boxes: Add appropriate color to compose header stream markers.

Style improvements:
 * Stream prefixes' color rendered.
 * The topic prefix is not rendered to make equivalence with the webapp.

Tests updated and added (marker/color rendering).

Partially fixes #783.

Author: Ezio-Sarthak

tests/ui_tools/test_boxes.py

@@ -315,10 +315,15 @@ def test__stream_box_autocomplete(self, mocker, write_box, text, state,
                                                     matching_streams)
 
     @pytest.mark.parametrize([
-        'stream_name', 'stream_id', 'is_valid_stream', 'expected_marker'], [
-      ('Secret stream', 99, True,  STREAM_MARKER_PRIVATE),
-      ('Stream 1',       1, True,  STREAM_MARKER_PUBLIC),
-      ('Stream 0',       0, False, STREAM_MARKER_INVALID),
+        'stream_name',
+        'stream_id',
+        'is_valid_stream',
+        'expected_marker',
+        'expected_color'
+    ], [
+      ('Secret stream', 99, True,  STREAM_MARKER_PRIVATE, '#ccc'),
+      ('Stream 1',       1, True,  STREAM_MARKER_PUBLIC,  '#b0a5fd'),
+      ('Stream 0',       0, False, STREAM_MARKER_INVALID, 'general_bar'),
     ], ids=[
         'private_stream',
         'public_stream',
@@ -327,7 +332,7 @@ def test__stream_box_autocomplete(self, mocker, write_box, text, state,
     def test__set_stream_write_box_style_markers(self, write_box, stream_id,
                                                  stream_name, is_valid_stream,
                                                  expected_marker, stream_dict,
-                                                 mocker):
+                                                 mocker, expected_color):
         # FIXME: Refactor when we have ~ Model.is_private_stream
         write_box.model.stream_dict = stream_dict
         write_box.model.is_valid_stream.return_value = is_valid_stream
@@ -337,8 +342,11 @@ def test__set_stream_write_box_style_markers(self, write_box, stream_id,
 
         write_box._set_stream_write_box_style(write_box, stream_name)
 
-        assert (write_box.header_write_box
-                [write_box.FOCUS_HEADER_PREFIX_STREAM].text) == expected_marker
+        stream_marker = (write_box.header_write_box
+                         [write_box.FOCUS_HEADER_PREFIX_STREAM])
+
+        assert stream_marker.text == expected_marker
+        assert stream_marker.attrib[0][0] == expected_color
 
     @pytest.mark.parametrize('text, expected_text', [
         ('Som', 'Some general stream'),

zulipterminal/ui_tools/boxes.py

@@ -117,8 +117,14 @@ def stream_box_view(self, stream_id: int, caption: str='', title: str='',
         )
         self.title_write_box.set_completer_delims("")
 
+        stream_marker = STREAM_MARKER_PUBLIC
+        color = None
+        if caption:
+            color = self.model.stream_dict[self.stream_id]['color']
+            if self.model.stream_dict[self.stream_id]['invite_only']:
+                stream_marker = STREAM_MARKER_PRIVATE
         self.header_write_box = urwid.Columns([
-            ('pack', urwid.Text(STREAM_MARKER_PUBLIC)),
+            ('pack', urwid.Text((color, STREAM_MARKER_PUBLIC))),
             self.stream_write_box,
             ('pack', urwid.Text(STREAM_TOPIC_SEPARATOR)),
             self.title_write_box], dividechars=1)
@@ -149,15 +155,17 @@ def _set_stream_write_box_style(self, widget: ReadlineEdit,
                                     new_text: str) -> None:
         # FIXME: Refactor when we have ~ Model.is_private_stream
         stream_marker = STREAM_MARKER_INVALID
+        color = 'general_bar'
         if self.model.is_valid_stream(new_text):
             stream = self.model.stream_dict[
                      self.model.stream_id_from_name(new_text)]
             if stream['invite_only']:
                 stream_marker = STREAM_MARKER_PRIVATE
             else:
                 stream_marker = STREAM_MARKER_PUBLIC
+            color = stream['color']
         (self.header_write_box[self.FOCUS_HEADER_PREFIX_STREAM]
-         .set_text(stream_marker))
+         .set_text((color, stream_marker)))
 
     def _topic_box_autocomplete(self, text: str, state: Optional[int]
                                 ) -> Optional[str]: