V8/usr/man/man9/button.9

.TH BUTTON 9.2
.SH NAME
button123, mouse, cursallow, cursinhibit, cursset, cursswitch, getrect123 \- mouse control
.SH SYNOPSIS
.B #include <jerq.h>
.PP
.B extern struct Mouse {
.br
.B "    Point xy;
.br
.B "    short buttons;
.br
.B } mouse;
.PP
.B int button(n)
.B int n;
.br
.B int button1(), button2(), button3();
.br
.B int button12(), button23(), button123();
.PP
.B void cursinhibit();
.br
.B void cursallow();
.PP
.B void cursset(p);
.B Point p;
.PP
.B Texture *cursswitch(t);
.B Texture *t;
.PP
.B Rectangle getrect(n)
.B int n;
.br
.B Rectangle getrect1(), getrect2(), getrect3();
.br
.B Rectangle getrect12(), getrect23(), getrect123();
.SH DESCRIPTION
For processes that request the mouse
(see
.IR request (9.2)),
the mouse state is updated asynchronously in the per-process structure
.IR mouse .
The coordinates of the mouse are held in
.IR mouse.xy ,
and the state of the buttons in
.IR mouse.buttons .
Each process's
.I mouse
structure is independent of the others, so that
(except for
.IR cursset )
actions such as
changing the tracking cursor do not affect
other process's use of the mouse.
.I Mouse
is
.I not
updated if the process does not `own' the mouse;
see
.IR  request (9.2).
.PP
The macro
.I button
and its counterparts return the state of the associated mouse button:
non-zero if the button is depressed, 0 otherwise.
The buttons are numbered 1 to 3 from left to right.
.I Button12
and the other multi-button functions return the
OR
of their states: true if either button 1 or button 2 is depressed
(as opposed to button 1 \fIand\fP button 2).
.PP
.I Cursinhibit
turns off interrupt-time cursor tracking
(the drawing of the cursor on the screen),
although the mouse coordinates are still kept current
and available.
.I Cursallow
enables interrupt-time cursor tracking.
.I Cursallow
and
.I cursinhibit
stack: to enable cursor tracking after two calls to
.IR cursinhibit ,
two calls to
.I cursallow
are required.
.PP
.I Cursset
moves the mouse cursor to the Point p.
.PP
.I Cursswitch
changes the mouse cursor (a 16\(mu16 pixel image) to that specified by the
Texture
.IR *t .
If the argument is
(Texture\ *)0,
the cursor is restored to the default arrow.
.I Cursswitch
returns the previous value of the cursor: the argument of the previous
call to
.I cursswitch.
.PP
.I Getrect
prompts the user with a box cursor and waits for a
rectangle to be swept out named button, identified as with the
.I button
primitives.
It returns the screen coordinates of the box swept.
The box may be partly or wholly outside the process's layer.