Question

Say I have 4 Activities: Login, Sync, Main, Details.

Main and Details can only be accessed if the user is logged in and passed the synchronization phase. Main can be accessed from an icon on the drawer. Details can be accessed from Main and from the notifications.

The user is logged off after 30 minutes of inactivity (with a timer on a Service).

I am not sure which way I should take to make sure the user is logged in. Here are my two scenarios:

• The icon launches Login which checks if the user is logged in, then launches Synch, which does the same and launches Main.
• The icon launchs Main which checks is the user is logged in, if not, launch Login. Login closes itself to show Main that was on the back stack.

And then there is also Details that needs to checks if the user is logged in.

The second scenario seems more correct to me, because it allows to launch other Activities than Main, but it will force me to duplicate the check code in every Activity that needs to have the user logged in. (I have more than 2 activities).

Why way should I take? Why?

Answer 1

You can extend a BaseActivity which implements all your checking code, then any new Activity you use will have it built in.

I use this in an app which has access to 50% of the Activities without logging in and displays a prompt using startActivityForResult(...) to catch the success or failure of the login attempt.

It works really well and keeps everything neatly encapsulated 🙂

EDIT

Here is a code snippet to modify as you wish:

/**
 * This is an abstract class that all Activities will be based on.
 */
public abstract class BaseActivity extends ActionBarActivity
{
    protected static final int    SHOW_WALLET       = 100;
    protected static final int    SHOW_OFFER_DETAIL = 101;
    protected static final int    REGISTER          = 102;
    protected static final int    SHOW_ACCOUNT      = 103;

    protected static final int    LOGGED_IN_OK      = 103;
    protected static final int    REGISTERED_OK     = 104;

    protected static final int    DIALOG_DELAY      = 300;
    // for passing data in extras
    protected static final String TEXT_SEARCH       = "text_search";
    protected static final String SEARCH_TERM       = "search_term";

    protected boolean             mAlternateTitle   = false;
    private Dialog                loading;
    private Runnable              showDialog;   

         protected final void openAccount()
        {
            Intent i;
            if ( LoginManager.getInstance().isLoggedIn() )
            {
                i = new Intent( this, MyAccountActivity.class );
                startActivity( i );
            }
            else
            {
                i = new Intent( this, LoginActivity.class );
                startActivityForResult( i, SHOW_ACCOUNT );
            }
        }

}