Question

Simple question… quite possibly not simple answers 🙂

I want to write an accessibility service for android in monodroid. I’m finding it difficult to work out the pieces. I can inherit from AccessibilityService, but there isn’t an AccessibilityServiceAttribute. I need specific content in the manifest file, but apparently the intent filter and service xml is not directly supported by monodroid… I believe.

I doubt this is something that many people have done, but as a beginner with Monodroid, I think I’m mainly just finding it difficult to put together the well supported “normal” app development, with the “supported” but not quite, accessibility service development.

I would appreciate any pointers. Thanks guys.

Answer 1

According to the docs:

An accessibility is declared as any other service in an AndroidManifest.xml but it must also specify that it handles the “android.accessibilityservice.AccessibilityService” Intent. Failure to declare this intent will cause the system to ignore the accessibility service.

Since it is declared the same way as any other service, you can make use of ServiceAttribute and IntentFilterAttribute to generate the entry in AndroidManifest.xml. For example:

[Service]
[IntentFilter(new[] { "android.accessibilityservice.AccessibilityService" })]
public class MyAccessibilityService : AccessibilityService
{
    public override void OnAccessibilityEvent(AccessibilityEvent e)
    {

    }

    public override void OnInterrupt()
    {
    }
}

When you build the application, Mono for Android will generate this in the manifest:

<service android:name="sample.MyAccessibilityService">
  <intent-filter>
    <action android:name="android.accessibilityservice.AccessibilityService" />
  </intent-filter>
</service>