# curs_mouse

## 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 **ncurs‐**
           **es**(3X).  Mouse events are represented by **KEY_MOUSE** pseudo-key val‐
           ues 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.
    
           •   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.
    
           •   If _oldmask_ is non-NULL, this function fills the indicated lo‐
               cation 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 hap‐
           pens 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 subse‐
           quent 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 co‐
           ordinates.
    
       **wenclose**
           The **wenclose** function tests whether a given pair of screen-rela‐
           tive character-cell coordinates is enclosed by a given window, re‐
           turning **TRUE** if it is and **FALSE** otherwise.  It is useful for de‐
           termining 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 coordi‐
           nates 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 in‐
               side the window, **FALSE** is returned.
    
           •   If _to_screen_ is **FALSE** , the pointers _pY, pX_ must reference win‐
               dow-relative coordinates.  They are converted to stdscr-rela‐
               tive 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 transforma‐
               tion 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 al‐
           tering 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 simu‐
           lated 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 parame‐
                  ter is zero,
    
              •   It returns an error if a mouse event was detected which did
                  not match the current _mousemask_.
    
              •   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 ter‐
           minal 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 curs‐
           es.
    
           SVr4 curses had support for the mouse in a variant of **xterm**(1).
           It is mentioned in a few places, but with no supporting documenta‐
           tion:
    
           •   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 es‐
               cape sequences sent to and received from the terminal.
    
               For instance the SVr4 curses library used the **get_mouse** capa‐
               bility to tell the terminal which mouse button events it
               should send, passing the mouse-button bit-mask to the termi‐
               nal.  Also, it could ask the terminal where the mouse was us‐
               ing 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.  PD‐
           Curses, however, does not use video terminals, making it unneces‐
           sary to be concerned about compatibility with the escape se‐
           quences.
    
           The feature macro **NCURSES_MOUSE_VERSION** is provided so the pre‐
           processor 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.  Ad‐
           ditional 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
    
              •   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**(3X) (and the **mousemask** function will al‐
           ways 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-sensi‐
           tive) 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 win‐
           dow with its keypad bit off, since they are interpreted as a vari‐
           ety 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 descrip‐
           tion, 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.
    


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