From 5fa7457171479ce9ec7913d2d50c68685e47aea3 Mon Sep 17 00:00:00 2001
From: Matthias Clasen <mclasen@redhat.com>
Date: Fri, 27 Oct 2023 21:46:40 -0400
Subject: [PATCH] gdk: Add private subsurface api

Add api to allow creating subsurfaces, and attaching textures
to them. This is just the api, there is no implementation yet.
---
 gdk/gdksurface.c        | 44 +++++++++++++++++++++++++++++++++++++++++
 gdk/gdksurfaceprivate.h | 35 ++++++++++++++++++++++++++++++++
 2 files changed, 79 insertions(+)

diff --git a/gdk/gdksurface.c b/gdk/gdksurface.c
index 89938bffb6..296c91e562 100644
--- a/gdk/gdksurface.c
+++ b/gdk/gdksurface.c
@@ -493,6 +493,12 @@ gdk_surface_real_get_scale (GdkSurface *surface)
   return 1.0;
 }
 
+static GdkSubsurface *
+gdk_surface_real_create_subsurface (GdkSurface *surface)
+{
+  return NULL;
+}
+
 static void
 gdk_surface_constructed (GObject *object)
 {
@@ -515,6 +521,7 @@ gdk_surface_class_init (GdkSurfaceClass *klass)
 
   klass->beep = gdk_surface_real_beep;
   klass->get_scale = gdk_surface_real_get_scale;
+  klass->create_subsurface = gdk_surface_real_create_subsurface;
 
   /**
    * GdkSurface:cursor: (attributes org.gtk.Property.get=gdk_surface_get_cursor org.gtk.Property.set=gdk_surface_set_cursor)
@@ -3054,3 +3061,40 @@ gdk_surface_leave_monitor (GdkSurface *surface,
 {
   g_signal_emit (surface, signals[LEAVE_MONITOR], 0, monitor);
 }
+
+GdkSubsurface *
+gdk_surface_create_subsurface (GdkSurface *surface)
+{
+  return GDK_SURFACE_GET_CLASS (surface)->create_subsurface (surface);
+}
+
+void
+gdk_subsurface_destroy (GdkSubsurface *subsurface)
+{
+  subsurface->class->destroy (subsurface);
+}
+
+void
+gdk_subsurface_attach (GdkSubsurface         *subsurface,
+                       GdkTexture            *texture,
+                       const graphene_rect_t *bounds)
+{
+  subsurface->class->attach (subsurface, texture, bounds);
+}
+
+/* If sibling is NULL, place the subsurface above its parent */
+void
+gdk_subsurface_place_above (GdkSubsurface *subsurface,
+                            GdkSubsurface *sibling)
+{
+  subsurface->class->place_above (subsurface, sibling);
+}
+
+/* If sibling is NULL, place the subsurface below its parent */
+void
+gdk_subsurface_place_below (GdkSubsurface *subsurface,
+                            GdkSubsurface *sibling)
+{
+  subsurface->class->place_below (subsurface, sibling);
+}
+
diff --git a/gdk/gdksurfaceprivate.h b/gdk/gdksurfaceprivate.h
index 1bf930822f..368a42a877 100644
--- a/gdk/gdksurfaceprivate.h
+++ b/gdk/gdksurfaceprivate.h
@@ -23,9 +23,14 @@
 #include "gdkenumtypes.h"
 #include "gdksurface.h"
 #include "gdktoplevel.h"
+#include <graphene.h>
 
 G_BEGIN_DECLS
 
+typedef struct _GdkSubsurface GdkSubsurface;
+
+typedef struct _GskRenderNode GskRenderNode;
+
 struct _GdkSurface
 {
   GObject parent_instance;
@@ -146,6 +151,9 @@ struct _GdkSurfaceClass
                                            cairo_region_t *region);
   void         (* request_layout)         (GdkSurface     *surface);
   gboolean     (* compute_size)           (GdkSurface     *surface);
+
+  GdkSubsurface *
+               (* create_subsurface)      (GdkSurface          *surface);
 };
 
 #define GDK_SURFACE_DESTROYED(d) (((GdkSurface *)(d))->destroyed)
@@ -334,7 +342,34 @@ void           gdk_surface_request_motion (GdkSurface *surface);
 
 gboolean       gdk_surface_supports_edge_constraints    (GdkSurface *surface);
 
+GdkSubsurface * gdk_surface_create_subsurface  (GdkSurface          *surface);
 
+typedef struct _GdkSubsurfaceClass GdkSubsurfaceClass;
+struct _GdkSubsurfaceClass
+{
+  void            (* destroy)     (GdkSubsurface         *subsurface);
+  void            (* attach)      (GdkSubsurface         *subsurface,
+                                   GdkTexture            *texture,
+                                   const graphene_rect_t *bounds);
+  void            (* place_above) (GdkSubsurface         *subsurface,
+                                   GdkSubsurface         *sibling);
+  void            (* place_below) (GdkSubsurface         *subsurface,
+                                   GdkSubsurface         *sibling);
+};
+
+struct _GdkSubsurface
+{
+  const GdkSubsurfaceClass *class;
+};
+
+void            gdk_subsurface_destroy     (GdkSubsurface         *subsurface);
+void            gdk_subsurface_attach      (GdkSubsurface         *subsurface,
+                                            GdkTexture            *texture,
+                                            const graphene_rect_t *bounds);
+void            gdk_subsurface_place_above (GdkSubsurface         *subsurface,
+                                            GdkSubsurface         *sibling);
+void            gdk_subsurface_place_below (GdkSubsurface         *subsurface,
+                                            GdkSubsurface         *sibling);
 
 G_END_DECLS