1/* 2 * Copyright (C) 2007 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17package android.widget; 18 19import android.annotation.IntDef; 20import android.annotation.NonNull; 21import android.content.Context; 22import android.content.Intent; 23import android.content.res.TypedArray; 24import android.graphics.Rect; 25import android.os.Bundle; 26import android.os.Trace; 27import android.util.AttributeSet; 28import android.util.MathUtils; 29import android.view.Gravity; 30import android.view.KeyEvent; 31import android.view.SoundEffectConstants; 32import android.view.View; 33import android.view.ViewDebug; 34import android.view.ViewGroup; 35import android.view.ViewHierarchyEncoder; 36import android.view.ViewRootImpl; 37import android.view.accessibility.AccessibilityNodeInfo; 38import android.view.accessibility.AccessibilityNodeInfo.AccessibilityAction; 39import android.view.accessibility.AccessibilityNodeProvider; 40import android.view.accessibility.AccessibilityNodeInfo.CollectionInfo; 41import android.view.accessibility.AccessibilityNodeInfo.CollectionItemInfo; 42import android.view.animation.GridLayoutAnimationController; 43import android.widget.RemoteViews.RemoteView; 44 45import com.android.internal.R; 46 47import java.lang.annotation.Retention; 48import java.lang.annotation.RetentionPolicy; 49 50 51/** 52 * A view that shows items in two-dimensional scrolling grid. The items in the 53 * grid come from the {@link ListAdapter} associated with this view. 54 * 55 * <p>See the <a href="{@docRoot}guide/topics/ui/layout/gridview.html">Grid 56 * View</a> guide.</p> 57 * 58 * @attr ref android.R.styleable#GridView_horizontalSpacing 59 * @attr ref android.R.styleable#GridView_verticalSpacing 60 * @attr ref android.R.styleable#GridView_stretchMode 61 * @attr ref android.R.styleable#GridView_columnWidth 62 * @attr ref android.R.styleable#GridView_numColumns 63 * @attr ref android.R.styleable#GridView_gravity 64 */ 65@RemoteView 66public class GridView extends AbsListView { 67 /** @hide */ 68 @IntDef({NO_STRETCH, STRETCH_SPACING, STRETCH_COLUMN_WIDTH, STRETCH_SPACING_UNIFORM}) 69 @Retention(RetentionPolicy.SOURCE) 70 public @interface StretchMode {} 71 72 /** 73 * Disables stretching. 74 * 75 * @see #setStretchMode(int) 76 */ 77 public static final int NO_STRETCH = 0; 78 /** 79 * Stretches the spacing between columns. 80 * 81 * @see #setStretchMode(int) 82 */ 83 public static final int STRETCH_SPACING = 1; 84 /** 85 * Stretches columns. 86 * 87 * @see #setStretchMode(int) 88 */ 89 public static final int STRETCH_COLUMN_WIDTH = 2; 90 /** 91 * Stretches the spacing between columns. The spacing is uniform. 92 * 93 * @see #setStretchMode(int) 94 */ 95 public static final int STRETCH_SPACING_UNIFORM = 3; 96 97 /** 98 * Creates as many columns as can fit on screen. 99 * 100 * @see #setNumColumns(int) 101 */ 102 public static final int AUTO_FIT = -1; 103 104 private int mNumColumns = AUTO_FIT; 105 106 private int mHorizontalSpacing = 0; 107 private int mRequestedHorizontalSpacing; 108 private int mVerticalSpacing = 0; 109 private int mStretchMode = STRETCH_COLUMN_WIDTH; 110 private int mColumnWidth; 111 private int mRequestedColumnWidth; 112 private int mRequestedNumColumns; 113 114 private View mReferenceView = null; 115 private View mReferenceViewInSelectedRow = null; 116 117 private int mGravity = Gravity.START; 118 119 private final Rect mTempRect = new Rect(); 120 121 public GridView(Context context) { 122 this(context, null); 123 } 124 125 public GridView(Context context, AttributeSet attrs) { 126 this(context, attrs, R.attr.gridViewStyle); 127 } 128 129 public GridView(Context context, AttributeSet attrs, int defStyleAttr) { 130 this(context, attrs, defStyleAttr, 0); 131 } 132 133 public GridView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) { 134 super(context, attrs, defStyleAttr, defStyleRes); 135 136 final TypedArray a = context.obtainStyledAttributes( 137 attrs, R.styleable.GridView, defStyleAttr, defStyleRes); 138 139 int hSpacing = a.getDimensionPixelOffset( 140 R.styleable.GridView_horizontalSpacing, 0); 141 setHorizontalSpacing(hSpacing); 142 143 int vSpacing = a.getDimensionPixelOffset( 144 R.styleable.GridView_verticalSpacing, 0); 145 setVerticalSpacing(vSpacing); 146 147 int index = a.getInt(R.styleable.GridView_stretchMode, STRETCH_COLUMN_WIDTH); 148 if (index >= 0) { 149 setStretchMode(index); 150 } 151 152 int columnWidth = a.getDimensionPixelOffset(R.styleable.GridView_columnWidth, -1); 153 if (columnWidth > 0) { 154 setColumnWidth(columnWidth); 155 } 156 157 int numColumns = a.getInt(R.styleable.GridView_numColumns, 1); 158 setNumColumns(numColumns); 159 160 index = a.getInt(R.styleable.GridView_gravity, -1); 161 if (index >= 0) { 162 setGravity(index); 163 } 164 165 a.recycle(); 166 } 167 168 @Override 169 public ListAdapter getAdapter() { 170 return mAdapter; 171 } 172 173 /** 174 * Sets up this AbsListView to use a remote views adapter which connects to a RemoteViewsService 175 * through the specified intent. 176 * @param intent the intent used to identify the RemoteViewsService for the adapter to connect to. 177 */ 178 @android.view.RemotableViewMethod 179 public void setRemoteViewsAdapter(Intent intent) { 180 super.setRemoteViewsAdapter(intent); 181 } 182 183 /** 184 * Sets the data behind this GridView. 185 * 186 * @param adapter the adapter providing the grid's data 187 */ 188 @Override 189 public void setAdapter(ListAdapter adapter) { 190 if (mAdapter != null && mDataSetObserver != null) { 191 mAdapter.unregisterDataSetObserver(mDataSetObserver); 192 } 193 194 resetList(); 195 mRecycler.clear(); 196 mAdapter = adapter; 197 198 mOldSelectedPosition = INVALID_POSITION; 199 mOldSelectedRowId = INVALID_ROW_ID; 200 201 // AbsListView#setAdapter will update choice mode states. 202 super.setAdapter(adapter); 203 204 if (mAdapter != null) { 205 mOldItemCount = mItemCount; 206 mItemCount = mAdapter.getCount(); 207 mDataChanged = true; 208 checkFocus(); 209 210 mDataSetObserver = new AdapterDataSetObserver(); 211 mAdapter.registerDataSetObserver(mDataSetObserver); 212 213 mRecycler.setViewTypeCount(mAdapter.getViewTypeCount()); 214 215 int position; 216 if (mStackFromBottom) { 217 position = lookForSelectablePosition(mItemCount - 1, false); 218 } else { 219 position = lookForSelectablePosition(0, true); 220 } 221 setSelectedPositionInt(position); 222 setNextSelectedPositionInt(position); 223 checkSelectionChanged(); 224 } else { 225 checkFocus(); 226 // Nothing selected 227 checkSelectionChanged(); 228 } 229 230 requestLayout(); 231 } 232 233 @Override 234 int lookForSelectablePosition(int position, boolean lookDown) { 235 final ListAdapter adapter = mAdapter; 236 if (adapter == null || isInTouchMode()) { 237 return INVALID_POSITION; 238 } 239 240 if (position < 0 || position >= mItemCount) { 241 return INVALID_POSITION; 242 } 243 return position; 244 } 245 246 /** 247 * {@inheritDoc} 248 */ 249 @Override 250 void fillGap(boolean down) { 251 final int numColumns = mNumColumns; 252 final int verticalSpacing = mVerticalSpacing; 253 254 final int count = getChildCount(); 255 256 if (down) { 257 int paddingTop = 0; 258 if ((mGroupFlags & CLIP_TO_PADDING_MASK) == CLIP_TO_PADDING_MASK) { 259 paddingTop = getListPaddingTop(); 260 } 261 final int startOffset = count > 0 ? 262 getChildAt(count - 1).getBottom() + verticalSpacing : paddingTop; 263 int position = mFirstPosition + count; 264 if (mStackFromBottom) { 265 position += numColumns - 1; 266 } 267 fillDown(position, startOffset); 268 correctTooHigh(numColumns, verticalSpacing, getChildCount()); 269 } else { 270 int paddingBottom = 0; 271 if ((mGroupFlags & CLIP_TO_PADDING_MASK) == CLIP_TO_PADDING_MASK) { 272 paddingBottom = getListPaddingBottom(); 273 } 274 final int startOffset = count > 0 ? 275 getChildAt(0).getTop() - verticalSpacing : getHeight() - paddingBottom; 276 int position = mFirstPosition; 277 if (!mStackFromBottom) { 278 position -= numColumns; 279 } else { 280 position--; 281 } 282 fillUp(position, startOffset); 283 correctTooLow(numColumns, verticalSpacing, getChildCount()); 284 } 285 } 286 287 /** 288 * Fills the list from pos down to the end of the list view. 289 * 290 * @param pos The first position to put in the list 291 * 292 * @param nextTop The location where the top of the item associated with pos 293 * should be drawn 294 * 295 * @return The view that is currently selected, if it happens to be in the 296 * range that we draw. 297 */ 298 private View fillDown(int pos, int nextTop) { 299 View selectedView = null; 300 301 int end = (mBottom - mTop); 302 if ((mGroupFlags & CLIP_TO_PADDING_MASK) == CLIP_TO_PADDING_MASK) { 303 end -= mListPadding.bottom; 304 } 305 306 while (nextTop < end && pos < mItemCount) { 307 View temp = makeRow(pos, nextTop, true); 308 if (temp != null) { 309 selectedView = temp; 310 } 311 312 // mReferenceView will change with each call to makeRow() 313 // do not cache in a local variable outside of this loop 314 nextTop = mReferenceView.getBottom() + mVerticalSpacing; 315 316 pos += mNumColumns; 317 } 318 319 setVisibleRangeHint(mFirstPosition, mFirstPosition + getChildCount() - 1); 320 return selectedView; 321 } 322 323 private View makeRow(int startPos, int y, boolean flow) { 324 final int columnWidth = mColumnWidth; 325 final int horizontalSpacing = mHorizontalSpacing; 326 327 final boolean isLayoutRtl = isLayoutRtl(); 328 329 int last; 330 int nextLeft; 331 332 if (isLayoutRtl) { 333 nextLeft = getWidth() - mListPadding.right - columnWidth - 334 ((mStretchMode == STRETCH_SPACING_UNIFORM) ? horizontalSpacing : 0); 335 } else { 336 nextLeft = mListPadding.left + 337 ((mStretchMode == STRETCH_SPACING_UNIFORM) ? horizontalSpacing : 0); 338 } 339 340 if (!mStackFromBottom) { 341 last = Math.min(startPos + mNumColumns, mItemCount); 342 } else { 343 last = startPos + 1; 344 startPos = Math.max(0, startPos - mNumColumns + 1); 345 346 if (last - startPos < mNumColumns) { 347 final int deltaLeft = (mNumColumns - (last - startPos)) * (columnWidth + horizontalSpacing); 348 nextLeft += (isLayoutRtl ? -1 : +1) * deltaLeft; 349 } 350 } 351 352 View selectedView = null; 353 354 final boolean hasFocus = shouldShowSelector(); 355 final boolean inClick = touchModeDrawsInPressedState(); 356 final int selectedPosition = mSelectedPosition; 357 358 View child = null; 359 final int nextChildDir = isLayoutRtl ? -1 : +1; 360 for (int pos = startPos; pos < last; pos++) { 361 // is this the selected item? 362 boolean selected = pos == selectedPosition; 363 // does the list view have focus or contain focus 364 365 final int where = flow ? -1 : pos - startPos; 366 child = makeAndAddView(pos, y, flow, nextLeft, selected, where); 367 368 nextLeft += nextChildDir * columnWidth; 369 if (pos < last - 1) { 370 nextLeft += nextChildDir * horizontalSpacing; 371 } 372 373 if (selected && (hasFocus || inClick)) { 374 selectedView = child; 375 } 376 } 377 378 mReferenceView = child; 379 380 if (selectedView != null) { 381 mReferenceViewInSelectedRow = mReferenceView; 382 } 383 384 return selectedView; 385 } 386 387 /** 388 * Fills the list from pos up to the top of the list view. 389 * 390 * @param pos The first position to put in the list 391 * 392 * @param nextBottom The location where the bottom of the item associated 393 * with pos should be drawn 394 * 395 * @return The view that is currently selected 396 */ 397 private View fillUp(int pos, int nextBottom) { 398 View selectedView = null; 399 400 int end = 0; 401 if ((mGroupFlags & CLIP_TO_PADDING_MASK) == CLIP_TO_PADDING_MASK) { 402 end = mListPadding.top; 403 } 404 405 while (nextBottom > end && pos >= 0) { 406 407 View temp = makeRow(pos, nextBottom, false); 408 if (temp != null) { 409 selectedView = temp; 410 } 411 412 nextBottom = mReferenceView.getTop() - mVerticalSpacing; 413 414 mFirstPosition = pos; 415 416 pos -= mNumColumns; 417 } 418 419 if (mStackFromBottom) { 420 mFirstPosition = Math.max(0, pos + 1); 421 } 422 423 setVisibleRangeHint(mFirstPosition, mFirstPosition + getChildCount() - 1); 424 return selectedView; 425 } 426 427 /** 428 * Fills the list from top to bottom, starting with mFirstPosition 429 * 430 * @param nextTop The location where the top of the first item should be 431 * drawn 432 * 433 * @return The view that is currently selected 434 */ 435 private View fillFromTop(int nextTop) { 436 mFirstPosition = Math.min(mFirstPosition, mSelectedPosition); 437 mFirstPosition = Math.min(mFirstPosition, mItemCount - 1); 438 if (mFirstPosition < 0) { 439 mFirstPosition = 0; 440 } 441 mFirstPosition -= mFirstPosition % mNumColumns; 442 return fillDown(mFirstPosition, nextTop); 443 } 444 445 private View fillFromBottom(int lastPosition, int nextBottom) { 446 lastPosition = Math.max(lastPosition, mSelectedPosition); 447 lastPosition = Math.min(lastPosition, mItemCount - 1); 448 449 final int invertedPosition = mItemCount - 1 - lastPosition; 450 lastPosition = mItemCount - 1 - (invertedPosition - (invertedPosition % mNumColumns)); 451 452 return fillUp(lastPosition, nextBottom); 453 } 454 455 private View fillSelection(int childrenTop, int childrenBottom) { 456 final int selectedPosition = reconcileSelectedPosition(); 457 final int numColumns = mNumColumns; 458 final int verticalSpacing = mVerticalSpacing; 459 460 int rowStart; 461 int rowEnd = -1; 462 463 if (!mStackFromBottom) { 464 rowStart = selectedPosition - (selectedPosition % numColumns); 465 } else { 466 final int invertedSelection = mItemCount - 1 - selectedPosition; 467 468 rowEnd = mItemCount - 1 - (invertedSelection - (invertedSelection % numColumns)); 469 rowStart = Math.max(0, rowEnd - numColumns + 1); 470 } 471 472 final int fadingEdgeLength = getVerticalFadingEdgeLength(); 473 final int topSelectionPixel = getTopSelectionPixel(childrenTop, fadingEdgeLength, rowStart); 474 475 final View sel = makeRow(mStackFromBottom ? rowEnd : rowStart, topSelectionPixel, true); 476 mFirstPosition = rowStart; 477 478 final View referenceView = mReferenceView; 479 480 if (!mStackFromBottom) { 481 fillDown(rowStart + numColumns, referenceView.getBottom() + verticalSpacing); 482 pinToBottom(childrenBottom); 483 fillUp(rowStart - numColumns, referenceView.getTop() - verticalSpacing); 484 adjustViewsUpOrDown(); 485 } else { 486 final int bottomSelectionPixel = getBottomSelectionPixel(childrenBottom, 487 fadingEdgeLength, numColumns, rowStart); 488 final int offset = bottomSelectionPixel - referenceView.getBottom(); 489 offsetChildrenTopAndBottom(offset); 490 fillUp(rowStart - 1, referenceView.getTop() - verticalSpacing); 491 pinToTop(childrenTop); 492 fillDown(rowEnd + numColumns, referenceView.getBottom() + verticalSpacing); 493 adjustViewsUpOrDown(); 494 } 495 496 return sel; 497 } 498 499 private void pinToTop(int childrenTop) { 500 if (mFirstPosition == 0) { 501 final int top = getChildAt(0).getTop(); 502 final int offset = childrenTop - top; 503 if (offset < 0) { 504 offsetChildrenTopAndBottom(offset); 505 } 506 } 507 } 508 509 private void pinToBottom(int childrenBottom) { 510 final int count = getChildCount(); 511 if (mFirstPosition + count == mItemCount) { 512 final int bottom = getChildAt(count - 1).getBottom(); 513 final int offset = childrenBottom - bottom; 514 if (offset > 0) { 515 offsetChildrenTopAndBottom(offset); 516 } 517 } 518 } 519 520 @Override 521 int findMotionRow(int y) { 522 final int childCount = getChildCount(); 523 if (childCount > 0) { 524 525 final int numColumns = mNumColumns; 526 if (!mStackFromBottom) { 527 for (int i = 0; i < childCount; i += numColumns) { 528 if (y <= getChildAt(i).getBottom()) { 529 return mFirstPosition + i; 530 } 531 } 532 } else { 533 for (int i = childCount - 1; i >= 0; i -= numColumns) { 534 if (y >= getChildAt(i).getTop()) { 535 return mFirstPosition + i; 536 } 537 } 538 } 539 } 540 return INVALID_POSITION; 541 } 542 543 /** 544 * Layout during a scroll that results from tracking motion events. Places 545 * the mMotionPosition view at the offset specified by mMotionViewTop, and 546 * then build surrounding views from there. 547 * 548 * @param position the position at which to start filling 549 * @param top the top of the view at that position 550 * @return The selected view, or null if the selected view is outside the 551 * visible area. 552 */ 553 private View fillSpecific(int position, int top) { 554 final int numColumns = mNumColumns; 555 556 int motionRowStart; 557 int motionRowEnd = -1; 558 559 if (!mStackFromBottom) { 560 motionRowStart = position - (position % numColumns); 561 } else { 562 final int invertedSelection = mItemCount - 1 - position; 563 564 motionRowEnd = mItemCount - 1 - (invertedSelection - (invertedSelection % numColumns)); 565 motionRowStart = Math.max(0, motionRowEnd - numColumns + 1); 566 } 567 568 final View temp = makeRow(mStackFromBottom ? motionRowEnd : motionRowStart, top, true); 569 570 // Possibly changed again in fillUp if we add rows above this one. 571 mFirstPosition = motionRowStart; 572 573 final View referenceView = mReferenceView; 574 // We didn't have anything to layout, bail out 575 if (referenceView == null) { 576 return null; 577 } 578 579 final int verticalSpacing = mVerticalSpacing; 580 581 View above; 582 View below; 583 584 if (!mStackFromBottom) { 585 above = fillUp(motionRowStart - numColumns, referenceView.getTop() - verticalSpacing); 586 adjustViewsUpOrDown(); 587 below = fillDown(motionRowStart + numColumns, referenceView.getBottom() + verticalSpacing); 588 // Check if we have dragged the bottom of the grid too high 589 final int childCount = getChildCount(); 590 if (childCount > 0) { 591 correctTooHigh(numColumns, verticalSpacing, childCount); 592 } 593 } else { 594 below = fillDown(motionRowEnd + numColumns, referenceView.getBottom() + verticalSpacing); 595 adjustViewsUpOrDown(); 596 above = fillUp(motionRowStart - 1, referenceView.getTop() - verticalSpacing); 597 // Check if we have dragged the bottom of the grid too high 598 final int childCount = getChildCount(); 599 if (childCount > 0) { 600 correctTooLow(numColumns, verticalSpacing, childCount); 601 } 602 } 603 604 if (temp != null) { 605 return temp; 606 } else if (above != null) { 607 return above; 608 } else { 609 return below; 610 } 611 } 612 613 private void correctTooHigh(int numColumns, int verticalSpacing, int childCount) { 614 // First see if the last item is visible 615 final int lastPosition = mFirstPosition + childCount - 1; 616 if (lastPosition == mItemCount - 1 && childCount > 0) { 617 // Get the last child ... 618 final View lastChild = getChildAt(childCount - 1); 619 620 // ... and its bottom edge 621 final int lastBottom = lastChild.getBottom(); 622 // This is bottom of our drawable area 623 final int end = (mBottom - mTop) - mListPadding.bottom; 624 625 // This is how far the bottom edge of the last view is from the bottom of the 626 // drawable area 627 int bottomOffset = end - lastBottom; 628 629 final View firstChild = getChildAt(0); 630 final int firstTop = firstChild.getTop(); 631 632 // Make sure we are 1) Too high, and 2) Either there are more rows above the 633 // first row or the first row is scrolled off the top of the drawable area 634 if (bottomOffset > 0 && (mFirstPosition > 0 || firstTop < mListPadding.top)) { 635 if (mFirstPosition == 0) { 636 // Don't pull the top too far down 637 bottomOffset = Math.min(bottomOffset, mListPadding.top - firstTop); 638 } 639 640 // Move everything down 641 offsetChildrenTopAndBottom(bottomOffset); 642 if (mFirstPosition > 0) { 643 // Fill the gap that was opened above mFirstPosition with more rows, if 644 // possible 645 fillUp(mFirstPosition - (mStackFromBottom ? 1 : numColumns), 646 firstChild.getTop() - verticalSpacing); 647 // Close up the remaining gap 648 adjustViewsUpOrDown(); 649 } 650 } 651 } 652 } 653 654 private void correctTooLow(int numColumns, int verticalSpacing, int childCount) { 655 if (mFirstPosition == 0 && childCount > 0) { 656 // Get the first child ... 657 final View firstChild = getChildAt(0); 658 659 // ... and its top edge 660 final int firstTop = firstChild.getTop(); 661 662 // This is top of our drawable area 663 final int start = mListPadding.top; 664 665 // This is bottom of our drawable area 666 final int end = (mBottom - mTop) - mListPadding.bottom; 667 668 // This is how far the top edge of the first view is from the top of the 669 // drawable area 670 int topOffset = firstTop - start; 671 final View lastChild = getChildAt(childCount - 1); 672 final int lastBottom = lastChild.getBottom(); 673 final int lastPosition = mFirstPosition + childCount - 1; 674 675 // Make sure we are 1) Too low, and 2) Either there are more rows below the 676 // last row or the last row is scrolled off the bottom of the drawable area 677 if (topOffset > 0 && (lastPosition < mItemCount - 1 || lastBottom > end)) { 678 if (lastPosition == mItemCount - 1 ) { 679 // Don't pull the bottom too far up 680 topOffset = Math.min(topOffset, lastBottom - end); 681 } 682 683 // Move everything up 684 offsetChildrenTopAndBottom(-topOffset); 685 if (lastPosition < mItemCount - 1) { 686 // Fill the gap that was opened below the last position with more rows, if 687 // possible 688 fillDown(lastPosition + (!mStackFromBottom ? 1 : numColumns), 689 lastChild.getBottom() + verticalSpacing); 690 // Close up the remaining gap 691 adjustViewsUpOrDown(); 692 } 693 } 694 } 695 } 696 697 /** 698 * Fills the grid based on positioning the new selection at a specific 699 * location. The selection may be moved so that it does not intersect the 700 * faded edges. The grid is then filled upwards and downwards from there. 701 * 702 * @param selectedTop Where the selected item should be 703 * @param childrenTop Where to start drawing children 704 * @param childrenBottom Last pixel where children can be drawn 705 * @return The view that currently has selection 706 */ 707 private View fillFromSelection(int selectedTop, int childrenTop, int childrenBottom) { 708 final int fadingEdgeLength = getVerticalFadingEdgeLength(); 709 final int selectedPosition = mSelectedPosition; 710 final int numColumns = mNumColumns; 711 final int verticalSpacing = mVerticalSpacing; 712 713 int rowStart; 714 int rowEnd = -1; 715 716 if (!mStackFromBottom) { 717 rowStart = selectedPosition - (selectedPosition % numColumns); 718 } else { 719 int invertedSelection = mItemCount - 1 - selectedPosition; 720 721 rowEnd = mItemCount - 1 - (invertedSelection - (invertedSelection % numColumns)); 722 rowStart = Math.max(0, rowEnd - numColumns + 1); 723 } 724 725 View sel; 726 View referenceView; 727 728 int topSelectionPixel = getTopSelectionPixel(childrenTop, fadingEdgeLength, rowStart); 729 int bottomSelectionPixel = getBottomSelectionPixel(childrenBottom, fadingEdgeLength, 730 numColumns, rowStart); 731 732 sel = makeRow(mStackFromBottom ? rowEnd : rowStart, selectedTop, true); 733 // Possibly changed again in fillUp if we add rows above this one. 734 mFirstPosition = rowStart; 735 736 referenceView = mReferenceView; 737 adjustForTopFadingEdge(referenceView, topSelectionPixel, bottomSelectionPixel); 738 adjustForBottomFadingEdge(referenceView, topSelectionPixel, bottomSelectionPixel); 739 740 if (!mStackFromBottom) { 741 fillUp(rowStart - numColumns, referenceView.getTop() - verticalSpacing); 742 adjustViewsUpOrDown(); 743 fillDown(rowStart + numColumns, referenceView.getBottom() + verticalSpacing); 744 } else { 745 fillDown(rowEnd + numColumns, referenceView.getBottom() + verticalSpacing); 746 adjustViewsUpOrDown(); 747 fillUp(rowStart - 1, referenceView.getTop() - verticalSpacing); 748 } 749 750 751 return sel; 752 } 753 754 /** 755 * Calculate the bottom-most pixel we can draw the selection into 756 * 757 * @param childrenBottom Bottom pixel were children can be drawn 758 * @param fadingEdgeLength Length of the fading edge in pixels, if present 759 * @param numColumns Number of columns in the grid 760 * @param rowStart The start of the row that will contain the selection 761 * @return The bottom-most pixel we can draw the selection into 762 */ 763 private int getBottomSelectionPixel(int childrenBottom, int fadingEdgeLength, 764 int numColumns, int rowStart) { 765 // Last pixel we can draw the selection into 766 int bottomSelectionPixel = childrenBottom; 767 if (rowStart + numColumns - 1 < mItemCount - 1) { 768 bottomSelectionPixel -= fadingEdgeLength; 769 } 770 return bottomSelectionPixel; 771 } 772 773 /** 774 * Calculate the top-most pixel we can draw the selection into 775 * 776 * @param childrenTop Top pixel were children can be drawn 777 * @param fadingEdgeLength Length of the fading edge in pixels, if present 778 * @param rowStart The start of the row that will contain the selection 779 * @return The top-most pixel we can draw the selection into 780 */ 781 private int getTopSelectionPixel(int childrenTop, int fadingEdgeLength, int rowStart) { 782 // first pixel we can draw the selection into 783 int topSelectionPixel = childrenTop; 784 if (rowStart > 0) { 785 topSelectionPixel += fadingEdgeLength; 786 } 787 return topSelectionPixel; 788 } 789 790 /** 791 * Move all views upwards so the selected row does not interesect the bottom 792 * fading edge (if necessary). 793 * 794 * @param childInSelectedRow A child in the row that contains the selection 795 * @param topSelectionPixel The topmost pixel we can draw the selection into 796 * @param bottomSelectionPixel The bottommost pixel we can draw the 797 * selection into 798 */ 799 private void adjustForBottomFadingEdge(View childInSelectedRow, 800 int topSelectionPixel, int bottomSelectionPixel) { 801 // Some of the newly selected item extends below the bottom of the 802 // list 803 if (childInSelectedRow.getBottom() > bottomSelectionPixel) { 804 805 // Find space available above the selection into which we can 806 // scroll upwards 807 int spaceAbove = childInSelectedRow.getTop() - topSelectionPixel; 808 809 // Find space required to bring the bottom of the selected item 810 // fully into view 811 int spaceBelow = childInSelectedRow.getBottom() - bottomSelectionPixel; 812 int offset = Math.min(spaceAbove, spaceBelow); 813 814 // Now offset the selected item to get it into view 815 offsetChildrenTopAndBottom(-offset); 816 } 817 } 818 819 /** 820 * Move all views upwards so the selected row does not interesect the top 821 * fading edge (if necessary). 822 * 823 * @param childInSelectedRow A child in the row that contains the selection 824 * @param topSelectionPixel The topmost pixel we can draw the selection into 825 * @param bottomSelectionPixel The bottommost pixel we can draw the 826 * selection into 827 */ 828 private void adjustForTopFadingEdge(View childInSelectedRow, 829 int topSelectionPixel, int bottomSelectionPixel) { 830 // Some of the newly selected item extends above the top of the list 831 if (childInSelectedRow.getTop() < topSelectionPixel) { 832 // Find space required to bring the top of the selected item 833 // fully into view 834 int spaceAbove = topSelectionPixel - childInSelectedRow.getTop(); 835 836 // Find space available below the selection into which we can 837 // scroll downwards 838 int spaceBelow = bottomSelectionPixel - childInSelectedRow.getBottom(); 839 int offset = Math.min(spaceAbove, spaceBelow); 840 841 // Now offset the selected item to get it into view 842 offsetChildrenTopAndBottom(offset); 843 } 844 } 845 846 /** 847 * Smoothly scroll to the specified adapter position. The view will 848 * scroll such that the indicated position is displayed. 849 * @param position Scroll to this adapter position. 850 */ 851 @android.view.RemotableViewMethod 852 public void smoothScrollToPosition(int position) { 853 super.smoothScrollToPosition(position); 854 } 855 856 /** 857 * Smoothly scroll to the specified adapter position offset. The view will 858 * scroll such that the indicated position is displayed. 859 * @param offset The amount to offset from the adapter position to scroll to. 860 */ 861 @android.view.RemotableViewMethod 862 public void smoothScrollByOffset(int offset) { 863 super.smoothScrollByOffset(offset); 864 } 865 866 /** 867 * Fills the grid based on positioning the new selection relative to the old 868 * selection. The new selection will be placed at, above, or below the 869 * location of the new selection depending on how the selection is moving. 870 * The selection will then be pinned to the visible part of the screen, 871 * excluding the edges that are faded. The grid is then filled upwards and 872 * downwards from there. 873 * 874 * @param delta Which way we are moving 875 * @param childrenTop Where to start drawing children 876 * @param childrenBottom Last pixel where children can be drawn 877 * @return The view that currently has selection 878 */ 879 private View moveSelection(int delta, int childrenTop, int childrenBottom) { 880 final int fadingEdgeLength = getVerticalFadingEdgeLength(); 881 final int selectedPosition = mSelectedPosition; 882 final int numColumns = mNumColumns; 883 final int verticalSpacing = mVerticalSpacing; 884 885 int oldRowStart; 886 int rowStart; 887 int rowEnd = -1; 888 889 if (!mStackFromBottom) { 890 oldRowStart = (selectedPosition - delta) - ((selectedPosition - delta) % numColumns); 891 892 rowStart = selectedPosition - (selectedPosition % numColumns); 893 } else { 894 int invertedSelection = mItemCount - 1 - selectedPosition; 895 896 rowEnd = mItemCount - 1 - (invertedSelection - (invertedSelection % numColumns)); 897 rowStart = Math.max(0, rowEnd - numColumns + 1); 898 899 invertedSelection = mItemCount - 1 - (selectedPosition - delta); 900 oldRowStart = mItemCount - 1 - (invertedSelection - (invertedSelection % numColumns)); 901 oldRowStart = Math.max(0, oldRowStart - numColumns + 1); 902 } 903 904 final int rowDelta = rowStart - oldRowStart; 905 906 final int topSelectionPixel = getTopSelectionPixel(childrenTop, fadingEdgeLength, rowStart); 907 final int bottomSelectionPixel = getBottomSelectionPixel(childrenBottom, fadingEdgeLength, 908 numColumns, rowStart); 909 910 // Possibly changed again in fillUp if we add rows above this one. 911 mFirstPosition = rowStart; 912 913 View sel; 914 View referenceView; 915 916 if (rowDelta > 0) { 917 /* 918 * Case 1: Scrolling down. 919 */ 920 921 final int oldBottom = mReferenceViewInSelectedRow == null ? 0 : 922 mReferenceViewInSelectedRow.getBottom(); 923 924 sel = makeRow(mStackFromBottom ? rowEnd : rowStart, oldBottom + verticalSpacing, true); 925 referenceView = mReferenceView; 926 927 adjustForBottomFadingEdge(referenceView, topSelectionPixel, bottomSelectionPixel); 928 } else if (rowDelta < 0) { 929 /* 930 * Case 2: Scrolling up. 931 */ 932 final int oldTop = mReferenceViewInSelectedRow == null ? 933 0 : mReferenceViewInSelectedRow .getTop(); 934 935 sel = makeRow(mStackFromBottom ? rowEnd : rowStart, oldTop - verticalSpacing, false); 936 referenceView = mReferenceView; 937 938 adjustForTopFadingEdge(referenceView, topSelectionPixel, bottomSelectionPixel); 939 } else { 940 /* 941 * Keep selection where it was 942 */ 943 final int oldTop = mReferenceViewInSelectedRow == null ? 944 0 : mReferenceViewInSelectedRow .getTop(); 945 946 sel = makeRow(mStackFromBottom ? rowEnd : rowStart, oldTop, true); 947 referenceView = mReferenceView; 948 } 949 950 if (!mStackFromBottom) { 951 fillUp(rowStart - numColumns, referenceView.getTop() - verticalSpacing); 952 adjustViewsUpOrDown(); 953 fillDown(rowStart + numColumns, referenceView.getBottom() + verticalSpacing); 954 } else { 955 fillDown(rowEnd + numColumns, referenceView.getBottom() + verticalSpacing); 956 adjustViewsUpOrDown(); 957 fillUp(rowStart - 1, referenceView.getTop() - verticalSpacing); 958 } 959 960 return sel; 961 } 962 963 private boolean determineColumns(int availableSpace) { 964 final int requestedHorizontalSpacing = mRequestedHorizontalSpacing; 965 final int stretchMode = mStretchMode; 966 final int requestedColumnWidth = mRequestedColumnWidth; 967 boolean didNotInitiallyFit = false; 968 969 if (mRequestedNumColumns == AUTO_FIT) { 970 if (requestedColumnWidth > 0) { 971 // Client told us to pick the number of columns 972 mNumColumns = (availableSpace + requestedHorizontalSpacing) / 973 (requestedColumnWidth + requestedHorizontalSpacing); 974 } else { 975 // Just make up a number if we don't have enough info 976 mNumColumns = 2; 977 } 978 } else { 979 // We picked the columns 980 mNumColumns = mRequestedNumColumns; 981 } 982 983 if (mNumColumns <= 0) { 984 mNumColumns = 1; 985 } 986 987 switch (stretchMode) { 988 case NO_STRETCH: 989 // Nobody stretches 990 mColumnWidth = requestedColumnWidth; 991 mHorizontalSpacing = requestedHorizontalSpacing; 992 break; 993 994 default: 995 int spaceLeftOver = availableSpace - (mNumColumns * requestedColumnWidth) - 996 ((mNumColumns - 1) * requestedHorizontalSpacing); 997 998 if (spaceLeftOver < 0) { 999 didNotInitiallyFit = true; 1000 } 1001 1002 switch (stretchMode) { 1003 case STRETCH_COLUMN_WIDTH: 1004 // Stretch the columns 1005 mColumnWidth = requestedColumnWidth + spaceLeftOver / mNumColumns; 1006 mHorizontalSpacing = requestedHorizontalSpacing; 1007 break; 1008 1009 case STRETCH_SPACING: 1010 // Stretch the spacing between columns 1011 mColumnWidth = requestedColumnWidth; 1012 if (mNumColumns > 1) { 1013 mHorizontalSpacing = requestedHorizontalSpacing + 1014 spaceLeftOver / (mNumColumns - 1); 1015 } else { 1016 mHorizontalSpacing = requestedHorizontalSpacing + spaceLeftOver; 1017 } 1018 break; 1019 1020 case STRETCH_SPACING_UNIFORM: 1021 // Stretch the spacing between columns 1022 mColumnWidth = requestedColumnWidth; 1023 if (mNumColumns > 1) { 1024 mHorizontalSpacing = requestedHorizontalSpacing + 1025 spaceLeftOver / (mNumColumns + 1); 1026 } else { 1027 mHorizontalSpacing = requestedHorizontalSpacing + spaceLeftOver; 1028 } 1029 break; 1030 } 1031 1032 break; 1033 } 1034 return didNotInitiallyFit; 1035 } 1036 1037 @Override 1038 protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { 1039 // Sets up mListPadding 1040 super.onMeasure(widthMeasureSpec, heightMeasureSpec); 1041 1042 int widthMode = MeasureSpec.getMode(widthMeasureSpec); 1043 int heightMode = MeasureSpec.getMode(heightMeasureSpec); 1044 int widthSize = MeasureSpec.getSize(widthMeasureSpec); 1045 int heightSize = MeasureSpec.getSize(heightMeasureSpec); 1046 1047 if (widthMode == MeasureSpec.UNSPECIFIED) { 1048 if (mColumnWidth > 0) { 1049 widthSize = mColumnWidth + mListPadding.left + mListPadding.right; 1050 } else { 1051 widthSize = mListPadding.left + mListPadding.right; 1052 } 1053 widthSize += getVerticalScrollbarWidth(); 1054 } 1055 1056 int childWidth = widthSize - mListPadding.left - mListPadding.right; 1057 boolean didNotInitiallyFit = determineColumns(childWidth); 1058 1059 int childHeight = 0; 1060 int childState = 0; 1061 1062 mItemCount = mAdapter == null ? 0 : mAdapter.getCount(); 1063 final int count = mItemCount; 1064 if (count > 0) { 1065 final View child = obtainView(0, mIsScrap); 1066 1067 AbsListView.LayoutParams p = (AbsListView.LayoutParams) child.getLayoutParams(); 1068 if (p == null) { 1069 p = (AbsListView.LayoutParams) generateDefaultLayoutParams(); 1070 child.setLayoutParams(p); 1071 } 1072 p.viewType = mAdapter.getItemViewType(0); 1073 p.isEnabled = mAdapter.isEnabled(0); 1074 p.forceAdd = true; 1075 1076 int childHeightSpec = getChildMeasureSpec( 1077 MeasureSpec.makeSafeMeasureSpec(MeasureSpec.getSize(heightMeasureSpec), 1078 MeasureSpec.UNSPECIFIED), 0, p.height); 1079 int childWidthSpec = getChildMeasureSpec( 1080 MeasureSpec.makeMeasureSpec(mColumnWidth, MeasureSpec.EXACTLY), 0, p.width); 1081 child.measure(childWidthSpec, childHeightSpec); 1082 1083 childHeight = child.getMeasuredHeight(); 1084 childState = combineMeasuredStates(childState, child.getMeasuredState()); 1085 1086 if (mRecycler.shouldRecycleViewType(p.viewType)) { 1087 mRecycler.addScrapView(child, -1); 1088 } 1089 } 1090 1091 if (heightMode == MeasureSpec.UNSPECIFIED) { 1092 heightSize = mListPadding.top + mListPadding.bottom + childHeight + 1093 getVerticalFadingEdgeLength() * 2; 1094 } 1095 1096 if (heightMode == MeasureSpec.AT_MOST) { 1097 int ourSize = mListPadding.top + mListPadding.bottom; 1098 1099 final int numColumns = mNumColumns; 1100 for (int i = 0; i < count; i += numColumns) { 1101 ourSize += childHeight; 1102 if (i + numColumns < count) { 1103 ourSize += mVerticalSpacing; 1104 } 1105 if (ourSize >= heightSize) { 1106 ourSize = heightSize; 1107 break; 1108 } 1109 } 1110 heightSize = ourSize; 1111 } 1112 1113 if (widthMode == MeasureSpec.AT_MOST && mRequestedNumColumns != AUTO_FIT) { 1114 int ourSize = (mRequestedNumColumns*mColumnWidth) 1115 + ((mRequestedNumColumns-1)*mHorizontalSpacing) 1116 + mListPadding.left + mListPadding.right; 1117 if (ourSize > widthSize || didNotInitiallyFit) { 1118 widthSize |= MEASURED_STATE_TOO_SMALL; 1119 } 1120 } 1121 1122 setMeasuredDimension(widthSize, heightSize); 1123 mWidthMeasureSpec = widthMeasureSpec; 1124 } 1125 1126 @Override 1127 protected void attachLayoutAnimationParameters(View child, 1128 ViewGroup.LayoutParams params, int index, int count) { 1129 1130 GridLayoutAnimationController.AnimationParameters animationParams = 1131 (GridLayoutAnimationController.AnimationParameters) params.layoutAnimationParameters; 1132 1133 if (animationParams == null) { 1134 animationParams = new GridLayoutAnimationController.AnimationParameters(); 1135 params.layoutAnimationParameters = animationParams; 1136 } 1137 1138 animationParams.count = count; 1139 animationParams.index = index; 1140 animationParams.columnsCount = mNumColumns; 1141 animationParams.rowsCount = count / mNumColumns; 1142 1143 if (!mStackFromBottom) { 1144 animationParams.column = index % mNumColumns; 1145 animationParams.row = index / mNumColumns; 1146 } else { 1147 final int invertedIndex = count - 1 - index; 1148 1149 animationParams.column = mNumColumns - 1 - (invertedIndex % mNumColumns); 1150 animationParams.row = animationParams.rowsCount - 1 - invertedIndex / mNumColumns; 1151 } 1152 } 1153 1154 @Override 1155 protected void layoutChildren() { 1156 final boolean blockLayoutRequests = mBlockLayoutRequests; 1157 if (!blockLayoutRequests) { 1158 mBlockLayoutRequests = true; 1159 } 1160 1161 try { 1162 super.layoutChildren(); 1163 1164 invalidate(); 1165 1166 if (mAdapter == null) { 1167 resetList(); 1168 invokeOnItemScrollListener(); 1169 return; 1170 } 1171 1172 final int childrenTop = mListPadding.top; 1173 final int childrenBottom = mBottom - mTop - mListPadding.bottom; 1174 1175 int childCount = getChildCount(); 1176 int index; 1177 int delta = 0; 1178 1179 View sel; 1180 View oldSel = null; 1181 View oldFirst = null; 1182 View newSel = null; 1183 1184 // Remember stuff we will need down below 1185 switch (mLayoutMode) { 1186 case LAYOUT_SET_SELECTION: 1187 index = mNextSelectedPosition - mFirstPosition; 1188 if (index >= 0 && index < childCount) { 1189 newSel = getChildAt(index); 1190 } 1191 break; 1192 case LAYOUT_FORCE_TOP: 1193 case LAYOUT_FORCE_BOTTOM: 1194 case LAYOUT_SPECIFIC: 1195 case LAYOUT_SYNC: 1196 break; 1197 case LAYOUT_MOVE_SELECTION: 1198 if (mNextSelectedPosition >= 0) { 1199 delta = mNextSelectedPosition - mSelectedPosition; 1200 } 1201 break; 1202 default: 1203 // Remember the previously selected view 1204 index = mSelectedPosition - mFirstPosition; 1205 if (index >= 0 && index < childCount) { 1206 oldSel = getChildAt(index); 1207 } 1208 1209 // Remember the previous first child 1210 oldFirst = getChildAt(0); 1211 } 1212 1213 boolean dataChanged = mDataChanged; 1214 if (dataChanged) { 1215 handleDataChanged(); 1216 } 1217 1218 // Handle the empty set by removing all views that are visible 1219 // and calling it a day 1220 if (mItemCount == 0) { 1221 resetList(); 1222 invokeOnItemScrollListener(); 1223 return; 1224 } 1225 1226 setSelectedPositionInt(mNextSelectedPosition); 1227 1228 AccessibilityNodeInfo accessibilityFocusLayoutRestoreNode = null; 1229 View accessibilityFocusLayoutRestoreView = null; 1230 int accessibilityFocusPosition = INVALID_POSITION; 1231 1232 // Remember which child, if any, had accessibility focus. This must 1233 // occur before recycling any views, since that will clear 1234 // accessibility focus. 1235 final ViewRootImpl viewRootImpl = getViewRootImpl(); 1236 if (viewRootImpl != null) { 1237 final View focusHost = viewRootImpl.getAccessibilityFocusedHost(); 1238 if (focusHost != null) { 1239 final View focusChild = getAccessibilityFocusedChild(focusHost); 1240 if (focusChild != null) { 1241 if (!dataChanged || focusChild.hasTransientState() 1242 || mAdapterHasStableIds) { 1243 // The views won't be changing, so try to maintain 1244 // focus on the current host and virtual view. 1245 accessibilityFocusLayoutRestoreView = focusHost; 1246 accessibilityFocusLayoutRestoreNode = viewRootImpl 1247 .getAccessibilityFocusedVirtualView(); 1248 } 1249 1250 // Try to maintain focus at the same position. 1251 accessibilityFocusPosition = getPositionForView(focusChild); 1252 } 1253 } 1254 } 1255 1256 // Pull all children into the RecycleBin. 1257 // These views will be reused if possible 1258 final int firstPosition = mFirstPosition; 1259 final RecycleBin recycleBin = mRecycler; 1260 1261 if (dataChanged) { 1262 for (int i = 0; i < childCount; i++) { 1263 recycleBin.addScrapView(getChildAt(i), firstPosition+i); 1264 } 1265 } else { 1266 recycleBin.fillActiveViews(childCount, firstPosition); 1267 } 1268 1269 // Clear out old views 1270 detachAllViewsFromParent(); 1271 recycleBin.removeSkippedScrap(); 1272 1273 switch (mLayoutMode) { 1274 case LAYOUT_SET_SELECTION: 1275 if (newSel != null) { 1276 sel = fillFromSelection(newSel.getTop(), childrenTop, childrenBottom); 1277 } else { 1278 sel = fillSelection(childrenTop, childrenBottom); 1279 } 1280 break; 1281 case LAYOUT_FORCE_TOP: 1282 mFirstPosition = 0; 1283 sel = fillFromTop(childrenTop); 1284 adjustViewsUpOrDown(); 1285 break; 1286 case LAYOUT_FORCE_BOTTOM: 1287 sel = fillUp(mItemCount - 1, childrenBottom); 1288 adjustViewsUpOrDown(); 1289 break; 1290 case LAYOUT_SPECIFIC: 1291 sel = fillSpecific(mSelectedPosition, mSpecificTop); 1292 break; 1293 case LAYOUT_SYNC: 1294 sel = fillSpecific(mSyncPosition, mSpecificTop); 1295 break; 1296 case LAYOUT_MOVE_SELECTION: 1297 // Move the selection relative to its old position 1298 sel = moveSelection(delta, childrenTop, childrenBottom); 1299 break; 1300 default: 1301 if (childCount == 0) { 1302 if (!mStackFromBottom) { 1303 setSelectedPositionInt(mAdapter == null || isInTouchMode() ? 1304 INVALID_POSITION : 0); 1305 sel = fillFromTop(childrenTop); 1306 } else { 1307 final int last = mItemCount - 1; 1308 setSelectedPositionInt(mAdapter == null || isInTouchMode() ? 1309 INVALID_POSITION : last); 1310 sel = fillFromBottom(last, childrenBottom); 1311 } 1312 } else { 1313 if (mSelectedPosition >= 0 && mSelectedPosition < mItemCount) { 1314 sel = fillSpecific(mSelectedPosition, oldSel == null ? 1315 childrenTop : oldSel.getTop()); 1316 } else if (mFirstPosition < mItemCount) { 1317 sel = fillSpecific(mFirstPosition, oldFirst == null ? 1318 childrenTop : oldFirst.getTop()); 1319 } else { 1320 sel = fillSpecific(0, childrenTop); 1321 } 1322 } 1323 break; 1324 } 1325 1326 // Flush any cached views that did not get reused above 1327 recycleBin.scrapActiveViews(); 1328 1329 if (sel != null) { 1330 positionSelector(INVALID_POSITION, sel); 1331 mSelectedTop = sel.getTop(); 1332 } else { 1333 final boolean inTouchMode = mTouchMode > TOUCH_MODE_DOWN 1334 && mTouchMode < TOUCH_MODE_SCROLL; 1335 if (inTouchMode) { 1336 // If the user's finger is down, select the motion position. 1337 final View child = getChildAt(mMotionPosition - mFirstPosition); 1338 if (child != null) { 1339 positionSelector(mMotionPosition, child); 1340 } 1341 } else if (mSelectedPosition != INVALID_POSITION) { 1342 // If we had previously positioned the selector somewhere, 1343 // put it back there. It might not match up with the data, 1344 // but it's transitioning out so it's not a big deal. 1345 final View child = getChildAt(mSelectorPosition - mFirstPosition); 1346 if (child != null) { 1347 positionSelector(mSelectorPosition, child); 1348 } 1349 } else { 1350 // Otherwise, clear selection. 1351 mSelectedTop = 0; 1352 mSelectorRect.setEmpty(); 1353 } 1354 } 1355 1356 // Attempt to restore accessibility focus, if necessary. 1357 if (viewRootImpl != null) { 1358 final View newAccessibilityFocusedView = viewRootImpl.getAccessibilityFocusedHost(); 1359 if (newAccessibilityFocusedView == null) { 1360 if (accessibilityFocusLayoutRestoreView != null 1361 && accessibilityFocusLayoutRestoreView.isAttachedToWindow()) { 1362 final AccessibilityNodeProvider provider = 1363 accessibilityFocusLayoutRestoreView.getAccessibilityNodeProvider(); 1364 if (accessibilityFocusLayoutRestoreNode != null && provider != null) { 1365 final int virtualViewId = AccessibilityNodeInfo.getVirtualDescendantId( 1366 accessibilityFocusLayoutRestoreNode.getSourceNodeId()); 1367 provider.performAction(virtualViewId, 1368 AccessibilityNodeInfo.ACTION_ACCESSIBILITY_FOCUS, null); 1369 } else { 1370 accessibilityFocusLayoutRestoreView.requestAccessibilityFocus(); 1371 } 1372 } else if (accessibilityFocusPosition != INVALID_POSITION) { 1373 // Bound the position within the visible children. 1374 final int position = MathUtils.constrain( 1375 accessibilityFocusPosition - mFirstPosition, 0, 1376 getChildCount() - 1); 1377 final View restoreView = getChildAt(position); 1378 if (restoreView != null) { 1379 restoreView.requestAccessibilityFocus(); 1380 } 1381 } 1382 } 1383 } 1384 1385 mLayoutMode = LAYOUT_NORMAL; 1386 mDataChanged = false; 1387 if (mPositionScrollAfterLayout != null) { 1388 post(mPositionScrollAfterLayout); 1389 mPositionScrollAfterLayout = null; 1390 } 1391 mNeedSync = false; 1392 setNextSelectedPositionInt(mSelectedPosition); 1393 1394 updateScrollIndicators(); 1395 1396 if (mItemCount > 0) { 1397 checkSelectionChanged(); 1398 } 1399 1400 invokeOnItemScrollListener(); 1401 } finally { 1402 if (!blockLayoutRequests) { 1403 mBlockLayoutRequests = false; 1404 } 1405 } 1406 } 1407 1408 1409 /** 1410 * Obtain the view and add it to our list of children. The view can be made 1411 * fresh, converted from an unused view, or used as is if it was in the 1412 * recycle bin. 1413 * 1414 * @param position Logical position in the list 1415 * @param y Top or bottom edge of the view to add 1416 * @param flow if true, align top edge to y. If false, align bottom edge to 1417 * y. 1418 * @param childrenLeft Left edge where children should be positioned 1419 * @param selected Is this position selected? 1420 * @param where to add new item in the list 1421 * @return View that was added 1422 */ 1423 private View makeAndAddView(int position, int y, boolean flow, int childrenLeft, 1424 boolean selected, int where) { 1425 View child; 1426 1427 if (!mDataChanged) { 1428 // Try to use an existing view for this position 1429 child = mRecycler.getActiveView(position); 1430 if (child != null) { 1431 // Found it -- we're using an existing child 1432 // This just needs to be positioned 1433 setupChild(child, position, y, flow, childrenLeft, selected, true, where); 1434 return child; 1435 } 1436 } 1437 1438 // Make a new view for this position, or convert an unused view if 1439 // possible 1440 child = obtainView(position, mIsScrap); 1441 1442 // This needs to be positioned and measured 1443 setupChild(child, position, y, flow, childrenLeft, selected, mIsScrap[0], where); 1444 1445 return child; 1446 } 1447 1448 /** 1449 * Add a view as a child and make sure it is measured (if necessary) and 1450 * positioned properly. 1451 * 1452 * @param child The view to add 1453 * @param position The position of the view 1454 * @param y The y position relative to which this view will be positioned 1455 * @param flow if true, align top edge to y. If false, align bottom edge 1456 * to y. 1457 * @param childrenLeft Left edge where children should be positioned 1458 * @param selected Is this position selected? 1459 * @param recycled Has this view been pulled from the recycle bin? If so it 1460 * does not need to be remeasured. 1461 * @param where Where to add the item in the list 1462 * 1463 */ 1464 private void setupChild(View child, int position, int y, boolean flow, int childrenLeft, 1465 boolean selected, boolean recycled, int where) { 1466 Trace.traceBegin(Trace.TRACE_TAG_VIEW, "setupGridItem"); 1467 1468 boolean isSelected = selected && shouldShowSelector(); 1469 final boolean updateChildSelected = isSelected != child.isSelected(); 1470 final int mode = mTouchMode; 1471 final boolean isPressed = mode > TOUCH_MODE_DOWN && mode < TOUCH_MODE_SCROLL && 1472 mMotionPosition == position; 1473 final boolean updateChildPressed = isPressed != child.isPressed(); 1474 1475 boolean needToMeasure = !recycled || updateChildSelected || child.isLayoutRequested(); 1476 1477 // Respect layout params that are already in the view. Otherwise make 1478 // some up... 1479 AbsListView.LayoutParams p = (AbsListView.LayoutParams) child.getLayoutParams(); 1480 if (p == null) { 1481 p = (AbsListView.LayoutParams) generateDefaultLayoutParams(); 1482 } 1483 p.viewType = mAdapter.getItemViewType(position); 1484 p.isEnabled = mAdapter.isEnabled(position); 1485 1486 if (recycled && !p.forceAdd) { 1487 attachViewToParent(child, where, p); 1488 } else { 1489 p.forceAdd = false; 1490 addViewInLayout(child, where, p, true); 1491 } 1492 1493 if (updateChildSelected) { 1494 child.setSelected(isSelected); 1495 if (isSelected) { 1496 requestFocus(); 1497 } 1498 } 1499 1500 if (updateChildPressed) { 1501 child.setPressed(isPressed); 1502 } 1503 1504 if (mChoiceMode != CHOICE_MODE_NONE && mCheckStates != null) { 1505 if (child instanceof Checkable) { 1506 ((Checkable) child).setChecked(mCheckStates.get(position)); 1507 } else if (getContext().getApplicationInfo().targetSdkVersion 1508 >= android.os.Build.VERSION_CODES.HONEYCOMB) { 1509 child.setActivated(mCheckStates.get(position)); 1510 } 1511 } 1512 1513 if (needToMeasure) { 1514 int childHeightSpec = ViewGroup.getChildMeasureSpec( 1515 MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 0, p.height); 1516 1517 int childWidthSpec = ViewGroup.getChildMeasureSpec( 1518 MeasureSpec.makeMeasureSpec(mColumnWidth, MeasureSpec.EXACTLY), 0, p.width); 1519 child.measure(childWidthSpec, childHeightSpec); 1520 } else { 1521 cleanupLayoutState(child); 1522 } 1523 1524 final int w = child.getMeasuredWidth(); 1525 final int h = child.getMeasuredHeight(); 1526 1527 int childLeft; 1528 final int childTop = flow ? y : y - h; 1529 1530 final int layoutDirection = getLayoutDirection(); 1531 final int absoluteGravity = Gravity.getAbsoluteGravity(mGravity, layoutDirection); 1532 switch (absoluteGravity & Gravity.HORIZONTAL_GRAVITY_MASK) { 1533 case Gravity.LEFT: 1534 childLeft = childrenLeft; 1535 break; 1536 case Gravity.CENTER_HORIZONTAL: 1537 childLeft = childrenLeft + ((mColumnWidth - w) / 2); 1538 break; 1539 case Gravity.RIGHT: 1540 childLeft = childrenLeft + mColumnWidth - w; 1541 break; 1542 default: 1543 childLeft = childrenLeft; 1544 break; 1545 } 1546 1547 if (needToMeasure) { 1548 final int childRight = childLeft + w; 1549 final int childBottom = childTop + h; 1550 child.layout(childLeft, childTop, childRight, childBottom); 1551 } else { 1552 child.offsetLeftAndRight(childLeft - child.getLeft()); 1553 child.offsetTopAndBottom(childTop - child.getTop()); 1554 } 1555 1556 if (mCachingStarted) { 1557 child.setDrawingCacheEnabled(true); 1558 } 1559 1560 if (recycled && (((AbsListView.LayoutParams)child.getLayoutParams()).scrappedFromPosition) 1561 != position) { 1562 child.jumpDrawablesToCurrentState(); 1563 } 1564 1565 Trace.traceEnd(Trace.TRACE_TAG_VIEW); 1566 } 1567 1568 /** 1569 * Sets the currently selected item 1570 * 1571 * @param position Index (starting at 0) of the data item to be selected. 1572 * 1573 * If in touch mode, the item will not be selected but it will still be positioned 1574 * appropriately. 1575 */ 1576 @Override 1577 public void setSelection(int position) { 1578 if (!isInTouchMode()) { 1579 setNextSelectedPositionInt(position); 1580 } else { 1581 mResurrectToPosition = position; 1582 } 1583 mLayoutMode = LAYOUT_SET_SELECTION; 1584 if (mPositionScroller != null) { 1585 mPositionScroller.stop(); 1586 } 1587 requestLayout(); 1588 } 1589 1590 /** 1591 * Makes the item at the supplied position selected. 1592 * 1593 * @param position the position of the new selection 1594 */ 1595 @Override 1596 void setSelectionInt(int position) { 1597 int previousSelectedPosition = mNextSelectedPosition; 1598 1599 if (mPositionScroller != null) { 1600 mPositionScroller.stop(); 1601 } 1602 1603 setNextSelectedPositionInt(position); 1604 layoutChildren(); 1605 1606 final int next = mStackFromBottom ? mItemCount - 1 - mNextSelectedPosition : 1607 mNextSelectedPosition; 1608 final int previous = mStackFromBottom ? mItemCount - 1 1609 - previousSelectedPosition : previousSelectedPosition; 1610 1611 final int nextRow = next / mNumColumns; 1612 final int previousRow = previous / mNumColumns; 1613 1614 if (nextRow != previousRow) { 1615 awakenScrollBars(); 1616 } 1617 1618 } 1619 1620 @Override 1621 public boolean onKeyDown(int keyCode, KeyEvent event) { 1622 return commonKey(keyCode, 1, event); 1623 } 1624 1625 @Override 1626 public boolean onKeyMultiple(int keyCode, int repeatCount, KeyEvent event) { 1627 return commonKey(keyCode, repeatCount, event); 1628 } 1629 1630 @Override 1631 public boolean onKeyUp(int keyCode, KeyEvent event) { 1632 return commonKey(keyCode, 1, event); 1633 } 1634 1635 private boolean commonKey(int keyCode, int count, KeyEvent event) { 1636 if (mAdapter == null) { 1637 return false; 1638 } 1639 1640 if (mDataChanged) { 1641 layoutChildren(); 1642 } 1643 1644 boolean handled = false; 1645 int action = event.getAction(); 1646 if (KeyEvent.isConfirmKey(keyCode) 1647 && event.hasNoModifiers() && action != KeyEvent.ACTION_UP) { 1648 handled = resurrectSelectionIfNeeded(); 1649 if (!handled && event.getRepeatCount() == 0 && getChildCount() > 0) { 1650 keyPressed(); 1651 handled = true; 1652 } 1653 } 1654 1655 if (!handled && action != KeyEvent.ACTION_UP) { 1656 switch (keyCode) { 1657 case KeyEvent.KEYCODE_DPAD_LEFT: 1658 if (event.hasNoModifiers()) { 1659 handled = resurrectSelectionIfNeeded() || arrowScroll(FOCUS_LEFT); 1660 } 1661 break; 1662 1663 case KeyEvent.KEYCODE_DPAD_RIGHT: 1664 if (event.hasNoModifiers()) { 1665 handled = resurrectSelectionIfNeeded() || arrowScroll(FOCUS_RIGHT); 1666 } 1667 break; 1668 1669 case KeyEvent.KEYCODE_DPAD_UP: 1670 if (event.hasNoModifiers()) { 1671 handled = resurrectSelectionIfNeeded() || arrowScroll(FOCUS_UP); 1672 } else if (event.hasModifiers(KeyEvent.META_ALT_ON)) { 1673 handled = resurrectSelectionIfNeeded() || fullScroll(FOCUS_UP); 1674 } 1675 break; 1676 1677 case KeyEvent.KEYCODE_DPAD_DOWN: 1678 if (event.hasNoModifiers()) { 1679 handled = resurrectSelectionIfNeeded() || arrowScroll(FOCUS_DOWN); 1680 } else if (event.hasModifiers(KeyEvent.META_ALT_ON)) { 1681 handled = resurrectSelectionIfNeeded() || fullScroll(FOCUS_DOWN); 1682 } 1683 break; 1684 1685 case KeyEvent.KEYCODE_PAGE_UP: 1686 if (event.hasNoModifiers()) { 1687 handled = resurrectSelectionIfNeeded() || pageScroll(FOCUS_UP); 1688 } else if (event.hasModifiers(KeyEvent.META_ALT_ON)) { 1689 handled = resurrectSelectionIfNeeded() || fullScroll(FOCUS_UP); 1690 } 1691 break; 1692 1693 case KeyEvent.KEYCODE_PAGE_DOWN: 1694 if (event.hasNoModifiers()) { 1695 handled = resurrectSelectionIfNeeded() || pageScroll(FOCUS_DOWN); 1696 } else if (event.hasModifiers(KeyEvent.META_ALT_ON)) { 1697 handled = resurrectSelectionIfNeeded() || fullScroll(FOCUS_DOWN); 1698 } 1699 break; 1700 1701 case KeyEvent.KEYCODE_MOVE_HOME: 1702 if (event.hasNoModifiers()) { 1703 handled = resurrectSelectionIfNeeded() || fullScroll(FOCUS_UP); 1704 } 1705 break; 1706 1707 case KeyEvent.KEYCODE_MOVE_END: 1708 if (event.hasNoModifiers()) { 1709 handled = resurrectSelectionIfNeeded() || fullScroll(FOCUS_DOWN); 1710 } 1711 break; 1712 1713 case KeyEvent.KEYCODE_TAB: 1714 // XXX Sometimes it is useful to be able to TAB through the items in 1715 // a GridView sequentially. Unfortunately this can create an 1716 // asymmetry in TAB navigation order unless the list selection 1717 // always reverts to the top or bottom when receiving TAB focus from 1718 // another widget. Leaving this behavior disabled for now but 1719 // perhaps it should be configurable (and more comprehensive). 1720 if (false) { 1721 if (event.hasNoModifiers()) { 1722 handled = resurrectSelectionIfNeeded() 1723 || sequenceScroll(FOCUS_FORWARD); 1724 } else if (event.hasModifiers(KeyEvent.META_SHIFT_ON)) { 1725 handled = resurrectSelectionIfNeeded() 1726 || sequenceScroll(FOCUS_BACKWARD); 1727 } 1728 } 1729 break; 1730 } 1731 } 1732 1733 if (handled) { 1734 return true; 1735 } 1736 1737 if (sendToTextFilter(keyCode, count, event)) { 1738 return true; 1739 } 1740 1741 switch (action) { 1742 case KeyEvent.ACTION_DOWN: 1743 return super.onKeyDown(keyCode, event); 1744 case KeyEvent.ACTION_UP: 1745 return super.onKeyUp(keyCode, event); 1746 case KeyEvent.ACTION_MULTIPLE: 1747 return super.onKeyMultiple(keyCode, count, event); 1748 default: 1749 return false; 1750 } 1751 } 1752 1753 /** 1754 * Scrolls up or down by the number of items currently present on screen. 1755 * 1756 * @param direction either {@link View#FOCUS_UP} or {@link View#FOCUS_DOWN} 1757 * @return whether selection was moved 1758 */ 1759 boolean pageScroll(int direction) { 1760 int nextPage = -1; 1761 1762 if (direction == FOCUS_UP) { 1763 nextPage = Math.max(0, mSelectedPosition - getChildCount()); 1764 } else if (direction == FOCUS_DOWN) { 1765 nextPage = Math.min(mItemCount - 1, mSelectedPosition + getChildCount()); 1766 } 1767 1768 if (nextPage >= 0) { 1769 setSelectionInt(nextPage); 1770 invokeOnItemScrollListener(); 1771 awakenScrollBars(); 1772 return true; 1773 } 1774 1775 return false; 1776 } 1777 1778 /** 1779 * Go to the last or first item if possible. 1780 * 1781 * @param direction either {@link View#FOCUS_UP} or {@link View#FOCUS_DOWN}. 1782 * 1783 * @return Whether selection was moved. 1784 */ 1785 boolean fullScroll(int direction) { 1786 boolean moved = false; 1787 if (direction == FOCUS_UP) { 1788 mLayoutMode = LAYOUT_SET_SELECTION; 1789 setSelectionInt(0); 1790 invokeOnItemScrollListener(); 1791 moved = true; 1792 } else if (direction == FOCUS_DOWN) { 1793 mLayoutMode = LAYOUT_SET_SELECTION; 1794 setSelectionInt(mItemCount - 1); 1795 invokeOnItemScrollListener(); 1796 moved = true; 1797 } 1798 1799 if (moved) { 1800 awakenScrollBars(); 1801 } 1802 1803 return moved; 1804 } 1805 1806 /** 1807 * Scrolls to the next or previous item, horizontally or vertically. 1808 * 1809 * @param direction either {@link View#FOCUS_LEFT}, {@link View#FOCUS_RIGHT}, 1810 * {@link View#FOCUS_UP} or {@link View#FOCUS_DOWN} 1811 * 1812 * @return whether selection was moved 1813 */ 1814 boolean arrowScroll(int direction) { 1815 final int selectedPosition = mSelectedPosition; 1816 final int numColumns = mNumColumns; 1817 1818 int startOfRowPos; 1819 int endOfRowPos; 1820 1821 boolean moved = false; 1822 1823 if (!mStackFromBottom) { 1824 startOfRowPos = (selectedPosition / numColumns) * numColumns; 1825 endOfRowPos = Math.min(startOfRowPos + numColumns - 1, mItemCount - 1); 1826 } else { 1827 final int invertedSelection = mItemCount - 1 - selectedPosition; 1828 endOfRowPos = mItemCount - 1 - (invertedSelection / numColumns) * numColumns; 1829 startOfRowPos = Math.max(0, endOfRowPos - numColumns + 1); 1830 } 1831 1832 switch (direction) { 1833 case FOCUS_UP: 1834 if (startOfRowPos > 0) { 1835 mLayoutMode = LAYOUT_MOVE_SELECTION; 1836 setSelectionInt(Math.max(0, selectedPosition - numColumns)); 1837 moved = true; 1838 } 1839 break; 1840 case FOCUS_DOWN: 1841 if (endOfRowPos < mItemCount - 1) { 1842 mLayoutMode = LAYOUT_MOVE_SELECTION; 1843 setSelectionInt(Math.min(selectedPosition + numColumns, mItemCount - 1)); 1844 moved = true; 1845 } 1846 break; 1847 } 1848 1849 final boolean isLayoutRtl = isLayoutRtl(); 1850 if (selectedPosition > startOfRowPos && ((direction == FOCUS_LEFT && !isLayoutRtl) || 1851 (direction == FOCUS_RIGHT && isLayoutRtl))) { 1852 mLayoutMode = LAYOUT_MOVE_SELECTION; 1853 setSelectionInt(Math.max(0, selectedPosition - 1)); 1854 moved = true; 1855 } else if (selectedPosition < endOfRowPos && ((direction == FOCUS_LEFT && isLayoutRtl) || 1856 (direction == FOCUS_RIGHT && !isLayoutRtl))) { 1857 mLayoutMode = LAYOUT_MOVE_SELECTION; 1858 setSelectionInt(Math.min(selectedPosition + 1, mItemCount - 1)); 1859 moved = true; 1860 } 1861 1862 if (moved) { 1863 playSoundEffect(SoundEffectConstants.getContantForFocusDirection(direction)); 1864 invokeOnItemScrollListener(); 1865 } 1866 1867 if (moved) { 1868 awakenScrollBars(); 1869 } 1870 1871 return moved; 1872 } 1873 1874 /** 1875 * Goes to the next or previous item according to the order set by the 1876 * adapter. 1877 */ 1878 boolean sequenceScroll(int direction) { 1879 int selectedPosition = mSelectedPosition; 1880 int numColumns = mNumColumns; 1881 int count = mItemCount; 1882 1883 int startOfRow; 1884 int endOfRow; 1885 if (!mStackFromBottom) { 1886 startOfRow = (selectedPosition / numColumns) * numColumns; 1887 endOfRow = Math.min(startOfRow + numColumns - 1, count - 1); 1888 } else { 1889 int invertedSelection = count - 1 - selectedPosition; 1890 endOfRow = count - 1 - (invertedSelection / numColumns) * numColumns; 1891 startOfRow = Math.max(0, endOfRow - numColumns + 1); 1892 } 1893 1894 boolean moved = false; 1895 boolean showScroll = false; 1896 switch (direction) { 1897 case FOCUS_FORWARD: 1898 if (selectedPosition < count - 1) { 1899 // Move to the next item. 1900 mLayoutMode = LAYOUT_MOVE_SELECTION; 1901 setSelectionInt(selectedPosition + 1); 1902 moved = true; 1903 // Show the scrollbar only if changing rows. 1904 showScroll = selectedPosition == endOfRow; 1905 } 1906 break; 1907 1908 case FOCUS_BACKWARD: 1909 if (selectedPosition > 0) { 1910 // Move to the previous item. 1911 mLayoutMode = LAYOUT_MOVE_SELECTION; 1912 setSelectionInt(selectedPosition - 1); 1913 moved = true; 1914 // Show the scrollbar only if changing rows. 1915 showScroll = selectedPosition == startOfRow; 1916 } 1917 break; 1918 } 1919 1920 if (moved) { 1921 playSoundEffect(SoundEffectConstants.getContantForFocusDirection(direction)); 1922 invokeOnItemScrollListener(); 1923 } 1924 1925 if (showScroll) { 1926 awakenScrollBars(); 1927 } 1928 1929 return moved; 1930 } 1931 1932 @Override 1933 protected void onFocusChanged(boolean gainFocus, int direction, Rect previouslyFocusedRect) { 1934 super.onFocusChanged(gainFocus, direction, previouslyFocusedRect); 1935 1936 int closestChildIndex = -1; 1937 if (gainFocus && previouslyFocusedRect != null) { 1938 previouslyFocusedRect.offset(mScrollX, mScrollY); 1939 1940 // figure out which item should be selected based on previously 1941 // focused rect 1942 Rect otherRect = mTempRect; 1943 int minDistance = Integer.MAX_VALUE; 1944 final int childCount = getChildCount(); 1945 for (int i = 0; i < childCount; i++) { 1946 // only consider view's on appropriate edge of grid 1947 if (!isCandidateSelection(i, direction)) { 1948 continue; 1949 } 1950 1951 final View other = getChildAt(i); 1952 other.getDrawingRect(otherRect); 1953 offsetDescendantRectToMyCoords(other, otherRect); 1954 int distance = getDistance(previouslyFocusedRect, otherRect, direction); 1955 1956 if (distance < minDistance) { 1957 minDistance = distance; 1958 closestChildIndex = i; 1959 } 1960 } 1961 } 1962 1963 if (closestChildIndex >= 0) { 1964 setSelection(closestChildIndex + mFirstPosition); 1965 } else { 1966 requestLayout(); 1967 } 1968 } 1969 1970 /** 1971 * Is childIndex a candidate for next focus given the direction the focus 1972 * change is coming from? 1973 * @param childIndex The index to check. 1974 * @param direction The direction, one of 1975 * {FOCUS_UP, FOCUS_DOWN, FOCUS_LEFT, FOCUS_RIGHT, FOCUS_FORWARD, FOCUS_BACKWARD} 1976 * @return Whether childIndex is a candidate. 1977 */ 1978 private boolean isCandidateSelection(int childIndex, int direction) { 1979 final int count = getChildCount(); 1980 final int invertedIndex = count - 1 - childIndex; 1981 1982 int rowStart; 1983 int rowEnd; 1984 1985 if (!mStackFromBottom) { 1986 rowStart = childIndex - (childIndex % mNumColumns); 1987 rowEnd = Math.max(rowStart + mNumColumns - 1, count); 1988 } else { 1989 rowEnd = count - 1 - (invertedIndex - (invertedIndex % mNumColumns)); 1990 rowStart = Math.max(0, rowEnd - mNumColumns + 1); 1991 } 1992 1993 switch (direction) { 1994 case View.FOCUS_RIGHT: 1995 // coming from left, selection is only valid if it is on left 1996 // edge 1997 return childIndex == rowStart; 1998 case View.FOCUS_DOWN: 1999 // coming from top; only valid if in top row 2000 return rowStart == 0; 2001 case View.FOCUS_LEFT: 2002 // coming from right, must be on right edge 2003 return childIndex == rowEnd; 2004 case View.FOCUS_UP: 2005 // coming from bottom, need to be in last row 2006 return rowEnd == count - 1; 2007 case View.FOCUS_FORWARD: 2008 // coming from top-left, need to be first in top row 2009 return childIndex == rowStart && rowStart == 0; 2010 case View.FOCUS_BACKWARD: 2011 // coming from bottom-right, need to be last in bottom row 2012 return childIndex == rowEnd && rowEnd == count - 1; 2013 default: 2014 throw new IllegalArgumentException("direction must be one of " 2015 + "{FOCUS_UP, FOCUS_DOWN, FOCUS_LEFT, FOCUS_RIGHT, " 2016 + "FOCUS_FORWARD, FOCUS_BACKWARD}."); 2017 } 2018 } 2019 2020 /** 2021 * Set the gravity for this grid. Gravity describes how the child views 2022 * are horizontally aligned. Defaults to Gravity.LEFT 2023 * 2024 * @param gravity the gravity to apply to this grid's children 2025 * 2026 * @attr ref android.R.styleable#GridView_gravity 2027 */ 2028 public void setGravity(int gravity) { 2029 if (mGravity != gravity) { 2030 mGravity = gravity; 2031 requestLayoutIfNecessary(); 2032 } 2033 } 2034 2035 /** 2036 * Describes how the child views are horizontally aligned. Defaults to Gravity.LEFT 2037 * 2038 * @return the gravity that will be applied to this grid's children 2039 * 2040 * @attr ref android.R.styleable#GridView_gravity 2041 */ 2042 public int getGravity() { 2043 return mGravity; 2044 } 2045 2046 /** 2047 * Set the amount of horizontal (x) spacing to place between each item 2048 * in the grid. 2049 * 2050 * @param horizontalSpacing The amount of horizontal space between items, 2051 * in pixels. 2052 * 2053 * @attr ref android.R.styleable#GridView_horizontalSpacing 2054 */ 2055 public void setHorizontalSpacing(int horizontalSpacing) { 2056 if (horizontalSpacing != mRequestedHorizontalSpacing) { 2057 mRequestedHorizontalSpacing = horizontalSpacing; 2058 requestLayoutIfNecessary(); 2059 } 2060 } 2061 2062 /** 2063 * Returns the amount of horizontal spacing currently used between each item in the grid. 2064 * 2065 * <p>This is only accurate for the current layout. If {@link #setHorizontalSpacing(int)} 2066 * has been called but layout is not yet complete, this method may return a stale value. 2067 * To get the horizontal spacing that was explicitly requested use 2068 * {@link #getRequestedHorizontalSpacing()}.</p> 2069 * 2070 * @return Current horizontal spacing between each item in pixels 2071 * 2072 * @see #setHorizontalSpacing(int) 2073 * @see #getRequestedHorizontalSpacing() 2074 * 2075 * @attr ref android.R.styleable#GridView_horizontalSpacing 2076 */ 2077 public int getHorizontalSpacing() { 2078 return mHorizontalSpacing; 2079 } 2080 2081 /** 2082 * Returns the requested amount of horizontal spacing between each item in the grid. 2083 * 2084 * <p>The value returned may have been supplied during inflation as part of a style, 2085 * the default GridView style, or by a call to {@link #setHorizontalSpacing(int)}. 2086 * If layout is not yet complete or if GridView calculated a different horizontal spacing 2087 * from what was requested, this may return a different value from 2088 * {@link #getHorizontalSpacing()}.</p> 2089 * 2090 * @return The currently requested horizontal spacing between items, in pixels 2091 * 2092 * @see #setHorizontalSpacing(int) 2093 * @see #getHorizontalSpacing() 2094 * 2095 * @attr ref android.R.styleable#GridView_horizontalSpacing 2096 */ 2097 public int getRequestedHorizontalSpacing() { 2098 return mRequestedHorizontalSpacing; 2099 } 2100 2101 /** 2102 * Set the amount of vertical (y) spacing to place between each item 2103 * in the grid. 2104 * 2105 * @param verticalSpacing The amount of vertical space between items, 2106 * in pixels. 2107 * 2108 * @see #getVerticalSpacing() 2109 * 2110 * @attr ref android.R.styleable#GridView_verticalSpacing 2111 */ 2112 public void setVerticalSpacing(int verticalSpacing) { 2113 if (verticalSpacing != mVerticalSpacing) { 2114 mVerticalSpacing = verticalSpacing; 2115 requestLayoutIfNecessary(); 2116 } 2117 } 2118 2119 /** 2120 * Returns the amount of vertical spacing between each item in the grid. 2121 * 2122 * @return The vertical spacing between items in pixels 2123 * 2124 * @see #setVerticalSpacing(int) 2125 * 2126 * @attr ref android.R.styleable#GridView_verticalSpacing 2127 */ 2128 public int getVerticalSpacing() { 2129 return mVerticalSpacing; 2130 } 2131 2132 /** 2133 * Control how items are stretched to fill their space. 2134 * 2135 * @param stretchMode Either {@link #NO_STRETCH}, 2136 * {@link #STRETCH_SPACING}, {@link #STRETCH_SPACING_UNIFORM}, or {@link #STRETCH_COLUMN_WIDTH}. 2137 * 2138 * @attr ref android.R.styleable#GridView_stretchMode 2139 */ 2140 public void setStretchMode(@StretchMode int stretchMode) { 2141 if (stretchMode != mStretchMode) { 2142 mStretchMode = stretchMode; 2143 requestLayoutIfNecessary(); 2144 } 2145 } 2146 2147 @StretchMode 2148 public int getStretchMode() { 2149 return mStretchMode; 2150 } 2151 2152 /** 2153 * Set the width of columns in the grid. 2154 * 2155 * @param columnWidth The column width, in pixels. 2156 * 2157 * @attr ref android.R.styleable#GridView_columnWidth 2158 */ 2159 public void setColumnWidth(int columnWidth) { 2160 if (columnWidth != mRequestedColumnWidth) { 2161 mRequestedColumnWidth = columnWidth; 2162 requestLayoutIfNecessary(); 2163 } 2164 } 2165 2166 /** 2167 * Return the width of a column in the grid. 2168 * 2169 * <p>This may not be valid yet if a layout is pending.</p> 2170 * 2171 * @return The column width in pixels 2172 * 2173 * @see #setColumnWidth(int) 2174 * @see #getRequestedColumnWidth() 2175 * 2176 * @attr ref android.R.styleable#GridView_columnWidth 2177 */ 2178 public int getColumnWidth() { 2179 return mColumnWidth; 2180 } 2181 2182 /** 2183 * Return the requested width of a column in the grid. 2184 * 2185 * <p>This may not be the actual column width used. Use {@link #getColumnWidth()} 2186 * to retrieve the current real width of a column.</p> 2187 * 2188 * @return The requested column width in pixels 2189 * 2190 * @see #setColumnWidth(int) 2191 * @see #getColumnWidth() 2192 * 2193 * @attr ref android.R.styleable#GridView_columnWidth 2194 */ 2195 public int getRequestedColumnWidth() { 2196 return mRequestedColumnWidth; 2197 } 2198 2199 /** 2200 * Set the number of columns in the grid 2201 * 2202 * @param numColumns The desired number of columns. 2203 * 2204 * @attr ref android.R.styleable#GridView_numColumns 2205 */ 2206 public void setNumColumns(int numColumns) { 2207 if (numColumns != mRequestedNumColumns) { 2208 mRequestedNumColumns = numColumns; 2209 requestLayoutIfNecessary(); 2210 } 2211 } 2212 2213 /** 2214 * Get the number of columns in the grid. 2215 * Returns {@link #AUTO_FIT} if the Grid has never been laid out. 2216 * 2217 * @attr ref android.R.styleable#GridView_numColumns 2218 * 2219 * @see #setNumColumns(int) 2220 */ 2221 @ViewDebug.ExportedProperty 2222 public int getNumColumns() { 2223 return mNumColumns; 2224 } 2225 2226 /** 2227 * Make sure views are touching the top or bottom edge, as appropriate for 2228 * our gravity 2229 */ 2230 private void adjustViewsUpOrDown() { 2231 final int childCount = getChildCount(); 2232 2233 if (childCount > 0) { 2234 int delta; 2235 View child; 2236 2237 if (!mStackFromBottom) { 2238 // Uh-oh -- we came up short. Slide all views up to make them 2239 // align with the top 2240 child = getChildAt(0); 2241 delta = child.getTop() - mListPadding.top; 2242 if (mFirstPosition != 0) { 2243 // It's OK to have some space above the first item if it is 2244 // part of the vertical spacing 2245 delta -= mVerticalSpacing; 2246 } 2247 if (delta < 0) { 2248 // We only are looking to see if we are too low, not too high 2249 delta = 0; 2250 } 2251 } else { 2252 // we are too high, slide all views down to align with bottom 2253 child = getChildAt(childCount - 1); 2254 delta = child.getBottom() - (getHeight() - mListPadding.bottom); 2255 2256 if (mFirstPosition + childCount < mItemCount) { 2257 // It's OK to have some space below the last item if it is 2258 // part of the vertical spacing 2259 delta += mVerticalSpacing; 2260 } 2261 2262 if (delta > 0) { 2263 // We only are looking to see if we are too high, not too low 2264 delta = 0; 2265 } 2266 } 2267 2268 if (delta != 0) { 2269 offsetChildrenTopAndBottom(-delta); 2270 } 2271 } 2272 } 2273 2274 @Override 2275 protected int computeVerticalScrollExtent() { 2276 final int count = getChildCount(); 2277 if (count > 0) { 2278 final int numColumns = mNumColumns; 2279 final int rowCount = (count + numColumns - 1) / numColumns; 2280 2281 int extent = rowCount * 100; 2282 2283 View view = getChildAt(0); 2284 final int top = view.getTop(); 2285 int height = view.getHeight(); 2286 if (height > 0) { 2287 extent += (top * 100) / height; 2288 } 2289 2290 view = getChildAt(count - 1); 2291 final int bottom = view.getBottom(); 2292 height = view.getHeight(); 2293 if (height > 0) { 2294 extent -= ((bottom - getHeight()) * 100) / height; 2295 } 2296 2297 return extent; 2298 } 2299 return 0; 2300 } 2301 2302 @Override 2303 protected int computeVerticalScrollOffset() { 2304 if (mFirstPosition >= 0 && getChildCount() > 0) { 2305 final View view = getChildAt(0); 2306 final int top = view.getTop(); 2307 int height = view.getHeight(); 2308 if (height > 0) { 2309 final int numColumns = mNumColumns; 2310 final int rowCount = (mItemCount + numColumns - 1) / numColumns; 2311 // In case of stackFromBottom the calculation of whichRow needs 2312 // to take into account that counting from the top the first row 2313 // might not be entirely filled. 2314 final int oddItemsOnFirstRow = isStackFromBottom() ? ((rowCount * numColumns) - 2315 mItemCount) : 0; 2316 final int whichRow = (mFirstPosition + oddItemsOnFirstRow) / numColumns; 2317 return Math.max(whichRow * 100 - (top * 100) / height + 2318 (int) ((float) mScrollY / getHeight() * rowCount * 100), 0); 2319 } 2320 } 2321 return 0; 2322 } 2323 2324 @Override 2325 protected int computeVerticalScrollRange() { 2326 // TODO: Account for vertical spacing too 2327 final int numColumns = mNumColumns; 2328 final int rowCount = (mItemCount + numColumns - 1) / numColumns; 2329 int result = Math.max(rowCount * 100, 0); 2330 if (mScrollY != 0) { 2331 // Compensate for overscroll 2332 result += Math.abs((int) ((float) mScrollY / getHeight() * rowCount * 100)); 2333 } 2334 return result; 2335 } 2336 2337 @Override 2338 public CharSequence getAccessibilityClassName() { 2339 return GridView.class.getName(); 2340 } 2341 2342 /** @hide */ 2343 @Override 2344 public void onInitializeAccessibilityNodeInfoInternal(AccessibilityNodeInfo info) { 2345 super.onInitializeAccessibilityNodeInfoInternal(info); 2346 2347 final int columnsCount = getNumColumns(); 2348 final int rowsCount = getCount() / columnsCount; 2349 final int selectionMode = getSelectionModeForAccessibility(); 2350 final CollectionInfo collectionInfo = CollectionInfo.obtain( 2351 rowsCount, columnsCount, false, selectionMode); 2352 info.setCollectionInfo(collectionInfo); 2353 2354 if (columnsCount > 0 || rowsCount > 0) { 2355 info.addAction(AccessibilityAction.ACTION_SCROLL_TO_POSITION); 2356 } 2357 } 2358 2359 /** @hide */ 2360 @Override 2361 public boolean performAccessibilityActionInternal(int action, Bundle arguments) { 2362 if (super.performAccessibilityActionInternal(action, arguments)) { 2363 return true; 2364 } 2365 2366 switch (action) { 2367 case R.id.accessibilityActionScrollToPosition: { 2368 // GridView only supports scrolling in one direction, so we can 2369 // ignore the column argument. 2370 final int numColumns = getNumColumns(); 2371 final int row = arguments.getInt(AccessibilityNodeInfo.ACTION_ARGUMENT_ROW_INT, -1); 2372 final int position = Math.min(row * numColumns, getCount() - 1); 2373 if (row >= 0) { 2374 // The accessibility service gets data asynchronously, so 2375 // we'll be a little lenient by clamping the last position. 2376 smoothScrollToPosition(position); 2377 return true; 2378 } 2379 } break; 2380 } 2381 2382 return false; 2383 } 2384 2385 @Override 2386 public void onInitializeAccessibilityNodeInfoForItem( 2387 View view, int position, AccessibilityNodeInfo info) { 2388 super.onInitializeAccessibilityNodeInfoForItem(view, position, info); 2389 2390 final int count = getCount(); 2391 final int columnsCount = getNumColumns(); 2392 final int rowsCount = count / columnsCount; 2393 2394 final int row; 2395 final int column; 2396 if (!mStackFromBottom) { 2397 column = position % columnsCount; 2398 row = position / columnsCount; 2399 } else { 2400 final int invertedIndex = count - 1 - position; 2401 2402 column = columnsCount - 1 - (invertedIndex % columnsCount); 2403 row = rowsCount - 1 - invertedIndex / columnsCount; 2404 } 2405 2406 final LayoutParams lp = (LayoutParams) view.getLayoutParams(); 2407 final boolean isHeading = lp != null && lp.viewType == ITEM_VIEW_TYPE_HEADER_OR_FOOTER; 2408 final boolean isSelected = isItemChecked(position); 2409 final CollectionItemInfo itemInfo = CollectionItemInfo.obtain( 2410 row, 1, column, 1, isHeading, isSelected); 2411 info.setCollectionItemInfo(itemInfo); 2412 } 2413 2414 /** @hide */ 2415 @Override 2416 protected void encodeProperties(@NonNull ViewHierarchyEncoder encoder) { 2417 super.encodeProperties(encoder); 2418 encoder.addProperty("numColumns", getNumColumns()); 2419 } 2420} 2421