Mouse Interaction

• zoom. Zoom mode allows the data to be shifted scaled and rotated in 2D and 3D by dragging the mouse across the display with a button pressed. The appication selects the modes for zooming according to data type at the time when the tool is installed. The button functions are:

  left drag   : up/down/left/right = image shift.
  
  middle drag : left/right = zoom in/out (from centre) 
                up/down = rotate display about view direction.
  
  right down  : up/down = 3D rotation about vertical display axis.
  

• pick. This sets up the basic functionality to choose items from the display for mainpulation and processing. Selected ietms are stored in a "pick-list" which is globally available to the software. The choice function and pick function are set by the application according to data type.

  left down and drag   : Highlight current choice.
  
  left up              : select curent choice and add to pick-list
  
  middle down          : apply selected funtion to pick-list data
  
  right down           : cancel pick-list
  

• mouse. This is intended to be a programmer defined function, and the behaviour will vary depending upon which sub-tool the Tv is installed with.