buttons: Mark muted streams during button creation.

Before we used to set stream as muted based on unread messages.
On startup this caused no stream to be marked as 'M'.
Now, we mark them as muted during button creation.

Tests amended.

Fixes: zulip#272, zulip#236

tests/ui/test_ui_tools.py

@@ -18,6 +18,7 @@
 from urwid import AttrWrap, Columns, Padding, Text
 
 VIEWS = "zulipterminal.ui_tools.views"
+TOPBUTTON = "zulipterminal.ui_tools.buttons.TopButton"
 
 
 class TestMessageView:
@@ -782,6 +783,8 @@ def test_menu_view(self, mocker, width=40):
         pm_button = mocker.patch(VIEWS + ".PMButton")
         mocker.patch(VIEWS + ".urwid.ListBox")
         mocker.patch(VIEWS + ".urwid.SimpleFocusListWalker")
+        mocker.patch(TOPBUTTON + ".set_muted_streams",
+                     return_value=None)
         left_col_view = LeftColumnView(width, self.view)
         home_button.assert_called_once_with(left_col_view.controller,
                                             count=2, width=width)
@@ -798,6 +801,8 @@ def test_streams_view(self, mocker, streams, pinned, width=40):
         stream_view = mocker.patch(VIEWS + '.StreamsView')
         line_box = mocker.patch(VIEWS + '.urwid.LineBox')
         divider = mocker.patch(VIEWS + '.urwid.Divider')
+        mocker.patch(TOPBUTTON + '.set_muted_streams',
+                     return_value=None)
 
         left_col_view = LeftColumnView(width, self.view)
 
@@ -1210,6 +1215,8 @@ class TestTopButton:
     def test_text_content(self, mocker,
                           prefix,
                           width, count, short_text, caption='caption'):
+        mocker.patch(TOPBUTTON + '.set_muted_streams',
+                     return_value=None)
         show_function = mocker.Mock()
 
         if isinstance(prefix, tuple):
@@ -1278,6 +1285,8 @@ class TestStreamButton:
     def test_text_content(self, mocker,
                           is_private, expected_prefix,
                           width, count, short_text, caption='caption'):
+        mocker.patch(TOPBUTTON + '.set_muted_streams',
+                     return_value=None)
         properties = [caption, 5, '#ffffff', is_private]
         view_mock = mocker.Mock()
         view_mock.palette = [(None, 'black', 'white')]
@@ -1328,6 +1337,8 @@ class TestUserButton:
     ])
     def test_text_content(self, mocker,
                           width, count, short_text, caption='caption'):
+        mocker.patch(TOPBUTTON + '.set_muted_streams',
+                     return_value=None)
         user = {
             'email': 'some_email',  # value unimportant
             'user_id': 5,           # value unimportant

zulipterminal/ui_tools/buttons.py

@@ -29,8 +29,14 @@ def __init__(self, controller: Any, caption: str,
         super().__init__("")
         self._w = self.widget(count)
         self.controller = controller
+        self.set_muted_streams()
         urwid.connect_signal(self, 'click', self.activate)
 
+    def set_muted_streams(self) -> None:
+        if self.caption in [self.controller.model.stream_dict[ele]['name']
+                            for ele in self.controller.model.muted_streams]:
+            self.update_count(-1)
+
     def update_count(self, count: int) -> None:
         self.count = count
         self._w = self.widget(count)