# curs_mouse 3x 2025-02-15 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 canonical mode is simulated in  a
           window  by  a  function  such  as getstr(3x) that expects a linefeed 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
               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".

           Calling  mouseinterval(0)  disables  click  resolution.   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 (which would happen with  a  zero  interval),  then  no  click
           resolution occurs.

           This    function    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 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,  the
           report begins with that sequence.

           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                       2025-02-15                    curs_mouse(3x)