GridLayoutManager.java revision c1f3bcf2f1deac4603cddfb9548380ba20a5f310
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.graphics.Rect; 17import android.support.v7.widget.RecyclerView; 18import android.support.v7.widget.RecyclerView.Adapter; 19import android.support.v7.widget.RecyclerView.Recycler; 20 21import static android.support.v7.widget.RecyclerView.NO_ID; 22import static android.support.v7.widget.RecyclerView.NO_POSITION; 23import static android.support.v7.widget.RecyclerView.HORIZONTAL; 24import static android.support.v7.widget.RecyclerView.VERTICAL; 25 26import android.support.v17.leanback.R; 27import android.util.Log; 28import android.view.FocusFinder; 29import android.view.View; 30import android.view.View.MeasureSpec; 31import android.view.ViewGroup; 32import android.view.animation.DecelerateInterpolator; 33import android.view.animation.Interpolator; 34 35import java.io.PrintWriter; 36import java.io.StringWriter; 37import java.util.ArrayList; 38 39final class GridLayoutManager extends RecyclerView.LayoutManager { 40 41 private static final String TAG = "GridLayoutManager"; 42 private static final boolean DEBUG = false; 43 44 private static final Interpolator sDefaultAnimationChildLayoutInterpolator 45 = new DecelerateInterpolator(); 46 47 private static final long DEFAULT_CHILD_ANIMATION_DURATION_MS = 250; 48 49 private String getTag() { 50 return TAG + ":" + mBaseListView.getId(); 51 } 52 53 private final BaseListView mBaseListView; 54 55 /** 56 * The orientation of a "row". 57 */ 58 private int mOrientation = HORIZONTAL; 59 60 private RecyclerView.Adapter mAdapter; 61 private RecyclerView.Recycler mRecycler; 62 63 private boolean mInLayout = false; 64 65 private OnChildSelectedListener mChildSelectedListener = null; 66 67 /** 68 * The focused position, it's not the currently visually aligned position 69 * but it is the final position that we intend to focus on. If there are 70 * multiple setSelection() called, mFocusPosition saves last value. 71 */ 72 private int mFocusPosition = NO_POSITION; 73 74 /** 75 * Force a full layout under certain situations. 76 */ 77 private boolean mForceFullLayout; 78 79 /** 80 * The scroll offsets of the viewport relative to the entire view. 81 */ 82 private int mScrollOffsetPrimary; 83 private int mScrollOffsetSecondary; 84 85 /** 86 * User-specified fixed size of each grid item in the secondary direction, can be 87 * 0 to be determined by parent size and number of rows. 88 */ 89 private int mItemLengthSecondaryRequested; 90 /** 91 * The fixed size of each grid item in the secondary direction. This corresponds to 92 * the row height, equal for all rows. Grid items may have variable length 93 * in the primary direction. 94 * 95 */ 96 private int mItemLengthSecondary; 97 98 /** 99 * Margin between items. 100 */ 101 private int mHorizontalMargin; 102 /** 103 * Margin between items vertically. 104 */ 105 private int mVerticalMargin; 106 /** 107 * Margin in main direction. 108 */ 109 private int mMarginPrimary; 110 /** 111 * Margin in second direction. 112 */ 113 private int mMarginSecondary; 114 115 /** 116 * The number of rows in the grid. 117 */ 118 private int mNumRows; 119 /** 120 * Number of rows requested, can be 0 to be determined by parent size and 121 * rowHeight. 122 */ 123 private int mNumRowsRequested = 1; 124 125 /** 126 * Tracking start/end position of each row for visible items. 127 */ 128 private StaggeredGrid.Row[] mRows; 129 130 /** 131 * Saves grid information of each view. 132 */ 133 private StaggeredGrid mGrid; 134 /** 135 * Position of first item (included) that has attached views. 136 */ 137 private int mFirstVisiblePos; 138 /** 139 * Position of last item (included) that has attached views. 140 */ 141 private int mLastVisiblePos; 142 143 /** 144 * Defines how item view is aligned in the window. 145 */ 146 private final WindowAlignment mWindowAlignment = new WindowAlignment(); 147 148 /** 149 * Defines how item view is aligned. 150 */ 151 private final ItemAlignment mItemAlignment = new ItemAlignment(); 152 153 /** 154 * Dimensions of the view, width or height depending on orientation. 155 */ 156 private int mSizePrimary; 157 158 /** 159 * Allow DPAD key to navigate out at the front of the View (where position = 0), 160 * default is false. 161 */ 162 private boolean mFocusOutFront; 163 164 /** 165 * Allow DPAD key to navigate out at the end of the view, default is false. 166 */ 167 private boolean mFocusOutEnd; 168 169 /** 170 * Animate layout changes from a child resizing or adding/removing a child. 171 */ 172 private boolean mAnimateChildLayout = true; 173 174 /** 175 * Interpolator used to animate layout of children. 176 */ 177 private Interpolator mAnimateLayoutChildInterpolator = sDefaultAnimationChildLayoutInterpolator; 178 179 /** 180 * Duration used to animate layout of children. 181 */ 182 private long mAnimateLayoutChildDuration = DEFAULT_CHILD_ANIMATION_DURATION_MS; 183 184 public GridLayoutManager(BaseListView baseListView) { 185 mBaseListView = baseListView; 186 } 187 188 public void setOrientation(int orientation) { 189 if (orientation != HORIZONTAL && orientation != VERTICAL) { 190 if (DEBUG) Log.v(getTag(), "invalid orientation: " + orientation); 191 return; 192 } 193 194 mOrientation = orientation; 195 mWindowAlignment.setOrientation(orientation); 196 mItemAlignment.setOrientation(orientation); 197 mForceFullLayout = true; 198 } 199 200 public void setWindowAlignment(int windowAlignment) { 201 mWindowAlignment.mainAxis().setWindowAlignment(windowAlignment); 202 } 203 204 public int getWindowAlignment() { 205 return mWindowAlignment.mainAxis().getWindowAlignment(); 206 } 207 208 public void setWindowAlignmentOffset(int alignmentOffset) { 209 mWindowAlignment.mainAxis().setWindowAlignmentOffset(alignmentOffset); 210 } 211 212 public int getWindowAlignmentOffset() { 213 return mWindowAlignment.mainAxis().getWindowAlignmentOffset(); 214 } 215 216 public void setWindowAlignmentOffsetPercent(float offsetPercent) { 217 mWindowAlignment.mainAxis().setWindowAlignmentOffsetPercent(offsetPercent); 218 } 219 220 public float getWindowAlignmentOffsetPercent() { 221 return mWindowAlignment.mainAxis().getWindowAlignmentOffsetPercent(); 222 } 223 224 public void setItemAlignmentOffset(int alignmentOffset) { 225 mItemAlignment.mainAxis().setItemAlignmentOffset(alignmentOffset); 226 updateChildAlignments(); 227 } 228 229 public int getItemAlignmentOffset() { 230 return mItemAlignment.mainAxis().getItemAlignmentOffset(); 231 } 232 233 public void setItemAlignmentOffsetPercent(float offsetPercent) { 234 mItemAlignment.mainAxis().setItemAlignmentOffsetPercent(offsetPercent); 235 updateChildAlignments(); 236 } 237 238 public float getItemAlignmentOffsetPercent() { 239 return mItemAlignment.mainAxis().getItemAlignmentOffsetPercent(); 240 } 241 242 public void setItemAlignmentViewId(int viewId) { 243 mItemAlignment.mainAxis().setItemAlignmentViewId(viewId); 244 updateChildAlignments(); 245 } 246 247 public int getItemAlignmentViewId() { 248 return mItemAlignment.mainAxis().getItemAlignmentViewId(); 249 } 250 251 public void setFocusOutAllowed(boolean throughFront, boolean throughEnd) { 252 mFocusOutFront = throughFront; 253 mFocusOutEnd = throughEnd; 254 } 255 256 public void setNumRows(int numRows) { 257 if (numRows < 0) throw new IllegalArgumentException(); 258 mNumRowsRequested = numRows; 259 mForceFullLayout = true; 260 } 261 262 public void setRowHeight(int height) { 263 if (height < 0) throw new IllegalArgumentException(); 264 mItemLengthSecondaryRequested = height; 265 } 266 267 public void setItemMargin(int margin) { 268 mVerticalMargin = mHorizontalMargin = margin; 269 mMarginPrimary = mMarginSecondary = margin; 270 } 271 272 public void setVerticalMargin(int margin) { 273 if (mOrientation == HORIZONTAL) { 274 mMarginSecondary = mVerticalMargin = margin; 275 } else { 276 mMarginPrimary = mVerticalMargin = margin; 277 } 278 } 279 280 public void setHorizontalMargin(int margin) { 281 if (mOrientation == HORIZONTAL) { 282 mMarginPrimary = mHorizontalMargin = margin; 283 } else { 284 mMarginSecondary = mHorizontalMargin = margin; 285 } 286 } 287 288 public int getVerticalMargin() { 289 return mVerticalMargin; 290 } 291 292 public int getHorizontalMargin() { 293 return mHorizontalMargin; 294 } 295 296 protected int getMeasuredLengthPrimary(View v) { 297 if (mOrientation == HORIZONTAL) { 298 float aspectRatio = (float) v.getMeasuredWidth() / (float) v.getMeasuredHeight(); 299 return (int) (aspectRatio * mItemLengthSecondary); 300 } else { 301 float aspectRatio = (float) v.getMeasuredHeight() / (float) v.getMeasuredWidth(); 302 return (int) (aspectRatio * mItemLengthSecondary); 303 } 304 } 305 306 protected boolean hasDoneFirstLayout() { 307 return mGrid != null; 308 } 309 310 public void setOnChildSelectedListener(OnChildSelectedListener listener) { 311 mChildSelectedListener = listener; 312 } 313 314 private int getPositionByView(View view) { 315 return getPositionByIndex(mBaseListView.indexOfChild(view)); 316 } 317 318 private int getPositionByIndex(int index) { 319 if (index < 0) { 320 return NO_POSITION; 321 } 322 return mFirstVisiblePos + index; 323 } 324 325 private View getViewByPosition(int position) { 326 int index = getIndexByPosition(position); 327 if (index < 0) { 328 return null; 329 } 330 return getChildAt(index); 331 } 332 333 private int getIndexByPosition(int position) { 334 if (mFirstVisiblePos < 0 || 335 position < mFirstVisiblePos || position > mLastVisiblePos) { 336 return NO_POSITION; 337 } 338 return position - mFirstVisiblePos; 339 } 340 341 private void dispatchChildSelected() { 342 if (mChildSelectedListener == null) { 343 return; 344 } 345 346 View view = getViewByPosition(mFocusPosition); 347 348 if (mFocusPosition != NO_POSITION) { 349 mChildSelectedListener.onChildSelected(mBaseListView, view, mFocusPosition, 350 mAdapter.getItemId(mFocusPosition)); 351 } else { 352 mChildSelectedListener.onChildSelected(mBaseListView, null, NO_POSITION, NO_ID); 353 } 354 } 355 356 @Override 357 public boolean canScrollHorizontally() { 358 // We can scroll horizontally if we have horizontal orientation, or if 359 // we are vertical and have more than one column. 360 return mOrientation == HORIZONTAL || mNumRows > 1; 361 } 362 363 @Override 364 public boolean canScrollVertically() { 365 // We can scroll vertically if we have vertical orientation, or if we 366 // are horizontal and have more than one row. 367 return mOrientation == VERTICAL || mNumRows > 1; 368 } 369 370 @Override 371 public RecyclerView.LayoutParams generateDefaultLayoutParams() { 372 return new RecyclerView.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, 373 ViewGroup.LayoutParams.WRAP_CONTENT); 374 } 375 376 private static GridLayoutManagerChildTag getViewTag(View v) { 377 return (GridLayoutManagerChildTag) v.getTag(R.id.lb_gridlayoutmanager_tag); 378 } 379 380 protected View getViewForPosition(int position) { 381 View v = mRecycler.getViewForPosition(mAdapter, position); 382 if (v != null) { 383 GridLayoutManagerChildTag tag = getViewTag(v); 384 if (tag == null) { 385 tag = new GridLayoutManagerChildTag(); 386 v.setTag(R.id.lb_gridlayoutmanager_tag, tag); 387 } 388 tag.attach(this, v); 389 } 390 return v; 391 } 392 393 private int getViewMin(View view) { 394 GridLayoutManagerChildTag tag = getViewTag(view); 395 return (mOrientation == HORIZONTAL) ? tag.getOpticalLeft() : tag.getOpticalTop(); 396 } 397 398 private int getViewMax(View view) { 399 GridLayoutManagerChildTag tag = getViewTag(view); 400 return (mOrientation == HORIZONTAL) ? tag.getOpticalRight() : tag.getOpticalBottom(); 401 } 402 403 private int getViewCenter(View view) { 404 return (mOrientation == HORIZONTAL) ? getViewCenterX(view) : getViewCenterY(view); 405 } 406 407 private int getViewCenterSecondary(View view) { 408 return (mOrientation == HORIZONTAL) ? getViewCenterY(view) : getViewCenterX(view); 409 } 410 411 private int getViewCenterX(View view) { 412 GridLayoutManagerChildTag tag = getViewTag(view); 413 return tag.getOpticalLeft() + tag.getAlignX(); 414 } 415 416 private int getViewCenterY(View view) { 417 GridLayoutManagerChildTag tag = getViewTag(view); 418 return tag.getOpticalTop() + tag.getAlignY(); 419 } 420 421 /** 422 * Re-initialize data structures for a data change or handling invisible 423 * selection. The method tries its best to preserve position information so 424 * that staggered grid looks same before and after re-initialize. 425 * @param focusPosition The initial focusPosition that we would like to 426 * focus on. 427 * @return Actual position that can be focused on. 428 */ 429 private int init(RecyclerView.Adapter adapter, RecyclerView.Recycler recycler, 430 int focusPosition) { 431 432 final int newItemCount = adapter.getItemCount(); 433 434 if (focusPosition == NO_POSITION && newItemCount > 0) { 435 // if focus position is never set before, initialize it to 0 436 focusPosition = 0; 437 } 438 // If adapter has changed then caches are invalid; otherwise, 439 // we try to maintain each row's position if number of rows keeps the same 440 // and existing mGrid contains the focusPosition. 441 if (mRows != null && mNumRows == mRows.length && 442 mGrid != null && mGrid.getSize() > 0 && focusPosition >= 0 && 443 focusPosition >= mGrid.getFirstIndex() && 444 focusPosition <= mGrid.getLastIndex()) { 445 // strip mGrid to a subset (like a column) that contains focusPosition 446 mGrid.stripDownTo(focusPosition); 447 // make sure that remaining items do not exceed new adapter size 448 int firstIndex = mGrid.getFirstIndex(); 449 int lastIndex = mGrid.getLastIndex(); 450 if (DEBUG) { 451 Log .v(getTag(), "mGrid firstIndex " + firstIndex + " lastIndex " + lastIndex); 452 } 453 for (int i = lastIndex; i >=firstIndex; i--) { 454 if (i >= newItemCount) { 455 mGrid.removeLast(); 456 } 457 } 458 if (mGrid.getSize() == 0) { 459 focusPosition = newItemCount - 1; 460 // initialize row start locations 461 for (int i = 0; i < mNumRows; i++) { 462 mRows[i].low = 0; 463 mRows[i].high = 0; 464 } 465 if (DEBUG) Log.v(getTag(), "mGrid zero size"); 466 } else { 467 // initialize row start locations 468 for (int i = 0; i < mNumRows; i++) { 469 mRows[i].low = Integer.MAX_VALUE; 470 mRows[i].high = Integer.MIN_VALUE; 471 } 472 firstIndex = mGrid.getFirstIndex(); 473 lastIndex = mGrid.getLastIndex(); 474 if (focusPosition > lastIndex) { 475 focusPosition = mGrid.getLastIndex(); 476 } 477 if (DEBUG) { 478 Log.v(getTag(), "mGrid firstIndex " + firstIndex + " lastIndex " 479 + lastIndex + " focusPosition " + focusPosition); 480 } 481 // fill rows with minimal view positions of the subset 482 for (int i = firstIndex; i <= lastIndex; i++) { 483 View v = getViewByPosition(i); 484 if (v == null) { 485 continue; 486 } 487 int row = mGrid.getLocation(i).row; 488 int low = getViewMin(v) + mScrollOffsetPrimary; 489 if (low < mRows[row].low) { 490 mRows[row].low = mRows[row].high = low; 491 } 492 } 493 // fill other rows that does not include the subset using first item 494 int firstItemRowPosition = mRows[mGrid.getLocation(firstIndex).row].low; 495 if (firstItemRowPosition == Integer.MAX_VALUE) { 496 firstItemRowPosition = 0; 497 } 498 for (int i = 0; i < mNumRows; i++) { 499 if (mRows[i].low == Integer.MAX_VALUE) { 500 mRows[i].low = mRows[i].high = firstItemRowPosition; 501 } 502 } 503 } 504 505 // Same adapter, we can reuse any attached views 506 detachAndScrapAttachedViews(recycler); 507 508 } else { 509 // otherwise recreate data structure 510 mRows = new StaggeredGrid.Row[mNumRows]; 511 for (int i = 0; i < mNumRows; i++) { 512 mRows[i] = new StaggeredGrid.Row(); 513 } 514 mGrid = new StaggeredGridDefault(); 515 if (newItemCount == 0) { 516 focusPosition = NO_POSITION; 517 } else if (focusPosition >= newItemCount) { 518 focusPosition = newItemCount - 1; 519 } 520 521 // Adapter may have changed so remove all attached views permanently 522 removeAllViews(); 523 524 mScrollOffsetPrimary = 0; 525 mScrollOffsetSecondary = 0; 526 mWindowAlignment.reset(); 527 } 528 529 mAdapter = adapter; 530 mRecycler = recycler; 531 mGrid.setProvider(mGridProvider); 532 // mGrid share the same Row array information 533 mGrid.setRows(mRows); 534 mFirstVisiblePos = mLastVisiblePos = NO_POSITION; 535 536 initScrollController(); 537 538 return focusPosition; 539 } 540 541 // TODO: use recyclerview support for measuring the whole container, once 542 // it's available. 543 void onMeasure(int widthSpec, int heightSpec, int[] result) { 544 int sizePrimary, sizeSecondary, modeSecondary, paddingSecondary; 545 int measuredSizeSecondary; 546 if (mOrientation == HORIZONTAL) { 547 sizePrimary = MeasureSpec.getSize(widthSpec); 548 sizeSecondary = MeasureSpec.getSize(heightSpec); 549 modeSecondary = MeasureSpec.getMode(heightSpec); 550 paddingSecondary = getPaddingTop() + getPaddingBottom(); 551 } else { 552 sizeSecondary = MeasureSpec.getSize(widthSpec); 553 sizePrimary = MeasureSpec.getSize(heightSpec); 554 modeSecondary = MeasureSpec.getMode(widthSpec); 555 paddingSecondary = getPaddingLeft() + getPaddingRight(); 556 } 557 switch (modeSecondary) { 558 case MeasureSpec.UNSPECIFIED: 559 if (mItemLengthSecondaryRequested == 0) { 560 if (mOrientation == HORIZONTAL) { 561 throw new IllegalStateException("Must specify rowHeight or view height"); 562 } else { 563 throw new IllegalStateException("Must specify columnWidth or view width"); 564 } 565 } 566 mItemLengthSecondary = mItemLengthSecondaryRequested; 567 if (mNumRowsRequested == 0) { 568 mNumRows = 1; 569 } else { 570 mNumRows = mNumRowsRequested; 571 } 572 measuredSizeSecondary = mItemLengthSecondary * mNumRows + mMarginSecondary 573 * (mNumRows - 1) + paddingSecondary; 574 break; 575 case MeasureSpec.AT_MOST: 576 case MeasureSpec.EXACTLY: 577 if (mNumRowsRequested == 0 && mItemLengthSecondaryRequested == 0) { 578 mNumRows = 1; 579 mItemLengthSecondary = sizeSecondary - paddingSecondary; 580 } else if (mNumRowsRequested == 0) { 581 mItemLengthSecondary = mItemLengthSecondaryRequested; 582 mNumRows = (sizeSecondary + mMarginSecondary) 583 / (mItemLengthSecondaryRequested + mMarginSecondary); 584 } else if (mItemLengthSecondaryRequested == 0) { 585 mNumRows = mNumRowsRequested; 586 mItemLengthSecondary = (sizeSecondary - paddingSecondary - mMarginSecondary 587 * (mNumRows - 1)) / mNumRows; 588 } else { 589 mNumRows = mNumRowsRequested; 590 mItemLengthSecondary = mItemLengthSecondaryRequested; 591 } 592 measuredSizeSecondary = sizeSecondary; 593 if (modeSecondary == MeasureSpec.AT_MOST) { 594 int childrenSize = mItemLengthSecondary * mNumRows + mMarginSecondary 595 * (mNumRows - 1) + paddingSecondary; 596 if (childrenSize < measuredSizeSecondary) { 597 measuredSizeSecondary = childrenSize; 598 } 599 } 600 break; 601 default: 602 throw new IllegalStateException("wrong spec"); 603 } 604 if (mOrientation == HORIZONTAL) { 605 result[0] = sizePrimary; 606 result[1] = measuredSizeSecondary; 607 } else { 608 result[0] = measuredSizeSecondary; 609 result[1] = sizePrimary; 610 } 611 if (DEBUG) { 612 Log.v(getTag(), "onMeasure result " + result[0] + ", " + result[1] 613 + " mItemLengthSecondary " + mItemLengthSecondary + " mNumRows " + mNumRows); 614 } 615 } 616 617 private void measureChild(View child) { 618 final ViewGroup.LayoutParams lp = child.getLayoutParams(); 619 620 int widthSpec, heightSpec; 621 if (mOrientation == HORIZONTAL) { 622 if (lp.width >= 0) { 623 widthSpec = MeasureSpec.makeMeasureSpec(lp.width, MeasureSpec.EXACTLY); 624 } else { 625 widthSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED); 626 } 627 heightSpec = MeasureSpec.makeMeasureSpec(mItemLengthSecondary, MeasureSpec.EXACTLY); 628 } else { 629 if (lp.height >= 0) { 630 heightSpec = MeasureSpec.makeMeasureSpec(lp.height, MeasureSpec.EXACTLY); 631 } else { 632 heightSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED); 633 } 634 widthSpec = MeasureSpec.makeMeasureSpec(mItemLengthSecondary, MeasureSpec.EXACTLY); 635 } 636 637 child.measure(widthSpec, heightSpec); 638 } 639 640 private StaggeredGrid.Provider mGridProvider = new StaggeredGrid.Provider() { 641 642 @Override 643 public int getCount() { 644 return mAdapter.getItemCount(); 645 } 646 647 @Override 648 public void createItem(int index, int rowIndex, boolean append) { 649 View v = getViewForPosition(index); 650 if (mFirstVisiblePos >= 0) { 651 // when StaggeredGrid append or prepend item, we must guarantee 652 // that sibling item has created views already. 653 if (append && index != mLastVisiblePos + 1) { 654 throw new RuntimeException(); 655 } else if (!append && index != mFirstVisiblePos - 1) { 656 throw new RuntimeException(); 657 } 658 } 659 660 if (append) { 661 addView(v); 662 } else { 663 addView(v, 0); 664 } 665 666 measureChild(v); 667 668 int length = getMeasuredLengthPrimary(v); 669 int start, end; 670 if (append) { 671 start = mRows[rowIndex].high; 672 if (start != mRows[rowIndex].low) { 673 // if there are existing item in the row, add margin between 674 start += mMarginPrimary; 675 } 676 end = start + length; 677 mRows[rowIndex].high = end; 678 } else { 679 end = mRows[rowIndex].low; 680 if (end != mRows[rowIndex].high) { 681 end -= mMarginPrimary; 682 } 683 start = end - length; 684 mRows[rowIndex].low = start; 685 } 686 if (mFirstVisiblePos < 0) { 687 mFirstVisiblePos = mLastVisiblePos = index; 688 } else { 689 if (append) { 690 mLastVisiblePos++; 691 } else { 692 mFirstVisiblePos--; 693 } 694 } 695 int startSecondary = rowIndex * (mItemLengthSecondary + mMarginSecondary); 696 layoutChild(v, start - mScrollOffsetPrimary, end - mScrollOffsetPrimary, 697 startSecondary - mScrollOffsetSecondary); 698 if (DEBUG) { 699 Log.d(getTag(), "addView " + index + " " + v); 700 } 701 updateScrollMin(); 702 updateScrollMax(); 703 } 704 }; 705 706 private void layoutChild(View v, int start, int end, int startSecondary) { 707 if (mOrientation == HORIZONTAL) { 708 v.layout(start, startSecondary, end, startSecondary + mItemLengthSecondary); 709 } else { 710 v.layout(startSecondary, start, startSecondary + mItemLengthSecondary, end); 711 } 712 updateChildAlignments(v); 713 } 714 715 private void updateChildAlignments(View v) { 716 GridLayoutManagerChildTag tag = getViewTag(v); 717 tag.setAlignX(mItemAlignment.horizontal.getAlignmentPosition(v, tag)); 718 tag.setAlignY(mItemAlignment.vertical.getAlignmentPosition(v, tag)); 719 } 720 721 private void updateChildAlignments() { 722 for (int i = 0, c = getChildCount(); i < c; i++) { 723 updateChildAlignments(getChildAt(i)); 724 } 725 } 726 727 /** 728 * append invisible view of saved location 729 */ 730 private void appendViewWithSavedLocation() { 731 int index = mLastVisiblePos + 1; 732 mGridProvider.createItem(index, mGrid.getLocation(index).row, true); 733 } 734 735 /** 736 * prepend invisible view of saved location 737 */ 738 private void prependViewWithSavedLocation() { 739 int index = mFirstVisiblePos - 1; 740 mGridProvider.createItem(index, mGrid.getLocation(index).row, false); 741 } 742 743 private boolean needsAppendVisibleItem() { 744 if (mLastVisiblePos < mFocusPosition) { 745 return true; 746 } 747 int right = mScrollOffsetPrimary + mSizePrimary; 748 for (int i = 0; i < mNumRows; i++) { 749 if (mRows[i].low == mRows[i].high) { 750 if (mRows[i].high < right) { 751 return true; 752 } 753 } else if (mRows[i].high < right - mMarginPrimary) { 754 return true; 755 } 756 } 757 return false; 758 } 759 760 private boolean needsPrependVisibleItem() { 761 if (mFirstVisiblePos > mFocusPosition) { 762 return true; 763 } 764 for (int i = 0; i < mNumRows; i++) { 765 if (mRows[i].low == mRows[i].high) { 766 if (mRows[i].low > mScrollOffsetPrimary) { 767 return true; 768 } 769 } else if (mRows[i].low - mMarginPrimary > mScrollOffsetPrimary) { 770 return true; 771 } 772 } 773 return false; 774 } 775 776 // Append one column if possible and return true if reach end. 777 private boolean appendOneVisibleItem() { 778 if (mLastVisiblePos >= 0 && mLastVisiblePos < mGrid.getLastIndex()) { 779 appendViewWithSavedLocation(); 780 } else if (mLastVisiblePos < mAdapter.getItemCount() - 1) { 781 mGrid.appendItems(mScrollOffsetPrimary + mSizePrimary); 782 } else { 783 return true; 784 } 785 return false; 786 } 787 788 private void appendVisibleItems() { 789 while (needsAppendVisibleItem()) { 790 if (appendOneVisibleItem()) { 791 break; 792 } 793 } 794 } 795 796 // Prepend one column if possible and return true if reach end. 797 private boolean prependOneVisibleItem() { 798 if (mFirstVisiblePos > 0) { 799 if (mFirstVisiblePos > mGrid.getFirstIndex()) { 800 prependViewWithSavedLocation(); 801 } else { 802 mGrid.prependItems(mScrollOffsetPrimary); 803 } 804 } else { 805 return true; 806 } 807 return false; 808 } 809 810 private void prependVisibleItems() { 811 while (needsPrependVisibleItem()) { 812 if (prependOneVisibleItem()) { 813 break; 814 } 815 } 816 } 817 818 // TODO: use removeAndRecycleViewAt() once we stop using tags. 819 private void removeChildAt(int position) { 820 View v = getViewByPosition(position); 821 if (v != null) { 822 if (DEBUG) { 823 Log.d(getTag(), "detachAndScrape " + position); 824 } 825 getViewTag(v).detach(); 826 removeAndRecycleViewAt(getIndexByPosition(position), mRecycler); 827 } 828 } 829 830 private void removeInvisibleViewsAtEnd() { 831 boolean update = false; 832 while(mLastVisiblePos > mFirstVisiblePos && mLastVisiblePos > mFocusPosition) { 833 View view = getViewByPosition(mLastVisiblePos); 834 if (getViewMin(view) > mSizePrimary) { 835 removeChildAt(mLastVisiblePos); 836 mLastVisiblePos--; 837 update = true; 838 } else { 839 break; 840 } 841 } 842 if (update) { 843 updateRowsMinMax(); 844 } 845 } 846 847 private void removeInvisibleViewsAtFront() { 848 boolean update = false; 849 while(mLastVisiblePos > mFirstVisiblePos && mFirstVisiblePos < mFocusPosition) { 850 View view = getViewByPosition(mFirstVisiblePos); 851 if (getViewMax(view) < 0) { 852 removeChildAt(mFirstVisiblePos); 853 mFirstVisiblePos++; 854 update = true; 855 } else { 856 break; 857 } 858 } 859 if (update) { 860 updateRowsMinMax(); 861 } 862 } 863 864 private void updateRowsMinMax() { 865 if (mFirstVisiblePos < 0) { 866 return; 867 } 868 for (int i = 0; i < mNumRows; i++) { 869 mRows[i].low = Integer.MAX_VALUE; 870 mRows[i].high = Integer.MIN_VALUE; 871 } 872 for (int i = mFirstVisiblePos; i <= mLastVisiblePos; i++) { 873 View view = getViewByPosition(i); 874 int row = mGrid.getLocation(i).row; 875 int low = getViewMin(view) + mScrollOffsetPrimary; 876 if (low < mRows[row].low) { 877 mRows[row].low = low; 878 } 879 int high = getViewMax(view) + mScrollOffsetPrimary; 880 if (high > mRows[row].high) { 881 mRows[row].high = high; 882 } 883 } 884 } 885 886 /** 887 * Relayout and re-positioning child for a possible new size and/or a new 888 * start. 889 * 890 * @param view View to measure and layout. 891 * @param start New start of the view or Integer.MIN_VALUE for not change. 892 * @return New start of next view. 893 */ 894 private int updateChildView(View view, int start, int startSecondary) { 895 if (start == Integer.MIN_VALUE) { 896 start = getViewMin(view); 897 } 898 int end; 899 if (mOrientation == HORIZONTAL) { 900 if (view.isLayoutRequested() || view.getMeasuredHeight() != mItemLengthSecondary) { 901 measureChild(view); 902 } 903 end = start + view.getMeasuredWidth(); 904 } else { 905 if (view.isLayoutRequested() || view.getMeasuredWidth() != mItemLengthSecondary) { 906 measureChild(view); 907 } 908 end = start + view.getMeasuredHeight(); 909 } 910 911 layoutChild(view, start, end, startSecondary); 912 return end + mMarginPrimary; 913 } 914 915 // create a temporary structure that remembers visible items from left to 916 // right on each row 917 private ArrayList<Integer>[] buildRows() { 918 ArrayList<Integer>[] rows = new ArrayList[mNumRows]; 919 for (int i = 0; i < mNumRows; i++) { 920 rows[i] = new ArrayList(); 921 } 922 if (mFirstVisiblePos >= 0) { 923 for (int i = mFirstVisiblePos; i <= mLastVisiblePos; i++) { 924 rows[mGrid.getLocation(i).row].add(i); 925 } 926 } 927 return rows; 928 } 929 930 // Fast layout when there is no structure change, adapter change, etc. 931 protected void fastRelayout() { 932 initScrollController(); 933 934 ArrayList<Integer>[] rows = buildRows(); 935 936 // relayout and repositioning views on each row 937 for (int i = 0; i < mNumRows; i++) { 938 ArrayList<Integer> row = rows[i]; 939 int start = Integer.MIN_VALUE; 940 int startSecondary = 941 i * (mItemLengthSecondary + mMarginSecondary) - mScrollOffsetSecondary; 942 for (int j = 0, size = row.size(); j < size; j++) { 943 int position = row.get(j); 944 start = updateChildView(getViewByPosition(position), start, startSecondary); 945 } 946 } 947 948 appendVisibleItems(); 949 prependVisibleItems(); 950 951 updateRowsMinMax(); 952 updateScrollMin(); 953 updateScrollMax(); 954 955 View focusView = getViewByPosition(mFocusPosition == NO_POSITION ? 0 : mFocusPosition); 956 if (focusView != null) { 957 scrollToView(focusView, false); 958 } 959 } 960 961 // Lays out items based on the current scroll position 962 @Override 963 public void layoutChildren(RecyclerView.Adapter adapter, RecyclerView.Recycler recycler, 964 boolean structureChanged) { 965 if (DEBUG) { 966 Log.v(getTag(), "layoutChildren start numRows " + mNumRows + " mScrollOffsetSecondary " 967 + mScrollOffsetSecondary + " mScrollOffsetPrimary " + mScrollOffsetPrimary 968 + " structureChanged " + structureChanged 969 + " mForceFullLayout " + mForceFullLayout); 970 Log.v(getTag(), "width " + getWidth() + " height " + getHeight()); 971 } 972 973 if (mNumRows == 0) { 974 // haven't done measure yet 975 return; 976 } 977 final int itemCount = adapter.getItemCount(); 978 if (itemCount < 0) { 979 return; 980 } 981 982 mInLayout = true; 983 984 // Track the old focus view so we can adjust our system scroll position 985 // so that any scroll animations happening now will remain valid. 986 int delta = 0, deltaSecondary = 0; 987 if (mFocusPosition != NO_POSITION) { 988 View focusView = getViewByPosition(mFocusPosition); 989 if (focusView != null) { 990 delta = mWindowAlignment.mainAxis().getSystemScrollPos( 991 getViewCenter(focusView) + mScrollOffsetPrimary) - mScrollOffsetPrimary; 992 deltaSecondary = 993 mWindowAlignment.secondAxis().getSystemScrollPos( 994 getViewCenterSecondary(focusView) + mScrollOffsetSecondary) 995 - mScrollOffsetSecondary; 996 } 997 } 998 999 boolean hasDoneFirstLayout = hasDoneFirstLayout(); 1000 if (!structureChanged && !mForceFullLayout && hasDoneFirstLayout) { 1001 fastRelayout(); 1002 } else { 1003 boolean hadFocus = mBaseListView.hasFocus(); 1004 1005 int newFocusPosition = init(adapter, recycler, mFocusPosition); 1006 if (DEBUG) { 1007 Log.v(getTag(), "mFocusPosition " + mFocusPosition + " newFocusPosition " 1008 + newFocusPosition); 1009 } 1010 1011 // depending on result of init(), either recreating everything 1012 // or try to reuse the row start positions near mFocusPosition 1013 if (mGrid.getSize() == 0) { 1014 // this is a fresh creating all items, starting from 1015 // mFocusPosition with a estimated row index. 1016 mGrid.setStart(newFocusPosition, StaggeredGrid.START_DEFAULT); 1017 1018 // Can't track the old focus view 1019 delta = deltaSecondary = 0; 1020 1021 } else { 1022 // mGrid remembers Locations for the column that 1023 // contains mFocusePosition and also mRows remembers start 1024 // positions of each row. 1025 // Manually re-create child views for that column 1026 int firstIndex = mGrid.getFirstIndex(); 1027 int lastIndex = mGrid.getLastIndex(); 1028 for (int i = firstIndex; i <= lastIndex; i++) { 1029 mGridProvider.createItem(i, mGrid.getLocation(i).row, true); 1030 } 1031 } 1032 // add visible views at end until reach the end of window 1033 appendVisibleItems(); 1034 // add visible views at front until reach the start of window 1035 prependVisibleItems(); 1036 // multiple rounds: scrollToView of first round may drag first/last child into 1037 // "visible window" and we update scrollMin/scrollMax then run second scrollToView 1038 int oldFirstVisible; 1039 int oldLastVisible; 1040 do { 1041 oldFirstVisible = mFirstVisiblePos; 1042 oldLastVisible = mLastVisiblePos; 1043 View focusView = getViewByPosition(newFocusPosition); 1044 // we need force to initialize the child view's position 1045 scrollToView(focusView, false); 1046 if (focusView != null && hadFocus) { 1047 focusView.requestFocus(); 1048 } 1049 appendVisibleItems(); 1050 prependVisibleItems(); 1051 removeInvisibleViewsAtFront(); 1052 removeInvisibleViewsAtEnd(); 1053 } while (mFirstVisiblePos != oldFirstVisible || mLastVisiblePos != oldLastVisible); 1054 } 1055 mForceFullLayout = false; 1056 1057 scrollDirectionPrimary(-delta); 1058 scrollDirectionSecondary(-deltaSecondary); 1059 appendVisibleItems(); 1060 prependVisibleItems(); 1061 removeInvisibleViewsAtFront(); 1062 removeInvisibleViewsAtEnd(); 1063 1064 if (DEBUG) { 1065 StringWriter sw = new StringWriter(); 1066 PrintWriter pw = new PrintWriter(sw); 1067 mGrid.debugPrint(pw); 1068 Log.d(getTag(), sw.toString()); 1069 } 1070 1071 removeAndRecycleScrap(recycler); 1072 attemptAnimateLayoutChild(); 1073 1074 if (!hasDoneFirstLayout) { 1075 dispatchChildSelected(); 1076 } 1077 mInLayout = false; 1078 if (DEBUG) Log.v(getTag(), "layoutChildren end"); 1079 } 1080 1081 private void offsetChildrenSecondary(int increment) { 1082 final int childCount = getChildCount(); 1083 if (mOrientation == HORIZONTAL) { 1084 for (int i = 0; i < childCount; i++) { 1085 getChildAt(i).offsetTopAndBottom(increment); 1086 } 1087 } else { 1088 for (int i = 0; i < childCount; i++) { 1089 getChildAt(i).offsetLeftAndRight(increment); 1090 } 1091 } 1092 mScrollOffsetSecondary -= increment; 1093 } 1094 1095 private void offsetChildrenPrimary(int increment) { 1096 final int childCount = getChildCount(); 1097 if (mOrientation == VERTICAL) { 1098 for (int i = 0; i < childCount; i++) { 1099 getChildAt(i).offsetTopAndBottom(increment); 1100 } 1101 } else { 1102 for (int i = 0; i < childCount; i++) { 1103 getChildAt(i).offsetLeftAndRight(increment); 1104 } 1105 } 1106 mScrollOffsetPrimary -= increment; 1107 } 1108 1109 @Override 1110 public int scrollHorizontallyBy(int dx, Adapter adapter, Recycler recycler) { 1111 if (DEBUG) Log.v(TAG, "scrollHorizontallyBy " + dx); 1112 1113 if (mOrientation == HORIZONTAL) { 1114 return scrollDirectionPrimary(dx); 1115 } else { 1116 return scrollDirectionSecondary(dx); 1117 } 1118 } 1119 1120 @Override 1121 public int scrollVerticallyBy(int dy, Adapter adapter, Recycler recycler) { 1122 if (DEBUG) Log.v(TAG, "scrollVerticallyBy " + dy); 1123 if (mOrientation == VERTICAL) { 1124 return scrollDirectionPrimary(dy); 1125 } else { 1126 return scrollDirectionSecondary(dy); 1127 } 1128 } 1129 1130 // scroll in main direction may add/prune views 1131 private int scrollDirectionPrimary(int da) { 1132 offsetChildrenPrimary(-da); 1133 if (mInLayout) { 1134 return da; 1135 } 1136 if (da > 0) { 1137 appendVisibleItems(); 1138 removeInvisibleViewsAtFront(); 1139 } else if (da < 0) { 1140 prependVisibleItems(); 1141 removeInvisibleViewsAtEnd(); 1142 } 1143 attemptAnimateLayoutChild(); 1144 mBaseListView.invalidate(); 1145 return da; 1146 } 1147 1148 // scroll in second direction will not add/prune views 1149 private int scrollDirectionSecondary(int dy) { 1150 offsetChildrenSecondary(-dy); 1151 mBaseListView.invalidate(); 1152 return dy; 1153 } 1154 1155 private void updateScrollMax() { 1156 if (mLastVisiblePos >= 0 && mLastVisiblePos == mAdapter.getItemCount() - 1) { 1157 int maxEdge = Integer.MIN_VALUE; 1158 for (int i = 0; i < mRows.length; i++) { 1159 if (mRows[i].high > maxEdge) { 1160 maxEdge = mRows[i].high; 1161 } 1162 } 1163 mWindowAlignment.mainAxis().setMaxEdge(maxEdge); 1164 if (DEBUG) Log.v(getTag(), "updating scroll maxEdge to " + maxEdge); 1165 } 1166 } 1167 1168 private void updateScrollMin() { 1169 if (mFirstVisiblePos == 0) { 1170 int minEdge = Integer.MAX_VALUE; 1171 for (int i = 0; i < mRows.length; i++) { 1172 if (mRows[i].low < minEdge) { 1173 minEdge = mRows[i].low; 1174 } 1175 } 1176 mWindowAlignment.mainAxis().setMinEdge(minEdge); 1177 if (DEBUG) Log.v(getTag(), "updating scroll minEdge to " + minEdge); 1178 } 1179 } 1180 1181 private void initScrollController() { 1182 mWindowAlignment.horizontal.setSize(getWidth()); 1183 mWindowAlignment.horizontal.setPadding(getPaddingLeft(), getPaddingRight()); 1184 mWindowAlignment.vertical.setSize(getHeight()); 1185 mWindowAlignment.vertical.setPadding(getPaddingTop(), getPaddingBottom()); 1186 mSizePrimary = mWindowAlignment.mainAxis().getSize(); 1187 mWindowAlignment.mainAxis().invalidateScrollMin(); 1188 mWindowAlignment.mainAxis().invalidateScrollMax(); 1189 1190 // second axis min/max is determined at initialization, the mainAxis 1191 // min/max is determined later when we scroll to first or last item 1192 mWindowAlignment.secondAxis().setMinEdge(0); 1193 mWindowAlignment.secondAxis().setMaxEdge(mItemLengthSecondary * mNumRows + mMarginSecondary 1194 * (mNumRows - 1)); 1195 1196 if (DEBUG) { 1197 Log.v(getTag(), "initScrollController mSizePrimary " + mSizePrimary + " " 1198 + " mItemLengthSecondary " + mItemLengthSecondary + " " + mWindowAlignment); 1199 } 1200 } 1201 1202 public void setSelection(RecyclerView parent, int position) { 1203 setSelection(parent, position, false); 1204 } 1205 1206 public void setSelectionSmooth(RecyclerView parent, int position) { 1207 setSelection(parent, position, true); 1208 } 1209 1210 public int getSelection() { 1211 return mFocusPosition; 1212 } 1213 1214 public void setSelection(RecyclerView parent, int position, boolean smooth) { 1215 if (mFocusPosition == position) { 1216 return; 1217 } 1218 View view = getViewByPosition(position); 1219 if (view != null) { 1220 scrollToView(view, smooth); 1221 } else { 1222 boolean right = position > mFocusPosition; 1223 mFocusPosition = position; 1224 if (smooth) { 1225 if (!hasDoneFirstLayout()) { 1226 Log.w(getTag(), "setSelectionSmooth should " + 1227 "not be called before first layout pass"); 1228 return; 1229 } 1230 if (right) { 1231 appendVisibleItems(); 1232 } else { 1233 prependVisibleItems(); 1234 } 1235 view = getViewByPosition(position); 1236 if (view != null) { 1237 scrollToView(view, smooth); 1238 } 1239 } else { 1240 mForceFullLayout = true; 1241 parent.requestLayout(); 1242 } 1243 } 1244 } 1245 1246 @Override 1247 public void onItemsAdded(RecyclerView recyclerView, int positionStart, int itemCount) { 1248 boolean needsLayout = false; 1249 if (itemCount != 0) { 1250 if (mFirstVisiblePos < 0) { 1251 needsLayout = true; 1252 } else if (!(positionStart > mLastVisiblePos + 1 || 1253 positionStart + itemCount < mFirstVisiblePos - 1)) { 1254 needsLayout = true; 1255 } 1256 } 1257 if (needsLayout) { 1258 recyclerView.requestLayout(); 1259 } 1260 } 1261 1262 @Override 1263 public boolean onRequestChildFocus(RecyclerView parent, View child, View focused) { 1264 if (!mInLayout) { 1265 scrollToView(child, true); 1266 } 1267 return true; 1268 } 1269 1270 @Override 1271 public boolean requestChildRectangleOnScreen(RecyclerView parent, View view, Rect rect, 1272 boolean immediate) { 1273 if (DEBUG) Log.v(getTag(), "requestChildRectangleOnScreen " + view + " " + rect); 1274 return false; 1275 } 1276 1277 int getScrollOffsetX() { 1278 return mOrientation == HORIZONTAL ? mScrollOffsetPrimary : mScrollOffsetSecondary; 1279 } 1280 1281 int getScrollOffsetY() { 1282 return mOrientation == HORIZONTAL ? mScrollOffsetSecondary : mScrollOffsetPrimary; 1283 } 1284 1285 public void getViewSelectedOffsets(View view, int[] offsets) { 1286 int scrollOffsetX = getScrollOffsetX(); 1287 int scrollOffsetY = getScrollOffsetY(); 1288 int viewCenterX = scrollOffsetX + getViewCenterX(view); 1289 int viewCenterY = scrollOffsetY + getViewCenterY(view); 1290 offsets[0] = mWindowAlignment.horizontal.getSystemScrollPos(viewCenterX) - scrollOffsetX; 1291 offsets[1] = mWindowAlignment.vertical.getSystemScrollPos(viewCenterY) - scrollOffsetY; 1292 } 1293 1294 /** 1295 * Scroll to a given child view and change mFocusPosition. 1296 */ 1297 private void scrollToView(View view, boolean smooth) { 1298 int newFocusPosition = getPositionByView(view); 1299 if (mInLayout || newFocusPosition != mFocusPosition) { 1300 mFocusPosition = newFocusPosition; 1301 dispatchChildSelected(); 1302 } 1303 if (view == null) { 1304 return; 1305 } 1306 if (!view.hasFocus() && mBaseListView.hasFocus()) { 1307 // transfer focus to the child if it does not have focus yet (e.g. triggered 1308 // by setSelection()) 1309 view.requestFocus(); 1310 } 1311 int viewCenterY = getScrollOffsetY() + getViewCenterY(view); 1312 int viewCenterX = getScrollOffsetX() + getViewCenterX(view); 1313 if (DEBUG) { 1314 Log.v(getTag(), "scrollToView smooth=" + smooth + " pos=" + mFocusPosition + " " 1315 + viewCenterX+","+viewCenterY + " " + mWindowAlignment); 1316 } 1317 1318 if (mInLayout || viewCenterX != mWindowAlignment.horizontal.getScrollCenter() 1319 || viewCenterY != mWindowAlignment.vertical.getScrollCenter()) { 1320 mWindowAlignment.horizontal.updateScrollCenter(viewCenterX); 1321 mWindowAlignment.vertical.updateScrollCenter(viewCenterY); 1322 int scrollX = mWindowAlignment.horizontal.getSystemScrollPos(); 1323 int scrollY = mWindowAlignment.vertical.getSystemScrollPos(); 1324 if (DEBUG) { 1325 Log.v(getTag(), "adjustSystemScrollPos " + scrollX + " " + scrollY + " " 1326 + mWindowAlignment); 1327 } 1328 1329 scrollX -= getScrollOffsetX(); 1330 scrollY -= getScrollOffsetY(); 1331 1332 if (DEBUG) Log.v(getTag(), "scrollX " + scrollX + " scrollY " + scrollY); 1333 1334 if (mInLayout) { 1335 if (mOrientation == HORIZONTAL) { 1336 scrollDirectionPrimary(scrollX); 1337 scrollDirectionSecondary(scrollY); 1338 } else { 1339 scrollDirectionPrimary(scrollY); 1340 scrollDirectionSecondary(scrollX); 1341 } 1342 } else if (smooth) { 1343 mBaseListView.smoothScrollBy(scrollX, scrollY); 1344 } else { 1345 mBaseListView.scrollBy(scrollX, scrollY); 1346 } 1347 } 1348 } 1349 1350 public void setAnimateChildLayout(boolean animateChildLayout) { 1351 mAnimateChildLayout = animateChildLayout; 1352 if (!mAnimateChildLayout) { 1353 for (int i = 0, c = getChildCount(); i < c; i++) { 1354 getViewTag(getChildAt(i)).endAnimate(); 1355 } 1356 } 1357 } 1358 1359 private void attemptAnimateLayoutChild() { 1360 for (int i = 0, c = getChildCount(); i < c; i++) { 1361 // TODO: start delay can be staggered 1362 getViewTag(getChildAt(i)).startAnimate(this, 0); 1363 } 1364 } 1365 1366 public boolean isChildLayoutAnimated() { 1367 return mAnimateChildLayout; 1368 } 1369 1370 public void setChildLayoutAnimationInterpolator(Interpolator interpolator) { 1371 mAnimateLayoutChildInterpolator = interpolator; 1372 } 1373 1374 public Interpolator getChildLayoutAnimationInterpolator() { 1375 return mAnimateLayoutChildInterpolator; 1376 } 1377 1378 public void setChildLayoutAnimationDuration(long duration) { 1379 mAnimateLayoutChildDuration = duration; 1380 } 1381 1382 public long getChildLayoutAnimationDuration() { 1383 return mAnimateLayoutChildDuration; 1384 } 1385 1386 private int findImmediateChildIndex(View view) { 1387 while (view != null && view != mBaseListView) { 1388 int index = mBaseListView.indexOfChild(view); 1389 if (index >= 0) { 1390 return index; 1391 } 1392 view = (View) view.getParent(); 1393 } 1394 return NO_POSITION; 1395 } 1396 1397 @Override 1398 public boolean onAddFocusables(RecyclerView recyclerView, 1399 ArrayList<View> views, int direction, int focusableMode) { 1400 // If this viewgroup or one of its children currently has focus then we 1401 // consider our children for focus searching. 1402 // Otherwise, we only want the system to ignore our children and pass 1403 // focus to the viewgroup, which will pass focus on to its children 1404 // appropriately. 1405 if (recyclerView.hasFocus()) { 1406 final int movement = getMovement(direction); 1407 if (movement != PREV_ITEM && movement != NEXT_ITEM) { 1408 // Move on secondary direction uses default addFocusables(). 1409 return false; 1410 } 1411 // Get current focus row. 1412 final View focused = recyclerView.findFocus(); 1413 final int focusedPos = getPositionByIndex(findImmediateChildIndex(focused)); 1414 final int focusedRow = mGrid != null && focusedPos != NO_POSITION ? 1415 mGrid.getLocation(focusedPos).row : NO_POSITION; 1416 // Add focusables within the same row. 1417 final int focusableCount = views.size(); 1418 final int descendantFocusability = recyclerView.getDescendantFocusability(); 1419 if (mGrid != null && descendantFocusability != ViewGroup.FOCUS_BLOCK_DESCENDANTS) { 1420 for (int i = 0, count = getChildCount(); i < count; i++) { 1421 final View child = getChildAt(i); 1422 if (child.getVisibility() != View.VISIBLE) { 1423 continue; 1424 } 1425 StaggeredGrid.Location loc = mGrid.getLocation(getPositionByIndex(i)); 1426 if (focusedRow == NO_POSITION || (loc != null && loc.row == focusedRow)) { 1427 child.addFocusables(views, direction, focusableMode); 1428 } 1429 } 1430 } 1431 // From ViewGroup.addFocusables(): 1432 // we add ourselves (if focusable) in all cases except for when we are 1433 // FOCUS_AFTER_DESCENDANTS and there are some descendants focusable. this is 1434 // to avoid the focus search finding layouts when a more precise search 1435 // among the focusable children would be more interesting. 1436 if (descendantFocusability != ViewGroup.FOCUS_AFTER_DESCENDANTS 1437 // No focusable descendants 1438 || (focusableCount == views.size())) { 1439 if (recyclerView.isFocusable()) { 1440 views.add(recyclerView); 1441 } 1442 } 1443 } else { 1444 if (recyclerView.isFocusable()) { 1445 views.add(recyclerView); 1446 } 1447 } 1448 return true; 1449 } 1450 1451 @Override 1452 public View onFocusSearchFailed(View focused, int direction, Adapter adapter, 1453 Recycler recycler) { 1454 if (DEBUG) Log.v(getTag(), "onFocusSearchFailed direction " + direction); 1455 1456 View view = null; 1457 int movement = getMovement(direction); 1458 final FocusFinder ff = FocusFinder.getInstance(); 1459 if (movement == NEXT_ITEM) { 1460 while (view == null && !appendOneVisibleItem()) { 1461 view = ff.findNextFocus(mBaseListView, focused, direction); 1462 } 1463 } else if (movement == PREV_ITEM){ 1464 while (view == null && !prependOneVisibleItem()) { 1465 view = ff.findNextFocus(mBaseListView, focused, direction); 1466 } 1467 } 1468 if (view == null) { 1469 // returning the same view to prevent focus lost when scrolling past the end of the list 1470 if (movement == PREV_ITEM) { 1471 view = mFocusOutFront ? null : focused; 1472 } else if (movement == NEXT_ITEM){ 1473 view = mFocusOutEnd ? null : focused; 1474 } 1475 } 1476 if (DEBUG) Log.v(getTag(), "returning view " + view); 1477 return view; 1478 } 1479 1480 private final static int PREV_ITEM = 0; 1481 private final static int NEXT_ITEM = 1; 1482 private final static int PREV_ROW = 2; 1483 private final static int NEXT_ROW = 3; 1484 1485 boolean focusSelectedChild(int direction, Rect previouslyFocusedRect) { 1486 View view = getViewByPosition(mFocusPosition); 1487 if (view != null) { 1488 if (!view.requestFocus(direction, previouslyFocusedRect)) { 1489 if (DEBUG) { 1490 Log.w(getTag(), "failed to request focus on " + view); 1491 } 1492 } else { 1493 return true; 1494 } 1495 } 1496 return false; 1497 } 1498 1499 private int getMovement(int direction) { 1500 int movement = View.FOCUS_LEFT; 1501 1502 if (mOrientation == HORIZONTAL) { 1503 switch(direction) { 1504 case View.FOCUS_LEFT: 1505 movement = PREV_ITEM; 1506 break; 1507 case View.FOCUS_RIGHT: 1508 movement = NEXT_ITEM; 1509 break; 1510 case View.FOCUS_UP: 1511 movement = PREV_ROW; 1512 break; 1513 case View.FOCUS_DOWN: 1514 movement = NEXT_ROW; 1515 break; 1516 } 1517 } else if (mOrientation == VERTICAL) { 1518 switch(direction) { 1519 case View.FOCUS_LEFT: 1520 movement = PREV_ROW; 1521 break; 1522 case View.FOCUS_RIGHT: 1523 movement = NEXT_ROW; 1524 break; 1525 case View.FOCUS_UP: 1526 movement = PREV_ITEM; 1527 break; 1528 case View.FOCUS_DOWN: 1529 movement = NEXT_ITEM; 1530 break; 1531 } 1532 } 1533 1534 return movement; 1535 } 1536 1537 @Override 1538 public void onAdapterChanged() { 1539 mGrid = null; 1540 mRows = null; 1541 super.onAdapterChanged(); 1542 } 1543} 1544