CursorDeviceMoveTo() is missing in Carbon

[Taxxodium]

Perhaps that is old news but I just found out that the function CursorDeviceMoveTo (which apparently move the cursor to another location) is not carbonized. Does anyone know a replacement or a trick to get the same feature in Carbon?

[Tobi]

Right, that is a painful problem. There is no Carbon API that moves the cursor to another position.
The only method to have the cursor moved in Carbon is by using InterfaceLib in case the app is running in OS 9 and the CoreGraphics DirectDisplay API in case running in OS X.

You must import the symbols directly your code because you cannot link to the needed libraries directly.

Use the GetSharedLibrary() / FindSymbol technique to link to the CursorDeviceMoveTo() function in case you are in OS 9 and some sort of LoadFrameworkBundle() if you are in X.
To do this you need a function which checks what system you are running in and determines the function to load.

Apple has sample code for exactly this problem, but I can't find it at the moment.
You can also try the GLUT command glutWarpPointer()

I hope this helps a bit.

-Tobi

[ylaporte]

I don't know if these are part of the carbon API (They are available on OSX) but there are a few places where you can find interesting things such as this:
http://developer.apple.com/technotes/tn/tn2007.html

of course the interesting section is controlling the mouse cursor...

[Tobi]

OK, it seems that you have not found a solution to the problem yet so I'm willing to give you my code for this. I also spend endless hours to find this code and modify it to my needs. It's from Apple sample code. The first is a function RunningOnCarbonX() that checks if the app is run in Mac OS X or a classic system. The second function ImportCursorRoutines() must be placed somewhere in your game's init. The last function SetCursorPosition() actually moves the cursor to a given position.
Please let me know if this works for you, or if you get any compile or link errors.
Good luck!

-Tobi


////// Some global variables //////
CursorDevicePtr gCursorDevice;//for classic only.
//OS 9 cursor stuff
typedef CALLBACK_API_C( void , CreateCursor )(CursorDevicePtr *theDevice);
typedef CALLBACK_API_C( void , MoveCursor )(CursorDevicePtr ourDevice, long absX, long absY);
CreateCursor CreateCursorFunction = nil;
MoveCursor MoveCursorFunction=nil;

///OS X cursor stuff
typedef UInt32 (*CGWarpMouseCursorPositionProcPtr)(CGPoint newCursorPosition);
typedef UInt32 (*CGSetLocalEventsSuppressionIntervalProcPtr)(doub le pSeconds);
static CGWarpMouseCursorPositionProcPtr sCGWarpMouseCursorPositionProcPtr = nil;


static Boolean RunningOnCarbonX(void)
{
static Boolean first = true;
static Boolean result = false;

if (first)
{
UInt32 response;

first = false;

result = (Gestalt(gestaltSystemVersion,
(SInt32 *) &response) == noErr)
&& (response >= 0x01000);

}
return result;
}



void ImportCursorRoutines()
{
OSErr err, anErr;
CFragConnectionID connID=kInvalidID;
CFragSymbolClass symClass;
Ptr mainAddr=nil;
Str255 errName;

if (RunningOnCarbonX())
{
if (nil == sCGWarpMouseCursorPositionProcPtr)
{
CFBundleRef tCFBundleRef;
anErr=LoadFrameworkBundle(CFSTR("ApplicationServices.framework"), &tCFBundleRef);

if (noErr == anErr)
{
CGSetLocalEventsSuppressionIntervalProcPtr tCGSetLocalEventsSuppressionIntervalProcPtr = nil;

sCGWarpMouseCursorPositionProcPtr = (CGWarpMouseCursorPositionProcPtr)
CFBundleGetFunctionPointerForName( tCFBundleRef, CFSTR("CGWarpMouseCursorPosition") );
if (nil == sCGWarpMouseCursorPositionProcPtr)
anErr = cfragNoSymbolErr;

tCGSetLocalEventsSuppressionIntervalProcPtr = (CGSetLocalEventsSuppressionIntervalProcPtr)
CFBundleGetFunctionPointerForName(tCFBundleRef,CFS TR("CGSetLocalEventsSuppressionInterval"));
if (nil != tCGSetLocalEventsSuppressionIntervalProcPtr)
(*tCGSetLocalEventsSuppressionIntervalProcPtr)(0.0 f);
}
}
}
else
{
err=GetSharedLibrary("\pInterfaceLib", kPowerPCCFragArch, kImportLibraryCFrag, &connID, &mainAddr, errName);
err=FindSymbol(connID, "\pCrsrDevNewDevice", (Ptr *) &CreateCursorFunction, &symClass);
(*CreateCursorFunction)(&gCursorDevice);
err=FindSymbol(connID, "\pCrsrDevMoveTo", (Ptr *) &MoveCursorFunction, &symClass);
}
}

void SetCursorPosition(int x, int y)
{
if (!RunningOnCarbonX())
{
(*MoveCursorFunction)(gCursorDevice, startLoc.h, startLoc.v);
}
else
{
CGPoint mouseLoc;

mouseLoc.x=x;
mouseLoc.y=y;
(*sCGWarpMouseCursorPositionProcPtr)(mouseLoc);
}
}