Microsoft-ui-xaml: Slider control: "Home" and "End" keystrokes behavior is confusing when orientation is vertical

[jbrianceau]

Describe the bug
When using a Slider with a vertical orientation like the one below, pressing the "Home" key moves the slider thumb to the bottom and pressing the "End" key moves the slider thumb to the top.

This is fine with horizontal sliders to go to the minimum value (to the left) when pressing "Home" and to the maximum value (to the right) when pressing "End", but this logic is confusing for vertical sliders as in that case the minimum value is at the bottom and the maximum one at the top of the slider.

Steps to reproduce the bug
Run the following XAML code, focus the slider with the keyboard and press "Home" or "End" key.

<Slider Height="150" Orientation="Vertical" />

Expected behavior
I would expect the slider thumb to go to the top when I press "Home" and to the bottom when I press "End".

Version Info
NuGet package version:
[Microsoft.UI.Xaml 2.4.3]

Windows app type:
| UWP | Win32 |
| :--------------- | :--------------- |
| Yes | |

| Windows 10 version | Saw the problem? |
| :--------------------------------- | :-------------------- |
| Insider Build (xxxxx) | |
| 20H2 (19042) | Yes |
| May 2020 Update (19041) | |
| November 2019 Update (18363) | |
| May 2019 Update (18362) | |
| October 2018 Update (17763) | |
| April 2018 Update (17134) | |
| Fall Creators Update (16299) | |
| Creators Update (15063) | |

| Device form factor | Saw the problem? |
| :----------------- | :--------------- |
| Desktop | Yes |
| Xbox | |
| Surface Hub | |
| IoT | |

[shaheedmalik]

I agree.

[robloo]

Home should map to the minimum value on the slider and End should map to the maximum value on the slider. This is really the only logically mapping and corresponds with what those keys mean when using them for text editing (Home is character index 0 (min) and End is character index N (max)). Within that context, the vertical slider is behaving correctly I believe.

[jbrianceau]

While I understand the rationale, I still find this not natural at all.
Even in a text editing scenario, one can also argue that the "Home" key brings the user to the beginning of the document, to the top and the "End" key brings the user to the end of the document, to the bottom.

Also, at least one other part of Windows using vertical sliders is already using "Home" and "End" keys that way: the system Volume Mixer

[shaheedmalik]

Home should map to the minimum value on the slider and End should map to the maximum value on the slider. This is really the only logically mapping and corresponds with what those keys mean when using them for text editing (Home is character index 0 (min) and End is character index N (max)). Within that context, the vertical slider is behaving correctly I believe.

The purpose of Home is the to go to the top. End is to go to the bottom.

[robloo]

For me it is more intuitive to leave it as is. I think this is just one of those things that means different things to different people and we won't all be in agreement. That said, Windows needs to be consistent. Microsoft likely needs to decide this based on usability studies.