Add smart_gaps inverse_outer command

Add a subcommand for `smart_gaps` that enables outer gaps only
on workspaces with exactly one visible child.
Also add documentation for `smart_gaps toggle`.

4 files changed, 37 insertions, 19 deletions

diff --git a/sway/commands/smart_gaps.c b/sway/commands/smart_gaps.c
index b27f9ccd..a6d165dc 100644
--- a/sway/commands/smart_gaps.c
+++ b/sway/commands/smart_gaps.c
@@ -15,7 +15,12 @@ struct cmd_results *cmd_smart_gaps(int argc, char **argv) {
 		return error;
 	}
 
-	config->smart_gaps = parse_boolean(argv[0], config->smart_gaps);
+	if (strcmp(argv[0], "inverse_outer") == 0) {
+		config->smart_gaps = SMART_GAPS_INVERSE_OUTER;
+	} else {
+		config->smart_gaps = parse_boolean(argv[0], config->smart_gaps)
+			? SMART_GAPS_ON : SMART_GAPS_OFF;
+	}
 
 	arrange_root();
 
diff --git a/sway/config.c b/sway/config.c
index e3daacda..35837212 100644
--- a/sway/config.c
+++ b/sway/config.c
@@ -266,7 +266,7 @@ static void config_defaults(struct sway_config *config) {
 	config->tiling_drag = true;
 	config->tiling_drag_threshold = 9;
 
-	config->smart_gaps = false;
+	config->smart_gaps = SMART_GAPS_OFF;
 	config->gaps_inner = 0;
 	config->gaps_outer.top = 0;
 	config->gaps_outer.right = 0;
diff --git a/sway/sway.5.scd b/sway/sway.5.scd
index e8d3d606..ec34a56c 100644
--- a/sway/sway.5.scd
+++ b/sway/sway.5.scd
@@ -692,9 +692,10 @@ The default colors are:
 	borders will only be enabled if the workspace has more than one visible
 	child and gaps equal to zero.
 
-*smart_gaps* on|off
+*smart_gaps* on|off|toggle|inverse_outer
 	If smart_gaps are _on_ gaps will only be enabled if a workspace has more
-	than one child.
+	than one child. If smart_gaps are _inverse_outer_ outer gaps will only
+	be enabled if a workspace has exactly one child.
 
 *mark* --add|--replace [--toggle] <identifier>
 	Marks are arbitrary labels that can be used to identify certain windows and
diff --git a/sway/tree/workspace.c b/sway/tree/workspace.c
index 8dd7789d..e3ff1513 100644
--- a/sway/tree/workspace.c
+++ b/sway/tree/workspace.c
@@ -844,24 +844,36 @@ struct sway_container *workspace_insert_tiling(struct sway_workspace *workspace,
 	return con;
 }
 
+bool workspace_has_single_visible_container(struct sway_workspace *ws) {
+	struct sway_seat *seat = input_manager_get_default_seat();
+	struct sway_container *focus =
+		seat_get_focus_inactive_tiling(seat, ws);
+	if (focus && !focus->view) {
+		focus = seat_get_focus_inactive_view(seat, &focus->node);
+	}
+	return (focus && focus->view && view_ancestor_is_only_visible(focus->view));
+}
+
 void workspace_add_gaps(struct sway_workspace *ws) {
-	if (config->smart_gaps) {
-		struct sway_seat *seat = input_manager_get_default_seat();
-		struct sway_container *focus =
-			seat_get_focus_inactive_tiling(seat, ws);
-		if (focus && !focus->view) {
-			focus = seat_get_focus_inactive_view(seat, &focus->node);
-		}
-		if (focus && focus->view && view_ancestor_is_only_visible(focus->view)) {
-			ws->current_gaps.top = 0;
-			ws->current_gaps.right = 0;
-			ws->current_gaps.bottom = 0;
-			ws->current_gaps.left = 0;
-			return;
-		}
+	if (config->smart_gaps == SMART_GAPS_ON
+			&& workspace_has_single_visible_container(ws)) {
+		ws->current_gaps.top = 0;
+		ws->current_gaps.right = 0;
+		ws->current_gaps.bottom = 0;
+		ws->current_gaps.left = 0;
+		return;
+	}
+
+	if (config->smart_gaps == SMART_GAPS_INVERSE_OUTER
+			&& !workspace_has_single_visible_container(ws)) {
+		ws->current_gaps.top = 0;
+		ws->current_gaps.right = 0;
+		ws->current_gaps.bottom = 0;
+		ws->current_gaps.left = 0;
+	} else {
+		ws->current_gaps = ws->gaps_outer;
 	}
 
-	ws->current_gaps = ws->gaps_outer;
 	// Add inner gaps and make sure we don't turn out negative
 	ws->current_gaps.top = fmax(0, ws->current_gaps.top + ws->gaps_inner);
 	ws->current_gaps.right = fmax(0, ws->current_gaps.right + ws->gaps_inner);