desktop-shell: Enable per-output fade animations

Instead of creating a single global fade surface across all outputs,
create a separate surface for each output.  This will permit
e.g. individual fades for each output (or blocking the fade-outs if
inhibiting idling as will come in a latter patch.)

This also fixes a potential issue if on multihead layout spanning a
desktop wider than 8096 (or higher than 8096), the fade animation may
not completely cover all surfaces.

This assumes the output geometry doesn't change larger during the course
of the fade animation.

Signed-off-by: Bryce Harrington <bryce@osg.samsung.com>

v5:
  + Use the new libweston-desktop API for dropping idle inhibitor to
  	ensure fade_out gets triggered if the client destroys the inhibitor
  	early.
  + Fix a crash when running multi-head due to double free of animations
  + Split idle inhibition implementation to a subsequent patch

desktop-shell/shell.c

@@ -194,6 +194,9 @@ surface_rotate(struct shell_surface *surface, struct weston_pointer *pointer);
 static void
 shell_fade_startup(struct desktop_shell *shell);
 
+static void
+shell_fade(struct desktop_shell *shell, enum fade_type type);
+
 static struct shell_seat *
 get_shell_seat(struct weston_seat *seat);
 
@@ -2784,9 +2787,6 @@ static const struct weston_desktop_api shell_desktop_api = {
 /* ************************ *
  * end of libweston-desktop *
  * ************************ */
-static void
-shell_fade(struct desktop_shell *shell, enum fade_type type);
-
 static void
 configure_static_view(struct weston_view *ev, struct weston_layer *layer)
 {
@@ -3770,16 +3770,16 @@ unlock(struct desktop_shell *shell)
 }
 
 static void
-shell_fade_done(struct weston_view_animation *animation, void *data)
+shell_fade_done_for_output(struct weston_view_animation *animation, void *data)
 {
-	struct desktop_shell *shell = data;
+	struct shell_output *shell_output = data;
+	struct desktop_shell *shell = shell_output->shell;
 
-	shell->fade.animation = NULL;
+	shell_output->fade.animation = NULL;
-
+	switch (shell_output->fade.type) {
-	switch (shell->fade.type) {
 	case FADE_IN:
-		weston_surface_destroy(shell->fade.view->surface);
+		weston_surface_destroy(shell_output->fade.view->surface);
-		shell->fade.view = NULL;
+		shell_output->fade.view = NULL;
 		break;
 	case FADE_OUT:
 		lock(shell);
@@ -3790,7 +3790,7 @@ shell_fade_done(struct weston_view_animation *animation, void *data)
 }
 
 static struct weston_view *
-shell_fade_create_surface(struct desktop_shell *shell)
+shell_fade_create_surface_for_output(struct desktop_shell *shell, struct shell_output *shell_output)
 {
 	struct weston_compositor *compositor = shell->compositor;
 	struct weston_surface *surface;
@@ -3806,8 +3806,8 @@ shell_fade_create_surface(struct desktop_shell *shell)
 		return NULL;
 	}
 
-	weston_surface_set_size(surface, 8192, 8192);
+	weston_surface_set_size(surface, shell_output->output->width, shell_output->output->height);
-	weston_view_set_position(view, 0, 0);
+	weston_view_set_position(view, shell_output->output->x, shell_output->output->y);
 	weston_surface_set_color(surface, 0.0, 0.0, 0.0, 1.0);
 	weston_layer_entry_insert(&compositor->fade_layer.view_list,
 				  &view->layer_link);
@@ -3822,6 +3822,7 @@ static void
 shell_fade(struct desktop_shell *shell, enum fade_type type)
 {
 	float tint;
+	struct shell_output *shell_output;
 
 	switch (type) {
 	case FADE_IN:
@@ -3831,36 +3832,38 @@ shell_fade(struct desktop_shell *shell, enum fade_type type)
 		tint = 1.0;
 		break;
 	default:
-		weston_log("shell: invalid fade type\n");
 		return;
 	}
 
-	shell->fade.type = type;
+	/* Create a separate fade surface for each output */
+	wl_list_for_each(shell_output, &shell->output_list, link) {
+		shell_output->fade.type = type;
 
-	if (shell->fade.view == NULL) {
+		if (shell_output->fade.view == NULL) {
-		shell->fade.view = shell_fade_create_surface(shell);
+			shell_output->fade.view = shell_fade_create_surface_for_output(shell, shell_output);
-		if (!shell->fade.view)
+			if (!shell_output->fade.view)
-			return;
+				return;
 
-		shell->fade.view->alpha = 1.0 - tint;
+			shell_output->fade.view->alpha = 1.0 - tint;
-		weston_view_update_transform(shell->fade.view);
+			weston_view_update_transform(shell_output->fade.view);
-	}
+		}
 
-	if (shell->fade.view->output == NULL) {
+		if (shell_output->fade.view->output == NULL) {
-		/* If the black view gets a NULL output, we lost the
+			/* If the black view gets a NULL output, we lost the
-		 * last output and we'll just cancel the fade.  This
+			 * last output and we'll just cancel the fade.  This
-		 * happens when you close the last window under the
+			 * happens when you close the last window under the
-		 * X11 or Wayland backends. */
+			 * X11 or Wayland backends. */
-		shell->locked = false;
+			shell->locked = false;
-		weston_surface_destroy(shell->fade.view->surface);
+			weston_surface_destroy(shell_output->fade.view->surface);
-		shell->fade.view = NULL;
+			shell_output->fade.view = NULL;
-	} else if (shell->fade.animation) {
+		} else if (shell_output->fade.animation) {
-		weston_fade_update(shell->fade.animation, tint);
+			weston_fade_update(shell_output->fade.animation, tint);
-	} else {
+		} else {
-		shell->fade.animation =
+			shell_output->fade.animation =
-			weston_fade_run(shell->fade.view,
+				weston_fade_run(shell_output->fade.view,
-					1.0 - tint, tint, 300.0,
+						1.0 - tint, tint, 300.0,
-					shell_fade_done, shell);
+						shell_fade_done_for_output, shell_output);
+		}
 	}
 }
 
@@ -3868,6 +3871,7 @@ static void
 do_shell_fade_startup(void *data)
 {
 	struct desktop_shell *shell = data;
+	struct shell_output *shell_output;
 
 	if (shell->startup_animation_type == ANIMATION_FADE) {
 		shell_fade(shell, FADE_IN);
@@ -3875,8 +3879,10 @@ do_shell_fade_startup(void *data)
 		weston_log("desktop shell: "
 			   "unexpected fade-in animation type %d\n",
 			   shell->startup_animation_type);
-		weston_surface_destroy(shell->fade.view->surface);
+		wl_list_for_each(shell_output, &shell->output_list, link) {
-		shell->fade.view = NULL;
+			weston_surface_destroy(shell_output->fade.view->surface);
+			shell_output->fade.view = NULL;
+		}
 	}
 }
 
@@ -3884,15 +3890,22 @@ static void
 shell_fade_startup(struct desktop_shell *shell)
 {
 	struct wl_event_loop *loop;
+	struct shell_output *shell_output;
+	bool has_fade = false;
 
-	if (!shell->fade.startup_timer)
+	wl_list_for_each(shell_output, &shell->output_list, link) {
-		return;
+		if (!shell_output->fade.startup_timer)
+			continue;
 
-	wl_event_source_remove(shell->fade.startup_timer);
+		wl_event_source_remove(shell_output->fade.startup_timer);
-	shell->fade.startup_timer = NULL;
+		shell_output->fade.startup_timer = NULL;
+		has_fade = true;
+	}
 
-	loop = wl_display_get_event_loop(shell->compositor->wl_display);
+	if (has_fade) {
-	wl_event_loop_add_idle(loop, do_shell_fade_startup, shell);
+		loop = wl_display_get_event_loop(shell->compositor->wl_display);
+		wl_event_loop_add_idle(loop, do_shell_fade_startup, shell);
+	}
 }
 
 static int
@@ -3913,27 +3926,30 @@ shell_fade_init(struct desktop_shell *shell)
 	 */
 
 	struct wl_event_loop *loop;
-
+	struct shell_output *shell_output;
-	if (shell->fade.view != NULL) {
-		weston_log("%s: warning: fade surface already exists\n",
-			   __func__);
-		return;
-	}
 
 	if (shell->startup_animation_type == ANIMATION_NONE)
 		return;
 
-	shell->fade.view = shell_fade_create_surface(shell);
+	wl_list_for_each(shell_output, &shell->output_list, link) {
-	if (!shell->fade.view)
+		if (shell_output->fade.view != NULL) {
-		return;
+			weston_log("%s: warning: fade surface already exists\n",
+				   __func__);
+			continue;
+		}
+
+		shell_output->fade.view = shell_fade_create_surface_for_output(shell, shell_output);
+		if (!shell_output->fade.view)
+			return;
 
-	weston_view_update_transform(shell->fade.view);
+		weston_view_update_transform(shell_output->fade.view);
-	weston_surface_damage(shell->fade.view->surface);
+		weston_surface_damage(shell_output->fade.view->surface);
 
-	loop = wl_display_get_event_loop(shell->compositor->wl_display);
+		loop = wl_display_get_event_loop(shell->compositor->wl_display);
-	shell->fade.startup_timer =
+		shell_output->fade.startup_timer =
-		wl_event_loop_add_timer(loop, fade_startup_timeout, shell);
+			wl_event_loop_add_timer(loop, fade_startup_timeout, shell);
-	wl_event_source_timer_update(shell->fade.startup_timer, 15000);
+		wl_event_source_timer_update(shell_output->fade.startup_timer, 15000);
+	}
 }
 
 static void
@@ -3948,7 +3964,7 @@ idle_handler(struct wl_listener *listener, void *data)
 		weston_seat_break_desktop_grabs(seat);
 
 	shell_fade(shell, FADE_OUT);
-	/* lock() is called from shell_fade_done() */
+	/* lock() is called from shell_fade_done_for_output() */
 }
 
 static void

desktop-shell/shell.h

@@ -122,6 +122,13 @@ struct shell_output {
 
 	struct weston_surface *background_surface;
 	struct wl_listener background_surface_listener;
+
+	struct {
+		struct weston_view *view;
+		struct weston_view_animation *animation;
+		enum fade_type type;
+		struct wl_event_source *startup_timer;
+	} fade;
 };
 
 struct weston_desktop;
@@ -192,13 +199,6 @@ struct desktop_shell {
 		struct wl_list surfaces;
 	} input_panel;
 
-	struct {
-		struct weston_view *view;
-		struct weston_view_animation *animation;
-		enum fade_type type;
-		struct wl_event_source *startup_timer;
-	} fade;
-
 	struct exposay exposay;
 
 	bool allow_zap;