Python Tkinter Text Widget with Auto & Custom Scroll
It's hard to tell what's really going on but have you considered using a Queue?
from Tkinter import *import time, Queue, threaddef simulate_input(queue): for i in range(100): info = time.time() queue.put(info) time.sleep(0.5)class Demo: def __init__(self, root, dataQueue): self.root = root self.dataQueue = dataQueue self.text = Text(self.root, height=10) self.scroller = Scrollbar(self.root, command=self.text.yview) self.text.config(yscrollcommand=self.scroller.set) self.text.tag_config('newline', background='green') self.scroller.pack(side='right', fill='y') self.text.pack(fill='both', expand=1) self.root.after_idle(self.poll) def poll(self): try: data = self.dataQueue.get_nowait() except Queue.Empty: pass else: self.text.tag_remove('newline', '1.0', 'end') position = self.scroller.get() self.text.insert('end', '%s\n' %(data), 'newline') if (position[1] == 1.0): self.text.see('end') self.root.after(1000, self.poll)q = Queue.Queue()root = Tk()app = Demo(root, q)worker = thread.start_new_thread(simulate_input, (q,))root.mainloop()
Regarding your demo script.
You're doing GUI stuff from the non-GUI thread. That tends to cause problems.
OK,
based on the valuable suggestions by noob oddy I was able to rewrite the example script by using the Tkinter.generate_event() method to generate asynchronous event and a queue to pass the information.
Every time a line is read from the stream (which is simulated by a constant string and a delay), I append the line to a queue (because passing objects to the event method is not supported AFAIK) and then create a new event.
The event callback method retrieves the message from the queue and adds it to the Text widged. This works because this method is called from the Tkinter mainloop an thus it cannot interfere with the other jobs.
Here is the script:
import re,sys,timefrom Tkinter import *import Tkinterimport threadingimport tracebackimport Queueclass ReaderThread(threading.Thread): def __init__(self, root, queue): print "Thread init" threading.Thread.__init__(self) self.root = root self.running = True self.q = queue def stop(self): print "Stopping thread" running = False def run(self): print "Thread started" time.sleep(5) try: while(self.running): # emulating delay when reading from serial interface time.sleep(0.05) curline = "the quick brown fox jumps over the lazy dog\n" try: self.q.put(curline) self.root.event_generate('<<AppendLine>>', when='tail') # If it failed, the window has been destoyed: over except TclError as e: print e break except Exception as e: traceback.print_exc(file=sys.stdout) print "Exception in receiver thread, stopping..." pass print "Thread stopped"class Transformer: def __init__(self): self.q = Queue.Queue() self.lineIndex = 1 pass def appendLine(self, event): line = self.q.get_nowait() if line == None: return i = self.lineIndex curIndex = "1.0" lowerEdge = 1.0 pos = 1.0 # get cur position pos = self.scrollbar.get()[1] # Disable scrollbar self.text.configure(yscrollcommand=None, state=NORMAL) # Add to text window self.text.insert(END, str(line)) startIndex = repr(i) + ".0" curIndex = repr(i) + ".end" # Perform colorization if i % 6 == 0: self.text.tag_add("warn", startIndex, curIndex) elif i % 6 == 1: self.text.tag_add("debug", startIndex, curIndex) elif i % 6 == 2: self.text.tag_add("info", startIndex, curIndex) elif i % 6 == 3: self.text.tag_add("error", startIndex, curIndex) elif i % 6 == 4: self.text.tag_add("fatal", startIndex, curIndex) i = i + 1 # Enable scrollbar self.text.configure(yscrollcommand=self.scrollbar.set, state=DISABLED) # Auto scroll down to the end if scroll bar was at the bottom before # Otherwise allow customer scrolling if pos == 1.0: self.text.yview(END) self.lineIndex = i def start(self): """starts to read linewise from self.in_stream and parses the read lines""" count = 1 self.root = Tk() self.root.title("Tkinter Auto-Scrolling Test")# self.root.bind('<<AppendLine>>', self.appendLine) self.topPane = PanedWindow(self.root, orient=HORIZONTAL) self.topPane.pack(side=TOP, fill=X) self.lowerPane = PanedWindow(self.root, orient=VERTICAL) self.scrollbar = Scrollbar(self.root) self.scrollbar.pack(side=RIGHT, fill=Y) self.text = Text(wrap=WORD, yscrollcommand=self.scrollbar.set) self.scrollbar.config(command=self.text.yview) # Color definition for log levels self.text.tag_config("debug",foreground="gray50") self.text.tag_config("info",foreground="green") self.text.tag_config("warn",foreground="orange") self.text.tag_config("error",foreground="red") self.text.tag_config("fatal",foreground="#8B008B") # set default color self.text.config(background="black", foreground="gray"); self.text.pack(expand=YES, fill=BOTH) self.lowerPane.add(self.text) self.lowerPane.pack(expand=YES, fill=BOTH) t = ReaderThread(self.root, self.q) print "Starting thread" t.start() try: self.root.mainloop() except Exception as e: print "Exception in window manager: ", e t.stop() t.join()if __name__ == "__main__": try: trans = Transformer() trans.start() except Exception as e: print "Error: ", e sys.exit(1) Thanks again to everybody who contributed for your help!