[mutter] wayland: Add support for the xdg-foreign protocol

[Jonas Ådahl <jadahl src gnome org>]

commit 6f8e6864b23f5a6119e30000439cb390d1c08800
Author: Jonas Ådahl <jadahl gmail com>
Date:   Thu Sep 24 08:05:25 2015 +0800

    wayland: Add support for the xdg-foreign protocol
    
    This commits adds support for exporting xdg_surface handles via
    xdg_exporter and importing them via xdg_importer.
    
    This bumps the required wayland-protocols version to 1.6.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=769786

 .gitignore                             |    2 +
 configure.ac                           |    2 +-
 src/Makefile.am                        |    4 +
 src/wayland/meta-wayland-versions.h    |    2 +
 src/wayland/meta-wayland-xdg-foreign.c |  464 ++++++++++++++++++++++++++++++++
 src/wayland/meta-wayland-xdg-foreign.h |   34 +++
 src/wayland/meta-wayland.c             |    2 +
 7 files changed, 509 insertions(+), 1 deletions(-)
---
diff --git a/.gitignore b/.gitignore
index 8350c5e..c743273 100644
--- a/.gitignore
+++ b/.gitignore
@@ -83,6 +83,8 @@ src/relative-pointer-unstable-v*-protocol.c
 src/relative-pointer-unstable-v*-server-protocol.h
 src/pointer-constraints-unstable-v*-protocol.c
 src/pointer-constraints-unstable-v*-server-protocol.h
+src/xdg-foreign-unstable-v*-protocol.c
+src/xdg-foreign-unstable-v*-server-protocol.h
 src/meta/meta-version.h
 doc/reference/*.args
 doc/reference/*.bak
diff --git a/configure.ac b/configure.ac
index 81c1b5b..b13090b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -272,7 +272,7 @@ AS_IF([test "$have_wayland" = "yes"], [
   AC_SUBST([WAYLAND_SCANNER])
   AC_DEFINE([HAVE_WAYLAND],[1],[Define if you want to enable Wayland support])
 
-  PKG_CHECK_MODULES(WAYLAND_PROTOCOLS, [wayland-protocols >= 1.5],
+  PKG_CHECK_MODULES(WAYLAND_PROTOCOLS, [wayland-protocols >= 1.6],
                    [ac_wayland_protocols_pkgdatadir=`$PKG_CONFIG --variable=pkgdatadir wayland-protocols`])
   AC_SUBST(WAYLAND_PROTOCOLS_DATADIR, $ac_wayland_protocols_pkgdatadir)
 ])
diff --git a/src/Makefile.am b/src/Makefile.am
index 4f698a0..891d8c4 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -69,6 +69,8 @@ mutter_built_sources += \
        pointer-constraints-unstable-v1-server-protocol.h               \
        tablet-unstable-v2-protocol.c                                   \
        tablet-unstable-v2-server-protocol.h                            \
+       xdg-foreign-unstable-v1-protocol.c                              \
+       xdg-foreign-unstable-v1-server-protocol.h                       \
        $(NULL)
 endif
 
@@ -337,6 +339,8 @@ libmutter_la_SOURCES +=                             \
        wayland/meta-wayland-versions.h         \
        wayland/meta-wayland-outputs.c          \
        wayland/meta-wayland-outputs.h          \
+       wayland/meta-wayland-xdg-foreign.c      \
+       wayland/meta-wayland-xdg-foreign.h      \
        wayland/meta-window-wayland.c           \
        wayland/meta-window-wayland.h           \
        wayland/meta-wayland-xdg-shell.c        \
diff --git a/src/wayland/meta-wayland-versions.h b/src/wayland/meta-wayland-versions.h
index 9d36130..009abd1 100644
--- a/src/wayland/meta-wayland-versions.h
+++ b/src/wayland/meta-wayland-versions.h
@@ -45,5 +45,7 @@
 #define META_GTK_SHELL1_VERSION             1
 #define META_WL_SUBCOMPOSITOR_VERSION       1
 #define META_ZWP_POINTER_GESTURES_V1_VERSION    1
+#define META_ZXDG_EXPORTER_V1_VERSION       1
+#define META_ZXDG_IMPORTER_V1_VERSION       1
 
 #endif
diff --git a/src/wayland/meta-wayland-xdg-foreign.c b/src/wayland/meta-wayland-xdg-foreign.c
new file mode 100644
index 0000000..9e19342
--- /dev/null
+++ b/src/wayland/meta-wayland-xdg-foreign.c
@@ -0,0 +1,464 @@
+/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
+
+/*
+ * Copyright (C) 2015 Red Hat Inc.
+ *
+ * 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.
+ *
+ * Written by:
+ *     Jonas Ådahl <jadahl gmail com>
+ */
+
+#include "config.h"
+
+#include "wayland/meta-wayland-xdg-foreign.h"
+
+#include <wayland-server.h>
+
+#include "wayland/meta-wayland-private.h"
+#include "wayland/meta-wayland-versions.h"
+#include "wayland/meta-wayland-xdg-shell.h"
+
+#include "xdg-foreign-unstable-v1-server-protocol.h"
+
+#define META_XDG_FOREIGN_HANDLE_LENGTH 32
+
+typedef struct _MetaWaylandXdgExported MetaWaylandXdgExported;
+typedef struct _MetaWaylandXdgImported MetaWaylandXdgImported;
+
+typedef struct _MetaWaylandXdgForeign
+{
+  MetaWaylandCompositor *compositor;
+  GRand *rand;
+
+  GHashTable *exported_surfaces;
+} MetaWaylandXdgForeign;
+
+struct _MetaWaylandXdgExported
+{
+  MetaWaylandXdgForeign *foreign;
+  struct wl_resource *resource;
+
+  MetaWaylandSurface *surface;
+  gulong surface_unmapped_handler_id;
+  char *handle;
+
+  GList *imported;
+};
+
+struct _MetaWaylandXdgImported
+{
+  MetaWaylandXdgForeign *foreign;
+  struct wl_resource *resource;
+
+  MetaWaylandSurface *parent_of;
+  gulong parent_of_unmapped_handler_id;
+
+  MetaWaylandXdgExported *exported;
+};
+
+static void
+meta_wayland_xdg_imported_destroy (MetaWaylandXdgImported *imported);
+
+static void
+xdg_exporter_destroy (struct wl_client   *client,
+                      struct wl_resource *resource)
+{
+  wl_resource_destroy (resource);
+}
+
+static char *
+generate_handle (MetaWaylandXdgForeign *foreign)
+{
+  char *handle = g_new0 (char, META_XDG_FOREIGN_HANDLE_LENGTH + 1);
+  int i;
+
+  /*
+   * Generate a random string of printable ASCII characters.
+   */
+  for (i = 0; i < META_XDG_FOREIGN_HANDLE_LENGTH; i++)
+    handle[i] = (char) g_rand_int_range (foreign->rand, 32, 127);
+
+  return handle;
+}
+
+static void
+xdg_exported_destroy (struct wl_client   *client,
+                      struct wl_resource *resource)
+{
+  wl_resource_destroy (resource);
+}
+
+static const struct zxdg_exported_v1_interface meta_xdg_exported_interface = {
+  xdg_exported_destroy,
+};
+
+static void
+meta_wayland_xdg_exported_destroy (MetaWaylandXdgExported *exported)
+{
+  MetaWaylandXdgForeign *foreign = exported->foreign;
+
+  while (exported->imported)
+    {
+      MetaWaylandXdgImported *imported = exported->imported->data;
+
+      zxdg_imported_v1_send_destroyed (imported->resource);
+      meta_wayland_xdg_imported_destroy (imported);
+    }
+
+  g_signal_handler_disconnect (exported->surface,
+                               exported->surface_unmapped_handler_id);
+  wl_resource_set_user_data (exported->resource, NULL);
+
+  g_hash_table_remove (foreign->exported_surfaces, exported->handle);
+
+  g_free (exported->handle);
+  g_free (exported);
+}
+
+static void
+xdg_exported_destructor (struct wl_resource *resource)
+{
+  MetaWaylandXdgExported *exported = wl_resource_get_user_data (resource);
+
+  if (exported)
+    meta_wayland_xdg_exported_destroy (exported);
+}
+
+static void
+exported_surface_unmapped (MetaWaylandSurface     *surface,
+                           MetaWaylandXdgExported *exported)
+{
+  meta_wayland_xdg_exported_destroy (exported);
+}
+
+static void
+xdg_exporter_export (struct wl_client   *client,
+                     struct wl_resource *resource,
+                     uint32_t            id,
+                     struct wl_resource *surface_resource)
+{
+  MetaWaylandXdgForeign *foreign = wl_resource_get_user_data (resource);
+  MetaWaylandSurface *surface = wl_resource_get_user_data (surface_resource);
+  struct wl_resource *xdg_exported_resource;
+  MetaWaylandXdgExported *exported;
+  char *handle;
+
+  if (!surface->role ||
+      !META_IS_WAYLAND_XDG_SURFACE (surface->role) ||
+      !surface->window)
+    {
+      wl_resource_post_error (resource,
+                              WL_DISPLAY_ERROR_INVALID_OBJECT,
+                              "exported surface had an invalid role");
+      return;
+    }
+
+  xdg_exported_resource =
+    wl_resource_create (client,
+                        &zxdg_exported_v1_interface,
+                        wl_resource_get_version (resource),
+                        id);
+  if (!xdg_exported_resource)
+    {
+      wl_client_post_no_memory (client);
+      return;
+    }
+
+  exported = g_new0 (MetaWaylandXdgExported, 1);
+  exported->foreign = foreign;
+  exported->surface = surface;
+  exported->resource = xdg_exported_resource;
+
+  exported->surface_unmapped_handler_id =
+    g_signal_connect (surface, "unmapped",
+                      G_CALLBACK (exported_surface_unmapped),
+                      exported);
+
+  wl_resource_set_implementation (xdg_exported_resource,
+                                  &meta_xdg_exported_interface,
+                                  exported,
+                                  xdg_exported_destructor);
+
+  while (TRUE)
+    {
+      handle = generate_handle (foreign);
+
+      if (!g_hash_table_contains (foreign->exported_surfaces, handle))
+        {
+          g_hash_table_insert (foreign->exported_surfaces, handle, exported);
+          break;
+        }
+
+      g_free (handle);
+    }
+
+  exported->handle = handle;
+
+  zxdg_exported_v1_send_handle (xdg_exported_resource, handle);
+}
+
+static const struct zxdg_exporter_v1_interface meta_xdg_exporter_interface = {
+  xdg_exporter_destroy,
+  xdg_exporter_export,
+};
+
+static void
+bind_xdg_exporter (struct wl_client *client,
+                   void             *data,
+                   uint32_t          version,
+                   uint32_t          id)
+{
+  MetaWaylandXdgForeign *foreign = data;
+  struct wl_resource *resource;
+
+  resource = wl_resource_create (client,
+                                 &zxdg_exporter_v1_interface,
+                                 META_ZXDG_EXPORTER_V1_VERSION,
+                                 id);
+
+  if (resource == NULL)
+    {
+      wl_client_post_no_memory (client);
+      return;
+    }
+
+  wl_resource_set_implementation (resource,
+                                  &meta_xdg_exporter_interface,
+                                  foreign, NULL);
+}
+
+static void
+xdg_imported_destroy (struct wl_client   *client,
+                      struct wl_resource *resource)
+{
+  wl_resource_destroy (resource);
+}
+
+static void
+imported_parent_of_unmapped (MetaWaylandSurface     *surface,
+                             MetaWaylandXdgImported *imported)
+{
+  imported->parent_of = NULL;
+}
+
+static gboolean
+is_valid_child (MetaWaylandSurface *surface)
+{
+  if (!surface)
+    return TRUE;
+
+  if (!surface->role)
+    return FALSE;
+
+  if (!META_IS_WAYLAND_XDG_SURFACE (surface->role))
+    return FALSE;
+
+  if (!surface->window)
+    return FALSE;
+
+  return TRUE;
+}
+
+static void
+xdg_imported_set_parent_of (struct wl_client   *client,
+                            struct wl_resource *resource,
+                            struct wl_resource *surface_resource)
+{
+  MetaWaylandXdgImported *imported = wl_resource_get_user_data (resource);
+  MetaWaylandSurface *surface;
+
+  if (!imported)
+    return;
+
+  if (surface_resource)
+    surface = wl_resource_get_user_data (surface_resource);
+  else
+    surface = NULL;
+
+  if (!is_valid_child (surface))
+    {
+      wl_resource_post_error (imported->resource,
+                              WL_DISPLAY_ERROR_INVALID_OBJECT,
+                              "set_parent_of was called with an invalid child");
+      return;
+    }
+
+  if (imported->parent_of)
+    g_signal_handler_disconnect (imported->parent_of,
+                                 imported->parent_of_unmapped_handler_id);
+
+  imported->parent_of = surface;
+
+  if (surface)
+    {
+      imported->parent_of_unmapped_handler_id =
+        g_signal_connect (surface, "unmapped",
+                          G_CALLBACK (imported_parent_of_unmapped),
+                          imported);
+      meta_window_set_transient_for (surface->window,
+                                     imported->exported->surface->window);
+    }
+}
+
+static const struct zxdg_imported_v1_interface meta_xdg_imported_interface = {
+  xdg_imported_destroy,
+  xdg_imported_set_parent_of,
+};
+
+static void
+xdg_importer_destroy (struct wl_client   *client,
+                      struct wl_resource *resource)
+{
+  wl_resource_destroy (resource);
+}
+
+static void
+meta_wayland_xdg_imported_destroy (MetaWaylandXdgImported *imported)
+{
+  MetaWaylandXdgExported *exported = imported->exported;
+
+  exported->imported = g_list_remove (exported->imported, imported);
+
+  if (imported->parent_of)
+    {
+      MetaWindow *window;
+
+      g_signal_handler_disconnect (imported->parent_of,
+                                   imported->parent_of_unmapped_handler_id);
+
+      window = imported->parent_of->window;
+      if (window)
+        meta_window_set_transient_for (window, NULL);
+    }
+
+  wl_resource_set_user_data (imported->resource, NULL);
+
+  g_free (imported);
+}
+
+static void
+xdg_imported_destructor (struct wl_resource *resource)
+{
+  MetaWaylandXdgImported *imported = wl_resource_get_user_data (resource);
+
+  if (!imported)
+    return;
+
+  meta_wayland_xdg_imported_destroy (imported);
+}
+
+static void
+xdg_importer_import (struct wl_client   *client,
+                     struct wl_resource *resource,
+                     uint32_t            id,
+                     const char         *handle)
+{
+  MetaWaylandXdgForeign *foreign = wl_resource_get_user_data (resource);
+  struct wl_resource *xdg_imported_resource;
+  MetaWaylandXdgImported *imported;
+  MetaWaylandXdgExported *exported;
+
+  xdg_imported_resource =
+    wl_resource_create (client,
+                        &zxdg_imported_v1_interface,
+                        wl_resource_get_version (resource),
+                        id);
+  if (!xdg_imported_resource)
+    {
+      wl_client_post_no_memory (client);
+      return;
+    }
+
+  wl_resource_set_implementation (xdg_imported_resource,
+                                  &meta_xdg_imported_interface,
+                                  NULL,
+                                  xdg_imported_destructor);
+
+  exported = g_hash_table_lookup (foreign->exported_surfaces, handle);
+  if (!exported || !META_IS_WAYLAND_XDG_SURFACE (exported->surface->role))
+    {
+      zxdg_imported_v1_send_destroyed (resource);
+      return;
+    }
+
+  imported = g_new0 (MetaWaylandXdgImported, 1);
+  imported->foreign = foreign;
+  imported->exported = exported;
+  imported->resource = xdg_imported_resource;
+
+  wl_resource_set_user_data (xdg_imported_resource, imported);
+
+  exported->imported = g_list_prepend (exported->imported, imported);
+}
+
+static const struct zxdg_importer_v1_interface meta_xdg_importer_interface = {
+  xdg_importer_destroy,
+  xdg_importer_import,
+};
+
+static void
+bind_xdg_importer (struct wl_client *client,
+                   void             *data,
+                   uint32_t          version,
+                   uint32_t          id)
+{
+  MetaWaylandXdgForeign *foreign = data;
+  struct wl_resource *resource;
+
+  resource = wl_resource_create (client,
+                                 &zxdg_importer_v1_interface,
+                                 META_ZXDG_IMPORTER_V1_VERSION,
+                                 id);
+
+  if (resource == NULL)
+    {
+      wl_client_post_no_memory (client);
+      return;
+    }
+
+  wl_resource_set_implementation (resource,
+                                  &meta_xdg_importer_interface,
+                                  foreign,
+                                  NULL);
+}
+
+gboolean
+meta_wayland_xdg_foreign_init (MetaWaylandCompositor *compositor)
+{
+  MetaWaylandXdgForeign *foreign;
+
+  foreign = g_new0 (MetaWaylandXdgForeign, 1);
+
+  foreign->compositor = compositor;
+  foreign->rand = g_rand_new ();
+  foreign->exported_surfaces = g_hash_table_new ((GHashFunc) g_str_hash,
+                                                 (GEqualFunc) g_str_equal);
+
+  if (wl_global_create (compositor->wayland_display,
+                        &zxdg_exporter_v1_interface, 1,
+                        foreign,
+                        bind_xdg_exporter) == NULL)
+    return FALSE;
+
+  if (wl_global_create (compositor->wayland_display,
+                        &zxdg_importer_v1_interface, 1,
+                        foreign,
+                        bind_xdg_importer) == NULL)
+    return FALSE;
+
+  return TRUE;
+}
diff --git a/src/wayland/meta-wayland-xdg-foreign.h b/src/wayland/meta-wayland-xdg-foreign.h
new file mode 100644
index 0000000..5542a30
--- /dev/null
+++ b/src/wayland/meta-wayland-xdg-foreign.h
@@ -0,0 +1,34 @@
+/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
+
+/*
+ * Copyright (C) 2015 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.
+ *
+ * Written by:
+ *     Jonas Ådahl <jadahl gmail com>
+ */
+
+#ifndef META_WAYLAND_FOREIGN_H
+#define META_WAYLAND_FOREIGN_H
+
+#include <glib.h>
+
+#include "wayland/meta-wayland-types.h"
+
+gboolean meta_wayland_xdg_foreign_init (MetaWaylandCompositor *compositor);
+
+#endif /* META_WAYLAND_FOREIGN_H */
diff --git a/src/wayland/meta-wayland.c b/src/wayland/meta-wayland.c
index 4a8e677..b360cf1 100644
--- a/src/wayland/meta-wayland.c
+++ b/src/wayland/meta-wayland.c
@@ -40,6 +40,7 @@
 #include "meta-wayland-outputs.h"
 #include "meta-wayland-data-device.h"
 #include "meta-wayland-tablet-manager.h"
+#include "meta-wayland-xdg-foreign.h"
 
 static MetaWaylandCompositor _meta_wayland_compositor;
 
@@ -339,6 +340,7 @@ meta_wayland_init (void)
   meta_wayland_seat_init (compositor);
   meta_wayland_relative_pointer_init (compositor);
   meta_wayland_pointer_constraints_init (compositor);
+  meta_wayland_xdg_foreign_init (compositor);
 
   if (!meta_xwayland_start (&compositor->xwayland_manager, compositor->wayland_display))
     g_error ("Failed to start X Wayland");