# curs_mouse 3x 2025-04-05 ncurses 6.5 Library calls

    curs_mouse(3x)                   Library calls                  curs_mouse(3x)

## NAME

           has_mouse,  getmouse,  ungetmouse,  mousemask,  wenclose,  mouse_trafo,
           wmouse_trafo, mouseinterval, mmask_t, MEVENT  -  get  mouse  events  in
           ncurses

## SYNOPSIS

           #include <curses.h>

           /* data types */
           typedef unsigned long mmask_t;

           typedef struct {
               short id;       /* ID to distinguish multiple devices */
               int x, y, z;    /* event coordinates */
               mmask_t bstate; /* button state bits */
           } MEVENT;

           /* functions */
           bool has_mouse(void);

           mmask_t mousemask(mmask_t new-mask, mmask_t * old-mask);

           int getmouse(MEVENT * event);
           int ungetmouse(MEVENT * event);

           bool wenclose(const WINDOW * win, int y, int x);

           bool mouse_trafo(int * pY, int * pX, bool to-screen);
           bool wmouse_trafo(const WINDOW * win,
                 int * pY, int * pX, bool to-screen);

           int mouseinterval(int erval);

## DESCRIPTION

           ncurses  provides  an  interface to the mouse or other pointing device.
           An application can register its interest in such  events;  the  library
           then  exposes  the availability of a mouse event via an input character
           reading function: this is wgetch(3x) in the non-wide  character  curses
           API  and wget_wch(3x) in the wide character API.  A queue distinct from
           that used for keyboard events accumulates the details of mouse  events.
           The  input  character  reading  function reports the KEY_MOUSE key code
           when a mouse event is available for collection.  A single  mouse  event
           queue serves all windows associated with the screen.

           The  MEVENT structure describes a mouse event.  Its y and x coordinates
           are screen-, not window-, relative.  The bstate member has exactly  one
           bit set indicating the event type.

           ncurses  ignores  mouse  events  when  input is in canonical ("cooked")
           mode, and produces an error beep when  they  occur  while  the  library
           simulates canonical mode in a window, as with getstr(3x), which expects
           a line feed to terminate its input loop.

### has_mouse

           The terminal type  or  operating  system  interface  must  support  the
           encoding  of  mouse  events.  has_mouse returns TRUE if ncurses's mouse
           driver initialized successfully, and FALSE otherwise.

### mousemask

           Use mousemask to select the varieties of mouse event  your  application
           wishes to receive.  By default, ncurses reports no mouse events.

           o   The  function  returns an updated copy of new-mask indicating which
               of the specified mouse events can be reported.

               If the screen is not initialized, or the  terminal  interface  does
               not report mouse events, mousemask returns 0.

           o   If  old-mask  is  not a null pointer, mousemask stores the previous
               value of the screen's mouse event mask there.

           As a side effect, setting a zero mouse mask  may  turn  off  the  mouse
           cursor; setting a nonzero mask may turn it on.  Whether this happens is
           device-dependent.

### Mouse Events

           Several mouse  event  types  may  be  selected;  construct  a  mask  by
           logically "or"-ing their values.

           Name                     Description
           ------------------------------------------------------------------------
           BUTTON1_PRESSED          mouse button 1 down
           BUTTON1_RELEASED         mouse button 1 up
           BUTTON1_CLICKED          mouse button 1 clicked
           BUTTON1_DOUBLE_CLICKED   mouse button 1 double clicked
           BUTTON1_TRIPLE_CLICKED   mouse button 1 triple clicked
           ------------------------------------------------------------------------
           BUTTON2_PRESSED          mouse button 2 down
           BUTTON2_RELEASED         mouse button 2 up
           BUTTON2_CLICKED          mouse button 2 clicked
           BUTTON2_DOUBLE_CLICKED   mouse button 2 double clicked
           BUTTON2_TRIPLE_CLICKED   mouse button 2 triple clicked
           ------------------------------------------------------------------------
           BUTTON3_PRESSED          mouse button 3 down
           BUTTON3_RELEASED         mouse button 3 up
           BUTTON3_CLICKED          mouse button 3 clicked
           BUTTON3_DOUBLE_CLICKED   mouse button 3 double clicked
           BUTTON3_TRIPLE_CLICKED   mouse button 3 triple clicked
           ------------------------------------------------------------------------
           BUTTON4_PRESSED          mouse button 4 down
           BUTTON4_RELEASED         mouse button 4 up
           BUTTON4_CLICKED          mouse button 4 clicked
           BUTTON4_DOUBLE_CLICKED   mouse button 4 double clicked
           BUTTON4_TRIPLE_CLICKED   mouse button 4 triple clicked
           ------------------------------------------------------------------------
           BUTTON5_PRESSED          mouse button 5 down
           BUTTON5_RELEASED         mouse button 5 up
           BUTTON5_CLICKED          mouse button 5 clicked
           BUTTON5_DOUBLE_CLICKED   mouse button 5 double clicked
           BUTTON5_TRIPLE_CLICKED   mouse button 5 triple clicked
           ------------------------------------------------------------------------
           BUTTON_SHIFT             a  shift  key  was  down  during  button state
                                    change
           BUTTON_CTRL              a control key was  down  during  button  state
                                    change
           BUTTON_ALT               an alt key was down during button state change
           ALL_MOUSE_EVENTS         report all button state changes
           REPORT_MOUSE_POSITION    report mouse movement
           ------------------------------------------------------------------------

### getmouse

           Once a class of mouse events has been made visible in a window, calling
           the  input  character  reading  function  on  that  window  may  return
           KEY_MOUSE  as an indicator that a mouse event is enqueued.  To read the
           event data and pop the  event  off  the  queue,  call  getmouse,  which
           returns  OK  if  a  mouse  event is visible in the given window and ERR
           otherwise.  When getmouse returns OK, it deposits data  describing  the
           mouse  event  in  the  event pointer you supply.  A subsequent getmouse
           call retrieves the next older event from the queue.

### ungetmouse

           ungetmouse behaves analogously to ungetch(3x).  It pushes  a  KEY_MOUSE
           event  onto  the  screen's  input queue, and event onto the mouse event
           queue.

### wenclose

           wenclose returns TRUE if the pair of screen-relative coordinates (y, x)
           is  enclosed by the given window win, and FALSE otherwise.  If win is a
           pad, wenclose uses its most recent screen coordinates as specified in a
           prefresh(3x) or pnoutrefresh(3x) call.

           wenclose  is useful for determining what subset of the screen's windows
           encloses the location of a mouse event; it is otherwise independent  of
           the ncurses mouse API.

### wmouse_trafo

           wmouse_trafo  transforms the given pair of coordinate pointers (pY, pX)
           from a win-relative basis to a screen-relative one or  vice  versa,  as
           to-screen  is TRUE or FALSE, respectively.  stdscr-relative coordinates
           are  not  always  identical  to  screen  coordinates:  curses  supports
           reservation  of  screen  lines  at  the  top  and/or  bottom  for other
           purposes; see ripoffline(3x) and slk_init(3x).

           If to-screen is TRUE and the pointers (pY,  pX)  reference  coordinates
           inside win, ncurses updates their values to stdscr-relative coordinates
           and returns TRUE.  If either pY or pX is a null pointer, or (pY, pX) is
           not inside win, wmouse_trafo returns FALSE.

           If  to-screen  is FALSE and the pointers (pY, pX) reference coordinates
           inside stdscr, ncurses updates their values to win-relative coordinates
           and returns TRUE.  If either pY or pX is a null pointer, or (pY, pX) is
           not inside stdscr, wmouse_trafo returns FALSE.

### mouse_trafo

           mouse_trafo applies the wmouse_trafo  translation  to  stdscr.   If  no
           screen  lines  are  reserved by ripoffline(3x) or slk_init(3x), this is
           the identity transformation.

### mouseinterval

           mouseinterval sets the maximum time (in thousandths of a  second)  that
           can  elapse between press and release events for them to be resolved as
           a click.  An application  might  interpret  button  press  and  release
           events separated by more than the mouse interval as a "long press", or,
           with motion, as a "drag".

           When ncurses detects a mouse event, it awaits further input activity up
           to  this  interval,  and then checks for a subsequent mouse event which
           can be combined with the first event.  If the timeout  expires  without
           input   activity,   then   no   click   resolution   occurs.    Calling
           mouseinterval(0) disables click resolution.

           mouseinterval   returns   the    previous    interval    value.     Use
           mouseinterval(-1) to obtain the interval without altering it.

           The  mouse  interval  is  set  to  one  sixth  of  a  second  when  the
           corresponding  screen  is  initialized,   e.g.,   in   initscr(3x)   or
           setupterm(3x).

## RETURN VALUE

           has_mouse, wenclose, mouse_trafo, and wmouse_trafo return TRUE or FALSE
           as noted above.

           getmouse and ungetmouse return ERR upon failure and OK upon success.

           getmouse fails if:

           o   no mouse driver was initialized,

           o   the mask of reportable events is zero,

           o   a mouse event was detected that does not match the mask, or

           o   no more events remain in the queue.

           ungetmouse returns ERR if the event queue is full.

           mousemask returns the mask of reportable events.

           mouseinterval returns the previous interval value, unless the  terminal
           was  not  initialized.   In  that case, it returns the maximum interval
           value (166).

## NOTES

           The  order  of  the  MEVENT  structure  members  is   not   guaranteed.
           Additional fields may be added to the structure in the future.

           Under  ncurses, these calls are implemented using either xterm's built-
           in mouse-tracking API or platform-specific drivers including

              o   Alessandro Rubini's gpm server

              o   FreeBSD sysmouse

              o   OS/2 EMX

           If you are using an unsupported configuration,  mouse  events  are  not
           visible to ncurses (and the mousemask function always returns 0).

           If  the  terminal  type  possesses  the  (nonstandard)  terminfo string
           capability XM, ncurses's xterm mouse driver uses it  when  initializing
           the  terminal  for  mouse  operation.  The default, if XM is not found,
           corresponds to private mode 1000 of xterm.

              \E[?1000%?%p1%{1}%=%th%el%;

           ncurses also recognizes xterm's newer private mode 1006.

              \E[?1006;1000%?%p1%{1}%=%th%el%;

           The id member of the mouse event structure is not  presently  used;  no
           terminal  type  or operating system interface supports reporting events
           from distinguishable pointing devices.  If you  synthesize  an  MEVENT,
           use an id of 0.

           The z member of the mouse event structure is not presently used.  It is
           intended for use with touch screens (which may  be  pressure-sensitive)
           or with 3D-mice/trackballs/power gloves.

           The  ALL_MOUSE_EVENTS  class  does  not  include REPORT_MOUSE_POSITION.
           They are distinct.  For example, in xterm,  wheel/scrolling  mice  send
           position  reports  as  a  sequence of presses of buttons 4 or 5 without
           matching button-releases.

## EXTENSIONS

           These functions are ncurses extensions,  and  are  not  found  in  SVr4
           curses,  4.4BSD  curses,  or  any other previous curses implementation.
           (SVr4 curses did have a getmouse function, which took no  argument  and
           returned an unsigned long.)

## PORTABILITY

           Applications employing the ncurses mouse extension should condition its
           use on the visibility of the NCURSES_MOUSE_VERSION preprocessor  macro.
           When  the  interface  changes,  the macro's value increments.  Multiple
           versions  are  available  when  ncurses  is  configured;  see   section
           "ALTERNATE CONFIGURATIONS" of ncurses(3x).  The following values may be
           specified.

              1  has definitions for reserved events.  The mask uses 28 bits.

              2  adds definitions  for  button  5,  removes  the  definitions  for
                 reserved events.  The mask uses 29 bits.

## HISTORY

           SVr4  (1989)  added  mouse  support  to its variant of xterm(1).  It is
           mentioned in a few places, with little supporting documentation.

           o   Its "libcurses"  manual  page  lists  functions  for  this  feature
               prototyped in curses.h.

                   extern int mouse_set(long int);
                   extern int mouse_on(long int);
                   extern int mouse_off(long int);
                   extern int request_mouse_pos(void);
                   extern int map_button(unsigned long);
                   extern void wmouse_position(WINDOW *, int *, int *);
                   extern unsigned long getmouse(void), getbmap(void);

           o   Its "terminfo" manual page lists capabilities for the feature.

                   buttons         btns    BT   Number of buttons on the mouse
                   get_mouse       getm    Gm   Curses should get button events
                   key_mouse       kmous   Km   0631, Mouse event has occurred
                   mouse_info      minfo   Mi   Mouse status information
                   req_mouse_pos   reqmp   RQ   Request mouse position report

           o   The  interface  made assumptions (as does ncurses) about the escape
               sequences sent to and received from the terminal.

               For instance, the SVr4 curses library  used  the  get_mouse  (getm)
               capability to tell the terminal which mouse button events it should
               send, passing the mouse-button bit mask to the terminal.  Also,  it
               could  ask the terminal where the mouse was using the req_mouse_pos
               (reqmp) capability.

               Those features required a terminal program that had  been  modified
               to work with SVr4 curses.  They were not part of the X Consortium's
               xterm.

           When developing the xterm mouse support for ncurses in September  1995,
           Eric  Raymond  was  uninterested in using the same interface due to its
           lack of documentation.  Later, in 1998, Mark Hesseling provided support
           in  PDCurses 2.3 using the SVr4 interface.  PDCurses, however, does not
           use video terminals,  making  it  unnecessary  to  be  concerned  about
           compatibility with the escape sequences.

## BUGS

           Mouse events from xterm are not ignored in canonical ("cooked") mode if
           they have been enabled by mousemask.  Instead, the xterm  mouse  report
           sequence appears in the string read.

           An  ncurses  window  must  enable keypad(3x) to correctly receive mouse
           event reports from xterm since they are  encoded  like  function  keys.
           Set the terminal's terminfo capability key_mouse (kmous) to "\E[M" (the
           beginning of the response from xterm for mouse clicks).   Other  values
           of  key_mouse  are  permitted  under  the same assumption -- that is, a
           mouse report begins with the value  of  the  key_mouse  (kmous)  string
           capability.

           Because there are no standard response sequences that serve to identify
           terminals supporting the xterm mouse protocol, ncurses assumes that  if
           key_mouse  (kmous)  is  defined  in the terminal description, or if the
           terminal type's primary name or aliases  contain  the  string  "xterm",
           then the terminal may send mouse events.  ncurses checks the kmous cap-
           code first, allowing use of newer xterm mouse protocols,  such  as  its
           private mode 1006.

## SEE ALSO

           curses(3x),     curs_inopts(3x),     curs_kernel(3x),     curs_pad(3x),
           curs_slk(3x), curs_variables(3x)

    ncurses 6.5                       2025-04-05                    curs_mouse(3x)