Show back button in chats

data/ui/app.briar.gtk.gresource.xml

@@ -6,5 +6,6 @@
     <file compressed="true" preprocess="xml-stripblanks">ui/login.ui</file>
     <file compressed="true" preprocess="xml-stripblanks">ui/main.ui</file>
     <file compressed="true" preprocess="xml-stripblanks">ui/setup.ui</file>
+    <file compressed="true" preprocess="xml-stripblanks">ui/toolbar_start.ui</file>
   </gresource>
 </gresources>

data/ui/toolbar_start.ui

+<?xml version="1.0" encoding="UTF-8"?>
+<!-- Generated with glade 3.22.1 -->
+<!-- Based on https://gitlab.gnome.org/World/lollypop/blob/1.0.12/data/ToolbarPlayback.ui -->
+<interface>
+  <requires lib="gtk+" version="3.10"/>
+  <object class="GtkImage" id="back_image">
+    <property name="visible">True</property>
+    <property name="can_focus">False</property>
+    <property name="icon_name">go-previous-symbolic</property>
+  </object>
+  <object class="GtkBox" id="toolbar_start">
+    <property name="visible">True</property>
+    <property name="can_focus">False</property>
+    <property name="spacing">5</property>
+    <child>
+      <object class="GtkButton" id="back_button">
+        <property name="visible">False</property>
+        <property name="valign">center</property>
+        <property name="image">back_image</property>
+      </object>
+      <packing>
+        <property name="expand">False</property>
+        <property name="fill">True</property>
+        <property name="position">0</property>
+      </packing>
+    </child>
+  </object>
+</interface>
+

src/briar/gtk/toolbar.py

+# Copyright (c) 2019 Nico Alt
+# Copyright (c) 2014-2019 Cedric Bellegarde <cedric.bellegarde@adishatz.org>
+# SPDX-License-Identifier: AGPL-3.0-only
+# License-Filename: LICENSE.md
+#
+# Initial version based on GNOME Lollypop
+# https://gitlab.gnome.org/World/lollypop/blob/1.0.12/lollypop/toolbar.py
+
+import gi
+gi.require_version('Gtk', '3.0')
+from gi.repository import Gtk
+
+
+class Toolbar(Gtk.HeaderBar):
+
+    def __init__(self):
+        super().__init__()
+        self._builder = Gtk.Builder()
+        self._builder.add_from_resource("/app/briar/gtk/ui/toolbar_start.ui")
+        toolbar_start = self._builder.get_object("toolbar_start")
+        self.set_title("Briar")
+        self.pack_start(toolbar_start)
+
+    def show_back_button(self, show, callback=None):
+        back_button = self._builder.get_object("back_button")
+        if not show:
+            back_button.hide()
+            return
+        if callback is None:
+            raise Exception("Callback needed when showing back button")
+        back_button.show()
+        back_button.connect("clicked", callback)
+

src/briar/gtk/window.py

@@ -6,6 +6,7 @@ from briar.gtk.containers.chat import ChatContainer
 from briar.gtk.containers.main import MainContainer
 from briar.gtk.containers.startup import StartupContainer
 from briar.gtk.define import App
+from briar.gtk.toolbar import Toolbar
 
 import gi
 gi.require_version('Gtk', '3.0')
@@ -23,8 +24,13 @@ class Window(Gtk.ApplicationWindow):
     def container(self):
         return self.__container
 
+    @property
+    def toolbar(self):
+        return self.__toolbar
+
     def __setup_content(self):
         self.__setup_size((600, 400))  # TODO: do properly (constants, save)
+        self.__setup_toolbar()
         self.__setup_grid()
         self.__setup_startup_container()
 
@@ -34,6 +40,12 @@ class Window(Gtk.ApplicationWindow):
            isinstance(size[1], int):
             self.resize(size[0], size[1])
 
+    def __setup_toolbar(self):
+        self.__toolbar = Toolbar()
+        self.__toolbar.show()
+        self.__toolbar.set_show_close_button(True)
+        self.set_titlebar(self.__toolbar)
+
     def __setup_grid(self):
         self.__grid = Gtk.Grid()
         self.__grid.set_orientation(Gtk.Orientation.HORIZONTAL)
@@ -66,4 +78,10 @@ class Window(Gtk.ApplicationWindow):
         self.__container = ChatContainer(contact_id)
         self.__container.show()
         self.__grid.add(self.__container)
+        self.__toolbar.show_back_button(True, self.__back_to_main)
 
+    def __back_to_main(self, widget):
+        self.__grid.destroy()
+        self.__setup_grid()
+        self.__toolbar.show_back_button(False)
+        self.__setup_main_container()