layout: Add a background for remote outputssandbox/mvlad/updates-pipewire

Shell client might not install a background for the remote outputs so
let's create one if we detect that. It will be just a black background.

As shell client might not install a background, wayland clients can have
an alpha channel and might need to have a background underneath, or the
application streamed on that remote output might be closed/removed but
we will still continue to display the last frame updated.

This includes also a correction to check for an app_id.

Bug-AGL: SPEC-5324
Signed-off-by: Marius Vlad <marius.vlad@collabora.com>
Change-Id: Iad1ceaae2ead62f1809cf2f0a58302474ff488d0

3 files changed, 63 insertions, 6 deletions

diff --git a/src/compositor.c b/src/compositor.c
index 36a12d4..207dbf2 100644
--- a/src/compositor.c
+++ b/src/compositor.c
@@ -307,6 +307,14 @@ ivi_ensure_output(struct ivi_compositor *ivi, struct ivi_backend *ivi_backend,
 		}
 	}
 
+	switch (weston_get_backend_type(ivi_backend->backend)) {
+	case WESTON_BACKEND_VNC:
+	case WESTON_BACKEND_RDP:
+	case WESTON_BACKEND_PIPEWIRE:
+		output->type = OUTPUT_REMOTE;
+		break;
+	default:
+	}
 
 	wl_list_insert(&ivi->outputs, &output->link);
 	ivi_output_configure_app_id(output);
diff --git a/src/desktop.c b/src/desktop.c
index b327fe6..5ec1e36 100644
--- a/src/desktop.c
+++ b/src/desktop.c
@@ -285,8 +285,9 @@ desktop_surface_removed(struct weston_desktop_surface *dsurface, void *userdata)
 	 * the DESKTOP role can happen here as well, because we can fall-back 
 	 * to that when we try to determine the role type. Application that
 	 * do not set the app_id will be land here, when destroyed */
-	if ((output == NULL && (surface->role == IVI_SURFACE_ROLE_NONE ||
-				surface->role == IVI_SURFACE_ROLE_DESKTOP)) ||
+	if ((output == NULL &&
+	     (surface->role == IVI_SURFACE_ROLE_NONE ||
+	      surface->role == IVI_SURFACE_ROLE_DESKTOP)) ||
 	     output->output == NULL)
 		goto skip_output_asignment;
 
@@ -333,8 +334,8 @@ desktop_surface_removed(struct weston_desktop_surface *dsurface, void *userdata)
 
 	if (surface->role == IVI_SURFACE_ROLE_TILE) {
 		ivi_layout_reset_split_surfaces(surface->ivi);
-		// activate previous when resizing back to give input set
-		// output active for allowing to resizing again if needed
+		/* activate previous when resizing back to give input set
+		 * output active for allowing to resizing again if needed */
 		if (output->previous_active)
 			ivi_layout_activate_by_surf(output, output->previous_active);
 	}
diff --git a/src/layout.c b/src/layout.c
index 6c1df75..45c5507 100644
--- a/src/layout.c
+++ b/src/layout.c
@@ -33,6 +33,7 @@
 #include <libweston/config-parser.h>
 #include <libweston/libweston.h>
 #include <libweston/desktop.h>
+#include <libweston/shell-utils.h>
 
 #define AGL_COMP_DEBUG
 
@@ -136,6 +137,12 @@ ivi_layout_get_surface_role_name(struct ivi_surface *surf)
 	return ivi_roles_as_string[surf->role];
 }
 
+static int
+black_surface_get_label(struct weston_surface *surface, char *buf, size_t len)
+{
+        return snprintf(buf, len, "remote output background surface");
+}
+
 static void
 ivi_background_init(struct ivi_compositor *ivi, struct ivi_output *output)
 {
@@ -145,7 +152,48 @@ ivi_background_init(struct ivi_compositor *ivi, struct ivi_output *output)
 	struct weston_surface *wsurface;
 
 	if (!bg) {
-		weston_log("WARNING: Output does not have a background\n");
+		struct weston_curtain *curtain = NULL;
+		struct ivi_surface *ivi_surf = NULL;
+
+		weston_log("WARNING: Output %s (type: %d) does not have a background.\n", output->output->name, output->type);
+		if (output->type != OUTPUT_REMOTE)
+			return;
+
+		weston_log("Installing a red background on output %s.\n",
+				output->output->name);
+
+		struct weston_curtain_params curtain_params = {
+			.r = 1.0, .g = 0.0, .b = 0.0, .a = 1.0,
+			.pos = woutput->pos,
+			.width = woutput->width, .height = woutput->height,
+			.get_label = black_surface_get_label,
+			.surface_private = NULL,
+			.surface_committed = NULL,
+			.capture_input = true,
+		};
+
+		curtain = weston_shell_utils_curtain_create(ivi->compositor, &curtain_params);
+
+		weston_surface_set_role(curtain->view->surface,
+					"remote-output-background-surface", NULL, 0);
+
+		weston_view_move_to_layer(curtain->view, &ivi->background.view_list);
+		weston_view_set_output(curtain->view, woutput);
+
+		ivi_surf = zalloc(sizeof(*ivi_surf));
+		ivi_surf->view = curtain->view;
+		ivi_surf->ivi = ivi;
+		output->background = ivi_surf;
+
+		weston_log("(background) position view %p, x %f, y %f, on output %s\n", curtain->view,
+				woutput->pos.c.x, woutput->pos.c.y, output->name);
+
+		/* this background will always be available displayed, while
+		 * the back curtain is installed/removed as we please */
+		remove_black_curtain(output);
+
+		/* force the surface to apepar on the remote side */
+		weston_compositor_damage_all(ivi->compositor);
 		return;
 	}
 
@@ -395,7 +443,7 @@ ivi_layout_activate_complete(struct ivi_output *output,
 		 * we're trying to complete activation with means we're
 		 * operating on the same app_id so do update previous_active as
 		 * it will overwrite it with the same value */
-		if (app_id && !strcmp(c_app_id, app_id)) {
+		if (c_app_id && app_id && !strcmp(c_app_id, app_id)) {
 			update_previous = false;
 		}
 	}