SpringLoadedDragController.java revision d3ef3065ab0941567c45e9aec98783138b623c68 
1/*
2 * Copyright (C) 2010 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.launcher2;
18
19public class SpringLoadedDragController implements OnAlarmListener {
20    // how long the user must hover over a mini-screen before it unshrinks
21    final long ENTER_SPRING_LOAD_HOVER_TIME = 1000;
22    final long EXIT_SPRING_LOAD_HOVER_TIME = 200;
23
24    Alarm mAlarm;
25
26    // the screen the user is currently hovering over, if any
27    private CellLayout mScreen;
28    private Launcher mLauncher;
29
30    public SpringLoadedDragController(Launcher launcher) {
31        mLauncher = launcher;
32        mAlarm = new Alarm();
33        mAlarm.setOnAlarmListener(this);
34    }
35
36    public void onDragEnter(CellLayout cl) {
37        mScreen = cl;
38        mAlarm.setAlarm(ENTER_SPRING_LOAD_HOVER_TIME);
39    }
40
41    public void onDragExit() {
42        if (mScreen != null) {
43            mScreen.onDragExit();
44        }
45        mScreen = null;
46        mAlarm.setAlarm(EXIT_SPRING_LOAD_HOVER_TIME);
47    }
48
49    // this is called when our timer runs out
50    public void onAlarm(Alarm alarm) {
51        if (mScreen != null) {
52            // we're currently hovering over a screen
53            mLauncher.enterSpringLoadedDragMode(mScreen);
54        } else {
55            mLauncher.exitSpringLoadedDragMode();
56        }
57    }
58}
59