Package org.eclipse.gef.editparts
Class ViewportAutoexposeHelper
java.lang.Object
org.eclipse.gef.editparts.ViewportAutoexposeHelper
- All Implemented Interfaces:
- AutoexposeHelper
An implementation of 
AutoexposeHelper that performs
 autoscrolling of a Viewport figure. This helper is for use with
 graphical editparts that contain a viewport figure. This helper will search
 the editpart and find the viewport. Autoscroll will occur when the detect
 location is inside the viewport's bounds, but near its edge. It will continue
 for as long as the location continues to meet these criteria. The autoscroll
 direction is approximated to the nearest orthogonal or diagonal direction
 (north, northeast, east, etc.).- 
Nested Class SummaryNested classes/interfaces inherited from interface org.eclipse.gef.AutoexposeHelperAutoexposeHelper.Search
- 
Field SummaryFields
- 
Constructor SummaryConstructorsConstructorDescriptionConstructs a new helper on the given GraphicalEditPart.ViewportAutoexposeHelper(GraphicalEditPart owner, Insets threshold) Constructs a new helper on the given GraphicalEditPart.
- 
Method Summary
- 
Field Details- 
owner
 
- 
- 
Constructor Details- 
ViewportAutoexposeHelperConstructs a new helper on the given GraphicalEditPart. The editpart must have aViewportsomewhere between its contentsPane and its figure inclusively.- Parameters:
- owner- the GraphicalEditPart that owns the Viewport
 
- 
ViewportAutoexposeHelperConstructs a new helper on the given GraphicalEditPart. The editpart must have aViewportsomewhere between its contentsPane and its figure inclusively.- Parameters:
- owner- the GraphicalEditPart that owns the Viewport
- threshold- the Expose Threshold to use when determining whether or not a scroll should occur.
 
 
- 
- 
Method Details- 
detectReturnstrueif the given point is inside the viewport, but near its edge.- Specified by:
- detectin interface- AutoexposeHelper
- Parameters:
- where- the mouse's current location in the viewer
- Returns:
- trueif the location is interesting
- See Also:
 
- 
stepReturnstrueif the given point is outside the viewport or near its edge. Scrolls the viewport by a calculated (time based) amount in the current direction. todo: investigate if we should allow auto expose when the pointer is outside the viewport- Specified by:
- stepin interface- AutoexposeHelper
- Parameters:
- where- the current location of the mouse in the viewer
- Returns:
- a hint indicating whether this helper should continue to be invoked
- See Also:
 
- 
toString
- 
findViewport
 
-