[mutter/wip/carlosg/xwayland-on-demand: 4/32] wayland: Add wayland MetaSelectionSource implementation

[Carlos Garnacho <carlosg src gnome org>]

commit 0bd711eb3c1f90cad8a83db8312229890f935ba4
Author: Carlos Garnacho <carlosg gnome org>
Date:   Mon Nov 19 17:34:18 2018 +0100

    wayland: Add wayland MetaSelectionSource implementation
    
    This object represents a Wayland selection owner. In order to invert the
    FD direction (we hand an output fd, but want an inpu fd), create an
    intermediate pipe so we can then create a GInputStream on top of it.

 src/Makefile.am                                    |   2 +
 src/meson.build                                    |   2 +
 .../meta-wayland-selection-source-private.h        |  46 +++++++
 src/wayland/meta-wayland-selection-source.c        | 148 +++++++++++++++++++++
 4 files changed, 198 insertions(+)
---
diff --git a/src/Makefile.am b/src/Makefile.am
index 8225b1dc3..54fec1e52 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -447,6 +447,8 @@ libmutter_@LIBMUTTER_API_VERSION@_la_SOURCES +=     \
        wayland/meta-wayland-popup.h            \
        wayland/meta-wayland-seat.c             \
        wayland/meta-wayland-seat.h             \
+       wayland/meta-wayland-selection-source.c         \
+       wayland/meta-wayland-selection-source-private.h \
        wayland/meta-wayland-tablet.c           \
        wayland/meta-wayland-tablet.h           \
        wayland/meta-wayland-tablet-manager.c   \
diff --git a/src/meson.build b/src/meson.build
index 642e2ed27..a20f81323 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -484,6 +484,8 @@ if have_wayland
     'wayland/meta-wayland-region.h',
     'wayland/meta-wayland-seat.c',
     'wayland/meta-wayland-seat.h',
+    'wayland/meta-wayland-selection-source.c',
+    'wayland/meta-wayland-selection-source-private.h',
     'wayland/meta-wayland-shell-surface.c',
     'wayland/meta-wayland-shell-surface.h',
     'wayland/meta-wayland-subsurface.c',
diff --git a/src/wayland/meta-wayland-selection-source-private.h 
b/src/wayland/meta-wayland-selection-source-private.h
new file mode 100644
index 000000000..5af26c397
--- /dev/null
+++ b/src/wayland/meta-wayland-selection-source-private.h
@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) 2018 Red Hat
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program 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
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ *
+ * Author: Carlos Garnacho <carlosg gnome org>
+ */
+
+#ifndef META_WAYLAND_SELECTION_SOURCE_H
+#define META_WAYLAND_SELECTION_SOURCE_H
+
+#include <wayland-server.h>
+
+#include "core/meta-selection-source.h"
+
+#define META_TYPE_WAYLAND_SELECTION_SOURCE (meta_wayland_selection_source_get_type ())
+
+G_DECLARE_FINAL_TYPE (MetaWaylandSelectionSource,
+                      meta_wayland_selection_source,
+                      META, WAYLAND_SELECTION_SOURCE,
+                      MetaSelectionSource)
+
+typedef void (* MetaWaylandSendFunc) (struct wl_resource *resource,
+                                      const char         *mimetype,
+                                      int                 fd);
+typedef void (* MetaWaylandCancelFunc) (struct wl_resource *resource);
+
+MetaSelectionSource * meta_wayland_selection_source_new (struct wl_resource    *resource,
+                                                         GList                 *mime_types,
+                                                         MetaWaylandSendFunc    send_func,
+                                                         MetaWaylandCancelFunc  cancel_func);
+
+#endif /* META_WAYLAND_SELECTION_SOURCE_H */
diff --git a/src/wayland/meta-wayland-selection-source.c b/src/wayland/meta-wayland-selection-source.c
new file mode 100644
index 000000000..103dcbb97
--- /dev/null
+++ b/src/wayland/meta-wayland-selection-source.c
@@ -0,0 +1,148 @@
+/*
+ * Copyright (C) 2018 Red Hat
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program 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
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ *
+ * Author: Carlos Garnacho <carlosg gnome org>
+ */
+#include "config.h"
+
+#include <glib-unix.h>
+#include <gio/gunixinputstream.h>
+
+#include "wayland/meta-wayland-selection-source-private.h"
+
+struct _MetaWaylandSelectionSource
+{
+  GObject parent_instance;
+  GList *mimetypes;
+  MetaWaylandSendFunc send_func;
+  MetaWaylandCancelFunc cancel_func;
+  struct wl_resource *resource;
+};
+
+G_DEFINE_TYPE (MetaWaylandSelectionSource, meta_wayland_selection_source,
+               META_TYPE_SELECTION_SOURCE)
+
+static void
+meta_wayland_selection_source_read_async (MetaSelectionSource *source,
+                                          const gchar         *mimetype,
+                                          GCancellable        *cancellable,
+                                          GAsyncReadyCallback  callback,
+                                          gpointer             user_data)
+{
+  MetaWaylandSelectionSource *source_wayland = META_WAYLAND_SELECTION_SOURCE (source);
+  GInputStream *stream;
+  GTask *task;
+  int pipe_fds[2];
+
+  if (!g_unix_open_pipe (pipe_fds, FD_CLOEXEC, NULL))
+    {
+      g_task_report_new_error (source, callback, user_data,
+                               meta_wayland_selection_source_read_async,
+                               G_IO_ERROR, G_IO_ERROR_FAILED,
+                               "Could not open pipe to read wayland selection");
+      return;
+    }
+
+  if (!g_unix_set_fd_nonblocking (pipe_fds[0], TRUE, NULL) ||
+      !g_unix_set_fd_nonblocking (pipe_fds[1], TRUE, NULL))
+    {
+      g_task_report_new_error (source, callback, user_data,
+                               meta_wayland_selection_source_read_async,
+                               G_IO_ERROR, G_IO_ERROR_FAILED,
+                               "Could not make pipe nonblocking");
+      close (pipe_fds[0]);
+      close (pipe_fds[1]);
+      return;
+    }
+
+  task = g_task_new (source, cancellable, callback, user_data);
+  g_task_set_source_tag (task, meta_wayland_selection_source_read_async);
+
+  stream = g_unix_input_stream_new (pipe_fds[0], TRUE);
+  source_wayland->send_func (source_wayland->resource, mimetype, pipe_fds[1]);
+  close (pipe_fds[1]);
+
+  g_task_return_pointer (task, stream, g_object_unref);
+  g_object_unref (task);
+}
+
+static GInputStream *
+meta_wayland_selection_source_read_finish (MetaSelectionSource  *source,
+                                           GAsyncResult         *result,
+                                           GError              **error)
+{
+  g_return_val_if_fail (g_task_is_valid (result, source), FALSE);
+  g_return_val_if_fail (g_task_get_source_tag (G_TASK (result)) ==
+                        meta_wayland_selection_source_read_async, FALSE);
+
+  return g_task_propagate_pointer (G_TASK (result), error);
+}
+
+static GList *
+meta_wayland_selection_source_get_mimetypes (MetaSelectionSource  *source)
+{
+  MetaWaylandSelectionSource *source_wayland = META_WAYLAND_SELECTION_SOURCE (source);
+
+  return g_list_copy_deep (source_wayland->mimetypes,
+                           (GCopyFunc) g_strdup, NULL);
+}
+
+static void
+meta_wayland_selection_source_inactive (MetaSelectionSource *source)
+{
+  MetaWaylandSelectionSource *source_wayland =
+    META_WAYLAND_SELECTION_SOURCE (source);
+
+  source_wayland->cancel_func (source_wayland->resource);
+  META_SELECTION_SOURCE_CLASS (meta_wayland_selection_source_parent_class)->inactive (source);
+}
+
+static void
+meta_wayland_selection_source_class_init (MetaWaylandSelectionSourceClass *klass)
+{
+  MetaSelectionSourceClass *source_class = META_SELECTION_SOURCE_CLASS (klass);
+
+  source_class->inactive = meta_wayland_selection_source_inactive;
+
+  source_class->read_async = meta_wayland_selection_source_read_async;
+  source_class->read_finish = meta_wayland_selection_source_read_finish;
+  source_class->get_mimetypes = meta_wayland_selection_source_get_mimetypes;
+}
+
+static void
+meta_wayland_selection_source_init (MetaWaylandSelectionSource *source)
+{
+}
+
+MetaSelectionSource *
+meta_wayland_selection_source_new (struct wl_resource    *resource,
+                                   GList                 *mime_types,
+                                   MetaWaylandSendFunc    send_func,
+                                   MetaWaylandCancelFunc  cancel_func)
+{
+  MetaWaylandSelectionSource *source;
+
+  source = g_object_new (META_TYPE_WAYLAND_SELECTION_SOURCE,
+                         NULL);
+  source->mimetypes = g_list_copy_deep (mime_types, (GCopyFunc) g_strdup, NULL);
+  source->send_func = send_func;
+  source->cancel_func = cancel_func;
+  source->resource = resource;
+
+  return META_SELECTION_SOURCE (source);
+}