How to draw Controls on canvas at linux? Or other ways to draw check box on VST

[Pixelmak]

Usually at the Windows i am using UxTheme library.

Like this

Code: Pascal  [Select][+][-]

1. procedure TxpLoginRegisterForm.GridAfterCellPaint(Sender: TBaseVirtualTree;
2.   TargetCanvas: TCanvas; Node: PVirtualNode; Column: TColumnIndex;
3.   const CellRect: TRect);
4. var
5.   r: TRect;
6.   size: TSize;
7.   h: HTHEME;
8.  
9.   data: PGridData;
10. const
11.   PADDING = 4;
12. begin
13.   if Column = IsWebColumn then
14.   begin
15.     r := CellRect;
16.  
17.     data := Grid.GetNodeData(Node);
18.     size.cx := GetSystemMetrics(SM_CXMENUCHECK);
19.     size.cy := GetSystemMetrics(SM_CYMENUCHECK);
20.  
21.     h := OpenThemeData(Sender.Handle, 'BUTTON');
22.  
23.     GetThemePartSize(h, TargetCanvas.Handle, BP_CHECKBOX, CBS_CHECKEDNORMAL, nil, TS_DRAW, size);
24.     r.Top    := CellRect.Top + (CellRect.Bottom - CellRect.Top - size.cy) div 2;
25.     r.Bottom := r.Top + size.cy;
26.     r.Left   := r.Left + PADDING;
27.     r.Right  := r.Left + size.cx;
28.  
29.     if data^.IsWeb=1 then
30.       DrawThemeBackground(h, TargetCanvas.Handle, BP_CHECKBOX, CBS_CHECKEDNORMAL, r, nil)
31.     else
32.       DrawThemeBackground(h, TargetCanvas.Handle, BP_CHECKBOX, CBS_UNCHECKEDNORMAL, r, nil);
33.  
34.     CloseThemeData(h);
35.   end;
36. end;
37.  

Is there a way to do the same for Linux? Or other ways to draw a checkbox?

[wp]

Checkbox theme drawing should be active in VTV by default (CheckImageKind = dkSystemDefault), AFIK there is no need to draw checkbox manually for this purpose.

In general, theme support is handled in the LCL in a cross-platform way by the unit "themes" and the ThemeServices methods.

[Pixelmak]

Checkbox theme drawing should be active in VTV by default (CheckImageKind = dkSystemDefault), AFIK there is no need to draw checkbox manually for this purpose.

I am using TVirtualStringTree where I have many columns, in each of which I need to draw a checkbox. But "CheckImageKind" adds a checkbox only to the root column.

In general, theme support is handled in the LCL in a cross-platform way by the unit "themes" and the ThemeServices methods.

Excellent! That's what I was looking for! Thank you so much!

Code: Pascal  [Select][+][-]

1. procedure TxpLoginRegisterForm.GridAfterCellPaint(Sender: TBaseVirtualTree;
2.   TargetCanvas: TCanvas; Node: PVirtualNode; Column: TColumnIndex;
3.   const CellRect: TRect);
4. var
5.   r: TRect;
6.   size: TSize;
7.   data: PGridData;
8.  
9.   Details: TThemedElementDetails;
10. const
11.   PADDING = 4;
12. begin
13.   if Column = IsWebColumn then
14.   begin
15.     r := CellRect;
16.  
17.     data := Grid.GetNodeData(Node);
18.     size.cx := GetSystemMetrics(SM_CXMENUCHECK);
19.     size.cy := GetSystemMetrics(SM_CYMENUCHECK);
20.  
21.     r.Top    := CellRect.Top + (CellRect.Bottom - CellRect.Top - size.cy) div 2;
22.     r.Bottom := r.Top + size.cy;
23.     r.Left   := r.Left + PADDING;
24.     r.Right  := r.Left + size.cx;
25.  
26.     if data^.IsWeb=1 then
27.       Details := ThemeServices.GetElementDetails(tbCheckBoxCheckedNormal)
28.     else
29.       Details := ThemeServices.GetElementDetails(tbCheckBoxUncheckedNormal);
30.  
31.     ThemeServices.DrawElement(TargetCanvas.Handle, Details, r, nil);
32.  
33.     CloseThemeData(h);
34.   end;
35. end;
36.