GridLayoutManager.java revision e14d72261ac77c75ee77bdeb4557b57f87feb242
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 + ":" + mBaseGridView.getId(); 51 } 52 53 private final BaseGridView mBaseGridView; 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(BaseGridView baseGridView) { 185 mBaseGridView = baseGridView; 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(mBaseGridView.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(mBaseGridView, view, mFocusPosition, 350 mAdapter.getItemId(mFocusPosition)); 351 } else { 352 mChildSelectedListener.onChildSelected(mBaseGridView, 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 } else { 676 final int lastRow = mRows.length - 1; 677 if (lastRow != rowIndex && mRows[lastRow].high != mRows[lastRow].low) { 678 // if there are existing item in the last row, insert 679 // the new item after the last item of last row. 680 start = mRows[lastRow].high + mMarginPrimary; 681 } 682 } 683 end = start + length; 684 mRows[rowIndex].high = end; 685 } else { 686 end = mRows[rowIndex].low; 687 if (end != mRows[rowIndex].high) { 688 end -= mMarginPrimary; 689 } else if (0 != rowIndex && mRows[0].high != mRows[0].low) { 690 // if there are existing item in the first row, insert 691 // the new item before the first item of first row. 692 end = mRows[0].low - mMarginPrimary; 693 } 694 start = end - length; 695 mRows[rowIndex].low = start; 696 } 697 if (mFirstVisiblePos < 0) { 698 mFirstVisiblePos = mLastVisiblePos = index; 699 } else { 700 if (append) { 701 mLastVisiblePos++; 702 } else { 703 mFirstVisiblePos--; 704 } 705 } 706 int startSecondary = rowIndex * (mItemLengthSecondary + mMarginSecondary); 707 layoutChild(v, start - mScrollOffsetPrimary, end - mScrollOffsetPrimary, 708 startSecondary - mScrollOffsetSecondary); 709 if (DEBUG) { 710 Log.d(getTag(), "addView " + index + " " + v); 711 } 712 updateScrollMin(); 713 updateScrollMax(); 714 } 715 }; 716 717 private void layoutChild(View v, int start, int end, int startSecondary) { 718 if (mOrientation == HORIZONTAL) { 719 v.layout(start, startSecondary, end, startSecondary + mItemLengthSecondary); 720 } else { 721 v.layout(startSecondary, start, startSecondary + mItemLengthSecondary, end); 722 } 723 updateChildAlignments(v); 724 } 725 726 private void updateChildAlignments(View v) { 727 GridLayoutManagerChildTag tag = getViewTag(v); 728 tag.setAlignX(mItemAlignment.horizontal.getAlignmentPosition(v, tag)); 729 tag.setAlignY(mItemAlignment.vertical.getAlignmentPosition(v, tag)); 730 } 731 732 private void updateChildAlignments() { 733 for (int i = 0, c = getChildCount(); i < c; i++) { 734 updateChildAlignments(getChildAt(i)); 735 } 736 } 737 738 /** 739 * append invisible view of saved location 740 */ 741 private void appendViewWithSavedLocation() { 742 int index = mLastVisiblePos + 1; 743 mGridProvider.createItem(index, mGrid.getLocation(index).row, true); 744 } 745 746 /** 747 * prepend invisible view of saved location 748 */ 749 private void prependViewWithSavedLocation() { 750 int index = mFirstVisiblePos - 1; 751 mGridProvider.createItem(index, mGrid.getLocation(index).row, false); 752 } 753 754 private boolean needsAppendVisibleItem() { 755 if (mLastVisiblePos < mFocusPosition) { 756 return true; 757 } 758 int right = mScrollOffsetPrimary + mSizePrimary; 759 for (int i = 0; i < mNumRows; i++) { 760 if (mRows[i].low == mRows[i].high) { 761 if (mRows[i].high < right) { 762 return true; 763 } 764 } else if (mRows[i].high < right - mMarginPrimary) { 765 return true; 766 } 767 } 768 return false; 769 } 770 771 private boolean needsPrependVisibleItem() { 772 if (mFirstVisiblePos > mFocusPosition) { 773 return true; 774 } 775 for (int i = 0; i < mNumRows; i++) { 776 if (mRows[i].low == mRows[i].high) { 777 if (mRows[i].low > mScrollOffsetPrimary) { 778 return true; 779 } 780 } else if (mRows[i].low - mMarginPrimary > mScrollOffsetPrimary) { 781 return true; 782 } 783 } 784 return false; 785 } 786 787 // Append one column if possible and return true if reach end. 788 private boolean appendOneVisibleItem() { 789 if (mLastVisiblePos >= 0 && mLastVisiblePos < mGrid.getLastIndex()) { 790 appendViewWithSavedLocation(); 791 } else if (mLastVisiblePos < mAdapter.getItemCount() - 1) { 792 mGrid.appendItems(mScrollOffsetPrimary + mSizePrimary); 793 } else { 794 return true; 795 } 796 return false; 797 } 798 799 private void appendVisibleItems() { 800 while (needsAppendVisibleItem()) { 801 if (appendOneVisibleItem()) { 802 break; 803 } 804 } 805 } 806 807 // Prepend one column if possible and return true if reach end. 808 private boolean prependOneVisibleItem() { 809 if (mFirstVisiblePos > 0) { 810 if (mFirstVisiblePos > mGrid.getFirstIndex()) { 811 prependViewWithSavedLocation(); 812 } else { 813 mGrid.prependItems(mScrollOffsetPrimary); 814 } 815 } else { 816 return true; 817 } 818 return false; 819 } 820 821 private void prependVisibleItems() { 822 while (needsPrependVisibleItem()) { 823 if (prependOneVisibleItem()) { 824 break; 825 } 826 } 827 } 828 829 // TODO: use removeAndRecycleViewAt() once we stop using tags. 830 private void removeChildAt(int position) { 831 View v = getViewByPosition(position); 832 if (v != null) { 833 if (DEBUG) { 834 Log.d(getTag(), "detachAndScrape " + position); 835 } 836 getViewTag(v).detach(); 837 removeAndRecycleViewAt(getIndexByPosition(position), mRecycler); 838 } 839 } 840 841 private void removeInvisibleViewsAtEnd() { 842 boolean update = false; 843 while(mLastVisiblePos > mFirstVisiblePos && mLastVisiblePos > mFocusPosition) { 844 View view = getViewByPosition(mLastVisiblePos); 845 if (getViewMin(view) > mSizePrimary) { 846 removeChildAt(mLastVisiblePos); 847 mLastVisiblePos--; 848 update = true; 849 } else { 850 break; 851 } 852 } 853 if (update) { 854 updateRowsMinMax(); 855 } 856 } 857 858 private void removeInvisibleViewsAtFront() { 859 boolean update = false; 860 while(mLastVisiblePos > mFirstVisiblePos && mFirstVisiblePos < mFocusPosition) { 861 View view = getViewByPosition(mFirstVisiblePos); 862 if (getViewMax(view) < 0) { 863 removeChildAt(mFirstVisiblePos); 864 mFirstVisiblePos++; 865 update = true; 866 } else { 867 break; 868 } 869 } 870 if (update) { 871 updateRowsMinMax(); 872 } 873 } 874 875 private void updateRowsMinMax() { 876 if (mFirstVisiblePos < 0) { 877 return; 878 } 879 for (int i = 0; i < mNumRows; i++) { 880 mRows[i].low = Integer.MAX_VALUE; 881 mRows[i].high = Integer.MIN_VALUE; 882 } 883 for (int i = mFirstVisiblePos; i <= mLastVisiblePos; i++) { 884 View view = getViewByPosition(i); 885 int row = mGrid.getLocation(i).row; 886 int low = getViewMin(view) + mScrollOffsetPrimary; 887 if (low < mRows[row].low) { 888 mRows[row].low = low; 889 } 890 int high = getViewMax(view) + mScrollOffsetPrimary; 891 if (high > mRows[row].high) { 892 mRows[row].high = high; 893 } 894 } 895 } 896 897 /** 898 * Relayout and re-positioning child for a possible new size and/or a new 899 * start. 900 * 901 * @param view View to measure and layout. 902 * @param start New start of the view or Integer.MIN_VALUE for not change. 903 * @return New start of next view. 904 */ 905 private int updateChildView(View view, int start, int startSecondary) { 906 if (start == Integer.MIN_VALUE) { 907 start = getViewMin(view); 908 } 909 int end; 910 if (mOrientation == HORIZONTAL) { 911 if (view.isLayoutRequested() || view.getMeasuredHeight() != mItemLengthSecondary) { 912 measureChild(view); 913 } 914 end = start + view.getMeasuredWidth(); 915 } else { 916 if (view.isLayoutRequested() || view.getMeasuredWidth() != mItemLengthSecondary) { 917 measureChild(view); 918 } 919 end = start + view.getMeasuredHeight(); 920 } 921 922 layoutChild(view, start, end, startSecondary); 923 return end + mMarginPrimary; 924 } 925 926 // create a temporary structure that remembers visible items from left to 927 // right on each row 928 private ArrayList<Integer>[] buildRows() { 929 ArrayList<Integer>[] rows = new ArrayList[mNumRows]; 930 for (int i = 0; i < mNumRows; i++) { 931 rows[i] = new ArrayList(); 932 } 933 if (mFirstVisiblePos >= 0) { 934 for (int i = mFirstVisiblePos; i <= mLastVisiblePos; i++) { 935 rows[mGrid.getLocation(i).row].add(i); 936 } 937 } 938 return rows; 939 } 940 941 // Fast layout when there is no structure change, adapter change, etc. 942 protected void fastRelayout() { 943 initScrollController(); 944 945 ArrayList<Integer>[] rows = buildRows(); 946 947 // relayout and repositioning views on each row 948 for (int i = 0; i < mNumRows; i++) { 949 ArrayList<Integer> row = rows[i]; 950 int start = Integer.MIN_VALUE; 951 int startSecondary = 952 i * (mItemLengthSecondary + mMarginSecondary) - mScrollOffsetSecondary; 953 for (int j = 0, size = row.size(); j < size; j++) { 954 int position = row.get(j); 955 start = updateChildView(getViewByPosition(position), start, startSecondary); 956 } 957 } 958 959 appendVisibleItems(); 960 prependVisibleItems(); 961 962 updateRowsMinMax(); 963 updateScrollMin(); 964 updateScrollMax(); 965 966 View focusView = getViewByPosition(mFocusPosition == NO_POSITION ? 0 : mFocusPosition); 967 if (focusView != null) { 968 scrollToView(focusView, false); 969 } 970 } 971 972 // Lays out items based on the current scroll position 973 @Override 974 public void layoutChildren(RecyclerView.Adapter adapter, RecyclerView.Recycler recycler, 975 boolean structureChanged) { 976 if (DEBUG) { 977 Log.v(getTag(), "layoutChildren start numRows " + mNumRows + " mScrollOffsetSecondary " 978 + mScrollOffsetSecondary + " mScrollOffsetPrimary " + mScrollOffsetPrimary 979 + " structureChanged " + structureChanged 980 + " mForceFullLayout " + mForceFullLayout); 981 Log.v(getTag(), "width " + getWidth() + " height " + getHeight()); 982 } 983 984 if (mNumRows == 0) { 985 // haven't done measure yet 986 return; 987 } 988 final int itemCount = adapter.getItemCount(); 989 if (itemCount < 0) { 990 return; 991 } 992 993 mInLayout = true; 994 995 // Track the old focus view so we can adjust our system scroll position 996 // so that any scroll animations happening now will remain valid. 997 int delta = 0, deltaSecondary = 0; 998 if (mFocusPosition != NO_POSITION) { 999 View focusView = getViewByPosition(mFocusPosition); 1000 if (focusView != null) { 1001 delta = mWindowAlignment.mainAxis().getSystemScrollPos( 1002 getViewCenter(focusView) + mScrollOffsetPrimary) - mScrollOffsetPrimary; 1003 deltaSecondary = 1004 mWindowAlignment.secondAxis().getSystemScrollPos( 1005 getViewCenterSecondary(focusView) + mScrollOffsetSecondary) 1006 - mScrollOffsetSecondary; 1007 } 1008 } 1009 1010 boolean hasDoneFirstLayout = hasDoneFirstLayout(); 1011 if (!structureChanged && !mForceFullLayout && hasDoneFirstLayout) { 1012 fastRelayout(); 1013 } else { 1014 boolean hadFocus = mBaseGridView.hasFocus(); 1015 1016 int newFocusPosition = init(adapter, recycler, mFocusPosition); 1017 if (DEBUG) { 1018 Log.v(getTag(), "mFocusPosition " + mFocusPosition + " newFocusPosition " 1019 + newFocusPosition); 1020 } 1021 1022 // depending on result of init(), either recreating everything 1023 // or try to reuse the row start positions near mFocusPosition 1024 if (mGrid.getSize() == 0) { 1025 // this is a fresh creating all items, starting from 1026 // mFocusPosition with a estimated row index. 1027 mGrid.setStart(newFocusPosition, StaggeredGrid.START_DEFAULT); 1028 1029 // Can't track the old focus view 1030 delta = deltaSecondary = 0; 1031 1032 } else { 1033 // mGrid remembers Locations for the column that 1034 // contains mFocusePosition and also mRows remembers start 1035 // positions of each row. 1036 // Manually re-create child views for that column 1037 int firstIndex = mGrid.getFirstIndex(); 1038 int lastIndex = mGrid.getLastIndex(); 1039 for (int i = firstIndex; i <= lastIndex; i++) { 1040 mGridProvider.createItem(i, mGrid.getLocation(i).row, true); 1041 } 1042 } 1043 // add visible views at end until reach the end of window 1044 appendVisibleItems(); 1045 // add visible views at front until reach the start of window 1046 prependVisibleItems(); 1047 // multiple rounds: scrollToView of first round may drag first/last child into 1048 // "visible window" and we update scrollMin/scrollMax then run second scrollToView 1049 int oldFirstVisible; 1050 int oldLastVisible; 1051 do { 1052 oldFirstVisible = mFirstVisiblePos; 1053 oldLastVisible = mLastVisiblePos; 1054 View focusView = getViewByPosition(newFocusPosition); 1055 // we need force to initialize the child view's position 1056 scrollToView(focusView, false); 1057 if (focusView != null && hadFocus) { 1058 focusView.requestFocus(); 1059 } 1060 appendVisibleItems(); 1061 prependVisibleItems(); 1062 removeInvisibleViewsAtFront(); 1063 removeInvisibleViewsAtEnd(); 1064 } while (mFirstVisiblePos != oldFirstVisible || mLastVisiblePos != oldLastVisible); 1065 } 1066 mForceFullLayout = false; 1067 1068 scrollDirectionPrimary(-delta); 1069 scrollDirectionSecondary(-deltaSecondary); 1070 appendVisibleItems(); 1071 prependVisibleItems(); 1072 removeInvisibleViewsAtFront(); 1073 removeInvisibleViewsAtEnd(); 1074 1075 if (DEBUG) { 1076 StringWriter sw = new StringWriter(); 1077 PrintWriter pw = new PrintWriter(sw); 1078 mGrid.debugPrint(pw); 1079 Log.d(getTag(), sw.toString()); 1080 } 1081 1082 removeAndRecycleScrap(recycler); 1083 attemptAnimateLayoutChild(); 1084 1085 if (!hasDoneFirstLayout) { 1086 dispatchChildSelected(); 1087 } 1088 mInLayout = false; 1089 if (DEBUG) Log.v(getTag(), "layoutChildren end"); 1090 } 1091 1092 private void offsetChildrenSecondary(int increment) { 1093 final int childCount = getChildCount(); 1094 if (mOrientation == HORIZONTAL) { 1095 for (int i = 0; i < childCount; i++) { 1096 getChildAt(i).offsetTopAndBottom(increment); 1097 } 1098 } else { 1099 for (int i = 0; i < childCount; i++) { 1100 getChildAt(i).offsetLeftAndRight(increment); 1101 } 1102 } 1103 mScrollOffsetSecondary -= increment; 1104 } 1105 1106 private void offsetChildrenPrimary(int increment) { 1107 final int childCount = getChildCount(); 1108 if (mOrientation == VERTICAL) { 1109 for (int i = 0; i < childCount; i++) { 1110 getChildAt(i).offsetTopAndBottom(increment); 1111 } 1112 } else { 1113 for (int i = 0; i < childCount; i++) { 1114 getChildAt(i).offsetLeftAndRight(increment); 1115 } 1116 } 1117 mScrollOffsetPrimary -= increment; 1118 } 1119 1120 @Override 1121 public int scrollHorizontallyBy(int dx, Adapter adapter, Recycler recycler) { 1122 if (DEBUG) Log.v(TAG, "scrollHorizontallyBy " + dx); 1123 1124 if (mOrientation == HORIZONTAL) { 1125 return scrollDirectionPrimary(dx); 1126 } else { 1127 return scrollDirectionSecondary(dx); 1128 } 1129 } 1130 1131 @Override 1132 public int scrollVerticallyBy(int dy, Adapter adapter, Recycler recycler) { 1133 if (DEBUG) Log.v(TAG, "scrollVerticallyBy " + dy); 1134 if (mOrientation == VERTICAL) { 1135 return scrollDirectionPrimary(dy); 1136 } else { 1137 return scrollDirectionSecondary(dy); 1138 } 1139 } 1140 1141 // scroll in main direction may add/prune views 1142 private int scrollDirectionPrimary(int da) { 1143 offsetChildrenPrimary(-da); 1144 if (mInLayout) { 1145 return da; 1146 } 1147 if (da > 0) { 1148 appendVisibleItems(); 1149 removeInvisibleViewsAtFront(); 1150 } else if (da < 0) { 1151 prependVisibleItems(); 1152 removeInvisibleViewsAtEnd(); 1153 } 1154 attemptAnimateLayoutChild(); 1155 mBaseGridView.invalidate(); 1156 return da; 1157 } 1158 1159 // scroll in second direction will not add/prune views 1160 private int scrollDirectionSecondary(int dy) { 1161 offsetChildrenSecondary(-dy); 1162 mBaseGridView.invalidate(); 1163 return dy; 1164 } 1165 1166 private void updateScrollMax() { 1167 if (mLastVisiblePos >= 0 && mLastVisiblePos == mAdapter.getItemCount() - 1) { 1168 int maxEdge = Integer.MIN_VALUE; 1169 for (int i = 0; i < mRows.length; i++) { 1170 if (mRows[i].high > maxEdge) { 1171 maxEdge = mRows[i].high; 1172 } 1173 } 1174 mWindowAlignment.mainAxis().setMaxEdge(maxEdge); 1175 if (DEBUG) Log.v(getTag(), "updating scroll maxEdge to " + maxEdge); 1176 } 1177 } 1178 1179 private void updateScrollMin() { 1180 if (mFirstVisiblePos == 0) { 1181 int minEdge = Integer.MAX_VALUE; 1182 for (int i = 0; i < mRows.length; i++) { 1183 if (mRows[i].low < minEdge) { 1184 minEdge = mRows[i].low; 1185 } 1186 } 1187 mWindowAlignment.mainAxis().setMinEdge(minEdge); 1188 if (DEBUG) Log.v(getTag(), "updating scroll minEdge to " + minEdge); 1189 } 1190 } 1191 1192 private void initScrollController() { 1193 mWindowAlignment.horizontal.setSize(getWidth()); 1194 mWindowAlignment.horizontal.setPadding(getPaddingLeft(), getPaddingRight()); 1195 mWindowAlignment.vertical.setSize(getHeight()); 1196 mWindowAlignment.vertical.setPadding(getPaddingTop(), getPaddingBottom()); 1197 mSizePrimary = mWindowAlignment.mainAxis().getSize(); 1198 mWindowAlignment.mainAxis().invalidateScrollMin(); 1199 mWindowAlignment.mainAxis().invalidateScrollMax(); 1200 1201 // second axis min/max is determined at initialization, the mainAxis 1202 // min/max is determined later when we scroll to first or last item 1203 mWindowAlignment.secondAxis().setMinEdge(0); 1204 mWindowAlignment.secondAxis().setMaxEdge(mItemLengthSecondary * mNumRows + mMarginSecondary 1205 * (mNumRows - 1)); 1206 1207 if (DEBUG) { 1208 Log.v(getTag(), "initScrollController mSizePrimary " + mSizePrimary + " " 1209 + " mItemLengthSecondary " + mItemLengthSecondary + " " + mWindowAlignment); 1210 } 1211 } 1212 1213 public void setSelection(RecyclerView parent, int position) { 1214 setSelection(parent, position, false); 1215 } 1216 1217 public void setSelectionSmooth(RecyclerView parent, int position) { 1218 setSelection(parent, position, true); 1219 } 1220 1221 public int getSelection() { 1222 return mFocusPosition; 1223 } 1224 1225 public void setSelection(RecyclerView parent, int position, boolean smooth) { 1226 if (mFocusPosition == position) { 1227 return; 1228 } 1229 View view = getViewByPosition(position); 1230 if (view != null) { 1231 scrollToView(view, smooth); 1232 } else { 1233 boolean right = position > mFocusPosition; 1234 mFocusPosition = position; 1235 if (smooth) { 1236 if (!hasDoneFirstLayout()) { 1237 Log.w(getTag(), "setSelectionSmooth should " + 1238 "not be called before first layout pass"); 1239 return; 1240 } 1241 if (right) { 1242 appendVisibleItems(); 1243 } else { 1244 prependVisibleItems(); 1245 } 1246 view = getViewByPosition(position); 1247 if (view != null) { 1248 scrollToView(view, smooth); 1249 } 1250 } else { 1251 mForceFullLayout = true; 1252 parent.requestLayout(); 1253 } 1254 } 1255 } 1256 1257 @Override 1258 public void onItemsAdded(RecyclerView recyclerView, int positionStart, int itemCount) { 1259 boolean needsLayout = false; 1260 if (itemCount != 0) { 1261 if (mFirstVisiblePos < 0) { 1262 needsLayout = true; 1263 } else if (!(positionStart > mLastVisiblePos + 1 || 1264 positionStart + itemCount < mFirstVisiblePos - 1)) { 1265 needsLayout = true; 1266 } 1267 } 1268 if (needsLayout) { 1269 recyclerView.requestLayout(); 1270 } 1271 } 1272 1273 @Override 1274 public boolean onRequestChildFocus(RecyclerView parent, View child, View focused) { 1275 if (!mInLayout) { 1276 scrollToView(child, true); 1277 } 1278 return true; 1279 } 1280 1281 @Override 1282 public boolean requestChildRectangleOnScreen(RecyclerView parent, View view, Rect rect, 1283 boolean immediate) { 1284 if (DEBUG) Log.v(getTag(), "requestChildRectangleOnScreen " + view + " " + rect); 1285 return false; 1286 } 1287 1288 int getScrollOffsetX() { 1289 return mOrientation == HORIZONTAL ? mScrollOffsetPrimary : mScrollOffsetSecondary; 1290 } 1291 1292 int getScrollOffsetY() { 1293 return mOrientation == HORIZONTAL ? mScrollOffsetSecondary : mScrollOffsetPrimary; 1294 } 1295 1296 public void getViewSelectedOffsets(View view, int[] offsets) { 1297 int scrollOffsetX = getScrollOffsetX(); 1298 int scrollOffsetY = getScrollOffsetY(); 1299 int viewCenterX = scrollOffsetX + getViewCenterX(view); 1300 int viewCenterY = scrollOffsetY + getViewCenterY(view); 1301 offsets[0] = mWindowAlignment.horizontal.getSystemScrollPos(viewCenterX) - scrollOffsetX; 1302 offsets[1] = mWindowAlignment.vertical.getSystemScrollPos(viewCenterY) - scrollOffsetY; 1303 } 1304 1305 /** 1306 * Scroll to a given child view and change mFocusPosition. 1307 */ 1308 private void scrollToView(View view, boolean smooth) { 1309 int newFocusPosition = getPositionByView(view); 1310 if (mInLayout || newFocusPosition != mFocusPosition) { 1311 mFocusPosition = newFocusPosition; 1312 dispatchChildSelected(); 1313 } 1314 if (view == null) { 1315 return; 1316 } 1317 if (!view.hasFocus() && mBaseGridView.hasFocus()) { 1318 // transfer focus to the child if it does not have focus yet (e.g. triggered 1319 // by setSelection()) 1320 view.requestFocus(); 1321 } 1322 int viewCenterY = getScrollOffsetY() + getViewCenterY(view); 1323 int viewCenterX = getScrollOffsetX() + getViewCenterX(view); 1324 if (DEBUG) { 1325 Log.v(getTag(), "scrollToView smooth=" + smooth + " pos=" + mFocusPosition + " " 1326 + viewCenterX+","+viewCenterY + " " + mWindowAlignment); 1327 } 1328 1329 if (mInLayout || viewCenterX != mWindowAlignment.horizontal.getScrollCenter() 1330 || viewCenterY != mWindowAlignment.vertical.getScrollCenter()) { 1331 mWindowAlignment.horizontal.updateScrollCenter(viewCenterX); 1332 mWindowAlignment.vertical.updateScrollCenter(viewCenterY); 1333 int scrollX = mWindowAlignment.horizontal.getSystemScrollPos(); 1334 int scrollY = mWindowAlignment.vertical.getSystemScrollPos(); 1335 if (DEBUG) { 1336 Log.v(getTag(), "adjustSystemScrollPos " + scrollX + " " + scrollY + " " 1337 + mWindowAlignment); 1338 } 1339 1340 scrollX -= getScrollOffsetX(); 1341 scrollY -= getScrollOffsetY(); 1342 1343 if (DEBUG) Log.v(getTag(), "scrollX " + scrollX + " scrollY " + scrollY); 1344 1345 if (mInLayout) { 1346 if (mOrientation == HORIZONTAL) { 1347 scrollDirectionPrimary(scrollX); 1348 scrollDirectionSecondary(scrollY); 1349 } else { 1350 scrollDirectionPrimary(scrollY); 1351 scrollDirectionSecondary(scrollX); 1352 } 1353 } else if (smooth) { 1354 mBaseGridView.smoothScrollBy(scrollX, scrollY); 1355 } else { 1356 mBaseGridView.scrollBy(scrollX, scrollY); 1357 } 1358 } 1359 } 1360 1361 public void setAnimateChildLayout(boolean animateChildLayout) { 1362 mAnimateChildLayout = animateChildLayout; 1363 if (!mAnimateChildLayout) { 1364 for (int i = 0, c = getChildCount(); i < c; i++) { 1365 getViewTag(getChildAt(i)).endAnimate(); 1366 } 1367 } 1368 } 1369 1370 private void attemptAnimateLayoutChild() { 1371 for (int i = 0, c = getChildCount(); i < c; i++) { 1372 // TODO: start delay can be staggered 1373 getViewTag(getChildAt(i)).startAnimate(this, 0); 1374 } 1375 } 1376 1377 public boolean isChildLayoutAnimated() { 1378 return mAnimateChildLayout; 1379 } 1380 1381 public void setChildLayoutAnimationInterpolator(Interpolator interpolator) { 1382 mAnimateLayoutChildInterpolator = interpolator; 1383 } 1384 1385 public Interpolator getChildLayoutAnimationInterpolator() { 1386 return mAnimateLayoutChildInterpolator; 1387 } 1388 1389 public void setChildLayoutAnimationDuration(long duration) { 1390 mAnimateLayoutChildDuration = duration; 1391 } 1392 1393 public long getChildLayoutAnimationDuration() { 1394 return mAnimateLayoutChildDuration; 1395 } 1396 1397 private int findImmediateChildIndex(View view) { 1398 while (view != null && view != mBaseGridView) { 1399 int index = mBaseGridView.indexOfChild(view); 1400 if (index >= 0) { 1401 return index; 1402 } 1403 view = (View) view.getParent(); 1404 } 1405 return NO_POSITION; 1406 } 1407 1408 @Override 1409 public boolean onAddFocusables(RecyclerView recyclerView, 1410 ArrayList<View> views, int direction, int focusableMode) { 1411 // If this viewgroup or one of its children currently has focus then we 1412 // consider our children for focus searching. 1413 // Otherwise, we only want the system to ignore our children and pass 1414 // focus to the viewgroup, which will pass focus on to its children 1415 // appropriately. 1416 if (recyclerView.hasFocus()) { 1417 final int movement = getMovement(direction); 1418 if (movement != PREV_ITEM && movement != NEXT_ITEM) { 1419 // Move on secondary direction uses default addFocusables(). 1420 return false; 1421 } 1422 // Get current focus row. 1423 final View focused = recyclerView.findFocus(); 1424 final int focusedPos = getPositionByIndex(findImmediateChildIndex(focused)); 1425 final int focusedRow = mGrid != null && focusedPos != NO_POSITION ? 1426 mGrid.getLocation(focusedPos).row : NO_POSITION; 1427 // Add focusables within the same row. 1428 final int focusableCount = views.size(); 1429 final int descendantFocusability = recyclerView.getDescendantFocusability(); 1430 if (mGrid != null && descendantFocusability != ViewGroup.FOCUS_BLOCK_DESCENDANTS) { 1431 for (int i = 0, count = getChildCount(); i < count; i++) { 1432 final View child = getChildAt(i); 1433 if (child.getVisibility() != View.VISIBLE) { 1434 continue; 1435 } 1436 StaggeredGrid.Location loc = mGrid.getLocation(getPositionByIndex(i)); 1437 if (focusedRow == NO_POSITION || (loc != null && loc.row == focusedRow)) { 1438 child.addFocusables(views, direction, focusableMode); 1439 } 1440 } 1441 } 1442 // From ViewGroup.addFocusables(): 1443 // we add ourselves (if focusable) in all cases except for when we are 1444 // FOCUS_AFTER_DESCENDANTS and there are some descendants focusable. this is 1445 // to avoid the focus search finding layouts when a more precise search 1446 // among the focusable children would be more interesting. 1447 if (descendantFocusability != ViewGroup.FOCUS_AFTER_DESCENDANTS 1448 // No focusable descendants 1449 || (focusableCount == views.size())) { 1450 if (recyclerView.isFocusable()) { 1451 views.add(recyclerView); 1452 } 1453 } 1454 } else { 1455 if (recyclerView.isFocusable()) { 1456 views.add(recyclerView); 1457 } 1458 } 1459 return true; 1460 } 1461 1462 @Override 1463 public View onFocusSearchFailed(View focused, int direction, Adapter adapter, 1464 Recycler recycler) { 1465 if (DEBUG) Log.v(getTag(), "onFocusSearchFailed direction " + direction); 1466 1467 View view = null; 1468 int movement = getMovement(direction); 1469 final FocusFinder ff = FocusFinder.getInstance(); 1470 if (movement == NEXT_ITEM) { 1471 while (view == null && !appendOneVisibleItem()) { 1472 view = ff.findNextFocus(mBaseGridView, focused, direction); 1473 } 1474 } else if (movement == PREV_ITEM){ 1475 while (view == null && !prependOneVisibleItem()) { 1476 view = ff.findNextFocus(mBaseGridView, focused, direction); 1477 } 1478 } 1479 if (view == null) { 1480 // returning the same view to prevent focus lost when scrolling past the end of the list 1481 if (movement == PREV_ITEM) { 1482 view = mFocusOutFront ? null : focused; 1483 } else if (movement == NEXT_ITEM){ 1484 view = mFocusOutEnd ? null : focused; 1485 } 1486 } 1487 if (DEBUG) Log.v(getTag(), "returning view " + view); 1488 return view; 1489 } 1490 1491 private final static int PREV_ITEM = 0; 1492 private final static int NEXT_ITEM = 1; 1493 private final static int PREV_ROW = 2; 1494 private final static int NEXT_ROW = 3; 1495 1496 boolean focusSelectedChild(int direction, Rect previouslyFocusedRect) { 1497 View view = getViewByPosition(mFocusPosition); 1498 if (view != null) { 1499 if (!view.requestFocus(direction, previouslyFocusedRect)) { 1500 if (DEBUG) { 1501 Log.w(getTag(), "failed to request focus on " + view); 1502 } 1503 } else { 1504 return true; 1505 } 1506 } 1507 return false; 1508 } 1509 1510 private int getMovement(int direction) { 1511 int movement = View.FOCUS_LEFT; 1512 1513 if (mOrientation == HORIZONTAL) { 1514 switch(direction) { 1515 case View.FOCUS_LEFT: 1516 movement = PREV_ITEM; 1517 break; 1518 case View.FOCUS_RIGHT: 1519 movement = NEXT_ITEM; 1520 break; 1521 case View.FOCUS_UP: 1522 movement = PREV_ROW; 1523 break; 1524 case View.FOCUS_DOWN: 1525 movement = NEXT_ROW; 1526 break; 1527 } 1528 } else if (mOrientation == VERTICAL) { 1529 switch(direction) { 1530 case View.FOCUS_LEFT: 1531 movement = PREV_ROW; 1532 break; 1533 case View.FOCUS_RIGHT: 1534 movement = NEXT_ROW; 1535 break; 1536 case View.FOCUS_UP: 1537 movement = PREV_ITEM; 1538 break; 1539 case View.FOCUS_DOWN: 1540 movement = NEXT_ITEM; 1541 break; 1542 } 1543 } 1544 1545 return movement; 1546 } 1547 1548 @Override 1549 public void onAdapterChanged() { 1550 mGrid = null; 1551 mRows = null; 1552 super.onAdapterChanged(); 1553 } 1554} 1555