## org.jfree.chart.plot
Class CrosshairState

    java.lang.Object
      org.jfree.chart.plot.CrosshairState

    public class CrosshairState

extends java.lang.Object

Maintains state information about crosshairs on a plot.

Constructor Summary
`CrosshairState()` Default constructor.
`CrosshairState(boolean calculateDistanceInDataSpace)` Creates a new info object.

Method Summary
`double` `getCrosshairX()` Get the x-value for the crosshair point.
`double` `getCrosshairY()` Get the y-value for the crosshair point.
`void` `setAnchor(java.awt.geom.Point2D anchor)` Sets the anchor point.
`void` `setCrosshairDistance(double distance)` Sets the distance between the anchor point and the current crosshair point.
`void` `setCrosshairX(double x)` Sets the x coordinate for the crosshair.
`void` `setCrosshairY(double y)` Sets the y coordinate for the crosshair.
`void` `updateCrosshairPoint(double x, double y, double transX, double transY, PlotOrientation orientation)` Evaluates a data point and if it is the closest to the anchor point it becomes the new crosshair point.
`void` `updateCrosshairX(double candidateX)` Evaluates an x-value and if it is the closest to the anchor point it becomes the new crosshair point.
`void` `updateCrosshairY(double candidateY)` Evaluates a y-value and if it is the closest to the anchor point it becomes the new crosshair point.

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Constructor Detail

### CrosshairState

    public CrosshairState()

  Default constructor.

### CrosshairState

    public CrosshairState(boolean calculateDistanceInDataSpace)

  Creates a new info object.

  Parameters:
    `calculateDistanceInDataSpace` - a flag that controls whether the distance is calculated in data space or Java2D space.

Method Detail

### setCrosshairDistance

    public void setCrosshairDistance(double distance)

  Sets the distance between the anchor point and the current crosshair point. As each data point is processed, its distance to the anchor point is compared with this value and, if it is closer, the data point becomes the new crosshair point.

  Parameters:
    `distance` - the distance.

### updateCrosshairPoint

    public void updateCrosshairPoint(double x,
                                     double y,
                                     double transX,
                                     double transY,
                                     PlotOrientation orientation)

  Evaluates a data point and if it is the closest to the anchor point it becomes the new crosshair point.

  To understand this method, you need to know the context in which it will be called. An instance of this class is passed to an `XYItemRenderer` as each data point is plotted. As the point is plotted, it is passed to this method to see if it should be the new crosshair point.

  Parameters:
    `x` - x coordinate (measured against the domain axis).
    `y` - y coordinate (measured against the range axis).
    `transX` - x translated into Java2D space.
    `transY` - y translated into Java2D space.
    `orientation` - the plot orientation.

### updateCrosshairX

    public void updateCrosshairX(double candidateX)

  Evaluates an x-value and if it is the closest to the anchor point it becomes the new crosshair point.

  Used in cases where only the x-axis is numerical.

  Parameters:
    `candidateX` - x position of the candidate for the new crosshair point.

### updateCrosshairY

    public void updateCrosshairY(double candidateY)

  Evaluates a y-value and if it is the closest to the anchor point it becomes the new crosshair point.

  Used in cases where only the y-axis is numerical.

  Parameters:
    `candidateY` - y position of the candidate for the new crosshair point.

### setAnchor

    public void setAnchor(java.awt.geom.Point2D anchor)

  Sets the anchor point. This is usually the mouse click point in a chart panel, and the crosshair point will often be the data item that is closest to the anchor point.

  Parameters:
    `anchor` - the anchor point.

### getCrosshairX

    public double getCrosshairX()

  Get the x-value for the crosshair point.

  Returns:
    the x position of the crosshair point.

### setCrosshairX

    public void setCrosshairX(double x)

  Sets the x coordinate for the crosshair. This is the coordinate in data space measured against the domain axis.

  Parameters:
    `x` - the coordinate.

### getCrosshairY

    public double getCrosshairY()

  Get the y-value for the crosshair point. This is the coordinate in data space measured against the range axis.

  Returns:
    the y position of the crosshair point.

### setCrosshairY

    public void setCrosshairY(double y)

  Sets the y coordinate for the crosshair.

  Parameters:
    `y` - the y coordinate.