swaybar: handle mode/hidden_state changes

As well as adding the hidden_state property to the bar config struct,
this commit handles barconfig_update events when the mode or
hidden_state changes, and uses a new function determine_bar_visibility
to hide or show the bar as required, using, respectively,
destroy_layer_surface, which is also newly added, and add_layer_surface,
which has been changed to allow dynamically adding the surface.

1 files changed, 55 insertions, 7 deletions

diff --git a/swaybar/bar.c b/swaybar/bar.c
index 77294136..6894383d 100644
--- a/swaybar/bar.c
+++ b/swaybar/bar.c
@@ -32,6 +32,7 @@
 
 static void bar_init(struct swaybar *bar) {
         bar->config = init_config();
+        bar->visible = true;
         wl_list_init(&bar->outputs);
 }
 
@@ -338,21 +339,65 @@ const struct wl_seat_listener seat_listener = {
 };
 
 static void add_layer_surface(struct swaybar_output *output) {
-        if (output->surface != NULL) {
+        if (output->layer_surface) {
                 return;
         }
         struct swaybar *bar = output->bar;
 
-        output->surface = wl_compositor_create_surface(bar->compositor);
-        assert(output->surface);
+        struct swaybar_config *config = bar->config;
+        bool hidden = strcmp(config->mode, "hide") == 0;
         output->layer_surface = zwlr_layer_shell_v1_get_layer_surface(
                         bar->layer_shell, output->surface, output->output,
+                        hidden ? ZWLR_LAYER_SHELL_V1_LAYER_TOP :
                         ZWLR_LAYER_SHELL_V1_LAYER_BOTTOM, "panel");
         assert(output->layer_surface);
         zwlr_layer_surface_v1_add_listener(output->layer_surface,
                         &layer_surface_listener, output);
-        zwlr_layer_surface_v1_set_anchor(output->layer_surface,
-                        bar->config->position);
+
+        zwlr_layer_surface_v1_set_anchor(output->layer_surface, config->position);
+        if (hidden) {
+                zwlr_layer_surface_v1_set_exclusive_zone(output->layer_surface, -1);
+        }
+}
+
+static void destroy_layer_surface(struct swaybar_output *output) {
+        if (!output->layer_surface) {
+                return;
+        }
+        zwlr_layer_surface_v1_destroy(output->layer_surface);
+        wl_surface_attach(output->surface, NULL, 0, 0); // detach buffer
+        output->layer_surface = NULL;
+        output->height = 0;
+        output->width = 0;
+        output->frame_scheduled = false;
+}
+
+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));
+
+        struct swaybar_output *output;
+        if (visible == bar->visible) {
+                if (visible && moving_layer) {
+                        // need to destroy layer surface to move to a different layer
+                        wl_list_for_each(output, &bar->outputs, link) {
+                                destroy_layer_surface(output);
+                                add_layer_surface(output);
+                        }
+                }
+        } else {
+                bar->visible = visible;
+                wl_list_for_each(output, &bar->outputs, link) {
+                        if (visible) {
+                                add_layer_surface(output);
+                        } else {
+                                destroy_layer_surface(output);
+                        }
+                }
+        }
+        return visible;
 }
 
 static bool bar_uses_output(struct swaybar *bar, const char *name) {
@@ -423,8 +468,11 @@ static void xdg_output_handle_done(void *data,
                 wl_list_remove(&output->link);
                 wl_list_insert(&bar->outputs, &output->link);
 
-                add_layer_surface(output);
-                set_output_dirty(output);
+                output->surface = wl_compositor_create_surface(bar->compositor);
+                assert(output->surface);
+                if (bar->visible) {
+                        add_layer_surface(output);
+                }
         }
 }