[Question] : How to specify 'default' font

[daemon2021]

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

Question

Operating System

Windows version 10

PySimpleGUI Port (tkinter, Qt, Wx, Web)

tkinter

---

Versions

Version information can be obtained by calling sg.main_get_debug_data()
Or you can print each version shown in ()

Python version (sg.sys.version)

3.8.6 (tags/v3.8.6:db45529, Sep 23 2020, 15:52:53) [MSC v.1927 64 bit (AMD64)]

PySimpleGUI Version (sg.__version__)

4.39.1

GUI Version (tkinter (sg.tclversion_detailed), PySide2, WxPython, Remi)

8.6.9

---

Your Experience In Months or Years (optional)

5 Years Python programming experience
35 Years Programming experience overall
Yes Have used another Python GUI Framework? (tkinter, Qt, etc) (yes/no is fine)

---

Troubleshooting

These items may solve your problem. Please check those you've done by changing - [ ] to - [X]

• Searched main docs for your problem www.PySimpleGUI.org
• Looked for Demo Programs that are similar to your goal Demos.PySimpleGUI.org
• If not tkinter - looked for Demo Programs for specific port
• For non tkinter - Looked at readme for your specific port if not PySimpleGUI (Qt, WX, Remi)
• Run your program outside of your debugger (from a command line)
• Searched through Issues (open and closed) to see if already reported Issues.PySimpleGUI.org
• Tried using the PySimpleGUI.py file on GitHub. Your problem may have already been fixed but not released

Detailed Description

I need to reference the default font without changing it (i.e. for using functions like sg.Text.char_width_in_pixels).
In documentation under "Common Element Parameters"/ "Font" it is reported as follows:

If you wish to leave the font family set to the default, you can put anything not a font name as the family. The PySimpleGUI Demo programs and documentation use the family 'Any' to demonstrate this fact.. You could use "default" if that's more clear to you.

There are 2 formats that can be used to specify a font... a string, and a tuple Tuple - (family, size, styles) String - "Family Size Styles"

I tried the above but I see an issue with the font size that it is bigger than default.
What is the correct/supported way of referencing the default font?

Code To Duplicate

import PySimpleGUI as sg

layout = [
    [sg.Text('Font not specified (default)'),],
    [sg.Text('Font specified as (\'Any\')', font=('Any')),],
    [sg.Text('Font specified as \'Any\'', font='Any'),],
    [sg.Text('Font specified as (\'Any 10\')', font=('Any 10')),],
    [sg.Text('Font specified as \'Any 10\'', font='Any 10'),],    
    [sg.Text('Font specified as None', font=None),],
]
window = sg.Window('Default font', layout, finalize=True)

while True:
    event, values = window.read()
    if event == sg.WIN_CLOSED:
        break
window.close()

Screenshot, Sketch, or Drawing

[daemon2021]

Let me better introduce the real usage context, because otherwise the above could seem a silly/trival issue.
I'm working with table updates and trying to control the autosize of columns.
I've already checked the other Issues #4117 and #3678.
Infact, looking at the wonderful solution provided by @jason990420 for resizing with monospaced fonts, I've been able to develop a more general solution for resizing both with proportional and monospaced fonts.
The strange thing here is that everything works perfectly when the font is declared explicitely with its size.
When I try to reference the default font as None or Any it seems that the width_in_pixels is measured using a font that has a bigger size that actual default.
It's a similar issue to the simpler one shown above with the Text element.
I wonder if there could be some criticality somewhere that could explain various issues with autosize of text fields.
Regards.

import PySimpleGUI as sg

sg.theme('DarkAmber')
##!font = ('Courier New', 11)
##!font = ('Helvetica', 10)
font = None

LONG_TXT = 'ParameterNameToLongToFitIntoAColumn'

headings = ['File', 'Parameter', 'foo', 'bar', 'baz', 'bam', 'biz']
data = [['A', LONG_TXT, 'C', 'D', 'E', 'F', 'G']]

col_widths = list(map(lambda x:len(x)+2, headings)) # find the widths of columns in character.
max_col_width = len(LONG_TXT)+2  # Set max midth of all columns of data to show

def update_table(table, headings, data, font):
    all_data = [headings] + data
    max_col_width = sg.Text.string_width_in_pixels(font, LONG_TXT+'__')
    col_widths = [min([max(map(lambda c: sg.Text.string_width_in_pixels(font, c+'__'), columns)), max_col_width]) for columns in zip(*all_data)]  
    table.update(values=data)   
    table_widget = table.Widget
    table_widget.pack_forget()
    for cid, width in zip(headings, col_widths):    
        table_widget.column(cid, width=width)
    table_widget.pack(side='left', fill='both', expand=True)

layout = [
    [sg.Table(
        values=[],
        headings=headings,
        auto_size_columns=False,
        #vertical_scroll_only=False,
        hide_vertical_scroll=True,
        def_col_width=20,
        num_rows=10,
        col_widths=col_widths,
        font=font,
        key='-TABLE-'),],
    [sg.Text('Defined font: '+str(font) ),],
    [sg.Button('Monospaced update w/ defined font'),],
    [sg.Button('Proportional update w/ defined font'),],
    [sg.Button('Proportional update w/ font=None'),],
    [sg.Button('Proportional update w/ font=\'Any\''),],
    [sg.Button('Proportional update w/ font=\'Any 10\''),],
]
window = sg.Window('Title', layout, finalize=True)

char_width = sg.Text.char_width_in_pixels(font)     # Get character width in pixel
table = window['-TABLE-']
table_widget = table.Widget
table.expand(expand_x=True, expand_y=True)          # Expand table in both directions of 'x' and 'y'
for cid in headings:
    table_widget.column(cid, stretch=True)          # Set column stretchable when window resize

while True:
    event, values = window.read()
    if event == sg.WIN_CLOSED:
        break
    elif event == 'Monospaced update w/ defined font':
        all_data = [headings] + data                # All data include headings
        # Find width in pixel and 2 extra characters for each column
        col_widths = [min([max(map(len, columns))+2, max_col_width])*char_width for columns in zip(*all_data)]
        table.update(values=data)                   # update all new data
        # Redraw table to update new size of table if horizontal scrollbar not used, care if widget too large to fit your window or screen.
        table_widget.pack_forget()
        for cid, width in zip(headings, col_widths):    # Set width for each column
            table_widget.column(cid, width=width)
        table_widget.pack(side='left', fill='both', expand=True)    # Redraw table
    elif event == 'Proportional update w/ defined font':
        update_table(table, headings, data, font)
    elif event == 'Proportional update w/ font=None':
        update_table(table, headings, data, None)
    elif event == 'Proportional update w/ font=\'Any\'':
        update_table(table, headings, data, 'Any')
    elif event == 'Proportional update w/ font=\'Any 10\'':
        update_table(table, headings, data, 'Any 10')
window.close()

[jason990420]

To specify a font, the best way is by using tuple (preferred) or string, like

font = "Arial 16 bold underline"                # or (Here "Courier New" will not work for string format)
font = ("Courier New", 12, "bold underline") 

Cases for font, including font family and font size

• If not specified or None in PySimpleGUI, sg.DEFAULT_FONT will be used.
• If specified, font exists in tkinter, then use it.
• If specified, font not exists in tkinter, then tkinter.font.nametofont("TkDefaultFont") will be used, use the size even if wrong font family specified and also size specified.

[sg.Text('Font not specified (default)'),],                     # Same as None
[sg.Text('Font specified as (\'Any\')', font=('Any')),],        # Same Python code as 'Any'
[sg.Text('Font specified as \'Any\'', font='Any'),],            # Set wrong family, got default font family and font size in tkinter
[sg.Text('Font specified as (\'Any 10\')', font=('Any 10')),],  # Same Python code as 'Any 10'
[sg.Text('Font specified as \'Any 10\'', font='Any 10'),],      # Wrong family, but with size
[sg.Text('Font specified as None', font=None),],                # Not sepcified, got default font family and font size in PySimpleGUI

[PySimpleGUI]

Fonts generally follow a hierarchy. First the element, then the window, then the system-wide. That's the basic/important progression.

I think your question though is about a very narrow issue, tables.

[daemon2021]

Yes, I'm working with tables, but the basic problem for me is to know the default font-size tuple.
The usage of 'Any' or 'default' as suggested in documentation is not sufficient because there is no control on size, as explained by @jason990420.
Now I see there is sg.DEFAULT_FONT... I don't see it documented, I think it's an internal. Can I use it?
Is there a defined way to get default font from the supported API?
Thanks

[jason990420]

sg.DEFAULT_FONT may also not exist in your system, then tkinter default font will be used.

[PySimpleGUI]

set_options is how to modify system level settings. You'll find them all there in that one call.

[daemon2021]

To me now it's clear, thank you for your time explaining the various cases.
For me the main take is that using 'Any' ...

Set wrong family, got default font family and font size in tkinter

I would suggest to officially expose sg.DEFAULT_FONT through the API.
It may not exist in the system, but it would allow to make layout adjustments in a way that is uniform to the internal one.
It would not require to explicitely define a font in order to fine tuning the layout.

Maybe a new get_options paired with the cited set_options could be straight way to give the user more control on the defaults.

Thank you again

[PySimpleGUI]

Ah, yes, for reading back the value that's set in set_options, the font setting is sg.DEFAULT_FONT.

My assumption was that users would set their own values, and that reading the "current value" was not as important.

The demo programs tend to use "ANY" for fonts where I wanted the default font to be used. I recently switched to using _ to make it even more apparent that this part of the setting isn't important/used.

It would not require to explicitely define a font in order to fine tuning the layout.

I'm not sure what you mean by this one.

The safest approach that the application could take is to set the font, explicitly.

I thought the documentation discussed the hierarchy. I know the lessons go through it in detail as I talk about it in each of the elements.

Settings follow this progression:
Element, then window, then system.

This section mentions this progression
https://pysimplegui.readthedocs.io/en/latest/#global-settings

That's the order of all settings, not just fonts. This allows one window to have a setting that applies to all elements in that window without having to set it on each element, and it also allows for other windows to use a common default that's system-wide.

Fonts and the formats are described in the "Common Parameters" section. It describes the string and tuple formats. And of course the demo programs they're used all over the place.

https://pysimplegui.readthedocs.io/en/latest/#common-element-parameters