enhancement: Introduces application-wide time format setting.

Initial time format settings are fetched during initial register call.
Event handler enables update of this setting as events are recieved
from the server.

Tests added.

Fixes #770

Author: mkp6781

tests/conftest.py

@@ -539,6 +539,7 @@ def initial_data(logged_on_user, users_fixture, streams_fixture):
                 }
             }
         },
+        'twenty_four_hour_time': True,
         'last_event_id': -1,
         'muted_topics': [],
         'realm_user_groups': [],

tests/model/test_model.py

@@ -179,6 +179,7 @@ def test_register_initial_desired_events(self, mocker, initial_data):
             'subscription',
             'typing',
             'update_message_flags',
+            'update_display_settings',
         ]
         fetch_event_types = [
             'realm',
@@ -189,6 +190,7 @@ def test_register_initial_desired_events(self, mocker, initial_data):
             'muted_topics',
             'realm_user',
             'realm_user_groups',
+            'update_display_settings',
             'zulip_version',
         ]
         model.client.register.assert_called_once_with(
@@ -1940,6 +1942,32 @@ def test__handle_subscription_event_subscribers_one_user_multiple_streams(
             new_subscribers = model.stream_dict[stream_id]['subscribers']
             assert new_subscribers == expected_subscribers
 
+    def test_update_twenty_four_hour_format(self, mocker, model):
+        event = {
+            'type': 'update_display_settings',
+            'setting_name': 'twenty_four_hour_time',
+            'setting': True
+        }
+        twenty_four_hr_format = False
+
+        first_msg_w = mocker.Mock()
+        second_msg_w = mocker.Mock()
+        first_msg_w.original_widget.message = {'id': 1}
+        second_msg_w.original_widget.message = {'id': 2}
+        self.controller.view.message_view = mocker.Mock(
+                                               log=[first_msg_w, second_msg_w])
+        create_msg_box_list = mocker.patch('zulipterminal.model.'
+                                           'create_msg_box_list')
+        # Test for change in time format
+        if event['setting_name'] == 'twenty_four_hour_time':
+            model.twenty_four_hr_format = twenty_four_hr_format
+            assert model.twenty_four_hr_format != event['setting']
+            model._handle_update_display_settings(event)
+            assert model.twenty_four_hr_format == event['setting']
+            assert create_msg_box_list.call_count == len(
+                                        self.controller.view.message_view.log)
+        assert model.controller.update_screen.called
+
     @pytest.mark.parametrize('muted_streams, stream_id, is_muted', [
         ({1},   1, True),
         ({1},   2, False),

zulipterminal/api_types.py

@@ -106,11 +106,18 @@ class UpdateMessageFlagsEvent(TypedDict):
     all: bool
 
 
+class UpdateDisplaySettings(TypedDict):
+    type: Literal['update_display_settings']
+    setting_name: str
+    setting: bool
+
+
 Event = Union[
     MessageEvent,
     UpdateMessageEvent,
     ReactionEvent,
     SubscriptionEvent,
     TypingEvent,
     UpdateMessageFlagsEvent,
+    UpdateDisplaySettings,
 ]

zulipterminal/model.py

@@ -96,6 +96,8 @@ def __init__(self, controller: Any) -> None:
                 ('typing', self._handle_typing_event),
                 ('update_message_flags',
                  self._handle_update_message_flags_event),
+                ('update_display_settings',
+                 self._handle_update_display_settings),
             ])
         )
 
@@ -149,6 +151,7 @@ def __init__(self, controller: Any) -> None:
         self.active_emoji_data = OrderedDict(sorted(all_emoji_data,
                                                     key=lambda e: e[0]))
 
+        self.twenty_four_hr_format = self.initial_data['twenty_four_hour_time']
         self.new_user_input = True
         self._start_presence_updates()
 
@@ -1166,10 +1169,17 @@ def _handle_update_message_flags_event(self, event: Event) -> None:
     def formatted_local_time(self, timestamp: int,
                              *, show_seconds: bool) -> str:
         local_time = datetime.datetime.fromtimestamp(timestamp)
-        if show_seconds:
-            return local_time.strftime('%a %b %d %H:%M:%S')
+        if self.twenty_four_hr_format:
+            if show_seconds:
+                time_string = '%a %b %d %H:%M:%S'
+            else:
+                time_string = '%a %b %d %H:%M'
         else:
-            return local_time.strftime('%a %b %d %H:%M')
+            if show_seconds:
+                time_string = '%a %b %d %I:%M:%S %p'
+            else:
+                time_string = '%a %b %d %I:%M %p'
+        return local_time.strftime(time_string)
 
     def _update_rendered_view(self, msg_id: int) -> None:
         """
@@ -1218,6 +1228,24 @@ def _update_rendered_view(self, msg_id: int) -> None:
                     self.controller.update_screen()
                     return
 
+    def _handle_update_display_settings(self, event: Event) -> None:
+        """
+        Handle change to user display setting (Eg: Time format)
+        """
+        assert event['type'] == "update_display_settings"
+        view = self.controller.view
+        if event['setting_name'] == 'twenty_four_hour_time':
+            self.twenty_four_hr_format = event['setting']
+            for msg_w in view.message_view.log:
+                msg_box = msg_w.original_widget
+                msg_id = msg_box.message['id']
+                last_msg = msg_box.last_message
+                msg_pos = view.message_view.log.index(msg_w)
+                msg_w_list = create_msg_box_list(self, [msg_id],
+                                                 last_message=last_msg)
+                view.message_view.log[msg_pos] = msg_w_list[0]
+        self.controller.update_screen()
+
     def _register_desired_events(self, *, fetch_data: bool=False) -> str:
         fetch_types = None if not fetch_data else [
             'realm',
@@ -1228,6 +1256,7 @@ def _register_desired_events(self, *, fetch_data: bool=False) -> str:
             'muted_topics',
             'realm_user',  # Enables cross_realm_bots
             'realm_user_groups',
+            'update_display_settings',
             # zulip_version and zulip_feature_level are always returned in
             # POST /register from Feature level 3.
             'zulip_version',