From 7e9ad9a67b7f66487a61f9ac97e8d5c4b88f74f4 Mon Sep 17 00:00:00 2001
From: Simon Ser <contact@emersion.fr>
Date: Wed, 6 May 2020 16:16:45 +0200
Subject: [PATCH] scene: add wlr_scene_node_toggle

This allows compositors to easily enable or disable a scene-graph node.
This can be used to show/hide a surface when the xdg_surface is
mapped/unmapped.
---
 include/wlr/types/wlr_scene.h |  7 +++++++
 types/wlr_scene.c             | 10 ++++++++++
 2 files changed, 17 insertions(+)

diff --git a/include/wlr/types/wlr_scene.h b/include/wlr/types/wlr_scene.h
index 300807fa7..549817b95 100644
--- a/include/wlr/types/wlr_scene.h
+++ b/include/wlr/types/wlr_scene.h
@@ -32,6 +32,7 @@ struct wlr_scene_node_state {
 
 	struct wl_list children; // wlr_scene_node_state.link
 
+	bool enabled;
 	int x, y;
 };
 
@@ -66,6 +67,12 @@ void wlr_scene_node_destroy(struct wlr_scene_node *node);
  * Atomically apply pending changes for this node and all of its children.
  */
 void wlr_scene_node_commit(struct wlr_scene_node *node);
+/**
+ * Enable or disable this node. If a node is disabled, all of its children are
+ * implicitly disabled as well. This state is double-buffered, see
+ * wlr_scene_node_commit.
+ */
+void wlr_scene_node_toggle(struct wlr_scene_node *node, bool enabled);
 /**
  * Set the position of the node relative to its parent. This state is
  * double-buffered, see wlr_scene_node_commit.
diff --git a/types/wlr_scene.c b/types/wlr_scene.c
index 626edf52d..eb4fa7335 100644
--- a/types/wlr_scene.c
+++ b/types/wlr_scene.c
@@ -21,6 +21,7 @@ static struct wlr_scene_surface *scene_node_get_surface(
 static void scene_node_state_init(struct wlr_scene_node_state *state) {
 	wl_list_init(&state->children);
 	wl_list_init(&state->link);
+	state->enabled = true;
 }
 
 static void scene_node_state_finish(struct wlr_scene_node_state *state) {
@@ -118,6 +119,7 @@ struct wlr_scene_surface *wlr_scene_surface_create(struct wlr_scene_node *parent
 
 static void scene_node_state_move(struct wlr_scene_node_state *dst,
 		const struct wlr_scene_node_state *src) {
+	dst->enabled = src->enabled;
 	dst->x = src->x;
 	dst->y = src->y;
 }
@@ -136,6 +138,10 @@ void wlr_scene_node_commit(struct wlr_scene_node *node) {
 	}
 }
 
+void wlr_scene_node_toggle(struct wlr_scene_node *node, bool enabled) {
+	node->pending.enabled = enabled;
+}
+
 void wlr_scene_node_move(struct wlr_scene_node *node, int x, int y) {
 	node->pending.x = x;
 	node->pending.y = y;
@@ -172,6 +178,10 @@ static void surface_iterator(struct wlr_surface *surface,
 static void scene_node_for_each_surface(struct wlr_scene_node *node,
 		int lx, int ly, wlr_surface_iterator_func_t user_iterator,
 		void *user_data) {
+	if (!node->current.enabled) {
+		return;
+	}
+
 	lx += node->current.x;
 	ly += node->current.y;