Hide status bar in Android ICS

Most of the Android developers that write applications for ICS should have noticed that it's impossible to run apps in full-screen. So how to remove the damned "status bar"? Let's check the code!

Policies needed to show/hide this bar are handled in this file:

frameworks/base/policy/src/com/android/internal/policy/impl/PhoneWindowManager.java

Now let's search for "mStatusBarCanHide".

At a certain point there is an explicative comment that says:

// Determine whether the status bar can hide based on the size
// of the screen.  We assume sizes > 600dp are tablets where we
// will use the system bar.

So it seems that the status bar in ICS can't be hidden only in devices that are considered "tablets".

I really don't care about modifying the calculations needed to check if a device is a tablet or no, so I made a really simple mod to switch back to the old fullscreen behaviour.

I added this flag:

boolean mStatusBarForceHide = true;

and then in the code I added a check for that flag:

if (topIsFullscreen) {
    if (mStatusBarCanHide || mStatusBarForceHide ) {
        if (DEBUG_LAYOUT) Log.v(TAG, "** HIDING status bar");
        if (mStatusBar.hideLw(true)) {
            changes |= FINISH_LAYOUT_REDO_LAYOUT;

            mHandler.post(new Runnable() { public void run() {
            if (mStatusBarService != null) {
                try {
                    mStatusBarService.collapse();
                } catch (RemoteException ex) {}
            }
            }});
        }
    } else if (DEBUG_LAYOUT) {
        Log.v(TAG, "Preventing status bar from hiding by policy")     
    }
} else {
    if (DEBUG_LAYOUT) Log.v(TAG, "** SHOWING status bar: top is not fullscreen");
        if (mStatusBar.showLw(true)) changes |= FINISH_LAYOUT_REDO_LAYOUT;
}

That's all!

Now the "android:theme="@android:style/Theme.Black.NoTitleBar.Fullscreen" flag in your AndroidManifest.xml should work like a charm!