dnd: Add GdkDrop base class for GdkDragContext

The ultimate goal of this patch series is to split GdkDragContext into
GdkDrop + GdkDrag classes for the destination and source side of a dnd
operation.

The refactoring is meant to work something like this:
1. Introduce GdkDrop as a base class
2. Make all drop related code (like GdkEvent) use GdkDrop instead of
   GdkDragContext. Move/duplicate APIs to allow that.
3. Port all drop contexts in the backends from GdkDragContext to GdkDrop
4. Delete all APIs in GdkDragContext that aren't needed anymore.
5. Make GdkDragContext no longer a GdkDrop subclass
6. Rename GdkDragContext to GdkDrag

1 files changed, 29 insertions, 1 deletions

diff --git a/gdk/gdkdnd.c b/gdk/gdkdnd.c
index 191ef7eb75..083adf9a5a 100644
--- a/gdk/gdkdnd.c
+++ b/gdk/gdkdnd.c
@@ -35,12 +35,16 @@
 #include "gdkenumtypes.h"
 #include "gdkeventsprivate.h"
 
+#define DROP_SUBCLASS 1
+
 typedef struct _GdkDragContextPrivate GdkDragContextPrivate;
 
 struct _GdkDragContextPrivate 
 {
+#ifndef DROP_SUBCLASS
   GdkDisplay *display;
   GdkDevice *device;
+#endif
   GdkContentFormats *formats;
 };
 
@@ -60,9 +64,11 @@ static struct {
 enum {
   PROP_0,
   PROP_CONTENT,
+#ifndef DROP_SUBCLASS
   PROP_DEVICE,
   PROP_DISPLAY,
   PROP_FORMATS,
+#endif
   N_PROPERTIES
 };
 
@@ -78,7 +84,7 @@ static GParamSpec *properties[N_PROPERTIES] = { NULL, };
 static guint signals[N_SIGNALS] = { 0 };
 static GList *contexts = NULL;
 
-G_DEFINE_TYPE_WITH_PRIVATE (GdkDragContext, gdk_drag_context, G_TYPE_OBJECT)
+G_DEFINE_TYPE_WITH_PRIVATE (GdkDragContext, gdk_drag_context, GDK_TYPE_DROP)
 
 /**
  * SECTION:dnd
@@ -114,11 +120,15 @@ G_DEFINE_TYPE_WITH_PRIVATE (GdkDragContext, gdk_drag_context, G_TYPE_OBJECT)
 GdkDisplay *
 gdk_drag_context_get_display (GdkDragContext *context)
 {
+#ifdef DROP_SUBCLASS
+  return gdk_drop_get_display (GDK_DROP (context));
+#else
   GdkDragContextPrivate *priv = gdk_drag_context_get_instance_private (context);
 
   g_return_val_if_fail (GDK_IS_DRAG_CONTEXT (context), NULL);
 
   return priv->display;
+#endif
 }
 
 /**
@@ -136,6 +146,12 @@ gdk_drag_context_get_formats (GdkDragContext *context)
 
   g_return_val_if_fail (GDK_IS_DRAG_CONTEXT (context), NULL);
 
+#ifdef DROP_SUBCLASS
+  GdkContentFormats *formats = gdk_drop_get_formats (GDK_DROP (context));
+
+  if (formats)
+    return formats;
+#endif
   return priv->formats;
 }
 
@@ -231,11 +247,15 @@ gdk_drag_context_get_dest_surface (GdkDragContext *context)
 GdkDevice *
 gdk_drag_context_get_device (GdkDragContext *context)
 {
+#ifdef DROP_SUBCLASS
+  return gdk_drop_get_device (GDK_DROP (context));
+#else
   GdkDragContextPrivate *priv = gdk_drag_context_get_instance_private (context);
 
   g_return_val_if_fail (GDK_IS_DRAG_CONTEXT (context), NULL);
 
   return priv->device;
+#endif
 }
 
 static void
@@ -264,6 +284,7 @@ gdk_drag_context_set_property (GObject      *gobject,
         }
       break;
 
+#ifndef DROP_SUBCLASS
     case PROP_DEVICE:
       priv->device = g_value_dup_object (value);
       g_assert (priv->device != NULL);
@@ -286,6 +307,7 @@ gdk_drag_context_set_property (GObject      *gobject,
           g_assert (priv->formats != NULL);
         }
       break;
+#endif
 
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
@@ -300,7 +322,9 @@ gdk_drag_context_get_property (GObject    *gobject,
                                GParamSpec *pspec)
 {
   GdkDragContext *context = GDK_DRAG_CONTEXT (gobject);
+#ifndef DROP_SUBCLASS
   GdkDragContextPrivate *priv = gdk_drag_context_get_instance_private (context);
+#endif
 
   switch (prop_id)
     {
@@ -308,6 +332,7 @@ gdk_drag_context_get_property (GObject    *gobject,
       g_value_set_object (value, context->content);
       break;
 
+#ifndef DROP_SUBCLASS
     case PROP_DEVICE:
       g_value_set_object (value, priv->device);
       break;
@@ -319,6 +344,7 @@ gdk_drag_context_get_property (GObject    *gobject,
     case PROP_FORMATS:
       g_value_set_boxed (value, priv->formats);
       break;
+#endif
 
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
@@ -405,6 +431,7 @@ gdk_drag_context_class_init (GdkDragContextClass *klass)
                          G_PARAM_STATIC_STRINGS |
                          G_PARAM_EXPLICIT_NOTIFY);
 
+#ifndef DROP_SUBCLASS
   /**
    * GdkDragContext:device:
    *
@@ -448,6 +475,7 @@ gdk_drag_context_class_init (GdkDragContextClass *klass)
                         G_PARAM_CONSTRUCT_ONLY |
                         G_PARAM_STATIC_STRINGS |
                         G_PARAM_EXPLICIT_NOTIFY);
+#endif
 
   /**
    * GdkDragContext::cancel: