Working With Model Items and Diagrams > Working with diagrams > Basics > Using the diagram thumbnail pane
  
Using the diagram thumbnail pane
The Diagram Thumbnail pane allows you to pan, zoom in and zoom out of the active diagram, which is useful when working with large diagrams.
The Diagram Thumbnail pane shows all the symbols of the active diagram and indicates which part of the active diagram is shown through a shaded area.
To pan the active diagram through the Thumbnail Pane:
Drag the shaded area to the required position, or
Click outside the shaded area, or
Use the arrow keys, or
Use the mouse wheel (pan up and down), or Shift + mouse wheel (pan left and right).
To zoom in and zoom out through the Thumbnail Pane:
Ctrl + mouse wheel, or
Ctrl + the following numeric keys + or -.