Add shell criteria token

Closes #2044.

include/sway/criteria.h

@@ -18,6 +18,7 @@ struct criteria {
 	char *target; // workspace or output name for `assign` criteria
 
 	pcre *title;
+	pcre *shell;
 	pcre *app_id;
 	pcre *class;
 	pcre *instance;

sway/criteria.c

@@ -13,6 +13,7 @@
 
 bool criteria_is_empty(struct criteria *criteria) {
 	return !criteria->title
+		&& !criteria->shell
 		&& !criteria->app_id
 		&& !criteria->class
 		&& !criteria->instance
@@ -29,6 +30,7 @@ bool criteria_is_empty(struct criteria *criteria) {
 
 void criteria_destroy(struct criteria *criteria) {
 	pcre_free(criteria->title);
+	pcre_free(criteria->shell);
 	pcre_free(criteria->app_id);
 	pcre_free(criteria->class);
 	pcre_free(criteria->instance);
@@ -53,6 +55,13 @@ static bool criteria_matches_view(struct criteria *criteria,
 		}
 	}
 
+	if (criteria->shell) {
+		const char *shell = view_get_type(view);
+		if (!shell || regex_cmp(shell, criteria->shell) != 0) {
+			return false;
+		}
+	}
+
 	if (criteria->app_id) {
 		const char *app_id = view_get_app_id(view);
 		if (!app_id || regex_cmp(app_id, criteria->app_id) != 0) {
@@ -206,6 +215,7 @@ enum criteria_token {
 	T_FLOATING,
 	T_ID,
 	T_INSTANCE,
+	T_SHELL,
 	T_TILING,
 	T_TITLE,
 	T_URGENT,
@@ -229,6 +239,8 @@ static enum criteria_token token_from_name(char *name) {
 		return T_ID;
 	} else if (strcmp(name, "instance") == 0) {
 		return T_INSTANCE;
+	} else if (strcmp(name, "shell") == 0) {
+		return T_SHELL;
 	} else if (strcmp(name, "title") == 0) {
 		return T_TITLE;
 	} else if (strcmp(name, "urgent") == 0) {
@@ -271,6 +283,9 @@ static char *get_focused_prop(enum criteria_token token) {
 	case T_INSTANCE:
 		value = view_get_instance(view);
 		break;
+	case T_SHELL:
+		value = view_get_type(view);
+		break;
 	case T_TITLE:
 		value = view_get_class(view);
 		break;
@@ -332,6 +347,9 @@ static bool parse_token(struct criteria *criteria, char *name, char *value) {
 	case T_TITLE:
 		generate_regex(&criteria->title, effective_value);
 		break;
+	case T_SHELL:
+		generate_regex(&criteria->shell, effective_value);
+		break;
 	case T_APP_ID:
 		generate_regex(&criteria->app_id, effective_value);
 		break;

sway/sway.5.scd

@@ -551,6 +551,11 @@ The following attributes may be matched with:
 	value is \_\_focused\_\_, then the window instance must be the same as that
 	of the currently focused window.
 
+*shell*
+	Compare value against the window shell, such as "xdg\_shell" or "xwayland".
+	Can be a regular expression. If value is \_\_focused\_\_, then the shell
+	must be the same as that of the currently focused window.
+
 *tiling*
 	Matches tiling windows.