Issue 500 diagonal scroll trackpad

[Billgonzo123]

Issue Number: 500

Link to issue

I restored the code from v0.21.0 and it has restored the functionality of touch pad diagonal scrolling. It does seem that on most browser you must initially move your fingers in a diagonal motion because scrolling seems to be locked to the initial direction of scrolling per event.

I have added a small bit of code so that when clicking inside the calendar component it can be dragged on the X and Y axis. To do this I turned dragStartPosition into an object containing x and y scroll values. I then use dragStartPosition.y to update the windows scroll position.

I also fixed a bug with the shiftKey modifier when scrolling. deltaY was prioritized in a ternary resulting in glitchy and confusing movement when touchpad scrolling was diagonal. deltaX is now prioritized.

[Billgonzo123]

The traditionalScroll prop mentioned in the issue seems to be undefined

[Billgonzo123]

oops, this was supposed to be a draft!

[lnagel]

This PR has been marked as outdated. Here's why:

The file this PR targets (src/lib/scroll/ScrollElement.js) no longer exists. The entire codebase has been rewritten in TypeScript, and the scroll handling component now lives at src/lib/scroll/ScrollElement.tsx. The new implementation has been completely rearchitected — it uses a createRef-based approach, Pointer Events API (replacing separate mouse/touch handlers), and has a fundamentally different scroll and drag model. The specific changes this PR introduced (making dragStartPosition an object with x/y for vertical drag support, prioritizing deltaX over deltaY in the shift+scroll handler, and adding window.scrollBy for diagonal trackpad scrolling) are no longer applicable because the scroll logic has been rewritten from scratch with its own touch and pointer handling that already accounts for both axes.

The current version is 0.30.0-beta.5 and uses TypeScript, dayjs (instead of moment), and Vite (instead of Webpack).

Thank you for the contribution! The idea/fix was appreciated even if the codebase has moved on.