hDuplicate Inside BeginGroup EndGroup

[Assembly]

Procedure MyDuplicate;

Var

Htemp:HANDLE;

hTemp1:Handle;

BEGIN;

BeginPoly;

Moveto(0,0);

Line(100,0);

LIne(0,-100);

ENDPOLY;

Htemp:=LnewObj;

BEGINGROUP;

Htemp:=Hduplicate(Htemp,100,0);

Htemp:=Hduplicate(Htemp,100,0);

ENDGROUP;

Message(Concat('Htemp:',Htemp,' Group:',lnewobj));

END;

RUN (MyDuplicate);

This procedure returns a Nil handle to the group.

If I move the poly creation to inside the group call it works.

?.

[MullinRJ]

Justin,

???Your way should work. I think it's a bug.

This will do the same thing, without the elegance of concise code.

Procedure MyDuplicate;
Var
Boo  :Boolean;
Htemp, GrpHnd: HANDLE;
BEGIN
BEGINPOLY;
	Moveto(0, 0);
	Line(100, 0);
	LIne(0, -100);
ENDPOLY;
Htemp := LnewObj;

GrpHnd := nil;
BEGINGROUPN(GrpHnd);
	Locus(0, 0);			{ dummy object }
ENDGROUP;

Htemp := Hduplicate(Htemp, 100, 0);
Boo := SetParent(HTemp, GrpHnd);	{ move inside group }
Htemp := Hduplicate(Htemp, 100, 0);	{ dups stay in group }
DelObject(FinGroup(GrpHnd));		{ Delete locus }

Message('Htemp: ', Htemp, '   Group: ', GrpHnd);
END;
RUN (MyDuplicate);

[Miguel Barrera]

Justin,

To my surprise, the following also compiled correctly and explains the reason for the group nil handle in your code.

Procedure MyDuplicate;
VAR
i,totDup: INTEGER;
grpHdl,Htemp:HANDLE;

BEGIN;

BeginGroup;
BeginPoly;
	Moveto(0,0);
	Line(100,0);
	LIne(0,-100);
ENDPOLY;
Htemp:=LnewObj;
EndGroup;
grpHdl:= LNewObj;

IF grpHdl <> NIL THEN
BEGIN
totDup:= 2;
FOR i:= 1 TO totDup DO
	Htemp:= HDuplicate(Htemp,100,0);
ResetBBox(grpHdl);
END;

Message(Concat('Htemp:',Htemp,' Group:',grpHdl));

END;

RUN (MyDuplicate);

The HDuplicate function places the duplicate in the same container as the original. Since you created the poly outside the group, all the duplicates are created outside the group and consequently, the group is empty at the end of the script and returns a nil handle.

But agree with Raymond that the duplicate should be placed in the right container to avoid any changes to HDuplicate in the future. Personally I use CreateDuplicateObject because it gives a handle to the duplicate object for further processing in case I need to modify its size or attributes.

Procedure MyDuplicate;
VAR
i,totDup: INTEGER;
grpHdl,Htemp,dupHdl:HANDLE;

BEGIN;

BeginGroup;
BeginPoly;
	Moveto(0,0);
	Line(100,0);
	LIne(0,-100);
ENDPOLY;
Htemp:=LnewObj;
EndGroup;
grpHdl:= LNewObj;

IF grpHdl <> NIL THEN
BEGIN
totDup:= 2;
FOR i:= 1 TO totDup DO
	BEGIN
	dupHdl:= CreateDuplicateObject(Htemp,grpHdl);
	HMove(dupHdl,i * 100,0);
	END;
ResetBBox(grpHdl);
END;

Message(Concat('Htemp:',Htemp,' Group:',grpHdl));

END;

RUN (MyDuplicate);

[Pat Stanford]

I don't think it is directly applicable to this problem, but I just want to bring up the fact that PIOs are not created during the running of a script, but rather during the redraw after the script is drawn.

This means that if you use a PIO inside a script, there is no way to get a handle to it and modify it as it has not been created.

Very annoying with no good work around if you don't have the original PIO code to work with.

[Assembly]

I note there is also a new function in 2011.

PROCEDURE BeginGroupN( VAR groupHandle :HANDLE);

Waiting for my copy so have not tested MyDuplicate with BeginGroupN.