close compose window on escape key

src/main.py

@@ -70,6 +70,7 @@ class Application(Gtk.Application):
         action = Gio.SimpleAction.new('preferences', None)
         action.connect('activate', self.on_preferences)
         self.add_action(action)
+        # TODO: this shortcut might need adjustment
         self.set_accels_for_action('app.preferences',["<Ctrl>,"])
 
         action = Gio.SimpleAction.new('about', None)

src/widgets.py

@@ -73,6 +73,12 @@ class ComposeWindow(Handy.Window):
 
         self.show_all()
 
+        self.connect('key-release-event', self.on_key_release)
+
+    def on_key_release(self, widget, ev, data=None):
+        if ev.keyval == Gdk.KEY_Escape:
+            self.close()
+
     def validate(self, widget):
         self.counter = self.max_length - self.buffer.get_char_count()
         self.counter_label.set_text(str(self.counter))