Merge "Integrate band selection into the files app." (00a3fb8a) · Commits · e / os / android_packages_apps_DocumentsUI

src/com/android/documentsui/BandSelectManager.java

deleted100644 → 0

+0 −335

Original line number	Original line	Diff line number	Diff line
	/*
	* Copyright (C) 2015 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	package com.android.documentsui;

	import static com.android.documentsui.Events.isMouseEvent;
	import static com.android.internal.util.Preconditions.checkState;

	import android.graphics.Point;
	import android.graphics.Rect;
	import android.graphics.drawable.Drawable;
	import android.support.v7.widget.RecyclerView;
	import android.support.v7.widget.RecyclerView.ViewHolder;
	import android.util.Log;
	import android.util.SparseBooleanArray;
	import android.view.MotionEvent;
	import android.view.View;

	/**
	* Provides mouse driven band-select support when used in conjuction with {@link RecyclerView} and
	* {@link MultiSelectManager}. This class is responsible for rendering the band select overlay and
	* selecting overlaid items via MultiSelectManager.
	*/
	public class BandSelectManager extends RecyclerView.SimpleOnItemTouchListener {

	private static final int NOT_SELECTED = -1;
	private static final int NOT_SET = -1;

	// For debugging purposes.
	private static final String TAG = "BandSelectManager";
	private static final boolean DEBUG = false;

	private final RecyclerView mRecyclerView;
	private final MultiSelectManager mSelectManager;
	private final Drawable mRegionSelectorDrawable;
	private final SparseBooleanArray mSelectedByBand = new SparseBooleanArray();

	private boolean mIsBandSelectActive = false;
	private Point mOrigin;
	private Point mPointer;
	private Rect mBounds;

	// Maintain the last selection made by band, so if bounds shrink back, we can deselect
	// the respective items.
	private int mCursorDeltaY = 0;
	private int mFirstSelected = NOT_SELECTED;

	// The time at which the current band selection-induced scroll began. If no scroll is in
	// progress, the value is NOT_SET.
	private long mScrollStartTime = NOT_SET;
	private final Runnable mScrollRunnable = new Runnable() {
	/**
	* The number of milliseconds of scrolling at which scroll speed continues to increase. At
	* first, the scroll starts slowly; then, the rate of scrolling increases until it reaches
	* its maximum value at after this many milliseconds.
	*/
	private static final long SCROLL_ACCELERATION_LIMIT_TIME_MS = 2000;

	@Override
	public void run() {
	// Compute the number of pixels the pointer's y-coordinate is past the view. Negative
	// values mean the pointer is at or before the top of the view, and positive values mean
	// that the pointer is at or after the bottom of the view. Note that one additional
	// pixel is added here so that the view still scrolls when the pointer is exactly at the
	// top or bottom.
	int pixelsPastView = 0;
	if (mPointer.y <= 0) {
	pixelsPastView = mPointer.y - 1;
	} else if (mPointer.y >= mRecyclerView.getHeight() - 1) {
	pixelsPastView = mPointer.y - mRecyclerView.getHeight() + 1;
	}

	if (!mIsBandSelectActive \|\| pixelsPastView == 0) {
	// If band selection is inactive, or if it is active but not at the edge of the
	// view, no scrolling is necessary.
	mScrollStartTime = NOT_SET;
	return;
	}

	if (mScrollStartTime == NOT_SET) {
	// If the pointer was previously not at the edge of the view but now is, set the
	// start time for the scroll.
	mScrollStartTime = System.currentTimeMillis();
	}

	// Compute the number of pixels to scroll, and scroll that many pixels.
	final int numPixels = computeNumPixelsToScroll(
	pixelsPastView, System.currentTimeMillis() - mScrollStartTime);
	mRecyclerView.scrollBy(0, numPixels);

	// Adjust the y-coordinate of the origin the opposite number of pixels so that the
	// origin remains in the same place relative to the view's items.
	mOrigin.y -= numPixels;
	resizeBandSelectRectangle();

	mRecyclerView.removeCallbacks(mScrollRunnable);
	mRecyclerView.postOnAnimation(this);
	}

	/**
	* Computes the number of pixels to scroll based on how far the pointer is past the end of
	* the view and how long it has been there. Roughly based on ItemTouchHelper's algorithm for
	* computing the number of pixels to scroll when an item is dragged to the end of a
	* {@link RecyclerView}.
	* @param pixelsPastView
	* @param scrollDuration
	* @return
	*/
	private int computeNumPixelsToScroll(int pixelsPastView, long scrollDuration) {
	final int maxScrollStep = computeMaxScrollStep(mRecyclerView);
	final int direction = (int) Math.signum(pixelsPastView);
	final int absPastView = Math.abs(pixelsPastView);

	// Calculate the ratio of how far out of the view the pointer currently resides to the
	// entire height of the view.
	final float outOfBoundsRatio = Math.min(
	1.0f, (float) absPastView / mRecyclerView.getHeight());
	// Interpolate this ratio and use it to compute the maximum scroll that should be
	// possible for this step.
	final float cappedScrollStep =
	direction * maxScrollStep * smoothOutOfBoundsRatio(outOfBoundsRatio);

	// Likewise, calculate the ratio of the time spent in the scroll to the limit.
	final float timeRatio = Math.min(
	1.0f, (float) scrollDuration / SCROLL_ACCELERATION_LIMIT_TIME_MS);
	// Interpolate this ratio and use it to compute the final number of pixels to scroll.
	final int numPixels = (int) (cappedScrollStep * smoothTimeRatio(timeRatio));

	// If the final number of pixels to scroll ends up being 0, the view should still scroll
	// at least one pixel.
	return numPixels != 0 ? numPixels : direction;
	}

	/**
	* Computes the maximum scroll allowed for a given animation frame. Currently, this
	* defaults to the height of the view, but this could be tweaked if this results in scrolls
	* that are too fast or too slow.
	* @param rv
	* @return
	*/
	private int computeMaxScrollStep(RecyclerView rv) {
	return rv.getHeight();
	}

	/**
	* Interpolates the given out of bounds ratio on a curve which starts at (0,0) and ends at
	* (1,1) and quickly approaches 1 near the start of that interval. This ensures that drags
	* that are at the edge or barely past the edge of the view still cause sufficient
	* scrolling. The equation y=(x-1)^5+1 is used, but this could also be tweaked if needed.
	* @param ratio A ratio which is in the range [0, 1].
	* @return A "smoothed" value, also in the range [0, 1].
	*/
	private float smoothOutOfBoundsRatio(float ratio) {
	return (float) Math.pow(ratio - 1.0f, 5) + 1.0f;
	}

	/**
	* Interpolates the given time ratio on a curve which starts at (0,0) and ends at (1,1) and
	* stays close to 0 for most input values except those very close to 1. This ensures that
	* scrolls start out very slowly but speed up drastically after the scroll has been in
	* progress close to SCROLL_ACCELERATION_LIMIT_TIME_MS. The equation y=x^5 is used, but this
	* could also be tweaked if needed.
	* @param ratio A ratio which is in the range [0, 1].
	* @return A "smoothed" value, also in the range [0, 1].
	*/
	private float smoothTimeRatio(float ratio) {
	return (float) Math.pow(ratio, 5);
	}
	};

	/**
	* @param recyclerView
	* @param multiSelectManager
	*/
	public BandSelectManager(RecyclerView recyclerView, MultiSelectManager multiSelectManager) {
	mRecyclerView = recyclerView;
	mSelectManager = multiSelectManager;
	mRegionSelectorDrawable =
	mRecyclerView.getContext().getTheme().getDrawable(R.drawable.band_select_overlay);

	mRecyclerView.addOnItemTouchListener(this);
	}

	@Override
	public boolean onInterceptTouchEvent(RecyclerView rv, MotionEvent e) {
	// Only intercept the event if it was triggered by a mouse. If band select is inactive,
	// do not intercept ACTION_UP events as they will not be processed.
	return isMouseEvent(e) &&
	(mIsBandSelectActive \|\| e.getActionMasked() != MotionEvent.ACTION_UP);
	}

	@Override
	public void onTouchEvent(RecyclerView rv, MotionEvent e) {
	checkState(isMouseEvent(e));
	processMotionEvent(e);
	}

	/**
	* Processes a MotionEvent by starting, ending, or resizing the band select overlay.
	* @param e
	*/
	private void processMotionEvent(MotionEvent e) {
	if (mIsBandSelectActive && e.getActionMasked() == MotionEvent.ACTION_UP) {
	endBandSelect();
	return;
	}

	mPointer = new Point((int) e.getX(), (int) e.getY());
	if (!mIsBandSelectActive) {
	startBandSelect();
	}

	scrollViewIfNecessary();
	resizeBandSelectRectangle();
	selectChildrenCoveredBySelection();
	}

	/**
	* Starts band select by adding the drawable to the RecyclerView's overlay.
	*/
	private void startBandSelect() {
	if (DEBUG) Log.d(TAG, "Starting band select from (" + mPointer.x + "," + mPointer.y + ").");
	mIsBandSelectActive = true;
	mOrigin = mPointer;
	mRecyclerView.getOverlay().add(mRegionSelectorDrawable);
	}

	/**
	* Scrolls the view if necessary.
	*/
	private void scrollViewIfNecessary() {
	mRecyclerView.removeCallbacks(mScrollRunnable);
	mScrollRunnable.run();
	mRecyclerView.invalidate();
	}

	/**
	* Resizes the band select rectangle by using the origin and the current pointer positoin as
	* two opposite corners of the selection.
	*/
	private void resizeBandSelectRectangle() {
	if (mBounds != null) {
	mCursorDeltaY = mPointer.y - mBounds.bottom;
	}

	mBounds = new Rect(Math.min(mOrigin.x, mPointer.x),
	Math.min(mOrigin.y, mPointer.y),
	Math.max(mOrigin.x, mPointer.x),
	Math.max(mOrigin.y, mPointer.y));

	mRegionSelectorDrawable.setBounds(mBounds);
	}

	/**
	* Selects the children covered by the band select overlay by delegating to MultiSelectManager.
	* TODO: Provide a finished implementation. This is down and dirty, proof of concept code.
	* Final optimized implementation, with support for managing offscreen selection to come.
	*/
	private void selectChildrenCoveredBySelection() {

	// track top and bottom selections. Details on why this is useful below.
	int first = NOT_SELECTED;
	int last = NOT_SELECTED;

	for (int i = 0; i < mRecyclerView.getChildCount(); i++) {

	View child = mRecyclerView.getChildAt(i);
	ViewHolder holder = mRecyclerView.getChildViewHolder(child);
	Rect childRect = new Rect();
	child.getHitRect(childRect);

	boolean shouldSelect = Rect.intersects(childRect, mBounds);
	int position = holder.getAdapterPosition();

	// This also allows us to clear the selection of elements
	// that only temporarily entered the bounds of the band.
	if (mSelectedByBand.get(position) && !shouldSelect) {
	mSelectManager.setItemSelected(position, false);
	mSelectedByBand.delete(position);
	}

	// We need to keep track of the first and last items selected.
	// We'll use this information along with cursor direction
	// to determine the starting point of the selection.
	// We provide this information to selection manager
	// to enable more natural user interaction when working
	// with Shift+Click and multiple contiguous selection ranges.
	if (shouldSelect) {
	if (first == NOT_SELECTED) {
	first = position;
	} else {
	last = position;
	}
	mSelectManager.setItemSelected(position, true);
	mSelectedByBand.put(position, true);
	}
	}

	// Remember which is the last selected item, so we can
	// share that with selection manager when band select ends.
	// It'll use that as it's begin selection point when
	// user SHIFT+Clicks.
	if (mCursorDeltaY < 0 && last != NOT_SELECTED) {
	mFirstSelected = last;
	} else if (mCursorDeltaY > 0 && first != NOT_SELECTED) {
	mFirstSelected = first;
	}
	}

	/**
	* Ends band select by removing the overlay.
	*/
	private void endBandSelect() {
	if (DEBUG) Log.d(TAG, "Ending band select.");
	mIsBandSelectActive = false;
	mSelectedByBand.clear();
	mRecyclerView.getOverlay().remove(mRegionSelectorDrawable);
	if (mFirstSelected != NOT_SELECTED) {
	mSelectManager.setSelectionFocusBegin(mFirstSelected);
	}
	}
	}

src/com/android/documentsui/BandSelectMatrix.java

deleted100644 → 0

+0 −645

File deleted.

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src/com/android/documentsui/DirectoryFragment.java

+1 −3

Original line number	Original line	Diff line number	Diff line
	@@ -1773,8 +1773,6 @@ public class DirectoryFragment extends Fragment {
	}		}

	@Override		@Override
	public void afterActivityCreated(DirectoryFragment fragment) {		public void afterActivityCreated(DirectoryFragment fragment) {}
	new BandSelectManager(fragment.mRecView, fragment.mSelectionManager);
	}
	}		}
	}		}

src/com/android/documentsui/MultiSelectManager.java

+1184 −60

File changed.

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tests/src/com/android/documentsui/BandSelectMatrixTest.java→tests/src/com/android/documentsui/BandSelectModelTest.java

+51 −42

Original line number	Original line	Diff line number	Diff line
	@@ -18,7 +18,7 @@ package com.android.documentsui;

	import static org.junit.Assert.*;		import static org.junit.Assert.*;

	import com.android.documentsui.BandSelectMatrix;		import com.android.documentsui.MultiSelectManager.BandSelectModel;

	import android.graphics.Point;		import android.graphics.Point;
	import android.graphics.Rect;		import android.graphics.Rect;
	@@ -28,13 +28,13 @@ import android.util.SparseBooleanArray;
	import org.junit.After;		import org.junit.After;
	import org.junit.Test;		import org.junit.Test;

	public class BandSelectMatrixTest {		public class BandSelectModelTest {

	private static final int VIEW_PADDING_PX = 5;		private static final int VIEW_PADDING_PX = 5;
	private static final int CHILD_VIEW_EDGE_PX = 100;		private static final int CHILD_VIEW_EDGE_PX = 100;
	private static final int VIEWPORT_HEIGHT = 500;		private static final int VIEWPORT_HEIGHT = 500;

	private static BandSelectMatrix matrix;		private static BandSelectModel model;
	private static TestHelper helper;		private static TestHelper helper;
	private static SparseBooleanArray lastSelection;		private static SparseBooleanArray lastSelection;
	private static int viewWidth;		private static int viewWidth;
	@@ -42,8 +42,8 @@ public class BandSelectMatrixTest {
	private static void setUp(int numChildren, int numColumns) {		private static void setUp(int numChildren, int numColumns) {
	helper = new TestHelper(numChildren, numColumns);		helper = new TestHelper(numChildren, numColumns);
	viewWidth = VIEW_PADDING_PX + numColumns * (VIEW_PADDING_PX + CHILD_VIEW_EDGE_PX);		viewWidth = VIEW_PADDING_PX + numColumns * (VIEW_PADDING_PX + CHILD_VIEW_EDGE_PX);
	matrix = new BandSelectMatrix(helper);		model = new BandSelectModel(helper);
	matrix.addOnSelectionChangedListener(new BandSelectMatrix.OnSelectionChangedListener() {		model.addOnSelectionChangedListener(new BandSelectModel.OnSelectionChangedListener() {

	@Override		@Override
	public void onSelectionChanged(SparseBooleanArray updatedSelection) {		public void onSelectionChanged(SparseBooleanArray updatedSelection) {
	@@ -54,7 +54,7 @@ public class BandSelectMatrixTest {

	@After		@After
	public void tearDown() {		public void tearDown() {
	matrix = null;		model = null;
	helper = null;		helper = null;
	lastSelection = null;		lastSelection = null;
	}		}
	@@ -62,111 +62,120 @@ public class BandSelectMatrixTest {
	@Test		@Test
	public void testSelectionLeftOfItems() {		public void testSelectionLeftOfItems() {
	setUp(20, 5);		setUp(20, 5);
	matrix.startSelection(new Point(0, 10));		model.startSelection(new Point(0, 10));
	matrix.resizeSelection(new Point(1, 11));		model.resizeSelection(new Point(1, 11));
	assertSelected(new int[0]);		assertSelected(new int[0]);
			assertEquals(BandSelectModel.NOT_SET, model.getPositionNearestOrigin());
	}		}

	@Test		@Test
	public void testSelectionRightOfItems() {		public void testSelectionRightOfItems() {
	setUp(20, 4);		setUp(20, 4);
	matrix.startSelection(new Point(viewWidth - 1, 10));		model.startSelection(new Point(viewWidth - 1, 10));
	matrix.resizeSelection(new Point(viewWidth - 2, 11));		model.resizeSelection(new Point(viewWidth - 2, 11));
	assertSelected(new int[0]);		assertSelected(new int[0]);
			assertEquals(BandSelectModel.NOT_SET, model.getPositionNearestOrigin());
	}		}

	@Test		@Test
	public void testSelectionAboveItems() {		public void testSelectionAboveItems() {
	setUp(20, 4);		setUp(20, 4);
	matrix.startSelection(new Point(10, 0));		model.startSelection(new Point(10, 0));
	matrix.resizeSelection(new Point(11, 1));		model.resizeSelection(new Point(11, 1));
	assertSelected(new int[0]);		assertSelected(new int[0]);
			assertEquals(BandSelectModel.NOT_SET, model.getPositionNearestOrigin());
	}		}

	@Test		@Test
	public void testSelectionBelowItems() {		public void testSelectionBelowItems() {
	setUp(5, 4);		setUp(5, 4);
	matrix.startSelection(new Point(10, VIEWPORT_HEIGHT - 1));		model.startSelection(new Point(10, VIEWPORT_HEIGHT - 1));
	matrix.resizeSelection(new Point(11, VIEWPORT_HEIGHT - 2));		model.resizeSelection(new Point(11, VIEWPORT_HEIGHT - 2));
	assertSelected(new int[0]);		assertSelected(new int[0]);
			assertEquals(BandSelectModel.NOT_SET, model.getPositionNearestOrigin());
	}		}

	@Test		@Test
	public void testVerticalSelectionBetweenItems() {		public void testVerticalSelectionBetweenItems() {
	setUp(20, 4);		setUp(20, 4);
	matrix.startSelection(new Point(106, 0));		model.startSelection(new Point(106, 0));
	matrix.resizeSelection(new Point(107, 200));		model.resizeSelection(new Point(107, 200));
	assertSelected(new int[0]);		assertSelected(new int[0]);
			assertEquals(BandSelectModel.NOT_SET, model.getPositionNearestOrigin());
	}		}

	@Test		@Test
	public void testHorizontalSelectionBetweenItems() {		public void testHorizontalSelectionBetweenItems() {
	setUp(20, 4);		setUp(20, 4);
	matrix.startSelection(new Point(0, 105));		model.startSelection(new Point(0, 105));
	matrix.resizeSelection(new Point(200, 106));		model.resizeSelection(new Point(200, 106));
	assertSelected(new int[0]);		assertSelected(new int[0]);
			assertEquals(BandSelectModel.NOT_SET, model.getPositionNearestOrigin());
	}		}

	@Test		@Test
	public void testGrowingAndShrinkingSelection() {		public void testGrowingAndShrinkingSelection() {
	setUp(20, 4);		setUp(20, 4);
	matrix.startSelection(new Point(0, 0));		model.startSelection(new Point(0, 0));
	matrix.resizeSelection(new Point(5, 5));		model.resizeSelection(new Point(5, 5));
	assertSelected(new int[] {0});		assertSelected(new int[] {0});
	matrix.resizeSelection(new Point(109, 109));		model.resizeSelection(new Point(109, 109));
	assertSelected(new int[] {0});		assertSelected(new int[] {0});
	matrix.resizeSelection(new Point(110, 109));		model.resizeSelection(new Point(110, 109));
	assertSelected(new int[] {0, 1});		assertSelected(new int[] {0, 1});
	matrix.resizeSelection(new Point(110, 110));		model.resizeSelection(new Point(110, 110));
	assertSelected(new int[] {0, 1, 4, 5});		assertSelected(new int[] {0, 1, 4, 5});
	matrix.resizeSelection(new Point(214, 214));		model.resizeSelection(new Point(214, 214));
	assertSelected(new int[] {0, 1, 4, 5});		assertSelected(new int[] {0, 1, 4, 5});
	matrix.resizeSelection(new Point(215, 214));		model.resizeSelection(new Point(215, 214));
	assertSelected(new int[] {0, 1, 2, 4, 5, 6});		assertSelected(new int[] {0, 1, 2, 4, 5, 6});
	matrix.resizeSelection(new Point(214, 214));		model.resizeSelection(new Point(214, 214));
	assertSelected(new int[] {0, 1, 4, 5});		assertSelected(new int[] {0, 1, 4, 5});
	matrix.resizeSelection(new Point(110, 110));		model.resizeSelection(new Point(110, 110));
	assertSelected(new int[] {0, 1, 4, 5});		assertSelected(new int[] {0, 1, 4, 5});
	matrix.resizeSelection(new Point(110, 109));		model.resizeSelection(new Point(110, 109));
	assertSelected(new int[] {0, 1});		assertSelected(new int[] {0, 1});
	matrix.resizeSelection(new Point(109, 109));		model.resizeSelection(new Point(109, 109));
	assertSelected(new int[] {0});		assertSelected(new int[] {0});
	matrix.resizeSelection(new Point(5, 5));		model.resizeSelection(new Point(5, 5));
	assertSelected(new int[] {0});		assertSelected(new int[] {0});
	matrix.resizeSelection(new Point(0, 0));		model.resizeSelection(new Point(0, 0));
	assertSelected(new int[0]);		assertSelected(new int[0]);
			assertEquals(BandSelectModel.NOT_SET, model.getPositionNearestOrigin());
	}		}

	@Test		@Test
	public void testSelectionMovingAroundOrigin() {		public void testSelectionMovingAroundOrigin() {
	setUp(16, 4);		setUp(16, 4);
	matrix.startSelection(new Point(210, 210));		model.startSelection(new Point(210, 210));
	matrix.resizeSelection(new Point(viewWidth - 1, 0));		model.resizeSelection(new Point(viewWidth - 1, 0));
	assertSelected(new int[] {2, 3, 6, 7});		assertSelected(new int[] {2, 3, 6, 7});
	matrix.resizeSelection(new Point(0, 0));		model.resizeSelection(new Point(0, 0));
	assertSelected(new int[] {0, 1, 4, 5});		assertSelected(new int[] {0, 1, 4, 5});
	matrix.resizeSelection(new Point(0, 420));		model.resizeSelection(new Point(0, 420));
	assertSelected(new int[] {8, 9, 12, 13});		assertSelected(new int[] {8, 9, 12, 13});
	matrix.resizeSelection(new Point(viewWidth - 1, 420));		model.resizeSelection(new Point(viewWidth - 1, 420));
	assertSelected(new int[] {10, 11, 14, 15});		assertSelected(new int[] {10, 11, 14, 15});
			assertEquals(10, model.getPositionNearestOrigin());
	}		}

	@Test		@Test
	public void testScrollingBandSelect() {		public void testScrollingBandSelect() {
	setUp(40, 4);		setUp(40, 4);
	matrix.startSelection(new Point(0, 0));		model.startSelection(new Point(0, 0));
	matrix.resizeSelection(new Point(100, VIEWPORT_HEIGHT - 1));		model.resizeSelection(new Point(100, VIEWPORT_HEIGHT - 1));
	assertSelected(new int[] {0, 4, 8, 12, 16});		assertSelected(new int[] {0, 4, 8, 12, 16});
	scroll(CHILD_VIEW_EDGE_PX);		scroll(CHILD_VIEW_EDGE_PX);
	assertSelected(new int[] {0, 4, 8, 12, 16, 20});		assertSelected(new int[] {0, 4, 8, 12, 16, 20});
	matrix.resizeSelection(new Point(200, VIEWPORT_HEIGHT - 1));		model.resizeSelection(new Point(200, VIEWPORT_HEIGHT - 1));
	assertSelected(new int[] {0, 1, 4, 5, 8, 9, 12, 13, 16, 17, 20, 21});		assertSelected(new int[] {0, 1, 4, 5, 8, 9, 12, 13, 16, 17, 20, 21});
	scroll(CHILD_VIEW_EDGE_PX);		scroll(CHILD_VIEW_EDGE_PX);
	assertSelected(new int[] {0, 1, 4, 5, 8, 9, 12, 13, 16, 17, 20, 21, 24, 25});		assertSelected(new int[] {0, 1, 4, 5, 8, 9, 12, 13, 16, 17, 20, 21, 24, 25});
	scroll(-2 * CHILD_VIEW_EDGE_PX);		scroll(-2 * CHILD_VIEW_EDGE_PX);
	assertSelected(new int[] {0, 1, 4, 5, 8, 9, 12, 13, 16, 17});		assertSelected(new int[] {0, 1, 4, 5, 8, 9, 12, 13, 16, 17});
	matrix.resizeSelection(new Point(100, VIEWPORT_HEIGHT - 1));		model.resizeSelection(new Point(100, VIEWPORT_HEIGHT - 1));
	assertSelected(new int[] {0, 4, 8, 12, 16});		assertSelected(new int[] {0, 4, 8, 12, 16});
			assertEquals(0, model.getPositionNearestOrigin());
	}		}

	private static void assertSelected(int[] selectedPositions) {		private static void assertSelected(int[] selectedPositions) {
	@@ -179,10 +188,10 @@ public class BandSelectMatrixTest {
	private static void scroll(int dy) {		private static void scroll(int dy) {
	assertTrue(helper.verticalOffset + VIEWPORT_HEIGHT + dy <= helper.getTotalHeight());		assertTrue(helper.verticalOffset + VIEWPORT_HEIGHT + dy <= helper.getTotalHeight());
	helper.verticalOffset += dy;		helper.verticalOffset += dy;
	matrix.onScrolled(null, 0, dy);		model.onScrolled(null, 0, dy);
	}		}

	private static final class TestHelper implements BandSelectMatrix.RecyclerViewHelper {		private static final class TestHelper implements MultiSelectManager.BandModelHelper {

	public int horizontalOffset = 0;		public int horizontalOffset = 0;
	public int verticalOffset = 0;		public int verticalOffset = 0;