Java Programmer's Guide and Reference

Telephony beans example

This section provides a step-by-step example to show you how to create a desktop softphone with Dial, Answer, and Hangup buttons using telephony beans and a visual builder.

The example includes IBM VisualAge^(TM) for Java illustrations, but you can use any visual builder that supports JavaBeans (the connections you make and the properties you set are similar regardless of the visual application builder tool you use).

Step 1: Add a CPLineResource

• Place a CPLineResource, which represents a single telephone line, near the bottom of your visual builder work area.
• Specify the CPLineResource properties, such as address, terminal, and user information. (After the application is created, you can change these parameters while the application is running.)

This step is illustrated in Figure 7.

Figure 7. Add a CPLineResource

Step 2: Start the CPLineResource

• Connect the start() event of the application to the start() method of the CPLineResource.
• If you are using the VisualAge for Java visual builder, you must make an "offscreen" connection from the nonvisual portion of the workspace to the CPLineResource. Click Show Expert Features to expose the start() event. Connect this to the start() method of CPLineResource.

This step is illustrated in Figure 8.

Figure 8. Start the CPLineResource

Step 3: Add the Telephony Action beans

• Add the MakeCall, AnswerCall, and DisconnectCall Action beans to the visual builder work area. (These Action beans represent the Dial, Answer, and Hangup button functions.)
• Associate the Action beans with the CPLineResource bean by doing the following:
  • Connect the lineResourceDataInitialized event of the CPLineResource bean to the associate method of the Action bean.
  • Choose the associate method that accepts the LineResourceDataEvent class as a parameter. VisualAge for Java users will then have to double-click on the connection and check the Pass Event Data check box in order to pass the LineResourceDataEvent in as a parameter. Doing this will change the connection from a dotted line to a solid line, indicating that the parameter is being passed in.

This step is illustrated in Figure 9.

Figure 9. Add the Telephony Action beans

Step 4: Add visible controls

• Add the Dial, Answer, and Hangup buttons
• Add a Number entry field
• Add the title of the application

This step is illustrated in Figure 10.

Figure 10. Add visible controls

Step 5: Connect visible controls to model

• Connect the actionPerformed event from each button (Dial, Answer, and Hangup) to the action() method of the corresponding button's invisible bean. This enables the action to be performed whenever the user clicks the button.
• Connect the textValueChanged event of the entry field to the destination property of the MakeCall bean.
• Connect the text property of the entry field to the value property of the connection. This ensures that whatever the user types into the entry field will also be set in the destination property of the bean.

This step is illustrated in Figure 11.

Figure 11. Connect visible controls to model

Step 6: Set the enable and disable states of buttons

• Connect the MakeCall bean's actionAdvancedEnabled event to the Dial button's setEnabled(boolean enableFlag) method. (In this case, enable the button, edit the connection, and set the parameter to true.)
• Connect the MakeCall bean's actionEnabled event to the Dial button's setEnabled(boolean enableFlag) method. (In this case, you want to enable the button; edit the connection and set the parameter to true.)
• Connect the MakeCall bean's actionDisabled event to the Dial button's setEnabled(boolean enableFlag) method. (In this case, you want to disable the button; edit the connection and set the parameter to false.)
• Connect the MakeCall bean's actionPermanentDisabled event to the Dial button's setEnabled(boolean enableFlag) method. (In this case, you want to disable the button; edit the connection and set the parameter to false.)
• Connect the AnswerCall bean to the Answer button and connect the DisconnectCall bean to the Hangup button by following the procedure for the MakeCall bean.

Step 7: Compile the code and test your application

Figure 12 illustrates the completed application. Generate the code using your visual builder and test your application.

Figure 12. Compile the code and test your application