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 = 550;
22    final long ENTER_SPRING_LOAD_CANCEL_HOVER_TIME = 950;
23    final long EXIT_SPRING_LOAD_HOVER_TIME = 200;
24
25    Alarm mAlarm;
26
27    // the screen the user is currently hovering over, if any
28    private CellLayout mScreen;
29    private Launcher mLauncher;
30
31    public SpringLoadedDragController(Launcher launcher) {
32        mLauncher = launcher;
33        mAlarm = new Alarm();
34        mAlarm.setOnAlarmListener(this);
35    }
36
37    public void cancel() {
38        mAlarm.cancelAlarm();
39    }
40
41    // Set a new alarm to expire for the screen that we are hovering over now
42    public void setAlarm(CellLayout cl) {
43        mAlarm.cancelAlarm();
44        mAlarm.setAlarm((cl == null) ? ENTER_SPRING_LOAD_CANCEL_HOVER_TIME :
45            ENTER_SPRING_LOAD_HOVER_TIME);
46        mScreen = cl;
47    }
48
49    // this is called when our timer runs out
50    public void onAlarm(Alarm alarm) {
51        if (mScreen != null) {
52            // Snap to the screen that we are hovering over now
53            Workspace w = mLauncher.getWorkspace();
54            int page = w.indexOfChild(mScreen);
55            if (page != w.getCurrentPage()) {
56                w.snapToPage(page);
57            }
58        } else {
59            mLauncher.getDragController().cancelDrag();
60        }
61    }
62}
63