AT&T UNIX™PC Unix System V Users Manual - tenox

TRACK ( 3T ) ( AT&T UNIX PC only ) TRACK ( 3T )
NAME
track - track mouse motion
SYNOPSIS
#include
int track(w, trk, op, butptr, whyptr)
int w, op, "'butptr, "'whyptr;
track_t •trk;
DESCRIPTION
Track allows the process to define an arbitrary number of "mouse
motion rectangles" and to learn when the mouse ventures into any
of them. In addition, track monitors keyboard input and mouse
button presses, returning each as appropriate.
Each motion rectangle has an x,y address, a width and height, and
an optional mouse icon to be displayed whenever the mouse is
located in that rectangle.
The first argument is the window descriptor. Trk is a pointer to a
track structure (see below). Op is T_BEGIN to initialize the track
operation, T_INPUT to accept mouse and keyboard input, and
T_END to terminate a track operation. These may be combined
to produce complex operations: T_BEGIN I TJNPUT will initialize
and begin tracking, etc. Butptr and whyptr are pointers to
return values. The int pointed to by butptr will receive the 3-bit
integer corresponding to the current mouse button state. Whyptr
points to an int which will receive the "reason" for the
return-one of MSIN, MSUP, or MSDOWN. MSIN means the
mouse has moved to a new rectangle (or the background), MSUP
and MSDOWN report mouse button changes.
The track structure controls track's operation:
typedef struct
{
char t_flags; /* flags */
char t_scalex; /* x & y scaling */
char t_scaley;
short t_lastx; /* last known x,y pos * /
short t_lasty;
struct icon *t_bicon; /* background icon * /
struct umdata t_umdata; /* save the mouse data * /
tkitem_t *t_tkitems; /* ptr to items * /
tkitem_t *t_curi; /* ptr to current item * /
} track_t;
T_flags contains either or both of MSUP and/or MSDOWN,
which enable mouse button reporting. If both flags are zero, button
presses have no effect-only motion rectangle transitions wake
the process.
T_scalex and t_scaley determine the scaling factor for all the
coordinates in the track items (see below). 1,1 gives unity scaling,
allowing the application to specify pixel coordinates. Values of 0
for either scale parameter cause track to substitute the
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