Opening a popup only when the mouse hasn't dragged

[rick-de-water]

Version/Branch of Dear ImGui:

Version: 1.69 WIP (16899)
Branch: docking

My Issue/Question:

I want to open a popup when the user right clicks with the mouse, but ONLY if the user hasn't dragged the mouse while holding the right mouse button.

I have tried combining ImGui::IsMouseReleased(1) with a check to see if ImGui::GetMouseDragDelta(1) returned a zero length vector, but the drag delta seems to already have been reset at that point.

Is there a way to check if the mouse was dragging when it was released? I would like to avoid keeping track of this myself.

[ocornut]

Hello Rick, You may be able to query io.MouseDragMaxDistanceSqr[] if it hasn’t been cleared. It would be preferable if you also described the nature of your use case in more details. A large portion of questions are better answered and solved knowing more about the context.

…

-Omar

[rick-de-water]

The context is a node graph. I use the left mouse button for selecting nodes, and the right mouse drag to scroll. But I also want the right mouse button to open a popup menu when all the user did was right click without scrolling. So that is why I need to know if the right mouse button was dragging when it was released.

[rick-de-water]

io.MouseDragMaxDistanceSqr seems to do the job, but it does completely ignore MouseDragThreshold.

I would prefer it if GetMouseDragDelta returned a non zero value on g.IO.MouseDown[button] || g.IO.MouseReleased[button] instead of just g.IO.MouseDown[button], but I don't know if that breaks anything.

[ocornut]

I made that change, it makes sense to me.

(I wish I had access to more large codebase to better study how people use functions xx and xx, but a quick survey of users of this on public github repo confirms the side-effect seem harmless).

Let me know if that indeeed solve your issue!

[rick-de-water]

It works great! But I just noticed that it is now inconsistent with IsMouseDragging, since that still returns false on the release frame. Should that function be updated as well?

[ocornut]

I think they are better left as is. IsMouseDragging() handle a very explicit request and changing it would probably break things. We are just making the delta available a little longer because it makes sense to query that information exactly as you do.