How to share data between activity and widget?

Question

I read the hellowidget tutorial and Dev Guide' App Widgets. Then I know how to create a widget which contains button or text or something.

But what I really want to do is making it interact with my app. For example, I want to create a widget that has a text view, and when I click it, it sends a PendingIntent to my activity in which I can edit the text.

I can do the step "sends a PendingIntent". But after I edit text in acitivy, how does the widget read it?

Answer 1

What you need to do is register a custom intent, for example ACTION_TEXT_CHANGED in your AppWidgetProvider like this for example:

public static final String ACTION_TEXT_CHANGED = "yourpackage.TEXT_CHANGED";

After this, you need to register in your AndroidManifest.xml that you want to receive this intents in the intent-filter section of your receiver tag like this:

<receiver android:name=".DrinkWaterAppWidgetProvider">
    <intent-filter>
        <action android:name="android.appwidget.action.APPWIDGET_UPDATE" />
        <action android:name="yourpackage.TEXT_CHANGED" />                
    </intent-filter>
    <meta-data android:name="android.appwidget.provider"
        android:resource="@xml/appwidget_info" />
</receiver>

Then you have to extend the onReceive method in your AppWidgetProvider and make sure that you're handling your intent like this:

@Override
public void onReceive(Context context, Intent intent) {
    super.onReceive(context, intent);
    if (intent.getAction().equals(ACTION_TEXT_CHANGED)) {
        // handle intent here
        String s = intent.getStringExtra("NewString");
    }
}

After all the above is set up, you just need to broadcast the intent in your activity after the text has changed like this:

Intent intent = new Intent(YourAppWidgetProvider.ACTION_TEXT_CHANGED);
intent.putExtra("NewString", textView.getText().toString());
getApplicationContext().sendBroadcast(intent);

Where "NewString" should be changed to the name you to give the the string.

I hope it helps.

Answer 2

You have to use the RemoteViews class to do it. Create an instance of RemoteViews class inside your AppWidgetProvider's onRefresh method and use the methods in it...

RemoteViews views = RemoteViews(packageName, layoutId);
views.setOnClickPendingIntent(viewId, pendingIntent);

Note that RemoteViews is limited in functionality when compared with the standard app views. But, you can achieve what you wanted to do with what they provide.