diff options
Diffstat (limited to 'src/com/android/launcher3/touch/BothAxesSwipeDetector.java')
-rw-r--r-- | src/com/android/launcher3/touch/BothAxesSwipeDetector.java | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/src/com/android/launcher3/touch/BothAxesSwipeDetector.java b/src/com/android/launcher3/touch/BothAxesSwipeDetector.java new file mode 100644 index 000000000..944391e9b --- /dev/null +++ b/src/com/android/launcher3/touch/BothAxesSwipeDetector.java @@ -0,0 +1,99 @@ +/* + * Copyright (C) 2019 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.launcher3.touch; + +import android.content.Context; +import android.graphics.PointF; +import android.view.MotionEvent; +import android.view.ViewConfiguration; + +import androidx.annotation.NonNull; +import androidx.annotation.VisibleForTesting; + +import com.android.launcher3.Utilities; + +/** + * Two dimensional scroll/drag/swipe gesture detector that reports x and y displacement/velocity. + */ +public class BothAxesSwipeDetector extends BaseSwipeDetector { + + public static final int DIRECTION_UP = 1 << 0; + // Note that this will track left instead of right in RTL. + public static final int DIRECTION_RIGHT = 1 << 1; + public static final int DIRECTION_DOWN = 1 << 2; + // Note that this will track right instead of left in RTL. + public static final int DIRECTION_LEFT = 1 << 3; + + /* Client of this gesture detector can register a callback. */ + private final Listener mListener; + + private int mScrollDirections; + + public BothAxesSwipeDetector(@NonNull Context context, @NonNull Listener l) { + this(ViewConfiguration.get(context), l, Utilities.isRtl(context.getResources())); + } + + @VisibleForTesting + protected BothAxesSwipeDetector(@NonNull ViewConfiguration config, @NonNull Listener l, + boolean isRtl) { + super(config, isRtl); + mListener = l; + } + + public void setDetectableScrollConditions(int scrollDirectionFlags, boolean ignoreSlop) { + mScrollDirections = scrollDirectionFlags; + mIgnoreSlopWhenSettling = ignoreSlop; + } + + @Override + protected boolean shouldScrollStart(PointF displacement) { + // Check if the client is interested in scroll in current direction. + boolean canScrollUp = (mScrollDirections & DIRECTION_UP) > 0 + && displacement.y <= -mTouchSlop; + boolean canScrollRight = (mScrollDirections & DIRECTION_RIGHT) > 0 + && displacement.x >= mTouchSlop; + boolean canScrollDown = (mScrollDirections & DIRECTION_DOWN) > 0 + && displacement.y >= mTouchSlop; + boolean canScrollLeft = (mScrollDirections & DIRECTION_LEFT) > 0 + && displacement.x <= -mTouchSlop; + return canScrollUp || canScrollRight || canScrollDown || canScrollLeft; + } + + @Override + protected void reportDragStartInternal(boolean recatch) { + mListener.onDragStart(!recatch); + } + + @Override + protected void reportDraggingInternal(PointF displacement, MotionEvent event) { + mListener.onDrag(displacement, event); + } + + @Override + protected void reportDragEndInternal(PointF velocity) { + mListener.onDragEnd(velocity); + } + + /** Listener to receive updates on the swipe. */ + public interface Listener { + /** @param start whether this was the original drag start, as opposed to a recatch. */ + void onDragStart(boolean start); + + boolean onDrag(PointF displacement, MotionEvent motionEvent); + + void onDragEnd(PointF velocity); + } +} |