The reason that fragments were originally created was to allow for modular layout options on larger screen devices. The classic example is the dual pane layout that adapts based on your screen size.
So the kinds of questions you might ask yourself to determine whether fragments are a good choice for you are:
- Do I want my app to adapt its look based on the screen size?
- Could I take advantage of a larger screen device to show 2, 3, 4 fragments on the same screen?
- Am I duplicating the same UI elements across all of my activities?
If yes, fragments are what you are looking for. If no you can probably use activities.
Fragments are certainly the future. In your example your base activity that contains all of your fragments could contain the search bar and could handle attaching new fragments and acting as the middle-man for dispatching data between fragments.
