CODEWITHSUNDEEP
androidandroid-appwidgetremoteview
drmrbrewer
drmrbrewer

Reputation: 12989

Proper way to update ImageView in a RemoteViews?

I'm trying to fetch an image from a remote URL and put it into an ImageView. The ImageView itself is within an app widget, so from my current understanding that means it is encapsulated within a RemoteViews and isn't really handled directly.

But I can never get the app widget to display an image. I'm fetching the image as a Bitmap from a remote URL using an AsyncTask extension, and it seems like the image is being fetched OK (a non-null bitmap is returned anyway), though as yet I can't display it to confirm.

I reckon I must be using the wrong method to actually update the app widget's ImageView.

Here is all the relevant code:

layout/new_app_widget.xml:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="@dimen/widget_margin" >

    <ImageView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/imageView"
        android:layout_alignParentTop="true"
        android:layout_alignParentLeft="true"
        android:contentDescription="@string/content" />
</RelativeLayout>

relevant bit from NewAppWidget.java:

public class NewAppWidget extends AppWidgetProvider {

...

static void updateAppWidget(Context context, AppWidgetManager appWidgetManager,
        int appWidgetId) {

    // Construct the RemoteViews object
    RemoteViews views = new RemoteViews(context.getPackageName(), R.layout.new_app_widget);

    String strURL = "http://example.com/YqLOSfr4.png";

    new ImageFetchAsyncTask(strURL, R.id.imageView).execute();
    // ^^^^^
    // in the above, I pass the URL and the id of the imageview, fetch
    // the bitmap, and in the onPostExecute() method I use
    // setImageViewBitmap(viewId, bitmap) to load the bitmap into the imageview
    // 
    // I don't have the code to hand, but I can provide it.  For now, someone
    // may be able to tell me somewhere else I'm doing something wrong

    // Instruct the widget manager to update the widget
    appWidgetManager.updateAppWidget(appWidgetId, views);
}

}

AndroidManifest.xml:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.mike.widgetapptest" >
    <uses-permission android:name="android.permission.INTERNET" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        android:debuggable="true"
        <activity
            android:name=".MyActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <receiver android:name=".NewAppWidget" >
            <intent-filter>
                <action android:name="android.appwidget.action.APPWIDGET_UPDATE" />
            </intent-filter>

            <meta-data
                android:name="android.appwidget.provider"
                android:resource="@xml/new_app_widget_info" />
        </receiver>
    </application>

</manifest>

Upvotes: 1

Views: 1556

Answers (1)

drmrbrewer
drmrbrewer

Reputation: 12989

Classic beginner's error... I was attempting to do something immediately following an async task, expecting the async task to have completed. So I moved what depends on the result of the async task into the onPostExecute() method of the async task, and voila... image displayed in my app widget!

Upvotes: 3

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