GridLayoutManager.java revision e3582bec2e51351a3116612ad529d7eb29a82bb7
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 if (mGrid == null) { 789 if (mState.getItemCount() > 0) { 790 measureScrapChild(mFocusPosition == NO_POSITION ? 0 : mFocusPosition, 791 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 792 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 793 mMeasuredDimension); 794 if (DEBUG) Log.v(TAG, "measured scrap child: " + mMeasuredDimension[0] + 795 " " + mMeasuredDimension[1]); 796 } else { 797 mMeasuredDimension[0] = mMeasuredDimension[1] = 0; 798 } 799 } 800 801 List<Integer>[] rows = mGrid == null ? null : 802 mGrid.getItemPositionsInRows(mFirstVisiblePos, mLastVisiblePos); 803 boolean changed = false; 804 805 for (int rowIndex = 0; rowIndex < mNumRows; rowIndex++) { 806 int rowSize = 0; 807 808 final int rowItemCount = rows == null ? 1 : rows[rowIndex].size(); 809 if (DEBUG) Log.v(getTag(), "processRowSizeSecondary row " + rowIndex + 810 " rowItemCount " + rowItemCount); 811 812 for (int i = 0; i < rowItemCount; i++) { 813 if (rows != null) { 814 final int position = rows[rowIndex].get(i); 815 final View view = findViewByPosition(position); 816 if (measure && view.isLayoutRequested()) { 817 measureChild(view); 818 } 819 mMeasuredDimension[0] = view.getMeasuredWidth(); 820 mMeasuredDimension[1] = view.getMeasuredHeight(); 821 } 822 final int secondarySize = mOrientation == HORIZONTAL ? 823 mMeasuredDimension[1] : mMeasuredDimension[0]; 824 if (secondarySize > rowSize) { 825 rowSize = secondarySize; 826 } 827 } 828 if (DEBUG) Log.v(getTag(), "row " + rowIndex + " rowItemCount " + rowItemCount + 829 " rowSize " + rowSize); 830 831 if (mRowSizeSecondary[rowIndex] != rowSize) { 832 if (DEBUG) Log.v(getTag(), "row size secondary changed: " + mRowSizeSecondary[rowIndex] + 833 ", " + rowSize); 834 835 mRowSizeSecondary[rowIndex] = rowSize; 836 changed = true; 837 } 838 } 839 840 return changed; 841 } 842 843 /** 844 * Checks if we need to update row secondary sizes. 845 */ 846 private void updateRowSecondarySizeRefresh() { 847 mRowSecondarySizeRefresh = processRowSizeSecondary(false); 848 if (mRowSecondarySizeRefresh) { 849 if (DEBUG) Log.v(getTag(), "mRowSecondarySizeRefresh now set"); 850 forceRequestLayout(); 851 } 852 } 853 854 private void forceRequestLayout() { 855 if (DEBUG) Log.v(getTag(), "forceRequestLayout"); 856 // RecyclerView prevents us from requesting layout in many cases 857 // (during layout, during scroll, etc.) 858 // For secondary row size wrap_content support we currently need a 859 // second layout pass to update the measured size after having measured 860 // and added child views in layoutChildren. 861 // Force the second layout by posting a delayed runnable. 862 // TODO: investigate allowing a second layout pass, 863 // or move child add/measure logic to the measure phase. 864 ViewCompat.postOnAnimation(mBaseGridView, mRequestLayoutRunnable); 865 } 866 867 private final Runnable mRequestLayoutRunnable = new Runnable() { 868 @Override 869 public void run() { 870 if (DEBUG) Log.v(getTag(), "request Layout from runnable"); 871 requestLayout(); 872 } 873 }; 874 875 @Override 876 public void onMeasure(Recycler recycler, State state, int widthSpec, int heightSpec) { 877 saveContext(recycler, state); 878 879 int sizePrimary, sizeSecondary, modeSecondary, paddingSecondary; 880 int measuredSizeSecondary; 881 if (mOrientation == HORIZONTAL) { 882 sizePrimary = MeasureSpec.getSize(widthSpec); 883 sizeSecondary = MeasureSpec.getSize(heightSpec); 884 modeSecondary = MeasureSpec.getMode(heightSpec); 885 paddingSecondary = getPaddingTop() + getPaddingBottom(); 886 } else { 887 sizeSecondary = MeasureSpec.getSize(widthSpec); 888 sizePrimary = MeasureSpec.getSize(heightSpec); 889 modeSecondary = MeasureSpec.getMode(widthSpec); 890 paddingSecondary = getPaddingLeft() + getPaddingRight(); 891 } 892 if (DEBUG) Log.v(getTag(), "onMeasure widthSpec " + Integer.toHexString(widthSpec) + 893 " heightSpec " + Integer.toHexString(heightSpec) + 894 " modeSecondary " + Integer.toHexString(modeSecondary) + 895 " sizeSecondary " + sizeSecondary + " " + this); 896 897 mMaxSizeSecondary = sizeSecondary; 898 899 if (mRowSizeSecondaryRequested == ViewGroup.LayoutParams.WRAP_CONTENT) { 900 mNumRows = mNumRowsRequested == 0 ? 1 : mNumRowsRequested; 901 mFixedRowSizeSecondary = 0; 902 903 if (mRowSizeSecondary == null || mRowSizeSecondary.length != mNumRows) { 904 mRowSizeSecondary = new int[mNumRows]; 905 } 906 907 // Measure all current children and update cached row heights 908 processRowSizeSecondary(true); 909 910 switch (modeSecondary) { 911 case MeasureSpec.UNSPECIFIED: 912 measuredSizeSecondary = getSizeSecondary() + paddingSecondary; 913 break; 914 case MeasureSpec.AT_MOST: 915 measuredSizeSecondary = Math.min(getSizeSecondary() + paddingSecondary, 916 mMaxSizeSecondary); 917 break; 918 case MeasureSpec.EXACTLY: 919 measuredSizeSecondary = mMaxSizeSecondary; 920 break; 921 default: 922 throw new IllegalStateException("wrong spec"); 923 } 924 925 } else { 926 switch (modeSecondary) { 927 case MeasureSpec.UNSPECIFIED: 928 if (mRowSizeSecondaryRequested == 0) { 929 if (mOrientation == HORIZONTAL) { 930 throw new IllegalStateException("Must specify rowHeight or view height"); 931 } else { 932 throw new IllegalStateException("Must specify columnWidth or view width"); 933 } 934 } 935 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 936 mNumRows = mNumRowsRequested == 0 ? 1 : mNumRowsRequested; 937 measuredSizeSecondary = mFixedRowSizeSecondary * mNumRows + mMarginSecondary 938 * (mNumRows - 1) + paddingSecondary; 939 break; 940 case MeasureSpec.AT_MOST: 941 case MeasureSpec.EXACTLY: 942 if (mNumRowsRequested == 0 && mRowSizeSecondaryRequested == 0) { 943 mNumRows = 1; 944 mFixedRowSizeSecondary = sizeSecondary - paddingSecondary; 945 } else if (mNumRowsRequested == 0) { 946 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 947 mNumRows = (sizeSecondary + mMarginSecondary) 948 / (mRowSizeSecondaryRequested + mMarginSecondary); 949 } else if (mRowSizeSecondaryRequested == 0) { 950 mNumRows = mNumRowsRequested; 951 mFixedRowSizeSecondary = (sizeSecondary - paddingSecondary - mMarginSecondary 952 * (mNumRows - 1)) / mNumRows; 953 } else { 954 mNumRows = mNumRowsRequested; 955 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 956 } 957 measuredSizeSecondary = sizeSecondary; 958 if (modeSecondary == MeasureSpec.AT_MOST) { 959 int childrenSize = mFixedRowSizeSecondary * mNumRows + mMarginSecondary 960 * (mNumRows - 1) + paddingSecondary; 961 if (childrenSize < measuredSizeSecondary) { 962 measuredSizeSecondary = childrenSize; 963 } 964 } 965 break; 966 default: 967 throw new IllegalStateException("wrong spec"); 968 } 969 } 970 if (mOrientation == HORIZONTAL) { 971 setMeasuredDimension(sizePrimary, measuredSizeSecondary); 972 } else { 973 setMeasuredDimension(measuredSizeSecondary, sizePrimary); 974 } 975 if (DEBUG) { 976 Log.v(getTag(), "onMeasure sizePrimary " + sizePrimary + 977 " measuredSizeSecondary " + measuredSizeSecondary + 978 " mFixedRowSizeSecondary " + mFixedRowSizeSecondary + 979 " mNumRows " + mNumRows); 980 } 981 982 leaveContext(); 983 } 984 985 private void measureChild(View child) { 986 final ViewGroup.LayoutParams lp = child.getLayoutParams(); 987 final int secondarySpec = (mRowSizeSecondaryRequested == ViewGroup.LayoutParams.WRAP_CONTENT) ? 988 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED) : 989 MeasureSpec.makeMeasureSpec(mFixedRowSizeSecondary, MeasureSpec.EXACTLY); 990 int widthSpec, heightSpec; 991 992 if (mOrientation == HORIZONTAL) { 993 widthSpec = ViewGroup.getChildMeasureSpec( 994 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 995 0, lp.width); 996 heightSpec = ViewGroup.getChildMeasureSpec(secondarySpec, 0, lp.height); 997 } else { 998 heightSpec = ViewGroup.getChildMeasureSpec( 999 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 1000 0, lp.height); 1001 widthSpec = ViewGroup.getChildMeasureSpec(secondarySpec, 0, lp.width); 1002 } 1003 1004 child.measure(widthSpec, heightSpec); 1005 1006 if (DEBUG) Log.v(getTag(), "measureChild secondarySpec " + Integer.toHexString(secondarySpec) + 1007 " widthSpec " + Integer.toHexString(widthSpec) + 1008 " heightSpec " + Integer.toHexString(heightSpec) + 1009 " measuredWidth " + child.getMeasuredWidth() + 1010 " measuredHeight " + child.getMeasuredHeight()); 1011 if (DEBUG) Log.v(getTag(), "child lp width " + lp.width + " height " + lp.height); 1012 } 1013 1014 private StaggeredGrid.Provider mGridProvider = new StaggeredGrid.Provider() { 1015 1016 @Override 1017 public int getCount() { 1018 return mState.getItemCount(); 1019 } 1020 1021 @Override 1022 public void createItem(int index, int rowIndex, boolean append) { 1023 View v = getViewForPosition(index); 1024 if (mFirstVisiblePos >= 0) { 1025 // when StaggeredGrid append or prepend item, we must guarantee 1026 // that sibling item has created views already. 1027 if (append && index != mLastVisiblePos + 1) { 1028 throw new RuntimeException(); 1029 } else if (!append && index != mFirstVisiblePos - 1) { 1030 throw new RuntimeException(); 1031 } 1032 } 1033 1034 // See recyclerView docs: we don't need re-add scraped view if it was removed. 1035 if (!((RecyclerView.LayoutParams) v.getLayoutParams()).isItemRemoved()) { 1036 if (append) { 1037 addView(v); 1038 } else { 1039 addView(v, 0); 1040 } 1041 measureChild(v); 1042 } 1043 1044 int length = mOrientation == HORIZONTAL ? v.getMeasuredWidth() : v.getMeasuredHeight(); 1045 int start, end; 1046 if (append) { 1047 start = mRows[rowIndex].high; 1048 if (start != mRows[rowIndex].low) { 1049 // if there are existing item in the row, add margin between 1050 start += mMarginPrimary; 1051 } else { 1052 final int lastRow = mRows.length - 1; 1053 if (lastRow != rowIndex && mRows[lastRow].high != mRows[lastRow].low) { 1054 // if there are existing item in the last row, insert 1055 // the new item after the last item of last row. 1056 start = mRows[lastRow].high + mMarginPrimary; 1057 } 1058 } 1059 end = start + length; 1060 mRows[rowIndex].high = end; 1061 } else { 1062 end = mRows[rowIndex].low; 1063 if (end != mRows[rowIndex].high) { 1064 end -= mMarginPrimary; 1065 } else if (0 != rowIndex && mRows[0].high != mRows[0].low) { 1066 // if there are existing item in the first row, insert 1067 // the new item before the first item of first row. 1068 end = mRows[0].low - mMarginPrimary; 1069 } 1070 start = end - length; 1071 mRows[rowIndex].low = start; 1072 } 1073 if (mFirstVisiblePos < 0) { 1074 mFirstVisiblePos = mLastVisiblePos = index; 1075 } else { 1076 if (append) { 1077 mLastVisiblePos++; 1078 } else { 1079 mFirstVisiblePos--; 1080 } 1081 } 1082 if (DEBUG) Log.v(getTag(), "start " + start + " end " + end); 1083 int startSecondary = getRowStartSecondary(rowIndex) - mScrollOffsetSecondary; 1084 layoutChild(rowIndex, v, start - mScrollOffsetPrimary, end - mScrollOffsetPrimary, 1085 startSecondary); 1086 if (DEBUG) { 1087 Log.d(getTag(), "addView " + index + " " + v); 1088 } 1089 if (index == mFirstVisiblePos) { 1090 updateScrollMin(); 1091 } 1092 if (index == mLastVisiblePos) { 1093 updateScrollMax(); 1094 } 1095 } 1096 }; 1097 1098 private void layoutChild(int rowIndex, View v, int start, int end, int startSecondary) { 1099 int sizeSecondary = mOrientation == HORIZONTAL ? v.getMeasuredHeight() 1100 : v.getMeasuredWidth(); 1101 if (mFixedRowSizeSecondary > 0) { 1102 sizeSecondary = Math.min(sizeSecondary, mFixedRowSizeSecondary); 1103 } 1104 final int verticalGravity = mGravity & Gravity.VERTICAL_GRAVITY_MASK; 1105 final int horizontalGravity = mGravity & Gravity.HORIZONTAL_GRAVITY_MASK; 1106 if (mOrientation == HORIZONTAL && verticalGravity == Gravity.TOP 1107 || mOrientation == VERTICAL && horizontalGravity == Gravity.LEFT) { 1108 // do nothing 1109 } else if (mOrientation == HORIZONTAL && verticalGravity == Gravity.BOTTOM 1110 || mOrientation == VERTICAL && horizontalGravity == Gravity.RIGHT) { 1111 startSecondary += getRowSizeSecondary(rowIndex) - sizeSecondary; 1112 } else if (mOrientation == HORIZONTAL && verticalGravity == Gravity.CENTER_VERTICAL 1113 || mOrientation == VERTICAL && horizontalGravity == Gravity.CENTER_HORIZONTAL) { 1114 startSecondary += (getRowSizeSecondary(rowIndex) - sizeSecondary) / 2; 1115 } 1116 int left, top, right, bottom; 1117 if (mOrientation == HORIZONTAL) { 1118 left = start; 1119 top = startSecondary; 1120 right = end; 1121 bottom = startSecondary + sizeSecondary; 1122 } else { 1123 top = start; 1124 left = startSecondary; 1125 bottom = end; 1126 right = startSecondary + sizeSecondary; 1127 } 1128 v.layout(left, top, right, bottom); 1129 updateChildOpticalInsets(v, left, top, right, bottom); 1130 updateChildAlignments(v); 1131 } 1132 1133 private void updateChildOpticalInsets(View v, int left, int top, int right, int bottom) { 1134 LayoutParams p = (LayoutParams) v.getLayoutParams(); 1135 p.setOpticalInsets(left - v.getLeft(), top - v.getTop(), 1136 v.getRight() - right, v.getBottom() - bottom); 1137 } 1138 1139 private void updateChildAlignments(View v) { 1140 LayoutParams p = (LayoutParams) v.getLayoutParams(); 1141 p.setAlignX(mItemAlignment.horizontal.getAlignmentPosition(v)); 1142 p.setAlignY(mItemAlignment.vertical.getAlignmentPosition(v)); 1143 } 1144 1145 private void updateChildAlignments() { 1146 for (int i = 0, c = getChildCount(); i < c; i++) { 1147 updateChildAlignments(getChildAt(i)); 1148 } 1149 } 1150 1151 private boolean needsAppendVisibleItem() { 1152 if (mLastVisiblePos < mFocusPosition) { 1153 return true; 1154 } 1155 int right = mScrollOffsetPrimary + mSizePrimary; 1156 for (int i = 0; i < mNumRows; i++) { 1157 if (mRows[i].low == mRows[i].high) { 1158 if (mRows[i].high < right) { 1159 return true; 1160 } 1161 } else if (mRows[i].high < right - mMarginPrimary) { 1162 return true; 1163 } 1164 } 1165 return false; 1166 } 1167 1168 private boolean needsPrependVisibleItem() { 1169 if (mFirstVisiblePos > mFocusPosition) { 1170 return true; 1171 } 1172 for (int i = 0; i < mNumRows; i++) { 1173 if (mRows[i].low == mRows[i].high) { 1174 if (mRows[i].low > mScrollOffsetPrimary) { 1175 return true; 1176 } 1177 } else if (mRows[i].low - mMarginPrimary > mScrollOffsetPrimary) { 1178 return true; 1179 } 1180 } 1181 return false; 1182 } 1183 1184 // Append one column if possible and return true if reach end. 1185 private boolean appendOneVisibleItem() { 1186 while (true) { 1187 if (mLastVisiblePos != NO_POSITION && mLastVisiblePos < mState.getItemCount() -1 && 1188 mLastVisiblePos < mGrid.getLastIndex()) { 1189 // append invisible view of saved location till last row 1190 final int index = mLastVisiblePos + 1; 1191 final int row = mGrid.getLocation(index).row; 1192 mGridProvider.createItem(index, row, true); 1193 if (row == mNumRows - 1) { 1194 return false; 1195 } 1196 } else if ((mLastVisiblePos == NO_POSITION && mState.getItemCount() > 0) || 1197 (mLastVisiblePos != NO_POSITION && 1198 mLastVisiblePos < mState.getItemCount() - 1)) { 1199 mGrid.appendItems(mScrollOffsetPrimary + mSizePrimary); 1200 return false; 1201 } else { 1202 return true; 1203 } 1204 } 1205 } 1206 1207 private void appendVisibleItems() { 1208 while (needsAppendVisibleItem()) { 1209 if (appendOneVisibleItem()) { 1210 break; 1211 } 1212 } 1213 } 1214 1215 // Prepend one column if possible and return true if reach end. 1216 private boolean prependOneVisibleItem() { 1217 while (true) { 1218 if (mFirstVisiblePos > 0) { 1219 if (mFirstVisiblePos > mGrid.getFirstIndex()) { 1220 // prepend invisible view of saved location till first row 1221 final int index = mFirstVisiblePos - 1; 1222 final int row = mGrid.getLocation(index).row; 1223 mGridProvider.createItem(index, row, false); 1224 if (row == 0) { 1225 return false; 1226 } 1227 } else { 1228 mGrid.prependItems(mScrollOffsetPrimary); 1229 return false; 1230 } 1231 } else { 1232 return true; 1233 } 1234 } 1235 } 1236 1237 private void prependVisibleItems() { 1238 while (needsPrependVisibleItem()) { 1239 if (prependOneVisibleItem()) { 1240 break; 1241 } 1242 } 1243 } 1244 1245 private void removeChildAt(int position) { 1246 View v = findViewByPosition(position); 1247 if (v != null) { 1248 if (DEBUG) { 1249 Log.d(getTag(), "removeAndRecycleViewAt " + position); 1250 } 1251 removeAndRecycleView(v, mRecycler); 1252 } 1253 } 1254 1255 private void removeInvisibleViewsAtEnd() { 1256 if (!mPruneChild) { 1257 return; 1258 } 1259 boolean update = false; 1260 while(mLastVisiblePos > mFirstVisiblePos && mLastVisiblePos > mFocusPosition) { 1261 View view = findViewByPosition(mLastVisiblePos); 1262 if (getViewMin(view) > mSizePrimary) { 1263 removeChildAt(mLastVisiblePos); 1264 mLastVisiblePos--; 1265 update = true; 1266 } else { 1267 break; 1268 } 1269 } 1270 if (update) { 1271 updateRowsMinMax(); 1272 } 1273 } 1274 1275 private void removeInvisibleViewsAtFront() { 1276 if (!mPruneChild) { 1277 return; 1278 } 1279 boolean update = false; 1280 while(mLastVisiblePos > mFirstVisiblePos && mFirstVisiblePos < mFocusPosition) { 1281 View view = findViewByPosition(mFirstVisiblePos); 1282 if (getViewMax(view) < 0) { 1283 removeChildAt(mFirstVisiblePos); 1284 mFirstVisiblePos++; 1285 update = true; 1286 } else { 1287 break; 1288 } 1289 } 1290 if (update) { 1291 updateRowsMinMax(); 1292 } 1293 } 1294 1295 private void updateRowsMinMax() { 1296 if (mFirstVisiblePos < 0) { 1297 return; 1298 } 1299 for (int i = 0; i < mNumRows; i++) { 1300 mRows[i].low = Integer.MAX_VALUE; 1301 mRows[i].high = Integer.MIN_VALUE; 1302 } 1303 for (int i = mFirstVisiblePos; i <= mLastVisiblePos; i++) { 1304 View view = findViewByPosition(i); 1305 int row = mGrid.getLocation(i).row; 1306 int low = getViewMin(view) + mScrollOffsetPrimary; 1307 if (low < mRows[row].low) { 1308 mRows[row].low = low; 1309 } 1310 int high = getViewMax(view) + mScrollOffsetPrimary; 1311 if (high > mRows[row].high) { 1312 mRows[row].high = high; 1313 } 1314 } 1315 } 1316 1317 // Fast layout when there is no structure change, adapter change, etc. 1318 protected void fastRelayout() { 1319 initScrollController(); 1320 1321 List<Integer>[] rows = mGrid.getItemPositionsInRows(mFirstVisiblePos, mLastVisiblePos); 1322 1323 // relayout and repositioning views on each row 1324 for (int i = 0; i < mNumRows; i++) { 1325 List<Integer> row = rows[i]; 1326 final int startSecondary = getRowStartSecondary(i) - mScrollOffsetSecondary; 1327 for (int j = 0, size = row.size(); j < size; j++) { 1328 final int position = row.get(j); 1329 final View view = findViewByPosition(position); 1330 int primaryDelta, start, end; 1331 1332 if (mOrientation == HORIZONTAL) { 1333 final int primarySize = view.getMeasuredWidth(); 1334 if (view.isLayoutRequested()) { 1335 measureChild(view); 1336 } 1337 start = getViewMin(view); 1338 end = start + view.getMeasuredWidth(); 1339 primaryDelta = view.getMeasuredWidth() - primarySize; 1340 if (primaryDelta != 0) { 1341 for (int k = j + 1; k < size; k++) { 1342 findViewByPosition(row.get(k)).offsetLeftAndRight(primaryDelta); 1343 } 1344 } 1345 } else { 1346 final int primarySize = view.getMeasuredHeight(); 1347 if (view.isLayoutRequested()) { 1348 measureChild(view); 1349 } 1350 start = getViewMin(view); 1351 end = start + view.getMeasuredHeight(); 1352 primaryDelta = view.getMeasuredHeight() - primarySize; 1353 if (primaryDelta != 0) { 1354 for (int k = j + 1; k < size; k++) { 1355 findViewByPosition(row.get(k)).offsetTopAndBottom(primaryDelta); 1356 } 1357 } 1358 } 1359 layoutChild(i, view, start, end, startSecondary); 1360 } 1361 } 1362 1363 updateRowsMinMax(); 1364 appendVisibleItems(); 1365 prependVisibleItems(); 1366 1367 updateRowsMinMax(); 1368 updateScrollMin(); 1369 updateScrollMax(); 1370 updateScrollSecondAxis(); 1371 1372 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED) { 1373 View focusView = findViewByPosition(mFocusPosition == NO_POSITION ? 0 : mFocusPosition); 1374 scrollToView(focusView, false); 1375 } 1376 } 1377 1378 private void removeAndRecycleAllViews(RecyclerView.Recycler recycler) { 1379 if (DEBUG) Log.v(TAG, "removeAndRecycleAllViews " + getChildCount()); 1380 for (int i = getChildCount() - 1; i >= 0; i--) { 1381 removeAndRecycleViewAt(i, recycler); 1382 } 1383 } 1384 1385 // Lays out items based on the current scroll position 1386 @Override 1387 public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state) { 1388 if (DEBUG) { 1389 Log.v(getTag(), "layoutChildren start numRows " + mNumRows + " mScrollOffsetSecondary " 1390 + mScrollOffsetSecondary + " mScrollOffsetPrimary " + mScrollOffsetPrimary 1391 + " inPreLayout " + state.isPreLayout() 1392 + " didStructureChange " + state.didStructureChange() 1393 + " mForceFullLayout " + mForceFullLayout); 1394 Log.v(getTag(), "width " + getWidth() + " height " + getHeight()); 1395 } 1396 1397 if (mNumRows == 0) { 1398 // haven't done measure yet 1399 return; 1400 } 1401 final int itemCount = state.getItemCount(); 1402 if (itemCount < 0) { 1403 return; 1404 } 1405 1406 if (!mLayoutEnabled) { 1407 discardLayoutInfo(); 1408 removeAndRecycleAllViews(recycler); 1409 return; 1410 } 1411 mInLayout = true; 1412 1413 saveContext(recycler, state); 1414 // Track the old focus view so we can adjust our system scroll position 1415 // so that any scroll animations happening now will remain valid. 1416 // We must use same delta in Pre Layout (if prelayout exists) and second layout. 1417 // So we cache the deltas in PreLayout and use it in second layout. 1418 int delta = 0, deltaSecondary = 0; 1419 if (!state.isPreLayout() && mUseDeltaInPreLayout) { 1420 delta = mDeltaInPreLayout; 1421 deltaSecondary = mDeltaSecondaryInPreLayout; 1422 } else { 1423 if (mFocusPosition != NO_POSITION 1424 && mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED) { 1425 // FIXME: we should get the remaining scroll animation offset from RecyclerView 1426 View focusView = findViewByPosition(mFocusPosition); 1427 if (focusView != null) { 1428 delta = mWindowAlignment.mainAxis().getSystemScrollPos(mScrollOffsetPrimary 1429 + getViewCenter(focusView), false, false) - mScrollOffsetPrimary; 1430 deltaSecondary = mWindowAlignment.secondAxis().getSystemScrollPos( 1431 mScrollOffsetSecondary + getViewCenterSecondary(focusView), 1432 false, false) - mScrollOffsetSecondary; 1433 if (mUseDeltaInPreLayout = state.isPreLayout()) { 1434 mDeltaInPreLayout = delta; 1435 mDeltaSecondaryInPreLayout = deltaSecondary; 1436 } 1437 } 1438 } 1439 } 1440 1441 final boolean hasDoneFirstLayout = hasDoneFirstLayout(); 1442 int savedFocusPos = mFocusPosition; 1443 boolean fastRelayout = false; 1444 if (!mState.didStructureChange() && !mForceFullLayout && hasDoneFirstLayout) { 1445 fastRelayout = true; 1446 fastRelayout(); 1447 } else { 1448 boolean hadFocus = mBaseGridView.hasFocus(); 1449 1450 int newFocusPosition = init(mFocusPosition); 1451 if (DEBUG) { 1452 Log.v(getTag(), "mFocusPosition " + mFocusPosition + " newFocusPosition " 1453 + newFocusPosition); 1454 } 1455 1456 // depending on result of init(), either recreating everything 1457 // or try to reuse the row start positions near mFocusPosition 1458 if (mGrid.getSize() == 0) { 1459 // this is a fresh creating all items, starting from 1460 // mFocusPosition with a estimated row index. 1461 mGrid.setStart(newFocusPosition, StaggeredGrid.START_DEFAULT); 1462 1463 // Can't track the old focus view 1464 delta = deltaSecondary = 0; 1465 1466 } else { 1467 // mGrid remembers Locations for the column that 1468 // contains mFocusePosition and also mRows remembers start 1469 // positions of each row. 1470 // Manually re-create child views for that column 1471 int firstIndex = mGrid.getFirstIndex(); 1472 int lastIndex = mGrid.getLastIndex(); 1473 for (int i = firstIndex; i <= lastIndex; i++) { 1474 mGridProvider.createItem(i, mGrid.getLocation(i).row, true); 1475 } 1476 } 1477 // add visible views at end until reach the end of window 1478 appendVisibleItems(); 1479 // add visible views at front until reach the start of window 1480 prependVisibleItems(); 1481 // multiple rounds: scrollToView of first round may drag first/last child into 1482 // "visible window" and we update scrollMin/scrollMax then run second scrollToView 1483 int oldFirstVisible; 1484 int oldLastVisible; 1485 do { 1486 oldFirstVisible = mFirstVisiblePos; 1487 oldLastVisible = mLastVisiblePos; 1488 View focusView = findViewByPosition(newFocusPosition); 1489 // we need force to initialize the child view's position 1490 scrollToView(focusView, false); 1491 if (focusView != null && hadFocus) { 1492 focusView.requestFocus(); 1493 } 1494 appendVisibleItems(); 1495 prependVisibleItems(); 1496 removeInvisibleViewsAtFront(); 1497 removeInvisibleViewsAtEnd(); 1498 } while (mFirstVisiblePos != oldFirstVisible || mLastVisiblePos != oldLastVisible); 1499 } 1500 mForceFullLayout = false; 1501 1502 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED) { 1503 scrollDirectionPrimary(-delta); 1504 scrollDirectionSecondary(-deltaSecondary); 1505 } 1506 appendVisibleItems(); 1507 prependVisibleItems(); 1508 removeInvisibleViewsAtFront(); 1509 removeInvisibleViewsAtEnd(); 1510 1511 if (DEBUG) { 1512 StringWriter sw = new StringWriter(); 1513 PrintWriter pw = new PrintWriter(sw); 1514 mGrid.debugPrint(pw); 1515 Log.d(getTag(), sw.toString()); 1516 } 1517 1518 if (mRowSecondarySizeRefresh) { 1519 mRowSecondarySizeRefresh = false; 1520 } else { 1521 updateRowSecondarySizeRefresh(); 1522 } 1523 1524 if (!state.isPreLayout()) { 1525 mUseDeltaInPreLayout = false; 1526 if (!fastRelayout || mFocusPosition != savedFocusPos) { 1527 dispatchChildSelected(); 1528 } 1529 } 1530 mInLayout = false; 1531 leaveContext(); 1532 if (DEBUG) Log.v(getTag(), "layoutChildren end"); 1533 } 1534 1535 private void offsetChildrenSecondary(int increment) { 1536 final int childCount = getChildCount(); 1537 if (mOrientation == HORIZONTAL) { 1538 for (int i = 0; i < childCount; i++) { 1539 getChildAt(i).offsetTopAndBottom(increment); 1540 } 1541 } else { 1542 for (int i = 0; i < childCount; i++) { 1543 getChildAt(i).offsetLeftAndRight(increment); 1544 } 1545 } 1546 } 1547 1548 private void offsetChildrenPrimary(int increment) { 1549 final int childCount = getChildCount(); 1550 if (mOrientation == VERTICAL) { 1551 for (int i = 0; i < childCount; i++) { 1552 getChildAt(i).offsetTopAndBottom(increment); 1553 } 1554 } else { 1555 for (int i = 0; i < childCount; i++) { 1556 getChildAt(i).offsetLeftAndRight(increment); 1557 } 1558 } 1559 } 1560 1561 @Override 1562 public int scrollHorizontallyBy(int dx, Recycler recycler, RecyclerView.State state) { 1563 if (DEBUG) Log.v(getTag(), "scrollHorizontallyBy " + dx); 1564 if (!mLayoutEnabled || !hasDoneFirstLayout()) { 1565 return 0; 1566 } 1567 saveContext(recycler, state); 1568 int result; 1569 if (mOrientation == HORIZONTAL) { 1570 result = scrollDirectionPrimary(dx); 1571 } else { 1572 result = scrollDirectionSecondary(dx); 1573 } 1574 leaveContext(); 1575 return result; 1576 } 1577 1578 @Override 1579 public int scrollVerticallyBy(int dy, Recycler recycler, RecyclerView.State state) { 1580 if (DEBUG) Log.v(getTag(), "scrollVerticallyBy " + dy); 1581 if (!mLayoutEnabled || !hasDoneFirstLayout()) { 1582 return 0; 1583 } 1584 saveContext(recycler, state); 1585 int result; 1586 if (mOrientation == VERTICAL) { 1587 result = scrollDirectionPrimary(dy); 1588 } else { 1589 result = scrollDirectionSecondary(dy); 1590 } 1591 leaveContext(); 1592 return result; 1593 } 1594 1595 // scroll in main direction may add/prune views 1596 private int scrollDirectionPrimary(int da) { 1597 if (da > 0) { 1598 if (!mWindowAlignment.mainAxis().isMaxUnknown()) { 1599 int maxScroll = mWindowAlignment.mainAxis().getMaxScroll(); 1600 if (mScrollOffsetPrimary + da > maxScroll) { 1601 da = maxScroll - mScrollOffsetPrimary; 1602 } 1603 } 1604 } else if (da < 0) { 1605 if (!mWindowAlignment.mainAxis().isMinUnknown()) { 1606 int minScroll = mWindowAlignment.mainAxis().getMinScroll(); 1607 if (mScrollOffsetPrimary + da < minScroll) { 1608 da = minScroll - mScrollOffsetPrimary; 1609 } 1610 } 1611 } 1612 if (da == 0) { 1613 return 0; 1614 } 1615 offsetChildrenPrimary(-da); 1616 mScrollOffsetPrimary += da; 1617 if (mInLayout) { 1618 return da; 1619 } 1620 1621 int childCount = getChildCount(); 1622 boolean updated; 1623 1624 if (da > 0) { 1625 appendVisibleItems(); 1626 } else if (da < 0) { 1627 prependVisibleItems(); 1628 } 1629 updated = getChildCount() > childCount; 1630 childCount = getChildCount(); 1631 1632 if (da > 0) { 1633 removeInvisibleViewsAtFront(); 1634 } else if (da < 0) { 1635 removeInvisibleViewsAtEnd(); 1636 } 1637 updated |= getChildCount() < childCount; 1638 1639 if (updated) { 1640 updateRowSecondarySizeRefresh(); 1641 } 1642 1643 mBaseGridView.invalidate(); 1644 return da; 1645 } 1646 1647 // scroll in second direction will not add/prune views 1648 private int scrollDirectionSecondary(int dy) { 1649 if (dy == 0) { 1650 return 0; 1651 } 1652 offsetChildrenSecondary(-dy); 1653 mScrollOffsetSecondary += dy; 1654 mBaseGridView.invalidate(); 1655 return dy; 1656 } 1657 1658 private void updateScrollMax() { 1659 if (mLastVisiblePos < 0) { 1660 return; 1661 } 1662 final boolean lastAvailable = mLastVisiblePos == mState.getItemCount() - 1; 1663 final boolean maxUnknown = mWindowAlignment.mainAxis().isMaxUnknown(); 1664 if (!lastAvailable && maxUnknown) { 1665 return; 1666 } 1667 int maxEdge = Integer.MIN_VALUE; 1668 int rowIndex = -1; 1669 for (int i = 0; i < mRows.length; i++) { 1670 if (mRows[i].high > maxEdge) { 1671 maxEdge = mRows[i].high; 1672 rowIndex = i; 1673 } 1674 } 1675 int maxScroll = Integer.MAX_VALUE; 1676 for (int i = mLastVisiblePos; i >= mFirstVisiblePos; i--) { 1677 StaggeredGrid.Location location = mGrid.getLocation(i); 1678 if (location != null && location.row == rowIndex) { 1679 int savedMaxEdge = mWindowAlignment.mainAxis().getMaxEdge(); 1680 mWindowAlignment.mainAxis().setMaxEdge(maxEdge); 1681 maxScroll = getPrimarySystemScrollPosition(findViewByPosition(i)); 1682 mWindowAlignment.mainAxis().setMaxEdge(savedMaxEdge); 1683 break; 1684 } 1685 } 1686 if (lastAvailable) { 1687 mWindowAlignment.mainAxis().setMaxEdge(maxEdge); 1688 mWindowAlignment.mainAxis().setMaxScroll(maxScroll); 1689 if (DEBUG) Log.v(getTag(), "updating scroll maxEdge to " + maxEdge + 1690 " scrollMax to " + maxScroll); 1691 } else { 1692 // the maxScroll for currently last visible item is larger, 1693 // so we must invalidate the max scroll value. 1694 if (maxScroll > mWindowAlignment.mainAxis().getMaxScroll()) { 1695 mWindowAlignment.mainAxis().invalidateScrollMax(); 1696 if (DEBUG) Log.v(getTag(), "Invalidate scrollMax since it should be " 1697 + "greater than " + maxScroll); 1698 } 1699 } 1700 } 1701 1702 private void updateScrollMin() { 1703 if (mFirstVisiblePos < 0) { 1704 return; 1705 } 1706 final boolean firstAvailable = mFirstVisiblePos == 0; 1707 final boolean minUnknown = mWindowAlignment.mainAxis().isMinUnknown(); 1708 if (!firstAvailable && minUnknown) { 1709 return; 1710 } 1711 int minEdge = Integer.MAX_VALUE; 1712 int rowIndex = -1; 1713 for (int i = 0; i < mRows.length; i++) { 1714 if (mRows[i].low < minEdge) { 1715 minEdge = mRows[i].low; 1716 rowIndex = i; 1717 } 1718 } 1719 int minScroll = Integer.MIN_VALUE; 1720 for (int i = mFirstVisiblePos; i <= mLastVisiblePos; i++) { 1721 StaggeredGrid.Location location = mGrid.getLocation(i); 1722 if (location != null && location.row == rowIndex) { 1723 int savedMinEdge = mWindowAlignment.mainAxis().getMinEdge(); 1724 mWindowAlignment.mainAxis().setMinEdge(minEdge); 1725 minScroll = getPrimarySystemScrollPosition(findViewByPosition(i)); 1726 mWindowAlignment.mainAxis().setMinEdge(savedMinEdge); 1727 break; 1728 } 1729 } 1730 if (firstAvailable) { 1731 mWindowAlignment.mainAxis().setMinEdge(minEdge); 1732 mWindowAlignment.mainAxis().setMinScroll(minScroll); 1733 if (DEBUG) Log.v(getTag(), "updating scroll minEdge to " + minEdge + 1734 " scrollMin to " + minScroll); 1735 } else { 1736 // the minScroll for currently first visible item is smaller, 1737 // so we must invalidate the min scroll value. 1738 if (minScroll < mWindowAlignment.mainAxis().getMinScroll()) { 1739 mWindowAlignment.mainAxis().invalidateScrollMin(); 1740 if (DEBUG) Log.v(getTag(), "Invalidate scrollMin, since it should be " 1741 + "less than " + minScroll); 1742 } 1743 } 1744 } 1745 1746 private void updateScrollSecondAxis() { 1747 mWindowAlignment.secondAxis().setMinEdge(0); 1748 mWindowAlignment.secondAxis().setMaxEdge(getSizeSecondary()); 1749 } 1750 1751 private void initScrollController() { 1752 mWindowAlignment.horizontal.setSize(getWidth()); 1753 mWindowAlignment.horizontal.setPadding(getPaddingLeft(), getPaddingRight()); 1754 mWindowAlignment.vertical.setSize(getHeight()); 1755 mWindowAlignment.vertical.setPadding(getPaddingTop(), getPaddingBottom()); 1756 mSizePrimary = mWindowAlignment.mainAxis().getSize(); 1757 1758 if (DEBUG) { 1759 Log.v(getTag(), "initScrollController mSizePrimary " + mSizePrimary 1760 + " mWindowAlignment " + mWindowAlignment); 1761 } 1762 } 1763 1764 public void setSelection(RecyclerView parent, int position) { 1765 setSelection(parent, position, false); 1766 } 1767 1768 public void setSelectionSmooth(RecyclerView parent, int position) { 1769 setSelection(parent, position, true); 1770 } 1771 1772 public int getSelection() { 1773 return mFocusPosition; 1774 } 1775 1776 public void setSelection(RecyclerView parent, int position, boolean smooth) { 1777 if (mFocusPosition == position) { 1778 return; 1779 } 1780 View view = findViewByPosition(position); 1781 if (view != null) { 1782 scrollToView(view, smooth); 1783 } else { 1784 mFocusPosition = position; 1785 if (!mLayoutEnabled) { 1786 return; 1787 } 1788 if (smooth) { 1789 if (!hasDoneFirstLayout()) { 1790 Log.w(getTag(), "setSelectionSmooth should " + 1791 "not be called before first layout pass"); 1792 return; 1793 } 1794 LinearSmoothScroller linearSmoothScroller = 1795 new LinearSmoothScroller(parent.getContext()) { 1796 @Override 1797 public PointF computeScrollVectorForPosition(int targetPosition) { 1798 if (getChildCount() == 0) { 1799 return null; 1800 } 1801 final int firstChildPos = getPosition(getChildAt(0)); 1802 final int direction = targetPosition < firstChildPos ? -1 : 1; 1803 if (mOrientation == HORIZONTAL) { 1804 return new PointF(direction, 0); 1805 } else { 1806 return new PointF(0, direction); 1807 } 1808 } 1809 @Override 1810 protected void onTargetFound(View targetView, 1811 RecyclerView.State state, Action action) { 1812 if (hasFocus()) { 1813 targetView.requestFocus(); 1814 } else { 1815 dispatchChildSelected(); 1816 } 1817 if (getScrollPosition(targetView, mTempDeltas)) { 1818 int dx, dy; 1819 if (mOrientation == HORIZONTAL) { 1820 dx = mTempDeltas[0]; 1821 dy = mTempDeltas[1]; 1822 } else { 1823 dx = mTempDeltas[1]; 1824 dy = mTempDeltas[0]; 1825 } 1826 final int distance = (int) Math.sqrt(dx * dx + dy * dy); 1827 final int time = calculateTimeForDeceleration(distance); 1828 action.update(dx, dy, time, mDecelerateInterpolator); 1829 } 1830 } 1831 }; 1832 linearSmoothScroller.setTargetPosition(position); 1833 startSmoothScroll(linearSmoothScroller); 1834 } else { 1835 mForceFullLayout = true; 1836 parent.requestLayout(); 1837 } 1838 } 1839 } 1840 1841 @Override 1842 public void onItemsAdded(RecyclerView recyclerView, int positionStart, int itemCount) { 1843 boolean needsLayout = false; 1844 if (itemCount != 0) { 1845 if (mFirstVisiblePos < 0) { 1846 needsLayout = true; 1847 } else if (!(positionStart > mLastVisiblePos + 1 || 1848 positionStart + itemCount < mFirstVisiblePos - 1)) { 1849 needsLayout = true; 1850 } 1851 } 1852 if (needsLayout) { 1853 recyclerView.requestLayout(); 1854 } 1855 } 1856 1857 @Override 1858 public boolean onRequestChildFocus(RecyclerView parent, View child, View focused) { 1859 if (mFocusSearchDisabled) { 1860 return true; 1861 } 1862 if (!mInLayout) { 1863 scrollToView(child, true); 1864 } 1865 return true; 1866 } 1867 1868 @Override 1869 public boolean requestChildRectangleOnScreen(RecyclerView parent, View view, Rect rect, 1870 boolean immediate) { 1871 if (DEBUG) Log.v(getTag(), "requestChildRectangleOnScreen " + view + " " + rect); 1872 return false; 1873 } 1874 1875 int getScrollOffsetX() { 1876 return mOrientation == HORIZONTAL ? mScrollOffsetPrimary : mScrollOffsetSecondary; 1877 } 1878 1879 int getScrollOffsetY() { 1880 return mOrientation == HORIZONTAL ? mScrollOffsetSecondary : mScrollOffsetPrimary; 1881 } 1882 1883 public void getViewSelectedOffsets(View view, int[] offsets) { 1884 if (mOrientation == HORIZONTAL) { 1885 offsets[0] = getPrimarySystemScrollPosition(view) - mScrollOffsetPrimary; 1886 offsets[1] = getSecondarySystemScrollPosition(view) - mScrollOffsetSecondary; 1887 } else { 1888 offsets[1] = getPrimarySystemScrollPosition(view) - mScrollOffsetPrimary; 1889 offsets[0] = getSecondarySystemScrollPosition(view) - mScrollOffsetSecondary; 1890 } 1891 } 1892 1893 private int getPrimarySystemScrollPosition(View view) { 1894 int viewCenterPrimary = mScrollOffsetPrimary + getViewCenter(view); 1895 int pos = getPositionByView(view); 1896 StaggeredGrid.Location location = mGrid.getLocation(pos); 1897 final int row = location.row; 1898 boolean isFirst = mFirstVisiblePos == 0; 1899 // TODO: change to use State object in onRequestChildFocus() 1900 boolean isLast = mLastVisiblePos == (mState == null ? 1901 getItemCount() : mState.getItemCount()) - 1; 1902 if (isFirst || isLast) { 1903 for (int i = getChildCount() - 1; i >= 0; i--) { 1904 int position = getPositionByIndex(i); 1905 StaggeredGrid.Location loc = mGrid.getLocation(position); 1906 if (loc != null && loc.row == row) { 1907 if (position < pos) { 1908 isFirst = false; 1909 } else if (position > pos) { 1910 isLast = false; 1911 } 1912 } 1913 } 1914 } 1915 return mWindowAlignment.mainAxis().getSystemScrollPos(viewCenterPrimary, isFirst, isLast); 1916 } 1917 1918 private int getSecondarySystemScrollPosition(View view) { 1919 int viewCenterSecondary = mScrollOffsetSecondary + getViewCenterSecondary(view); 1920 int pos = getPositionByView(view); 1921 StaggeredGrid.Location location = mGrid.getLocation(pos); 1922 final int row = location.row; 1923 boolean isFirst = row == 0; 1924 boolean isLast = row == mGrid.getNumRows() - 1; 1925 return mWindowAlignment.secondAxis().getSystemScrollPos(viewCenterSecondary, 1926 isFirst, isLast); 1927 } 1928 1929 /** 1930 * Scroll to a given child view and change mFocusPosition. 1931 */ 1932 private void scrollToView(View view, boolean smooth) { 1933 int newFocusPosition = getPositionByView(view); 1934 if (newFocusPosition != mFocusPosition) { 1935 mFocusPosition = newFocusPosition; 1936 if (!mInLayout) { 1937 dispatchChildSelected(); 1938 } 1939 } 1940 if (mBaseGridView.isChildrenDrawingOrderEnabledInternal()) { 1941 mBaseGridView.invalidate(); 1942 } 1943 if (view == null) { 1944 return; 1945 } 1946 if (!view.hasFocus() && mBaseGridView.hasFocus()) { 1947 // transfer focus to the child if it does not have focus yet (e.g. triggered 1948 // by setSelection()) 1949 view.requestFocus(); 1950 } 1951 if (getScrollPosition(view, mTempDeltas)) { 1952 scrollGrid(mTempDeltas[0], mTempDeltas[1], smooth); 1953 } 1954 } 1955 1956 private boolean getScrollPosition(View view, int[] deltas) { 1957 switch (mFocusScrollStrategy) { 1958 case BaseGridView.FOCUS_SCROLL_ALIGNED: 1959 default: 1960 return getAlignedPosition(view, deltas); 1961 case BaseGridView.FOCUS_SCROLL_ITEM: 1962 case BaseGridView.FOCUS_SCROLL_PAGE: 1963 return getNoneAlignedPosition(view, deltas); 1964 } 1965 } 1966 1967 private boolean getNoneAlignedPosition(View view, int[] deltas) { 1968 int pos = getPositionByView(view); 1969 int viewMin = getViewMin(view); 1970 int viewMax = getViewMax(view); 1971 // we either align "firstView" to left/top padding edge 1972 // or align "lastView" to right/bottom padding edge 1973 View firstView = null; 1974 View lastView = null; 1975 int paddingLow = mWindowAlignment.mainAxis().getPaddingLow(); 1976 int clientSize = mWindowAlignment.mainAxis().getClientSize(); 1977 final int row = mGrid.getLocation(pos).row; 1978 if (viewMin < paddingLow) { 1979 // view enters low padding area: 1980 firstView = view; 1981 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_PAGE) { 1982 // scroll one "page" left/top, 1983 // align first visible item of the "page" at the low padding edge. 1984 while (!prependOneVisibleItem()) { 1985 List<Integer> positions = 1986 mGrid.getItemPositionsInRows(mFirstVisiblePos, pos)[row]; 1987 firstView = findViewByPosition(positions.get(0)); 1988 if (viewMax - getViewMin(firstView) > clientSize) { 1989 if (positions.size() > 1) { 1990 firstView = findViewByPosition(positions.get(1)); 1991 } 1992 break; 1993 } 1994 } 1995 } 1996 } else if (viewMax > clientSize + paddingLow) { 1997 // view enters high padding area: 1998 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_PAGE) { 1999 // scroll whole one page right/bottom, align view at the low padding edge. 2000 firstView = view; 2001 do { 2002 List<Integer> positions = 2003 mGrid.getItemPositionsInRows(pos, mLastVisiblePos)[row]; 2004 lastView = findViewByPosition(positions.get(positions.size() - 1)); 2005 if (getViewMax(lastView) - viewMin > clientSize) { 2006 lastView = null; 2007 break; 2008 } 2009 } while (!appendOneVisibleItem()); 2010 if (lastView != null) { 2011 // however if we reached end, we should align last view. 2012 firstView = null; 2013 } 2014 } else { 2015 lastView = view; 2016 } 2017 } 2018 int scrollPrimary = 0; 2019 int scrollSecondary = 0; 2020 if (firstView != null) { 2021 scrollPrimary = getViewMin(firstView) - paddingLow; 2022 } else if (lastView != null) { 2023 scrollPrimary = getViewMax(lastView) - (paddingLow + clientSize); 2024 } 2025 View secondaryAlignedView; 2026 if (firstView != null) { 2027 secondaryAlignedView = firstView; 2028 } else if (lastView != null) { 2029 secondaryAlignedView = lastView; 2030 } else { 2031 secondaryAlignedView = view; 2032 } 2033 scrollSecondary = getSecondarySystemScrollPosition(secondaryAlignedView); 2034 scrollSecondary -= mScrollOffsetSecondary; 2035 if (scrollPrimary != 0 || scrollSecondary != 0) { 2036 deltas[0] = scrollPrimary; 2037 deltas[1] = scrollSecondary; 2038 return true; 2039 } 2040 return false; 2041 } 2042 2043 private boolean getAlignedPosition(View view, int[] deltas) { 2044 int scrollPrimary = getPrimarySystemScrollPosition(view); 2045 int scrollSecondary = getSecondarySystemScrollPosition(view); 2046 if (DEBUG) { 2047 Log.v(getTag(), "getAlignedPosition " + scrollPrimary + " " + scrollSecondary 2048 +" " + mWindowAlignment); 2049 } 2050 scrollPrimary -= mScrollOffsetPrimary; 2051 scrollSecondary -= mScrollOffsetSecondary; 2052 if (scrollPrimary != 0 || scrollSecondary != 0) { 2053 deltas[0] = scrollPrimary; 2054 deltas[1] = scrollSecondary; 2055 return true; 2056 } 2057 return false; 2058 } 2059 2060 private void scrollGrid(int scrollPrimary, int scrollSecondary, boolean smooth) { 2061 if (mInLayout) { 2062 scrollDirectionPrimary(scrollPrimary); 2063 scrollDirectionSecondary(scrollSecondary); 2064 } else { 2065 int scrollX; 2066 int scrollY; 2067 if (mOrientation == HORIZONTAL) { 2068 scrollX = scrollPrimary; 2069 scrollY = scrollSecondary; 2070 } else { 2071 scrollX = scrollSecondary; 2072 scrollY = scrollPrimary; 2073 } 2074 if (smooth) { 2075 mBaseGridView.smoothScrollBy(scrollX, scrollY); 2076 } else { 2077 mBaseGridView.scrollBy(scrollX, scrollY); 2078 } 2079 } 2080 } 2081 2082 public void setPruneChild(boolean pruneChild) { 2083 if (mPruneChild != pruneChild) { 2084 mPruneChild = pruneChild; 2085 if (mPruneChild) { 2086 requestLayout(); 2087 } 2088 } 2089 } 2090 2091 public boolean getPruneChild() { 2092 return mPruneChild; 2093 } 2094 2095 private int findImmediateChildIndex(View view) { 2096 while (view != null && view != mBaseGridView) { 2097 int index = mBaseGridView.indexOfChild(view); 2098 if (index >= 0) { 2099 return index; 2100 } 2101 view = (View) view.getParent(); 2102 } 2103 return NO_POSITION; 2104 } 2105 2106 void setFocusSearchDisabled(boolean disabled) { 2107 mFocusSearchDisabled = disabled; 2108 } 2109 2110 boolean isFocusSearchDisabled() { 2111 return mFocusSearchDisabled; 2112 } 2113 2114 @Override 2115 public View onInterceptFocusSearch(View focused, int direction) { 2116 if (mFocusSearchDisabled) { 2117 return focused; 2118 } 2119 return null; 2120 } 2121 2122 boolean hasPreviousViewInSameRow(int pos) { 2123 if (mGrid == null || pos == NO_POSITION) { 2124 return false; 2125 } 2126 if (mFirstVisiblePos > 0) { 2127 return true; 2128 } 2129 final int focusedRow = mGrid.getLocation(pos).row; 2130 for (int i = getChildCount() - 1; i >= 0; i--) { 2131 int position = getPositionByIndex(i); 2132 StaggeredGrid.Location loc = mGrid.getLocation(position); 2133 if (loc != null && loc.row == focusedRow) { 2134 if (position < pos) { 2135 return true; 2136 } 2137 } 2138 } 2139 return false; 2140 } 2141 2142 @Override 2143 public boolean onAddFocusables(RecyclerView recyclerView, 2144 ArrayList<View> views, int direction, int focusableMode) { 2145 if (mFocusSearchDisabled) { 2146 return true; 2147 } 2148 // If this viewgroup or one of its children currently has focus then we 2149 // consider our children for focus searching in main direction on the same row. 2150 // If this viewgroup has no focus and using focus align, we want the system 2151 // to ignore our children and pass focus to the viewgroup, which will pass 2152 // focus on to its children appropriately. 2153 // If this viewgroup has no focus and not using focus align, we want to 2154 // consider the child that does not overlap with padding area. 2155 if (recyclerView.hasFocus()) { 2156 final int movement = getMovement(direction); 2157 if (movement != PREV_ITEM && movement != NEXT_ITEM) { 2158 // Move on secondary direction uses default addFocusables(). 2159 return false; 2160 } 2161 final View focused = recyclerView.findFocus(); 2162 final int focusedPos = getPositionByIndex(findImmediateChildIndex(focused)); 2163 // Add focusables of focused item. 2164 if (focusedPos != NO_POSITION) { 2165 findViewByPosition(focusedPos).addFocusables(views, direction, focusableMode); 2166 } 2167 final int focusedRow = mGrid != null && focusedPos != NO_POSITION ? 2168 mGrid.getLocation(focusedPos).row : NO_POSITION; 2169 // Add focusables of next neighbor of same row on the focus search direction. 2170 if (mGrid != null) { 2171 final int focusableCount = views.size(); 2172 for (int i = 0, count = getChildCount(); i < count; i++) { 2173 int index = movement == NEXT_ITEM ? i : count - 1 - i; 2174 final View child = getChildAt(index); 2175 if (child.getVisibility() != View.VISIBLE) { 2176 continue; 2177 } 2178 int position = getPositionByIndex(index); 2179 StaggeredGrid.Location loc = mGrid.getLocation(position); 2180 if (focusedRow == NO_POSITION || (loc != null && loc.row == focusedRow)) { 2181 if (focusedPos == NO_POSITION || 2182 (movement == NEXT_ITEM && position > focusedPos) 2183 || (movement == PREV_ITEM && position < focusedPos)) { 2184 child.addFocusables(views, direction, focusableMode); 2185 if (views.size() > focusableCount) { 2186 break; 2187 } 2188 } 2189 } 2190 } 2191 } 2192 } else { 2193 if (mFocusScrollStrategy != BaseGridView.FOCUS_SCROLL_ALIGNED) { 2194 // adding views not overlapping padding area to avoid scrolling in gaining focus 2195 int left = mWindowAlignment.mainAxis().getPaddingLow(); 2196 int right = mWindowAlignment.mainAxis().getClientSize() + left; 2197 int focusableCount = views.size(); 2198 for (int i = 0, count = getChildCount(); i < count; i++) { 2199 View child = getChildAt(i); 2200 if (child.getVisibility() == View.VISIBLE) { 2201 if (getViewMin(child) >= left && getViewMax(child) <= right) { 2202 child.addFocusables(views, direction, focusableMode); 2203 } 2204 } 2205 } 2206 // if we cannot find any, then just add all children. 2207 if (views.size() == focusableCount) { 2208 for (int i = 0, count = getChildCount(); i < count; i++) { 2209 View child = getChildAt(i); 2210 if (child.getVisibility() == View.VISIBLE) { 2211 child.addFocusables(views, direction, focusableMode); 2212 } 2213 } 2214 if (views.size() != focusableCount) { 2215 return true; 2216 } 2217 } else { 2218 return true; 2219 } 2220 // if still cannot find any, fall through and add itself 2221 } 2222 if (recyclerView.isFocusable()) { 2223 views.add(recyclerView); 2224 } 2225 } 2226 return true; 2227 } 2228 2229 @Override 2230 public View onFocusSearchFailed(View focused, int direction, Recycler recycler, 2231 RecyclerView.State state) { 2232 if (DEBUG) Log.v(getTag(), "onFocusSearchFailed direction " + direction); 2233 2234 saveContext(recycler, state); 2235 View view = null; 2236 int movement = getMovement(direction); 2237 final FocusFinder ff = FocusFinder.getInstance(); 2238 if (movement == NEXT_ITEM) { 2239 while (view == null && !appendOneVisibleItem()) { 2240 view = ff.findNextFocus(mBaseGridView, focused, direction); 2241 } 2242 } else if (movement == PREV_ITEM){ 2243 while (view == null && !prependOneVisibleItem()) { 2244 view = ff.findNextFocus(mBaseGridView, focused, direction); 2245 } 2246 } 2247 if (view == null) { 2248 // returning the same view to prevent focus lost when scrolling past the end of the list 2249 if (movement == PREV_ITEM) { 2250 view = mFocusOutFront ? null : focused; 2251 } else if (movement == NEXT_ITEM){ 2252 view = mFocusOutEnd ? null : focused; 2253 } 2254 } 2255 leaveContext(); 2256 if (DEBUG) Log.v(getTag(), "returning view " + view); 2257 return view; 2258 } 2259 2260 boolean gridOnRequestFocusInDescendants(RecyclerView recyclerView, int direction, 2261 Rect previouslyFocusedRect) { 2262 switch (mFocusScrollStrategy) { 2263 case BaseGridView.FOCUS_SCROLL_ALIGNED: 2264 default: 2265 return gridOnRequestFocusInDescendantsAligned(recyclerView, 2266 direction, previouslyFocusedRect); 2267 case BaseGridView.FOCUS_SCROLL_PAGE: 2268 case BaseGridView.FOCUS_SCROLL_ITEM: 2269 return gridOnRequestFocusInDescendantsUnaligned(recyclerView, 2270 direction, previouslyFocusedRect); 2271 } 2272 } 2273 2274 private boolean gridOnRequestFocusInDescendantsAligned(RecyclerView recyclerView, 2275 int direction, Rect previouslyFocusedRect) { 2276 View view = findViewByPosition(mFocusPosition); 2277 if (view != null) { 2278 boolean result = view.requestFocus(direction, previouslyFocusedRect); 2279 if (!result && DEBUG) { 2280 Log.w(getTag(), "failed to request focus on " + view); 2281 } 2282 return result; 2283 } 2284 return false; 2285 } 2286 2287 private boolean gridOnRequestFocusInDescendantsUnaligned(RecyclerView recyclerView, 2288 int direction, Rect previouslyFocusedRect) { 2289 // focus to view not overlapping padding area to avoid scrolling in gaining focus 2290 int index; 2291 int increment; 2292 int end; 2293 int count = getChildCount(); 2294 if ((direction & View.FOCUS_FORWARD) != 0) { 2295 index = 0; 2296 increment = 1; 2297 end = count; 2298 } else { 2299 index = count - 1; 2300 increment = -1; 2301 end = -1; 2302 } 2303 int left = mWindowAlignment.mainAxis().getPaddingLow(); 2304 int right = mWindowAlignment.mainAxis().getClientSize() + left; 2305 for (int i = index; i != end; i += increment) { 2306 View child = getChildAt(i); 2307 if (child.getVisibility() == View.VISIBLE) { 2308 if (getViewMin(child) >= left && getViewMax(child) <= right) { 2309 if (child.requestFocus(direction, previouslyFocusedRect)) { 2310 return true; 2311 } 2312 } 2313 } 2314 } 2315 return false; 2316 } 2317 2318 private final static int PREV_ITEM = 0; 2319 private final static int NEXT_ITEM = 1; 2320 private final static int PREV_ROW = 2; 2321 private final static int NEXT_ROW = 3; 2322 2323 private int getMovement(int direction) { 2324 int movement = View.FOCUS_LEFT; 2325 2326 if (mOrientation == HORIZONTAL) { 2327 switch(direction) { 2328 case View.FOCUS_LEFT: 2329 movement = PREV_ITEM; 2330 break; 2331 case View.FOCUS_RIGHT: 2332 movement = NEXT_ITEM; 2333 break; 2334 case View.FOCUS_UP: 2335 movement = PREV_ROW; 2336 break; 2337 case View.FOCUS_DOWN: 2338 movement = NEXT_ROW; 2339 break; 2340 } 2341 } else if (mOrientation == VERTICAL) { 2342 switch(direction) { 2343 case View.FOCUS_LEFT: 2344 movement = PREV_ROW; 2345 break; 2346 case View.FOCUS_RIGHT: 2347 movement = NEXT_ROW; 2348 break; 2349 case View.FOCUS_UP: 2350 movement = PREV_ITEM; 2351 break; 2352 case View.FOCUS_DOWN: 2353 movement = NEXT_ITEM; 2354 break; 2355 } 2356 } 2357 2358 return movement; 2359 } 2360 2361 int getChildDrawingOrder(RecyclerView recyclerView, int childCount, int i) { 2362 View view = findViewByPosition(mFocusPosition); 2363 if (view == null) { 2364 return i; 2365 } 2366 int focusIndex = recyclerView.indexOfChild(view); 2367 // supposely 0 1 2 3 4 5 6 7 8 9, 4 is the center item 2368 // drawing order is 0 1 2 3 9 8 7 6 5 4 2369 if (i < focusIndex) { 2370 return i; 2371 } else if (i < childCount - 1) { 2372 return focusIndex + childCount - 1 - i; 2373 } else { 2374 return focusIndex; 2375 } 2376 } 2377 2378 @Override 2379 public void onAdapterChanged(RecyclerView.Adapter oldAdapter, 2380 RecyclerView.Adapter newAdapter) { 2381 discardLayoutInfo(); 2382 mFocusPosition = NO_POSITION; 2383 super.onAdapterChanged(oldAdapter, newAdapter); 2384 } 2385 2386 private void discardLayoutInfo() { 2387 mGrid = null; 2388 mRows = null; 2389 mRowSizeSecondary = null; 2390 mFirstVisiblePos = -1; 2391 mLastVisiblePos = -1; 2392 mRowSecondarySizeRefresh = false; 2393 } 2394 2395 public void setLayoutEnabled(boolean layoutEnabled) { 2396 if (mLayoutEnabled != layoutEnabled) { 2397 mLayoutEnabled = layoutEnabled; 2398 requestLayout(); 2399 } 2400 } 2401} 2402