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 Summary
Nested classes/interfaces inherited from interface org.eclipse.gef.AutoexposeHelper
AutoexposeHelper.Search
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Field Summary
Fields -
Constructor Summary
ConstructorsConstructorDescriptionConstructs a new helper on the given GraphicalEditPart.ViewportAutoexposeHelper
(GraphicalEditPart owner, Insets threshold) Constructs a new helper on the given GraphicalEditPart. -
Method Summary
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Field Details
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owner
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Constructor Details
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ViewportAutoexposeHelper
Constructs a new helper on the given GraphicalEditPart. The editpart must have aViewport
somewhere between its contentsPane and its figure inclusively.- Parameters:
owner
- the GraphicalEditPart that owns the Viewport
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ViewportAutoexposeHelper
Constructs a new helper on the given GraphicalEditPart. The editpart must have aViewport
somewhere between its contentsPane and its figure inclusively.- Parameters:
owner
- the GraphicalEditPart that owns the Viewportthreshold
- the Expose Threshold to use when determining whether or not a scroll should occur.
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Method Details
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detect
Returnstrue
if the given point is inside the viewport, but near its edge.- Specified by:
detect
in interfaceAutoexposeHelper
- Parameters:
where
- the mouse's current location in the viewer- Returns:
true
if the location is interesting- See Also:
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step
Returnstrue
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 interfaceAutoexposeHelper
- 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:
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toString
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findViewport
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