Question

I’ve got this question regarding Android activities and AndroidManifest.xml. The question arised when I was working with Java servlets, and wanted to create a “module-based” or something similar to plugin based server. This is working fine, and I can dynamically load the servlets I want, using a code approach similar to this: Dynamically add a servlet to the servletConfig. The servlets are dynamically found and mapped during the server startup.

The question here is not how to find the proper activities, or how to create a new instance of them, or how to start them, that part I have figured out. I can iterate over my packages and find the appropriate Activity-classes, create new instances of them and add them to a list.

I’ve been using a interface which all the Activities must implement in order to be a valid activity. That way, I can create new parts, extentions or new features for my application, and everything just works. In my application I have a list of button that users can click on, and the button list is generated by adding them to my view using a ListView.

private void displayLoadedContent() {
    View v = inflateLayout(R.layout.buttonlayout);
    ListView view = (ListView) v.findViewById(R.id.list);
    view.setAdapter(new ListButtonAdapter(this, content));
}

where content is declared as

List<MyActivityInterface> content;

and ListButtonAdapter extends BaseAdapter.

So no problem there. The problem is that I have to declare each and every single one of my activites in AndroidManifest.xml. That file is like a big list of possible acitivies to display, and kind of messy, so I’m not going to display the code here.

I realize that I’ll have to add one activity to the manifest, but I was hoping that the one activity should be enough. My approach can in many ways be looked as a Front Controller pattern, where each of the activities is responsible for loading and displaying the acitivity they need.

I’m simply asking if it’s even possible to dynamically registrer activities in the manifest (or allow them to run in another way), and if no, is there any other valid solution?

Answer 1

Android requires that each activity to be registered in your AndroidManifest.xml file ahead of time. When deployed, your app will live on a device as an .apk file, which can’t be modified (aside from being updated/replaced with a new APK).

If I understand the question correctly, you simply don’t want to have to list a large number of activities in your manifest file? Fragments don’t need to be registered in the manifest file, so if your goal is to dynamically swap out UI components, that would be the answer. Fragments are available back to 1.6 via the Support library.