fix only one end of imline object

I have checked the setConstrainedPosition feature, but it seems to only constrain both ends. What I want to achieve is to fix one end of imline object while leave the other end freely movable. Thanks in advance!

Answer 1

[Image Analyst]

I don't think you can do that with imline(). What you'd have to do is to use the mouse move callback to erase the prior line and draw a new line, with line() not imline(), from the fixed point to the current point where the cursor is.

[Yinan Xuan]

Thanks for your reply! However, in the case where there are two lines present at the same time. How can I choose which one to "drag" in your method?

[Image Analyst]

You have the current point. Then you can look up "point line distance" on the web for a formula. I'd move which ever line is closest to your current point.