FolderAutoScrollHelper.java revision 4cda5b770db7f375a4766fe6c0d657b9d5303374 
1/*
2 * Copyright (C) 2013 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 com.android.launcher3;
18
19import android.widget.ScrollView;
20
21/**
22 * An implementation of {@link AutoScrollHelper} that knows how to scroll
23 * through a {@link Folder}.
24 */
25public class FolderAutoScrollHelper extends AutoScrollHelper {
26    private static final float MAX_SCROLL_VELOCITY = 1500f;
27
28    private final ScrollView mTarget;
29
30    public FolderAutoScrollHelper(ScrollView target) {
31        super(target);
32
33        mTarget = target;
34
35        setActivationDelay(0);
36        setEdgeType(EDGE_TYPE_INSIDE);
37        setExclusive(true);
38        setMaximumVelocity(MAX_SCROLL_VELOCITY, MAX_SCROLL_VELOCITY);
39    }
40
41    @Override
42    public void scrollTargetBy(int deltaX, int deltaY) {
43        mTarget.scrollBy(deltaX, deltaY);
44    }
45
46    @Override
47    public boolean canTargetScrollHorizontally(int direction) {
48        // List do not scroll horizontally.
49        return false;
50    }
51
52    @Override
53    public boolean canTargetScrollVertically(int direction) {
54        return mTarget.canScrollVertically(direction);
55    }
56}