TGroupBox WMPaint ...

[Espectr0]

Hola!

a question, why when I override WMPaint msg of the TGroupBox when painting (fillrect for example) not occupy all the real space?
In the image I show on the left with override and on the right without.

how can I solve it?

Thanks

[jamie]

may have something to do with the widget that currently paints the area to fix some issue of colors not being correct for the caption of the Group Box.

 Also, there could be a ClipRect attached to the control.
etc.

 Hard to say. Maybe you should show a short piece of your code where you are doing this, you may need to allow the inherited paint first then you can over paint that.

[Espectr0]

I tried leaving the "inherited" but it doesn't look complete either, just the "client" part let's say...
I put basic code to show:

Code: Pascal  [Select][+][-]

1. procedure TMyGroupBox.WMPaint(var Msg: TLMPaint);
2. var
3.   ACanvas: TCanvas;
4. begin
5.   inherited;
6.  
7.   ACanvas := TCanvas.Create;
8.   try
9.     ACanvas.Handle := Msg.DC;
10.     ACanvas.Brush.Color := clRed;
11.     ACanvas.FillRect(0, 0, self.width, self.height);
12.   finally
13.     ReleaseDC(0, ACanvas.Handle);
14.     ACanvas.Free;
15.   end;
16. end;
17.  

[Thaddy]

Assuming you are on Windows, you must also implement WM_NCPAINT.

[KodeZwerg]

Not tested but my guess is, that than you have same result as just setting color the normal way (upper bevel will not be the actual clientrect that he wants to color)

[lainz]

Use a TPanel and play with ChildSizing to get the same behaviour as GroupBox. Tpanel can be fully painted.

[Espectr0]

Added the message @Thaddy recommended but i can't get it to work :S

[Espectr0]

Using the Subclass technique I was able to paint as I want:

Code: Pascal  [Select][+][-]

1. unit UWGroupBox;
2.  
3. //------------------------------------------------------------------------------
4.  
5. {$mode ObjFPC}{$H+}
6.  
7. interface
8.  
9. uses
10.   Classes, Controls, SysUtils, Graphics, StdCtrls, LCLType, LMessages, LCLIntf,
11.   LazarusPackageIntf, Types;
12.  
13. type
14.  
15.   { TUWGroupBox }
16.  
17.   TUWGroupBox = class(TGroupBox)
18.   {$IFDEF WINDOWS}
19.   private
20.     FOwnerDraw: Boolean;
21.     procedure SetOwnerDraw(const AValue: Boolean);
22.   public
23.     constructor Create(TheOwner: TComponent); override;
24.   {$ENDIF}
25.   published
26.     {$IFDEF WINDOWS}
27.     property OwnerDraw: Boolean read FOwnerDraw write SetOwnerDraw;
28.     {$ENDIF}
29.     property Align;
30.     property Anchors;
31.     property AutoSize;
32.     property BidiMode;
33.     property BorderSpacing;
34.     property Caption;
35.     property ChildSizing;
36.     property ClientHeight;
37.     property ClientWidth;
38.     property Color;
39.     property Constraints;
40.     property DockSite;
41.     property DoubleBuffered;
42.     property DragCursor;
43.     property DragKind;
44.     property DragMode;
45.     property Enabled;
46.     property Font;
47.     property ParentBackground;
48.     property ParentBidiMode;
49.     property ParentColor;
50.     property ParentDoubleBuffered;
51.     property ParentFont;
52.     property ParentShowHint;
53.     property PopupMenu;
54.     property ShowHint;
55.     property TabOrder;
56.     property TabStop;
57.     property Visible;
58.     property OnChangeBounds;
59.     property OnClick;
60.     property OnContextPopup;
61.     property OnDblClick;
62.     property OnDragDrop;
63.     property OnDockDrop;
64.     property OnDockOver;
65.     property OnDragOver;
66.     property OnEndDock;
67.     property OnEndDrag;
68.     property OnEnter;
69.     property OnExit;
70.     property OnGetSiteInfo;
71.     property OnKeyDown;
72.     property OnKeyPress;
73.     property OnKeyUp;
74.     property OnMouseDown;
75.     property OnMouseEnter;
76.     property OnMouseLeave;
77.     property OnMouseMove;
78.     property OnMouseUp;
79.     property OnMouseWheel;
80.     property OnMouseWheelDown;
81.     property OnMouseWheelUp;
82.     property OnResize;
83.     property OnStartDock;
84.     property OnStartDrag;
85.     property OnUnDock;
86.     property OnUTF8KeyPress;
87.   end;
88.  
89. // -----------------------------------------------------------------------------
90.  
91. implementation
92.  
93. {$IFDEF WINDOWS}
94. uses
95.   Windows, CommCtrl, Themes;
96.  
97. const
98.   ID_UWGROUPBOX = 1;
99.   TEXT_MARGIN   = 8;
100.  
101. //------------------------------------------------------------------------------
102.  
103. { UWGroupBox }
104.  
105. //------------------------------------------------------------------------------
106.  
107. function NewWndProc(Wnd: HWND; uMsg: UINT; wParam: WPARAM; lParam: LPARAM; uISubClass: UINT_PTR; dwRefData: DWORD_PTR): LRESULT; stdcall;
108. var
109.   AGroupBox: TUWGroupBox absolute dwRefData;
110.   ACanvas: TCanvas;
111.   DC: HDC;
112.   PS: PAINTSTRUCT;
113.   R: TRect;
114.   CaptionRect,
115.   OuterRect: TRect;
116.   Box: TThemedButton;
117.   Details: TThemedElementDetails;
118.   ATextStyle: TTextStyle;
119.   fw, fh: Integer;
120. begin
121.   case uMsg of
122.     //WM_NCPAINT,
123.     WM_PAINT:
124.     begin
125.       DC := BeginPaint(Wnd, @PS);
126.       try
127.         ACanvas := TCanvas.Create;
128.         try
129.           with ACanvas do
130.           begin
131.             Handle      := DC;
132.             Brush.Style := bsClear;
133.             Font        := AGroupBox.Font;
134.             Brush.Color := AGroupBox.Color;
135.             FillRect(PS.rcPaint);
136.             Font.GetTextSize(AGroupBox.Caption, fw, fh);
137.  
138.             if AGroupBox.Caption <> '' then
139.             begin
140.               CaptionRect := Types.Rect(0, 0, fw, fh);
141.               OffsetRect(CaptionRect, TEXT_MARGIN, 0)
142.             end
143.             else
144.               CaptionRect := Types.Rect(0, 0, 0, 0);
145.  
146.             OuterRect     := PS.rcPaint;
147.             OuterRect.Top := (CaptionRect.Bottom-CaptionRect.Top) div 2;
148.  
149.             with CaptionRect do
150.               ExcludeClipRect(Handle, Left, Top, Right, Bottom);
151.  
152.             if AGroupBox.Enabled then
153.               Box := tbGroupBoxNormal
154.             else
155.               Box := tbGroupBoxDisabled;
156.  
157.             // Draw themed frame
158.             Details := ThemeServices.GetElementDetails(Box);
159.             ThemeServices.DrawElement(Handle, Details, OuterRect);
160.             SelectClipRgn(Handle, 0);
161.             // Draw caption
162.             if AGroupBox.Caption <> '' then
163.             begin
164.               R := Types.Rect(TEXT_MARGIN, 0, fw+TEXT_MARGIN, fh);
165.               FillByte(ATextStyle, SizeOf(TTextStyle), 0);
166.               with ATextStyle do
167.               begin
168.                 SingleLine  := True;
169.                 Clipping    := True;
170.               end;
171.               ACanvas.TextRect(R, R.Left, R.Top, AGroupBox.Caption, ATextStyle);
172.             end;
173.           end
174.         finally
175.           ReleaseDC(Wnd, ACanvas.Handle);
176.           ACanvas.Free;
177.         end;
178.       finally
179.         EndPaint(Wnd, @PS);
180.       end;
181.       Result:= 0;
182.     end;
183.   else
184.     Result := DefSubclassProc(Wnd, uMsg, wParam, lParam);
185.   end
186. end;
187.  
188. //------------------------------------------------------------------------------
189.  
190. constructor TUWGroupBox.Create(TheOwner: TComponent);
191. begin
192.   inherited Create(TheOwner);
193.   FOwnerDraw := False;
194. end;
195.  
196. //------------------------------------------------------------------------------
197.  
198. procedure TUWGroupBox.SetOwnerDraw(const AValue: Boolean);
199. begin
200.   if FOwnerDraw <> AValue then
201.   begin
202.     FOwnerDraw := AValue;
203.  
204.     if FOwnerDraw then
205.       SetWindowSubclass(Handle, @NewWndProc, ID_UWGROUPBOX, DWORD_PTR(Self))
206.     else
207.       RemoveWindowSubclass(Handle, @NewWndProc, ID_UWGROUPBOX);
208.  
209.     Invalidate;
210.   end;
211. end;
212. {$ENDIF}
213.  
214. // -----------------------------------------------------------------------------
215.  

but the problem I have now is that the controls inside the group type "TGraphicControl" (like TLabel) overlap them when painting (disappear)

any idea what i'm doing wrong?