Sdl/OpenGl Keyboard management

[code_glitch]

Chesso: Yes, this is cross platform so windowze API is no go, especially since I don't use windowze...
User137: Yes, I am looking at doing a -32 on a-z keys automatically, but does it also work with caps, backspace and num lock?

I've had no luck at all getting it to work. So I guess there is no sdl function to do this? Or does anyone have an engine that has that functionality integrated (open source please)? I don't use lazarus so my plain fpc install wont have the VCL. My executable size is already knocking on 800k due to all the libs I'm using.

cheers,
code_glitch.

[User137]

Lazarus seems to use CN_CHAR message for onKeyPress. Look up TWinControl in controls.pas and wincontrol.inc.
TWinControl.CNChar() sends to DoKeyPress(). Seems pretty complicated process to me and there was no documentation for CN_CHAR.

Backspace is very simple... if key number is VK_BACK then text:=copy(text,1,length(text)-1);
At least if not allowing cursor moving to the middle of text, or selecting part of text. I'm afraid for graphical application all funtionality of TEdit has to be coded by self.

If you can simulate onKeyPress event by some means there is some hints from my UI class:

// note: caretPos is a property with built in limitations to value range.

procedure TUIEdit.KeyPress(c: char);
var l: integer;
begin
  if byte(c)>31 then begin
    FText:=UTF8toSys(FText);
    l:=length(FText);
    SetText(SysToUTF8(copy(FText,1,caretPos)+c+copy(FText,caretPos+1,l-caretPos)));
    caretPos:=caretPos+1;
  end;
end;

procedure TUIEdit.KeyDown(key: word; shift: TShiftState);
var l,p: integer;
begin
  l:=length(text);
  case byte(key) of
    VK_LEFT: caretPos:=caretPos-1;
    VK_RIGHT: caretPos:=caretPos+1;
    VK_HOME: caretPos:=0;
    VK_END: caretPos:=l;
    VK_DELETE:
      if (caretPos<l) and (l>0) then begin
        FText:=UTF8toSys(FText);
        SetText(SysToUTF8(copy(text,1,caretPos)+copy(text,caretPos+2,l-caretPos)));
      end;
    VK_BACK:
      if caretPos>0 then begin
        p:=caretPos; caretPos:=caretPos-1;
        FText:=UTF8toSys(FText);
        SetText(SysToUTF8(copy(text,1,p-1)+copy(text,p+1,l-p)));
      end;
    VK_RETURN: Focused:=false;
  end;
end;

[code_glitch]

Thanks for those, will start implementing it all in my code as soon as I can... A little pressed for time recently, but its nice to get all solutions done so they are ready to be implemented the next time I get some time.

[paul_nicholls]

Perhaps this SDL tutorial "Getting String Input" might help?

http://www.lazyfoo.net/SDL_tutorials/lesson23/index.php

It isn't Pascal, but should be easy to get info from

cheers,
Paul

[code_glitch]

Thanks paul, looked through and sure enough a solution for sdl to handle it automatically which is indeed very nice as it means I dont have to re-write my event handlers.

cheers for that great find.

[code_glitch]

Just for future reference let me say that the solution for this is to use SdlEvent^.Key.KeySym.Unicode rather then SdlEvent^.Key.KeySym.Sym with Sdl_EnableUnicode(1) and then using chr() and ord() as required to get special characters, upper-case, lower-case and etc...

End of line.

[paul_nicholls]

Good to know

cheers,
Paul