[glibmm] Add the Gio::FileDescriptorBased interface

[Kjell Ahlstedt <kjellahl src gnome org>]

commit 4c3f450bb5fd7579a9909bf3be3c1b362850f555
Author: Kjell Ahlstedt <kjellahlstedt gmail com>
Date:   Fri Jun 23 09:25:02 2017 +0200

    Add the Gio::FileDescriptorBased interface
    
    GUnixInputStream and GUnixOutputStream implement GFileDescriptorBased.

 gio/giomm.h                     |    3 ++
 gio/src/filedescriptorbased.ccg |   18 ++++++++++++++
 gio/src/filedescriptorbased.hg  |   50 +++++++++++++++++++++++++++++++++++++++
 gio/src/filelist.am             |    1 +
 gio/src/gio_vfuncs.defs         |    7 +++++
 5 files changed, 79 insertions(+), 0 deletions(-)
---
diff --git a/gio/giomm.h b/gio/giomm.h
index 8d5376b..3b79ed1 100644
--- a/gio/giomm.h
+++ b/gio/giomm.h
@@ -72,6 +72,9 @@
 #include <giomm/file.h>
 #include <giomm/fileattributeinfo.h>
 #include <giomm/fileattributeinfolist.h>
+#ifndef G_OS_WIN32
+#include <giomm/filedescriptorbased.h>
+#endif
 #include <giomm/fileenumerator.h>
 #include <giomm/fileicon.h>
 #include <giomm/fileinfo.h>
diff --git a/gio/src/filedescriptorbased.ccg b/gio/src/filedescriptorbased.ccg
new file mode 100644
index 0000000..84882c1
--- /dev/null
+++ b/gio/src/filedescriptorbased.ccg
@@ -0,0 +1,18 @@
+/* Copyright (C) 2017 The giomm Development Team
+ *
+ * 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/>.
+ */
+
+#include <gio/gio.h>
+#include <gio/gfiledescriptorbased.h>
diff --git a/gio/src/filedescriptorbased.hg b/gio/src/filedescriptorbased.hg
new file mode 100644
index 0000000..9d8308e
--- /dev/null
+++ b/gio/src/filedescriptorbased.hg
@@ -0,0 +1,50 @@
+/* Copyright (C) 2017 The giomm Development Team
+ *
+ * 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/>.
+ */
+
+#include <glibmm/interface.h>
+
+_DEFS(giomm,gio)
+_PINCLUDE(glibmm/private/interface_p.h)
+
+#ifndef DOXYGEN_SHOULD_SKIP_THIS
+typedef struct _GFileDescriptorBasedIface GFileDescriptorBasedIface;
+#endif /* DOXYGEN_SHOULD_SKIP_THIS */
+
+namespace Gio
+{
+
+/** Interface for file descriptor based IO.
+ *
+ * %FileDescriptorBased is implemented by streams (implementations of
+ * Gio::InputStream or Gio::OutputStream) that are based on file descriptors.
+ *
+ * @ingroup Streams
+ *
+ * @newin{2,54}
+ */
+class FileDescriptorBased : public Glib::Interface
+{
+  _CLASS_INTERFACE(FileDescriptorBased, GFileDescriptorBased, G_FILE_DESCRIPTOR_BASED, 
GFileDescriptorBasedIface)
+  _GTKMMPROC_WIN32_NO_WRAP
+
+public:
+  _WRAP_METHOD(int get_fd() const, g_file_descriptor_based_get_fd, newin "2,54")
+
+protected:
+  _WRAP_VFUNC(int get_fd() const, "get_fd")
+};
+
+} // namespace Gio
diff --git a/gio/src/filelist.am b/gio/src/filelist.am
index 7342df8..11515fa 100644
--- a/gio/src/filelist.am
+++ b/gio/src/filelist.am
@@ -137,6 +137,7 @@ giomm_files_any_hg =                        \
        zlibcompressor.hg
 
 giomm_files_posix_hg =                 \
+       filedescriptorbased.hg \
        unixconnection.hg               \
        unixcredentialsmessage.hg       \
        unixfdlist.hg                   \
diff --git a/gio/src/gio_vfuncs.defs b/gio/src/gio_vfuncs.defs
index f8c94da..8dfac73 100644
--- a/gio/src/gio_vfuncs.defs
+++ b/gio/src/gio_vfuncs.defs
@@ -577,6 +577,13 @@
   )
 )
 
+; GFileDescriptorBased
+
+(define-vfunc get_fd
+ (of-object "GFileDescriptorBased")
+ (return-type "int")
+)
+
 ; GFileInputStream
 
 (define-vfunc tell