BUG: Scrollbars Disappear if Objects Placed Past Certain Length (216985)

MORE INFORMATION

By design, objects should not be placed beyond the coordinates (video resolution * 2 - object height or width) in a form.For example, if the video resolution is 800x600, then placing a command button's Top property to 1173 (600 * 2 - 27) on a form with vertical scrollbars will allow the user to scroll down the form and select that command button at run-time. If the command button's Top property is set to 1174, then the scrollbars will disappear and the command button cannot be accessed. This number is based on the vertical resolution being 600, and the height of the command button being 27.

The same situation occurs if the command button is positioned on a form with horizontal scrollbars. Setting the Left property of the command button to 1516 (800 * 2 - 84) would allow the user to scroll across the form and select the command button. Any number higher than that will make the scrollbars disappear on the form.

This can be a problem if the form is run on another computer with a lower resolution setting. For example, if a form is created on a computer with 1024x768 resolution and then run on a computer with 800x600 resolution, the scrollbars will not be visible at the lower resolution. To ensure that the scrollbars are visible at all resolutions, any objects placed on the form would have to be set to the above formula using 640x480 as the base for the video resolution.

It is not by design that the scrollbars disappear if an object is placed past these points: the scrollbars should stay active, but the user would not be able to scroll to any object that has been placed past these coordinates.

Steps to Reproduce Behavior

1. Run the following code. It creates a form with vertical and horizontal scrollbars that will have a command button in the bottom-right corner when both scrollbars are scrolled all the way down and right:

        scr_horizontal=SYSMETRIC(1) * 2 - 84 && Add one to the width or height
        scr_vertical=SYSMETRIC(2) * 2 - 27   && and the scrollbars will disappear.
        ? scr_horizontal
        ? scr_vertical
        DO get_form with scr_horizontal, scr_vertical
   
        PROCEDURE get_form
   
        PARAMETERS but_width, but_height
        PUBLIC oform1
        oform1=NEWOBJECT("form1")
        oform1.Show
        RETURN
   
        ****************************************
        DEFINE CLASS form1 AS form
                 Top = 0
                 Left = 0
                 Height = 241
                 Width = 209
                 ScrollBars = 3
                 DoCreate = .T.
                 Caption = "Form1"
                 Name = "Form1"
   
                        ADD OBJECT command1 AS commandbutton WITH ;
                               Top = 0, ;
                               Left = 0, ;
                               Height = 27, ;
                               Width = 84, ;
                               Caption = "Command1", ;
                               Name = "Command1"
   
                          PROCEDURE Init
                                Thisform.Command1.Left = but_width
                                Thisform.Command1.Top = but_height
                         ENDPROC
        ENDDEFINE
   					

2. Increase the values of either the scr_horizontal or scr_vertical variable by one (1) and note that the scrollbars disappear.