Defining an Event Handler

See Also

You can define event handlers using a component's property sheet or contextual menu. You can also define an event handler using the Connection wizard.

To define an event handler using the property sheet:

1. In the Component Inspector, select the Events tab in the component's property sheet.

   Alternatively, select the component in the Explorer, choose Properties from the contextual menu, and select the Events tab in the Properties window.

2. Click the value of the desired event in the list. Initially, the value for all events is <none>. When you click the value field, <none> is replaced with the default event name.
3. Enter the handler name in the property sheet or the Handlers dialog box:
   • To enter the handler name in the property sheet, press Enter to use the default handler name or type a different name and press Enter.

     After you press Enter, the code for the listener and the empty body of the handler method is generated. If you do not press Enter, no code is generated.

   • Alternatively, click the ellipsis (...) button to display the Handlers dialog box. Click the Add button to add a new handler name to the list of handlers. Click OK. The code for the listener and the empty body of the handler method is generated.
4. Add your code for the new event handler in the Source Editor.

To define an event handler using the contextual menu:

1. Right-click on a form component in the Explorer or Component Palette.
2. Choose Events from the contextual menu and move through the submenus to choose the event. The default name is given to the event handler. Bold menu items in the Events submenus indicate event handlers that have already been defined.
3. Add your code for the new event handler in the Source Editor.

If multiple events are of the same type (for example, focusGained and focusLost are both of the type java.awt.event.FocusEvent), you can use the same handler for all of them. For example, you could set both focusGained and focusLost to use the button1FocusChange handler. You can also use the same handler for the same event on multiple components.

You can set the style of how the code for component events and their handlers is generated. Choose Tools  Options. Expand the Editing node and select Form Editor Settings. Select the Expert tab on the property sheet and set the Listener Generation Style property. You can choose between the Anonymous Innerclasses, One Innerclass, and Main Class styles. See Configuring the Form Editor for a description of these options and other Form Editor Settings.