Tkinter Freeze on grid_remove - python

So I am trying to build a GUI where I enter some information, clear the entry fields, and then add new entry fields. However, when I try to clear the frame from the root via grid_remove, the application freezes. The relevant code is below.
import tkinter
from threading import Thread
class PinGui(tkinter.Frame):
def __init__(self, client):
self.client = client
self.root = client.root
self.add_pin = client.add_pin
self.end = client.end
tkinter.Frame.__init__(self, self.root)
self.grid_widgets()
self.grid_buttons()
self.bind_keys()
self.grid(padx=32, pady=32)
def grid_buttons(self, b1='Add', b2='Reset', b3='Quit'):
self.addButton = tkinter.Button(self, text=b1, command=self.validate)
self.resetButton = tkinter.Button(self, text=b2, command=self.reset)
self.quitButton = tkinter.Button(self, text=b3, command=self.end)
self.buttons = [self.addButton, self.resetButton, self.quitButton]
for i in range(3): self.buttons[i].grid(row=i, column=11)
def grid_widgets(self):
widths = [3,3,4,4,6]
self.pin_vars = []
self.pin_fields = []
for i in range(5):
self.pin_vars.append(tkinter.StringVar())
self.pin_fields.append(
tkinter.Entry(self,width=widths[i], textvariable=self.pin_vars[i])
)
self.pin_fields[i].grid(row=0, column=2*i, padx=3)
self.pin_fields[0].focus_set()
def bind_keys(self):
self.root.bind_all("<Return>", self.validate)
self.root.bind_all("<Escape>", self.end)
def validate(self, args=None):
self.client.pin = []
for field in self.pin_fields:
self.client.pin.append(field.get())
Thread(target=self.add_pin).start()
def ungrid(self):
for field in self.pin_fields: field.grid_remove()
for button in self.buttons: button.grid_remove()
self.display.grid_remove()
And:
class PinClient:
def __init__(self):
self.root = tkinter.Tk()
self.gui = PinGui(self)
self.pins = []
def add_pin(self):
self.gui.reset()
if 'display' in self.__dict__:
self.pins.append(self.pin)
self.display.add_pin(self.pin)
self.ping("Enter PIN for Comp %s:" % len(self.display.col1))
if len(self.display.col1) > 5:
self.end() # THIS IS WHERE IT FREEZES
else:
self.subject = self.pin
self.display = Display(self.root, self.pin)
self.display.grid(row=1, padx=32, pady=32)
self.ping("Enter PIN for Comp 1:")
def ping(self, msg):
self.gui.d_var.set(msg)
def end(self, args=None):
self.gui.ungrid()
class Display(tkinter.Frame):
def __init__(self, master, pin):
tkinter.Frame.__init__(self, master)
self.pin = pin
self.col1 = []
self.col2 = []
self.col1.append(tkinter.Label(self, text="Subject:"))
self.col2.append(tkinter.Label(self, text=self.pin))
self.grid_widgets()
def grid_widgets(self):
self.ungrid()
for i in range(len(self.col1)):
self.col1[i].grid(row=i, column=0)
self.col2[i].grid(row=i, column=1)
def ungrid(self):
for i in range(len(self.col1)):
self.col1[i].grid_remove()
self.col2[i].grid_remove()
def add_pin(self, pin):
self.col1.append(tkinter.Label(self, text="Comp %s:" % len(self.col1)))
self.col2.append(tkinter.Label(self, text=pin))
i = len(self.col1)
self.col1[i-1].grid(row=i, column=0)
self.col2[i-1].grid(row=i, column=1)
It seems to be somehow related to the threading, but I haven't been able to find any reason this should freeze. Any help is greatly appreciated!

Tkinter is not thread safe. If you do anything in a thread other than the main thread that touches a GUI object then you will get unpredictable results. Almost certainly, it is threading that is causing your problem, since you are trying to access widgets from the worker thread.

Related

communication between tkinter toplevels

I'm working on a little project and made a little on-screen keyboard as a tkinter Toplevel
my application is buildt like this:
Root-Window (Tk-Widget)
input 1 (Entry-Widget)
input 2 (Entry-Widget)
input 3 (Text-Widget)
on_screen-keyboard (Toplevel-Widget)
the Toplevel-Widget contains Buttons, with callbacks that should enter text in the entries (just like keyboard-Buttons)
What I want is a communication between children of the keyboard/the keyboard and the last active input-Widget. My Problem is, that I don't know, how to say the keyboard, to which input-Widget it should send the message.
import tkinter as tk
from tkinter import ttk
class MainWindow(tk.Tk):
def __init__(self, *args, **kwargs):
tk.Tk.__init__(self, *args, **kwargs)
self.active_input = tk.Variable(value=None)
ttk.Button(self, text="show Keyboard", command=lambda: Keyboard(self)).pack()
self.text = tk.StringVar(value="")
self.input1 = ttk.Entry(self)
self.input1.bind("<FocusIn>", lambda e: self.active_input.set(self.input1))
self.input2 = ttk.Entry(self)
self.input2.bind("<FocusIn>", lambda e: self.active_input.set(self.input2))
self.input3 = tk.Text(self, height=3, width=15)
self.input3.bind("<FocusIn>", lambda e: self.active_input.set(self.input3))
self.input1.pack()
self.input3.pack()
self.input2.pack()
class Keyboard(tk.Toplevel):
OPENED = False
NAME = "- Keyboard -"
NUM = [{"text":"1", "width":1},
{"text":"2", "width":1},
{"text":"3", "width":2}]
CHAR= [{"text":"A", "width":1},
{"text":"B", "width":1},
{"text":"C", "width":2}]
def __init__(self, master):
if not Keyboard.OPENED:
Keyboard.OPENED = True
print("keyboard opened!")
self.master = master
tk.Toplevel.__init__(self, master)
self.title(self.NAME)
self.protocol("WM_DELETE_WINDOW", self.close)
self.keyb_nb = ttk.Notebook(self)
self.keyb_nb.pack()
self.num_tab = ttk.Frame(self.keyb_nb)
self.createPad(self.num_tab, Keyboard.NUM,2)
self.keyb_nb.add(self.num_tab, text="123")
self.char_tab = ttk.Frame(self.keyb_nb)
self.createPad(self.char_tab, Keyboard.CHAR, 2)
self.keyb_nb.add(self.char_tab, text="ABC")
def createPad(self, master, pad:list, max_col):
self.co_count = 0
self.ro = 1
for button in pad:
button["id"] = ttk.Button(master, width=6*button["width"], text=button["text"], command=self.bclicked(button))
if self.co_count >= max_col:
self.ro = self.ro + 1
self.co_count = 0
button["id"].grid(row=self.ro, columnspan=button["width"], column=self.co_count)
self.co_count = self.co_count+button["width"]
def bclicked(self, button:dict):
"""
reciver = self.master.active_input #I think the Problem here is, that the variable contains a string, not a widget
reciever.focus_force()
reciever.insert(index=tk.INSERT, string=button["text"])
"""
pass
def close(self):
Keyboard.OPENED = False
self.destroy()
print("keyboard closed!")
root = MainWindow()
root.mainloop()
Here the init of the Mainwindow and the bclicked of the Keyboard class are important...
the code is debug-ready
I would prefer a solution, similar to the communication in the internet (sender=button, receiver-id, message), but very welcome every working solution
btw: I'm also looking for a solution, how I don't have to force the input to focus and the Toplevel stays an the highest layer of the screen (that if I focus the Tk-Widget/one of the inputs/the button, the keyboard will stay in front of it)
SUMMARY: how do I find out, which of the 3 input-widgets was active at last, when the keyboard-toplevel has already the focus?
I may made more changes than needed, but mainly focus on the method keyboard_triger() and pass_key_to_master(), this two use the idea that the variable master implements, having access to call methods out of scope.
Olso the method set_focused_object() stores a reference to the last object beeng focused, note than it stores the widget and not the event, it's easyer than searching each time the object
import tkinter as tk
from tkinter import ttk
class MainWindow(tk.Tk):
def keyboard_triger(self, key):
# to identify wath object is just use
# isinstance(self.active_input, ttk.Entry)
self.active_input.insert(tk.END, key)
def new_keyboard(self):
Keyboard(self)
def set_focused_object(self, event):
self.active_input = event.widget
def __init__(self):
tk.Tk.__init__(self)
self.active_input = None
ttk.Button(self, text="Show Keyboard", command=self.new_keyboard).pack()
self.input1 = ttk.Entry(self)
self.input1.bind("<FocusIn>", self.set_focused_object)
self.input1.pack()
self.input2 = ttk.Entry(self)
self.input2.bind("<FocusIn>", self.set_focused_object)
self.input2.pack()
self.input3 = tk.Text(self, height=3, width=15)
self.input3.bind("<FocusIn>", self.set_focused_object)
self.input3.pack()
class Keyboard(tk.Toplevel):
def pass_key_to_master(self, key):
self.master.keyboard_triger(key)
def __init__(self, master):
tk.Toplevel.__init__(self, master)
self.master = master
self.title('Keyboard')
# this way of agruping keys stores the kwags
# of the drawing method
keys = {
'A': {'x': 0, 'y': 0},
'B': {'x': 20, 'y': 20},
'C': {'x': 50, 'y': 50}
}
# expected structure
# {string key: reference to the button}
self.buttons = {}
for i in keys:
self.buttons[i] = tk.Button( # i=i is required to make a instance
self, text=i, command=lambda i=i: self.pass_key_to_master(i)
)
self.buttons[i].place(**keys[i])
if __name__ == '__main__':
root = MainWindow()
root.mainloop()
Your code maybe could have a better construction.(But I didn't revise your code construction.)
Followed by your code,I use a global variable.And fix some errors in your code.And it could work normally in my computer.
import tkinter as tk
from tkinter import ttk
class MainWindow(tk.Tk):
def __init__(self, *args, **kwargs):
tk.Tk.__init__(self, *args, **kwargs)
self.active_input = tk.Variable(value=None)
ttk.Button(self, text="show Keyboard", command=lambda: Keyboard(self)).pack()
global focusedWidget
focusedWidget = None
self.text = tk.StringVar(value="")
self.input1 = ttk.Entry(self)
self.input1.bind("<FocusIn>", self.getFocusWidget)
self.input2 = ttk.Entry(self)
self.input2.bind("<FocusIn>", self.getFocusWidget)
self.input3 = tk.Text(self, height=3, width=15)
self.input3.bind("<FocusIn>", self.getFocusWidget)
self.input1.pack()
self.input3.pack()
self.input2.pack()
def getFocusWidget(self,event): # this function could be a static function
global focusedWidget
focusedWidget = event.widget
class Keyboard(tk.Toplevel):
OPENED = False
NAME = "- Keyboard -"
NUM = [{"text":"1", "width":1},
{"text":"2", "width":1},
{"text":"3", "width":2}]
CHAR= [{"text":"A", "width":1},
{"text":"B", "width":1},
{"text":"C", "width":2}]
def __init__(self, master):
if not Keyboard.OPENED:
Keyboard.OPENED = True
print("keyboard opened!")
self.master = master
tk.Toplevel.__init__(self, master)
self.title(self.NAME)
self.protocol("WM_DELETE_WINDOW", self.close)
self.keyb_nb = ttk.Notebook(self)
self.keyb_nb.pack()
self.num_tab = ttk.Frame(self.keyb_nb)
self.createPad(self.num_tab, Keyboard.NUM,2)
self.keyb_nb.add(self.num_tab, text="123")
self.char_tab = ttk.Frame(self.keyb_nb)
self.createPad(self.char_tab, Keyboard.CHAR, 2)
self.keyb_nb.add(self.char_tab, text="ABC")
def createPad(self, master, pad:list, max_col):
self.co_count = 0
self.ro = 1
for button in pad:
button["id"] = ttk.Button(master, width=6*button["width"], text=button["text"], command=lambda button=button:self.bclicked(button)) # this lambda expression has some errors.
if self.co_count >= max_col:
self.ro = self.ro + 1
self.co_count = 0
button["id"].grid(row=self.ro, columnspan=button["width"], column=self.co_count)
self.co_count = self.co_count+button["width"]
def bclicked(self, button:dict):
global focusedWidget
"""
reciver = self.master.active_input #I think the Problem here is, that the variable contains a string, not a widget
reciever.focus_force()
reciever.insert(index=tk.INSERT, string=button["text"])
"""
if not focusedWidget: # If user hasn't click a entry or text widget.
print("Please select a entry or text")
return
if focusedWidget.widgetName=='ttk::entry': # use if statement to check the type of selected entry.
focusedWidget.insert(index=tk.INSERT,string=button["text"])
else:
focusedWidget.insert("end",button["text"])
def close(self):
Keyboard.OPENED = False
self.destroy()
print("keyboard closed!")
root = MainWindow()
root.mainloop()

Python tkinter threading and window refresh

I'm using python and tkinter to build a visualization tool that can refresh and visualize an updating object. Right now, the object can't change because the threading is not working. Any help or general knowledge would be appreciated. I'm relatively new to threading and tkinter.
example object I want to ingest
class color1:
def __init__(self, color):
self.color = color
def change_col(self, new_color):
self.color = new_color
def pass_col(self):
return(self)
my visualization code
class my_visual(threading.Thread):
def __init__(self, col1):
threading.Thread.__init__(self)
self.start()
self.col1 = col1
def viz(self):
self.root = Tk()
btn1 = Button(self.root, text = 'Refresh', command = self.refresh)
btn1.pack()
frame = Frame(self.root, width = 100, height = 100, bg = self.col1.color)
frame.pack()
btn2 = Button(self.root, text = 'Close', command = self.exit)
btn2.pack()
self.root.mainloop()
def refresh(self):
self.root.quit()
self.root.destroy()
self.col1 = self.col1.pass_col()
self.viz()
def exit(self):
self.root.quit()
self.root.destroy()
Code that works
c = color1('RED')
test = my_visual(c)
test.viz()
Code that doesn't work
In this version, the refresh works, but the threading doesn't. When the threading is working, the refresh won't pick up that the object has changed.
c.change_col('BLUE')
If you extend the threading.Thread class you need to override the run() method with your custom functionality. With no run method, the thread dies immediately. You can test whether a thread is alive with my_visual.is_alive().
The problem is that your test.viz() is an infinite loop because of self.root.mainloop(), so you cannot do anything once you called that function. The solution is to use a thread for test.viz(), and your thread for the class my_visual is no more necessary.
I added a time.sleep of 2 seconds before the refresh makes it blue, otherwise the color is blue at beginning.
Here you go :
import threading
from tkinter import *
import time
class color1:
def __init__(self, color):
self.color = color
def change_col(self, new_color):
self.color = new_color
def pass_col(self):
return(self)
class my_visual():
def __init__(self, col1):
self.col1 = col1
def viz(self):
self.root = Tk()
btn1 = Button(self.root, text = 'Refresh', command = self.refresh)
btn1.pack()
frame = Frame(self.root, width = 100, height = 100, bg = self.col1.color)
frame.pack()
btn2 = Button(self.root, text = 'Close', command = self.exit)
btn2.pack()
self.root.mainloop()
def refresh(self):
self.root.quit()
self.root.destroy()
self.col1 = self.col1.pass_col()
print("self.col1", self.col1, self.col1.color)
self.viz()
def exit(self):
self.root.quit()
self.root.destroy()
c = color1('RED')
test = my_visual(c)
t2 = threading.Thread(target = test.viz)
t2.start()
time.sleep(2)
print('Now you can change to blue when refreshing')
c.change_col('BLUE')

Close a tkinter GUI after a period of time

I want to create a GUI that shows a message and it is automatically destroyed after some time. I saw this question in different posts but none of the solutions proposed worked out for my App. Here a small part of the code
class MessageShort(tkSimpleDialog.Dialog):
def __init__(self, parent, text, time):
self.top=Toplevel.__init__(self, parent)
self.transient(parent)
self.parent = parent
self.text=text
self.time=time
body = Frame(self)
self.initial_focus = self.body(body)
body.pack(padx=10, pady=10)
if not self.initial_focus:
self.initial_focus = self
self.geometry("+%d+%d" % (parent.winfo_rootx()+200,
parent.winfo_rooty()+75))
self.initial_focus.focus_set()
self.wait_window(self)
def body(self, master):
m=Message(master, text=self.text).grid(row=0,column=0,sticky=W)
master.after(self.time,master.destroy())
MessageShort(root,"Select date and decimal format",2000)#call from another part to the class to create the GUI message
root = Tk()
app = App(root) #main App
root.mainloop()
The App have different Menus and Tkinter classes to display the different tools
With the current code I close the App and I just want to close the message but not the App
Create a timer and set destroying the root as it's callback:
from threading import Timer
import time
def called_after_timer():
if(root != None):
root.destroy()
t = Timer(20 * 60, called_after_timeout)
t.start()
# do something else, such as
time.sleep(1500)
Finally I got something that seems to work
class MessageShort(tkSimpleDialog.Dialog):
def __init__(self, parent, text, time):
self.top=Toplevel.__init__(self, parent)
self.transient(parent)
self.parent = parent
self.text=text
self.time=time
body = Frame(self)
self.initial_focus = self.body(body)
body.pack(padx=10, pady=10)
if not self.initial_focus:
self.initial_focus = self
self.geometry("+%d+%d" % (parent.winfo_rootx()+200,
parent.winfo_rooty()+75))
self.initial_focus.focus_set()
self.wait_window(self)
def body(self, master):
m=Message(master, text=self.text).grid(row=0,column=0,sticky=W)
master.after(self.time,self.destroy)
MessageShort(root,"Select date and decimal format",2000)#call from another part to the class to create the GUI message
root = Tk()
app = App(root) #main App
root.mainloop()
In the last line self.master.destroy destroys m but not the container itself. So it has to call to self.destroy

configure tkinter object from separate class

I have a simple program with two classes, one controls a relay board via a serial.serial connection. The other class is for a GUI which will send commands to the relay class and then display the status of the relay board.
I'm having an issue with sending messages from the relay class to the tkinter class. The messages only appear once the relay command has finished. I've cut down my program below. Test.test() represents a function in my relay class where as the MainWindow class is my GUI.
Someone has pointed out to use threading to handle the messages being passed between the classes. Is that my only option? I have not delved into threading yet.
from Tkinter import *
import time
import ScrolledText
class Test():
def test(self):
main.textboxupdate(" test start ")
time.sleep(2)
main.textboxupdate(" test middle ")
time.sleep(2)
main.textboxupdate(" test end ")
class MainWindow(Frame):
def __init__(self, *args, **kwargs):
Frame.__init__(self, *args, **kwargs)
self.canvas = Canvas(width=1200,height=700)
self.canvas.pack(expand=YES,fill=BOTH)
self.frame = Frame(self.canvas)
self.TextBox = ScrolledText.ScrolledText(self.frame)
self.open = Button(self.frame, text="Open Cover",
command=test.test)
def createtextbox(self, statusmsg):
self.frame.place(x=0,y=0)
self.TextBox.config(state = NORMAL)
self.TextBox.insert(END, statusmsg,('error'))
self.TextBox.config(state = 'disabled', height = 2, width = 35)
self.TextBox.see(END)
self.TextBox.grid(columnspan=2, rowspan = 1)
self.open.grid()
def textboxupdate(self, statusmsg):
statusmsg = statusmsg +'\n'
self.TextBox.config(state = NORMAL)
self.TextBox.insert(END, statusmsg,('error'))
self.TextBox.config(state = 'disabled', height = 10, width = 50)
self.TextBox.see(END)
test = Test()
root = Tk()
main = MainWindow(root)
main.createtextbox('Startup\n')
root.mainloop()
Here's one option:
from Tkinter import *
import time
import ScrolledText
import threading, Queue
class Test():
def __init__(self):
self.msg_queue = Queue.Queue()
def test(self):
self.msg_queue.put(" test start ")
time.sleep(2)
self.msg_queue.put(" test middle ")
time.sleep(2)
self.msg_queue.put(" test end ")
class MainWindow(Frame):
def __init__(self, *args, **kwargs):
Frame.__init__(self, *args, **kwargs)
self.canvas = Canvas(width=1200,height=700)
self.canvas.pack(expand=YES,fill=BOTH)
self.frame = Frame(self.canvas)
self.TextBox = ScrolledText.ScrolledText(self.frame)
self.open = Button(self.frame, text="Open Cover",
command=self.create_thread)
self.test_thread = None
self.createtextbox("")
def create_thread(self):
self.test_thread = threading.Thread(target=test.test)
self.test_thread.start()
self.after(10, self.update_textbox)
def update_textbox(self):
while not test.msg_queue.empty():
self.textboxupdate(test.msg_queue.get())
if self.test_thread.is_alive():
self.after(10, self.update_textbox)
else:
self.test_thread = None
def createtextbox(self, statusmsg):
self.frame.place(x=0,y=0)
self.TextBox.config(state = NORMAL)
self.TextBox.insert(END, statusmsg,('error'))
self.TextBox.config(state = 'disabled', height = 2, width = 35)
self.TextBox.see(END)
self.TextBox.grid(columnspan=2, rowspan = 1)
self.open.grid()
def textboxupdate(self, statusmsg):
statusmsg = statusmsg +'\n'
self.TextBox.config(state = NORMAL)
self.TextBox.insert(END, statusmsg,('error'))
self.TextBox.config(state = 'disabled', height = 10, width = 50)
self.TextBox.see(END)
self.update_idletasks()
test = Test()
main = MainWindow()
main.pack()
main.mainloop()
The first change is that instead of calling a function, Test.test puts the messages onto a queue. Test.test is started in a separate thread by MainWindow.start_thread. MainWindow.start_thread also schedules a check on the thread by asking tkinter to call update_textbox after 10 milliseconds (self.after(10, self.update_textbox)). This function takes all the new messages off the queue, and displays them. Then, if the thread is still running, it reschedules itself, otherwise it resets the MainWindow.

Receiveing input from Python's tkinter entry widget and displaying it in a label

The program I am working with currently requires input from the user to be displayed on the programs window. I have researched on both the internet and stackoverflow, discovering several solutions to my problem, but none seem to work. My goal is to receive input from the user via Python's tkinter entry widget and display the results in a new label, while taking out my initial one and the entry box, however, the program is rejecting my attempts at an answer.
What strategy, lines of code/library's, or pieces of advice do you have for me to accomplish my goal?
My existing solutions:
.get()
textvariable=self.entdat
Existing code is as follows:
from Tkinter import *
import time
class Input(Frame):
def __init__(self, parent=None, **kw):
Frame.__init__(self, parent, background="white")
self.parent = parent
self.initUI()
self.entdat = StringVar
self.timestr = StringVar()
self.makeWidgets()
def makeWidgets(self):
self.ol = Label(text="Objective:")
self.ol.pack(side=TOP)
self.ew = Entry()
self.ew.pack(side=TOP)
self.b = Button(text="OK", command=self.clicked)
self.b.pack(side=TOP)
def clicked(self):
self.entdat = self.ew.get()
self.dat = Label(textvariable=self.ew.get())
self.dat.pack(side=TOP)
self.hide_Widget()
def hide_Widget(event):
event.ew.pack_forget()
event.ol.pack_forget()
event.b.pack_forget()
def main():
root = Tk()
root.geometry("240x135+25+50")
tm = Input(root)
tm.pack(side=TOP)
root.mainloop()
if __name__ == '__main__':
main()
I amended your code, so that it executes at least, and hopefully in a way you want.
from Tkinter import *
class Input(Frame):
def __init__(self, parent=None, **kw):
Frame.__init__(self, parent, background="white")
self.parent = parent
self.entdat = StringVar()
self.makeWidgets()
def makeWidgets(self):
self.ol = Label(text="Objective:")
self.ol.pack(side=TOP)
self.ew = Entry(textvariable=self.entdat)
self.ew.pack(side=TOP)
self.b = Button(text="OK", command=self.clicked)
self.b.pack(side=TOP)
def clicked(self):
self.dat = Label(self, textvariable=self.entdat )
self.dat.pack(side=TOP)
self.distroy_Widget()
def distroy_Widget(self):
self.ew.destroy()
self.ol.destroy()
self.b.destroy()
def main():
root = Tk()
root.geometry("240x135+25+50")
tm = Input(root)
tm.pack(side=TOP)
root.mainloop()
if __name__ == '__main__':
main()
Hope it helps.

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