degesch: add a prompt hook

degesch.c

@@ -1984,6 +1984,20 @@ struct irc_hook_vtable
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 
+struct prompt_hook
+{
+	struct hook super;                  ///< Common hook fields
+	struct prompt_hook_vtable *vtable;  ///< Methods
+};
+
+struct prompt_hook_vtable
+{
+	/// Returns what the prompt should look like right now based on other state
+	char *(*make) (struct prompt_hook *self);
+};
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
 struct completion_word
 {
 	size_t start;                       ///< Offset to start of word
@@ -2086,6 +2100,7 @@ struct app_context
 	struct plugin *plugins;             ///< Loaded plugins
 	struct hook *input_hooks;           ///< Input hooks
 	struct hook *irc_hooks;             ///< IRC hooks
+	struct hook *prompt_hooks;          ///< Prompt hooks
 	struct hook *completion_hooks;      ///< Autocomplete hooks
 }
 *g_ctx;
@@ -5920,6 +5935,18 @@ make_server_postfix (struct buffer *buffer, struct str *output)
 static void
 make_prompt (struct app_context *ctx, struct str *output)
 {
+	LIST_FOR_EACH (struct hook, iter, ctx->prompt_hooks)
+	{
+		struct prompt_hook *hook = (struct prompt_hook *) iter;
+		char *made = hook->vtable->make (hook);
+		if (made)
+		{
+			str_append (output, made);
+			free (made);
+			return;
+		}
+	}
+
 	struct buffer *buffer = ctx->current_buffer;
 	if (!buffer)
 		return;
@@ -5954,6 +5981,7 @@ make_prompt (struct app_context *ctx, struct str *output)
 		make_server_postfix (buffer, output);
 
 	str_append_c (output, ']');
+	str_append_c (output, ' ');
 }
 
 static void
@@ -5976,7 +6004,6 @@ on_refresh_prompt (struct app_context *ctx)
 	struct str prompt;
 	str_init (&prompt);
 	make_prompt (ctx, &prompt);
-	str_append_c (&prompt, ' ');
 	char *localized = iconv_xstrdup (ctx->term_from_utf8, prompt.str, -1, NULL);
 	str_free (&prompt);
 
@@ -8752,6 +8779,7 @@ enum lua_hook_type
 	XLUA_HOOK_DEFUNCT,                  ///< No longer functional
 	XLUA_HOOK_INPUT,                    ///< Input hook
 	XLUA_HOOK_IRC,                      ///< IRC hook
+	XLUA_HOOK_PROMPT,                   ///< Prompt hook
 	XLUA_HOOK_COMPLETION,               ///< Autocomplete
 	XLUA_HOOK_TIMER,                    ///< One-shot timer
 };
@@ -8766,6 +8794,7 @@ struct lua_hook
 		struct hook hook;               ///< Hook base structure
 		struct input_hook input_hook;   ///< Input hook
 		struct irc_hook irc_hook;       ///< IRC hook
+		struct prompt_hook prompt_hook; ///< IRC hook
 		struct completion_hook c_hook;  ///< Autocomplete hook
 
 		struct poller_timer timer;      ///< Timer
@@ -8785,6 +8814,9 @@ lua_hook_unhook (lua_State *L)
 	case XLUA_HOOK_IRC:
 		LIST_UNLINK (hook->plugin->ctx->irc_hooks,        &hook->data.hook);
 		break;
+	case XLUA_HOOK_PROMPT:
+		LIST_UNLINK (hook->plugin->ctx->prompt_hooks,     &hook->data.hook);
+		break;
 	case XLUA_HOOK_COMPLETION:
 		LIST_UNLINK (hook->plugin->ctx->completion_hooks, &hook->data.hook);
 		break;
@@ -8879,6 +8911,36 @@ struct irc_hook_vtable lua_irc_hook_vtable =
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 
+static char *
+lua_prompt_hook_make (struct prompt_hook *self)
+{
+	struct lua_hook *hook =
+		CONTAINER_OF (self, struct lua_hook, data.prompt_hook);
+	struct lua_plugin *plugin = hook->plugin;
+	lua_State *L = plugin->L;
+
+	lua_rawgeti (L, LUA_REGISTRYINDEX, hook->ref_callback);
+	lua_rawgetp (L, LUA_REGISTRYINDEX, hook);  // 1: hook
+
+	struct error *e = NULL;
+	char *prompt = xstrdup ("");
+	if (lua_plugin_call (plugin, 1, 1, &e))
+	{
+		lua_plugin_handle_string_filter_result (plugin, &prompt, false, &e);
+		lua_pop (L, 1);
+	}
+	if (e)
+		lua_plugin_log_error (plugin, "Prompt hook", e);
+	return prompt;
+}
+
+struct prompt_hook_vtable lua_prompt_hook_vtable =
+{
+	.make = lua_prompt_hook_make,
+};
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
 static void
 lua_plugin_push_completion (lua_State *L, struct completion *data)
 {
@@ -9037,6 +9099,18 @@ lua_plugin_hook_irc (lua_State *L)
 	return 1;
 }
 
+static int
+lua_plugin_hook_prompt (lua_State *L)
+{
+	struct lua_plugin *plugin = lua_touserdata (L, lua_upvalueindex (1));
+	struct lua_hook *hook = lua_plugin_push_hook
+		(plugin, 1, XLUA_HOOK_PROMPT, luaL_optinteger (L, 2, 0));
+	hook->data.prompt_hook.vtable = &lua_prompt_hook_vtable;
+	plugin->ctx->prompt_hooks =
+		hook_insert (plugin->ctx->prompt_hooks, &hook->data.hook);
+	return 1;
+}
+
 static int
 lua_plugin_hook_completion (lua_State *L)
 {
@@ -9745,6 +9819,7 @@ static luaL_Reg lua_plugin_library[] =
 	{ "parse",           lua_plugin_parse           },
 	{ "hook_input",      lua_plugin_hook_input      },
 	{ "hook_irc",        lua_plugin_hook_irc        },
+	{ "hook_prompt",     lua_plugin_hook_prompt     },
 	{ "hook_completion", lua_plugin_hook_completion },
 	{ "hook_timer",      lua_plugin_hook_timer      },
 	{ "setup_config",    lua_plugin_setup_config    },