8 files changed, 44 insertions, 12 deletions
diff --git a/include/ipc.h b/include/ipc.h
index a3f60e19..9063b933 100644
--- a/include/ipc.h
+++ b/include/ipc.h
@@ -30,6 +30,9 @@ enum ipc_command_type {
 	IPC_EVENT_BINDING = ((1<<31) | 5),
 	IPC_EVENT_SHUTDOWN = ((1<<31) | 6),
 	IPC_EVENT_TICK = ((1<<31) | 7),
+
+	// sway-specific event types
+	IPC_EVENT_BAR_STATE_UPDATE = ((1<<31) | 20),
 };
 
 #endif
diff --git a/include/sway/config.h b/include/sway/config.h
index f21ecbb1..be5a00b5 100644
--- a/include/sway/config.h
+++ b/include/sway/config.h
@@ -191,6 +191,7 @@ struct bar_config {
 	 * In "show" mode, it will always be shown on top of the active workspace.
 	 */
 	char *hidden_state;
+	bool visible_by_modifier; // only relevant in "hide" mode
 	/**
 	 * Id name used to identify the bar through IPC.
 	 *
diff --git a/include/sway/ipc-server.h b/include/sway/ipc-server.h
index 80180ec4..3c43f74d 100644
--- a/include/sway/ipc-server.h
+++ b/include/sway/ipc-server.h
@@ -15,6 +15,7 @@ void ipc_event_workspace(struct sway_workspace *old,
 		struct sway_workspace *new, const char *change);
 void ipc_event_window(struct sway_container *window, const char *change);
 void ipc_event_barconfig_update(struct bar_config *bar);
+void ipc_event_bar_state_update(struct bar_config *bar);
 void ipc_event_mode(const char *mode, bool pango);
 void ipc_event_shutdown(const char *reason);
 void ipc_event_binding(struct sway_binding *binding);
diff --git a/include/swaybar/bar.h b/include/swaybar/bar.h
index de234111..9ff3fe7b 100644
--- a/include/swaybar/bar.h
+++ b/include/swaybar/bar.h
@@ -37,7 +37,7 @@ enum hotspot_event_handling {
 };
 
 struct swaybar_hotspot {
-	struct wl_list link;
+	struct wl_list link; // swaybar_output::hotspots
 	int x, y, width, height;
 	enum hotspot_event_handling (*callback)(struct swaybar_output *output,
 			int x, int y, enum x11_button button, void *data);
@@ -46,6 +46,15 @@ struct swaybar_hotspot {
 };
 
 struct swaybar {
+	char *id;
+	char *mode;
+	bool mode_pango_markup;
+
+	// only relevant when bar is in "hide" mode
+	bool visible_by_modifier;
+	bool visible_by_urgency;
+	bool visible;
+
 	struct wl_display *display;
 	struct wl_compositor *compositor;
 	struct zwlr_layer_shell_v1 *layer_shell;
@@ -60,11 +69,11 @@ struct swaybar {
 	int ipc_event_socketfd;
 	int ipc_socketfd;
 
-	struct wl_list outputs;
+	struct wl_list outputs; // swaybar_output::link
 };
 
 struct swaybar_output {
-	struct wl_list link;
+	struct wl_list link; // swaybar::outputs
 	struct swaybar *bar;
 	struct wl_output *output;
 	struct zxdg_output_v1 *xdg_output;
@@ -72,8 +81,8 @@ struct swaybar_output {
 	struct zwlr_layer_surface_v1 *layer_surface;
 	uint32_t wl_name;
 
-	struct wl_list workspaces;
-	struct wl_list hotspots;
+	struct wl_list workspaces; // swaybar_workspace::link
+	struct wl_list hotspots; // swaybar_hotspot::link
 
 	char *name;
 	bool focused;
@@ -88,7 +97,7 @@ struct swaybar_output {
 };
 
 struct swaybar_workspace {
-	struct wl_list link;
+	struct wl_list link; // swaybar_output::workspaces
 	int num;
 	char *name;
 	bool focused;
@@ -96,10 +105,24 @@ struct swaybar_workspace {
 	bool urgent;
 };
 
-bool bar_setup(struct swaybar *bar, const char *socket_path, const char *bar_id);
+bool bar_setup(struct swaybar *bar, const char *socket_path);
 void bar_run(struct swaybar *bar);
 void bar_teardown(struct swaybar *bar);
 
+/*
+ * Determines whether the bar should be visible and changes it to be so.
+ * If the current visibility of the bar is the different to what it should be,
+ * then it adds or destroys the layer surface as required,
+ * as well as sending the cont or stop signal to the status command.
+ * If the current visibility of the bar is already what it should be,
+ * then this function is a no-op, unless moving_layer is true, which occurs
+ * when the bar changes from "hide" to "dock" mode or vice versa, and the bar
+ * needs to be destroyed and re-added in order to change its layer.
+ *
+ * Returns true if the bar is now visible, otherwise false.
+ */
+bool determine_bar_visibility(struct swaybar *bar, bool moving_layer);
+void free_hotspots(struct wl_list *list);
 void free_workspaces(struct wl_list *list);
 
 #endif
diff --git a/include/swaybar/config.h b/include/swaybar/config.h
index d0336c27..5d40790a 100644
--- a/include/swaybar/config.h
+++ b/include/swaybar/config.h
@@ -13,7 +13,7 @@ struct box_colors {
 };
 
 struct config_output {
-	struct wl_list link;
+	struct wl_list link; // swaybar_config::outputs
 	char *name;
 	size_t index;
 };
@@ -31,7 +31,8 @@ struct swaybar_config {
 	char *font;
 	char *sep_symbol;
 	char *mode;
-	bool mode_pango_markup;
+	char *hidden_state;
+	char *modifier;
 	bool strip_workspace_numbers;
 	bool binding_mode_indicator;
 	bool wrap_scroll;
diff --git a/include/swaybar/i3bar.h b/include/swaybar/i3bar.h
index 12d9b317..d4a48e07 100644
--- a/include/swaybar/i3bar.h
+++ b/include/swaybar/i3bar.h
@@ -5,7 +5,7 @@
 #include "status_line.h"
 
 struct i3bar_block {
-	struct wl_list link;
+	struct wl_list link; // status_link::blocks
 	int ref_count;
 	char *full_text, *short_text, *align;
 	bool urgent;
diff --git a/include/swaybar/ipc.h b/include/swaybar/ipc.h
index 8731dac2..d8cd0c76 100644
--- a/include/swaybar/ipc.h
+++ b/include/swaybar/ipc.h
@@ -3,9 +3,9 @@
 #include <stdbool.h>
 #include "swaybar/bar.h"
 
-bool ipc_initialize(struct swaybar *bar, const char *bar_id);
+bool ipc_initialize(struct swaybar *bar);
 bool handle_ipc_readable(struct swaybar *bar);
-void ipc_get_workspaces(struct swaybar *bar);
+bool ipc_get_workspaces(struct swaybar *bar);
 void ipc_send_workspace_command(struct swaybar *bar, const char *ws);
 void ipc_execute_binding(struct swaybar *bar, struct swaybar_binding *bind);
 
diff --git a/include/swaybar/status_line.h b/include/swaybar/status_line.h
index ca88b0c5..5e7e8771 100644
--- a/include/swaybar/status_line.h
+++ b/include/swaybar/status_line.h
@@ -22,6 +22,9 @@ struct status_line {
 	const char *text;
 	struct wl_list blocks; // i3bar_block::link
 
+	int stop_signal;
+	int cont_signal;
+
 	bool click_events;
 	bool clicked;
 	char *buffer;