CODEWITHSUNDEEP
tkinter
bhaskarc
bhaskarc

Reputation: 9541

Grid remove forgetting configuration

Here's a Tkinter program with two modes to select from. Selecting 'blue' shows the blue frame and selecting 'green' shows a green frame.

enter image description here

The code that does this:

from tkinter import Tk, Frame, Button, ttk

class App():

    def __init__(self, parent):
      self.parent = parent
      self.build_mode_selector_frame()
      self.build_green_frame()
      self.build_blue_frame()

    def build_mode_selector_frame(self):
      choices = ['blue','green']
      self.mode_selector_frame = Frame(self.parent, width=300, height=50)
      self.mode_selector = ttk.Combobox(self.mode_selector_frame, values=choices)
      self.mode_selector.bind("<<ComboboxSelected>>", self.on_mode_changed)
      self.mode_selector.grid(row=0, column=1)
      self.mode_selector_frame.grid(row=0, column=0)

    def build_blue_frame(self):
      self.blue_frame = Frame(self.parent, width=300, height=50, background="blue")
      self.blue_frame.grid(row=1, column=0)
      #Button(self.blue_frame).grid(row=0, column=1)


    def build_green_frame(self):
      self.green_frame = Frame(self.parent, width=300, height=50, background="green")
      self.green_frame.grid(row=1, column=0)

    def show_blue_frame(self):
      self.green_frame.grid_remove()
      self.blue_frame.grid()

    def show_green_frame(self):
      self.green_frame.grid()
      self.blue_frame.grid_remove()

    def on_mode_changed(self, event):
      selected_mode = self.mode_selector.get()
      if selected_mode == 'blue':
        self.show_blue_frame()
      elif selected_mode == 'green':
        self.show_green_frame()



root = Tk()
App(root)
root.mainloop()

This uses grid_remove() and the grid() to hide and show the elements.

But now if I add a button to the blue frame (uncomment the button line in the build_blue_frame method above), grid_remove seems to loose all the frame information like height and color as can seen in this gif.

enter image description here

Isn't grid_remove supposed to remember all the configuration like height, background color etc, even after a button is added to the frame?

Upvotes: 2

Views: 519

Answers (1)

Bryan Oakley
Bryan Oakley

Reputation: 386352

Isn't grid_remove supposed to remember all the configuration like height, background color etc, even after a button is added to the frame?

No. grid_remove only remembers the data that grid knows about (row, column, sticky, etc). It doesn't remember anything about the attributes of the widget that is being removed.

The behavior you are seeing is how tkinter is designed to work. If a widget has children, it will grow or shrink to fit the children as best that it can. When you add the button to the blue frame, and because you didn't configure the blue frame to "stick" to the edges of the space it is in, the blue frame will shrink to fit the button.

As a general rule, you should almost always give a sticky value when using grid. You also should give at least one row and one column a weight (with grid_rowconfigure and grid_columnconfigure) so that the children will use up an extra space.

Upvotes: 1

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