After reading the first four modules we are now able to create a MIDlet managing its own GUI using HIGH and LOW level APIs. In this module we’ll talk about memory management, a very important feature of small device applications. We’ll deal with two types of memory:

- Volatile memory
- Non-volatile memory (persistent memory) Read more »

In the third module we studied how to create midlet user interfaces using the high level API. We learned that, using that API, we can develop portable GUIs delegating to the underlying device the creation of specific widgets such as Lists, TextFields and so on. We stated that if we need more control over the device’s screen we need to use a different API – called Low Level API – which allows us to have complete control over the device at the cost of a portability loss. For instance, if we have to build a List using the High Level API we just create a List instance and then we add it to a Form. If we want the same result using the Low Level API, we have to manage list items and draw them on the screen using graphic primitives: lines, curves and rectangles must be painted using specific methods. In this case, of course, we need to know the screen dimension, then we have to choose the colors, draw list items and so on. Read more »