*****************************************************************
* Neveprise Inc. Delphi FAQ					*
*****************************************************************
* Section: Desktop		Topic:   Changing taskbar props	*
* Created: July 26th, 1999	Revised: July 27th, 1999 	*
* Updates: www.neveprise.de	Info:	 support@neveprise.de	*
*****************************************************************

Q: How can I change the properties of the Windows taskbar?

A: There is not very much to change, as far as I know. However, you
	can change the buttons / icons that represent running apps.
	This includes default width and gaps between'em. The other
	things to change are Window tracing (the animation effect
	happening when mini- or maximizing apps - normally you set
	this property under Settings|Taskbar) as well as hiding or
	disabling the startbutton (well, it is more a gag than usefull).
	The function below can also be used just to get info on these
	properties.
	To explain the function: the type TTaskBarCommand indicates
	what you want the function to do, Switch (boolean) defines
	if you want to enable or disble something, Metric (word) is
	used for setting width or gap, and the result is width or gap
	in pixels if you call the FUnction width tbGetIconGap or
	tbGetIconWidth. In all other cases, it returns a pseudo-boolean
	to tell if the function was successfull, e.g. 1 equals true,
	0 equals false.

interface 

type TTaskBarCommand = (
	tbSetIconWidth, //metrics of app' icons
	tbSetIconGap,
	tbGetIconWidth,
	tbGetIconGap,
	tbSetWindowTracing, //animation on window resize
	tbGetWindowTracing,
	tbHideStartButton, //nice gag: hide the startbutton
	tbDisableStartButton

);

implementation

function TaskBarH(Command: TTaskBarCommand; Switch: boolean; Metric:word): word;
var hWnd:  THandle;
    Reg:   TRegIniFile; //we use it cos one command does not work right...:-(
    mRect: TMinimizedMetrics; 
    TAI:   TAnimationInfo;
    Rgn:   hRgn; //similar to TRect (^PRect)
begin
Result:=0;
Reg:=TRegIniFile.Create('');
Reg.RootKey:=HKEY_CURRENT_USER;
if Command=tbSetIconWidth then begin //we want to set default width of buttons
   mRect.cbSize:=SizeOf(mRect); //init record
   mRect.iWidth:=Metric; //fill the right parameter with info
   if SystemParametersInfo(SPI_SetMinimizedMetrics, SizeOf(mRect),@mRect,SPIF_UpdateIniFile)=true then Result:=1 else Result:=0; //and set
end;
if Command=tbSetIconGap then begin //we want to set distances between buttons
   mRect.cbSize:=SizeOf(mRect); //init record
   mRect.iHorzGap:=Metric; //fill it with our values
   mRect.iVertGap:=Metric;
   if SystemParametersInfo(SPI_SetMinimizedMetrics, SizeOf(mRect),@mRect,SPIF_UpdateIniFile)=true then Result:=1 else Result:=0; //and set'em
end;
if Command=tbGetIconWidth then begin //retrieves button;s width
   mRect.cbSize:=SizeOf(mRect); //init record
   SystemParametersInfo(SPI_GetMinimizedMetrics, SizeOf(mRect),@mRect,SPIF_SendWinIniChange); //fill it
   Result:=mRect.iWidth; //return result
end;
if Command=tbGetIconGap then begin //retrieve distance between buttons
   mRect.cbSize:=SizeOf(mRect);
   SystemParametersInfo(SPI_GetMinimizedMetrics, SizeOf(mRect),@mRect,SPIF_SendWinIniChange);
   Result:=mRect.iHorzGap;
end;
if Command=tbSetWindowTracing then begin //we want to set window animation
//the following code is commented out, although it should work; but in fact it
//does not, so we write into the Registry
//   TAI.cbSize:=SizeOf(TAI);
//   if Switch=true then TAI.iMinAnimate:=0 else TAI.iMinAnimate:=1;
//   TAI.cbSize:=SizeOf(TAI);
//   if SystemParametersInfo(SPI_GetAnimation,0,@TAI,SPIF_UpdateIniFile)=true then Result:=1 else Result:=0;
   Reg.WriteBool('\Control Panel\Desktop','DragFullWindows',Switch); //switch tells if on/off
   Result:=1;
end;
if Command=tbGetWindowTracing then begin //we want to know, if window animation is on
   TAI.cbSize:=SizeOf(TAi); //init record
   SystemParametersInfo(SPI_SetAnimation,0,@TAI,0); //fill TAI with values
   if TAI.iMinAnimate>0 then Result:=1 else Result:=0; //return pseudo-bool as result
   //above: if iMinAnimate>0 then animation is on
end;
if Command=tbHideStartButton then begin //we want to hide or show the start button (switch decides what we do)
   Rgn:= CreateRectRgn(0,0,0,0); //set button's dimensions: none
   if Switch=true then SetWindowRgn(FindWindowEx(FindWindow('Shell_TrayWnd',nil),0,'Button',nil),Rgn,true) //size the button to null
      else SetWindowRgn(FindWindowEx(FindWindow('Shell_TrayWnd',nil),0,'Button',nil),0,true); //no, we want it back
end;
if Command=tbDisableStartButton then begin //we want to enable or disable the start button (and switch decides)
   Rgn:= CreateRectRgn(0,0,0,0); //nil doesn't work, so we make a dummy
   if Switch=true then EnableWindow(FindWindowEx(FindWindow('Shell_TrayWnd',nil),0,'Button',nil),false) //we disable it
      else EnableWindow(FindWindowEx(FindWindow('Shell_TrayWnd',nil),0,'Button',nil),true); //we enable it
end;
Reg.free;
end;



	Blazko