boxes/utils/view: Sets current narrow label for empty narrow.

A dummy message is used to update label for
empty narrow headers which did not change before.
Both streams and PM covered

Fixes: zulip#259
Fixes: zulip#266

Author: sumanthvrao

zulipterminal/core.py

@@ -133,9 +133,11 @@ 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_caption=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_caption=button.caption)
 
         self._finalize_show(w_list)
 
@@ -167,6 +169,11 @@ def narrow_to_topic(self, button: Any) -> None:
         self._finalize_show(w_list)
 
     def narrow_to_user(self, button: Any) -> None:
+        pm_details = {
+                    'caption': button.caption,
+                    'recipient_email': button.email,
+                    'sender_id': self.model.user_id
+                    }
         if hasattr(button, 'message'):
             emails = [recipient['email']
                       for recipient in button.message['display_recipient']
@@ -198,9 +205,11 @@ def narrow_to_user(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'],
+                pm_details=pm_details)
         else:
-            w_list = create_msg_box_list(self.model, msg_id_list)
+            w_list = create_msg_box_list(
+                self.model, msg_id_list, pm_details=pm_details)
 
         self._finalize_show(w_list)
 

zulipterminal/model.py

@@ -492,6 +492,12 @@ def append_message(self, event: Event) -> None:
                 last_message = self.msg_list.log[-1].original_widget.message
             else:
                 last_message = None
+            # Removing the dummy message when a new message comes
+            if self.msg_list.log:
+                dummy_message = self.msg_list.log[0].original_widget.message
+                if dummy_message.get('id') is None:
+                    del self.msg_list.log[0]
+
             msg_w_list = create_msg_box_list(self, [response['id']],
                                              last_message=last_message)
             if not msg_w_list:

zulipterminal/ui_tools/boxes.py

@@ -117,13 +117,14 @@ 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, is_empty_narrow: bool=False) -> None:
         self.model = model
         self.message = message
         self.caption = ''
         self.stream_id = None  # type: Union[int, None]
         self.title = ''
         self.email = ''
+        self.is_in_empty_narrow = is_empty_narrow
         self.user_id = None  # type: Union[int, None]
         self.last_message = last_message
         # if this is the first message
@@ -146,6 +147,8 @@ def _time_for_message(self, message: Dict[str, Any]) -> str:
         return ctime(message['timestamp'])[:-8]
 
     def need_recipient_header(self) -> bool:
+        if self.is_in_empty_narrow:
+            return True
         last_msg = self.last_message
         if self.message['type'] == 'stream':
             if (last_msg['type'] == 'stream' and
@@ -167,6 +170,15 @@ def need_recipient_header(self) -> bool:
         else:
             raise RuntimeError("Invalid message type")
 
+    def _check_if_self_PM(self) -> bool:
+        recipient_list = self.message['display_recipient']
+        if len(recipient_list) == 1 and \
+            recipient_list[0]['email'] == \
+                self.model.user_email:
+            return True
+        else:
+            return False
+
     def stream_header(self) -> Any:
         bar_color = self.model.stream_dict[self.stream_id]['color']
         bar_color = 's' + bar_color[:2] + bar_color[3] + bar_color[5]
@@ -180,11 +192,14 @@ def stream_header(self) -> Any:
         return header
 
     def private_header(self) -> Any:
-        self.recipients = ', '.join(list(
-            recipient['full_name']
-            for recipient in self.message['display_recipient']
-            if recipient['email'] != self.model.user_email
-        ))
+        if self._check_if_self_PM():
+            self.recipients = self.message['display_recipient'][0]['full_name']
+        else:
+            self.recipients = ', '.join(list(
+                recipient['full_name']
+                for recipient in self.message['display_recipient']
+                if recipient['email'] != self.model.user_email
+            ))
         title_markup = ('header', [
             ('custom', 'Private Messages with'),
             ('selected', ": "),
@@ -419,11 +434,14 @@ def mouse_event(self, size: Tuple[int, int], event: Any, button: Any,
 
     def get_recipients(self) -> str:
         emails = []
-        for recipient in self.message['display_recipient']:
-            email = recipient['email']
-            if email == self.model.user_email:
-                continue
-            emails.append(recipient['email'])
+        if self._check_if_self_PM():
+            emails.append(self.model.user_email)
+        else:
+            for recipient in self.message['display_recipient']:
+                email = recipient['email']
+                if email == self.model.user_email:
+                    continue
+                emails.append(recipient['email'])
         return ', '.join(emails)
 
     def keypress(self, size: Tuple[int, int], key: str) -> str:
@@ -458,19 +476,22 @@ 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.is_in_empty_narrow:
             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.is_in_empty_narrow:
             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.is_in_empty_narrow:
             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

@@ -1,13 +1,16 @@
 from typing import Any, Iterable, List, Union, Dict
 
 import urwid
+import time
 
 from zulipterminal.ui_tools.boxes import MessageBox
 
 
 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_caption: Any=None,
+                        pm_details: Any=None) -> List[Any]:
     """
     MessageBox for every message displayed is created here.
     """
@@ -18,8 +21,47 @@ 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
+    is_empty_narrow = False
     last_msg = last_message
     muted_msgs = 0  # No of messages that are muted.
+    if last_msg is not None and last_msg['id'] is None:
+        last_message = None
+    # We create a dummy message to show in narrows with
+    # no previous messages, whose author is welcome bot.
+    if (message_list == [] and (stream_caption is not None or
+                                pm_details is not None)):
+        msg = {}
+        if stream_caption is not None:
+            msg.update({
+                'type': 'stream',
+                'display_recipient': stream_caption,
+                'stream_id': model.stream_id,
+                'subject': model.stream_dict[model.stream_id]['description'],
+                })
+        elif pm_details is not None:
+            msg.update({
+                'type': 'private',
+                'display_recipient': [{'full_name': pm_details['caption'],
+                                       'email': pm_details['recipient_email'],
+                                       'id': None}],
+                'sender_id': pm_details['sender_id'],
+                })
+        msg.update({
+            'content': "<p> There are no messages in this stream. </p>",
+            'client': 'Internal',
+            'sender_full_name': 'Welcome Bot',
+            'sender_short_name': 'welcome-bot',
+            'content_type': 'text/html',
+            'sender_email': '[email protected]',
+            'sender_realm_str': 'zulip',
+            'timestamp': int(time.time()),
+            'id': None,
+            'reactions': [],
+            'flags': ['read']
+            })
+        message_list.append(msg)
+        is_empty_narrow = True
+
     for msg in message_list:
         # Remove messages of muted topics / streams.
         if is_muted(msg, model):
@@ -37,11 +79,13 @@ def create_msg_box_list(model: Any, messages: Union[None, Iterable[Any]]=None,
         if 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, is_empty_narrow),
                     msg_flag,
                     'msg_selected'
         ))
-        last_msg = msg
+        # We don't want to set dummy message as last message.
+        if not is_empty_narrow:
+            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: