vis: refactor Lua integration

Lua support can now be disabled at compile time using:

 $ make CONFIG_LUA=0

This commit also adds an initial Lua API and provides a few
default hooks.

We now also require Lua >= 5.2 due to the uservalue constructs.
In principle the same functionality could be implemented using
function environments from Lua 5.1.

1 files changed, 15 insertions, 103 deletions

diff --git a/vis.c b/vis.c
index 3825500..f23c42e 100644
--- a/vis.c
+++ b/vis.c
@@ -34,9 +34,6 @@
 #include <sys/ioctl.h>
 #include <sys/mman.h>
 #include <pwd.h>
-#include <lauxlib.h>
-#include <lualib.h>
-#include <lua.h>
 #include <termkey.h>
 
 #include "vis.h"
@@ -67,7 +64,8 @@ static void file_free(Vis *vis, File *file) {
 		return;
 	if (--file->refcount > 0)
 		return;
-
+	if (vis->event && vis->event->file_close)
+		vis->event->file_close(vis, file);
 	text_free(file->text);
 	free((char*)file->name);
 
@@ -120,30 +118,17 @@ static File *file_new(Vis *vis, const char *filename) {
 
 	if (filename)
 		file->name = strdup(filename);
+	if (vis->event && vis->event->file_open)
+		vis->event->file_open(vis, file);
 	return file;
 }
 
 void vis_window_name(Win *win, const char *filename) {
-	lua_State *L = win->vis->lua;
 	File *file = win->file;
 	if (filename != file->name) {
 		free((char*)file->name);
 		file->name = filename ? strdup(filename) : NULL;
 	}
-
-	if (filename && L) {
-		lua_getglobal(L, "vis");
-		lua_getfield(L, -1, "lexers");
-		lua_getfield(L, -1, "lexer_name");
-		lua_pushstring(L, filename);
-		lua_pcall(L, 1, 1, 0);
-		if (lua_isstring(L, -1)) {
-			const char *lexer_name = lua_tostring(L, -1);
-			if (lexer_name)
-				view_syntax_set(win->view, lexer_name);
-		}
-		lua_pop(L, 2); /* return value: lexer name, lexers variable */
-	}
 }
 
 static void windows_invalidate(Vis *vis, size_t start, size_t end) {
@@ -189,6 +174,8 @@ static Win *window_new_file(Vis *vis, File *file) {
 	vis->windows = win;
 	vis->win = win;
 	vis->ui->window_focus(win->ui);
+	if (vis->event && vis->event->win_open)
+		vis->event->win_open(vis, win);
 	return win;
 }
 
@@ -278,6 +265,8 @@ bool vis_window_new(Vis *vis, const char *filename) {
 
 void vis_window_close(Win *win) {
 	Vis *vis = win->vis;
+	if (vis->event && vis->event->win_close)
+		vis->event->win_close(vis, win);
 	file_free(vis, win->file);
 	if (win->prev)
 		win->prev->next = win->next;
@@ -295,70 +284,14 @@ void vis_window_close(Win *win) {
 	vis_draw(vis);
 }
 
-Vis *vis_new(Ui *ui) {
+Vis *vis_new(Ui *ui, VisEvent *event) {
 	if (!ui)
 		return NULL;
 	Vis *vis = calloc(1, sizeof(Vis));
 	if (!vis)
 		return NULL;
-	lua_State *L = luaL_newstate();
-	if (!(vis->lua = L))
-		goto err;
-	luaL_openlibs(L);
-
-	/* try to get users home directory */
-	const char *home = getenv("HOME");
-	if (!home || !*home) {
-		struct passwd *pw = getpwuid(getuid());
-		if (pw)
-			home = pw->pw_dir;
-	}
-
-	/* extends lua's package.path with:
-	 * - $VIS_PATH/lexers
-	 * - $HOME/.vis/lexers
-	 * - /usr/local/share/vis/lexers
-	 * - /usr/share/vis/lexers
-	 * - package.path (standard lua search path)
-	 */
-	int paths = 3;
-	lua_getglobal(L, "package");
-
-	const char *vis_path = getenv("VIS_PATH");
-	if (vis_path) {
-		lua_pushstring(L, vis_path);
-		lua_pushstring(L, "/lexers/?.lua;");
-		lua_concat(L, 2);
-		paths++;
-	}
-
-	if (home && *home) {
-		lua_pushstring(L, home);
-		lua_pushstring(L, "/.vis/lexers/?.lua;");
-		lua_concat(L, 2);
-		paths++;
-	}
-
-	lua_pushstring(L, "/usr/local/share/vis/lexers/?.lua;");
-	lua_pushstring(L, "/usr/share/vis/lexers/?.lua;");
-	lua_getfield(L, -paths, "path");
-	lua_concat(L, paths);
-	lua_setfield(L, -2, "path");
-	lua_pop(L, 1); /* package */
-
-	/* try to load the lexer module */
-	lua_getglobal(L, "require");
-	lua_pushstring(L, "lexer");
-	if (lua_pcall(L, 1, 1, 0)) {
-		lua_close(L);
-		vis->lua = L = NULL;
-	} else {
-		lua_newtable(L); /* vis */
-		lua_pushvalue(L, -2); /* require return value */
-		lua_setfield(L, -2, "lexers");
-		lua_setglobal(L, "vis");
-	}
-
+	if (event && event->vis_start)
+		event->vis_start(vis);
 	vis->ui = ui;
 	vis->ui->init(vis->ui, vis);
 	vis->tabwidth = 8;
@@ -381,6 +314,7 @@ Vis *vis_new(Ui *ui) {
 	if (!(vis->search_pattern = text_regex_new()))
 		goto err;
 	vis->mode_prev = vis->mode = &vis_modes[VIS_MODE_NORMAL];
+	vis->event = event;
 	return vis;
 err:
 	vis_free(vis);
@@ -390,8 +324,9 @@ err:
 void vis_free(Vis *vis) {
 	if (!vis)
 		return;
-	if (vis->lua)
-		lua_close(vis->lua);
+	if (vis->event && vis->event->vis_quit)
+		vis->event->vis_quit(vis);
+	vis->event = NULL;
 	while (vis->windows)
 		vis_window_close(vis->windows);
 	file_free(vis, vis->prompt->file);
@@ -1352,26 +1287,3 @@ const char *vis_file_name(File *file) {
 	return file->name;
 }
 
-bool vis_theme_load(Vis *vis, const char *name) {
-	lua_State *L = vis->lua;
-	if (!L)
-		return false;
-	/* package.loaded['themes/'..name] = nil
-	 * require 'themes/'..name */
-	lua_pushstring(L, "themes/");
-	lua_pushstring(L, name);
-	lua_concat(L, 2);
-	lua_getglobal(L, "package");
-	lua_getfield(L, -1, "loaded");
-	lua_pushvalue(L, -3);
-	lua_pushnil(L);
-	lua_settable(L, -3);
-	lua_pop(L, 2);
-	lua_getglobal(L, "require");
-	lua_pushvalue(L, -2);
-	if (lua_pcall(L, 1, 0, 0))
-		return false;
-	for (Win *win = vis->windows; win; win = win->next)
-		view_syntax_set(win->view, view_syntax_get(win->view));
-	return true;
-}