GridLayoutManager.java revision 2d8ec4a44f2ffcfb83247c5f0e12e45aec7e4174
1/* 2 * Copyright (C) 2014 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except 5 * in compliance with the License. You may obtain a copy of the License at 6 * 7 * http://www.apache.org/licenses/LICENSE-2.0 8 * 9 * Unless required by applicable law or agreed to in writing, software distributed under the License 10 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express 11 * or implied. See the License for the specific language governing permissions and limitations under 12 * the License. 13 */ 14package android.support.v17.leanback.widget; 15 16import android.animation.TimeAnimator; 17import android.content.Context; 18import android.graphics.Rect; 19import android.support.v7.widget.RecyclerView; 20import android.support.v7.widget.RecyclerView.Adapter; 21import android.support.v7.widget.RecyclerView.Recycler; 22 23import static android.support.v7.widget.RecyclerView.NO_ID; 24import static android.support.v7.widget.RecyclerView.NO_POSITION; 25import static android.support.v7.widget.RecyclerView.HORIZONTAL; 26import static android.support.v7.widget.RecyclerView.VERTICAL; 27 28import android.util.AttributeSet; 29import android.util.Log; 30import android.view.FocusFinder; 31import android.view.Gravity; 32import android.view.View; 33import android.view.ViewParent; 34import android.view.View.MeasureSpec; 35import android.view.ViewGroup.MarginLayoutParams; 36import android.view.ViewGroup; 37import android.view.animation.DecelerateInterpolator; 38import android.view.animation.Interpolator; 39 40import java.io.PrintWriter; 41import java.io.StringWriter; 42import java.util.ArrayList; 43import java.util.List; 44 45final class GridLayoutManager extends RecyclerView.LayoutManager { 46 47 /* 48 * LayoutParams for {@link HorizontalGridView} and {@link VerticalGridView}. 49 * The class currently does three internal jobs: 50 * - Saves optical bounds insets. 51 * - Caches focus align view center. 52 * - Manages child view layout animation. 53 */ 54 static class LayoutParams extends RecyclerView.LayoutParams { 55 56 // The view is saved only during animation. 57 private View mView; 58 59 // For placement 60 private int mLeftInset; 61 private int mTopInset; 62 private int mRighInset; 63 private int mBottomInset; 64 65 // For alignment 66 private int mAlignX; 67 private int mAlignY; 68 69 // For animations 70 private TimeAnimator mAnimator; 71 private long mDuration; 72 private boolean mFirstAttached; 73 // current virtual view position (scrollOffset + left/top) in the GridLayoutManager 74 private int mViewX, mViewY; 75 // animation start value of translation x and y 76 private float mAnimationStartTranslationX, mAnimationStartTranslationY; 77 78 public LayoutParams(Context c, AttributeSet attrs) { 79 super(c, attrs); 80 } 81 82 public LayoutParams(int width, int height) { 83 super(width, height); 84 } 85 86 public LayoutParams(MarginLayoutParams source) { 87 super(source); 88 } 89 90 public LayoutParams(ViewGroup.LayoutParams source) { 91 super(source); 92 } 93 94 public LayoutParams(RecyclerView.LayoutParams source) { 95 super(source); 96 } 97 98 public LayoutParams(LayoutParams source) { 99 super(source); 100 } 101 102 void onViewAttached() { 103 endAnimate(); 104 mFirstAttached = true; 105 } 106 107 void onViewDetached() { 108 endAnimate(); 109 } 110 111 int getAlignX() { 112 return mAlignX; 113 } 114 115 int getAlignY() { 116 return mAlignY; 117 } 118 119 int getOpticalLeft(View view) { 120 return view.getLeft() + mLeftInset; 121 } 122 123 int getOpticalTop(View view) { 124 return view.getTop() + mTopInset; 125 } 126 127 int getOpticalRight(View view) { 128 return view.getRight() - mRighInset; 129 } 130 131 int getOpticalBottom(View view) { 132 return view.getBottom() - mBottomInset; 133 } 134 135 int getOpticalWidth(View view) { 136 return view.getWidth() - mLeftInset - mRighInset; 137 } 138 139 int getOpticalHeight(View view) { 140 return view.getHeight() - mTopInset - mBottomInset; 141 } 142 143 void setAlignX(int alignX) { 144 mAlignX = alignX; 145 } 146 147 void setAlignY(int alignY) { 148 mAlignY = alignY; 149 } 150 151 void setOpticalInsets(int leftInset, int topInset, int rightInset, int bottomInset) { 152 mLeftInset = leftInset; 153 mTopInset = topInset; 154 mRighInset = rightInset; 155 mBottomInset = bottomInset; 156 } 157 158 private TimeAnimator.TimeListener mTimeListener = new TimeAnimator.TimeListener() { 159 @Override 160 public void onTimeUpdate(TimeAnimator animation, long totalTime, long deltaTime) { 161 if (mView == null) { 162 return; 163 } 164 if (totalTime >= mDuration) { 165 endAnimate(); 166 } else { 167 float fraction = (float) (totalTime / (double)mDuration); 168 float fractionToEnd = 1 - mAnimator 169 .getInterpolator().getInterpolation(fraction); 170 mView.setTranslationX(fractionToEnd * mAnimationStartTranslationX); 171 mView.setTranslationY(fractionToEnd * mAnimationStartTranslationY); 172 invalidateItemDecoration(); 173 } 174 } 175 }; 176 177 void startAnimate(GridLayoutManager layout, View view, long startDelay) { 178 if (mAnimator == null) { 179 mAnimator = new TimeAnimator(); 180 mAnimator.setTimeListener(mTimeListener); 181 } 182 if (mFirstAttached) { 183 // first time record the initial location and return without animation 184 // TODO do we need initial animation? 185 mViewX = layout.getScrollOffsetX() + getOpticalLeft(view); 186 mViewY = layout.getScrollOffsetY() + getOpticalTop(view); 187 mFirstAttached = false; 188 return; 189 } 190 mView = view; 191 int newViewX = layout.getScrollOffsetX() + getOpticalLeft(mView); 192 int newViewY = layout.getScrollOffsetY() + getOpticalTop(mView); 193 if (newViewX != mViewX || newViewY != mViewY) { 194 mAnimator.cancel(); 195 mAnimationStartTranslationX = mView.getTranslationX(); 196 mAnimationStartTranslationY = mView.getTranslationY(); 197 mAnimationStartTranslationX += mViewX - newViewX; 198 mAnimationStartTranslationY += mViewY - newViewY; 199 mDuration = layout.getChildLayoutAnimationDuration(); 200 mAnimator.setDuration(mDuration); 201 mAnimator.setInterpolator(layout.getChildLayoutAnimationInterpolator()); 202 mAnimator.setStartDelay(startDelay); 203 mAnimator.start(); 204 mViewX = newViewX; 205 mViewY = newViewY; 206 } 207 } 208 209 void endAnimate() { 210 if (mAnimator != null) { 211 mAnimator.end(); 212 } 213 if (mView != null) { 214 mView.setTranslationX(0); 215 mView.setTranslationY(0); 216 mView = null; 217 } 218 } 219 220 private void invalidateItemDecoration() { 221 ViewParent parent = mView.getParent(); 222 if (parent instanceof RecyclerView) { 223 // TODO: we only need invalidate parent if it has ItemDecoration 224 ((RecyclerView) parent).invalidate(); 225 } 226 } 227 } 228 229 private static final String TAG = "GridLayoutManager"; 230 private static final boolean DEBUG = false; 231 232 private static final Interpolator sDefaultAnimationChildLayoutInterpolator 233 = new DecelerateInterpolator(); 234 235 private static final long DEFAULT_CHILD_ANIMATION_DURATION_MS = 250; 236 237 private String getTag() { 238 return TAG + ":" + mBaseGridView.getId(); 239 } 240 241 private final BaseGridView mBaseGridView; 242 243 /** 244 * The orientation of a "row". 245 */ 246 private int mOrientation = HORIZONTAL; 247 248 private RecyclerView.Adapter mAdapter; 249 private RecyclerView.Recycler mRecycler; 250 251 private boolean mInLayout = false; 252 253 private OnChildSelectedListener mChildSelectedListener = null; 254 255 /** 256 * The focused position, it's not the currently visually aligned position 257 * but it is the final position that we intend to focus on. If there are 258 * multiple setSelection() called, mFocusPosition saves last value. 259 */ 260 private int mFocusPosition = NO_POSITION; 261 262 /** 263 * Force a full layout under certain situations. 264 */ 265 private boolean mForceFullLayout; 266 267 /** 268 * The scroll offsets of the viewport relative to the entire view. 269 */ 270 private int mScrollOffsetPrimary; 271 private int mScrollOffsetSecondary; 272 273 /** 274 * User-specified fixed size of each grid item in the secondary direction, can be 275 * 0 to be determined by parent size and number of rows. 276 */ 277 private int mItemLengthSecondaryRequested; 278 /** 279 * The fixed size of each grid item in the secondary direction. This corresponds to 280 * the row height, equal for all rows. Grid items may have variable length 281 * in the primary direction. 282 * 283 */ 284 private int mItemLengthSecondary; 285 286 /** 287 * Margin between items. 288 */ 289 private int mHorizontalMargin; 290 /** 291 * Margin between items vertically. 292 */ 293 private int mVerticalMargin; 294 /** 295 * Margin in main direction. 296 */ 297 private int mMarginPrimary; 298 /** 299 * Margin in second direction. 300 */ 301 private int mMarginSecondary; 302 /** 303 * How to position child in secondary direction. 304 */ 305 private int mGravity = Gravity.LEFT | Gravity.TOP; 306 /** 307 * The number of rows in the grid. 308 */ 309 private int mNumRows; 310 /** 311 * Number of rows requested, can be 0 to be determined by parent size and 312 * rowHeight. 313 */ 314 private int mNumRowsRequested = 1; 315 316 /** 317 * Tracking start/end position of each row for visible items. 318 */ 319 private StaggeredGrid.Row[] mRows; 320 321 /** 322 * Saves grid information of each view. 323 */ 324 private StaggeredGrid mGrid; 325 /** 326 * Position of first item (included) that has attached views. 327 */ 328 private int mFirstVisiblePos; 329 /** 330 * Position of last item (included) that has attached views. 331 */ 332 private int mLastVisiblePos; 333 334 /** 335 * Focus Scroll strategy. 336 */ 337 private int mFocusScrollStrategy = BaseGridView.FOCUS_SCROLL_ALIGNED; 338 /** 339 * Defines how item view is aligned in the window. 340 */ 341 private final WindowAlignment mWindowAlignment = new WindowAlignment(); 342 343 /** 344 * Defines how item view is aligned. 345 */ 346 private final ItemAlignment mItemAlignment = new ItemAlignment(); 347 348 /** 349 * Dimensions of the view, width or height depending on orientation. 350 */ 351 private int mSizePrimary; 352 353 /** 354 * Allow DPAD key to navigate out at the front of the View (where position = 0), 355 * default is false. 356 */ 357 private boolean mFocusOutFront; 358 359 /** 360 * Allow DPAD key to navigate out at the end of the view, default is false. 361 */ 362 private boolean mFocusOutEnd; 363 364 /** 365 * Animate layout changes from a child resizing or adding/removing a child. 366 */ 367 private boolean mAnimateChildLayout = true; 368 369 /** 370 * Interpolator used to animate layout of children. 371 */ 372 private Interpolator mAnimateLayoutChildInterpolator = sDefaultAnimationChildLayoutInterpolator; 373 374 /** 375 * Duration used to animate layout of children. 376 */ 377 private long mAnimateLayoutChildDuration = DEFAULT_CHILD_ANIMATION_DURATION_MS; 378 379 public GridLayoutManager(BaseGridView baseGridView) { 380 mBaseGridView = baseGridView; 381 } 382 383 public void setOrientation(int orientation) { 384 if (orientation != HORIZONTAL && orientation != VERTICAL) { 385 if (DEBUG) Log.v(getTag(), "invalid orientation: " + orientation); 386 return; 387 } 388 389 mOrientation = orientation; 390 mWindowAlignment.setOrientation(orientation); 391 mItemAlignment.setOrientation(orientation); 392 mForceFullLayout = true; 393 } 394 395 public int getFocusScrollStrategy() { 396 return mFocusScrollStrategy; 397 } 398 399 public void setFocusScrollStrategy(int focusScrollStrategy) { 400 mFocusScrollStrategy = focusScrollStrategy; 401 } 402 403 public void setWindowAlignment(int windowAlignment) { 404 mWindowAlignment.mainAxis().setWindowAlignment(windowAlignment); 405 } 406 407 public int getWindowAlignment() { 408 return mWindowAlignment.mainAxis().getWindowAlignment(); 409 } 410 411 public void setWindowAlignmentOffset(int alignmentOffset) { 412 mWindowAlignment.mainAxis().setWindowAlignmentOffset(alignmentOffset); 413 } 414 415 public int getWindowAlignmentOffset() { 416 return mWindowAlignment.mainAxis().getWindowAlignmentOffset(); 417 } 418 419 public void setWindowAlignmentOffsetPercent(float offsetPercent) { 420 mWindowAlignment.mainAxis().setWindowAlignmentOffsetPercent(offsetPercent); 421 } 422 423 public float getWindowAlignmentOffsetPercent() { 424 return mWindowAlignment.mainAxis().getWindowAlignmentOffsetPercent(); 425 } 426 427 public void setItemAlignmentOffset(int alignmentOffset) { 428 mItemAlignment.mainAxis().setItemAlignmentOffset(alignmentOffset); 429 updateChildAlignments(); 430 } 431 432 public int getItemAlignmentOffset() { 433 return mItemAlignment.mainAxis().getItemAlignmentOffset(); 434 } 435 436 public void setItemAlignmentOffsetPercent(float offsetPercent) { 437 mItemAlignment.mainAxis().setItemAlignmentOffsetPercent(offsetPercent); 438 updateChildAlignments(); 439 } 440 441 public float getItemAlignmentOffsetPercent() { 442 return mItemAlignment.mainAxis().getItemAlignmentOffsetPercent(); 443 } 444 445 public void setItemAlignmentViewId(int viewId) { 446 mItemAlignment.mainAxis().setItemAlignmentViewId(viewId); 447 updateChildAlignments(); 448 } 449 450 public int getItemAlignmentViewId() { 451 return mItemAlignment.mainAxis().getItemAlignmentViewId(); 452 } 453 454 public void setFocusOutAllowed(boolean throughFront, boolean throughEnd) { 455 mFocusOutFront = throughFront; 456 mFocusOutEnd = throughEnd; 457 } 458 459 public void setNumRows(int numRows) { 460 if (numRows < 0) throw new IllegalArgumentException(); 461 mNumRowsRequested = numRows; 462 mForceFullLayout = true; 463 } 464 465 public void setRowHeight(int height) { 466 if (height < 0) throw new IllegalArgumentException(); 467 mItemLengthSecondaryRequested = height; 468 } 469 470 public void setItemMargin(int margin) { 471 mVerticalMargin = mHorizontalMargin = margin; 472 mMarginPrimary = mMarginSecondary = margin; 473 } 474 475 public void setVerticalMargin(int margin) { 476 if (mOrientation == HORIZONTAL) { 477 mMarginSecondary = mVerticalMargin = margin; 478 } else { 479 mMarginPrimary = mVerticalMargin = margin; 480 } 481 } 482 483 public void setHorizontalMargin(int margin) { 484 if (mOrientation == HORIZONTAL) { 485 mMarginPrimary = mHorizontalMargin = margin; 486 } else { 487 mMarginSecondary = mHorizontalMargin = margin; 488 } 489 } 490 491 public int getVerticalMargin() { 492 return mVerticalMargin; 493 } 494 495 public int getHorizontalMargin() { 496 return mHorizontalMargin; 497 } 498 499 public void setGravity(int gravity) { 500 mGravity = gravity; 501 } 502 503 protected boolean hasDoneFirstLayout() { 504 return mGrid != null; 505 } 506 507 public void setOnChildSelectedListener(OnChildSelectedListener listener) { 508 mChildSelectedListener = listener; 509 } 510 511 private int getPositionByView(View view) { 512 return getPositionByIndex(mBaseGridView.indexOfChild(view)); 513 } 514 515 private int getPositionByIndex(int index) { 516 if (index < 0) { 517 return NO_POSITION; 518 } 519 return mFirstVisiblePos + index; 520 } 521 522 private View getViewByPosition(int position) { 523 int index = getIndexByPosition(position); 524 if (index < 0) { 525 return null; 526 } 527 return getChildAt(index); 528 } 529 530 private int getIndexByPosition(int position) { 531 if (mFirstVisiblePos < 0 || 532 position < mFirstVisiblePos || position > mLastVisiblePos) { 533 return NO_POSITION; 534 } 535 return position - mFirstVisiblePos; 536 } 537 538 private void dispatchChildSelected() { 539 if (mChildSelectedListener == null) { 540 return; 541 } 542 543 View view = getViewByPosition(mFocusPosition); 544 545 if (mFocusPosition != NO_POSITION) { 546 mChildSelectedListener.onChildSelected(mBaseGridView, view, mFocusPosition, 547 mAdapter.getItemId(mFocusPosition)); 548 } else { 549 mChildSelectedListener.onChildSelected(mBaseGridView, null, NO_POSITION, NO_ID); 550 } 551 } 552 553 @Override 554 public boolean canScrollHorizontally() { 555 // We can scroll horizontally if we have horizontal orientation, or if 556 // we are vertical and have more than one column. 557 return mOrientation == HORIZONTAL || mNumRows > 1; 558 } 559 560 @Override 561 public boolean canScrollVertically() { 562 // We can scroll vertically if we have vertical orientation, or if we 563 // are horizontal and have more than one row. 564 return mOrientation == VERTICAL || mNumRows > 1; 565 } 566 567 @Override 568 public RecyclerView.LayoutParams generateDefaultLayoutParams() { 569 return new LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, 570 ViewGroup.LayoutParams.WRAP_CONTENT); 571 } 572 573 @Override 574 public RecyclerView.LayoutParams generateLayoutParams(Context context, AttributeSet attrs) { 575 return new LayoutParams(context, attrs); 576 } 577 578 @Override 579 public RecyclerView.LayoutParams generateLayoutParams(ViewGroup.LayoutParams lp) { 580 if (lp instanceof LayoutParams) { 581 return new LayoutParams((LayoutParams) lp); 582 } else if (lp instanceof RecyclerView.LayoutParams) { 583 return new LayoutParams((RecyclerView.LayoutParams) lp); 584 } else if (lp instanceof MarginLayoutParams) { 585 return new LayoutParams((MarginLayoutParams) lp); 586 } else { 587 return new LayoutParams(lp); 588 } 589 } 590 591 protected View getViewForPosition(int position) { 592 View v = mRecycler.getViewForPosition(mAdapter, position); 593 if (v != null) { 594 ((LayoutParams) v.getLayoutParams()).onViewAttached(); 595 } 596 return v; 597 } 598 599 final int getOpticalLeft(View v) { 600 return ((LayoutParams) v.getLayoutParams()).getOpticalLeft(v); 601 } 602 603 final int getOpticalRight(View v) { 604 return ((LayoutParams) v.getLayoutParams()).getOpticalRight(v); 605 } 606 607 final int getOpticalTop(View v) { 608 return ((LayoutParams) v.getLayoutParams()).getOpticalTop(v); 609 } 610 611 final int getOpticalBottom(View v) { 612 return ((LayoutParams) v.getLayoutParams()).getOpticalBottom(v); 613 } 614 615 private int getViewMin(View v) { 616 return (mOrientation == HORIZONTAL) ? getOpticalLeft(v) : getOpticalTop(v); 617 } 618 619 private int getViewMax(View v) { 620 return (mOrientation == HORIZONTAL) ? getOpticalRight(v) : getOpticalBottom(v); 621 } 622 623 private int getViewCenter(View view) { 624 return (mOrientation == HORIZONTAL) ? getViewCenterX(view) : getViewCenterY(view); 625 } 626 627 private int getViewCenterSecondary(View view) { 628 return (mOrientation == HORIZONTAL) ? getViewCenterY(view) : getViewCenterX(view); 629 } 630 631 private int getViewCenterX(View v) { 632 LayoutParams p = (LayoutParams) v.getLayoutParams(); 633 return p.getOpticalLeft(v) + p.getAlignX(); 634 } 635 636 private int getViewCenterY(View v) { 637 LayoutParams p = (LayoutParams) v.getLayoutParams(); 638 return p.getOpticalTop(v) + p.getAlignY(); 639 } 640 641 /** 642 * Re-initialize data structures for a data change or handling invisible 643 * selection. The method tries its best to preserve position information so 644 * that staggered grid looks same before and after re-initialize. 645 * @param focusPosition The initial focusPosition that we would like to 646 * focus on. 647 * @return Actual position that can be focused on. 648 */ 649 private int init(RecyclerView.Adapter adapter, RecyclerView.Recycler recycler, 650 int focusPosition) { 651 652 final int newItemCount = adapter.getItemCount(); 653 654 if (focusPosition == NO_POSITION && newItemCount > 0) { 655 // if focus position is never set before, initialize it to 0 656 focusPosition = 0; 657 } 658 // If adapter has changed then caches are invalid; otherwise, 659 // we try to maintain each row's position if number of rows keeps the same 660 // and existing mGrid contains the focusPosition. 661 if (mRows != null && mNumRows == mRows.length && 662 mGrid != null && mGrid.getSize() > 0 && focusPosition >= 0 && 663 focusPosition >= mGrid.getFirstIndex() && 664 focusPosition <= mGrid.getLastIndex()) { 665 // strip mGrid to a subset (like a column) that contains focusPosition 666 mGrid.stripDownTo(focusPosition); 667 // make sure that remaining items do not exceed new adapter size 668 int firstIndex = mGrid.getFirstIndex(); 669 int lastIndex = mGrid.getLastIndex(); 670 if (DEBUG) { 671 Log .v(getTag(), "mGrid firstIndex " + firstIndex + " lastIndex " + lastIndex); 672 } 673 for (int i = lastIndex; i >=firstIndex; i--) { 674 if (i >= newItemCount) { 675 mGrid.removeLast(); 676 } 677 } 678 if (mGrid.getSize() == 0) { 679 focusPosition = newItemCount - 1; 680 // initialize row start locations 681 for (int i = 0; i < mNumRows; i++) { 682 mRows[i].low = 0; 683 mRows[i].high = 0; 684 } 685 if (DEBUG) Log.v(getTag(), "mGrid zero size"); 686 } else { 687 // initialize row start locations 688 for (int i = 0; i < mNumRows; i++) { 689 mRows[i].low = Integer.MAX_VALUE; 690 mRows[i].high = Integer.MIN_VALUE; 691 } 692 firstIndex = mGrid.getFirstIndex(); 693 lastIndex = mGrid.getLastIndex(); 694 if (focusPosition > lastIndex) { 695 focusPosition = mGrid.getLastIndex(); 696 } 697 if (DEBUG) { 698 Log.v(getTag(), "mGrid firstIndex " + firstIndex + " lastIndex " 699 + lastIndex + " focusPosition " + focusPosition); 700 } 701 // fill rows with minimal view positions of the subset 702 for (int i = firstIndex; i <= lastIndex; i++) { 703 View v = getViewByPosition(i); 704 if (v == null) { 705 continue; 706 } 707 int row = mGrid.getLocation(i).row; 708 int low = getViewMin(v) + mScrollOffsetPrimary; 709 if (low < mRows[row].low) { 710 mRows[row].low = mRows[row].high = low; 711 } 712 } 713 // fill other rows that does not include the subset using first item 714 int firstItemRowPosition = mRows[mGrid.getLocation(firstIndex).row].low; 715 if (firstItemRowPosition == Integer.MAX_VALUE) { 716 firstItemRowPosition = 0; 717 } 718 for (int i = 0; i < mNumRows; i++) { 719 if (mRows[i].low == Integer.MAX_VALUE) { 720 mRows[i].low = mRows[i].high = firstItemRowPosition; 721 } 722 } 723 } 724 725 // Same adapter, we can reuse any attached views 726 detachAndScrapAttachedViews(recycler); 727 728 } else { 729 // otherwise recreate data structure 730 mRows = new StaggeredGrid.Row[mNumRows]; 731 for (int i = 0; i < mNumRows; i++) { 732 mRows[i] = new StaggeredGrid.Row(); 733 } 734 mGrid = new StaggeredGridDefault(); 735 if (newItemCount == 0) { 736 focusPosition = NO_POSITION; 737 } else if (focusPosition >= newItemCount) { 738 focusPosition = newItemCount - 1; 739 } 740 741 // Adapter may have changed so remove all attached views permanently 742 removeAllViews(); 743 744 mScrollOffsetPrimary = 0; 745 mScrollOffsetSecondary = 0; 746 mWindowAlignment.reset(); 747 } 748 749 mAdapter = adapter; 750 mRecycler = recycler; 751 mGrid.setProvider(mGridProvider); 752 // mGrid share the same Row array information 753 mGrid.setRows(mRows); 754 mFirstVisiblePos = mLastVisiblePos = NO_POSITION; 755 756 initScrollController(); 757 758 return focusPosition; 759 } 760 761 @Override 762 public void onMeasure(int widthSpec, int heightSpec) { 763 int sizePrimary, sizeSecondary, modeSecondary, paddingSecondary; 764 int measuredSizeSecondary; 765 if (mOrientation == HORIZONTAL) { 766 sizePrimary = MeasureSpec.getSize(widthSpec); 767 sizeSecondary = MeasureSpec.getSize(heightSpec); 768 modeSecondary = MeasureSpec.getMode(heightSpec); 769 paddingSecondary = getPaddingTop() + getPaddingBottom(); 770 } else { 771 sizeSecondary = MeasureSpec.getSize(widthSpec); 772 sizePrimary = MeasureSpec.getSize(heightSpec); 773 modeSecondary = MeasureSpec.getMode(widthSpec); 774 paddingSecondary = getPaddingLeft() + getPaddingRight(); 775 } 776 switch (modeSecondary) { 777 case MeasureSpec.UNSPECIFIED: 778 if (mItemLengthSecondaryRequested == 0) { 779 if (mOrientation == HORIZONTAL) { 780 throw new IllegalStateException("Must specify rowHeight or view height"); 781 } else { 782 throw new IllegalStateException("Must specify columnWidth or view width"); 783 } 784 } 785 mItemLengthSecondary = mItemLengthSecondaryRequested; 786 if (mNumRowsRequested == 0) { 787 mNumRows = 1; 788 } else { 789 mNumRows = mNumRowsRequested; 790 } 791 measuredSizeSecondary = mItemLengthSecondary * mNumRows + mMarginSecondary 792 * (mNumRows - 1) + paddingSecondary; 793 break; 794 case MeasureSpec.AT_MOST: 795 case MeasureSpec.EXACTLY: 796 if (mNumRowsRequested == 0 && mItemLengthSecondaryRequested == 0) { 797 mNumRows = 1; 798 mItemLengthSecondary = sizeSecondary - paddingSecondary; 799 } else if (mNumRowsRequested == 0) { 800 mItemLengthSecondary = mItemLengthSecondaryRequested; 801 mNumRows = (sizeSecondary + mMarginSecondary) 802 / (mItemLengthSecondaryRequested + mMarginSecondary); 803 } else if (mItemLengthSecondaryRequested == 0) { 804 mNumRows = mNumRowsRequested; 805 mItemLengthSecondary = (sizeSecondary - paddingSecondary - mMarginSecondary 806 * (mNumRows - 1)) / mNumRows; 807 } else { 808 mNumRows = mNumRowsRequested; 809 mItemLengthSecondary = mItemLengthSecondaryRequested; 810 } 811 measuredSizeSecondary = sizeSecondary; 812 if (modeSecondary == MeasureSpec.AT_MOST) { 813 int childrenSize = mItemLengthSecondary * mNumRows + mMarginSecondary 814 * (mNumRows - 1) + paddingSecondary; 815 if (childrenSize < measuredSizeSecondary) { 816 measuredSizeSecondary = childrenSize; 817 } 818 } 819 break; 820 default: 821 throw new IllegalStateException("wrong spec"); 822 } 823 if (mOrientation == HORIZONTAL) { 824 setMeasuredDimension(sizePrimary, measuredSizeSecondary); 825 } else { 826 setMeasuredDimension(measuredSizeSecondary, sizePrimary); 827 } 828 if (DEBUG) { 829 Log.v(getTag(), "onMeasure sizePrimary " + sizePrimary + 830 " measuredSizeSecondary " + measuredSizeSecondary + 831 " mItemLengthSecondary " + mItemLengthSecondary + 832 " mNumRows " + mNumRows); 833 } 834 } 835 836 private void measureChild(View child) { 837 final ViewGroup.LayoutParams lp = child.getLayoutParams(); 838 839 int widthSpec, heightSpec; 840 if (mOrientation == HORIZONTAL) { 841 widthSpec = ViewGroup.getChildMeasureSpec( 842 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 0, lp.width); 843 heightSpec = ViewGroup.getChildMeasureSpec(MeasureSpec.makeMeasureSpec( 844 mItemLengthSecondary, MeasureSpec.EXACTLY), 0, lp.height); 845 } else { 846 heightSpec = ViewGroup.getChildMeasureSpec( 847 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 0, lp.height); 848 widthSpec = ViewGroup.getChildMeasureSpec(MeasureSpec.makeMeasureSpec( 849 mItemLengthSecondary, MeasureSpec.EXACTLY), 0, lp.width); 850 } 851 852 child.measure(widthSpec, heightSpec); 853 } 854 855 private StaggeredGrid.Provider mGridProvider = new StaggeredGrid.Provider() { 856 857 @Override 858 public int getCount() { 859 return mAdapter.getItemCount(); 860 } 861 862 @Override 863 public void createItem(int index, int rowIndex, boolean append) { 864 View v = getViewForPosition(index); 865 if (mFirstVisiblePos >= 0) { 866 // when StaggeredGrid append or prepend item, we must guarantee 867 // that sibling item has created views already. 868 if (append && index != mLastVisiblePos + 1) { 869 throw new RuntimeException(); 870 } else if (!append && index != mFirstVisiblePos - 1) { 871 throw new RuntimeException(); 872 } 873 } 874 875 if (append) { 876 addView(v); 877 } else { 878 addView(v, 0); 879 } 880 881 measureChild(v); 882 883 int length = mOrientation == HORIZONTAL ? v.getMeasuredWidth() : v.getMeasuredHeight(); 884 int start, end; 885 if (append) { 886 start = mRows[rowIndex].high; 887 if (start != mRows[rowIndex].low) { 888 // if there are existing item in the row, add margin between 889 start += mMarginPrimary; 890 } else { 891 final int lastRow = mRows.length - 1; 892 if (lastRow != rowIndex && mRows[lastRow].high != mRows[lastRow].low) { 893 // if there are existing item in the last row, insert 894 // the new item after the last item of last row. 895 start = mRows[lastRow].high + mMarginPrimary; 896 } 897 } 898 end = start + length; 899 mRows[rowIndex].high = end; 900 } else { 901 end = mRows[rowIndex].low; 902 if (end != mRows[rowIndex].high) { 903 end -= mMarginPrimary; 904 } else if (0 != rowIndex && mRows[0].high != mRows[0].low) { 905 // if there are existing item in the first row, insert 906 // the new item before the first item of first row. 907 end = mRows[0].low - mMarginPrimary; 908 } 909 start = end - length; 910 mRows[rowIndex].low = start; 911 } 912 if (mFirstVisiblePos < 0) { 913 mFirstVisiblePos = mLastVisiblePos = index; 914 } else { 915 if (append) { 916 mLastVisiblePos++; 917 } else { 918 mFirstVisiblePos--; 919 } 920 } 921 int startSecondary = rowIndex * (mItemLengthSecondary + mMarginSecondary); 922 layoutChild(v, start - mScrollOffsetPrimary, end - mScrollOffsetPrimary, 923 startSecondary - mScrollOffsetSecondary); 924 if (DEBUG) { 925 Log.d(getTag(), "addView " + index + " " + v); 926 } 927 updateScrollMin(); 928 updateScrollMax(); 929 } 930 }; 931 932 private void layoutChild(View v, int start, int end, int startSecondary) { 933 int measuredSecondary = mOrientation == HORIZONTAL ? v.getMeasuredHeight() 934 : v.getMeasuredWidth(); 935 if (measuredSecondary > mItemLengthSecondary) { 936 measuredSecondary = mItemLengthSecondary; 937 } 938 final int verticalGravity = mGravity & Gravity.VERTICAL_GRAVITY_MASK; 939 final int horizontalGravity = mGravity & Gravity.HORIZONTAL_GRAVITY_MASK; 940 if (mOrientation == HORIZONTAL && verticalGravity == Gravity.TOP 941 || mOrientation == VERTICAL && horizontalGravity == Gravity.LEFT) { 942 // do nothing 943 } else if (mOrientation == HORIZONTAL && verticalGravity == Gravity.BOTTOM 944 || mOrientation == VERTICAL && horizontalGravity == Gravity.RIGHT) { 945 startSecondary += mItemLengthSecondary - measuredSecondary; 946 } else if (mOrientation == HORIZONTAL && verticalGravity == Gravity.CENTER_VERTICAL 947 || mOrientation == VERTICAL && horizontalGravity == Gravity.CENTER_HORIZONTAL) { 948 startSecondary += (mItemLengthSecondary - measuredSecondary) / 2; 949 } 950 int left, top, right, bottom; 951 if (mOrientation == HORIZONTAL) { 952 left = start; 953 top = startSecondary; 954 right = end; 955 bottom = startSecondary + measuredSecondary; 956 } else { 957 top = start; 958 left = startSecondary; 959 bottom = end; 960 right = startSecondary + measuredSecondary; 961 } 962 v.layout(left, top, right, bottom); 963 updateChildOpticalInsets(v, left, top, right, bottom); 964 updateChildAlignments(v); 965 } 966 967 private void updateChildOpticalInsets(View v, int left, int top, int right, int bottom) { 968 LayoutParams p = (LayoutParams) v.getLayoutParams(); 969 p.setOpticalInsets(left - v.getLeft(), top - v.getTop(), 970 v.getRight() - right, v.getBottom() - bottom); 971 } 972 973 private void updateChildAlignments(View v) { 974 LayoutParams p = (LayoutParams) v.getLayoutParams(); 975 p.setAlignX(mItemAlignment.horizontal.getAlignmentPosition(v)); 976 p.setAlignY(mItemAlignment.vertical.getAlignmentPosition(v)); 977 } 978 979 private void updateChildAlignments() { 980 for (int i = 0, c = getChildCount(); i < c; i++) { 981 updateChildAlignments(getChildAt(i)); 982 } 983 } 984 985 private boolean needsAppendVisibleItem() { 986 if (mLastVisiblePos < mFocusPosition) { 987 return true; 988 } 989 int right = mScrollOffsetPrimary + mSizePrimary; 990 for (int i = 0; i < mNumRows; i++) { 991 if (mRows[i].low == mRows[i].high) { 992 if (mRows[i].high < right) { 993 return true; 994 } 995 } else if (mRows[i].high < right - mMarginPrimary) { 996 return true; 997 } 998 } 999 return false; 1000 } 1001 1002 private boolean needsPrependVisibleItem() { 1003 if (mFirstVisiblePos > mFocusPosition) { 1004 return true; 1005 } 1006 for (int i = 0; i < mNumRows; i++) { 1007 if (mRows[i].low == mRows[i].high) { 1008 if (mRows[i].low > mScrollOffsetPrimary) { 1009 return true; 1010 } 1011 } else if (mRows[i].low - mMarginPrimary > mScrollOffsetPrimary) { 1012 return true; 1013 } 1014 } 1015 return false; 1016 } 1017 1018 // Append one column if possible and return true if reach end. 1019 private boolean appendOneVisibleItem() { 1020 while (true) { 1021 if (mLastVisiblePos != NO_POSITION && mLastVisiblePos < mAdapter.getItemCount() -1 && 1022 mLastVisiblePos < mGrid.getLastIndex()) { 1023 // append invisible view of saved location till last row 1024 final int index = mLastVisiblePos + 1; 1025 final int row = mGrid.getLocation(index).row; 1026 mGridProvider.createItem(index, row, true); 1027 if (row == mNumRows - 1) { 1028 return false; 1029 } 1030 } else if ((mLastVisiblePos == NO_POSITION && mAdapter.getItemCount() > 0) || 1031 (mLastVisiblePos != NO_POSITION && 1032 mLastVisiblePos < mAdapter.getItemCount() - 1)) { 1033 mGrid.appendItems(mScrollOffsetPrimary + mSizePrimary); 1034 return false; 1035 } else { 1036 return true; 1037 } 1038 } 1039 } 1040 1041 private void appendVisibleItems() { 1042 while (needsAppendVisibleItem()) { 1043 if (appendOneVisibleItem()) { 1044 break; 1045 } 1046 } 1047 } 1048 1049 // Prepend one column if possible and return true if reach end. 1050 private boolean prependOneVisibleItem() { 1051 while (true) { 1052 if (mFirstVisiblePos > 0) { 1053 if (mFirstVisiblePos > mGrid.getFirstIndex()) { 1054 // prepend invisible view of saved location till first row 1055 final int index = mFirstVisiblePos - 1; 1056 final int row = mGrid.getLocation(index).row; 1057 mGridProvider.createItem(index, row, false); 1058 if (row == 0) { 1059 return false; 1060 } 1061 } else { 1062 mGrid.prependItems(mScrollOffsetPrimary); 1063 return false; 1064 } 1065 } else { 1066 return true; 1067 } 1068 } 1069 } 1070 1071 private void prependVisibleItems() { 1072 while (needsPrependVisibleItem()) { 1073 if (prependOneVisibleItem()) { 1074 break; 1075 } 1076 } 1077 } 1078 1079 private void removeChildAt(int position) { 1080 View v = getViewByPosition(position); 1081 if (v != null) { 1082 if (DEBUG) { 1083 Log.d(getTag(), "removeAndRecycleViewAt " + position); 1084 } 1085 ((LayoutParams) v.getLayoutParams()).onViewDetached(); 1086 removeAndRecycleViewAt(getIndexByPosition(position), mRecycler); 1087 } 1088 } 1089 1090 private void removeInvisibleViewsAtEnd() { 1091 boolean update = false; 1092 while(mLastVisiblePos > mFirstVisiblePos && mLastVisiblePos > mFocusPosition) { 1093 View view = getViewByPosition(mLastVisiblePos); 1094 if (getViewMin(view) > mSizePrimary) { 1095 removeChildAt(mLastVisiblePos); 1096 mLastVisiblePos--; 1097 update = true; 1098 } else { 1099 break; 1100 } 1101 } 1102 if (update) { 1103 updateRowsMinMax(); 1104 } 1105 } 1106 1107 private void removeInvisibleViewsAtFront() { 1108 boolean update = false; 1109 while(mLastVisiblePos > mFirstVisiblePos && mFirstVisiblePos < mFocusPosition) { 1110 View view = getViewByPosition(mFirstVisiblePos); 1111 if (getViewMax(view) < 0) { 1112 removeChildAt(mFirstVisiblePos); 1113 mFirstVisiblePos++; 1114 update = true; 1115 } else { 1116 break; 1117 } 1118 } 1119 if (update) { 1120 updateRowsMinMax(); 1121 } 1122 } 1123 1124 private void updateRowsMinMax() { 1125 if (mFirstVisiblePos < 0) { 1126 return; 1127 } 1128 for (int i = 0; i < mNumRows; i++) { 1129 mRows[i].low = Integer.MAX_VALUE; 1130 mRows[i].high = Integer.MIN_VALUE; 1131 } 1132 for (int i = mFirstVisiblePos; i <= mLastVisiblePos; i++) { 1133 View view = getViewByPosition(i); 1134 int row = mGrid.getLocation(i).row; 1135 int low = getViewMin(view) + mScrollOffsetPrimary; 1136 if (low < mRows[row].low) { 1137 mRows[row].low = low; 1138 } 1139 int high = getViewMax(view) + mScrollOffsetPrimary; 1140 if (high > mRows[row].high) { 1141 mRows[row].high = high; 1142 } 1143 } 1144 } 1145 1146 /** 1147 * Relayout and re-positioning child for a possible new size and/or a new 1148 * start. 1149 * 1150 * @param view View to measure and layout. 1151 * @param start New start of the view or Integer.MIN_VALUE for not change. 1152 * @return New start of next view. 1153 */ 1154 private int updateChildView(View view, int start, int startSecondary) { 1155 if (start == Integer.MIN_VALUE) { 1156 start = getViewMin(view); 1157 } 1158 int end; 1159 if (mOrientation == HORIZONTAL) { 1160 if (view.isLayoutRequested() || view.getMeasuredHeight() != mItemLengthSecondary) { 1161 measureChild(view); 1162 } 1163 end = start + view.getMeasuredWidth(); 1164 } else { 1165 if (view.isLayoutRequested() || view.getMeasuredWidth() != mItemLengthSecondary) { 1166 measureChild(view); 1167 } 1168 end = start + view.getMeasuredHeight(); 1169 } 1170 1171 layoutChild(view, start, end, startSecondary); 1172 return end + mMarginPrimary; 1173 } 1174 1175 // Fast layout when there is no structure change, adapter change, etc. 1176 protected void fastRelayout() { 1177 initScrollController(); 1178 1179 List<Integer>[] rows = mGrid.getItemPositionsInRows(mFirstVisiblePos, mLastVisiblePos); 1180 1181 // relayout and repositioning views on each row 1182 for (int i = 0; i < mNumRows; i++) { 1183 List<Integer> row = rows[i]; 1184 int start = Integer.MIN_VALUE; 1185 int startSecondary = 1186 i * (mItemLengthSecondary + mMarginSecondary) - mScrollOffsetSecondary; 1187 for (int j = 0, size = row.size(); j < size; j++) { 1188 int position = row.get(j); 1189 start = updateChildView(getViewByPosition(position), start, startSecondary); 1190 } 1191 } 1192 1193 appendVisibleItems(); 1194 prependVisibleItems(); 1195 1196 updateRowsMinMax(); 1197 updateScrollMin(); 1198 updateScrollMax(); 1199 1200 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED) { 1201 View focusView = getViewByPosition(mFocusPosition == NO_POSITION ? 0 : mFocusPosition); 1202 scrollToView(focusView, false); 1203 } 1204 } 1205 1206 // Lays out items based on the current scroll position 1207 @Override 1208 public void onLayoutChildren(RecyclerView.Adapter adapter, RecyclerView.Recycler recycler, 1209 boolean structureChanged, RecyclerView.State state) { 1210 if (DEBUG) { 1211 Log.v(getTag(), "layoutChildren start numRows " + mNumRows + " mScrollOffsetSecondary " 1212 + mScrollOffsetSecondary + " mScrollOffsetPrimary " + mScrollOffsetPrimary 1213 + " structureChanged " + structureChanged 1214 + " mForceFullLayout " + mForceFullLayout); 1215 Log.v(getTag(), "width " + getWidth() + " height " + getHeight()); 1216 } 1217 1218 if (mNumRows == 0) { 1219 // haven't done measure yet 1220 return; 1221 } 1222 final int itemCount = adapter.getItemCount(); 1223 if (itemCount < 0) { 1224 return; 1225 } 1226 1227 mInLayout = true; 1228 1229 // Track the old focus view so we can adjust our system scroll position 1230 // so that any scroll animations happening now will remain valid. 1231 int delta = 0, deltaSecondary = 0; 1232 if (mFocusPosition != NO_POSITION 1233 && mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED) { 1234 View focusView = getViewByPosition(mFocusPosition); 1235 if (focusView != null) { 1236 delta = mWindowAlignment.mainAxis().getSystemScrollPos( 1237 getViewCenter(focusView) + mScrollOffsetPrimary) - mScrollOffsetPrimary; 1238 deltaSecondary = 1239 mWindowAlignment.secondAxis().getSystemScrollPos( 1240 getViewCenterSecondary(focusView) + mScrollOffsetSecondary) 1241 - mScrollOffsetSecondary; 1242 } 1243 } 1244 1245 boolean hasDoneFirstLayout = hasDoneFirstLayout(); 1246 if (!structureChanged && !mForceFullLayout && hasDoneFirstLayout) { 1247 fastRelayout(); 1248 } else { 1249 boolean hadFocus = mBaseGridView.hasFocus(); 1250 1251 int newFocusPosition = init(adapter, recycler, mFocusPosition); 1252 if (DEBUG) { 1253 Log.v(getTag(), "mFocusPosition " + mFocusPosition + " newFocusPosition " 1254 + newFocusPosition); 1255 } 1256 1257 // depending on result of init(), either recreating everything 1258 // or try to reuse the row start positions near mFocusPosition 1259 if (mGrid.getSize() == 0) { 1260 // this is a fresh creating all items, starting from 1261 // mFocusPosition with a estimated row index. 1262 mGrid.setStart(newFocusPosition, StaggeredGrid.START_DEFAULT); 1263 1264 // Can't track the old focus view 1265 delta = deltaSecondary = 0; 1266 1267 } else { 1268 // mGrid remembers Locations for the column that 1269 // contains mFocusePosition and also mRows remembers start 1270 // positions of each row. 1271 // Manually re-create child views for that column 1272 int firstIndex = mGrid.getFirstIndex(); 1273 int lastIndex = mGrid.getLastIndex(); 1274 for (int i = firstIndex; i <= lastIndex; i++) { 1275 mGridProvider.createItem(i, mGrid.getLocation(i).row, true); 1276 } 1277 } 1278 // add visible views at end until reach the end of window 1279 appendVisibleItems(); 1280 // add visible views at front until reach the start of window 1281 prependVisibleItems(); 1282 // multiple rounds: scrollToView of first round may drag first/last child into 1283 // "visible window" and we update scrollMin/scrollMax then run second scrollToView 1284 int oldFirstVisible; 1285 int oldLastVisible; 1286 do { 1287 oldFirstVisible = mFirstVisiblePos; 1288 oldLastVisible = mLastVisiblePos; 1289 View focusView = getViewByPosition(newFocusPosition); 1290 // we need force to initialize the child view's position 1291 scrollToView(focusView, false); 1292 if (focusView != null && hadFocus) { 1293 focusView.requestFocus(); 1294 } 1295 appendVisibleItems(); 1296 prependVisibleItems(); 1297 removeInvisibleViewsAtFront(); 1298 removeInvisibleViewsAtEnd(); 1299 } while (mFirstVisiblePos != oldFirstVisible || mLastVisiblePos != oldLastVisible); 1300 } 1301 mForceFullLayout = false; 1302 1303 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_ALIGNED) { 1304 scrollDirectionPrimary(-delta); 1305 scrollDirectionSecondary(-deltaSecondary); 1306 } 1307 appendVisibleItems(); 1308 prependVisibleItems(); 1309 removeInvisibleViewsAtFront(); 1310 removeInvisibleViewsAtEnd(); 1311 1312 if (DEBUG) { 1313 StringWriter sw = new StringWriter(); 1314 PrintWriter pw = new PrintWriter(sw); 1315 mGrid.debugPrint(pw); 1316 Log.d(getTag(), sw.toString()); 1317 } 1318 1319 removeAndRecycleScrap(recycler); 1320 attemptAnimateLayoutChild(); 1321 1322 if (!hasDoneFirstLayout) { 1323 dispatchChildSelected(); 1324 } 1325 mInLayout = false; 1326 if (DEBUG) Log.v(getTag(), "layoutChildren end"); 1327 } 1328 1329 private void offsetChildrenSecondary(int increment) { 1330 final int childCount = getChildCount(); 1331 if (mOrientation == HORIZONTAL) { 1332 for (int i = 0; i < childCount; i++) { 1333 getChildAt(i).offsetTopAndBottom(increment); 1334 } 1335 } else { 1336 for (int i = 0; i < childCount; i++) { 1337 getChildAt(i).offsetLeftAndRight(increment); 1338 } 1339 } 1340 mScrollOffsetSecondary -= increment; 1341 } 1342 1343 private void offsetChildrenPrimary(int increment) { 1344 final int childCount = getChildCount(); 1345 if (mOrientation == VERTICAL) { 1346 for (int i = 0; i < childCount; i++) { 1347 getChildAt(i).offsetTopAndBottom(increment); 1348 } 1349 } else { 1350 for (int i = 0; i < childCount; i++) { 1351 getChildAt(i).offsetLeftAndRight(increment); 1352 } 1353 } 1354 mScrollOffsetPrimary -= increment; 1355 } 1356 1357 @Override 1358 public int scrollHorizontallyBy(int dx, Adapter adapter, Recycler recycler, 1359 RecyclerView.State state) { 1360 if (DEBUG) Log.v(TAG, "scrollHorizontallyBy " + dx); 1361 1362 if (mOrientation == HORIZONTAL) { 1363 return scrollDirectionPrimary(dx); 1364 } else { 1365 return scrollDirectionSecondary(dx); 1366 } 1367 } 1368 1369 @Override 1370 public int scrollVerticallyBy(int dy, Adapter adapter, Recycler recycler, 1371 RecyclerView.State state) { 1372 if (DEBUG) Log.v(TAG, "scrollVerticallyBy " + dy); 1373 if (mOrientation == VERTICAL) { 1374 return scrollDirectionPrimary(dy); 1375 } else { 1376 return scrollDirectionSecondary(dy); 1377 } 1378 } 1379 1380 // scroll in main direction may add/prune views 1381 private int scrollDirectionPrimary(int da) { 1382 offsetChildrenPrimary(-da); 1383 if (mInLayout) { 1384 return da; 1385 } 1386 if (da > 0) { 1387 appendVisibleItems(); 1388 removeInvisibleViewsAtFront(); 1389 } else if (da < 0) { 1390 prependVisibleItems(); 1391 removeInvisibleViewsAtEnd(); 1392 } 1393 attemptAnimateLayoutChild(); 1394 mBaseGridView.invalidate(); 1395 return da; 1396 } 1397 1398 // scroll in second direction will not add/prune views 1399 private int scrollDirectionSecondary(int dy) { 1400 offsetChildrenSecondary(-dy); 1401 mBaseGridView.invalidate(); 1402 return dy; 1403 } 1404 1405 private void updateScrollMax() { 1406 if (mLastVisiblePos >= 0 && mLastVisiblePos == mAdapter.getItemCount() - 1) { 1407 int maxEdge = Integer.MIN_VALUE; 1408 for (int i = 0; i < mRows.length; i++) { 1409 if (mRows[i].high > maxEdge) { 1410 maxEdge = mRows[i].high; 1411 } 1412 } 1413 mWindowAlignment.mainAxis().setMaxEdge(maxEdge); 1414 if (DEBUG) Log.v(getTag(), "updating scroll maxEdge to " + maxEdge); 1415 } 1416 } 1417 1418 private void updateScrollMin() { 1419 if (mFirstVisiblePos == 0) { 1420 int minEdge = Integer.MAX_VALUE; 1421 for (int i = 0; i < mRows.length; i++) { 1422 if (mRows[i].low < minEdge) { 1423 minEdge = mRows[i].low; 1424 } 1425 } 1426 mWindowAlignment.mainAxis().setMinEdge(minEdge); 1427 if (DEBUG) Log.v(getTag(), "updating scroll minEdge to " + minEdge); 1428 } 1429 } 1430 1431 private void initScrollController() { 1432 mWindowAlignment.horizontal.setSize(getWidth()); 1433 mWindowAlignment.horizontal.setPadding(getPaddingLeft(), getPaddingRight()); 1434 mWindowAlignment.vertical.setSize(getHeight()); 1435 mWindowAlignment.vertical.setPadding(getPaddingTop(), getPaddingBottom()); 1436 mSizePrimary = mWindowAlignment.mainAxis().getSize(); 1437 mWindowAlignment.mainAxis().invalidateScrollMin(); 1438 mWindowAlignment.mainAxis().invalidateScrollMax(); 1439 1440 // second axis min/max is determined at initialization, the mainAxis 1441 // min/max is determined later when we scroll to first or last item 1442 mWindowAlignment.secondAxis().setMinEdge(0); 1443 mWindowAlignment.secondAxis().setMaxEdge(mItemLengthSecondary * mNumRows + mMarginSecondary 1444 * (mNumRows - 1)); 1445 1446 if (DEBUG) { 1447 Log.v(getTag(), "initScrollController mSizePrimary " + mSizePrimary + " " 1448 + " mItemLengthSecondary " + mItemLengthSecondary + " " + mWindowAlignment); 1449 } 1450 } 1451 1452 public void setSelection(RecyclerView parent, int position) { 1453 setSelection(parent, position, false); 1454 } 1455 1456 public void setSelectionSmooth(RecyclerView parent, int position) { 1457 setSelection(parent, position, true); 1458 } 1459 1460 public int getSelection() { 1461 return mFocusPosition; 1462 } 1463 1464 public void setSelection(RecyclerView parent, int position, boolean smooth) { 1465 if (mFocusPosition == position) { 1466 return; 1467 } 1468 View view = getViewByPosition(position); 1469 if (view != null) { 1470 scrollToView(view, smooth); 1471 } else { 1472 boolean right = position > mFocusPosition; 1473 mFocusPosition = position; 1474 if (smooth) { 1475 if (!hasDoneFirstLayout()) { 1476 Log.w(getTag(), "setSelectionSmooth should " + 1477 "not be called before first layout pass"); 1478 return; 1479 } 1480 if (right) { 1481 appendVisibleItems(); 1482 } else { 1483 prependVisibleItems(); 1484 } 1485 scrollToView(getViewByPosition(position), smooth); 1486 } else { 1487 mForceFullLayout = true; 1488 parent.requestLayout(); 1489 } 1490 } 1491 } 1492 1493 @Override 1494 public void onItemsAdded(RecyclerView recyclerView, int positionStart, int itemCount) { 1495 boolean needsLayout = false; 1496 if (itemCount != 0) { 1497 if (mFirstVisiblePos < 0) { 1498 needsLayout = true; 1499 } else if (!(positionStart > mLastVisiblePos + 1 || 1500 positionStart + itemCount < mFirstVisiblePos - 1)) { 1501 needsLayout = true; 1502 } 1503 } 1504 if (needsLayout) { 1505 recyclerView.requestLayout(); 1506 } 1507 } 1508 1509 @Override 1510 public boolean onRequestChildFocus(RecyclerView parent, View child, View focused) { 1511 if (!mInLayout) { 1512 scrollToView(child, true); 1513 } 1514 return true; 1515 } 1516 1517 @Override 1518 public boolean requestChildRectangleOnScreen(RecyclerView parent, View view, Rect rect, 1519 boolean immediate) { 1520 if (DEBUG) Log.v(getTag(), "requestChildRectangleOnScreen " + view + " " + rect); 1521 return false; 1522 } 1523 1524 int getScrollOffsetX() { 1525 return mOrientation == HORIZONTAL ? mScrollOffsetPrimary : mScrollOffsetSecondary; 1526 } 1527 1528 int getScrollOffsetY() { 1529 return mOrientation == HORIZONTAL ? mScrollOffsetSecondary : mScrollOffsetPrimary; 1530 } 1531 1532 public void getViewSelectedOffsets(View view, int[] offsets) { 1533 int scrollOffsetX = getScrollOffsetX(); 1534 int scrollOffsetY = getScrollOffsetY(); 1535 int viewCenterX = scrollOffsetX + getViewCenterX(view); 1536 int viewCenterY = scrollOffsetY + getViewCenterY(view); 1537 offsets[0] = mWindowAlignment.horizontal.getSystemScrollPos(viewCenterX) - scrollOffsetX; 1538 offsets[1] = mWindowAlignment.vertical.getSystemScrollPos(viewCenterY) - scrollOffsetY; 1539 } 1540 1541 /** 1542 * Scroll to a given child view and change mFocusPosition. 1543 */ 1544 private void scrollToView(View view, boolean smooth) { 1545 int newFocusPosition = getPositionByView(view); 1546 if (mInLayout || newFocusPosition != mFocusPosition) { 1547 mFocusPosition = newFocusPosition; 1548 dispatchChildSelected(); 1549 } 1550 if (mBaseGridView.isChildrenDrawingOrderEnabledInternal()) { 1551 mBaseGridView.invalidate(); 1552 } 1553 if (view == null) { 1554 return; 1555 } 1556 if (!view.hasFocus() && mBaseGridView.hasFocus()) { 1557 // transfer focus to the child if it does not have focus yet (e.g. triggered 1558 // by setSelection()) 1559 view.requestFocus(); 1560 } 1561 switch (mFocusScrollStrategy) { 1562 case BaseGridView.FOCUS_SCROLL_ALIGNED: 1563 default: 1564 scrollToAlignedPosition(view, smooth); 1565 break; 1566 case BaseGridView.FOCUS_SCROLL_ITEM: 1567 case BaseGridView.FOCUS_SCROLL_PAGE: 1568 scrollItemOrPage(view, smooth); 1569 break; 1570 } 1571 } 1572 1573 private void scrollItemOrPage(View view, boolean smooth) { 1574 int pos = getPositionByView(view); 1575 int viewMin = getViewMin(view); 1576 int viewMax = getViewMax(view); 1577 // we either align "firstView" to left/top padding edge 1578 // or align "lastView" to right/bottom padding edge 1579 View firstView = null; 1580 View lastView = null; 1581 int paddingLow = mWindowAlignment.mainAxis().getPaddingLow(); 1582 int clientSize = mWindowAlignment.mainAxis().getClientSize(); 1583 final int row = mGrid.getLocation(pos).row; 1584 if (viewMin < paddingLow) { 1585 // view enters low padding area: 1586 firstView = view; 1587 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_PAGE) { 1588 // scroll one "page" left/top, 1589 // align first visible item of the "page" at the low padding edge. 1590 while (!prependOneVisibleItem()) { 1591 List<Integer> positions = 1592 mGrid.getItemPositionsInRows(mFirstVisiblePos, pos)[row]; 1593 firstView = getViewByPosition(positions.get(0)); 1594 if (viewMax - getViewMin(firstView) > clientSize) { 1595 if (positions.size() > 1) { 1596 firstView = getViewByPosition(positions.get(1)); 1597 } 1598 break; 1599 } 1600 } 1601 } 1602 } else if (viewMax > clientSize + paddingLow) { 1603 // view enters high padding area: 1604 if (mFocusScrollStrategy == BaseGridView.FOCUS_SCROLL_PAGE) { 1605 // scroll whole one page right/bottom, align view at the low padding edge. 1606 firstView = view; 1607 do { 1608 List<Integer> positions = 1609 mGrid.getItemPositionsInRows(pos, mLastVisiblePos)[row]; 1610 lastView = getViewByPosition(positions.get(positions.size() - 1)); 1611 if (getViewMax(lastView) - viewMin > clientSize) { 1612 lastView = null; 1613 break; 1614 } 1615 } while (!appendOneVisibleItem()); 1616 if (lastView != null) { 1617 // however if we reached end, we should align last view. 1618 firstView = null; 1619 } 1620 } else { 1621 lastView = view; 1622 } 1623 } 1624 int scrollPrimary = 0; 1625 int scrollSecondary = 0; 1626 if (firstView != null) { 1627 scrollPrimary = getViewMin(firstView) - paddingLow; 1628 } else if (lastView != null) { 1629 scrollPrimary = getViewMax(lastView) - (paddingLow + clientSize); 1630 } 1631 View secondaryAlignedView; 1632 if (firstView != null) { 1633 secondaryAlignedView = firstView; 1634 } else if (lastView != null) { 1635 secondaryAlignedView = lastView; 1636 } else { 1637 secondaryAlignedView = view; 1638 } 1639 int viewCenterSecondary = mScrollOffsetSecondary + 1640 getViewCenterSecondary(secondaryAlignedView); 1641 mWindowAlignment.secondAxis().updateScrollCenter(viewCenterSecondary); 1642 scrollSecondary = mWindowAlignment.secondAxis().getSystemScrollPos(); 1643 scrollSecondary -= mScrollOffsetSecondary; 1644 scrollGrid(scrollPrimary, scrollSecondary, smooth); 1645 } 1646 1647 private void scrollToAlignedPosition(View view, boolean smooth) { 1648 int viewCenterPrimary = mScrollOffsetPrimary + getViewCenter(view); 1649 int viewCenterSecondary = mScrollOffsetSecondary + getViewCenterSecondary(view); 1650 if (DEBUG) { 1651 Log.v(getTag(), "scrollAligned smooth=" + smooth + " pos=" + mFocusPosition + " " 1652 + viewCenterPrimary +","+viewCenterSecondary + " " + mWindowAlignment); 1653 } 1654 1655 if (mInLayout || viewCenterPrimary != mWindowAlignment.mainAxis().getScrollCenter() 1656 || viewCenterSecondary != mWindowAlignment.secondAxis().getScrollCenter()) { 1657 mWindowAlignment.mainAxis().updateScrollCenter(viewCenterPrimary); 1658 mWindowAlignment.secondAxis().updateScrollCenter(viewCenterSecondary); 1659 int scrollPrimary = mWindowAlignment.mainAxis().getSystemScrollPos(); 1660 int scrollSecondary = mWindowAlignment.secondAxis().getSystemScrollPos(); 1661 if (DEBUG) { 1662 Log.v(getTag(), "scrollAligned " + scrollPrimary + " " + scrollSecondary 1663 +" " + mWindowAlignment); 1664 } 1665 1666 scrollPrimary -= mScrollOffsetPrimary; 1667 scrollSecondary -= mScrollOffsetSecondary; 1668 1669 scrollGrid(scrollPrimary, scrollSecondary, smooth); 1670 } 1671 } 1672 1673 private void scrollGrid(int scrollPrimary, int scrollSecondary, boolean smooth) { 1674 if (mInLayout) { 1675 scrollDirectionPrimary(scrollPrimary); 1676 scrollDirectionSecondary(scrollSecondary); 1677 } else { 1678 int scrollX; 1679 int scrollY; 1680 if (mOrientation == HORIZONTAL) { 1681 scrollX = scrollPrimary; 1682 scrollY = scrollSecondary; 1683 } else { 1684 scrollX = scrollSecondary; 1685 scrollY = scrollPrimary; 1686 } 1687 if (smooth) { 1688 mBaseGridView.smoothScrollBy(scrollX, scrollY); 1689 } else { 1690 mBaseGridView.scrollBy(scrollX, scrollY); 1691 } 1692 } 1693 } 1694 1695 public void setAnimateChildLayout(boolean animateChildLayout) { 1696 mAnimateChildLayout = animateChildLayout; 1697 for (int i = 0, c = getChildCount(); i < c; i++) { 1698 View v = getChildAt(i); 1699 LayoutParams p = (LayoutParams) v.getLayoutParams(); 1700 if (!mAnimateChildLayout) { 1701 p.endAnimate(); 1702 } else { 1703 // record initial location values 1704 p.mFirstAttached = true; 1705 p.startAnimate(this, v, 0); 1706 } 1707 } 1708 } 1709 1710 private void attemptAnimateLayoutChild() { 1711 if (!mAnimateChildLayout) { 1712 return; 1713 } 1714 for (int i = 0, c = getChildCount(); i < c; i++) { 1715 // TODO: start delay can be staggered 1716 View v = getChildAt(i); 1717 ((LayoutParams) v.getLayoutParams()).startAnimate(this, v, 0); 1718 } 1719 } 1720 1721 public boolean isChildLayoutAnimated() { 1722 return mAnimateChildLayout; 1723 } 1724 1725 public void setChildLayoutAnimationInterpolator(Interpolator interpolator) { 1726 mAnimateLayoutChildInterpolator = interpolator; 1727 } 1728 1729 public Interpolator getChildLayoutAnimationInterpolator() { 1730 return mAnimateLayoutChildInterpolator; 1731 } 1732 1733 public void setChildLayoutAnimationDuration(long duration) { 1734 mAnimateLayoutChildDuration = duration; 1735 } 1736 1737 public long getChildLayoutAnimationDuration() { 1738 return mAnimateLayoutChildDuration; 1739 } 1740 1741 private int findImmediateChildIndex(View view) { 1742 while (view != null && view != mBaseGridView) { 1743 int index = mBaseGridView.indexOfChild(view); 1744 if (index >= 0) { 1745 return index; 1746 } 1747 view = (View) view.getParent(); 1748 } 1749 return NO_POSITION; 1750 } 1751 1752 @Override 1753 public boolean onAddFocusables(RecyclerView recyclerView, 1754 ArrayList<View> views, int direction, int focusableMode) { 1755 // If this viewgroup or one of its children currently has focus then we 1756 // consider our children for focus searching in main direction on the same row. 1757 // If this viewgroup has no focus and using focus align, we want the system 1758 // to ignore our children and pass focus to the viewgroup, which will pass 1759 // focus on to its children appropriately. 1760 // If this viewgroup has no focus and not using focus align, we want to 1761 // consider the child that does not overlap with padding area. 1762 if (recyclerView.hasFocus()) { 1763 final int movement = getMovement(direction); 1764 if (movement != PREV_ITEM && movement != NEXT_ITEM) { 1765 // Move on secondary direction uses default addFocusables(). 1766 return false; 1767 } 1768 final View focused = recyclerView.findFocus(); 1769 final int focusedPos = getPositionByIndex(findImmediateChildIndex(focused)); 1770 // Add focusables of focused item. 1771 if (focusedPos != NO_POSITION) { 1772 getViewByPosition(focusedPos).addFocusables(views, direction, focusableMode); 1773 } 1774 final int focusedRow = mGrid != null && focusedPos != NO_POSITION ? 1775 mGrid.getLocation(focusedPos).row : NO_POSITION; 1776 // Add focusables of next neighbor of same row on the focus search direction. 1777 if (mGrid != null) { 1778 final int focusableCount = views.size(); 1779 for (int i = 0, count = getChildCount(); i < count; i++) { 1780 int index = movement == NEXT_ITEM ? i : count - 1 - i; 1781 final View child = getChildAt(index); 1782 if (child.getVisibility() != View.VISIBLE) { 1783 continue; 1784 } 1785 int position = getPositionByIndex(index); 1786 StaggeredGrid.Location loc = mGrid.getLocation(position); 1787 if (focusedRow == NO_POSITION || (loc != null && loc.row == focusedRow)) { 1788 if (focusedPos == NO_POSITION || 1789 (movement == NEXT_ITEM && position > focusedPos) 1790 || (movement == PREV_ITEM && position < focusedPos)) { 1791 child.addFocusables(views, direction, focusableMode); 1792 if (views.size() > focusableCount) { 1793 break; 1794 } 1795 } 1796 } 1797 } 1798 } 1799 } else { 1800 if (mFocusScrollStrategy != BaseGridView.FOCUS_SCROLL_ALIGNED) { 1801 // adding views not overlapping padding area to avoid scrolling in gaining focus 1802 int left = mWindowAlignment.mainAxis().getPaddingLow(); 1803 int right = mWindowAlignment.mainAxis().getClientSize() + left; 1804 int focusableCount = views.size(); 1805 for (int i = 0, count = getChildCount(); i < count; i++) { 1806 View child = getChildAt(i); 1807 if (child.getVisibility() == View.VISIBLE) { 1808 if (getViewMin(child) >= left && getViewMax(child) <= right) { 1809 child.addFocusables(views, direction, focusableMode); 1810 } 1811 } 1812 } 1813 // if we cannot find any, then just add all children. 1814 if (views.size() == focusableCount) { 1815 for (int i = 0, count = getChildCount(); i < count; i++) { 1816 View child = getChildAt(i); 1817 if (child.getVisibility() == View.VISIBLE) { 1818 child.addFocusables(views, direction, focusableMode); 1819 } 1820 } 1821 if (views.size() != focusableCount) { 1822 return true; 1823 } 1824 } else { 1825 return true; 1826 } 1827 // if still cannot find any, fall through and add itself 1828 } 1829 if (recyclerView.isFocusable()) { 1830 views.add(recyclerView); 1831 } 1832 } 1833 return true; 1834 } 1835 1836 @Override 1837 public View onFocusSearchFailed(View focused, int direction, Adapter adapter, 1838 Recycler recycler) { 1839 if (DEBUG) Log.v(getTag(), "onFocusSearchFailed direction " + direction); 1840 1841 View view = null; 1842 int movement = getMovement(direction); 1843 final FocusFinder ff = FocusFinder.getInstance(); 1844 if (movement == NEXT_ITEM) { 1845 while (view == null && !appendOneVisibleItem()) { 1846 view = ff.findNextFocus(mBaseGridView, focused, direction); 1847 } 1848 } else if (movement == PREV_ITEM){ 1849 while (view == null && !prependOneVisibleItem()) { 1850 view = ff.findNextFocus(mBaseGridView, focused, direction); 1851 } 1852 } 1853 if (view == null) { 1854 // returning the same view to prevent focus lost when scrolling past the end of the list 1855 if (movement == PREV_ITEM) { 1856 view = mFocusOutFront ? null : focused; 1857 } else if (movement == NEXT_ITEM){ 1858 view = mFocusOutEnd ? null : focused; 1859 } 1860 } 1861 if (DEBUG) Log.v(getTag(), "returning view " + view); 1862 return view; 1863 } 1864 1865 boolean gridOnRequestFocusInDescendants(RecyclerView recyclerView, int direction, 1866 Rect previouslyFocusedRect) { 1867 switch (mFocusScrollStrategy) { 1868 case BaseGridView.FOCUS_SCROLL_ALIGNED: 1869 default: 1870 return gridOnRequestFocusInDescendantsAligned(recyclerView, 1871 direction, previouslyFocusedRect); 1872 case BaseGridView.FOCUS_SCROLL_PAGE: 1873 case BaseGridView.FOCUS_SCROLL_ITEM: 1874 return gridOnRequestFocusInDescendantsUnaligned(recyclerView, 1875 direction, previouslyFocusedRect); 1876 } 1877 } 1878 1879 private boolean gridOnRequestFocusInDescendantsAligned(RecyclerView recyclerView, 1880 int direction, Rect previouslyFocusedRect) { 1881 View view = getViewByPosition(mFocusPosition); 1882 if (view != null) { 1883 boolean result = view.requestFocus(direction, previouslyFocusedRect); 1884 if (!result && DEBUG) { 1885 Log.w(getTag(), "failed to request focus on " + view); 1886 } 1887 return result; 1888 } 1889 return false; 1890 } 1891 1892 private boolean gridOnRequestFocusInDescendantsUnaligned(RecyclerView recyclerView, 1893 int direction, Rect previouslyFocusedRect) { 1894 // focus to view not overlapping padding area to avoid scrolling in gaining focus 1895 int index; 1896 int increment; 1897 int end; 1898 int count = getChildCount(); 1899 if ((direction & View.FOCUS_FORWARD) != 0) { 1900 index = 0; 1901 increment = 1; 1902 end = count; 1903 } else { 1904 index = count - 1; 1905 increment = -1; 1906 end = -1; 1907 } 1908 int left = mWindowAlignment.mainAxis().getPaddingLow(); 1909 int right = mWindowAlignment.mainAxis().getClientSize() + left; 1910 for (int i = index; i != end; i += increment) { 1911 View child = getChildAt(i); 1912 if (child.getVisibility() == View.VISIBLE) { 1913 if (getViewMin(child) >= left && getViewMax(child) <= right) { 1914 if (child.requestFocus(direction, previouslyFocusedRect)) { 1915 return true; 1916 } 1917 } 1918 } 1919 } 1920 return false; 1921 } 1922 1923 private final static int PREV_ITEM = 0; 1924 private final static int NEXT_ITEM = 1; 1925 private final static int PREV_ROW = 2; 1926 private final static int NEXT_ROW = 3; 1927 1928 private int getMovement(int direction) { 1929 int movement = View.FOCUS_LEFT; 1930 1931 if (mOrientation == HORIZONTAL) { 1932 switch(direction) { 1933 case View.FOCUS_LEFT: 1934 movement = PREV_ITEM; 1935 break; 1936 case View.FOCUS_RIGHT: 1937 movement = NEXT_ITEM; 1938 break; 1939 case View.FOCUS_UP: 1940 movement = PREV_ROW; 1941 break; 1942 case View.FOCUS_DOWN: 1943 movement = NEXT_ROW; 1944 break; 1945 } 1946 } else if (mOrientation == VERTICAL) { 1947 switch(direction) { 1948 case View.FOCUS_LEFT: 1949 movement = PREV_ROW; 1950 break; 1951 case View.FOCUS_RIGHT: 1952 movement = NEXT_ROW; 1953 break; 1954 case View.FOCUS_UP: 1955 movement = PREV_ITEM; 1956 break; 1957 case View.FOCUS_DOWN: 1958 movement = NEXT_ITEM; 1959 break; 1960 } 1961 } 1962 1963 return movement; 1964 } 1965 1966 int getChildDrawingOrder(RecyclerView recyclerView, int childCount, int i) { 1967 int focusIndex = getIndexByPosition(mFocusPosition); 1968 if (focusIndex == NO_POSITION) { 1969 return i; 1970 } 1971 // supposely 0 1 2 3 4 5 6 7 8 9, 4 is the center item 1972 // drawing order is 0 1 2 3 9 8 7 6 5 4 1973 if (i < focusIndex) { 1974 return i; 1975 } else if (i < childCount - 1) { 1976 return focusIndex + childCount - 1 - i; 1977 } else { 1978 return focusIndex; 1979 } 1980 } 1981 1982 @Override 1983 public void onAdapterChanged(RecyclerView.Adapter oldAdapter, 1984 RecyclerView.Adapter newAdapter) { 1985 mGrid = null; 1986 mRows = null; 1987 super.onAdapterChanged(oldAdapter, newAdapter); 1988 } 1989} 1990