GridLayoutManager.java revision c35968d173f900d8024bdf38174e2225c9a7f311
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.animation.TimeAnimator; 17import android.content.Context; 18import android.graphics.PointF; 19import android.graphics.Rect; 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; 39import android.view.animation.DecelerateInterpolator; 40import android.view.animation.Interpolator; 41 42import java.io.PrintWriter; 43import java.io.StringWriter; 44import java.util.ArrayList; 45import java.util.List; 46 47final class GridLayoutManager extends RecyclerView.LayoutManager { 48 49 /* 50 * LayoutParams for {@link HorizontalGridView} and {@link VerticalGridView}. 51 * The class currently does two internal jobs: 52 * - Saves optical bounds insets. 53 * - Caches focus align view center. 54 */ 55 static class LayoutParams extends RecyclerView.LayoutParams { 56 57 // The view is saved only during animation. 58 private View mView; 59 60 // For placement 61 private int mLeftInset; 62 private int mTopInset; 63 private int mRighInset; 64 private int mBottomInset; 65 66 // For alignment 67 private int mAlignX; 68 private int mAlignY; 69 70 public LayoutParams(Context c, AttributeSet attrs) { 71 super(c, attrs); 72 } 73 74 public LayoutParams(int width, int height) { 75 super(width, height); 76 } 77 78 public LayoutParams(MarginLayoutParams source) { 79 super(source); 80 } 81 82 public LayoutParams(ViewGroup.LayoutParams source) { 83 super(source); 84 } 85 86 public LayoutParams(RecyclerView.LayoutParams source) { 87 super(source); 88 } 89 90 public LayoutParams(LayoutParams source) { 91 super(source); 92 } 93 94 int getAlignX() { 95 return mAlignX; 96 } 97 98 int getAlignY() { 99 return mAlignY; 100 } 101 102 int getOpticalLeft(View view) { 103 return view.getLeft() + mLeftInset; 104 } 105 106 int getOpticalTop(View view) { 107 return view.getTop() + mTopInset; 108 } 109 110 int getOpticalRight(View view) { 111 return view.getRight() - mRighInset; 112 } 113 114 int getOpticalBottom(View view) { 115 return view.getBottom() - mBottomInset; 116 } 117 118 int getOpticalWidth(View view) { 119 return view.getWidth() - mLeftInset - mRighInset; 120 } 121 122 int getOpticalHeight(View view) { 123 return view.getHeight() - mTopInset - mBottomInset; 124 } 125 126 int getOpticalLeftInset() { 127 return mLeftInset; 128 } 129 130 int getOpticalRightInset() { 131 return mRighInset; 132 } 133 134 int getOpticalTopInset() { 135 return mTopInset; 136 } 137 138 int getOpticalBottomInset() { 139 return mBottomInset; 140 } 141 142 void setAlignX(int alignX) { 143 mAlignX = alignX; 144 } 145 146 void setAlignY(int alignY) { 147 mAlignY = alignY; 148 } 149 150 void setOpticalInsets(int leftInset, int topInset, int rightInset, int bottomInset) { 151 mLeftInset = leftInset; 152 mTopInset = topInset; 153 mRighInset = rightInset; 154 mBottomInset = bottomInset; 155 } 156 157 private void invalidateItemDecoration() { 158 ViewParent parent = mView.getParent(); 159 if (parent instanceof RecyclerView) { 160 // TODO: we only need invalidate parent if it has ItemDecoration 161 ((RecyclerView) parent).invalidate(); 162 } 163 } 164 } 165 166 private static final String TAG = "GridLayoutManager"; 167 private static final boolean DEBUG = false; 168 169 private static final Interpolator sDefaultAnimationChildLayoutInterpolator 170 = new DecelerateInterpolator(); 171 172 private static final long DEFAULT_CHILD_ANIMATION_DURATION_MS = 250; 173 174 private String getTag() { 175 return TAG + ":" + mBaseGridView.getId(); 176 } 177 178 private final BaseGridView mBaseGridView; 179 180 /** 181 * The orientation of a "row". 182 */ 183 private int mOrientation = HORIZONTAL; 184 185 private RecyclerView.State mState; 186 private RecyclerView.Recycler mRecycler; 187 188 private boolean mInLayout = false; 189 190 private OnChildSelectedListener mChildSelectedListener = null; 191 192 /** 193 * The focused position, it's not the currently visually aligned position 194 * but it is the final position that we intend to focus on. If there are 195 * multiple setSelection() called, mFocusPosition saves last value. 196 */ 197 private int mFocusPosition = NO_POSITION; 198 199 /** 200 * Force a full layout under certain situations. 201 */ 202 private boolean mForceFullLayout; 203 204 /** 205 * True if layout is enabled. 206 */ 207 private boolean mLayoutEnabled = true; 208 209 /** 210 * The scroll offsets of the viewport relative to the entire view. 211 */ 212 private int mScrollOffsetPrimary; 213 private int mScrollOffsetSecondary; 214 215 /** 216 * User-specified row height/column width. Can be WRAP_CONTENT. 217 */ 218 private int mRowSizeSecondaryRequested; 219 220 /** 221 * The fixed size of each grid item in the secondary direction. This corresponds to 222 * the row height, equal for all rows. Grid items may have variable length 223 * in the primary direction. 224 */ 225 private int mFixedRowSizeSecondary; 226 227 /** 228 * Tracks the secondary size of each row. 229 */ 230 private int[] mRowSizeSecondary; 231 232 /** 233 * Flag controlling whether the current/next layout should 234 * be updating the secondary size of rows. 235 */ 236 private boolean mRowSecondarySizeRefresh; 237 238 /** 239 * The maximum measured size of the view. 240 */ 241 private int mMaxSizeSecondary; 242 243 /** 244 * Margin between items. 245 */ 246 private int mHorizontalMargin; 247 /** 248 * Margin between items vertically. 249 */ 250 private int mVerticalMargin; 251 /** 252 * Margin in main direction. 253 */ 254 private int mMarginPrimary; 255 /** 256 * Margin in second direction. 257 */ 258 private int mMarginSecondary; 259 /** 260 * How to position child in secondary direction. 261 */ 262 private int mGravity = Gravity.LEFT | Gravity.TOP; 263 /** 264 * The number of rows in the grid. 265 */ 266 private int mNumRows; 267 /** 268 * Number of rows requested, can be 0 to be determined by parent size and 269 * rowHeight. 270 */ 271 private int mNumRowsRequested = 1; 272 273 /** 274 * Tracking start/end position of each row for visible items. 275 */ 276 private StaggeredGrid.Row[] mRows; 277 278 /** 279 * Saves grid information of each view. 280 */ 281 private StaggeredGrid mGrid; 282 /** 283 * Position of first item (included) that has attached views. 284 */ 285 private int mFirstVisiblePos; 286 /** 287 * Position of last item (included) that has attached views. 288 */ 289 private int mLastVisiblePos; 290 291 /** 292 * Focus Scroll strategy. 293 */ 294 private int mFocusScrollStrategy = BaseGridView.FOCUS_SCROLL_ALIGNED; 295 /** 296 * Defines how item view is aligned in the window. 297 */ 298 private final WindowAlignment mWindowAlignment = new WindowAlignment(); 299 300 /** 301 * Defines how item view is aligned. 302 */ 303 private final ItemAlignment mItemAlignment = new ItemAlignment(); 304 305 /** 306 * Dimensions of the view, width or height depending on orientation. 307 */ 308 private int mSizePrimary; 309 310 /** 311 * Allow DPAD key to navigate out at the front of the View (where position = 0), 312 * default is false. 313 */ 314 private boolean mFocusOutFront; 315 316 /** 317 * Allow DPAD key to navigate out at the end of the view, default is false. 318 */ 319 private boolean mFocusOutEnd; 320 321 /** 322 * True if focus search is disabled. 323 */ 324 private boolean mFocusSearchDisabled; 325 326 /** 327 * Animate layout changes from a child resizing or adding/removing a child. 328 */ 329 private boolean mAnimateChildLayout = true; 330 331 /** 332 * True if prune child, might be disabled during transition. 333 */ 334 private boolean mPruneChild = true; 335 336 private int[] mTempDeltas = new int[2]; 337 338 private boolean mUseDeltaInPreLayout; 339 340 private int mDeltaInPreLayout, mDeltaSecondaryInPreLayout; 341 342 /** 343 * Temporaries used for measuring. 344 */ 345 private int[] mMeasuredDimension = new int[2]; 346 347 public GridLayoutManager(BaseGridView baseGridView) { 348 mBaseGridView = baseGridView; 349 } 350 351 public void setOrientation(int orientation) { 352 if (orientation != HORIZONTAL && orientation != VERTICAL) { 353 if (DEBUG) Log.v(getTag(), "invalid orientation: " + orientation); 354 return; 355 } 356 357 mOrientation = orientation; 358 mWindowAlignment.setOrientation(orientation); 359 mItemAlignment.setOrientation(orientation); 360 mForceFullLayout = true; 361 } 362 363 public int getFocusScrollStrategy() { 364 return mFocusScrollStrategy; 365 } 366 367 public void setFocusScrollStrategy(int focusScrollStrategy) { 368 mFocusScrollStrategy = focusScrollStrategy; 369 } 370 371 public void setWindowAlignment(int windowAlignment) { 372 mWindowAlignment.mainAxis().setWindowAlignment(windowAlignment); 373 } 374 375 public int getWindowAlignment() { 376 return mWindowAlignment.mainAxis().getWindowAlignment(); 377 } 378 379 public void setWindowAlignmentOffset(int alignmentOffset) { 380 mWindowAlignment.mainAxis().setWindowAlignmentOffset(alignmentOffset); 381 } 382 383 public int getWindowAlignmentOffset() { 384 return mWindowAlignment.mainAxis().getWindowAlignmentOffset(); 385 } 386 387 public void setWindowAlignmentOffsetPercent(float offsetPercent) { 388 mWindowAlignment.mainAxis().setWindowAlignmentOffsetPercent(offsetPercent); 389 } 390 391 public float getWindowAlignmentOffsetPercent() { 392 return mWindowAlignment.mainAxis().getWindowAlignmentOffsetPercent(); 393 } 394 395 public void setItemAlignmentOffset(int alignmentOffset) { 396 mItemAlignment.mainAxis().setItemAlignmentOffset(alignmentOffset); 397 updateChildAlignments(); 398 } 399 400 public int getItemAlignmentOffset() { 401 return mItemAlignment.mainAxis().getItemAlignmentOffset(); 402 } 403 404 public void setItemAlignmentOffsetWithPadding(boolean withPadding) { 405 mItemAlignment.mainAxis().setItemAlignmentOffsetWithPadding(withPadding); 406 updateChildAlignments(); 407 } 408 409 public boolean isItemAlignmentOffsetWithPadding() { 410 return mItemAlignment.mainAxis().isItemAlignmentOffsetWithPadding(); 411 } 412 413 public void setItemAlignmentOffsetPercent(float offsetPercent) { 414 mItemAlignment.mainAxis().setItemAlignmentOffsetPercent(offsetPercent); 415 updateChildAlignments(); 416 } 417 418 public float getItemAlignmentOffsetPercent() { 419 return mItemAlignment.mainAxis().getItemAlignmentOffsetPercent(); 420 } 421 422 public void setItemAlignmentViewId(int viewId) { 423 mItemAlignment.mainAxis().setItemAlignmentViewId(viewId); 424 updateChildAlignments(); 425 } 426 427 public int getItemAlignmentViewId() { 428 return mItemAlignment.mainAxis().getItemAlignmentViewId(); 429 } 430 431 public void setFocusOutAllowed(boolean throughFront, boolean throughEnd) { 432 mFocusOutFront = throughFront; 433 mFocusOutEnd = throughEnd; 434 } 435 436 public void setNumRows(int numRows) { 437 if (numRows < 0) throw new IllegalArgumentException(); 438 mNumRowsRequested = numRows; 439 mForceFullLayout = true; 440 } 441 442 /** 443 * Set the row height. May be WRAP_CONTENT, or a size in pixels. 444 */ 445 public void setRowHeight(int height) { 446 if (height >= 0 || height == ViewGroup.LayoutParams.WRAP_CONTENT) { 447 mRowSizeSecondaryRequested = height; 448 } else { 449 throw new IllegalArgumentException("Invalid row height: " + height); 450 } 451 } 452 453 public void setItemMargin(int margin) { 454 mVerticalMargin = mHorizontalMargin = margin; 455 mMarginPrimary = mMarginSecondary = margin; 456 } 457 458 public void setVerticalMargin(int margin) { 459 if (mOrientation == HORIZONTAL) { 460 mMarginSecondary = mVerticalMargin = margin; 461 } else { 462 mMarginPrimary = mVerticalMargin = margin; 463 } 464 } 465 466 public void setHorizontalMargin(int margin) { 467 if (mOrientation == HORIZONTAL) { 468 mMarginPrimary = mHorizontalMargin = margin; 469 } else { 470 mMarginSecondary = mHorizontalMargin = margin; 471 } 472 } 473 474 public int getVerticalMargin() { 475 return mVerticalMargin; 476 } 477 478 public int getHorizontalMargin() { 479 return mHorizontalMargin; 480 } 481 482 public void setGravity(int gravity) { 483 mGravity = gravity; 484 } 485 486 protected boolean hasDoneFirstLayout() { 487 return mGrid != null; 488 } 489 490 public void setOnChildSelectedListener(OnChildSelectedListener listener) { 491 mChildSelectedListener = listener; 492 } 493 494 private int getPositionByView(View view) { 495 if (view == null) { 496 return NO_POSITION; 497 } 498 RecyclerView.ViewHolder vh = mBaseGridView.getChildViewHolder(view); 499 if (vh == null) { 500 return NO_POSITION; 501 } 502 return vh.getPosition(); 503 } 504 505 private int getPositionByIndex(int index) { 506 return getPositionByView(getChildAt(index)); 507 } 508 509 private void dispatchChildSelected() { 510 if (mChildSelectedListener == null) { 511 return; 512 } 513 if (mFocusPosition != NO_POSITION) { 514 View view = findViewByPosition(mFocusPosition); 515 if (view != null) { 516 RecyclerView.ViewHolder vh = mBaseGridView.getChildViewHolder(view); 517 mChildSelectedListener.onChildSelected(mBaseGridView, view, mFocusPosition, 518 vh == null? NO_ID: vh.getItemId()); 519 return; 520 } 521 } 522 mChildSelectedListener.onChildSelected(mBaseGridView, null, NO_POSITION, NO_ID); 523 } 524 525 @Override 526 public boolean canScrollHorizontally() { 527 // We can scroll horizontally if we have horizontal orientation, or if 528 // we are vertical and have more than one column. 529 return mOrientation == HORIZONTAL || mNumRows > 1; 530 } 531 532 @Override 533 public boolean canScrollVertically() { 534 // We can scroll vertically if we have vertical orientation, or if we 535 // are horizontal and have more than one row. 536 return mOrientation == VERTICAL || mNumRows > 1; 537 } 538 539 @Override 540 public RecyclerView.LayoutParams generateDefaultLayoutParams() { 541 return new LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, 542 ViewGroup.LayoutParams.WRAP_CONTENT); 543 } 544 545 @Override 546 public RecyclerView.LayoutParams generateLayoutParams(Context context, AttributeSet attrs) { 547 return new LayoutParams(context, attrs); 548 } 549 550 @Override 551 public RecyclerView.LayoutParams generateLayoutParams(ViewGroup.LayoutParams lp) { 552 if (lp instanceof LayoutParams) { 553 return new LayoutParams((LayoutParams) lp); 554 } else if (lp instanceof RecyclerView.LayoutParams) { 555 return new LayoutParams((RecyclerView.LayoutParams) lp); 556 } else if (lp instanceof MarginLayoutParams) { 557 return new LayoutParams((MarginLayoutParams) lp); 558 } else { 559 return new LayoutParams(lp); 560 } 561 } 562 563 protected View getViewForPosition(int position) { 564 return mRecycler.getViewForPosition(position); 565 } 566 567 final int getOpticalLeft(View v) { 568 return ((LayoutParams) v.getLayoutParams()).getOpticalLeft(v); 569 } 570 571 final int getOpticalRight(View v) { 572 return ((LayoutParams) v.getLayoutParams()).getOpticalRight(v); 573 } 574 575 final int getOpticalTop(View v) { 576 return ((LayoutParams) v.getLayoutParams()).getOpticalTop(v); 577 } 578 579 final int getOpticalBottom(View v) { 580 return ((LayoutParams) v.getLayoutParams()).getOpticalBottom(v); 581 } 582 583 private int getViewMin(View v) { 584 return (mOrientation == HORIZONTAL) ? getOpticalLeft(v) : getOpticalTop(v); 585 } 586 587 private int getViewMax(View v) { 588 return (mOrientation == HORIZONTAL) ? getOpticalRight(v) : getOpticalBottom(v); 589 } 590 591 private int getViewCenter(View view) { 592 return (mOrientation == HORIZONTAL) ? getViewCenterX(view) : getViewCenterY(view); 593 } 594 595 private int getViewCenterSecondary(View view) { 596 return (mOrientation == HORIZONTAL) ? getViewCenterY(view) : getViewCenterX(view); 597 } 598 599 private int getViewCenterX(View v) { 600 LayoutParams p = (LayoutParams) v.getLayoutParams(); 601 return p.getOpticalLeft(v) + p.getAlignX(); 602 } 603 604 private int getViewCenterY(View v) { 605 LayoutParams p = (LayoutParams) v.getLayoutParams(); 606 return p.getOpticalTop(v) + p.getAlignY(); 607 } 608 609 /** 610 * Save Recycler and State for convenience. Must be paired with leaveContext(). 611 */ 612 private void saveContext(Recycler recycler, State state) { 613 if (mRecycler != null || mState != null) { 614 Log.e(TAG, "Recycler information was not released, bug!"); 615 } 616 mRecycler = recycler; 617 mState = state; 618 } 619 620 /** 621 * Discard saved Recycler and State. 622 */ 623 private void leaveContext() { 624 mRecycler = null; 625 mState = null; 626 } 627 628 /** 629 * Re-initialize data structures for a data change or handling invisible 630 * selection. The method tries its best to preserve position information so 631 * that staggered grid looks same before and after re-initialize. 632 * @param focusPosition The initial focusPosition that we would like to 633 * focus on. 634 * @return Actual position that can be focused on. 635 */ 636 private int init(int focusPosition) { 637 638 final int newItemCount = mState.getItemCount(); 639 640 if (focusPosition == NO_POSITION && newItemCount > 0) { 641 // if focus position is never set before, initialize it to 0 642 focusPosition = 0; 643 } 644 // If adapter has changed then caches are invalid; otherwise, 645 // we try to maintain each row's position if number of rows keeps the same 646 // and existing mGrid contains the focusPosition. 647 if (mRows != null && mNumRows == mRows.length && 648 mGrid != null && mGrid.getSize() > 0 && focusPosition >= 0 && 649 focusPosition >= mGrid.getFirstIndex() && 650 focusPosition <= mGrid.getLastIndex()) { 651 // strip mGrid to a subset (like a column) that contains focusPosition 652 mGrid.stripDownTo(focusPosition); 653 // make sure that remaining items do not exceed new adapter size 654 int firstIndex = mGrid.getFirstIndex(); 655 int lastIndex = mGrid.getLastIndex(); 656 if (DEBUG) { 657 Log .v(getTag(), "mGrid firstIndex " + firstIndex + " lastIndex " + lastIndex); 658 } 659 for (int i = lastIndex; i >=firstIndex; i--) { 660 if (i >= newItemCount) { 661 mGrid.removeLast(); 662 } 663 } 664 if (mGrid.getSize() == 0) { 665 focusPosition = newItemCount - 1; 666 // initialize row start locations 667 for (int i = 0; i < mNumRows; i++) { 668 mRows[i].low = 0; 669 mRows[i].high = 0; 670 } 671 if (DEBUG) Log.v(getTag(), "mGrid zero size"); 672 } else { 673 // initialize row start locations 674 for (int i = 0; i < mNumRows; i++) { 675 mRows[i].low = Integer.MAX_VALUE; 676 mRows[i].high = Integer.MIN_VALUE; 677 } 678 firstIndex = mGrid.getFirstIndex(); 679 lastIndex = mGrid.getLastIndex(); 680 if (focusPosition > lastIndex) { 681 focusPosition = mGrid.getLastIndex(); 682 } 683 if (DEBUG) { 684 Log.v(getTag(), "mGrid firstIndex " + firstIndex + " lastIndex " 685 + lastIndex + " focusPosition " + focusPosition); 686 } 687 // fill rows with minimal view positions of the subset 688 for (int i = firstIndex; i <= lastIndex; i++) { 689 View v = findViewByPosition(i); 690 if (v == null) { 691 continue; 692 } 693 int row = mGrid.getLocation(i).row; 694 int low = getViewMin(v) + mScrollOffsetPrimary; 695 if (low < mRows[row].low) { 696 mRows[row].low = mRows[row].high = low; 697 } 698 } 699 int firstItemRowPosition = mRows[mGrid.getLocation(firstIndex).row].low; 700 if (firstItemRowPosition == Integer.MAX_VALUE) { 701 firstItemRowPosition = 0; 702 } 703 if (mState.didStructureChange()) { 704 // if there is structure change, the removed item might be in the 705 // subset, so it is meaningless to maintain the low locations. 706 for (int i = 0; i < mNumRows; i++) { 707 mRows[i].low = firstItemRowPosition; 708 mRows[i].high = firstItemRowPosition; 709 } 710 } else { 711 // fill other rows that does not include the subset using first item 712 for (int i = 0; i < mNumRows; i++) { 713 if (mRows[i].low == Integer.MAX_VALUE) { 714 mRows[i].low = mRows[i].high = firstItemRowPosition; 715 } 716 } 717 } 718 } 719 720 // Same adapter, we can reuse any attached views 721 detachAndScrapAttachedViews(mRecycler); 722 723 } else { 724 // otherwise recreate data structure 725 mRows = new StaggeredGrid.Row[mNumRows]; 726 727 for (int i = 0; i < mNumRows; i++) { 728 mRows[i] = new StaggeredGrid.Row(); 729 } 730 mGrid = new StaggeredGridDefault(); 731 if (newItemCount == 0) { 732 focusPosition = NO_POSITION; 733 } else if (focusPosition >= newItemCount) { 734 focusPosition = newItemCount - 1; 735 } 736 737 // Adapter may have changed so remove all attached views permanently 738 removeAndRecycleAllViews(mRecycler); 739 740 mScrollOffsetPrimary = 0; 741 mScrollOffsetSecondary = 0; 742 mWindowAlignment.reset(); 743 } 744 745 mGrid.setProvider(mGridProvider); 746 // mGrid share the same Row array information 747 mGrid.setRows(mRows); 748 mFirstVisiblePos = mLastVisiblePos = NO_POSITION; 749 750 initScrollController(); 751 updateScrollSecondAxis(); 752 753 return focusPosition; 754 } 755 756 private int getRowSizeSecondary(int rowIndex) { 757 if (mFixedRowSizeSecondary != 0) { 758 return mFixedRowSizeSecondary; 759 } 760 if (mRowSizeSecondary == null) { 761 return 0; 762 } 763 return mRowSizeSecondary[rowIndex]; 764 } 765 766 private int getRowStartSecondary(int rowIndex) { 767 int start = 0; 768 for (int i = 0; i < rowIndex; i++) { 769 start += getRowSizeSecondary(i) + mMarginSecondary; 770 } 771 return start; 772 } 773 774 private int getSizeSecondary() { 775 return getRowStartSecondary(mNumRows - 1) + getRowSizeSecondary(mNumRows - 1); 776 } 777 778 private void measureScrapChild(int position, int widthSpec, int heightSpec, 779 int[] measuredDimension) { 780 View view = mRecycler.getViewForPosition(position); 781 if (view != null) { 782 LayoutParams p = (LayoutParams) view.getLayoutParams(); 783 int childWidthSpec = ViewGroup.getChildMeasureSpec(widthSpec, 784 getPaddingLeft() + getPaddingRight(), p.width); 785 int childHeightSpec = ViewGroup.getChildMeasureSpec(heightSpec, 786 getPaddingTop() + getPaddingBottom(), p.height); 787 view.measure(childWidthSpec, childHeightSpec); 788 measuredDimension[0] = view.getMeasuredWidth(); 789 measuredDimension[1] = view.getMeasuredHeight(); 790 mRecycler.recycleView(view); 791 } 792 } 793 794 private boolean processRowSizeSecondary(boolean measure) { 795 if (mFixedRowSizeSecondary != 0) { 796 return false; 797 } 798 799 if (mGrid == null) { 800 if (mState.getItemCount() > 0) { 801 measureScrapChild(mFocusPosition == NO_POSITION ? 0 : mFocusPosition, 802 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 803 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 804 mMeasuredDimension); 805 if (DEBUG) Log.v(TAG, "measured scrap child: " + mMeasuredDimension[0] + 806 " " + mMeasuredDimension[1]); 807 } else { 808 mMeasuredDimension[0] = mMeasuredDimension[1] = 0; 809 } 810 } 811 812 List<Integer>[] rows = mGrid == null ? null : 813 mGrid.getItemPositionsInRows(mFirstVisiblePos, mLastVisiblePos); 814 boolean changed = false; 815 816 for (int rowIndex = 0; rowIndex < mNumRows; rowIndex++) { 817 int rowSize = 0; 818 819 final int rowItemCount = rows == null ? 1 : rows[rowIndex].size(); 820 if (DEBUG) Log.v(getTag(), "processRowSizeSecondary row " + rowIndex + 821 " rowItemCount " + rowItemCount); 822 823 for (int i = 0; i < rowItemCount; i++) { 824 if (rows != null) { 825 final int position = rows[rowIndex].get(i); 826 final View view = findViewByPosition(position); 827 if (measure && view.isLayoutRequested()) { 828 measureChild(view); 829 } 830 mMeasuredDimension[0] = view.getMeasuredWidth(); 831 mMeasuredDimension[1] = view.getMeasuredHeight(); 832 } 833 final int secondarySize = mOrientation == HORIZONTAL ? 834 mMeasuredDimension[1] : mMeasuredDimension[0]; 835 if (secondarySize > rowSize) { 836 rowSize = secondarySize; 837 } 838 } 839 if (DEBUG) Log.v(getTag(), "row " + rowIndex + " rowItemCount " + rowItemCount + 840 " rowSize " + rowSize); 841 842 if (mRowSizeSecondary[rowIndex] != rowSize) { 843 if (DEBUG) Log.v(getTag(), "row size secondary changed: " + mRowSizeSecondary[rowIndex] + 844 ", " + rowSize); 845 846 mRowSizeSecondary[rowIndex] = rowSize; 847 changed = true; 848 } 849 } 850 851 return changed; 852 } 853 854 /** 855 * Checks if we need to update row secondary sizes. 856 */ 857 private void updateRowSecondarySizeRefresh() { 858 mRowSecondarySizeRefresh = processRowSizeSecondary(false); 859 if (mRowSecondarySizeRefresh) { 860 if (DEBUG) Log.v(getTag(), "mRowSecondarySizeRefresh now set"); 861 forceRequestLayout(); 862 } 863 } 864 865 private void forceRequestLayout() { 866 if (DEBUG) Log.v(getTag(), "forceRequestLayout"); 867 // RecyclerView prevents us from requesting layout in many cases 868 // (during layout, during scroll, etc.) 869 // For secondary row size wrap_content support we currently need a 870 // second layout pass to update the measured size after having measured 871 // and added child views in layoutChildren. 872 // Force the second layout by posting a delayed runnable. 873 // TODO: investigate allowing a second layout pass, 874 // or move child add/measure logic to the measure phase. 875 mBaseGridView.getHandler().post(new Runnable() { 876 @Override 877 public void run() { 878 if (DEBUG) Log.v(getTag(), "request Layout from runnable"); 879 requestLayout(); 880 } 881 }); 882 } 883 884 @Override 885 public void onMeasure(Recycler recycler, State state, int widthSpec, int heightSpec) { 886 saveContext(recycler, state); 887 888 int sizePrimary, sizeSecondary, modeSecondary, paddingSecondary; 889 int measuredSizeSecondary; 890 if (mOrientation == HORIZONTAL) { 891 sizePrimary = MeasureSpec.getSize(widthSpec); 892 sizeSecondary = MeasureSpec.getSize(heightSpec); 893 modeSecondary = MeasureSpec.getMode(heightSpec); 894 paddingSecondary = getPaddingTop() + getPaddingBottom(); 895 } else { 896 sizeSecondary = MeasureSpec.getSize(widthSpec); 897 sizePrimary = MeasureSpec.getSize(heightSpec); 898 modeSecondary = MeasureSpec.getMode(widthSpec); 899 paddingSecondary = getPaddingLeft() + getPaddingRight(); 900 } 901 if (DEBUG) Log.v(getTag(), "onMeasure widthSpec " + Integer.toHexString(widthSpec) + 902 " heightSpec " + Integer.toHexString(heightSpec) + 903 " modeSecondary " + Integer.toHexString(modeSecondary) + 904 " sizeSecondary " + sizeSecondary + " " + this); 905 906 mMaxSizeSecondary = sizeSecondary; 907 908 if (mRowSizeSecondaryRequested == ViewGroup.LayoutParams.WRAP_CONTENT) { 909 mNumRows = mNumRowsRequested == 0 ? 1 : mNumRowsRequested; 910 mFixedRowSizeSecondary = 0; 911 912 if (mRowSizeSecondary == null || mRowSizeSecondary.length != mNumRows) { 913 mRowSizeSecondary = new int[mNumRows]; 914 } 915 916 // Measure all current children and update cached row heights 917 processRowSizeSecondary(true); 918 919 switch (modeSecondary) { 920 case MeasureSpec.UNSPECIFIED: 921 measuredSizeSecondary = getSizeSecondary() + paddingSecondary; 922 break; 923 case MeasureSpec.AT_MOST: 924 measuredSizeSecondary = Math.min(getSizeSecondary() + paddingSecondary, 925 mMaxSizeSecondary); 926 break; 927 case MeasureSpec.EXACTLY: 928 measuredSizeSecondary = mMaxSizeSecondary; 929 break; 930 default: 931 throw new IllegalStateException("wrong spec"); 932 } 933 934 } else { 935 switch (modeSecondary) { 936 case MeasureSpec.UNSPECIFIED: 937 if (mRowSizeSecondaryRequested == 0) { 938 if (mOrientation == HORIZONTAL) { 939 throw new IllegalStateException("Must specify rowHeight or view height"); 940 } else { 941 throw new IllegalStateException("Must specify columnWidth or view width"); 942 } 943 } 944 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 945 mNumRows = mNumRowsRequested == 0 ? 1 : mNumRowsRequested; 946 measuredSizeSecondary = mFixedRowSizeSecondary * mNumRows + mMarginSecondary 947 * (mNumRows - 1) + paddingSecondary; 948 break; 949 case MeasureSpec.AT_MOST: 950 case MeasureSpec.EXACTLY: 951 if (mNumRowsRequested == 0 && mRowSizeSecondaryRequested == 0) { 952 mNumRows = 1; 953 mFixedRowSizeSecondary = sizeSecondary - paddingSecondary; 954 } else if (mNumRowsRequested == 0) { 955 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 956 mNumRows = (sizeSecondary + mMarginSecondary) 957 / (mRowSizeSecondaryRequested + mMarginSecondary); 958 } else if (mRowSizeSecondaryRequested == 0) { 959 mNumRows = mNumRowsRequested; 960 mFixedRowSizeSecondary = (sizeSecondary - paddingSecondary - mMarginSecondary 961 * (mNumRows - 1)) / mNumRows; 962 } else { 963 mNumRows = mNumRowsRequested; 964 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 965 } 966 measuredSizeSecondary = sizeSecondary; 967 if (modeSecondary == MeasureSpec.AT_MOST) { 968 int childrenSize = mFixedRowSizeSecondary * mNumRows + mMarginSecondary 969 * (mNumRows - 1) + paddingSecondary; 970 if (childrenSize < measuredSizeSecondary) { 971 measuredSizeSecondary = childrenSize; 972 } 973 } 974 break; 975 default: 976 throw new IllegalStateException("wrong spec"); 977 } 978 } 979 if (mOrientation == HORIZONTAL) { 980 setMeasuredDimension(sizePrimary, measuredSizeSecondary); 981 } else { 982 setMeasuredDimension(measuredSizeSecondary, sizePrimary); 983 } 984 if (DEBUG) { 985 Log.v(getTag(), "onMeasure sizePrimary " + sizePrimary + 986 " measuredSizeSecondary " + measuredSizeSecondary + 987 " mFixedRowSizeSecondary " + mFixedRowSizeSecondary + 988 " mNumRows " + mNumRows); 989 } 990 991 leaveContext(); 992 } 993 994 private void measureChild(View child) { 995 final ViewGroup.LayoutParams lp = child.getLayoutParams(); 996 final int secondarySpec = (mRowSizeSecondaryRequested == ViewGroup.LayoutParams.WRAP_CONTENT) ? 997 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED) : 998 MeasureSpec.makeMeasureSpec(mFixedRowSizeSecondary, MeasureSpec.EXACTLY); 999 int widthSpec, heightSpec; 1000 1001 if (mOrientation == HORIZONTAL) { 1002 widthSpec = ViewGroup.getChildMeasureSpec( 1003 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 1004 0, lp.width); 1005 heightSpec = ViewGroup.getChildMeasureSpec(secondarySpec, 0, lp.height); 1006 } else { 1007 heightSpec = ViewGroup.getChildMeasureSpec( 1008 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 1009 0, lp.height); 1010 widthSpec = ViewGroup.getChildMeasureSpec(secondarySpec, 0, lp.width); 1011 } 1012 1013 child.measure(widthSpec, heightSpec); 1014 1015 if (DEBUG) Log.v(getTag(), "measureChild secondarySpec " + Integer.toHexString(secondarySpec) + 1016 " widthSpec " + Integer.toHexString(widthSpec) + 1017 " heightSpec " + Integer.toHexString(heightSpec) + 1018 " measuredWidth " + child.getMeasuredWidth() + 1019 " measuredHeight " + child.getMeasuredHeight()); 1020 if (DEBUG) Log.v(getTag(), "child lp width " + lp.width + " height " + lp.height); 1021 } 1022 1023 private StaggeredGrid.Provider mGridProvider = new StaggeredGrid.Provider() { 1024 1025 @Override 1026 public int getCount() { 1027 return mState.getItemCount(); 1028 } 1029 1030 @Override 1031 public void createItem(int index, int rowIndex, boolean append) { 1032 View v = getViewForPosition(index); 1033 if (mFirstVisiblePos >= 0) { 1034 // when StaggeredGrid append or prepend item, we must guarantee 1035 // that sibling item has created views already. 1036 if (append && index != mLastVisiblePos + 1) { 1037 throw new RuntimeException(); 1038 } else if (!append && index != mFirstVisiblePos - 1) { 1039 throw new RuntimeException(); 1040 } 1041 } 1042 1043 // See recyclerView docs: we don't need re-add scraped view if it was removed. 1044 if (!((RecyclerView.LayoutParams) v.getLayoutParams()).isItemRemoved()) { 1045 if (append) { 1046 addView(v); 1047 } else { 1048 addView(v, 0); 1049 } 1050 measureChild(v); 1051 } 1052 1053 int length = mOrientation == HORIZONTAL ? v.getMeasuredWidth() : v.getMeasuredHeight(); 1054 int start, end; 1055 if (append) { 1056 start = mRows[rowIndex].high; 1057 if (start != mRows[rowIndex].low) { 1058 // if there are existing item in the row, add margin between 1059 start += mMarginPrimary; 1060 } else { 1061 final int lastRow = mRows.length - 1; 1062 if (lastRow != rowIndex && mRows[lastRow].high != mRows[lastRow].low) { 1063 // if there are existing item in the last row, insert 1064 // the new item after the last item of last row. 1065 start = mRows[lastRow].high + mMarginPrimary; 1066 } 1067 } 1068 end = start + length; 1069 mRows[rowIndex].high = end; 1070 } else { 1071 end = mRows[rowIndex].low; 1072 if (end != mRows[rowIndex].high) { 1073 end -= mMarginPrimary; 1074 } else if (0 != rowIndex && mRows[0].high != mRows[0].low) { 1075 // if there are existing item in the first row, insert 1076 // the new item before the first item of first row. 1077 end = mRows[0].low - mMarginPrimary; 1078 } 1079 start = end - length; 1080 mRows[rowIndex].low = start; 1081 } 1082 if (mFirstVisiblePos < 0) { 1083 mFirstVisiblePos = mLastVisiblePos = index; 1084 } else { 1085 if (append) { 1086 mLastVisiblePos++; 1087 } else { 1088 mFirstVisiblePos--; 1089 } 1090 } 1091 if (DEBUG) Log.v(getTag(), "start " + start + " end " + end); 1092 int startSecondary = getRowStartSecondary(rowIndex) - mScrollOffsetSecondary; 1093 layoutChild(rowIndex, v, start - mScrollOffsetPrimary, end - mScrollOffsetPrimary, 1094 startSecondary); 1095 if (DEBUG) { 1096 Log.d(getTag(), "addView " + index + " " + v); 1097 } 1098 if (index == mFirstVisiblePos) { 1099 updateScrollMin(); 1100 } 1101 if (index == mLastVisiblePos) { 1102 updateScrollMax(); 1103 } 1104 } 1105 }; 1106 1107 private void layoutChild(int rowIndex, View v, int start, int end, int startSecondary) { 1108 int sizeSecondary = mOrientation == HORIZONTAL ? v.getMeasuredHeight() 1109 : v.getMeasuredWidth(); 1110 if (mFixedRowSizeSecondary > 0) { 1111 sizeSecondary = Math.min(sizeSecondary, mFixedRowSizeSecondary); 1112 } 1113 final int verticalGravity = mGravity & Gravity.VERTICAL_GRAVITY_MASK; 1114 final int horizontalGravity = mGravity & Gravity.HORIZONTAL_GRAVITY_MASK; 1115 if (mOrientation == HORIZONTAL && verticalGravity == Gravity.TOP 1116 || mOrientation == VERTICAL && horizontalGravity == Gravity.LEFT) { 1117 // do nothing 1118 } else if (mOrientation == HORIZONTAL && verticalGravity == Gravity.BOTTOM 1119 || mOrientation == VERTICAL && horizontalGravity == Gravity.RIGHT) { 1120 startSecondary += getRowSizeSecondary(rowIndex) - sizeSecondary; 1121 } else if (mOrientation == HORIZONTAL && verticalGravity == Gravity.CENTER_VERTICAL 1122 || mOrientation == VERTICAL && horizontalGravity == Gravity.CENTER_HORIZONTAL) { 1123 startSecondary += (getRowSizeSecondary(rowIndex) - sizeSecondary) / 2; 1124 } 1125 int left, top, right, bottom; 1126 if (mOrientation == HORIZONTAL) { 1127 left = start; 1128 top = startSecondary; 1129 right = end; 1130 bottom = startSecondary + sizeSecondary; 1131 } else { 1132 top = start; 1133 left = startSecondary; 1134 bottom = end; 1135 right = startSecondary + sizeSecondary; 1136 } 1137 v.layout(left, top, right, bottom); 1138 updateChildOpticalInsets(v, left, top, right, bottom); 1139 updateChildAlignments(v); 1140 } 1141 1142 private void updateChildOpticalInsets(View v, int left, int top, int right, int bottom) { 1143 LayoutParams p = (LayoutParams) v.getLayoutParams(); 1144 p.setOpticalInsets(left - v.getLeft(), top - v.getTop(), 1145 v.getRight() - right, v.getBottom() - bottom); 1146 } 1147 1148 private void updateChildAlignments(View v) { 1149 LayoutParams p = (LayoutParams) v.getLayoutParams(); 1150 p.setAlignX(mItemAlignment.horizontal.getAlignmentPosition(v)); 1151 p.setAlignY(mItemAlignment.vertical.getAlignmentPosition(v)); 1152 } 1153 1154 private void updateChildAlignments() { 1155 for (int i = 0, c = getChildCount(); i < c; i++) { 1156 updateChildAlignments(getChildAt(i)); 1157 } 1158 } 1159 1160 private boolean needsAppendVisibleItem() { 1161 if (mLastVisiblePos < mFocusPosition) { 1162 return true; 1163 } 1164 int right = mScrollOffsetPrimary + mSizePrimary; 1165 for (int i = 0; i < mNumRows; i++) { 1166 if (mRows[i].low == mRows[i].high) { 1167 if (mRows[i].high < right) { 1168 return true; 1169 } 1170 } else if (mRows[i].high < right - mMarginPrimary) { 1171 return true; 1172 } 1173 } 1174 return false; 1175 } 1176 1177 private boolean needsPrependVisibleItem() { 1178 if (mFirstVisiblePos > mFocusPosition) { 1179 return true; 1180 } 1181 for (int i = 0; i < mNumRows; i++) { 1182 if (mRows[i].low == mRows[i].high) { 1183 if (mRows[i].low > mScrollOffsetPrimary) { 1184 return true; 1185 } 1186 } else if (mRows[i].low - mMarginPrimary > mScrollOffsetPrimary) { 1187 return true; 1188 } 1189 } 1190 return false; 1191 } 1192 1193 // Append one column if possible and return true if reach end. 1194 private boolean appendOneVisibleItem() { 1195 while (true) { 1196 if (mLastVisiblePos != NO_POSITION && mLastVisiblePos < mState.getItemCount() -1 && 1197 mLastVisiblePos < mGrid.getLastIndex()) { 1198 // append invisible view of saved location till last row 1199 final int index = mLastVisiblePos + 1; 1200 final int row = mGrid.getLocation(index).row; 1201 mGridProvider.createItem(index, row, true); 1202 if (row == mNumRows - 1) { 1203 return false; 1204 } 1205 } else if ((mLastVisiblePos == NO_POSITION && mState.getItemCount() > 0) || 1206 (mLastVisiblePos != NO_POSITION && 1207 mLastVisiblePos < mState.getItemCount() - 1)) { 1208 mGrid.appendItems(mScrollOffsetPrimary + mSizePrimary); 1209 return false; 1210 } else { 1211 return true; 1212 } 1213 } 1214 } 1215 1216 private void appendVisibleItems() { 1217 while (needsAppendVisibleItem()) { 1218 if (appendOneVisibleItem()) { 1219 break; 1220 } 1221 } 1222 } 1223 1224 // Prepend one column if possible and return true if reach end. 1225 private boolean prependOneVisibleItem() { 1226 while (true) { 1227 if (mFirstVisiblePos > 0) { 1228 if (mFirstVisiblePos > mGrid.getFirstIndex()) { 1229 // prepend invisible view of saved location till first row 1230 final int index = mFirstVisiblePos - 1; 1231 final int row = mGrid.getLocation(index).row; 1232 mGridProvider.createItem(index, row, false); 1233 if (row == 0) { 1234 return false; 1235 } 1236 } else { 1237 mGrid.prependItems(mScrollOffsetPrimary); 1238 return false; 1239 } 1240 } else { 1241 return true; 1242 } 1243 } 1244 } 1245 1246 private void prependVisibleItems() { 1247 while (needsPrependVisibleItem()) { 1248 if (prependOneVisibleItem()) { 1249 break; 1250 } 1251 } 1252 } 1253 1254 private void removeChildAt(int position) { 1255 View v = findViewByPosition(position); 1256 if (v != null) { 1257 if (DEBUG) { 1258 Log.d(getTag(), "removeAndRecycleViewAt " + position); 1259 } 1260 removeAndRecycleView(v, mRecycler); 1261 } 1262 } 1263 1264 private void removeInvisibleViewsAtEnd() { 1265 if (!mPruneChild) { 1266 return; 1267 } 1268 boolean update = false; 1269 while(mLastVisiblePos > mFirstVisiblePos && mLastVisiblePos > mFocusPosition) { 1270 View view = findViewByPosition(mLastVisiblePos); 1271 if (getViewMin(view) > mSizePrimary) { 1272 removeChildAt(mLastVisiblePos); 1273 mLastVisiblePos--; 1274 update = true; 1275 } else { 1276 break; 1277 } 1278 } 1279 if (update) { 1280 updateRowsMinMax(); 1281 } 1282 } 1283 1284 private void removeInvisibleViewsAtFront() { 1285 if (!mPruneChild) { 1286 return; 1287 } 1288 boolean update = false; 1289 while(mLastVisiblePos > mFirstVisiblePos && mFirstVisiblePos < mFocusPosition) { 1290 View view = findViewByPosition(mFirstVisiblePos); 1291 if (getViewMax(view) < 0) { 1292 removeChildAt(mFirstVisiblePos); 1293 mFirstVisiblePos++; 1294 update = true; 1295 } else { 1296 break; 1297 } 1298 } 1299 if (update) { 1300 updateRowsMinMax(); 1301 } 1302 } 1303 1304 private void updateRowsMinMax() { 1305 if (mFirstVisiblePos < 0) { 1306 return; 1307 } 1308 for (int i = 0; i < mNumRows; i++) { 1309 mRows[i].low = Integer.MAX_VALUE; 1310 mRows[i].high = Integer.MIN_VALUE; 1311 } 1312 for (int i = mFirstVisiblePos; i <= mLastVisiblePos; i++) { 1313 View view = findViewByPosition(i); 1314 int row = mGrid.getLocation(i).row; 1315 int low = getViewMin(view) + mScrollOffsetPrimary; 1316 if (low < mRows[row].low) { 1317 mRows[row].low = low; 1318 } 1319 int high = getViewMax(view) + mScrollOffsetPrimary; 1320 if (high > mRows[row].high) { 1321 mRows[row].high = high; 1322 } 1323 } 1324 } 1325 1326 // Fast layout when there is no structure change, adapter change, etc. 1327 protected void fastRelayout() { 1328 initScrollController(); 1329 1330 List<Integer>[] rows = mGrid.getItemPositionsInRows(mFirstVisiblePos, mLastVisiblePos); 1331 1332 // relayout and repositioning views on each row 1333 for (int i = 0; i < mNumRows; i++) { 1334 List<Integer> row = rows[i]; 1335 final int startSecondary = getRowStartSecondary(i) - mScrollOffsetSecondary; 1336 for (int j = 0, size = row.size(); j < size; j++) { 1337 final int position = row.get(j); 1338 final View view = findViewByPosition(position); 1339 int primaryDelta, start, end; 1340 1341 if (mOrientation == HORIZONTAL) { 1342 final int primarySize = view.getMeasuredWidth(); 1343 if (view.isLayoutRequested()) { 1344 measureChild(view); 1345 } 1346 start = getViewMin(view); 1347 end = start + view.getMeasuredWidth(); 1348 primaryDelta = view.getMeasuredWidth() - primarySize; 1349 if (primaryDelta != 0) { 1350 for (int k = j + 1; k < size; k++) { 1351 findViewByPosition(row.get(k)).offsetLeftAndRight(primaryDelta); 1352 } 1353 } 1354 } else { 1355 final int primarySize = view.getMeasuredHeight(); 1356 if (view.isLayoutRequested()) { 1357 measureChild(view); 1358 } 1359 start = getViewMin(view); 1360 end = start + view.getMeasuredHeight(); 1361 primaryDelta = view.getMeasuredHeight() - primarySize; 1362 if (primaryDelta != 0) { 1363 for (int k = j + 1; k < size; k++) { 1364 findViewByPosition(row.get(k)).offsetTopAndBottom(primaryDelta); 1365 } 1366 } 1367 } 1368 layoutChild(i, view, start, end, startSecondary); 1369 } 1370 } 1371 1372 updateRowsMinMax(); 1373 appendVisibleItems(); 1374 prependVisibleItems(); 1375 1376 updateRowsMinMax(); 1377 updateScrollMin(); 1378 updateScrollMax(); 1379 updateScrollSecondAxis(); 1380 1381 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED) { 1382 View focusView = findViewByPosition(mFocusPosition == NO_POSITION ? 0 : mFocusPosition); 1383 scrollToView(focusView, false); 1384 } 1385 } 1386 1387 @Override 1388 public boolean supportsPredictiveItemAnimations() { 1389 return mAnimateChildLayout; 1390 } 1391 1392 private void removeAndRecycleAllViews(RecyclerView.Recycler recycler) { 1393 if (DEBUG) Log.v(TAG, "removeAndRecycleAllViews " + getChildCount()); 1394 for (int i = getChildCount() - 1; i >= 0; i--) { 1395 removeAndRecycleViewAt(i, recycler); 1396 } 1397 } 1398 1399 // Lays out items based on the current scroll position 1400 @Override 1401 public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state) { 1402 if (DEBUG) { 1403 Log.v(getTag(), "layoutChildren start numRows " + mNumRows + " mScrollOffsetSecondary " 1404 + mScrollOffsetSecondary + " mScrollOffsetPrimary " + mScrollOffsetPrimary 1405 + " inPreLayout " + state.isPreLayout() 1406 + " didStructureChange " + state.didStructureChange() 1407 + " mForceFullLayout " + mForceFullLayout); 1408 Log.v(getTag(), "width " + getWidth() + " height " + getHeight()); 1409 } 1410 1411 if (mNumRows == 0) { 1412 // haven't done measure yet 1413 return; 1414 } 1415 final int itemCount = state.getItemCount(); 1416 if (itemCount < 0) { 1417 return; 1418 } 1419 1420 if (!mLayoutEnabled) { 1421 discardLayoutInfo(); 1422 removeAndRecycleAllViews(recycler); 1423 return; 1424 } 1425 mInLayout = true; 1426 1427 saveContext(recycler, state); 1428 // Track the old focus view so we can adjust our system scroll position 1429 // so that any scroll animations happening now will remain valid. 1430 // We must use same delta in Pre Layout (if prelayout exists) and second layout. 1431 // So we cache the deltas in PreLayout and use it in second layout. 1432 int delta = 0, deltaSecondary = 0; 1433 if (!state.isPreLayout() && mUseDeltaInPreLayout) { 1434 delta = mDeltaInPreLayout; 1435 deltaSecondary = mDeltaSecondaryInPreLayout; 1436 } else { 1437 if (mFocusPosition != NO_POSITION 1438 && mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED) { 1439 View focusView = findViewByPosition(mFocusPosition); 1440 if (focusView != null) { 1441 delta = mWindowAlignment.mainAxis().getSystemScrollPos( 1442 getViewCenter(focusView) + mScrollOffsetPrimary) - mScrollOffsetPrimary; 1443 deltaSecondary = 1444 mWindowAlignment.secondAxis().getSystemScrollPos( 1445 getViewCenterSecondary(focusView) + mScrollOffsetSecondary) 1446 - mScrollOffsetSecondary; 1447 if (mUseDeltaInPreLayout = state.isPreLayout()) { 1448 mDeltaInPreLayout = delta; 1449 mDeltaSecondaryInPreLayout = deltaSecondary; 1450 } 1451 } 1452 } 1453 } 1454 1455 final boolean hasDoneFirstLayout = hasDoneFirstLayout(); 1456 int savedFocusPos = mFocusPosition; 1457 boolean fastRelayout = false; 1458 if (!mState.didStructureChange() && !mForceFullLayout && hasDoneFirstLayout) { 1459 fastRelayout = true; 1460 fastRelayout(); 1461 } else { 1462 boolean hadFocus = mBaseGridView.hasFocus(); 1463 1464 int newFocusPosition = init(mFocusPosition); 1465 if (DEBUG) { 1466 Log.v(getTag(), "mFocusPosition " + mFocusPosition + " newFocusPosition " 1467 + newFocusPosition); 1468 } 1469 1470 // depending on result of init(), either recreating everything 1471 // or try to reuse the row start positions near mFocusPosition 1472 if (mGrid.getSize() == 0) { 1473 // this is a fresh creating all items, starting from 1474 // mFocusPosition with a estimated row index. 1475 mGrid.setStart(newFocusPosition, StaggeredGrid.START_DEFAULT); 1476 1477 // Can't track the old focus view 1478 delta = deltaSecondary = 0; 1479 1480 } else { 1481 // mGrid remembers Locations for the column that 1482 // contains mFocusePosition and also mRows remembers start 1483 // positions of each row. 1484 // Manually re-create child views for that column 1485 int firstIndex = mGrid.getFirstIndex(); 1486 int lastIndex = mGrid.getLastIndex(); 1487 for (int i = firstIndex; i <= lastIndex; i++) { 1488 mGridProvider.createItem(i, mGrid.getLocation(i).row, true); 1489 } 1490 } 1491 // add visible views at end until reach the end of window 1492 appendVisibleItems(); 1493 // add visible views at front until reach the start of window 1494 prependVisibleItems(); 1495 // multiple rounds: scrollToView of first round may drag first/last child into 1496 // "visible window" and we update scrollMin/scrollMax then run second scrollToView 1497 int oldFirstVisible; 1498 int oldLastVisible; 1499 do { 1500 oldFirstVisible = mFirstVisiblePos; 1501 oldLastVisible = mLastVisiblePos; 1502 View focusView = findViewByPosition(newFocusPosition); 1503 // we need force to initialize the child view's position 1504 scrollToView(focusView, false); 1505 if (focusView != null && hadFocus) { 1506 focusView.requestFocus(); 1507 } 1508 appendVisibleItems(); 1509 prependVisibleItems(); 1510 removeInvisibleViewsAtFront(); 1511 removeInvisibleViewsAtEnd(); 1512 } while (mFirstVisiblePos != oldFirstVisible || mLastVisiblePos != oldLastVisible); 1513 } 1514 mForceFullLayout = false; 1515 1516 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED) { 1517 scrollDirectionPrimary(-delta); 1518 scrollDirectionSecondary(-deltaSecondary); 1519 } 1520 appendVisibleItems(); 1521 prependVisibleItems(); 1522 removeInvisibleViewsAtFront(); 1523 removeInvisibleViewsAtEnd(); 1524 1525 if (DEBUG) { 1526 StringWriter sw = new StringWriter(); 1527 PrintWriter pw = new PrintWriter(sw); 1528 mGrid.debugPrint(pw); 1529 Log.d(getTag(), sw.toString()); 1530 } 1531 1532 if (mRowSecondarySizeRefresh) { 1533 mRowSecondarySizeRefresh = false; 1534 } else { 1535 updateRowSecondarySizeRefresh(); 1536 } 1537 1538 if (!state.isPreLayout()) { 1539 mUseDeltaInPreLayout = false; 1540 if (!fastRelayout || mFocusPosition != savedFocusPos) { 1541 dispatchChildSelected(); 1542 } 1543 } 1544 mInLayout = false; 1545 leaveContext(); 1546 if (DEBUG) Log.v(getTag(), "layoutChildren end"); 1547 } 1548 1549 private void offsetChildrenSecondary(int increment) { 1550 final int childCount = getChildCount(); 1551 if (mOrientation == HORIZONTAL) { 1552 for (int i = 0; i < childCount; i++) { 1553 getChildAt(i).offsetTopAndBottom(increment); 1554 } 1555 } else { 1556 for (int i = 0; i < childCount; i++) { 1557 getChildAt(i).offsetLeftAndRight(increment); 1558 } 1559 } 1560 } 1561 1562 private void offsetChildrenPrimary(int increment) { 1563 final int childCount = getChildCount(); 1564 if (mOrientation == VERTICAL) { 1565 for (int i = 0; i < childCount; i++) { 1566 getChildAt(i).offsetTopAndBottom(increment); 1567 } 1568 } else { 1569 for (int i = 0; i < childCount; i++) { 1570 getChildAt(i).offsetLeftAndRight(increment); 1571 } 1572 } 1573 } 1574 1575 @Override 1576 public int scrollHorizontallyBy(int dx, Recycler recycler, RecyclerView.State state) { 1577 if (DEBUG) Log.v(getTag(), "scrollHorizontallyBy " + dx); 1578 if (!mLayoutEnabled || !hasDoneFirstLayout()) { 1579 return 0; 1580 } 1581 saveContext(recycler, state); 1582 int result; 1583 if (mOrientation == HORIZONTAL) { 1584 result = scrollDirectionPrimary(dx); 1585 } else { 1586 result = scrollDirectionSecondary(dx); 1587 } 1588 leaveContext(); 1589 return result; 1590 } 1591 1592 @Override 1593 public int scrollVerticallyBy(int dy, Recycler recycler, RecyclerView.State state) { 1594 if (DEBUG) Log.v(getTag(), "scrollVerticallyBy " + dy); 1595 if (!mLayoutEnabled || !hasDoneFirstLayout()) { 1596 return 0; 1597 } 1598 saveContext(recycler, state); 1599 int result; 1600 if (mOrientation == VERTICAL) { 1601 result = scrollDirectionPrimary(dy); 1602 } else { 1603 result = scrollDirectionSecondary(dy); 1604 } 1605 leaveContext(); 1606 return result; 1607 } 1608 1609 // scroll in main direction may add/prune views 1610 private int scrollDirectionPrimary(int da) { 1611 if (da > 0) { 1612 if (!mWindowAlignment.mainAxis().isMaxUnknown()) { 1613 int maxScroll = mWindowAlignment.mainAxis().getMaxScroll(); 1614 if (mScrollOffsetPrimary + da > maxScroll) { 1615 da = maxScroll - mScrollOffsetPrimary; 1616 } 1617 } 1618 } else if (da < 0) { 1619 if (!mWindowAlignment.mainAxis().isMinUnknown()) { 1620 int minScroll = mWindowAlignment.mainAxis().getMinScroll(); 1621 if (mScrollOffsetPrimary + da < minScroll) { 1622 da = minScroll - mScrollOffsetPrimary; 1623 } 1624 } 1625 } 1626 if (da == 0) { 1627 return 0; 1628 } 1629 offsetChildrenPrimary(-da); 1630 mScrollOffsetPrimary += da; 1631 if (mInLayout) { 1632 return da; 1633 } 1634 1635 int childCount = getChildCount(); 1636 boolean updated; 1637 1638 if (da > 0) { 1639 appendVisibleItems(); 1640 } else if (da < 0) { 1641 prependVisibleItems(); 1642 } 1643 updated = getChildCount() > childCount; 1644 childCount = getChildCount(); 1645 1646 if (da > 0) { 1647 removeInvisibleViewsAtFront(); 1648 } else if (da < 0) { 1649 removeInvisibleViewsAtEnd(); 1650 } 1651 updated |= getChildCount() < childCount; 1652 1653 if (updated) { 1654 updateRowSecondarySizeRefresh(); 1655 } 1656 1657 mBaseGridView.invalidate(); 1658 return da; 1659 } 1660 1661 // scroll in second direction will not add/prune views 1662 private int scrollDirectionSecondary(int dy) { 1663 if (dy == 0) { 1664 return 0; 1665 } 1666 offsetChildrenSecondary(-dy); 1667 mScrollOffsetSecondary += dy; 1668 mBaseGridView.invalidate(); 1669 return dy; 1670 } 1671 1672 private void updateScrollMax() { 1673 if (mLastVisiblePos < 0) { 1674 return; 1675 } 1676 final boolean lastAvailable = mLastVisiblePos == mState.getItemCount() - 1; 1677 final boolean maxUnknown = mWindowAlignment.mainAxis().isMaxUnknown(); 1678 if (!lastAvailable && maxUnknown) { 1679 return; 1680 } 1681 int maxEdge = Integer.MIN_VALUE; 1682 int rowIndex = -1; 1683 for (int i = 0; i < mRows.length; i++) { 1684 if (mRows[i].high > maxEdge) { 1685 maxEdge = mRows[i].high; 1686 rowIndex = i; 1687 } 1688 } 1689 int maxScroll = Integer.MAX_VALUE; 1690 for (int i = mLastVisiblePos; i >= mFirstVisiblePos; i--) { 1691 StaggeredGrid.Location location = mGrid.getLocation(i); 1692 if (location != null && location.row == rowIndex) { 1693 int savedMaxEdge = mWindowAlignment.mainAxis().getMaxEdge(); 1694 mWindowAlignment.mainAxis().setMaxEdge(maxEdge); 1695 maxScroll = mWindowAlignment 1696 .mainAxis().getSystemScrollPos(mScrollOffsetPrimary 1697 + getViewCenter(findViewByPosition(i))); 1698 mWindowAlignment.mainAxis().setMaxEdge(savedMaxEdge); 1699 break; 1700 } 1701 } 1702 if (lastAvailable) { 1703 mWindowAlignment.mainAxis().setMaxEdge(maxEdge); 1704 mWindowAlignment.mainAxis().setMaxScroll(maxScroll); 1705 if (DEBUG) Log.v(getTag(), "updating scroll maxEdge to " + maxEdge + 1706 " scrollMax to " + maxScroll); 1707 } else { 1708 // the maxScroll for currently last visible item is larger, 1709 // so we must invalidate the max scroll value. 1710 if (maxScroll > mWindowAlignment.mainAxis().getMaxScroll()) { 1711 mWindowAlignment.mainAxis().invalidateScrollMax(); 1712 if (DEBUG) Log.v(getTag(), "Invalidate scrollMax since it should be " 1713 + "greater than " + maxScroll); 1714 } 1715 } 1716 } 1717 1718 private void updateScrollMin() { 1719 if (mFirstVisiblePos < 0) { 1720 return; 1721 } 1722 final boolean firstAvailable = mFirstVisiblePos == 0; 1723 final boolean minUnknown = mWindowAlignment.mainAxis().isMinUnknown(); 1724 if (!firstAvailable && minUnknown) { 1725 return; 1726 } 1727 int minEdge = Integer.MAX_VALUE; 1728 int rowIndex = -1; 1729 for (int i = 0; i < mRows.length; i++) { 1730 if (mRows[i].low < minEdge) { 1731 minEdge = mRows[i].low; 1732 rowIndex = i; 1733 } 1734 } 1735 int minScroll = Integer.MIN_VALUE; 1736 for (int i = mFirstVisiblePos; i <= mLastVisiblePos; i++) { 1737 StaggeredGrid.Location location = mGrid.getLocation(i); 1738 if (location != null && location.row == rowIndex) { 1739 int savedMinEdge = mWindowAlignment.mainAxis().getMinEdge(); 1740 mWindowAlignment.mainAxis().setMinEdge(minEdge); 1741 minScroll = mWindowAlignment 1742 .mainAxis().getSystemScrollPos(mScrollOffsetPrimary 1743 + getViewCenter(findViewByPosition(i))); 1744 mWindowAlignment.mainAxis().setMinEdge(savedMinEdge); 1745 break; 1746 } 1747 } 1748 if (firstAvailable) { 1749 mWindowAlignment.mainAxis().setMinEdge(minEdge); 1750 mWindowAlignment.mainAxis().setMinScroll(minScroll); 1751 if (DEBUG) Log.v(getTag(), "updating scroll minEdge to " + minEdge + 1752 " scrollMin to " + minScroll); 1753 } else { 1754 // the minScroll for currently first visible item is smaller, 1755 // so we must invalidate the min scroll value. 1756 if (minScroll < mWindowAlignment.mainAxis().getMinScroll()) { 1757 mWindowAlignment.mainAxis().invalidateScrollMin(); 1758 if (DEBUG) Log.v(getTag(), "Invalidate scrollMin, since it should be " 1759 + "less than " + minScroll); 1760 } 1761 } 1762 } 1763 1764 private void updateScrollSecondAxis() { 1765 mWindowAlignment.secondAxis().setMinEdge(0); 1766 mWindowAlignment.secondAxis().setMaxEdge(getSizeSecondary()); 1767 } 1768 1769 private void initScrollController() { 1770 mWindowAlignment.horizontal.setSize(getWidth()); 1771 mWindowAlignment.horizontal.setPadding(getPaddingLeft(), getPaddingRight()); 1772 mWindowAlignment.vertical.setSize(getHeight()); 1773 mWindowAlignment.vertical.setPadding(getPaddingTop(), getPaddingBottom()); 1774 mSizePrimary = mWindowAlignment.mainAxis().getSize(); 1775 1776 if (DEBUG) { 1777 Log.v(getTag(), "initScrollController mSizePrimary " + mSizePrimary 1778 + " mWindowAlignment " + mWindowAlignment); 1779 } 1780 } 1781 1782 public void setSelection(RecyclerView parent, int position) { 1783 setSelection(parent, position, false); 1784 } 1785 1786 public void setSelectionSmooth(RecyclerView parent, int position) { 1787 setSelection(parent, position, true); 1788 } 1789 1790 public int getSelection() { 1791 return mFocusPosition; 1792 } 1793 1794 public void setSelection(RecyclerView parent, int position, boolean smooth) { 1795 if (mFocusPosition == position) { 1796 return; 1797 } 1798 View view = findViewByPosition(position); 1799 if (view != null) { 1800 scrollToView(view, smooth); 1801 } else { 1802 mFocusPosition = position; 1803 if (!mLayoutEnabled) { 1804 return; 1805 } 1806 if (smooth) { 1807 if (!hasDoneFirstLayout()) { 1808 Log.w(getTag(), "setSelectionSmooth should " + 1809 "not be called before first layout pass"); 1810 return; 1811 } 1812 LinearSmoothScroller linearSmoothScroller = 1813 new LinearSmoothScroller(parent.getContext()) { 1814 @Override 1815 public PointF computeScrollVectorForPosition(int targetPosition) { 1816 if (getChildCount() == 0) { 1817 return null; 1818 } 1819 final int firstChildPos = getPosition(getChildAt(0)); 1820 final int direction = targetPosition < firstChildPos ? -1 : 1; 1821 if (mOrientation == HORIZONTAL) { 1822 return new PointF(direction, 0); 1823 } else { 1824 return new PointF(0, direction); 1825 } 1826 } 1827 @Override 1828 protected void onTargetFound(View targetView, 1829 RecyclerView.State state, Action action) { 1830 if (hasFocus()) { 1831 targetView.requestFocus(); 1832 } else { 1833 dispatchChildSelected(); 1834 } 1835 if (getScrollPosition(targetView, mTempDeltas)) { 1836 int dx, dy; 1837 if (mOrientation == HORIZONTAL) { 1838 dx = mTempDeltas[0]; 1839 dy = mTempDeltas[1]; 1840 } else { 1841 dx = mTempDeltas[1]; 1842 dy = mTempDeltas[0]; 1843 } 1844 final int distance = (int) Math.sqrt(dx * dx + dy * dy); 1845 final int time = calculateTimeForDeceleration(distance); 1846 action.update(dx, dy, time, mDecelerateInterpolator); 1847 } 1848 } 1849 }; 1850 linearSmoothScroller.setTargetPosition(position); 1851 startSmoothScroll(linearSmoothScroller); 1852 } else { 1853 mForceFullLayout = true; 1854 parent.requestLayout(); 1855 } 1856 } 1857 } 1858 1859 @Override 1860 public void onItemsAdded(RecyclerView recyclerView, int positionStart, int itemCount) { 1861 boolean needsLayout = false; 1862 if (itemCount != 0) { 1863 if (mFirstVisiblePos < 0) { 1864 needsLayout = true; 1865 } else if (!(positionStart > mLastVisiblePos + 1 || 1866 positionStart + itemCount < mFirstVisiblePos - 1)) { 1867 needsLayout = true; 1868 } 1869 } 1870 if (needsLayout) { 1871 recyclerView.requestLayout(); 1872 } 1873 } 1874 1875 @Override 1876 public boolean onRequestChildFocus(RecyclerView parent, View child, View focused) { 1877 if (mFocusSearchDisabled) { 1878 return true; 1879 } 1880 if (!mInLayout) { 1881 scrollToView(child, true); 1882 } 1883 return true; 1884 } 1885 1886 @Override 1887 public boolean requestChildRectangleOnScreen(RecyclerView parent, View view, Rect rect, 1888 boolean immediate) { 1889 if (DEBUG) Log.v(getTag(), "requestChildRectangleOnScreen " + view + " " + rect); 1890 return false; 1891 } 1892 1893 int getScrollOffsetX() { 1894 return mOrientation == HORIZONTAL ? mScrollOffsetPrimary : mScrollOffsetSecondary; 1895 } 1896 1897 int getScrollOffsetY() { 1898 return mOrientation == HORIZONTAL ? mScrollOffsetSecondary : mScrollOffsetPrimary; 1899 } 1900 1901 public void getViewSelectedOffsets(View view, int[] offsets) { 1902 int scrollOffsetX = getScrollOffsetX(); 1903 int scrollOffsetY = getScrollOffsetY(); 1904 int viewCenterX = scrollOffsetX + getViewCenterX(view); 1905 int viewCenterY = scrollOffsetY + getViewCenterY(view); 1906 offsets[0] = mWindowAlignment.horizontal.getSystemScrollPos(viewCenterX) - scrollOffsetX; 1907 offsets[1] = mWindowAlignment.vertical.getSystemScrollPos(viewCenterY) - scrollOffsetY; 1908 } 1909 1910 /** 1911 * Scroll to a given child view and change mFocusPosition. 1912 */ 1913 private void scrollToView(View view, boolean smooth) { 1914 int newFocusPosition = getPositionByView(view); 1915 if (newFocusPosition != mFocusPosition) { 1916 mFocusPosition = newFocusPosition; 1917 if (!mInLayout) { 1918 dispatchChildSelected(); 1919 } 1920 } 1921 if (mBaseGridView.isChildrenDrawingOrderEnabledInternal()) { 1922 mBaseGridView.invalidate(); 1923 } 1924 if (view == null) { 1925 return; 1926 } 1927 if (!view.hasFocus() && mBaseGridView.hasFocus()) { 1928 // transfer focus to the child if it does not have focus yet (e.g. triggered 1929 // by setSelection()) 1930 view.requestFocus(); 1931 } 1932 if (getScrollPosition(view, mTempDeltas)) { 1933 scrollGrid(mTempDeltas[0], mTempDeltas[1], smooth); 1934 } 1935 } 1936 1937 private boolean getScrollPosition(View view, int[] deltas) { 1938 switch (mFocusScrollStrategy) { 1939 case BaseGridView.FOCUS_SCROLL_ALIGNED: 1940 default: 1941 return getAlignedPosition(view, deltas); 1942 case BaseGridView.FOCUS_SCROLL_ITEM: 1943 case BaseGridView.FOCUS_SCROLL_PAGE: 1944 return getNoneAlignedPosition(view, deltas); 1945 } 1946 } 1947 1948 private boolean getNoneAlignedPosition(View view, int[] deltas) { 1949 int pos = getPositionByView(view); 1950 int viewMin = getViewMin(view); 1951 int viewMax = getViewMax(view); 1952 // we either align "firstView" to left/top padding edge 1953 // or align "lastView" to right/bottom padding edge 1954 View firstView = null; 1955 View lastView = null; 1956 int paddingLow = mWindowAlignment.mainAxis().getPaddingLow(); 1957 int clientSize = mWindowAlignment.mainAxis().getClientSize(); 1958 final int row = mGrid.getLocation(pos).row; 1959 if (viewMin < paddingLow) { 1960 // view enters low padding area: 1961 firstView = view; 1962 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_PAGE) { 1963 // scroll one "page" left/top, 1964 // align first visible item of the "page" at the low padding edge. 1965 while (!prependOneVisibleItem()) { 1966 List<Integer> positions = 1967 mGrid.getItemPositionsInRows(mFirstVisiblePos, pos)[row]; 1968 firstView = findViewByPosition(positions.get(0)); 1969 if (viewMax - getViewMin(firstView) > clientSize) { 1970 if (positions.size() > 1) { 1971 firstView = findViewByPosition(positions.get(1)); 1972 } 1973 break; 1974 } 1975 } 1976 } 1977 } else if (viewMax > clientSize + paddingLow) { 1978 // view enters high padding area: 1979 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_PAGE) { 1980 // scroll whole one page right/bottom, align view at the low padding edge. 1981 firstView = view; 1982 do { 1983 List<Integer> positions = 1984 mGrid.getItemPositionsInRows(pos, mLastVisiblePos)[row]; 1985 lastView = findViewByPosition(positions.get(positions.size() - 1)); 1986 if (getViewMax(lastView) - viewMin > clientSize) { 1987 lastView = null; 1988 break; 1989 } 1990 } while (!appendOneVisibleItem()); 1991 if (lastView != null) { 1992 // however if we reached end, we should align last view. 1993 firstView = null; 1994 } 1995 } else { 1996 lastView = view; 1997 } 1998 } 1999 int scrollPrimary = 0; 2000 int scrollSecondary = 0; 2001 if (firstView != null) { 2002 scrollPrimary = getViewMin(firstView) - paddingLow; 2003 } else if (lastView != null) { 2004 scrollPrimary = getViewMax(lastView) - (paddingLow + clientSize); 2005 } 2006 View secondaryAlignedView; 2007 if (firstView != null) { 2008 secondaryAlignedView = firstView; 2009 } else if (lastView != null) { 2010 secondaryAlignedView = lastView; 2011 } else { 2012 secondaryAlignedView = view; 2013 } 2014 int viewCenterSecondary = mScrollOffsetSecondary + 2015 getViewCenterSecondary(secondaryAlignedView); 2016 scrollSecondary = mWindowAlignment.secondAxis().getSystemScrollPos(viewCenterSecondary); 2017 scrollSecondary -= mScrollOffsetSecondary; 2018 if (scrollPrimary != 0 || scrollSecondary != 0) { 2019 deltas[0] = scrollPrimary; 2020 deltas[1] = scrollSecondary; 2021 return true; 2022 } 2023 return false; 2024 } 2025 2026 private boolean getAlignedPosition(View view, int[] deltas) { 2027 int viewCenterPrimary = mScrollOffsetPrimary + getViewCenter(view); 2028 int viewCenterSecondary = mScrollOffsetSecondary + getViewCenterSecondary(view); 2029 2030 int scrollPrimary = mWindowAlignment.mainAxis().getSystemScrollPos(viewCenterPrimary); 2031 int scrollSecondary = mWindowAlignment.secondAxis().getSystemScrollPos(viewCenterSecondary); 2032 if (DEBUG) { 2033 Log.v(getTag(), "getAlignedPosition " + scrollPrimary + " " + scrollSecondary 2034 +" " + mWindowAlignment); 2035 } 2036 scrollPrimary -= mScrollOffsetPrimary; 2037 scrollSecondary -= mScrollOffsetSecondary; 2038 if (scrollPrimary != 0 || scrollSecondary != 0) { 2039 deltas[0] = scrollPrimary; 2040 deltas[1] = scrollSecondary; 2041 return true; 2042 } 2043 return false; 2044 } 2045 2046 private void scrollGrid(int scrollPrimary, int scrollSecondary, boolean smooth) { 2047 if (mInLayout) { 2048 scrollDirectionPrimary(scrollPrimary); 2049 scrollDirectionSecondary(scrollSecondary); 2050 } else { 2051 int scrollX; 2052 int scrollY; 2053 if (mOrientation == HORIZONTAL) { 2054 scrollX = scrollPrimary; 2055 scrollY = scrollSecondary; 2056 } else { 2057 scrollX = scrollSecondary; 2058 scrollY = scrollPrimary; 2059 } 2060 if (smooth) { 2061 mBaseGridView.smoothScrollBy(scrollX, scrollY); 2062 } else { 2063 mBaseGridView.scrollBy(scrollX, scrollY); 2064 } 2065 } 2066 } 2067 2068 public void setAnimateChildLayout(boolean animateChildLayout) { 2069 mAnimateChildLayout = animateChildLayout; 2070 } 2071 2072 public boolean isChildLayoutAnimated() { 2073 return mAnimateChildLayout; 2074 } 2075 2076 public void setPruneChild(boolean pruneChild) { 2077 if (mPruneChild != pruneChild) { 2078 mPruneChild = pruneChild; 2079 if (mPruneChild) { 2080 requestLayout(); 2081 } 2082 } 2083 } 2084 2085 public boolean getPruneChild() { 2086 return mPruneChild; 2087 } 2088 2089 private int findImmediateChildIndex(View view) { 2090 while (view != null && view != mBaseGridView) { 2091 int index = mBaseGridView.indexOfChild(view); 2092 if (index >= 0) { 2093 return index; 2094 } 2095 view = (View) view.getParent(); 2096 } 2097 return NO_POSITION; 2098 } 2099 2100 void setFocusSearchDisabled(boolean disabled) { 2101 mFocusSearchDisabled = disabled; 2102 } 2103 2104 boolean isFocusSearchDisabled() { 2105 return mFocusSearchDisabled; 2106 } 2107 2108 @Override 2109 public View onInterceptFocusSearch(View focused, int direction) { 2110 if (mFocusSearchDisabled) { 2111 return focused; 2112 } 2113 return null; 2114 } 2115 2116 boolean hasPreviousViewInSameRow(int pos) { 2117 if (mGrid == null || pos == NO_POSITION) { 2118 return false; 2119 } 2120 if (mFirstVisiblePos > 0) { 2121 return true; 2122 } 2123 final int focusedRow = mGrid.getLocation(pos).row; 2124 for (int i = getChildCount() - 1; i >= 0; i--) { 2125 int position = getPositionByIndex(i); 2126 StaggeredGrid.Location loc = mGrid.getLocation(position); 2127 if (loc != null && loc.row == focusedRow) { 2128 if (position < pos) { 2129 return true; 2130 } 2131 } 2132 } 2133 return false; 2134 } 2135 2136 @Override 2137 public boolean onAddFocusables(RecyclerView recyclerView, 2138 ArrayList<View> views, int direction, int focusableMode) { 2139 if (mFocusSearchDisabled) { 2140 return true; 2141 } 2142 // If this viewgroup or one of its children currently has focus then we 2143 // consider our children for focus searching in main direction on the same row. 2144 // If this viewgroup has no focus and using focus align, we want the system 2145 // to ignore our children and pass focus to the viewgroup, which will pass 2146 // focus on to its children appropriately. 2147 // If this viewgroup has no focus and not using focus align, we want to 2148 // consider the child that does not overlap with padding area. 2149 if (recyclerView.hasFocus()) { 2150 final int movement = getMovement(direction); 2151 if (movement != PREV_ITEM && movement != NEXT_ITEM) { 2152 // Move on secondary direction uses default addFocusables(). 2153 return false; 2154 } 2155 final View focused = recyclerView.findFocus(); 2156 final int focusedPos = getPositionByIndex(findImmediateChildIndex(focused)); 2157 // Add focusables of focused item. 2158 if (focusedPos != NO_POSITION) { 2159 findViewByPosition(focusedPos).addFocusables(views, direction, focusableMode); 2160 } 2161 final int focusedRow = mGrid != null && focusedPos != NO_POSITION ? 2162 mGrid.getLocation(focusedPos).row : NO_POSITION; 2163 // Add focusables of next neighbor of same row on the focus search direction. 2164 if (mGrid != null) { 2165 final int focusableCount = views.size(); 2166 for (int i = 0, count = getChildCount(); i < count; i++) { 2167 int index = movement == NEXT_ITEM ? i : count - 1 - i; 2168 final View child = getChildAt(index); 2169 if (child.getVisibility() != View.VISIBLE) { 2170 continue; 2171 } 2172 int position = getPositionByIndex(index); 2173 StaggeredGrid.Location loc = mGrid.getLocation(position); 2174 if (focusedRow == NO_POSITION || (loc != null && loc.row == focusedRow)) { 2175 if (focusedPos == NO_POSITION || 2176 (movement == NEXT_ITEM && position > focusedPos) 2177 || (movement == PREV_ITEM && position < focusedPos)) { 2178 child.addFocusables(views, direction, focusableMode); 2179 if (views.size() > focusableCount) { 2180 break; 2181 } 2182 } 2183 } 2184 } 2185 } 2186 } else { 2187 if (mFocusScrollStrategy != BaseGridView.FOCUS_SCROLL_ALIGNED) { 2188 // adding views not overlapping padding area to avoid scrolling in gaining focus 2189 int left = mWindowAlignment.mainAxis().getPaddingLow(); 2190 int right = mWindowAlignment.mainAxis().getClientSize() + left; 2191 int focusableCount = views.size(); 2192 for (int i = 0, count = getChildCount(); i < count; i++) { 2193 View child = getChildAt(i); 2194 if (child.getVisibility() == View.VISIBLE) { 2195 if (getViewMin(child) >= left && getViewMax(child) <= right) { 2196 child.addFocusables(views, direction, focusableMode); 2197 } 2198 } 2199 } 2200 // if we cannot find any, then just add all children. 2201 if (views.size() == focusableCount) { 2202 for (int i = 0, count = getChildCount(); i < count; i++) { 2203 View child = getChildAt(i); 2204 if (child.getVisibility() == View.VISIBLE) { 2205 child.addFocusables(views, direction, focusableMode); 2206 } 2207 } 2208 if (views.size() != focusableCount) { 2209 return true; 2210 } 2211 } else { 2212 return true; 2213 } 2214 // if still cannot find any, fall through and add itself 2215 } 2216 if (recyclerView.isFocusable()) { 2217 views.add(recyclerView); 2218 } 2219 } 2220 return true; 2221 } 2222 2223 @Override 2224 public View onFocusSearchFailed(View focused, int direction, Recycler recycler, 2225 RecyclerView.State state) { 2226 if (DEBUG) Log.v(getTag(), "onFocusSearchFailed direction " + direction); 2227 2228 saveContext(recycler, state); 2229 View view = null; 2230 int movement = getMovement(direction); 2231 final FocusFinder ff = FocusFinder.getInstance(); 2232 if (movement == NEXT_ITEM) { 2233 while (view == null && !appendOneVisibleItem()) { 2234 view = ff.findNextFocus(mBaseGridView, focused, direction); 2235 } 2236 } else if (movement == PREV_ITEM){ 2237 while (view == null && !prependOneVisibleItem()) { 2238 view = ff.findNextFocus(mBaseGridView, focused, direction); 2239 } 2240 } 2241 if (view == null) { 2242 // returning the same view to prevent focus lost when scrolling past the end of the list 2243 if (movement == PREV_ITEM) { 2244 view = mFocusOutFront ? null : focused; 2245 } else if (movement == NEXT_ITEM){ 2246 view = mFocusOutEnd ? null : focused; 2247 } 2248 } 2249 leaveContext(); 2250 if (DEBUG) Log.v(getTag(), "returning view " + view); 2251 return view; 2252 } 2253 2254 boolean gridOnRequestFocusInDescendants(RecyclerView recyclerView, int direction, 2255 Rect previouslyFocusedRect) { 2256 switch (mFocusScrollStrategy) { 2257 case BaseGridView.FOCUS_SCROLL_ALIGNED: 2258 default: 2259 return gridOnRequestFocusInDescendantsAligned(recyclerView, 2260 direction, previouslyFocusedRect); 2261 case BaseGridView.FOCUS_SCROLL_PAGE: 2262 case BaseGridView.FOCUS_SCROLL_ITEM: 2263 return gridOnRequestFocusInDescendantsUnaligned(recyclerView, 2264 direction, previouslyFocusedRect); 2265 } 2266 } 2267 2268 private boolean gridOnRequestFocusInDescendantsAligned(RecyclerView recyclerView, 2269 int direction, Rect previouslyFocusedRect) { 2270 View view = findViewByPosition(mFocusPosition); 2271 if (view != null) { 2272 boolean result = view.requestFocus(direction, previouslyFocusedRect); 2273 if (!result && DEBUG) { 2274 Log.w(getTag(), "failed to request focus on " + view); 2275 } 2276 return result; 2277 } 2278 return false; 2279 } 2280 2281 private boolean gridOnRequestFocusInDescendantsUnaligned(RecyclerView recyclerView, 2282 int direction, Rect previouslyFocusedRect) { 2283 // focus to view not overlapping padding area to avoid scrolling in gaining focus 2284 int index; 2285 int increment; 2286 int end; 2287 int count = getChildCount(); 2288 if ((direction & View.FOCUS_FORWARD) != 0) { 2289 index = 0; 2290 increment = 1; 2291 end = count; 2292 } else { 2293 index = count - 1; 2294 increment = -1; 2295 end = -1; 2296 } 2297 int left = mWindowAlignment.mainAxis().getPaddingLow(); 2298 int right = mWindowAlignment.mainAxis().getClientSize() + left; 2299 for (int i = index; i != end; i += increment) { 2300 View child = getChildAt(i); 2301 if (child.getVisibility() == View.VISIBLE) { 2302 if (getViewMin(child) >= left && getViewMax(child) <= right) { 2303 if (child.requestFocus(direction, previouslyFocusedRect)) { 2304 return true; 2305 } 2306 } 2307 } 2308 } 2309 return false; 2310 } 2311 2312 private final static int PREV_ITEM = 0; 2313 private final static int NEXT_ITEM = 1; 2314 private final static int PREV_ROW = 2; 2315 private final static int NEXT_ROW = 3; 2316 2317 private int getMovement(int direction) { 2318 int movement = View.FOCUS_LEFT; 2319 2320 if (mOrientation == HORIZONTAL) { 2321 switch(direction) { 2322 case View.FOCUS_LEFT: 2323 movement = PREV_ITEM; 2324 break; 2325 case View.FOCUS_RIGHT: 2326 movement = NEXT_ITEM; 2327 break; 2328 case View.FOCUS_UP: 2329 movement = PREV_ROW; 2330 break; 2331 case View.FOCUS_DOWN: 2332 movement = NEXT_ROW; 2333 break; 2334 } 2335 } else if (mOrientation == VERTICAL) { 2336 switch(direction) { 2337 case View.FOCUS_LEFT: 2338 movement = PREV_ROW; 2339 break; 2340 case View.FOCUS_RIGHT: 2341 movement = NEXT_ROW; 2342 break; 2343 case View.FOCUS_UP: 2344 movement = PREV_ITEM; 2345 break; 2346 case View.FOCUS_DOWN: 2347 movement = NEXT_ITEM; 2348 break; 2349 } 2350 } 2351 2352 return movement; 2353 } 2354 2355 int getChildDrawingOrder(RecyclerView recyclerView, int childCount, int i) { 2356 View view = findViewByPosition(mFocusPosition); 2357 if (view == null) { 2358 return i; 2359 } 2360 int focusIndex = recyclerView.indexOfChild(view); 2361 // supposely 0 1 2 3 4 5 6 7 8 9, 4 is the center item 2362 // drawing order is 0 1 2 3 9 8 7 6 5 4 2363 if (i < focusIndex) { 2364 return i; 2365 } else if (i < childCount - 1) { 2366 return focusIndex + childCount - 1 - i; 2367 } else { 2368 return focusIndex; 2369 } 2370 } 2371 2372 @Override 2373 public void onAdapterChanged(RecyclerView.Adapter oldAdapter, 2374 RecyclerView.Adapter newAdapter) { 2375 discardLayoutInfo(); 2376 mFocusPosition = NO_POSITION; 2377 super.onAdapterChanged(oldAdapter, newAdapter); 2378 } 2379 2380 private void discardLayoutInfo() { 2381 mGrid = null; 2382 mRows = null; 2383 mRowSizeSecondary = null; 2384 mFirstVisiblePos = -1; 2385 mLastVisiblePos = -1; 2386 mRowSecondarySizeRefresh = false; 2387 } 2388 2389 public void setLayoutEnabled(boolean layoutEnabled) { 2390 if (mLayoutEnabled != layoutEnabled) { 2391 mLayoutEnabled = layoutEnabled; 2392 requestLayout(); 2393 } 2394 } 2395} 2396