RFC: add ability for clients to be shown over the lock screen

include/sway/layers.h

@@ -13,6 +13,7 @@ struct sway_layer_surface {
 	struct wl_listener node_destroy;
 	struct wl_listener new_popup;
 
+	bool show_over_lockscreen;
 	bool mapped;
 
 	struct wlr_scene_tree *popups;

include/sway/lockscreen-overlay.h

@@ -0,0 +1,4 @@
+#include <wayland-server-core.h>
+
+struct sway_lockscreen_overlay;
+struct sway_lockscreen_overlay *sway_lockscreen_overlay_create(struct wl_display *display);

include/sway/server.h

@@ -97,6 +97,8 @@ struct sway_server {
 		struct wl_listener manager_destroy;
 	} session_lock;
 
+	struct sway_lockscreen_overlay *lockscreen_overlay;
+
 	struct wlr_output_power_manager_v1 *output_power_manager_v1;
 	struct wl_listener output_power_manager_set_mode;
 	struct wlr_input_method_manager_v2 *input_method;

protocols/kde-lockscreen-overlay-v1.xml

@@ -0,0 +1,38 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<protocol name="kde_lockscreen_overlay_v1">
+  <copyright><![CDATA[
+    SPDX-FileCopyrightText: 2022 Aleix Pol Gonzalez <[email protected]>
+
+    SPDX-License-Identifier: LGPL-2.1-or-later
+  ]]></copyright>
+
+  <interface name="kde_lockscreen_overlay_v1" version="1">
+    <description summary="Allow surfaces over the lockscreen">
+        Allows a client to request a surface to be visible when the system is locked.
+
+        This is meant to be used for specific high urgency cases like phone calls or alarms.
+
+        Warning! The protocol described in this file is a desktop environment
+        implementation detail. Regular clients must not use this protocol.
+        Backward incompatible changes may be added without bumping the major
+        version of the extension.
+      </description>
+
+    <enum name="error">
+      <entry name="invalid_surface_state" value="0" summary="the client provided an invalid surface state"/>
+    </enum>
+
+    <request name="allow">
+      <description summary="Tell about which surface could be raised above the lockscreen">
+          Informs the compositor that the surface could be shown when the screen is locked. This request should be called while the surface is unmapped.
+        </description>
+      <arg name="surface" type="object" interface="wl_surface"/>
+    </request>
+
+    <request name="destroy" type="destructor">
+      <description summary="Destroy the kde_lockscreen_overlay_v1">
+          This won't affect the surface previously marked with the allow request.
+        </description>
+    </request>
+  </interface>
+</protocol>

protocols/meson.build

@@ -18,6 +18,7 @@ protocols = [
 	'wlr-layer-shell-unstable-v1.xml',
 	'idle.xml',
 	'wlr-output-power-management-unstable-v1.xml',
+	'kde-lockscreen-overlay-v1.xml',
 ]
 
 wl_protos_src = []

sway/desktop/layer_shell.c

@@ -15,6 +15,7 @@
 #include "sway/input/input-manager.h"
 #include "sway/input/seat.h"
 #include "sway/layers.h"
+#include "sway/lock.h"
 #include "sway/output.h"
 #include "sway/server.h"
 #include "sway/tree/arrange.h"
@@ -54,7 +55,7 @@ struct wlr_layer_surface_v1 *toplevel_layer_surface_from_surface(
 }
 
 static void arrange_surface(struct sway_output *output, const struct wlr_box *full_area,
-		struct wlr_box *usable_area, struct wlr_scene_tree *tree, bool exclusive) {
+		struct wlr_box *usable_area, struct wlr_scene_tree *tree, bool exclusive, bool locked) {
 	struct wlr_scene_node *node;
 	wl_list_for_each(node, &tree->children, link) {
 		struct sway_layer_surface *surface = scene_descriptor_try_get(node,
@@ -64,6 +65,17 @@ static void arrange_surface(struct sway_output *output, const struct wlr_box *fu
 			continue;
 		}
 
+		if (!surface->show_over_lockscreen) {
+			wlr_scene_node_set_enabled(node, !locked);
+			/* wlr_scene_node_set_enabled(node, true); */
+			if (locked) {
+				continue;
+			}
+		} else {
+			// TODO: not sure why this is required 
+			wlr_scene_node_set_enabled(node, true);
+		}
+
 		if (!surface->scene->layer_surface->initialized) {
 			continue;
 		}
@@ -82,19 +94,26 @@ void arrange_layers(struct sway_output *output) {
 			&usable_area.width, &usable_area.height);
 	const struct wlr_box full_area = usable_area;
 
-	arrange_surface(output, &full_area, &usable_area, output->layers.shell_overlay, true);
-	arrange_surface(output, &full_area, &usable_area, output->layers.shell_top, true);
-	arrange_surface(output, &full_area, &usable_area, output->layers.shell_bottom, true);
-	arrange_surface(output, &full_area, &usable_area, output->layers.shell_background, true);
+	bool locked = server.session_lock.lock;
+
+	if (locked) {
+		sway_log(SWAY_INFO, "arranging locked layout");
+	}
+
+	arrange_surface(output, &full_area, &usable_area, output->layers.shell_overlay, true, locked);
+	arrange_surface(output, &full_area, &usable_area, output->layers.shell_top, true, locked);
+	arrange_surface(output, &full_area, &usable_area, output->layers.shell_bottom, true, locked);
+	arrange_surface(output, &full_area, &usable_area, output->layers.shell_background, true, locked);
 
-	arrange_surface(output, &full_area, &usable_area, output->layers.shell_overlay, false);
-	arrange_surface(output, &full_area, &usable_area, output->layers.shell_top, false);
-	arrange_surface(output, &full_area, &usable_area, output->layers.shell_bottom, false);
-	arrange_surface(output, &full_area, &usable_area, output->layers.shell_background, false);
+	arrange_surface(output, &full_area, &usable_area, output->layers.shell_overlay, false, locked);
+	arrange_surface(output, &full_area, &usable_area, output->layers.shell_top, false, locked);
+	arrange_surface(output, &full_area, &usable_area, output->layers.shell_bottom, false, locked);
+	arrange_surface(output, &full_area, &usable_area, output->layers.shell_background, false, locked);
 
 	if (!wlr_box_equal(&usable_area, &output->usable_area)) {
 		sway_log(SWAY_DEBUG, "Usable area changed, rearranging output");
 		output->usable_area = usable_area;
+		arrange_locks();
 		arrange_output(output);
 	} else {
 		arrange_popups(root->layers.popup);

sway/desktop/transaction.c

@@ -623,13 +623,22 @@ void arrange_popups(struct wlr_scene_tree *popups) {
 
 static void arrange_root(struct sway_root *root) {
 	struct sway_container *fs = root->fullscreen_global;
+	bool locked = server.session_lock.lock;
 
 	wlr_scene_node_set_enabled(&root->layers.shell_background->node, !fs);
 	wlr_scene_node_set_enabled(&root->layers.shell_bottom->node, !fs);
-	wlr_scene_node_set_enabled(&root->layers.tiling->node, !fs);
-	wlr_scene_node_set_enabled(&root->layers.floating->node, !fs);
+	wlr_scene_node_set_enabled(&root->layers.tiling->node, !fs && !locked);
+	wlr_scene_node_set_enabled(&root->layers.floating->node, !fs && !locked);
 	wlr_scene_node_set_enabled(&root->layers.shell_top->node, !fs);
-	wlr_scene_node_set_enabled(&root->layers.fullscreen->node, !fs);
+	wlr_scene_node_set_enabled(&root->layers.fullscreen->node, !fs && !locked);
+	wlr_scene_node_set_enabled(&root->layers.fullscreen_global->node, !locked);
+#if WLR_HAS_XWAYLAND
+	wlr_scene_node_set_enabled(&root->layers.unmanaged->node, !locked);
+#endif
+
+	if (server.session_lock.lock) {
+		sway_log(SWAY_INFO, "arranging locked layout");
+	}
 
 	// hide all contents in the scratchpad
 	for (int i = 0; i < root->scratchpad->length; i++) {

sway/input/seat.c

@@ -1068,7 +1068,20 @@ void seat_configure_xcursor(struct sway_seat *seat) {
 bool seat_is_input_allowed(struct sway_seat *seat,
 		struct wlr_surface *surface) {
 	if (server.session_lock.lock) {
-		return sway_session_lock_has_surface(server.session_lock.lock, surface);
+		if (sway_session_lock_has_surface(server.session_lock.lock, surface)) {
+			return true;
+		}
+
+		struct wlr_layer_surface_v1 *layer_surface =
+			wlr_layer_surface_v1_try_from_wlr_surface(surface);
+		struct sway_layer_surface *layer =
+			layer_surface ? layer_surface->data : NULL;
+
+		if (layer && layer->show_over_lockscreen) {
+			return true;
+		}
+
+		return false;
 	}
 	return true;
 }

sway/lock.c

@@ -4,10 +4,12 @@
 #include "log.h"
 #include "sway/input/cursor.h"
 #include "sway/input/keyboard.h"
+#include "sway/desktop/transaction.h"
 #include "sway/input/seat.h"
 #include "sway/layers.h"
 #include "sway/output.h"
 #include "sway/server.h"
+#include "sway/tree/arrange.h"
 #include "sway/lock.h"
 
 struct sway_session_lock_output {
@@ -79,13 +81,13 @@ static void handle_surface_destroy(struct wl_listener *listener, void *data) {
 }
 
 static void lock_output_reconfigure(struct sway_session_lock_output *output) {
-	int width = output->output->width;
-	int height = output->output->height;
+	struct wlr_box usable_area = output->output->usable_area;
 
-	wlr_scene_rect_set_size(output->background, width, height);
+	wlr_scene_node_set_position(&output->tree->node, usable_area.x, usable_area.y);
+	wlr_scene_rect_set_size(output->background, usable_area.width, usable_area.height);
 
 	if (output->surface) {
-		wlr_session_lock_surface_v1_configure(output->surface, width, height);
+		wlr_session_lock_surface_v1_configure(output->surface, usable_area.width, usable_area.height);
 	}
 }
 
@@ -234,6 +236,9 @@ static void handle_unlock(struct wl_listener *listener, void *data) {
 		struct sway_output *output = root->outputs->items[i];
 		arrange_layers(output);
 	}
+
+	arrange_root();
+	transaction_commit_dirty();
 }
 
 static void handle_abandon(struct wl_listener *listener, void *data) {
@@ -295,8 +300,17 @@ static void handle_session_lock(struct wl_listener *listener, void *data) {
 	sway_lock->destroy.notify = handle_abandon;
 	wl_signal_add(&lock->events.destroy, &sway_lock->destroy);
 
-	wlr_session_lock_v1_send_locked(lock);
 	server.session_lock.lock = sway_lock;
+
+	for (int i = 0; i < root->outputs->length; ++i) {
+		struct sway_output *output = root->outputs->items[i];
+		arrange_layers(output);
+	}
+
+	arrange_root();
+	transaction_commit_dirty();
+
+	wlr_session_lock_v1_send_locked(lock);
 }
 
 static void handle_session_lock_destroy(struct wl_listener *listener, void *data) {

sway/lockscreen-overlay.c

@@ -0,0 +1,87 @@
+#include "sway/lockscreen-overlay.h"
+#include "sway/desktop/transaction.h"
+#include "sway/layers.h"
+
+#include "kde-lockscreen-overlay-v1-protocol.h"
+#include "log.h"
+#include "sway/tree/arrange.h"
+
+#include <stdlib.h>
+#include <wayland-server-core.h>
+
+#include <wlr/types/wlr_compositor.h>
+#include <wlr/types/wlr_layer_shell_v1.h>
+
+struct sway_lockscreen_overlay {
+};
+
+static void kde_lockscreen_overlay_allow(struct wl_client *client,
+		struct wl_resource *resource, struct wl_resource *surface) {
+	sway_log(SWAY_ERROR, "at %s:%d", __func__, __LINE__);
+
+	struct wlr_surface *overlay_surface = wlr_surface_from_resource(surface);
+	// TODO: send a protocol error for each of these checks?
+	if (!overlay_surface) {
+		sway_log(SWAY_ERROR, "No overlay surface found");
+		return;
+	}
+
+	struct wlr_layer_surface_v1 *wlr_layer_surface =
+		wlr_layer_surface_v1_try_from_wlr_surface(overlay_surface);
+	if (!wlr_layer_surface) {
+		sway_log(SWAY_ERROR, "no wlr_layer surface found");
+		return;
+	}
+
+	struct sway_layer_surface *layer_surface = wlr_layer_surface->data;
+	if (!layer_surface) {
+		sway_log(SWAY_ERROR, "no sway_layer surface found");
+		return;
+	}
+
+	layer_surface->show_over_lockscreen = true;
+
+	arrange_layers(layer_surface->output);
+	arrange_root();
+	transaction_commit_dirty();
+}
+
+static void kde_lockscreen_overlay_destroy(struct wl_client *client,
+		struct wl_resource *resource) {
+	wl_resource_destroy(resource);
+}
+
+static const struct kde_lockscreen_overlay_v1_interface impl = {
+	.allow = kde_lockscreen_overlay_allow,
+	.destroy = kde_lockscreen_overlay_destroy,
+};
+
+static void lockscreen_overlay_bind(
+	struct wl_client *client,
+	void *data,
+	uint32_t version,
+	uint32_t id
+) {
+	struct sway_lockscreen_overlay *overlay = data;
+
+	struct wl_resource *resource = wl_resource_create(client,
+		&kde_lockscreen_overlay_v1_interface, version, id);
+	if (!resource) {
+		wl_client_post_no_memory(client);
+		return;
+	}
+
+	wl_resource_set_implementation(resource, &impl, overlay, NULL);
+}
+
+struct sway_lockscreen_overlay *sway_lockscreen_overlay_create(struct wl_display *display) {
+	struct sway_lockscreen_overlay *overlay = calloc(1, sizeof(*overlay));
+
+	wl_global_create(
+		display,
+		&kde_lockscreen_overlay_v1_interface, 1,
+		overlay, lockscreen_overlay_bind
+	);
+
+	return overlay;
+}

sway/meson.build

@@ -6,6 +6,7 @@ sway_sources = files(
 	'ipc-json.c',
 	'ipc-server.c',
 	'lock.c',
+	'lockscreen-overlay.c',
 	'main.c',
 	'realtime.c',
 	'scene_descriptor.c',

sway/server.c

@@ -57,6 +57,7 @@
 #include "sway/server.h"
 #include "sway/input/cursor.h"
 #include "sway/tree/root.h"
+#include "sway/lockscreen-overlay.h"
 
 #if WLR_HAS_XWAYLAND
 #include <wlr/xwayland/shell.h>
@@ -352,6 +353,8 @@ bool server_init(struct sway_server *server) {
 		wlr_ext_foreign_toplevel_list_v1_create(server->wl_display, SWAY_FOREIGN_TOPLEVEL_LIST_VERSION);
 	server->foreign_toplevel_manager =
 		wlr_foreign_toplevel_manager_v1_create(server->wl_display);
+	server->lockscreen_overlay =
+		sway_lockscreen_overlay_create(server->wl_display);
 
 	sway_session_lock_init();
 

sway/tree/root.c

@@ -50,10 +50,10 @@ struct sway_root *root_create(struct wl_display *wl_display) {
 #if WLR_HAS_XWAYLAND
 	root->layers.unmanaged = alloc_scene_tree(root->layer_tree, &failed);
 #endif
+	root->layers.session_lock = alloc_scene_tree(root->layer_tree, &failed);
 	root->layers.shell_overlay = alloc_scene_tree(root->layer_tree, &failed);
 	root->layers.popup = alloc_scene_tree(root->layer_tree, &failed);
 	root->layers.seat = alloc_scene_tree(root->layer_tree, &failed);
-	root->layers.session_lock = alloc_scene_tree(root->layer_tree, &failed);
 
 	if (!failed && !scene_descriptor_assign(&root->layers.seat->node,
 			SWAY_SCENE_DESC_NON_INTERACTIVE, (void *)1)) {