Is there a control like TGraphicControl with Handle ?

[sainimu78]

On windows the Handle is a HWND.

I create a gl render context using a third party library. It is ok with TWinControl.Handle, but TWinControl will erase my painted context because DoubleBuffered = False doesn't work when the globel var ThemeService with ThemeEnabled, here is the code lazarus\lcl\interfaces\win32\win32callback.inc, SendPaintMessage

Code: Pascal  [Select][+][-]

1.   // check if double buffering is requested
2.   useDoubleBuffer := (ControlDC = 0) and (lWinControl.DoubleBuffered or ThemeServices.ThemesEnabled);
3.  

I can use TGraphicControl to paint completely by myself,  but it has no Handle.

[Thaddy]

TOpenGLCanvas maybe?

[sainimu78]

TOpenGLCanvas maybe?

Not just support gl in my case.
I want a control of LCL that has Handle and can be painted completely by myself.

I know how TOpenGLCanvas works, maybe I can modify it to meet my reqirement, but I rather use LCL because LCL has an official team supporting.

I add a Boolean switch UseWinControlCustomPaint to TWinControl
Is this good ? Will I make a feature request with the patch to bugtracker?

in lazarus\lcl\interfaces\win32\win32callback.inc, SendPaintMessage,

Code: Pascal  [Select][+][-]

1.   if(ControlDC = 0)and(lWinControl.UseWinControlCustomPaint = True)then
2.   begin
3.     DC := Windows.BeginPaint(Window, @PS);
4.     PaintMsg.Msg := LM_PAINT;
5.     PaintMsg.PaintStruct := @PS;
6.     PaintMsg.DC := DC;
7.     DeliverMessage(lWinControl, PaintMsg);
8.     Windows.EndPaint(Window, @PS);
9.     Exit;
10.   end;
11.  

[Thaddy]

You really want to mix two completely different paint engines? (GDI and OGL) Then simply assign the OpenGLCanvas to the window where you need it. Under Windows that has a THandle/Hwnd.

[sainimu78]

You really want to mix two completely different paint engines? (GDI and OGL) Then simply assign the OpenGLCanvas to the window where you need it. Under Windows that has a THandle/Hwnd.

You mean TOpenGLControl instead ?
Oh no, it desn't sound so easy, I think I should override so many functions of it.

So no such control in LCL, maybe I should commit the patch and see what they say.

[Thaddy]

I really do not see where you have to override anything? Really?! Of course not.
Show us some code?
BTW: SDL can also play accelerated in a window, may be that's an option for you.

[sainimu78]

You'r right, there is nothing to be overridden, but it works not expectly, triggering 3 times OnResize on showing up. I should override SetBounds

I simply want to create native windows and native controls and do message loop, SDL is not enough.

[jamie]

Have you looked at the TCustomControl?

 You can create your own TWinControl and handle a lot of the messaging.

[sainimu78]

Have you looked at the TCustomControl?

 You can create your own TWinControl and handle a lot of the messaging.

Year, it is almost the same as TWinControl in my case and it will erase my painted context too due to double buffering in SendPaintMessage

[jamie]

You need to override the paint handler, its that simple..

Return it as handled to the OS so it does not attempt any more processing..

As for the WM_ERASEBKKGRD you can handle that too, just add a message handler for it and
return it as handled, don't be calling any inherited methods..