DigitalClock.java

/*
 * Copyright (C) 2008 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.androsz.electricsleepbeta.alarmclock;

import java.text.DateFormatSymbols;
import java.util.Calendar;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.database.ContentObserver;
import android.graphics.Typeface;
import android.os.Handler;
import android.provider.Settings;
import android.text.format.DateFormat;
import android.util.AttributeSet;
import android.view.View;
import android.widget.LinearLayout;
import android.widget.TextView;

import com.androsz.electricsleepbeta.R;

/**
 * Displays the time
 */
public class DigitalClock extends LinearLayout {

	static class AmPm {
		private final TextView mAmPm;
		private final String mAmString, mPmString;

		AmPm(final View parent) {
			mAmPm = (TextView) parent.findViewById(R.id.am_pm);

			final String[] ampm = new DateFormatSymbols().getAmPmStrings();
			mAmString = ampm[0];
			mPmString = ampm[1];
		}

		void setIsMorning(final boolean isMorning) {
			mAmPm.setText(isMorning ? mAmString : mPmString);
		}

		void setShowAmPm(final boolean show) {
			mAmPm.setVisibility(show ? View.VISIBLE : View.GONE);
		}
	}

	private class FormatChangeObserver extends ContentObserver {
		public FormatChangeObserver() {
			super(new Handler());
		}

		@Override
		public void onChange(final boolean selfChange) {
			setDateFormat();
			updateTime();
		}
	}

	private final static String M12 = "h:mm";
	private AmPm mAmPm;
	private boolean mAttached;
	private Calendar mCalendar;
	private String mFormat;
	private ContentObserver mFormatChangeObserver;

	/* called by system on minute ticks */
	private final Handler mHandler = new Handler();
	private final BroadcastReceiver mIntentReceiver = new BroadcastReceiver() {
		@Override
		public void onReceive(final Context context, final Intent intent) {
			if (mLive && intent.getAction().equals(Intent.ACTION_TIMEZONE_CHANGED)) {
				mCalendar = Calendar.getInstance();
			}
			// Post a runnable to avoid blocking the broadcast.
			mHandler.post(new Runnable() {
				@Override
				public void run() {
					updateTime();
				}
			});
		}
	};

	private boolean mLive = true;

	private TextView mTimeDisplay;

	public DigitalClock(final Context context) {
		this(context, null);
	}

	public DigitalClock(final Context context, final AttributeSet attrs) {
		super(context, attrs);
	}

	@Override
	protected void onAttachedToWindow() {
		super.onAttachedToWindow();

		if (Log.LOGV) {
			Log.v("onAttachedToWindow " + this);
		}

		if (mAttached) {
			return;
		}
		mAttached = true;

		if (mLive) {
			/* monitor time ticks, time changed, timezone */
			final IntentFilter filter = new IntentFilter();
			filter.addAction(Intent.ACTION_TIME_TICK);
			filter.addAction(Intent.ACTION_TIME_CHANGED);
			filter.addAction(Intent.ACTION_TIMEZONE_CHANGED);
			getContext().registerReceiver(mIntentReceiver, filter);
		}

		/* monitor 12/24-hour display preference */
		mFormatChangeObserver = new FormatChangeObserver();
		getContext().getContentResolver().registerContentObserver(Settings.System.CONTENT_URI,
				true, mFormatChangeObserver);

		updateTime();
	}

	@Override
	protected void onDetachedFromWindow() {
		super.onDetachedFromWindow();

		if (!mAttached) {
			return;
		}
		mAttached = false;

		if (mLive) {
			getContext().unregisterReceiver(mIntentReceiver);
		}
		getContext().getContentResolver().unregisterContentObserver(mFormatChangeObserver);
	}

	@Override
	protected void onFinishInflate() {
		super.onFinishInflate();

		final Typeface tf = Typeface.MONOSPACE;
		mTimeDisplay = (TextView) findViewById(R.id.timeDisplay);
		mTimeDisplay.setTypeface(tf);
		mAmPm = new AmPm(this);
		mCalendar = Calendar.getInstance();

		setDateFormat();
	}

	private void setDateFormat() {
		mFormat = Alarms.get24HourMode(getContext()) ? Alarms.M24 : M12;
		mAmPm.setShowAmPm(mFormat == M12);
	}

	void setLive(final boolean live) {
		mLive = live;
	}

	void setTypeface(final Typeface tf) {
		mTimeDisplay.setTypeface(tf);
	}

	private void updateTime() {
		if (mLive) {
			mCalendar.setTimeInMillis(System.currentTimeMillis());
		}

		final CharSequence newTime = DateFormat.format(mFormat, mCalendar);
		mTimeDisplay.setText(newTime);
		mAmPm.setIsMorning(mCalendar.get(Calendar.AM_PM) == 0);
	}

	void updateTime(final Calendar c) {
		mCalendar = c;
		updateTime();
	}
}