User Interface Research Group - Masatomo Kobayashi - Boomerang


Throw Catch

What is this study about?

We show that a throwing gesture, which considers the speed of cursor movement, successfully suspends and resumes dragging operations. This technique allows users to perform any operation required to make the target visible, e.g., window-switching and scrolling, before dropping the dragged object. It makes drag-and-drop an alternative to cut-and-paste interactions without using context menus, toolbar buttons, or keyboard.

To perform another operation before dropping, the user throws the dragged object by releasing the mouse button while continuing to move the pointer. Then the user can complete any operation to make the hidden target visible. After finishing, the user catches the object by clicking where it was thrown, and then resumes the suspended dragging operation. We also introduce advanced features including grouping, copying, and deleting to assist flexible drag-and-drop interactions.


Demo: Icon Manager

  1. Drag an icon.
  2. Throw it to suspend the dragging operation.
  3. Switch the active window, scroll a window, open folders, etc.
  4. Drop another icon onto the suspended icon to make a group.
  5. Catch the icon(s) to resume the suspended operation.
  6. Drop it anywhere.


  1. Kobayashi, M. and Igarashi, T. Boomerang: Suspendable Drag-and-Drop Interactions Based on a Throw-and-Catch Metaphor. In Proceedings of UIST 2007, Newport, RI, October 2007, pp.187-190. PDF (669KB) ACM DL
KOBAYASHI Masatomo <kobayash at>
Last Updated: Tue, 30-Oct-2007 JST