# curs_mouse 3x 2023-10-07 ncurses 6.4 Library calls

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

## NAME

           has_mouse,  getmouse,  ungetmouse,  mousemask,  wenclose,  mouse_trafo,
           wmouse_trafo, mouseinterval - get mouse events in curses

## SYNOPSIS

           #include <curses.h>

           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;

           bool has_mouse(void);

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

           mmask_t mousemask(mmask_t newmask, mmask_t *oldmask);

           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

           These functions provide an interface to mouse events from  ncurses(3x).
           Mouse  events  are  represented  by  KEY_MOUSE pseudo-key values in the
           wgetch(3x) input stream.

### mousemask

           To make mouse events visible, use the mousemask  function.   This  sets
           the  mouse  events  to  be  reported.   By default, no mouse events are
           reported.

           o   The function returns an updated copy of newmask to  indicate  which
               of the specified mouse events can be reported.

               If the screen has not been initialized, or if the terminal does not
               support mouse-events, this function returns 0.

           o   If oldmask is non-NULL, this function fills the indicated  location
               with the previous value of the current screen's mouse event mask.

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

### Mouse events

           Here are the mouse event type masks which may be defined:

           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             shift was down during button state change
           BUTTON_CTRL              control was down during button state change
           BUTTON_ALT               alt 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 wgetch function on that window may return KEY_MOUSE as an indicator
           that a mouse event has been queued.  To read the event data and pop the
           event off the queue, call getmouse.  This function will return OK if  a
           mouse  event  is  actually  visible in the given window, ERR otherwise.
           When getmouse returns OK, the data deposited as y and x  in  the  event
           structure    coordinates   will   be   screen-relative   character-cell
           coordinates.  The returned state mask will have exactly one bit set  to
           indicate the event type.  The corresponding data in the queue is marked
           invalid.  A subsequent call to getmouse will retrieve  the  next  older
           item from the queue.

### ungetmouse

           The  ungetmouse  function  behaves analogously to ungetch.  It pushes a
           KEY_MOUSE event onto the input queue, and associates  with  that  event
           the given state data and screen-relative character-cell coordinates.

### wenclose

           The  wenclose  function  tests  whether a given pair of screen-relative
           character-cell coordinates is enclosed by  a  given  window,  returning
           TRUE  if  it is and FALSE otherwise.  It is useful for determining what
           subset of the screen windows enclose the location of a mouse event.

### wmouse_trafo

           The wmouse_trafo function transforms a given pair of  coordinates  from
           stdscr-relative coordinates to coordinates relative to the given window
           or vice versa.   The  resulting  stdscr-relative  coordinates  are  not
           always identical to window-relative coordinates due to the mechanism to
           reserve lines on top or bottom of the screen for  other  purposes  (see
           the ripoffline and slk_init(3x) calls, for example).

           o   If  the  parameter  to_screen  is  TRUE,  the  pointers pY, pX must
               reference the coordinates of a  location  inside  the  window  win.
               They  are  converted  to  window-relative  coordinates and returned
               through the  pointers.   If  the  conversion  was  successful,  the
               function returns TRUE.

           o   If one of the parameters was NULL or the location is not inside the
               window, FALSE is returned.

           o   If to_screen is FALSE, the pointers pY, pX must  reference  window-
               relative   coordinates.   They  are  converted  to  stdscr-relative
               coordinates if the window win encloses this point.   In  this  case
               the function returns TRUE.

           o   If  one  of  the  parameters is NULL or the point is not inside the
               window, FALSE is returned.  The  referenced  coordinates  are  only
               replaced  by  the  converted  coordinates if the transformation was
               successful.

### mouse_trafo

           The mouse_trafo function performs the same translation as wmouse_trafo,
           using stdscr for win.

### mouseinterval

           The  mouseinterval  function  sets  the maximum time (in thousands of a
           second) that can elapse between press and release events for them to be
           recognized   as   a  click.   Use  mouseinterval(0)  to  disable  click
           resolution.  This function returns the previous  interval  value.   Use
           mouseinterval(-1)  to  obtain  the  interval  without altering it.  The
           default is one sixth of a second.

### has_mouse

           The has_mouse function returns  TRUE  if  the  mouse  driver  has  been
           successfully initialized.

           Note  that  mouse  events will be ignored when input is in cooked mode,
           and will cause an error beep when cooked mode is being simulated  in  a
           window  by a function such as getstr that expects a linefeed for input-
           loop termination.

## RETURN VALUE

           getmouse and ungetmouse return the integer ERR upon failure or OK  upon
           successful completion:

              getmouse
                   returns an error.

              o   If  no mouse driver was initialized, or if the mask parameter is
                  zero,

              o   It returns an error if a mouse event was detected which did  not
                  match the current mousemask.

              o   It also returns an error if no more events remain in the queue.

              ungetmouse
                   returns an error if the FIFO 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).

           wenclose and wmouse_trafo are boolean functions returning TRUE or FALSE
           depending on their test result.

## PORTABILITY

           These calls were designed for  ncurses,  and  are  not  found  in  SVr4
           curses, 4.4BSD curses, or any other previous version of curses.

           SVr4  curses had support for the mouse in a variant of xterm(1).  It is
           mentioned in a few places, but with no supporting documentation:

           o   the "libcurses" manual page lists functions for this feature  which
               are 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   the "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  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
               capability.

               Those features required a terminal which had been modified to  work
               with 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.

           The feature macro NCURSES_MOUSE_VERSION is provided so the preprocessor
           can  be  used  to  test  whether  these  features  are present.  If the
           interface is  changed,  the  value  of  NCURSES_MOUSE_VERSION  will  be
           incremented.   These  values for NCURSES_MOUSE_VERSION may be specified
           when configuring ncurses:

              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.

           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 will not be
           visible to ncurses (and the mousemask function will always return 0).

           If the terminfo entry contains a XM string, this is used in  the  xterm
           mouse  driver  to control the way the terminal is initialized for mouse
           operation.  The default, if XM is not  found,  corresponds  to  private
           mode 1000 of xterm:

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

           The mouse driver also recognizes a newer xterm private mode 1006, e.g.,

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

           The  z  member  in  the  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.

## BUGS

           Mouse events under xterm will not in  fact  be  ignored  during  cooked
           mode, if they have been enabled by mousemask.  Instead, the xterm mouse
           report sequence will appear in the string read.

           Mouse events under xterm will not be detected  correctly  in  a  window
           with  its  keypad  bit  off, since they are interpreted as a variety of
           function key.  Your terminfo  description  should  have  kmous  set  to
           "\E[M"  (the  beginning  of  the response from xterm for mouse clicks).
           Other values for kmous are permitted, but under  the  same  assumption,
           i.e., it is the beginning of the response.

           Because  there  are  no standard terminal responses that would serve to
           identify terminals which support  the  xterm  mouse  protocol,  ncurses
           assumes that if kmous is defined in the terminal description, or if the
           terminal description's primary  name  or  aliases  contain  the  string
           "xterm", then the terminal may send mouse events.  The kmous capability
           is checked first, allowing the use of newer xterm mouse protocols  such
           as xterm's private mode 1006.

## SEE ALSO

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

    ncurses 6.4                       2023-10-07                    curs_mouse(3x)