[wip] Initial stab on inline images support, with many problems

[elinks/images.git] / src / terminal / event.c

/** Event system support routines.
 * @file */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <errno.h>
#include <stdlib.h>
#include <string.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

#include "elinks.h"

#include "intl/gettext/libintl.h"
#include "main/main.h"                  /* terminate */
#include "main/object.h"
#include "session/session.h"
#include "terminal/draw.h"
#include "terminal/event.h"
#include "terminal/kbd.h"
#include "terminal/mouse.h"
#include "terminal/tab.h"
#include "terminal/terminal.h"
#include "terminal/screen.h"
#include "terminal/window.h"
#include "util/conv.h"
#include "util/error.h"
#include "util/memory.h"
#include "util/snprintf.h"
#include "util/string.h"
#include "viewer/text/textarea.h"
#include "viewer/timer.h"


/** Information used for communication between ELinks instances */
struct terminal_interlink {
        /** How big the input queue is */
        int qlen;
        /** How much is free */
        int qfreespace;

        /** UTF-8 input key value decoding data. */
        struct {
                unicode_val_T ucs;
                int len;
                unicode_val_T min;
                /** Modifier keys from the key event that carried the
                 * first byte of the character.  We need this because
                 * ELinks sees e.g. ESC U+00F6 as 0x1B 0xC3 0xB6 and
                 * converts it to Alt-0xC3 0xB6, attaching the
                 * modifier to the first byte only.  */
                term_event_modifier_T modifier;
        } utf8;

        /** This is the queue of events as coming from the other
         * ELinks instance owning the hosting terminal. */
        unsigned char input_queue[1];
};


void
term_send_event(struct terminal *term, struct term_event *ev)
{
        struct window *win;

        assert(ev && term);
        if_assert_failed return;

        switch (ev->ev) {
        case EVENT_INIT:
        case EVENT_RESIZE:
        {
                int width = ev->info.size.width;
                int height = ev->info.size.height;

                if (width < 0 || height < 0) {
                        ERROR(gettext("Bad terminal size: %d, %d"),
                              width, height);
                        break;
                }

                resize_screen(term, width, height, ev->info.size.xres, ev->info.size.yres);
                erase_screen(term);
                /* Fall through */
        }
        case EVENT_REDRAW:
                /* Nasty hack to avoid assertion failures when doing -remote
                 * stuff and the client exits right away */
                if (!term->screen->image) break;

                clear_terminal(term);
                term->redrawing = TREDRAW_DELAYED;
                /* Note that you do NOT want to ever go and create new
                 * window inside EVENT_INIT handler (it'll get second
                 * EVENT_INIT here). Perhaps the best thing you could do
                 * is registering a bottom-half handler which will open
                 * additional windows.
                 * --pasky */
                if (ev->ev == EVENT_RESIZE) {
                        /* We want to propagate EVENT_RESIZE even to inactive
                         * tabs! Nothing wrong will get drawn (in the final
                         * result) as the active tab is always the first one,
                         * thus will be drawn last here. Thanks, Witek!
                         * --pasky */
                        foreachback (win, term->windows)
                                win->handler(win, ev);

                } else {
                        foreachback (win, term->windows)
                                if (!inactive_tab(win))
                                        win->handler(win, ev);
                }
                term->redrawing = TREDRAW_READY;
                break;

        case EVENT_MOUSE:
        case EVENT_KBD:
        case EVENT_ABORT:
                assert(!list_empty(term->windows));
                if_assert_failed break;

                /* We need to send event to correct tab, not to the first one. --karpov */
                /* ...if we want to send it to a tab at all. --pasky */
                win = term->windows.next;
                if (win->type == WINDOW_TAB) {
                        win = get_current_tab(term);
                        assertm(win != NULL, "No tab to send the event to!");
                        if_assert_failed return;
                }

                win->handler(win, ev);
        }
}

static void
term_send_ucs(struct terminal *term, unicode_val_T u,
              term_event_modifier_T modifier)
{
#ifdef CONFIG_UTF8
        struct term_event ev;

        set_kbd_term_event(&ev, u, modifier);
        term_send_event(term, &ev);
#else  /* !CONFIG_UTF8 */
        struct term_event ev;
        const unsigned char *recoded;

        set_kbd_term_event(&ev, KBD_UNDEF, modifier);
        recoded = u2cp_no_nbsp(u, get_terminal_codepage(term));
        if (!recoded) recoded = "*";
        while (*recoded) {
                ev.info.keyboard.key = *recoded;
                term_send_event(term, &ev);
                recoded++;
        }
#endif /* !CONFIG_UTF8 */
}

static void
check_terminal_name(struct terminal *term, struct terminal_info *info)
{
        unsigned char name[MAX_TERM_LEN + 10];
        int i;

        /* We check TERM env. var for sanity, and fallback to _template_ if
         * needed. This way we prevent elinks.conf potential corruption. */
        for (i = 0; info->name[i]; i++) {
                if (isident(info->name[i])) continue;

                usrerror(_("Warning: terminal name contains illicit chars.", term));
                return;
        }

        snprintf(name, sizeof(name), "terminal.%s", info->name);

        /* Unlock the default _template_ option tree that was asigned by
         * init_term() and get the correct one. */
        object_unlock(term->spec);
        term->spec = get_opt_rec(config_options, name);
        object_lock(term->spec);
#ifdef CONFIG_UTF8
        /* Probably not best place for set this. But now we finally have
         * term->spec and term->utf8 should be set before decode session info.
         * --Scrool */
        term->utf8_cp = is_cp_utf8(get_terminal_codepage(term));
        /* Force UTF-8 I/O if the UTF-8 charset is selected.  Various
         * places assume that the terminal's charset is unibyte if
         * UTF-8 I/O is disabled.  (bug 827) */
        term->utf8_io = term->utf8_cp
                || get_opt_bool_tree(term->spec, "utf_8_io", NULL);
#endif /* CONFIG_UTF8 */
}

#ifdef CONFIG_MOUSE
static int
ignore_mouse_event(struct terminal *term, struct term_event *ev)
{
        struct term_event_mouse *prev = &term->prev_mouse_event;
        struct term_event_mouse *current = &ev->info.mouse;

        if (check_mouse_action(ev, B_UP)
            && current->y == prev->y
            && (current->button & ~BM_ACT) == (prev->button & ~BM_ACT)) {
                do_not_ignore_next_mouse_event(term);

                return 1;
        }

        copy_struct(prev, current);

        return 0;
}
#endif

static int
handle_interlink_event(struct terminal *term, struct interlink_event *ilev)
{
        struct terminal_info *info = NULL;
        struct terminal_interlink *interlink = term->interlink;
        struct term_event tev;

        switch (ilev->ev) {
        case EVENT_INIT:
                if (interlink->qlen < TERMINAL_INFO_SIZE)
                        return 0;

                info = (struct terminal_info *) ilev;

                if (interlink->qlen < TERMINAL_INFO_SIZE + info->length)
                        return 0;

                info->name[MAX_TERM_LEN - 1] = 0;
                check_terminal_name(term, info);

                memcpy(term->cwd, info->cwd, MAX_CWD_LEN);
                term->cwd[MAX_CWD_LEN - 1] = 0;

                term->environment = info->system_env;

                /* We need to make sure that it is possible to draw on the
                 * terminal screen before decoding the session info so that
                 * handling of bad URL syntax by openning msg_box() will be
                 * possible. */
                set_init_term_event(&tev,
                                    ilev->info.size.width,
                                    ilev->info.size.height,
                                    ilev->info.size.xres,
                                    ilev->info.size.yres);
                term_send_event(term, &tev);

                /* Either the initialization of the first session failed or we
                 * are doing a remote session so quit.*/
                if (!decode_session_info(term, info)) {
                        destroy_terminal(term);
                        /* Make sure the user is notified if the initialization
                         * of the first session fails. */
                        if (program.terminate) {
                                usrerror(_("Failed to create session.", term));
                                program.retval = RET_FATAL;
                        }
                        return 0;
                }

                ilev->ev = EVENT_REDRAW;
                /* Fall through */
        case EVENT_REDRAW:
        case EVENT_RESIZE:
                set_wh_term_event(&tev, ilev->ev,
                                  ilev->info.size.width,
                                  ilev->info.size.height,
                                  ilev->info.size.xres,
                                  ilev->info.size.yres);
                term_send_event(term, &tev);

                /* If textarea_data is set and the terminal is not blocked,
                 * then this resize event must be the result of exiting the
                 * external editor. */
                if (term->textarea_data && term->blocked == -1)
                        textarea_edit(1, term, NULL, NULL, NULL);

                break;

        case EVENT_MOUSE:
#ifdef CONFIG_MOUSE
                reset_timer();
                tev.ev = ilev->ev;
                copy_struct(&tev.info.mouse, &ilev->info.mouse);
                if (!ignore_mouse_event(term, &tev))
                        term_send_event(term, &tev);
#endif
                break;

        case EVENT_KBD:
        {
                int utf8_io = -1;
                int key = ilev->info.keyboard.key;
                term_event_modifier_T modifier = ilev->info.keyboard.modifier;

                if (key >= 0x100)
                        key = -key;

                reset_timer();

                if (key == KBD_CTRL_C) {
                        destroy_terminal(term);
                        return 0;
                }

                /* Character Conversions.  */
#ifdef CONFIG_UTF8
                /* struct term_event_keyboard carries UCS-4.
                 * - If the "utf_8_io" option is true or the "charset"
                 *   option refers to UTF-8, then term->utf8_io is true,
                 *   and handle_interlink_event() converts from UTF-8
                 *   to UCS-4.
                 * - Otherwise, handle_interlink_event() converts from
                 *   the codepage specified with the "charset" option
                 *   to UCS-4.  */
                utf8_io = term->utf8_io;
#else
                /* struct term_event_keyboard carries bytes in the
                 * charset of the terminal.
                 * - If the "utf_8_io" option is true, then
                 *   handle_interlink_event() converts from UTF-8 to
                 *   UCS-4, and term_send_ucs() converts from UCS-4 to
                 *   the codepage specified with the "charset" option;
                 *   this codepage cannot be UTF-8.
                 * - Otherwise, handle_interlink_event() passes the
                 *   bytes straight through.  */
                utf8_io = get_opt_bool_tree(term->spec, "utf_8_io", NULL);
#endif /* CONFIG_UTF8 */

                /* In UTF-8 byte sequences that have more than one byte, the
                 * first byte is between 0xC0 and 0xFF and the remaining bytes
                 * are between 0x80 and 0xBF.  If there is just one byte, then
                 * it is between 0x00 and 0x7F and it is straight ASCII.
                 * (All 'betweens' are inclusive.) */

                if (interlink->utf8.len) {
                        /* A previous call to handle_interlink_event
                         * got a UTF-8 start byte. */

                        if (key >= 0x80 && key <= 0xBF && utf8_io) {
                                /* This is a UTF-8 continuation byte. */

                                interlink->utf8.ucs <<= 6;
                                interlink->utf8.ucs |= key & 0x3F;
                                if (! --interlink->utf8.len) {
                                        unicode_val_T u = interlink->utf8.ucs;

                                        /* UTF-8 allows neither overlong
                                         * sequences nor surrogates.  */
                                        if (u < interlink->utf8.min
                                            || is_utf16_surrogate(u))
                                                u = UCS_REPLACEMENT_CHARACTER;
                                        term_send_ucs(term, u,
                                                      term->interlink->utf8.modifier);
                                }
                                break;

                        } else {
                                /* The byte sequence for this character
                                 * is ending prematurely.  Send
                                 * UCS_REPLACEMENT_CHARACTER for the
                                 * terminated character, but don't break;
                                 * let this byte be handled below. */

                                interlink->utf8.len = 0;
                                term_send_ucs(term, UCS_REPLACEMENT_CHARACTER,
                                              term->interlink->utf8.modifier);
                        }
                }

                /* Note: We know that key <= 0xFF. */

                if (key < 0x80 || !utf8_io) {
                        /* This byte is not part of a multibyte character
                         * encoding: either it is outside of the ranges for
                         * UTF-8 start and continuation bytes or UTF-8 I/O mode
                         * is disabled. */

#ifdef CONFIG_UTF8
                        if (key >= 0 && !utf8_io) {
                                /* Not special and UTF-8 mode is disabled:
                                 * recode from the terminal charset to UCS-4. */

                                key = cp2u(get_terminal_codepage(term), key);
                                term_send_ucs(term, key, modifier);
                                break;
                        }
#endif /* !CONFIG_UTF8 */

                        /* It must be special (e.g., F1 or Enter)
                         * or a single-byte UTF-8 character. */
                        set_kbd_term_event(&tev, key, modifier);
                        term_send_event(term, &tev);
                        break;

                } else if ((key & 0xC0) == 0xC0 && (key & 0xFE) != 0xFE) {
                        /* This is a UTF-8 start byte. */

                        /* Minimum character values for UTF-8 octet
                         * sequences of each length, from RFC 2279.
                         * According to the RFC, UTF-8 decoders should
                         * reject characters that are encoded with
                         * more octets than necessary.  (RFC 3629,
                         * which ELinks does not yet otherwise follow,
                         * tightened the "should" to "MUST".)  */
                        static const unicode_val_T min[] = {
                                0x00000080, /* ... 0x000007FF with 2 octets */
                                0x00000800, /* ... 0x0000FFFF with 3 octets */
                                0x00010000, /* ... 0x001FFFFF with 4 octets */
                                0x00200000, /* ... 0x03FFFFFF with 5 octets */
                                0x04000000  /* ... 0x7FFFFFFF with 6 octets */
                        };
                        unsigned int mask;
                        int len = 0;

                        /* Set @len = the number of contiguous 1's
                         * in the most significant bits of the first
                         * octet, i.e. @key.  It is also the number
                         * of octets in the character.  Leave @mask
                         * pointing to the first 0 bit found.  */
                        for (mask = 0x80; key & mask; mask >>= 1)
                                len++;

                        /* This will hold because @key was checked above.  */
                        assert(len >= 2 && len <= 6);
                        if_assert_failed goto invalid_utf8_start_byte;

                        interlink->utf8.min = min[len - 2];
                        interlink->utf8.len = len - 1;
                        interlink->utf8.ucs = key & (mask - 1);
                        interlink->utf8.modifier = modifier;
                        break;
                }

invalid_utf8_start_byte:
                term_send_ucs(term, UCS_REPLACEMENT_CHARACTER, modifier);
                break;
        }

        case EVENT_ABORT:
                destroy_terminal(term);
                return 0;

        default:
                ERROR(gettext("Bad event %d"), ilev->ev);
        }

        /* For EVENT_INIT we read a liitle more */
        if (info) return TERMINAL_INFO_SIZE + info->length;
        return sizeof(*ilev);
}

void
in_term(struct terminal *term)
{
        struct terminal_interlink *interlink = term->interlink;
        ssize_t r;
        unsigned char *iq;

        /* Mark this as the most recently used terminal.  */
        move_to_top_of_list(terminals, term);

        if (!interlink
            || !interlink->qfreespace
            || interlink->qfreespace - interlink->qlen > ALLOC_GR) {
                int qlen = interlink ? interlink->qlen : 0;
                int queuesize = ((qlen + ALLOC_GR) & ~(ALLOC_GR - 1));
                int newsize = sizeof(*interlink) + queuesize;

                interlink = mem_realloc(interlink, newsize);
                if (!interlink) {
                        destroy_terminal(term);
                        return;
                }

                /* Blank the members for the first allocation */
                if (!term->interlink)
                        memset(interlink, 0, sizeof(*interlink));

                term->interlink = interlink;
                interlink->qfreespace = queuesize - interlink->qlen;
        }

        iq = interlink->input_queue;
        r = safe_read(term->fdin, iq + interlink->qlen, interlink->qfreespace);
        if (r <= 0) {
                if (r == -1 && errno != ECONNRESET)
                        ERROR(gettext("Could not read event: %d (%s)"),
                              errno, (unsigned char *) strerror(errno));

                destroy_terminal(term);
                return;
        }

        interlink->qlen += r;
        interlink->qfreespace -= r;

        while (interlink->qlen >= sizeof(struct interlink_event)) {
                struct interlink_event *ev = (struct interlink_event *) iq;
                int event_size = handle_interlink_event(term, ev);

                /* If the event was not handled save the bytes in the queue for
                 * later in case more stuff is read later. */
                if (!event_size) break;

                /* Acount for the handled bytes */
                interlink->qlen -= event_size;
                interlink->qfreespace += event_size;

                /* If there are no more bytes to handle stop else move next
                 * event bytes to the front of the queue. */
                if (!interlink->qlen) break;
                memmove(iq, iq + event_size, interlink->qlen);
        }
}