Hi everyone,
I'm subclassing a TCustomComboBox to display tabular info, using
TabbedTextOut. (a TTabComboBox).
With Win98 items can be right aligned against the tabstop by passing a
negative value in the TabArray.
I need to detect, in the DropDown event of the ComboBox, if a Vertical
ScrollBar will be visible so I can increase the DropDown width by the width
of the VScrollBar to stop clipping of the items captions that are right
aligned.
I thought this would work:
procedure TTabComboBox.DropDown(Sender: TObject);
var
nScrollBarWidth: integer;
begin
//get the width of a VScrollBar...
nScrollBarWidth := GetSystemMetrics(SM_CXVSCROLL)
//if VScrollBar is visible increase thedropdown width...
if (GetWindowLong(Handle, GWL_STYLE) and WS_VSCROLL) <> 0 then
Perform(CB_SETDROPPEDWIDTH, Abs(LongestTab) + nMargin, 0)
else
Perform(CB_SETDROPPEDWIDTH, Abs(LongestTab) + nScrollBarWidth +
nMargin, 0)
end;
but it doesn't! The DropDownWidth is set from LongestTab OK, but the
GetWindowLong call always returns 0 whether the vertical ScrollBar is
visible or not.
Any pointers on how to do this would be greatly appreciated.
I'm using Delphi 6.240 and WIN 98SE.
Regards,
Dave Atkin
