Implement bar gaps

Adds the bar subcommand `gaps <amount>|<horizontal> <vertical>|<top>
<right> <bottom> <left>` to set gaps for swaybar. Due to restrictions on
margins for a layer_surface, only the sides that are anchored to an edge
of the screen can have gaps. Since there is support for per-side outer
gaps for workspaces, those should be able to be used instead for the
last side.

3 files changed, 52 insertions, 1 deletions

diff --git a/swaybar/config.c b/swaybar/config.c
index 16febb2e..10c78c8a 100644
--- a/swaybar/config.c
+++ b/swaybar/config.c
@@ -40,6 +40,12 @@ struct swaybar_config *init_config(void) {
 	/* height */
 	config->height = 0;
 
+	/* gaps */
+	config->gaps.top = 0;
+	config->gaps.right = 0;
+	config->gaps.bottom = 0;
+	config->gaps.left = 0;
+
 	/* colors */
 	config->colors.background = 0x000000FF;
 	config->colors.focused_background = 0x000000FF;
diff --git a/swaybar/ipc.c b/swaybar/ipc.c
index db4360c1..2b930786 100644
--- a/swaybar/ipc.c
+++ b/swaybar/ipc.c
@@ -153,7 +153,7 @@ static bool ipc_parse_config(
 		return false;
 	}
 	json_object *markup, *mode, *hidden_state, *position, *status_command;
-	json_object *font, *bar_height, *wrap_scroll, *workspace_buttons;
+	json_object *font, *gaps, *bar_height, *wrap_scroll, *workspace_buttons;
 	json_object *strip_workspace_numbers, *strip_workspace_name;
 	json_object *binding_mode_indicator, *verbose, *colors, *sep_symbol;
 	json_object *outputs, *bindings;
@@ -162,6 +162,7 @@ static bool ipc_parse_config(
 	json_object_object_get_ex(bar_config, "position", &position);
 	json_object_object_get_ex(bar_config, "status_command", &status_command);
 	json_object_object_get_ex(bar_config, "font", &font);
+	json_object_object_get_ex(bar_config, "gaps", &gaps);
 	json_object_object_get_ex(bar_config, "bar_height", &bar_height);
 	json_object_object_get_ex(bar_config, "wrap_scroll", &wrap_scroll);
 	json_object_object_get_ex(bar_config, "workspace_buttons", &workspace_buttons);
@@ -207,6 +208,24 @@ static bool ipc_parse_config(
 	if (bar_height) {
 		config->height = json_object_get_int(bar_height);
 	}
+	if (gaps) {
+		json_object *top = json_object_object_get(gaps, "top");
+		if (top) {
+			config->gaps.top = json_object_get_int(top);
+		}
+		json_object *right = json_object_object_get(gaps, "right");
+		if (right) {
+			config->gaps.right = json_object_get_int(right);
+		}
+		json_object *bottom = json_object_object_get(gaps, "bottom");
+		if (bottom) {
+			config->gaps.bottom = json_object_get_int(bottom);
+		}
+		json_object *left = json_object_object_get(gaps, "left");
+		if (left) {
+			config->gaps.left = json_object_get_int(left);
+		}
+	}
 	if (markup) {
 		config->pango_markup = json_object_get_boolean(markup);
 	}
@@ -446,6 +465,27 @@ static bool handle_barconfig_update(struct swaybar *bar,
 	config->mode = strdup(json_object_get_string(json_mode));
 	wlr_log(WLR_DEBUG, "Changing bar mode to %s", config->mode);
 
+	json_object *gaps;
+	json_object_object_get_ex(json_config, "gaps", &gaps);
+	if (gaps) {
+		json_object *top = json_object_object_get(gaps, "top");
+		if (top) {
+			config->gaps.top = json_object_get_int(top);
+		}
+		json_object *right = json_object_object_get(gaps, "right");
+		if (right) {
+			config->gaps.right = json_object_get_int(right);
+		}
+		json_object *bottom = json_object_object_get(gaps, "bottom");
+		if (bottom) {
+			config->gaps.bottom = json_object_get_int(bottom);
+		}
+		json_object *left = json_object_object_get(gaps, "left");
+		if (left) {
+			config->gaps.left = json_object_get_int(left);
+		}
+	}
+
 	return determine_bar_visibility(bar, true);
 }
 
diff --git a/swaybar/render.c b/swaybar/render.c
index 8269a840..77cfecbf 100644
--- a/swaybar/render.c
+++ b/swaybar/render.c
@@ -506,6 +506,11 @@ void render_frame(struct swaybar_output *output) {
 	if (height != output->height || output->width == 0) {
 		// Reconfigure surface
 		zwlr_layer_surface_v1_set_size(output->layer_surface, 0, height);
+		zwlr_layer_surface_v1_set_margin(output->layer_surface,
+				output->bar->config->gaps.top,
+				output->bar->config->gaps.right,
+				output->bar->config->gaps.bottom,
+				output->bar->config->gaps.left);
 		if (strcmp(output->bar->config->mode, "dock") == 0) {
 			zwlr_layer_surface_v1_set_exclusive_zone(output->layer_surface, height);
 		}