cage: add basic wlr-output-management support

Co-authored-by: Dima Krasner <dima@dimakrasner.com>

cage.c

@@ -28,6 +28,7 @@
 #include <wlr/types/wlr_idle.h>
 #include <wlr/types/wlr_idle_inhibit_v1.h>
 #include <wlr/types/wlr_output_layout.h>
+#include <wlr/types/wlr_output_management_v1.h>
 #include <wlr/types/wlr_presentation_time.h>
 #include <wlr/types/wlr_scene.h>
 #include <wlr/types/wlr_screencopy_v1.h>
@@ -340,6 +341,8 @@ main(int argc, char *argv[])
 		ret = 1;
 		goto end;
 	}
+	server.output_layout_change.notify = handle_output_layout_change;
+	wl_signal_add(&server.output_layout->events.change, &server.output_layout_change);
 
 	server.scene = wlr_scene_create();
 	if (!server.scene) {
@@ -472,6 +475,17 @@ main(int argc, char *argv[])
 		goto end;
 	}
 
+	server.output_manager_v1 = wlr_output_manager_v1_create(server.wl_display);
+	if (!server.output_manager_v1) {
+		wlr_log(WLR_ERROR, "Unable to create the output manager");
+		ret = 1;
+		goto end;
+	}
+	server.output_manager_apply.notify = handle_output_manager_apply;
+	wl_signal_add(&server.output_manager_v1->events.apply, &server.output_manager_apply);
+	server.output_manager_test.notify = handle_output_manager_test;
+	wl_signal_add(&server.output_manager_v1->events.test, &server.output_manager_test);
+
 	gamma_control_manager = wlr_gamma_control_manager_v1_create(server.wl_display);
 	if (!gamma_control_manager) {
 		wlr_log(WLR_ERROR, "Unable to create the gamma control manager");

output.c

@@ -28,6 +28,7 @@
 #include <wlr/types/wlr_output.h>
 #include <wlr/types/wlr_output_damage.h>
 #include <wlr/types/wlr_output_layout.h>
+#include <wlr/types/wlr_output_management_v1.h>
 #include <wlr/types/wlr_scene.h>
 #include <wlr/types/wlr_xdg_shell.h>
 #include <wlr/util/log.h>
@@ -41,6 +42,32 @@
 #include "xwayland.h"
 #endif
 
+#define OUTPUT_CONFIG_UPDATED                                                                                          \
+	(WLR_OUTPUT_STATE_ENABLED | WLR_OUTPUT_STATE_SCALE | WLR_OUTPUT_STATE_TRANSFORM |                              \
+	 WLR_OUTPUT_STATE_ADAPTIVE_SYNC_ENABLED)
+
+static void
+update_output_manager_config(struct cg_server *server)
+{
+	struct wlr_output_configuration_v1 *config = wlr_output_configuration_v1_create();
+
+	struct cg_output *output;
+	wl_list_for_each (output, &server->outputs, link) {
+		struct wlr_output *wlr_output = output->wlr_output;
+		struct wlr_output_configuration_head_v1 *config_head =
+			wlr_output_configuration_head_v1_create(config, wlr_output);
+		struct wlr_box output_box;
+
+		wlr_output_layout_get_box(server->output_layout, wlr_output, &output_box);
+		if (!wlr_box_empty(&output_box)) {
+			config_head->state.x = output_box.x;
+			config_head->state.y = output_box.y;
+		}
+	}
+
+	wlr_output_manager_v1_set_configuration(server->output_manager_v1, config);
+}
+
 static void
 output_enable(struct cg_output *output)
 {
@@ -57,6 +84,8 @@ output_enable(struct cg_output *output)
 
 	output->scene_output = wlr_scene_get_scene_output(output->server->scene, wlr_output);
 	assert(output->scene_output != NULL);
+
+	update_output_manager_config(output->server);
 }
 
 static void
@@ -77,6 +106,44 @@ output_disable(struct cg_output *output)
 	wlr_output_commit(wlr_output);
 }
 
+static bool
+output_apply_config(struct cg_output *output, struct wlr_output_configuration_head_v1 *head, bool test_only)
+{
+	wlr_output_enable(output->wlr_output, head->state.enabled);
+
+	if (head->state.enabled) {
+		/* Do not mess with these parameters for output to be disabled */
+		wlr_output_set_scale(output->wlr_output, head->state.scale);
+		wlr_output_set_transform(output->wlr_output, head->state.transform);
+
+		if (head->state.mode) {
+			wlr_output_set_mode(output->wlr_output, head->state.mode);
+		} else {
+			wlr_output_set_custom_mode(output->wlr_output, head->state.custom_mode.width,
+						   head->state.custom_mode.height, head->state.custom_mode.refresh);
+		}
+	}
+
+	if (test_only) {
+		bool ret = wlr_output_test(output->wlr_output);
+		wlr_output_rollback(output->wlr_output);
+		return ret;
+	}
+
+	/* Apply output configuration */
+	if (!wlr_output_commit(output->wlr_output)) {
+		return false;
+	}
+
+	if (head->state.enabled) {
+		wlr_output_layout_add(output->server->output_layout, head->state.output, head->state.x, head->state.y);
+	} else {
+		wlr_output_layout_remove(output->server->output_layout, output->wlr_output);
+	}
+
+	return true;
+}
+
 static void
 handle_output_frame(struct wl_listener *listener, void *data)
 {
@@ -99,15 +166,21 @@ handle_output_commit(struct wl_listener *listener, void *data)
 	struct cg_output *output = wl_container_of(listener, output, commit);
 	struct wlr_output_event_commit *event = data;
 
-	if (!output->wlr_output->enabled) {
+	/* Notes:
-		return;
+	 * - output layout change will also be called if needed to position the views
+	 * - always update output manager configuration even if the output is now disabled */
+
+	if (event->committed & WLR_OUTPUT_STATE_ENABLED) {
+		if (output->wlr_output->enabled) {
+			output->scene_output = wlr_scene_get_scene_output(output->server->scene, output->wlr_output);
+			assert(output->scene_output != NULL);
+		} else {
+			output->scene_output = NULL;
+		}
 	}
 
-	if (event->committed & WLR_OUTPUT_STATE_TRANSFORM) {
+	if (event->committed & OUTPUT_CONFIG_UPDATED) {
-		struct cg_view *view;
+		update_output_manager_config(output->server);
-		wl_list_for_each (view, &output->server->views, link) {
-			view_position(view);
-		}
 	}
 }
 
@@ -120,10 +193,17 @@ handle_output_mode(struct wl_listener *listener, void *data)
 		return;
 	}
 
-	struct cg_view *view;
+	view_position_all(output->server);
-	wl_list_for_each (view, &output->server->views, link) {
+	update_output_manager_config(output->server);
-		view_position(view);
+}
-	}
+
+void
+handle_output_layout_change(struct wl_listener *listener, void *data)
+{
+	struct cg_server *server = wl_container_of(listener, server, output_layout_change);
+
+	view_position_all(server);
+	update_output_manager_config(server);
 }
 
 static void
@@ -149,11 +229,7 @@ output_destroy(struct cg_output *output)
 		struct cg_output *prev = wl_container_of(server->outputs.next, prev, link);
 		if (prev) {
 			output_enable(prev);
-
+			view_position_all(server);
-			struct cg_view *view;
-			wl_list_for_each (view, &server->views, link) {
-				view_position(view);
-			}
 		}
 	}
 }
@@ -230,11 +306,7 @@ handle_new_output(struct wl_listener *listener, void *data)
 	}
 
 	output_enable(output);
-
+	view_position_all(output->server);
-	struct cg_view *view;
-	wl_list_for_each (view, &output->server->views, link) {
-		view_position(view);
-	}
 }
 
 void
@@ -255,3 +327,49 @@ output_set_window_title(struct cg_output *output, const char *title)
 #endif
 	}
 }
+
+static bool
+output_config_apply(struct cg_server *server, struct wlr_output_configuration_v1 *config, bool test_only)
+{
+	struct wlr_output_configuration_head_v1 *head;
+
+	wl_list_for_each (head, &config->heads, link) {
+		struct cg_output *output = head->state.output->data;
+
+		if (!output_apply_config(output, head, test_only)) {
+			return false;
+		}
+	}
+
+	return true;
+}
+
+void
+handle_output_manager_apply(struct wl_listener *listener, void *data)
+{
+	struct cg_server *server = wl_container_of(listener, server, output_manager_apply);
+	struct wlr_output_configuration_v1 *config = data;
+
+	if (output_config_apply(server, config, false)) {
+		wlr_output_configuration_v1_send_succeeded(config);
+	} else {
+		wlr_output_configuration_v1_send_failed(config);
+	}
+
+	wlr_output_configuration_v1_destroy(config);
+}
+
+void
+handle_output_manager_test(struct wl_listener *listener, void *data)
+{
+	struct cg_server *server = wl_container_of(listener, server, output_manager_test);
+	struct wlr_output_configuration_v1 *config = data;
+
+	if (output_config_apply(server, config, true)) {
+		wlr_output_configuration_v1_send_succeeded(config);
+	} else {
+		wlr_output_configuration_v1_send_failed(config);
+	}
+
+	wlr_output_configuration_v1_destroy(config);
+}

output.h

@@ -21,6 +21,9 @@ struct cg_output {
 	struct wl_list link; // cg_server::outputs
 };
 
+void handle_output_manager_apply(struct wl_listener *listener, void *data);
+void handle_output_manager_test(struct wl_listener *listener, void *data);
+void handle_output_layout_change(struct wl_listener *listener, void *data);
 void handle_new_output(struct wl_listener *listener, void *data);
 void output_set_window_title(struct cg_output *output, const char *title);
 

server.h

@@ -37,6 +37,7 @@ struct cg_server {
 	 * some outputs may be disabled. */
 	struct wl_list outputs; // cg_output::link
 	struct wl_listener new_output;
+	struct wl_listener output_layout_change;
 
 	struct wl_listener xdg_toplevel_decoration;
 	struct wl_listener new_xdg_shell_surface;
@@ -46,6 +47,9 @@ struct cg_server {
 #if CAGE_HAS_XWAYLAND
 	struct wl_listener new_xwayland_surface;
 #endif
+	struct wlr_output_manager_v1 *output_manager_v1;
+	struct wl_listener output_manager_apply;
+	struct wl_listener output_manager_test;
 
 	bool xdg_decoration;
 	bool allow_vt_switch;

view.c

@@ -97,6 +97,15 @@ view_position(struct cg_view *view)
 	}
 }
 
+void
+view_position_all(struct cg_server *server)
+{
+	struct cg_view *view;
+	wl_list_for_each (view, &server->views, link) {
+		view_position(view);
+	}
+}
+
 void
 view_unmap(struct cg_view *view)
 {

view.h

@@ -49,6 +49,7 @@ bool view_is_primary(struct cg_view *view);
 bool view_is_transient_for(struct cg_view *child, struct cg_view *parent);
 void view_activate(struct cg_view *view, bool activate);
 void view_position(struct cg_view *view);
+void view_position_all(struct cg_server *server);
 void view_unmap(struct cg_view *view);
 void view_map(struct cg_view *view, struct wlr_surface *surface);
 void view_destroy(struct cg_view *view);