Handling Events - Beginning Java - page 941

}

Directory "Sketcher 6 using Action objects"

Add this definition to the SketcherFrame class following the previous inner class. In this class you retain
the typeID to identify the element type. This makes the listener operation simple and fast. Because each ob-
ject corresponds to a particular element type, there is no need for any testing of the event in the actionPer-
formed() method — you just store the typeID as the new element type in the elementType member of the
SketcherFrame class.
Add the following statement to the SketcherFrame class to define members that store references to
TypeAction objects, following the statement that defines the members storing FileAction references:

// Element type actions
private TypeAction lineAction, rectangleAction, circleAction, curveAction;
private TypeAction[] typeActions; // Type actions as an array

Directory "Sketcher 6 using Action objects"

You have a convenience array here for Action objects, too.

Actions for Color Menu Items
The third inner class to SketcherFrame defining Action objects for the Color menu items is just as simple:

// Handles color menu items
class ColorAction extends AbstractAction {
// Create an action with a name and a color
public ColorAction(String name, Color color) {
super(name);
this.color = color;

}

// Create an action with a name, a color, and an accelerator
public ColorAction(String name, Color color, char ch, int modifiers) {
this(name, color);
putValue(ACCELERATOR_KEY, KeyStroke.getKeyStroke(ch, modifiers));

// Now find the character to underline
int index = name.toUpperCase().indexOf(ch);
if(index != -1) {
putValue(DISPLAYED_MNEMONIC_INDEX_KEY, index);

}

}