Question

I have an Android app that I would like to convert to an Android library. The app is based around one activity whose entire XML layout contains only a webview that covers the entire screen. The library UI (really, just the webview) must now be integrated into the layout of other apps. For example, one parent app has a tab structure. I would like to have the library webview displayed in one of the tabs, with the tabs always visible at the bottom of the screen. Ordinarily, I’d opt to set the app-library boundary at the activity level but that does not work in this case — we cannot pop up a new Activity from the library because that would cover all of the screen and the tabs at the bottom.

What is the best way to convert this to a library so that it works within the tab structure of the parent app? Where should the app-library boundary be? Some of my ideas are:

1. Let the library user create an activity with the custom layout that he prefers (tabs in this case). Make sure that the layout contains a webview. Use findViewById to get the webview object and pass this object into the library for the library to use to display pages. Main disadvantage here is that parts of the library need to hook up some Broadcast receivers onto the parent activity (which is not really part of the library in this scenario), and this coupling seems rather dubious.

2. Perhaps use fragments which were introduced in Android 3.0. However, these mostly seem geared towards tablets. Would these work in this case?

3. Is there another option compatible with Android 2.1+ that I am not aware of?

Answer 1

I decided to go with Fragments, using the compatibility library.

http://developer.android.com/guide/topics/fundamentals/fragments.html
http://developer.android.com/sdk/compatibility-library.html

Fragments are really the best choice in this case because:

1. They have a life cycle similar to that of activities, making conversion easy.
2. They are a chunk of UI with related functionality, which is exactly what’s needed in this case.