This manifest attribute makes the canvas background transparent so that the system background can be seen. It does not work with full-screen canvases. LWUIT's canvas is always full screen.
In full touch devices, the background color is read during the application startup.
The slider component is practically unusable.
When the UI has a spinner component, you can not move the focus away from the spinner.
The LWUIT library is added to every LWUIT application. The application needs to be obfuscated to keep the binary size moderate. The LWUIT UI framework takes 700-800 KB of space, but with obfuscation it goes down to 350KB or even less, depending on the complexity of the application.
LWUIT is not optimised for applications that require very high-speed
graphics (full-blown games). LCDUI's Canvas and GameCanvas are better choices there.
The Series 40 device portfolio ranges from very price-competitive entry devices with a 128 x 160 pixel display and keyboard input to capable touch UI phones with a QVGA display and enhanced CPU and RAM. You need to carefully select your application features for each target device as some animations and transitions may not run smoothly on lower-end devices. If those features are in use, scaling down the application for low-end devices is needed to ensure a good user experience on each device.