Start layer-shell

include/desktop/desktop.h

@@ -14,6 +14,7 @@
 struct kiwmi_desktop {
     struct wlr_compositor *compositor;
     struct wlr_xdg_shell *xdg_shell;
+    struct wlr_layer_shell_v1 *layer_shell;
     struct wlr_data_device_manager *data_device_manager;
     struct wlr_output_layout *output_layout;
     struct wl_list outputs; // struct kiwmi_output::link
@@ -21,6 +22,7 @@ struct kiwmi_desktop {
     struct wl_list views; // struct kiwmi_view::link
 
     struct wl_listener xdg_shell_new_surface;
+    struct wl_listener layer_shell_new_surface;
     struct wl_listener new_output;
 
     struct {

include/desktop/layer_shell.h

@@ -0,0 +1,34 @@
+/* Copyright (c), Niclas Meyer <niclas@countingsort.com>
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at https://mozilla.org/MPL/2.0/.
+ */
+
+#ifndef KIWMI_DESKTOP_LAYER_SHELL_H
+#define KIWMI_DESKTOP_LAYER_SHELL_H
+
+#include <stdbool.h>
+
+#include <wayland-server.h>
+#include <wlr/types/wlr_box.h>
+
+#include "desktop/output.h"
+
+struct kiwmi_layer {
+    struct wl_list link;
+    struct wlr_layer_surface_v1 *layer_surface;
+
+    struct kiwmi_output *output;
+
+    struct wl_listener destroy;
+    struct wl_listener commit;
+
+    struct wlr_box geom;
+};
+
+void arrange_layers(struct kiwmi_output *output);
+
+void layer_shell_new_surface_notify(struct wl_listener *listener, void *data);
+
+#endif /* KIWMI_DESKTOP_LAYER_SHELL_H */

include/desktop/output.h

@@ -19,6 +19,8 @@ struct kiwmi_output {
     struct wl_listener mode;
     struct wl_listener transform;
 
+    struct wl_list layers[4]; // struct kiwmi_layer_surface::link
+
     struct {
         struct wl_signal destroy;
         struct wl_signal resize;

include/desktop/view.h

@@ -54,7 +54,8 @@ struct kiwmi_view_impl {
         struct kiwmi_view *view,
         wlr_surface_iterator_func_t iterator,
         void *user_data);
-    void (*get_size)(struct kiwmi_view *view, uint32_t *width, uint32_t *height);
+    void (
+        *get_size)(struct kiwmi_view *view, uint32_t *width, uint32_t *height);
     void (*set_activated)(struct kiwmi_view *view, bool activated);
     void (*set_size)(struct kiwmi_view *view, uint32_t width, uint32_t height);
     void (*set_tiled)(struct kiwmi_view *view, enum wlr_edges edges);

kiwmi/desktop/desktop.c

@@ -14,10 +14,12 @@
 #include <wlr/types/wlr_compositor.h>
 #include <wlr/types/wlr_data_device.h>
 #include <wlr/types/wlr_export_dmabuf_v1.h>
+#include <wlr/types/wlr_layer_shell_v1.h>
 #include <wlr/types/wlr_output_layout.h>
 #include <wlr/types/wlr_xdg_output_v1.h>
 #include <wlr/types/wlr_xdg_shell.h>
 
+#include "desktop/layer_shell.h"
 #include "desktop/output.h"
 #include "desktop/xdg_shell.h"
 #include "server.h"
@@ -41,6 +43,12 @@ desktop_init(struct kiwmi_desktop *desktop, struct wlr_renderer *renderer)
         &desktop->xdg_shell->events.new_surface,
         &desktop->xdg_shell_new_surface);
 
+    desktop->layer_shell = wlr_layer_shell_v1_create(server->wl_display);
+    desktop->layer_shell_new_surface.notify = layer_shell_new_surface_notify;
+    wl_signal_add(
+        &desktop->layer_shell->events.new_surface,
+        &desktop->layer_shell_new_surface);
+
     desktop->focused_view = NULL;
 
     wl_list_init(&desktop->outputs);

kiwmi/desktop/layer_shell.c

@@ -0,0 +1,353 @@
+/* Copyright (c), Niclas Meyer <niclas@countingsort.com>
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at https://mozilla.org/MPL/2.0/.
+ */
+
+#include "desktop/layer_shell.h"
+
+#include <stdlib.h>
+
+#include <wayland-server.h>
+#include <wlr/types/wlr_layer_shell_v1.h>
+#include <wlr/util/log.h>
+
+#include "desktop/desktop.h"
+#include "wayland-util.h"
+#include "wlr-layer-shell-unstable-v1-protocol.h"
+
+static void
+kiwmi_layer_destroy_notify(struct wl_listener *listener, void *UNUSED(data))
+{
+    struct kiwmi_layer *layer = wl_container_of(listener, layer, destroy);
+
+    wl_list_remove(&layer->link);
+    wl_list_remove(&layer->destroy.link);
+
+    wlr_layer_surface_v1_close(layer->layer_surface);
+
+    free(layer);
+}
+
+static void
+kiwmi_layer_commit_notify(struct wl_listener *listener, void *UNUSED(data))
+{
+    struct kiwmi_layer *surface = wl_container_of(listener, surface, commit);
+    struct kiwmi_output *output = surface->output;
+
+    arrange_layers(output);
+}
+
+static void
+apply_exclusive(
+    struct wlr_box *usable_area,
+    uint32_t anchor,
+    int32_t exclusive,
+    int32_t margin_top,
+    int32_t margin_bottom,
+    int32_t margin_left,
+    int32_t margin_right)
+{
+    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,
+        },
+    };
+
+    size_t nedges = sizeof(edges) / sizeof(edges[0]);
+    for (size_t i = 0; i < nedges; ++i) {
+        if ((anchor & edges[i].anchors) == edges[i].anchors
+            && exclusive + edges[i].margin > 0) {
+            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 kiwmi_output *output,
+    struct wl_list *layers,
+    struct wlr_box *usable_area,
+    bool exclusive)
+{
+    struct wlr_box full_area = {0};
+
+    wlr_output_effective_resolution(
+        output->wlr_output, &full_area.width, &full_area.height);
+
+    struct kiwmi_layer *layer;
+    wl_list_for_each_reverse (layer, layers, link) {
+        struct wlr_layer_surface_v1 *layer_surface = layer->layer_surface;
+        struct wlr_layer_surface_v1_state *state   = &layer_surface->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 arranged_area = {
+            .width  = state->desired_width,
+            .height = state->desired_height,
+        };
+
+        // horizontal
+        const uint32_t both_horiz = ZWLR_LAYER_SURFACE_V1_ANCHOR_LEFT
+            | ZWLR_LAYER_SURFACE_V1_ANCHOR_RIGHT;
+
+        if ((state->anchor & both_horiz) && arranged_area.width == 0) {
+            arranged_area.x     = bounds.x;
+            arranged_area.width = bounds.width;
+        } else if (state->anchor & ZWLR_LAYER_SURFACE_V1_ANCHOR_LEFT) {
+            arranged_area.x = bounds.x;
+        } else if (state->anchor & ZWLR_LAYER_SURFACE_V1_ANCHOR_RIGHT) {
+            arranged_area.x = bounds.x + (bounds.width - arranged_area.width);
+        } else {
+            arranged_area.x =
+                bounds.x + ((bounds.width / 2) - (arranged_area.width / 2));
+        }
+
+        // vertical
+        const uint32_t both_vert = ZWLR_LAYER_SURFACE_V1_ANCHOR_TOP
+            | ZWLR_LAYER_SURFACE_V1_ANCHOR_BOTTOM;
+        if ((state->anchor & both_vert) && arranged_area.height == 0) {
+            arranged_area.y      = bounds.y;
+            arranged_area.height = bounds.height;
+        } else if (state->anchor & ZWLR_LAYER_SURFACE_V1_ANCHOR_TOP) {
+            arranged_area.y = bounds.y;
+        } else if (state->anchor & ZWLR_LAYER_SURFACE_V1_ANCHOR_BOTTOM) {
+            arranged_area.y = bounds.y + (bounds.height - arranged_area.height);
+        } else {
+            arranged_area.y =
+                bounds.y + ((bounds.height / 2) - (arranged_area.height / 2));
+        }
+
+        // left and right margin
+        if ((state->anchor & both_horiz) == both_horiz) {
+            arranged_area.x += state->margin.left;
+            arranged_area.width -= state->margin.left + state->margin.right;
+        } else if (state->anchor & ZWLR_LAYER_SURFACE_V1_ANCHOR_LEFT) {
+            arranged_area.x += state->margin.left;
+        } else if (state->anchor & ZWLR_LAYER_SURFACE_V1_ANCHOR_RIGHT) {
+            arranged_area.x -= state->margin.right;
+        }
+
+        // top and bottom margin
+        if ((state->anchor & both_vert) == both_vert) {
+            arranged_area.y += state->margin.top;
+            arranged_area.height -= state->margin.top + state->margin.bottom;
+        } else if (state->anchor & ZWLR_LAYER_SURFACE_V1_ANCHOR_TOP) {
+            arranged_area.y += state->margin.top;
+        } else if (state->anchor & ZWLR_LAYER_SURFACE_V1_ANCHOR_BOTTOM) {
+            arranged_area.y -= state->margin.bottom;
+        }
+
+        if (arranged_area.width < 0 || arranged_area.height < 0) {
+            wlr_log(
+                WLR_ERROR,
+                "Bad width/height: %d, %d",
+                arranged_area.width,
+                arranged_area.height);
+            wlr_layer_surface_v1_close(layer_surface);
+            continue;
+        }
+
+        layer->geom = arranged_area;
+
+        apply_exclusive(
+            usable_area,
+            state->anchor,
+            state->exclusive_zone,
+            state->margin.top,
+            state->margin.bottom,
+            state->margin.left,
+            state->margin.right);
+
+        wlr_layer_surface_v1_configure(
+            layer_surface, arranged_area.width, arranged_area.height);
+    }
+}
+
+void
+arrange_layers(struct kiwmi_output *output)
+{
+    struct wlr_box usable_area = {0};
+
+    wlr_output_effective_resolution(
+        output->wlr_output, &usable_area.width, &usable_area.height);
+
+    // arrange exclusive layers
+    arrange_layer(
+        output,
+        &output->layers[ZWLR_LAYER_SHELL_V1_LAYER_OVERLAY],
+        &usable_area,
+        true);
+    arrange_layer(
+        output,
+        &output->layers[ZWLR_LAYER_SHELL_V1_LAYER_TOP],
+        &usable_area,
+        true);
+    arrange_layer(
+        output,
+        &output->layers[ZWLR_LAYER_SHELL_V1_LAYER_BOTTOM],
+        &usable_area,
+        true);
+    arrange_layer(
+        output,
+        &output->layers[ZWLR_LAYER_SHELL_V1_LAYER_BACKGROUND],
+        &usable_area,
+        true);
+
+    // arrange non-exclusive layers
+    arrange_layer(
+        output,
+        &output->layers[ZWLR_LAYER_SHELL_V1_LAYER_OVERLAY],
+        &usable_area,
+        false);
+    arrange_layer(
+        output,
+        &output->layers[ZWLR_LAYER_SHELL_V1_LAYER_TOP],
+        &usable_area,
+        false);
+    arrange_layer(
+        output,
+        &output->layers[ZWLR_LAYER_SHELL_V1_LAYER_BOTTOM],
+        &usable_area,
+        false);
+    arrange_layer(
+        output,
+        &output->layers[ZWLR_LAYER_SHELL_V1_LAYER_BACKGROUND],
+        &usable_area,
+        false);
+
+    uint32_t layers_above_shell[] = {
+        ZWLR_LAYER_SHELL_V1_LAYER_OVERLAY,
+        ZWLR_LAYER_SHELL_V1_LAYER_TOP,
+    };
+    size_t nlayers = sizeof(layers_above_shell) / sizeof(layers_above_shell[0]);
+    struct kiwmi_layer *layer;
+    struct kiwmi_layer *topmost = NULL;
+    for (size_t i = 0; i < nlayers; ++i) {
+        wl_list_for_each_reverse (
+            layer, &output->layers[layers_above_shell[i]], link) {
+            if (layer->layer_surface->current.keyboard_interactive) {
+                topmost = layer;
+                break;
+            }
+        }
+
+        if (topmost) {
+            break;
+        }
+    }
+
+    // TODO: focus topmost
+}
+
+void
+layer_shell_new_surface_notify(struct wl_listener *listener, void *data)
+{
+    struct kiwmi_desktop *desktop =
+        wl_container_of(listener, desktop, layer_shell_new_surface);
+    struct wlr_layer_surface_v1 *layer_surface = data;
+
+    wlr_log(
+        WLR_DEBUG,
+        "New layer_shell surface namespace='%s'",
+        layer_surface->namespace);
+
+    if (!layer_surface->output) {
+        // TODO: assign active output
+        wlr_log(WLR_ERROR, "TODO: assign active output");
+        struct kiwmi_output *output;
+        wl_list_for_each (output, &desktop->outputs, link) {
+            layer_surface->output = output->wlr_output;
+            break;
+        }
+    }
+
+    struct kiwmi_layer *layer = malloc(sizeof(*layer));
+    if (!layer) {
+        wlr_log(WLR_ERROR, "Failed too allocate kiwmi_layer_shell");
+        return;
+    }
+
+    struct kiwmi_output *output = layer_surface->output->data;
+
+    size_t len = sizeof(output->layers) / sizeof(output->layers[0]);
+    if (layer_surface->layer >= len) {
+        wlr_log(
+            WLR_ERROR, "Bad layer surface layer '%d'", layer_surface->layer);
+        wlr_layer_surface_v1_close(layer_surface);
+        free(layer);
+        return;
+    }
+
+    layer->layer_surface = layer_surface;
+    layer->output        = output;
+
+    layer->destroy.notify = kiwmi_layer_destroy_notify;
+    wl_signal_add(&layer_surface->events.destroy, &layer->destroy);
+
+    layer->commit.notify = kiwmi_layer_commit_notify;
+    wl_signal_add(&layer_surface->surface->events.commit, &layer->commit);
+
+    wl_list_insert(&output->layers[layer_surface->layer], &layer->link);
+
+    // Temporarily set the layer's current state to client_pending
+    // So that we can easily arrange it
+    struct wlr_layer_surface_v1_state old_state = layer_surface->current;
+    layer_surface->current                      = layer_surface->client_pending;
+    arrange_layers(output);
+    layer_surface->current = old_state;
+}

kiwmi/desktop/output.c

@@ -12,6 +12,7 @@
 #include <wayland-server.h>
 #include <wlr/backend.h>
 #include <wlr/render/wlr_renderer.h>
+#include <wlr/types/wlr_layer_shell_v1.h>
 #include <wlr/types/wlr_matrix.h>
 #include <wlr/types/wlr_output.h>
 #include <wlr/types/wlr_output_layout.h>
@@ -20,23 +21,76 @@
 #include <wlr/util/log.h>
 
 #include "desktop/desktop.h"
+#include "desktop/layer_shell.h"
 #include "desktop/view.h"
 #include "input/cursor.h"
 #include "input/input.h"
 #include "server.h"
+#include "wayland-util.h"
 
 struct render_data {
     struct wlr_output *output;
-    struct kiwmi_view *view;
     struct wlr_renderer *renderer;
     struct timespec *when;
+    struct wlr_output_layout *output_layout;
+    void *data;
 };
 
+static void
+render_layer_surface(struct wlr_surface *surface, int x, int y, void *data)
+{
+    struct render_data *rdata               = data;
+    struct wlr_output *output               = rdata->output;
+    struct wlr_output_layout *output_layout = rdata->output_layout;
+    struct wlr_box *geom                    = rdata->data;
+
+    struct wlr_texture *texture = wlr_surface_get_texture(surface);
+    if (!texture) {
+        return;
+    }
+
+    double ox = 0;
+    double oy = 0;
+    wlr_output_layout_output_coords(output_layout, output, &ox, &oy);
+
+    ox += x + geom->x;
+    oy += y + geom->y;
+
+    struct wlr_box box = {
+        .x      = ox * output->scale,
+        .y      = oy * output->scale,
+        .width  = surface->current.width * output->scale,
+        .height = surface->current.height * output->scale,
+    };
+
+    float matrix[9];
+    enum wl_output_transform transform =
+        wlr_output_transform_invert(surface->current.transform);
+    wlr_matrix_project_box(
+        matrix, &box, transform, 0, output->transform_matrix);
+
+    wlr_render_texture_with_matrix(rdata->renderer, texture, matrix, 1);
+
+    wlr_surface_send_frame_done(surface, rdata->when);
+}
+
+static void
+render_layer(struct wl_list *layer, struct render_data *rdata)
+{
+    struct kiwmi_layer *surface;
+    wl_list_for_each (surface, layer, link) {
+        rdata->data = &surface->geom;
+
+        wlr_layer_surface_v1_for_each_surface(
+            surface->layer_surface, render_layer_surface, rdata);
+    }
+}
+
 static void
 render_surface(struct wlr_surface *surface, int sx, int sy, void *data)
 {
     struct render_data *rdata = data;
-    struct kiwmi_view *view   = rdata->view;
+    struct kiwmi_view *view   = rdata->data;
     struct wlr_output *output = rdata->output;
 
     struct wlr_texture *texture = wlr_surface_get_texture(surface);
@@ -76,6 +130,7 @@ output_frame_notify(struct wl_listener *listener, void *data)
     struct kiwmi_output *output   = wl_container_of(listener, output, frame);
     struct wlr_output *wlr_output = data;
     struct kiwmi_desktop *desktop = output->desktop;
+    struct wlr_output_layout *output_layout = desktop->output_layout;
     struct wlr_renderer *renderer =
         wlr_backend_get_renderer(wlr_output->backend);
 
@@ -95,22 +150,30 @@ output_frame_notify(struct wl_listener *listener, void *data)
     wlr_renderer_begin(renderer, width, height);
     wlr_renderer_clear(renderer, (float[]){0.0f, 1.0f, 0.0f, 1.0f});
 
+    struct render_data rdata = {
+        .output        = output->wlr_output,
+        .renderer      = renderer,
+        .when          = &now,
+        .output_layout = output_layout,
+    };
+
+    render_layer(&output->layers[ZWLR_LAYER_SHELL_V1_LAYER_BACKGROUND], &rdata);
+    render_layer(&output->layers[ZWLR_LAYER_SHELL_V1_LAYER_BOTTOM], &rdata);
+
     struct kiwmi_view *view;
     wl_list_for_each_reverse (view, &desktop->views, link) {
         if (view->hidden || !view->mapped) {
             continue;
         }
 
-        struct render_data rdata = {
+        rdata.data = view;
-            .output   = output->wlr_output,
-            .view     = view,
-            .renderer = renderer,
-            .when     = &now,
-        };
 
         view_for_each_surface(view, render_surface, &rdata);
     }
 
+    render_layer(&output->layers[ZWLR_LAYER_SHELL_V1_LAYER_TOP], &rdata);
+    render_layer(&output->layers[ZWLR_LAYER_SHELL_V1_LAYER_OVERLAY], &rdata);
+
     wlr_output_render_software_cursors(wlr_output, NULL);
     wlr_renderer_end(renderer);
 
@@ -139,6 +202,8 @@ output_mode_notify(struct wl_listener *listener, void *UNUSED(data))
 {
     struct kiwmi_output *output = wl_container_of(listener, output, mode);
 
+    arrange_layers(output);
+
     wl_signal_emit(&output->events.resize, output);
 }
 
@@ -147,6 +212,8 @@ output_transform_notify(struct wl_listener *listener, void *UNUSED(data))
 {
     struct kiwmi_output *output = wl_container_of(listener, output, transform);
 
+    arrange_layers(output);
+
     wl_signal_emit(&output->events.resize, output);
 }
 
@@ -198,6 +265,8 @@ new_output_notify(struct wl_listener *listener, void *data)
         return;
     }
 
+    wlr_output->data = output;
+
     struct kiwmi_cursor *cursor = server->input.cursor;
 
     wlr_xcursor_manager_load(cursor->xcursor_manager, wlr_output->scale);
@@ -208,6 +277,11 @@ new_output_notify(struct wl_listener *listener, void *data)
 
     wlr_output_create_global(wlr_output);
 
+    size_t len_outputs = sizeof(output->layers) / sizeof(output->layers[0]);
+    for (size_t i = 0; i < len_outputs; ++i) {
+        wl_list_init(&output->layers[i]);
+    }
+
     wl_signal_init(&output->events.destroy);
     wl_signal_init(&output->events.resize);
 

kiwmi/desktop/xdg_shell.c

@@ -71,11 +71,14 @@ xdg_shell_view_for_each_surface(
 }
 
 static void
-xdg_shell_view_get_size(struct kiwmi_view *view, uint32_t *width, uint32_t *height)
+xdg_shell_view_get_size(
+    struct kiwmi_view *view,
+    uint32_t *width,
+    uint32_t *height)
 {
     struct wlr_box *geom = &view->xdg_surface->geometry;
 
-    *width = geom->width;
+    *width  = geom->width;
     *height = geom->height;
 }
 

kiwmi/meson.build

@@ -2,6 +2,7 @@ kiwmi_sources = files(
   'main.c',
   'server.c',
   'desktop/desktop.c',
+  'desktop/layer_shell.c',
   'desktop/output.c',
   'desktop/view.c',
   'desktop/xdg_shell.c',

protocols/meson.build

@@ -4,6 +4,7 @@ wayland_scanner_bin   = wayland_scanner.get_pkgconfig_variable('wayland_scanner'
 protocols_server = [
   wayland_protocols_dir / 'stable/xdg-shell/xdg-shell.xml',
   'kiwmi-ipc.xml',
+  'wlr-layer-shell-unstable-v1.xml',
 ]
 
 protocols_server_src = []

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

@@ -0,0 +1,301 @@
+<?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="2">
+    <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.
+
+        You may pass NULL for output to allow the compositor to decide which
+        output to use. Generally this will be the one that the user most
+        recently interacted with.
+
+        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" allow-null="true"/>
+      <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="2">
+    <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 (layer, 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 orthogonal 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 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 one
+        edge or an edge and both perpendicular edges. If the surface is not
+        anchored, anchored to only two perpendicular edges (a corner), anchored
+        to only two parallel edges or anchored to all edges, a positive value
+        will be treated the same as zero.
+
+        A positive zone is the distance from the edge in surface-local
+        coordinates to consider 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 exclusive zone. If set to -1, the surface
+        indicates that it would not like to be moved to accommodate 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>
+
+    <!-- Version 2 additions -->
+
+    <request name="set_layer" since="2">
+      <description summary="change the layer of the surface">
+        Change the layer that the surface is rendered on.
+
+        Layer is double-buffered, see wl_surface.commit.
+      </description>
+      <arg name="layer" type="uint" enum="layer" summary="layer to move this surface to"/>
+    </request>
+  </interface>
+</protocol>