Implement focus handling for containers

The previous implementation of focus handling assumed that only views can be
focused. Containers can also be focused with a command like `focus parent` or
`focus child`.

Change `set_focused_container()` to handle the case of the given container
being a container with children and update borders accordingly.

include/border.h

@@ -16,6 +16,11 @@ struct border {
  */
 void border_clear(struct border *border);
 
+/**
+ * Recursively update all of the borders within a container.
+ */
+void update_container_border(swayc_t *container);
+
 void render_view_borders(wlc_handle view);
 void update_view_border(swayc_t *view);
 void map_update_view_border(swayc_t *view, void *data);

sway/border.c

@@ -308,6 +308,9 @@ void update_view_border(swayc_t *view) {
 	swayc_t *focused = get_focused_view(&root_container);
 	swayc_t *container = swayc_parent_by_type(view, C_CONTAINER);
 	swayc_t *focused_inactive = NULL;
+
+	bool is_child_of_focused = swayc_is_parent_of(get_focused_container(&root_container), view);
+
 	if (container) {
 		focused_inactive = swayc_focus_by_type(container, C_VIEW);
 	} else {
@@ -334,7 +337,7 @@ void update_view_border(swayc_t *view) {
 		cr = create_border_buffer(view, g, &surface);
 
 		bool render_top = !should_hide_top_border(view, view->y);
-		if (view == focused) {
+		if (view == focused || is_child_of_focused) {
 			render_borders(view, cr, &config->border_colors.focused, render_top);
 		} else {
 			render_borders(view, cr, &config->border_colors.focused_inactive, render_top);
@@ -360,7 +363,7 @@ void update_view_border(swayc_t *view) {
 				break;
 			}
 
-			if (focused == view) {
+			if (focused == view || is_child_of_focused) {
 				render_borders(view, cr, &config->border_colors.focused, true);
 			} else if (focused_inactive == view) {
 				render_borders(view, cr, &config->border_colors.focused_inactive, true);
@@ -375,7 +378,7 @@ void update_view_border(swayc_t *view) {
 				break;
 			}
 
-			if (focused == view) {
+			if (focused == view || is_child_of_focused) {
 				render_borders(view, cr, &config->border_colors.focused, false);
 				render_title_bar(view, cr, &view->border_geometry,
 					&config->border_colors.focused);
@@ -403,6 +406,17 @@ void update_view_border(swayc_t *view) {
 	}
 }
 
+void update_container_border(swayc_t *container) {
+	if (container->type == C_VIEW) {
+		update_view_border(container);
+		return;
+	} else {
+		for (int i = 0; i < container->children->length; ++i) {
+			update_container_border(container->children->items[i]);
+		}
+	}
+}
+
 void render_view_borders(wlc_handle view) {
 	swayc_t *c = swayc_by_handle(view);
 

sway/focus.c

@@ -115,7 +115,7 @@ bool set_focused_container(swayc_t *c) {
 
 	// Get workspace for c, get that workspaces current focused container.
 	swayc_t *workspace = swayc_active_workspace_for(c);
-	swayc_t *focused = get_focused_view(workspace);
+	swayc_t *focused = get_focused_container(workspace);
 
 	if (swayc_is_fullscreen(focused) && focused != c) {
 		// if switching to a workspace with a fullscreen view,
@@ -140,33 +140,32 @@ bool set_focused_container(swayc_t *c) {
 	}
 
 	// get new focused view and set focus to it.
-	p = get_focused_view(c);
-	if (p->type == C_VIEW && !(wlc_view_get_type(p->handle) & WLC_BIT_POPUP)) {
+	if (c->type == C_CONTAINER || (c->type == C_VIEW && !(wlc_view_get_type(p->handle) & WLC_BIT_POPUP))) {
 		// unactivate previous focus
 		if (focused->type == C_VIEW) {
 			wlc_view_set_state(focused->handle, WLC_BIT_ACTIVATED, false);
-			update_view_border(focused);
 		}
+		update_container_border(focused);
 		// activate current focus
-		if (p->type == C_VIEW) {
-			wlc_view_set_state(p->handle, WLC_BIT_ACTIVATED, true);
-			// set focus if view_focus is unlocked
-			if (!locked_view_focus) {
-				wlc_view_focus(p->handle);
-				if (p->parent->layout != L_TABBED
-					&& p->parent->layout != L_STACKED) {
-					update_view_border(p);
-				}
+		if (c->type == C_VIEW) {
+			wlc_view_set_state(c->handle, WLC_BIT_ACTIVATED, true);
+		}
+		// set focus if view_focus is unlocked
+		if (!locked_view_focus) {
+			wlc_view_focus(c->handle);
+			if (c->parent->layout != L_TABBED
+					&& c->parent->layout != L_STACKED) {
+				update_container_border(c);
 			}
 		}
 
 		// rearrange if parent container is tabbed/stacked
-		swayc_t *parent = swayc_tabbed_stacked_ancestor(p);
+		swayc_t *parent = swayc_tabbed_stacked_ancestor(c);
 		if (parent != NULL) {
 			arrange_backgrounds();
 			arrange_windows(parent, -1, -1);
 		}
-	} else if (p->type == C_WORKSPACE) {
+	} else if (c->type == C_WORKSPACE) {
 		// remove previous focus if view_focus is unlocked
 		if (!locked_view_focus) {
 			wlc_view_focus(0);