Question

I have developed some apps for Android, and this questions stays always:

How should I structure my UI? Should I launch activity after activity and leave the phone to make the “back” button, or should I choose more optimized, but more complex to implement, way with switching manually Views and then manually doing the “Back” button functionality?

What do you think (or know) is the better practice?

Answer 1

I would say that multiple Activities almost always makes more sense. I just don’t think Android is designed for constantly switching its own views – you miss out on so much. You have to implement Back yourself, you don’t get any inter-Activity transitions, you have to implement a lot of internal logic to resume an application in the correct state. If you don’t partition your app into Activities, it makes it a lot more difficult later on to change the flow of your application. It also results in one mega-Activity that can be a lot harder to handle than a lot of smaller pieces of code.

I have trouble imagining that speed is really an issue; if it is then there’s something wrong with the way you’re initializing each Activity. For example, I used try to pass Serializable objects between Activities, and that proved to be incredibly slow; when I switched to a faster method of passing objects, the speed of launching Activities increased immensely.

Also, I think it’s telling that the Android guidelines for Activity and Task Design don’t mention switching Views at all; it’s centered around an Activity-as-View design.