DigitalClock.java revision 8a78fd4d9572dff95432fcc4ba0e87563415b728 
1/*
2 * Copyright (C) 2006 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.content.res.Resources;
21import android.database.ContentObserver;
22import android.os.Handler;
23import android.os.SystemClock;
24import android.provider.Settings;
25import android.text.format.DateFormat;
26import android.util.AttributeSet;
27import android.view.accessibility.AccessibilityEvent;
28import android.view.accessibility.AccessibilityNodeInfo;
29
30import java.util.Calendar;
31
32/**
33 * Like AnalogClock, but digital.  Shows seconds.
34 *
35 * FIXME: implement separate views for hours/minutes/seconds, so
36 * proportional fonts don't shake rendering
37 */
38
39public class DigitalClock extends TextView {
40
41    Calendar mCalendar;
42    private final static String m12 = "h:mm:ss aa";
43    private final static String m24 = "k:mm:ss";
44    private FormatChangeObserver mFormatChangeObserver;
45
46    private Runnable mTicker;
47    private Handler mHandler;
48
49    private boolean mTickerStopped = false;
50
51    String mFormat;
52
53    public DigitalClock(Context context) {
54        super(context);
55        initClock(context);
56    }
57
58    public DigitalClock(Context context, AttributeSet attrs) {
59        super(context, attrs);
60        initClock(context);
61    }
62
63    private void initClock(Context context) {
64        Resources r = mContext.getResources();
65
66        if (mCalendar == null) {
67            mCalendar = Calendar.getInstance();
68        }
69
70        mFormatChangeObserver = new FormatChangeObserver();
71        getContext().getContentResolver().registerContentObserver(
72                Settings.System.CONTENT_URI, true, mFormatChangeObserver);
73
74        setFormat();
75    }
76
77    @Override
78    protected void onAttachedToWindow() {
79        mTickerStopped = false;
80        super.onAttachedToWindow();
81        mHandler = new Handler();
82
83        /**
84         * requests a tick on the next hard-second boundary
85         */
86        mTicker = new Runnable() {
87                public void run() {
88                    if (mTickerStopped) return;
89                    mCalendar.setTimeInMillis(System.currentTimeMillis());
90                    setText(DateFormat.format(mFormat, mCalendar));
91                    invalidate();
92                    long now = SystemClock.uptimeMillis();
93                    long next = now + (1000 - now % 1000);
94                    mHandler.postAtTime(mTicker, next);
95                }
96            };
97        mTicker.run();
98    }
99
100    @Override
101    protected void onDetachedFromWindow() {
102        super.onDetachedFromWindow();
103        mTickerStopped = true;
104    }
105
106    /**
107     * Pulls 12/24 mode from system settings
108     */
109    private boolean get24HourMode() {
110        return android.text.format.DateFormat.is24HourFormat(getContext());
111    }
112
113    private void setFormat() {
114        if (get24HourMode()) {
115            mFormat = m24;
116        } else {
117            mFormat = m12;
118        }
119    }
120
121    private class FormatChangeObserver extends ContentObserver {
122        public FormatChangeObserver() {
123            super(new Handler());
124        }
125
126        @Override
127        public void onChange(boolean selfChange) {
128            setFormat();
129        }
130    }
131
132    @Override
133    public void onInitializeAccessibilityEvent(AccessibilityEvent event) {
134        super.onInitializeAccessibilityEvent(event);
135        event.setClassName(DigitalClock.class.getName());
136    }
137
138    @Override
139    public void onInitializeAccessibilityNodeInfo(AccessibilityNodeInfo info) {
140        super.onInitializeAccessibilityNodeInfo(info);
141        info.setClassName(DigitalClock.class.getName());
142    }
143}
144