# curs_mouse 3x

    curs_mouse(3x)                                                  curs_mouse(3x)

## NAME

           has_mouse, getmouse, ungetmouse, mousemask, wenclose, mouse_trafo,
           wmouse_trafo, mouseinterval - mouse interface through 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  will
           set  the  mouse events to be reported.  By default, no mouse events are
           reported.  The function will return a mask to  indicate  which  of  the
           specified  mouse events can be reported; on complete failure it returns
           0.  If oldmask is non-NULL, this function fills the indicated  location
           with the previous value of the given window'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 coordi-
           nates.  The returned state mask will have exactly one bit set to  indi-
           cate the event type.  The corresponding data in the queue is marked in-
           valid.  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  al-
           ways  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 refer-
               ence 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 coor-
               dinates 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 re-
               placed  by the converted coordinates if the transformation was suc-
               cessful.

### 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 resolu-
           tion.  This function returns the previous interval value.  Use mousein-
           terval(-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  suc-
           cessfully 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 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(3x), 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.   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  capa-
               bility.

               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  com-
           patibility 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  inter-
           face  is changed, the value of NCURSES_MOUSE_VERSION will be increment-
           ed.  These values for NCURSES_MOUSE_VERSION may be specified when  con-
           figuring ncurses:

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

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

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

           Under  ncurses(3x),  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(3x) (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 in-
           tended 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  as-
           sumes  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_kernel(3x), curs_slk(3x), curs_variables(3x).

                                                                    curs_mouse(3x)