views: Markup stream description using MessageBox.transform_content().

Footlinks support is added in a subsequent commit.

Test amended.

Fixes zulip#743.

Author: preetmishra

tests/ui/test_ui_tools.py

@@ -1454,9 +1454,15 @@ def mock_external_classes(self, mocker, monkeypatch):
         self.controller.model.is_muted_stream.return_value = False
         self.controller.model.is_pinned_stream.return_value = False
         mocker.patch(VIEWS + ".urwid.SimpleFocusListWalker", return_value=[])
+        mocker.patch(VIEWS + '.MessageBox.transform_content',
+                     return_value=('Hey', OrderedDict(), list()))
         stream_id = 10
-        self.controller.model.stream_dict = {stream_id: {'name': 'books',
-                                                         'description': 'hey'}}
+        self.controller.model.stream_dict = {
+            stream_id: {
+                'name': 'books',
+                'rendered_description': '<p>Hey</p>',
+            }
+        }
         self.stream_info_view = StreamInfoView(self.controller, stream_id)
 
     @pytest.mark.parametrize('key', {*keys_for_command('GO_BACK'),

zulipterminal/ui_tools/views.py

@@ -14,7 +14,7 @@
 from zulipterminal.helper import (
     Message, asynch, edit_mode_captions, match_stream, match_user,
 )
-from zulipterminal.ui_tools.boxes import PanelSearchBox
+from zulipterminal.ui_tools.boxes import MessageBox, PanelSearchBox
 from zulipterminal.ui_tools.buttons import (
     HomeButton, MentionedButton, MessageLinkButton, PMButton, StarredButton,
     StreamButton, TopicButton, UnreadPMButton, UserButton,
@@ -1047,8 +1047,11 @@ def __init__(self, controller: Any, stream_id: int) -> None:
         self.controller = controller
         stream = controller.model.stream_dict[stream_id]
         title = '# {}'.format(stream['name'])
-        desc = stream['description']
-        stream_info_content = [('', [desc]), ('Stream settings', [])]
+        rendered_desc = stream['rendered_description']
+
+        stream_info_content = (
+            [('Stream settings', [])]
+        )  # type: PopUpViewTableContent
         popup_width, column_widths = self.calculate_table_widths(
             stream_info_content, len(title))
 
@@ -1064,12 +1067,23 @@ def __init__(self, controller: Any, stream_id: int) -> None:
         urwid.connect_signal(pinned_setting, 'change',
                              self.toggle_pinned_status)
 
+        markup_desc, *_ = MessageBox.transform_content(
+            rendered_desc,
+            self.controller.model.server_url,
+        )
+        desc = urwid.Text(markup_desc)
+
         # Manual because calculate_table_widths does not support checkboxes.
         # Add 4 to checkbox label to accomodate the checkbox itself.
         popup_width = max(popup_width, len(muted_setting.label) + 4,
-                          len(pinned_setting.label) + 4)
+                          len(pinned_setting.label) + 4, desc.pack()[0])
         self.widgets = self.make_table_with_categories(stream_info_content,
                                                        column_widths)
+
+        # Stream description.
+        self.widgets.insert(0, desc)
+        self.widgets.insert(1, urwid.Text(''))  # Add a newline.
+
         self.widgets.append(muted_setting)
         self.widgets.append(pinned_setting)
         super().__init__(controller, self.widgets, 'STREAM_DESC', popup_width,