Support window-rules

Two types of window rules are supported, actions and properties. They are
defined as shown below.

    <windowRules>

      <!-- Action -->
      <windowRule identifier="some-application">
        <action name="Maximize"/>
      </windowRule>

      <!-- Property -->
      <windowRule identifier="foo*" serverDecoration="yes|no"/>

    </windowRules>

Rules are applied if windows match the criteria defined by the
'identifier' attribute which relates to app_id for native Wayland windows
and WM_CLASS for XWayland clients.

Matching against patterns with '*' (wildcard) and '?' (joker) is
supported.

Add 'serverDecoration' property.

src/window-rules.c

@@ -0,0 +1,76 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#define _POSIX_C_SOURCE 200809L
+#include "config.h"
+#include <assert.h>
+#include <cairo.h>
+#include <glib.h>
+#include <strings.h>
+#include <wlr/util/log.h>
+#include "action.h"
+#include "common/match.h"
+#include "config/rcxml.h"
+#include "labwc.h"
+#include "view.h"
+#include "window-rules.h"
+
+void
+window_rules_apply(struct view *view, enum window_rule_event event)
+{
+	const char *identifier = view_get_string_prop(view, "app_id");
+	if (!identifier) {
+		return;
+	}
+
+	struct window_rule *rule;
+	wl_list_for_each(rule, &rc.window_rules, link) {
+		if (!rule->identifier || rule->event != event) {
+			continue;
+		}
+		if (match_glob(rule->identifier, identifier)) {
+			actions_run(view, view->server, &rule->actions, 0);
+		}
+	}
+}
+
+enum property
+window_rules_get_property(struct view *view, const char *property)
+{
+	assert(property);
+
+	const char *identifier = view_get_string_prop(view, "app_id");
+	if (!identifier) {
+		goto out;
+	}
+
+	/*
+	 * We iterate in reverse here because later items in list have higher
+	 * priority. For example, in the config below we want the return value
+	 * for foot's "serverDecoration" property to be "default".
+	 *
+	 *     <windowRules>
+	 *       <windowRule identifier="*" serverDecoration="no"/>
+	 *       <windowRule identifier="foot" serverDecoration="default"/>
+	 *     </windowRules>
+	 */
+	struct window_rule *rule;
+	wl_list_for_each_reverse(rule, &rc.window_rules, link) {
+		if (!rule->identifier) {
+			continue;
+		}
+		/*
+		 * Only return if property != LAB_PROP_UNSPECIFIED otherwise a
+		 * <windowRule> which does not set a particular property
+		 * attribute would still return here if that property was asked
+		 * for.
+		 */
+		if (match_glob(rule->identifier, identifier)) {
+			if (!strcasecmp(property, "serverDecoration")) {
+				if (rule->server_decoration) {
+					return rule->server_decoration;
+				}
+			}
+		}
+	}
+out:
+	return LAB_PROP_UNSPECIFIED;
+}