J2ME UI Architecture

J2ME UI Architecture




J2ME applications use the javax.microedition.lcdui package to implement the user interface on the LCD screens of mobile devices. Here we will go through the basic structure of the LCD UI implementation followed by a little detail about how to use the high and low level elements and handling commands. This won’t be a very detailed study. After this brief knowledge, you can always look at the API documentation and learn about the specific features of each element.



How do they appear? Display & Displayable


Before we start looking into the specific elements, let’s first know how the display functions in java lcdui.

User Interface Architecture

j2me user interface architecture

As you might already have guessed, the grandfather of all display elements is the Displayable class. It has too children –

Screen

Screen is extended by a number of children –

In the next section we will learn how to work with the high-level display elements i.e. the children of Screen.