The PitchforkAnnotationCreationModifier

The PitchforkAnnotationCreationModifier is a chart modifier that allows for interactive creation of PitchforkAnnotation instances using a 3-tap workflow.

Overview

When this modifier is enabled, users can place the 3 required points (Handle, High, Low) by tapping on the chart.

Each tap confirms the position of the next point.
A "rubber-band" dashed line provides a preview of the next segment between the last confirmed point and the current touch position.
Once the third point is placed, the annotation is finalized, and the modifier automatically resets to create the next one.

Properties

The following properties can be used to configure the PitchforkAnnotationCreationModifier:

Property	Description
xAxisId	Sets the ID of the X-Axis that the created annotations should be measured against.
yAxisId	Sets the ID of the Y-Axis that the created annotations should be measured against.
rubberBandStroke	Sets the pen style for the preview line shown during creation.

Event Listeners

You can receive a notification when an annotation is fully created by setting an OnAnnotationCreatedListener:

setAnnotationCreationListener(OnAnnotationCreatedListener listener): Passes the newly created annotation instance to the listener.

Using PitchforkAnnotationCreationModifier

The following code demonstrates how to add and configure a PitchforkAnnotationCreationModifier:

Java
Kotlin

// Create a PitchforkAnnotationCreationModifier
final PitchforkAnnotationCreationModifier pitchforkCreationModifier = new PitchforkAnnotationCreationModifier();

// Optional: Set a listener to be notified when an annotation is created
pitchforkCreationModifier.setAnnotationCreationListener(newAnnotation -> {
    // Configure the newly created annotation if needed
    newAnnotation.setIsEditable(true);
});

// Add the modifier to the surface
surface.getChartModifiers().add(pitchforkCreationModifier);

// Create a PitchforkAnnotationCreationModifier
val pitchforkCreationModifier = PitchforkAnnotationCreationModifier().apply {
    // Optional: Set a listener to be notified when an annotation is created
    setAnnotationCreationListener { newAnnotation ->
        // Configure the newly created annotation if needed
        newAnnotation.setIsEditable(true)
    }
}

// Add the modifier to the surface
surface.chartModifiers.add(pitchforkCreationModifier)

Customizing the Modifier

The PitchforkAnnotationCreationModifier is designed for extensibility. You can customize its behavior by extending it and overriding its protected methods.

Java
Kotlin

// Define a custom PitchforkAnnotationCreationModifier
private static class CustomPitchforkAnnotationCreationModifier extends PitchforkAnnotationCreationModifier {
    @Override
    protected void configureRubberBandAnnotation(IAnnotation annotation) {
        super.configureRubberBandAnnotation(annotation);
        
        // Customize the rubber-band styling
        if (annotation instanceof LineAnnotation) {
            ((LineAnnotation) annotation).setStroke(new SolidPenStyle(Color.YELLOW, true, 2f, new float[]{10, 5}));
        }
    }

    @Override
    protected void onAnnotationCreated(IAnnotation newAnnotation) {
        super.onAnnotationCreated(newAnnotation);
        
        // Custom logic after annotation is fully created
        newAnnotation.setIsEditable(true);
    }
}

void useCustomPitchforkAnnotationCreationModifier(@NonNull SciChartSurface surface) {
    // Use the custom modifier
    final CustomPitchforkAnnotationCreationModifier customModifier = new CustomPitchforkAnnotationCreationModifier();
    
    surface.getChartModifiers().add(customModifier);
}

// Define a custom PitchforkAnnotationCreationModifier
private class CustomPitchforkAnnotationCreationModifier : PitchforkAnnotationCreationModifier() {
    override fun configureRubberBandAnnotation(annotation: IAnnotation) {
        super.configureRubberBandAnnotation(annotation)
        
        // Customize the rubber-band styling
        if (annotation is LineAnnotation) {
            annotation.stroke = SolidPenStyle(Color.YELLOW, true, 2f, floatArrayOf(10f, 5f))
        }
    }

    override fun onAnnotationCreated(newAnnotation: IAnnotation) {
        super.onAnnotationCreated(newAnnotation)
        
        // Custom logic after annotation is fully created
        newAnnotation.setIsEditable(true)
    }
}

fun useCustomPitchforkAnnotationCreationModifier(surface: SciChartSurface) {
    // Use the custom modifier
    val customModifier = CustomPitchforkAnnotationCreationModifier()
    
    surface.chartModifiers.add(customModifier)
}

Note

To learn more about other Annotation Types, available out of the box in SciChart, please find the comprehensive list in the Annotation APIs article.