ui_ncurses_input.c File Reference

NCurses UI backend — input handling. More...

#include "cm.h"
#include "ui_backend.h"
#include "ui_ncurses_internal.h"
#include <poll.h>
#include <stddef.h>
#include <string.h>
#include <termios.h>

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Functions
void	ui_flush_input ()
	Flush any pending input events from the NotCurses context. This function discards any input events that have been queued but not yet processed.
int	ui_get_event (UiSurface *s, ss_t w, UiChyron *chyron, UiEvent *ev, int timeout_ms)
	Read input events.
int	ui_get_event_no_mouse (UiSurface *s, ss_t w, UiEvent *ev)
	Wait for an input event on target (or stdscr if NULL) without mouse support.
int	ui_mice_enable (int mask)
	Enable or disable mouse support.
int	ui_mousemask (int mask)
	Enable or disable mouse support.

Detailed Description

NCurses UI backend — input handling.

Translates raw NCurses key codes and mouse events into the portable UiEvent representation defined in ui_backend.h.

Definition in file ui_ncurses_input.c.

Function Documentation

ui_flush_input()

void ui_flush_input

(

)

Flush any pending input events from the NotCurses context. This function discards any input events that have been queued but not yet processed.

Definition at line 102 of file ui_ncurses_input.c.

                      {
    if (ui && ui->tty_fd >= 0) {
        tcflush(ui->tty_fd, TCIFLUSH);
    }
}

References ui.

Referenced by ui_get_event(), ui_get_event_no_mouse(), and view_init_input().

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ui_get_event()

int ui_get_event	(	UiSurface *	s,
		ss_t	w,
		UiChyron *	chyron,
		UiEvent *	ev,
		int	timeout_ms )

Read input events.

Wait for an input event from the NotCurses context.

Parameters

s	Surface - may contain multiple widgets (planes/panels)
w	Widget index (A surface may contain multilple widgets)
chyron	A zoned group of Actions or Commands
ev	Event data structure
timeout_ms	Timeout in milliseconds (0 for no wait, -1 for infinite wait).

Returns

0 on success, -1 if ev is NULL.

Parameters

ui	UI runtime context.
target	Unused for NotCurses (events are global to the context).
ev	Output UiEvent structure.
timeout_ms	Milliseconds to wait; -1 = block indefinitely.

Returns

0 on success, -1 if ui or ev is NULL.

Definition at line 116 of file ui_ncurses_input.c.

                                                                                      {
    if (!ev)
        return -1;
    int ch;
    ui_flush_input();
    ui_render();
    if (timeout_ms < 0)
        timeout_ms = -1; // Block waiting for input
    if (timeout_ms > 0) {
        // ------------------------------------------------------------
        // Poll for input on the TTY and any registered external files
        // ------------------------------------------------------------
        struct pollfd fds[1 + MAX_EXT_FDS];
        int token_id;
        int reg_idx;
        memset(fds, 0, sizeof(fds));
        fds[0].fd = ui->tty_fd;
        fds[0].events = POLLIN; // also POLLERR | POLLHUP | POLLNVAL
        nfds_t nfds = 1;
        nfds_t ext_start_idx = nfds;
        for (nfds_t i = 0; i < ui_ctx.ext_nfds; i++) {
            fds[nfds].fd = ui_ctx.ext_fds[i].fd;
            fds[nfds].events = POLLIN; // also POLLERR | POLLHUP | POLLNVAL
            nfds++;
        }
        int poll_rc = poll(fds, nfds, timeout_ms);
        if (poll_rc < 0) {
            if (errno == EINTR)
                return 0; // continue
            return -1;
        }
        if (poll_rc == 0) { // timed out with no input
            token_id = UIKEY_TIMEOUT;
            return token_id;
        }
        bool ui_ready = (fds[0].revents & POLLIN);
        if (!ui_ready) {
            for (nfds_t i = ext_start_idx; i < nfds; i++) {
                if (fds[i].revents & (POLLIN | POLLHUP | POLLERR)) {
                    reg_idx = i - ext_start_idx;
                    token_id = ui_ctx.ext_fds[reg_idx].token_id;
                    return token_id;
                }
            }
        } else
            timeout_ms = -1;
    }
    memset(ev, 0, sizeof(*ev));
    mousemask(ALL_MOUSE_EVENTS | REPORT_MOUSE_POSITION, NULL);
    wtimeout(s->mwin[w], timeout_ms);
    do {
        curs_set(2);
        ch = wgetch(s->mwin[w]);
        if (sig_received != 0) {
            if (handle_signal(sig_received))
                ch = ui_display_error(em0, em1, em2, nullptr);
            if (ch == 'q' || ch == 'Q' || ch == UIKEY_F09)
                exit(EXIT_FAILURE);
            sig_received = 0;
            return 0;
        }
        if (timeout_ms > 0 && ch == ERR) {
            ch = 0;
            break;
        }
        if (ch == ERR)
            continue;
        ev->key = translate_key(ch);
        if (ev->key == UIKEY_CHAR)
            ev->ch = (uint32_t)ch; /* Unicode codepoint */
        else if (ev->key == UIKEY_MOUSE) {
            MEVENT me;
            if (getmouse(&me) != OK) {
                ch = 0;
                continue;
            }
            ev->bstate = me.bstate;
            ev->y = me.y;
            ev->x = me.x;
            if (me.bstate == UIKEY_BUTTON4_PRESSED)
                ev->mouse_action = UIKEY_SCROLL_UP;
            else if (me.bstate == UIKEY_BUTTON5_PRESSED)
                ev->mouse_action = UIKEY_SCROLL_DOWN;
            else if (me.bstate == UIKEY_BUTTON1_CLICKED)
                ev->mouse_action = UIKEY_BUTTON1_CLICKED;
            for (ss_t i = WIN; i < SUB_SFC_MAX; i++) {
                if (s->mwin[i] != NULL &&
                    wenclose(s->mwin[i], me.y, me.x) &&
                    wmouse_trafo(s->mwin[i], &me.y, &me.x, false)) {
                    ch = ev->mouse_action;
                    ev->bstate = me.bstate;
                    ev->in_win = i;
                    ev->y = me.y;
                    ev->x = me.x;
                    break;
                }
            }
            if (ev->in_win == w)
                ev->mouse_inside = true;
            if (chyron && ev->mouse_action == UIKEY_BUTTON1_CLICKED) {
                if (ev->in_win == chyron->w && ev->y == chyron->y) {
                    ev->key = ui_get_chyron_key(chyron, ev->x);
                    return ev->key;
                } else
                    return 0;
            }
        }
    } while (ch == ERR);
    curs_set(0);
    return ch;
}

References UiEvent::bstate, UiEvent::ch, em0, em1, em2, ui_context_t::ext_fds, ui_context_t::ext_nfds, ext_fd_reg_t::fd, handle_signal(), UiEvent::in_win, UiEvent::key, UiEvent::mouse_action, UiEvent::mouse_inside, sig_received, SUB_SFC_MAX, ext_fd_reg_t::token_id, ui, ui_ctx, ui_display_error(), ui_flush_input(), ui_get_chyron_key(), ui_render(), UiEvent::x, and UiEvent::y.

Referenced by cf_accept(), field_editor(), form_post(), form_process(), get_cmd_char(), main(), menu_cmd_processor(), picker(), ui_action_disposition(), ui_answer_yn(), ui_display_error(), ui_perror(), and ui_timeout_prompt().

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ui_get_event_no_mouse()

int ui_get_event_no_mouse	(	UiSurface *	s,
		ss_t	w,
		UiEvent *	ev )

Wait for an input event on target (or stdscr if NULL) without mouse support.

Parameters

ui	UI runtime context (unused — event comes from the window).
target	Surface to read from, or NULL for stdscr.
ev	Output UiEvent structure.

Returns

0 on success, -1 if ev is NULL.

Definition at line 234 of file ui_ncurses_input.c.

                                                             {
    int ch;
    mousemask(0, NULL);
    curs_set(2);
    ui_flush_input();
    cbreak();
    do {
        curs_set(2);
        ch = wgetch(s->mwin[w]);
        curs_set(0);
        ev->key = translate_key(ch);
        if (ev->key == UIKEY_CHAR) {
            ev->ch = (uint32_t)ch;
            break;
        }
    } while (ch == ERR);
    curs_set(0);
    return ch;
}

ui_mice_enable()

int ui_mice_enable

(

int

mask

)

Enable or disable mouse support.

Parameters

mask	Mouse event mask (0 to disable, non-zero to enable).

Returns

0 on success, -1 if UI is not initialized.

Definition at line 274 of file ui_ncurses_input.c.

                             {
    if (!ui)
        return -1;
    if (mask)
        mousemask(mask, nullptr);
    else
        mousemask(ALL_MOUSE_EVENTS | REPORT_MOUSE_POSITION, nullptr);
    return 0;
}

ui_mousemask()

int ui_mousemask

(

int

mask

)

Enable or disable mouse support.

Parameters

mask	Mouse event mask (0 to disable, non-zero to enable).

Returns

0 on success, -1 if UI is not initialized.

Definition at line 261 of file ui_ncurses_input.c.

                           {
    if (!ui)
        return -1;
    if (mask)
        mousemask(mask, nullptr);
    else
        mousemask(ALL_MOUSE_EVENTS | REPORT_MOUSE_POSITION, nullptr);
    return 0;
}