Adding Operations to Components
To add an operation to an individual component, add code
to the actual body class instead of the shadow class. Edit
code for the shadow class when an operation is being added to a group or
subgroup.
You can add operations in the following ways:
Operations can be added to beans with the Operations dialog box or by
manual coding, see the section Adding Operations to
Beans.
To add an operation to a
component through the Operations dialog box:
- Select the component in the layout.
- Open the attribute editor by clicking on its button in the main toolbar.
- Open the Operations dialog box by clicking the Edit operations
button in the attribute editor.
- Click the Insert button to add an operation (GUI builder provides a
default name, Opsnumber, for the operation; you can rename the
operation by typing a name in the Op name box).
Use the Delete button to remove operations from the list.
If you accidentally delete operations, you can click Reset
to reset the list to its state after the last Apply
operation. There is no Undo, so you
cannot reverse changes that you have applied.
- Click the Filter button to set the triggering event--either an event
filter or a message filter.
Filters are described in Filters.
New style 1.1 events are not supported in this release. For
information on new-style and old-event handling, see the JDK
documentation,
"Java AWT: Delegation Event Model". (You may have to reset the proxies
on the Java Workshop help browser if you have difficulties reaching
the Delegation Event Model.)
- Click the Action button to set the desired response to the
trigger.
- Select the appropriate action type
(action types are described in Actions).
As you add more filters and actions, you can test them
in the layout window. Custom actions added in the
Action dialog box are available only when running the
application.
- Save the operation settings by clicking OK in the Operations
dialog box.
To add an operation
directly to the source file:
- Create the layout with GUI builder.
- Save the layout and generate a .gui file.
- Click on the Open button in the Edit/Debug toolbar and select the
project.java file.
- Add code to the "group" file in the handleEvent() method.
For example:
public boolean handleEvent(Message msg, Event evt) {
if (evt.target == gui.button1.getBody() &&
evt.id == Event.ACTION_EVENT) {
System.out.println("got a click on button1");
return true;
}
return super.handleEvent(msg, evt);
}
To add an operation
using both methods:
Adding Operations to Beans
Adding operations to a bean with the Operations dialog box is done exactly
as described at the beginning of this page.
Code generated for the operations are in the JDK 1.0.2 propagation-style
events. To use new-style event handling, you must implement the code
manually.
When you add operations to a bean using the Operations dialog box, the
events fired by the bean do not show up on the list of event
filters. You must manually add code to register listeners for those events.
To register listeners:
- Add a listener interface to the implementation line.
- Add a listener function to the group.
For example,
public class MyApp extends Group implements ActionListener{
...
protected void createGroup() {
// make the group an action listener of the bean
Bean body = (Bean)gui.bean1.getBody();
body.addActionListener(this);
...
public void actionPerformed(ActionEvent e) {
...
}
}
Getting Bean Information
When you are adding operations, you can find out what method can be
called for a particular bean with the Bean Info dialog box. The Bean
Info dialog box provides you with the following information about a
selected bean:
- Properties
- Property types
- Accessor methods
- Indexed properties
- Events
- Registration methods
- Listener methods
- Methods (including inherited methods)
To look up the specific
features of a bean:
- Select the bean in the layout window.
- Choose GUI -> Bean Info on Selected Component.
- Click the Properties, Events, or Methods tab.
See also:
- What Is a Component Operation?
- Laying Out GUI Interfaces
- Generating Java Source Code
- GUI Builder Runtime Classes
- What Are Groups and Shadows?
- More On Groups and Shadows
- Visual Java GUI Builder API Documentation
- Visual Java GUI
Builder Runtime Packages
- Class Hierarchy
- Index of All
Fields and Methods