How can I get a blocking modal input dialog box in standard Python?
I need the user to input a value before the code can proceed.
Here is some not-working test code, but the idea is that I should be able to call MyDialog from anywhere in the script, so this is just a simplified example.
import tkinter
class MyDialog:
def __init__(self, prompt):
self.top = tkinter.Toplevel()
tkinter.Label(self.top, text=prompt).pack()
self.e = tkinter.Entry(self.top)
self.e.pack(padx=5)
tkinter.Button(self.top, text="OK", command=self.ok).pack(pady=5)
def ok(self):
self.top.destroy()
return self.e.get()
root = tkinter.Tk()
userName = MyDialog('Enter your name')
tkinter.Label(root, text="Hello {}".format(userName)).pack()
root.mainloop()
The dialog should not only disable the master window, but block whatever code called it. And it should be able to pass the value back to the calling code.
The solution requires two critical pieces. First, use grab_set to block all events in the other window (or, more correctly, send all events to the dialog window). Second, use wait_window to prevent the method from returning until the dialog has been destroyed.
That being said, you shouldn't be using it like in your example. You need to have the mainloop running before you create the window. It might work OK on some platforms, but in general you shouldn't expect your GUI to behave properly until mainloop is running.
Here's a simple example:
import Tkinter as tk
class MyDialog(object):
def __init__(self, parent, prompt):
self.toplevel = tk.Toplevel(parent)
self.var = tk.StringVar()
label = tk.Label(self.toplevel, text=prompt)
entry = tk.Entry(self.toplevel, width=40, textvariable=self.var)
button = tk.Button(self.toplevel, text="OK", command=self.toplevel.destroy)
label.pack(side="top", fill="x")
entry.pack(side="top", fill="x")
button.pack(side="bottom", anchor="e", padx=4, pady=4)
def show(self):
self.toplevel.grab_set()
self.toplevel.wait_window()
value = self.var.get()
return value
class Example(tk.Frame):
def __init__(self, parent):
tk.Frame.__init__(self, parent)
self.button = tk.Button(self, text="Click me!", command=self.on_click)
self.label = tk.Label(self, text="", width=40)
self.label.pack(side="top", fill="x")
self.button.pack(padx=20, pady=20)
def on_click(self):
result = MyDialog(self, "Enter your name:").show()
self.label.configure(text="your result: '%s'" % result)
if __name__ == "__main__":
root = tk.Tk()
Example(root).pack(fill="both", expand=True)
root.mainloop()
Related
I want to create some simple tkinter python app (like StickyNotes on Windows), i have create the class mainApplication and i do not know how to by just simply triggering the button create another instance of this class which will be displayed pararell to other window (or even multiple windows). I know how to assigned function to pushButton, and other simple stuff but the problem is with this pararell window displaying. Thanks in advance for help.
class mainApplication(Frame):
_ids = count(0)
def __init__(self, parent):
""" """
self.id = next(self._ids)
Frame.__init__(self, parent)
self.parent = parent
self.parent.minsize(width=200,height=100)
self.parent.geometry(('%dx%d+%d+%d' % (200, 100, 1700, 0+self.id*100)))
self.initUI()
def initUI(self):
""" """
self.parent.title("a2l")
self.pack(fill=BOTH, expand=True)
style = Style()
style.configure("TFrame", background="#333")
frame1 = Frame(self, style="TFrame")
frame1.pack(fill=X)
self.lbl0 = Label(frame1, text="api", width=7, background="#333", foreground = "red")
self.lbl0.pack(side=TOP, padx=5, pady=5)
self.closeButton = Button(self, text="new", command = self.createNewInstance)
self.closeButton.pack(side=RIGHT, padx=5, pady=5)
#=======================================================================
# self.generateButton = Button(self, text="GENERATE", command = self.)
# self.generateButton.pack(side=RIGHT, padx=5, pady=5)
#=======================================================================
def createNewInstance(self):
y = mainApplication()
return y
if __name__ == "__main__":
root = Tk()
x = mainApplication(root).pack(side="top", expand=False)
Tk().mainloop()
You shouldn't create more than one Tk() window in one application with tkinter. Instead tkinter provides a widget called Toplevel which can be useful for this kind of thing.
It creates another window which can exist along side the Tk() window and alongside other Toplevel widgets.
You could use this to create a series of persistent windows with whatever text or widgets you wanted on them at any kind of trigger including a Button.
See my example below for a demonstration:
from tkinter import *
class App:
def __init__(self, root):
self.root = root
self.top = [] #list to contain the Toplevel widgets
self.entry = Entry(self.root)
self.button = Button(self.root, text="Create window", command=self.command)
self.entry.pack()
self.button.pack()
def command(self): #called when button is pressed
self.top.append(Toplevel(self.root)) #adds new Toplevel to the list
Label(self.top[len(self.top)-1], text=self.entry.get()).pack() #Adds label equal to the entry widget to the new toplevel
root = Tk()
App(root)
root.mainloop()
NameError: name 'onOpen' is not defined
There is something wrong with the command function. I am not sure what I did wrong here. I had the code tested before the onOpen function and it works fine.
import tkinter as tk
from tkinter import filedialog
class Application(tk.Frame):
def __init__(self, master=None):
tk.Frame.__init__(self, master)
self.pack()
self.createWidgets()
def onOpen():
""" Ask the user to choose a file and update the values of label change button"""
button_label.set(filedialog.askopenfilename(filetypes = ()))
def createWidgets(self):
#instruction label
self.labelInstruct = tk.Label(self, text="Instructions:", padx=10, pady=10)
self.labelInstruct = tk.Label(self, text="All you have to do is insert the file and save it.\n The conversion is instant", padx=10, pady=10)
self.labelInstruct.pack()
#insertfile button
self.ifbut = tk.Button(self, text="Insert File", command=onOpen)
self.ifbut.pack()
button_label = tk.StringVar(self)
text = tk.Label(self, textvariable = button_label)
text.pack()
#save button
self.saveLabel = tk.Label(self, text="Save File", padx=10, pady=10)
self.saveLabel.pack()
self.saveButton = tk.Button(self)
self.saveButton.pack()
#quit button
self.quitButton = tk.Button(self, text='Quit',
command=self.quit)
self.quitButton.pack()
app = Application()
app.master.title('Sample application')
app.mainloop()
Seeing that there are many problems with the way this code is written I am only going to point out a few of them and tackle the main question from the OP.
Lets start with the fact that you need to define the main window with something like root = tk.Tk() and you also need to make sure all your methods in your class have the argument self as the first argument.
Also any variable you are defining also should have self so that the class can interact with it. This (button_label) for example should be self.button_label.
There is no reason to use return the way you are trying to in the onOpen(self): method. Return does not work like that. Return is there so you can return a value to something that is calling the function/method to be used for something else and is not for setting the value of something.
Note that I also add the root window variable to the app = Application(root) line. This lets us pass the main window into the class.
all and all the following should work for the onOpen(self): function but the rest still needs some work.
import tkinter as tk
from tkinter import filedialog
class Application(tk.Frame):
def __init__(self, parent):
tk.Frame.__init__(self, parent)
self.parent = parent
self.pack()
self.createWidgets()
def onOpen(self):
""" Ask the user to choose a file and update the values of label change button"""
self.button_label.set(filedialog.askopenfilename(filetypes = ()))
def createWidgets(self):
#instruction label
self.labelInstruct = tk.Label(self.parent, text="Instructions:", padx=10, pady=10)
self.labelInstruct = tk.Label(self.parent, text="All you have to do is insert the file and save it.\n The conversion is instant", padx=10, pady=10)
self.labelInstruct.pack()
#insert file button
self.ifbut = tk.Button(self.parent, text="Insert File", command = self.onOpen)
self.ifbut.pack()
self.button_label = tk.StringVar()
self.text = tk.Label(self.parent, textvariable = self.button_label)
self.text.pack()
#save button
self.saveLabel = tk.Label(self.parent, text="Save File", padx=10, pady=10)
self.saveLabel.pack()
self.saveButton = tk.Button(self.parent, text = "Save")
self.saveButton.pack()
#quit button
self.quitButton = tk.Button(self.parent, text='Quit', command=self.quit)
self.quitButton.pack()
root = tk.Tk()
app = Application(root)
app.master.title('Sample application')
app.mainloop()
You need to return the function value as below:
def onOpen():
""" Ask the user to choose a file and update the values of label change button"""
return button_label.set(filedialog.askopenfilename(filetypes = ()))
I searched how to get the input and this should work but it doesnt...
i dont understand why it doesnt working... its start running and get stuck in the mainloop line... it shows nothing
from Tkinter import *
class GUI:
def __init__(self):
self.root = Tk()
self.label1 = Label(self.root, text="name")
self.label2 = Label(self.root, text="password")
self.entry1 = Entry(self.root)
self.entry2 = Entry(self.root, show="*")
self.button = Button(self.root, text="hello", command=self.printName)
self.button.pack()
self.label1.grid(row=0, sticky=W) # N, S, E, W
self.label2.grid(row=1, sticky=E)
self.entry1.grid(row=0, column=1)
self.entry2.grid(row=1, column=1)
self.c = Checkbutton(self.root, text="forgot my password")
self.c.grid(columnspan=2)
self.root.mainloop()
def printName(self):
print self.entry1.get()
hi = GUI()
The problem is that you are using both grid and pack for widgets that share the same parent. You can't do that -- you have to pick one or the other.
Also, to be pedantic you should ove the call of self.root.mainloop() outside of the __init__. The reason is that with it being inside, the object is never fully created because mainloop won't return until the widget is destroyed. Typically you call mainloop in the same scope that created the root window.
For example:
hi = GUI()
hi.root.mainloop()
If you don't like referencing the internal widget, give GUI a method like start or mainloop:
class GUI():
...
def start(self):
self.root.mainloop()
...
hi = GUI()
hi.start()
this is my code. I can't put label2 to self.main, and I don't know, how to write a generic function code, that would close the child widgets, that can be specified in the arguments.
import tkinter
class mainwin:
def __init__(self):
self.root = tkinter.Tk()
self.main = tkinter.Canvas(self.root, width=200, height=400)
self.main.place(x=0, y=0, relwidth=1, relheight=1)
self.main.config(bg='green')
self.root.mainloop()
class addlabel:
def __init__(self):
self.label2 = tkinter.Label(mainwin.main, height=2, width=50, text='Hello Noob!!')
#can't put on the canvas 'main'
self.label2.place(x=0, y=50)
self.exit_button = tkinter.Button(self.label2, text='Exit')
self.exit.button.bind('<1>', quit_from_widget)
'''
class quit_from_widget:
def __init__(self):
# what code should be written here, to quit any child widget.
'''
mainwin()
addlabel()
You might be able to use:
mylist = parent.winfo_children();
Then use a for loop and destroy() to close them off
The main reason you can't put the label in is because you are calling mainloop() before addLabel. The program loops through the code and doesn't execute addlabel() until you close the mainwin() function.
secondly, you can't do mainw.main. the class has no reference to that function. instead try adding a parent function to your addlabel like so:
class addlabel:
def __init__(self, parent):
self.label2 = tkinter.Label(parent, height=2, width=50, text='Hello Noob!!')
self.label2.place(x=0, y=50)
self.exit_button = tkinter.Button(self.label2, text='Exit')
self.exit_button.bind('<1>', quit)
Then, when you call the function in mainw class (before the self.root.mainloop() line) you would write:
addlabel(self.main)
import tkinter
class mainwin:
def __init__(self):
self.root = tkinter.Tk()
self.main = tkinter.Canvas(self.root, width=200, height=400)
self.main.place(x=0, y=0, relwidth=1, relheight=1)
self.main.config(bg='green')
self.root.mainloop()
class CustomLabel(tkinter.Frame):
def __init__(self, parent):
tkinter.Frame.__init__(self, parent)
self.label = tkinter.Label(self, height=20, width=30, bg='Red', fg='white', text='Hello')
self.exit_button = tkinter.Button(self, command=self.destroy)
# pack these widgets into this frame. You can use grid or
# place, but pack is easiest for such a simple layout
self.exit_button.pack(side="right")
self.label.pack(side="left", fill="both", expand=True)
window = mainwin()
label = CustomLabel(window.main)
nothing happens. gives green background and the child widget is not visible. but when closing, he writes an error:
....
(widgetName, self._w) + extra + self._options(cnf))
_tkinter.TclError: can't invoke "frame" command: application has been destroyed
Process finished with exit code 1
I'm working on my very first Python GUI and I'm trying to modify this tkinter example, but I simply cannot figure out how to write a callback function for the OK button that will pass on the entered value to the main program.
#!/usr/bin/python
# -*- coding: utf-8 -*-
from Tkinter import Tk, BOTH, StringVar, IntVar
from ttk import Frame, Button, Style, Label, Entry
class Example(Frame):
def __init__(self, parent):
Frame.__init__(self, parent)
self.parent = parent
self.initUI()
def initUI(self):
self.parent.title("Get Value")
self.style = Style()
self.style.theme_use("default")
self.pack(fill=BOTH, expand=1)
valueLabel = Label(self, text="Value: ")
valueLabel.place(x=10, y=10)
value=StringVar(None)
value.set("this is the default value")
valueEntry=Entry(self, textvariable=value)
valueEntry.place(x=70, y=10)
quitButton = Button(self, text="Quit", command=self.quit)
quitButton.place(x=10, y=50)
okButton = Button(self, text="OK", command=self.quit)
okButton.place(x=120, y=50)
def main():
root = Tk()
root.geometry("220x100+300+300")
app = Example(root)
root.mainloop()
if __name__ == '__main__':
main()
I've read a gazillion of tutorials, but none of them explains this clearly. Theoretically, I should be able to get the selected value with value.get(), but I keep getting error messages no matter where I put it. Also, AFAIK, I should be able to define a default value with value.set(), but this doesn't seem to have an effect, since the text box is empty when I run the program.
What is the easiest way to pass on values to the main python program after root.mainloop() terminates? (The actual dialog box contains several entry boxes for entering string and integer values.)
I.e. I want to be able to use something like:
root = Tk()
root.geometry("220x100+300+300")
app = Example(root)
root.mainloop()
print value
print value2
print value3
How do I define default values for entry boxes?
Change every occurrence of the value variable with self.value. This should fix it and the default value will be displayed.
UPDATE
from Tkinter import Tk, BOTH, StringVar, IntVar
from ttk import Frame, Button, Style, Label, Entry
class Example(Frame):
def __init__(self, parent):
Frame.__init__(self, parent)
self.parent = parent
self.initUI()
def showMe(self):
print(self.value.get())
def initUI(self):
self.parent.title("Get Value")
self.style = Style()
self.style.theme_use("default")
self.pack(fill=BOTH, expand=1)
valueLabel = Label(self, text="Value: ")
valueLabel.place(x=10, y=10)
self.value=StringVar(None)
self.value.set("this is the default value")
valueEntry=Entry(self, textvariable=self.value)
valueEntry.place(x=70, y=10)
quitButton = Button(self, text="Quit", command=self.quit)
quitButton.place(x=10, y=50)
okButton = Button(self, text="OK", command=self.showMe)
okButton.place(x=120, y=50)
def main():
root = Tk()
root.geometry("220x100+300+300")
app = Example(root)
root.mainloop()
if __name__ == '__main__':
main()
Both your quitButton and okButton call the self.quit functions. So no mater what value you enter when you press the OK button you are calling the quit function which has its own problems as well outside the scope of your question.
Try to define value as self.value and make the okButton call a function that does: print self.value.get().