Add clipboard API and new input capture session construction API

libportal/clipboard.c

@@ -0,0 +1,350 @@
+/*
+ * Copyright (C) 2025 Red Hat
+ *
+ * This file 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, version 3.0 of the
+ * License.
+ *
+ * This file 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 program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * SPDX-License-Identifier: LGPL-3.0-only
+ */
+
+#include "config.h"
+
+#include <gio/gunixfdlist.h>
+
+#include "clipboard.h"
+#include "portal-private.h"
+#include "session-private.h"
+
+static void
+on_selection_owner_changed (GDBusConnection *bus,
+                            const char *sender_name,
+                            const char *object_path,
+                            const char *interface_name,
+                            const char *signal_name,
+                            GVariant *parameters,
+                            gpointer data)
+{
+  XdpPortal *portal = data;
+  XdpSession *session;
+  g_autoptr(GVariant) variant = NULL;
+  const char *session_handle = NULL;
+  gboolean session_is_owner = FALSE;
+  g_autofree const char **mime_types = NULL;
+
+  g_variant_get (parameters, "(o@a{sv})", &session_handle, &variant);
+
+  session = xdp_portal_lookup_session (portal, session_handle);
+  if (!session)
+    return;
+
+  g_variant_lookup (variant, "session_is_owner", "b", &session_is_owner);
+  g_variant_lookup (variant, "mime_types", "^a&s", &mime_types);
+
+  session->is_selection_owned_by_session = session_is_owner;
+  g_clear_pointer (&session->selection_mime_types, g_strfreev);
+  session->selection_mime_types = g_strdupv ((GStrv) mime_types);
+
+  g_signal_emit_by_name (session, "selection-owner-changed",
+                         mime_types, session_is_owner);
+}
+
+static void
+on_selection_transfer (GDBusConnection *bus,
+                       const char *sender_name,
+                       const char *object_path,
+                       const char *interface_name,
+                       const char *signal_name,
+                       GVariant *parameters,
+                       gpointer data)
+{
+  XdpPortal *portal = data;
+  XdpSession *session;
+  g_autoptr(GVariant) variant = NULL;
+  const char *session_handle = NULL;
+  const char *mime_type = NULL;
+  unsigned int serial = 0;
+
+  g_variant_get (parameters, "(osu)", &session_handle, &mime_type, &serial);
+
+  session = xdp_portal_lookup_session (portal, session_handle);
+  if (!session)
+    return;
+
+  g_signal_emit_by_name (session, "selection-transfer",
+                         mime_type, serial);
+}
+
+void
+ensure_signal_listeners (XdpPortal *portal)
+{
+  if (portal->selection_owner_changed_signal)
+    return;
+
+  portal->selection_owner_changed_signal =
+    g_dbus_connection_signal_subscribe (portal->bus,
+                                        PORTAL_BUS_NAME,
+                                        "org.freedesktop.portal.Clipboard",
+                                        "SelectionOwnerChanged",
+                                        PORTAL_OBJECT_PATH,
+                                        NULL,
+                                        G_DBUS_SIGNAL_FLAGS_NO_MATCH_RULE,
+                                        on_selection_owner_changed,
+                                        portal,
+                                        NULL);
+  portal->selection_transfer_signal =
+    g_dbus_connection_signal_subscribe (portal->bus,
+                                        PORTAL_BUS_NAME,
+                                        "org.freedesktop.portal.Clipboard",
+                                        "SelectionTransfer",
+                                        PORTAL_OBJECT_PATH,
+                                        NULL,
+                                        G_DBUS_SIGNAL_FLAGS_NO_MATCH_RULE,
+                                        on_selection_transfer,
+                                        portal,
+                                        NULL);
+}
+
+/**
+ * xdp_session_request_clipboard:
+ * @session: a [class@Session] in initial state
+ *
+ * Requests clipboard integration on the session.
+ */
+void
+xdp_session_request_clipboard (XdpSession *session)
+{
+  GVariantBuilder options;
+
+  g_variant_builder_init (&options, G_VARIANT_TYPE_VARDICT);
+  g_dbus_connection_call (session->portal->bus,
+                          PORTAL_BUS_NAME,
+                          PORTAL_OBJECT_PATH,
+                          "org.freedesktop.portal.Clipboard",
+                          "RequestClipboard",
+                          g_variant_new ("(oa{sv})",
+                                         session->id,
+                                         &options),
+                          NULL,
+                          G_DBUS_CALL_FLAGS_NONE,
+                          -1, NULL, NULL, NULL);
+
+  ensure_signal_listeners (session->portal);
+}
+
+/**
+ * xdp_session_is_clipboard_enabed:
+ * @session: a [class@Session]
+ *
+ * Returns TRUE if the session has enabled clipboard integration.
+ */
+gboolean
+xdp_session_is_clipboard_enabled (XdpSession *session)
+{
+  return session->is_clipboard_enabled;
+}
+
+/**
+ * xdp_session_is_selection_owned_by_session:
+ * @session: a [class@Session]
+ *
+ * Return TRUE if the most recently received clipboard selection owner is the
+ * selection of this session.
+ */
+gboolean
+xdp_session_is_selection_owned_by_session (XdpSession *session)
+{
+  return session->is_selection_owned_by_session;
+}
+
+/**
+ * xdp_session_get_selection_mime_types:
+ * @session: a [class@Session]
+ *
+ * Get the currently advertised mime types of the current clipboard selection
+ * owner.
+ *
+ * Returns: (transfer none): A NULL terminated array of mime type strings.
+ */
+const char **
+xdp_session_get_selection_mime_types (XdpSession *session)
+{
+  return (const char **) session->selection_mime_types;
+}
+
+/**
+ * xdp_session_set_selection:
+ * @session: a [class@Session]
+ * @mime_types: (transfer none): A NULL terminated array of mime type strings.
+ *
+ * Set the clipboard selection to advertise support for the passed list of mime
+ * types.
+ *
+ * When some entity in the windowing system requests to retrieve the contents of
+ * the selection, the [signal@Session::selection-transfer] signal is emitted. In
+ * response to this, the caller of this function must respond by calling
+ * [[email protected]_write] with the serial number passed via the
+ * mentioned signal.
+ */
+void
+xdp_session_set_selection (XdpSession *session,
+                           const char **mime_types)
+{
+  GVariantBuilder mime_types_builder;
+  GVariantBuilder options;
+  int i = 0;
+
+  g_variant_builder_init (&mime_types_builder, G_VARIANT_TYPE ("as"));
+  for (i = 0; mime_types[i]; i++)
+    g_variant_builder_add (&mime_types_builder, "s", mime_types[i]);
+
+  g_variant_builder_init (&options, G_VARIANT_TYPE_VARDICT);
+  g_variant_builder_add (&options, "{sv}",
+                         "mime_types", g_variant_builder_end (&mime_types_builder));
+  g_dbus_connection_call (session->portal->bus,
+                          PORTAL_BUS_NAME,
+                          PORTAL_OBJECT_PATH,
+                          "org.freedesktop.portal.Clipboard",
+                          "SetSelection",
+                          g_variant_new ("(oa{sv})",
+                                         session->id,
+                                         &options),
+                          NULL,
+                          G_DBUS_CALL_FLAGS_NONE,
+                          -1, NULL, NULL, NULL);
+}
+
+/**
+ * xdp_session_selection_write:
+ * @session: a [class@Session]
+ * @serial: a serial number
+ *
+ * Retrieve a file descriptor to write the content of the clipboard selection
+ * to. The content should be formatted according to the mime type of the mime
+ * type passed via the [signal@Session::selection-transfer] that carried the
+ * passed serial number.
+ *
+ * Returns: a file descriptor to a pipe to write the clipboard
+ * selection content to, or -1 on error. The caller must close the file
+ * descriptor when finished with it.
+ */
+int
+xdp_session_selection_write (XdpSession *session,
+                             unsigned int serial)
+{
+  g_autoptr(GVariant) ret = NULL;
+  g_autoptr(GError) error = NULL;
+  g_autoptr(GUnixFDList) fd_list = NULL;
+  int fd_out;
+
+  ret =
+    g_dbus_connection_call_with_unix_fd_list_sync (session->portal->bus,
+                                                   PORTAL_BUS_NAME,
+                                                   PORTAL_OBJECT_PATH,
+                                                   "org.freedesktop.portal.Clipboard",
+                                                   "SelectionWrite",
+                                                   g_variant_new ("(ou)",
+                                                                  session->id,
+                                                                  serial),
+                                                   G_VARIANT_TYPE ("(h)"),
+                                                   G_DBUS_CALL_FLAGS_NONE,
+                                                   -1,
+                                                   NULL,
+                                                   &fd_list,
+                                                   NULL,
+                                                   &error);
+  if (!ret)
+    {
+      g_warning ("Failed to write selection: %s", error->message);
+      return -1;
+    }
+
+  g_variant_get (ret, "(h)", &fd_out);
+
+  return g_unix_fd_list_get (fd_list, fd_out, NULL);
+}
+
+/**
+ * xdp_session_selection_write_done:
+ * @session: a [class@Session]
+ * @serial: a serial number
+ * @success: TRUE if the transfer was successful
+ *
+ * Notify whether a clipboard selection write operation associated with the
+ * passed serial was successful or not.
+ */
+void
+xdp_session_selection_write_done (XdpSession   *session,
+                                  unsigned int  serial,
+                                  gboolean      success)
+{
+  g_dbus_connection_call (session->portal->bus,
+                          PORTAL_BUS_NAME,
+                          PORTAL_OBJECT_PATH,
+                          "org.freedesktop.portal.Clipboard",
+                          "SetSelection",
+                          g_variant_new ("(oub)",
+                                         session->id,
+                                         serial,
+                                         success),
+                          NULL,
+                          G_DBUS_CALL_FLAGS_NONE,
+                          -1, NULL, NULL, NULL);
+}
+
+/**
+ * xdp_session_selection_read:
+ * @session: a [class@Session]
+ * @mime_type: a string containing the requested mime type
+ *
+ * Request to read the contents of the current clipboard selection in the passed
+ * mime type format. On success a file descriptor is returned, which can be read
+ * from to retrieve the clipboard selection content.
+ *
+ * Returns: A file descriptor, or -1 on error. The caller must close the file
+ * descriptor when finished with it.
+ */
+int
+xdp_session_selection_read (XdpSession *session,
+                            const char *mime_type)
+{
+  g_autoptr(GVariant) ret = NULL;
+  g_autoptr(GError) error = NULL;
+  g_autoptr(GUnixFDList) fd_list = NULL;
+  int fd_out;
+
+  ret =
+    g_dbus_connection_call_with_unix_fd_list_sync (session->portal->bus,
+                                                   PORTAL_BUS_NAME,
+                                                   PORTAL_OBJECT_PATH,
+                                                   "org.freedesktop.portal.Clipboard",
+                                                   "SelectionRead",
+                                                   g_variant_new ("(os)",
+                                                                  session->id,
+                                                                  mime_type),
+                                                   G_VARIANT_TYPE ("(h)"),
+                                                   G_DBUS_CALL_FLAGS_NONE,
+                                                   -1,
+                                                   NULL,
+                                                   &fd_list,
+                                                   NULL,
+                                                   &error);
+  if (!ret)
+    {
+      g_warning ("Failed to write selection: %s", error->message);
+      return -1;
+    }
+
+  g_variant_get (ret, "(h)", &fd_out);
+
+  return g_unix_fd_list_get (fd_list, fd_out, NULL);
+}