Sending Intent to Home and Widget Add

Question

I'm trying to figure out how to send an intent to the home screen to add a Widget to it if I can. Any ideas? Here is some code I've been fooling around with to at least prompt the Add Widget selection.

AppWidgetManager mAppWidgetManager;
AppWidgetHost mAppWidgetHost;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    selectWidget();

    mAppWidgetManager = AppWidgetManager.getInstance(this);
    mAppWidgetHost = new AppWidgetHost(this, R.id.APPWIDGET_HOST_ID);
}

void selectWidget() {
    int appWidgetId = this.mAppWidgetHost.allocateAppWidgetId();
    Intent pickIntent = new Intent(AppWidgetManager.ACTION_APPWIDGET_PICK);
    pickIntent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, appWidgetId);
    startActivityForResult(pickIntent, R.id.REQUEST_PICK_APPWIDGET);
}

Thank you to anybody who contributes.

Answer 1

You can send the ACTION_APPWIDGET_PICK intent to the system, but your app cannot process it, unless what you're coding is a Home screen replacement, i.e. a launcher.

Take a look at the documentation for App Widget Host, in particular the section about Host Binding. The code you're using in the selectWidget() method is the same used in the original Launcher app (under title Binding app widgets on Android 4.0 and lower). Then comes an implementation for onActivityResult, where the intent is processed. This method is what is missing in your code, but if you include it, you will end up doing all the work the Home screen app does (see addAppWidget(Intent data) next in that page).

If you continue reading the App Widget Host doc, you will see that the binding process changed on Android 4.1 and there is also a new intent for this task that requires a permission in the manifest. And to complicate things more, keep in mind @CommonsWare's comment: there are a lot of Home screen implementations, that probably do the binding process differently :(

To summarize: there's no way to get the list of app widgets and process what the user selected, neither is a way to ask the launcher app to do this for us, unfortunately. Perhaps in a future Android version, as this comment in the latest Launcher source code reveals:

/** We will likely flesh this out later, to handle allow external apps to place widgets, but for now, we just want to expose the action around for checking elsewhere. */