lite/src/api/system.c

#define _XOPEN_SOURCE 700

#include <sys/stat.h>

#include <stdbool.h>
#include <ctype.h>
#include <dirent.h>
#include <unistd.h>
#include <errno.h>
#include <limits.h>
#include <stdlib.h>
#include <SDL2/SDL.h>

#include "api.h"
#include "rencache.h"

extern SDL_Window *window;

static const char* button_name(int button)
{
	switch (button) {
	case 1  : return "left";
	case 2  : return "middle";
	case 3  : return "right";
	default : return "?";
	}
}

static char* key_name(char *dst, int sym)
{
	strcpy(dst, SDL_GetKeyName(sym));
	for (char *p = dst; *p; p++)
		*p = tolower(*p);
	return dst;
}


static int f_poll_event(lua_State *L)
{
	char buf[16];
	int mx, my, wx, wy;
	SDL_Event e;

top:
	if ( !SDL_PollEvent(&e) )
		return 0;

	switch (e.type) {
	case SDL_QUIT:
		lua_pushstring(L, "quit");
		return 1;

	case SDL_WINDOWEVENT:
		if (e.window.event == SDL_WINDOWEVENT_RESIZED) {
			lua_pushstring(L, "resized");
			lua_pushnumber(L, e.window.data1);
			lua_pushnumber(L, e.window.data2);
			return 3;
		} else if (e.window.event == SDL_WINDOWEVENT_EXPOSED) {
			rencache_invalidate();
			lua_pushstring(L, "exposed");
			return 1;
		}
		/* on some systems, when alt-tabbing to the window SDL will
		 * queue up several KEYDOWN events for the `tab` key; we flush
		 * all keydown events on focus so these are discarded */
		if (e.window.event == SDL_WINDOWEVENT_FOCUS_GAINED)
			SDL_FlushEvent(SDL_KEYDOWN);
		goto top;

	case SDL_DROPFILE:
		SDL_GetGlobalMouseState(&mx, &my);
		SDL_GetWindowPosition(window, &wx, &wy);
		lua_pushstring(L, "filedropped");
		lua_pushstring(L, e.drop.file);
		lua_pushnumber(L, mx - wx);
		lua_pushnumber(L, my - wy);
		SDL_free(e.drop.file);
		return 4;

	case SDL_KEYDOWN:
		lua_pushstring(L, "keypressed");
		lua_pushstring(L, key_name(buf, e.key.keysym.sym));
		return 2;

	case SDL_KEYUP:
		lua_pushstring(L, "keyreleased");
		lua_pushstring(L, key_name(buf, e.key.keysym.sym));
		return 2;

	case SDL_TEXTINPUT:
		lua_pushstring(L, "textinput");
		lua_pushstring(L, e.text.text);
		return 2;

	case SDL_MOUSEBUTTONDOWN:
		if (e.button.button == 1)
			SDL_CaptureMouse(1);
		lua_pushstring(L, "mousepressed");
		lua_pushstring(L, button_name(e.button.button));
		lua_pushnumber(L, e.button.x);
		lua_pushnumber(L, e.button.y);
		lua_pushnumber(L, e.button.clicks);
		return 5;

	case SDL_MOUSEBUTTONUP:
		if (e.button.button == 1)
			SDL_CaptureMouse(0);
		lua_pushstring(L, "mousereleased");
		lua_pushstring(L, button_name(e.button.button));
		lua_pushnumber(L, e.button.x);
		lua_pushnumber(L, e.button.y);
		return 4;

	case SDL_MOUSEMOTION:
		lua_pushstring(L, "mousemoved");
		lua_pushnumber(L, e.motion.x);
		lua_pushnumber(L, e.motion.y);
		lua_pushnumber(L, e.motion.xrel);
		lua_pushnumber(L, e.motion.yrel);
		return 5;

	case SDL_MOUSEWHEEL:
		lua_pushstring(L, "mousewheel");
		lua_pushnumber(L, e.wheel.y);
		lua_pushnumber(L, e.wheel.x);
		return 3;

	default:
		goto top;
	}

	return 0;
}

static int f_wait_event(lua_State *L)
{
	double n = luaL_checknumber(L, 1);
	lua_pushboolean(L, SDL_WaitEventTimeout(NULL, n * 1000));
	return 1;
}


static SDL_Cursor* cursor_cache[SDL_SYSTEM_CURSOR_HAND + 1];

static const char *cursor_opts[] = {
    "arrow",
    "ibeam",
    "sizeh",
    "sizev",
    "hand",
    NULL
};

static const int cursor_enums[] = {
    SDL_SYSTEM_CURSOR_ARROW,
    SDL_SYSTEM_CURSOR_IBEAM,
    SDL_SYSTEM_CURSOR_SIZEWE,
    SDL_SYSTEM_CURSOR_SIZENS,
    SDL_SYSTEM_CURSOR_HAND
};

static int f_set_cursor(lua_State *L)
{
	int opt = luaL_checkoption(L, 1, "arrow", cursor_opts);
	int n = cursor_enums[opt];
	SDL_Cursor *cursor = cursor_cache[n];
	if (!cursor) {
		cursor = SDL_CreateSystemCursor(n);
		cursor_cache[n] = cursor;
	}
	SDL_SetCursor(cursor);
	return 0;
}

static int f_set_window_title(lua_State *L)
{
	const char *title = luaL_checkstring(L, 1);
	SDL_SetWindowTitle(window, title);
	return 0;
}

static const char *window_opts[] = { "normal", "maximized", "fullscreen", 0 };
enum { WIN_NORMAL, WIN_MAXIMIZED, WIN_FULLSCREEN };

static int f_set_window_mode(lua_State *L)
{
	int n = luaL_checkoption(L, 1, "normal", window_opts);
	SDL_SetWindowFullscreen(window,
	    n == WIN_FULLSCREEN ? SDL_WINDOW_FULLSCREEN_DESKTOP : 0);
	if (n == WIN_NORMAL)
		SDL_RestoreWindow(window);
	if (n == WIN_MAXIMIZED)
		SDL_MaximizeWindow(window);
	return 0;
}

static int f_window_has_focus(lua_State *L)
{
  unsigned flags = SDL_GetWindowFlags(window);
  lua_pushboolean(L, flags & SDL_WINDOW_INPUT_FOCUS);
  return 1;
}

static int f_show_confirm_dialog(lua_State *L)
{
	const char *title = luaL_checkstring(L, 1);
	const char *msg = luaL_checkstring(L, 2);

	SDL_MessageBoxButtonData buttons[] = {
	    { SDL_MESSAGEBOX_BUTTON_RETURNKEY_DEFAULT, 1, "Yes" },
	    { SDL_MESSAGEBOX_BUTTON_ESCAPEKEY_DEFAULT, 0, "No" },
	};
	SDL_MessageBoxData data = {
	    .title = title,
	    .message = msg,
	    .numbuttons = 2,
	    .buttons = buttons,
	};
	int buttonid;
	SDL_ShowMessageBox(&data, &buttonid);
	lua_pushboolean(L, buttonid == 1);
	return 1;
}

static int f_chdir(lua_State *L)
{
	const char *path = luaL_checkstring(L, 1);
	int err = chdir(path);
	if (err)
		luaL_error(L, "chdir() failed");
	return 0;
}


static int f_list_dir(lua_State *L)
{
	const char *path = luaL_checkstring(L, 1);

	DIR *dir = opendir(path);
	if (!dir) {
		lua_pushnil(L);
		lua_pushstring(L, strerror(errno));
		return 2;
	}

	lua_newtable(L);
	int i = 1;
	struct dirent *entry;
	while ( (entry = readdir(dir)) ) {
		if (strcmp(entry->d_name, "." ) == 0)
			continue;
		if (strcmp(entry->d_name, "..") == 0)
			continue;
		lua_pushstring(L, entry->d_name);
		lua_rawseti(L, -2, i);
		i++;
	}

	closedir(dir);
	return 1;
}

static int f_absolute_path(lua_State *L)
{
	const char *path = luaL_checkstring(L, 1);
	char *res = realpath(path, NULL);
	if (!res)
		return 0;
	lua_pushstring(L, res);
	free(res);
	return 1;
}

static int f_get_file_info(lua_State *L)
{
	const char *path = luaL_checkstring(L, 1);

	struct stat s;
	int err = stat(path, &s);
	if (err < 0) {
		lua_pushnil(L);
		lua_pushstring(L, strerror(errno));
		return 2;
	}

	lua_newtable(L);
	lua_pushnumber(L, s.st_mtime);
	lua_setfield(L, -2, "modified");

	lua_pushnumber(L, s.st_size);
	lua_setfield(L, -2, "size");

	if (S_ISREG(s.st_mode)) {
		lua_pushstring(L, "file");
	} else if (S_ISDIR(s.st_mode)) {
		lua_pushstring(L, "dir");
	} else {
		lua_pushnil(L);
	}
	lua_setfield(L, -2, "type");

	return 1;
}

static int f_get_clipboard(lua_State *L)
{
	char *text = SDL_GetClipboardText();
	if (!text)
		return 0;
	lua_pushstring(L, text);
	SDL_free(text);
	return 1;
}

static int f_set_clipboard(lua_State *L)
{
	const char *text = luaL_checkstring(L, 1);
	SDL_SetClipboardText(text);
	return 0;
}

static int f_get_time(lua_State *L)
{
	double n = SDL_GetPerformanceCounter() / (double)SDL_GetPerformanceFrequency();
	lua_pushnumber(L, n);
	return 1;
}

static int f_sleep(lua_State *L)
{
	double n = luaL_checknumber(L, 1);
	SDL_Delay(n * 1000);
	return 0;
}


static int f_exec(lua_State *L)
{
	size_t len;
	const char *cmd = luaL_checklstring(L, 1, &len);
	char *buf = malloc(len + 32);
	if (!buf)
		luaL_error(L, "buffer allocation failed");
	sprintf(buf, "%s &", cmd);
	int res = system(buf);
	(void) res;
	free(buf);
	return 0;
}


static int f_fuzzy_match(lua_State *L)
{
	const char *str = luaL_checkstring(L, 1);
	const char *ptn = luaL_checkstring(L, 2);
	int score = 0;
	int run = 0;

	while (*str && *ptn) {
		while (*str == ' ')
			str++;
		while (*ptn == ' ')
			ptn++;
		if (tolower(*str) == tolower(*ptn)) {
			score += run * 10 - (*str != *ptn);
			run++;
			ptn++;
		} else {
			score -= 10;
			run = 0;
		}
		str++;
	}
	if (*ptn)
		return 0;

	lua_pushnumber(L, score - (int) strlen(str));
	return 1;
}


static const luaL_Reg lib[] = {
    { "poll_event",          f_poll_event          },
    { "wait_event",          f_wait_event          },
    { "set_cursor",          f_set_cursor          },
    { "set_window_title",    f_set_window_title    },
    { "set_window_mode",     f_set_window_mode     },
    { "window_has_focus",    f_window_has_focus    },
    { "show_confirm_dialog", f_show_confirm_dialog },
    { "chdir",               f_chdir               },
    { "list_dir",            f_list_dir            },
    { "absolute_path",       f_absolute_path       },
    { "get_file_info",       f_get_file_info       },
    { "get_clipboard",       f_get_clipboard       },
    { "set_clipboard",       f_set_clipboard       },
    { "get_time",            f_get_time            },
    { "sleep",               f_sleep               },
    { "exec",                f_exec                },
    { "fuzzy_match",         f_fuzzy_match         },
    { NULL, NULL }
};


int luaopen_system(lua_State *L)
{
	luaL_newlib(L, lib);
	return 1;
}