Android – Patterns when to use Activity Transition vs Dynamic Fragments

androidandroid-3.0-honeycombandroid-activityandroid-fragmentsandroid-layout

Are there any patterns on how to handle UI Transitions in Android Activities vs Fragments? I am currently looking into a UI that has at most 3 columns in Landscape.
I would like the UI to start with 1 column all the way across the screen and then on selection of something move in the second column and then on clicking on something in the second fade in the 3rd on tablets and phones and fade out the 1st column on phones.
I am wondering when I should do this as an Activity transition and when I should just use Fragments with Views that Appear. As far as I have read fragments can be moved over to other activities so my choice is either implement Activities with static column layouts that then transition taking the fragments with them or have one Activity with all 3 columns and have the Activity manage the Appearing of the Fragments. Both approaches could work but I was interested in pros and cons from as many angles for both solutions.

There are two questions similar to what I am asking but don't quite answer mine

Best Answer

Fragments can seem like more code up front (since you're putting a view in a fragment, and a fragment in an Activity, instead of just a view in an Activity), but they're great at saving you from headaches in just this kind of situation- Definitely go with Fragments. They even handle the transitions for you.

We have some sample code called "Honeycomb Gallery" you can take a look at here, which has a two-column-plus-actionbar layout, and the ability to show/hide the leftmost column. This should give you a good head start in figuring out how to do layout for multiple fragments and show/hide them.

FYI, one important trade-off to using multiple fragments in an Activity instead of multiple Activities, is that fragments don't directly respond to intents - For instance, if you had a note-taking app where "View Note" page was an Activity, and you changed it so that there was a "view note" Fragment inside the main Activity, then you'd have to set it up such that the main Activity received a note ID AND a note action (create, view, edit, whatever) in the Intent, as opposed to just having the "view note" activity receive the note ID in the Intent. The main Activity would then need to set up the fragments on the page accordingly. Not a huge deal, but if external accessibility to various parts of your application via Intent is important, then it might be easier to break your app out into a few Activities, as well as use fragments to represent the individual components.

Related Solutions

Android – Activity transition in Android

Here's the code to do a nice smooth fade between two Activities..

Create a file called fadein.xml in res/anim

<?xml version="1.0" encoding="utf-8"?>
<alpha xmlns:android="http://schemas.android.com/apk/res/android"
   android:interpolator="@android:anim/accelerate_interpolator"
   android:fromAlpha="0.0" android:toAlpha="1.0" android:duration="2000" />

Create a file called fadeout.xml in res/anim

<?xml version="1.0" encoding="utf-8"?>

<alpha xmlns:android="http://schemas.android.com/apk/res/android"
   android:interpolator="@android:anim/accelerate_interpolator"
   android:fromAlpha="1.0" android:toAlpha="0.0" android:duration="2000" />

If you want to fade from Activity A to Activity B, put the following in the onCreate() method for Activity B. Before setContentView() works for me.

overridePendingTransition(R.anim.fadein, R.anim.fadeout);

If the fades are too slow for you, change android:duration in the xml files above to something smaller.

Android – How to handle button clicks using the XML onClick within Fragments

I prefer using the following solution for handling onClick events. This works for Activity and Fragments as well.

public class StartFragment extends Fragment implements OnClickListener{

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {

        View v = inflater.inflate(R.layout.fragment_start, container, false);

        Button b = (Button) v.findViewById(R.id.StartButton);
        b.setOnClickListener(this);
        return v;
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
        case R.id.StartButton:

            ...

            break;
        }
    }
}

Best Answer

Related Solutions

Android – Activity transition in Android

Android – How to handle button clicks using the XML onClick within Fragments

Related Topic