diff --git a/include/sway/container.h b/include/sway/container.h
index 96e4db69..1a173f3e 100644
--- a/include/sway/container.h
+++ b/include/sway/container.h
@@ -132,4 +132,6 @@ swayc_t *new_output(struct sway_output *sway_output);
 swayc_t *new_workspace(swayc_t *output, const char *name);
 swayc_t *new_view(swayc_t *sibling, struct sway_view *sway_view);
 
+swayc_t *swayc_parent_by_type(swayc_t *container, enum swayc_types type);
+
 #endif
diff --git a/include/sway/layout.h b/include/sway/layout.h
index 6356ad00..505036a0 100644
--- a/include/sway/layout.h
+++ b/include/sway/layout.h
@@ -7,5 +7,6 @@ void init_layout(void);
 void add_child(struct sway_container *parent, struct sway_container *child);
 enum swayc_layouts default_layout(struct sway_container *output);
 void sort_workspaces(struct sway_container *output);
+void arrange_windows(struct sway_container *container, double width, double height);
 
 #endif
diff --git a/include/sway/output.h b/include/sway/output.h
index e2f81bcb..895cb07d 100644
--- a/include/sway/output.h
+++ b/include/sway/output.h
@@ -13,6 +13,7 @@ struct sway_output {
 	struct sway_server *server;
 	struct timespec last_frame;
 	struct wl_listener frame;
+	struct wl_listener resolution;
 };
 
 #endif
diff --git a/include/sway/view.h b/include/sway/view.h
index 2675a6f5..9d503674 100644
--- a/include/sway/view.h
+++ b/include/sway/view.h
@@ -52,6 +52,8 @@ struct sway_view {
 	struct {
 		const char *(*get_prop)(struct sway_view *view,
 				enum sway_view_prop prop);
+		void (*set_dimensions)(struct sway_view *view,
+				int width, int height);
 	} iface;
 };
 
diff --git a/sway/desktop/output.c b/sway/desktop/output.c
index 9e0c18e4..033a4c44 100644
--- a/sway/desktop/output.c
+++ b/sway/desktop/output.c
@@ -8,6 +8,7 @@
 #include <wlr/render/matrix.h>
 #include "log.h"
 #include "sway/container.h"
+#include "sway/layout.h"
 #include "sway/output.h"
 #include "sway/server.h"
 #include "sway/view.h"
@@ -25,10 +26,9 @@ static void output_frame_view(swayc_t *view, void *data) {
 		return;
 	}
 	// TODO
-	// - Force sway's resolution
 	// - Deal with wlr_output_layout
-	int width = surface->current->width;
-	int height = surface->current->height;
+	int width = sway_view->swayc->width;
+	int height = sway_view->swayc->height;
 	int render_width = width * wlr_output->scale;
 	int render_height = height * wlr_output->scale;
 	double ox = view->x, oy = view->y;
@@ -101,6 +101,12 @@ static void output_frame_notify(struct wl_listener *listener, void *data) {
 	soutput->last_frame = now;
 }
 
+static void output_resolution_notify(struct wl_listener *listener, void *data) {
+	struct sway_output *soutput = wl_container_of(
+			listener, soutput, resolution);
+	arrange_windows(soutput->swayc, -1, -1);
+}
+
 void output_add_notify(struct wl_listener *listener, void *data) {
 	struct sway_server *server = wl_container_of(listener, server, output_add);
 	struct wlr_output *wlr_output = data;
@@ -113,6 +119,9 @@ void output_add_notify(struct wl_listener *listener, void *data) {
 
 	output->frame.notify = output_frame_notify;
 	wl_signal_add(&wlr_output->events.frame, &output->frame);
+
+	output->resolution.notify = output_resolution_notify;
+	wl_signal_add(&wlr_output->events.resolution, &output->resolution);
 }
 
 void output_remove_notify(struct wl_listener *listener, void *data) {
diff --git a/sway/desktop/xdg_shell_v6.c b/sway/desktop/xdg_shell_v6.c
index e2a61ebf..8f1885c1 100644
--- a/sway/desktop/xdg_shell_v6.c
+++ b/sway/desktop/xdg_shell_v6.c
@@ -1,15 +1,21 @@
 #define _POSIX_C_SOURCE 199309L
+#include <stdbool.h>
 #include <stdlib.h>
 #include <wayland-server.h>
 #include <wlr/types/wlr_xdg_shell_v6.h>
 #include "sway/container.h"
+#include "sway/layout.h"
 #include "sway/server.h"
 #include "sway/view.h"
 #include "log.h"
 
+static bool assert_xdg(struct sway_view *view) {
+	return sway_assert(view->type == SWAY_XDG_SHELL_V6_VIEW,
+			"Expected xdg shell v6 view!");
+}
+
 static const char *get_prop(struct sway_view *view, enum sway_view_prop prop) {
-	if (!sway_assert(view->type == SWAY_XDG_SHELL_V6_VIEW,
-				"xdg get_prop for non-xdg view!")) {
+	if (!assert_xdg(view)) {
 		return NULL;
 	}
 	switch (prop) {
@@ -22,6 +28,12 @@ static const char *get_prop(struct sway_view *view, enum sway_view_prop prop) {
 	}
 }
 
+static void set_dimensions(struct sway_view *view, int width, int height) {
+	if (assert_xdg(view)) {
+		wlr_xdg_toplevel_v6_set_size(view->wlr_xdg_surface_v6, width, height);
+	}
+}
+
 void handle_xdg_shell_v6_surface(struct wl_listener *listener, void *data) {
 	struct sway_server *server = wl_container_of(
 			listener, server, xdg_shell_v6_surface);
@@ -48,13 +60,13 @@ void handle_xdg_shell_v6_surface(struct wl_listener *listener, void *data) {
 	}
 	sway_view->type = SWAY_XDG_SHELL_V6_VIEW;
 	sway_view->iface.get_prop = get_prop;
+	sway_view->iface.set_dimensions = set_dimensions;
 	sway_view->wlr_xdg_surface_v6 = xdg_surface;
 	sway_view->sway_xdg_surface_v6 = sway_surface;
 	sway_view->surface = xdg_surface->surface;
 	sway_surface->view = sway_view;
 	
 	// TODO:
-	// - Add to tree
 	// - Wire up listeners
 	// - Handle popups
 	// - Look up pid and open on appropriate workspace
@@ -67,4 +79,6 @@ void handle_xdg_shell_v6_surface(struct wl_listener *listener, void *data) {
 
 	swayc_t *cont = new_view(parent, sway_view);
 	sway_view->swayc = cont;
+
+	arrange_windows(cont->parent, -1, -1);
 }
diff --git a/sway/tree/container.c b/sway/tree/container.c
index d3931612..a83c0f6b 100644
--- a/sway/tree/container.c
+++ b/sway/tree/container.c
@@ -108,3 +108,16 @@ swayc_t *new_view(swayc_t *sibling, struct sway_view *sway_view) {
 	}
 	return swayc;
 }
+
+swayc_t *swayc_parent_by_type(swayc_t *container, enum swayc_types type) {
+	if (!sway_assert(container, "container is NULL")) {
+		return NULL;
+	}
+	if (!sway_assert(type < C_TYPES && type >= C_ROOT, "invalid type")) {
+		return NULL;
+	}
+	do {
+		container = container->parent;
+	} while (container && container->type != type);
+	return container;
+}
diff --git a/sway/tree/layout.c b/sway/tree/layout.c
index 5a70c570..3d6b404d 100644
--- a/sway/tree/layout.c
+++ b/sway/tree/layout.c
@@ -1,10 +1,14 @@
 #define _POSIX_C_SOURCE 200809L
 #include <ctype.h>
+#include <math.h>
 #include <stdbool.h>
 #include <stdlib.h>
 #include <string.h>
+#include <wlr/types/wlr_output.h>
 #include <wlr/types/wlr_output_layout.h>
 #include "sway/container.h"
+#include "sway/output.h"
+#include "sway/view.h"
 #include "list.h"
 #include "log.h"
 
@@ -70,3 +74,204 @@ static int sort_workspace_cmp_qsort(const void *_a, const void *_b) {
 void sort_workspaces(swayc_t *output) {
 	list_stable_sort(output->children, sort_workspace_cmp_qsort);
 }
+
+static void apply_horiz_layout(swayc_t *container, const double x,
+				const double y, const double width,
+				const double height, const int start,
+				const int end);
+
+static void apply_vert_layout(swayc_t *container, const double x,
+				const double y, const double width,
+				const double height, const int start,
+				const int end);
+
+void arrange_windows(swayc_t *container, double width, double height) {
+	int i;
+	if (width == -1 || height == -1) {
+		width = container->width;
+		height = container->height;
+	}
+	// pixels are indivisible. if we don't round the pixels, then the view
+	// calculations will be off (e.g. 50.5 + 50.5 = 101, but in reality it's
+	// 50 + 50 = 100). doing it here cascades properly to all width/height/x/y.
+	width = floor(width);
+	height = floor(height);
+
+	sway_log(L_DEBUG, "Arranging layout for %p %s %fx%f+%f,%f", container,
+		 container->name, container->width, container->height, container->x,
+		 container->y);
+
+	double x = 0, y = 0;
+	switch (container->type) {
+	case C_ROOT:
+		// TODO: wlr_output_layout probably
+		for (i = 0; i < container->children->length; ++i) {
+			swayc_t *output = container->children->items[i];
+			sway_log(L_DEBUG, "Arranging output '%s' at %f,%f",
+					output->name, output->x, output->y);
+			arrange_windows(output, -1, -1);
+		}
+		return;
+	case C_OUTPUT:
+		{
+			int _width, _height;
+			wlr_output_effective_resolution(
+					container->sway_output->wlr_output, &_width, &_height);
+			width = container->width = _width;
+			height = container->height = _height;
+		}
+		// arrange all workspaces:
+		for (i = 0; i < container->children->length; ++i) {
+			swayc_t *child = container->children->items[i];
+			arrange_windows(child, -1, -1);
+		}
+		return;
+	case C_WORKSPACE:
+		{
+			swayc_t *output = swayc_parent_by_type(container, C_OUTPUT);
+			width = output->width, height = output->height;
+			container->x = x;
+			container->y = y;
+			width = container->width;
+			height = container->height;
+			sway_log(L_DEBUG, "Arranging workspace '%s' at %f, %f",
+					container->name, container->x, container->y);
+		}
+		// children are properly handled below
+		break;
+	case C_VIEW:
+		{
+			container->width = width;
+			container->height = height;
+			container->sway_view->iface.set_dimensions(container->sway_view,
+					container->width, container->height);
+			sway_log(L_DEBUG, "Set view to %.f x %.f @ %.f, %.f",
+					container->width, container->height,
+					container->x, container->y);
+		}
+		return;
+	default:
+		container->width = width;
+		container->height = height;
+		x = container->x;
+		y = container->y;
+		break;
+	}
+
+	switch (container->layout) {
+	case L_HORIZ:
+		apply_horiz_layout(container, x, y, width, height, 0,
+			container->children->length);
+		break;
+	case L_VERT:
+		apply_vert_layout(container, x, y, width, height, 0,
+			container->children->length);
+		break;
+	default:
+		sway_log(L_DEBUG, "TODO: arrange layout type %d", container->layout);
+		apply_horiz_layout(container, x, y, width, height, 0,
+			container->children->length);
+		break;
+	}
+}
+
+static void apply_horiz_layout(swayc_t *container,
+		const double x, const double y,
+		const double width, const double height,
+		const int start, const int end) {
+	double scale = 0;
+	// Calculate total width
+	for (int i = start; i < end; ++i) {
+		double *old_width = &((swayc_t *)container->children->items[i])->width;
+		if (*old_width <= 0) {
+			if (end - start > 1) {
+				*old_width = width / (end - start - 1);
+			} else {
+				*old_width = width;
+			}
+		}
+		scale += *old_width;
+	}
+	scale = width / scale;
+
+	// Resize windows
+	double child_x = x;
+	if (scale > 0.1) {
+		sway_log(L_DEBUG, "Arranging %p horizontally", container);
+		for (int i = start; i < end; ++i) {
+			swayc_t *child = container->children->items[i];
+			sway_log(L_DEBUG,
+				 "Calculating arrangement for %p:%d (will scale %f by %f)",
+				 child, child->type, width, scale);
+			child->x = child_x;
+			child->y = y;
+
+			if (i == end - 1) {
+				double remaining_width = x + width - child_x;
+				arrange_windows(child, remaining_width, height);
+			} else {
+				arrange_windows(child, child->width * scale, height);
+			}
+			child_x += child->width;
+		}
+
+		// update focused view border last because it may
+		// depend on the title bar geometry of its siblings.
+		/* TODO WLR
+		if (focused && container->children->length > 1) {
+			update_container_border(focused);
+		}
+		*/
+	}
+}
+
+void apply_vert_layout(swayc_t *container,
+		const double x, const double y,
+		const double width, const double height, const int start,
+		const int end) {
+	int i;
+	double scale = 0;
+	// Calculate total height
+	for (i = start; i < end; ++i) {
+		double *old_height = &((swayc_t *)container->children->items[i])->height;
+		if (*old_height <= 0) {
+			if (end - start > 1) {
+				*old_height = height / (end - start - 1);
+			} else {
+				*old_height = height;
+			}
+		}
+		scale += *old_height;
+	}
+	scale = height / scale;
+
+	// Resize
+	double child_y = y;
+	if (scale > 0.1) {
+		sway_log(L_DEBUG, "Arranging %p vertically", container);
+		for (i = start; i < end; ++i) {
+			swayc_t *child = container->children->items[i];
+			sway_log(L_DEBUG,
+				 "Calculating arrangement for %p:%d (will scale %f by %f)",
+				 child, child->type, height, scale);
+			child->x = x;
+			child->y = child_y;
+
+			if (i == end - 1) {
+				double remaining_height = y + height - child_y;
+				arrange_windows(child, width, remaining_height);
+			} else {
+				arrange_windows(child, width, child->height * scale);
+			}
+			child_y += child->height;
+		}
+
+		// update focused view border last because it may
+		// depend on the title bar geometry of its siblings.
+		/* TODO WLR
+		if (focused && container->children->length > 1) {
+			update_container_border(focused);
+		}
+		*/
+	}
+}