python 3.2.5 grid sticky/weight not working

0
votes

Below is a simple illustration of the problem. It consists of a grid layout where I've placed a button widget in row 0 and a text widget in row 1.

What I want is for the text widget in row 1 to expand with the form while keeping the top of the text widget anchored NW (row 0 not expanding). The problem is that the horizontal(column expands correctly, but the text widget row does not. If I get rid of the button the text widget expands correctly. Also the original form I've put together is more involved and is best served using a grid. So basically using pack isn't a solution. Any help would be appreciated.

################################################

from tkinter import *

class Application(Frame):

    def __init__(self, parent):
        Frame.__init__(self, parent)
        self.parent = parent

        self.initGui()

    # ##################################################################
    # Initialize GUI widgets    
    def initGui(self):
        self.parent.title("Test Grid")
        self.parent.resizable(width=TRUE, height=TRUE)
        self.grid(sticky=W+E+N+S, padx=20, pady=20)
        self.parent.columnconfigure(0, weight=1)
        self.columnconfigure(0, weight=1)
        self.parent.rowconfigure(1, weight=1)
        self.rowconfigure(1, weight=1)

        # Add a button to row 0
        self.btn = Button(self, text="Button", width=20)
        self.btn.grid(row=0, column=0, padx=(0,10),pady=(0,10), sticky=N+W)

        # Add a text box and v-scrollbar to row 1
        self.txtOut = Text(self, width=80, height=20)
        self.scrOut = Scrollbar(self)
        self.txtOut.grid(row=1,column=0,padx=(0,18),sticky=N+E+S+W)
        self.scrOut.grid(row=1,column=0,sticky=N+S+E)
        self.scrOut.config(command=self.txtOut.yview)
        self.txtOut.config(yscrollcommand=self.scrOut.set)
        print(self.grid_size())

def main():
    root = Tk()
    app = Application(parent=root)   
    app.mainloop()

if __name__ == '__main__':
    main()
2
pythontkinter
As pointed by Bryan, there is a typo when you grid application in root. To hunt down this kind of geometry management bug, you can colorize your widget: root["bg"] = "red"; app["bg"] = "blue" to identify how each widget behave. - FabienAndre
The self.parent is not necessary and does nothing to change the code. If I remove those two statements, does that remove the typo to which you are referring? - user3557730
Bryan said The core problem is that you are putting the application frame in row 0 (zero), but you are giving row 1 (one) a weight of 1 (one), thus replacing self.parent.rowconfigure(1, weight=1) by self.parent.rowconfigure( 0 , weight=1) do the job. - FabienAndre

2 Answers

1
votes

There's a case where using pack probably is a solution. It won't cause any conflicts if you pack the instance of the Frame (Application) inside the root window, then grid widgets inside that frame. It'll cut down on the headache of all the rowconfigure and columnconfigure methods and just makes more sense to me.

def initGui(self):
    self.parent.title("Test Grid")
    self.parent.resizable(width=TRUE, height=TRUE)

    self.pack(fill=BOTH, expand=1, padx=20, pady=20)
    self.columnconfigure(0, weight=1)
    self.rowconfigure(1, weight=1)
1
votes

The core problem is that you are putting the application frame in row 0 (zero), but you are giving row 1 (one) a weight of 1 (one). That is why the text widget doesn't expand when you resize the window.

This is really hard to see because you mix grid commands of a widget in its parent, along with its own children widgets. It makes it hard to quickly scan the code to see what the layout options are, because you can't assume all of the grid, pack or place commands only affect child widgets.

Another minor problem with your code is that you've put the text widget and scrollbar in the same column.

Here's how I would change the code: remove the self.grid and self.parent.*configure commands from initGui. Then, use pack to add the application frame to the root window at the point where it's created. Also, move the scrollbar to column 1.

class Application(Frame):

    def __init__(self, parent):
        Frame.__init__(self, parent)
        self.parent = parent

        self.initGui()

    # ##################################################################
    # Initialize GUI widgets    
    def initGui(self):
        self.parent.title("Test Grid")
        self.parent.resizable(width=TRUE, height=TRUE)
        self.columnconfigure(0, weight=1)
        self.rowconfigure(1, weight=1)

        # Add a button to row 0
        self.btn = Button(self, text="Button", width=20)
        self.btn.grid(row=0, column=0, padx=(0,10),pady=(0,10), sticky=N+W)

        # Add a text box and v-scrollbar to row 1
        self.txtOut = Text(self, width=80, height=20)
        self.scrOut = Scrollbar(self)
        self.txtOut.grid(row=1,column=0,padx=(0,18),sticky=N+E+S+W)
        self.scrOut.grid(row=1,column=1,sticky=N+S)
        self.scrOut.config(command=self.txtOut.yview)
        self.txtOut.config(yscrollcommand=self.scrOut.set)
        print(self.grid_size())

def main():
    root = Tk()
    app = Application(parent=root)   
    app.pack(fill="both", expand=True)
    app.mainloop()

if __name__ == '__main__':
    main()