When to use which constructor for ComponentName in Android?

Question

I am a little bit confused about the ComponentName class in Android.

There are different ways to get to a component name object, but I don\'t know when to use which... a

Answer 1

Robert Tupelo-Schneck's answer is right about preferring objects against Strings. Here's how I see it.

• To refer to your own components, use:

  new ComponentName(getApplicationContext(), WidgetProvider.class);
  

• To refer to some dynamically referenced component in your own app, use:

  // values/strings.xml: de.zordid.sampleapp.widget.WidgetProvider
  String fqcn = getResources().getString(R.string.provider);
  new ComponentName(getApplicationContext(), fqcn);
  

  This is useful when you want to use Android's resource qualifiers to decide which component to use, you can override the default string in values-*/strings.xml.

• To refer to another application's component, use:

  int componentFlags = GET_ACTIVITIES | GET_PROVIDERS | GET_RECEIVERS | GET_SERVICES;
  PackageInfo otherApp = context.getPackageManager().getPackageInfo("com.other.app", componentFlags);
  ComponentInfo info = otherApp.activities[i]; // or providers/receivers/...
  new ComponentName(info.packageName, info.name);
  

About .Names and

• net.twisterrob.app.android.App
• net.twisterrob.app.android.GlideSetup
• net.twisterrob.app.android.subpackage.SearchResultsActivity
• net.twisterrob.app.android.subpackage.Activity
• net.twisterrob.app.android.content.AppProvider

on the server side backend of the app and/or some shared model classes:

• net.twisterrob.app.data.*
• net.twisterrob.app.backend.*
• net.twisterrob.app.web.*

in my Android helper library:

• net.twisterrob.android.activity.AboutActivity

other libraries:

• android.support.v4.content.FileProvider

This way everything is namespaced in net.twisterrob.app. The android app being just a single part of the whole inside it's own subpackage.

AndroidManifest.xml (irrelevant parts omitted)

build.gradle

android {
    defaultConfig {
        // this is what will be used when you upload it to the Play Store
        applicationId 'net.twisterrob.app'
    }
    buildTypes {
        debug {
            // The neatest trick ever!
            // Released application: net.twisterrob.app
            // IDE built debug application: net.twisterrob.app.debug
            // This will allow you to have your installed released version
            // and sideloaded debug application at the same time working independently.
            // All the ContentProvider authorities within a system must have a unique name 
            // so using ${applicationId} as authority will result in having two different content providers.
            applicationIdSuffix '.debug'
        }
    }
}

To check out what your final manifest will look like after all the merging open build\intermediates\manifests\full\debug\AndroidManifest.xml.