Technical Resources at AEGIS

PowerBuilder Tips

Using the Enter Key to Tab through a DataWindow

Tip By: Mike Barlotta

Have you ever had to develop an application that was data entry intensive and the users insist that the enter key move them along from field to field. Usually users require this feature because it is what they are used to or because of the position of the enter and tab keys on the keyboard itself. An easy way to accomplish this is to simulate the pressing of the tab key whenever the user hits the enter key by simply posting a message to the windows que. Post is a Powerscript function that adds a message to the message queue for a window. Although not spelled out in the help it also can add messages for controls, including datawindows. By sending the message WM_KEYDOWN (9) with the Virtual Key code for the Tab key (256) we achieve the desired result.

In the datawindow, declare an event mapped to pbm_dwnprocessenter in your datawindow and add the following line of code:

Post( Handle(this),256,9,0 )
Return 1

This technique also works well on window controls, such as moving between single line edits. By mapping an event to pbm_keydown and placing the following lines of code.

IF key = KeyEnter! THEN
  Post(Handle(this), 256,9,0)
END IF

This last tip does not work well with buttons since the hitting of the Enter key actually triggers the clicked event on the button when it is the default button. However placing this code in the clicked event alleviates that problem. Note that the button still needs a pbm_keydown event as noted above if it is not a default button to process the enter as a tab.

IF KeyDown(KeyEnter!) THEN
	Post(Handle(this), 256, 9 ,0)
	RETURN 0
END IF

You can use the Send() function in place of the Post() function, both seem to work well. Try to persuade users against this if possible and se this tip only as a last resort since changing default behaviors can cause side effects