Sets current stream marker for empty streams.

Current stream headers for empty/muted/new streams
used to not get updated. We now introduce a dummy
message to update label.

Fixes: zulip#259

Author: sumanthvrao

zulipterminal/core.py

@@ -132,9 +132,11 @@ def narrow_to_stream(self, button: Any) -> None:
 
         if hasattr(button, 'message'):
             w_list = create_msg_box_list(
-                self.model, msg_id_list, button.message['id'])
+                self.model, msg_id_list, button.message['id'],
+                stream_cap=button.caption)
         else:
-            w_list = create_msg_box_list(self.model, msg_id_list)
+            w_list = create_msg_box_list(self.model, msg_id_list,
+                                         stream_cap=button.caption)
 
         self._finalize_show(w_list)
 

zulipterminal/ui_tools/boxes.py

@@ -120,13 +120,15 @@ def keypress(self, size: Tuple[int, int], key: str) -> str:
 
 class MessageBox(urwid.Pile):
     def __init__(self, message: Dict[str, Any], model: Any,
-                 last_message: Any) -> None:
+                 last_message: Any, empty_stream: bool=False) -> None:
         self.model = model
         self.message = message
         self.caption = ''
         self.stream_id = None  # type: Union[int, None]
         self.title = ''
         self.email = ''
+        # if this is the only message in the stream
+        self.empty_stream = empty_stream
         self.user_id = None  # type: Union[int, None]
         self.last_message = last_message
         # if this is the first message
@@ -149,6 +151,8 @@ def _time_for_message(self, message: Dict[str, Any]) -> str:
         return ctime(message['timestamp'])[:-8]
 
     def need_recipient_header(self) -> bool:
+        if(self.empty_stream):
+            return True
         last_msg = self.last_message
         if self.message['type'] == 'stream':
             if (last_msg['type'] == 'stream' and
@@ -334,6 +338,11 @@ def main_view(self) -> List[Any]:
         else:
             recipient_header = None
 
+        # Dummy messages with just headers and no content
+        if self.empty_stream:
+            parts = [(recipient_header, recipient_header is not None)]
+            return [part for part, condition in parts if condition]
+
         # Content Header
         message = {
             key: {
@@ -461,19 +470,19 @@ def keypress(self, size: Tuple[int, int], key: str) -> str:
                 self.model.controller.narrow_to_topic(self)
         elif is_command_key('GO_BACK', key):
             self.model.controller.show_all_messages(self)
-        elif is_command_key('REPLY_AUTHOR', key):
+        elif is_command_key('REPLY_AUTHOR', key) and not self.empty_stream:
             self.model.controller.view.write_box.private_box_view(
                 email=self.message['sender_email']
             )
-        elif is_command_key('MENTION_REPLY', key):
+        elif is_command_key('MENTION_REPLY', key) and not self.empty_stream:
             self.keypress(size, 'enter')
             mention = '@**' + self.message['sender_full_name'] + '** '
             self.model.controller.view.write_box.msg_write_box.set_edit_text(
                 mention)
             self.model.controller.view.write_box.msg_write_box.set_edit_pos(
                 len(mention))
             self.model.controller.view.middle_column.set_focus('footer')
-        elif is_command_key('QUOTE_REPLY', key):
+        elif is_command_key('QUOTE_REPLY', key) and not self.empty_stream:
             self.keypress(size, 'enter')
             quote = '```quote\n' + self.message['content'] + '\n```\n'
             self.model.controller.view.write_box.msg_write_box.set_edit_text(

zulipterminal/ui_tools/utils.py

@@ -7,7 +7,8 @@
 
 def create_msg_box_list(model: Any, messages: Union[None, Iterable[Any]]=None,
                         focus_msg_id: Union[None, int]=None,
-                        last_message: Union[None, Any]=None) -> List[Any]:
+                        last_message: Union[None, Any]=None,
+                        stream_cap: Any=None) -> List[Any]:
     """
     MessageBox for every message displayed is created here.
     """
@@ -18,11 +19,27 @@ def create_msg_box_list(model: Any, messages: Union[None, Iterable[Any]]=None,
     message_list.sort(key=lambda msg: msg['timestamp'])
     w_list = []
     focus_msg = None
+    empty_stream = False
     last_msg = last_message
     muted_msgs = 0  # No of messages that are muted.
+
+    # We create a dummy message to show as stream header.
+    # This message has only type, caption and empty subject
+    if message_list == [] and stream_cap is not None:
+        msg = {}
+        msg['type'] = 'stream'
+        msg['display_recipient'] = stream_cap
+        msg['stream_id'] = model.stream_id
+        msg['subject'] = ''
+        msg['id'] = None
+        msg['reactions'] = []
+        msg['flags'] = ['read']
+        message_list.append(msg)
+        empty_stream = True
+
     for msg in message_list:
         # Remove messages of muted topics / streams.
-        if is_muted(msg, model):
+        if not empty_stream and is_muted(msg, model):
             muted_msgs += 1
             continue
 
@@ -34,14 +51,16 @@ def create_msg_box_list(model: Any, messages: Union[None, Iterable[Any]]=None,
             msg_flag = None
         elif focus_msg is None:
             focus_msg = message_list.index(msg) - muted_msgs
-        if msg['id'] == focus_msg_id:
+        if not empty_stream and msg['id'] == focus_msg_id:
             focus_msg = message_list.index(msg) - muted_msgs
         w_list.append(urwid.AttrMap(
-                    MessageBox(msg, model, last_msg),
+                    MessageBox(msg, model, last_msg, empty_stream),
                     msg_flag,
                     'msg_selected'
         ))
-        last_msg = msg
+        # We don't want to set dummy message as last message.
+        if not empty_stream:
+            last_msg = msg
     if focus_msg is not None:
         model.set_focus_in_current_narrow(focus_msg)
     return w_list

zulipterminal/ui_tools/views.py

@@ -51,6 +51,9 @@ def load_old_messages(self, anchor: int=10000000000) -> None:
         ids_to_keep = self.model.get_message_ids_in_current_narrow()
         if self.log:
             top_message_id = self.log[0].original_widget.message['id']
+            # This for the dummy message
+            if top_message_id is None:
+                return
             ids_to_keep.remove(top_message_id)  # update this id
             no_update_baseline = {top_message_id}
         else: