Introduce GdkToplevel

This is a new interface for toplevel surfaces.

gdk/gdk.h

@@ -69,6 +69,7 @@
 #include <gdk/gdkvulkancontext.h>
 #include <gdk/gdksurface.h>
 #include <gdk/gdkpopup.h>
+#include <gdk/gdktoplevel.h>
 
 #include <gdk/gdk-autocleanup.h>
 

gdk/gdktoplevel.c

@@ -0,0 +1,80 @@
+/*
+ * Copyright © 2020 Red Hat, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors: Matthias Clasen <mclasen@redhat.com>
+ */
+
+#include "config.h"
+
+#include "gdktoplevelprivate.h"
+
+/**
+ * SECTION:gdktoplevel
+ * @Short_description: Interface for toplevel surfaces
+ * @Title: Toplevels
+ *
+ * A #GdkToplevel is a freestanding toplevel surface.
+ */
+
+
+/* FIXME: this can't have GdkSurface as a prerequisite
+ * as long as GdkSurface implements this interface itself
+ */
+G_DEFINE_INTERFACE (GdkToplevel, gdk_toplevel, G_TYPE_OBJECT)
+
+static gboolean
+gdk_toplevel_default_present (GdkToplevel       *toplevel,
+                              int                width,
+                              int                height,
+                              GdkToplevelLayout *layout)
+{
+  return FALSE;
+}
+
+static void
+gdk_toplevel_default_init (GdkToplevelInterface *iface)
+{
+  iface->present = gdk_toplevel_default_present;
+}
+
+/**
+ * gdk_toplevel_present:
+ * @toplevel: the #GdkToplevel to show
+ * @width: the unconstrained toplevel width to layout
+ * @height: the unconstrained toplevel height to layout
+ * @layout: the #GdkToplevelLayout object used to layout
+ *
+ * Present @toplevel after having processed the #GdkToplevelLayout rules.
+ * If the toplevel was previously now showing, it will be showed,
+ * otherwise it will change layout according to @layout.
+ *
+ * Presenting may fail.
+ *
+ * Returns: %FALSE if @toplevel failed to be presented, otherwise %TRUE.
+ */
+gboolean
+gdk_toplevel_present (GdkToplevel       *toplevel,
+                      int                width,
+                      int                height,
+                      GdkToplevelLayout *layout)
+{
+  g_return_val_if_fail (GDK_IS_TOPLEVEL (toplevel), FALSE);
+  g_return_val_if_fail (width > 0, FALSE);
+  g_return_val_if_fail (height > 0, FALSE);
+  g_return_val_if_fail (layout != NULL, FALSE);
+
+  return GDK_TOPLEVEL_GET_IFACE (toplevel)->present (toplevel, width, height, layout);
+}

gdk/gdktoplevel.h

@@ -0,0 +1,45 @@
+/*
+ * Copyright © 2020 Red Hat, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors: Matthias Clasen <mclasen@redhat.com>
+ */
+
+#ifndef __GDK_TOPLEVEL_H__
+#define __GDK_TOPLEVEL_H__
+
+#if !defined (__GDK_H_INSIDE__) && !defined (GTK_COMPILATION)
+#error "Only <gdk/gdk.h> can be included directly."
+#endif
+
+#include <gdk/gdksurface.h>
+#include <gdk/gdktoplevellayout.h>
+
+G_BEGIN_DECLS
+
+#define GDK_TYPE_TOPLEVEL               (gdk_toplevel_get_type ())
+
+GDK_AVAILABLE_IN_ALL
+G_DECLARE_INTERFACE (GdkToplevel, gdk_toplevel, GDK, TOPLEVEL, GObject)
+
+GDK_AVAILABLE_IN_ALL
+gboolean        gdk_toplevel_present            (GdkToplevel       *toplevel,
+                                                 int                width,
+                                                 int                height,
+                                                 GdkToplevelLayout *layout);
+
+G_END_DECLS
+
+#endif /* __GDK_TOPLEVEL_H__ */

gdk/gdktoplevelprivate.h

@@ -0,0 +1,21 @@
+#ifndef __GDK_TOPLEVEL_PRIVATE_H__
+#define __GDK_TOPLEVEL_PRIVATE_H__
+
+#include "gdktoplevel.h"
+
+G_BEGIN_DECLS
+
+
+struct _GdkToplevelInterface
+{
+  GTypeInterface g_iface;
+
+  gboolean      (* present)             (GdkToplevel       *toplevel,
+                                         int                width,
+                                         int                height,
+                                         GdkToplevelLayout *layout);
+};
+
+G_END_DECLS
+
+#endif /* __GDK_TOPLEVEL_PRIVATE_H__ */

gdk/meson.build

@@ -47,6 +47,7 @@ gdk_public_sources = files([
   'gdkprofiler.c',
   'gdkpopup.c',
   'gdktoplevellayout.c',
+  'gdktoplevel.c',
 ])
 
 gdk_public_headers = files([
@@ -93,6 +94,7 @@ gdk_public_headers = files([
   'gdkpopuplayout.h',
   'gdkpopup.h',
   'gdktoplevellayout.h',
+  'gdktoplevel.h',
 ])
 install_headers(gdk_public_headers, subdir: 'gtk-4.0/gdk/')