From 42dcb79f14761296eb7885c41adf3d2becb46cc0 Mon Sep 17 00:00:00 2001
From: Tim Su <tim@todoroo.com>
Date: Wed, 29 Sep 2010 14:40:02 -0700
Subject: [PATCH] Added sync background service

---
 .../astrid/sync/SyncBackgroundService.java    | 150 ++++++++++++++++++
 1 file changed, 150 insertions(+)
 create mode 100644 src/com/todoroo/astrid/sync/SyncBackgroundService.java

diff --git a/src/com/todoroo/astrid/sync/SyncBackgroundService.java b/src/com/todoroo/astrid/sync/SyncBackgroundService.java
new file mode 100644
index 0000000..fb8fbb4
--- /dev/null
+++ b/src/com/todoroo/astrid/sync/SyncBackgroundService.java
@@ -0,0 +1,150 @@
+package com.todoroo.astrid.sync;
+
+import android.app.AlarmManager;
+import android.app.PendingIntent;
+import android.app.Service;
+import android.content.Context;
+import android.content.Intent;
+import android.os.IBinder;
+import android.util.Log;
+
+import com.todoroo.andlib.service.Autowired;
+import com.todoroo.andlib.service.ContextManager;
+import com.todoroo.andlib.service.DependencyInjectionService;
+import com.todoroo.andlib.service.ExceptionService;
+import com.todoroo.andlib.utility.DateUtilities;
+import com.todoroo.andlib.utility.Preferences;
+
+/**
+ * Performs synchronization service logic in background service to avoid
+ * ANR (application not responding) messages.
+ * <p>
+ * Starting this service
+ *  schedules a repeating alarm which handles
+ * synchronization with your serv
+ *
+ * @author Tim Su
+ *
+ */
+abstract public class SyncBackgroundService extends Service {
+
+	/** Minimum time before an auto-sync */
+	private static final long AUTO_SYNC_MIN_OFFSET = 5*60*1000L;
+
+    /** alarm identifier */
+    public static final String SYNC_ACTION = "sync"; //$NON-NLS-1$
+
+    @Autowired private ExceptionService exceptionService;
+
+    // --- abstract methods
+
+    abstract protected SyncProvider<?> getSyncProvider();
+
+    abstract protected SyncProviderUtilities getSyncUtilities();
+
+    // --- implementation
+
+    public SyncBackgroundService() {
+        DependencyInjectionService.getInstance().inject(this);
+    }
+
+    /** Receive the alarm - start the synchronize service! */
+    @Override
+    public void onStart(Intent intent, int startId) {
+        try {
+            if(intent != null && SYNC_ACTION.equals(intent.getAction()))
+                startSynchronization(this);
+        } catch (Exception e) {
+            exceptionService.reportError(getSyncUtilities().getIdentifier() + "-bg-sync", e); //$NON-NLS-1$
+        }
+    }
+
+    /** Start the actual synchronization */
+    private void startSynchronization(Context context) {
+        if(context == null || context.getResources() == null)
+            return;
+
+        ContextManager.setContext(context);
+
+        if(!getSyncUtilities().isLoggedIn())
+            return;
+
+        getSyncProvider().synchronize(context);
+    }
+
+
+    @Override
+    public IBinder onBind(Intent intent) {
+        return null;
+    }
+
+    // --- alarm management
+
+    /**
+     * Schedules repeating alarm for auto-synchronization
+     */
+    public void scheduleService() {
+        int syncFrequencySeconds = Preferences.getIntegerFromString(
+                getSyncUtilities().getSyncIntervalKey(), -1);
+        Context context = ContextManager.getContext();
+        if(syncFrequencySeconds <= 0) {
+    	    unscheduleService(context);
+    	    return;
+    	}
+
+    	// figure out synchronization frequency
+        long interval = 1000L * syncFrequencySeconds;
+        long offset = computeNextSyncOffset(interval);
+
+        // give a little padding
+        offset = Math.max(offset, AUTO_SYNC_MIN_OFFSET);
+
+        AlarmManager am = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
+        PendingIntent pendingIntent = PendingIntent.getService(context, 0,
+                createAlarmIntent(context), PendingIntent.FLAG_UPDATE_CURRENT);
+
+        Log.i("Astrid", "Autosync set for " + offset / 1000 //$NON-NLS-1$ //$NON-NLS-2$
+            + " seconds repeating every " + syncFrequencySeconds); //$NON-NLS-1$
+
+        // cancel all existing
+        am.cancel(pendingIntent);
+
+        // schedule new
+        am.setRepeating(AlarmManager.RTC_WAKEUP, System.currentTimeMillis() + offset,
+                interval, pendingIntent);
+    }
+
+
+    /**
+     * Removes repeating alarm for auto-synchronization
+     */
+    private void unscheduleService(Context context) {
+        AlarmManager am = (AlarmManager)context.getSystemService(Context.ALARM_SERVICE);
+        PendingIntent pendingIntent = PendingIntent.getService(context, 0,
+                createAlarmIntent(context), PendingIntent.FLAG_UPDATE_CURRENT);
+        am.cancel(pendingIntent);
+    }
+
+    /** Create the alarm intent */
+    private Intent createAlarmIntent(Context context) {
+        Intent intent = new Intent(context, getClass());
+        intent.setAction(SYNC_ACTION);
+        return intent;
+    }
+
+    // --- utility methods
+
+
+    private long computeNextSyncOffset(long interval) {
+        // figure out last synchronize time
+        long lastSyncDate = getSyncUtilities().getLastSyncDate();
+
+        // if user never synchronized, give them a full offset period before bg sync
+        if(lastSyncDate != 0)
+            return Math.max(0, lastSyncDate + interval - DateUtilities.now());
+        else
+            return interval;
+    }
+
+
+}