Horizontal dragging auto-scroll

[ttttotem]

Issue: #172652
Problem: horizontal dragging does not autoscroll
Solution:
Extension of vertical autoscroll introduced in #161378
Example:
https://github.com/user-attachments/assets/cee1f841-9a00-42bd-844d-9c4d4cecf1f6

[ttttotem]

@microsoft-github-policy-service agree

[ttttotem]

@microsoft-github-policy-service agree

[alexdima]

Thank you and apologies for the slow turn-around time!

[aiday-mar]

Hi @ttttotem thanks for this PR. By git bisecting I have found that this PR causes the issue : #263098. Specifically it's the changes in the file mouseHandler.ts inside of the method _getPositionOutsideEditor() that cause this issue. I think we need to either:

• quickly find a solution to the above issue
• revert this PR

The linked issue is rather important so it should maybe made into a candidate with a quick fix.

[aiday-mar]

To add more context about the issue above, the PR incorrectly computes that the cursor is outside of the editor, when it is inside of the editor in the following check:

		if (e.relativePos.x <= xLeftBoundary) {
			const outsideDistance = xLeftBoundary - e.relativePos.x;
			const position = new Position(possibleLineNumber, 1);			return MouseTarget.createOutsideEditor(mouseColumn, position, 'left', outsideDistance);
		}