TComboBox with csOwnerDrawFixed and right aligned text

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2 total messages Started by Ami Halperin Thu, 05 Jun 2008 10:43

#229

Author: Ami Halperin
Date: Thu, 05 Jun 2008 10:43

34 lines
2147 bytes

Hi,
I have implemented a TComboBox with style set csOwnerDrawFixed, It was done 
to set the Font of the items without changing the height of the combo (Is 
there a different way?).
On DrawItem we draw the text to fit bidimode of right aligned languages:
procedure TBiDiComboBox.OnDrawItem(Control: TWinControl; Index: Integer;
  Rect: TRect; State: TOwnerDrawState);
var
   x   : Integer;
   txt : String;
begin
  Canvas.FillRect(Rect) ;
  if BiDiMode = bdRightToLeft then
  begin
    // align the text to the right
    txt := Items[Index];
    x := Rect.Right - Canvas.TextWidth(txt) - 4;
    Canvas.TextOut(x, Rect.Top, txt);
  end
  else
  begin
    if Index >= 0 then
      Canvas.TextOut(Rect.Left + 2, Rect.Top, Items[Index]);
  end;
end;

The problem is that on some computers it works fine but on others when you 
first drop down the list you see only the left side of the items drawn on 
the right side.
After you go over the items with the mouse it works fine.
Do you know of a way to fix it? Is it because of the ComCtl32.dll version?

Thanks in advance,
Chaim

Re: TComboBox with csOwnerDrawFixed and right aligned text

#230

Author: Remy Lebeau (TeamB)
Date: Thu, 05 Jun 2008 18:54

27 lines
1809 bytes

"Ami Halperin" <Ami_h@mer.co.il> wrote in message 
news:4847b55c@newsgroups.borland.com...

> On DrawItem we draw the text to fit bidimode of right aligned languages:
<snip>

I would suggest changing your drawing code to use the Win32 API DrawText() 
function instead.  TControl has a DrawTextBiDiModeFlags() method.  For 
example:

    procedure TBiDiComboBox.DrawItem(Index: Integer; Rect: TRect; State: 
TOwnerDrawState);
    var
        txt : String;
        Flags: Longint;
    begin
        Canvas.FillRect(Rect) ;
        txt := Items[Index];
        Flags := DrawTextBiDiModeFlags(DT_SINGLELINE or DT_VCENTER or 
DT_NOPREFIX);
        Windows.DrawText(Canvas.Handle, PChar(txt), Length(txt), Rect, 
Flags);
    end;


Gambit

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