Inconsistent clamping behavior in automation editor

[Wallacoloo]

When moving a point in the automation editor, if I drag the cursor outside of the window to the right, the point will still follow the cursor. But if I drag it outside the left of the editor, then it stops updating. The gif below should explain it better.

This behavior seems inconsistent. Is it by design or is it a flaw?

(This behavior was observed in a fresh build from the git repository using the latest commit: c1a2fde)

[Spekular]

It's probably because you can always drag a point more to the right, whereas there's a left boundary. You certainly ought to be able to drag to the left when you're not at that border though.

[Wallacoloo]

To be clear, there is about another 1.25 measures offscreen to the left in that gif. This was not the result of trying to place an automation point at some time < 0.

[Spekular]

Yup, I noticed the scrollbar. I'm just guessing that the reason for the boundary is to prevent
people from placing points too far left, and no exception has been made for
when you've actually got a valid area on the left. Would be cool if even when you're at the edge it would let you drag beyond and place the point at the intersect of the edge and the line between your cursor and the next point (to make it behave as if there were a point beyond the edge). Or "just" snap properly to the edge and get the cursor height.

[tresf]

Possible location:

AutomationEditor.cpp#L613

It should set the point to 0 rather than not processing the mouse move event. It is a rather large function, but should be a relatively small change. @Spekular you have some experience in this regard... do you have any interest in patching this behavior?

[Wallacoloo]

Unless you really want to take this on, I'd like to give it a try instead. Been meaning to contribute to lmms for a while.

[tresf]

Unless you really want to take this on, I'd like to give it a try instead. Been meaning to contribute to lmms for a while.

Absolutely, please do! 👍 If you need any help to get started, please ask!

[tresf]

Closed via #1910. Thanks @Wallacoloo!