[PATCH v3 08/13] python/aqmp-tui: add syntax highlighting

[G S Niteesh Babu]

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>
---
 python/qemu/aqmp/aqmp_tui.py | 52 +++++++++++++++++++++++++++---------
 1 file changed, 40 insertions(+), 12 deletions(-)

diff --git a/python/qemu/aqmp/aqmp_tui.py b/python/qemu/aqmp/aqmp_tui.py
index ab9ada793a..0d5ec62cb7 100644
--- a/python/qemu/aqmp/aqmp_tui.py
+++ b/python/qemu/aqmp/aqmp_tui.py
@@ -19,6 +19,8 @@
     Union,
 )
 
+from pygments import lexers
+from pygments import token as Token
 import urwid
 import urwid_readline
 
@@ -35,6 +37,22 @@
 LOGGER = logging.getLogger()
 
 
+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 given multiline JSON message into a single line message.
@@ -57,17 +75,14 @@ def __init__(self, address: Union[str, Tuple[str, int]]) -> 
None:
         self.aloop: Optional[Any] = None  # FIXME: Use more concrete type.
         super().__init__()
 
-    def add_to_history(self, msg: str) -> None:
-        urwid.emit_signal(self, UPDATE_MSG, msg)
+    def add_to_history(self, msg: str, level: Optional[str] = None) -> None:
+        urwid.emit_signal(self, UPDATE_MSG, msg, level)
 
     def _cb_outbound(self, msg: Message) -> Message:
         # FIXME: I think the ideal way to omit these messages during in-TUI
-        # logging will be to add a filter to the logger. We can use regex to
-        # filter out messages starting with 'Request:' or 'Response:' but I
-        # think a better approach will be encapsulate the message in an object
-        # and filter based on the object. Encapsulation of the message will
-        # also be necessary when we want different formatting of messages
-        # inside TUI.
+        # logging will be to add a filter to the logger. We can use
+        # regex/startswith to filter out messages starting with 'Request:' or
+        # 'Response:'. If possible please suggest other ideas.
         handler = LOGGER.handlers[0]
         if not isinstance(handler, TUILogHandler):
             LOGGER.debug('Request: %s', str(msg))
@@ -156,6 +171,9 @@ def _get_formatted_address(self) -> str:
             self._set_status('Server shutdown')
 
     def run(self, debug: bool = False) -> None:
+        screen = urwid.raw_display.Screen()
+        screen.set_terminal_properties(256)
+
         self.aloop = asyncio.get_event_loop()
         self.aloop.set_debug(debug)
 
@@ -167,6 +185,8 @@ def run(self, debug: bool = False) -> None:
         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)
 
@@ -251,7 +271,8 @@ def __init__(self, master: App) -> None:
         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:
         self.history.append(urwid.Text(history))
         if self.history:
             self.history.set_focus(len(self.history) - 1)
@@ -271,8 +292,15 @@ def __init__(self, master: App) -> None:
         super().__init__(self.body)
         urwid.connect_signal(self.master, UPDATE_MSG, self.cb_add_to_history)
 
-    def cb_add_to_history(self, msg: str) -> None:
-        self.history.add_to_history(msg)
+    def cb_add_to_history(self, msg: str, level: Optional[str] = None) -> None:
+        formatted = []
+        if level:
+            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):
@@ -298,7 +326,7 @@ def emit(self, record: LogRecord) -> None:
         level = record.levelname
         msg = record.getMessage()
         msg = f'[{level}]: {msg}'
-        self.tui.add_to_history(msg)
+        self.tui.add_to_history(msg, level)
 
 
 def main() -> None:
-- 
2.17.1