Question

While writing my first Blackberry application using Java, I am confused between inheriting from MainScreen and Screen classes.

My initial understanding was that there should be just a single MainScreen-derived class in an application, since we would like to define the screen title and other embellishments only once. All the rest of the screens (which are invoked on top of the MainScreen) should derive from Screen.

However, this doesn’t seem to be true as I have not been able to get a screen completely cover the non-title area of the previous MainScreen.

Is there anything specific which I have overlooked in understanding how multiple screens in a Blackberry application should be created?

Answer 1

Have you read this on BlackBerry’s developer site?

And also this?

I do often have one and only one MainScreen in my application. Other screens can derive from Screen or FullScreen. Whether or not you need every screen to be a MainScreen depends on whether your UI design requires things like the header (title) and footer (status) in each screen, which MainScreen provides.

Are you saying that you’re adding other screens, and they simply aren’t taking up enough space? If you want additional screens to occupy the full screen, I would subclass FullScreen, not just Screen.

And, you’re showing new screens (after the initial MainScreen) with UiApplication.pushScreen() and UiApplication.popScreen()?