swaybar: hide mode visibility improvements

This allows swaybar to become visible when the mode changes (to any
mode other than the default). swaybar will be hidden again when the
modifier is pressed and released or when switching back to the default
mode.

This also applies the same logic to visible by urgency to hide swaybar
when the modifier is pressed and released.

These changes are to match i3's behavior.

include/swaybar/bar.h

@@ -23,6 +23,7 @@ struct swaybar {
 	// only relevant when bar is in "hide" mode
 	bool visible_by_modifier;
 	bool visible_by_urgency;
+	bool visible_by_mode;
 	bool visible;
 
 	struct wl_display *display;

swaybar/bar.c

@@ -148,7 +148,8 @@ bool determine_bar_visibility(struct swaybar *bar, bool moving_layer) {
 	struct swaybar_config *config = bar->config;
 	bool visible = !(strcmp(config->mode, "invisible") == 0 ||
 		(strcmp(config->mode, config->hidden_state) == 0 // both "hide"
-			&& !bar->visible_by_modifier && !bar->visible_by_urgency));
+			&& !bar->visible_by_modifier && !bar->visible_by_urgency
+			&& !bar->visible_by_mode));
 
 	// Create/destroy layer surfaces as needed
 	struct swaybar_output *output;

swaybar/ipc.c

@@ -499,6 +499,13 @@ static bool handle_bar_state_update(struct swaybar *bar, json_object *event) {
 	json_object *visible_by_modifier;
 	json_object_object_get_ex(event, "visible_by_modifier", &visible_by_modifier);
 	bar->visible_by_modifier = json_object_get_boolean(visible_by_modifier);
+	if (bar->visible_by_modifier) {
+		// If the bar is visible by modifier, clear both visible by mode and
+		// urgency as modifier has precedence and the bar should be hidden
+		// again when it is no longer visible by modifier.
+		bar->visible_by_mode = false;
+		bar->visible_by_urgency = false;
+	}
 	return determine_bar_visibility(bar, false);
 }
 
@@ -578,6 +585,8 @@ bool handle_ipc_readable(struct swaybar *bar) {
 			const char *change = json_object_get_string(json_change);
 			free(bar->mode);
 			bar->mode = strcmp(change, "default") != 0 ? strdup(change) : NULL;
+			bar->visible_by_mode = bar->mode != NULL;
+			determine_bar_visibility(bar, false);
 		} else {
 			sway_log(SWAY_ERROR, "failed to parse response");
 			bar_is_dirty = false;