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.gallery3d.ui;
18
19import android.view.MotionEvent;
20
21public class DownUpDetector {
22    public interface DownUpListener {
23        void onDown(MotionEvent e);
24        void onUp(MotionEvent e);
25    }
26
27    private boolean mStillDown;
28    private DownUpListener mListener;
29
30    public DownUpDetector(DownUpListener listener) {
31        mListener = listener;
32    }
33
34    private void setState(boolean down, MotionEvent e) {
35        if (down == mStillDown) return;
36        mStillDown = down;
37        if (down) {
38            mListener.onDown(e);
39        } else {
40            mListener.onUp(e);
41        }
42    }
43
44    public void onTouchEvent(MotionEvent ev) {
45        switch (ev.getAction() & MotionEvent.ACTION_MASK) {
46        case MotionEvent.ACTION_DOWN:
47            setState(true, ev);
48            break;
49
50        case MotionEvent.ACTION_UP:
51        case MotionEvent.ACTION_CANCEL:
52        case MotionEvent.ACTION_POINTER_DOWN:  // Multitouch event - abort.
53            setState(false, ev);
54            break;
55        }
56    }
57
58    public boolean isDown() {
59        return mStillDown;
60    }
61}
62