The XabcdAnnotationCreationModifier

The XabcdAnnotationCreationModifier is a chart modifier that allows for interactive creation of XabcdAnnotation instances using a multi-tap workflow.

Overview

When this modifier is enabled, users can place the 5 required points (X, A, B, C, D) 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 fifth point (D) 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 XabcdAnnotationCreationModifier:

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 XabcdAnnotationCreationModifier

The following code demonstrates how to add and configure an XabcdAnnotationCreationModifier:

Java
Kotlin

// Create an XabcdAnnotationCreationModifier
final XabcdAnnotationCreationModifier xabcdCreationModifier = new XabcdAnnotationCreationModifier();

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

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

// Create an XabcdAnnotationCreationModifier
val xabcdCreationModifier = XabcdAnnotationCreationModifier().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(xabcdCreationModifier)

Customizing the Modifier

The XabcdAnnotationCreationModifier is designed for extensibility. You can customize its behavior by extending it and overriding its protected methods. This allows you to change the annotation type, customize the rubber-band preview, or add post-creation logic.

Java
Kotlin

// Define a custom XabcdAnnotationCreationModifier
private static class CustomXabcdAnnotationCreationModifier extends XabcdAnnotationCreationModifier {
    @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 useCustomXabcdAnnotationCreationModifier(@NonNull SciChartSurface surface) {
    // Use the custom modifier
    final CustomXabcdAnnotationCreationModifier customModifier = new CustomXabcdAnnotationCreationModifier();
    
    surface.getChartModifiers().add(customModifier);
}

// Define a custom XabcdAnnotationCreationModifier
private class CustomXabcdAnnotationCreationModifier : XabcdAnnotationCreationModifier() {
    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 useCustomXabcdAnnotationCreationModifier(surface: SciChartSurface) {
    // Use the custom modifier
    val customModifier = CustomXabcdAnnotationCreationModifier()
    
    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.