Provided by: ncurses-doc_6.1+20190803-1ubuntu1_all bug

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(3NCURSES).  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 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).

       ·   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.

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

       ·   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.

       ·   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.

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

          ·   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(3NCURSES), 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:

       ·   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);

       ·   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

       ·   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(3NCURSES), these calls are implemented using either xterm's built-in  mouse-
       tracking API or platform-specific drivers including

          ·   Alessandro Rubini's gpm server

          ·   FreeBSD sysmouse

          ·   OS/2 EMX

       If  you  are  using  an  unsupported  configuration,  mouse  events will not be visible to
       ncurses(3NCURSES) (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

       ncurses(3NCURSES), kernel(3NCURSES), slk(3NCURSES), curses_variables(3NCURSES).

                                                                                  mouse(3NCURSES)