src/com/android/calendar/CalendarUtils.java - platform/packages/apps/Calendar - Git at Google

 /*
  * Copyright (C) 2010 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.android.calendar;

 import android.content.AsyncQueryHandler;
 import android.content.ContentResolver;
 import android.content.ContentValues;
 import android.content.Context;
 import android.content.SharedPreferences;
 import android.database.Cursor;
 import android.provider.CalendarContract.CalendarCache;
 import android.text.TextUtils;
 import android.text.format.DateUtils;
 import android.text.format.Time;
 import android.util.Log;

 import java.util.Formatter;
 import java.util.HashSet;
 import java.util.Locale;

 /**
  * A class containing utility methods related to Calendar apps.
  *
  * This class is expected to move into the app framework eventually.
  */
 public class CalendarUtils {
     private static final boolean DEBUG = false;
     private static final String TAG = "CalendarUtils";

     /**
      * This class contains methods specific to reading and writing time zone
      * values.
      */
     public static class TimeZoneUtils {
         private static final String[] TIMEZONE_TYPE_ARGS = { CalendarCache.KEY_TIMEZONE_TYPE };
         private static final String[] TIMEZONE_INSTANCES_ARGS =
                 { CalendarCache.KEY_TIMEZONE_INSTANCES };
         public static final String[] CALENDAR_CACHE_POJECTION = {
                 CalendarCache.KEY, CalendarCache.VALUE
         };

         private static StringBuilder mSB = new StringBuilder(50);
         private static Formatter mF = new Formatter(mSB, Locale.getDefault());
         private volatile static boolean mFirstTZRequest = true;
         private volatile static boolean mTZQueryInProgress = false;

         private volatile static boolean mUseHomeTZ = false;
         private volatile static String mHomeTZ = Time.getCurrentTimezone();

         private static HashSet<Runnable> mTZCallbacks = new HashSet<Runnable>();
         private static int mToken = 1;
         private static AsyncTZHandler mHandler;

         // The name of the shared preferences file. This name must be maintained for historical
         // reasons, as it's what PreferenceManager assigned the first time the file was created.
         private final String mPrefsName;

         /**
          * This is the key used for writing whether or not a home time zone should
          * be used in the Calendar app to the Calendar Preferences.
          */
         public static final String KEY_HOME_TZ_ENABLED = "preferences_home_tz_enabled";
         /**
          * This is the key used for writing the time zone that should be used if
          * home time zones are enabled for the Calendar app.
          */
         public static final String KEY_HOME_TZ = "preferences_home_tz";

         /**
          * This is a helper class for handling the async queries and updates for the
          * time zone settings in Calendar.
          */
         private class AsyncTZHandler extends AsyncQueryHandler {
             public AsyncTZHandler(ContentResolver cr) {
                 super(cr);
             }

             @Override
             protected void onQueryComplete(int token, Object cookie, Cursor cursor) {
                 synchronized (mTZCallbacks) {
                     if (cursor == null) {
                         mTZQueryInProgress = false;
                         mFirstTZRequest = true;
                         return;
                     }

                     boolean writePrefs = false;
                     // Check the values in the db
                     int keyColumn = cursor.getColumnIndexOrThrow(CalendarCache.KEY);
                     int valueColumn = cursor.getColumnIndexOrThrow(CalendarCache.VALUE);
                     while(cursor.moveToNext()) {
                         String key = cursor.getString(keyColumn);
                         String value = cursor.getString(valueColumn);
                         if (TextUtils.equals(key, CalendarCache.KEY_TIMEZONE_TYPE)) {
                             boolean useHomeTZ = !TextUtils.equals(
                                     value, CalendarCache.TIMEZONE_TYPE_AUTO);
                             if (useHomeTZ != mUseHomeTZ) {
                                 writePrefs = true;
                                 mUseHomeTZ = useHomeTZ;
                             }
                         } else if (TextUtils.equals(
                                 key, CalendarCache.KEY_TIMEZONE_INSTANCES_PREVIOUS)) {
                             if (!TextUtils.isEmpty(value) && !TextUtils.equals(mHomeTZ, value)) {
                                 writePrefs = true;
                                 mHomeTZ = value;
                             }
                         }
                     }
                     cursor.close();
                     if (writePrefs) {
                         SharedPreferences prefs = getSharedPreferences((Context)cookie, mPrefsName);
                         // Write the prefs
                         setSharedPreference(prefs, KEY_HOME_TZ_ENABLED, mUseHomeTZ);
                         setSharedPreference(prefs, KEY_HOME_TZ, mHomeTZ);
                     }

                     mTZQueryInProgress = false;
                     for (Runnable callback : mTZCallbacks) {
                         if (callback != null) {
                             callback.run();
                         }
                     }
                     mTZCallbacks.clear();
                 }
             }
         }

         /**
          * The name of the file where the shared prefs for Calendar are stored
          * must be provided. All activities within an app should provide the
          * same preferences name or behavior may become erratic.
          *
          * @param prefsName
          */
         public TimeZoneUtils(String prefsName) {
             mPrefsName = prefsName;
         }

         /**
          * Formats a date or a time range according to the local conventions.
          *
          * This formats a date/time range using Calendar's time zone and the
          * local conventions for the region of the device.
          *
          * If the {@link DateUtils#FORMAT_UTC} flag is used it will pass in
          * the UTC time zone instead.
          *
          * @param context the context is required only if the time is shown
          * @param startMillis the start time in UTC milliseconds
          * @param endMillis the end time in UTC milliseconds
          * @param flags a bit mask of options See
          * {@link DateUtils#formatDateRange(Context, Formatter, long, long, int, String) formatDateRange}
          * @return a string containing the formatted date/time range.
          */
         public String formatDateRange(Context context, long startMillis,
                 long endMillis, int flags) {
             String date;
             String tz;
             if ((flags & DateUtils.FORMAT_UTC) != 0) {
                 tz = Time.TIMEZONE_UTC;
             } else {
                 tz = getTimeZone(context, null);
             }
             synchronized (mSB) {
                 mSB.setLength(0);
                 date = DateUtils.formatDateRange(context, mF, startMillis, endMillis, flags,
                         tz).toString();
             }
             return date;
         }

         /**
          * Writes a new home time zone to the db.
          *
          * Updates the home time zone in the db asynchronously and updates
          * the local cache. Sending a time zone of
          * {@link CalendarCache#TIMEZONE_TYPE_AUTO} will cause it to be set
          * to the device's time zone. null or empty tz will be ignored.
          *
          * @param context The calling activity
          * @param timeZone The time zone to set Calendar to, or
          * {@link CalendarCache#TIMEZONE_TYPE_AUTO}
          */
         public void setTimeZone(Context context, String timeZone) {
             if (TextUtils.isEmpty(timeZone)) {
                 if (DEBUG) {
                     Log.d(TAG, "Empty time zone, nothing to be done.");
                 }
                 return;
             }
             boolean updatePrefs = false;
             synchronized (mTZCallbacks) {
                 if (CalendarCache.TIMEZONE_TYPE_AUTO.equals(timeZone)) {
                     if (mUseHomeTZ) {
                         updatePrefs = true;
                     }
                     mUseHomeTZ = false;
                 } else {
                     if (!mUseHomeTZ || !TextUtils.equals(mHomeTZ, timeZone)) {
                         updatePrefs = true;
                     }
                     mUseHomeTZ = true;
                     mHomeTZ = timeZone;
                 }
             }
             if (updatePrefs) {
                 // Write the prefs
                 SharedPreferences prefs = getSharedPreferences(context, mPrefsName);
                 setSharedPreference(prefs, KEY_HOME_TZ_ENABLED, mUseHomeTZ);
                 setSharedPreference(prefs, KEY_HOME_TZ, mHomeTZ);

                 // Update the db
                 ContentValues values = new ContentValues();
                 if (mHandler != null) {
                     mHandler.cancelOperation(mToken);
                 }

                 mHandler = new AsyncTZHandler(context.getContentResolver());

                 // skip 0 so query can use it
                 if (++mToken == 0) {
                     mToken = 1;
                 }

                 // Write the use home tz setting
                 values.put(CalendarCache.VALUE, mUseHomeTZ ? CalendarCache.TIMEZONE_TYPE_HOME
                         : CalendarCache.TIMEZONE_TYPE_AUTO);
                 mHandler.startUpdate(mToken, null, CalendarCache.URI, values, "key=?",
                         TIMEZONE_TYPE_ARGS);

                 // If using a home tz write it to the db
                 if (mUseHomeTZ) {
                     ContentValues values2 = new ContentValues();
                     values2.put(CalendarCache.VALUE, mHomeTZ);
                     mHandler.startUpdate(mToken, null, CalendarCache.URI, values2,
                             "key=?", TIMEZONE_INSTANCES_ARGS);
                 }
             }
         }

         /**
          * Gets the time zone that Calendar should be displayed in
          *
          * This is a helper method to get the appropriate time zone for Calendar. If this
          * is the first time this method has been called it will initiate an asynchronous
          * query to verify that the data in preferences is correct. The callback supplied
          * will only be called if this query returns a value other than what is stored in
          * preferences and should cause the calling activity to refresh anything that
          * depends on calling this method.
          *
          * @param context The calling activity
          * @param callback The runnable that should execute if a query returns new values
          * @return The string value representing the time zone Calendar should display
          */
         public String getTimeZone(Context context, Runnable callback) {
             synchronized (mTZCallbacks){
                 if (mFirstTZRequest) {
                     mTZQueryInProgress = true;
                     mFirstTZRequest = false;

                     SharedPreferences prefs = getSharedPreferences(context, mPrefsName);
                     mUseHomeTZ = prefs.getBoolean(KEY_HOME_TZ_ENABLED, false);
                     mHomeTZ = prefs.getString(KEY_HOME_TZ, Time.getCurrentTimezone());

                     // When the async query returns it should synchronize on
                     // mTZCallbacks, update mUseHomeTZ, mHomeTZ, and the
                     // preferences, set mTZQueryInProgress to false, and call all
                     // the runnables in mTZCallbacks.
                     if (mHandler == null) {
                         mHandler = new AsyncTZHandler(context.getContentResolver());
                     }
                     mHandler.startQuery(0, context, CalendarCache.URI, CALENDAR_CACHE_POJECTION,
                             null, null, null);
                 }
                 if (mTZQueryInProgress) {
                     mTZCallbacks.add(callback);
                 }
             }
             return mUseHomeTZ ? mHomeTZ : Time.getCurrentTimezone();
         }

         /**
          * Forces a query of the database to check for changes to the time zone.
          * This should be called if another app may have modified the db. If a
          * query is already in progress the callback will be added to the list
          * of callbacks to be called when it returns.
          *
          * @param context The calling activity
          * @param callback The runnable that should execute if a query returns
          *            new values
          */
         public void forceDBRequery(Context context, Runnable callback) {
             synchronized (mTZCallbacks){
                 if (mTZQueryInProgress) {
                     mTZCallbacks.add(callback);
                     return;
                 }
                 mFirstTZRequest = true;
                 getTimeZone(context, callback);
             }
         }
     }

         /**
          * A helper method for writing a String value to the preferences
          * asynchronously.
          *
          * @param context A context with access to the correct preferences
          * @param key The preference to write to
          * @param value The value to write
          */
         public static void setSharedPreference(SharedPreferences prefs, String key, String value) {
 //            SharedPreferences prefs = getSharedPreferences(context);
             SharedPreferences.Editor editor = prefs.edit();
             editor.putString(key, value);
             editor.apply();
         }

         /**
          * A helper method for writing a boolean value to the preferences
          * asynchronously.
          *
          * @param context A context with access to the correct preferences
          * @param key The preference to write to
          * @param value The value to write
          */
         public static void setSharedPreference(SharedPreferences prefs, String key, boolean value) {
 //            SharedPreferences prefs = getSharedPreferences(context, prefsName);
             SharedPreferences.Editor editor = prefs.edit();
             editor.putBoolean(key, value);
             editor.apply();
         }

         /** Return a properly configured SharedPreferences instance */
         public static SharedPreferences getSharedPreferences(Context context, String prefsName) {
             return context.getSharedPreferences(prefsName, Context.MODE_PRIVATE);
         }
 }
	/*
	* Copyright (C) 2010 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.android.calendar;

	import android.content.AsyncQueryHandler;
	import android.content.ContentResolver;
	import android.content.ContentValues;
	import android.content.Context;
	import android.content.SharedPreferences;
	import android.database.Cursor;
	import android.provider.CalendarContract.CalendarCache;
	import android.text.TextUtils;
	import android.text.format.DateUtils;
	import android.text.format.Time;
	import android.util.Log;

	import java.util.Formatter;
	import java.util.HashSet;
	import java.util.Locale;

	/**
	* A class containing utility methods related to Calendar apps.
	*
	* This class is expected to move into the app framework eventually.
	*/
	public class CalendarUtils {
	private static final boolean DEBUG = false;
	private static final String TAG = "CalendarUtils";

	/**
	* This class contains methods specific to reading and writing time zone
	* values.
	*/
	public static class TimeZoneUtils {
	private static final String[] TIMEZONE_TYPE_ARGS = { CalendarCache.KEY_TIMEZONE_TYPE };
	private static final String[] TIMEZONE_INSTANCES_ARGS =
	{ CalendarCache.KEY_TIMEZONE_INSTANCES };
	public static final String[] CALENDAR_CACHE_POJECTION = {
	CalendarCache.KEY, CalendarCache.VALUE
	};

	private static StringBuilder mSB = new StringBuilder(50);
	private static Formatter mF = new Formatter(mSB, Locale.getDefault());
	private volatile static boolean mFirstTZRequest = true;
	private volatile static boolean mTZQueryInProgress = false;

	private volatile static boolean mUseHomeTZ = false;
	private volatile static String mHomeTZ = Time.getCurrentTimezone();

	private static HashSet<Runnable> mTZCallbacks = new HashSet<Runnable>();
	private static int mToken = 1;
	private static AsyncTZHandler mHandler;

	// The name of the shared preferences file. This name must be maintained for historical
	// reasons, as it's what PreferenceManager assigned the first time the file was created.
	private final String mPrefsName;

	/**
	* This is the key used for writing whether or not a home time zone should
	* be used in the Calendar app to the Calendar Preferences.
	*/
	public static final String KEY_HOME_TZ_ENABLED = "preferences_home_tz_enabled";
	/**
	* This is the key used for writing the time zone that should be used if
	* home time zones are enabled for the Calendar app.
	*/
	public static final String KEY_HOME_TZ = "preferences_home_tz";

	/**
	* This is a helper class for handling the async queries and updates for the
	* time zone settings in Calendar.
	*/
	private class AsyncTZHandler extends AsyncQueryHandler {
	public AsyncTZHandler(ContentResolver cr) {
	super(cr);
	}

	@Override
	protected void onQueryComplete(int token, Object cookie, Cursor cursor) {
	synchronized (mTZCallbacks) {
	if (cursor == null) {
	mTZQueryInProgress = false;
	mFirstTZRequest = true;
	return;
	}

	boolean writePrefs = false;
	// Check the values in the db
	int keyColumn = cursor.getColumnIndexOrThrow(CalendarCache.KEY);
	int valueColumn = cursor.getColumnIndexOrThrow(CalendarCache.VALUE);
	while(cursor.moveToNext()) {
	String key = cursor.getString(keyColumn);
	String value = cursor.getString(valueColumn);
	if (TextUtils.equals(key, CalendarCache.KEY_TIMEZONE_TYPE)) {
	boolean useHomeTZ = !TextUtils.equals(
	value, CalendarCache.TIMEZONE_TYPE_AUTO);
	if (useHomeTZ != mUseHomeTZ) {
	writePrefs = true;
	mUseHomeTZ = useHomeTZ;
	}
	} else if (TextUtils.equals(
	key, CalendarCache.KEY_TIMEZONE_INSTANCES_PREVIOUS)) {
	if (!TextUtils.isEmpty(value) && !TextUtils.equals(mHomeTZ, value)) {
	writePrefs = true;
	mHomeTZ = value;
	}
	}
	}
	cursor.close();
	if (writePrefs) {
	SharedPreferences prefs = getSharedPreferences((Context)cookie, mPrefsName);
	// Write the prefs
	setSharedPreference(prefs, KEY_HOME_TZ_ENABLED, mUseHomeTZ);
	setSharedPreference(prefs, KEY_HOME_TZ, mHomeTZ);
	}

	mTZQueryInProgress = false;
	for (Runnable callback : mTZCallbacks) {
	if (callback != null) {
	callback.run();
	}
	}
	mTZCallbacks.clear();
	}
	}
	}

	/**
	* The name of the file where the shared prefs for Calendar are stored
	* must be provided. All activities within an app should provide the
	* same preferences name or behavior may become erratic.
	*
	* @param prefsName
	*/
	public TimeZoneUtils(String prefsName) {
	mPrefsName = prefsName;
	}

	/**
	* Formats a date or a time range according to the local conventions.
	*
	* This formats a date/time range using Calendar's time zone and the
	* local conventions for the region of the device.
	*
	* If the {@link DateUtils#FORMAT_UTC} flag is used it will pass in
	* the UTC time zone instead.
	*
	* @param context the context is required only if the time is shown
	* @param startMillis the start time in UTC milliseconds
	* @param endMillis the end time in UTC milliseconds
	* @param flags a bit mask of options See
	* {@link DateUtils#formatDateRange(Context, Formatter, long, long, int, String) formatDateRange}
	* @return a string containing the formatted date/time range.
	*/
	public String formatDateRange(Context context, long startMillis,
	long endMillis, int flags) {
	String date;
	String tz;
	if ((flags & DateUtils.FORMAT_UTC) != 0) {
	tz = Time.TIMEZONE_UTC;
	} else {
	tz = getTimeZone(context, null);
	}
	synchronized (mSB) {
	mSB.setLength(0);
	date = DateUtils.formatDateRange(context, mF, startMillis, endMillis, flags,
	tz).toString();
	}
	return date;
	}

	/**
	* Writes a new home time zone to the db.
	*
	* Updates the home time zone in the db asynchronously and updates
	* the local cache. Sending a time zone of
	* {@link CalendarCache#TIMEZONE_TYPE_AUTO} will cause it to be set
	* to the device's time zone. null or empty tz will be ignored.
	*
	* @param context The calling activity
	* @param timeZone The time zone to set Calendar to, or
	* {@link CalendarCache#TIMEZONE_TYPE_AUTO}
	*/
	public void setTimeZone(Context context, String timeZone) {
	if (TextUtils.isEmpty(timeZone)) {
	if (DEBUG) {
	Log.d(TAG, "Empty time zone, nothing to be done.");
	}
	return;
	}
	boolean updatePrefs = false;
	synchronized (mTZCallbacks) {
	if (CalendarCache.TIMEZONE_TYPE_AUTO.equals(timeZone)) {
	if (mUseHomeTZ) {
	updatePrefs = true;
	}
	mUseHomeTZ = false;
	} else {
	if (!mUseHomeTZ \|\| !TextUtils.equals(mHomeTZ, timeZone)) {
	updatePrefs = true;
	}
	mUseHomeTZ = true;
	mHomeTZ = timeZone;
	}
	}
	if (updatePrefs) {
	// Write the prefs
	SharedPreferences prefs = getSharedPreferences(context, mPrefsName);
	setSharedPreference(prefs, KEY_HOME_TZ_ENABLED, mUseHomeTZ);
	setSharedPreference(prefs, KEY_HOME_TZ, mHomeTZ);

	// Update the db
	ContentValues values = new ContentValues();
	if (mHandler != null) {
	mHandler.cancelOperation(mToken);
	}

	mHandler = new AsyncTZHandler(context.getContentResolver());

	// skip 0 so query can use it
	if (++mToken == 0) {
	mToken = 1;
	}

	// Write the use home tz setting
	values.put(CalendarCache.VALUE, mUseHomeTZ ? CalendarCache.TIMEZONE_TYPE_HOME
	: CalendarCache.TIMEZONE_TYPE_AUTO);
	mHandler.startUpdate(mToken, null, CalendarCache.URI, values, "key=?",
	TIMEZONE_TYPE_ARGS);

	// If using a home tz write it to the db
	if (mUseHomeTZ) {
	ContentValues values2 = new ContentValues();
	values2.put(CalendarCache.VALUE, mHomeTZ);
	mHandler.startUpdate(mToken, null, CalendarCache.URI, values2,
	"key=?", TIMEZONE_INSTANCES_ARGS);
	}
	}
	}

	/**
	* Gets the time zone that Calendar should be displayed in
	*
	* This is a helper method to get the appropriate time zone for Calendar. If this
	* is the first time this method has been called it will initiate an asynchronous
	* query to verify that the data in preferences is correct. The callback supplied
	* will only be called if this query returns a value other than what is stored in
	* preferences and should cause the calling activity to refresh anything that
	* depends on calling this method.
	*
	* @param context The calling activity
	* @param callback The runnable that should execute if a query returns new values
	* @return The string value representing the time zone Calendar should display
	*/
	public String getTimeZone(Context context, Runnable callback) {
	synchronized (mTZCallbacks){
	if (mFirstTZRequest) {
	mTZQueryInProgress = true;
	mFirstTZRequest = false;

	SharedPreferences prefs = getSharedPreferences(context, mPrefsName);
	mUseHomeTZ = prefs.getBoolean(KEY_HOME_TZ_ENABLED, false);
	mHomeTZ = prefs.getString(KEY_HOME_TZ, Time.getCurrentTimezone());

	// When the async query returns it should synchronize on
	// mTZCallbacks, update mUseHomeTZ, mHomeTZ, and the
	// preferences, set mTZQueryInProgress to false, and call all
	// the runnables in mTZCallbacks.
	if (mHandler == null) {
	mHandler = new AsyncTZHandler(context.getContentResolver());
	}
	mHandler.startQuery(0, context, CalendarCache.URI, CALENDAR_CACHE_POJECTION,
	null, null, null);
	}
	if (mTZQueryInProgress) {
	mTZCallbacks.add(callback);
	}
	}
	return mUseHomeTZ ? mHomeTZ : Time.getCurrentTimezone();
	}

	/**
	* Forces a query of the database to check for changes to the time zone.
	* This should be called if another app may have modified the db. If a
	* query is already in progress the callback will be added to the list
	* of callbacks to be called when it returns.
	*
	* @param context The calling activity
	* @param callback The runnable that should execute if a query returns
	* new values
	*/
	public void forceDBRequery(Context context, Runnable callback) {
	synchronized (mTZCallbacks){
	if (mTZQueryInProgress) {
	mTZCallbacks.add(callback);
	return;
	}
	mFirstTZRequest = true;
	getTimeZone(context, callback);
	}
	}
	}

	/**
	* A helper method for writing a String value to the preferences
	* asynchronously.
	*
	* @param context A context with access to the correct preferences
	* @param key The preference to write to
	* @param value The value to write
	*/
	public static void setSharedPreference(SharedPreferences prefs, String key, String value) {
	// SharedPreferences prefs = getSharedPreferences(context);
	SharedPreferences.Editor editor = prefs.edit();
	editor.putString(key, value);
	editor.apply();
	}

	/**
	* A helper method for writing a boolean value to the preferences
	* asynchronously.
	*
	* @param context A context with access to the correct preferences
	* @param key The preference to write to
	* @param value The value to write
	*/
	public static void setSharedPreference(SharedPreferences prefs, String key, boolean value) {
	// SharedPreferences prefs = getSharedPreferences(context, prefsName);
	SharedPreferences.Editor editor = prefs.edit();
	editor.putBoolean(key, value);
	editor.apply();
	}

	/** Return a properly configured SharedPreferences instance */
	public static SharedPreferences getSharedPreferences(Context context, String prefsName) {
	return context.getSharedPreferences(prefsName, Context.MODE_PRIVATE);
	}
	}