gtk: Allocate everything from GtkNativeClass::layout

This changes allocation of the widget trees to happen as a side effect
to the GdkSurface::layout signal, which first passes the GtkNative
instance where it is then forwarded to the implementations of the
GtkNative interface.

The implementations of GtkNative are the ones doing the actual
gtk_widget_allocate(), and they do so in their GtkNativeClass::layout
function.

1 files changed, 121 insertions, 0 deletions

diff --git a/gtk/gtknative.c b/gtk/gtknative.c
index 328d0c61fd..45ad317cbf 100644
--- a/gtk/gtknative.c
+++ b/gtk/gtknative.c
@@ -24,6 +24,15 @@
 #include "gdk/gdk-private.h"
 #include "gtkprivate.h"
 #include "gtkintl.h"
+#include "gtkcssnodeprivate.h"
+
+typedef struct _GtkNativePrivate
+{
+  gulong update_handler_id;
+  gulong layout_handler_id;
+} GtkNativePrivate;
+
+static GQuark quark_gtk_native_private;
 
 /**
  * SECTION:gtknative
@@ -60,11 +69,107 @@ gtk_native_default_check_resize (GtkNative *self)
 }
 
 static void
+gtk_native_default_layout (GtkNative *self,
+                           int        width,
+                           int        height)
+{
+}
+
+static void
 gtk_native_default_init (GtkNativeInterface *iface)
 {
   iface->get_renderer = gtk_native_default_get_renderer;
   iface->get_surface_transform = gtk_native_default_get_surface_transform;
   iface->check_resize = gtk_native_default_check_resize;
+  iface->layout = gtk_native_default_layout;
+
+  quark_gtk_native_private = g_quark_from_static_string ("gtk-native-private");
+}
+
+static void
+frame_clock_update_cb (GdkFrameClock *clock,
+                       GtkNative     *native)
+{
+  if (GTK_IS_ROOT (native))
+    gtk_css_node_validate (gtk_widget_get_css_node (GTK_WIDGET (native)));
+}
+
+static void
+gtk_native_layout (GtkNative *self,
+                   int        width,
+                   int        height)
+{
+  return GTK_NATIVE_GET_IFACE (self)->layout (self, width, height);
+}
+
+static void
+surface_layout_cb (GdkSurface *surface,
+                   int         width,
+                   int         height,
+                   GtkNative  *native)
+{
+  gtk_native_layout (native, width, height);
+
+  if (gtk_widget_needs_allocate (GTK_WIDGET (native)))
+    gtk_native_queue_relayout (native);
+}
+
+static void
+verify_priv_unrealized (gpointer user_data)
+{
+  GtkNativePrivate *priv = user_data;
+
+  g_warn_if_fail (priv->update_handler_id == 0);
+  g_warn_if_fail (priv->layout_handler_id == 0);
+
+  g_free (priv);
+}
+
+void
+gtk_native_realize (GtkNative *self)
+{
+  GdkSurface *surface;
+  GdkFrameClock *clock;
+  GtkNativePrivate *priv;
+
+  g_return_if_fail (g_object_get_qdata (G_OBJECT (self),
+                                        quark_gtk_native_private) == NULL);
+
+  surface = gtk_native_get_surface (self);
+  clock = gdk_surface_get_frame_clock (surface);
+  g_return_if_fail (clock != NULL);
+
+  priv = g_new0 (GtkNativePrivate, 1);
+  priv->update_handler_id = g_signal_connect_after (clock, "update",
+                                              G_CALLBACK (frame_clock_update_cb),
+                                              self);
+  priv->layout_handler_id = g_signal_connect (surface, "layout",
+                                              G_CALLBACK (surface_layout_cb),
+                                              self);
+  g_object_set_qdata_full (G_OBJECT (self),
+                           quark_gtk_native_private,
+                           priv,
+                           verify_priv_unrealized);
+}
+
+void
+gtk_native_unrealize (GtkNative *self)
+{
+  GtkNativePrivate *priv;
+  GdkSurface *surface;
+  GdkFrameClock *clock;
+
+  priv = g_object_get_qdata (G_OBJECT (self), quark_gtk_native_private);
+  g_return_if_fail (priv != NULL);
+
+  surface = gtk_native_get_surface (self);
+  clock = gdk_surface_get_frame_clock (surface);
+  g_return_if_fail (clock != NULL);
+
+  g_clear_signal_handler (&priv->update_handler_id, clock);
+  g_clear_signal_handler (&priv->layout_handler_id, surface);
+
+  g_object_set_qdata (G_OBJECT (self), quark_gtk_native_private, NULL);
 }
 
 /**
@@ -157,3 +262,19 @@ gtk_native_get_for_surface (GdkSurface *surface)
 
   return NULL;
 }
+
+void
+gtk_native_queue_relayout (GtkNative *self)
+{
+  GtkWidget *widget = GTK_WIDGET (self);
+  GdkSurface *surface;
+  GdkFrameClock *clock;
+
+  surface = gtk_widget_get_surface (widget);
+  clock = gtk_widget_get_frame_clock (widget);
+  if (clock == NULL)
+    return;
+
+  gdk_frame_clock_request_phase (clock, GDK_FRAME_CLOCK_PHASE_UPDATE);
+  gdk_surface_request_layout (surface);
+}