GridLayoutManager.java revision dafdf6a770fb84c1228f442db64550aae6fc11ae
1/* 2 * Copyright (C) 2014 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except 5 * in compliance with the License. You may obtain a copy of the License at 6 * 7 * http://www.apache.org/licenses/LICENSE-2.0 8 * 9 * Unless required by applicable law or agreed to in writing, software distributed under the License 10 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express 11 * or implied. See the License for the specific language governing permissions and limitations under 12 * the License. 13 */ 14package android.support.v17.leanback.widget; 15 16import android.content.Context; 17import android.graphics.PointF; 18import android.graphics.Rect; 19import android.support.v4.view.ViewCompat; 20import android.support.v7.widget.LinearSmoothScroller; 21import android.support.v7.widget.RecyclerView; 22import android.support.v7.widget.RecyclerView.Recycler; 23import android.support.v7.widget.RecyclerView.State; 24 25import static android.support.v7.widget.RecyclerView.NO_ID; 26import static android.support.v7.widget.RecyclerView.NO_POSITION; 27import static android.support.v7.widget.RecyclerView.HORIZONTAL; 28import static android.support.v7.widget.RecyclerView.VERTICAL; 29 30import android.util.AttributeSet; 31import android.util.Log; 32import android.view.FocusFinder; 33import android.view.Gravity; 34import android.view.View; 35import android.view.ViewParent; 36import android.view.View.MeasureSpec; 37import android.view.ViewGroup.MarginLayoutParams; 38import android.view.ViewGroup; 39 40import java.io.PrintWriter; 41import java.io.StringWriter; 42import java.util.ArrayList; 43import java.util.List; 44 45final class GridLayoutManager extends RecyclerView.LayoutManager { 46 47 /* 48 * LayoutParams for {@link HorizontalGridView} and {@link VerticalGridView}. 49 * The class currently does two internal jobs: 50 * - Saves optical bounds insets. 51 * - Caches focus align view center. 52 */ 53 static class LayoutParams extends RecyclerView.LayoutParams { 54 55 // The view is saved only during animation. 56 private View mView; 57 58 // For placement 59 private int mLeftInset; 60 private int mTopInset; 61 private int mRighInset; 62 private int mBottomInset; 63 64 // For alignment 65 private int mAlignX; 66 private int mAlignY; 67 68 public LayoutParams(Context c, AttributeSet attrs) { 69 super(c, attrs); 70 } 71 72 public LayoutParams(int width, int height) { 73 super(width, height); 74 } 75 76 public LayoutParams(MarginLayoutParams source) { 77 super(source); 78 } 79 80 public LayoutParams(ViewGroup.LayoutParams source) { 81 super(source); 82 } 83 84 public LayoutParams(RecyclerView.LayoutParams source) { 85 super(source); 86 } 87 88 public LayoutParams(LayoutParams source) { 89 super(source); 90 } 91 92 int getAlignX() { 93 return mAlignX; 94 } 95 96 int getAlignY() { 97 return mAlignY; 98 } 99 100 int getOpticalLeft(View view) { 101 return view.getLeft() + mLeftInset; 102 } 103 104 int getOpticalTop(View view) { 105 return view.getTop() + mTopInset; 106 } 107 108 int getOpticalRight(View view) { 109 return view.getRight() - mRighInset; 110 } 111 112 int getOpticalBottom(View view) { 113 return view.getBottom() - mBottomInset; 114 } 115 116 int getOpticalWidth(View view) { 117 return view.getWidth() - mLeftInset - mRighInset; 118 } 119 120 int getOpticalHeight(View view) { 121 return view.getHeight() - mTopInset - mBottomInset; 122 } 123 124 int getOpticalLeftInset() { 125 return mLeftInset; 126 } 127 128 int getOpticalRightInset() { 129 return mRighInset; 130 } 131 132 int getOpticalTopInset() { 133 return mTopInset; 134 } 135 136 int getOpticalBottomInset() { 137 return mBottomInset; 138 } 139 140 void setAlignX(int alignX) { 141 mAlignX = alignX; 142 } 143 144 void setAlignY(int alignY) { 145 mAlignY = alignY; 146 } 147 148 void setOpticalInsets(int leftInset, int topInset, int rightInset, int bottomInset) { 149 mLeftInset = leftInset; 150 mTopInset = topInset; 151 mRighInset = rightInset; 152 mBottomInset = bottomInset; 153 } 154 155 private void invalidateItemDecoration() { 156 ViewParent parent = mView.getParent(); 157 if (parent instanceof RecyclerView) { 158 // TODO: we only need invalidate parent if it has ItemDecoration 159 ((RecyclerView) parent).invalidate(); 160 } 161 } 162 } 163 164 private static final String TAG = "GridLayoutManager"; 165 private static final boolean DEBUG = false; 166 167 private String getTag() { 168 return TAG + ":" + mBaseGridView.getId(); 169 } 170 171 private final BaseGridView mBaseGridView; 172 173 /** 174 * The orientation of a "row". 175 */ 176 private int mOrientation = HORIZONTAL; 177 178 private RecyclerView.State mState; 179 private RecyclerView.Recycler mRecycler; 180 181 private boolean mInLayout = false; 182 183 private OnChildSelectedListener mChildSelectedListener = null; 184 185 /** 186 * The focused position, it's not the currently visually aligned position 187 * but it is the final position that we intend to focus on. If there are 188 * multiple setSelection() called, mFocusPosition saves last value. 189 */ 190 private int mFocusPosition = NO_POSITION; 191 192 /** 193 * Force a full layout under certain situations. 194 */ 195 private boolean mForceFullLayout; 196 197 /** 198 * True if layout is enabled. 199 */ 200 private boolean mLayoutEnabled = true; 201 202 /** 203 * The scroll offsets of the viewport relative to the entire view. 204 */ 205 private int mScrollOffsetPrimary; 206 private int mScrollOffsetSecondary; 207 208 /** 209 * User-specified row height/column width. Can be WRAP_CONTENT. 210 */ 211 private int mRowSizeSecondaryRequested; 212 213 /** 214 * The fixed size of each grid item in the secondary direction. This corresponds to 215 * the row height, equal for all rows. Grid items may have variable length 216 * in the primary direction. 217 */ 218 private int mFixedRowSizeSecondary; 219 220 /** 221 * Tracks the secondary size of each row. 222 */ 223 private int[] mRowSizeSecondary; 224 225 /** 226 * Flag controlling whether the current/next layout should 227 * be updating the secondary size of rows. 228 */ 229 private boolean mRowSecondarySizeRefresh; 230 231 /** 232 * The maximum measured size of the view. 233 */ 234 private int mMaxSizeSecondary; 235 236 /** 237 * Margin between items. 238 */ 239 private int mHorizontalMargin; 240 /** 241 * Margin between items vertically. 242 */ 243 private int mVerticalMargin; 244 /** 245 * Margin in main direction. 246 */ 247 private int mMarginPrimary; 248 /** 249 * Margin in second direction. 250 */ 251 private int mMarginSecondary; 252 /** 253 * How to position child in secondary direction. 254 */ 255 private int mGravity = Gravity.LEFT | Gravity.TOP; 256 /** 257 * The number of rows in the grid. 258 */ 259 private int mNumRows; 260 /** 261 * Number of rows requested, can be 0 to be determined by parent size and 262 * rowHeight. 263 */ 264 private int mNumRowsRequested = 1; 265 266 /** 267 * Tracking start/end position of each row for visible items. 268 */ 269 private StaggeredGrid.Row[] mRows; 270 271 /** 272 * Saves grid information of each view. 273 */ 274 private StaggeredGrid mGrid; 275 /** 276 * Position of first item (included) that has attached views. 277 */ 278 private int mFirstVisiblePos; 279 /** 280 * Position of last item (included) that has attached views. 281 */ 282 private int mLastVisiblePos; 283 284 /** 285 * Focus Scroll strategy. 286 */ 287 private int mFocusScrollStrategy = BaseGridView.FOCUS_SCROLL_ALIGNED; 288 /** 289 * Defines how item view is aligned in the window. 290 */ 291 private final WindowAlignment mWindowAlignment = new WindowAlignment(); 292 293 /** 294 * Defines how item view is aligned. 295 */ 296 private final ItemAlignment mItemAlignment = new ItemAlignment(); 297 298 /** 299 * Dimensions of the view, width or height depending on orientation. 300 */ 301 private int mSizePrimary; 302 303 /** 304 * Allow DPAD key to navigate out at the front of the View (where position = 0), 305 * default is false. 306 */ 307 private boolean mFocusOutFront; 308 309 /** 310 * Allow DPAD key to navigate out at the end of the view, default is false. 311 */ 312 private boolean mFocusOutEnd; 313 314 /** 315 * True if focus search is disabled. 316 */ 317 private boolean mFocusSearchDisabled; 318 319 /** 320 * True if prune child, might be disabled during transition. 321 */ 322 private boolean mPruneChild = true; 323 324 private int[] mTempDeltas = new int[2]; 325 326 private boolean mUseDeltaInPreLayout; 327 328 private int mDeltaInPreLayout, mDeltaSecondaryInPreLayout; 329 330 /** 331 * Temporaries used for measuring. 332 */ 333 private int[] mMeasuredDimension = new int[2]; 334 335 public GridLayoutManager(BaseGridView baseGridView) { 336 mBaseGridView = baseGridView; 337 } 338 339 public void setOrientation(int orientation) { 340 if (orientation != HORIZONTAL && orientation != VERTICAL) { 341 if (DEBUG) Log.v(getTag(), "invalid orientation: " + orientation); 342 return; 343 } 344 345 mOrientation = orientation; 346 mWindowAlignment.setOrientation(orientation); 347 mItemAlignment.setOrientation(orientation); 348 mForceFullLayout = true; 349 } 350 351 public int getFocusScrollStrategy() { 352 return mFocusScrollStrategy; 353 } 354 355 public void setFocusScrollStrategy(int focusScrollStrategy) { 356 mFocusScrollStrategy = focusScrollStrategy; 357 } 358 359 public void setWindowAlignment(int windowAlignment) { 360 mWindowAlignment.mainAxis().setWindowAlignment(windowAlignment); 361 } 362 363 public int getWindowAlignment() { 364 return mWindowAlignment.mainAxis().getWindowAlignment(); 365 } 366 367 public void setWindowAlignmentOffset(int alignmentOffset) { 368 mWindowAlignment.mainAxis().setWindowAlignmentOffset(alignmentOffset); 369 } 370 371 public int getWindowAlignmentOffset() { 372 return mWindowAlignment.mainAxis().getWindowAlignmentOffset(); 373 } 374 375 public void setWindowAlignmentOffsetPercent(float offsetPercent) { 376 mWindowAlignment.mainAxis().setWindowAlignmentOffsetPercent(offsetPercent); 377 } 378 379 public float getWindowAlignmentOffsetPercent() { 380 return mWindowAlignment.mainAxis().getWindowAlignmentOffsetPercent(); 381 } 382 383 public void setItemAlignmentOffset(int alignmentOffset) { 384 mItemAlignment.mainAxis().setItemAlignmentOffset(alignmentOffset); 385 updateChildAlignments(); 386 } 387 388 public int getItemAlignmentOffset() { 389 return mItemAlignment.mainAxis().getItemAlignmentOffset(); 390 } 391 392 public void setItemAlignmentOffsetWithPadding(boolean withPadding) { 393 mItemAlignment.mainAxis().setItemAlignmentOffsetWithPadding(withPadding); 394 updateChildAlignments(); 395 } 396 397 public boolean isItemAlignmentOffsetWithPadding() { 398 return mItemAlignment.mainAxis().isItemAlignmentOffsetWithPadding(); 399 } 400 401 public void setItemAlignmentOffsetPercent(float offsetPercent) { 402 mItemAlignment.mainAxis().setItemAlignmentOffsetPercent(offsetPercent); 403 updateChildAlignments(); 404 } 405 406 public float getItemAlignmentOffsetPercent() { 407 return mItemAlignment.mainAxis().getItemAlignmentOffsetPercent(); 408 } 409 410 public void setItemAlignmentViewId(int viewId) { 411 mItemAlignment.mainAxis().setItemAlignmentViewId(viewId); 412 updateChildAlignments(); 413 } 414 415 public int getItemAlignmentViewId() { 416 return mItemAlignment.mainAxis().getItemAlignmentViewId(); 417 } 418 419 public void setFocusOutAllowed(boolean throughFront, boolean throughEnd) { 420 mFocusOutFront = throughFront; 421 mFocusOutEnd = throughEnd; 422 } 423 424 public void setNumRows(int numRows) { 425 if (numRows < 0) throw new IllegalArgumentException(); 426 mNumRowsRequested = numRows; 427 mForceFullLayout = true; 428 } 429 430 /** 431 * Set the row height. May be WRAP_CONTENT, or a size in pixels. 432 */ 433 public void setRowHeight(int height) { 434 if (height >= 0 || height == ViewGroup.LayoutParams.WRAP_CONTENT) { 435 mRowSizeSecondaryRequested = height; 436 } else { 437 throw new IllegalArgumentException("Invalid row height: " + height); 438 } 439 } 440 441 public void setItemMargin(int margin) { 442 mVerticalMargin = mHorizontalMargin = margin; 443 mMarginPrimary = mMarginSecondary = margin; 444 } 445 446 public void setVerticalMargin(int margin) { 447 if (mOrientation == HORIZONTAL) { 448 mMarginSecondary = mVerticalMargin = margin; 449 } else { 450 mMarginPrimary = mVerticalMargin = margin; 451 } 452 } 453 454 public void setHorizontalMargin(int margin) { 455 if (mOrientation == HORIZONTAL) { 456 mMarginPrimary = mHorizontalMargin = margin; 457 } else { 458 mMarginSecondary = mHorizontalMargin = margin; 459 } 460 } 461 462 public int getVerticalMargin() { 463 return mVerticalMargin; 464 } 465 466 public int getHorizontalMargin() { 467 return mHorizontalMargin; 468 } 469 470 public void setGravity(int gravity) { 471 mGravity = gravity; 472 } 473 474 protected boolean hasDoneFirstLayout() { 475 return mGrid != null; 476 } 477 478 public void setOnChildSelectedListener(OnChildSelectedListener listener) { 479 mChildSelectedListener = listener; 480 } 481 482 private int getPositionByView(View view) { 483 if (view == null) { 484 return NO_POSITION; 485 } 486 LayoutParams params = (LayoutParams) view.getLayoutParams(); 487 if (params == null || params.isItemRemoved()) { 488 // when item is removed, the position value can be any value. 489 return NO_POSITION; 490 } 491 return params.getViewPosition(); 492 } 493 494 private int getPositionByIndex(int index) { 495 return getPositionByView(getChildAt(index)); 496 } 497 498 private void dispatchChildSelected() { 499 if (mChildSelectedListener == null) { 500 return; 501 } 502 if (mFocusPosition != NO_POSITION) { 503 View view = findViewByPosition(mFocusPosition); 504 if (view != null) { 505 RecyclerView.ViewHolder vh = mBaseGridView.getChildViewHolder(view); 506 mChildSelectedListener.onChildSelected(mBaseGridView, view, mFocusPosition, 507 vh == null? NO_ID: vh.getItemId()); 508 return; 509 } 510 } 511 mChildSelectedListener.onChildSelected(mBaseGridView, null, NO_POSITION, NO_ID); 512 } 513 514 @Override 515 public boolean canScrollHorizontally() { 516 // We can scroll horizontally if we have horizontal orientation, or if 517 // we are vertical and have more than one column. 518 return mOrientation == HORIZONTAL || mNumRows > 1; 519 } 520 521 @Override 522 public boolean canScrollVertically() { 523 // We can scroll vertically if we have vertical orientation, or if we 524 // are horizontal and have more than one row. 525 return mOrientation == VERTICAL || mNumRows > 1; 526 } 527 528 @Override 529 public RecyclerView.LayoutParams generateDefaultLayoutParams() { 530 return new LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, 531 ViewGroup.LayoutParams.WRAP_CONTENT); 532 } 533 534 @Override 535 public RecyclerView.LayoutParams generateLayoutParams(Context context, AttributeSet attrs) { 536 return new LayoutParams(context, attrs); 537 } 538 539 @Override 540 public RecyclerView.LayoutParams generateLayoutParams(ViewGroup.LayoutParams lp) { 541 if (lp instanceof LayoutParams) { 542 return new LayoutParams((LayoutParams) lp); 543 } else if (lp instanceof RecyclerView.LayoutParams) { 544 return new LayoutParams((RecyclerView.LayoutParams) lp); 545 } else if (lp instanceof MarginLayoutParams) { 546 return new LayoutParams((MarginLayoutParams) lp); 547 } else { 548 return new LayoutParams(lp); 549 } 550 } 551 552 protected View getViewForPosition(int position) { 553 return mRecycler.getViewForPosition(position); 554 } 555 556 final int getOpticalLeft(View v) { 557 return ((LayoutParams) v.getLayoutParams()).getOpticalLeft(v); 558 } 559 560 final int getOpticalRight(View v) { 561 return ((LayoutParams) v.getLayoutParams()).getOpticalRight(v); 562 } 563 564 final int getOpticalTop(View v) { 565 return ((LayoutParams) v.getLayoutParams()).getOpticalTop(v); 566 } 567 568 final int getOpticalBottom(View v) { 569 return ((LayoutParams) v.getLayoutParams()).getOpticalBottom(v); 570 } 571 572 private int getViewMin(View v) { 573 return (mOrientation == HORIZONTAL) ? getOpticalLeft(v) : getOpticalTop(v); 574 } 575 576 private int getViewMax(View v) { 577 return (mOrientation == HORIZONTAL) ? getOpticalRight(v) : getOpticalBottom(v); 578 } 579 580 private int getViewCenter(View view) { 581 return (mOrientation == HORIZONTAL) ? getViewCenterX(view) : getViewCenterY(view); 582 } 583 584 private int getViewCenterSecondary(View view) { 585 return (mOrientation == HORIZONTAL) ? getViewCenterY(view) : getViewCenterX(view); 586 } 587 588 private int getViewCenterX(View v) { 589 LayoutParams p = (LayoutParams) v.getLayoutParams(); 590 return p.getOpticalLeft(v) + p.getAlignX(); 591 } 592 593 private int getViewCenterY(View v) { 594 LayoutParams p = (LayoutParams) v.getLayoutParams(); 595 return p.getOpticalTop(v) + p.getAlignY(); 596 } 597 598 /** 599 * Save Recycler and State for convenience. Must be paired with leaveContext(). 600 */ 601 private void saveContext(Recycler recycler, State state) { 602 if (mRecycler != null || mState != null) { 603 Log.e(TAG, "Recycler information was not released, bug!"); 604 } 605 mRecycler = recycler; 606 mState = state; 607 } 608 609 /** 610 * Discard saved Recycler and State. 611 */ 612 private void leaveContext() { 613 mRecycler = null; 614 mState = null; 615 } 616 617 /** 618 * Re-initialize data structures for a data change or handling invisible 619 * selection. The method tries its best to preserve position information so 620 * that staggered grid looks same before and after re-initialize. 621 * @param focusPosition The initial focusPosition that we would like to 622 * focus on. 623 * @return Actual position that can be focused on. 624 */ 625 private int init(int focusPosition) { 626 627 final int newItemCount = mState.getItemCount(); 628 629 if (focusPosition == NO_POSITION && newItemCount > 0) { 630 // if focus position is never set before, initialize it to 0 631 focusPosition = 0; 632 } 633 // If adapter has changed then caches are invalid; otherwise, 634 // we try to maintain each row's position if number of rows keeps the same 635 // and existing mGrid contains the focusPosition. 636 if (mRows != null && mNumRows == mRows.length && 637 mGrid != null && mGrid.getSize() > 0 && focusPosition >= 0 && 638 focusPosition >= mGrid.getFirstIndex() && 639 focusPosition <= mGrid.getLastIndex()) { 640 // strip mGrid to a subset (like a column) that contains focusPosition 641 mGrid.stripDownTo(focusPosition); 642 // make sure that remaining items do not exceed new adapter size 643 int firstIndex = mGrid.getFirstIndex(); 644 int lastIndex = mGrid.getLastIndex(); 645 if (DEBUG) { 646 Log .v(getTag(), "mGrid firstIndex " + firstIndex + " lastIndex " + lastIndex); 647 } 648 for (int i = lastIndex; i >=firstIndex; i--) { 649 if (i >= newItemCount) { 650 mGrid.removeLast(); 651 } 652 } 653 if (mGrid.getSize() == 0) { 654 focusPosition = newItemCount - 1; 655 // initialize row start locations 656 for (int i = 0; i < mNumRows; i++) { 657 mRows[i].low = 0; 658 mRows[i].high = 0; 659 } 660 if (DEBUG) Log.v(getTag(), "mGrid zero size"); 661 } else { 662 // initialize row start locations 663 for (int i = 0; i < mNumRows; i++) { 664 mRows[i].low = Integer.MAX_VALUE; 665 mRows[i].high = Integer.MIN_VALUE; 666 } 667 firstIndex = mGrid.getFirstIndex(); 668 lastIndex = mGrid.getLastIndex(); 669 if (focusPosition > lastIndex) { 670 focusPosition = mGrid.getLastIndex(); 671 } 672 if (DEBUG) { 673 Log.v(getTag(), "mGrid firstIndex " + firstIndex + " lastIndex " 674 + lastIndex + " focusPosition " + focusPosition); 675 } 676 // fill rows with minimal view positions of the subset 677 for (int i = firstIndex; i <= lastIndex; i++) { 678 View v = findViewByPosition(i); 679 if (v == null) { 680 continue; 681 } 682 int row = mGrid.getLocation(i).row; 683 int low = getViewMin(v) + mScrollOffsetPrimary; 684 if (low < mRows[row].low) { 685 mRows[row].low = mRows[row].high = low; 686 } 687 } 688 int firstItemRowPosition = mRows[mGrid.getLocation(firstIndex).row].low; 689 if (firstItemRowPosition == Integer.MAX_VALUE) { 690 firstItemRowPosition = 0; 691 } 692 if (mState.didStructureChange()) { 693 // if there is structure change, the removed item might be in the 694 // subset, so it is meaningless to maintain the low locations. 695 for (int i = 0; i < mNumRows; i++) { 696 mRows[i].low = firstItemRowPosition; 697 mRows[i].high = firstItemRowPosition; 698 } 699 } else { 700 // fill other rows that does not include the subset using first item 701 for (int i = 0; i < mNumRows; i++) { 702 if (mRows[i].low == Integer.MAX_VALUE) { 703 mRows[i].low = mRows[i].high = firstItemRowPosition; 704 } 705 } 706 } 707 } 708 709 // Same adapter, we can reuse any attached views 710 detachAndScrapAttachedViews(mRecycler); 711 712 } else { 713 // otherwise recreate data structure 714 mRows = new StaggeredGrid.Row[mNumRows]; 715 716 for (int i = 0; i < mNumRows; i++) { 717 mRows[i] = new StaggeredGrid.Row(); 718 } 719 mGrid = new StaggeredGridDefault(); 720 if (newItemCount == 0) { 721 focusPosition = NO_POSITION; 722 } else if (focusPosition >= newItemCount) { 723 focusPosition = newItemCount - 1; 724 } 725 726 // Adapter may have changed so remove all attached views permanently 727 removeAndRecycleAllViews(mRecycler); 728 729 mScrollOffsetPrimary = 0; 730 mScrollOffsetSecondary = 0; 731 mWindowAlignment.reset(); 732 } 733 734 mGrid.setProvider(mGridProvider); 735 // mGrid share the same Row array information 736 mGrid.setRows(mRows); 737 mFirstVisiblePos = mLastVisiblePos = NO_POSITION; 738 739 initScrollController(); 740 updateScrollSecondAxis(); 741 742 return focusPosition; 743 } 744 745 private int getRowSizeSecondary(int rowIndex) { 746 if (mFixedRowSizeSecondary != 0) { 747 return mFixedRowSizeSecondary; 748 } 749 if (mRowSizeSecondary == null) { 750 return 0; 751 } 752 return mRowSizeSecondary[rowIndex]; 753 } 754 755 private int getRowStartSecondary(int rowIndex) { 756 int start = 0; 757 for (int i = 0; i < rowIndex; i++) { 758 start += getRowSizeSecondary(i) + mMarginSecondary; 759 } 760 return start; 761 } 762 763 private int getSizeSecondary() { 764 return getRowStartSecondary(mNumRows - 1) + getRowSizeSecondary(mNumRows - 1); 765 } 766 767 private void measureScrapChild(int position, int widthSpec, int heightSpec, 768 int[] measuredDimension) { 769 View view = mRecycler.getViewForPosition(position); 770 if (view != null) { 771 LayoutParams p = (LayoutParams) view.getLayoutParams(); 772 int childWidthSpec = ViewGroup.getChildMeasureSpec(widthSpec, 773 getPaddingLeft() + getPaddingRight(), p.width); 774 int childHeightSpec = ViewGroup.getChildMeasureSpec(heightSpec, 775 getPaddingTop() + getPaddingBottom(), p.height); 776 view.measure(childWidthSpec, childHeightSpec); 777 measuredDimension[0] = view.getMeasuredWidth(); 778 measuredDimension[1] = view.getMeasuredHeight(); 779 mRecycler.recycleView(view); 780 } 781 } 782 783 private boolean processRowSizeSecondary(boolean measure) { 784 if (mFixedRowSizeSecondary != 0) { 785 return false; 786 } 787 788 List<Integer>[] rows = mGrid == null ? null : 789 mGrid.getItemPositionsInRows(mFirstVisiblePos, mLastVisiblePos); 790 boolean changed = false; 791 int scrapChildWidth = -1; 792 int scrapChildHeight = -1; 793 794 for (int rowIndex = 0; rowIndex < mNumRows; rowIndex++) { 795 final int rowItemCount = rows == null ? 0 : rows[rowIndex].size(); 796 if (DEBUG) Log.v(getTag(), "processRowSizeSecondary row " + rowIndex + 797 " rowItemCount " + rowItemCount); 798 799 int rowSize = -1; 800 for (int i = 0; i < rowItemCount; i++) { 801 final View view = findViewByPosition(rows[rowIndex].get(i)); 802 if (view == null) { 803 continue; 804 } 805 if (measure && view.isLayoutRequested()) { 806 measureChild(view); 807 } 808 final int secondarySize = mOrientation == HORIZONTAL ? 809 view.getMeasuredHeight() : view.getMeasuredWidth(); 810 if (secondarySize > rowSize) { 811 rowSize = secondarySize; 812 } 813 } 814 815 if (measure && rowSize < 0 && mState.getItemCount() > 0) { 816 if (scrapChildWidth < 0 && scrapChildHeight < 0) { 817 measureScrapChild(mFocusPosition == NO_POSITION ? 0 : mFocusPosition, 818 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 819 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 820 mMeasuredDimension); 821 scrapChildWidth = mMeasuredDimension[0]; 822 scrapChildHeight = mMeasuredDimension[1]; 823 if (DEBUG) Log.v(TAG, "measured scrap child: " + scrapChildWidth + 824 " " + scrapChildHeight); 825 } 826 rowSize = mOrientation == HORIZONTAL ? scrapChildHeight : scrapChildWidth; 827 } 828 829 if (rowSize < 0) { 830 rowSize = 0; 831 } 832 833 if (DEBUG) Log.v(getTag(), "row " + rowIndex + " rowItemCount " + rowItemCount + 834 " rowSize " + rowSize); 835 836 if (mRowSizeSecondary[rowIndex] != rowSize) { 837 if (DEBUG) Log.v(getTag(), "row size secondary changed: " + mRowSizeSecondary[rowIndex] + 838 ", " + rowSize); 839 840 mRowSizeSecondary[rowIndex] = rowSize; 841 changed = true; 842 } 843 } 844 845 return changed; 846 } 847 848 /** 849 * Checks if we need to update row secondary sizes. 850 */ 851 private void updateRowSecondarySizeRefresh() { 852 mRowSecondarySizeRefresh = processRowSizeSecondary(false); 853 if (mRowSecondarySizeRefresh) { 854 if (DEBUG) Log.v(getTag(), "mRowSecondarySizeRefresh now set"); 855 forceRequestLayout(); 856 } 857 } 858 859 private void forceRequestLayout() { 860 if (DEBUG) Log.v(getTag(), "forceRequestLayout"); 861 // RecyclerView prevents us from requesting layout in many cases 862 // (during layout, during scroll, etc.) 863 // For secondary row size wrap_content support we currently need a 864 // second layout pass to update the measured size after having measured 865 // and added child views in layoutChildren. 866 // Force the second layout by posting a delayed runnable. 867 // TODO: investigate allowing a second layout pass, 868 // or move child add/measure logic to the measure phase. 869 ViewCompat.postOnAnimation(mBaseGridView, mRequestLayoutRunnable); 870 } 871 872 private final Runnable mRequestLayoutRunnable = new Runnable() { 873 @Override 874 public void run() { 875 if (DEBUG) Log.v(getTag(), "request Layout from runnable"); 876 requestLayout(); 877 } 878 }; 879 880 @Override 881 public void onMeasure(Recycler recycler, State state, int widthSpec, int heightSpec) { 882 saveContext(recycler, state); 883 884 int sizePrimary, sizeSecondary, modeSecondary, paddingSecondary; 885 int measuredSizeSecondary; 886 if (mOrientation == HORIZONTAL) { 887 sizePrimary = MeasureSpec.getSize(widthSpec); 888 sizeSecondary = MeasureSpec.getSize(heightSpec); 889 modeSecondary = MeasureSpec.getMode(heightSpec); 890 paddingSecondary = getPaddingTop() + getPaddingBottom(); 891 } else { 892 sizeSecondary = MeasureSpec.getSize(widthSpec); 893 sizePrimary = MeasureSpec.getSize(heightSpec); 894 modeSecondary = MeasureSpec.getMode(widthSpec); 895 paddingSecondary = getPaddingLeft() + getPaddingRight(); 896 } 897 if (DEBUG) Log.v(getTag(), "onMeasure widthSpec " + Integer.toHexString(widthSpec) + 898 " heightSpec " + Integer.toHexString(heightSpec) + 899 " modeSecondary " + Integer.toHexString(modeSecondary) + 900 " sizeSecondary " + sizeSecondary + " " + this); 901 902 mMaxSizeSecondary = sizeSecondary; 903 904 if (mRowSizeSecondaryRequested == ViewGroup.LayoutParams.WRAP_CONTENT) { 905 mNumRows = mNumRowsRequested == 0 ? 1 : mNumRowsRequested; 906 mFixedRowSizeSecondary = 0; 907 908 if (mRowSizeSecondary == null || mRowSizeSecondary.length != mNumRows) { 909 mRowSizeSecondary = new int[mNumRows]; 910 } 911 912 // Measure all current children and update cached row heights 913 processRowSizeSecondary(true); 914 915 switch (modeSecondary) { 916 case MeasureSpec.UNSPECIFIED: 917 measuredSizeSecondary = getSizeSecondary() + paddingSecondary; 918 break; 919 case MeasureSpec.AT_MOST: 920 measuredSizeSecondary = Math.min(getSizeSecondary() + paddingSecondary, 921 mMaxSizeSecondary); 922 break; 923 case MeasureSpec.EXACTLY: 924 measuredSizeSecondary = mMaxSizeSecondary; 925 break; 926 default: 927 throw new IllegalStateException("wrong spec"); 928 } 929 930 } else { 931 switch (modeSecondary) { 932 case MeasureSpec.UNSPECIFIED: 933 if (mRowSizeSecondaryRequested == 0) { 934 if (mOrientation == HORIZONTAL) { 935 throw new IllegalStateException("Must specify rowHeight or view height"); 936 } else { 937 throw new IllegalStateException("Must specify columnWidth or view width"); 938 } 939 } 940 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 941 mNumRows = mNumRowsRequested == 0 ? 1 : mNumRowsRequested; 942 measuredSizeSecondary = mFixedRowSizeSecondary * mNumRows + mMarginSecondary 943 * (mNumRows - 1) + paddingSecondary; 944 break; 945 case MeasureSpec.AT_MOST: 946 case MeasureSpec.EXACTLY: 947 if (mNumRowsRequested == 0 && mRowSizeSecondaryRequested == 0) { 948 mNumRows = 1; 949 mFixedRowSizeSecondary = sizeSecondary - paddingSecondary; 950 } else if (mNumRowsRequested == 0) { 951 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 952 mNumRows = (sizeSecondary + mMarginSecondary) 953 / (mRowSizeSecondaryRequested + mMarginSecondary); 954 } else if (mRowSizeSecondaryRequested == 0) { 955 mNumRows = mNumRowsRequested; 956 mFixedRowSizeSecondary = (sizeSecondary - paddingSecondary - mMarginSecondary 957 * (mNumRows - 1)) / mNumRows; 958 } else { 959 mNumRows = mNumRowsRequested; 960 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 961 } 962 measuredSizeSecondary = sizeSecondary; 963 if (modeSecondary == MeasureSpec.AT_MOST) { 964 int childrenSize = mFixedRowSizeSecondary * mNumRows + mMarginSecondary 965 * (mNumRows - 1) + paddingSecondary; 966 if (childrenSize < measuredSizeSecondary) { 967 measuredSizeSecondary = childrenSize; 968 } 969 } 970 break; 971 default: 972 throw new IllegalStateException("wrong spec"); 973 } 974 } 975 if (mOrientation == HORIZONTAL) { 976 setMeasuredDimension(sizePrimary, measuredSizeSecondary); 977 } else { 978 setMeasuredDimension(measuredSizeSecondary, sizePrimary); 979 } 980 if (DEBUG) { 981 Log.v(getTag(), "onMeasure sizePrimary " + sizePrimary + 982 " measuredSizeSecondary " + measuredSizeSecondary + 983 " mFixedRowSizeSecondary " + mFixedRowSizeSecondary + 984 " mNumRows " + mNumRows); 985 } 986 987 leaveContext(); 988 } 989 990 private void measureChild(View child) { 991 final ViewGroup.LayoutParams lp = child.getLayoutParams(); 992 final int secondarySpec = (mRowSizeSecondaryRequested == ViewGroup.LayoutParams.WRAP_CONTENT) ? 993 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED) : 994 MeasureSpec.makeMeasureSpec(mFixedRowSizeSecondary, MeasureSpec.EXACTLY); 995 int widthSpec, heightSpec; 996 997 if (mOrientation == HORIZONTAL) { 998 widthSpec = ViewGroup.getChildMeasureSpec( 999 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 1000 0, lp.width); 1001 heightSpec = ViewGroup.getChildMeasureSpec(secondarySpec, 0, lp.height); 1002 } else { 1003 heightSpec = ViewGroup.getChildMeasureSpec( 1004 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 1005 0, lp.height); 1006 widthSpec = ViewGroup.getChildMeasureSpec(secondarySpec, 0, lp.width); 1007 } 1008 1009 child.measure(widthSpec, heightSpec); 1010 1011 if (DEBUG) Log.v(getTag(), "measureChild secondarySpec " + Integer.toHexString(secondarySpec) + 1012 " widthSpec " + Integer.toHexString(widthSpec) + 1013 " heightSpec " + Integer.toHexString(heightSpec) + 1014 " measuredWidth " + child.getMeasuredWidth() + 1015 " measuredHeight " + child.getMeasuredHeight()); 1016 if (DEBUG) Log.v(getTag(), "child lp width " + lp.width + " height " + lp.height); 1017 } 1018 1019 private StaggeredGrid.Provider mGridProvider = new StaggeredGrid.Provider() { 1020 1021 @Override 1022 public int getCount() { 1023 return mState.getItemCount(); 1024 } 1025 1026 @Override 1027 public void createItem(int index, int rowIndex, boolean append) { 1028 View v = getViewForPosition(index); 1029 if (mFirstVisiblePos >= 0) { 1030 // when StaggeredGrid append or prepend item, we must guarantee 1031 // that sibling item has created views already. 1032 if (append && index != mLastVisiblePos + 1) { 1033 throw new RuntimeException(); 1034 } else if (!append && index != mFirstVisiblePos - 1) { 1035 throw new RuntimeException(); 1036 } 1037 } 1038 1039 // See recyclerView docs: we don't need re-add scraped view if it was removed. 1040 if (!((RecyclerView.LayoutParams) v.getLayoutParams()).isItemRemoved()) { 1041 if (append) { 1042 addView(v); 1043 } else { 1044 addView(v, 0); 1045 } 1046 measureChild(v); 1047 } 1048 1049 int length = mOrientation == HORIZONTAL ? v.getMeasuredWidth() : v.getMeasuredHeight(); 1050 int start, end; 1051 if (append) { 1052 start = mRows[rowIndex].high; 1053 if (start != mRows[rowIndex].low) { 1054 // if there are existing item in the row, add margin between 1055 start += mMarginPrimary; 1056 } else { 1057 final int lastRow = mRows.length - 1; 1058 if (lastRow != rowIndex && mRows[lastRow].high != mRows[lastRow].low) { 1059 // if there are existing item in the last row, insert 1060 // the new item after the last item of last row. 1061 start = mRows[lastRow].high + mMarginPrimary; 1062 } 1063 } 1064 end = start + length; 1065 mRows[rowIndex].high = end; 1066 } else { 1067 end = mRows[rowIndex].low; 1068 if (end != mRows[rowIndex].high) { 1069 end -= mMarginPrimary; 1070 } else if (0 != rowIndex && mRows[0].high != mRows[0].low) { 1071 // if there are existing item in the first row, insert 1072 // the new item before the first item of first row. 1073 end = mRows[0].low - mMarginPrimary; 1074 } 1075 start = end - length; 1076 mRows[rowIndex].low = start; 1077 } 1078 if (mFirstVisiblePos < 0) { 1079 mFirstVisiblePos = mLastVisiblePos = index; 1080 } else { 1081 if (append) { 1082 mLastVisiblePos++; 1083 } else { 1084 mFirstVisiblePos--; 1085 } 1086 } 1087 if (DEBUG) Log.v(getTag(), "start " + start + " end " + end); 1088 int startSecondary = getRowStartSecondary(rowIndex) - mScrollOffsetSecondary; 1089 layoutChild(rowIndex, v, start - mScrollOffsetPrimary, end - mScrollOffsetPrimary, 1090 startSecondary); 1091 if (DEBUG) { 1092 Log.d(getTag(), "addView " + index + " " + v); 1093 } 1094 if (index == mFirstVisiblePos) { 1095 updateScrollMin(); 1096 } 1097 if (index == mLastVisiblePos) { 1098 updateScrollMax(); 1099 } 1100 } 1101 }; 1102 1103 private void layoutChild(int rowIndex, View v, int start, int end, int startSecondary) { 1104 int sizeSecondary = mOrientation == HORIZONTAL ? v.getMeasuredHeight() 1105 : v.getMeasuredWidth(); 1106 if (mFixedRowSizeSecondary > 0) { 1107 sizeSecondary = Math.min(sizeSecondary, mFixedRowSizeSecondary); 1108 } 1109 final int verticalGravity = mGravity & Gravity.VERTICAL_GRAVITY_MASK; 1110 final int horizontalGravity = mGravity & Gravity.HORIZONTAL_GRAVITY_MASK; 1111 if (mOrientation == HORIZONTAL && verticalGravity == Gravity.TOP 1112 || mOrientation == VERTICAL && horizontalGravity == Gravity.LEFT) { 1113 // do nothing 1114 } else if (mOrientation == HORIZONTAL && verticalGravity == Gravity.BOTTOM 1115 || mOrientation == VERTICAL && horizontalGravity == Gravity.RIGHT) { 1116 startSecondary += getRowSizeSecondary(rowIndex) - sizeSecondary; 1117 } else if (mOrientation == HORIZONTAL && verticalGravity == Gravity.CENTER_VERTICAL 1118 || mOrientation == VERTICAL && horizontalGravity == Gravity.CENTER_HORIZONTAL) { 1119 startSecondary += (getRowSizeSecondary(rowIndex) - sizeSecondary) / 2; 1120 } 1121 int left, top, right, bottom; 1122 if (mOrientation == HORIZONTAL) { 1123 left = start; 1124 top = startSecondary; 1125 right = end; 1126 bottom = startSecondary + sizeSecondary; 1127 } else { 1128 top = start; 1129 left = startSecondary; 1130 bottom = end; 1131 right = startSecondary + sizeSecondary; 1132 } 1133 v.layout(left, top, right, bottom); 1134 updateChildOpticalInsets(v, left, top, right, bottom); 1135 updateChildAlignments(v); 1136 } 1137 1138 private void updateChildOpticalInsets(View v, int left, int top, int right, int bottom) { 1139 LayoutParams p = (LayoutParams) v.getLayoutParams(); 1140 p.setOpticalInsets(left - v.getLeft(), top - v.getTop(), 1141 v.getRight() - right, v.getBottom() - bottom); 1142 } 1143 1144 private void updateChildAlignments(View v) { 1145 LayoutParams p = (LayoutParams) v.getLayoutParams(); 1146 p.setAlignX(mItemAlignment.horizontal.getAlignmentPosition(v)); 1147 p.setAlignY(mItemAlignment.vertical.getAlignmentPosition(v)); 1148 } 1149 1150 private void updateChildAlignments() { 1151 for (int i = 0, c = getChildCount(); i < c; i++) { 1152 updateChildAlignments(getChildAt(i)); 1153 } 1154 } 1155 1156 private boolean needsAppendVisibleItem() { 1157 if (mLastVisiblePos < mFocusPosition) { 1158 return true; 1159 } 1160 int right = mScrollOffsetPrimary + mSizePrimary; 1161 for (int i = 0; i < mNumRows; i++) { 1162 if (mRows[i].low == mRows[i].high) { 1163 if (mRows[i].high < right) { 1164 return true; 1165 } 1166 } else if (mRows[i].high < right - mMarginPrimary) { 1167 return true; 1168 } 1169 } 1170 return false; 1171 } 1172 1173 private boolean needsPrependVisibleItem() { 1174 if (mFirstVisiblePos > mFocusPosition) { 1175 return true; 1176 } 1177 for (int i = 0; i < mNumRows; i++) { 1178 if (mRows[i].low == mRows[i].high) { 1179 if (mRows[i].low > mScrollOffsetPrimary) { 1180 return true; 1181 } 1182 } else if (mRows[i].low - mMarginPrimary > mScrollOffsetPrimary) { 1183 return true; 1184 } 1185 } 1186 return false; 1187 } 1188 1189 // Append one column if possible and return true if reach end. 1190 private boolean appendOneVisibleItem() { 1191 while (true) { 1192 if (mLastVisiblePos != NO_POSITION && mLastVisiblePos < mState.getItemCount() -1 && 1193 mLastVisiblePos < mGrid.getLastIndex()) { 1194 // append invisible view of saved location till last row 1195 final int index = mLastVisiblePos + 1; 1196 final int row = mGrid.getLocation(index).row; 1197 mGridProvider.createItem(index, row, true); 1198 if (row == mNumRows - 1) { 1199 return false; 1200 } 1201 } else if ((mLastVisiblePos == NO_POSITION && mState.getItemCount() > 0) || 1202 (mLastVisiblePos != NO_POSITION && 1203 mLastVisiblePos < mState.getItemCount() - 1)) { 1204 mGrid.appendItems(mScrollOffsetPrimary + mSizePrimary); 1205 return false; 1206 } else { 1207 return true; 1208 } 1209 } 1210 } 1211 1212 private void appendVisibleItems() { 1213 while (needsAppendVisibleItem()) { 1214 if (appendOneVisibleItem()) { 1215 break; 1216 } 1217 } 1218 } 1219 1220 // Prepend one column if possible and return true if reach end. 1221 private boolean prependOneVisibleItem() { 1222 while (true) { 1223 if (mFirstVisiblePos > 0) { 1224 if (mFirstVisiblePos > mGrid.getFirstIndex()) { 1225 // prepend invisible view of saved location till first row 1226 final int index = mFirstVisiblePos - 1; 1227 final int row = mGrid.getLocation(index).row; 1228 mGridProvider.createItem(index, row, false); 1229 if (row == 0) { 1230 return false; 1231 } 1232 } else { 1233 mGrid.prependItems(mScrollOffsetPrimary); 1234 return false; 1235 } 1236 } else { 1237 return true; 1238 } 1239 } 1240 } 1241 1242 private void prependVisibleItems() { 1243 while (needsPrependVisibleItem()) { 1244 if (prependOneVisibleItem()) { 1245 break; 1246 } 1247 } 1248 } 1249 1250 private void removeChildAt(int position) { 1251 View v = findViewByPosition(position); 1252 if (v != null) { 1253 if (DEBUG) { 1254 Log.d(getTag(), "removeAndRecycleViewAt " + position); 1255 } 1256 removeAndRecycleView(v, mRecycler); 1257 } 1258 } 1259 1260 private void removeInvisibleViewsAtEnd() { 1261 if (!mPruneChild) { 1262 return; 1263 } 1264 boolean update = false; 1265 while(mLastVisiblePos > mFirstVisiblePos && mLastVisiblePos > mFocusPosition) { 1266 View view = findViewByPosition(mLastVisiblePos); 1267 if (getViewMin(view) > mSizePrimary) { 1268 removeChildAt(mLastVisiblePos); 1269 mLastVisiblePos--; 1270 update = true; 1271 } else { 1272 break; 1273 } 1274 } 1275 if (update) { 1276 updateRowsMinMax(); 1277 } 1278 } 1279 1280 private void removeInvisibleViewsAtFront() { 1281 if (!mPruneChild) { 1282 return; 1283 } 1284 boolean update = false; 1285 while(mLastVisiblePos > mFirstVisiblePos && mFirstVisiblePos < mFocusPosition) { 1286 View view = findViewByPosition(mFirstVisiblePos); 1287 if (getViewMax(view) < 0) { 1288 removeChildAt(mFirstVisiblePos); 1289 mFirstVisiblePos++; 1290 update = true; 1291 } else { 1292 break; 1293 } 1294 } 1295 if (update) { 1296 updateRowsMinMax(); 1297 } 1298 } 1299 1300 private void updateRowsMinMax() { 1301 if (mFirstVisiblePos < 0) { 1302 return; 1303 } 1304 for (int i = 0; i < mNumRows; i++) { 1305 mRows[i].low = Integer.MAX_VALUE; 1306 mRows[i].high = Integer.MIN_VALUE; 1307 } 1308 for (int i = mFirstVisiblePos; i <= mLastVisiblePos; i++) { 1309 View view = findViewByPosition(i); 1310 int row = mGrid.getLocation(i).row; 1311 int low = getViewMin(view) + mScrollOffsetPrimary; 1312 if (low < mRows[row].low) { 1313 mRows[row].low = low; 1314 } 1315 int high = getViewMax(view) + mScrollOffsetPrimary; 1316 if (high > mRows[row].high) { 1317 mRows[row].high = high; 1318 } 1319 } 1320 } 1321 1322 // Fast layout when there is no structure change, adapter change, etc. 1323 protected void fastRelayout() { 1324 initScrollController(); 1325 1326 List<Integer>[] rows = mGrid.getItemPositionsInRows(mFirstVisiblePos, mLastVisiblePos); 1327 1328 // relayout and repositioning views on each row 1329 for (int i = 0; i < mNumRows; i++) { 1330 List<Integer> row = rows[i]; 1331 final int startSecondary = getRowStartSecondary(i) - mScrollOffsetSecondary; 1332 for (int j = 0, size = row.size(); j < size; j++) { 1333 final int position = row.get(j); 1334 final View view = findViewByPosition(position); 1335 int primaryDelta, start, end; 1336 1337 if (mOrientation == HORIZONTAL) { 1338 final int primarySize = view.getMeasuredWidth(); 1339 if (view.isLayoutRequested()) { 1340 measureChild(view); 1341 } 1342 start = getViewMin(view); 1343 end = start + view.getMeasuredWidth(); 1344 primaryDelta = view.getMeasuredWidth() - primarySize; 1345 if (primaryDelta != 0) { 1346 for (int k = j + 1; k < size; k++) { 1347 findViewByPosition(row.get(k)).offsetLeftAndRight(primaryDelta); 1348 } 1349 } 1350 } else { 1351 final int primarySize = view.getMeasuredHeight(); 1352 if (view.isLayoutRequested()) { 1353 measureChild(view); 1354 } 1355 start = getViewMin(view); 1356 end = start + view.getMeasuredHeight(); 1357 primaryDelta = view.getMeasuredHeight() - primarySize; 1358 if (primaryDelta != 0) { 1359 for (int k = j + 1; k < size; k++) { 1360 findViewByPosition(row.get(k)).offsetTopAndBottom(primaryDelta); 1361 } 1362 } 1363 } 1364 layoutChild(i, view, start, end, startSecondary); 1365 } 1366 } 1367 1368 updateRowsMinMax(); 1369 appendVisibleItems(); 1370 prependVisibleItems(); 1371 1372 updateRowsMinMax(); 1373 updateScrollMin(); 1374 updateScrollMax(); 1375 updateScrollSecondAxis(); 1376 1377 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED) { 1378 View focusView = findViewByPosition(mFocusPosition == NO_POSITION ? 0 : mFocusPosition); 1379 scrollToView(focusView, false); 1380 } 1381 } 1382 1383 public void removeAndRecycleAllViews(RecyclerView.Recycler recycler) { 1384 if (DEBUG) Log.v(TAG, "removeAndRecycleAllViews " + getChildCount()); 1385 for (int i = getChildCount() - 1; i >= 0; i--) { 1386 removeAndRecycleViewAt(i, recycler); 1387 } 1388 } 1389 1390 // Lays out items based on the current scroll position 1391 @Override 1392 public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state) { 1393 if (DEBUG) { 1394 Log.v(getTag(), "layoutChildren start numRows " + mNumRows + " mScrollOffsetSecondary " 1395 + mScrollOffsetSecondary + " mScrollOffsetPrimary " + mScrollOffsetPrimary 1396 + " inPreLayout " + state.isPreLayout() 1397 + " didStructureChange " + state.didStructureChange() 1398 + " mForceFullLayout " + mForceFullLayout); 1399 Log.v(getTag(), "width " + getWidth() + " height " + getHeight()); 1400 } 1401 1402 if (mNumRows == 0) { 1403 // haven't done measure yet 1404 return; 1405 } 1406 final int itemCount = state.getItemCount(); 1407 if (itemCount < 0) { 1408 return; 1409 } 1410 1411 if (!mLayoutEnabled) { 1412 discardLayoutInfo(); 1413 removeAndRecycleAllViews(recycler); 1414 return; 1415 } 1416 mInLayout = true; 1417 1418 saveContext(recycler, state); 1419 // Track the old focus view so we can adjust our system scroll position 1420 // so that any scroll animations happening now will remain valid. 1421 // We must use same delta in Pre Layout (if prelayout exists) and second layout. 1422 // So we cache the deltas in PreLayout and use it in second layout. 1423 int delta = 0, deltaSecondary = 0; 1424 if (!state.isPreLayout() && mUseDeltaInPreLayout) { 1425 delta = mDeltaInPreLayout; 1426 deltaSecondary = mDeltaSecondaryInPreLayout; 1427 } else { 1428 if (mFocusPosition != NO_POSITION 1429 && mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED) { 1430 // FIXME: we should get the remaining scroll animation offset from RecyclerView 1431 View focusView = findViewByPosition(mFocusPosition); 1432 if (focusView != null) { 1433 delta = mWindowAlignment.mainAxis().getSystemScrollPos(mScrollOffsetPrimary 1434 + getViewCenter(focusView), false, false) - mScrollOffsetPrimary; 1435 deltaSecondary = mWindowAlignment.secondAxis().getSystemScrollPos( 1436 mScrollOffsetSecondary + getViewCenterSecondary(focusView), 1437 false, false) - mScrollOffsetSecondary; 1438 if (mUseDeltaInPreLayout = state.isPreLayout()) { 1439 mDeltaInPreLayout = delta; 1440 mDeltaSecondaryInPreLayout = deltaSecondary; 1441 } 1442 } 1443 } 1444 } 1445 1446 final boolean hasDoneFirstLayout = hasDoneFirstLayout(); 1447 int savedFocusPos = mFocusPosition; 1448 boolean fastRelayout = false; 1449 if (!mState.didStructureChange() && !mForceFullLayout && hasDoneFirstLayout) { 1450 fastRelayout = true; 1451 fastRelayout(); 1452 } else { 1453 boolean hadFocus = mBaseGridView.hasFocus(); 1454 1455 int newFocusPosition = init(mFocusPosition); 1456 if (DEBUG) { 1457 Log.v(getTag(), "mFocusPosition " + mFocusPosition + " newFocusPosition " 1458 + newFocusPosition); 1459 } 1460 1461 // depending on result of init(), either recreating everything 1462 // or try to reuse the row start positions near mFocusPosition 1463 if (mGrid.getSize() == 0) { 1464 // this is a fresh creating all items, starting from 1465 // mFocusPosition with a estimated row index. 1466 mGrid.setStart(newFocusPosition, StaggeredGrid.START_DEFAULT); 1467 1468 // Can't track the old focus view 1469 delta = deltaSecondary = 0; 1470 1471 } else { 1472 // mGrid remembers Locations for the column that 1473 // contains mFocusePosition and also mRows remembers start 1474 // positions of each row. 1475 // Manually re-create child views for that column 1476 int firstIndex = mGrid.getFirstIndex(); 1477 int lastIndex = mGrid.getLastIndex(); 1478 for (int i = firstIndex; i <= lastIndex; i++) { 1479 mGridProvider.createItem(i, mGrid.getLocation(i).row, true); 1480 } 1481 } 1482 // add visible views at end until reach the end of window 1483 appendVisibleItems(); 1484 // add visible views at front until reach the start of window 1485 prependVisibleItems(); 1486 // multiple rounds: scrollToView of first round may drag first/last child into 1487 // "visible window" and we update scrollMin/scrollMax then run second scrollToView 1488 int oldFirstVisible; 1489 int oldLastVisible; 1490 do { 1491 oldFirstVisible = mFirstVisiblePos; 1492 oldLastVisible = mLastVisiblePos; 1493 View focusView = findViewByPosition(newFocusPosition); 1494 // we need force to initialize the child view's position 1495 scrollToView(focusView, false); 1496 if (focusView != null && hadFocus) { 1497 focusView.requestFocus(); 1498 } 1499 appendVisibleItems(); 1500 prependVisibleItems(); 1501 removeInvisibleViewsAtFront(); 1502 removeInvisibleViewsAtEnd(); 1503 } while (mFirstVisiblePos != oldFirstVisible || mLastVisiblePos != oldLastVisible); 1504 } 1505 mForceFullLayout = false; 1506 1507 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED) { 1508 scrollDirectionPrimary(-delta); 1509 scrollDirectionSecondary(-deltaSecondary); 1510 } 1511 appendVisibleItems(); 1512 prependVisibleItems(); 1513 removeInvisibleViewsAtFront(); 1514 removeInvisibleViewsAtEnd(); 1515 1516 if (DEBUG) { 1517 StringWriter sw = new StringWriter(); 1518 PrintWriter pw = new PrintWriter(sw); 1519 mGrid.debugPrint(pw); 1520 Log.d(getTag(), sw.toString()); 1521 } 1522 1523 if (mRowSecondarySizeRefresh) { 1524 mRowSecondarySizeRefresh = false; 1525 } else { 1526 updateRowSecondarySizeRefresh(); 1527 } 1528 1529 if (!state.isPreLayout()) { 1530 mUseDeltaInPreLayout = false; 1531 if (!fastRelayout || mFocusPosition != savedFocusPos) { 1532 dispatchChildSelected(); 1533 } 1534 } 1535 mInLayout = false; 1536 leaveContext(); 1537 if (DEBUG) Log.v(getTag(), "layoutChildren end"); 1538 } 1539 1540 private void offsetChildrenSecondary(int increment) { 1541 final int childCount = getChildCount(); 1542 if (mOrientation == HORIZONTAL) { 1543 for (int i = 0; i < childCount; i++) { 1544 getChildAt(i).offsetTopAndBottom(increment); 1545 } 1546 } else { 1547 for (int i = 0; i < childCount; i++) { 1548 getChildAt(i).offsetLeftAndRight(increment); 1549 } 1550 } 1551 } 1552 1553 private void offsetChildrenPrimary(int increment) { 1554 final int childCount = getChildCount(); 1555 if (mOrientation == VERTICAL) { 1556 for (int i = 0; i < childCount; i++) { 1557 getChildAt(i).offsetTopAndBottom(increment); 1558 } 1559 } else { 1560 for (int i = 0; i < childCount; i++) { 1561 getChildAt(i).offsetLeftAndRight(increment); 1562 } 1563 } 1564 } 1565 1566 @Override 1567 public int scrollHorizontallyBy(int dx, Recycler recycler, RecyclerView.State state) { 1568 if (DEBUG) Log.v(getTag(), "scrollHorizontallyBy " + dx); 1569 if (!mLayoutEnabled || !hasDoneFirstLayout()) { 1570 return 0; 1571 } 1572 saveContext(recycler, state); 1573 int result; 1574 if (mOrientation == HORIZONTAL) { 1575 result = scrollDirectionPrimary(dx); 1576 } else { 1577 result = scrollDirectionSecondary(dx); 1578 } 1579 leaveContext(); 1580 return result; 1581 } 1582 1583 @Override 1584 public int scrollVerticallyBy(int dy, Recycler recycler, RecyclerView.State state) { 1585 if (DEBUG) Log.v(getTag(), "scrollVerticallyBy " + dy); 1586 if (!mLayoutEnabled || !hasDoneFirstLayout()) { 1587 return 0; 1588 } 1589 saveContext(recycler, state); 1590 int result; 1591 if (mOrientation == VERTICAL) { 1592 result = scrollDirectionPrimary(dy); 1593 } else { 1594 result = scrollDirectionSecondary(dy); 1595 } 1596 leaveContext(); 1597 return result; 1598 } 1599 1600 // scroll in main direction may add/prune views 1601 private int scrollDirectionPrimary(int da) { 1602 if (da > 0) { 1603 if (!mWindowAlignment.mainAxis().isMaxUnknown()) { 1604 int maxScroll = mWindowAlignment.mainAxis().getMaxScroll(); 1605 if (mScrollOffsetPrimary + da > maxScroll) { 1606 da = maxScroll - mScrollOffsetPrimary; 1607 } 1608 } 1609 } else if (da < 0) { 1610 if (!mWindowAlignment.mainAxis().isMinUnknown()) { 1611 int minScroll = mWindowAlignment.mainAxis().getMinScroll(); 1612 if (mScrollOffsetPrimary + da < minScroll) { 1613 da = minScroll - mScrollOffsetPrimary; 1614 } 1615 } 1616 } 1617 if (da == 0) { 1618 return 0; 1619 } 1620 offsetChildrenPrimary(-da); 1621 mScrollOffsetPrimary += da; 1622 if (mInLayout) { 1623 return da; 1624 } 1625 1626 int childCount = getChildCount(); 1627 boolean updated; 1628 1629 if (da > 0) { 1630 appendVisibleItems(); 1631 } else if (da < 0) { 1632 prependVisibleItems(); 1633 } 1634 updated = getChildCount() > childCount; 1635 childCount = getChildCount(); 1636 1637 if (da > 0) { 1638 removeInvisibleViewsAtFront(); 1639 } else if (da < 0) { 1640 removeInvisibleViewsAtEnd(); 1641 } 1642 updated |= getChildCount() < childCount; 1643 1644 if (updated) { 1645 updateRowSecondarySizeRefresh(); 1646 } 1647 1648 mBaseGridView.invalidate(); 1649 return da; 1650 } 1651 1652 // scroll in second direction will not add/prune views 1653 private int scrollDirectionSecondary(int dy) { 1654 if (dy == 0) { 1655 return 0; 1656 } 1657 offsetChildrenSecondary(-dy); 1658 mScrollOffsetSecondary += dy; 1659 mBaseGridView.invalidate(); 1660 return dy; 1661 } 1662 1663 private void updateScrollMax() { 1664 if (mLastVisiblePos < 0) { 1665 return; 1666 } 1667 final boolean lastAvailable = mLastVisiblePos == mState.getItemCount() - 1; 1668 final boolean maxUnknown = mWindowAlignment.mainAxis().isMaxUnknown(); 1669 if (!lastAvailable && maxUnknown) { 1670 return; 1671 } 1672 int maxEdge = Integer.MIN_VALUE; 1673 int rowIndex = -1; 1674 for (int i = 0; i < mRows.length; i++) { 1675 if (mRows[i].high > maxEdge) { 1676 maxEdge = mRows[i].high; 1677 rowIndex = i; 1678 } 1679 } 1680 int maxScroll = Integer.MAX_VALUE; 1681 for (int i = mLastVisiblePos; i >= mFirstVisiblePos; i--) { 1682 StaggeredGrid.Location location = mGrid.getLocation(i); 1683 if (location != null && location.row == rowIndex) { 1684 int savedMaxEdge = mWindowAlignment.mainAxis().getMaxEdge(); 1685 mWindowAlignment.mainAxis().setMaxEdge(maxEdge); 1686 maxScroll = getPrimarySystemScrollPosition(findViewByPosition(i)); 1687 mWindowAlignment.mainAxis().setMaxEdge(savedMaxEdge); 1688 break; 1689 } 1690 } 1691 if (lastAvailable) { 1692 mWindowAlignment.mainAxis().setMaxEdge(maxEdge); 1693 mWindowAlignment.mainAxis().setMaxScroll(maxScroll); 1694 if (DEBUG) Log.v(getTag(), "updating scroll maxEdge to " + maxEdge + 1695 " scrollMax to " + maxScroll); 1696 } else { 1697 // the maxScroll for currently last visible item is larger, 1698 // so we must invalidate the max scroll value. 1699 if (maxScroll > mWindowAlignment.mainAxis().getMaxScroll()) { 1700 mWindowAlignment.mainAxis().invalidateScrollMax(); 1701 if (DEBUG) Log.v(getTag(), "Invalidate scrollMax since it should be " 1702 + "greater than " + maxScroll); 1703 } 1704 } 1705 } 1706 1707 private void updateScrollMin() { 1708 if (mFirstVisiblePos < 0) { 1709 return; 1710 } 1711 final boolean firstAvailable = mFirstVisiblePos == 0; 1712 final boolean minUnknown = mWindowAlignment.mainAxis().isMinUnknown(); 1713 if (!firstAvailable && minUnknown) { 1714 return; 1715 } 1716 int minEdge = Integer.MAX_VALUE; 1717 int rowIndex = -1; 1718 for (int i = 0; i < mRows.length; i++) { 1719 if (mRows[i].low < minEdge) { 1720 minEdge = mRows[i].low; 1721 rowIndex = i; 1722 } 1723 } 1724 int minScroll = Integer.MIN_VALUE; 1725 for (int i = mFirstVisiblePos; i <= mLastVisiblePos; i++) { 1726 StaggeredGrid.Location location = mGrid.getLocation(i); 1727 if (location != null && location.row == rowIndex) { 1728 int savedMinEdge = mWindowAlignment.mainAxis().getMinEdge(); 1729 mWindowAlignment.mainAxis().setMinEdge(minEdge); 1730 minScroll = getPrimarySystemScrollPosition(findViewByPosition(i)); 1731 mWindowAlignment.mainAxis().setMinEdge(savedMinEdge); 1732 break; 1733 } 1734 } 1735 if (firstAvailable) { 1736 mWindowAlignment.mainAxis().setMinEdge(minEdge); 1737 mWindowAlignment.mainAxis().setMinScroll(minScroll); 1738 if (DEBUG) Log.v(getTag(), "updating scroll minEdge to " + minEdge + 1739 " scrollMin to " + minScroll); 1740 } else { 1741 // the minScroll for currently first visible item is smaller, 1742 // so we must invalidate the min scroll value. 1743 if (minScroll < mWindowAlignment.mainAxis().getMinScroll()) { 1744 mWindowAlignment.mainAxis().invalidateScrollMin(); 1745 if (DEBUG) Log.v(getTag(), "Invalidate scrollMin, since it should be " 1746 + "less than " + minScroll); 1747 } 1748 } 1749 } 1750 1751 private void updateScrollSecondAxis() { 1752 mWindowAlignment.secondAxis().setMinEdge(0); 1753 mWindowAlignment.secondAxis().setMaxEdge(getSizeSecondary()); 1754 } 1755 1756 private void initScrollController() { 1757 mWindowAlignment.horizontal.setSize(getWidth()); 1758 mWindowAlignment.horizontal.setPadding(getPaddingLeft(), getPaddingRight()); 1759 mWindowAlignment.vertical.setSize(getHeight()); 1760 mWindowAlignment.vertical.setPadding(getPaddingTop(), getPaddingBottom()); 1761 mSizePrimary = mWindowAlignment.mainAxis().getSize(); 1762 1763 if (DEBUG) { 1764 Log.v(getTag(), "initScrollController mSizePrimary " + mSizePrimary 1765 + " mWindowAlignment " + mWindowAlignment); 1766 } 1767 } 1768 1769 public void setSelection(RecyclerView parent, int position) { 1770 setSelection(parent, position, false); 1771 } 1772 1773 public void setSelectionSmooth(RecyclerView parent, int position) { 1774 setSelection(parent, position, true); 1775 } 1776 1777 public int getSelection() { 1778 return mFocusPosition; 1779 } 1780 1781 public void setSelection(RecyclerView parent, int position, boolean smooth) { 1782 if (mFocusPosition == position) { 1783 return; 1784 } 1785 View view = findViewByPosition(position); 1786 if (view != null) { 1787 scrollToView(view, smooth); 1788 } else { 1789 mFocusPosition = position; 1790 if (!mLayoutEnabled) { 1791 return; 1792 } 1793 if (smooth) { 1794 if (!hasDoneFirstLayout()) { 1795 Log.w(getTag(), "setSelectionSmooth should " + 1796 "not be called before first layout pass"); 1797 return; 1798 } 1799 LinearSmoothScroller linearSmoothScroller = 1800 new LinearSmoothScroller(parent.getContext()) { 1801 @Override 1802 public PointF computeScrollVectorForPosition(int targetPosition) { 1803 if (getChildCount() == 0) { 1804 return null; 1805 } 1806 final int firstChildPos = getPosition(getChildAt(0)); 1807 final int direction = targetPosition < firstChildPos ? -1 : 1; 1808 if (mOrientation == HORIZONTAL) { 1809 return new PointF(direction, 0); 1810 } else { 1811 return new PointF(0, direction); 1812 } 1813 } 1814 @Override 1815 protected void onTargetFound(View targetView, 1816 RecyclerView.State state, Action action) { 1817 if (hasFocus()) { 1818 targetView.requestFocus(); 1819 } 1820 dispatchChildSelected(); 1821 if (getScrollPosition(targetView, mTempDeltas)) { 1822 int dx, dy; 1823 if (mOrientation == HORIZONTAL) { 1824 dx = mTempDeltas[0]; 1825 dy = mTempDeltas[1]; 1826 } else { 1827 dx = mTempDeltas[1]; 1828 dy = mTempDeltas[0]; 1829 } 1830 final int distance = (int) Math.sqrt(dx * dx + dy * dy); 1831 final int time = calculateTimeForDeceleration(distance); 1832 action.update(dx, dy, time, mDecelerateInterpolator); 1833 } 1834 } 1835 }; 1836 linearSmoothScroller.setTargetPosition(position); 1837 startSmoothScroll(linearSmoothScroller); 1838 } else { 1839 mForceFullLayout = true; 1840 parent.requestLayout(); 1841 } 1842 } 1843 } 1844 1845 @Override 1846 public void onItemsAdded(RecyclerView recyclerView, int positionStart, int itemCount) { 1847 boolean needsLayout = false; 1848 if (itemCount != 0) { 1849 if (mFirstVisiblePos < 0) { 1850 needsLayout = true; 1851 } else if (!(positionStart > mLastVisiblePos + 1 || 1852 positionStart + itemCount < mFirstVisiblePos - 1)) { 1853 needsLayout = true; 1854 } 1855 } 1856 if (needsLayout) { 1857 recyclerView.requestLayout(); 1858 } 1859 } 1860 1861 @Override 1862 public boolean onRequestChildFocus(RecyclerView parent, View child, View focused) { 1863 if (mFocusSearchDisabled) { 1864 return true; 1865 } 1866 if (!mInLayout) { 1867 scrollToView(child, true); 1868 } 1869 return true; 1870 } 1871 1872 @Override 1873 public boolean requestChildRectangleOnScreen(RecyclerView parent, View view, Rect rect, 1874 boolean immediate) { 1875 if (DEBUG) Log.v(getTag(), "requestChildRectangleOnScreen " + view + " " + rect); 1876 return false; 1877 } 1878 1879 int getScrollOffsetX() { 1880 return mOrientation == HORIZONTAL ? mScrollOffsetPrimary : mScrollOffsetSecondary; 1881 } 1882 1883 int getScrollOffsetY() { 1884 return mOrientation == HORIZONTAL ? mScrollOffsetSecondary : mScrollOffsetPrimary; 1885 } 1886 1887 public void getViewSelectedOffsets(View view, int[] offsets) { 1888 if (mOrientation == HORIZONTAL) { 1889 offsets[0] = getPrimarySystemScrollPosition(view) - mScrollOffsetPrimary; 1890 offsets[1] = getSecondarySystemScrollPosition(view) - mScrollOffsetSecondary; 1891 } else { 1892 offsets[1] = getPrimarySystemScrollPosition(view) - mScrollOffsetPrimary; 1893 offsets[0] = getSecondarySystemScrollPosition(view) - mScrollOffsetSecondary; 1894 } 1895 } 1896 1897 private int getPrimarySystemScrollPosition(View view) { 1898 int viewCenterPrimary = mScrollOffsetPrimary + getViewCenter(view); 1899 int pos = getPositionByView(view); 1900 StaggeredGrid.Location location = mGrid.getLocation(pos); 1901 final int row = location.row; 1902 boolean isFirst = mFirstVisiblePos == 0; 1903 // TODO: change to use State object in onRequestChildFocus() 1904 boolean isLast = mLastVisiblePos == (mState == null ? 1905 getItemCount() : mState.getItemCount()) - 1; 1906 if (isFirst || isLast) { 1907 for (int i = getChildCount() - 1; i >= 0; i--) { 1908 int position = getPositionByIndex(i); 1909 StaggeredGrid.Location loc = mGrid.getLocation(position); 1910 if (loc != null && loc.row == row) { 1911 if (position < pos) { 1912 isFirst = false; 1913 } else if (position > pos) { 1914 isLast = false; 1915 } 1916 } 1917 } 1918 } 1919 return mWindowAlignment.mainAxis().getSystemScrollPos(viewCenterPrimary, isFirst, isLast); 1920 } 1921 1922 private int getSecondarySystemScrollPosition(View view) { 1923 int viewCenterSecondary = mScrollOffsetSecondary + getViewCenterSecondary(view); 1924 int pos = getPositionByView(view); 1925 StaggeredGrid.Location location = mGrid.getLocation(pos); 1926 final int row = location.row; 1927 boolean isFirst = row == 0; 1928 boolean isLast = row == mGrid.getNumRows() - 1; 1929 return mWindowAlignment.secondAxis().getSystemScrollPos(viewCenterSecondary, 1930 isFirst, isLast); 1931 } 1932 1933 /** 1934 * Scroll to a given child view and change mFocusPosition. 1935 */ 1936 private void scrollToView(View view, boolean smooth) { 1937 int newFocusPosition = getPositionByView(view); 1938 if (newFocusPosition != mFocusPosition) { 1939 mFocusPosition = newFocusPosition; 1940 if (!mInLayout) { 1941 dispatchChildSelected(); 1942 } 1943 } 1944 if (mBaseGridView.isChildrenDrawingOrderEnabledInternal()) { 1945 mBaseGridView.invalidate(); 1946 } 1947 if (view == null) { 1948 return; 1949 } 1950 if (!view.hasFocus() && mBaseGridView.hasFocus()) { 1951 // transfer focus to the child if it does not have focus yet (e.g. triggered 1952 // by setSelection()) 1953 view.requestFocus(); 1954 } 1955 if (getScrollPosition(view, mTempDeltas)) { 1956 scrollGrid(mTempDeltas[0], mTempDeltas[1], smooth); 1957 } 1958 } 1959 1960 private boolean getScrollPosition(View view, int[] deltas) { 1961 switch (mFocusScrollStrategy) { 1962 case BaseGridView.FOCUS_SCROLL_ALIGNED: 1963 default: 1964 return getAlignedPosition(view, deltas); 1965 case BaseGridView.FOCUS_SCROLL_ITEM: 1966 case BaseGridView.FOCUS_SCROLL_PAGE: 1967 return getNoneAlignedPosition(view, deltas); 1968 } 1969 } 1970 1971 private boolean getNoneAlignedPosition(View view, int[] deltas) { 1972 int pos = getPositionByView(view); 1973 int viewMin = getViewMin(view); 1974 int viewMax = getViewMax(view); 1975 // we either align "firstView" to left/top padding edge 1976 // or align "lastView" to right/bottom padding edge 1977 View firstView = null; 1978 View lastView = null; 1979 int paddingLow = mWindowAlignment.mainAxis().getPaddingLow(); 1980 int clientSize = mWindowAlignment.mainAxis().getClientSize(); 1981 final int row = mGrid.getLocation(pos).row; 1982 if (viewMin < paddingLow) { 1983 // view enters low padding area: 1984 firstView = view; 1985 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_PAGE) { 1986 // scroll one "page" left/top, 1987 // align first visible item of the "page" at the low padding edge. 1988 while (!prependOneVisibleItem()) { 1989 List<Integer> positions = 1990 mGrid.getItemPositionsInRows(mFirstVisiblePos, pos)[row]; 1991 firstView = findViewByPosition(positions.get(0)); 1992 if (viewMax - getViewMin(firstView) > clientSize) { 1993 if (positions.size() > 1) { 1994 firstView = findViewByPosition(positions.get(1)); 1995 } 1996 break; 1997 } 1998 } 1999 } 2000 } else if (viewMax > clientSize + paddingLow) { 2001 // view enters high padding area: 2002 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_PAGE) { 2003 // scroll whole one page right/bottom, align view at the low padding edge. 2004 firstView = view; 2005 do { 2006 List<Integer> positions = 2007 mGrid.getItemPositionsInRows(pos, mLastVisiblePos)[row]; 2008 lastView = findViewByPosition(positions.get(positions.size() - 1)); 2009 if (getViewMax(lastView) - viewMin > clientSize) { 2010 lastView = null; 2011 break; 2012 } 2013 } while (!appendOneVisibleItem()); 2014 if (lastView != null) { 2015 // however if we reached end, we should align last view. 2016 firstView = null; 2017 } 2018 } else { 2019 lastView = view; 2020 } 2021 } 2022 int scrollPrimary = 0; 2023 int scrollSecondary = 0; 2024 if (firstView != null) { 2025 scrollPrimary = getViewMin(firstView) - paddingLow; 2026 } else if (lastView != null) { 2027 scrollPrimary = getViewMax(lastView) - (paddingLow + clientSize); 2028 } 2029 View secondaryAlignedView; 2030 if (firstView != null) { 2031 secondaryAlignedView = firstView; 2032 } else if (lastView != null) { 2033 secondaryAlignedView = lastView; 2034 } else { 2035 secondaryAlignedView = view; 2036 } 2037 scrollSecondary = getSecondarySystemScrollPosition(secondaryAlignedView); 2038 scrollSecondary -= mScrollOffsetSecondary; 2039 if (scrollPrimary != 0 || scrollSecondary != 0) { 2040 deltas[0] = scrollPrimary; 2041 deltas[1] = scrollSecondary; 2042 return true; 2043 } 2044 return false; 2045 } 2046 2047 private boolean getAlignedPosition(View view, int[] deltas) { 2048 int scrollPrimary = getPrimarySystemScrollPosition(view); 2049 int scrollSecondary = getSecondarySystemScrollPosition(view); 2050 if (DEBUG) { 2051 Log.v(getTag(), "getAlignedPosition " + scrollPrimary + " " + scrollSecondary 2052 +" " + mWindowAlignment); 2053 } 2054 scrollPrimary -= mScrollOffsetPrimary; 2055 scrollSecondary -= mScrollOffsetSecondary; 2056 if (scrollPrimary != 0 || scrollSecondary != 0) { 2057 deltas[0] = scrollPrimary; 2058 deltas[1] = scrollSecondary; 2059 return true; 2060 } 2061 return false; 2062 } 2063 2064 private void scrollGrid(int scrollPrimary, int scrollSecondary, boolean smooth) { 2065 if (mInLayout) { 2066 scrollDirectionPrimary(scrollPrimary); 2067 scrollDirectionSecondary(scrollSecondary); 2068 } else { 2069 int scrollX; 2070 int scrollY; 2071 if (mOrientation == HORIZONTAL) { 2072 scrollX = scrollPrimary; 2073 scrollY = scrollSecondary; 2074 } else { 2075 scrollX = scrollSecondary; 2076 scrollY = scrollPrimary; 2077 } 2078 if (smooth) { 2079 mBaseGridView.smoothScrollBy(scrollX, scrollY); 2080 } else { 2081 mBaseGridView.scrollBy(scrollX, scrollY); 2082 } 2083 } 2084 } 2085 2086 public void setPruneChild(boolean pruneChild) { 2087 if (mPruneChild != pruneChild) { 2088 mPruneChild = pruneChild; 2089 if (mPruneChild) { 2090 requestLayout(); 2091 } 2092 } 2093 } 2094 2095 public boolean getPruneChild() { 2096 return mPruneChild; 2097 } 2098 2099 private int findImmediateChildIndex(View view) { 2100 while (view != null && view != mBaseGridView) { 2101 int index = mBaseGridView.indexOfChild(view); 2102 if (index >= 0) { 2103 return index; 2104 } 2105 view = (View) view.getParent(); 2106 } 2107 return NO_POSITION; 2108 } 2109 2110 void setFocusSearchDisabled(boolean disabled) { 2111 mFocusSearchDisabled = disabled; 2112 } 2113 2114 boolean isFocusSearchDisabled() { 2115 return mFocusSearchDisabled; 2116 } 2117 2118 @Override 2119 public View onInterceptFocusSearch(View focused, int direction) { 2120 if (mFocusSearchDisabled) { 2121 return focused; 2122 } 2123 return null; 2124 } 2125 2126 boolean hasPreviousViewInSameRow(int pos) { 2127 if (mGrid == null || pos == NO_POSITION) { 2128 return false; 2129 } 2130 if (mFirstVisiblePos > 0) { 2131 return true; 2132 } 2133 final int focusedRow = mGrid.getLocation(pos).row; 2134 for (int i = getChildCount() - 1; i >= 0; i--) { 2135 int position = getPositionByIndex(i); 2136 StaggeredGrid.Location loc = mGrid.getLocation(position); 2137 if (loc != null && loc.row == focusedRow) { 2138 if (position < pos) { 2139 return true; 2140 } 2141 } 2142 } 2143 return false; 2144 } 2145 2146 @Override 2147 public boolean onAddFocusables(RecyclerView recyclerView, 2148 ArrayList<View> views, int direction, int focusableMode) { 2149 if (mFocusSearchDisabled) { 2150 return true; 2151 } 2152 // If this viewgroup or one of its children currently has focus then we 2153 // consider our children for focus searching in main direction on the same row. 2154 // If this viewgroup has no focus and using focus align, we want the system 2155 // to ignore our children and pass focus to the viewgroup, which will pass 2156 // focus on to its children appropriately. 2157 // If this viewgroup has no focus and not using focus align, we want to 2158 // consider the child that does not overlap with padding area. 2159 if (recyclerView.hasFocus()) { 2160 final int movement = getMovement(direction); 2161 if (movement != PREV_ITEM && movement != NEXT_ITEM) { 2162 // Move on secondary direction uses default addFocusables(). 2163 return false; 2164 } 2165 final View focused = recyclerView.findFocus(); 2166 final int focusedPos = getPositionByIndex(findImmediateChildIndex(focused)); 2167 // Add focusables of focused item. 2168 if (focusedPos != NO_POSITION) { 2169 findViewByPosition(focusedPos).addFocusables(views, direction, focusableMode); 2170 } 2171 final int focusedRow = mGrid != null && focusedPos != NO_POSITION ? 2172 mGrid.getLocation(focusedPos).row : NO_POSITION; 2173 // Add focusables of next neighbor of same row on the focus search direction. 2174 if (mGrid != null) { 2175 final int focusableCount = views.size(); 2176 for (int i = 0, count = getChildCount(); i < count; i++) { 2177 int index = movement == NEXT_ITEM ? i : count - 1 - i; 2178 final View child = getChildAt(index); 2179 if (child.getVisibility() != View.VISIBLE) { 2180 continue; 2181 } 2182 int position = getPositionByIndex(index); 2183 StaggeredGrid.Location loc = mGrid.getLocation(position); 2184 if (focusedRow == NO_POSITION || (loc != null && loc.row == focusedRow)) { 2185 if (focusedPos == NO_POSITION || 2186 (movement == NEXT_ITEM && position > focusedPos) 2187 || (movement == PREV_ITEM && position < focusedPos)) { 2188 child.addFocusables(views, direction, focusableMode); 2189 if (views.size() > focusableCount) { 2190 break; 2191 } 2192 } 2193 } 2194 } 2195 } 2196 } else { 2197 if (mFocusScrollStrategy != BaseGridView.FOCUS_SCROLL_ALIGNED) { 2198 // adding views not overlapping padding area to avoid scrolling in gaining focus 2199 int left = mWindowAlignment.mainAxis().getPaddingLow(); 2200 int right = mWindowAlignment.mainAxis().getClientSize() + left; 2201 int focusableCount = views.size(); 2202 for (int i = 0, count = getChildCount(); i < count; i++) { 2203 View child = getChildAt(i); 2204 if (child.getVisibility() == View.VISIBLE) { 2205 if (getViewMin(child) >= left && getViewMax(child) <= right) { 2206 child.addFocusables(views, direction, focusableMode); 2207 } 2208 } 2209 } 2210 // if we cannot find any, then just add all children. 2211 if (views.size() == focusableCount) { 2212 for (int i = 0, count = getChildCount(); i < count; i++) { 2213 View child = getChildAt(i); 2214 if (child.getVisibility() == View.VISIBLE) { 2215 child.addFocusables(views, direction, focusableMode); 2216 } 2217 } 2218 if (views.size() != focusableCount) { 2219 return true; 2220 } 2221 } else { 2222 return true; 2223 } 2224 // if still cannot find any, fall through and add itself 2225 } 2226 if (recyclerView.isFocusable()) { 2227 views.add(recyclerView); 2228 } 2229 } 2230 return true; 2231 } 2232 2233 @Override 2234 public View onFocusSearchFailed(View focused, int direction, Recycler recycler, 2235 RecyclerView.State state) { 2236 if (DEBUG) Log.v(getTag(), "onFocusSearchFailed direction " + direction); 2237 2238 View view = null; 2239 int movement = getMovement(direction); 2240 if (mNumRows == 1) { 2241 // for simple row, use LinearSmoothScroller to smooth animation. 2242 // It will stay at a fixed cap speed in continuous scroll. 2243 if (movement == NEXT_ITEM) { 2244 int newPos = mFocusPosition + mNumRows; 2245 if (newPos < getItemCount()) { 2246 setSelectionSmooth(mBaseGridView, newPos); 2247 view = focused; 2248 } else { 2249 if (!mFocusOutEnd) { 2250 view = focused; 2251 } 2252 } 2253 } else if (movement == PREV_ITEM){ 2254 int newPos = mFocusPosition - mNumRows; 2255 if (newPos >= 0) { 2256 setSelectionSmooth(mBaseGridView, newPos); 2257 view = focused; 2258 } else { 2259 if (!mFocusOutFront) { 2260 view = focused; 2261 } 2262 } 2263 } 2264 } else if (mNumRows > 1) { 2265 // for possible staggered grid, we need guarantee focus to same row/column. 2266 // TODO: we may also use LinearSmoothScroller. 2267 saveContext(recycler, state); 2268 final FocusFinder ff = FocusFinder.getInstance(); 2269 if (movement == NEXT_ITEM) { 2270 while (view == null && !appendOneVisibleItem()) { 2271 view = ff.findNextFocus(mBaseGridView, focused, direction); 2272 } 2273 } else if (movement == PREV_ITEM){ 2274 while (view == null && !prependOneVisibleItem()) { 2275 view = ff.findNextFocus(mBaseGridView, focused, direction); 2276 } 2277 } 2278 if (view == null) { 2279 // returning the same view to prevent focus lost when scrolling past the end of the list 2280 if (movement == PREV_ITEM) { 2281 view = mFocusOutFront ? null : focused; 2282 } else if (movement == NEXT_ITEM){ 2283 view = mFocusOutEnd ? null : focused; 2284 } 2285 } 2286 leaveContext(); 2287 } 2288 if (DEBUG) Log.v(getTag(), "returning view " + view); 2289 return view; 2290 } 2291 2292 boolean gridOnRequestFocusInDescendants(RecyclerView recyclerView, int direction, 2293 Rect previouslyFocusedRect) { 2294 switch (mFocusScrollStrategy) { 2295 case BaseGridView.FOCUS_SCROLL_ALIGNED: 2296 default: 2297 return gridOnRequestFocusInDescendantsAligned(recyclerView, 2298 direction, previouslyFocusedRect); 2299 case BaseGridView.FOCUS_SCROLL_PAGE: 2300 case BaseGridView.FOCUS_SCROLL_ITEM: 2301 return gridOnRequestFocusInDescendantsUnaligned(recyclerView, 2302 direction, previouslyFocusedRect); 2303 } 2304 } 2305 2306 private boolean gridOnRequestFocusInDescendantsAligned(RecyclerView recyclerView, 2307 int direction, Rect previouslyFocusedRect) { 2308 View view = findViewByPosition(mFocusPosition); 2309 if (view != null) { 2310 boolean result = view.requestFocus(direction, previouslyFocusedRect); 2311 if (!result && DEBUG) { 2312 Log.w(getTag(), "failed to request focus on " + view); 2313 } 2314 return result; 2315 } 2316 return false; 2317 } 2318 2319 private boolean gridOnRequestFocusInDescendantsUnaligned(RecyclerView recyclerView, 2320 int direction, Rect previouslyFocusedRect) { 2321 // focus to view not overlapping padding area to avoid scrolling in gaining focus 2322 int index; 2323 int increment; 2324 int end; 2325 int count = getChildCount(); 2326 if ((direction & View.FOCUS_FORWARD) != 0) { 2327 index = 0; 2328 increment = 1; 2329 end = count; 2330 } else { 2331 index = count - 1; 2332 increment = -1; 2333 end = -1; 2334 } 2335 int left = mWindowAlignment.mainAxis().getPaddingLow(); 2336 int right = mWindowAlignment.mainAxis().getClientSize() + left; 2337 for (int i = index; i != end; i += increment) { 2338 View child = getChildAt(i); 2339 if (child.getVisibility() == View.VISIBLE) { 2340 if (getViewMin(child) >= left && getViewMax(child) <= right) { 2341 if (child.requestFocus(direction, previouslyFocusedRect)) { 2342 return true; 2343 } 2344 } 2345 } 2346 } 2347 return false; 2348 } 2349 2350 private final static int PREV_ITEM = 0; 2351 private final static int NEXT_ITEM = 1; 2352 private final static int PREV_ROW = 2; 2353 private final static int NEXT_ROW = 3; 2354 2355 private int getMovement(int direction) { 2356 int movement = View.FOCUS_LEFT; 2357 2358 if (mOrientation == HORIZONTAL) { 2359 switch(direction) { 2360 case View.FOCUS_LEFT: 2361 movement = PREV_ITEM; 2362 break; 2363 case View.FOCUS_RIGHT: 2364 movement = NEXT_ITEM; 2365 break; 2366 case View.FOCUS_UP: 2367 movement = PREV_ROW; 2368 break; 2369 case View.FOCUS_DOWN: 2370 movement = NEXT_ROW; 2371 break; 2372 } 2373 } else if (mOrientation == VERTICAL) { 2374 switch(direction) { 2375 case View.FOCUS_LEFT: 2376 movement = PREV_ROW; 2377 break; 2378 case View.FOCUS_RIGHT: 2379 movement = NEXT_ROW; 2380 break; 2381 case View.FOCUS_UP: 2382 movement = PREV_ITEM; 2383 break; 2384 case View.FOCUS_DOWN: 2385 movement = NEXT_ITEM; 2386 break; 2387 } 2388 } 2389 2390 return movement; 2391 } 2392 2393 int getChildDrawingOrder(RecyclerView recyclerView, int childCount, int i) { 2394 View view = findViewByPosition(mFocusPosition); 2395 if (view == null) { 2396 return i; 2397 } 2398 int focusIndex = recyclerView.indexOfChild(view); 2399 // supposely 0 1 2 3 4 5 6 7 8 9, 4 is the center item 2400 // drawing order is 0 1 2 3 9 8 7 6 5 4 2401 if (i < focusIndex) { 2402 return i; 2403 } else if (i < childCount - 1) { 2404 return focusIndex + childCount - 1 - i; 2405 } else { 2406 return focusIndex; 2407 } 2408 } 2409 2410 @Override 2411 public void onAdapterChanged(RecyclerView.Adapter oldAdapter, 2412 RecyclerView.Adapter newAdapter) { 2413 discardLayoutInfo(); 2414 mFocusPosition = NO_POSITION; 2415 super.onAdapterChanged(oldAdapter, newAdapter); 2416 } 2417 2418 private void discardLayoutInfo() { 2419 mGrid = null; 2420 mRows = null; 2421 mRowSizeSecondary = null; 2422 mFirstVisiblePos = -1; 2423 mLastVisiblePos = -1; 2424 mRowSecondarySizeRefresh = false; 2425 } 2426 2427 public void setLayoutEnabled(boolean layoutEnabled) { 2428 if (mLayoutEnabled != layoutEnabled) { 2429 mLayoutEnabled = layoutEnabled; 2430 requestLayout(); 2431 } 2432 } 2433} 2434