Re-Adding "Send by Email" (#1822)

* Adding ComposeEmail Portal

* Added fix to avoid portal to crash

* Send by Mail: Support file descriptors

Thanks @Marukesu!

* Added link for clarification of bug in portal

* Fixed code style issues

Co-authored-by: Jeremy Wootten <jeremy@elementaryos.org>

plugins/meson.build

@@ -3,3 +3,4 @@ subdir('pantheon-files-trash')
 subdir('pantheon-files-ctags')
 subdir('pantheon-files-cloud')
 subdir('git')
+subdir('send-by-email')

plugins/send-by-email/Portal.vala

@@ -0,0 +1,62 @@
+/*-
+ * Copyright (c) 2021 elementary, Inc. (https://elementary.io)
+ *
+ * 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 3 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, see <http://www.gnu.org/licenses/>.
+*/
+
+namespace Portal {
+    const string DBUS_DESKTOP_PATH = "/org/freedesktop/portal/desktop";
+    const string DBUS_DESKTOP_NAME = "org.freedesktop.portal.Desktop";
+    Email? email = null;
+
+    public static string generate_token () {
+        return "%s_%i".printf (
+            GLib.Application.get_default ().application_id.replace (".", "_"),
+            Random.int_range (0, int32.MAX)
+        );
+    }
+
+    [DBus (name = "org.freedesktop.portal.Email")]
+    interface Email : DBusProxy {
+        [DBus (name = "version")]
+        public abstract uint version { get; }
+
+        public static Email @get () throws IOError, DBusError {
+            if (email == null) {
+                var connection = GLib.Application.get_default ().get_dbus_connection ();
+                email = connection.get_proxy_sync<Email> (DBUS_DESKTOP_NAME, DBUS_DESKTOP_PATH);
+            }
+
+            return email;
+        }
+
+        [DBus (visible = false)]
+        public ObjectPath compose_email (string window_handle, HashTable<string, Variant> options, UnixFDList? attachments) throws Error {
+            var options_builder = new VariantBuilder (VariantType.VARDICT);
+            options.foreach ((key, val) => {
+                options_builder.add ("{sv}", key, val);
+            });
+
+            var response = call_with_unix_fd_list_sync (
+                "ComposeEmail",
+                new Variant ("(sa{sv})", window_handle, options_builder),
+                DBusCallFlags.NONE,
+                -1,
+                attachments
+            );
+
+            return (ObjectPath) response.get_child_value (0).get_string ();
+        }
+    }
+}

plugins/send-by-email/meson.build

@@ -0,0 +1,17 @@
+send_by_email_plugin_dir = join_paths(plugin_dir, 'core')
+
+gdk_dep = [ dependency('gdk-x11-3.0'), dependency('gdk-wayland-3.0') ]
+
+shared_module(
+    'pantheon-files-send-by-email',
+    'plugin.vala',
+    'Portal.vala',
+    dependencies: [pantheon_files_core_dep, gdk_dep],
+    install: true,
+    install_dir: send_by_email_plugin_dir
+)
+
+install_data(
+    'pantheon-files-send-by-email.plug',
+    install_dir: send_by_email_plugin_dir
+)

plugins/send-by-email/pantheon-files-send-by-email.plug

@@ -0,0 +1,3 @@
+[Plugin]
+Name=Send by Email
+File=libpantheon-files-send-by-email.so

plugins/send-by-email/plugin.vala

@@ -0,0 +1,146 @@
+/*
+* Copyright 2021 elementary, Inc. (https://elementary.io)
+*
+* 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 3 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., 51 Franklin Street, Fifth Floor,
+* Boston, MA 02110-1301 USA
+*/
+
+public class Files.Plugins.SendByEmailMenuItem : Gtk.MenuItem {
+    private GLib.File[] files;
+
+    public SendByEmailMenuItem (GLib.File[] files) {
+        this.files = files;
+
+        label = _("Send by Email");
+    }
+
+    public override void activate () {
+        try {
+            var portal = Portal.Email.get ();
+
+            window_export.begin ((obj, res) => {
+                var options = new HashTable<string, Variant> (str_hash, str_equal);
+                options["handle_token"] = Portal.generate_token ();
+
+                var files_builder = new VariantBuilder (new VariantType ("ah"));
+                var file_descriptors = new UnixFDList ();
+                foreach (var file in files) {
+                    var fd = Posix.open (file.get_path (), Posix.O_RDONLY | Posix.O_CLOEXEC);
+                    if (fd == -1) {
+                        warning ("send-by-mail: cannot open file: '%s'", file.get_path ());
+                        continue;
+                    }
+
+                    try {
+                        files_builder.add ("h", file_descriptors.append (fd));
+                    } catch (Error e) {
+                        warning ("send-by-mail: cannot append file descriptor: %s", e.message);
+                    }
+                }
+
+                options["attachment_fds"] = files_builder.end ();
+
+                /** Even though the org.freedesktop.portal.Email portal specs
+                * claims that "all the keys in the options are are optional",
+                * the portal does not work if no "addresses" key is passed.
+                * This is a bug in the Gtk backend of the portal:
+                * https://github.com/flatpak/xdg-desktop-portal-gtk/issues/343
+                */
+                if (portal.version > 2) {
+                    options["addresses"] = new Variant ("as", null);
+                }
+
+                try {
+                    var handle = window_export.end (res);
+                    portal.compose_email (handle, options, file_descriptors);
+
+                } catch (Error e) {
+                    warning (e.message);
+                }
+            });
+        } catch (Error e) {
+            warning (e.message);
+        }
+    }
+
+    private async string window_export () {
+        var window = get_toplevel ().get_window ();
+
+        if (window is Gdk.X11.Window) {
+            var xid = ((Gdk.X11.Window) window).get_xid ();
+            return "x11:%x".printf ((uint) xid);
+        } else if (window is Gdk.Wayland.Window) {
+            var handle = "wayland:";
+            ((Gdk.Wayland.Window) window).export_handle ((w, h) => {
+                handle += h;
+                window_export.callback ();
+            });
+            yield;
+
+            if (handle != "wayland:") {
+                return handle;
+            }
+
+            return "";
+
+        } else {
+            warning ("Unknown windowing system, not exporting window");
+            return "";
+        }
+    }
+}
+
+public class Files.Plugins.SendByEmail : Files.Plugins.Base {
+
+    public override void context_menu (Gtk.Widget widget, List<Files.File> gof_files) {
+        var menu = widget as Gtk.Menu;
+
+        if (gof_files == null || gof_files.length () == 0) {
+            return;
+        }
+
+        var files = get_file_array (gof_files);
+        if (files != null && files.length > 0) {
+            add_menuitem (menu, new Gtk.SeparatorMenuItem ());
+            add_menuitem (menu, new SendByEmailMenuItem (files));
+        }
+    }
+
+    private void add_menuitem (Gtk.Menu menu, Gtk.MenuItem menu_item) {
+        menu.append (menu_item);
+        menu_item.show ();
+        plugins.menuitem_references.add (menu_item);
+    }
+
+    private static GLib.File[] get_file_array (List<Files.File> files) {
+        GLib.File[] file_array = new GLib.File[0];
+
+        foreach (unowned Files.File file in files) {
+            if (file.location != null && !file.is_directory && file.is_readable ()) {
+                if (file.location.get_uri_scheme () == "recent") {
+                    file_array += GLib.File.new_for_uri (file.get_display_target_uri ());
+                } else {
+                    file_array += file.location;
+                }
+            }
+        }
+
+        return file_array;
+    }
+}
+
+public Files.Plugins.Base module_init () {
+    return new Files.Plugins.SendByEmail ();
+}