enhancement: core/themes: Enclosing the title inside popup.

This is a follow-up commit from PR #849.

Visible improvements:
 * Title standouts more in a popup.
 * Popup border blends with the background.

Author: Ezio-Sarthak

zulipterminal/config/themes.py

@@ -43,6 +43,8 @@
     'edit_tag': 'standout',
     'edit_author': 'bold',
     'edit_time': 'bold',
+    'popup_border': 'standout',
+    'popup_title': 'bold',
 }
 
 
@@ -171,6 +173,10 @@
          None,             DEF['white'],              DEF['black']),
         ('muted',          'light blue',              'black',
          None,             DEF['light_blue'],         DEF['black']),
+        ('popup_title',    'black',                   'white',
+         None,             DEF['black'],              DEF['white']),
+        ('popup_border',   'white',                   'black',
+         None,             DEF['white'],              DEF['black']),
     ],
     'gruvbox_dark': [
         # default colorscheme on 16 colors, gruvbox colorscheme
@@ -251,6 +257,10 @@
          None,             WHITE,             BLACK),
         ('muted',          'light blue',      'black',
          None,             LIGHTBLUE,         BLACK),
+        ('popup_title',    'black',           'white',
+         None,             BLACK,             WHITE),
+        ('popup_border',   'white',           'black',
+         None,             WHITE,             BLACK),
     ],
     'zt_light': [
         (None,             'black',           'white'),
@@ -291,6 +301,8 @@
         ('edit_time',      'dark blue',       'white'),
         ('current_user',   'dark gray',       'white'),
         ('muted',          'dark gray',       'white'),
+        ('popup_title',    'white',           'black'),
+        ('popup_border',   'black',           'white'),
     ],
     'zt_blue': [
         (None,             'black',           'light blue'),
@@ -331,6 +343,8 @@
         ('edit_time',      'dark blue',       'light blue'),
         ('current_user',   'light gray',      'light blue'),
         ('muted',          'light gray',      'light blue'),
+        ('popup_title',    'light blue',      'white'),
+        ('popup_border',   'white',           'light blue'),
     ]
 }  # type: Dict[str, ThemeSpec]
 

zulipterminal/core.py

@@ -162,19 +162,28 @@ def maximum_popup_dimensions(self) -> Tuple[int, int]:
         return max_cols, max_rows
 
     def show_pop_up(self, to_show: Any) -> None:
-        double_lines = dict(tlcorner='╔', tline='═', trcorner='╗',
-                            rline='║', lline='║',
-                            blcorner='╚', bline='═', brcorner='╝')
+        border_lines = dict(tlcorner='▛', tline='▀', trcorner='▜',
+                            rline='▐', lline='▌',
+                            blcorner='▙', bline='▄', brcorner='▟')
+        text = urwid.Text(to_show.title, align='center')
+        title_map = urwid.AttrMap(urwid.Filler(text), 'popup_title')
+        title_box_adapter = urwid.BoxAdapter(title_map, height=1)
+        title_box = urwid.LineBox(
+            title_box_adapter, tlcorner='▀', tline='▀', trcorner='▀',
+            rline='', lline='', blcorner='', bline='', brcorner=''
+        )
+        title = urwid.AttrMap(title_box, 'popup_title')
+        content = urwid.LineBox(to_show, **border_lines)
         self.loop.widget = urwid.Overlay(
-            urwid.LineBox(to_show,
-                          to_show.title,
-                          **double_lines),
+            urwid.AttrMap(urwid.Frame(header=title, body=content),
+                          'popup_border'),
             self.view,
             align='center',
             valign='middle',
             # +2 to both of the following, due to LineBox
+            # +2 to height, due to title enhancement
             width=to_show.width + 2,
-            height=to_show.height + 2,
+            height=to_show.height + 4,
         )
 
     def exit_popup(self) -> None: