ZoomButton.java revision d24b8183b93e781080b2c16c487e60d51c12da31 
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.KeyEvent;
24import android.view.MotionEvent;
25import android.view.View;
26import android.view.GestureDetector.SimpleOnGestureListener;
27import android.view.View.OnLongClickListener;
28
29
30public class ZoomButton extends ImageButton implements OnLongClickListener {
31
32    private final Handler mHandler;
33    private final Runnable mRunnable = new Runnable() {
34        public void run() {
35            if ((mOnClickListener != null) && mIsInLongpress && isEnabled()) {
36                mOnClickListener.onClick(ZoomButton.this);
37                mHandler.postDelayed(this, mZoomSpeed);
38            }
39        }
40    };
41    private final GestureDetector mGestureDetector;
42
43    private long mZoomSpeed = 1000;
44    private boolean mIsInLongpress;
45
46    public ZoomButton(Context context) {
47        this(context, null);
48    }
49
50    public ZoomButton(Context context, AttributeSet attrs) {
51        this(context, attrs, 0);
52    }
53
54    public ZoomButton(Context context, AttributeSet attrs, int defStyle) {
55        super(context, attrs, defStyle);
56        mHandler = new Handler();
57        mGestureDetector = new GestureDetector(context, new SimpleOnGestureListener() {
58            @Override
59            public void onLongPress(MotionEvent e) {
60                onLongClick(ZoomButton.this);
61            }
62        });
63        setOnLongClickListener(this);
64    }
65
66    @Override
67    public boolean onTouchEvent(MotionEvent event) {
68        mGestureDetector.onTouchEvent(event);
69        if ((event.getAction() == MotionEvent.ACTION_CANCEL)
70                || (event.getAction() == MotionEvent.ACTION_UP)) {
71            mIsInLongpress = false;
72        }
73        return super.onTouchEvent(event);
74    }
75
76    public void setZoomSpeed(long speed) {
77        mZoomSpeed = speed;
78    }
79
80    public boolean onLongClick(View v) {
81        mIsInLongpress = true;
82        mHandler.post(mRunnable);
83        return true;
84    }
85
86    @Override
87    public boolean onKeyUp(int keyCode, KeyEvent event) {
88        mIsInLongpress = false;
89        return super.onKeyUp(keyCode, event);
90    }
91
92    @Override
93    public void setEnabled(boolean enabled) {
94        if (!enabled) {
95
96            /* If we're being disabled reset the state back to unpressed
97             * as disabled views don't get events and therefore we won't
98             * get the up event to reset the state.
99             */
100            setPressed(false);
101        }
102        super.setEnabled(enabled);
103    }
104
105    @Override
106    public boolean dispatchUnhandledMove(View focused, int direction) {
107        clearFocus();
108        return super.dispatchUnhandledMove(focused, direction);
109    }
110}
111