weston: Port RDP backend to new output handling API

This is a complete port of the RDP backend that uses
the recently added output handling API for output
configuration.

Output can be configured at runtime by passing the
necessary configuration parameters, which can be
filled in manually or obtained from the command line
using previously added functionality. It is required
that the scale and transform values are set using
the previously added functionality.

After everything has been set, output needs to be
enabled manually using weston_output_enable().

v2:

 - Rename output_configure() to output_set_size()
   in plugin API and describe it.
 - Manually fetch parsed_options from wet_compositor.
 - Call rdp_output_disable() explicitly from
   rdp_output_destroy().

v3:

 - Disallow calling rdp_output_set_size more than once.
 - Manually assign a hardcoded name to an output as that's
   now mandatory.
 - Use weston_compositor_add_pending_output().
 - Bump weston_rdp_backend_config version to 2.

Reviewed-by: Quentin Glidic <sardemff7+git@sardemff7.net>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Signed-off-by: Armin Krezović <krezovic.armin@gmail.com>

compositor/main.c

@@ -1282,14 +1282,47 @@ load_headless_backend(struct weston_compositor *c,
 	return 0;
 }
 
+static void
+rdp_backend_output_configure(struct wl_listener *listener, void *data)
+{
+	struct weston_output *output = data;
+	struct wet_compositor *compositor = to_wet_compositor(output->compositor);
+	struct wet_output_config *parsed_options = compositor->parsed_options;
+	const struct weston_rdp_output_api *api = weston_rdp_output_get_api(output->compositor);
+	int width = 640;
+	int height = 480;
+
+	assert(parsed_options);
+
+	if (!api) {
+		weston_log("Cannot use weston_rdp_output_api.\n");
+		return;
+	}
+
+	if (parsed_options->width)
+		width = parsed_options->width;
+
+	if (parsed_options->height)
+		height = parsed_options->height;
+
+	weston_output_set_scale(output, 1);
+	weston_output_set_transform(output, WL_OUTPUT_TRANSFORM_NORMAL);
+
+	if (api->output_set_size(output, width, height) < 0) {
+		weston_log("Cannot configure output \"%s\" using weston_rdp_output_api.\n",
+			   output->name);
+		return;
+	}
+
+	weston_output_enable(output);
+}
+
 static void
 weston_rdp_backend_config_init(struct weston_rdp_backend_config *config)
 {
 	config->base.struct_version = WESTON_RDP_BACKEND_CONFIG_VERSION;
 	config->base.struct_size = sizeof(struct weston_rdp_backend_config);
 
-	config->width = 640;
-	config->height = 480;
 	config->bind_address = NULL;
 	config->port = 3389;
 	config->rdp_key = NULL;
@@ -1306,12 +1339,16 @@ load_rdp_backend(struct weston_compositor *c,
 	struct weston_rdp_backend_config config  = {{ 0, }};
 	int ret = 0;
 
+	struct wet_output_config *parsed_options = wet_init_parsed_options(c);
+	if (!parsed_options)
+		return -1;
+
 	weston_rdp_backend_config_init(&config);
 
 	const struct weston_option rdp_options[] = {
 		{ WESTON_OPTION_BOOLEAN, "env-socket", 0, &config.env_socket },
-		{ WESTON_OPTION_INTEGER, "width", 0, &config.width },
-		{ WESTON_OPTION_INTEGER, "height", 0, &config.height },
+		{ WESTON_OPTION_INTEGER, "width", 0, &parsed_options->width },
+		{ WESTON_OPTION_INTEGER, "height", 0, &parsed_options->height },
 		{ WESTON_OPTION_STRING,  "address", 0, &config.bind_address },
 		{ WESTON_OPTION_INTEGER, "port", 0, &config.port },
 		{ WESTON_OPTION_BOOLEAN, "no-clients-resize", 0, &config.no_clients_resize },
@@ -1325,10 +1362,17 @@ load_rdp_backend(struct weston_compositor *c,
 	ret = weston_compositor_load_backend(c, WESTON_BACKEND_RDP,
 					     &config.base);
 
+	if (ret < 0)
+		goto out;
+
+	wet_set_pending_output_handler(c, rdp_backend_output_configure);
+
+out:
 	free(config.bind_address);
 	free(config.rdp_key);
 	free(config.server_cert);
 	free(config.server_key);
+
 	return ret;
 }
 

libweston/compositor-rdp.c

@@ -25,6 +25,7 @@
 
 #include "config.h"
 
+#include <assert.h>
 #include <stdint.h>
 #include <stdlib.h>
 #include <string.h>
@@ -371,15 +372,6 @@ rdp_output_repaint(struct weston_output *output_base, pixman_region32_t *damage)
 	return 0;
 }
 
-static void
-rdp_output_destroy(struct weston_output *output_base)
-{
-	struct rdp_output *output = to_rdp_output(output_base);
-
-	wl_event_source_remove(output->finish_frame_timer);
-	free(output);
-}
-
 static int
 finish_frame_handler(void *data)
 {
@@ -471,16 +463,15 @@ rdp_switch_mode(struct weston_output *output, struct weston_mode *target_mode)
 }
 
 static int
-rdp_backend_create_output(struct rdp_backend *b, int width, int height)
+rdp_output_set_size(struct weston_output *base,
+		    int width, int height)
 {
-	struct rdp_output *output;
-	struct wl_event_loop *loop;
+	struct rdp_output *output = to_rdp_output(base);
 	struct weston_mode *currentMode;
 	struct weston_mode initMode;
 
-	output = zalloc(sizeof *output);
-	if (output == NULL)
-		return -1;
+	/* We can only be called once. */
+	assert(!output->base.current_mode);
 
 	wl_list_init(&output->peers);
 	wl_list_init(&output->base.mode_list);
@@ -492,48 +483,100 @@ rdp_backend_create_output(struct rdp_backend *b, int width, int height)
 
 	currentMode = ensure_matching_mode(&output->base, &initMode);
 	if (!currentMode)
-		goto out_free_output;
+		return -1;
 
 	output->base.current_mode = output->base.native_mode = currentMode;
-	weston_output_init(&output->base, b->compositor, 0, 0, width, height,
-			   WL_OUTPUT_TRANSFORM_NORMAL, 1);
-
 	output->base.make = "weston";
 	output->base.model = "rdp";
+
+	/* XXX: Calculate proper size. */
+	output->base.mm_width = width;
+	output->base.mm_height = height;
+
+	output->base.start_repaint_loop = rdp_output_start_repaint_loop;
+	output->base.repaint = rdp_output_repaint;
+	output->base.assign_planes = NULL;
+	output->base.set_backlight = NULL;
+	output->base.set_dpms = NULL;
+	output->base.switch_mode = rdp_switch_mode;
+
+	return 0;
+}
+
+static int
+rdp_output_enable(struct weston_output *base)
+{
+	struct rdp_output *output = to_rdp_output(base);
+	struct rdp_backend *b = to_rdp_backend(base->compositor);
+	struct wl_event_loop *loop;
+
 	output->shadow_surface = pixman_image_create_bits(PIXMAN_x8r8g8b8,
-			width, height,
-		    NULL,
-		    width * 4);
+							  output->base.current_mode->width,
+							  output->base.current_mode->height,
+							  NULL,
+							  output->base.current_mode->width * 4);
 	if (output->shadow_surface == NULL) {
 		weston_log("Failed to create surface for frame buffer.\n");
-		goto out_output;
+		return -1;
 	}
 
-	if (pixman_renderer_output_create(&output->base) < 0)
-		goto out_shadow_surface;
+	if (pixman_renderer_output_create(&output->base) < 0) {
+		pixman_image_unref(output->shadow_surface);
+		return -1;
+	}
 
 	loop = wl_display_get_event_loop(b->compositor->wl_display);
 	output->finish_frame_timer = wl_event_loop_add_timer(loop, finish_frame_handler, output);
 
-	output->base.start_repaint_loop = rdp_output_start_repaint_loop;
-	output->base.repaint = rdp_output_repaint;
-	output->base.destroy = rdp_output_destroy;
-	output->base.assign_planes = NULL;
-	output->base.set_backlight = NULL;
-	output->base.set_dpms = NULL;
-	output->base.switch_mode = rdp_switch_mode;
 	b->output = output;
 
-	weston_compositor_add_output(b->compositor, &output->base);
 	return 0;
+}
+
+static int
+rdp_output_disable(struct weston_output *base)
+{
+	struct rdp_output *output = to_rdp_output(base);
+	struct rdp_backend *b = to_rdp_backend(base->compositor);
+
+	if (!output->base.enabled)
+		return 0;
+
+	wl_event_source_remove(output->finish_frame_timer);
+	b->output = NULL;
 
-out_shadow_surface:
-	pixman_image_unref(output->shadow_surface);
-out_output:
+	return 0;
+}
+
+static void
+rdp_output_destroy(struct weston_output *base)
+{
+	struct rdp_output *output = to_rdp_output(base);
+
+	rdp_output_disable(&output->base);
 	weston_output_destroy(&output->base);
-out_free_output:
+
 	free(output);
-	return -1;
+}
+
+static int
+rdp_backend_create_output(struct weston_compositor *compositor)
+{
+	struct rdp_output *output;
+
+	output = zalloc(sizeof *output);
+	if (output == NULL)
+		return -1;
+
+	output->base.name =  strdup("rdp");
+	output->base.destroy = rdp_output_destroy;
+	output->base.disable = rdp_output_disable;
+	output->base.enable = rdp_output_enable;
+
+	weston_output_init_pending(&output->base, compositor);
+	weston_compositor_add_pending_output(&output->base, compositor);
+
+	return 0;
 }
 
 static void
@@ -1216,6 +1259,10 @@ rdp_incoming_peer(freerdp_listener *instance, freerdp_peer *client)
 	FREERDP_CB_RETURN(TRUE);
 }
 
+static const struct weston_rdp_output_api api = {
+	rdp_output_set_size,
+};
+
 static struct rdp_backend *
 rdp_backend_create(struct weston_compositor *compositor,
 		   struct weston_rdp_backend_config *config)
@@ -1223,7 +1270,7 @@ rdp_backend_create(struct weston_compositor *compositor,
 	struct rdp_backend *b;
 	char *fd_str;
 	char *fd_tail;
-	int fd;
+	int fd, ret;
 
 	b = zalloc(sizeof *b);
 	if (b == NULL)
@@ -1251,7 +1298,7 @@ rdp_backend_create(struct weston_compositor *compositor,
 	if (pixman_renderer_init(compositor) < 0)
 		goto err_compositor;
 
-	if (rdp_backend_create_output(b, config->width, config->height) < 0)
+	if (rdp_backend_create_output(compositor) < 0)
 		goto err_compositor;
 
 	compositor->capabilities |= WESTON_CAP_ARBITRARY_MODES;
@@ -1282,6 +1329,15 @@ rdp_backend_create(struct weston_compositor *compositor,
 	}
 
 	compositor->backend = &b->base;
+
+	ret = weston_plugin_api_register(compositor, WESTON_RDP_OUTPUT_API_NAME,
+					 &api, sizeof(api));
+
+	if (ret < 0) {
+		weston_log("Failed to register output API.\n");
+		goto err_output;
+	}
+
 	return b;
 
 err_listener:
@@ -1301,8 +1357,6 @@ err_free_strings:
 static void
 config_init_to_defaults(struct weston_rdp_backend_config *config)
 {
-	config->width = 640;
-	config->height = 480;
 	config->bind_address = NULL;
 	config->port = 3389;
 	config->rdp_key = NULL;

libweston/compositor-rdp.h

@@ -31,13 +31,33 @@ extern "C" {
 #endif
 
 #include "compositor.h"
+#include "plugin-registry.h"
 
-#define WESTON_RDP_BACKEND_CONFIG_VERSION 1
+#define WESTON_RDP_OUTPUT_API_NAME "weston_rdp_output_api_v1"
+
+struct weston_rdp_output_api {
+	/** Initialize a RDP output with specified width and height.
+	 *
+	 * Returns 0 on success, -1 on failure.
+	 */
+	int (*output_set_size)(struct weston_output *output,
+			       int width, int height);
+};
+
+static inline const struct weston_rdp_output_api *
+weston_rdp_output_get_api(struct weston_compositor *compositor)
+{
+	const void *api;
+	api = weston_plugin_api_get(compositor, WESTON_RDP_OUTPUT_API_NAME,
+				    sizeof(struct weston_rdp_output_api));
+
+	return (const struct weston_rdp_output_api *)api;
+}
+
+#define WESTON_RDP_BACKEND_CONFIG_VERSION 2
 
 struct weston_rdp_backend_config {
 	struct weston_backend_config base;
-	int width;
-	int height;
 	char *bind_address;
 	int port;
 	char *rdp_key;