Manual Pages  — curs_mouse

 has_mouse,  getmouse,  ungetmouse,  mousemask,  wenclose,  mouse_trafo,  wmouse_trafo,  mouseinterval - get mouse events in curses

SYNOPSIS DESCRIPTION has_mouse mousemask Mouse Events getmouse ungetmouse wenclose wmouse_trafo mouse_trafo mouseinterval RETURN VALUE NOTES EXTENSIONS PORTABILITY BUGS SEE ALSO

#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);

mmask_t mousemask(mmask_t newmask, mmask_t *oldmask);

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);

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.

The  has_mouse function returns TRUE if the mouse driver has been successfully initialized, and FALSE otherwise.

Mouse events are ignored when input is in cooked mode, and 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.

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 mouse mask may turn off the mouse pointer; setting a nonzero mask may turn it on. Whether this happens is device-dependent.

Here are the mouse event type masks which may be defined:

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.

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.

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.

If the parameter is a pad,  wenclose uses the most recent screen coordinates used for this pad in  prefresh(3X) or  pnoutrefresh(3X).

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 screen coordinates due to the mechanism to reserve lines on top or bottom of the screen for other purposes (see the  ripoffline(3X) 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  stdscr-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  stdscr-relative coordinates. They are converted to window-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.

The  mouse_trafo function performs the same translation as  wmouse_trafo, using  stdscr for win.

The  mouseinterval function sets the maximum time (in thousands 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.

Calling  mouseinterval(0) disables click resolution. 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 (which would happen with a zero interval), then no click resolution will occur.

This function 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).

 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).

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  term info 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.

These functions were designed for  ncurses(3X), 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.)

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.

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.
»	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.

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  term info 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.

 curses(3X),  curs_inopts(3X),  curs_kernel(3X),  curs_pad(3X),  curs_slk(3X),  curs_variables(3X)