5.2. Keyboard Keys
In this section, we introduce you to the keys of the phone keyboard. Although there is nothing particularly difficult in registering the click of a key, there are several things worth noticing.
First, a single physical key may produce different results based on the keyboard mode: for instance, a key might produce an upper or lower case 'a' depending whether some other key is active. Second, there are several different key events: the user can select a key, hold it down and release it – all these events can be registered separately.
With the help of the next three examples, we show three different approaches to programming keyboard keys. Each example takes a slightly different approach, but basically they all do the same thing:
If the user presses the up-arrow key (navigation key up), a note dialog tells us that the up-arrow key was pressed, as shown in Figure 5.2.
If the user presses keyboard key 2, a note dialog tells us that key 2 was pressed.
Figure 5-2. Up arrow is pressed
Even though all three approaches are used here to accomplish the same task, each of them is best suited to handle a particular use case: