ZoomButton.java revision 9066cfe9886ac131c34d59ed0e2d287b0e3c0087 
1/*
2 * Copyright (C) 2008 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 android.widget;
18
19import android.content.Context;
20import android.os.Handler;
21import android.util.AttributeSet;
22import android.view.GestureDetector;
23import android.view.HapticFeedbackConstants;
24import android.view.KeyEvent;
25import android.view.MotionEvent;
26import android.view.View;
27import android.view.GestureDetector.SimpleOnGestureListener;
28import android.view.View.OnLongClickListener;
29
30
31public class ZoomButton extends ImageButton implements OnLongClickListener {
32
33    private final Handler mHandler;
34    private final Runnable mRunnable = new Runnable() {
35        public void run() {
36            if ((mOnClickListener != null) && mIsInLongpress && isEnabled()) {
37                mOnClickListener.onClick(ZoomButton.this);
38                mHandler.postDelayed(this, mZoomSpeed);
39            }
40        }
41    };
42    private final GestureDetector mGestureDetector;
43
44    private long mZoomSpeed = 1000;
45    private boolean mIsInLongpress;
46
47    public ZoomButton(Context context) {
48        this(context, null);
49    }
50
51    public ZoomButton(Context context, AttributeSet attrs) {
52        this(context, attrs, 0);
53    }
54
55    public ZoomButton(Context context, AttributeSet attrs, int defStyle) {
56        super(context, attrs, defStyle);
57        mHandler = new Handler();
58        mGestureDetector = new GestureDetector(context, new SimpleOnGestureListener() {
59            @Override
60            public void onLongPress(MotionEvent e) {
61                performHapticFeedback(HapticFeedbackConstants.LONG_PRESS);
62                onLongClick(ZoomButton.this);
63            }
64        });
65        setOnLongClickListener(this);
66    }
67
68    @Override
69    public boolean onTouchEvent(MotionEvent event) {
70        mGestureDetector.onTouchEvent(event);
71        if ((event.getAction() == MotionEvent.ACTION_CANCEL)
72                || (event.getAction() == MotionEvent.ACTION_UP)) {
73            mIsInLongpress = false;
74        }
75        return super.onTouchEvent(event);
76    }
77
78    public void setZoomSpeed(long speed) {
79        mZoomSpeed = speed;
80    }
81
82    public boolean onLongClick(View v) {
83        mIsInLongpress = true;
84        mHandler.post(mRunnable);
85        return true;
86    }
87
88    @Override
89    public boolean onKeyUp(int keyCode, KeyEvent event) {
90        mIsInLongpress = false;
91        return super.onKeyUp(keyCode, event);
92    }
93
94    @Override
95    public void setEnabled(boolean enabled) {
96        if (!enabled) {
97
98            /* If we're being disabled reset the state back to unpressed
99             * as disabled views don't get events and therefore we won't
100             * get the up event to reset the state.
101             */
102            setPressed(false);
103        }
104        super.setEnabled(enabled);
105    }
106
107    @Override
108    public boolean dispatchUnhandledMove(View focused, int direction) {
109        clearFocus();
110        return super.dispatchUnhandledMove(focused, direction);
111    }
112}
113