Provided by: ncurses-doc_6.4+20240113-1ubuntu2_all 
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(3NCURSES). Mouse events are
represented by KEY_MOUSE pseudo-key values in the wgetch(3NCURSES) 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 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(3NCURSES) 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, and FALSE
otherwise.
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
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:
• no mouse driver was initialized,
• the mask of reportable events is zero,
• a mouse event was detected that does not match the mask,
• 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
• 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 (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(3NCURSES), 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(3NCURSES). 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.
• 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);
• 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
• 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
ncurses(3NCURSES), inopts(3NCURSES), kernel(3NCURSES), slk(3NCURSES), curses_variables(3NCURSES)
ncurses 6.4 2024-01-13 mouse(3NCURSES)