SyncButton.java

package com.android.settings.widget.buttons;

import android.content.ContentResolver;
import android.content.Context;
import android.content.SharedPreferences;
import android.net.ConnectivityManager;

import com.android.settings.R;
import com.android.settings.widget.SettingsAppWidgetProvider;
import com.android.settings.widget.WidgetSettings;

public class SyncButton extends WidgetButton {

	static SyncButton ownButton=null;

	/**
	 * Toggle auto-sync
	 * 
	 * @param context
	 */
	public void toggleState(Context context) {
		ConnectivityManager connManager = (ConnectivityManager) context
		.getSystemService(Context.CONNECTIVITY_SERVICE);
		boolean backgroundData = getBackgroundDataState(context);
		boolean sync = ContentResolver.getMasterSyncAutomatically();

		// four cases to handle:
		// setting toggled from off to on:
		// 1. background data was off, sync was off: turn on both
		if (!backgroundData && !sync) {
			connManager.setBackgroundDataSetting(true);
			ContentResolver.setMasterSyncAutomatically(true);
		}

		// 2. background data was off, sync was on: turn on background data
		if (!backgroundData && sync) {
			connManager.setBackgroundDataSetting(true);
		}

		// 3. background data was on, sync was off: turn on sync
		if (backgroundData && !sync) {
			ContentResolver.setMasterSyncAutomatically(true);
		}

		// setting toggled from on to off:
		// 4. background data was on, sync was on: turn off sync
		if (backgroundData && sync) {
			ContentResolver.setMasterSyncAutomatically(false);
		}
	}	

	public void toggleState(Context context, int newState) {
		if(getSync(context) && newState==SettingsAppWidgetProvider.STATE_DISABLED) {
			toggleState(context);
		} else if(!getSync(context) && newState==SettingsAppWidgetProvider.STATE_ENABLED) {
			toggleState(context);			
		}
	}

	/**
	 * Gets the state of background data.
	 * 
	 * @param context
	 * @return true if enabled
	 */
	private static boolean getBackgroundDataState(Context context) {
		ConnectivityManager connManager = (ConnectivityManager) context
		.getSystemService(Context.CONNECTIVITY_SERVICE);
		return connManager.getBackgroundDataSetting();
	}

	/**
	 * Gets the state of auto-sync.
	 * 
	 * @param context
	 * @return true if enabled
	 */
	private static boolean getSync(Context context) {
		boolean backgroundData = getBackgroundDataState(context);
		boolean sync = ContentResolver.getMasterSyncAutomatically();
		return backgroundData && sync;
	}



	public void updateState(Context context,
			SharedPreferences globalPreferences, int[] appWidgetIds) {
		if (getSync(context)) {
			currentIcon=R.drawable.ic_appwidget_settings_sync_on;
			currentState=SettingsAppWidgetProvider.STATE_ENABLED;
		} else {
			currentIcon=R.drawable.ic_appwidget_settings_sync_off;
			currentState=SettingsAppWidgetProvider.STATE_DISABLED;
		}		
	}

	public static SyncButton getInstance() {
		if (ownButton==null)
			ownButton = new SyncButton();

		return ownButton;
	}

	@Override
	void initButton() {
		buttonID=WidgetButton.BUTTON_SYNC;
		preferenceName=WidgetSettings.TOGGLE_SYNC;
	}

}