import datetime
import queue
import logging
import signal
import time
import threading
import tkinter as tk
from tkinter.scrolledtext import ScrolledText
from tkinter import ttk, VERTICAL, HORIZONTAL, N, S, E, W
logger = logging.getLogger(__name__)
class Clock(threading.Thread):
"""Class to display the time every seconds
Every 5 seconds, the time is displayed using the logging.ERROR level
to show that different colors are associated to the log levels
"""
def __init__(self):
super().__init__()
self._stop_event = threading.Event()
def run(self):
logger.debug('Clock started')
previous = -1
while not self._stop_event.is_set():
now = datetime.datetime.now()
if previous != now.second:
previous = now.second
if now.second % 5 == 0:
level = logging.ERROR
else:
level = logging.INFO
logger.log(level, now)
time.sleep(0.2)
def stop(self):
self._stop_event.set()
class QueueHandler(logging.Handler):
"""Class to send logging records to a queue
It can be used from different threads
The ConsoleUi class polls this queue to display records in a ScrolledText widget
"""
# Example from Moshe Kaplan: https://gist.github.com/moshekaplan/c425f861de7bbf28ef06
# (https://stackoverflow.com/questions/13318742/python-logging-to-tkinter-text-widget) is not thread safe!
# See https://stackoverflow.com/questions/43909849/tkinter-python-crashes-on-new-thread-trying-to-log-on-main-thread
def __init__(self, log_queue):
super().__init__()
self.log_queue = log_queue
def emit(self, record):
self.log_queue.put(record)
class ConsoleUi:
"""Poll messages from a logging queue and display them in a scrolled text widget"""
def __init__(self, frame):
self.frame = frame
# Create a ScrolledText wdiget
self.scrolled_text = ScrolledText(frame, state='disabled', height=12)
self.scrolled_text.grid(row=0, column=0, sticky=(N, S, W, E))
self.scrolled_text.configure(font='TkFixedFont')
self.scrolled_text.tag_config('INFO', foreground='black')
self.scrolled_text.tag_config('DEBUG', foreground='gray')
self.scrolled_text.tag_config('WARNING', foreground='orange')
self.scrolled_text.tag_config('ERROR', foreground='red')
self.scrolled_text.tag_config('CRITICAL', foreground='red', underline=1)
# Create a logging handler using a queue
self.log_queue = queue.Queue()
self.queue_handler = QueueHandler(self.log_queue)
formatter = logging.Formatter('%(asctime)s: %(message)s')
self.queue_handler.setFormatter(formatter)
logger.addHandler(self.queue_handler)
# Start polling messages from the queue
self.frame.after(100, self.poll_log_queue)
def display(self, record):
msg = self.queue_handler.format(record)
self.scrolled_text.configure(state='normal')
self.scrolled_text.insert(tk.END, msg + '\n', record.levelname)
self.scrolled_text.configure(state='disabled')
# Autoscroll to the bottom
self.scrolled_text.yview(tk.END)
def poll_log_queue(self):
# Check every 100ms if there is a new message in the queue to display
while True:
try:
record = self.log_queue.get(block=False)
except queue.Empty:
break
else:
self.display(record)
self.frame.after(100, self.poll_log_queue)
class FormUi:
def __init__(self, frame):
self.frame = frame
# Create a combobbox to select the logging level
values = ['DEBUG', 'INFO', 'WARNING', 'ERROR', 'CRITICAL']
self.level = tk.StringVar()
ttk.Label(self.frame, text='Level:').grid(column=0, row=0, sticky=W)
self.combobox = ttk.Combobox(
self.frame,
textvariable=self.level,
width=25,
state='readonly',
values=values
)
self.combobox.current(0)
self.combobox.grid(column=1, row=0, sticky=(W, E))
# Create a text field to enter a message
self.message = tk.StringVar()
ttk.Label(self.frame, text='Message:').grid(column=0, row=1, sticky=W)
ttk.Entry(self.frame, textvariable=self.message, width=25).grid(column=1, row=1, sticky=(W, E))
# Add a button to log the message
self.button = ttk.Button(self.frame, text='Submit', command=self.submit_message)
self.button.grid(column=1, row=2, sticky=W)
def submit_message(self):
# Get the logging level numeric value
lvl = getattr(logging, self.level.get())
logger.log(lvl, self.message.get())
class ThirdUi:
def __init__(self, frame):
self.frame = frame
ttk.Label(self.frame, text='This is just an example of a third frame').grid(column=0, row=1, sticky=W)
ttk.Label(self.frame, text='With another line here!').grid(column=0, row=4, sticky=W)
class App:
def __init__(self, root):
self.root = root
root.title('Logging Handler')
root.columnconfigure(0, weight=1)
root.rowconfigure(0, weight=1)
# Create the panes and frames
vertical_pane = ttk.PanedWindow(self.root, orient=VERTICAL)
vertical_pane.grid(row=0, column=0, sticky="nsew")
horizontal_pane = ttk.PanedWindow(vertical_pane, orient=HORIZONTAL)
vertical_pane.add(horizontal_pane)
form_frame = ttk.Labelframe(horizontal_pane, text="MyForm")
form_frame.columnconfigure(1, weight=1)
horizontal_pane.add(form_frame, weight=1)
console_frame = ttk.Labelframe(horizontal_pane, text="Console")
console_frame.columnconfigure(0, weight=1)
console_frame.rowconfigure(0, weight=1)
horizontal_pane.add(console_frame, weight=1)
third_frame = ttk.Labelframe(vertical_pane, text="Third Frame")
vertical_pane.add(third_frame, weight=1)
# Initialize all frames
self.form = FormUi(form_frame)
self.console = ConsoleUi(console_frame)
self.third = ThirdUi(third_frame)
self.clock = Clock()
self.clock.start()
self.root.protocol('WM_DELETE_WINDOW', self.quit)
self.root.bind('<Control-q>', self.quit)
signal.signal(signal.SIGINT, self.quit)
def quit(self, *args):
self.clock.stop()
self.root.destroy()
def main():
logging.basicConfig(level=logging.DEBUG)
root = tk.Tk()
app = App(root)
app.root.mainloop()
if __name__ == '__main__':
main()
