python/aqmp-tui: Add syntax highlighting

Add syntax highlighting for the incoming and outgoing QMP messages.
This is achieved using the pygments module which was added in a
previous commit.

The current implementation is a really simple one which doesn't
allow for any configuration. In future this has to be improved
to allow for easier theme config using an external config of
some sort.

Signed-off-by: G S Niteesh Babu <niteesh.gs@gmail.com>
Message-Id: <20210823220746.28295-6-niteesh.gs@gmail.com>
Signed-off-by: John Snow <jsnow@redhat.com>

python/qemu/aqmp/aqmp_tui.py

@@ -30,6 +30,8 @@ from typing import (
     cast,
 )
 
+from pygments import lexers
+from pygments import token as Token
 import urwid
 import urwid_readline
 
@@ -45,6 +47,22 @@ from .util import create_task, pretty_traceback
 UPDATE_MSG: str = 'UPDATE_MSG'
 
 
+palette = [
+    (Token.Punctuation, '', '', '', 'h15,bold', 'g7'),
+    (Token.Text, '', '', '', '', 'g7'),
+    (Token.Name.Tag, '', '', '', 'bold,#f88', 'g7'),
+    (Token.Literal.Number.Integer, '', '', '', '#fa0', 'g7'),
+    (Token.Literal.String.Double, '', '', '', '#6f6', 'g7'),
+    (Token.Keyword.Constant, '', '', '', '#6af', 'g7'),
+    ('DEBUG', '', '', '', '#ddf', 'g7'),
+    ('INFO', '', '', '', 'g100', 'g7'),
+    ('WARNING', '', '', '', '#ff6', 'g7'),
+    ('ERROR', '', '', '', '#a00', 'g7'),
+    ('CRITICAL', '', '', '', '#a00', 'g7'),
+    ('background', '', 'black', '', '', 'g7'),
+]
+
+
 def format_json(msg: str) -> str:
     """
     Formats valid/invalid multi-line JSON message into a single-line message.
@@ -353,6 +371,9 @@ class App(QMPClient):
         :param debug:
             Enables/Disables asyncio event loop debugging
         """
+        screen = urwid.raw_display.Screen()
+        screen.set_terminal_properties(256)
+
         self.aloop = asyncio.get_event_loop()
         self.aloop.set_debug(debug)
 
@@ -364,6 +385,8 @@ class App(QMPClient):
         event_loop = urwid.AsyncioEventLoop(loop=self.aloop)
         main_loop = urwid.MainLoop(urwid.AttrMap(self.window, 'background'),
                                    unhandled_input=self.unhandled_input,
+                                   screen=screen,
+                                   palette=palette,
                                    handle_mouse=True,
                                    event_loop=event_loop)
 
@@ -487,7 +510,8 @@ class HistoryBox(urwid.ListBox):
         self.history = urwid.SimpleFocusListWalker([])
         super().__init__(self.history)
 
-    def add_to_history(self, history: str) -> None:
+    def add_to_history(self,
+                       history: Union[str, List[Tuple[str, str]]]) -> None:
         """
         Appends a message to the list and set the focus to the last appended
         message.
@@ -531,10 +555,18 @@ class HistoryWindow(urwid.Frame):
 
         :param msg:
             The message to be appended to the history box.
+        :param level:
+            The log level of the message, if it is a log message.
         """
+        formatted = []
         if level:
             msg = f'[{level}]: {msg}'
-        self.history.add_to_history(msg)
+            formatted.append((level, msg))
+        else:
+            lexer = lexers.JsonLexer()  # pylint: disable=no-member
+            for token in lexer.get_tokens(msg):
+                formatted.append(token)
+        self.history.add_to_history(formatted)
 
 
 class Window(urwid.Frame):