Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!rice!uw-beaver!cornell!johnhlee
From: johnhlee@viola.cs.cornell.edu (John H. Lee)
Newsgroups: comp.sys.amiga.programmer
Subject: Re: Prop gadgets and FOLLOWMOUSE
Message-ID: <52041@cornell.UUCP>
Date: 14 Feb 91 19:16:42 GMT
References: <1991Feb8.213305.15745@ssd.kodak.com> <51884@cornell.UUCP> <DGG.91Feb12135350@kaos.ksr.com>
Sender: nobody@cornell.UUCP
Reply-To: johnhlee@cs.cornell.edu (John H. Lee)
Organization: Cornell Univ. CS Dept, Ithaca NY
Lines: 153
Summary:
Followup-To:

In article <DGG.91Feb12135350@kaos.ksr.com> dgg@ksr.com (David Grubbs) writes:
>Why all the text descriptions?  If you have an efficient algorithm, then
>include it.  An English description of a C program is useful only to a CompSci
>teacher, not the students.

Uh oh!  I hope that English isn't your second language, with <insert favorite
programming language here> as your first!  :-)

I thought the concept was rather simple, but I have enclosed some excerpts
from my test program that demonstrate the work-around I came up with.
(BTW, the idea behind the program was to demonstrate the ability to design
and create prop gadgets that work like the sliders in DECwindows or the
VAXstation VWS windowing system.  The numerical value of the slider is
displayed directly above the knob and is updated and moved with the knob
as the user drags the knob.)


[...]
#define	G_PROP1		1
#define	G_PROP2		2

#define	GADGET(g)	((struct Gadget *)(g))

[...]

static struct Gadget
		prop2 = {
	NULL,
	10, 25, 200, 12,
	GADGHNONE | GADGIMAGE,
	GADGIMMEDIATE | FOLLOWMOUSE | RELVERIFY,
	PROPGADGET,
	(APTR)&thumb2_img,
	NULL,
	NULL,
	0L,
	(APTR)&prop2_info,
	G_PROP2,
	(APTR)&pv2_info
},
		prop1 = {
	&prop2,
	10, 55, 200, 12,
	GADGHNONE | GADGIMAGE,
	GADGIMMEDIATE | FOLLOWMOUSE | RELVERIFY,
	PROPGADGET,
	(APTR)&thumb1_img,
	NULL,
	NULL,
	0L,
	(APTR)&prop1_info,
	G_PROP1,
	(APTR)&pv1_info
};


static struct NewWindow	windowdata = {
	10, 10,
	300, 70,
	-1, -1,
	CLOSEWINDOW | GADGETUP | GADGETDOWN | MOUSEMOVE,
	WINDOWCLOSE | WINDOWDRAG | SMART_REFRESH | ACTIVATE,
	&prop1,
	NULL,
	"Prop Gadget Test",
	NULL,
	NULL,
	0, 0, 0, 0,
	WBENCHSCREEN
};



static struct Window	*window = NULL;



void	CloseAll(void),
	FatalError(char *),
	UpdateProp(struct Gadget *, struct Window *);




main()
{
BOOL	notDone = TRUE;
ULONG	sigm_ctlc = SIGBREAKF_CTRL_C,
	sigm_window,
	sigs;
struct IntuiMessage	*msg;
ULONG	class;
APTR	iaddr;
struct Gadget	*g_iaddr = NULL;


	if ((IntuitionBase = (struct IntuitionBase *)
		OpenLibrary("intuition.library", 0L)) == NULL)
		FatalError("Unable to open intuition.library");

	if ((window = OpenWindow(&windowdata)) == NULL)
		FatalError("Unable to open window");
	sigm_window = 1L << window->UserPort->mp_SigBit;

	UpdateProp(&prop1, window);
	UpdateProp(&prop2, window);

	while (notDone) {
	    sigs = Wait(sigm_ctlc | sigm_window);

	    if (sigs & sigm_ctlc) notDone = FALSE;

	    else {
		while (msg = (struct IntuiMessage *)GetMsg(window->UserPort)) {
		    class = msg->Class;
		    iaddr = msg->IAddress;
		    ReplyMsg((struct Message *)msg);

		    switch (class) {
		      case CLOSEWINDOW:
			notDone = FALSE;
			break;
		      case GADGETDOWN:
			if (GADGET(iaddr)->GadgetType == PROPGADGET)
				g_iaddr = GADGET(iaddr);
			break;
		      case GADGETUP:
			if ((g_iaddr != NULL) && (g_iaddr == GADGET(iaddr))) {
				UpdateProp(g_iaddr, window);
				g_iaddr = NULL;
			} /* if */
			break;
		      case MOUSEMOVE:
			if (g_iaddr != NULL) UpdateProp(g_iaddr, window);
			break;
		      default:
			break;
		    } /* case */
		} /* while */
	    } /* else */
	} /* while */

	CloseAll();

	exit(0);
} /* main */

[...]

-------------------------------------------------------------------------------
The DiskDoctor threatens the crew!  Next time on AmigaDos: The Next Generation.
	John Lee		Internet: johnhlee@cs.cornell.edu
The above opinions of those of the user, and not of this machine.