Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages


home | help
MOUSE(3)		   Library Functions Manual		      MOUSE(3)

       initmouse,   readmouse,	 closemouse,  moveto,  cursorswitch,  getrect,
       drawgetrect, menuhit, setcursor - mouse control

       #include	<u.h>
       #include	<libc.h>
       #include	<draw.h>
       #include	<thread.h>
       #include	<mouse.h>
       #include	<cursor.h>

       Mousectl	 *initmouse(char *file,	Image *i)

       int	 readmouse(Mousectl *mc)

       int	 atomouse();

       void	 closemouse(Mousectl *mc)

       void	 moveto(Mousectl *mc, Point pt)

       void	 setcursor(Mousectl *mc, Cursor	*c)

       Rectangle getrect(int but, Mousectl *mc)

       void	 drawgetrect(Rectangle r, int up)

       int	 menuhit(int but, Mousectl *mc,	Menu *menu, Screen *scr)

       These functions access and control a mouse in a multi-threaded environ-
       ment.   They  use  the message-passing Channel interface	in the threads
       library (see thread(3));	programs that wish a more  event-driven,  sin-
       gle-threaded approach should use	event(3).

       The  state  of  the mouse is recorded in	a structure, Mouse, defined in

	      typedef struct Mouse Mouse;
	      struct Mouse
		    int	      buttons;	 /* bit	array: LMR=124 */
		    Point     xy;
		    ulong     msec;

       The Point xy records the	position of the	cursor,	buttons	the  state  of
       the  buttons  (three bits representing, from bit	0 up, the buttons from
       left to right, 0	if the button is released, 1 if	it  is	pressed),  and
       msec, a millisecond time	stamp.

       The  routine initmouse returns a	structure through which	one may	access
       the mouse:

	      typedef struct Mousectl Mousectl;
	      struct Mousectl
		    Channel   *c;	 /* chan(Mouse)[16] */
		    Channel   *resizec;	 /* chan(int)[2] */

		    char      *file;
		    int	      mfd;	 /* to mouse file */
		    int	      cfd;	 /* to cursor file */
		    int	      pid;	 /* of slave proc */
		    Image*    image;	 /* of associated window/display */

       The arguments to	initmouse are a	file naming the	device file  connected
       to the mouse and	an Image (see draw(3)) on which	the mouse will be vis-
       ible.   Typically  the  file  is	 nil,  which  requests	 the   default
       /dev/mouse;  and	 the  image is the window in which the program is run-
       ning, held in the variable screen after a call to initdraw.

       Once the	Mousectl is set	up, mouse motion will be reported by  messages
       of  type	 Mouse	sent  on the Channel Mousectl.c.  Typically, a message
       will be sent every time a read of /dev/mouse succeeds, which  is	 every
       time the	state of the mouse changes.

       When the	window is resized, a message is	sent on	Mousectl.resizec.  The
       actual value sent may be	discarded; the receipt of  the	message	 tells
       the  program  that it should call getwindow (see	graphics(3)) to	recon-
       nect to the window.

       Readmouse updates the Mouse structure held in the Mousectl, blocking if
       the  state  has not changed since the last readmouse or message sent on
       the channel.  It	calls flushimage (see graphics(3)) before blocking, so
       any buffered graphics requests are displayed.

       Closemouse closes the file descriptors associated with the mouse, kills
       the slave processes, and	frees the Mousectl structure.

       Moveto moves the	mouse cursor on	the display to the position  specified
       by pt.

       Setcursor sets the image	of the cursor to that specified	by c.  If c is
       nil, the	cursor is set to the default.  The format of the  cursor  data
       is spelled out in <cursor.h> and	described in graphics(3).

       Getrect	returns	the dimensions of a rectangle swept by the user, using
       the mouse, in the manner	rio(1) or sam(1) uses to create	a new  window.
       The  but	 argument  specifies which button the user must	press to sweep
       the window; any other button press cancels the  action.	 The  returned
       rectangle is all	zeros if the user cancels.

       Getrect	uses  successive calls to drawgetrect to maintain the red rec-
       tangle showing the sweep-in-progress.  The rectangle  to	 be  drawn  is
       specified  by rc	and the	up parameter says whether to draw (1) or erase
       (0) the rectangle.

       Menuhit provides	a simple menu mechanism.  It uses a Menu structure de-
       fined in	<mouse.h>:

	      typedef struct Menu Menu;
	      struct Menu
		    char      **item;
		    char      *(*gen)(int);
		    int	      lasthit;

       Menuhit	behaves	 the  same  as	its  namesake  emenuhit	 described  in
       event(3), with two exceptions.  First, it uses a	Mousectl to access the
       mouse rather than using the event interface; and	second,	it creates the
       menu as a true window on	the Screen scr (see window(3)),	permitting the
       menu  to	be displayed in	parallel with other activities on the display.
       If scr is null, menuhit behaves like emenuhit, creating	backing	 store
       for  the	 menu, writing the menu	directly on the	display, and restoring
       the display when	the menu is removed.


       graphics(3), draw(3), event(3), keyboard(3), thread(3).



Want to link to this manual page? Use this URL:

home | help