Pysimplegui: [ Bug] Element.expand() faulty

[HrkInTheWild]

Type of Issues (Enhancement, Error, Bug, Question)

Bug: When window is resized, fields do not expand correctly. You should use pack(expand=1) on the parent frame ONLY when fill=BOTH. Corrected code below.

Operating System

Windows 10

Python version

3.72

PySimpleGUI Port and Version

tkinter, 4.12

Your Experience Levels In Months or Years

3 yrs Python programming experience
50 yrs Programming experience overall, yes I am very old
yes, I Have used another Python GUI Framework (tkinter, Qt, etc) previously (yes/no is fine)?

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Code or partial code causing the problem

Corrected version of Element.expand():

`
def expand(self, expand_x=False, expand_y=False):
"""
Causes the Element to expand to fill available space in the X and Y directions. Can specify which or both directions

    :param expand_x: (Bool) If True Element will expand in the Horizontal directions
    :param expand_y:  (Bool) If True Element will expand in the Vertical directions
    """
    xpand = False
    if expand_x and expand_y:
        fill = tk.BOTH
        xpand = True
    elif expand_x:
        fill = tk.X
    elif expand_y:
        fill = tk.Y
    else:
        return

    self.Widget.pack(expand=True, fill=fill)
    self.ParentRowFrame.pack(expand=xpand, fill=fill)

`

Testing:

`import PySimpleGUI as sg

layout = [
[sg.Text('Red',background_color='red', key='r'), sg.Text('Yellow', background_color='yellow',key='y')],
[sg.Text('Green',background_color='green', key='g')],
[sg.Text('Blue',background_color='blue', key='b')]
]

window = sg.Window('Just testing',layout,size=(200,200),
margins=(0, 0), element_padding=(0, 0),
resizable=True, finalize=True)
window['y'].expand(expand_x=True)
window['g'].expand(expand_x=True, expand_y=True)
window['b'].expand(expand_x=True)

while True:
event, values = window.read()
if not event: break
`

[HrkInTheWild]

Or maybe you should just avoid on the parent frame pack(expand=1,fill='x'). Vertical expansion looks funny but does not break anything else. Horizontal does.

[PySimpleGUI]

Can you post a couple of screenshots showing where you're seeing problems? Something that shows what breaks and when would be helpful.

What you see in terms of the architecture and APIs is an evolution of PySimpleGUI. It started out being a window that wasn't resizable. It was only in the past few months that resizing with expanding elements was possible.

The row frame is required to make the layouts. It contains all of the widgets that are on a single row. If it doesn't expand / fill then neither do the widgets inside of it.

[HrkInTheWild]

Sure. This is "before":

... and this is "after":

... and this the proposed change:

    def expand(self, expand_x=False, expand_y=False):
        """
        Causes the Element to expand to fill available space in the X and Y directions.  Can specify which or both directions

        :param expand_x: (Bool) If True Element will expand in the Horizontal directions
        :param expand_y:  (Bool) If True Element will expand in the Vertical directions
        """
        xpand = False
        if expand_x and expand_y:
            fill = tk.BOTH
            xpand=True
        elif expand_x:
            fill = tk.X
        elif expand_y:
            fill = tk.Y
        else:
            return

        self.Widget.pack(expand=True, fill=fill)
        self.ParentRowFrame.pack(expand=xpand, fill=fill)

... and this is my test program:

import PySimpleGUI as sg

layout = [
    [sg.Text('Red',background_color='red', key='r'), 
        sg.Text('Yellow', background_color='yellow',key='y')],
    [sg.Text('Green',background_color='green', key='g')],
    [sg.Text('Blue',background_color='blue', key='b')]
]

window = sg.Window('Just testing',layout,size=(200,200), 
    margins=(0, 0), element_padding=(0, 0), 
    resizable=True, finalize=True)
window['y'].expand(expand_x=True)
window['g'].expand(expand_x=True, expand_y=True)
window['b'].expand(expand_x=True)

while True:
    event, values = window.read()
    if not event: break

Yes I understand the principle. But a frame (row) does not need to and should not "expand" in order to just x-fill. Expand means "use ALL available space". Tkinter documentation is a bit vague on this point, and the pack geometry manager is quirky. I would use grid.

[PySimpleGUI]

Hmmm... I need a third parameter perhaps that indicates if the element should in addition to expanding, fill. My assumption was that if someone is asking for an expand, they also would like fill to occur.

Grid is not an option.

[PySimpleGUI]

I've added a third parameter to control the row expansion.

    def expand(self, expand_x=False, expand_y=False, expand_row=True):
        """
        Causes the Element to expand to fill available space in the X and Y directions.  Can specify which or both directions

        :param expand_x: (Bool) If True Element will expand in the Horizontal directions
        :param expand_y:  (Bool) If True Element will expand in the Vertical directions
        :param expand_row:  (Bool) If True the row containing the element will also expand. Without this your element is "trapped" within the row
        """
        if expand_x and expand_y:
            fill = tk.BOTH
        elif expand_x:
            fill = tk.X
        elif expand_y:
            fill = tk.Y
        else:
            return

        self.Widget.pack(expand=True, fill=fill)
        self.ParentRowFrame.pack(expand=expand_row, fill=fill)

While still not ideal, it provides the most potential options for the developer. The default is True so that existing applications are not negatively impacted. Of course anyone is capable of accessing any of these Widgets directly should this not be enough options. There are / will be some limitations encountered using PySimpleGUI. It's a balance between simplicity and capabilities.

[HrkInTheWild]

Now you must modify all elements with expand_x or expand_y but not both by adding expand_row=False. If not thus modified, existing applications are not negatively impacted, but they work just as badly as before.

[PySimpleGUI]

@HrkInTheWild you've got the option to replace the method with your own by either forking the code or simply replacing that one method. I'm trying to provide a solution that works for the existing install base as well as newcomers. It's the best that I can offer at this point. If PySimpleGUI isn't for you, it isn't for you.