[ Bug] set_vscroll_position on multiline broken in version 4.61.0.206

从 PySimpleGUI.py 中 set_vscroll_position 的实现开始，检查它在 tkinter 端口上如何与 multiline 元素和 cprint 交互。使用一个最小程序重现报告的滚动行为，并比较 4.60.5 和 4.61.0.206 版本。完成的标准是 multiline 输出能够正确滚动，而不需要 window.refresh()，也不会导致闪烁。

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

Bug

Operating System

Windows 10

PySimpleGUI Port (tkinter, Qt, Wx, Web)

tkinter

Versions

Python version: 3.12.0 (tags/v3.12.0:0fb18b0, Oct 2 2023, 13:03:39) [MSC v.1935 64 bit (AMD64)]
port: tkinter
tkinter version: 8.6.13
PySimpleGUI version: 4.60.5
PySimpleGUI filename: C:\Users\Simon\AppData\Roaming\Python\Python312\site-packages\PySimpleGUI\PySimpleGUI.py

Your Experience In Months or Years (optional)

Years Python programming experience - 1 year

Years Programming experience overall - 40 plus years (doesn't mean I'm any good though)

Have used another Python GUI Framework? (tkinter, Qt, etc) (yes/no is fine) - No

Anything else you think would be helpful?

Troubleshooting

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

• [X ] Searched main docs for your problem www.PySimpleGUI.org
• Looked for Demo Programs that are similar to your goal. It is recommend you use the Demo Browser! Demos.PySimpleGUI.org
• [X ] None of your GUI code was generated by an AI algorithm like GPT
• 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)
• [ X] 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
• Have upgraded to the latest release of PySimpleGUI on PyPI (lastest official version)
• [X ] Tried using the PySimpleGUI.py file on GitHub. Your problem may have already been fixed but not released

Detailed Description

Looks like a bug, but it might just be the way I am using it.

Using cprint to print to multiline element. Using set_vscroll_position when output has more lines than multiline can show.

Worked beautifully in pysimplegui 4.60.5

Upgraded to pysimplegui 4.61.0.206 to take advantage of something... can't remember what it was. Some days later realised that
my cprint to multiline does not scroll / scrolls by a tiny amount in pysimplegui 4.61.0.206. It can be made to work with an additional call to window.refresh(), but this makes the multiline flash in a most unattractive manner.

Reverted to version 4.60.5 and it works beautifully again. No window.refresh required and no flashing.

Code To Duplicate

A short program that isolates and demonstrates the problem (Do not paste your massive program, but instead 10-20 lines that clearly show the problem)

This pre-formatted code block is all set for you to paste in your bit of code:

# Paste your code here
# It will take some effort to create a short program to isolate the issue. If you are not already aware of this I will try to produce something.

Screenshot, Sketch, or Drawing

Watcha Makin?

A program to replay chess games from my games database. I use cprint to get the current move highlighted in red in the multiline.