To handle these events, either implement this interface, or extend the abstract class ViewPortAdapter overriding only the methods of interest. ChartViewer.addViewPortListener can then be used to register the handler object to the ChartViewer.
| Method | Inherited | Description |
|---|---|---|
| viewPortChanged | (Self) | The system will call this method when the viewport is changed through mouse actions, or when ChartViewer.updateViewPort is called. |
| selectionChanged | (Self) | The system will call this method when the user is selecting a region on the chart using "drag to select" mouse actions. |