term.c

/*
 * Copyright (c) 2014 The Chromium OS Authors. All rights reserved.
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include <ctype.h>
#include <libtsm.h>
#include <paths.h>
#include <stdio.h>

#include "font.h"
#include "input.h"
#include "keysym.h"
#include "shl_pty.h"
#include "term.h"
#include "util.h"
#include "video.h"

struct term {
	struct tsm_screen *screen;
	struct tsm_vte *vte;
	struct shl_pty *pty;
	int pty_bridge;
	int pid;
	tsm_age_t age;
	int char_x, char_y;
	int pitch;
	uint32_t *dst_image;
	int shift_state;
	int control_state;
};

static struct term term;

static void __attribute__ ((noreturn)) term_run_child()
{
	char **argv = (char *[]) {
		getenv("SHELL") ? : _PATH_BSHELL,
		"-il",
		NULL
	};

	printf("Welcome to frecon!\n");
	printf("running %s\n", argv[0]);
	/* XXX figure out how to fix "top" for xterm-256color */
	setenv("TERM", "xterm", 1);
	execve(argv[0], argv, environ);
	exit(1);
}

static int term_draw_cell(struct tsm_screen *screen, uint32_t id,
			  const uint32_t * ch, size_t len,
			  unsigned int cwidth, unsigned int posx,
			  unsigned int posy,
			  const struct tsm_screen_attr *attr,
			  tsm_age_t age, void *data)
{
	uint32_t front_color, back_color;

	if (age && term.age && age <= term.age)
		return 0;

	front_color = (attr->fr << 16) | (attr->fg << 8) | attr->fb;
	back_color = (attr->br << 16) | (attr->bg << 8) | attr->bb;

	if (attr->inverse) {
		uint32_t tmp = front_color;
		front_color = back_color;
		back_color = tmp;
	}

	if (len)
		font_render(term.dst_image, posx, posy, term.pitch, *ch,
			    front_color, back_color);
	else
		font_fillchar(term.dst_image, posx, posy, term.pitch,
			      front_color, back_color);

	return 0;
}

void term_redraw()
{
	term.dst_image = video_lock();
	term.age = tsm_screen_draw(term.screen, term_draw_cell, NULL);
	video_unlock();
}

void term_key_event(uint32_t keysym, int32_t unicode)
{

	if (tsm_vte_handle_keyboard(term.vte, keysym, 0, 0, unicode))
		tsm_screen_sb_reset(term.screen);

	term_redraw();
}

static void term_read_cb(struct shl_pty *pty, char *u8, size_t len, void *data)
{
	struct term *term = data;

	tsm_vte_input(term->vte, u8, len);

	term_redraw();
}

static void term_write_cb(struct tsm_vte *vte, const char *u8, size_t len,
			  void *data)
{
	struct term *term = data;
	int r;

	r = shl_pty_write(term->pty, u8, len);
	if (r < 0)
		printf("OOM in pty-write (%d)", r);

	shl_pty_dispatch(term->pty);
}

static const char *sev2str_table[] = {
	"FATAL",
	"ALERT",
	"CRITICAL",
	"ERROR",
	"WARNING",
	"NOTICE",
	"INFO",
	"DEBUG"
};

static const char *sev2str(unsigned int sev)
{
	if (sev > 7)
		return "DEBUG";

	return sev2str_table[sev];
}

static void log_tsm(void *data, const char *file, int line, const char *fn,
		    const char *subs, unsigned int sev, const char *format,
		    va_list args)
{
	fprintf(stderr, "%s: %s: ", sev2str(sev), subs);
	vfprintf(stderr, format, args);
	fprintf(stderr, "\n");
}

static int term_special_key(struct input_key_event *ev)
{
	switch (ev->code) {
	case KEY_LEFTSHIFT:
	case KEY_RIGHTSHIFT:
		term.shift_state = ! !ev->value;
		return 1;
	case KEY_LEFTCTRL:
	case KEY_RIGHTCTRL:
		term.control_state = ! !ev->value;
		return 1;
	}

	if (term.shift_state && ev->value) {
		switch (ev->code) {
		case KEY_PAGEUP:
			tsm_screen_sb_page_up(term.screen, 1);
			term_redraw();
			return 1;
		case KEY_PAGEDOWN:
			tsm_screen_sb_page_down(term.screen, 1);
			term_redraw();
			return 1;
		case KEY_UP:
			tsm_screen_sb_up(term.screen, 1);
			term_redraw();
			return 1;
		case KEY_DOWN:
			tsm_screen_sb_down(term.screen, 1);
			term_redraw();
			return 1;
		}
	}

	return 0;
}

static void term_get_keysym_and_unicode(struct input_key_event *event,
					uint32_t * keysym, uint32_t * unicode)
{
	struct {
		uint32_t code;
		uint32_t keysym;
	} non_ascii_keys[] = {
		{ KEY_ESC, KEYSYM_ESC},
		{ KEY_HOME, KEYSYM_HOME},
		{ KEY_LEFT, KEYSYM_LEFT},
		{ KEY_UP, KEYSYM_UP},
		{ KEY_RIGHT, KEYSYM_RIGHT},
		{ KEY_DOWN, KEYSYM_DOWN},
		{ KEY_PAGEUP, KEYSYM_PAGEUP},
		{ KEY_PAGEDOWN, KEYSYM_PAGEDOWN},
		{ KEY_END, KEYSYM_END},
		{ KEY_INSERT, KEYSYM_INSERT},
		{ KEY_DELETE, KEYSYM_DELETE},
	};

	for (unsigned i = 0; i < ARRAY_SIZE(non_ascii_keys); i++) {
		if (non_ascii_keys[i].code == event->code) {
			*keysym = non_ascii_keys[i].keysym;
			*unicode = -1;
			return;
		}
	}

	if (event->code >= ARRAY_SIZE(keysym_table) / 2) {
		*keysym = '?';
	} else {
		*keysym = keysym_table[event->code * 2 + term.shift_state];
		if ((term.control_state) && isascii(*keysym))
			*keysym = tolower(*keysym) - 'a' + 1;
	}

	*unicode = *keysym;
}

int term_run()
{
	int input_fd = input_get_fd();
	int pty_fd = term.pty_bridge;
	fd_set read_set, exception_set;

	while (1) {
		FD_ZERO(&read_set);
		FD_SET(input_fd, &read_set);
		FD_SET(pty_fd, &read_set);
		FD_ZERO(&exception_set);
		FD_SET(input_fd, &exception_set);
		FD_SET(pty_fd, &exception_set);

		int maxfd = MAX(input_fd, pty_fd) + 1;

		select(maxfd, &read_set, NULL, &exception_set, NULL);

		if (FD_ISSET(input_fd, &exception_set)
		    || FD_ISSET(pty_fd, &exception_set))
			return -1;

		if (FD_ISSET(input_fd, &read_set)) {
			struct input_key_event *event;
			event = input_get_event();
			if (event) {
				if (!term_special_key(event) && event->value) {
					uint32_t keysym, unicode;
					term_get_keysym_and_unicode(event,
								    &keysym,
								    &unicode);
					term_key_event(keysym, unicode);
				}

				input_put_event(event);
			}
		}

		if (FD_ISSET(pty_fd, &read_set)) {
			shl_pty_bridge_dispatch(term.pty_bridge, 0);
		}
	}
	return 0;
}

int term_init(int32_t width, int32_t height, int32_t pitch, int32_t scaling)
{
	const int scrollback_size = 200;
	uint32_t char_width, char_height;
	int ret;

	font_init(scaling);
	font_get_size(&char_width, &char_height);

	term.char_x = width / char_width;
	term.char_y = height / char_height;
	term.pitch = pitch;

	ret = tsm_screen_new(&term.screen, log_tsm, &term);
	if (ret < 0)
		return ret;

	tsm_screen_set_max_sb(term.screen, scrollback_size);

	ret = tsm_vte_new(&term.vte, term.screen, term_write_cb, &term, log_tsm,
			  &term);

	if (ret < 0)
		return ret;

	term.pty_bridge = shl_pty_bridge_new();
	if (term.pty_bridge < 0)
		return term.pty_bridge;

	ret = shl_pty_open(&term.pty, term_read_cb, &term, term.char_x,
			   term.char_y);
	if (ret < 0) {
		return ret;
	} else if (!ret) {
		term_run_child();
		exit(1);
	}

	ret = shl_pty_bridge_add(term.pty_bridge, term.pty);
	if (ret) {
		shl_pty_close(term.pty);
		return ret;
	}

	term.pid = shl_pty_get_child(term.pty);

	ret = tsm_screen_resize(term.screen, term.char_x, term.char_y);
	if (ret < 0)
		return ret;

	ret = shl_pty_resize(term.pty, term.char_x, term.char_y);
	if (ret < 0)
		return ret;

	return 0;
}

void term_close()
{
}