red dot in the listbox

[xinyiman]

Who tells me how to draw a colored dot at the beginning of each row of a listbox? Just as well a square. Just that I can put the color at the beginning of the item. Accepted cross-platform solutions

[molly]

http://lazarus-ccr.sourceforge.net/docs/lcl/stdctrls/tcustomlistbox.ondrawitem.html

[engkin]

Basic example:

Code: Pascal  [Select][+][-]

1. procedure TForm1.ListBox1DrawItem(Control: TWinControl; Index: Integer;
2.   ARect: TRect; State: TOwnerDrawState);
3. var
4.   LB: TListBox;
5.   tmpStyle: TTextStyle;
6.   BRect: TRect;
7.   VCenter: LongInt;
8. begin
9.   if not (Control is TListBox) then
10.     exit;
11.   LB := TListBox(Control);
12.   with LB.Canvas do
13.   begin
14.     { Fill the background }
15.     if (odSelected in State) then
16.       Brush.Color := clLime
17.     else
18.       Brush.Color := LB.Color;
19.     FillRect(ARect);
20.  
21.     { Draw a red rectangle }
22.     VCenter := (ARect.Bottom+ARect.Top) div 2;
23.     BRect := Bounds(ARect.Left+2, VCenter-4, 4, 4);
24.     Brush.Color := clRed;
25.     FillRect(BRect);
26.     { Draw a blue rectangle }
27.     BRect := Bounds(ARect.Left+6, VCenter, 4, 4);
28.     Brush.Color := clBlue;
29.     FillRect(BRect);
30.  
31.     { Draw the text }
32.     Font.Color := clNavy; { or clWindowText }
33.     tmpStyle := TextStyle;
34.     tmpStyle.Layout := tlCenter; { Center the text vertically }
35.     tmpStyle.Opaque := False;  { Leave the background intact }
36.     TextRect(ARect, ARect.Left+2+4+4+2, ARect.Top, LB.Items[Index], tmpStyle);
37.   end;
38. end;
39.  

[xinyiman]

It does not work on mac

[balazsszekely]

@xinyiman
It does! I can make a screenshot if you like. 

[xinyiman]

attach source . because one does not do me

[balazsszekely]

@xinyiman
attach source . because one does not do me

What source? @engkin already provided the source. Add lcltype to the uses clauses and set listbox style property to lbOwnerDrawFixed.

[xinyiman]

you're right, I had forgotten to set the property .

lbOwnerDrawFixed

I am just stupid one. Thank you all

[xinyiman]

a curiosity , if I wanted to do the same thing on a combobox I have to make some changes and in theory I just copy and paste the code into the combobox making sure to change TListBox with TComboBox

[balazsszekely]

@xinyiman
a curiosity , if I wanted to do the same thing on a combobox I have to make some changes and in theory I just copy and paste the code into the combobox making sure to change TListBox with TComboBox

Under OSX the TComboBox OnDrawItems event is never called, so it won't work: http://forum.lazarus.freepascal.org/index.php/topic,32104.msg206679.html#msg206679

[xinyiman]

Ok, thank you