I am building a tutoring application that can be used to draw objects and then one is able to drag them around. I would like to know what is the best thing to do when someone clicks on an object and starts to drag it.
I was told I should "lock" it - prevent it from being grabbed by someone else at the same time and being able to drag it. But that would require sending a request to the server (and then to all other users connected to the tutoring session) to lock it which might take a bit of time (what if a teacher is in USA and student is in Africa on dialup)? I was also told I should loop until I see that the object was locked by me. This way, the user might not be able to grab and drag and object for several seconds (UX design problem).
I proposed perhaps to only enable one to drag object you drew, but that seems short sided. Any suggestions? Thank you!