Eclipse GEF
2.1

org.eclipse.gef.editparts
Class ViewportAutoexposeHelper

java.lang.Object
  |
  +--org.eclipse.gef.editparts.ViewportHelper
        |
        +--org.eclipse.gef.editparts.ViewportAutoexposeHelper
All Implemented Interfaces:
AutoexposeHelper

public class ViewportAutoexposeHelper
extends org.eclipse.gef.editparts.ViewportHelper
implements 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 Summary
 
Nested classes inherited from class org.eclipse.gef.AutoexposeHelper
AutoexposeHelper.Search
 
Field Summary
protected  GraphicalEditPart owner
           
 
Constructor Summary
ViewportAutoexposeHelper(GraphicalEditPart owner)
          Constructs a new helper on the given GraphicalEditPart.
 
Method Summary
 boolean detect(Point where)
          Returns true if the given point is inside the viewport, but near its edge.
protected  Viewport findViewport(GraphicalEditPart part)
           
 boolean step(Point where)
          Returns true if the given point is inside the viewport, but near its edge.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

owner

protected GraphicalEditPart owner
Constructor Detail

ViewportAutoexposeHelper

public ViewportAutoexposeHelper(GraphicalEditPart owner)
Constructs a new helper on the given GraphicalEditPart. The editpart must have a Viewport somewhere between its contentsPane and its figure inclusively.

Parameters:
owner - the GraphicalEditPart that owns the Viewport
Method Detail

detect

public boolean detect(Point where)
Returns true if the given point is inside the viewport, but near its edge.

Specified by:
detect in interface AutoexposeHelper
Parameters:
where - the mouse's current location in the viewer
Returns:
true if the location is interesting
See Also:
AutoexposeHelper.detect(org.eclipse.draw2d.geometry.Point)

step

public boolean step(Point where)
Returns true if the given point is inside the viewport, but near its edge. Scrolls the viewport by a small amount in the current direction.

Specified by:
step in 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:
AutoexposeHelper.step(org.eclipse.draw2d.geometry.Point)

findViewport

protected Viewport findViewport(GraphicalEditPart part)

Eclipse GEF
2.1

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