Fix gaps issues

* In layout command, arrange parent of parent - not sure why this is
needed but it is
* Remove gap adjustment when rendering
* Workspace should use outer gaps, not inner
* Add exceptions for tabbed and stacked containers
* Don't mess with gap state when splitting a container

sway/commands/layout.c

@@ -103,7 +103,7 @@ struct cmd_results *cmd_layout(int argc, char **argv) {
 			parent->prev_split_layout = prev;
 		}
 		container_notify_subtree_changed(parent);
-		arrange_windows(parent);
+		arrange_windows(parent->parent);
 	}
 
 	return cmd_results_new(CMD_SUCCESS, NULL, NULL);

sway/desktop/render.c

@@ -619,9 +619,7 @@ static void render_container_tabbed(struct sway_output *output,
 	struct sway_container *current = pstate->focused_inactive_child;
 	struct border_colors *current_colors = &config->border_colors.unfocused;
 
-	double width_gap_adjustment = 2 * pstate->current_gaps;
-	int tab_width =
-		(pstate->swayc_width - width_gap_adjustment) / pstate->children->length;
+	int tab_width = (pstate->swayc_width) / pstate->children->length;
 
 	// Render tabs
 	for (int i = 0; i < pstate->children->length; ++i) {
@@ -656,8 +654,7 @@ static void render_container_tabbed(struct sway_output *output,
 
 		// Make last tab use the remaining width of the parent
 		if (i == pstate->children->length - 1) {
-			tab_width =
-				pstate->swayc_width - width_gap_adjustment - tab_width * i;
+			tab_width = pstate->swayc_width - tab_width * i;
 		}
 
 		render_titlebar(output, damage, child, x, pstate->swayc_y, tab_width,

sway/tree/container.c

@@ -1159,7 +1159,17 @@ void container_add_gaps(struct sway_container *c) {
 				"Expected a container or view")) {
 		return;
 	}
-	if (c->current_gaps > 0 || c->type != C_VIEW) {
+	if (c->current_gaps > 0) {
+		return;
+	}
+	// Linear containers don't have gaps because it'd create double gaps
+	if (c->type == C_CONTAINER &&
+			c->layout != L_TABBED && c->layout != L_STACKED) {
+		return;
+	}
+	// Children of tabbed/stacked containers re-use the gaps of the container
+	enum sway_container_layout layout = c->parent->layout;
+	if (layout == L_TABBED || layout == L_STACKED) {
 		return;
 	}
 
@@ -1355,20 +1365,16 @@ struct sway_container *container_split(struct sway_container *child,
 
 	wlr_log(WLR_DEBUG, "creating container %p around %p", cont, child);
 
-	child->type == C_WORKSPACE ? workspace_remove_gaps(child)
-		: container_remove_gaps(child);
-
 	cont->prev_split_layout = L_NONE;
 	cont->width = child->width;
 	cont->height = child->height;
 	cont->x = child->x;
 	cont->y = child->y;
+	cont->current_gaps = child->current_gaps;
 
 	struct sway_seat *seat = input_manager_get_default_seat(input_manager);
 	bool set_focus = (seat_get_focus(seat) == child);
 
-	container_add_gaps(cont);
-
 	if (child->type == C_WORKSPACE) {
 		struct sway_container *workspace = child;
 		while (workspace->children->length) {

sway/tree/workspace.c

@@ -694,7 +694,15 @@ void workspace_add_gaps(struct sway_container *ws) {
 		return;
 	}
 
-	ws->current_gaps = ws->has_gaps ? ws->gaps_inner : config->gaps_inner;
+	ws->current_gaps = ws->has_gaps ? ws->gaps_outer : config->gaps_outer;
+
+	if (ws->layout == L_TABBED || ws->layout == L_STACKED) {
+		// We have to add inner gaps for this, because children of tabbed and
+		// stacked containers don't apply their own gaps - they assume the
+		// tabbed/stacked container is using gaps.
+		ws->current_gaps += ws->has_gaps ? ws->gaps_inner : config->gaps_inner;
+	}
+
 	ws->x += ws->current_gaps;
 	ws->y += ws->current_gaps;
 	ws->width -= 2 * ws->current_gaps;