diff --git a/include/container.h b/include/container.h
index bd92058d6..fd621490d 100644
--- a/include/container.h
+++ b/include/container.h
@@ -55,6 +55,7 @@ struct sway_container {
 	struct sway_container *focused;
 };
 
+// Container Creation
 
 swayc_t *new_output(wlc_handle handle);
 swayc_t *new_workspace(swayc_t *output, const char *name);
@@ -65,13 +66,23 @@ swayc_t *new_view(swayc_t *sibling, wlc_handle handle);
 // Creates view as a new floating view which is in the active workspace
 swayc_t *new_floating_view(wlc_handle handle);
 
+// Container Destroying
 
 swayc_t *destroy_output(swayc_t *output);
 // Destroys workspace if empty and returns parent pointer, else returns NULL
 swayc_t *destroy_workspace(swayc_t *workspace);
+// Destroyes container and all parent container if they are empty, returns
+// topmost non-empty parent. returns NULL otherwise
 swayc_t *destroy_container(swayc_t *container);
+// Destroys view and all empty parent containers. return topmost non-empty
+// parent
 swayc_t *destroy_view(swayc_t *view);
 
+// Container Lookup
+
+swayc_t *swayc_parent_by_type(swayc_t *container, enum swayc_types);
+swayc_t *swayc_parent_by_layout(swayc_t *container, enum swayc_layouts);
+
 swayc_t *find_container(swayc_t *container, bool (*test)(swayc_t *view, void *data), void *data);
 void container_map(swayc_t *, void (*f)(swayc_t *, void *), void *);
 
diff --git a/sway/commands.c b/sway/commands.c
index 644b80050..3ac7f4dd4 100644
--- a/sway/commands.c
+++ b/sway/commands.c
@@ -390,7 +390,6 @@ static bool cmd_layout(struct sway_config *config, int argc, char **argv) {
 		return false;
 	}
 	swayc_t *parent = get_focused_container(&root_container);
-
 	while (parent->type == C_VIEW) {
 		parent = parent->parent;
 	}
@@ -512,9 +511,7 @@ static bool cmd_fullscreen(struct sway_config *config, int argc, char **argv) {
 	// Resize workspace if going from  fullscreen -> notfullscreen
 	// otherwise just resize container
 	if (current) {
-		while (container->type != C_WORKSPACE) {
-			container = container->parent;
-		}
+		container = swayc_parent_by_type(container, C_WORKSPACE);
 	}
 	// Only resize container when going into fullscreen
 	arrange_windows(container, -1, -1);
diff --git a/sway/container.c b/sway/container.c
index 4559a5f56..7ccc2e098 100644
--- a/sway/container.c
+++ b/sway/container.c
@@ -8,6 +8,8 @@
 #include "layout.h"
 #include "log.h"
 
+#define ASSERT_NONNULL(PTR) \
+	sway_assert (PTR, "%s: " #PTR "must be non-null", __func__)
 
 static swayc_t *new_swayc(enum swayc_types type) {
 	swayc_t *c = calloc(1, sizeof(swayc_t));
@@ -20,37 +22,40 @@ static swayc_t *new_swayc(enum swayc_types type) {
 	return c;
 }
 
-static void free_swayc(swayc_t *c) {
+static void free_swayc(swayc_t *cont) {
+	if (!ASSERT_NONNULL(cont)) {
+		return;
+	}
 	// TODO does not properly handle containers with children,
 	// TODO but functions that call this usually check for that
-	if (c->children) {
-		if (c->children->length) {
+	if (cont->children) {
+		if (cont->children->length) {
 			int i;
-			for (i = 0; i < c->children->length; ++i) {
-				free_swayc(c->children->items[i]);
+			for (i = 0; i < cont->children->length; ++i) {
+				free_swayc(cont->children->items[i]);
 			}
 		}
-		list_free(c->children);
+		list_free(cont->children);
 	}
-	if (c->floating) {
-		if (c->floating->length) {
+	if (cont->floating) {
+		if (cont->floating->length) {
 			int i;
-			for (i = 0; i < c->floating->length; ++i) {
-				free_swayc(c->floating->items[i]);
+			for (i = 0; i < cont->floating->length; ++i) {
+				free_swayc(cont->floating->items[i]);
 			}
 		}
-		list_free(c->floating);
+		list_free(cont->floating);
 	}
-	if (c->parent) {
-		remove_child(c);
+	if (cont->parent) {
+		remove_child(cont);
 	}
-	if (c->name) {
-		free(c->name);
+	if (cont->name) {
+		free(cont->name);
 	}
-	free(c);
+	free(cont);
 }
 
-/* New containers */
+// New containers
 
 static bool workspace_test(swayc_t *view, void *name) {
 	return strcasecmp(view->name, (char *)name) == 0;
@@ -103,6 +108,9 @@ swayc_t *new_output(wlc_handle handle) {
 }
 
 swayc_t *new_workspace(swayc_t *output, const char *name) {
+	if (!ASSERT_NONNULL(output)) {
+		return NULL;
+	}
 	sway_log(L_DEBUG, "Added workspace %s for output %u", name, (unsigned int)output->handle);
 	swayc_t *workspace = new_swayc(C_WORKSPACE);
 
@@ -120,6 +128,9 @@ swayc_t *new_workspace(swayc_t *output, const char *name) {
 }
 
 swayc_t *new_container(swayc_t *child, enum swayc_layouts layout) {
+	if (!ASSERT_NONNULL(child)) {
+		return NULL;
+	}
 	swayc_t *cont = new_swayc(C_CONTAINER);
 
 	sway_log(L_DEBUG, "creating container %p around %p", cont, child);
@@ -162,6 +173,9 @@ swayc_t *new_container(swayc_t *child, enum swayc_layouts layout) {
 }
 
 swayc_t *new_view(swayc_t *sibling, wlc_handle handle) {
+	if (!ASSERT_NONNULL(sibling)) {
+		return NULL;
+	}
 	const char *title = wlc_view_get_title(handle);
 	swayc_t *view = new_swayc(C_VIEW);
 	sway_log(L_DEBUG, "Adding new view %lu:%s to container %p %d",
@@ -172,14 +186,14 @@ swayc_t *new_view(swayc_t *sibling, wlc_handle handle) {
 	view->visible = true;
 	view->is_focused = true;
 	// Setup geometry
+	const struct wlc_geometry* geometry = wlc_view_get_geometry(handle);
 	view->width = 0;
 	view->height = 0;
+	view->desired_width = geometry->size.w;
+	view->desired_height = geometry->size.h;
 
 	view->gaps = config->gaps_inner;
 
-	view->desired_width = -1;
-	view->desired_height = -1;
-
 	view->is_floating = false;
 
 	if (sibling->type == C_WORKSPACE) {
@@ -225,9 +239,12 @@ swayc_t *new_floating_view(wlc_handle handle) {
 	return view;
 }
 
-/* Destroy container */
+// Destroy container
 
 swayc_t *destroy_output(swayc_t *output) {
+	if (!ASSERT_NONNULL(output)) {
+		return NULL;
+	}
 	if (output->children->length == 0) {
 		// TODO move workspaces to other outputs
 	}
@@ -237,23 +254,21 @@ swayc_t *destroy_output(swayc_t *output) {
 }
 
 swayc_t *destroy_workspace(swayc_t *workspace) {
+	if (!ASSERT_NONNULL(workspace)) {
+		return NULL;
+	}
 	// NOTE: This is called from elsewhere without checking children length
 	// TODO move containers to other workspaces?
 	// for now just dont delete
 	
 	// Do not destroy this if it's the last workspace on this output
-	swayc_t *output = workspace->parent;
-	while (output && output->type != C_OUTPUT) {
-		output = output->parent;
-	}
-	if (output) {
-		if (output->children->length == 1) {
-			return NULL;
-		}
+	swayc_t *output = swayc_parent_by_type(workspace, C_OUTPUT);
+	if (output && output->children->length == 1) {
+		return NULL;
 	}
 
 	if (workspace->children->length == 0) {
-		sway_log(L_DEBUG, "Workspace: Destroying workspace '%s'", workspace->name);
+		sway_log(L_DEBUG, "%s: '%s'", __func__, workspace->name);
 		swayc_t *parent = workspace->parent;
 		free_swayc(workspace);
 		return parent;
@@ -262,6 +277,9 @@ swayc_t *destroy_workspace(swayc_t *workspace) {
 }
 
 swayc_t *destroy_container(swayc_t *container) {
+	if (!ASSERT_NONNULL(container)) {
+		return NULL;
+	}
 	while (container->children->length == 0 && container->type == C_CONTAINER) {
 		sway_log(L_DEBUG, "Container: Destroying container '%p'", container);
 		swayc_t *parent = container->parent;
@@ -272,8 +290,7 @@ swayc_t *destroy_container(swayc_t *container) {
 }
 
 swayc_t *destroy_view(swayc_t *view) {
-	if (view == NULL) {
-		sway_log(L_DEBUG, "Warning: NULL passed into destroy_view");
+	if (!ASSERT_NONNULL(view)) {
 		return NULL;
 	}
 	sway_log(L_DEBUG, "Destroying view '%p'", view);
@@ -287,6 +304,34 @@ swayc_t *destroy_view(swayc_t *view) {
 	return parent;
 }
 
+// Container lookup
+
+swayc_t *swayc_parent_by_type(swayc_t *container, enum swayc_types type) {
+	if (!ASSERT_NONNULL(container)) {
+		return NULL;
+	}
+	if (!sway_assert(type < C_TYPES && type >= C_ROOT, "%s: invalid type", __func__)) {
+		return NULL;
+	}
+	do {
+		container = container->parent;
+	} while(container && container->type != type);
+	return container;
+}
+
+swayc_t *swayc_parent_by_layout(swayc_t *container, enum swayc_layouts layout) {
+	if (!ASSERT_NONNULL(container)) {
+		return NULL;
+	}
+	if (!sway_assert(layout < L_LAYOUTS && layout >= L_NONE, "%s: invalid layout", __func__)) {
+		return NULL;
+	}
+	do {
+		container = container->parent;
+	} while (container && container->layout != layout);
+	return container;
+}
+
 swayc_t *find_container(swayc_t *container, bool (*test)(swayc_t *view, void *data), void *data) {
 	if (!container->children) {
 		return NULL;
@@ -316,25 +361,27 @@ swayc_t *find_container(swayc_t *container, bool (*test)(swayc_t *view, void *da
 }
 
 void container_map(swayc_t *container, void (*f)(swayc_t *view, void *data), void *data) {
-	if (!container || !container->children || !container->children->length)  {
-		return;
-	}
-	int i;
-	for (i = 0; i < container->children->length; ++i) {
-		swayc_t *child = container->children->items[i];
-		f(child, data);
-		container_map(child, f, data);
-	}
-	if (container->type == C_WORKSPACE) {
-		for (i = 0; i < container->floating->length; ++i) {
-			swayc_t *child = container->floating->items[i];
+	if (container && container->children && container->children->length)  {
+		int i;
+		for (i = 0; i < container->children->length; ++i) {
+			swayc_t *child = container->children->items[i];
 			f(child, data);
 			container_map(child, f, data);
 		}
+		if (container->type == C_WORKSPACE) {
+			for (i = 0; i < container->floating->length; ++i) {
+				swayc_t *child = container->floating->items[i];
+				f(child, data);
+				container_map(child, f, data);
+			}
+		}
 	}
 }
 
 void set_view_visibility(swayc_t *view, void *data) {
+	if (!ASSERT_NONNULL(view)) {
+		return;
+	}
 	uint32_t *p = data;
 	if (view->type == C_VIEW) {
 		wlc_view_set_mask(view->handle, *p);
@@ -348,6 +395,9 @@ void set_view_visibility(swayc_t *view, void *data) {
 }
 
 void reset_gaps(swayc_t *view, void *data) {
+	if (!ASSERT_NONNULL(view)) {
+		return;
+	}
 	if (view->type == C_OUTPUT) {
 		view->gaps = config->gaps_outer;
 	}
diff --git a/sway/handlers.c b/sway/handlers.c
index 5993223d3..79628fe5c 100644
--- a/sway/handlers.c
+++ b/sway/handlers.c
@@ -20,10 +20,7 @@ static struct wlc_origin mouse_origin;
 static bool pointer_test(swayc_t *view, void *_origin) {
 	const struct wlc_origin *origin = _origin;
 	// Determine the output that the view is under
-	swayc_t *parent = view;
-	while (parent->type != C_OUTPUT) {
-		parent = parent->parent;
-	}
+	swayc_t *parent = swayc_parent_by_type(view, C_OUTPUT);
 	if (origin->x >= view->x && origin->y >= view->y
 		&& origin->x < view->x + view->width && origin->y < view->y + view->height
 		&& view->visible && parent == root_container.focused) {
@@ -191,10 +188,7 @@ static bool handle_view_created(wlc_handle handle) {
 
 	if (newview) {
 		set_focused_container(newview);
-		swayc_t *output = newview->parent;
-		while (output && output->type != C_OUTPUT) {
-			output = output->parent;
-		}
+		swayc_t *output = swayc_parent_by_type(newview, C_OUTPUT);
 		arrange_windows(output, -1, -1);
 	}
 	return true;
@@ -262,10 +256,7 @@ static void handle_view_state_request(wlc_handle view, enum wlc_view_state_bit s
 			arrange_windows(c->parent, -1, -1);
 			// Set it as focused window for that workspace if its going fullscreen
 			if (toggle) {
-				swayc_t *ws = c;
-				while (ws->type != C_WORKSPACE) {
-					ws = ws->parent;
-				}
+				swayc_t *ws = swayc_parent_by_type(c, C_WORKSPACE);
 				// Set ws focus to c
 				set_focused_container_for(ws, c);
 			}
diff --git a/sway/layout.c b/sway/layout.c
index 78b3dd279..8c011fdb5 100644
--- a/sway/layout.c
+++ b/sway/layout.c
@@ -161,10 +161,7 @@ void arrange_windows(swayc_t *container, int width, int height) {
 				}
 			};
 			if (wlc_view_get_state(container->handle) & WLC_BIT_FULLSCREEN) {
-				swayc_t *parent = container;
-				while (parent->type != C_OUTPUT) {
-					parent = parent->parent;
-				}
+				swayc_t *parent = swayc_parent_by_type(container, C_OUTPUT);
 				geometry.origin.x = 0;
 				geometry.origin.y = 0;
 				geometry.size.w = parent->width;
@@ -263,10 +260,7 @@ void arrange_windows(swayc_t *container, int width, int height) {
 					}
 				};
 				if (wlc_view_get_state(view->handle) & WLC_BIT_FULLSCREEN) {
-					swayc_t *parent = view;
-					while (parent->type != C_OUTPUT) {
-						parent = parent->parent;
-					}
+					swayc_t *parent = swayc_parent_by_type(view, C_OUTPUT);
 					geometry.origin.x = 0;
 					geometry.origin.y = 0;
 					geometry.size.w = parent->width;
diff --git a/sway/workspace.c b/sway/workspace.c
index 0f44d3b06..d436da8e2 100644
--- a/sway/workspace.c
+++ b/sway/workspace.c
@@ -75,9 +75,7 @@ char *workspace_next_name(void) {
 
 swayc_t *workspace_create(const char* name) {
 	swayc_t *parent = get_focused_container(&root_container);
-	while (parent->type != C_OUTPUT) {
-		parent = parent->parent;
-	}
+	parent = swayc_parent_by_type(parent, C_OUTPUT);
 	return new_workspace(parent, name);
 }