Annotation plugin

Charba provides out of the box the feature to enable Annotation which can add annotations on a chart instance.

It can draw lines, boxes, points, labels, polygons and ellipses on the chart area.

The annotation plugin work with line, bar, scatter and bubble charts that use linear, logarithmic, time or category scales.

info

The annotation plugin will not work on any chart that does not have exactly two axes, including pie, radar and polar area charts.

Activation

The annotation plugin is injected directly in the document.

The plugin ID is a constant everywhere available, AnnotationPlugin.ID, in AnnotationPlugin entry point.

This plugin registers itself globally, meaning that once injected, all charts will display annotations. In case you want it enabled only for a few charts, you can enable it as following:

// --------------------------------------
// enabling the plugin without any parameter
// the plugin is NOT registered to all charts
// --------------------------------------
AnnotationPlugin.enable();

// --------------------------------------
// enabling the plugin with `true` parameter
// the plugin is registered to all charts
// --------------------------------------
AnnotationPlugin.enable(true);

To activate the plugin in a specific chart, it's enough to provide the configuration options (see below) or enabling it by:

// --------------------------------------
// ENABLING the plugin to a chart instance 
// storing a plugin options 
// --------------------------------------
// creates a plugin options
AnnotationOptions options = new AnnotationOptions();
// sets default draw time
options.setDrawTime(DrawTime.BEFORE_DRAW);
// stores the plugin options directly by the options
options.store(chart);

// --------------------------------------
// ENABLING the plugin to a chart instance 
// by a boolean using default plugin 
// options
// --------------------------------------
chart.getOptions().getPlugins().setEnabled(AnnotationPlugin.ID, true);

Configuration

The plugin options can be changed at 2 different levels and are evaluated with the following priority:

• per chart by chart.getOptions().getPlugins().setOptions method
• or globally by Defaults.get().getGlobal().getPlugins().setOptions method

The configuration AnnotationOptions class is the entry point of plugin configuration.

// -------------------------
// CONFIGURES the annotation
// by AnnotationId id
// -------------------------
// creates a plugin options
AnnotationOptions options = new AnnotationOptions();
// creates an annotation
LineAnnotation line = new LineAnnotation();
... // additional label configuration
// sets the line annotation to the options
options.setAnnotations(line);
// stores the plugin options directly by the options
options.store();

You can also change the default for all charts instances, as following:

// creates a plugin options
AnnotationOptions options = new AnnotationOptions();
// creates an annotation
LineAnnotation line = new LineAnnotation();
... // additional label configuration
// sets the line annotation to the options
options.setAnnotations(line);

// --------------------------------------
// STORING plugin options
// --------------------------------------
// stores the plugin options by plugin ID
Defaults.get().getGlobal().getPlugin().setOptions(AnnotationPlugin.ID, options);
// stores the plugin options without plugin ID
Defaults.get().getGlobal().getPlugin().setOptions(options);
// stores the plugin options directly by the options
options.store();

If you need to read the plugin options, there is the specific factory, AnnotationOptionsFactory as static reference inside the AnnotationPlugin entry point which can be used to retrieve the options from chart as following:

// gets options reference
AnnotationOptions options;

// --------------------------------------
// GETTING plugin options from chart
// --------------------------------------
if (chart.getOptions().getPlugin().hasOptions(AnnotationPlugin.ID)){
   // retrieves the plugin options by plugin ID
   options = chart.getOptions().getPlugin().getOptions(AnnotationPlugin.ID, AnnotationPlugin.FACTORY);
   //retrieves the plugin options without plugin ID
   options = chart.getOptions().getPlugin().getOptions(AnnotationPlugin.FACTORY);
}

Default element options

Every annotation type is a chart element and the common options for a specific type can be configured by elements in the chart and global options:

• per chart by chart.getOptions().getElements().getElement(ElementFactory) method
• or globally by Defaults.get().getGlobal().getElements().getElement(ElementFactory) method

The annotation options are providing a ElementFactory instance in order to enable to get and change the options at annotation type level.

// ----------------------------------------------------
// Setting option for all box annotations of the  chart
// ----------------------------------------------------
BoxAnnotation boxElement = chart.getOptions().getElements().getElement(BoxAnnotation.FACTORY);
// checks if consistent
if (boxElement != null) {
   // set font family for all box labels of the chart
   boxElement.getLabel().getFont().setFamily("courier");
}
// ----------------------------------------------------
// Setting option for all box annotations
// ----------------------------------------------------
BoxAnnotation boxElement = Defaults.get().getGlobal().getElements().getElement(BoxAnnotation.FACTORY);
// checks if consistent
if (boxElement != null) {
   // set font family for all box labels of all charts
   boxElement.getLabel().getFont().setFamily("courier");
}

caution

If the annotation plugin is not activated (see Activation), the annotation element options can not be set because the result will be always an inconsistent options instance.

Identifier

Every annotation configuration can be add to the AnnotationOptions, assigning a unique identifier.

The identifier of a label configuration can be set by a string or by a specific class, AnnotationId.

// -------------------------
// CONFIGURES the annotation
// by AnnotationId id
// -------------------------
// creates a plugin options
AnnotationOptions options = new AnnotationOptions();
// creates annotation id
AnnotationId annotationId = AnnotationId.create("myAnnotation1");
// creates and adds a line annotation by "myAnnotation1" id
LineAnnotation line = new LineAnnotation(annotationId);
// configures the line annotation
line.setDrawTime(DrawTime.AFTER_DATASETS_DRAW);
line.setBorderColor(HtmlColor.BLACK);
line.setBorderWidth(5);
... // additional label configuration
// sets the line annotation to the options
options.setAnnotations(line);
// stores the plugin options directly by the options
options.store();

caution

If the annotation id is not provided, a unique id for the annotation is created automatically, which can be retrieve by getId() method of the annotation.

You can access to the configured annotations configurations as following:

// ------------------------
// GETS the configured 
// annotations
// ------------------------
// retrieves the plugin options by plugin ID
AnnotationOptions options = chart.getOptions().getPlugin().getOptions(AnnotationPlugin.FACTORY);
// gets all annotations configurations
List<AbstractAnnotation> allAnnotations = options.getAnnotations();
// gets "myAnnotation1" annotation configuration
AbstractAnnotation annotation1 = options.getAnnotation(AnnotationId.create("myAnnotation1"));
// gets "myAnnotation2" annotation configuration
AbstractAnnotation annotation2 = options.getAnnotation("myAnnotation2");

Options

The configuration class AnnotationOptions contains all properties needed to configure the plugin.

// creates a plugin options
AnnotationOptions options = new AnnotationOptions();
// sets default draw time
options.setDrawTime(DrawTime.BEFORE_DRAW);

The following options are available at the top level. They apply to all annotations unless they are overwritten on a per-annotation basis:

Name	Type	Default	Description
clip	boolean	true	If true, the annotations are clipped to the chart area.
drawTime	DrawTime	DrawTime.AFTER_DATASETS_DRAW	Defines when the annotations are drawn. This allows positioning of the annotation relative to the other elements of the graph.
events	IsEvent[] - Set<IsEvent>	Defaults.get().getGlobal() .getEvents()	The events option defines the browser events that the plugin should listen to. This overrides the options at chart level.
interaction	Interaction	see below	To configure which events trigger plugin interactions.

Interaction

Interaction uses the same format as a chart instance.

caution

InteractionMode.INDEX and InteractionMode.DATASET modes are not supported by the plugin. If set, the plugin will use InteractionMode.NEAREST mode.

InteractionAxis.R is not supported by the plugin. If set, the plugin will use InteractionAxis.XY mode.

Draw time

The DrawTime option for an annotation determines where in the chart life cycle the drawing occurs. Four potential options are available:

Option	Description
BEFORE_DRAW	Occurs before any drawing takes place
BEFORE_DATASETS_DRAW	Occurs after drawing of axes, but before data sets
AFTER_DATASETS_DRAW	Occurs after drawing of data sets but before items such as the tooltip
AFTER_DRAW	After other drawing is completed.

Box

Box annotations are used to draw rectangles on the chart area. This can be useful for highlighting different areas of a chart.

Every plugin options can have an unlimited number of boxes annotations.

// creates a plugin options
AnnotationOptions options = new AnnotationOptions();
// creates an annotation
// without id (a unique one is created automatically)
BoxAnnotation box = new BoxAnnotation();
box.setDrawTime(DrawTime.BEFORE_DATASETS_DRAW);
box.setXScaleID(DefaultScaleId.X);
box.setYScaleID(DefaultScaleId.Y);
box.setXMin("January");
box.setXMax("April");
box.setBackgroundColor(GwtMaterialColor.YELLOW_LIGHTEN_3.alpha(0.3D));
box.setBorderWidth(0);
// stores the annotation in the main options
options.setAnnotations(box);

The complete options are described by following table:

Name	Type	Default	Scriptable	Description
adjustScaleRange	boolean	true	Yes	If true, the scale range should be adjusted if this annotation is out of range.
backgroundColor	String - IsColor	Defaults.get().getGlobal() .getColorAsString()	Yes	The fill color of the box. See default colors.
backgroundShadowColor	String - IsColor	HtmlColor.TRANSPARENT	Yes	The color of shadows. See MDN.
borderCapStyle	CapStyle	CapStyle.BUTT	Yes	Cap style of the border line. See MDN.
borderColor	String - IsColor	Defaults.get().getGlobal() .getColorAsString()	Yes	The stroke color of the box. See default colors.
borderDash	int[]	[]	Yes	The length and spacing of dashes. See MDN.
borderDashOffset	double	0	Yes	The offset for line dashes. See MDN.
borderJoinStyle	JoinStyle	JoinStyle.MITER	Yes	Border line joint style. See MDN
borderRadius	int - BarBorderRadius	0	Yes	The radius in pixels of box rectangle.
borderShadowColor	String - IsColor	HtmlColor.TRANSPARENT	Yes	The color of border shadows. See MDN.
borderWidth	int	1	Yes	The stroke width of the box.
display	boolean	true	Yes	Whether or not this annotation is visible.
drawTime	DrawTime	DrawTime. AFTER_DATASETS_DRAW	Yes	Defines when the annotation is drawn. This allows positioning of the annotation relative to the other elements of the graph.
rotation	double	0	Yes	The rotation of annotation, in degrees.
shadowBlur	double	0	Yes	The amount of blur applied to shadows. See MDN.
shadowOffsetX	int	0	Yes	The distance that shadows will be offset horizontally. See MDN.
shadowOffsetY	int	0	Yes	The distance that shadows will be offset vertically. See MDN.
xMax	String - double - Date	null	Yes	Right edge of the box in units along the x axis.
xMin	String - double - Date	null	Yes	Left edge of the box in units along the x axis.
xScaleID	String - ScaleId	null	-	The ID of the X scale to bind onto.
yMax	String - double - Date	null	Yes	Top edge of the box in units along the y axis.
yMin	String - double - Date	null	Yes	Bottom edge of the box in units along the y axis.
yScaleID	String - ScaleId	null	-	The ID of the Y scale to bind onto.
z	int	0	Yes	All visible elements will be drawn in ascending order of z option, with the same drawTime option.

If one of the axes does not match an axis in the chart, the box will take the entire chart dimension.

The 4 coordinates, xMin, xMax, yMin, yMax are optional. If not specified, the box is expanded out to the edges in the respective direction.

Box scriptable options

Some options also accept a callback which is called at runtime and that takes the context as single argument, see here the details, which is representing contextual information and chart instance.

// creates a plugin options
AnnotationOptions options = new AnnotationOptions();
// creates an annotation
BoxAnnotation box = new BoxAnnotation();
// sets callback for border width options
box.setBorderWidth(new WidthCallback<AnnotationContext>(){

   @Override
   public Integer invoke(AnnotationContext context){
      // logic
      return borderWidth;
   }
});
// stores the annotation in the main options
options.setAnnotations(box);

The following options can be set by a callback:

Name	Callback	Returned types
adjustScaleRange	AdjustScaleRangeCallback	boolean
backgroundColor	ColorCallback<AnnotationContext>	String - IsColor - Pattern
backgroundShadowColor	ColorCallback<AnnotationContext>	String - IsColor
borderCapStyle	CapStyleCallback<AnnotationContext>	CapStyle
borderColor	ColorCallback<AnnotationContext>	String - IsColor
borderDash	BorderDashCallback<AnnotationContext>	List<Integer>
borderDashOffset	BorderDashOffsetCallback<AnnotationContext>	double
borderJoinStyle	JoinStyleCallback<AnnotationContext>	JoinStyle
borderRadius	BorderRadiusCallback<AnnotationContext>	int - - BarBorderRadius
backgroundShadowColor	ColorCallback<AnnotationContext>	String - IsColor
borderWidth	WidthCallback<AnnotationContext>	int
display	SimpleDisplayCallback<AnnotationContext>	boolean
drawTime	DrawTimeCallback	DrawTime
rotation	RotationCallback<AnnotationContext>	double
shadowBlur	ShadowBlurCallback	double
shadowOffsetX	ShadowOffsetCallback	int
shadowOffsetY	ShadowOffsetCallback	int
xMax	ValueCallback	String - double - Date
xMin	ValueCallback	String - double - Date
yMax	ValueCallback	String - double - Date
yMin	ValueCallback	String - double - Date
z	ZCallback	int

Box label

A box annotation can have a label to draw in the box.

Every box annotation can have ONLY 1 label.

// creates a plugin options
AnnotationOptions options = new AnnotationOptions();
// creates an annotation
// without id (a unique one is created automatically)
BoxAnnotation box = new BoxAnnotation();
// sets label configuration
box.getLabel().setDisplay(true);
box.getLabel().setContent("My threshold");
// stores the annotation in the main options
options.setAnnotations(box);

The complete options are described by following table:

Name	Type	Default	Scriptable	Description
color	String - IsColor	#fff -	Yes	The text color of the label.
content	String - String[] - Img - Canvas	null	Yes	The content to show in the label. Provide an array to display values on a new line.
display	boolean	false	Yes	Whether or not the label is shown.
drawTime	DrawTime	See description	-	Defines when the label is drawn. Defaults to the box annotation draw time if unset.
font	Font	See description	Yes	The text font of the label. The default value is the global font with the weight set to Weight.BOLD. See Font.
imageHeight	int - String	Undefined.INTEGER - null	Yes	Overrides the height of the image. Could be set in pixel by a number, or in percentage of current height of image by a string. If uset, uses the height of the image. It is used only when the content is an image.
imageWidth	int - String	Undefined.INTEGER - null	Yes	Overrides the width of the image. Could be set in pixel by a number, or in percentage of current width of image by a string. If unset, uses the width of the image. It is used only when the content is an image.
padding	Padding	6	Yes	Number of pixels to add above and below the title text. See padding documentation for more details.
position	AlignPosition	See position	Yes	Anchor position of label on box.
rotation	double	0	Yes	The rotation of label, in degrees.
textAlign	TextAlign	TextAlign.START	Yes	Horizontal alignment on the label content when is set as a multiple lines text.
textStrokeColor	String - IsColor	HtmlColor.TRANSPARENT	Yes	The stroke color of the text.
textStrokeWidth	int	0	Yes	The stroke width of the text.
xAdjust	double	0	Yes	Adjustment along x-axis (left-right) of label relative to computed position. Negative values move the label left, positive right.
yAdjust	double	0	Yes	Adjustment along y-axis (top-bottom) of label relative to computed position. Negative values move the label up, positive down.
z	int	0	Yes	All visible elements will be drawn in ascending order of z option, with the same drawTime option.

Box label position

AlignPosition can define the x property for the horizontal alignment in the box. Similarly, the y property defines the vertical alignment in the box.

Possible options for both properties are LabelPosition.START, LabelPosition.CENTER, LabelPosition.END, or a double, a value between 0 and 1, is representing the percentage on the size where the label will be located.

Default is LabelPosition.CENTER.

Box label scriptable options

Some options also accept a callback which is called at runtime and that takes the context as single argument, see here the details, which is representing contextual information and chart instance.

// creates a plugin options
AnnotationOptions options = new AnnotationOptions();
// creates an annotation
BoxAnnotation box = new BoxAnnotation();
// sets callback for color options
box.getLabel().setColor(new ColorCallback<AnnotationContext>(){

   @Override
   public IsColor invoke(AnnotationContext context){
      // logic
      return color;
   }
});
// stores the annotation in the main options
options.setAnnotations(box);

The following options can be set by a callback:

Name	Callback	Returned types
color	ColorCallback<AnnotationContext>	String - IsColor
content	ContentCallback	String - List<String> - Img - Canvas
display	SimpleDisplayCallback<AnnotationContext>	boolean
font	FontCallback<AnnotationContext>	FontItem
imageHeight	ImageSizeCallback	String - int
imageWidth	ImageSizeCallback	String - int
padding	PaddingCallback<AnnotationContext>	PaddingItem
rotation	RotationCallback<AnnotationContext>	double
position	LabelAlignPositionCallback	AlignPosition
textAlign	TextAlignCallback<AnnotationContext>	TextAlign
textStrokeColor	ColorCallback<AnnotationContext>	String - IsColor
textStrokeWidth	WidthCallback<AnnotationContext>	int
xAdjust	AdjustSizeCallback	double
yAdjust	AdjustSizeCallback	double
z	ZCallback	int

Ellipse

Ellipse annotations are used to draw ellipses on the chart area. This can be useful for highlighting different areas of a chart.

Every plugin options can have an unlimited number of ellipses annotations.

// creates a plugin options
AnnotationOptions options = new AnnotationOptions();
// creates an annotation
// without id (a unique one is created automatically)
EllipseAnnotation ellipse = new EllipseAnnotation();
ellipse.setDrawTime(DrawTime.BEFORE_DATASETS_DRAW);
ellipse.setXScaleID(DefaultScaleId.X);
ellipse.setYScaleID(DefaultScaleId.Y);
ellipse.setXMin("February");
ellipse.setXMax("April");
ellipse.setYMin(10);
ellipse.setYMax(60);
ellipse.setBackgroundColor(GwtMaterialColor.INDIGO_LIGHTEN_3.alpha(0.3D));
ellipse.setBorderWidth(4);
ellipse.setBorderColor(GwtMaterialColor.INDIGO_LIGHTEN_3);
ellipse.setBorderDash(3,3);
// stores the annotation in the main options
options.setAnnotations(ellipse);

If one of the axes does not match an axis in the chart, the ellipse will take the entire chart dimension.

The 4 coordinates, xMin, xMax, yMin, yMax are optional. If not specified, the ellipse is expanded out to the edges in the respective direction.

The complete options are described by following table:

Name	Type	Default	Scriptable	Description
adjustScaleRange	boolean	true	Yes	If true, the scale range should be adjusted if this annotation is out of range.
backgroundColor	String - IsColor	Defaults.get().getGlobal() .getColorAsString()	Yes	The fill color of the ellipse. See default colors.
backgroundShadowColor	String - IsColor	HtmlColor.TRANSPARENT	Yes	The color of shadows. See MDN.
borderColor	String - IsColor	Defaults.get().getGlobal() .getColorAsString()	Yes	The stroke color of the ellipse. See default colors.
borderDash	int[]	[]	Yes	The length and spacing of dashes. See MDN.
borderDashOffset	double	0	Yes	The offset for line dashes. See MDN.
borderShadowColor	String - IsColor	HtmlColor.TRANSPARENT	Yes	The color of border shadows. See MDN.
borderWidth	int	1	Yes	The stroke width of the ellipse.
display	boolean	true	Yes	Whether or not this annotation is visible.
drawTime	DrawTime	DrawTime. AFTER_DATASETS_DRAW	Yes	Defines when the annotation is drawn. This allows positioning of the annotation relative to the other elements of the graph.
rotation	double	0	Yes	The rotation of annotation, in degrees.
shadowBlur	double	0	Yes	The amount of blur applied to shadows. See MDN.
shadowOffsetX	int	0	Yes	The distance that shadows will be offset horizontally. See MDN.
shadowOffsetY	int	0	Yes	The distance that shadows will be offset vertically. See MDN.
xMax	String - double - Date	null	Yes	Right edge of the ellipse in units along the x axis.
xMin	String - double - Date	null	Yes	Left edge of the ellipse in units along the x axis.
xScaleID	String - ScaleId	null	-	The ID of the X scale to bind onto.
yMax	String - double - Date	null	Yes	Top edge of the ellipse in units along the y axis.
yMin	String - double - Date	null	Yes	Bottom edge of the ellipse in units along the y axis.
yScaleID	String - ScaleId	null	-	The ID of the Y scale to bind onto.
z	int	0	Yes	All visible elements will be drawn in ascending order of z option, with the same drawTime option.

Ellipse scriptable options

Some options also accept a callback which is called at runtime and that takes the context as single argument, see here the details, which is representing contextual information and chart instance.

// creates a plugin options
AnnotationOptions options = new AnnotationOptions();
// creates an annotation
EllipseAnnotation ellipse = new EllipseAnnotation();
// sets callback for border width options
ellipse.setBorderWidth(new WidthCallback<AnnotationContext>(){

   @Override
   public Integer invoke(AnnotationContext context){
      // logic
      return borderWidth;
   }
});
// stores the annotation in the main options
options.setAnnotations(ellipse);

The following options can be set by a callback:

Name	Callback	Returned types
adjustScaleRange	AdjustScaleRangeCallback	boolean
backgroundColor	ColorCallback<AnnotationContext>	String - IsColor - Pattern
backgroundShadowColor	ColorCallback<AnnotationContext>	String - IsColor
borderColor	ColorCallback<AnnotationContext>	String - IsColor
borderDash	BorderDashCallback<AnnotationContext>	List<Integer>
borderDashOffset	BorderDashOffsetCallback<AnnotationContext>	double
borderShadowColor	ColorCallback<AnnotationContext>	String - IsColor
borderWidth	WidthCallback<AnnotationContext>	int
display	SimpleDisplayCallback<AnnotationContext>	boolean
drawTime	DrawTimeCallback	DrawTime
rotation	RotationCallback<AnnotationContext>	double
shadowBlur	ShadowBlurCallback	double
shadowOffsetX	ShadowOffsetCallback	int
shadowOffsetY	ShadowOffsetCallback	int
xMax	ValueCallback	String - double - Date
xMin	ValueCallback	String - double - Date
yMax	ValueCallback	String - double - Date
yMin	ValueCallback	String - double - Date
z	ZCallback	int

Ellipse label

An ellipse annotation can have a label to draw in the ellipse.

Every ellipse annotation can have ONLY 1 label.

// creates a plugin options
AnnotationOptions options = new AnnotationOptions();
// creates an annotation
// without id (a unique one is created automatically)
EllipseAnnotation ellipse = new EllipseAnnotation();
// sets label configuration
ellipse.getLabel().setDisplay(true);
ellipse.getLabel().setContent("My label");
// stores the annotation in the main options
options.setAnnotations(ellipse);

The complete options are described by following table:

Name	Type	Default	Scriptable	Description
color	String - IsColor	#fff -	Yes	The text color of the label.
content	String - String[] - Img - Canvas	null	Yes	The content to show in the label. Provide an array to display values on a new line.
display	boolean	false	Yes	Whether or not the label is shown.
drawTime	DrawTime	See description	-	Defines when the label is drawn. Defaults to the box annotation draw time if unset.
font	Font	See description	Yes	The text font of the label. The default value is the global font with the weight set to Weight.BOLD. See Font.
imageHeight	int - String	Undefined.INTEGER - null	Yes	Overrides the height of the image. Could be set in pixel by a number, or in percentage of current height of image by a string. If uset, uses the height of the image. It is used only when the content is an image.
imageWidth	int - String	Undefined.INTEGER - null	Yes	Overrides the width of the image. Could be set in pixel by a number, or in percentage of current width of image by a string. If unset, uses the width of the image. It is used only when the content is an image.
padding	Padding	6	Yes	Number of pixels to add above and below the title text. See padding documentation for more details.
position	AlignPosition	See position	Yes	Anchor position of label on box.
rotation	double	0	Yes	The rotation of label, in degrees.
textAlign	TextAlign	TextAlign.START	Yes	Horizontal alignment on the label content when is set as a multiple lines text.
textStrokeColor	String - IsColor	HtmlColor.TRANSPARENT	Yes	The stroke color of the text.
textStrokeWidth	int	0	Yes	The stroke width of the text.
xAdjust	double	0	Yes	Adjustment along x-axis (left-right) of label relative to computed position. Negative values move the label left, positive right.
yAdjust	double	0	Yes	Adjustment along y-axis (top-bottom) of label relative to computed position. Negative values move the label up, positive down.
z	int	0	Yes	All visible elements will be drawn in ascending order of z option, with the same drawTime option.

Ellipse label scriptable options

Some options also accept a callback which is called at runtime and that takes the context as single argument, see here the details, which is representing contextual information and chart instance.

// creates a plugin options
AnnotationOptions options = new AnnotationOptions();
// creates an annotation
EllipseAnnotation ellipse = new EllipseAnnotation();
// sets callback for color options
ellipse.getLabel().setColor(new ColorCallback<AnnotationContext>(){

   @Override
   public IsColor invoke(AnnotationContext context){
      // logic
      return color;
   }
});
// stores the annotation in the main options
options.setAnnotations(ellipse);

The following options can be set by a callback:

Name	Callback	Returned types
color	ColorCallback<AnnotationContext>	String - IsColor
content	ContentCallback	String - List<String> - Img - Canvas
display	SimpleDisplayCallback<AnnotationContext>	boolean
font	FontCallback<AnnotationContext>	FontItem
imageHeight	ImageSizeCallback	String - int
imageWidth	ImageSizeCallback	String - int
padding	PaddingCallback<AnnotationContext>	PaddingItem
rotation	RotationCallback<AnnotationContext>	double
position	LabelAlignPositionCallback	AlignPosition
textAlign	TextAlignCallback<AnnotationContext>	TextAlign
textStrokeColor	ColorCallback<AnnotationContext>	String - IsColor
textStrokeWidth	WidthCallback<AnnotationContext>	int
xAdjust	AdjustSizeCallback	double
yAdjust	AdjustSizeCallback	double
z	ZCallback	int

Label

Label annotations are used to add contents on the chart area. This can be useful for describing values that are of interest.

Every plugin options can have an unlimited number of labels annotations.

// creates a plugin options
AnnotationOptions options = new AnnotationOptions();
// creates an annotation
// without id (a unique one is created automatically)
LabelAnnotation label = new LabelAnnotation();
label.setDrawTime(DrawTime.AFTER_DRAW);
label.setXScaleID(DefaultScaleId.X);
label.setYScaleID(DefaultScaleId.Y);
label.setXValue("February");
label.setYValue(50);
label.setContent("My label");
// stores the annotation in the main options
options.setAnnotations(label);

The complete options are described by following table:

Name	Type	Default	Scriptable	Description
adjustScaleRange	boolean	true	Yes	If true, the scale range should be adjusted if this annotation is out of range.
backgroundColor	String - IsColor	HtmlColor.TRANSPARENT	Yes	The fill color of the label box. See default colors.
backgroundShadowColor	String - IsColor	HtmlColor.TRANSPARENT	Yes	The color of shadows. See MDN.
borderCapStyle	CapStyle	CapStyle.BUTT	Yes	Cap style of the border label box. See MDN.
borderColor	String - IsColor	Defaults.get().getGlobal() .getColorAsString()	Yes	The stroke color of the label box. See default colors.
borderDash	int[]	[]	Yes	The length and spacing of dashes. See MDN.
borderDashOffset	double	0	Yes	The offset for line dashes. See MDN.
borderJoinStyle	JoinStyle	JoinStyle.MITER	Yes	Border line joint style. See MDN
borderRadius	int - BarBorderRadius	0	Yes	The radius in pixels of label box.
borderShadowColor	String - IsColor	HtmlColor.TRANSPARENT	Yes	The color of border shadows. See MDN.
borderWidth	int	0	Yes	The stroke width of the label box.
color	String - IsColor	HtmlColor.BLACK -	Yes	The text color of the label.
content	String - String[] - Img - Canvas	null	Yes	The content to show in the label. Provide an array to display values on a new line.
display	boolean	true	Yes	Whether or not this annotation is visible.
drawTime	DrawTime	DrawTime. AFTER_DATASETS_DRAW	Yes	Defines when the annotation is drawn. This allows positioning of the annotation relative to the other elements of the graph.
font	Font	See description	Yes	The text font of the label. The default value is the global font. See Font.
imageHeight	int - String	Undefined.INTEGER - null	Yes	Overrides the height of the image. Could be set in pixel by a number, or in percentage of current height of image by a string. If uset, uses the height of the image. It is used only when the content is an image.
imageWidth	int - String	Undefined.INTEGER - null	Yes	Overrides the width of the image. Could be set in pixel by a number, or in percentage of current width of image by a string. If unset, uses the width of the image. It is used only when the content is an image.
padding	Padding	6	Yes	Number of pixels to add above and below the title text. See padding documentation for more details.
position	AlignPosition	See position	Yes	Anchor position of label.
rotation	double	0	Yes	The rotation of annotation, in degrees.
shadowBlur	double	0	Yes	The amount of blur applied to shadows. See MDN.
shadowOffsetX	int	0	Yes	The distance that shadows will be offset horizontally. See MDN.
shadowOffsetY	int	0	Yes	The distance that shadows will be offset vertically. See MDN.
textAlign	TextAlign	TextAlign.CENTER	Yes	Horizontal alignment on the label content when is set as a multiple lines text.
textStrokeColor	String - IsColor	HtmlColor.TRANSPARENT	Yes	The stroke color of the text.
textStrokeWidth	int	0	Yes	The stroke width of the text.
xAdjust	double	0	Yes	Adjustment along x-axis (left-right) of point relative to computed position. Negative values move the point left, positive right.
xMax	String - double - Date	null	Yes	X coordinate of end two of the box, whose center is used as the center of the point, in units along the x axis.
xMin	String - double - Date	null	Yes	X coordinate of end one of the box, whose center is used as the center of the point, in units along the x axis.
xScaleID	String - ScaleId	null	-	The ID of the X scale to bind onto.
xValue	String - double - Date	null	Yes	X coordinate of the center of point in units along the x axis.
yAdjust	double	0	Yes	Adjustment along y-axis (top-bottom) of point relative to computed position. Negative values move the point up, positive down.
yMax	String - double - Date	null	Yes	Y coordinate of end one of the box, whose center is used as the center of the point, in units along the y axis.
yMin	String - double - Date	null	Yes	Y coordinate of end one of the box, whose center is used as the center of the point, in units along the y axis.
yScaleID	String - ScaleId	null	-	The ID of the Y scale to bind onto.
yValue	String - double - Date	null	Yes	Y coordinate of the center of point in units along the y axis.
z	int	0	Yes	All visible elements will be drawn in ascending order of z option, with the same drawTime option.

If one of the axes does not match an axis in the chart, the point annotation will take the center of the chart as point. The 2 coordinates, xValue, yValue are optional. If not specified, the point annotation will take the center of the chart as point.

The 4 coordinates, xMin, xMax, yMin, yMax are optional. If not specified, the box is expanded out to the edges in the respective direction and the box size is used to calculated the center of the point.

Label position

AlignPosition can define the x property for the horizontal alignment of the label with respect to the selected point. Similarly, the y property defines the vertical alignment.

Possible options for both properties are LabelPosition.START, LabelPosition.CENTER, LabelPosition.END, or a double, a value between 0 and 1, is representing the percentage on the size where the label will be located.

Default is LabelPosition.CENTER.

Label scriptable options

Some options also accept a callback which is called at runtime and that takes the context as single argument, see here the details, which is representing contextual information and chart instance.

// creates a plugin options
AnnotationOptions options = new AnnotationOptions();
// creates an annotation
LabelAnnotation label = new LabelAnnotation();
// sets callback for border width options
label.setBorderWidth(new WidthCallback<AnnotationContext>(){

   @Override
   public Integer invoke(AnnotationContext context){
      // logic
      return borderWidth;
   }
});
// stores the annotation in the main options
options.setAnnotations(label);

The following options can be set by a callback:

Name	Callback	Returned types
adjustScaleRange	AdjustScaleRangeCallback	boolean
backgroundColor	ColorCallback<AnnotationContext>	String - IsColor - Pattern
backgroundShadowColor	ColorCallback<AnnotationContext>	String - IsColor
borderCapStyle	CapStyleCallback<AnnotationContext>	CapStyle
borderColor	ColorCallback<AnnotationContext>	String - IsColor
borderDash	BorderDashCallback<AnnotationContext>	List<Integer>
borderDashOffset	BorderDashOffsetCallback<AnnotationContext>	double
borderJoinStyle	JoinStyleCallback<AnnotationContext>	JoinStyle
borderRadius	BorderRadiusCallback<AnnotationContext>	int - - BarBorderRadius
borderShadowColor	ColorCallback<AnnotationContext>	String - IsColor
borderWidth	WidthCallback<AnnotationContext>	int
color	ColorCallback<AnnotationContext>	String - IsColor
content	ContentCallback	String - List<String> - Img - Canvas
display	SimpleDisplayCallback<AnnotationContext>	boolean
drawTime	DrawTimeCallback	DrawTime
font	FontCallback<AnnotationContext>	FontItem
imageHeight	ImageSizeCallback	String - int
imageWidth	ImageSizeCallback	String - int
padding	PaddingCallback<AnnotationContext>	PaddingItem
position	LabelAlignPositionCallback	AlignPosition
rotation	RotationCallback<AnnotationContext>	double
textAlign	TextAlignCallback<AnnotationContext>	TextAlign
shadowBlur	ShadowBlurCallback	double
shadowOffsetX	ShadowOffsetCallback	int
shadowOffsetY	ShadowOffsetCallback	int
textStrokeColor	ColorCallback<AnnotationContext>	String - IsColor
textStrokeWidth	WidthCallback<AnnotationContext>	int
xAdjust	AdjustSizeCallback	double
xMax	ValueCallback	String - double - Date
xMin	ValueCallback	String - double - Date
xValue	ValueCallback	String - double - Date
yAdjust	AdjustSizeCallback	double
yMax	ValueCallback	String - double - Date
yMin	ValueCallback	String - double - Date
yValue	ValueCallback	String - double - Date
z	ZCallback	int

Callout

The callout connects the label by a line to the selected point.

Every label annotation can have ONLY 1 callout.

// creates a plugin options
AnnotationOptions options = new AnnotationOptions();
// creates an annotation
// without id (a unique one is created automatically)
LabelAnnotation label = new LabelAnnotation();
// sets callout configuration
line.getCallout().setDisplay(true);
// stores the annotation in the main options
options.setAnnotations(line);

The complete options are described by following table:

Name	Type	Default	Scriptable	Description
borderCapStyle	CapStyle	CapStyle.BUTT	Yes	Cap style of the callout line. See MDN.
borderColor	String - IsColor	HtmlColor.BLACK -	Yes	The color of the callout line.
borderDash	int[]	[]	Yes	Length and spacing of dashes. See MDN.
borderDashOffset	double	0	Yes	Offset for line dashes. See MDN.
borderJoinStyle	JoinStyle	JoinStyle.MITER	Yes	Callout line joint style. See MDN.
borderWidth	int	1	Yes	The width of the callout line in pixels.
display	boolean	false	Yes	Whether or not the callout is shown.
margin	int	5	Yes	Amount of pixels between the label and the callout separator.
position	CalloutPosition	CalloutPosition.AUTO	Yes	The position of callout, with respect to the label.
side	int	5	Yes	Width of the starter line of callout pointer.
start	double - int	0.5D	Yes	The percentage of the separator dimension to use as starting point for callout pointer. Could be set in pixel by an integer, or in percentage of the separator dimension by a double, a value between 0 and 1.

Callout scriptable options

Some options also accept a callback which is called at runtime and that takes the context as single argument, see here the details, which is representing contextual information and chart instance.

// creates a plugin options
AnnotationOptions options = new AnnotationOptions();
// creates an annotation
LabelAnnotation label = new LabelAnnotation();
// sets callback for border color options
label.getCallout().setBorderColor(new ColorCallback<AnnotationContext>(){

   @Override
   public IsColor invoke(AnnotationContext context){
      // logic
      return color;
   }
});
// stores the annotation in the main options
options.setAnnotations(label);

The following options can be set by a callback:

Name	Callback	Returned types
borderCapStyle	CapStyleCallback<AnnotationContext>	CapStyle
borderColor	ColorCallback<AnnotationContext>	String - IsColor
borderDash	BorderDashCallback<AnnotationContext>	List<Integer>
borderDashOffset	BorderDashOffsetCallback<AnnotationContext>	double
borderJoinStyle	JoinStyleCallback<AnnotationContext>	JoinStyle
borderWidth	WidthCallback<AnnotationContext>	int
display	SimpleDisplayCallback<AnnotationContext>	boolean
margin	MarginCallback	int
position	CalloutPositionCallback	CalloutPosition
side	SideCallback	int
start	[StartCallback](https://pepstock-org.github.io/Charba/5.8/org/pepstock/charba/client/annotation/callbacks/StartCallback](https.html)	double - int

Line

Line annotations are used to draw lines on the chart area. This can be useful for highlighting information such as a threshold.

Every plugin options can have an unlimited number of lines annotations.

// creates a plugin options
AnnotationOptions options = new AnnotationOptions();
// creates an annotation
// without id (a unique one is created automatically)
LineAnnotation line = new LineAnnotation();
line.setDrawTime(DrawTime.AFTER_DRAW);
line.setScaleID(DefaultScaleId.X.value());
line.setBorderColor(HtmlColor.DARK_GRAY);
line.setBorderWidth(2);
line.setValue(new Date());
// sets label configuration
line.getLabel().setDisplay(true);
line.getLabel().setContent("Now");
line.getLabel().setPosition(LabelPosition.START);
// stores the annotation in the main options
options.setAnnotations(line);

The complete options are described by following table:

Name	Type	Default	Scriptable	Description
adjustScaleRange	boolean	true	Yes	If true, the scale range should be adjusted if this annotation is out of range.
borderColor	String - IsColor	Defaults.get().getGlobal() .getColorAsString()	Yes	The stroke color of the line.
borderDash	int[]	[]	Yes	the line dash pattern used when stroking lines, using an array of values which specify alternating lengths of lines and gaps which describe the pattern.
borderDashOffset	int	0	Yes	Offset for line dashes. See MDN
borderShadowColor	String - IsColor	HtmlColor.TRANSPARENT	Yes	The color of border shadows. See MDN.
borderWidth	int	2	Yes	The stroke width of the line.
display	boolean	true	Yes	Whether or not this annotation is visible.
drawTime	DrawTime	DrawTime. AFTER_DATASETS_DRAW	Yes	Defines when the annotation is drawn. This allows positioning of the annotation relative to the other elements of the graph.
endValue	String - double - Date	null	Yes	End two of the line when a single scale is specified.
scaleID	String - ScaleId	null	-	ID of the scale in single scale mode. If unset, xScaleID and yScaleID are used.
shadowBlur	double	0	Yes	The amount of blur applied to shadows. See MDN.
shadowOffsetX	int	0	Yes	The distance that shadows will be offset horizontally. See MDN.
shadowOffsetY	int	0	Yes	The distance that shadows will be offset vertically. See MDN.
value	String - double - Date	null	Yes	End one of the line when a single scale is specified.
xMax	String - double - Date	null	Yes	X coordinate of end two of the line in units along the x axis.
xMin	String - double - Date	null	Yes	X coordinate of end one of the line in units along the x axis.
xScaleID	String - ScaleId	null	-	The ID of the X scale to bind onto.
yMax	String - double - Date	null	Yes	Y coordinate of end one of the line in units along the y axis.
yMin	String - double - Date	null	Yes	Y coordinate of end one of the line in units along the y axis.
yScaleID	String - ScaleId	null	-	The ID of the Y scale to bind onto.
z	int	0	Yes	All visible elements will be drawn in ascending order of z option, with the same drawTime option.

If one of the axes does not match an axis in the chart, the line will take the entire chart dimension.

The 4 coordinates, xMin, xMax, yMin, yMax are optional. If not specified, the line is expanded out to the edges in the respective direction.

The line can be positioned in two different ways:

• if scaleID is set, then value and endValue must also be set to indicate the end points of the line. The line will be perpendicular to the axis identified by scaleID.
• if scaleID is unset, then xScaleID and yScaleID are used to draw a line from (xMin, yMin) to (xMax, yMax).

Line scriptable options

Some options also accept a callback which is called at runtime and that takes the context as single argument, see here the details, which is representing contextual information and chart instance.

// creates a plugin options
AnnotationOptions options = new AnnotationOptions();
// creates an annotation
LineAnnotation line = new LineAnnotation();
// sets callback for border width options
line.setBorderWidth(new WidthCallback<AnnotationContext>(){

   @Override
   public Integer invoke(AnnotationContext context){
      // logic
      return borderWidth;
   }
});
// stores the annotation in the main options
options.setAnnotations(line);

The following options can be set by a callback:

Name	Callback	Returned types
adjustScaleRange	AdjustScaleRangeCallback	boolean
borderColor	ColorCallback<AnnotationContext>	String - IsColor
borderDash	BorderDashCallback<AnnotationContext>	List<Integer>
borderDashOffset	BorderDashOffsetCallback<AnnotationContext>	double
borderShadowColor	ColorCallback<AnnotationContext>	String - IsColor
borderWidth	WidthCallback<AnnotationContext>	int
display	SimpleDisplayCallback<AnnotationContext>	boolean
drawTime	DrawTimeCallback	DrawTime
endValue	ValueCallback	String - double - Date
shadowBlur	ShadowBlurCallback	double
shadowOffsetX	ShadowOffsetCallback	int
shadowOffsetY	ShadowOffsetCallback	int
value	ValueCallback	String - double - Date
xMax	ValueCallback	String - double - Date
xMin	ValueCallback	String - double - Date
yMax	ValueCallback	String - double - Date
yMin	ValueCallback	String - double - Date
z	ZCallback	int

Line label

A line annotation can have a label to draw on the line.

Every line annotation can have ONLY 1 label.

// creates a plugin options
AnnotationOptions options = new AnnotationOptions();
// creates an annotation
// without id (a unique one is created automatically)
LineAnnotation line = new LineAnnotation();
// sets label configuration
line.getLabel().setDisplay(true);
line.getLabel().setContent("My threshold");
line.getLabel().setBackgroundColor(HtmlColor.RED);
// stores the annotation in the main options
options.setAnnotations(line);

The complete options are described by following table:

Name	Type	Default	Scriptable	Description
autoRotation	boolean	false	-	If true, the rotation option is ignored and the label uses the degrees of the line.
backgroundColor	String - IsColor	rgba(0,0,0,0.8) -	Yes	Background color of the label container.
backgroundShadowColor	String - IsColor	HtmlColor.TRANSPARENT	Yes	The color of shadows. See MDN.
borderCapStyle	CapStyle	CapStyle.BUTT	Yes	Cap style of the line. See MDN.
borderColor	String - IsColor	HtmlColor.BLACK -	Yes	The color of the line.
borderDash	int[]	[]	Yes	Length and spacing of dashes. See MDN.
borderDashOffset	double	0	Yes	Offset for line dashes. See MDN.
borderJoinStyle	JoinStyle	JoinStyle.MITER	Yes	Line joint style. See MDN.
borderRadius	int - BarBorderRadius	6	Yes	The radius of label box in pixels.
borderShadowColor	String - IsColor	HtmlColor.TRANSPARENT	Yes	The color of border shadows. See MDN.
borderWidth	int	0	Yes	The width of the line in pixels.
color	String - IsColor	#fff -	Yes	The text color of the label.
content	String - String[] - Img - Canvas	null	Yes	The content to show in the label. Provide an array to display values on a new line.
display	boolean	false	Yes	Whether or not the label is shown.
drawTime	DrawTime	See description	-	Defines when the label is drawn. Defaults to the line annotation draw time if unset.
font	Font	See description	Yes	The text font of the label. The default value is the global font with the style set to FontStyle.BOLD. See Font.
imageHeight	int - String	Undefined.INTEGER - null	Yes	Overrides the height of the image. Could be set in pixel by a number, or in percentage of current height of image by a string. If uset, uses the height of the image. It is used only when the content is an image.
imageWidth	int - String	Undefined.INTEGER - null	Yes	Overrides the width of the image. Could be set in pixel by a number, or in percentage of current width of image by a string. If unset, uses the width of the image. It is used only when the content is an image.
padding	Padding	6	Yes	Number of pixels to add above and below the title text. See padding documentation for more details.
position	LabelPosition - double	LabelPosition.CENTER	Yes	Anchor position of label on line. If set by a double, a value between 0 and 1, is representing the percentage on the size where the label will be located.
rotation	double	0	Yes	The rotation of label, in degrees.
shadowBlur	double	0	Yes	The amount of blur applied to shadows. See MDN.
shadowOffsetX	int	0	Yes	The distance that shadows will be offset horizontally. See MDN.
shadowOffsetY	int	0	Yes	The distance that shadows will be offset vertically. See MDN.
textAlign	TextAlign	TextAlign.CENTER	Yes	Horizontal alignment on the label content when is set as a multiple lines text.
textStrokeColor	String - IsColor	HtmlColor.TRANSPARENT	Yes	The stroke color of the text.
textStrokeWidth	int	0	Yes	The stroke width of the text.
xAdjust	double	0	Yes	Adjustment along x-axis (left-right) of label relative to computed position. Negative values move the label left, positive right.
yAdjust	double	0	Yes	Adjustment along y-axis (top-bottom) of label relative to computed position. Negative values move the label up, positive down.
z	int	0	Yes	All visible elements will be drawn in ascending order of z option, with the same drawTime option.

Line label scriptable options

Some options also accept a callback which is called at runtime and that takes the context as single argument, see here the details, which is representing contextual information and chart instance.

// creates a plugin options
AnnotationOptions options = new AnnotationOptions();
// creates an annotation
LineAnnotation line = new LineAnnotation();
// sets callback for background color options
line.getLabel().setBackgroundColor(new ColorCallback<AnnotationContext>(){

   @Override
   public IsColor invoke(AnnotationContext context){
      // logic
      return color;
   }
});
// stores the annotation in the main options
options.setAnnotations(line);

The following options can be set by a callback:

Name	Callback	Returned types
backgroundColor	ColorCallback<AnnotationContext>	String - IsColor - Pattern
backgroundShadowColor	ColorCallback<AnnotationContext>	String - IsColor
borderCapStyle	CapStyleCallback<AnnotationContext>	CapStyle
borderColor	ColorCallback<AnnotationContext>	String - IsColor
borderDash	BorderDashCallback<AnnotationContext>	List<Integer>
borderDashOffset	BorderDashOffsetCallback<AnnotationContext>	double
borderJoinStyle	JoinStyleCallback<AnnotationContext>	JoinStyle
borderRadius	BorderRadiusCallback<AnnotationContext>	int - - BarBorderRadius
borderShadowColor	ColorCallback<AnnotationContext>	String - IsColor
borderWidth	WidthCallback<AnnotationContext>	int
color	ColorCallback<AnnotationContext>	String - IsColor
content	ContentCallback	String - List<String> - Img - Canvas
display	SimpleDisplayCallback<AnnotationContext>	boolean
font	FontCallback<AnnotationContext>	FontItem
imageHeight	ImageSizeCallback	String - int
imageWidth	ImageSizeCallback	String - int
padding	PaddingCallback<AnnotationContext>	PaddingItem
position	LabelPositionCallback	double - LabelPosition
rotation	RotationCallback<AnnotationContext>	double(1)
shadowBlur	ShadowBlurCallback	double
shadowOffsetX	ShadowOffsetCallback	int
shadowOffsetY	ShadowOffsetCallback	int
textAlign	TextAlignCallback<AnnotationContext>	TextAlign
textStrokeColor	ColorCallback<AnnotationContext>	String - IsColor
textStrokeWidth	WidthCallback<AnnotationContext>	int
xAdjust	AdjustSizeCallback	double
yAdjust	AdjustSizeCallback	double
z	ZCallback	int

⁽¹⁾To enable autoRotation by the rotation callback, the value to return must be Double.NaN.

// sets callback for auto rotation
line.getLabel().setRotation(new RotationCallback<AnnotationContext>(){

   @Override
   public Double invoke(AnnotationContext context){
      return Double.NaN; // autoRotation is set
   }
});

Callout

The callout connects the label by a line to the line annotation.

Every line annotation can have ONLY 1 line label and callout.

// creates a plugin options
AnnotationOptions options = new AnnotationOptions();
// creates an annotation
// without id (a unique one is created automatically)
LineAnnotation line = new LineAnnotation();
// sets label configuration
line.getLabel().setDisplay(true);
line.getLabel().setContent("My threshold");
line.getLabel().setBackgroundColor(HtmlColor.RED);
line.getLabel().setYAdjust(-100);
// sets callout configuration
line.getLabel().getCallout().setDisplay(true);
// stores the annotation in the main options
options.setAnnotations(line);

The complete options are described by following table:

Name	Type	Default	Scriptable	Description
borderCapStyle	CapStyle	CapStyle.BUTT	Yes	Cap style of the callout line. See MDN.
borderColor	String - IsColor	HtmlColor.BLACK -	Yes	The color of the callout line.
borderDash	int[]	[]	Yes	Length and spacing of dashes. See MDN.
borderDashOffset	double	0	Yes	Offset for line dashes. See MDN.
borderJoinStyle	JoinStyle	JoinStyle.MITER	Yes	Callout line joint style. See MDN.
borderWidth	int	1	Yes	The width of the callout line in pixels.
display	boolean	false	Yes	Whether or not the callout is shown.
margin	int	5	Yes	Amount of pixels between the label and the callout separator.
position	CalloutPosition	CalloutPosition.AUTO	Yes	The position of callout, with respect to the label.
side	int	5	Yes	Width of the starter line of callout pointer.
start	double - int	0.5D	Yes	The percentage of the separator dimension to use as starting point for callout pointer. Could be set in pixel by an integer, or in percentage of the separator dimension by a double, a value between 0 and 1.

Line label Callout scriptable options

Some options also accept a callback which is called at runtime and that takes the context as single argument, see here the details, which is representing contextual information and chart instance.

// creates a plugin options
AnnotationOptions options = new AnnotationOptions();
// creates an annotation
LineAnnotation line = new LineAnnotation();
// sets label configuration
line.getLabel().setDisplay(true);
line.getLabel().setContent("My threshold");
line.getLabel().setBackgroundColor(HtmlColor.RED);
line.getLabel().setYAdjust(-100);
line.getLabel().getCallout().setDisplay(true);
// sets callback for border color options
line.getLabel().getCallout().setBorderColor(new ColorCallback<AnnotationContext>(){

   @Override
   public IsColor invoke(AnnotationContext context){
      // logic
      return color;
   }
});
// stores the annotation in the main options
options.setAnnotations(label);

The following options can be set by a callback:

Name	Callback	Returned types
borderCapStyle	CapStyleCallback<AnnotationContext>	CapStyle
borderColor	ColorCallback<AnnotationContext>	String - IsColor
borderDash	BorderDashCallback<AnnotationContext>	List<Integer>
borderDashOffset	BorderDashOffsetCallback<AnnotationContext>	double
borderJoinStyle	JoinStyleCallback<AnnotationContext>	JoinStyle
borderWidth	WidthCallback<AnnotationContext>	int
display	SimpleDisplayCallback<AnnotationContext>	boolean
margin	MarginCallback	int
position	CalloutPositionCallback	CalloutPosition
side	SideCallback	int
start	[StartCallback](https://pepstock-org.github.io/Charba/5.8/org/pepstock/charba/client/annotation/callbacks/StartCallback](https.html)	double - int

Arrow heads

Enabling it, you can add arrow heads at start and/or end of a line. It uses the borderWidth of the line options to configure the line width of the arrow head.

// creates a plugin options
AnnotationOptions options = new AnnotationOptions();
// creates an annotation
// without id (a unique one is created automatically)
LineAnnotation line = new LineAnnotation();
// sets arrowheads configuration
line.getArrowHeads().setDisplay(true);
line.getArrowHeads().setLength(20);
line.getArrowHeads().setWidth(12);
// stores the annotation in the main options
options.setAnnotations(line);

The following options can be specified per (line.getArrowHeads().getStart() and/or line.getArrowHeads().getEnd()) arrow head, or at the top level (line.getArrowHeads()) which apply to all arrow heads.

The complete options are described by following table:

Name	Type	Default	Scriptable	Description
backgroundColor	String - IsColor	lineAnnotation.borderColor	Yes	Background color of the arrow head.
backgroundShadowColor	String - IsColor	HtmlColor.TRANSPARENT	Yes	The color of shadows. See MDN.
borderColor	String - IsColor	lineAnnotation.borderColor	Yes	The border arrow head color.
borderDash	int[]	lineAnnotation.borderDash	Yes	Length and spacing of dashes. See MDN.
borderDashOffset	double	lineAnnotation.borderDashOffset	Yes	Offset for line dashes. See MDN.
borderShadowColor	String - IsColor	lineAnnotation.borderShadowColor	Yes	The color of border shadows. See MDN.
borderWidth	int	lineAnnotation.borderWidth	Yes	The width of the line in pixels.
display	boolean	false	Yes	Whether or not the arrow head is shown.
end	ArrowHeads	-	-	To configure the arrow head at the end of the line.
fill	boolean	false	Yes	Whether or not the arrow head is filled.
length	int	12	Yes	The length of the arrow head in pixels.
shadowBlur	double	lineAnnotation.shadowBlur	Yes	The amount of blur applied to shadows. See MDN.
shadowOffsetX	int	lineAnnotation.shadowOffsetX	Yes	The distance that shadows will be offset horizontally. See MDN.
shadowOffsetY	int	lineAnnotation.shadowOffsetY	Yes	The distance that shadows will be offset vertically. See MDN.
start	ArrowHeads	-	-	To configure the arrow head at the start of the line.
width	int	6	Yes	The width of the arrow head in pixels.

ArrowHeads scriptable options

Some options also accept a callback which is called at runtime and that takes the context as single argument, see here the details, which is representing contextual information and chart instance.

// creates a plugin options
AnnotationOptions options = new AnnotationOptions();
// creates an annotation
LineAnnotation line = new LineAnnotation();
// sets callback for background color options
line.getArrowHeads().setBackgroundColor(new ColorCallback<AnnotationContext>(){

   @Override
   public IsColor invoke(AnnotationContext context){
      // logic
      return color;
   }
});
// stores the annotation in the main options
options.setAnnotations(line);

The following options can be set by a callback:

Name	Callback	Returned types
backgroundColor	ColorCallback<AnnotationContext>	String - IsColor - Pattern
backgroundShadowColor	ColorCallback<AnnotationContext>	String - IsColor
borderColor	ColorCallback<AnnotationContext>	String - IsColor
borderDash	BorderDashCallback<AnnotationContext>	List<Integer>
borderDashOffset	BorderDashOffsetCallback<AnnotationContext>	double
borderShadowColor	ColorCallback<AnnotationContext>	String - IsColor
borderWidth	WidthCallback<AnnotationContext>	int
display	SimpleDisplayCallback<AnnotationContext>	boolean
fill	FillCallback	boolean
length	LengthCallback	int
shadowBlur	ShadowBlurCallback	double
shadowOffsetX	ShadowOffsetCallback	int
shadowOffsetY	ShadowOffsetCallback	int
width	WidthCallback<AnnotationContext>	int

Point

Point annotations are used to mark points on the chart area. This can be useful for highlighting values that are of interest.

Every plugin options can have an unlimited number of points annotations.

// creates a plugin options
AnnotationOptions options = new AnnotationOptions();
// creates an annotation
// without id (a unique one is created automatically)
PointAnnotation point = new PointAnnotation();
// sets annotation configuration
point.setXScaleID(DefaultScaleId.X);
point.setYScaleID(DefaultScaleId.Y);
point.setXValue("February");
point.setYValue(50);
point.setRadius(10);
point.setBackgroundColor(HtmlColor.YELLOW.alpha(0.3D));
point.setBorderWidth(2);
point.setBorderColor(HtmlColor.YELLOW.darker());
// stores the annotation in the main options
options.setAnnotations(point);

The complete options are described by following table:

Name	Type	Default	Scriptable	Description
adjustScaleRange	boolean	true	Yes	If true, the scale range should be adjusted if this annotation is out of range.
backgroundColor	String - IsColor	Defaults.get().getGlobal() .getColorAsString()	Yes	The fill color of the point. See default colors.
backgroundShadowColor	String - IsColor	HtmlColor.TRANSPARENT	Yes	The color of shadows. See MDN.
borderColor	String - IsColor	Defaults.get().getGlobal() .getColorAsString()	Yes	The stroke color of the point.
borderDash	int[]	[]	Yes	The line dash pattern used when stroking lines, using an array of values which specify alternating lengths of lines and gaps which describe the pattern.
borderDashOffset	int	0	Yes	Offset for border dashes. See MDN
borderShadowColor	String - IsColor	HtmlColor.TRANSPARENT	Yes	The color of border shadows. See MDN.
borderWidth	int	1	Yes	The stroke width of the point.
display	boolean	true	Yes	Whether or not this annotation is visible.
drawTime	DrawTime	DrawTime. AFTER_DATASETS_DRAW	Yes	Defines when the annotation is drawn. This allows positioning of the annotation relative to the other elements of the graph.
pointStyle	PointStyle - Img - Canvas	PointStyle.CIRCLE	Yes	Style of the point.
radius	double	10	Yes	Size of the point in pixels.
rotation	double	0	Yes	The rotation of the point, in degrees.
shadowBlur	double	0	Yes	The amount of blur applied to shadows. See MDN.
shadowOffsetX	int	0	Yes	The distance that shadows will be offset horizontally. See MDN.
shadowOffsetY	int	0	Yes	The distance that shadows will be offset vertically. See MDN.
xAdjust	double	0	Yes	Adjustment along x-axis (left-right) of point relative to computed position. Negative values move the point left, positive right.
xMax	String - double - Date	null	Yes	X coordinate of end two of the box, whose center is used as the center of the point, in units along the x axis.
xMin	String - double - Date	null	Yes	X coordinate of end one of the box, whose center is used as the center of the point, in units along the x axis.
xScaleID	String - ScaleId	null	-	The ID of the X scale to bind onto.
xValue	String - double - Date	null	Yes	X coordinate of the center of point in units along the x axis.
yAdjust	double	0	Yes	Adjustment along y-axis (top-bottom) of point relative to computed position. Negative values move the point up, positive down.
yMax	String - double - Date	null	Yes	Y coordinate of end one of the box, whose center is used as the center of the point, in units along the y axis.
yMin	String - double - Date	null	Yes	Y coordinate of end one of the box, whose center is used as the center of the point, in units along the y axis.
yScaleID	String - ScaleId	null	-	The ID of the Y scale to bind onto.
yValue	String - double - Date	null	Yes	Y coordinate of the center of point in units along the y axis.
z	int	0	Yes	All visible elements will be drawn in ascending order of z option, with the same drawTime option.

If one of the axes does not match an axis in the chart, the point annotation will take the center of the chart as point. The 2 coordinates, xValue, yValue are optional. If not specified, the point annotation will take the center of the chart as point.

The 4 coordinates, xMin, xMax, yMin, yMax are optional. If not specified, the box is expanded out to the edges in the respective direction and the box size is used to calculated the center of the point. To enable to use the box positioning, the radius must be set to 0.

Point scriptable options

Some options also accept a callback which is called at runtime and that takes the context as single argument, see here the details, which is representing contextual information and chart instance.

// creates a plugin options
AnnotationOptions options = new AnnotationOptions();
// creates an annotation
PointAnnotation point = new PointAnnotation();
// sets callback for border width options
point.setBorderWidth(new WidthCallback<AnnotationContext>(){

   @Override
   public Integer invoke(AnnotationContext context){
      // logic
      return borderWidth;
   }
});
// stores the annotation in the main options
options.setAnnotations(point);

The following options can be set by a callback:

Name	Callback	Returned types
adjustScaleRange	AdjustScaleRangeCallback	boolean
backgroundColor	ColorCallback<AnnotationContext>	String - IsColor - Pattern
backgroundShadowColor	ColorCallback<AnnotationContext>	String - IsColor
borderColor	ColorCallback<AnnotationContext>	String - IsColor
borderDash	BorderDashCallback<AnnotationContext>	List<Integer>
borderDashOffset	BorderDashOffsetCallback<AnnotationContext>	double
borderShadowColor	ColorCallback<AnnotationContext>	String - IsColor
borderWidth	WidthCallback<AnnotationContext>	int
display	SimpleDisplayCallback<AnnotationContext>	boolean
drawTime	DrawTimeCallback	DrawTime
pointStyle	PointStyleCallback<AnnotationContext>	PointStyle - Img - Canvas
radius	RadiusCallback<AnnotationContext>	double
rotation	RotationCallback<AnnotationContext>	double
shadowBlur	ShadowBlurCallback	double
shadowOffsetX	ShadowOffsetCallback	int
shadowOffsetY	ShadowOffsetCallback	int
xAdjust	AdjustSizeCallback	double
xMax	ValueCallback	String - double - Date
xMin	ValueCallback	String - double - Date
xValue	ValueCallback	String - double - Date
yAdjust	AdjustSizeCallback	double
yMax	ValueCallback	String - double - Date
yMin	ValueCallback	String - double - Date
yValue	ValueCallback	String - double - Date
z	ZCallback	int

Polygon

Polygon annotations are used to mark whatever polygon (for instance triangle, square or pentagon) on the chart area. This can be useful for highlighting values that are of interest.

Every plugin options can have an unlimited number of polygons annotations.

// creates a plugin options
AnnotationOptions options = new AnnotationOptions();
// creates an annotation
// without id (a unique one is created automatically)
PolygonAnnotation polygon = new PolygonAnnotation();
// sets annotation configuration
polygon.setXScaleID(DefaultScaleId.X);
polygon.setYScaleID(DefaultScaleId.Y);
polygon.setXValue("February");
polygon.setYValue(50);
polygon.setRadius(10);
// pentagon
polygon.setSides(5);
polygon.setBackgroundColor(HtmlColor.YELLOW.alpha(0.3D));
polygon.setBorderWidth(2);
polygon.setBorderColor(HtmlColor.YELLOW.darker());
// stores the annotation in the main options
options.setAnnotations(polygon);

The complete options are described by following table:

Name	Type	Default	Scriptable	Description
adjustScaleRange	boolean	true	Yes	If true, the scale range should be adjusted if this annotation is out of range.
backgroundColor	String - IsColor	Defaults.get().getGlobal() .getColorAsString()	Yes	The fill color of the polygon. See default colors.
backgroundShadowColor	String - IsColor	HtmlColor.TRANSPARENT	Yes	The color of shadows. See MDN.
borderCapStyle	CapStyle	CapStyle.BUTT	Yes	Cap style of the border line. See MDN.
borderColor	String - IsColor	Defaults.get().getGlobal() .getColorAsString()	Yes	The stroke color of the polygon.
borderDash	int[]	[]	Yes	The line dash pattern used when stroking lines, using an array of values which specify alternating lengths of lines and gaps which describe the pattern.
borderDashOffset	int	0	Yes	Offset for border dashes. See MDN
borderJoinStyle	JoinStyle	JoinStyle.MITER	Yes	Border line joint style. See MDN
borderShadowColor	String - IsColor	HtmlColor.TRANSPARENT	Yes	The color of border shadows. See MDN.
borderWidth	int	1	Yes	The stroke width of the polygon.
display	boolean	true	Yes	Whether or not this annotation is visible.
drawTime	DrawTime	DrawTime. AFTER_DATASETS_DRAW	Yes	Defines when the annotation is drawn. This allows positioning of the annotation relative to the other elements of the graph.
radius	double	10	Yes	Size of the polygon in pixels.
rotation	double	0	Yes	The rotation of the polygon, in degrees.
shadowBlur	double	0	Yes	The amount of blur applied to shadows. See MDN.
shadowOffsetX	int	0	Yes	The distance that shadows will be offset horizontally. See MDN.
shadowOffsetY	int	0	Yes	The distance that shadows will be offset vertically. See MDN.
sides	int	3	Yes	Amount of sides of polygon.
xAdjust	double	0	Yes	Adjustment along x-axis (left-right) of polygon relative to computed position. Negative values move the polygon left, positive right.
xMax	String - double - Date	null	Yes	X coordinate of end two of the box, whose center is used as the center of the polygon, in units along the x axis.
xMin	String - double - Date	null	Yes	X coordinate of end one of the box, whose center is used as the center of the polygon, in units along the x axis.
xScaleID	String - ScaleId	null	-	The ID of the X scale to bind onto.
xValue	String - double - Date	null	Yes	X coordinate of the center of polygon in units along the x axis.
yAdjust	double	0	Yes	Adjustment along y-axis (top-bottom) of polygon relative to computed position. Negative values move the polygon up, positive down.
yMax	String - double - Date	null	Yes	Y coordinate of end one of the box, whose center is used as the center of the polygon, in units along the y axis.
yMin	String - double - Date	null	Yes	Y coordinate of end one of the box, whose center is used as the center of the polygon, in units along the y axis.
yScaleID	String - ScaleId	null	-	The ID of the Y scale to bind onto.
yValue	String - double - Date	null	Yes	Y coordinate of the center of polygon in units along the y axis.
z	int	0	Yes	All visible elements will be drawn in ascending order of z option, with the same drawTime option.

If one of the axes does not match an axis in the chart, the point annotation will take the center of the chart as point. The 2 coordinates, xValue, yValue are optional. If not specified, the point annotation will take the center of the chart as point.

The 4 coordinates, xMin, xMax, yMin, yMax are optional. If not specified, the box is expanded out to the edges in the respective direction and the box size is used to calculated the center of the point. To enable to use the box positioning, the radius must be set to 0.

Polygon scriptable options

Some options also accept a callback which is called at runtime and that takes the context as single argument, see here the details, which is representing contextual information and chart instance.

// creates a plugin options
AnnotationOptions options = new AnnotationOptions();
// creates an annotation
PolygonAnnotation polygon = new PolygonAnnotation();
// sets callback for border width options
polygon.setBorderWidth(new WidthCallback<AnnotationContext>(){

   @Override
   public Integer invoke(AnnotationContext context){
      // logic
      return borderWidth;
   }
});
// stores the annotation in the main options
options.setAnnotations(polygon);

The following options can be set by a callback:

Name	Callback	Returned types
adjustScaleRange	AdjustScaleRangeCallback	boolean
backgroundColor	ColorCallback<AnnotationContext>	String - IsColor - Pattern
backgroundShadowColor	ColorCallback<AnnotationContext>	String - IsColor
borderCapStyle	CapStyleCallback<AnnotationContext>	CapStyle
borderColor	ColorCallback<AnnotationContext>	String - IsColor
borderDash	BorderDashCallback<AnnotationContext>	List<Integer>
borderDashOffset	BorderDashOffsetCallback<AnnotationContext>	double
borderJoinStyle	JoinStyleCallback<AnnotationContext>	JoinStyle
borderShadowColor	ColorCallback<AnnotationContext>	String - IsColor
borderWidth	WidthCallback<AnnotationContext>	int
display	SimpleDisplayCallback<AnnotationContext>	boolean
drawTime	DrawTimeCallback	DrawTime
radius	RadiusCallback<AnnotationContext>	double
rotation	RotationCallback<AnnotationContext>	double
shadowBlur	ShadowBlurCallback	double
shadowOffsetX	ShadowOffsetCallback	int
shadowOffsetY	ShadowOffsetCallback	int
sides	SidesCallback	int
xAdjust	AdjustSizeCallback	double
xMax	ValueCallback	String - double - Date
xMin	ValueCallback	String - double - Date
xValue	ValueCallback	String - double - Date
yAdjust	AdjustSizeCallback	double
yMax	ValueCallback	String - double - Date
yMin	ValueCallback	String - double - Date
yValue	ValueCallback	String - double - Date
z	ZCallback	int

Events

All annotations provide a set of callbacks which can be enabled to catch events on them.

To catch events is enough to set the events which you want to catch at AnnotationOptions and set a callback instance in the annotation.

// creates a plugin options
AnnotationOptions options = new AnnotationOptions();
// creates an annotation
// without id (a unique one is created automatically)
BoxAnnotation box = new BoxAnnotation();
// sets callback for specific annotation
box.setClickCallback(new ClickCallback(){
            
    @Override
    public boolean onClick(IsChart chart, AbstractAnnotation annotation, ChartEventContext event){
        // logic
        return false; // no redrawing
    }
});

You can also catch events with listeners defined for all defined annotations with a single instance, defining it to AnnotationOptions.

// creates a plugin options
AnnotationOptions options = new AnnotationOptions();
// sets callback for all annotations
options.setClickCallback(new ClickCallback(){
            
    @Override
    public boolean onClick(IsChart chart, AbstractAnnotation annotation, ChartEventContext event){
        // logic
        return false; // no redrawing
    }
});

These are the table of callbacks to implement:

Event	Callback type	Description
enter	EnterCallback	Called when the mouse enters the annotation.
leave	LeaveCallback	Called when the mouse leaves the annotation.
click	ClickCallback	Called when a click occurs on the annotation.

info

If the event callback returns true, the chart will re-render automatically after processing the event completely. This is important when there are the annotations that require re-draws (for instance, after a change of a rendering options).

Scriptable context

Some options also accept a callback which is called at runtime and that takes the context as single argument, AnnotationContext representing contextual information and chart instance.

// creates a plugin options
AnnotationOptions options = new AnnotationOptions();
// creates an annotation
BoxAnnotation box = new BoxAnnotation();
// sets callback for border width options
box.setBorderWidth(new WidthCallback<AnnotationContext>(){

   @Override
   public Integer invoke(AnnotationContext context){
      // logic
      return borderWidth;
   }
});
// stores the annotation in the main options
options.setAnnotations(box);

The context object contains the following properties:

Name	Type	Description
annotation	AbstractAnnotation	The annotation configuration where the options is defined as scriptable.
attributes	NativeObjectContainer	User object which you can store your options at runtime.
chart	IsChart	Chart instance.
element	AnnotationElement	The element instance related to the annotation.
shared	Map<String, Object>	A map that can be used to share objects among all contexts for all annotation.
type	ContextType	The type of the context. It can be ContextType.CHART or ContextType.ANNOTATION