log: Add swayc_log, use at a few key places.

swayc_log works just like sway_log, but appends type and name from given
container to the log output.

include/log.h

@@ -23,4 +23,6 @@ bool _sway_assert(bool condition, const char* format, ...) __attribute__((format
 void error_handler(int sig);
 
 void layout_log(const swayc_t *c, int depth);
+const char *swayc_type_string(enum swayc_types type);
+void swayc_log(log_importance_t verbosity, swayc_t *cont, const char* format, ...) __attribute__((format(printf,3,4)));
 #endif

sway/focus.c

@@ -76,7 +76,7 @@ bool set_focused_container(swayc_t *c) {
 	if (locked_container_focus || !c) {
 		return false;
 	}
-	sway_log(L_DEBUG, "Setting focus to %p:%ld", c, c->handle);
+	swayc_log(L_DEBUG, c, "Setting focus to %p:%ld", c, c->handle);
 
 	// Get workspace for c, get that workspaces current focused container.
 	swayc_t *workspace = swayc_active_workspace_for(c);

sway/layout.c

@@ -349,7 +349,7 @@ void update_geometry(swayc_t *container) {
 static void arrange_windows_r(swayc_t *container, double width, double height) {
 	int i;
 	if (width == -1 || height == -1) {
-		sway_log(L_DEBUG, "Arranging layout for %p", container);
+		swayc_log(L_DEBUG, container, "Arranging layout for %p", container);
 		width = container->width;
 		height = container->height;
 	}

sway/log.c

@@ -187,4 +187,31 @@ void layout_log(const swayc_t *c, int depth) {
 		}
 	}
 }
+
+const char *swayc_type_string(enum swayc_types type) {
+	return type == C_ROOT ? "ROOT" :
+		type == C_OUTPUT ? "OUTPUT" :
+		type == C_WORKSPACE ? "WORKSPACE" :
+		type == C_CONTAINER ? "CONTAINER" :
+		type == C_VIEW   ? "VIEW" :
+		"UNKNOWN";
+}
+
+// Like sway_log, but also appends some info about given container to log output.
+void swayc_log(log_importance_t verbosity, swayc_t *cont, const char* format, ...) {
+	sway_assert(cont, "swayc_log: no container ...");
+	va_list args;
+	va_start(args, format);
+	char *txt = malloc(128);
+	vsprintf(txt, format, args);
+	va_end(args);
+
+	char *debug_txt = malloc(32);
+	snprintf(debug_txt, 32, "%s '%s'", swayc_type_string(cont->type), cont->name);
+
+	sway_log(verbosity, "%s (%s)", txt, debug_txt);
+	free(txt);
+	free(debug_txt);
+}
+
 /* XXX:DEBUG:XXX */