GridLayoutManager.java revision e34cae48707e70442aca13e1b4ab55757292828d
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.Rect; 19import android.support.v7.widget.RecyclerView; 20import android.support.v7.widget.RecyclerView.Adapter; 21import android.support.v7.widget.RecyclerView.Recycler; 22import android.support.v7.widget.RecyclerView.State; 23 24import static android.support.v7.widget.RecyclerView.NO_ID; 25import static android.support.v7.widget.RecyclerView.NO_POSITION; 26import static android.support.v7.widget.RecyclerView.HORIZONTAL; 27import static android.support.v7.widget.RecyclerView.VERTICAL; 28 29import android.util.AttributeSet; 30import android.util.Log; 31import android.view.FocusFinder; 32import android.view.Gravity; 33import android.view.View; 34import android.view.ViewParent; 35import android.view.View.MeasureSpec; 36import android.view.ViewGroup.MarginLayoutParams; 37import android.view.ViewGroup; 38import android.view.animation.DecelerateInterpolator; 39import android.view.animation.Interpolator; 40 41import java.io.PrintWriter; 42import java.io.StringWriter; 43import java.util.ArrayList; 44import java.util.List; 45 46final class GridLayoutManager extends RecyclerView.LayoutManager { 47 48 /* 49 * LayoutParams for {@link HorizontalGridView} and {@link VerticalGridView}. 50 * The class currently does three internal jobs: 51 * - Saves optical bounds insets. 52 * - Caches focus align view center. 53 * - Manages child view layout animation. 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 // For animations 71 private TimeAnimator mAnimator; 72 private long mDuration; 73 private boolean mFirstAttached; 74 // current virtual view position (scrollOffset + left/top) in the GridLayoutManager 75 private int mViewX, mViewY; 76 // animation start value of translation x and y 77 private float mAnimationStartTranslationX, mAnimationStartTranslationY; 78 79 public LayoutParams(Context c, AttributeSet attrs) { 80 super(c, attrs); 81 } 82 83 public LayoutParams(int width, int height) { 84 super(width, height); 85 } 86 87 public LayoutParams(MarginLayoutParams source) { 88 super(source); 89 } 90 91 public LayoutParams(ViewGroup.LayoutParams source) { 92 super(source); 93 } 94 95 public LayoutParams(RecyclerView.LayoutParams source) { 96 super(source); 97 } 98 99 public LayoutParams(LayoutParams source) { 100 super(source); 101 } 102 103 void onViewAttached() { 104 endAnimate(); 105 mFirstAttached = true; 106 } 107 108 void onViewDetached() { 109 endAnimate(); 110 } 111 112 int getAlignX() { 113 return mAlignX; 114 } 115 116 int getAlignY() { 117 return mAlignY; 118 } 119 120 int getOpticalLeft(View view) { 121 return view.getLeft() + mLeftInset; 122 } 123 124 int getOpticalTop(View view) { 125 return view.getTop() + mTopInset; 126 } 127 128 int getOpticalRight(View view) { 129 return view.getRight() - mRighInset; 130 } 131 132 int getOpticalBottom(View view) { 133 return view.getBottom() - mBottomInset; 134 } 135 136 int getOpticalWidth(View view) { 137 return view.getWidth() - mLeftInset - mRighInset; 138 } 139 140 int getOpticalHeight(View view) { 141 return view.getHeight() - mTopInset - mBottomInset; 142 } 143 144 void setAlignX(int alignX) { 145 mAlignX = alignX; 146 } 147 148 void setAlignY(int alignY) { 149 mAlignY = alignY; 150 } 151 152 void setOpticalInsets(int leftInset, int topInset, int rightInset, int bottomInset) { 153 mLeftInset = leftInset; 154 mTopInset = topInset; 155 mRighInset = rightInset; 156 mBottomInset = bottomInset; 157 } 158 159 private TimeAnimator.TimeListener mTimeListener = new TimeAnimator.TimeListener() { 160 @Override 161 public void onTimeUpdate(TimeAnimator animation, long totalTime, long deltaTime) { 162 if (mView == null) { 163 return; 164 } 165 if (totalTime >= mDuration) { 166 endAnimate(); 167 } else { 168 float fraction = (float) (totalTime / (double)mDuration); 169 float fractionToEnd = 1 - mAnimator 170 .getInterpolator().getInterpolation(fraction); 171 mView.setTranslationX(fractionToEnd * mAnimationStartTranslationX); 172 mView.setTranslationY(fractionToEnd * mAnimationStartTranslationY); 173 invalidateItemDecoration(); 174 } 175 } 176 }; 177 178 void startAnimate(GridLayoutManager layout, View view, long startDelay) { 179 if (mAnimator == null) { 180 mAnimator = new TimeAnimator(); 181 mAnimator.setTimeListener(mTimeListener); 182 } 183 if (mFirstAttached) { 184 // first time record the initial location and return without animation 185 // TODO do we need initial animation? 186 mViewX = layout.getScrollOffsetX() + getOpticalLeft(view); 187 mViewY = layout.getScrollOffsetY() + getOpticalTop(view); 188 mFirstAttached = false; 189 return; 190 } 191 mView = view; 192 int newViewX = layout.getScrollOffsetX() + getOpticalLeft(mView); 193 int newViewY = layout.getScrollOffsetY() + getOpticalTop(mView); 194 if (newViewX != mViewX || newViewY != mViewY) { 195 mAnimator.cancel(); 196 mAnimationStartTranslationX = mView.getTranslationX(); 197 mAnimationStartTranslationY = mView.getTranslationY(); 198 mAnimationStartTranslationX += mViewX - newViewX; 199 mAnimationStartTranslationY += mViewY - newViewY; 200 mDuration = layout.getChildLayoutAnimationDuration(); 201 mAnimator.setDuration(mDuration); 202 mAnimator.setInterpolator(layout.getChildLayoutAnimationInterpolator()); 203 mAnimator.setStartDelay(startDelay); 204 mAnimator.start(); 205 mViewX = newViewX; 206 mViewY = newViewY; 207 } 208 } 209 210 void endAnimate() { 211 if (mAnimator != null) { 212 mAnimator.end(); 213 } 214 if (mView != null) { 215 mView.setTranslationX(0); 216 mView.setTranslationY(0); 217 mView = null; 218 } 219 } 220 221 private void invalidateItemDecoration() { 222 ViewParent parent = mView.getParent(); 223 if (parent instanceof RecyclerView) { 224 // TODO: we only need invalidate parent if it has ItemDecoration 225 ((RecyclerView) parent).invalidate(); 226 } 227 } 228 } 229 230 private static final String TAG = "GridLayoutManager"; 231 private static final boolean DEBUG = false; 232 233 private static final Interpolator sDefaultAnimationChildLayoutInterpolator 234 = new DecelerateInterpolator(); 235 236 private static final long DEFAULT_CHILD_ANIMATION_DURATION_MS = 250; 237 238 private String getTag() { 239 return TAG + ":" + mBaseGridView.getId(); 240 } 241 242 private final BaseGridView mBaseGridView; 243 244 /** 245 * The orientation of a "row". 246 */ 247 private int mOrientation = HORIZONTAL; 248 249 private RecyclerView.Adapter mAdapter; 250 private RecyclerView.Recycler mRecycler; 251 252 private boolean mInLayout = false; 253 254 private OnChildSelectedListener mChildSelectedListener = null; 255 256 /** 257 * The focused position, it's not the currently visually aligned position 258 * but it is the final position that we intend to focus on. If there are 259 * multiple setSelection() called, mFocusPosition saves last value. 260 */ 261 private int mFocusPosition = NO_POSITION; 262 263 /** 264 * Force a full layout under certain situations. 265 */ 266 private boolean mForceFullLayout; 267 268 /** 269 * The scroll offsets of the viewport relative to the entire view. 270 */ 271 private int mScrollOffsetPrimary; 272 private int mScrollOffsetSecondary; 273 274 /** 275 * User-specified row height/column width. Can be WRAP_CONTENT. 276 */ 277 private int mRowSizeSecondaryRequested; 278 279 /** 280 * The fixed size of each grid item in the secondary direction. This corresponds to 281 * the row height, equal for all rows. Grid items may have variable length 282 * in the primary direction. 283 */ 284 private int mFixedRowSizeSecondary; 285 286 /** 287 * Tracks the secondary size of each row. 288 */ 289 private int[] mRowSizeSecondary; 290 291 /** 292 * Flag controlling whether the current/next layout should 293 * be updating the secondary size of rows. 294 */ 295 private boolean mRowSecondarySizeRefresh; 296 297 /** 298 * The maximum measured size of the view. 299 */ 300 private int mMaxSizeSecondary; 301 302 /** 303 * Margin between items. 304 */ 305 private int mHorizontalMargin; 306 /** 307 * Margin between items vertically. 308 */ 309 private int mVerticalMargin; 310 /** 311 * Margin in main direction. 312 */ 313 private int mMarginPrimary; 314 /** 315 * Margin in second direction. 316 */ 317 private int mMarginSecondary; 318 /** 319 * How to position child in secondary direction. 320 */ 321 private int mGravity = Gravity.LEFT | Gravity.TOP; 322 /** 323 * The number of rows in the grid. 324 */ 325 private int mNumRows; 326 /** 327 * Number of rows requested, can be 0 to be determined by parent size and 328 * rowHeight. 329 */ 330 private int mNumRowsRequested = 1; 331 332 /** 333 * Tracking start/end position of each row for visible items. 334 */ 335 private StaggeredGrid.Row[] mRows; 336 337 /** 338 * Saves grid information of each view. 339 */ 340 private StaggeredGrid mGrid; 341 /** 342 * Position of first item (included) that has attached views. 343 */ 344 private int mFirstVisiblePos; 345 /** 346 * Position of last item (included) that has attached views. 347 */ 348 private int mLastVisiblePos; 349 350 /** 351 * Focus Scroll strategy. 352 */ 353 private int mFocusScrollStrategy = BaseGridView.FOCUS_SCROLL_ALIGNED; 354 /** 355 * Defines how item view is aligned in the window. 356 */ 357 private final WindowAlignment mWindowAlignment = new WindowAlignment(); 358 359 /** 360 * Defines how item view is aligned. 361 */ 362 private final ItemAlignment mItemAlignment = new ItemAlignment(); 363 364 /** 365 * Dimensions of the view, width or height depending on orientation. 366 */ 367 private int mSizePrimary; 368 369 /** 370 * Allow DPAD key to navigate out at the front of the View (where position = 0), 371 * default is false. 372 */ 373 private boolean mFocusOutFront; 374 375 /** 376 * Allow DPAD key to navigate out at the end of the view, default is false. 377 */ 378 private boolean mFocusOutEnd; 379 380 /** 381 * True if focus search is disabled. 382 */ 383 private boolean mFocusSearchDisabled; 384 385 /** 386 * Animate layout changes from a child resizing or adding/removing a child. 387 */ 388 private boolean mAnimateChildLayout = true; 389 390 /** 391 * Interpolator used to animate layout of children. 392 */ 393 private Interpolator mAnimateLayoutChildInterpolator = sDefaultAnimationChildLayoutInterpolator; 394 395 /** 396 * Duration used to animate layout of children. 397 */ 398 private long mAnimateLayoutChildDuration = DEFAULT_CHILD_ANIMATION_DURATION_MS; 399 400 public GridLayoutManager(BaseGridView baseGridView) { 401 mBaseGridView = baseGridView; 402 } 403 404 public void setOrientation(int orientation) { 405 if (orientation != HORIZONTAL && orientation != VERTICAL) { 406 if (DEBUG) Log.v(getTag(), "invalid orientation: " + orientation); 407 return; 408 } 409 410 mOrientation = orientation; 411 mWindowAlignment.setOrientation(orientation); 412 mItemAlignment.setOrientation(orientation); 413 mForceFullLayout = true; 414 } 415 416 public int getFocusScrollStrategy() { 417 return mFocusScrollStrategy; 418 } 419 420 public void setFocusScrollStrategy(int focusScrollStrategy) { 421 mFocusScrollStrategy = focusScrollStrategy; 422 } 423 424 public void setWindowAlignment(int windowAlignment) { 425 mWindowAlignment.mainAxis().setWindowAlignment(windowAlignment); 426 } 427 428 public int getWindowAlignment() { 429 return mWindowAlignment.mainAxis().getWindowAlignment(); 430 } 431 432 public void setWindowAlignmentOffset(int alignmentOffset) { 433 mWindowAlignment.mainAxis().setWindowAlignmentOffset(alignmentOffset); 434 } 435 436 public int getWindowAlignmentOffset() { 437 return mWindowAlignment.mainAxis().getWindowAlignmentOffset(); 438 } 439 440 public void setWindowAlignmentOffsetPercent(float offsetPercent) { 441 mWindowAlignment.mainAxis().setWindowAlignmentOffsetPercent(offsetPercent); 442 } 443 444 public float getWindowAlignmentOffsetPercent() { 445 return mWindowAlignment.mainAxis().getWindowAlignmentOffsetPercent(); 446 } 447 448 public void setItemAlignmentOffset(int alignmentOffset) { 449 mItemAlignment.mainAxis().setItemAlignmentOffset(alignmentOffset); 450 updateChildAlignments(); 451 } 452 453 public int getItemAlignmentOffset() { 454 return mItemAlignment.mainAxis().getItemAlignmentOffset(); 455 } 456 457 public void setItemAlignmentOffsetPercent(float offsetPercent) { 458 mItemAlignment.mainAxis().setItemAlignmentOffsetPercent(offsetPercent); 459 updateChildAlignments(); 460 } 461 462 public float getItemAlignmentOffsetPercent() { 463 return mItemAlignment.mainAxis().getItemAlignmentOffsetPercent(); 464 } 465 466 public void setItemAlignmentViewId(int viewId) { 467 mItemAlignment.mainAxis().setItemAlignmentViewId(viewId); 468 updateChildAlignments(); 469 } 470 471 public int getItemAlignmentViewId() { 472 return mItemAlignment.mainAxis().getItemAlignmentViewId(); 473 } 474 475 public void setFocusOutAllowed(boolean throughFront, boolean throughEnd) { 476 mFocusOutFront = throughFront; 477 mFocusOutEnd = throughEnd; 478 } 479 480 public void setNumRows(int numRows) { 481 if (numRows < 0) throw new IllegalArgumentException(); 482 mNumRowsRequested = numRows; 483 mForceFullLayout = true; 484 } 485 486 /** 487 * Set the row height. May be WRAP_CONTENT, or a size in pixels. 488 */ 489 public void setRowHeight(int height) { 490 if (height >= 0 || height == ViewGroup.LayoutParams.WRAP_CONTENT) { 491 mRowSizeSecondaryRequested = height; 492 } else { 493 throw new IllegalArgumentException("Invalid row height: " + height); 494 } 495 } 496 497 public void setItemMargin(int margin) { 498 mVerticalMargin = mHorizontalMargin = margin; 499 mMarginPrimary = mMarginSecondary = margin; 500 } 501 502 public void setVerticalMargin(int margin) { 503 if (mOrientation == HORIZONTAL) { 504 mMarginSecondary = mVerticalMargin = margin; 505 } else { 506 mMarginPrimary = mVerticalMargin = margin; 507 } 508 } 509 510 public void setHorizontalMargin(int margin) { 511 if (mOrientation == HORIZONTAL) { 512 mMarginPrimary = mHorizontalMargin = margin; 513 } else { 514 mMarginSecondary = mHorizontalMargin = margin; 515 } 516 } 517 518 public int getVerticalMargin() { 519 return mVerticalMargin; 520 } 521 522 public int getHorizontalMargin() { 523 return mHorizontalMargin; 524 } 525 526 public void setGravity(int gravity) { 527 mGravity = gravity; 528 } 529 530 protected boolean hasDoneFirstLayout() { 531 return mGrid != null; 532 } 533 534 public void setOnChildSelectedListener(OnChildSelectedListener listener) { 535 mChildSelectedListener = listener; 536 } 537 538 private int getPositionByView(View view) { 539 return getPositionByIndex(mBaseGridView.indexOfChild(view)); 540 } 541 542 private int getPositionByIndex(int index) { 543 if (index < 0) { 544 return NO_POSITION; 545 } 546 return mFirstVisiblePos + index; 547 } 548 549 private View getViewByPosition(int position) { 550 int index = getIndexByPosition(position); 551 if (index < 0) { 552 return null; 553 } 554 return getChildAt(index); 555 } 556 557 private int getIndexByPosition(int position) { 558 if (mFirstVisiblePos < 0 || 559 position < mFirstVisiblePos || position > mLastVisiblePos) { 560 return NO_POSITION; 561 } 562 return position - mFirstVisiblePos; 563 } 564 565 private void dispatchChildSelected() { 566 if (mChildSelectedListener == null) { 567 return; 568 } 569 570 View view = getViewByPosition(mFocusPosition); 571 572 if (mFocusPosition != NO_POSITION) { 573 mChildSelectedListener.onChildSelected(mBaseGridView, view, mFocusPosition, 574 mAdapter.getItemId(mFocusPosition)); 575 } else { 576 mChildSelectedListener.onChildSelected(mBaseGridView, null, NO_POSITION, NO_ID); 577 } 578 } 579 580 @Override 581 public boolean canScrollHorizontally() { 582 // We can scroll horizontally if we have horizontal orientation, or if 583 // we are vertical and have more than one column. 584 return mOrientation == HORIZONTAL || mNumRows > 1; 585 } 586 587 @Override 588 public boolean canScrollVertically() { 589 // We can scroll vertically if we have vertical orientation, or if we 590 // are horizontal and have more than one row. 591 return mOrientation == VERTICAL || mNumRows > 1; 592 } 593 594 @Override 595 public RecyclerView.LayoutParams generateDefaultLayoutParams() { 596 return new LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, 597 ViewGroup.LayoutParams.WRAP_CONTENT); 598 } 599 600 @Override 601 public RecyclerView.LayoutParams generateLayoutParams(Context context, AttributeSet attrs) { 602 return new LayoutParams(context, attrs); 603 } 604 605 @Override 606 public RecyclerView.LayoutParams generateLayoutParams(ViewGroup.LayoutParams lp) { 607 if (lp instanceof LayoutParams) { 608 return new LayoutParams((LayoutParams) lp); 609 } else if (lp instanceof RecyclerView.LayoutParams) { 610 return new LayoutParams((RecyclerView.LayoutParams) lp); 611 } else if (lp instanceof MarginLayoutParams) { 612 return new LayoutParams((MarginLayoutParams) lp); 613 } else { 614 return new LayoutParams(lp); 615 } 616 } 617 618 protected View getViewForPosition(int position) { 619 View v = mRecycler.getViewForPosition(mAdapter, position); 620 if (v != null) { 621 ((LayoutParams) v.getLayoutParams()).onViewAttached(); 622 } 623 return v; 624 } 625 626 final int getOpticalLeft(View v) { 627 return ((LayoutParams) v.getLayoutParams()).getOpticalLeft(v); 628 } 629 630 final int getOpticalRight(View v) { 631 return ((LayoutParams) v.getLayoutParams()).getOpticalRight(v); 632 } 633 634 final int getOpticalTop(View v) { 635 return ((LayoutParams) v.getLayoutParams()).getOpticalTop(v); 636 } 637 638 final int getOpticalBottom(View v) { 639 return ((LayoutParams) v.getLayoutParams()).getOpticalBottom(v); 640 } 641 642 private int getViewMin(View v) { 643 return (mOrientation == HORIZONTAL) ? getOpticalLeft(v) : getOpticalTop(v); 644 } 645 646 private int getViewMax(View v) { 647 return (mOrientation == HORIZONTAL) ? getOpticalRight(v) : getOpticalBottom(v); 648 } 649 650 private int getViewCenter(View view) { 651 return (mOrientation == HORIZONTAL) ? getViewCenterX(view) : getViewCenterY(view); 652 } 653 654 private int getViewCenterSecondary(View view) { 655 return (mOrientation == HORIZONTAL) ? getViewCenterY(view) : getViewCenterX(view); 656 } 657 658 private int getViewCenterX(View v) { 659 LayoutParams p = (LayoutParams) v.getLayoutParams(); 660 return p.getOpticalLeft(v) + p.getAlignX(); 661 } 662 663 private int getViewCenterY(View v) { 664 LayoutParams p = (LayoutParams) v.getLayoutParams(); 665 return p.getOpticalTop(v) + p.getAlignY(); 666 } 667 668 /** 669 * Re-initialize data structures for a data change or handling invisible 670 * selection. The method tries its best to preserve position information so 671 * that staggered grid looks same before and after re-initialize. 672 * @param focusPosition The initial focusPosition that we would like to 673 * focus on. 674 * @return Actual position that can be focused on. 675 */ 676 private int init(RecyclerView.Adapter adapter, RecyclerView.Recycler recycler, 677 int focusPosition) { 678 679 final int newItemCount = adapter.getItemCount(); 680 681 if (focusPosition == NO_POSITION && newItemCount > 0) { 682 // if focus position is never set before, initialize it to 0 683 focusPosition = 0; 684 } 685 // If adapter has changed then caches are invalid; otherwise, 686 // we try to maintain each row's position if number of rows keeps the same 687 // and existing mGrid contains the focusPosition. 688 if (mRows != null && mNumRows == mRows.length && 689 mGrid != null && mGrid.getSize() > 0 && focusPosition >= 0 && 690 focusPosition >= mGrid.getFirstIndex() && 691 focusPosition <= mGrid.getLastIndex()) { 692 // strip mGrid to a subset (like a column) that contains focusPosition 693 mGrid.stripDownTo(focusPosition); 694 // make sure that remaining items do not exceed new adapter size 695 int firstIndex = mGrid.getFirstIndex(); 696 int lastIndex = mGrid.getLastIndex(); 697 if (DEBUG) { 698 Log .v(getTag(), "mGrid firstIndex " + firstIndex + " lastIndex " + lastIndex); 699 } 700 for (int i = lastIndex; i >=firstIndex; i--) { 701 if (i >= newItemCount) { 702 mGrid.removeLast(); 703 } 704 } 705 if (mGrid.getSize() == 0) { 706 focusPosition = newItemCount - 1; 707 // initialize row start locations 708 for (int i = 0; i < mNumRows; i++) { 709 mRows[i].low = 0; 710 mRows[i].high = 0; 711 } 712 if (DEBUG) Log.v(getTag(), "mGrid zero size"); 713 } else { 714 // initialize row start locations 715 for (int i = 0; i < mNumRows; i++) { 716 mRows[i].low = Integer.MAX_VALUE; 717 mRows[i].high = Integer.MIN_VALUE; 718 } 719 firstIndex = mGrid.getFirstIndex(); 720 lastIndex = mGrid.getLastIndex(); 721 if (focusPosition > lastIndex) { 722 focusPosition = mGrid.getLastIndex(); 723 } 724 if (DEBUG) { 725 Log.v(getTag(), "mGrid firstIndex " + firstIndex + " lastIndex " 726 + lastIndex + " focusPosition " + focusPosition); 727 } 728 // fill rows with minimal view positions of the subset 729 for (int i = firstIndex; i <= lastIndex; i++) { 730 View v = getViewByPosition(i); 731 if (v == null) { 732 continue; 733 } 734 int row = mGrid.getLocation(i).row; 735 int low = getViewMin(v) + mScrollOffsetPrimary; 736 if (low < mRows[row].low) { 737 mRows[row].low = mRows[row].high = low; 738 } 739 } 740 // fill other rows that does not include the subset using first item 741 int firstItemRowPosition = mRows[mGrid.getLocation(firstIndex).row].low; 742 if (firstItemRowPosition == Integer.MAX_VALUE) { 743 firstItemRowPosition = 0; 744 } 745 for (int i = 0; i < mNumRows; i++) { 746 if (mRows[i].low == Integer.MAX_VALUE) { 747 mRows[i].low = mRows[i].high = firstItemRowPosition; 748 } 749 } 750 } 751 752 // Same adapter, we can reuse any attached views 753 detachAndScrapAttachedViews(recycler); 754 755 } else { 756 // otherwise recreate data structure 757 mRows = new StaggeredGrid.Row[mNumRows]; 758 mRowSizeSecondary = new int[mNumRows]; 759 760 for (int i = 0; i < mNumRows; i++) { 761 mRows[i] = new StaggeredGrid.Row(); 762 } 763 mGrid = new StaggeredGridDefault(); 764 if (newItemCount == 0) { 765 focusPosition = NO_POSITION; 766 } else if (focusPosition >= newItemCount) { 767 focusPosition = newItemCount - 1; 768 } 769 770 // Adapter may have changed so remove all attached views permanently 771 removeAllViews(); 772 773 mScrollOffsetPrimary = 0; 774 mScrollOffsetSecondary = 0; 775 mWindowAlignment.reset(); 776 } 777 778 mAdapter = adapter; 779 mRecycler = recycler; 780 mGrid.setProvider(mGridProvider); 781 // mGrid share the same Row array information 782 mGrid.setRows(mRows); 783 mFirstVisiblePos = mLastVisiblePos = NO_POSITION; 784 785 initScrollController(); 786 updateScrollSecondAxis(); 787 788 return focusPosition; 789 } 790 791 private int getRowSizeSecondary(int rowIndex) { 792 if (mFixedRowSizeSecondary != 0) { 793 return mFixedRowSizeSecondary; 794 } 795 if (mRowSizeSecondary == null) { 796 return 0; 797 } 798 return mRowSizeSecondary[rowIndex]; 799 } 800 801 private int getRowStartSecondary(int rowIndex) { 802 int start = 0; 803 for (int i = 0; i < rowIndex; i++) { 804 start += getRowSizeSecondary(i) + mMarginSecondary; 805 } 806 return start; 807 } 808 809 private int getSizeSecondary() { 810 return getRowStartSecondary(mNumRows - 1) + getRowSizeSecondary(mNumRows - 1); 811 } 812 813 private boolean processRowSizeSecondary(boolean measure) { 814 if (mFixedRowSizeSecondary != 0) { 815 return false; 816 } 817 818 List<Integer>[] rows = mGrid.getItemPositionsInRows(mFirstVisiblePos, mLastVisiblePos); 819 boolean changed = false; 820 821 for (int rowIndex = 0; rowIndex < mNumRows; rowIndex++) { 822 int rowSize = 0; 823 824 final int rowItemCount = rows[rowIndex].size(); 825 if (DEBUG) Log.v(getTag(), "processRowSizeSecondary row " + rowIndex + 826 " rowItemCount " + rowItemCount); 827 828 for (int i = 0; i < rowItemCount; i++) { 829 final int position = rows[rowIndex].get(i); 830 final View view = getViewByPosition(position); 831 if (measure && view.isLayoutRequested()) { 832 measureChild(view, rowIndex); 833 } 834 // If this view isn't visible, we ignore it. 835 if (getOpticalRight(view) < 0 || getOpticalLeft(view) > getWidth() || 836 getOpticalBottom(view) < 0 || getOpticalTop(view) > getHeight()) { 837 continue; 838 } 839 final int secondarySize = mOrientation == HORIZONTAL ? 840 view.getMeasuredHeight() : view.getMeasuredWidth(); 841 if (secondarySize > rowSize) { 842 rowSize = secondarySize; 843 } 844 } 845 if (DEBUG) Log.v(getTag(), "row " + rowIndex + " rowItemCount " + rowItemCount + 846 " rowSize " + rowSize); 847 848 if (mRowSizeSecondary[rowIndex] != rowSize) { 849 if (DEBUG) Log.v(getTag(), "row size secondary changed: " + mRowSizeSecondary[rowIndex] + 850 ", " + rowSize); 851 852 mRowSizeSecondary[rowIndex] = rowSize; 853 changed = true; 854 } 855 } 856 857 return changed; 858 } 859 860 /** 861 * Checks if we need to update row secondary sizes. 862 */ 863 private void updateRowSecondarySizeRefresh() { 864 mRowSecondarySizeRefresh = processRowSizeSecondary(false); 865 if (mRowSecondarySizeRefresh) { 866 if (DEBUG) Log.v(getTag(), "mRowSecondarySizeRefresh now set"); 867 forceRequestLayout(); 868 } 869 } 870 871 private void forceRequestLayout() { 872 if (DEBUG) Log.v(getTag(), "forceRequestLayout"); 873 // RecyclerView prevents us from requesting layout in many cases 874 // (during layout, during scroll, etc.) 875 // For secondary row size wrap_content support we currently need a 876 // second layout pass to update the measured size after having measured 877 // and added child views in layoutChildren. 878 // Force the second layout by posting a delayed runnable. 879 // TODO: investigate allowing a second layout pass, 880 // or move child add/measure logic to the measure phase. 881 mBaseGridView.getHandler().post(new Runnable() { 882 @Override 883 public void run() { 884 if (DEBUG) Log.v(getTag(), "request Layout from runnable"); 885 requestLayout(); 886 } 887 }); 888 } 889 890 @Override 891 public void onMeasure(int widthSpec, int heightSpec) { 892 int sizePrimary, sizeSecondary, modeSecondary, paddingSecondary; 893 int measuredSizeSecondary; 894 if (mOrientation == HORIZONTAL) { 895 sizePrimary = MeasureSpec.getSize(widthSpec); 896 sizeSecondary = MeasureSpec.getSize(heightSpec); 897 modeSecondary = MeasureSpec.getMode(heightSpec); 898 paddingSecondary = getPaddingTop() + getPaddingBottom(); 899 } else { 900 sizeSecondary = MeasureSpec.getSize(widthSpec); 901 sizePrimary = MeasureSpec.getSize(heightSpec); 902 modeSecondary = MeasureSpec.getMode(widthSpec); 903 paddingSecondary = getPaddingLeft() + getPaddingRight(); 904 } 905 if (DEBUG) Log.v(getTag(), "onMeasure widthSpec " + Integer.toHexString(widthSpec) + 906 " heightSpec " + Integer.toHexString(heightSpec) + 907 " modeSecondary " + Integer.toHexString(modeSecondary) + 908 " sizeSecondary " + sizeSecondary + " " + this); 909 910 mMaxSizeSecondary = sizeSecondary; 911 912 if (mRowSizeSecondaryRequested == ViewGroup.LayoutParams.WRAP_CONTENT) { 913 mNumRows = mNumRowsRequested == 0 ? 1 : mNumRowsRequested; 914 mFixedRowSizeSecondary = 0; 915 916 // Measure all current children and update cached row heights 917 if (mGrid != null) { 918 processRowSizeSecondary(true); 919 } 920 921 switch (modeSecondary) { 922 case MeasureSpec.UNSPECIFIED: 923 measuredSizeSecondary = getSizeSecondary() + paddingSecondary; 924 break; 925 case MeasureSpec.AT_MOST: 926 measuredSizeSecondary = Math.min(getSizeSecondary() + paddingSecondary, 927 mMaxSizeSecondary); 928 break; 929 case MeasureSpec.EXACTLY: 930 measuredSizeSecondary = mMaxSizeSecondary; 931 break; 932 default: 933 throw new IllegalStateException("wrong spec"); 934 } 935 936 } else { 937 switch (modeSecondary) { 938 case MeasureSpec.UNSPECIFIED: 939 if (mRowSizeSecondaryRequested == 0) { 940 if (mOrientation == HORIZONTAL) { 941 throw new IllegalStateException("Must specify rowHeight or view height"); 942 } else { 943 throw new IllegalStateException("Must specify columnWidth or view width"); 944 } 945 } 946 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 947 mNumRows = mNumRowsRequested == 0 ? 1 : mNumRowsRequested; 948 measuredSizeSecondary = mFixedRowSizeSecondary * mNumRows + mMarginSecondary 949 * (mNumRows - 1) + paddingSecondary; 950 break; 951 case MeasureSpec.AT_MOST: 952 case MeasureSpec.EXACTLY: 953 if (mNumRowsRequested == 0 && mRowSizeSecondaryRequested == 0) { 954 mNumRows = 1; 955 mFixedRowSizeSecondary = sizeSecondary - paddingSecondary; 956 } else if (mNumRowsRequested == 0) { 957 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 958 mNumRows = (sizeSecondary + mMarginSecondary) 959 / (mRowSizeSecondaryRequested + mMarginSecondary); 960 } else if (mRowSizeSecondaryRequested == 0) { 961 mNumRows = mNumRowsRequested; 962 mFixedRowSizeSecondary = (sizeSecondary - paddingSecondary - mMarginSecondary 963 * (mNumRows - 1)) / mNumRows; 964 } else { 965 mNumRows = mNumRowsRequested; 966 mFixedRowSizeSecondary = mRowSizeSecondaryRequested; 967 } 968 measuredSizeSecondary = sizeSecondary; 969 if (modeSecondary == MeasureSpec.AT_MOST) { 970 int childrenSize = mFixedRowSizeSecondary * mNumRows + mMarginSecondary 971 * (mNumRows - 1) + paddingSecondary; 972 if (childrenSize < measuredSizeSecondary) { 973 measuredSizeSecondary = childrenSize; 974 } 975 } 976 break; 977 default: 978 throw new IllegalStateException("wrong spec"); 979 } 980 } 981 if (mOrientation == HORIZONTAL) { 982 setMeasuredDimension(sizePrimary, measuredSizeSecondary); 983 } else { 984 setMeasuredDimension(measuredSizeSecondary, sizePrimary); 985 } 986 if (DEBUG) { 987 Log.v(getTag(), "onMeasure sizePrimary " + sizePrimary + 988 " measuredSizeSecondary " + measuredSizeSecondary + 989 " mFixedRowSizeSecondary " + mFixedRowSizeSecondary + 990 " mNumRows " + mNumRows); 991 } 992 } 993 994 private void measureChild(View child, int rowIndex) { 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 mAdapter.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 if (append) { 1044 addView(v); 1045 } else { 1046 addView(v, 0); 1047 } 1048 1049 measureChild(v, rowIndex); 1050 1051 int length = mOrientation == HORIZONTAL ? v.getMeasuredWidth() : v.getMeasuredHeight(); 1052 int start, end; 1053 if (append) { 1054 start = mRows[rowIndex].high; 1055 if (start != mRows[rowIndex].low) { 1056 // if there are existing item in the row, add margin between 1057 start += mMarginPrimary; 1058 } else { 1059 final int lastRow = mRows.length - 1; 1060 if (lastRow != rowIndex && mRows[lastRow].high != mRows[lastRow].low) { 1061 // if there are existing item in the last row, insert 1062 // the new item after the last item of last row. 1063 start = mRows[lastRow].high + mMarginPrimary; 1064 } 1065 } 1066 end = start + length; 1067 mRows[rowIndex].high = end; 1068 } else { 1069 end = mRows[rowIndex].low; 1070 if (end != mRows[rowIndex].high) { 1071 end -= mMarginPrimary; 1072 } else if (0 != rowIndex && mRows[0].high != mRows[0].low) { 1073 // if there are existing item in the first row, insert 1074 // the new item before the first item of first row. 1075 end = mRows[0].low - mMarginPrimary; 1076 } 1077 start = end - length; 1078 mRows[rowIndex].low = start; 1079 } 1080 if (mFirstVisiblePos < 0) { 1081 mFirstVisiblePos = mLastVisiblePos = index; 1082 } else { 1083 if (append) { 1084 mLastVisiblePos++; 1085 } else { 1086 mFirstVisiblePos--; 1087 } 1088 } 1089 if (DEBUG) Log.v(getTag(), "start " + start + " end " + end); 1090 int startSecondary = getRowStartSecondary(rowIndex) - mScrollOffsetSecondary; 1091 layoutChild(rowIndex, v, start - mScrollOffsetPrimary, end - mScrollOffsetPrimary, 1092 startSecondary); 1093 if (DEBUG) { 1094 Log.d(getTag(), "addView " + index + " " + v); 1095 } 1096 updateScrollMin(); 1097 updateScrollMax(); 1098 } 1099 }; 1100 1101 private void layoutChild(int rowIndex, View v, int start, int end, int startSecondary) { 1102 int sizeSecondary = mOrientation == HORIZONTAL ? v.getMeasuredHeight() 1103 : v.getMeasuredWidth(); 1104 if (mFixedRowSizeSecondary > 0) { 1105 sizeSecondary = Math.min(sizeSecondary, mFixedRowSizeSecondary); 1106 } 1107 final int verticalGravity = mGravity & Gravity.VERTICAL_GRAVITY_MASK; 1108 final int horizontalGravity = mGravity & Gravity.HORIZONTAL_GRAVITY_MASK; 1109 if (mOrientation == HORIZONTAL && verticalGravity == Gravity.TOP 1110 || mOrientation == VERTICAL && horizontalGravity == Gravity.LEFT) { 1111 // do nothing 1112 } else if (mOrientation == HORIZONTAL && verticalGravity == Gravity.BOTTOM 1113 || mOrientation == VERTICAL && horizontalGravity == Gravity.RIGHT) { 1114 startSecondary += getRowSizeSecondary(rowIndex) - sizeSecondary; 1115 } else if (mOrientation == HORIZONTAL && verticalGravity == Gravity.CENTER_VERTICAL 1116 || mOrientation == VERTICAL && horizontalGravity == Gravity.CENTER_HORIZONTAL) { 1117 startSecondary += (getRowSizeSecondary(rowIndex) - sizeSecondary) / 2; 1118 } 1119 int left, top, right, bottom; 1120 if (mOrientation == HORIZONTAL) { 1121 left = start; 1122 top = startSecondary; 1123 right = end; 1124 bottom = startSecondary + sizeSecondary; 1125 } else { 1126 top = start; 1127 left = startSecondary; 1128 bottom = end; 1129 right = startSecondary + sizeSecondary; 1130 } 1131 v.layout(left, top, right, bottom); 1132 updateChildOpticalInsets(v, left, top, right, bottom); 1133 updateChildAlignments(v); 1134 } 1135 1136 private void updateChildOpticalInsets(View v, int left, int top, int right, int bottom) { 1137 LayoutParams p = (LayoutParams) v.getLayoutParams(); 1138 p.setOpticalInsets(left - v.getLeft(), top - v.getTop(), 1139 v.getRight() - right, v.getBottom() - bottom); 1140 } 1141 1142 private void updateChildAlignments(View v) { 1143 LayoutParams p = (LayoutParams) v.getLayoutParams(); 1144 p.setAlignX(mItemAlignment.horizontal.getAlignmentPosition(v)); 1145 p.setAlignY(mItemAlignment.vertical.getAlignmentPosition(v)); 1146 } 1147 1148 private void updateChildAlignments() { 1149 for (int i = 0, c = getChildCount(); i < c; i++) { 1150 updateChildAlignments(getChildAt(i)); 1151 } 1152 } 1153 1154 private boolean needsAppendVisibleItem() { 1155 if (mLastVisiblePos < mFocusPosition) { 1156 return true; 1157 } 1158 int right = mScrollOffsetPrimary + mSizePrimary; 1159 for (int i = 0; i < mNumRows; i++) { 1160 if (mRows[i].low == mRows[i].high) { 1161 if (mRows[i].high < right) { 1162 return true; 1163 } 1164 } else if (mRows[i].high < right - mMarginPrimary) { 1165 return true; 1166 } 1167 } 1168 return false; 1169 } 1170 1171 private boolean needsPrependVisibleItem() { 1172 if (mFirstVisiblePos > mFocusPosition) { 1173 return true; 1174 } 1175 for (int i = 0; i < mNumRows; i++) { 1176 if (mRows[i].low == mRows[i].high) { 1177 if (mRows[i].low > mScrollOffsetPrimary) { 1178 return true; 1179 } 1180 } else if (mRows[i].low - mMarginPrimary > mScrollOffsetPrimary) { 1181 return true; 1182 } 1183 } 1184 return false; 1185 } 1186 1187 // Append one column if possible and return true if reach end. 1188 private boolean appendOneVisibleItem() { 1189 while (true) { 1190 if (mLastVisiblePos != NO_POSITION && mLastVisiblePos < mAdapter.getItemCount() -1 && 1191 mLastVisiblePos < mGrid.getLastIndex()) { 1192 // append invisible view of saved location till last row 1193 final int index = mLastVisiblePos + 1; 1194 final int row = mGrid.getLocation(index).row; 1195 mGridProvider.createItem(index, row, true); 1196 if (row == mNumRows - 1) { 1197 return false; 1198 } 1199 } else if ((mLastVisiblePos == NO_POSITION && mAdapter.getItemCount() > 0) || 1200 (mLastVisiblePos != NO_POSITION && 1201 mLastVisiblePos < mAdapter.getItemCount() - 1)) { 1202 mGrid.appendItems(mScrollOffsetPrimary + mSizePrimary); 1203 return false; 1204 } else { 1205 return true; 1206 } 1207 } 1208 } 1209 1210 private void appendVisibleItems() { 1211 while (needsAppendVisibleItem()) { 1212 if (appendOneVisibleItem()) { 1213 break; 1214 } 1215 } 1216 } 1217 1218 // Prepend one column if possible and return true if reach end. 1219 private boolean prependOneVisibleItem() { 1220 while (true) { 1221 if (mFirstVisiblePos > 0) { 1222 if (mFirstVisiblePos > mGrid.getFirstIndex()) { 1223 // prepend invisible view of saved location till first row 1224 final int index = mFirstVisiblePos - 1; 1225 final int row = mGrid.getLocation(index).row; 1226 mGridProvider.createItem(index, row, false); 1227 if (row == 0) { 1228 return false; 1229 } 1230 } else { 1231 mGrid.prependItems(mScrollOffsetPrimary); 1232 return false; 1233 } 1234 } else { 1235 return true; 1236 } 1237 } 1238 } 1239 1240 private void prependVisibleItems() { 1241 while (needsPrependVisibleItem()) { 1242 if (prependOneVisibleItem()) { 1243 break; 1244 } 1245 } 1246 } 1247 1248 private void removeChildAt(int position) { 1249 View v = getViewByPosition(position); 1250 if (v != null) { 1251 if (DEBUG) { 1252 Log.d(getTag(), "removeAndRecycleViewAt " + position); 1253 } 1254 ((LayoutParams) v.getLayoutParams()).onViewDetached(); 1255 removeAndRecycleViewAt(getIndexByPosition(position), mRecycler); 1256 } 1257 } 1258 1259 private void removeInvisibleViewsAtEnd() { 1260 boolean update = false; 1261 while(mLastVisiblePos > mFirstVisiblePos && mLastVisiblePos > mFocusPosition) { 1262 View view = getViewByPosition(mLastVisiblePos); 1263 if (getViewMin(view) > mSizePrimary) { 1264 removeChildAt(mLastVisiblePos); 1265 mLastVisiblePos--; 1266 update = true; 1267 } else { 1268 break; 1269 } 1270 } 1271 if (update) { 1272 updateRowsMinMax(); 1273 } 1274 } 1275 1276 private void removeInvisibleViewsAtFront() { 1277 boolean update = false; 1278 while(mLastVisiblePos > mFirstVisiblePos && mFirstVisiblePos < mFocusPosition) { 1279 View view = getViewByPosition(mFirstVisiblePos); 1280 if (getViewMax(view) < 0) { 1281 removeChildAt(mFirstVisiblePos); 1282 mFirstVisiblePos++; 1283 update = true; 1284 } else { 1285 break; 1286 } 1287 } 1288 if (update) { 1289 updateRowsMinMax(); 1290 } 1291 } 1292 1293 private void updateRowsMinMax() { 1294 if (mFirstVisiblePos < 0) { 1295 return; 1296 } 1297 for (int i = 0; i < mNumRows; i++) { 1298 mRows[i].low = Integer.MAX_VALUE; 1299 mRows[i].high = Integer.MIN_VALUE; 1300 } 1301 for (int i = mFirstVisiblePos; i <= mLastVisiblePos; i++) { 1302 View view = getViewByPosition(i); 1303 int row = mGrid.getLocation(i).row; 1304 int low = getViewMin(view) + mScrollOffsetPrimary; 1305 if (low < mRows[row].low) { 1306 mRows[row].low = low; 1307 } 1308 int high = getViewMax(view) + mScrollOffsetPrimary; 1309 if (high > mRows[row].high) { 1310 mRows[row].high = high; 1311 } 1312 } 1313 } 1314 1315 /** 1316 * Relayout and re-positioning child for a possible new size and/or a new 1317 * start. 1318 * 1319 * @param view View to measure and layout. 1320 * @param start New start of the view or Integer.MIN_VALUE for not change. 1321 * @return New start of next view. 1322 */ 1323 private int updateChildView(int rowIndex, View view, int start) { 1324 if (start == Integer.MIN_VALUE) { 1325 start = getViewMin(view); 1326 } 1327 int end; 1328 if (mOrientation == HORIZONTAL) { 1329 if (view.isLayoutRequested()) { 1330 measureChild(view, rowIndex); 1331 } 1332 end = start + view.getMeasuredWidth(); 1333 } else { 1334 if (view.isLayoutRequested()) { 1335 measureChild(view, rowIndex); 1336 } 1337 end = start + view.getMeasuredHeight(); 1338 } 1339 1340 final int startSecondary = getRowStartSecondary(rowIndex) - mScrollOffsetSecondary; 1341 layoutChild(rowIndex, view, start, end, startSecondary); 1342 return end + mMarginPrimary; 1343 } 1344 1345 // Fast layout when there is no structure change, adapter change, etc. 1346 protected void fastRelayout() { 1347 initScrollController(); 1348 1349 List<Integer>[] rows = mGrid.getItemPositionsInRows(mFirstVisiblePos, mLastVisiblePos); 1350 1351 // relayout and repositioning views on each row 1352 for (int i = 0; i < mNumRows; i++) { 1353 List<Integer> row = rows[i]; 1354 int start = Integer.MIN_VALUE; 1355 for (int j = 0, size = row.size(); j < size; j++) { 1356 int position = row.get(j); 1357 start = updateChildView(i, getViewByPosition(position), start); 1358 } 1359 } 1360 1361 appendVisibleItems(); 1362 prependVisibleItems(); 1363 1364 updateRowsMinMax(); 1365 updateScrollMin(); 1366 updateScrollMax(); 1367 updateScrollSecondAxis(); 1368 1369 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED) { 1370 View focusView = getViewByPosition(mFocusPosition == NO_POSITION ? 0 : mFocusPosition); 1371 scrollToView(focusView, false); 1372 } 1373 } 1374 1375 // Lays out items based on the current scroll position 1376 @Override 1377 public void onLayoutChildren(RecyclerView.Adapter adapter, RecyclerView.Recycler recycler, 1378 boolean structureChanged, RecyclerView.State state) { 1379 if (DEBUG) { 1380 Log.v(getTag(), "layoutChildren start numRows " + mNumRows + " mScrollOffsetSecondary " 1381 + mScrollOffsetSecondary + " mScrollOffsetPrimary " + mScrollOffsetPrimary 1382 + " structureChanged " + structureChanged 1383 + " mForceFullLayout " + mForceFullLayout); 1384 Log.v(getTag(), "width " + getWidth() + " height " + getHeight()); 1385 } 1386 1387 if (mNumRows == 0) { 1388 // haven't done measure yet 1389 return; 1390 } 1391 final int itemCount = adapter.getItemCount(); 1392 if (itemCount < 0) { 1393 return; 1394 } 1395 1396 mInLayout = true; 1397 1398 // Track the old focus view so we can adjust our system scroll position 1399 // so that any scroll animations happening now will remain valid. 1400 int delta = 0, deltaSecondary = 0; 1401 if (mFocusPosition != NO_POSITION 1402 && mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED) { 1403 View focusView = getViewByPosition(mFocusPosition); 1404 if (focusView != null) { 1405 delta = mWindowAlignment.mainAxis().getSystemScrollPos( 1406 getViewCenter(focusView) + mScrollOffsetPrimary) - mScrollOffsetPrimary; 1407 deltaSecondary = 1408 mWindowAlignment.secondAxis().getSystemScrollPos( 1409 getViewCenterSecondary(focusView) + mScrollOffsetSecondary) 1410 - mScrollOffsetSecondary; 1411 } 1412 } 1413 1414 boolean hasDoneFirstLayout = hasDoneFirstLayout(); 1415 if (!structureChanged && !mForceFullLayout && hasDoneFirstLayout) { 1416 fastRelayout(); 1417 } else { 1418 boolean hadFocus = mBaseGridView.hasFocus(); 1419 1420 int newFocusPosition = init(adapter, recycler, mFocusPosition); 1421 if (DEBUG) { 1422 Log.v(getTag(), "mFocusPosition " + mFocusPosition + " newFocusPosition " 1423 + newFocusPosition); 1424 } 1425 1426 // depending on result of init(), either recreating everything 1427 // or try to reuse the row start positions near mFocusPosition 1428 if (mGrid.getSize() == 0) { 1429 // this is a fresh creating all items, starting from 1430 // mFocusPosition with a estimated row index. 1431 mGrid.setStart(newFocusPosition, StaggeredGrid.START_DEFAULT); 1432 1433 // Can't track the old focus view 1434 delta = deltaSecondary = 0; 1435 1436 } else { 1437 // mGrid remembers Locations for the column that 1438 // contains mFocusePosition and also mRows remembers start 1439 // positions of each row. 1440 // Manually re-create child views for that column 1441 int firstIndex = mGrid.getFirstIndex(); 1442 int lastIndex = mGrid.getLastIndex(); 1443 for (int i = firstIndex; i <= lastIndex; i++) { 1444 mGridProvider.createItem(i, mGrid.getLocation(i).row, true); 1445 } 1446 } 1447 // add visible views at end until reach the end of window 1448 appendVisibleItems(); 1449 // add visible views at front until reach the start of window 1450 prependVisibleItems(); 1451 // multiple rounds: scrollToView of first round may drag first/last child into 1452 // "visible window" and we update scrollMin/scrollMax then run second scrollToView 1453 int oldFirstVisible; 1454 int oldLastVisible; 1455 do { 1456 oldFirstVisible = mFirstVisiblePos; 1457 oldLastVisible = mLastVisiblePos; 1458 View focusView = getViewByPosition(newFocusPosition); 1459 // we need force to initialize the child view's position 1460 scrollToView(focusView, false); 1461 if (focusView != null && hadFocus) { 1462 focusView.requestFocus(); 1463 } 1464 appendVisibleItems(); 1465 prependVisibleItems(); 1466 removeInvisibleViewsAtFront(); 1467 removeInvisibleViewsAtEnd(); 1468 } while (mFirstVisiblePos != oldFirstVisible || mLastVisiblePos != oldLastVisible); 1469 } 1470 mForceFullLayout = false; 1471 1472 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED) { 1473 scrollDirectionPrimary(-delta); 1474 scrollDirectionSecondary(-deltaSecondary); 1475 } 1476 appendVisibleItems(); 1477 prependVisibleItems(); 1478 removeInvisibleViewsAtFront(); 1479 removeInvisibleViewsAtEnd(); 1480 1481 if (DEBUG) { 1482 StringWriter sw = new StringWriter(); 1483 PrintWriter pw = new PrintWriter(sw); 1484 mGrid.debugPrint(pw); 1485 Log.d(getTag(), sw.toString()); 1486 } 1487 1488 removeAndRecycleScrap(recycler); 1489 attemptAnimateLayoutChild(); 1490 1491 if (mRowSecondarySizeRefresh) { 1492 mRowSecondarySizeRefresh = false; 1493 } else { 1494 updateRowSecondarySizeRefresh(); 1495 } 1496 1497 if (!hasDoneFirstLayout) { 1498 dispatchChildSelected(); 1499 } 1500 mInLayout = false; 1501 if (DEBUG) Log.v(getTag(), "layoutChildren end"); 1502 } 1503 1504 private void offsetChildrenSecondary(int increment) { 1505 final int childCount = getChildCount(); 1506 if (mOrientation == HORIZONTAL) { 1507 for (int i = 0; i < childCount; i++) { 1508 getChildAt(i).offsetTopAndBottom(increment); 1509 } 1510 } else { 1511 for (int i = 0; i < childCount; i++) { 1512 getChildAt(i).offsetLeftAndRight(increment); 1513 } 1514 } 1515 mScrollOffsetSecondary -= increment; 1516 } 1517 1518 private void offsetChildrenPrimary(int increment) { 1519 final int childCount = getChildCount(); 1520 if (mOrientation == VERTICAL) { 1521 for (int i = 0; i < childCount; i++) { 1522 getChildAt(i).offsetTopAndBottom(increment); 1523 } 1524 } else { 1525 for (int i = 0; i < childCount; i++) { 1526 getChildAt(i).offsetLeftAndRight(increment); 1527 } 1528 } 1529 mScrollOffsetPrimary -= increment; 1530 } 1531 1532 @Override 1533 public int scrollHorizontallyBy(int dx, Adapter adapter, Recycler recycler, 1534 RecyclerView.State state) { 1535 if (DEBUG) Log.v(TAG, "scrollHorizontallyBy " + dx); 1536 1537 if (mOrientation == HORIZONTAL) { 1538 return scrollDirectionPrimary(dx); 1539 } else { 1540 return scrollDirectionSecondary(dx); 1541 } 1542 } 1543 1544 @Override 1545 public int scrollVerticallyBy(int dy, Adapter adapter, Recycler recycler, 1546 RecyclerView.State state) { 1547 if (DEBUG) Log.v(TAG, "scrollVerticallyBy " + dy); 1548 if (mOrientation == VERTICAL) { 1549 return scrollDirectionPrimary(dy); 1550 } else { 1551 return scrollDirectionSecondary(dy); 1552 } 1553 } 1554 1555 // scroll in main direction may add/prune views 1556 private int scrollDirectionPrimary(int da) { 1557 offsetChildrenPrimary(-da); 1558 if (mInLayout) { 1559 return da; 1560 } 1561 1562 int childCount = getChildCount(); 1563 boolean updated; 1564 1565 if (da > 0) { 1566 appendVisibleItems(); 1567 } else if (da < 0) { 1568 prependVisibleItems(); 1569 } 1570 updated = getChildCount() > childCount; 1571 childCount = getChildCount(); 1572 1573 if (da > 0) { 1574 removeInvisibleViewsAtFront(); 1575 } else if (da < 0) { 1576 removeInvisibleViewsAtEnd(); 1577 } 1578 updated |= getChildCount() < childCount; 1579 1580 attemptAnimateLayoutChild(); 1581 if (updated) { 1582 updateRowSecondarySizeRefresh(); 1583 } 1584 1585 mBaseGridView.invalidate(); 1586 return da; 1587 } 1588 1589 // scroll in second direction will not add/prune views 1590 private int scrollDirectionSecondary(int dy) { 1591 offsetChildrenSecondary(-dy); 1592 mBaseGridView.invalidate(); 1593 return dy; 1594 } 1595 1596 private void updateScrollMax() { 1597 if (mLastVisiblePos >= 0 && mLastVisiblePos == mAdapter.getItemCount() - 1) { 1598 int maxEdge = Integer.MIN_VALUE; 1599 for (int i = 0; i < mRows.length; i++) { 1600 if (mRows[i].high > maxEdge) { 1601 maxEdge = mRows[i].high; 1602 } 1603 } 1604 mWindowAlignment.mainAxis().setMaxEdge(maxEdge); 1605 if (DEBUG) Log.v(getTag(), "updating scroll maxEdge to " + maxEdge); 1606 } 1607 } 1608 1609 private void updateScrollMin() { 1610 if (mFirstVisiblePos == 0) { 1611 int minEdge = Integer.MAX_VALUE; 1612 for (int i = 0; i < mRows.length; i++) { 1613 if (mRows[i].low < minEdge) { 1614 minEdge = mRows[i].low; 1615 } 1616 } 1617 mWindowAlignment.mainAxis().setMinEdge(minEdge); 1618 if (DEBUG) Log.v(getTag(), "updating scroll minEdge to " + minEdge); 1619 } 1620 } 1621 1622 private void updateScrollSecondAxis() { 1623 mWindowAlignment.secondAxis().setMinEdge(0); 1624 mWindowAlignment.secondAxis().setMaxEdge(getSizeSecondary()); 1625 } 1626 1627 private void initScrollController() { 1628 mWindowAlignment.horizontal.setSize(getWidth()); 1629 mWindowAlignment.horizontal.setPadding(getPaddingLeft(), getPaddingRight()); 1630 mWindowAlignment.vertical.setSize(getHeight()); 1631 mWindowAlignment.vertical.setPadding(getPaddingTop(), getPaddingBottom()); 1632 mSizePrimary = mWindowAlignment.mainAxis().getSize(); 1633 mWindowAlignment.mainAxis().invalidateScrollMin(); 1634 mWindowAlignment.mainAxis().invalidateScrollMax(); 1635 1636 if (DEBUG) { 1637 Log.v(getTag(), "initScrollController mSizePrimary " + mSizePrimary 1638 + " mWindowAlignment " + mWindowAlignment); 1639 } 1640 } 1641 1642 public void setSelection(RecyclerView parent, int position) { 1643 setSelection(parent, position, false); 1644 } 1645 1646 public void setSelectionSmooth(RecyclerView parent, int position) { 1647 setSelection(parent, position, true); 1648 } 1649 1650 public int getSelection() { 1651 return mFocusPosition; 1652 } 1653 1654 public void setSelection(RecyclerView parent, int position, boolean smooth) { 1655 if (mFocusPosition == position) { 1656 return; 1657 } 1658 View view = getViewByPosition(position); 1659 if (view != null) { 1660 scrollToView(view, smooth); 1661 } else { 1662 boolean right = position > mFocusPosition; 1663 mFocusPosition = position; 1664 if (smooth) { 1665 if (!hasDoneFirstLayout()) { 1666 Log.w(getTag(), "setSelectionSmooth should " + 1667 "not be called before first layout pass"); 1668 return; 1669 } 1670 if (right) { 1671 appendVisibleItems(); 1672 } else { 1673 prependVisibleItems(); 1674 } 1675 scrollToView(getViewByPosition(position), smooth); 1676 } else { 1677 mForceFullLayout = true; 1678 parent.requestLayout(); 1679 } 1680 } 1681 } 1682 1683 @Override 1684 public void onItemsAdded(RecyclerView recyclerView, int positionStart, int itemCount) { 1685 boolean needsLayout = false; 1686 if (itemCount != 0) { 1687 if (mFirstVisiblePos < 0) { 1688 needsLayout = true; 1689 } else if (!(positionStart > mLastVisiblePos + 1 || 1690 positionStart + itemCount < mFirstVisiblePos - 1)) { 1691 needsLayout = true; 1692 } 1693 } 1694 if (needsLayout) { 1695 recyclerView.requestLayout(); 1696 } 1697 } 1698 1699 @Override 1700 public boolean onRequestChildFocus(RecyclerView parent, View child, View focused) { 1701 if (mFocusSearchDisabled) { 1702 return true; 1703 } 1704 if (!mInLayout) { 1705 scrollToView(child, true); 1706 } 1707 return true; 1708 } 1709 1710 @Override 1711 public boolean requestChildRectangleOnScreen(RecyclerView parent, View view, Rect rect, 1712 boolean immediate) { 1713 if (DEBUG) Log.v(getTag(), "requestChildRectangleOnScreen " + view + " " + rect); 1714 return false; 1715 } 1716 1717 int getScrollOffsetX() { 1718 return mOrientation == HORIZONTAL ? mScrollOffsetPrimary : mScrollOffsetSecondary; 1719 } 1720 1721 int getScrollOffsetY() { 1722 return mOrientation == HORIZONTAL ? mScrollOffsetSecondary : mScrollOffsetPrimary; 1723 } 1724 1725 public void getViewSelectedOffsets(View view, int[] offsets) { 1726 int scrollOffsetX = getScrollOffsetX(); 1727 int scrollOffsetY = getScrollOffsetY(); 1728 int viewCenterX = scrollOffsetX + getViewCenterX(view); 1729 int viewCenterY = scrollOffsetY + getViewCenterY(view); 1730 offsets[0] = mWindowAlignment.horizontal.getSystemScrollPos(viewCenterX) - scrollOffsetX; 1731 offsets[1] = mWindowAlignment.vertical.getSystemScrollPos(viewCenterY) - scrollOffsetY; 1732 } 1733 1734 /** 1735 * Scroll to a given child view and change mFocusPosition. 1736 */ 1737 private void scrollToView(View view, boolean smooth) { 1738 int newFocusPosition = getPositionByView(view); 1739 if (mInLayout || newFocusPosition != mFocusPosition) { 1740 mFocusPosition = newFocusPosition; 1741 dispatchChildSelected(); 1742 } 1743 if (mBaseGridView.isChildrenDrawingOrderEnabledInternal()) { 1744 mBaseGridView.invalidate(); 1745 } 1746 if (view == null) { 1747 return; 1748 } 1749 if (!view.hasFocus() && mBaseGridView.hasFocus()) { 1750 // transfer focus to the child if it does not have focus yet (e.g. triggered 1751 // by setSelection()) 1752 view.requestFocus(); 1753 } 1754 switch (mFocusScrollStrategy) { 1755 case BaseGridView.FOCUS_SCROLL_ALIGNED: 1756 default: 1757 scrollToAlignedPosition(view, smooth); 1758 break; 1759 case BaseGridView.FOCUS_SCROLL_ITEM: 1760 case BaseGridView.FOCUS_SCROLL_PAGE: 1761 scrollItemOrPage(view, smooth); 1762 break; 1763 } 1764 } 1765 1766 private void scrollItemOrPage(View view, boolean smooth) { 1767 int pos = getPositionByView(view); 1768 int viewMin = getViewMin(view); 1769 int viewMax = getViewMax(view); 1770 // we either align "firstView" to left/top padding edge 1771 // or align "lastView" to right/bottom padding edge 1772 View firstView = null; 1773 View lastView = null; 1774 int paddingLow = mWindowAlignment.mainAxis().getPaddingLow(); 1775 int clientSize = mWindowAlignment.mainAxis().getClientSize(); 1776 final int row = mGrid.getLocation(pos).row; 1777 if (viewMin < paddingLow) { 1778 // view enters low padding area: 1779 firstView = view; 1780 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_PAGE) { 1781 // scroll one "page" left/top, 1782 // align first visible item of the "page" at the low padding edge. 1783 while (!prependOneVisibleItem()) { 1784 List<Integer> positions = 1785 mGrid.getItemPositionsInRows(mFirstVisiblePos, pos)[row]; 1786 firstView = getViewByPosition(positions.get(0)); 1787 if (viewMax - getViewMin(firstView) > clientSize) { 1788 if (positions.size() > 1) { 1789 firstView = getViewByPosition(positions.get(1)); 1790 } 1791 break; 1792 } 1793 } 1794 } 1795 } else if (viewMax > clientSize + paddingLow) { 1796 // view enters high padding area: 1797 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_PAGE) { 1798 // scroll whole one page right/bottom, align view at the low padding edge. 1799 firstView = view; 1800 do { 1801 List<Integer> positions = 1802 mGrid.getItemPositionsInRows(pos, mLastVisiblePos)[row]; 1803 lastView = getViewByPosition(positions.get(positions.size() - 1)); 1804 if (getViewMax(lastView) - viewMin > clientSize) { 1805 lastView = null; 1806 break; 1807 } 1808 } while (!appendOneVisibleItem()); 1809 if (lastView != null) { 1810 // however if we reached end, we should align last view. 1811 firstView = null; 1812 } 1813 } else { 1814 lastView = view; 1815 } 1816 } 1817 int scrollPrimary = 0; 1818 int scrollSecondary = 0; 1819 if (firstView != null) { 1820 scrollPrimary = getViewMin(firstView) - paddingLow; 1821 } else if (lastView != null) { 1822 scrollPrimary = getViewMax(lastView) - (paddingLow + clientSize); 1823 } 1824 View secondaryAlignedView; 1825 if (firstView != null) { 1826 secondaryAlignedView = firstView; 1827 } else if (lastView != null) { 1828 secondaryAlignedView = lastView; 1829 } else { 1830 secondaryAlignedView = view; 1831 } 1832 int viewCenterSecondary = mScrollOffsetSecondary + 1833 getViewCenterSecondary(secondaryAlignedView); 1834 mWindowAlignment.secondAxis().updateScrollCenter(viewCenterSecondary); 1835 scrollSecondary = mWindowAlignment.secondAxis().getSystemScrollPos(); 1836 scrollSecondary -= mScrollOffsetSecondary; 1837 scrollGrid(scrollPrimary, scrollSecondary, smooth); 1838 } 1839 1840 private void scrollToAlignedPosition(View view, boolean smooth) { 1841 int viewCenterPrimary = mScrollOffsetPrimary + getViewCenter(view); 1842 int viewCenterSecondary = mScrollOffsetSecondary + getViewCenterSecondary(view); 1843 if (DEBUG) { 1844 Log.v(getTag(), "scrollAligned smooth=" + smooth + " pos=" + mFocusPosition + " " 1845 + viewCenterPrimary +","+viewCenterSecondary + " " + mWindowAlignment); 1846 } 1847 1848 if (mInLayout || viewCenterPrimary != mWindowAlignment.mainAxis().getScrollCenter() 1849 || viewCenterSecondary != mWindowAlignment.secondAxis().getScrollCenter()) { 1850 mWindowAlignment.mainAxis().updateScrollCenter(viewCenterPrimary); 1851 mWindowAlignment.secondAxis().updateScrollCenter(viewCenterSecondary); 1852 int scrollPrimary = mWindowAlignment.mainAxis().getSystemScrollPos(); 1853 int scrollSecondary = mWindowAlignment.secondAxis().getSystemScrollPos(); 1854 if (DEBUG) { 1855 Log.v(getTag(), "scrollAligned " + scrollPrimary + " " + scrollSecondary 1856 +" " + mWindowAlignment); 1857 } 1858 1859 scrollPrimary -= mScrollOffsetPrimary; 1860 scrollSecondary -= mScrollOffsetSecondary; 1861 1862 scrollGrid(scrollPrimary, scrollSecondary, smooth); 1863 } 1864 } 1865 1866 private void scrollGrid(int scrollPrimary, int scrollSecondary, boolean smooth) { 1867 if (mInLayout) { 1868 scrollDirectionPrimary(scrollPrimary); 1869 scrollDirectionSecondary(scrollSecondary); 1870 } else { 1871 int scrollX; 1872 int scrollY; 1873 if (mOrientation == HORIZONTAL) { 1874 scrollX = scrollPrimary; 1875 scrollY = scrollSecondary; 1876 } else { 1877 scrollX = scrollSecondary; 1878 scrollY = scrollPrimary; 1879 } 1880 if (smooth) { 1881 mBaseGridView.smoothScrollBy(scrollX, scrollY); 1882 } else { 1883 mBaseGridView.scrollBy(scrollX, scrollY); 1884 } 1885 } 1886 } 1887 1888 public void setAnimateChildLayout(boolean animateChildLayout) { 1889 mAnimateChildLayout = animateChildLayout; 1890 for (int i = 0, c = getChildCount(); i < c; i++) { 1891 View v = getChildAt(i); 1892 LayoutParams p = (LayoutParams) v.getLayoutParams(); 1893 if (!mAnimateChildLayout) { 1894 p.endAnimate(); 1895 } else { 1896 // record initial location values 1897 p.mFirstAttached = true; 1898 p.startAnimate(this, v, 0); 1899 } 1900 } 1901 } 1902 1903 private void attemptAnimateLayoutChild() { 1904 if (!mAnimateChildLayout) { 1905 return; 1906 } 1907 for (int i = 0, c = getChildCount(); i < c; i++) { 1908 // TODO: start delay can be staggered 1909 View v = getChildAt(i); 1910 ((LayoutParams) v.getLayoutParams()).startAnimate(this, v, 0); 1911 } 1912 } 1913 1914 public boolean isChildLayoutAnimated() { 1915 return mAnimateChildLayout; 1916 } 1917 1918 public void setChildLayoutAnimationInterpolator(Interpolator interpolator) { 1919 mAnimateLayoutChildInterpolator = interpolator; 1920 } 1921 1922 public Interpolator getChildLayoutAnimationInterpolator() { 1923 return mAnimateLayoutChildInterpolator; 1924 } 1925 1926 public void setChildLayoutAnimationDuration(long duration) { 1927 mAnimateLayoutChildDuration = duration; 1928 } 1929 1930 public long getChildLayoutAnimationDuration() { 1931 return mAnimateLayoutChildDuration; 1932 } 1933 1934 private int findImmediateChildIndex(View view) { 1935 while (view != null && view != mBaseGridView) { 1936 int index = mBaseGridView.indexOfChild(view); 1937 if (index >= 0) { 1938 return index; 1939 } 1940 view = (View) view.getParent(); 1941 } 1942 return NO_POSITION; 1943 } 1944 1945 void setFocusSearchDisabled(boolean disabled) { 1946 mFocusSearchDisabled = disabled; 1947 } 1948 1949 boolean isFocusSearchDisabled() { 1950 return mFocusSearchDisabled; 1951 } 1952 1953 @Override 1954 public View onInterceptFocusSearch(View focused, int direction) { 1955 if (mFocusSearchDisabled) { 1956 return focused; 1957 } 1958 return null; 1959 } 1960 1961 boolean hasNextViewInSameRow(int pos) { 1962 if (mGrid == null || pos == NO_POSITION) { 1963 return false; 1964 } 1965 final int focusedRow = mGrid.getLocation(pos).row; 1966 for (int i = 0, count = getChildCount(); i < count; i++) { 1967 int position = getPositionByIndex(i); 1968 StaggeredGrid.Location loc = mGrid.getLocation(position); 1969 if (loc != null && loc.row == focusedRow) { 1970 if (position > pos) { 1971 return true; 1972 } 1973 } 1974 } 1975 return false; 1976 } 1977 1978 boolean hasPreviousViewInSameRow(int pos) { 1979 if (mGrid == null || pos == NO_POSITION) { 1980 return false; 1981 } 1982 final int focusedRow = mGrid.getLocation(pos).row; 1983 for (int i = getChildCount() - 1; i >= 0; i--) { 1984 int position = getPositionByIndex(i); 1985 StaggeredGrid.Location loc = mGrid.getLocation(position); 1986 if (loc != null && loc.row == focusedRow) { 1987 if (position < pos) { 1988 return true; 1989 } 1990 } 1991 } 1992 return false; 1993 } 1994 1995 @Override 1996 public boolean onAddFocusables(RecyclerView recyclerView, 1997 ArrayList<View> views, int direction, int focusableMode) { 1998 if (mFocusSearchDisabled) { 1999 return true; 2000 } 2001 // If this viewgroup or one of its children currently has focus then we 2002 // consider our children for focus searching in main direction on the same row. 2003 // If this viewgroup has no focus and using focus align, we want the system 2004 // to ignore our children and pass focus to the viewgroup, which will pass 2005 // focus on to its children appropriately. 2006 // If this viewgroup has no focus and not using focus align, we want to 2007 // consider the child that does not overlap with padding area. 2008 if (recyclerView.hasFocus()) { 2009 final int movement = getMovement(direction); 2010 if (movement != PREV_ITEM && movement != NEXT_ITEM) { 2011 // Move on secondary direction uses default addFocusables(). 2012 return false; 2013 } 2014 final View focused = recyclerView.findFocus(); 2015 final int focusedPos = getPositionByIndex(findImmediateChildIndex(focused)); 2016 // Add focusables of focused item. 2017 if (focusedPos != NO_POSITION) { 2018 getViewByPosition(focusedPos).addFocusables(views, direction, focusableMode); 2019 } 2020 final int focusedRow = mGrid != null && focusedPos != NO_POSITION ? 2021 mGrid.getLocation(focusedPos).row : NO_POSITION; 2022 // Add focusables of next neighbor of same row on the focus search direction. 2023 if (mGrid != null) { 2024 final int focusableCount = views.size(); 2025 for (int i = 0, count = getChildCount(); i < count; i++) { 2026 int index = movement == NEXT_ITEM ? i : count - 1 - i; 2027 final View child = getChildAt(index); 2028 if (child.getVisibility() != View.VISIBLE) { 2029 continue; 2030 } 2031 int position = getPositionByIndex(index); 2032 StaggeredGrid.Location loc = mGrid.getLocation(position); 2033 if (focusedRow == NO_POSITION || (loc != null && loc.row == focusedRow)) { 2034 if (focusedPos == NO_POSITION || 2035 (movement == NEXT_ITEM && position > focusedPos) 2036 || (movement == PREV_ITEM && position < focusedPos)) { 2037 child.addFocusables(views, direction, focusableMode); 2038 if (views.size() > focusableCount) { 2039 break; 2040 } 2041 } 2042 } 2043 } 2044 } 2045 } else { 2046 if (mFocusScrollStrategy != BaseGridView.FOCUS_SCROLL_ALIGNED) { 2047 // adding views not overlapping padding area to avoid scrolling in gaining focus 2048 int left = mWindowAlignment.mainAxis().getPaddingLow(); 2049 int right = mWindowAlignment.mainAxis().getClientSize() + left; 2050 int focusableCount = views.size(); 2051 for (int i = 0, count = getChildCount(); i < count; i++) { 2052 View child = getChildAt(i); 2053 if (child.getVisibility() == View.VISIBLE) { 2054 if (getViewMin(child) >= left && getViewMax(child) <= right) { 2055 child.addFocusables(views, direction, focusableMode); 2056 } 2057 } 2058 } 2059 // if we cannot find any, then just add all children. 2060 if (views.size() == focusableCount) { 2061 for (int i = 0, count = getChildCount(); i < count; i++) { 2062 View child = getChildAt(i); 2063 if (child.getVisibility() == View.VISIBLE) { 2064 child.addFocusables(views, direction, focusableMode); 2065 } 2066 } 2067 if (views.size() != focusableCount) { 2068 return true; 2069 } 2070 } else { 2071 return true; 2072 } 2073 // if still cannot find any, fall through and add itself 2074 } 2075 if (recyclerView.isFocusable()) { 2076 views.add(recyclerView); 2077 } 2078 } 2079 return true; 2080 } 2081 2082 @Override 2083 public View onFocusSearchFailed(View focused, int direction, Adapter adapter, 2084 Recycler recycler) { 2085 if (DEBUG) Log.v(getTag(), "onFocusSearchFailed direction " + direction); 2086 2087 View view = null; 2088 int movement = getMovement(direction); 2089 final FocusFinder ff = FocusFinder.getInstance(); 2090 if (movement == NEXT_ITEM) { 2091 while (view == null && !appendOneVisibleItem()) { 2092 view = ff.findNextFocus(mBaseGridView, focused, direction); 2093 } 2094 } else if (movement == PREV_ITEM){ 2095 while (view == null && !prependOneVisibleItem()) { 2096 view = ff.findNextFocus(mBaseGridView, focused, direction); 2097 } 2098 } 2099 if (view == null) { 2100 // returning the same view to prevent focus lost when scrolling past the end of the list 2101 if (movement == PREV_ITEM) { 2102 view = mFocusOutFront ? null : focused; 2103 } else if (movement == NEXT_ITEM){ 2104 view = mFocusOutEnd ? null : focused; 2105 } 2106 } 2107 if (DEBUG) Log.v(getTag(), "returning view " + view); 2108 return view; 2109 } 2110 2111 boolean gridOnRequestFocusInDescendants(RecyclerView recyclerView, int direction, 2112 Rect previouslyFocusedRect) { 2113 switch (mFocusScrollStrategy) { 2114 case BaseGridView.FOCUS_SCROLL_ALIGNED: 2115 default: 2116 return gridOnRequestFocusInDescendantsAligned(recyclerView, 2117 direction, previouslyFocusedRect); 2118 case BaseGridView.FOCUS_SCROLL_PAGE: 2119 case BaseGridView.FOCUS_SCROLL_ITEM: 2120 return gridOnRequestFocusInDescendantsUnaligned(recyclerView, 2121 direction, previouslyFocusedRect); 2122 } 2123 } 2124 2125 private boolean gridOnRequestFocusInDescendantsAligned(RecyclerView recyclerView, 2126 int direction, Rect previouslyFocusedRect) { 2127 View view = getViewByPosition(mFocusPosition); 2128 if (view != null) { 2129 boolean result = view.requestFocus(direction, previouslyFocusedRect); 2130 if (!result && DEBUG) { 2131 Log.w(getTag(), "failed to request focus on " + view); 2132 } 2133 return result; 2134 } 2135 return false; 2136 } 2137 2138 private boolean gridOnRequestFocusInDescendantsUnaligned(RecyclerView recyclerView, 2139 int direction, Rect previouslyFocusedRect) { 2140 // focus to view not overlapping padding area to avoid scrolling in gaining focus 2141 int index; 2142 int increment; 2143 int end; 2144 int count = getChildCount(); 2145 if ((direction & View.FOCUS_FORWARD) != 0) { 2146 index = 0; 2147 increment = 1; 2148 end = count; 2149 } else { 2150 index = count - 1; 2151 increment = -1; 2152 end = -1; 2153 } 2154 int left = mWindowAlignment.mainAxis().getPaddingLow(); 2155 int right = mWindowAlignment.mainAxis().getClientSize() + left; 2156 for (int i = index; i != end; i += increment) { 2157 View child = getChildAt(i); 2158 if (child.getVisibility() == View.VISIBLE) { 2159 if (getViewMin(child) >= left && getViewMax(child) <= right) { 2160 if (child.requestFocus(direction, previouslyFocusedRect)) { 2161 return true; 2162 } 2163 } 2164 } 2165 } 2166 return false; 2167 } 2168 2169 private final static int PREV_ITEM = 0; 2170 private final static int NEXT_ITEM = 1; 2171 private final static int PREV_ROW = 2; 2172 private final static int NEXT_ROW = 3; 2173 2174 private int getMovement(int direction) { 2175 int movement = View.FOCUS_LEFT; 2176 2177 if (mOrientation == HORIZONTAL) { 2178 switch(direction) { 2179 case View.FOCUS_LEFT: 2180 movement = PREV_ITEM; 2181 break; 2182 case View.FOCUS_RIGHT: 2183 movement = NEXT_ITEM; 2184 break; 2185 case View.FOCUS_UP: 2186 movement = PREV_ROW; 2187 break; 2188 case View.FOCUS_DOWN: 2189 movement = NEXT_ROW; 2190 break; 2191 } 2192 } else if (mOrientation == VERTICAL) { 2193 switch(direction) { 2194 case View.FOCUS_LEFT: 2195 movement = PREV_ROW; 2196 break; 2197 case View.FOCUS_RIGHT: 2198 movement = NEXT_ROW; 2199 break; 2200 case View.FOCUS_UP: 2201 movement = PREV_ITEM; 2202 break; 2203 case View.FOCUS_DOWN: 2204 movement = NEXT_ITEM; 2205 break; 2206 } 2207 } 2208 2209 return movement; 2210 } 2211 2212 int getChildDrawingOrder(RecyclerView recyclerView, int childCount, int i) { 2213 int focusIndex = getIndexByPosition(mFocusPosition); 2214 if (focusIndex == NO_POSITION) { 2215 return i; 2216 } 2217 // supposely 0 1 2 3 4 5 6 7 8 9, 4 is the center item 2218 // drawing order is 0 1 2 3 9 8 7 6 5 4 2219 if (i < focusIndex) { 2220 return i; 2221 } else if (i < childCount - 1) { 2222 return focusIndex + childCount - 1 - i; 2223 } else { 2224 return focusIndex; 2225 } 2226 } 2227 2228 @Override 2229 public void onAdapterChanged(RecyclerView.Adapter oldAdapter, 2230 RecyclerView.Adapter newAdapter) { 2231 mGrid = null; 2232 mRows = null; 2233 mRowSizeSecondary = null; 2234 mRowSecondarySizeRefresh = false; 2235 super.onAdapterChanged(oldAdapter, newAdapter); 2236 } 2237} 2238