Class ViewportAutoexposeHelper

  • All Implemented Interfaces:
    AutoexposeHelper

    public class ViewportAutoexposeHelper
    extends java.lang.Object
    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.).
    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      boolean detect​(org.eclipse.draw2d.geometry.Point where)
      Returns true if the given point is inside the viewport, but near its edge.
      protected org.eclipse.draw2d.Viewport findViewport​(GraphicalEditPart part)  
      boolean step​(org.eclipse.draw2d.geometry.Point where)
      Returns true if the given point is outside the viewport or near its edge.
      java.lang.String toString()  
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
    • 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
      • ViewportAutoexposeHelper

        public ViewportAutoexposeHelper​(GraphicalEditPart owner,
                                        org.eclipse.draw2d.geometry.Insets threshold)
        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
        threshold - the Expose Threshold to use when determing whether or not a scroll should occur.
    • Method Detail

      • step

        public boolean step​(org.eclipse.draw2d.geometry.Point where)
        Returns true if 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:
        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)
      • toString

        public java.lang.String toString()
        Overrides:
        toString in class java.lang.Object
        See Also:
        Object.toString()
      • findViewport

        protected org.eclipse.draw2d.Viewport findViewport​(GraphicalEditPart part)