create app notification widget

[Danielle Foré]

Not sure if we want to copy Android and call this "Granite.Widgets.Toast". Just committed an example to Switchboard's Online Accounts plug. It basically looks like this:

                var close_button = new Gtk.Button.from_icon_name ("close-symbolic", Gtk.IconSize.MENU);
                close_button.get_style_context ().add_class ("close-button");
                close_button.clicked.connect (() => {
                    // Response here
                    app_notification.reveal_child = false;
                });

                notification_label = new Gtk.Label ("");
                var button = new Gtk.Button.with_label (_("Button"));
                button.clicked.connect (() => {
                    // Response here
                    app_notification.reveal_child = false;
                });

                var notification_box = new Gtk.Grid ();
                notification_box.column_spacing = 12;
                notification_box.add (close_button);
                notification_box.add (notification_label);
                notification_box.add (button);

                var notification_frame = new Gtk.Frame (null);
                notification_frame.get_style_context ().add_class ("app-notification");
                notification_frame.add (notification_box);

                app_notification = new Gtk.Revealer ();
                app_notification.margin = 3;
                app_notification.halign = Gtk.Align.CENTER;
                app_notification.valign = Gtk.Align.START;
                app_notification.add (notification_frame);

Then you stick that in an overlay and show/hide when necessary. Things to consider:

* Do we want to hard code the availability of a single button? I'm pretty sure we don't want to be able to pack arbitrary widgets. Is there a case for two buttons or should we recommend that developers use an alert in that case?

* Should these time out? On Android toasts time out

[Cassidy James Blaede (cassidyjames)]

One action and a dismiss makes sense to me. And a default timeout also makes sense.

[Zisu Andrei (matzipan)]

" Is there a case for two buttons or should we recommend that developers use an alert in that case?"

I'd say the quicker we use it, the quicker we find out.

The timeout should be something along the lines of 5-10 seconds after the user has performed the action which triggered the toast.