dragable and selectable

Hello,

I need a list which you can select a item and drag it around, thats no problem. Then you need to select it or multi select with crtl. also, thats no problem. but how do i turn off the multi selection which my arrow? like when you hold the left mouse button you can select a few with hovering over it. How can i turn that off?

and whats the best way to combine that?