Java interface

I have a project in progress, but it has reached a stage where I need help. When the user is using the interface it is necessary to insert a .dat file (generated by ANSYS) to generate a 3D graph with a point cloud. Each point is called a node and has x, y and z coordinates. In this graph, it is possible to find out what the coordinates are by dragging the mouse over the point. With the coordinates, you open another window to insert them and thus find out the node number. What I want to change is to make this step easier. One option would be that when the mouse is clicked over the point, it is possible to find out the number of the node or that by dragging the mouse over it, the node number is already shown.