I'm trying to update a label in a python tkinter application when another widget is selected.
I created a small tool, that demonstrates the issue. The tool will create a small GUI with a label on top. This label should show the number of the box that was selected.
Problem is that when a box number is selected by a mouse click, the number is not shown in the top label. Clicking the box number should call setSelected, which should call app.setLabel(string). However, I get the error "global name 'app' is not defined"
How do I make the object 'app' global?
#!/usr/bin/env python
import Tkinter
def setSelected(string):
app.setLabel(string)
class Gui():
Boxes = []
def __init__(self):
self._root = Tkinter.Tk()
self._root.protocol("WM_DELETE_WINDOW", self._applicationExit)
self._string = Tkinter.StringVar()
self.setLabel('None')
self._label = Tkinter.Label(self._root, textvariable = self._string,
width = 10)
self._label.grid(row = 0, column = 0, padx = 5, pady = 5)
self._createBoxOverview()
self._root.mainloop()
def _applicationExit(self, event = None):
self._root.destroy()
def _createBoxOverview(self):
_frame = Tkinter.LabelFrame(self._root, text = 'Boxes')
for _id in range(4):
self.Boxes.append(Box(_frame, _id))
self.Boxes[_id].grid(row = 0, column = _id)
_frame.grid(row = 1, column = 0, padx = 5, pady = 5)
def setLabel(self, string):
self._string.set(string)
class Box(Tkinter.Label):
def __init__(self, master, id):
Tkinter.Label.__init__(self, master)
self._id = str(id)
self._text = Tkinter.StringVar()
self._text.set(self._id)
self.config(textvariable = self._text, width = 3)
self.bind("<Button-1>", self._onSelect)
def _onSelect(self, event):
setSelected(self._id)
if __name__ == '__main__':
app = Gui()
The issue is that you are creating root (Tk() App) and calling root.mainloop() , inside __init__() itself, so app does not completely get created, since it would only get created if you return from __init__() , but you do not do that until you close the app.
The easiest solution for your case would be to move the root object outisde Gui() class. Example -
import Tkinter
def setSelected(string):
app.setLabel(string)
class Gui():
Boxes = []
def __init__(self, root):
self._root = root
self._root.protocol("WM_DELETE_WINDOW", self._applicationExit)
self._string = Tkinter.StringVar()
self.setLabel('None')
self._label = Tkinter.Label(self._root, textvariable = self._string,
width = 10)
self._label.grid(row = 0, column = 0, padx = 5, pady = 5)
self._createBoxOverview()
def _applicationExit(self, event = None):
self._root.destroy()
def _createBoxOverview(self):
_frame = Tkinter.LabelFrame(self._root, text = 'Boxes')
for _id in range(4):
self.Boxes.append(Box(_frame, _id))
self.Boxes[_id].grid(row = 0, column = _id)
_frame.grid(row = 1, column = 0, padx = 5, pady = 5)
def setLabel(self, string):
self._string.set(string)
class Box(Tkinter.Label):
def __init__(self, master, id):
Tkinter.Label.__init__(self, master)
self._id = str(id)
self._text = Tkinter.StringVar()
self._text.set(self._id)
self.config(textvariable = self._text, width = 3)
self.bind("<Button-1>", self._onSelect)
def _onSelect(self, event):
setSelected(self._id)
if __name__ == '__main__':
root = Tkinter.Tk()
app = Gui(root)
root.mainloop()
Related
I am new to tkinter and I would like to create a tkinter interface with "entries" , a canvas with a picture , and a button. I expected only one tk window but there is a second small empty tk window when I run my code. I guess it is because of the class I use but I'm not sure..
Here is my code :
from tkinter import*
import tkinter as tk
import time
class Application(Tk):
def __init__(self,transfo,nb_itération):
Tk.__init__(self)
self.transfo = transfo
self.nb_itération = nb_itération
def affichage_graphique(self):
self.matrix_hex = extraction_rgb(tk.PhotoImage(file='obama_128.gif'))
self.width , self.height = len(self.matrix_hex[0]) , len(self.matrix_hex)
self.WIDTH, self.HEIGHT = 8*self.width+6, 8*self.height+6
self.cnv = Canvas(self, width=self.WIDTH, height=self.HEIGHT, bg='white',highlightthickness=0)
self.cnv.grid(row = 2 , columnspan = 3)
self.txt1 = Label(self, text = 'Transformation :').grid(row = 0 , sticky = E)
self.txt2 = Label(self, text = 'Nombre d\'itérations : ').grid(row = 1 , sticky = E)
self.entr1 = Entry(self)
self.entr2 = Entry(self)
self.entr1.grid(row = 0, column = 1, sticky = W)
self.entr2.grid(row = 1, column = 1, sticky = W)
Button(self, text="Quitter", command=self.destroy).grid(row = 0 , column = 2)
if self.transfo == photomaton or self.transfo == boulanger:
print("valeur par défaut mauvaise")
self.cnv.delete(ALL)
self.img01 = self.PhotoImage(width=self.width*4, height=self.height*4)
self.img = self.PhotoImage(width=self.width*4, height=self.height*4)
self.matrix_hex4 = [[x for x in range(self.width*4)] for y in range(self.height*4)]
self.matrix_4 = [[x for x in range(self.width*4)] for y in range(self.height*4)]
self.img.put(data=self.matrix_4 , to=(0,0))
self.cnv.create_image(0, 0, image=self.img, anchor=tk.NW)
self.img01.put(data=self.matrix_hex4, to=(0,0))
self.cnv.create_image(self.WIDTH, 0, image=self.img01, anchor=tk.NE)
self.cnv.bind('<Button-1>',self.click_handler)
else:
self.img = tk.PhotoImage(width=self.width*4, height=self.height*4)
self.img.put(data=self.matrix_4 , to=(0,0))
self.cnv.create_image(0, 0, image=self.img, anchor=tk.NW)
self.entr1.insert(0,"photomaton")
self.entr2.insert(0,"1")
self.entr2.bind("<Return>",Programme().Enter)
class Programme(Application):
def __init__(self,transfo = 0, nb_itération = 0 ,orbites =[],période = []):
self.choice = 0
self.orbites = orbites
self.période = période
self.transfo = transfo
self.nb_itération = nb_itération
Application.__init__(self, self.transfo , self.nb_itération)
def Enter(self,event):
self.choix_transfo = self.entr1.get()
self.nb_itération = self.entr2.get()
return self.choix_transfo , self.nb_itération
def start(self):
self.affichage_graphique()
prog = Programme()
prog.start()
prog.mainloop()
The problem seems to be on this line:
self.entr2.bind("<Return>",Programme().Enter)
This line has multiple problems:
it will create a second Program() instance (assuming that this is a typo), thus creating a second Tk window (because Program extends Tk)
it will do so immediately, not only when the button is clicked, and bind the method of that new instance to the button
Instead, you probably want to use
self.entr2.bind("<Return>", self.Enter)
to call the Enter method of the current Program instance, or
self.entr2.bind("<Return>", lambda: Program().Enter)
if you actually want to create a second Program window when the button is clicked; however, in this case you will also have to call the gui method in order to initialize the widgets.
Note that there are a few other problems in your code, as discussed in comments, but I assume that those don't exist in your actual code, otherwise you would not get that behaviour.
You are creating a new window in two places. First, with this:
prog = Programme()
The second is here:
self.entr2.bind("<Return>",Programme().Enter)
Why? The above code is functionally identical to this:
p = Programme()
self.entr2.bind("<Return>", p.Enter)
The normal way to call functions defined in your program class is to use the existing reference. Since your code is being run in a method belonging to the Programme class, you can do this:
self.entr2.bind("<Return>", self.Enter)
I am creating a simple GUI program to manage priorities. I am having troubles with adding items to the listbox. I tried to create an instance of Priority class by passing two attributes to the constructor and then use g.listBox.insert(END, item), but it seems it doesn't work like that. I am getting an error:
/usr/bin/python3.5 /home/cali/PycharmProjects/priorities/priorities.py
Exception in Tkinter callback Traceback (most recent call last):
File "/usr/lib/python3.5/tkinter/init.py", line 1553, in call
return self.func(*args) File "/home/cali/PycharmProjects/priorities/priorities.py", line 52, in
addItem
item = Priority(subject = g.textBox.get("1.0", 'end-1c'), priority = g.textBox.get("1.0", 'end-1c')) AttributeError: 'GuiPart' object has no attribute 'textBox'
Process finished with exit code 0
Here is what I have done:
# priorities.py
# GUI program to manage priorities
from tkinter import *
class Priority:
def __init__(self, subject, priority):
self.subject = subject
self.priority = priority
def subject(self):
return self.subject
def priority(self):
return self.priority
class GuiPart:
def __init__(self):
self.root = self.createWindow()
def createWindow(self):
root = Tk()
root.resizable(width = False, height = False)
root.title("Priorities")
return root
def createWidgets(self):
Button(self.root,
text = "Add",
command = self.addItem).grid(row = 2, column = 0, sticky = W + E)
Button(self.root,
text="Remove",
command = self.removeItem).grid(row = 2, column = 1, sticky = W + E)
Button(self.root,
text="Edit",
command = self.editItem).grid(row = 2, column = 2, sticky = W + E)
listBox = Listbox(width = 30).grid(row = 1, sticky = W + E, columnspan = 3)
textBox = Text(height=10, width=30).grid(row = 3, columnspan = 3, sticky = W + E + N + S)
def addItem(self):
item = Priority(subject = g.textBox.get("1.0", 'end-1c'), priority = g.textBox.get("1.0", 'end-1c'))
g.listBox.insert(END, item)
def removeItem(self):
pass
def editItem(self):
pass
class Client:
pass
if __name__ == "__main__":
g = GuiPart()
g.createWidgets()
g.root.mainloop()
I'm using Python 3.5.
So if I understood your aim, you are trying to describe a priority by allowing the user to type, within the text zone widget, its information which consists in its subject and order; after that, the user can click on the "Add" button to insert the priority information into your list box.
There are lot of things to consider around your code. If I go to fix and comment them one by one, I believe my answer will be long while I feel lazy today.
I think my program below is easy to understand (ask a clarification otherwise). I did not find specifications inherent to how the propriety information is typed in the text zone. So my program below works under the assumption the user types the priority subject on the first line of the text area, and then uses a new line to type the priority order. The click on "Add" button will lead to the insertion of these 2 data on the same line of the text box widget as shown below:
Here is an MCVE:
import tkinter as tk
class ProioritiesManager(tk.Frame):
def __init__(self, master):
tk.Frame.__init__(self, master)
self.master = master
self.master.resizable(width = False, height = False)
self.master.title("Priorities")
self.create_buttons()
self.create_listbox()
self.create_priorities_description_zone()
def create_buttons(self):
add_item = tk.Button(self.master, text='Add', command=self.add_item)
add_item.grid(row=2, column=0, sticky=tk.W+tk.E)
remove_item = tk.Button(self.master, text='Remove', command=self.remove_item)
remove_item.grid(row=2, column=1, sticky=tk.W+tk.E)
edit_item = tk.Button(self.master, text='Edit', command=self.edit_item)
edit_item.grid(row=2, column=2, sticky=tk.W+tk.E)
def create_listbox(self):
self.item_alternatives = tk.Listbox(self.master, width=30)
self.item_alternatives.grid(row=1, sticky=tk.W+tk.E, columnspan=3)
def create_priorities_description_zone(self):
self.priority_text_zone = tk.Text(self.master, height=10, width=30)
self.priority_text_zone.grid(row=3, columnspan=3, sticky=tk.W+tk.E+tk.N+tk.S)
def get_priority_subject(self):
return self.priority_text_zone.get('1.0', '1.0 lineend')
def get_priority_order(self):
return self.priority_text_zone.get('2.0', '2.0 lineend')
def add_item(self):
self.item_alternatives.insert(tk.END, self.get_priority_subject()+' '+ self.get_priority_order())
def remove_item(self):
pass
def edit_item(self):
pass
if __name__ == "__main__":
root = tk.Tk()
ProioritiesManager(root)
root.mainloop()
If you want to give a good UX to your GUI then it would be nice if you add a button to allow the user to clear the content of the text area so that he can type in a new priority:
For this purpose, you can add a rest button to create_buttons() function by adding these 2 lines of code:
clear_text_area = tk.Button(self.master, text='Reset', command=self.reset_priority_text_zone)
clear_text_area.grid(row=4, column=2)
The callback reset_priority_text_zone() is defined this way:
def reset_priority_text_zone(self):
self.priority_text_zone.delete('1.0', tk.END)
These Lines are causing Error :
listBox = Listbox(width = 30).grid(row = 1, sticky = W + E, columnspan = 3)
textBox = Text(height=10, width=30).grid(row = 3, columnspan = 3, sticky = W + E + N + S)
Do it like this:
self.listBox = Listbox(self.root,width = 30)
self.listBox.grid(row = 1, sticky = W + E, columnspan = 3)
self.textBox = Text(self.root,height=10, width=30)
self.textBox.grid(row = 3, columnspan = 3, sticky = W + E + N + S)
Actually you are not creating listBox and textBox objects instead grid is returning to listBox and textBox
I have created a custom matplotlib toolbar, and I'm working on the functions associated with the custom toolbar's buttons. One of the buttons functions will (eventually) return a list position that best represents a user's selected position from a plot. I was having a bit of difficulty making this work in my mind, so I made a simple example (trying to avoid using globals) where a label not associated with the toolbar is updated when the toolbar button is pressed.
class TrackPlotToolbar(NavigationToolbar2TkAgg):
toolitems = [t for t in NavigationToolbar2TkAgg.toolitems if
t[0] in ('Home', 'Pan', 'Zoom', 'Save')]
toolitems.append(('Trace', 'Trace Track Position', 'Trace', 'Trace_old'))
def __init__(self, plotCanvas, frame):
self.TraceListOld = []
self.TraceListNew = []
NavigationToolbar2TkAgg.__init__(self, plotCanvas, frame)
def set_message(self, msg):
pass
def Trace_old(self):
gui.infoLabel.text = "abrakadabra"
gui.infoLabel.update()
return 1
class gui(Frame):
def __init__(self, parent):
Frame.__init__(self, parent)
self.grid()
self.parent = parent
self.infoLabel = Label(master = self, text = 'magic')
self.initUI()
def initUI(self):
TestPlot = FigureCanvasTkAgg(TestFig, self)
TestPlot.get_tk_widget().grid(column = 0,\
row = 0, columnspan = 3, rowspan = 5)
TestFrame = Frame(self)
TestFrame.grid(column = 2, row =6, columnspan = 3)
shockToolbar = TrackPlotToolbar(TestPlot,TestFrame)
shockToolbar.update()
self.infoLabel.grid(column = 2, row = 7)
def main():
root = Tk()
app = gui(root)
root.mainloop()
if __name__ == '__main__':
main()
Am I taking the wrong approach? Is it possible to inquire for new data on an event associated with a class inside of the parent class?
I am currently building a user based system, where I have a class for a login screen in pythons tkinter. Once the user information is correct it will initiate a class for the menu. I'm using an SQL database which python reads and checks user information with. I'm going to need the username of the user to be passed to the menu class so the class knows what information to display on that menu.
from tkinter import *
class Login:
def __init__(self, master):
self.master = master
self.label = Label(self.master, text = "enter name")
self.entry = Entry(self.master)
self.button = Button(self.master, text = "submit", command = self.loadMenu)
self.label.grid(row = 0, column = 0)
self.entry.grid(row = 0, column = 1)
self.button.grid(row = 1, column = 0, columnspan = 2)
self.name = self.entry.get()
def loadMenu(self):
self.menu = Toplevel(self.master)
self.app = Menu(self.menu)
class Menu:
def __init__(self, master):
self.master = master
self.label = Label(self.master, text = "dave")
self.label.grid(row = 0, column = 0)
def main():
root = Tk()
run = Login(root)
root.mainloop()
if __name__ == '__main__':
main()
In the above example code, what method could be used to pass the variable 'self.name' to class menu so that it can be displayed in a label? I am trying not to use a global variable. Many Thanks.
Your class Menu, needs a method to set the name. e.g.:
class myMenu:
def __init__(self,...):
....
def set_Me(self,some_name):
self.some_name = some_name
# or
self.label.setName(some_name)
in the main program you call:
self.app.set_Me(self.name)
The above is pseudo code. But you should get the idea.
This technique you can use to pass variables to any class at any time.
If you need to pass variable only once:
class my_class:
def __init__(self,my_variable):
self.my_variable = my_variable
class AppetiserClass():
root = Tk()
root.title("Appetiser Page")
root.geometry("1920x1080")
meal1 = 0
def plus1():
global meal1
meal1 = meal1 + 1
DisplayButton["text"]=str(meal1)
return
def neg1():
global meal1
meal1 = meal1 + 1
DisplayButton["text"]=str(meal1)
return
app = Frame(root)
app.grid()
Label(app, text = "", width = 75, height = 20).grid(row = 1, column = 0, sticky = N)
DisplayButton = Button(app, text = meal1)
DisplayButton.grid(column = 1, row = 2, sticky = W)
DisplayButton.config(height = 10, width = 10 )
Plus1Button = Button(app, text = "+1", command=plus1, bg="green")
Plus1Button.grid(column = 2, row = 2, sticky = W)
Plus1Button.config(height = 10, width = 10 )
Neg1Button = Button(app, text = "-1", command=neg1, bg="green")
Neg1Button.grid(column = 3, row = 2, sticky = W)
Neg1Button.config(height = 10, width = 10 )
root.mainloop()
The problem I am having is that I have set a value to my global variable (meal1, being 0) but when I press the +1, or -1 button, a value is not being displayed on the "DislpayButton" and I am receiving this message:
"NameError: global name 'DisplayButton' is not defined "
"DisplayButton", is a button i have placed, to display a value onto. Nothing more, but I am receiving this error message.
If i remove the classes, and just run this code, with the single window, The code works fine.
Any help would be much appreciated!
If your indentation is correct, the problem isn't that DisplayButton and meal1 are global, it's that they're class-level and you're not accessing it that way, which means you should use self keyword to access it. (It doesn't have to be "self" - the first argument of any function in a class always defines the variable through which you can access other members in the same class - but it's Python style to use "self.") Add self as an argument to all your functions in that class, like so:
def neg1(self):
And then access meal1 and DisplayButton through self:
self.meal1 += 1
and:
self.DisplayButton["text"] = str(meal1)
I've re-written your class so that all the important stuff within the class can be accessed by everything else using self:
from tkinter import *
class AppetiserClass:
meal1 = 0
root = Tk()
app = Frame(self.root)
def __init__(self):
self.root.title("Appetiser Page")
self.root.geometry("1920x1080")
self.app.grid()
Label(self.app, text = "", width = 75, height = 20).grid(row = 1, column = 0, sticky = N)
self.DisplayButton = Button(self.app, text = self.meal1)
self.DisplayButton.grid(column = 1, row = 2, sticky = W)
self.DisplayButton.config(height = 10, width = 10 )
self.Plus1Button = Button(self.app, text = "+1", command=self.plus1, bg="green")
self.Plus1Button.grid(column = 2, row = 2, sticky = W)
self.Plus1Button.config(height = 10, width = 10 )
self.Neg1Button = Button(self.app, text = "-1", command=self.neg1, bg="green")
self.Neg1Button.grid(column = 3, row = 2, sticky = W)
self.Neg1Button.config(height = 10, width = 10 )
self.root.mainloop()
def plus1(self):
self.meal1 += 1
self.DisplayButton["text"]=str(self.meal1)
def neg1(self):
self.meal1 -= 1
self.DisplayButton["text"]=str(self.meal1)
if __name__ == "__main__":
AppetiserClass()
I changed a decent amount. First off, you had a lot of code written outside any particular method, which is something I prefer to keep inside the class methods except for class variable definitions (meal1 = 0 and etc.). It's fairly arbitrary - anything defined within a method as self.whatever has the same accessibility as stuff defined at the class scope. I've also made it so that you can keep reference to your buttons with self.ButtonName. Lastly, I've made it so that the window is instantiated only if you're running the file and not importing your code into a different file.