Stop a Tkinter frame from resizing according to widget sizes

Question

root = Tk()

descriptionFrame = Frame(root)

definitionFrame = LabelFrame(descriptionFrame, text="Definition")
definitionScroll = Scrollbar(definitionFrame)
definitionCanvas = Canvas(definitionFrame, width=30, height=4, yscrollcommand=definitionScroll.set)
definitionScroll.config(command=definitionCanvas.yview)
definitionLabel = Label(definitionCanvas, text="n/a")

descriptionFrame.pack()
definitionFrame.pack()
definitionScroll.pack(side=RIGHT, fill=Y)
definitionCanvas.pack(side=LEFT, fill=BOTH, expand=True)
definitionLabel.pack(fill=BOTH, expand=True)

root.mainloop()

I have this code. The Canvas is set to have a width of 30 and height of 4, but when I run this, it ignores the width and height of the Canvas and the resulting window is sized around the Label instead. I've tried using pack_propagate(False) on every single Frame in the code, but it doesn't affect anything for the definitionFrame, but when I use it on descriptionFrame it results in an empty window. How would I create a GUI where all the frames and the window are sized to the Canvas size of width 30 and height 4?

Thanks.

Answer 1

To answer your specific question of how to stop a frame (or any container widget) from resizing to fit its contents, you call either pack_propagate(False) or grid_propagate(False) depending on which geometry manager you are using. If you've tried that and it wasn't working, you did it wrong. Since you didn't post that code we can't diagnose what went wrong.

When you call pack_propagate(False) you have to make sure that widget has an appropriate size. Labels and buttons will have a default size to fit their text, but a frame will have a default size of 1x1, making the contents nearly invisible. If using this on a frame, then, make sure to give it an explicit width and height.