# curs_mouse 3x 2024-04-20 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 - 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);

           mmask_t mousemask(mmask_t newmask, mmask_t *oldmask);

           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

           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.

### has_mouse

           The has_mouse function returns  TRUE  if  the  mouse  driver  has  been
           successfully initialized, and FALSE otherwise.

           Mouse  events  are  ignored  when input is in cooked mode, and 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.

### 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 mouse mask 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.

           If the parameter is  a  pad,  wenclose  uses  the  most  recent  screen
           coordinates used for this pad in prefresh(3x) or pnoutrefresh(3x).

### 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 screen coordinates due to the mechanism to  reserve
           lines  on  top  or  bottom  of  the  screen for other purposes (see the
           ripoffline(3x) 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  stdscr-relative  coordinates  and  returned
               through  the  pointers.   If  the  conversion  was  successful, the
               function returns TRUE.

               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
               stdscr-relative coordinates.  They are converted to window-relative
               coordinates  if  the  window win encloses this point.  In this case
               the function returns TRUE.

               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
           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 will occur.

           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,

           o   or if no more events remain in the queue.

           ungetmouse returns an error 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 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.

## EXTENSIONS

           These  functions  were  designed  for ncurses(3x), 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 a different type.)

## 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.

           SVr4 curses had support for the mouse in a 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 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 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 cooked  mode  if  they  have
           been  enabled  by  mousemask.  Instead, the xterm mouse report sequence
           appears in the string read.

           Mouse event reports from xterm are not detected correctly in  a  window
           with  keypad application mode disabled, since they are interpreted as a
           variety of function key.  Set the terminal's terminfo capability  kmous
           to  "\E[M" (the beginning of the response from xterm for mouse clicks).
           Other values of kmous 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
           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.  The kmous capability is checked 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                       2024-04-20                    curs_mouse(3x)