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$Id: curs_mouse.3x,v 1.98 2024/04/20 19:02:07 tom Exp $
.\} .\} . .. \%has_mouse, \%getmouse, \%ungetmouse, \%mousemask, \%wenclose, \%mouse_trafo, \%wmouse_trafo, \%mouseinterval - get mouse events in curses

#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. .bP 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. .bP 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:

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

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). .bP 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. .bP 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: .bP no mouse driver was initialized, .bP the mask of reportable events is zero, .bP a mouse event was detected that does not match the mask, .bP 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

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:

The mouse driver also recognizes a newer \%xterm private mode 1006, e.g.,

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.

SVr4 curses had support for the mouse in a variant of \%xterm(1). It is mentioned in a few places, with little supporting documentation. .bP Its \*(``libcurses\*('' manual page lists functions for this feature prototyped in \%curses.h.

.bP Its \*(``terminfo\*('' manual page lists capabilities for the feature. These don't appear in in the SVID 4th edition, Volume 3,
terminfo(TI_ENV) man page. They can be found in, e.g., the "z/OS
V1R1.0 C Curses" book, Chapter 17, pp. 179-186 (PDF 213-220).
.bP 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 \*(``\eE[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)