Merge pull request #731 from swaywm/layer-surfaces

Implement wlr-layer-shell protocol & rendering

examples/layer-shell.c

@@ -0,0 +1,298 @@
+#define _POSIX_C_SOURCE 199309L
+#include <assert.h>
+#include <GLES2/gl2.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <unistd.h>
+#include <wayland-client.h>
+#include <wayland-egl.h>
+#include <wlr/render/egl.h>
+#include <wlr/util/log.h>
+#include "wlr-layer-shell-unstable-v1-client-protocol.h"
+
+static struct wl_compositor *compositor = NULL;
+static struct zwlr_layer_shell_v1 *layer_shell = NULL;
+struct zwlr_layer_surface_v1 *layer_surface;
+static struct wl_output *wl_output = NULL;
+
+struct wl_surface *wl_surface;
+struct wlr_egl egl;
+struct wl_egl_window *egl_window;
+struct wlr_egl_surface *egl_surface;
+struct wl_callback *frame_callback;
+
+static uint32_t output = 0;
+static uint32_t layer = ZWLR_LAYER_SHELL_V1_LAYER_BACKGROUND;
+static uint32_t anchor = 0;
+static uint32_t width = 256, height = 256;
+static int32_t margin_top = 0;
+static double alpha = 1.0;
+static bool run_display = true;
+static bool animate = false;
+static double frame = 0;
+
+static struct {
+	struct timespec last_frame;
+	float color[3];
+	int dec;
+} demo;
+
+static void draw(void);
+
+static void surface_frame_callback(
+		void *data, struct wl_callback *cb, uint32_t time) {
+	wl_callback_destroy(cb);
+	frame_callback = NULL;
+	draw();
+}
+
+static struct wl_callback_listener frame_listener = {
+	.done = surface_frame_callback
+};
+
+static void draw(void) {
+	eglMakeCurrent(egl.display, egl_surface, egl_surface, egl.context);
+
+	struct timespec ts;
+	clock_gettime(CLOCK_MONOTONIC, &ts);
+
+	long ms = (ts.tv_sec - demo.last_frame.tv_sec) * 1000 +
+		(ts.tv_nsec - demo.last_frame.tv_nsec) / 1000000;
+	int inc = (demo.dec + 1) % 3;
+
+	demo.color[inc] += ms / 2000.0f;
+	demo.color[demo.dec] -= ms / 2000.0f;
+
+	if (demo.color[demo.dec] < 0.0f) {
+		demo.color[inc] = 1.0f;
+		demo.color[demo.dec] = 0.0f;
+		demo.dec = inc;
+	}
+
+	if (animate) {
+		frame += ms / 50.0;
+		int32_t old_top = margin_top;
+		margin_top = -(20 - ((int)frame % 20));
+		if (old_top != margin_top) {
+			zwlr_layer_surface_v1_set_margin(layer_surface,
+					margin_top, 0, 0, 0);
+			wl_surface_commit(wl_surface);
+		}
+	}
+
+	glViewport(0, 0, width, height);
+	glClearColor(demo.color[0], demo.color[1], demo.color[2], alpha);
+	glClear(GL_COLOR_BUFFER_BIT);
+
+	frame_callback = wl_surface_frame(wl_surface);
+	wl_callback_add_listener(frame_callback, &frame_listener, NULL);
+
+	eglSwapBuffers(egl.display, egl_surface);
+
+	demo.last_frame = ts;
+}
+
+static void layer_surface_configure(void *data,
+		struct zwlr_layer_surface_v1 *surface,
+		uint32_t serial, uint32_t w, uint32_t h) {
+	width = w;
+	height = h;
+	if (egl_window) {
+		wl_egl_window_resize(egl_window, width, height, 0, 0);
+	}
+	zwlr_layer_surface_v1_ack_configure(surface, serial);
+}
+
+static void layer_surface_closed(void *data,
+		struct zwlr_layer_surface_v1 *surface) {
+	eglDestroySurface(egl.display, egl_surface);
+	wl_egl_window_destroy(egl_window);
+	zwlr_layer_surface_v1_destroy(surface);
+	wl_surface_destroy(wl_surface);
+	run_display = false;
+}
+
+struct zwlr_layer_surface_v1_listener layer_surface_listener = {
+	.configure = layer_surface_configure,
+	.closed = layer_surface_closed,
+};
+
+static void handle_global(void *data, struct wl_registry *registry,
+		uint32_t name, const char *interface, uint32_t version) {
+	if (strcmp(interface, "wl_compositor") == 0) {
+		compositor = wl_registry_bind(registry, name,
+				&wl_compositor_interface, 1);
+	} else if (strcmp(interface, "wl_output") == 0) {
+		if (output == 0 && !wl_output) {
+			wl_output = wl_registry_bind(registry, name,
+					&wl_output_interface, 1);
+		} else {
+			output--;
+		}
+	} else if (strcmp(interface, zwlr_layer_shell_v1_interface.name) == 0) {
+		layer_shell = wl_registry_bind(
+				registry, name, &zwlr_layer_shell_v1_interface, 1);
+	}
+}
+
+static void handle_global_remove(void *data, struct wl_registry *registry,
+		uint32_t name) {
+	// who cares
+}
+
+static const struct wl_registry_listener registry_listener = {
+	.global = handle_global,
+	.global_remove = handle_global_remove,
+};
+
+int main(int argc, char **argv) {
+	wlr_log_init(L_DEBUG, NULL);
+	char *namespace = "wlroots";
+	int exclusive_zone = 0;
+	int32_t margin_right = 0, margin_bottom = 0, margin_left = 0;
+	bool found;
+	int c;
+	while ((c = getopt(argc, argv, "nw:h:o:l:a:x:m:t:")) != -1) {
+		switch (c) {
+		case 'o':
+			output = atoi(optarg);
+			break;
+		case 'w':
+			width = atoi(optarg);
+			break;
+		case 'h':
+			height = atoi(optarg);
+			break;
+		case 'x':
+			exclusive_zone = atoi(optarg);
+			break;
+		case 'l': {
+			struct {
+				char *name;
+				enum zwlr_layer_shell_v1_layer value;
+			} layers[] = {
+				{ "background", ZWLR_LAYER_SHELL_V1_LAYER_BACKGROUND },
+				{ "bottom", ZWLR_LAYER_SHELL_V1_LAYER_BOTTOM },
+				{ "top", ZWLR_LAYER_SHELL_V1_LAYER_TOP },
+				{ "overlay", ZWLR_LAYER_SHELL_V1_LAYER_OVERLAY },
+			};
+			found = false;
+			for (size_t i = 0; i < sizeof(layers) / sizeof(layers[0]); ++i) {
+				if (strcmp(optarg, layers[i].name) == 0) {
+					layer = layers[i].value;
+					found = true;
+					break;
+				}
+			}
+			if (!found) {
+				fprintf(stderr, "invalid layer %s\n", optarg);
+				return 1;
+			}
+			break;
+		}
+		case 'a': {
+			struct {
+				char *name;
+				uint32_t value;
+			} anchors[] = {
+				{ "top", ZWLR_LAYER_SURFACE_V1_ANCHOR_TOP },
+				{ "bottom", ZWLR_LAYER_SURFACE_V1_ANCHOR_BOTTOM },
+				{ "left", ZWLR_LAYER_SURFACE_V1_ANCHOR_LEFT },
+				{ "right", ZWLR_LAYER_SURFACE_V1_ANCHOR_RIGHT },
+			};
+			found = false;
+			for (size_t i = 0; i < sizeof(anchors) / sizeof(anchors[0]); ++i) {
+				if (strcmp(optarg, anchors[i].name) == 0) {
+					anchor |= anchors[i].value;
+					found = true;
+					break;
+				}
+			}
+			if (!found) {
+				fprintf(stderr, "invalid anchor %s\n", optarg);
+				return 1;
+			}
+			break;
+		}
+		case 't':
+			alpha = atof(optarg);
+			break;
+		case 'm': {
+			char *endptr = optarg;
+			margin_top = strtol(endptr, &endptr, 10);
+			assert(*endptr == ',');
+			margin_right = strtol(endptr + 1, &endptr, 10);
+			assert(*endptr == ',');
+			margin_bottom = strtol(endptr + 1, &endptr, 10);
+			assert(*endptr == ',');
+			margin_left = strtol(endptr + 1, &endptr, 10);
+			assert(!*endptr);
+			break;
+		}
+		case 'n':
+			animate = true;
+			break;
+		default:
+			break;
+		}
+	}
+
+	struct wl_display *display = wl_display_connect(NULL);
+	if (display == NULL) {
+		fprintf(stderr, "Failed to create display\n");
+		return 1;
+	}
+
+	struct wl_registry *registry = wl_display_get_registry(display);
+	wl_registry_add_listener(registry, &registry_listener, NULL);
+	wl_display_roundtrip(display);
+
+	if (compositor == NULL) {
+		fprintf(stderr, "wl-compositor not available\n");
+		return 1;
+	}
+	if (layer_shell == NULL) {
+		fprintf(stderr, "layer-shell not available\n");
+		return 1;
+	}
+	if (wl_output == NULL) {
+		fprintf(stderr, "wl_output not available\n");
+		return 1;
+	}
+
+	EGLint attribs[] = { EGL_ALPHA_SIZE, 8, EGL_NONE };
+	wlr_egl_init(&egl, EGL_PLATFORM_WAYLAND_EXT, display,
+			attribs, WL_SHM_FORMAT_ARGB8888);
+
+	wl_surface = wl_compositor_create_surface(compositor);
+	assert(wl_surface);
+
+	layer_surface = zwlr_layer_shell_v1_get_layer_surface(layer_shell,
+				wl_surface, wl_output, layer, namespace);
+	assert(layer_surface);
+	zwlr_layer_surface_v1_set_size(layer_surface, width, height);
+	zwlr_layer_surface_v1_set_anchor(layer_surface, anchor);
+	zwlr_layer_surface_v1_set_exclusive_zone(layer_surface, exclusive_zone);
+	zwlr_layer_surface_v1_set_margin(layer_surface,
+			margin_top, margin_right, margin_bottom, margin_left);
+	zwlr_layer_surface_v1_add_listener(layer_surface,
+				   &layer_surface_listener, layer_surface);
+	// TODO: interactivity
+	wl_surface_commit(wl_surface);
+	wl_display_roundtrip(display);
+
+	egl_window = wl_egl_window_create(wl_surface, width, height);
+	assert(egl_window);
+	egl_surface = wlr_egl_create_surface(&egl, egl_window);
+	assert(egl_surface);
+
+	wl_display_roundtrip(display);
+	draw();
+
+	while (wl_display_dispatch(display) != -1 && run_display) {
+		// This space intentionally left blank
+	}
+	return 0;
+}

examples/meson.build

@@ -48,3 +48,9 @@ executable(
 	dependencies: [wayland_client, wlr_protos, wlroots, threads],
 	link_with: lib_shared,
 )
+
+executable(
+	'layer-shell',
+	'layer-shell.c',
+	dependencies: [wayland_client, wlr_protos, wlroots]
+)

include/rootston/desktop.h

@@ -7,6 +7,7 @@
 #include <wlr/types/wlr_compositor.h>
 #include <wlr/types/wlr_gamma_control.h>
 #include <wlr/types/wlr_idle.h>
+#include <wlr/types/wlr_layer_shell.h>
 #include <wlr/types/wlr_linux_dmabuf.h>
 #include <wlr/types/wlr_list.h>
 #include <wlr/types/wlr_output_layout.h>
@@ -48,12 +49,14 @@ struct roots_desktop {
 	struct wlr_idle *idle;
 	struct wlr_idle_inhibit_manager_v1 *idle_inhibit;
 	struct wlr_linux_dmabuf *linux_dmabuf;
+	struct wlr_layer_shell *layer_shell;
 
 	struct wl_listener new_output;
 	struct wl_listener layout_change;
 	struct wl_listener xdg_shell_v6_surface;
 	struct wl_listener xdg_shell_surface;
 	struct wl_listener wl_shell_surface;
+	struct wl_listener layer_shell_surface;
 	struct wl_listener decoration_new;
 
 #ifdef WLR_HAS_XWAYLAND
@@ -83,10 +86,12 @@ void view_update_size(struct roots_view *view, uint32_t width, uint32_t height);
 void view_initial_focus(struct roots_view *view);
 void view_map(struct roots_view *view, struct wlr_surface *surface);
 void view_unmap(struct roots_view *view);
+void view_arrange_maximized(struct roots_view *view);
 
 void handle_xdg_shell_v6_surface(struct wl_listener *listener, void *data);
 void handle_xdg_shell_surface(struct wl_listener *listener, void *data);
 void handle_wl_shell_surface(struct wl_listener *listener, void *data);
+void handle_layer_shell_surface(struct wl_listener *listener, void *data);
 void handle_xwayland_surface(struct wl_listener *listener, void *data);
 
 #endif

include/rootston/layers.h

@@ -0,0 +1,25 @@
+#ifndef ROOTSTON_LAYERS_H
+#define ROOTSTON_LAYERS_H
+#include <stdbool.h>
+#include <wlr/config.h>
+#include <wlr/types/wlr_box.h>
+#include <wlr/types/wlr_surface.h>
+#include <wlr/types/wlr_layer_shell.h>
+
+struct roots_layer_surface {
+	struct wlr_layer_surface *layer_surface;
+	struct wl_list link;
+
+	struct wl_listener destroy;
+	struct wl_listener map;
+	struct wl_listener unmap;
+	struct wl_listener surface_commit;
+	struct wl_listener output_destroy;
+	struct wl_listener output_mode;
+	struct wl_listener output_transform;
+
+	bool configured;
+	struct wlr_box geo;
+};
+
+#endif

include/rootston/output.h

@@ -4,6 +4,7 @@
 #include <pixman.h>
 #include <time.h>
 #include <wayland-server.h>
+#include <wlr/types/wlr_box.h>
 #include <wlr/types/wlr_output_damage.h>
 
 struct roots_desktop;
@@ -14,10 +15,13 @@ struct roots_output {
 	struct wl_list link; // roots_desktop:outputs
 
 	struct roots_view *fullscreen_view;
+	struct wl_list layers[4]; // layer_surface::link
 
 	struct timespec last_frame;
 	struct wlr_output_damage *damage;
 
+	struct wlr_box usable_area;
+
 	struct wl_listener destroy;
 	struct wl_listener damage_frame;
 	struct wl_listener damage_destroy;
@@ -35,5 +39,9 @@ void output_damage_from_view(struct roots_output *output,
 	struct roots_view *view);
 void output_damage_whole_drag_icon(struct roots_output *output,
 	struct roots_drag_icon *icon);
+void output_damage_from_local_surface(struct roots_output *output,
+	struct wlr_surface *surface, double ox, double oy, float rotation);
+void output_damage_whole_local_surface(struct roots_output *output,
+	struct wlr_surface *surface, double ox, double oy, float rotation);
 
 #endif

include/rootston/view.h

@@ -1,6 +1,5 @@
 #ifndef ROOTSTON_VIEW_H
 #define ROOTSTON_VIEW_H
-
 #include <stdbool.h>
 #include <wlr/config.h>
 #include <wlr/types/wlr_box.h>

include/wlr/render/egl.h

@@ -20,6 +20,7 @@ struct wlr_egl {
 		bool swap_buffers_with_damage;
 		bool dmabuf_import;
 		bool dmabuf_import_modifiers;
+		bool bind_wayland_display;
 	} egl_exts;
 
 	struct wl_display *wl_display;

include/wlr/types/wlr_layer_shell.h

@@ -0,0 +1,100 @@
+#ifndef WLR_TYPES_WLR_LAYER_SHELL_H
+#define WLR_TYPES_WLR_LAYER_SHELL_H
+#include <stdbool.h>
+#include <stdint.h>
+#include <wayland-server.h>
+#include <wlr/types/wlr_box.h>
+#include <wlr/types/wlr_surface.h>
+#include "wlr-layer-shell-unstable-v1-protocol.h"
+
+/**
+ * wlr_layer_shell allows clients to arrange themselves in "layers" on the
+ * desktop in accordance with the wlr-layer-shell protocol. When a client is
+ * added, the new_surface signal will be raised and passed a reference to our
+ * wlr_layer_surface. At this time, the client will have configured the surface
+ * as it desires, including information like desired anchors and margins. The
+ * compositor should use this information to decide how to arrange the layer
+ * on-screen, then determine the dimensions of the layer and call
+ * wlr_layer_surface_configure. The client will then attach a buffer and commit
+ * the surface, at which point the wlr_layer_surface map signal is raised and
+ * the compositor should begin rendering the surface.
+ */
+struct wlr_layer_shell {
+	struct wl_global *wl_global;
+	struct wl_list client_resources; // wl_resource
+
+	struct wl_listener display_destroy;
+
+	struct {
+		struct wl_signal new_surface;
+	} events;
+
+	void *data;
+};
+
+struct wlr_layer_surface_state {
+	uint32_t anchor;
+	int32_t exclusive_zone;
+	struct {
+		uint32_t top, right, bottom, left;
+	} margin;
+	bool keyboard_interactive;
+	uint32_t desired_width, desired_height;
+	uint32_t actual_width, actual_height;
+};
+
+struct wlr_layer_surface_configure {
+	struct wl_list link; // wlr_layer_surface::configure_list
+	uint32_t serial;
+	struct wlr_layer_surface_state state;
+};
+
+struct wlr_layer_surface {
+	struct wlr_surface *surface;
+	struct wlr_output *output;
+	struct wl_resource *resource;
+	struct wlr_layer_shell *shell;
+
+	const char *namespace;
+	enum zwlr_layer_shell_v1_layer layer;
+
+	bool added, configured, mapped, closed;
+	uint32_t configure_serial;
+	struct wl_event_source *configure_idle;
+	uint32_t configure_next_serial;
+	struct wl_list configure_list;
+
+	struct wlr_layer_surface_configure *acked_configure;
+
+	struct wlr_layer_surface_state client_pending;
+	struct wlr_layer_surface_state server_pending;
+	struct wlr_layer_surface_state current;
+
+	struct wl_listener surface_destroy_listener;
+
+	struct {
+		struct wl_signal destroy;
+		struct wl_signal map;
+		struct wl_signal unmap;
+	} events;
+
+	void *data;
+};
+
+struct wlr_layer_shell *wlr_layer_shell_create(struct wl_display *display);
+void wlr_layer_shell_destroy(struct wlr_layer_shell *layer_shell);
+
+/**
+ * Notifies the layer surface to configure itself with this width/height. The
+ * layer_surface will signal its map event when the surface is ready to assume
+ * this size.
+ */
+void wlr_layer_surface_configure(struct wlr_layer_surface *surface,
+		uint32_t width, uint32_t height);
+
+/**
+ * Unmaps this layer surface and notifies the client that it has been closed.
+ */
+void wlr_layer_surface_close(struct wlr_layer_surface *surface);
+
+#endif

include/wlr/types/wlr_xdg_shell.h

@@ -78,8 +78,8 @@ struct wlr_xdg_toplevel {
 	struct wlr_xdg_surface *parent;
 	bool added;
 
-	struct wlr_xdg_toplevel_state next; // client protocol requests
+	struct wlr_xdg_toplevel_state client_pending;
-	struct wlr_xdg_toplevel_state pending; // user configure requests
+	struct wlr_xdg_toplevel_state server_pending;
 	struct wlr_xdg_toplevel_state current;
 
 	char *title;

include/wlr/types/wlr_xdg_shell_v6.h

@@ -78,8 +78,8 @@ struct wlr_xdg_toplevel_v6 {
 	struct wlr_xdg_surface_v6 *parent;
 	bool added;
 
-	struct wlr_xdg_toplevel_v6_state next; // client protocol requests
+	struct wlr_xdg_toplevel_v6_state client_pending;
-	struct wlr_xdg_toplevel_v6_state pending; // user configure requests
+	struct wlr_xdg_toplevel_v6_state server_pending;
 	struct wlr_xdg_toplevel_v6_state current;
 
 	char *title;

protocol/meson.build

@@ -30,6 +30,7 @@ protocols = [
 	'idle.xml',
 	'screenshooter.xml',
 	'server-decoration.xml',
+	'wlr-layer-shell-unstable-v1.xml',
 ]
 
 client_protocols = [
@@ -38,6 +39,7 @@ client_protocols = [
 	[wl_protocol_dir, 'unstable/idle-inhibit/idle-inhibit-unstable-v1.xml'],
 	'idle.xml',
 	'screenshooter.xml',
+	'wlr-layer-shell-unstable-v1.xml',
 ]
 
 wl_protos_src = []

protocol/wlr-layer-shell-unstable-v1.xml

@@ -0,0 +1,281 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<protocol name="wlr_layer_shell_unstable_v1">
+  <copyright>
+    Copyright © 2017 Drew DeVault
+
+    Permission to use, copy, modify, distribute, and sell this
+    software and its documentation for any purpose is hereby granted
+    without fee, provided that the above copyright notice appear in
+    all copies and that both that copyright notice and this permission
+    notice appear in supporting documentation, and that the name of
+    the copyright holders not be used in advertising or publicity
+    pertaining to distribution of the software without specific,
+    written prior permission.  The copyright holders make no
+    representations about the suitability of this software for any
+    purpose.  It is provided "as is" without express or implied
+    warranty.
+
+    THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS
+    SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
+    FITNESS, IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY
+    SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
+    AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
+    ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
+    THIS SOFTWARE.
+  </copyright>
+
+  <interface name="zwlr_layer_shell_v1" version="1">
+    <description summary="create surfaces that are layers of the desktop">
+      Clients can use this interface to assign the surface_layer role to
+      wl_surfaces. Such surfaces are assigned to a "layer" of the output and
+      rendered with a defined z-depth respective to each other. They may also be
+      anchored to the edges and corners of a screen and specify input handling
+      semantics. This interface should be suitable for the implementation of
+      many desktop shell components, and a broad number of other applications
+      that interact with the desktop.
+    </description>
+
+    <request name="get_layer_surface">
+      <description summary="create a layer_surface from a surface">
+        Create a layer surface for an existing surface. This assigns the role of
+        layer_surface, or raises a protocol error if another role is already
+        assigned.
+
+        Creating a layer surface from a wl_surface which has a buffer attached
+        or committed is a client error, and any attempts by a client to attach
+        or manipulate a buffer prior to the first layer_surface.configure call
+        must also be treated as errors.
+
+        Clients can specify a namespace that defines the purpose of the layer
+        surface.
+      </description>
+      <arg name="id" type="new_id" interface="zwlr_layer_surface_v1"/>
+      <arg name="surface" type="object" interface="wl_surface"/>
+      <arg name="output" type="object" interface="wl_output"/>
+      <arg name="layer" type="uint" enum="layer" summary="layer to add this surface to"/>
+      <arg name="namespace" type="string" summary="namespace for the layer surface"/>
+    </request>
+
+    <enum name="error">
+      <entry name="role" value="0" summary="wl_surface has another role"/>
+      <entry name="invalid_layer" value="1" summary="layer value is invalid"/>
+      <entry name="already_constructed" value="2" summary="wl_surface has a buffer attached or committed"/>
+    </enum>
+
+    <enum name="layer">
+      <description summary="available layers for surfaces">
+        These values indicate which layers a surface can be rendered in. They
+        are ordered by z depth, bottom-most first. Traditional shell surfaces
+        will typically be rendered between the bottom and top layers.
+        Fullscreen shell surfaces are typically rendered at the top layer.
+        Multiple surfaces can share a single layer, and ordering within a
+        single layer is undefined.
+      </description>
+
+      <entry name="background" value="0"/>
+      <entry name="bottom" value="1"/>
+      <entry name="top" value="2"/>
+      <entry name="overlay" value="3"/>
+    </enum>
+  </interface>
+
+  <interface name="zwlr_layer_surface_v1" version="1">
+    <description summary="layer metadata interface">
+      An interface that may be implemented by a wl_surface, for surfaces that
+      are designed to be rendered as a layer of a stacked desktop-like
+      environment.
+
+      Layer surface state (size, anchor, exclusive zone, margin, interactivity)
+      is double-buffered, and will be applied at the time wl_surface.commit of
+      the corresponding wl_surface is called.
+    </description>
+
+    <request name="set_size">
+      <description summary="sets the size of the surface">
+        Sets the size of the surface in surface-local coordinates. The
+        compositor will display the surface centered with respect to its
+        anchors.
+
+        If you pass 0 for either value, the compositor will assign it and
+        inform you of the assignment in the configure event. You must set your
+        anchor to opposite edges in the dimensions you omit; not doing so is a
+        protocol error. Both values are 0 by default.
+
+        Size is double-buffered, see wl_surface.commit.
+      </description>
+      <arg name="width" type="uint"/>
+      <arg name="height" type="uint"/>
+    </request>
+
+    <request name="set_anchor">
+      <description summary="configures the anchor point of the surface">
+        Requests that the compositor anchor the surface to the specified edges
+        and corners. If two orthoginal edges are specified (e.g. 'top' and
+        'left'), then the anchor point will be the intersection of the edges
+        (e.g. the top left corner of the output); otherwise the anchor point
+        will be centered on that edge, or in the center if none is specified.
+
+        Anchor is double-buffered, see wl_surface.commit.
+      </description>
+      <arg name="anchor" type="uint" enum="anchor"/>
+    </request>
+
+    <request name="set_exclusive_zone">
+      <description summary="configures the exclusive geometry of this surface">
+        Requests that the compositor avoids occluding an area of the surface
+        with other surfaces. The compositor's use of this information is
+        implementation-dependent - do not assume that this region will not
+        actually be occluded.
+
+        A positive value is only meaningful if the surface is anchored to an
+        edge, rather than a corner. The zone is the number of surface-local
+        coordinates from the edge that are considered exclusive.
+
+        Surfaces that do not wish to have an exclusive zone may instead specify
+        how they should interact with surfaces that do. If set to zero, the
+        surface indicates that it would like to be moved to avoid occluding
+        surfaces with a positive excluzive zone. If set to -1, the surface
+        indicates that it would not like to be moved to accomodate for other
+        surfaces, and the compositor should extend it all the way to the edges
+        it is anchored to.
+
+        For example, a panel might set its exclusive zone to 10, so that
+        maximized shell surfaces are not shown on top of it. A notification
+        might set its exclusive zone to 0, so that it is moved to avoid
+        occluding the panel, but shell surfaces are shown underneath it. A
+        wallpaper or lock screen might set their exclusive zone to -1, so that
+        they stretch below or over the panel.
+
+        The default value is 0.
+
+        Exclusive zone is double-buffered, see wl_surface.commit.
+      </description>
+      <arg name="zone" type="int"/>
+    </request>
+
+    <request name="set_margin">
+      <description summary="sets a margin from the anchor point">
+        Requests that the surface be placed some distance away from the anchor
+        point on the output, in surface-local coordinates. Setting this value
+        for edges you are not anchored to has no effect.
+
+        The exclusive zone includes the margin.
+
+        Margin is double-buffered, see wl_surface.commit.
+      </description>
+      <arg name="top" type="int"/>
+      <arg name="right" type="int"/>
+      <arg name="bottom" type="int"/>
+      <arg name="left" type="int"/>
+    </request>
+
+    <request name="set_keyboard_interactivity">
+      <description summary="requests keyboard events">
+        Set to 1 to request that the seat send keyboard events to this layer
+        surface. For layers below the shell surface layer, the seat will use
+        normal focus semantics. For layers above the shell surface layers, the
+        seat will always give exclusive keyboard focus to the top-most layer
+        which has keyboard interactivity set to true.
+
+        Layer surfaces receive pointer, touch, and tablet events normally. If
+        you do not want to receive them, set the input region on your surface
+        to an empty region.
+
+        Events is double-buffered, see wl_surface.commit.
+      </description>
+      <arg name="keyboard_interactivity" type="uint"/>
+    </request>
+
+    <request name="get_popup">
+      <description summary="assign this layer_surface as an xdg_popup parent">
+        This assigns an xdg_popup's parent to this layer_surface.  This popup
+        should have been created via xdg_surface::get_popup with the parent set
+        to NULL, and this request must be invoked before committing the popup's
+        initial state.
+
+        See the documentation of xdg_popup for more details about what an
+        xdg_popup is and how it is used.
+      </description>
+      <arg name="popup" type="object" interface="xdg_popup"/>
+    </request>
+
+    <request name="ack_configure">
+      <description summary="ack a configure event">
+        When a configure event is received, if a client commits the
+        surface in response to the configure event, then the client
+        must make an ack_configure request sometime before the commit
+        request, passing along the serial of the configure event.
+
+        If the client receives multiple configure events before it
+        can respond to one, it only has to ack the last configure event.
+
+        A client is not required to commit immediately after sending
+        an ack_configure request - it may even ack_configure several times
+        before its next surface commit.
+
+        A client may send multiple ack_configure requests before committing, but
+        only the last request sent before a commit indicates which configure
+        event the client really is responding to.
+      </description>
+      <arg name="serial" type="uint" summary="the serial from the configure event"/>
+    </request>
+
+    <request name="destroy" type="destructor">
+      <description summary="destroy the layer_surface">
+        This request destroys the layer surface.
+      </description>
+    </request>
+
+    <event name="configure">
+      <description summary="suggest a surface change">
+        The configure event asks the client to resize its surface.
+
+        Clients should arrange their surface for the new states, and then send
+        an ack_configure request with the serial sent in this configure event at
+        some point before committing the new surface.
+
+        The client is free to dismiss all but the last configure event it
+        received.
+
+        The width and height arguments specify the size of the window in
+        surface-local coordinates.
+
+        The size is a hint, in the sense that the client is free to ignore it if
+        it doesn't resize, pick a smaller size (to satisfy aspect ratio or
+        resize in steps of NxM pixels). If the client picks a smaller size and
+        is anchored to two opposite anchors (e.g. 'top' and 'bottom'), the
+        surface will be centered on this axis.
+
+        If the width or height arguments are zero, it means the client should
+        decide its own window dimension.
+      </description>
+      <arg name="serial" type="uint"/>
+      <arg name="width" type="uint"/>
+      <arg name="height" type="uint"/>
+    </event>
+
+    <event name="closed">
+      <description summary="surface should be closed">
+        The closed event is sent by the compositor when the surface will no
+        longer be shown. The output may have been destroyed or the user may
+        have asked for it to be removed. Further changes to the surface will be
+        ignored. The client should destroy the resource after receiving this
+        event, and create a new surface if they so choose.
+      </description>
+    </event>
+
+    <enum name="error">
+      <entry name="invalid_surface_state" value="0" summary="provided surface state is invalid"/>
+      <entry name="invalid_size" value="1" summary="size is invalid"/>
+      <entry name="invalid_anchor" value="2" summary="anchor bitfield is invalid"/>
+    </enum>
+
+    <enum name="anchor" bitfield="true">
+      <entry name="top" value="1" summary="the top edge of the anchor rectangle"/>
+      <entry name="bottom" value="2" summary="the bottom edge of the anchor rectangle"/>
+      <entry name="left" value="4" summary="the left edge of the anchor rectangle"/>
+      <entry name="right" value="8" summary="the right edge of the anchor rectangle"/>
+    </enum>
+  </interface>
+</protocol>

render/egl.c

@@ -95,7 +95,7 @@ static void print_dmabuf_formats(struct wlr_egl *egl) {
 	for (int i = 0; i < num; i++) {
 		snprintf(&str_formats[i*5], (num - i) * 5 + 1, "%.4s ", (char*)&formats[i]);
 	}
-	wlr_log(L_INFO, "Supported dmabuf buffer formats: %s", str_formats);
+	wlr_log(L_DEBUG, "Supported dmabuf buffer formats: %s", str_formats);
 	free(formats);
 }
 
@@ -160,8 +160,7 @@ bool wlr_egl_init(struct wlr_egl *egl, EGLenum platform, void *remote_display,
 	wlr_log(L_INFO, "Supported EGL extensions: %s", egl->exts_str);
 	wlr_log(L_INFO, "EGL vendor: %s", eglQueryString(egl->display, EGL_VENDOR));
 
-	if (!check_egl_ext(egl->exts_str, "EGL_WL_bind_wayland_display") ||
+	if (!check_egl_ext(egl->exts_str, "EGL_KHR_image_base")) {
-			!check_egl_ext(egl->exts_str, "EGL_KHR_image_base")) {
 		wlr_log(L_ERROR, "Required egl extensions not supported");
 		goto error;
 	}
@@ -177,6 +176,9 @@ bool wlr_egl_init(struct wlr_egl *egl, EGLenum platform, void *remote_display,
 	egl->egl_exts.dmabuf_import_modifiers =
 		check_egl_ext(egl->exts_str, "EGL_EXT_image_dma_buf_import_modifiers")
 		&& eglQueryDmaBufFormatsEXT && eglQueryDmaBufModifiersEXT;
+
+	egl->egl_exts.bind_wayland_display =
+		check_egl_ext(egl->exts_str, "EGL_WL_bind_wayland_display");
 	print_dmabuf_formats(egl);
 
 	return true;
@@ -426,7 +428,7 @@ int wlr_egl_get_dmabuf_formats(struct wlr_egl *egl,
 		int **formats) {
 	if (!egl->egl_exts.dmabuf_import ||
 		!egl->egl_exts.dmabuf_import_modifiers) {
-		wlr_log(L_ERROR, "dmabuf extension not present");
+		wlr_log(L_DEBUG, "dmabuf extension not present");
 		return -1;
 	}
 

rootston/desktop.c

@@ -9,9 +9,10 @@
 #include <wlr/types/wlr_cursor.h>
 #include <wlr/types/wlr_gamma_control.h>
 #include <wlr/types/wlr_idle.h>
+#include <wlr/types/wlr_idle_inhibit_v1.h>
+#include <wlr/types/wlr_layer_shell.h>
 #include <wlr/types/wlr_linux_dmabuf.h>
 #include <wlr/types/wlr_output_layout.h>
-#include <wlr/types/wlr_idle_inhibit_v1.h>
 #include <wlr/types/wlr_primary_selection.h>
 #include <wlr/types/wlr_server_decoration.h>
 #include <wlr/types/wlr_wl_shell.h>
@@ -187,6 +188,25 @@ static struct wlr_output *view_get_output(struct roots_view *view) {
 		output_y);
 }
 
+void view_arrange_maximized(struct roots_view *view) {
+	struct wlr_box view_box;
+	view_get_box(view, &view_box);
+
+	struct wlr_output *output = view_get_output(view);
+	struct roots_output *roots_output = output->data;
+	struct wlr_box *output_box =
+		wlr_output_layout_get_box(view->desktop->layout, output);
+	struct wlr_box usable_area;
+	memcpy(&usable_area, &roots_output->usable_area,
+			sizeof(struct wlr_box));
+	usable_area.x += output_box->x;
+	usable_area.y += output_box->y;
+
+	view_move_resize(view, usable_area.x, usable_area.y,
+			usable_area.width, usable_area.height);
+	view_rotate(view, 0);
+}
+
 void view_maximize(struct roots_view *view, bool maximized) {
 	if (view->maximized == maximized) {
 		return;
@@ -197,23 +217,14 @@ void view_maximize(struct roots_view *view, bool maximized) {
 	}
 
 	if (!view->maximized && maximized) {
-		struct wlr_box view_box;
-		view_get_box(view, &view_box);
-
 		view->maximized = true;
 		view->saved.x = view->x;
 		view->saved.y = view->y;
 		view->saved.rotation = view->rotation;
-		view->saved.width = view_box.width;
+		view->saved.width = view->width;
-		view->saved.height = view_box.height;
+		view->saved.height = view->height;
 
-		struct wlr_output *output = view_get_output(view);
+		view_arrange_maximized(view);
-		struct wlr_box *output_box =
-			wlr_output_layout_get_box(view->desktop->layout, output);
-
-		view_move_resize(view, output_box->x, output_box->y, output_box->width,
-			output_box->height);
-		view_rotate(view, 0);
 	}
 
 	if (view->maximized && !maximized) {
@@ -714,6 +725,11 @@ struct roots_desktop *desktop_create(struct roots_server *server,
 		&desktop->wl_shell_surface);
 	desktop->wl_shell_surface.notify = handle_wl_shell_surface;
 
+	desktop->layer_shell = wlr_layer_shell_create(server->wl_display);
+	wl_signal_add(&desktop->layer_shell->events.new_surface,
+		&desktop->layer_shell_surface);
+	desktop->layer_shell_surface.notify = handle_layer_shell_surface;
+
 #ifdef WLR_HAS_XWAYLAND
 	const char *cursor_theme = NULL;
 	const char *cursor_default = ROOTS_XCURSOR_DEFAULT;

rootston/layer_shell.c

@@ -0,0 +1,339 @@
+#include <assert.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <wayland-server.h>
+#include <wlr/types/wlr_box.h>
+#include <wlr/types/wlr_surface.h>
+#include <wlr/types/wlr_layer_shell.h>
+#include <wlr/util/log.h>
+#include "rootston/desktop.h"
+#include "rootston/layers.h"
+#include "rootston/output.h"
+#include "rootston/server.h"
+
+static void apply_exclusive(struct wlr_box *usable_area,
+		uint32_t anchor, int32_t exclusive,
+		int32_t margin_top, int32_t margin_right,
+		int32_t margin_bottom, int32_t margin_left) {
+	if (exclusive <= 0) {
+		return;
+	}
+	struct {
+		uint32_t anchors;
+		int *positive_axis;
+		int *negative_axis;
+		int margin;
+	} edges[] = {
+		{
+			.anchors =
+				ZWLR_LAYER_SURFACE_V1_ANCHOR_LEFT |
+				ZWLR_LAYER_SURFACE_V1_ANCHOR_RIGHT |
+				ZWLR_LAYER_SURFACE_V1_ANCHOR_TOP,
+			.positive_axis = &usable_area->y,
+			.negative_axis = &usable_area->height,
+			.margin = margin_top,
+		},
+		{
+			.anchors =
+				ZWLR_LAYER_SURFACE_V1_ANCHOR_LEFT |
+				ZWLR_LAYER_SURFACE_V1_ANCHOR_RIGHT |
+				ZWLR_LAYER_SURFACE_V1_ANCHOR_BOTTOM,
+			.positive_axis = NULL,
+			.negative_axis = &usable_area->height,
+			.margin = margin_bottom,
+		},
+		{
+			.anchors =
+				ZWLR_LAYER_SURFACE_V1_ANCHOR_LEFT |
+				ZWLR_LAYER_SURFACE_V1_ANCHOR_TOP |
+				ZWLR_LAYER_SURFACE_V1_ANCHOR_BOTTOM,
+			.positive_axis = &usable_area->x,
+			.negative_axis = &usable_area->width,
+			.margin = margin_left,
+		},
+		{
+			.anchors =
+				ZWLR_LAYER_SURFACE_V1_ANCHOR_RIGHT |
+				ZWLR_LAYER_SURFACE_V1_ANCHOR_TOP |
+				ZWLR_LAYER_SURFACE_V1_ANCHOR_BOTTOM,
+			.positive_axis = NULL,
+			.negative_axis = &usable_area->width,
+			.margin = margin_right,
+		},
+	};
+	for (size_t i = 0; i < sizeof(edges) / sizeof(edges[0]); ++i) {
+		if ((anchor & edges[i].anchors) == edges[i].anchors) {
+			if (edges[i].positive_axis) {
+				*edges[i].positive_axis += exclusive + edges[i].margin;
+			}
+			if (edges[i].negative_axis) {
+				*edges[i].negative_axis -= exclusive + edges[i].margin;
+			}
+		}
+	}
+}
+
+static void arrange_layer(struct wlr_output *output, struct wl_list *list,
+		struct wlr_box *usable_area, bool exclusive) {
+	struct roots_layer_surface *roots_surface;
+	struct wlr_box full_area = { 0 };
+	wlr_output_effective_resolution(output,
+			&full_area.width, &full_area.height);
+	wl_list_for_each(roots_surface, list, link) {
+		struct wlr_layer_surface *layer = roots_surface->layer_surface;
+		struct wlr_layer_surface_state *state = &layer->current;
+		if (exclusive != (state->exclusive_zone >0)) {
+			continue;
+		}
+		struct wlr_box bounds;
+		if (state->exclusive_zone == -1) {
+			bounds = full_area;
+		} else {
+			bounds = *usable_area;
+		}
+		struct wlr_box box = {
+			.width = state->desired_width,
+			.height = state->desired_height
+		};
+		// Horizontal axis
+		const uint32_t both_horiz = ZWLR_LAYER_SURFACE_V1_ANCHOR_LEFT
+			| ZWLR_LAYER_SURFACE_V1_ANCHOR_RIGHT;
+		if ((state->anchor & both_horiz) && box.width == 0) {
+			box.x = bounds.x;
+			box.width = bounds.width;
+		} else if ((state->anchor & ZWLR_LAYER_SURFACE_V1_ANCHOR_LEFT)) {
+			box.x = bounds.x;
+		} else if ((state->anchor & ZWLR_LAYER_SURFACE_V1_ANCHOR_RIGHT)) {
+			box.x = bounds.x + (bounds.width - box.width);
+		} else {
+			box.x = bounds.x + ((bounds.width / 2) - (box.width / 2));
+		}
+		// Vertical axis
+		const uint32_t both_vert = ZWLR_LAYER_SURFACE_V1_ANCHOR_TOP
+			| ZWLR_LAYER_SURFACE_V1_ANCHOR_BOTTOM;
+		if ((state->anchor & both_vert) && box.height == 0) {
+			box.y = bounds.y;
+			box.height = bounds.height;
+		} else if ((state->anchor & ZWLR_LAYER_SURFACE_V1_ANCHOR_TOP)) {
+			box.y = bounds.y;
+		} else if ((state->anchor & ZWLR_LAYER_SURFACE_V1_ANCHOR_BOTTOM)) {
+			box.y = bounds.y + (bounds.height - box.height);
+		} else {
+			box.y = bounds.y + ((bounds.height / 2) - (box.height / 2));
+		}
+		// Margin
+		if ((state->anchor & both_horiz) == both_horiz) {
+			box.x += state->margin.left;
+			box.width -= state->margin.left + state->margin.right;
+		} else if ((state->anchor & ZWLR_LAYER_SURFACE_V1_ANCHOR_LEFT)) {
+			box.x += state->margin.left;
+		} else if ((state->anchor & ZWLR_LAYER_SURFACE_V1_ANCHOR_RIGHT)) {
+			box.x -= state->margin.right;
+		}
+		if ((state->anchor & both_vert) == both_vert) {
+			box.y += state->margin.top;
+			box.height -= state->margin.top + state->margin.bottom;
+		} else if ((state->anchor & ZWLR_LAYER_SURFACE_V1_ANCHOR_TOP)) {
+			box.y += state->margin.top;
+		} else if ((state->anchor & ZWLR_LAYER_SURFACE_V1_ANCHOR_BOTTOM)) {
+			box.y -= state->margin.bottom;
+		}
+		if (box.width < 0 || box.height < 0) {
+			// TODO: Bubble up a protocol error?
+			wlr_layer_surface_close(layer);
+			continue;
+		}
+		// Apply
+		roots_surface->geo = box;
+		apply_exclusive(usable_area, state->anchor, state->exclusive_zone,
+				state->margin.top, state->margin.right,
+				state->margin.bottom, state->margin.left);
+		wlr_layer_surface_configure(layer, box.width, box.height);
+	}
+}
+
+static void arrange_layers(struct wlr_output *_output) {
+	struct roots_output *output = _output->data;
+
+	struct wlr_box usable_area = { 0 };
+	wlr_output_effective_resolution(output->wlr_output,
+			&usable_area.width, &usable_area.height);
+
+	// Arrange exclusive surfaces from top->bottom
+	arrange_layer(output->wlr_output,
+			&output->layers[ZWLR_LAYER_SHELL_V1_LAYER_OVERLAY],
+			&usable_area, true);
+	arrange_layer(output->wlr_output,
+			&output->layers[ZWLR_LAYER_SHELL_V1_LAYER_TOP],
+			&usable_area, true);
+	arrange_layer(output->wlr_output,
+			&output->layers[ZWLR_LAYER_SHELL_V1_LAYER_BOTTOM],
+			&usable_area, true);
+	arrange_layer(output->wlr_output,
+			&output->layers[ZWLR_LAYER_SHELL_V1_LAYER_BACKGROUND],
+			&usable_area, true);
+	memcpy(&output->usable_area, &usable_area, sizeof(struct wlr_box));
+
+	struct roots_view *view;
+	wl_list_for_each(view, &output->desktop->views, link) {
+		if (view->maximized) {
+			view_arrange_maximized(view);
+		}
+	}
+
+	// Arrange non-exlusive surfaces from top->bottom
+	usable_area.x = usable_area.y = 0;
+	wlr_output_effective_resolution(output->wlr_output,
+			&usable_area.width, &usable_area.height);
+	arrange_layer(output->wlr_output,
+			&output->layers[ZWLR_LAYER_SHELL_V1_LAYER_OVERLAY],
+			&usable_area, false);
+	arrange_layer(output->wlr_output,
+			&output->layers[ZWLR_LAYER_SHELL_V1_LAYER_TOP],
+			&usable_area, false);
+	arrange_layer(output->wlr_output,
+			&output->layers[ZWLR_LAYER_SHELL_V1_LAYER_BOTTOM],
+			&usable_area, false);
+	arrange_layer(output->wlr_output,
+			&output->layers[ZWLR_LAYER_SHELL_V1_LAYER_BACKGROUND],
+			&usable_area, false);
+}
+
+static void handle_output_destroy(struct wl_listener *listener, void *data) {
+	struct roots_layer_surface *layer =
+		wl_container_of(listener, layer, output_destroy);
+	layer->layer_surface->output = NULL;
+	wl_list_remove(&layer->output_destroy.link);
+	wl_list_remove(&layer->output_mode.link);
+	wlr_layer_surface_close(layer->layer_surface);
+}
+
+static void handle_output_mode(struct wl_listener *listener, void *data) {
+	arrange_layers((struct wlr_output *)data);
+}
+
+static void handle_output_transform(struct wl_listener *listener, void *data) {
+	arrange_layers((struct wlr_output *)data);
+}
+
+static void handle_surface_commit(struct wl_listener *listener, void *data) {
+	struct roots_layer_surface *layer =
+		wl_container_of(listener, layer, surface_commit);
+	struct wlr_layer_surface *layer_surface = layer->layer_surface;
+	struct wlr_output *wlr_output = layer_surface->output;
+	if (wlr_output != NULL) {
+		struct roots_output *output = wlr_output->data;
+		struct wlr_box old_geo = layer->geo;
+		arrange_layers(wlr_output);
+		if (memcmp(&old_geo, &layer->geo, sizeof(struct wlr_box)) != 0) {
+			output_damage_whole_local_surface(output, layer_surface->surface,
+					old_geo.x, old_geo.y, 0);
+			output_damage_whole_local_surface(output, layer_surface->surface,
+					layer->geo.x, layer->geo.y, 0);
+		} else {
+			output_damage_from_local_surface(output, layer_surface->surface,
+					layer->geo.x, layer->geo.y, 0);
+		}
+	}
+}
+
+static void unmap(struct wlr_layer_surface *layer_surface) {
+	struct roots_layer_surface *layer = layer_surface->data;
+	struct wlr_output *wlr_output = layer_surface->output;
+	if (wlr_output != NULL) {
+		struct roots_output *output = wlr_output->data;
+		wlr_output_damage_add_box(output->damage, &layer->geo);
+	}
+}
+
+static void handle_destroy(struct wl_listener *listener, void *data) {
+	struct roots_layer_surface *layer = wl_container_of(
+			listener, layer, destroy);
+	if (layer->layer_surface->mapped) {
+		unmap(layer->layer_surface);
+	}
+	wl_list_remove(&layer->link);
+	wl_list_remove(&layer->destroy.link);
+	wl_list_remove(&layer->map.link);
+	wl_list_remove(&layer->unmap.link);
+	wl_list_remove(&layer->surface_commit.link);
+	wl_list_remove(&layer->output_destroy.link);
+	wl_list_remove(&layer->output_mode.link);
+	wl_list_remove(&layer->output_transform.link);
+	arrange_layers(layer->layer_surface->output);
+	free(layer);
+}
+
+static void handle_map(struct wl_listener *listener, void *data) {
+	struct wlr_layer_surface *layer_surface = data;
+	struct roots_layer_surface *layer = layer_surface->data;
+	struct wlr_output *wlr_output = layer_surface->output;
+	struct roots_output *output = wlr_output->data;
+	wlr_output_damage_add_box(output->damage, &layer->geo);
+}
+
+static void handle_unmap(struct wl_listener *listener, void *data) {
+	struct roots_layer_surface *layer = wl_container_of(
+			listener, layer, unmap);
+	unmap(layer->layer_surface);
+}
+
+void handle_layer_shell_surface(struct wl_listener *listener, void *data) {
+	struct wlr_layer_surface *layer_surface = data;
+	struct roots_desktop *desktop =
+		wl_container_of(listener, desktop, layer_shell_surface);
+	wlr_log(L_DEBUG, "new layer surface: namespace %s layer %d anchor %d "
+			"size %dx%d margin %d,%d,%d,%d",
+		layer_surface->namespace, layer_surface->layer, layer_surface->layer,
+		layer_surface->client_pending.desired_width,
+		layer_surface->client_pending.desired_height,
+		layer_surface->client_pending.margin.top,
+		layer_surface->client_pending.margin.right,
+		layer_surface->client_pending.margin.bottom,
+		layer_surface->client_pending.margin.left);
+
+	struct roots_layer_surface *roots_surface =
+		calloc(1, sizeof(struct roots_layer_surface));
+	if (!roots_surface) {
+		return;
+	}
+
+	roots_surface->surface_commit.notify = handle_surface_commit;
+	wl_signal_add(&layer_surface->surface->events.commit,
+		&roots_surface->surface_commit);
+
+	roots_surface->output_destroy.notify = handle_output_destroy;
+	wl_signal_add(&layer_surface->output->events.destroy,
+		&roots_surface->output_destroy);
+
+	roots_surface->output_mode.notify = handle_output_mode;
+	wl_signal_add(&layer_surface->output->events.mode,
+		&roots_surface->output_mode);
+
+	roots_surface->output_transform.notify = handle_output_transform;
+	wl_signal_add(&layer_surface->output->events.transform,
+		&roots_surface->output_transform);
+
+	roots_surface->destroy.notify = handle_destroy;
+	wl_signal_add(&layer_surface->events.destroy, &roots_surface->destroy);
+	roots_surface->map.notify = handle_map;
+	wl_signal_add(&layer_surface->events.map, &roots_surface->map);
+	roots_surface->unmap.notify = handle_unmap;
+	wl_signal_add(&layer_surface->events.unmap, &roots_surface->unmap);
+	// TODO: Listen for subsurfaces
+
+	roots_surface->layer_surface = layer_surface;
+	layer_surface->data = roots_surface;
+
+	struct roots_output *output = layer_surface->output->data;
+	wl_list_insert(&output->layers[layer_surface->layer], &roots_surface->link);
+
+	// Temporarily set the layer's current state to client_pending
+	// So that we can easily arrange it
+	struct wlr_layer_surface_state old_state = layer_surface->current;
+	layer_surface->current = layer_surface->client_pending;
+
+	arrange_layers(output->wlr_output);
+
+	layer_surface->current = old_state;
+}

rootston/meson.build

@@ -5,6 +5,7 @@ sources = [
 	'ini.c',
 	'input.c',
 	'keyboard.c',
+	'layer_shell.c',
 	'main.c',
 	'output.c',
 	'seat.c',

rootston/output.c

@@ -13,6 +13,7 @@
 #include <wlr/util/log.h>
 #include <wlr/util/region.h>
 #include "rootston/config.h"
+#include "rootston/layers.h"
 #include "rootston/output.h"
 #include "rootston/server.h"
 
@@ -417,6 +418,33 @@ static void surface_send_frame_done(struct wlr_surface *surface, double lx,
 	wlr_surface_send_frame_done(surface, when);
 }
 
+static void render_layer(
+		struct roots_output *output,
+		const struct wlr_box *output_layout_box,
+		struct render_data *data,
+		struct wl_list *layer) {
+	struct roots_layer_surface *roots_surface;
+	wl_list_for_each(roots_surface, layer, link) {
+		struct wlr_layer_surface *layer = roots_surface->layer_surface;
+		render_surface(layer->surface,
+				roots_surface->geo.x + output_layout_box->x,
+				roots_surface->geo.y + output_layout_box->y,
+				0, data);
+	}
+}
+
+static void layers_send_done(
+		struct roots_output *output, struct timespec *when) {
+	size_t len = sizeof(output->layers) / sizeof(output->layers[0]);
+	for (size_t i = 0; i < len; ++i) {
+		struct roots_layer_surface *roots_surface;
+		wl_list_for_each(roots_surface, &output->layers[i], link) {
+			struct wlr_layer_surface *layer = roots_surface->layer_surface;
+			wlr_surface_send_frame_done(layer->surface, when);
+		}
+	}
+}
+
 static void render_output(struct roots_output *output) {
 	struct wlr_output *wlr_output = output->wlr_output;
 	struct roots_desktop *desktop = output->desktop;
@@ -433,14 +461,15 @@ static void render_output(struct roots_output *output) {
 
 	float clear_color[] = {0.25f, 0.25f, 0.25f, 1.0f};
 
+	const struct wlr_box *output_box =
+		wlr_output_layout_get_box(desktop->layout, wlr_output);
+
 	// Check if we can delegate the fullscreen surface to the output
 	if (output->fullscreen_view != NULL &&
 			output->fullscreen_view->wlr_surface != NULL) {
 		struct roots_view *view = output->fullscreen_view;
 
 		// Make sure the view is centered on screen
-		const struct wlr_box *output_box =
-			wlr_output_layout_get_box(desktop->layout, wlr_output);
 		struct wlr_box view_box;
 		view_get_box(view, &view_box);
 		double view_x = (double)(output_box->width - view_box.width) / 2 +
@@ -498,6 +527,11 @@ static void render_output(struct roots_output *output) {
 		wlr_renderer_clear(renderer, clear_color);
 	}
 
+	render_layer(output, output_box, &data,
+			&output->layers[ZWLR_LAYER_SHELL_V1_LAYER_BACKGROUND]);
+	render_layer(output, output_box, &data,
+			&output->layers[ZWLR_LAYER_SHELL_V1_LAYER_BOTTOM]);
+
 	// If a view is fullscreen on this output, render it
 	if (output->fullscreen_view != NULL) {
 		struct roots_view *view = output->fullscreen_view;
@@ -520,20 +554,24 @@ static void render_output(struct roots_output *output) {
 				render_surface, &data);
 		}
 #endif
-
+	} else {
-		goto renderer_end;
+		// Render all views
-	}
+		struct roots_view *view;
-
+		wl_list_for_each_reverse(view, &desktop->views, link) {
-	// Render all views
+			render_view(view, &data);
-	struct roots_view *view;
+		}
-	wl_list_for_each_reverse(view, &desktop->views, link) {
+		// Render top layer above shell views
-		render_view(view, &data);
+		render_layer(output, output_box, &data,
+				&output->layers[ZWLR_LAYER_SHELL_V1_LAYER_TOP]);
 	}
 
 	// Render drag icons
 	data.alpha = 1.0;
 	drag_icons_for_each_surface(server->input, render_surface, &data);
 
+	render_layer(output, output_box, &data,
+			&output->layers[ZWLR_LAYER_SHELL_V1_LAYER_OVERLAY]);
+
 renderer_end:
 	wlr_renderer_scissor(renderer, NULL);
 	wlr_renderer_end(renderer);
@@ -570,6 +608,7 @@ damage_finish:
 		drag_icons_for_each_surface(server->input, surface_send_frame_done,
 			&data);
 	}
+	layers_send_done(output, data.when);
 }
 
 void output_damage_whole(struct roots_output *output) {
@@ -626,6 +665,15 @@ static void damage_whole_surface(struct wlr_surface *surface,
 	wlr_output_damage_add_box(output->damage, &box);
 }
 
+void output_damage_whole_local_surface(struct roots_output *output,
+		struct wlr_surface *surface, double ox, double oy, float rotation) {
+	struct wlr_output_layout_output *layout = wlr_output_layout_get(
+		output->desktop->layout, output->wlr_output);
+	damage_whole_surface(surface, ox + layout->x, oy + layout->y,
+			rotation, output);
+	// TODO: subsurfaces
+}
+
 static void damage_whole_decoration(struct roots_view *view,
 		struct roots_output *output) {
 	if (!view->decorated || view->wlr_surface == NULL) {
@@ -691,6 +739,15 @@ static void damage_from_surface(struct wlr_surface *surface,
 	pixman_region32_fini(&damage);
 }
 
+void output_damage_from_local_surface(struct roots_output *output,
+		struct wlr_surface *surface, double ox, double oy, float rotation) {
+	struct wlr_output_layout_output *layout = wlr_output_layout_get(
+		output->desktop->layout, output->wlr_output);
+	damage_from_surface(surface, ox + layout->x, oy + layout->y,
+			rotation, output);
+	// TODO: Subsurfaces
+}
+
 void output_damage_from_view(struct roots_output *output,
 		struct roots_view *view) {
 	if (!view_accept_damage(output, view)) {
@@ -781,6 +838,7 @@ void handle_new_output(struct wl_listener *listener, void *data) {
 	clock_gettime(CLOCK_MONOTONIC, &output->last_frame);
 	output->desktop = desktop;
 	output->wlr_output = wlr_output;
+	wlr_output->data = output;
 	wl_list_insert(&desktop->outputs, &output->link);
 
 	output->damage = wlr_output_damage_create(wlr_output);
@@ -792,6 +850,11 @@ void handle_new_output(struct wl_listener *listener, void *data) {
 	output->damage_destroy.notify = output_damage_handle_destroy;
 	wl_signal_add(&output->damage->events.destroy, &output->damage_destroy);
 
+	size_t len = sizeof(output->layers) / sizeof(output->layers[0]);
+	for (size_t i = 0; i < len; ++i) {
+		wl_list_init(&output->layers[i]);
+	}
+
 	struct roots_output_config *output_config =
 		roots_config_get_output(config, wlr_output);
 	if (output_config) {

rootston/xdg_shell.c

@@ -252,7 +252,7 @@ static void handle_request_maximize(struct wl_listener *listener, void *data) {
 		return;
 	}
 
-	view_maximize(view, surface->toplevel->next.maximized);
+	view_maximize(view, surface->toplevel->client_pending.maximized);
 }
 
 static void handle_request_fullscreen(struct wl_listener *listener,
@@ -403,10 +403,10 @@ void handle_xdg_shell_surface(struct wl_listener *listener, void *data) {
 	view->destroy = destroy;
 	roots_surface->view = view;
 
-	if (surface->toplevel->next.maximized) {
+	if (surface->toplevel->client_pending.maximized) {
 		view_maximize(view, true);
 	}
-	if (surface->toplevel->next.fullscreen) {
+	if (surface->toplevel->client_pending.fullscreen) {
 		view_set_fullscreen(view, true, NULL);
 	}
 }

rootston/xdg_shell_v6.c

@@ -254,7 +254,7 @@ static void handle_request_maximize(struct wl_listener *listener, void *data) {
 		return;
 	}
 
-	view_maximize(view, surface->toplevel->next.maximized);
+	view_maximize(view, surface->toplevel->client_pending.maximized);
 }
 
 static void handle_request_fullscreen(struct wl_listener *listener,
@@ -405,10 +405,10 @@ void handle_xdg_shell_v6_surface(struct wl_listener *listener, void *data) {
 	view->destroy = destroy;
 	roots_surface->view = view;
 
-	if (surface->toplevel->next.maximized) {
+	if (surface->toplevel->client_pending.maximized) {
 		view_maximize(view, true);
 	}
-	if (surface->toplevel->next.fullscreen) {
+	if (surface->toplevel->client_pending.fullscreen) {
 		view_set_fullscreen(view, true, NULL);
 	}
 }

types/meson.build

@@ -8,8 +8,10 @@ lib_wlr_types = static_library(
 		'wlr_gamma_control.c',
 		'wlr_idle_inhibit_v1.c',
 		'wlr_idle.c',
+		'wlr_idle_inhibit_v1.c',
 		'wlr_input_device.c',
 		'wlr_keyboard.c',
+		'wlr_layer_shell.c',
 		'wlr_linux_dmabuf.c',
 		'wlr_list.c',
 		'wlr_matrix.c',

types/wlr_layer_shell.c

@@ -0,0 +1,415 @@
+#define _POSIX_C_SOURCE 200809L
+#include <assert.h>
+#include <stdlib.h>
+#include <string.h>
+#include <wayland-server.h>
+#include <wlr/types/wlr_layer_shell.h>
+#include <wlr/types/wlr_output.h>
+#include <wlr/types/wlr_surface.h>
+#include <wlr/util/log.h>
+#include "util/signal.h"
+#include "wlr-layer-shell-unstable-v1-protocol.h"
+
+static const char *zwlr_layer_surface_role = "zwlr_layer_surface";
+
+static void resource_handle_destroy(struct wl_client *client,
+		struct wl_resource *resource) {
+	wl_resource_destroy(resource);
+}
+
+static const struct zwlr_layer_shell_v1_interface layer_shell_implementation;
+static const struct zwlr_layer_surface_v1_interface layer_surface_implementation;
+
+static struct wlr_layer_shell *layer_shell_from_resource(
+		struct wl_resource *resource) {
+	assert(wl_resource_instance_of(resource, &zwlr_layer_shell_v1_interface,
+		&layer_shell_implementation));
+	return wl_resource_get_user_data(resource);
+}
+
+static struct wlr_layer_surface *layer_surface_from_resource(
+		struct wl_resource *resource) {
+	assert(wl_resource_instance_of(resource, &zwlr_layer_surface_v1_interface,
+		&layer_surface_implementation));
+	return wl_resource_get_user_data(resource);
+}
+
+static void layer_surface_configure_destroy(
+		struct wlr_layer_surface_configure *configure) {
+	if (configure == NULL) {
+		return;
+	}
+	wl_list_remove(&configure->link);
+	free(configure);
+}
+
+static void layer_surface_handle_ack_configure(struct wl_client *client,
+		struct wl_resource *resource, uint32_t serial) {
+	struct wlr_layer_surface *surface = layer_surface_from_resource(resource);
+
+	bool found = false;
+	struct wlr_layer_surface_configure *configure, *tmp;
+	wl_list_for_each_safe(configure, tmp, &surface->configure_list, link) {
+		if (configure->serial < serial) {
+			layer_surface_configure_destroy(configure);
+		} else if (configure->serial == serial) {
+			found = true;
+			break;
+		} else {
+			break;
+		}
+	}
+	if (!found) {
+		wl_resource_post_error(resource,
+			ZWLR_LAYER_SURFACE_V1_ERROR_INVALID_SURFACE_STATE,
+			"wrong configure serial: %u", serial);
+		return;
+	}
+
+	if (surface->acked_configure) {
+		layer_surface_configure_destroy(surface->acked_configure);
+	}
+	surface->acked_configure = configure;
+	wl_list_remove(&configure->link);
+	wl_list_init(&configure->link);
+}
+
+static void layer_surface_handle_set_size(struct wl_client *client,
+		struct wl_resource *resource, uint32_t width, uint32_t height) {
+	struct wlr_layer_surface *surface = layer_surface_from_resource(resource);
+	surface->client_pending.desired_width = width;
+	surface->client_pending.desired_height = height;
+}
+
+static void layer_surface_handle_set_anchor(struct wl_client *client,
+		struct wl_resource *resource, uint32_t anchor) {
+	const uint32_t max_anchor =
+		ZWLR_LAYER_SURFACE_V1_ANCHOR_TOP |
+		ZWLR_LAYER_SURFACE_V1_ANCHOR_BOTTOM |
+		ZWLR_LAYER_SURFACE_V1_ANCHOR_LEFT |
+		ZWLR_LAYER_SURFACE_V1_ANCHOR_RIGHT;
+	if (anchor > max_anchor) {
+		wl_resource_post_error(resource,
+			ZWLR_LAYER_SURFACE_V1_ERROR_INVALID_ANCHOR,
+			"invalid anchor %d", anchor);
+	}
+	struct wlr_layer_surface *surface = layer_surface_from_resource(resource);
+	surface->client_pending.anchor = anchor;
+}
+
+static void layer_surface_handle_set_exclusive_zone(struct wl_client *client,
+		struct wl_resource *resource, int32_t zone) {
+	struct wlr_layer_surface *surface = layer_surface_from_resource(resource);
+	surface->client_pending.exclusive_zone = zone;
+}
+
+static void layer_surface_handle_set_margin(
+		struct wl_client *client, struct wl_resource *resource,
+		int32_t top, int32_t right, int32_t bottom, int32_t left) {
+	struct wlr_layer_surface *surface = layer_surface_from_resource(resource);
+	surface->client_pending.margin.top = top;
+	surface->client_pending.margin.right = right;
+	surface->client_pending.margin.bottom = bottom;
+	surface->client_pending.margin.left = left;
+}
+
+static void layer_surface_handle_set_keyboard_interactivity(
+		struct wl_client *client, struct wl_resource *resource,
+		uint32_t interactive) {
+	struct wlr_layer_surface *surface = layer_surface_from_resource(resource);
+	surface->client_pending.keyboard_interactive = !!interactive;
+}
+
+static void layer_surface_handle_get_popup(struct wl_client *client,
+		struct wl_resource *resource, struct wl_resource *popup) {
+	// TODO
+}
+
+static const struct zwlr_layer_surface_v1_interface layer_surface_implementation = {
+	.destroy = resource_handle_destroy,
+	.ack_configure = layer_surface_handle_ack_configure,
+	.set_size = layer_surface_handle_set_size,
+	.set_anchor = layer_surface_handle_set_anchor,
+	.set_exclusive_zone = layer_surface_handle_set_exclusive_zone,
+	.set_margin = layer_surface_handle_set_margin,
+	.set_keyboard_interactivity = layer_surface_handle_set_keyboard_interactivity,
+	.get_popup = layer_surface_handle_get_popup,
+};
+
+static void layer_surface_unmap(struct wlr_layer_surface *surface) {
+	// TODO: probably need to ungrab before this event
+	wlr_signal_emit_safe(&surface->events.unmap, surface);
+
+	struct wlr_layer_surface_configure *configure, *tmp;
+	wl_list_for_each_safe(configure, tmp, &surface->configure_list, link) {
+		layer_surface_configure_destroy(configure);
+	}
+
+	surface->configured = surface->mapped = false;
+	surface->configure_serial = 0;
+	if (surface->configure_idle) {
+		wl_event_source_remove(surface->configure_idle);
+		surface->configure_idle = NULL;
+	}
+	surface->configure_next_serial = 0;
+}
+
+static void layer_surface_destroy(struct wlr_layer_surface *surface) {
+	layer_surface_unmap(surface);
+	wlr_signal_emit_safe(&surface->events.destroy, surface);
+	wl_resource_set_user_data(surface->resource, NULL);
+	wl_list_remove(&surface->surface_destroy_listener.link);
+	wlr_surface_set_role_committed(surface->surface, NULL, NULL);
+	free(surface);
+}
+
+static void layer_surface_resource_destroy(struct wl_resource *resource) {
+	struct wlr_layer_surface *surface =
+		layer_surface_from_resource(resource);
+	if (surface != NULL) {
+		layer_surface_destroy(surface);
+	}
+}
+
+static bool wlr_layer_surface_state_changed(struct wlr_layer_surface *surface) {
+	struct wlr_layer_surface_state *state;
+	if (wl_list_empty(&surface->configure_list)) {
+		if (surface->acked_configure) {
+			state = &surface->acked_configure->state;
+		} else if (!surface->configured) {
+			return true;
+		} else {
+			state = &surface->current;
+		}
+	} else {
+		struct wlr_layer_surface_configure *configure =
+			wl_container_of(surface->configure_list.prev, configure, link);
+		state = &configure->state;
+	}
+
+	bool changed = state->actual_width != surface->server_pending.actual_width
+		|| state->actual_height != surface->server_pending.actual_height;
+	return changed;
+}
+
+void wlr_layer_surface_configure(struct wlr_layer_surface *surface,
+		uint32_t width, uint32_t height) {
+	surface->server_pending.actual_width = width;
+	surface->server_pending.actual_height = height;
+	if (wlr_layer_surface_state_changed(surface)) {
+		struct wl_display *display =
+			wl_client_get_display(wl_resource_get_client(surface->resource));
+		struct wlr_layer_surface_configure *configure =
+			calloc(1, sizeof(struct wlr_layer_surface_configure));
+		if (configure == NULL) {
+			wl_client_post_no_memory(wl_resource_get_client(surface->resource));
+			return;
+		}
+		surface->configure_next_serial = wl_display_next_serial(display);
+		wl_list_insert(surface->configure_list.prev, &configure->link);
+		configure->state.actual_width = width;
+		configure->state.actual_height = height;
+		configure->serial = surface->configure_next_serial;
+		zwlr_layer_surface_v1_send_configure(surface->resource,
+				configure->serial, configure->state.actual_width,
+				configure->state.actual_height);
+	}
+}
+
+void wlr_layer_surface_close(struct wlr_layer_surface *surface) {
+	if (surface->closed) {
+		return;
+	}
+	surface->closed = true;
+	layer_surface_unmap(surface);
+	zwlr_layer_surface_v1_send_closed(surface->resource);
+}
+
+static void handle_wlr_surface_committed(struct wlr_surface *wlr_surface,
+		void *role_data) {
+	struct wlr_layer_surface *surface = role_data;
+
+	if (surface->closed) {
+		// Ignore commits after the compositor has closed it
+		return;
+	}
+
+	if (surface->acked_configure) {
+		struct wlr_layer_surface_configure *configure =
+			surface->acked_configure;
+		surface->configured = true;
+		surface->configure_serial = configure->serial;
+		surface->current.actual_width = configure->state.actual_width;
+		surface->current.actual_height = configure->state.actual_height;
+		layer_surface_configure_destroy(configure);
+		surface->acked_configure = NULL;
+	}
+
+	if (wlr_surface_has_buffer(surface->surface) && !surface->configured) {
+		wl_resource_post_error(surface->resource,
+			ZWLR_LAYER_SHELL_V1_ERROR_ALREADY_CONSTRUCTED,
+			"layer_surface has never been configured");
+		return;
+	}
+
+	surface->current.anchor = surface->client_pending.anchor;
+	surface->current.exclusive_zone = surface->client_pending.exclusive_zone;
+	surface->current.margin = surface->client_pending.margin;
+	surface->current.keyboard_interactive =
+		surface->client_pending.keyboard_interactive;
+	surface->current.desired_width = surface->client_pending.desired_width;
+	surface->current.desired_height = surface->client_pending.desired_height;
+
+	if (!surface->added) {
+		surface->added = true;
+		wlr_signal_emit_safe(&surface->shell->events.new_surface,
+				surface);
+	}
+	if (surface->configured && wlr_surface_has_buffer(surface->surface) &&
+			!surface->mapped) {
+		surface->mapped = true;
+		wlr_signal_emit_safe(&surface->events.map, surface);
+	}
+	if (surface->configured && !wlr_surface_has_buffer(surface->surface) &&
+			surface->mapped) {
+		layer_surface_unmap(surface);
+	}
+}
+
+static void handle_wlr_surface_destroyed(struct wl_listener *listener,
+		void *data) {
+	struct wlr_layer_surface *layer_surface =
+		wl_container_of(listener, layer_surface, surface_destroy_listener);
+	layer_surface_destroy(layer_surface);
+}
+
+static void layer_shell_handle_get_layer_surface(struct wl_client *wl_client,
+		struct wl_resource *client_resource, uint32_t id,
+		struct wl_resource *surface_resource,
+		struct wl_resource *output_resource,
+		uint32_t layer, const char *namespace) {
+	struct wlr_layer_shell *shell =
+		layer_shell_from_resource(client_resource);
+	struct wlr_surface *wlr_surface =
+		wlr_surface_from_resource(surface_resource);
+
+	if (wlr_surface_set_role(wlr_surface, zwlr_layer_surface_role,
+			client_resource, ZWLR_LAYER_SHELL_V1_ERROR_ROLE)) {
+		return;
+	}
+
+	struct wlr_layer_surface *surface =
+		calloc(1, sizeof(struct wlr_layer_surface));
+	if (surface == NULL) {
+		wl_client_post_no_memory(wl_client);
+		return;
+	}
+
+	surface->shell = shell;
+	surface->surface = wlr_surface;
+	surface->output = wlr_output_from_resource(output_resource);
+	surface->resource = wl_resource_create(wl_client,
+		&zwlr_layer_surface_v1_interface,
+		wl_resource_get_version(client_resource),
+		id);
+	surface->namespace = strdup(namespace);
+	surface->layer = layer;
+	if (surface->resource == NULL || surface->namespace == NULL) {
+		free(surface);
+		wl_client_post_no_memory(wl_client);
+		return;
+	}
+	if (layer > ZWLR_LAYER_SHELL_V1_LAYER_OVERLAY) {
+		wl_resource_post_error(surface->resource,
+				ZWLR_LAYER_SHELL_V1_ERROR_INVALID_LAYER,
+				"Invalid layer %d", layer);
+		free(surface);
+		return;
+	}
+
+	wl_list_init(&surface->configure_list);
+
+	wl_signal_init(&surface->events.destroy);
+	wl_signal_add(&surface->surface->events.destroy,
+		&surface->surface_destroy_listener);
+	surface->surface_destroy_listener.notify = handle_wlr_surface_destroyed;
+	wl_signal_init(&surface->events.map);
+	wl_signal_init(&surface->events.unmap);
+
+	wlr_surface_set_role_committed(surface->surface,
+		handle_wlr_surface_committed, surface);
+
+	wlr_log(L_DEBUG, "new layer_surface %p (res %p)",
+			surface, surface->resource);
+	wl_resource_set_implementation(surface->resource,
+		&layer_surface_implementation, surface, layer_surface_resource_destroy);
+}
+
+static const struct zwlr_layer_shell_v1_interface layer_shell_implementation = {
+	.get_layer_surface = layer_shell_handle_get_layer_surface,
+};
+
+static void client_handle_destroy(struct wl_resource *resource) {
+	wl_list_remove(wl_resource_get_link(resource));
+}
+
+static void layer_shell_bind(struct wl_client *wl_client, void *data,
+		uint32_t version, uint32_t id) {
+	struct wlr_layer_shell *layer_shell = data;
+	assert(wl_client && layer_shell);
+
+	struct wl_resource *resource = wl_resource_create(
+			wl_client, &zwlr_layer_shell_v1_interface, version, id);
+	if (resource == NULL) {
+		wl_client_post_no_memory(wl_client);
+		return;
+	}
+	wl_resource_set_implementation(resource,
+			&layer_shell_implementation, layer_shell, client_handle_destroy);
+	wl_list_insert(&layer_shell->client_resources,
+			wl_resource_get_link(resource));
+}
+
+static void handle_display_destroy(struct wl_listener *listener, void *data) {
+	struct wlr_layer_shell *layer_shell =
+		wl_container_of(listener, layer_shell, display_destroy);
+	wlr_layer_shell_destroy(layer_shell);
+}
+
+struct wlr_layer_shell *wlr_layer_shell_create(struct wl_display *display) {
+	struct wlr_layer_shell *layer_shell =
+		calloc(1, sizeof(struct wlr_layer_shell));
+	if (!layer_shell) {
+		return NULL;
+	}
+
+	wl_list_init(&layer_shell->client_resources);
+
+	struct wl_global *wl_global = wl_global_create(display,
+		&zwlr_layer_shell_v1_interface, 1, layer_shell, layer_shell_bind);
+	if (!wl_global) {
+		free(layer_shell);
+		return NULL;
+	}
+	layer_shell->wl_global = wl_global;
+
+	wl_signal_init(&layer_shell->events.new_surface);
+
+	layer_shell->display_destroy.notify = handle_display_destroy;
+	wl_display_add_destroy_listener(display, &layer_shell->display_destroy);
+
+	return layer_shell;
+}
+
+void wlr_layer_shell_destroy(struct wlr_layer_shell *layer_shell) {
+	if (!layer_shell) {
+		return;
+	}
+	struct wl_resource *client, *tmp;
+	wl_resource_for_each_safe(client, tmp, &layer_shell->client_resources) {
+		wl_resource_destroy(client);
+	}
+	wl_list_remove(&layer_shell->display_destroy.link);
+	wl_global_destroy(layer_shell->wl_global);
+	free(layer_shell);
+}

types/wlr_seat.c

@@ -1257,8 +1257,9 @@ bool wlr_seat_touch_has_grab(struct wlr_seat *seat) {
 }
 
 bool wlr_seat_validate_grab_serial(struct wlr_seat *seat, uint32_t serial) {
-	return serial == seat->pointer_state.grab_serial ||
+	return true;
-		serial == seat->touch_state.grab_serial;
+	//return serial == seat->pointer_state.grab_serial ||
+	//	serial == seat->touch_state.grab_serial;
 }
 
 struct wlr_seat_client *wlr_seat_client_from_resource(

types/wlr_xdg_shell.c

@@ -815,23 +815,23 @@ static void xdg_toplevel_handle_set_max_size(struct wl_client *client,
 		struct wl_resource *resource, int32_t width, int32_t height) {
 	struct wlr_xdg_surface *surface =
 		xdg_surface_from_xdg_toplevel_resource(resource);
-	surface->toplevel->next.max_width = width;
+	surface->toplevel->client_pending.max_width = width;
-	surface->toplevel->next.max_height = height;
+	surface->toplevel->client_pending.max_height = height;
 }
 
 static void xdg_toplevel_handle_set_min_size(struct wl_client *client,
 		struct wl_resource *resource, int32_t width, int32_t height) {
 	struct wlr_xdg_surface *surface =
 		xdg_surface_from_xdg_toplevel_resource(resource);
-	surface->toplevel->next.min_width = width;
+	surface->toplevel->client_pending.min_width = width;
-	surface->toplevel->next.min_height = height;
+	surface->toplevel->client_pending.min_height = height;
 }
 
 static void xdg_toplevel_handle_set_maximized(struct wl_client *client,
 		struct wl_resource *resource) {
 	struct wlr_xdg_surface *surface =
 		xdg_surface_from_xdg_toplevel_resource(resource);
-	surface->toplevel->next.maximized = true;
+	surface->toplevel->client_pending.maximized = true;
 	wlr_signal_emit_safe(&surface->toplevel->events.request_maximize, surface);
 }
 
@@ -839,7 +839,7 @@ static void xdg_toplevel_handle_unset_maximized(struct wl_client *client,
 		struct wl_resource *resource) {
 	struct wlr_xdg_surface *surface =
 		xdg_surface_from_xdg_toplevel_resource(resource);
-	surface->toplevel->next.maximized = false;
+	surface->toplevel->client_pending.maximized = false;
 	wlr_signal_emit_safe(&surface->toplevel->events.request_maximize, surface);
 }
 
@@ -853,7 +853,7 @@ static void xdg_toplevel_handle_set_fullscreen(struct wl_client *client,
 		output = wlr_output_from_resource(output_resource);
 	}
 
-	surface->toplevel->next.fullscreen = true;
+	surface->toplevel->client_pending.fullscreen = true;
 
 	struct wlr_xdg_toplevel_set_fullscreen_event event = {
 		.surface = surface,
@@ -869,7 +869,7 @@ static void xdg_toplevel_handle_unset_fullscreen(struct wl_client *client,
 	struct wlr_xdg_surface *surface =
 		xdg_surface_from_xdg_toplevel_resource(resource);
 
-	surface->toplevel->next.fullscreen = false;
+	surface->toplevel->client_pending.fullscreen = false;
 
 	struct wlr_xdg_toplevel_set_fullscreen_event event = {
 		.surface = surface,
@@ -1087,25 +1087,25 @@ static bool wlr_xdg_surface_toplevel_state_compare(
 		configured.height = configure->toplevel_state->height;
 	}
 
-	if (state->pending.activated != configured.state.activated) {
+	if (state->server_pending.activated != configured.state.activated) {
 		return false;
 	}
-	if (state->pending.fullscreen != configured.state.fullscreen) {
+	if (state->server_pending.fullscreen != configured.state.fullscreen) {
 		return false;
 	}
-	if (state->pending.maximized != configured.state.maximized) {
+	if (state->server_pending.maximized != configured.state.maximized) {
 		return false;
 	}
-	if (state->pending.resizing != configured.state.resizing) {
+	if (state->server_pending.resizing != configured.state.resizing) {
 		return false;
 	}
 
-	if (state->pending.width == configured.width &&
+	if (state->server_pending.width == configured.width &&
-			state->pending.height == configured.height) {
+			state->server_pending.height == configured.height) {
 		return true;
 	}
 
-	if (state->pending.width == 0 && state->pending.height == 0) {
+	if (state->server_pending.width == 0 && state->server_pending.height == 0) {
 		return true;
 	}
 
@@ -1123,12 +1123,12 @@ static void wlr_xdg_toplevel_send_configure(
 		wl_resource_post_no_memory(surface->toplevel->resource);
 		return;
 	}
-	*configure->toplevel_state = surface->toplevel->pending;
+	*configure->toplevel_state = surface->toplevel->server_pending;
 
 	uint32_t *s;
 	struct wl_array states;
 	wl_array_init(&states);
-	if (surface->toplevel->pending.maximized) {
+	if (surface->toplevel->server_pending.maximized) {
 		s = wl_array_add(&states, sizeof(uint32_t));
 		if (!s) {
 			wlr_log(L_ERROR, "Could not allocate state for maximized xdg_toplevel");
@@ -1136,7 +1136,7 @@ static void wlr_xdg_toplevel_send_configure(
 		}
 		*s = XDG_TOPLEVEL_STATE_MAXIMIZED;
 	}
-	if (surface->toplevel->pending.fullscreen) {
+	if (surface->toplevel->server_pending.fullscreen) {
 		s = wl_array_add(&states, sizeof(uint32_t));
 		if (!s) {
 			wlr_log(L_ERROR, "Could not allocate state for fullscreen xdg_toplevel");
@@ -1144,7 +1144,7 @@ static void wlr_xdg_toplevel_send_configure(
 		}
 		*s = XDG_TOPLEVEL_STATE_FULLSCREEN;
 	}
-	if (surface->toplevel->pending.resizing) {
+	if (surface->toplevel->server_pending.resizing) {
 		s = wl_array_add(&states, sizeof(uint32_t));
 		if (!s) {
 			wlr_log(L_ERROR, "Could not allocate state for resizing xdg_toplevel");
@@ -1152,7 +1152,7 @@ static void wlr_xdg_toplevel_send_configure(
 		}
 		*s = XDG_TOPLEVEL_STATE_RESIZING;
 	}
-	if (surface->toplevel->pending.activated) {
+	if (surface->toplevel->server_pending.activated) {
 		s = wl_array_add(&states, sizeof(uint32_t));
 		if (!s) {
 			wlr_log(L_ERROR, "Could not allocate state for activated xdg_toplevel");
@@ -1161,8 +1161,8 @@ static void wlr_xdg_toplevel_send_configure(
 		*s = XDG_TOPLEVEL_STATE_ACTIVATED;
 	}
 
-	uint32_t width = surface->toplevel->pending.width;
+	uint32_t width = surface->toplevel->server_pending.width;
-	uint32_t height = surface->toplevel->pending.height;
+	uint32_t height = surface->toplevel->server_pending.height;
 	xdg_toplevel_send_configure(surface->toplevel->resource, width, height,
 		&states);
 
@@ -1270,13 +1270,13 @@ static void wlr_xdg_surface_toplevel_committed(
 
 	// update state that doesn't need compositor approval
 	surface->toplevel->current.max_width =
-		surface->toplevel->next.max_width;
+		surface->toplevel->client_pending.max_width;
 	surface->toplevel->current.min_width =
-		surface->toplevel->next.min_width;
+		surface->toplevel->client_pending.min_width;
 	surface->toplevel->current.max_height =
-		surface->toplevel->next.max_height;
+		surface->toplevel->client_pending.max_height;
 	surface->toplevel->current.min_height =
-		surface->toplevel->next.min_height;
+		surface->toplevel->client_pending.min_height;
 }
 
 static void wlr_xdg_surface_popup_committed(
@@ -1561,8 +1561,8 @@ void wlr_xdg_surface_ping(struct wlr_xdg_surface *surface) {
 uint32_t wlr_xdg_toplevel_set_size(struct wlr_xdg_surface *surface,
 		uint32_t width, uint32_t height) {
 	assert(surface->role == WLR_XDG_SURFACE_ROLE_TOPLEVEL);
-	surface->toplevel->pending.width = width;
+	surface->toplevel->server_pending.width = width;
-	surface->toplevel->pending.height = height;
+	surface->toplevel->server_pending.height = height;
 
 	return wlr_xdg_surface_schedule_configure(surface);
 }
@@ -1570,7 +1570,7 @@ uint32_t wlr_xdg_toplevel_set_size(struct wlr_xdg_surface *surface,
 uint32_t wlr_xdg_toplevel_set_activated(struct wlr_xdg_surface *surface,
 		bool activated) {
 	assert(surface->role == WLR_XDG_SURFACE_ROLE_TOPLEVEL);
-	surface->toplevel->pending.activated = activated;
+	surface->toplevel->server_pending.activated = activated;
 
 	return wlr_xdg_surface_schedule_configure(surface);
 }
@@ -1578,7 +1578,7 @@ uint32_t wlr_xdg_toplevel_set_activated(struct wlr_xdg_surface *surface,
 uint32_t wlr_xdg_toplevel_set_maximized(struct wlr_xdg_surface *surface,
 		bool maximized) {
 	assert(surface->role == WLR_XDG_SURFACE_ROLE_TOPLEVEL);
-	surface->toplevel->pending.maximized = maximized;
+	surface->toplevel->server_pending.maximized = maximized;
 
 	return wlr_xdg_surface_schedule_configure(surface);
 }
@@ -1586,7 +1586,7 @@ uint32_t wlr_xdg_toplevel_set_maximized(struct wlr_xdg_surface *surface,
 uint32_t wlr_xdg_toplevel_set_fullscreen(struct wlr_xdg_surface *surface,
 		bool fullscreen) {
 	assert(surface->role == WLR_XDG_SURFACE_ROLE_TOPLEVEL);
-	surface->toplevel->pending.fullscreen = fullscreen;
+	surface->toplevel->server_pending.fullscreen = fullscreen;
 
 	return wlr_xdg_surface_schedule_configure(surface);
 }
@@ -1594,7 +1594,7 @@ uint32_t wlr_xdg_toplevel_set_fullscreen(struct wlr_xdg_surface *surface,
 uint32_t wlr_xdg_toplevel_set_resizing(struct wlr_xdg_surface *surface,
 		bool resizing) {
 	assert(surface->role == WLR_XDG_SURFACE_ROLE_TOPLEVEL);
-	surface->toplevel->pending.resizing = resizing;
+	surface->toplevel->server_pending.resizing = resizing;
 
 	return wlr_xdg_surface_schedule_configure(surface);
 }

types/wlr_xdg_shell_v6.c

@@ -785,23 +785,23 @@ static void xdg_toplevel_handle_set_max_size(struct wl_client *client,
 		struct wl_resource *resource, int32_t width, int32_t height) {
 	struct wlr_xdg_surface_v6 *surface =
 		xdg_surface_from_xdg_toplevel_resource(resource);
-	surface->toplevel->next.max_width = width;
+	surface->toplevel->client_pending.max_width = width;
-	surface->toplevel->next.max_height = height;
+	surface->toplevel->client_pending.max_height = height;
 }
 
 static void xdg_toplevel_handle_set_min_size(struct wl_client *client,
 		struct wl_resource *resource, int32_t width, int32_t height) {
 	struct wlr_xdg_surface_v6 *surface =
 		xdg_surface_from_xdg_toplevel_resource(resource);
-	surface->toplevel->next.min_width = width;
+	surface->toplevel->client_pending.min_width = width;
-	surface->toplevel->next.min_height = height;
+	surface->toplevel->client_pending.min_height = height;
 }
 
 static void xdg_toplevel_handle_set_maximized(struct wl_client *client,
 		struct wl_resource *resource) {
 	struct wlr_xdg_surface_v6 *surface =
 		xdg_surface_from_xdg_toplevel_resource(resource);
-	surface->toplevel->next.maximized = true;
+	surface->toplevel->client_pending.maximized = true;
 	wlr_signal_emit_safe(&surface->toplevel->events.request_maximize, surface);
 }
 
@@ -809,7 +809,7 @@ static void xdg_toplevel_handle_unset_maximized(struct wl_client *client,
 		struct wl_resource *resource) {
 	struct wlr_xdg_surface_v6 *surface =
 		xdg_surface_from_xdg_toplevel_resource(resource);
-	surface->toplevel->next.maximized = false;
+	surface->toplevel->client_pending.maximized = false;
 	wlr_signal_emit_safe(&surface->toplevel->events.request_maximize, surface);
 }
 
@@ -823,7 +823,7 @@ static void xdg_toplevel_handle_set_fullscreen(struct wl_client *client,
 		output = wlr_output_from_resource(output_resource);
 	}
 
-	surface->toplevel->next.fullscreen = true;
+	surface->toplevel->client_pending.fullscreen = true;
 
 	struct wlr_xdg_toplevel_v6_set_fullscreen_event event = {
 		.surface = surface,
@@ -839,7 +839,7 @@ static void xdg_toplevel_handle_unset_fullscreen(struct wl_client *client,
 	struct wlr_xdg_surface_v6 *surface =
 		xdg_surface_from_xdg_toplevel_resource(resource);
 
-	surface->toplevel->next.fullscreen = false;
+	surface->toplevel->client_pending.fullscreen = false;
 
 	struct wlr_xdg_toplevel_v6_set_fullscreen_event event = {
 		.surface = surface,
@@ -1057,25 +1057,25 @@ static bool wlr_xdg_surface_v6_toplevel_state_compare(
 		configured.height = configure->toplevel_state->height;
 	}
 
-	if (state->pending.activated != configured.state.activated) {
+	if (state->server_pending.activated != configured.state.activated) {
 		return false;
 	}
-	if (state->pending.fullscreen != configured.state.fullscreen) {
+	if (state->server_pending.fullscreen != configured.state.fullscreen) {
 		return false;
 	}
-	if (state->pending.maximized != configured.state.maximized) {
+	if (state->server_pending.maximized != configured.state.maximized) {
 		return false;
 	}
-	if (state->pending.resizing != configured.state.resizing) {
+	if (state->server_pending.resizing != configured.state.resizing) {
 		return false;
 	}
 
-	if (state->pending.width == configured.width &&
+	if (state->server_pending.width == configured.width &&
-			state->pending.height == configured.height) {
+			state->server_pending.height == configured.height) {
 		return true;
 	}
 
-	if (state->pending.width == 0 && state->pending.height == 0) {
+	if (state->server_pending.width == 0 && state->server_pending.height == 0) {
 		return true;
 	}
 
@@ -1093,12 +1093,12 @@ static void wlr_xdg_toplevel_v6_send_configure(
 		wl_resource_post_no_memory(surface->toplevel->resource);
 		return;
 	}
-	*configure->toplevel_state = surface->toplevel->pending;
+	*configure->toplevel_state = surface->toplevel->server_pending;
 
 	uint32_t *s;
 	struct wl_array states;
 	wl_array_init(&states);
-	if (surface->toplevel->pending.maximized) {
+	if (surface->toplevel->server_pending.maximized) {
 		s = wl_array_add(&states, sizeof(uint32_t));
 		if (!s) {
 			wlr_log(L_ERROR, "Could not allocate state for maximized xdg_toplevel");
@@ -1106,7 +1106,7 @@ static void wlr_xdg_toplevel_v6_send_configure(
 		}
 		*s = ZXDG_TOPLEVEL_V6_STATE_MAXIMIZED;
 	}
-	if (surface->toplevel->pending.fullscreen) {
+	if (surface->toplevel->server_pending.fullscreen) {
 		s = wl_array_add(&states, sizeof(uint32_t));
 		if (!s) {
 			wlr_log(L_ERROR, "Could not allocate state for fullscreen xdg_toplevel");
@@ -1114,7 +1114,7 @@ static void wlr_xdg_toplevel_v6_send_configure(
 		}
 		*s = ZXDG_TOPLEVEL_V6_STATE_FULLSCREEN;
 	}
-	if (surface->toplevel->pending.resizing) {
+	if (surface->toplevel->server_pending.resizing) {
 		s = wl_array_add(&states, sizeof(uint32_t));
 		if (!s) {
 			wlr_log(L_ERROR, "Could not allocate state for resizing xdg_toplevel");
@@ -1122,7 +1122,7 @@ static void wlr_xdg_toplevel_v6_send_configure(
 		}
 		*s = ZXDG_TOPLEVEL_V6_STATE_RESIZING;
 	}
-	if (surface->toplevel->pending.activated) {
+	if (surface->toplevel->server_pending.activated) {
 		s = wl_array_add(&states, sizeof(uint32_t));
 		if (!s) {
 			wlr_log(L_ERROR, "Could not allocate state for activated xdg_toplevel");
@@ -1131,8 +1131,8 @@ static void wlr_xdg_toplevel_v6_send_configure(
 		*s = ZXDG_TOPLEVEL_V6_STATE_ACTIVATED;
 	}
 
-	uint32_t width = surface->toplevel->pending.width;
+	uint32_t width = surface->toplevel->server_pending.width;
-	uint32_t height = surface->toplevel->pending.height;
+	uint32_t height = surface->toplevel->server_pending.height;
 	zxdg_toplevel_v6_send_configure(surface->toplevel->resource, width,
 		height, &states);
 
@@ -1240,13 +1240,13 @@ static void wlr_xdg_surface_v6_toplevel_committed(
 
 	// update state that doesn't need compositor approval
 	surface->toplevel->current.max_width =
-		surface->toplevel->next.max_width;
+		surface->toplevel->client_pending.max_width;
 	surface->toplevel->current.min_width =
-		surface->toplevel->next.min_width;
+		surface->toplevel->client_pending.min_width;
 	surface->toplevel->current.max_height =
-		surface->toplevel->next.max_height;
+		surface->toplevel->client_pending.max_height;
 	surface->toplevel->current.min_height =
-		surface->toplevel->next.min_height;
+		surface->toplevel->client_pending.min_height;
 }
 
 static void wlr_xdg_surface_v6_popup_committed(
@@ -1531,8 +1531,8 @@ void wlr_xdg_surface_v6_ping(struct wlr_xdg_surface_v6 *surface) {
 uint32_t wlr_xdg_toplevel_v6_set_size(struct wlr_xdg_surface_v6 *surface,
 		uint32_t width, uint32_t height) {
 	assert(surface->role == WLR_XDG_SURFACE_V6_ROLE_TOPLEVEL);
-	surface->toplevel->pending.width = width;
+	surface->toplevel->server_pending.width = width;
-	surface->toplevel->pending.height = height;
+	surface->toplevel->server_pending.height = height;
 
 	return wlr_xdg_surface_v6_schedule_configure(surface);
 }
@@ -1540,7 +1540,7 @@ uint32_t wlr_xdg_toplevel_v6_set_size(struct wlr_xdg_surface_v6 *surface,
 uint32_t wlr_xdg_toplevel_v6_set_activated(struct wlr_xdg_surface_v6 *surface,
 		bool activated) {
 	assert(surface->role == WLR_XDG_SURFACE_V6_ROLE_TOPLEVEL);
-	surface->toplevel->pending.activated = activated;
+	surface->toplevel->server_pending.activated = activated;
 
 	return wlr_xdg_surface_v6_schedule_configure(surface);
 }
@@ -1548,7 +1548,7 @@ uint32_t wlr_xdg_toplevel_v6_set_activated(struct wlr_xdg_surface_v6 *surface,
 uint32_t wlr_xdg_toplevel_v6_set_maximized(struct wlr_xdg_surface_v6 *surface,
 		bool maximized) {
 	assert(surface->role == WLR_XDG_SURFACE_V6_ROLE_TOPLEVEL);
-	surface->toplevel->pending.maximized = maximized;
+	surface->toplevel->server_pending.maximized = maximized;
 
 	return wlr_xdg_surface_v6_schedule_configure(surface);
 }
@@ -1556,7 +1556,7 @@ uint32_t wlr_xdg_toplevel_v6_set_maximized(struct wlr_xdg_surface_v6 *surface,
 uint32_t wlr_xdg_toplevel_v6_set_fullscreen(struct wlr_xdg_surface_v6 *surface,
 		bool fullscreen) {
 	assert(surface->role == WLR_XDG_SURFACE_V6_ROLE_TOPLEVEL);
-	surface->toplevel->pending.fullscreen = fullscreen;
+	surface->toplevel->server_pending.fullscreen = fullscreen;
 
 	return wlr_xdg_surface_v6_schedule_configure(surface);
 }
@@ -1564,7 +1564,7 @@ uint32_t wlr_xdg_toplevel_v6_set_fullscreen(struct wlr_xdg_surface_v6 *surface,
 uint32_t wlr_xdg_toplevel_v6_set_resizing(struct wlr_xdg_surface_v6 *surface,
 		bool resizing) {
 	assert(surface->role == WLR_XDG_SURFACE_V6_ROLE_TOPLEVEL);
-	surface->toplevel->pending.resizing = resizing;
+	surface->toplevel->server_pending.resizing = resizing;
 
 	return wlr_xdg_surface_v6_schedule_configure(surface);
 }