BUG: GotFocus() Sets Commandbutton Default to Initial Setting

MORE INFORMATION

A command button with a Default property set to .T., appears with a darkened border. It also responds as if clicked when you press the ENTER key when focus is on another control, such as a text box.

Steps to Reproduce Behavior

1. Run the following code from a program (.prg) file:

               PUBLIC oForm1
         oForm1=CREATEOBJECT("form1")
         oForm1.Show
   
         DEFINE CLASS Form1 AS form
            AutoCenter = .T.
            Height = 252
            Width = 326
            Name = "Form1"
   
            ADD OBJECT Text1 AS textbox WITH ;
               Height = 23, ;
               Left = 36, ;
               Top = 24, ;
               Width = 100, ;
               Name = "Text1"
   
            ADD OBJECT Command1 AS commandbutton WITH ;
               Top = 24, ;
               Left = 204, ;
               Height = 27, ;
               Width = 84, ;
               TabStop = .F., ;
               Name = "Command1", ;
               Default = .T.
   
            ADD OBJECT Command2 AS commandbutton WITH ;
               Top = 72, ;
               Left = 204, ;
               Height = 27, ;
               Width = 84, ;
               TabStop = .F., ;
               Name = "Command2"
   
            ADD OBJECT Edit1 AS editbox WITH ;
               Height = 49, ;
               Left = 48, ;
               Top = 192, ;
               Width = 216, ;
               Name = "Edit1"
   
            PROCEDURE Text1.LostFocus
               ThisForm.Command1.default = .T.
            ENDPROC
   
            PROCEDURE Edit1.LostFocus
               ThisForm.Command2.default = .T.
            ENDPROC
   
         ENDDEFINE

2. Tab through the text box and edit box.

Command1 remains the default command button. The property is actually set, but a reset to the original default occurs in the intrinsic GotFocus behavior for all Visual FoxPro controls.

This following program demonstrates this behavior. You issue a GotFocus() in the GotFocus() event for the text box and edit box, to cause the intrinsic behavior to occur, then you set the default button. In this case, the default button actually changes.

Sample Code

      PUBLIC oForm1
      oForm1=CREATEOBJECT("form1")
      oForm1.Show

      DEFINE CLASS Form1 AS form
         AutoCenter = .T.
         Height = 252
         Width = 326
         Name = "Form1"

         ADD OBJECT Text1 AS textbox WITH ;
            Height = 23, ;
            Left = 36, ;
            Top = 24, ;
            Width = 100, ;
            Name = "Text1"

         ADD OBJECT Command1 AS commandbutton WITH ;
            Top = 24, ;
            Left = 204, ;
            Height = 27, ;
            Width = 84, ;
            TabStop = .F., ;
            Name = "Command1", ;
            Default = .T.

         ADD OBJECT Command2 AS commandbutton WITH ;
            Top = 72, ;
            Left = 204, ;
            Height = 27, ;
            Width = 84, ;
            TabStop = .F., ;
            Name = "Command2"

         ADD OBJECT Edit1 AS editbox WITH ;
            Height = 49, ;
            Left = 48, ;
            Top = 192, ;
            Width = 216, ;
            Name = "Edit1"

         PROCEDURE text1.GotFocus
            DoDefault()
            ThisForm.Command1.default = .T.
         ENDPROC

         PROCEDURE edit1.GotFocus
            DoDefault()
            ThisForm.Command2.default = .T.
         ENDPROC
      ENDDEFINE
				

A potential workaround, which is likely to be difficult to implement, would be to use code like the preceding code to manage your default command buttons. Keep in mind that the intrinsic GotFocus behavior does the reset, so the GotFocus() event for all controls, even those which do not set a command button to default, causes the reset to occur. A workaround would involve adding code to all control's GotFocus() method to find and store the current default button, issue a DoDefault(), and restore the correct default button. However, the DoDefault() function only works in Visual FoxPro 5.0 and later versions.

Code similar to the following could be added to the GotFocus() method for all controls on a form for a workaround:

Sample Code

   LOCAL loDefaultButton, lni
   WITH thisform
      FOR lni = 1 to .Controlcount
         IF .Controls(lni).Baseclass = 'Commandbutton' ;
               and .Controls(lni).Default = .t.
            loDefaultButton = .Controls(lni)
         ENDIF
      ENDFOR
   ENDWITH
   DoDefault()
   IF type('loDefaultButton') = "O"
      loDefaultButton.Default = .t.
   ENDIF
				

Note that this assumes that any default command buttons are directly on the form, and not in a non-form container such as a container or page. It fails to find a command button not directly on the form.