Android: AppWidget with custom view not working

I am creating a appwidget that consists of a single custom view called Foo.

xml/widget.xml:

<appwidget-provider
 xmlns:android="http://schemas.android.com/apk/res/android"
 android:minWidth="294dp"
 android:minHeight="72dp"
 android:updatePeriodMillis="0"
 android:initialLayout="@layout/widget_layout">
</appwidget-provider>

layout/widget_layout

<LinearLayout
 xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="fill_parent"
 android:layout_height="fill_parent">
 <package.name.Foo
 android:layout_width="fill_parent"
 android:layout_height="fill_parent"
 />
</LinearLayout>

Foo:

  public class Foo extends View 
  {..}

I tested the Foo view in a normal android app, and it works perfectly. However, when I try to run the widget I get "error while loading widget". When I remove the Foo view from the widget, everything is fine. So it has something to do with the Foo view.

Unfortunately I can't get any more specific errors in DDMS, cause I don't know of a way to debug widgets.

I would like to know if it is indeed possible to use your own custom views in a app-widget? Am I doing som开发者_StackOverflow社区ething wrong here?

I pretty much left my custom view intact, and implemented an ImageView for my widget, then rendered the view using the getDrawingCache()

MyView myView = new MyView(context);
myView.measure(150,150);
myView.layout(0,0,150,150);
myView.setDrawingCacheEnabled(true);
Bitmap bitmap=myView.getDrawingCache();
remoteViews.setImageViewBitmap(R.id.dial, bitmap);

Another way to do this without using getDrawingCache() :

MyView myView = new MyView(this);
myView.measure(500, 500);
myView.layout(0, 0, 500, 500);
Bitmap bitmap = Bitmap.createBitmap(500, 500, Bitmap.Config.ARGB_8888);
myView.draw(new Canvas(bitmap));
remoteViews.setImageViewBitmap(R.id.imageView, bitmap);

I used cache not to redraw all the view so I couldn't use the code above. And I find it more elegant. I hope it could be useful to someone.

You cannot have ANY custom view used in widget. In fact, even those android-predfined views are not all supported.

For detailed list of supported widgets/layouts, please read the documentation. Anything other than those documented cannot be placed in widgets.

see the documentation.

AnalogClock, Button, Chronometer, ImageButton, ImageView, ProgressBar and TextView are the supported views. For layouts you have to use FrameLayout, LinearLayout or RelativeLayout.