(int dy, Recycler recycler, RecyclerView.State state) { 1781 if (DEBUG) Log.v(getTag(), "scrollVerticallyBy " + dy); 1782 if (!mLayoutEnabled || !hasDoneFirstLayout()) { 1783 return 0; 1784 } 1785 saveContext(recycler, state); 1786 int result; 1787 if (mOrientation == VERTICAL) { 1788 result = scrollDirectionPrimary(dy); 1789 } else { 1790 result = scrollDirectionSecondary(dy); 1791 } 1792 leaveContext(); 1793 return result; 1794 } 1795 1796 // scroll in main direction may add/prune views 1797 private int scrollDirectionPrimary(int da) { 1798 if (TRACE) TraceHelper.beginSection("scrollPrimary"); 1799 boolean isMaxUnknown = false, isMinUnknown = false; 1800 int minScroll = 0, maxScroll = 0; 1801 if (da > 0) { 1802 isMaxUnknown = mWindowAlignment.mainAxis().isMaxUnknown(); 1803 if (!isMaxUnknown) { 1804 maxScroll = mWindowAlignment.mainAxis().getMaxScroll(); 1805 if (mScrollOffsetPrimary + da > maxScroll) { 1806 da = maxScroll - mScrollOffsetPrimary; 1807 } 1808 } 1809 } else if (da < 0) { 1810 isMinUnknown = mWindowAlignment.mainAxis().isMinUnknown(); 1811 if (!isMinUnknown) { 1812 minScroll = mWindowAlignment.mainAxis().getMinScroll(); 1813 if (mScrollOffsetPrimary + da < minScroll) { 1814 da = minScroll - mScrollOffsetPrimary; 1815 } 1816 } 1817 } 1818 if (da == 0) { 1819 if (TRACE) TraceHelper.endSection(); 1820 return 0; 1821 } 1822 offsetChildrenPrimary(-da); 1823 mScrollOffsetPrimary += da; 1824 if (mInLayout) { 1825 if (TRACE) TraceHelper.endSection(); 1826 return da; 1827 } 1828 1829 int childCount = getChildCount(); 1830 boolean updated; 1831 1832 if (da > 0) { 1833 if (mReverseFlowPrimary) { 1834 prependVisibleItems(); 1835 } else { 1836 appendVisibleItems(); 1837 } 1838 } else if (da < 0) { 1839 if (mReverseFlowPrimary) { 1840 appendVisibleItems(); 1841 } else { 1842 prependVisibleItems(); 1843 } 1844 } 1845 updated = getChildCount() > childCount; 1846 childCount = getChildCount(); 1847 1848 if (TRACE) TraceHelper.beginSection("remove"); 1849 if (da > 0) { 1850 if (mReverseFlowPrimary) { 1851 removeInvisibleViewsAtEnd(); 1852 } else { 1853 removeInvisibleViewsAtFront(); 1854 } 1855 } else if (da < 0) { 1856 if (mReverseFlowPrimary) { 1857 removeInvisibleViewsAtFront(); 1858 } else { 1859 removeInvisibleViewsAtEnd(); 1860 } 1861 } 1862 if (TRACE) TraceHelper.endSection(); 1863 1864 updated |= getChildCount() < childCount; 1865 if (updated) { 1866 updateRowSecondarySizeRefresh(); 1867 } 1868 1869 mBaseGridView.invalidate(); 1870 if (TRACE) TraceHelper.endSection(); 1871 return da; 1872 } 1873 1874 // scroll in second direction will not add/prune views 1875 private int scrollDirectionSecondary(int dy) { 1876 if (dy == 0) { 1877 return 0; 1878 } 1879 offsetChildrenSecondary(-dy); 1880 mScrollOffsetSecondary += dy; 1881 mBaseGridView.invalidate(); 1882 return dy; 1883 } 1884 1885 private void updateScrollMax() { 1886 int highVisiblePos = (!mReverseFlowPrimary) ? mLastVisiblePos : mFirstVisiblePos; 1887 int highMaxPos = (!mReverseFlowPrimary) ? mState.getItemCount() - 1 : 0; 1888 if (highVisiblePos < 0) { 1889 return; 1890 } 1891 final boolean highAvailable = highVisiblePos == highMaxPos; 1892 final boolean maxUnknown = mWindowAlignment.mainAxis().isMaxUnknown(); 1893 if (!highAvailable && maxUnknown) { 1894 return; 1895 } 1896 int maxEdge = Integer.MIN_VALUE; 1897 int rowIndex = -1; 1898 for (int i = 0; i < mRows.length; i++) { 1899 if (mRows[i].high > maxEdge) { 1900 maxEdge = mRows[i].high; 1901 rowIndex = i; 1902 } 1903 } 1904 int maxScroll = Integer.MAX_VALUE; 1905 for (int i = mFirstVisiblePos; i <= mLastVisiblePos; i++) { 1906 int pos = mReverseFlowPrimary ? i : mLastVisiblePos-i+mFirstVisiblePos; 1907 StaggeredGrid.Location location = mGrid.getLocation(pos); 1908 if (location != null && location.row == rowIndex) { 1909 int savedMaxEdge = mWindowAlignment.mainAxis().getMaxEdge(); 1910 mWindowAlignment.mainAxis().setMaxEdge(maxEdge); 1911 maxScroll = getPrimarySystemScrollPosition(findViewByPosition(pos)); 1912 mWindowAlignment.mainAxis().setMaxEdge(savedMaxEdge); 1913 break; 1914 } 1915 } 1916 if (highAvailable) { 1917 mWindowAlignment.mainAxis().setMaxEdge(maxEdge); 1918 mWindowAlignment.mainAxis().setMaxScroll(maxScroll); 1919 if (DEBUG) Log.v(getTag(), "updating scroll maxEdge to " + maxEdge + 1920 " scrollMax to " + maxScroll); 1921 } else { 1922 // the maxScroll for currently last visible item is larger, 1923 // so we must invalidate the max scroll value. 1924 if (maxScroll > mWindowAlignment.mainAxis().getMaxScroll()) { 1925 mWindowAlignment.mainAxis().invalidateScrollMax(); 1926 if (DEBUG) Log.v(getTag(), "Invalidate scrollMax since it should be " 1927 + "greater than " + maxScroll); 1928 } 1929 } 1930 } 1931 1932 private void updateScrollMin() { 1933 int lowVisiblePos = (!mReverseFlowPrimary) ? mFirstVisiblePos : mLastVisiblePos; 1934 int lowMinPos = (!mReverseFlowPrimary) ? 0 : mState.getItemCount() - 1; 1935 if (lowVisiblePos < 0) { 1936 return; 1937 } 1938 final boolean lowAvailable = lowVisiblePos == lowMinPos; 1939 final boolean minUnknown = mWindowAlignment.mainAxis().isMinUnknown(); 1940 if (!lowAvailable && minUnknown) { 1941 return; 1942 } 1943 int minEdge = Integer.MAX_VALUE; 1944 int rowIndex = -1; 1945 for (int i = 0; i < mRows.length; i++) { 1946 if (mRows[i].low < minEdge) { 1947 minEdge = mRows[i].low; 1948 rowIndex = i; 1949 } 1950 } 1951 int minScroll = Integer.MIN_VALUE; 1952 for (int i = mFirstVisiblePos; i <= mLastVisiblePos; i++) { 1953 int pos = mReverseFlowPrimary ? mLastVisiblePos-i+mFirstVisiblePos : i; 1954 StaggeredGrid.Location location = mGrid.getLocation(pos); 1955 if (location != null && location.row == rowIndex) { 1956 int savedMinEdge = mWindowAlignment.mainAxis().getMinEdge(); 1957 mWindowAlignment.mainAxis().setMinEdge(minEdge); 1958 minScroll = getPrimarySystemScrollPosition(findViewByPosition(pos)); 1959 mWindowAlignment.mainAxis().setMinEdge(savedMinEdge); 1960 break; 1961 } 1962 } 1963 if (lowAvailable) { 1964 mWindowAlignment.mainAxis().setMinEdge(minEdge); 1965 mWindowAlignment.mainAxis().setMinScroll(minScroll); 1966 if (DEBUG) Log.v(getTag(), "updating scroll minEdge to " + minEdge + 1967 " scrollMin to " + minScroll); 1968 } else { 1969 // the minScroll for currently first visible item is smaller, 1970 // so we must invalidate the min scroll value. 1971 if (minScroll < mWindowAlignment.mainAxis().getMinScroll()) { 1972 mWindowAlignment.mainAxis().invalidateScrollMin(); 1973 if (DEBUG) Log.v(getTag(), "Invalidate scrollMin, since it should be " 1974 + "less than " + minScroll); 1975 } 1976 } 1977 } 1978 1979 private void updateScrollSecondAxis() { 1980 mWindowAlignment.secondAxis().setMinEdge(0); 1981 mWindowAlignment.secondAxis().setMaxEdge(getSizeSecondary()); 1982 } 1983 1984 private void initScrollController() { 1985 mWindowAlignment.reset(); 1986 mWindowAlignment.horizontal.setSize(getWidth()); 1987 mWindowAlignment.vertical.setSize(getHeight()); 1988 mWindowAlignment.horizontal.setPadding(getPaddingLeft(), getPaddingRight()); 1989 mWindowAlignment.vertical.setPadding(getPaddingTop(), getPaddingBottom()); 1990 mSizePrimary = mWindowAlignment.mainAxis().getSize(); 1991 mScrollOffsetPrimary = -mWindowAlignment.mainAxis().getPaddingLow(); 1992 mScrollOffsetSecondary = -mWindowAlignment.secondAxis().getPaddingLow(); 1993 1994 if (DEBUG) { 1995 Log.v(getTag(), "initScrollController mSizePrimary " + mSizePrimary 1996 + " mWindowAlignment " + mWindowAlignment 1997 + " mScrollOffsetPrimary " + mScrollOffsetPrimary); 1998 } 1999 } 2000 2001 private void updateScrollController() { 2002 // mScrollOffsetPrimary and mScrollOffsetSecondary includes the padding. 2003 // e.g. when topPadding is 16 for horizontal grid view, the initial 2004 // mScrollOffsetSecondary is -16. fastLayout() put views based on offsets(not padding), 2005 // when padding changes to 20, we also need update mScrollOffsetSecondary to -20 before 2006 // fastLayout() is performed 2007 int paddingPrimaryDiff, paddingSecondaryDiff; 2008 if (mOrientation == HORIZONTAL) { 2009 paddingPrimaryDiff = getPaddingLeft() - mWindowAlignment.horizontal.getPaddingLow(); 2010 paddingSecondaryDiff = getPaddingTop() - mWindowAlignment.vertical.getPaddingLow(); 2011 } else { 2012 paddingPrimaryDiff = getPaddingTop() - mWindowAlignment.vertical.getPaddingLow(); 2013 paddingSecondaryDiff = getPaddingLeft() - mWindowAlignment.horizontal.getPaddingLow(); 2014 } 2015 mScrollOffsetPrimary -= paddingPrimaryDiff; 2016 mScrollOffsetSecondary -= paddingSecondaryDiff; 2017 2018 mWindowAlignment.horizontal.setSize(getWidth()); 2019 mWindowAlignment.vertical.setSize(getHeight()); 2020 mWindowAlignment.horizontal.setPadding(getPaddingLeft(), getPaddingRight()); 2021 mWindowAlignment.vertical.setPadding(getPaddingTop(), getPaddingBottom()); 2022 mSizePrimary = mWindowAlignment.mainAxis().getSize(); 2023 2024 if (DEBUG) { 2025 Log.v(getTag(), "updateScrollController mSizePrimary " + mSizePrimary 2026 + " mWindowAlignment " + mWindowAlignment 2027 + " mScrollOffsetPrimary " + mScrollOffsetPrimary); 2028 } 2029 } 2030 2031 public void setSelection(RecyclerView parent, int position) { 2032 setSelection(parent, position, false); 2033 } 2034 2035 public void setSelectionSmooth(RecyclerView parent, int position) { 2036 setSelection(parent, position, true); 2037 } 2038 2039 public int getSelection() { 2040 return mFocusPosition; 2041 } 2042 2043 public void setSelection(RecyclerView parent, int position, boolean smooth) { 2044 if (mFocusPosition != position && position != NO_POSITION) { 2045 scrollToSelection(parent, position, smooth); 2046 } 2047 } 2048 2049 private void scrollToSelection(RecyclerView parent, int position, boolean smooth) { 2050 if (TRACE) TraceHelper.beginSection("scrollToSelection"); 2051 View view = findViewByPosition(position); 2052 if (view != null) { 2053 mInSelection = true; 2054 scrollToView(view, smooth); 2055 mInSelection = false; 2056 } else { 2057 mFocusPosition = position; 2058 mFocusPositionOffset = 0; 2059 if (!mLayoutEnabled) { 2060 return; 2061 } 2062 if (smooth) { 2063 if (!hasDoneFirstLayout()) { 2064 Log.w(getTag(), "setSelectionSmooth should " + 2065 "not be called before first layout pass"); 2066 return; 2067 } 2068 LinearSmoothScroller linearSmoothScroller = 2069 new LinearSmoothScroller(parent.getContext()) { 2070 @Override 2071 public PointF computeScrollVectorForPosition(int targetPosition) { 2072 if (getChildCount() == 0) { 2073 return null; 2074 } 2075 final int firstChildPos = getPosition(getChildAt(0)); 2076 // TODO We should be able to deduce direction from bounds of current and target focus, 2077 // rather than making assumptions about positions and directionality 2078 final boolean isStart = mReverseFlowPrimary ? targetPosition > firstChildPos : targetPosition < firstChildPos; 2079 final int direction = isStart ? -1 : 1; 2080 if (mOrientation == HORIZONTAL) { 2081 return new PointF(direction, 0); 2082 } else { 2083 return new PointF(0, direction); 2084 } 2085 } 2086 @Override 2087 protected void onTargetFound(View targetView, 2088 RecyclerView.State state, Action action) { 2089 if (hasFocus()) { 2090 targetView.requestFocus(); 2091 } 2092 dispatchChildSelected(); 2093 if (getScrollPosition(targetView, mTempDeltas)) { 2094 int dx, dy; 2095 if (mOrientation == HORIZONTAL) { 2096 dx = mTempDeltas[0]; 2097 dy = mTempDeltas[1]; 2098 } else { 2099 dx = mTempDeltas[1]; 2100 dy = mTempDeltas[0]; 2101 } 2102 final int distance = (int) Math.sqrt(dx * dx + dy * dy); 2103 final int time = calculateTimeForDeceleration(distance); 2104 action.update(dx, dy, time, mDecelerateInterpolator); 2105 } 2106 } 2107 }; 2108 linearSmoothScroller.setTargetPosition(position); 2109 startSmoothScroll(linearSmoothScroller); 2110 } else { 2111 mForceFullLayout = true; 2112 parent.requestLayout(); 2113 } 2114 } 2115 if (TRACE) TraceHelper.endSection(); 2116 } 2117 2118 @Override 2119 public void onItemsAdded(RecyclerView recyclerView, int positionStart, int itemCount) { 2120 if (DEBUG) Log.v(getTag(), "onItemsAdded positionStart " 2121 + positionStart + " itemCount " + itemCount); 2122 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE 2123 && getChildAt(mFocusPosition) != null) { 2124 int pos = mFocusPosition + mFocusPositionOffset; 2125 if (positionStart <= pos) { 2126 mFocusPositionOffset += itemCount; 2127 } 2128 } 2129 mChildrenStates.clear(); 2130 } 2131 2132 @Override 2133 public void onItemsChanged(RecyclerView recyclerView) { 2134 if (DEBUG) Log.v(getTag(), "onItemsChanged"); 2135 mFocusPositionOffset = 0; 2136 mChildrenStates.clear(); 2137 } 2138 2139 @Override 2140 public void onItemsRemoved(RecyclerView recyclerView, int positionStart, int itemCount) { 2141 if (DEBUG) Log.v(getTag(), "onItemsRemoved positionStart " 2142 + positionStart + " itemCount " + itemCount); 2143 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE 2144 && getChildAt(mFocusPosition) != null) { 2145 int pos = mFocusPosition + mFocusPositionOffset; 2146 if (positionStart <= pos) { 2147 if (positionStart + itemCount > pos) { 2148 // stop updating offset after the focus item was removed 2149 mFocusPositionOffset = Integer.MIN_VALUE; 2150 } else { 2151 mFocusPositionOffset -= itemCount; 2152 } 2153 } 2154 } 2155 mChildrenStates.clear(); 2156 } 2157 2158 @Override 2159 public void onItemsMoved(RecyclerView recyclerView, int fromPosition, int toPosition, 2160 int itemCount) { 2161 if (DEBUG) Log.v(getTag(), "onItemsMoved fromPosition " 2162 + fromPosition + " toPosition " + toPosition); 2163 if (mFocusPosition != NO_POSITION && mFocusPositionOffset != Integer.MIN_VALUE 2164 && getChildAt(mFocusPosition) != null) { 2165 int pos = mFocusPosition + mFocusPositionOffset; 2166 if (fromPosition <= pos && pos < fromPosition + itemCount) { 2167 // moved items include focused position 2168 mFocusPositionOffset += toPosition - fromPosition; 2169 } else if (fromPosition < pos && toPosition > pos - itemCount) { 2170 // move items before focus position to after focused position 2171 mFocusPositionOffset -= itemCount; 2172 } else if (fromPosition > pos && toPosition < pos) { 2173 // move items after focus position to before focused position 2174 mFocusPositionOffset += itemCount; 2175 } 2176 } 2177 mChildrenStates.clear(); 2178 } 2179 2180 @Override 2181 public void onItemsUpdated(RecyclerView recyclerView, int positionStart, int itemCount) { 2182 if (DEBUG) Log.v(getTag(), "onItemsUpdated positionStart " 2183 + positionStart + " itemCount " + itemCount); 2184 for (int i = positionStart, end = positionStart + itemCount; i < end; i++) { 2185 mChildrenStates.remove(i); 2186 } 2187 } 2188 2189 @Override 2190 public boolean onRequestChildFocus(RecyclerView parent, View child, View focused) { 2191 if (mFocusSearchDisabled) { 2192 return true; 2193 } 2194 if (getPositionByView(child) == NO_POSITION) { 2195 // This shouldn't happen, but in case it does be sure not to attempt a 2196 // scroll to a view whose item has been removed. 2197 return true; 2198 } 2199 if (!mInLayout && !mInSelection) { 2200 scrollToView(child, true); 2201 } 2202 return true; 2203 } 2204 2205 @Override 2206 public boolean requestChildRectangleOnScreen(RecyclerView parent, View view, Rect rect, 2207 boolean immediate) { 2208 if (DEBUG) Log.v(getTag(), "requestChildRectangleOnScreen " + view + " " + rect); 2209 return false; 2210 } 2211 2212 int getScrollOffsetX() { 2213 return mOrientation == HORIZONTAL ? mScrollOffsetPrimary : mScrollOffsetSecondary; 2214 } 2215 2216 int getScrollOffsetY() { 2217 return mOrientation == HORIZONTAL ? mScrollOffsetSecondary : mScrollOffsetPrimary; 2218 } 2219 2220 public void getViewSelectedOffsets(View view, int[] offsets) { 2221 if (mOrientation == HORIZONTAL) { 2222 offsets[0] = getPrimarySystemScrollPosition(view) - mScrollOffsetPrimary; 2223 offsets[1] = getSecondarySystemScrollPosition(view) - mScrollOffsetSecondary; 2224 } else { 2225 offsets[1] = getPrimarySystemScrollPosition(view) - mScrollOffsetPrimary; 2226 offsets[0] = getSecondarySystemScrollPosition(view) - mScrollOffsetSecondary; 2227 } 2228 } 2229 2230 private int getPrimarySystemScrollPosition(View view) { 2231 final int viewCenterPrimary = mScrollOffsetPrimary + getViewCenter(view); 2232 final int viewMin = getViewMin(view); 2233 final int viewMax = getViewMax(view); 2234 // TODO: change to use State object in onRequestChildFocus() 2235 boolean isMin, isMax; 2236 if (!mReverseFlowPrimary) { 2237 isMin = mFirstVisiblePos == 0; 2238 isMax = mLastVisiblePos == (mState == null ? 2239 getItemCount() : mState.getItemCount()) - 1; 2240 } else { 2241 isMax = mFirstVisiblePos == 0; 2242 isMin = mLastVisiblePos == (mState == null ? 2243 getItemCount() : mState.getItemCount()) - 1; 2244 } 2245 for (int i = getChildCount() - 1; (isMin || isMax) && i >= 0; i--) { 2246 View v = getChildAt(i); 2247 if (v == view || v == null) { 2248 continue; 2249 } 2250 if (isMin && getViewMin(v) < viewMin) { 2251 isMin = false; 2252 } 2253 if (isMax && getViewMax(v) > viewMax) { 2254 isMax = false; 2255 } 2256 } 2257 return mWindowAlignment.mainAxis().getSystemScrollPos(viewCenterPrimary, isMin, isMax); 2258 } 2259 2260 private int getSecondarySystemScrollPosition(View view) { 2261 int viewCenterSecondary = mScrollOffsetSecondary + getViewCenterSecondary(view); 2262 int pos = getPositionByView(view); 2263 StaggeredGrid.Location location = mGrid.getLocation(pos); 2264 final int row = location.row; 2265 final boolean isMin, isMax; 2266 if (!mReverseFlowSecondary) { 2267 isMin = row == 0; 2268 isMax = row == mGrid.getNumRows() - 1; 2269 } else { 2270 isMax = row == 0; 2271 isMin = row == mGrid.getNumRows() - 1; 2272 } 2273 return mWindowAlignment.secondAxis().getSystemScrollPos(viewCenterSecondary, isMin, isMax); 2274 } 2275 2276 /** 2277 * Scroll to a given child view and change mFocusPosition. 2278 */ 2279 private void scrollToView(View view, boolean smooth) { 2280 int newFocusPosition = getPositionByView(view); 2281 if (newFocusPosition != mFocusPosition) { 2282 mFocusPosition = newFocusPosition; 2283 mFocusPositionOffset = 0; 2284 if (!mInLayout) { 2285 dispatchChildSelected(); 2286 } 2287 } 2288 if (mBaseGridView.isChildrenDrawingOrderEnabledInternal()) { 2289 mBaseGridView.invalidate(); 2290 } 2291 if (view == null) { 2292 return; 2293 } 2294 if (!view.hasFocus() && mBaseGridView.hasFocus()) { 2295 // transfer focus to the child if it does not have focus yet (e.g. triggered 2296 // by setSelection()) 2297 view.requestFocus(); 2298 } 2299 if (!mScrollEnabled) { 2300 return; 2301 } 2302 if (getScrollPosition(view, mTempDeltas)) { 2303 scrollGrid(mTempDeltas[0], mTempDeltas[1], smooth); 2304 } 2305 } 2306 2307 private boolean getScrollPosition(View view, int[] deltas) { 2308 switch (mFocusScrollStrategy) { 2309 case BaseGridView.FOCUS_SCROLL_ALIGNED: 2310 default: 2311 return getAlignedPosition(view, deltas); 2312 case BaseGridView.FOCUS_SCROLL_ITEM: 2313 case BaseGridView.FOCUS_SCROLL_PAGE: 2314 return getNoneAlignedPosition(view, deltas); 2315 } 2316 } 2317 2318 private boolean getNoneAlignedPosition(View view, int[] deltas) { 2319 int pos = getPositionByView(view); 2320 int viewMin = getViewMin(view); 2321 int viewMax = getViewMax(view); 2322 // we either align "firstView" to left/top padding edge 2323 // or align "lastView" to right/bottom padding edge 2324 View firstView = null; 2325 View lastView = null; 2326 int paddingLow = mWindowAlignment.mainAxis().getPaddingLow(); 2327 int clientSize = mWindowAlignment.mainAxis().getClientSize(); 2328 final int row = mGrid.getLocation(pos).row; 2329 if (viewMin < paddingLow) { 2330 // view enters low padding area: 2331 firstView = view; 2332 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_PAGE) { 2333 // scroll one "page" left/top, 2334 // align first visible item of the "page" at the low padding edge. 2335 while (!prependOneVisibleItem()) { 2336 List<Integer> positions = 2337 mGrid.getItemPositionsInRows(mFirstVisiblePos, pos)[row]; 2338 firstView = findViewByPosition(positions.get(0)); 2339 if (viewMax - getViewMin(firstView) > clientSize) { 2340 if (positions.size() > 1) { 2341 firstView = findViewByPosition(positions.get(1)); 2342 } 2343 break; 2344 } 2345 } 2346 } 2347 } else if (viewMax > clientSize + paddingLow) { 2348 // view enters high padding area: 2349 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_PAGE) { 2350 // scroll whole one page right/bottom, align view at the low padding edge. 2351 firstView = view; 2352 do { 2353 List<Integer> positions = 2354 mGrid.getItemPositionsInRows(pos, mLastVisiblePos)[row]; 2355 lastView = findViewByPosition(positions.get(positions.size() - 1)); 2356 if (getViewMax(lastView) - viewMin > clientSize) { 2357 lastView = null; 2358 break; 2359 } 2360 } while (!appendOneVisibleItem()); 2361 if (lastView != null) { 2362 // however if we reached end, we should align last view. 2363 firstView = null; 2364 } 2365 } else { 2366 lastView = view; 2367 } 2368 } 2369 int scrollPrimary = 0; 2370 int scrollSecondary = 0; 2371 if (firstView != null) { 2372 scrollPrimary = getViewMin(firstView) - paddingLow; 2373 } else if (lastView != null) { 2374 scrollPrimary = getViewMax(lastView) - (paddingLow + clientSize); 2375 } 2376 View secondaryAlignedView; 2377 if (firstView != null) { 2378 secondaryAlignedView = firstView; 2379 } else if (lastView != null) { 2380 secondaryAlignedView = lastView; 2381 } else { 2382 secondaryAlignedView = view; 2383 } 2384 scrollSecondary = getSecondarySystemScrollPosition(secondaryAlignedView); 2385 scrollSecondary -= mScrollOffsetSecondary; 2386 if (scrollPrimary != 0 || scrollSecondary != 0) { 2387 deltas[0] = scrollPrimary; 2388 deltas[1] = scrollSecondary; 2389 return true; 2390 } 2391 return false; 2392 } 2393 2394 private boolean getAlignedPosition(View view, int[] deltas) { 2395 int scrollPrimary = getPrimarySystemScrollPosition(view); 2396 int scrollSecondary = getSecondarySystemScrollPosition(view); 2397 if (DEBUG) { 2398 Log.v(getTag(), "getAlignedPosition " + scrollPrimary + " " + scrollSecondary 2399 + " " + mWindowAlignment); 2400 Log.v(getTag(), "getAlignedPosition " + mScrollOffsetPrimary + " " + mScrollOffsetSecondary); 2401 } 2402 scrollPrimary -= mScrollOffsetPrimary; 2403 scrollSecondary -= mScrollOffsetSecondary; 2404 if (scrollPrimary != 0 || scrollSecondary != 0) { 2405 deltas[0] = scrollPrimary; 2406 deltas[1] = scrollSecondary; 2407 return true; 2408 } 2409 return false; 2410 } 2411 2412 private void scrollGrid(int scrollPrimary, int scrollSecondary, boolean smooth) { 2413 if (mInLayout) { 2414 scrollDirectionPrimary(scrollPrimary); 2415 scrollDirectionSecondary(scrollSecondary); 2416 } else { 2417 int scrollX; 2418 int scrollY; 2419 if (mOrientation == HORIZONTAL) { 2420 scrollX = scrollPrimary; 2421 scrollY = scrollSecondary; 2422 } else { 2423 scrollX = scrollSecondary; 2424 scrollY = scrollPrimary; 2425 } 2426 if (smooth) { 2427 mBaseGridView.smoothScrollBy(scrollX, scrollY); 2428 } else { 2429 mBaseGridView.scrollBy(scrollX, scrollY); 2430 } 2431 } 2432 } 2433 2434 public void setPruneChild(boolean pruneChild) { 2435 if (mPruneChild != pruneChild) { 2436 mPruneChild = pruneChild; 2437 if (mPruneChild) { 2438 requestLayout(); 2439 } 2440 } 2441 } 2442 2443 public boolean getPruneChild() { 2444 return mPruneChild; 2445 } 2446 2447 public void setScrollEnabled(boolean scrollEnabled) { 2448 if (mScrollEnabled != scrollEnabled) { 2449 mScrollEnabled = scrollEnabled; 2450 if (mScrollEnabled && mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED 2451 && mFocusPosition != NO_POSITION) { 2452 scrollToSelection(mBaseGridView, mFocusPosition, true); 2453 } 2454 } 2455 } 2456 2457 public boolean isScrollEnabled() { 2458 return mScrollEnabled; 2459 } 2460 2461 private int findImmediateChildIndex(View view) { 2462 while (view != null && view != mBaseGridView) { 2463 int index = mBaseGridView.indexOfChild(view); 2464 if (index >= 0) { 2465 return index; 2466 } 2467 view = (View) view.getParent(); 2468 } 2469 return NO_POSITION; 2470 } 2471 2472 void setFocusSearchDisabled(boolean disabled) { 2473 mFocusSearchDisabled = disabled; 2474 } 2475 2476 boolean isFocusSearchDisabled() { 2477 return mFocusSearchDisabled; 2478 } 2479 2480 @Override 2481 public View onInterceptFocusSearch(View focused, int direction) { 2482 if (mFocusSearchDisabled) { 2483 return focused; 2484 } 2485 return null; 2486 } 2487 2488 boolean hasPreviousViewInSameRow(int pos) { 2489 if (mGrid == null || pos == NO_POSITION) { 2490 return false; 2491 } 2492 if (mFirstVisiblePos > 0) { 2493 return true; 2494 } 2495 final int focusedRow = mGrid.getLocation(pos).row; 2496 for (int i = getChildCount() - 1; i >= 0; i--) { 2497 int position = getPositionByIndex(i); 2498 StaggeredGrid.Location loc = mGrid.getLocation(position); 2499 if (loc != null && loc.row == focusedRow) { 2500 if (position < pos) { 2501 return true; 2502 } 2503 } 2504 } 2505 return false; 2506 } 2507 2508 @Override 2509 public boolean onAddFocusables(RecyclerView recyclerView, 2510 ArrayList<View> views, int direction, int focusableMode) { 2511 if (mFocusSearchDisabled) { 2512 return true; 2513 } 2514 // If this viewgroup or one of its children currently has focus then we 2515 // consider our children for focus searching in main direction on the same row. 2516 // If this viewgroup has no focus and using focus align, we want the system 2517 // to ignore our children and pass focus to the viewgroup, which will pass 2518 // focus on to its children appropriately. 2519 // If this viewgroup has no focus and not using focus align, we want to 2520 // consider the child that does not overlap with padding area. 2521 if (recyclerView.hasFocus()) { 2522 final int movement = getMovement(direction); 2523 if (movement != PREV_ITEM && movement != NEXT_ITEM) { 2524 // Move on secondary direction uses default addFocusables(). 2525 return false; 2526 } 2527 final View focused = recyclerView.findFocus(); 2528 final int focusedPos = getPositionByIndex(findImmediateChildIndex(focused)); 2529 // Add focusables of focused item. 2530 if (focusedPos != NO_POSITION) { 2531 findViewByPosition(focusedPos).addFocusables(views, direction, focusableMode); 2532 } 2533 final int focusedRow = mGrid != null && focusedPos != NO_POSITION ? 2534 mGrid.getLocation(focusedPos).row : NO_POSITION; 2535 // Add focusables of next neighbor of same row on the focus search direction. 2536 if (mGrid != null) { 2537 final int focusableCount = views.size(); 2538 for (int i = 0, count = getChildCount(); i < count; i++) { 2539 int index = movement == NEXT_ITEM ? i : count - 1 - i; 2540 final View child = getChildAt(index); 2541 if (child.getVisibility() != View.VISIBLE) { 2542 continue; 2543 } 2544 int position = getPositionByIndex(index); 2545 StaggeredGrid.Location loc = mGrid.getLocation(position); 2546 if (focusedRow == NO_POSITION || (loc != null && loc.row == focusedRow)) { 2547 if (focusedPos == NO_POSITION || 2548 (movement == NEXT_ITEM && position > focusedPos) 2549 || (movement == PREV_ITEM && position < focusedPos)) { 2550 child.addFocusables(views, direction, focusableMode); 2551 if (views.size() > focusableCount) { 2552 break; 2553 } 2554 } 2555 } 2556 } 2557 } 2558 } else { 2559 if (mFocusScrollStrategy != BaseGridView.FOCUS_SCROLL_ALIGNED) { 2560 // adding views not overlapping padding area to avoid scrolling in gaining focus 2561 int left = mWindowAlignment.mainAxis().getPaddingLow(); 2562 int right = mWindowAlignment.mainAxis().getClientSize() + left; 2563 int focusableCount = views.size(); 2564 for (int i = 0, count = getChildCount(); i < count; i++) { 2565 View child = getChildAt(i); 2566 if (child.getVisibility() == View.VISIBLE) { 2567 if (getViewMin(child) >= left && getViewMax(child) <= right) { 2568 child.addFocusables(views, direction, focusableMode); 2569 } 2570 } 2571 } 2572 // if we cannot find any, then just add all children. 2573 if (views.size() == focusableCount) { 2574 for (int i = 0, count = getChildCount(); i < count; i++) { 2575 View child = getChildAt(i); 2576 if (child.getVisibility() == View.VISIBLE) { 2577 child.addFocusables(views, direction, focusableMode); 2578 } 2579 } 2580 if (views.size() != focusableCount) { 2581 return true; 2582 } 2583 } else { 2584 return true; 2585 } 2586 // if still cannot find any, fall through and add itself 2587 } 2588 if (recyclerView.isFocusable()) { 2589 views.add(recyclerView); 2590 } 2591 } 2592 return true; 2593 } 2594 2595 @Override 2596 public View onFocusSearchFailed(View focused, int direction, Recycler recycler, 2597 RecyclerView.State state) { 2598 if (DEBUG) Log.v(getTag(), "onFocusSearchFailed direction " + direction); 2599 2600 View view = null; 2601 int movement = getMovement(direction); 2602 final boolean isScroll = mBaseGridView.getScrollState() != RecyclerView.SCROLL_STATE_IDLE; 2603 if (mNumRows == 1) { 2604 // for simple row, use LinearSmoothScroller to smooth animation. 2605 // It will stay at a fixed cap speed in continuous scroll. 2606 if (movement == NEXT_ITEM) { 2607 int newPos = mFocusPosition + mNumRows; 2608 if (newPos < getItemCount() && mScrollEnabled) { 2609 setSelectionSmooth(mBaseGridView, newPos); 2610 view = focused; 2611 } else { 2612 if (isScroll || !mFocusOutEnd) { 2613 view = focused; 2614 } 2615 } 2616 } else if (movement == PREV_ITEM){ 2617 int newPos = mFocusPosition - mNumRows; 2618 if (newPos >= 0 && mScrollEnabled) { 2619 setSelectionSmooth(mBaseGridView, newPos); 2620 view = focused; 2621 } else { 2622 if (isScroll || !mFocusOutFront) { 2623 view = focused; 2624 } 2625 } 2626 } 2627 } else if (mNumRows > 1) { 2628 // for possible staggered grid, we need guarantee focus to same row/column. 2629 // TODO: we may also use LinearSmoothScroller. 2630 saveContext(recycler, state); 2631 final FocusFinder ff = FocusFinder.getInstance(); 2632 if (movement == NEXT_ITEM) { 2633 while (view == null && !appendOneVisibleItem()) { 2634 view = ff.findNextFocus(mBaseGridView, focused, direction); 2635 } 2636 } else if (movement == PREV_ITEM){ 2637 while (view == null && !prependOneVisibleItem()) { 2638 view = ff.findNextFocus(mBaseGridView, focused, direction); 2639 } 2640 } 2641 if (view == null) { 2642 // returning the same view to prevent focus lost when scrolling past the end of the list 2643 if (movement == PREV_ITEM) { 2644 view = mFocusOutFront && !isScroll ? null : focused; 2645 } else if (movement == NEXT_ITEM){ 2646 view = mFocusOutEnd && !isScroll ? null : focused; 2647 } 2648 } 2649 leaveContext(); 2650 } 2651 if (DEBUG) Log.v(getTag(), "returning view " + view); 2652 return view; 2653 } 2654 2655 boolean gridOnRequestFocusInDescendants(RecyclerView recyclerView, int direction, 2656 Rect previouslyFocusedRect) { 2657 switch (mFocusScrollStrategy) { 2658 case BaseGridView.FOCUS_SCROLL_ALIGNED: 2659 default: 2660 return gridOnRequestFocusInDescendantsAligned(recyclerView, 2661 direction, previouslyFocusedRect); 2662 case BaseGridView.FOCUS_SCROLL_PAGE: 2663 case BaseGridView.FOCUS_SCROLL_ITEM: 2664 return gridOnRequestFocusInDescendantsUnaligned(recyclerView, 2665 direction, previouslyFocusedRect); 2666 } 2667 } 2668 2669 private boolean gridOnRequestFocusInDescendantsAligned(RecyclerView recyclerView, 2670 int direction, Rect previouslyFocusedRect) { 2671 View view = findViewByPosition(mFocusPosition); 2672 if (view != null) { 2673 boolean result = view.requestFocus(direction, previouslyFocusedRect); 2674 if (!result && DEBUG) { 2675 Log.w(getTag(), "failed to request focus on " + view); 2676 } 2677 return result; 2678 } 2679 return false; 2680 } 2681 2682 private boolean gridOnRequestFocusInDescendantsUnaligned(RecyclerView recyclerView, 2683 int direction, Rect previouslyFocusedRect) { 2684 // focus to view not overlapping padding area to avoid scrolling in gaining focus 2685 int index; 2686 int increment; 2687 int end; 2688 int count = getChildCount(); 2689 if ((direction & View.FOCUS_FORWARD) != 0) { 2690 index = 0; 2691 increment = 1; 2692 end = count; 2693 } else { 2694 index = count - 1; 2695 increment = -1; 2696 end = -1; 2697 } 2698 int left = mWindowAlignment.mainAxis().getPaddingLow(); 2699 int right = mWindowAlignment.mainAxis().getClientSize() + left; 2700 for (int i = index; i != end; i += increment) { 2701 View child = getChildAt(i); 2702 if (child.getVisibility() == View.VISIBLE) { 2703 if (getViewMin(child) >= left && getViewMax(child) <= right) { 2704 if (child.requestFocus(direction, previouslyFocusedRect)) { 2705 return true; 2706 } 2707 } 2708 } 2709 } 2710 return false; 2711 } 2712 2713 private final static int PREV_ITEM = 0; 2714 private final static int NEXT_ITEM = 1; 2715 private final static int PREV_ROW = 2; 2716 private final static int NEXT_ROW = 3; 2717 2718 private int getMovement(int direction) { 2719 int movement = View.FOCUS_LEFT; 2720 2721 if (mOrientation == HORIZONTAL) { 2722 switch(direction) { 2723 case View.FOCUS_LEFT: 2724 movement = (!mReverseFlowPrimary) ? PREV_ITEM : NEXT_ITEM; 2725 break; 2726 case View.FOCUS_RIGHT: 2727 movement = (!mReverseFlowPrimary) ? NEXT_ITEM : PREV_ITEM; 2728 break; 2729 case View.FOCUS_UP: 2730 movement = PREV_ROW; 2731 break; 2732 case View.FOCUS_DOWN: 2733 movement = NEXT_ROW; 2734 break; 2735 } 2736 } else if (mOrientation == VERTICAL) { 2737 switch(direction) { 2738 case View.FOCUS_LEFT: 2739 movement = (!mReverseFlowPrimary) ? PREV_ROW : NEXT_ROW; 2740 break; 2741 case View.FOCUS_RIGHT: 2742 movement = (!mReverseFlowPrimary) ? NEXT_ROW : PREV_ROW; 2743 break; 2744 case View.FOCUS_UP: 2745 movement = PREV_ITEM; 2746 break; 2747 case View.FOCUS_DOWN: 2748 movement = NEXT_ITEM; 2749 break; 2750 } 2751 } 2752 2753 return movement; 2754 } 2755 2756 int getChildDrawingOrder(RecyclerView recyclerView, int childCount, int i) { 2757 View view = findViewByPosition(mFocusPosition); 2758 if (view == null) { 2759 return i; 2760 } 2761 int focusIndex = recyclerView.indexOfChild(view); 2762 // supposely 0 1 2 3 4 5 6 7 8 9, 4 is the center item 2763 // drawing order is 0 1 2 3 9 8 7 6 5 4 2764 if (i < focusIndex) { 2765 return i; 2766 } else if (i < childCount - 1) { 2767 return focusIndex + childCount - 1 - i; 2768 } else { 2769 return focusIndex; 2770 } 2771 } 2772 2773 @Override 2774 public void onAdapterChanged(RecyclerView.Adapter oldAdapter, 2775 RecyclerView.Adapter newAdapter) { 2776 if (DEBUG) Log.v(getTag(), "onAdapterChanged to " + newAdapter); 2777 if (oldAdapter != null) { 2778 discardLayoutInfo(); 2779 mFocusPosition = NO_POSITION; 2780 mFocusPositionOffset = 0; 2781 mChildrenStates.clear(); 2782 } 2783 super.onAdapterChanged(oldAdapter, newAdapter); 2784 } 2785 2786 private void discardLayoutInfo() { 2787 mGrid = null; 2788 mRows = null; 2789 mRowSizeSecondary = null; 2790 mFirstVisiblePos = -1; 2791 mLastVisiblePos = -1; 2792 mRowSecondarySizeRefresh = false; 2793 } 2794 2795 public void setLayoutEnabled(boolean layoutEnabled) { 2796 if (mLayoutEnabled != layoutEnabled) { 2797 mLayoutEnabled = layoutEnabled; 2798 requestLayout(); 2799 } 2800 } 2801 2802 void setChildrenVisibility(int visiblity) { 2803 mChildVisibility = visiblity; 2804 if (mChildVisibility != -1) { 2805 int count = getChildCount(); 2806 for (int i= 0; i < count; i++) { 2807 getChildAt(i).setVisibility(mChildVisibility); 2808 } 2809 } 2810 } 2811 2812 final static class SavedState implements Parcelable { 2813 2814 int index; // index inside adapter of the current view 2815 Bundle childStates = Bundle.EMPTY; 2816 2817 @Override 2818 public void writeToParcel(Parcel out, int flags) { 2819 out.writeInt(index); 2820 out.writeBundle(childStates); 2821 } 2822 2823 @SuppressWarnings("hiding") 2824 public static final Parcelable.Creator<SavedState> CREATOR = 2825 new Parcelable.Creator<SavedState>() { 2826 @Override 2827 public SavedState createFromParcel(Parcel in) { 2828 return new SavedState(in); 2829 } 2830 2831 @Override 2832 public SavedState[] newArray(int size) { 2833 return new SavedState[size]; 2834 } 2835 }; 2836 2837 @Override 2838 public int describeContents() { 2839 return 0; 2840 } 2841 2842 SavedState(Parcel in) { 2843 index = in.readInt(); 2844 childStates = in.readBundle(GridLayoutManager.class.getClassLoader()); 2845 } 2846 2847 SavedState() { 2848 } 2849 } 2850 2851 @Override 2852 public Parcelable onSaveInstanceState() { 2853 if (DEBUG) Log.v(getTag(), "onSaveInstanceState getSelection() " + getSelection()); 2854 SavedState ss = new SavedState(); 2855 for (int i = 0, count = getChildCount(); i < count; i++) { 2856 View view = getChildAt(i); 2857 int position = getPositionByView(view); 2858 if (position != NO_POSITION) { 2859 mChildrenStates.saveOnScreenView(view, position); 2860 } 2861 } 2862 ss.index = getSelection(); 2863 ss.childStates = mChildrenStates.saveAsBundle(); 2864 return ss; 2865 } 2866 2867 @Override 2868 public void onRestoreInstanceState(Parcelable state) { 2869 if (!(state instanceof SavedState)) { 2870 return; 2871 } 2872 SavedState loadingState = (SavedState)state; 2873 mFocusPosition = loadingState.index; 2874 mFocusPositionOffset = 0; 2875 mChildrenStates.loadFromBundle(loadingState.childStates); 2876 mForceFullLayout = true; 2877 requestLayout(); 2878 if (DEBUG) Log.v(getTag(), "onRestoreInstanceState mFocusPosition " + mFocusPosition); 2879 } 2880} 2881