curs_mouse(3X) Library calls curs_mouse(3X)
NAME
has_mouse, getmouse, ungetmouse, mousemask, wenclose, mouse_trafo,
wmouse_trafo, mouseinterval, mmask_t, MEVENT - get mouse events in
ncurses
SYNOPSIS
#include <curses.h>
/* data types */
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;
/* functions */
bool has_mouse(void);
mmask_t mousemask(mmask_t new-mask, mmask_t * old-mask);
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
ncurses provides an interface to the mouse or other pointing device. An
application can register its interest in such events; the library then
exposes the availability of a mouse event via an input character reading
function: this is wgetch(3X) in the non-wide character curses API and
wget_wch(3X) in the wide character API. A queue distinct from that used
for keyboard events accumulates the details of mouse events. The input
character reading function reports the KEY_MOUSE key code when a mouse
event is available for collection. A single mouse event queue serves all
windows associated with the screen.
The MEVENT structure describes a mouse event. Its y and x coordinates
are screen-, not window-, relative. The bstate member has exactly one
bit set indicating the event type.
ncurses ignores mouse events when input is in canonical ("cooked") mode,
and produces an error beep when they occur while the library simulates
canonical mode in a window, as with getstr(3X) (wide-character API users:
get_wstr(3X)), which expects a line feed to terminate its input loop.
has_mouse
The terminal type or operating system interface must support the encoding
of mouse events. has_mouse returns TRUE if ncurses's mouse driver
initialized successfully, and FALSE otherwise.
mousemask
Use mousemask to select the varieties of mouse event your application
wishes to receive. By default, ncurses reports no mouse events.
o The function returns an updated copy of new-mask indicating which
event types of interest are reportable by the terminal's mouse
protocol.
If the screen is not initialized, or the terminal interface does not
report mouse events, mousemask returns 0.
o If old-mask is not a null pointer, mousemask stores the previous
value of the screen's mouse event mask there.
As a side effect, setting a zero mouse mask may turn off the mouse
cursor; setting a nonzero mask may turn it on. Whether this happens is
device-dependent.
Mouse Events
Several mouse event types may be selected; construct a mask by logically
"or"-ing their values.
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 a shift key was down during button state change
BUTTON_CTRL a control key was down during button state
change
BUTTON_ALT an alt key was down during button state change
ALL_MOUSE_EVENTS report all button state changes
REPORT_MOUSE_POSITION report mouse movement
--------------------------------------------------------------------------
getmouse
When a window is configured to report a non-empty set of event types,
calling the input character reading function on that window may return
KEY_MOUSE to indicate availability of an enqueued mouse event. To read
the event data and remove it from the queue, call getmouse, which returns
OK if a mouse event is visible in the given window and ERR otherwise.
When getmouse returns OK, it deposits data describing the mouse event in
the event pointer you supply. A subsequent getmouse call retrieves the
next older event from the queue.
ungetmouse
ungetmouse behaves analogously to ungetch(3X). It pushes a KEY_MOUSE
event onto the screen's input queue, and event onto the mouse event
queue.
wenclose
wenclose returns TRUE if the pair of screen-relative coordinates (y, x)
is enclosed by the given window win, and FALSE otherwise. If win is a
pad, wenclose uses its most recent screen coordinates as specified in a
prefresh(3X) or pnoutrefresh(3X) call.
wenclose is useful for determining what subset of the screen's windows
encloses the location of a mouse event; it is otherwise independent of
the ncurses mouse API.
wmouse_trafo
wmouse_trafo transforms the given pair of coordinate pointers (pY, pX)
from a win-relative basis to a screen-relative one or vice versa, as
to-screen is TRUE or FALSE, respectively. stdscr-relative coordinates
are not always identical to screen coordinates: curses supports
reservation of screen lines at the top and/or bottom for other purposes;
see ripoffline(3X) and slk_init(3X).
If to-screen is TRUE and the pointers (pY, pX) reference coordinates
inside win, ncurses updates their values to stdscr-relative coordinates
and returns TRUE. If either pY or pX is a null pointer, or (pY, pX) is
not inside win, wmouse_trafo returns FALSE.
If to-screen is FALSE and the pointers (pY, pX) reference coordinates
inside stdscr, ncurses updates their values to win-relative coordinates
and returns TRUE. If either pY or pX is a null pointer, or (pY, pX) is
not inside stdscr, wmouse_trafo returns FALSE.
mouse_trafo
mouse_trafo applies the wmouse_trafo translation to stdscr. If no screen
lines are reserved by ripoffline(3X) or slk_init(3X), this is the
identity transformation.
mouseinterval
mouseinterval sets the maximum time (in thousandths 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".
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, then no click resolution occurs. Calling mouseinterval(0)
disables click resolution.
mouseinterval 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, or
o no more events remain in the queue.
ungetmouse returns ERR 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 are not
visible to ncurses (and the mousemask function always returns 0).
If the terminal type possesses the (nonstandard) terminfo string
capability XM, ncurses's xterm mouse driver uses it when initializing the
terminal for mouse operation. The default, if XM is not found,
corresponds to private mode 1000 of xterm.
\E[?1000%?%p1%{1}%=%th%el%;
ncurses also recognizes xterm's newer private mode 1006.
\E[?1006;1000%?%p1%{1}%=%th%el%;
The id member of the mouse event structure is not presently used; no
terminal type or operating system interface supports reporting events
from distinguishable pointing devices. If you synthesize an MEVENT, use
an id of 0.
The z member of the mouse 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 are ncurses extensions, 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 an
unsigned long.)
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.
HISTORY
SVr4 (1989) added mouse support to its 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 (getm)
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
(reqmp) 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 canonical ("cooked") mode if
they have been enabled by mousemask. Instead, the xterm mouse report
sequence appears in the string read.
An ncurses window must enable keypad(3X) to correctly receive mouse event
reports from xterm since they are encoded like function keys. Set the
terminal's terminfo capability key_mouse (kmous) to "\E[M" (the beginning
of the response from xterm for mouse clicks). Other values of key_mouse
are permitted under the same assumption -- that is, a mouse report begins
with the value of the key_mouse (kmous) string capability.
Because there are no standard response sequences that serve to identify
terminals supporting the xterm mouse protocol, ncurses assumes that if
key_mouse (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. ncurses checks the kmous cap-code
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 6.6 2025-11-11 curs_mouse(3X)