Chapter 5. MIDP GUI Programming
User interface requirements for handheld devices are different from those for desktop computers. For example, the display size of handheld devices is smaller, and input devices do not always include pointing tools such as a mouse or pen input. For these reasons, you cannot follow the same user-interface programming guidelines for applications running on handheld devices that you can on desktop computers.
The CLDC itself does not define any GUI functionality. Instead, the official GUI classes for the J2ME are included in profiles such as the MIDP and are defined by the Java Community Process (JCP). You’ll note that the GUI classes included in the MIDP are not based on the Abstract Window Toolkit (AWT). That seems like a major issue, which brings us to the following question.
Why Not Reuse the AWT?
After a great deal of consideration, the MIDP Expert Group decided not to subset the existing AWT and Project Swing classes for the following reasons:
AWT is designed for desktop computers and optimized for these machines.
AWT assumes certain user interaction models. The component set of the AWT is designed to work with a pointing device such as a mouse; however, many handheld devices, such as cell phones, have only a keypad for user input.
AWT has a rich feature set, and includes support for functionality that is not found or is impractical to implement on handheld devices. For example, the AWT has extensive support for window management, such as resizing ...
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