## org.jfree.chart.plot
Class CrosshairState

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

Direct Known Subclasses:
  CategoryCrosshairState, XYCrosshairState

    public class CrosshairState

extends java.lang.Object

Maintains state information about crosshairs on a plot between successive calls to the renderer's draw method. This class is used internally by JFreeChart - it is not intended for external use.

Constructor Summary
`CrosshairState()` Creates a new `CrosshairState` instance that calculates distance in Java2D space.
`CrosshairState(boolean calculateDistanceInDataSpace)` Creates a new `CrosshairState` instance.

Method Summary
`java.awt.geom.Point2D` `getAnchor()` Returns the anchor point.
`double` `getAnchorX()` Returns the x-coordinate (in data space) for the anchor point.
`double` `getAnchorY()` Returns the y-coordinate (in data space) for the anchor point.
`double` `getCrosshairDistance()` Returns the distance between the anchor point and the current crosshair point.
`double` `getCrosshairX()` Get the x-value for the crosshair point.
`double` `getCrosshairY()` Get the y-value for the crosshair point.
`int` `getDatasetIndex()` Returns the dataset index that the crosshair values relate to.
`int` `getDomainAxisIndex()` Deprecated. As of version 1.0.11, the domain axis should be determined using the dataset index.
`int` `getRangeAxisIndex()` Deprecated. As of version 1.0.11, the domain axis should be determined using the dataset index.
`void` `setAnchor(java.awt.geom.Point2D anchor)` Sets the anchor point.
`void` `setAnchorX(double x)` Sets the x-coordinate (in data space) for the anchor point.
`void` `setAnchorY(double y)` Sets the y-coordinate (in data space) for 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` `setDatasetIndex(int index)` Sets the dataset index that the current crosshair values relate to.
`void` `updateCrosshairPoint(double x, double y, double transX, double transY, PlotOrientation orientation)` Deprecated. Use `updateCrosshairPoint(double, double, int, int, double, double, PlotOrientation)`. See bug report 1086307.
`void` `updateCrosshairPoint(double x, double y, int domainAxisIndex, int rangeAxisIndex, 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)` Deprecated. Use `updateCrosshairX(double, int)`. See bug report 1086307.
`void` `updateCrosshairX(double candidateX, int domainAxisIndex)` Evaluates an x-value and if it is the closest to the anchor x-value it becomes the new crosshair value.
`void` `updateCrosshairY(double candidateY)` Deprecated. Use `updateCrosshairY(double, int)`. See bug report 1086307.
`void` `updateCrosshairY(double candidateY, int rangeAxisIndex)` Evaluates a y-value and if it is the closest to the anchor y-value it becomes the new crosshair value.

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

Constructor Detail

### CrosshairState

    public CrosshairState()

  Creates a new `CrosshairState` instance that calculates distance in Java2D space.

### CrosshairState

    public CrosshairState(boolean calculateDistanceInDataSpace)

  Creates a new `CrosshairState` instance.

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

Method Detail

### getCrosshairDistance

    public double getCrosshairDistance()

  Returns the distance between the anchor point and the current crosshair point.

  Returns:
    The distance.
  Since:
    1.0.3
  See Also:
    `setCrosshairDistance(double)`

### 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.
  See Also:
    `getCrosshairDistance()`

### updateCrosshairPoint

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

  Deprecated. Use `updateCrosshairPoint(double, double, int, int, double, double, PlotOrientation)`. See bug report 1086307.

  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.

### updateCrosshairPoint

    public void updateCrosshairPoint(double x,
                                     double y,
                                     int domainAxisIndex,
                                     int rangeAxisIndex,
                                     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).
    `domainAxisIndex` - the index of the domain axis for this point.
    `rangeAxisIndex` - the index of the range axis for this point.
    `transX` - x translated into Java2D space.
    `transY` - y translated into Java2D space.
    `orientation` - the plot orientation.
  Since:
    1.0.4

### updateCrosshairX

    public void updateCrosshairX(double candidateX)

  Deprecated. Use `updateCrosshairX(double, int)`. See bug report 1086307.

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

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

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

### updateCrosshairX

    public void updateCrosshairX(double candidateX,
                                 int domainAxisIndex)

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

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

  Parameters:
    `candidateX` - x position of the candidate for the new crosshair point.
    `domainAxisIndex` - the index of the domain axis for this x-value.
  Since:
    1.0.4

### updateCrosshairY

    public void updateCrosshairY(double candidateY)

  Deprecated. Use `updateCrosshairY(double, int)`. See bug report 1086307.

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

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

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

### updateCrosshairY

    public void updateCrosshairY(double candidateY,
                                 int rangeAxisIndex)

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

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

  Parameters:
    `candidateY` - y position of the candidate for the new crosshair point.
    `rangeAxisIndex` - the index of the range axis for this y-value.
  Since:
    1.0.4

### getAnchor

    public java.awt.geom.Point2D getAnchor()

  Returns the anchor point.

  Returns:
    The anchor point.
  Since:
    1.0.3
  See Also:
    `setAnchor(Point2D)`

### 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.
  Note that the x and y coordinates (in data space) are not updated by this method - the caller is responsible for ensuring that this happens in sync.

  Parameters:
    `anchor` - the anchor point (`null` permitted).
  See Also:
    `getAnchor()`

### getAnchorX

    public double getAnchorX()

  Returns the x-coordinate (in data space) for the anchor point.

  Returns:
    The x-coordinate of the anchor point.
  Since:
    1.0.3

### setAnchorX

    public void setAnchorX(double x)

  Sets the x-coordinate (in data space) for the anchor point. Note that this does NOT update the anchor itself - the caller is responsible for ensuring this is done in sync.

  Parameters:
    `x` - the x-coordinate.
  Since:
    1.0.3

### getAnchorY

    public double getAnchorY()

  Returns the y-coordinate (in data space) for the anchor point.

  Returns:
    The y-coordinate of teh anchor point.
  Since:
    1.0.3

### setAnchorY

    public void setAnchorY(double y)

  Sets the y-coordinate (in data space) for the anchor point. Note that this does NOT update the anchor itself - the caller is responsible for ensuring this is done in sync.

  Parameters:
    `y` - the y-coordinate.
  Since:
    1.0.3

### getCrosshairX

    public double getCrosshairX()

  Get the x-value for the crosshair point.

  Returns:
    The x position of the crosshair point.
  See Also:
    `setCrosshairX(double)`

### 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.
  See Also:
    `getCrosshairX()`, `setCrosshairY(double)`, `updateCrosshairPoint(double, double, double, double, PlotOrientation)`

### 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.
  See Also:
    `setCrosshairY(double)`

### setCrosshairY

    public void setCrosshairY(double y)

  Sets the y coordinate for the crosshair.

  Parameters:
    `y` - the y coordinate.
  See Also:
    `getCrosshairY()`, `setCrosshairX(double)`, `updateCrosshairPoint(double, double, double, double, PlotOrientation)`

### getDatasetIndex

    public int getDatasetIndex()

  Returns the dataset index that the crosshair values relate to. The dataset is mapped to specific axes, and this is how the crosshairs are mapped also.

  Returns:
    The dataset index.
  Since:
    1.0.11
  See Also:
    `setDatasetIndex(int)`

### setDatasetIndex

    public void setDatasetIndex(int index)

  Sets the dataset index that the current crosshair values relate to.

  Parameters:
    `index` - the dataset index.
  Since:
    1.0.11
  See Also:
    `getDatasetIndex()`

### getDomainAxisIndex

    public int getDomainAxisIndex()

  Deprecated. As of version 1.0.11, the domain axis should be determined using the dataset index.

  Returns the domain axis index for the crosshair x-value.

  Returns:
    The domain axis index.
  Since:
    1.0.4

### getRangeAxisIndex

    public int getRangeAxisIndex()

  Deprecated. As of version 1.0.11, the domain axis should be determined using the dataset index.

  Returns the range axis index for the crosshair y-value.

  Returns:
    The range axis index.
  Since:
    1.0.4