An introduction to the SciChart iOS Charts Annotations API, which allows UIView elements to be placed over the iOS Chart at specific X and Y data-values.
This can be used to display Text Labels, Boxes, Lines and Custom markers over the chart at specific X,Y locations as well as Watermarks or other custom UI at specific points on the viewport.

Annotation Types Include:

– AxisMarkerAnnotation
– BoxAnnotation
– CustomAnnotation
– HorizontalLineAnnotation
– LineAnnotation
– LineArrowAnnotation
– TextAnnotation
– VerticalLineAnnotation

Documentation Links

– iOS Annotations API Documentation
– Combining Multiple Annotations
– iOS Annotations Module – Doxygen

// AnnotationsChartView.m

//
//  AnnotationsView.m
//  SciChartDemo
//
//  Created by Yaroslav Pelyukh on 3/29/16.
//  Copyright © 2016 SciChart Ltd. All rights reserved.
//

#import "AnnotationsChartView.h"
#import <SciChart/SciChart.h>

@implementation AnnotationsChartView


@synthesize surface;

-(instancetype)initWithFrame:(CGRect)frame{
    self = [super initWithFrame:frame];
    
    if (self) {
        SCIChartSurface * view = [[SCIChartSurface alloc]init];
        surface = view;
        
        [surface setTranslatesAutoresizingMaskIntoConstraints:NO];
        
        [self addSubview:surface];
        NSDictionary *layout = @{@"SciChart":surface};
        
        [self addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"|-(0)-[SciChart]-(0)-|" options:0 metrics:0 views:layout]];
        [self addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|-(0)-[SciChart]-(0)-|" options:0 metrics:0 views:layout]];
        
        [self initializeSurfaceData];
    }
    
    return self;
}

-(void) initializeSurfaceData{
    
    SCITextFormattingStyle *textFormatting = [SCITextFormattingStyle new];
    
    SCINumericAxis *yAxis = [SCINumericAxis new];
    [yAxis.style setLabelStyle:textFormatting];
    [yAxis setGrowBy: [[SCIDoubleRange alloc]initWithMin:SCIGeneric(0.1) Max:SCIGeneric(0.1)]];
    [yAxis setVisibleRange: [[SCIDoubleRange alloc]initWithMin:SCIGeneric(0.0) Max:SCIGeneric(10.0)]];
    [surface.yAxes add:yAxis];
    
    SCINumericAxis *xAxis = [SCINumericAxis new];
    [xAxis.style setLabelStyle:textFormatting];
    [xAxis setGrowBy: [[SCIDoubleRange alloc]initWithMin:SCIGeneric(0.1) Max:SCIGeneric(0.1)]];
    [xAxis setVisibleRange: [[SCIDoubleRange alloc]initWithMin:SCIGeneric(0.0) Max:SCIGeneric(10.0)]];
    [surface.xAxes add:xAxis];
    
    SCIPinchZoomModifier *pzm = [SCIPinchZoomModifier new];
    SCIZoomExtentsModifier *zem = [SCIZoomExtentsModifier new];
    SCIZoomPanModifier *zpm = [SCIZoomPanModifier new];
    zpm.clipModeX = SCIClipMode_None;
    
    SCIChartModifierCollection *gm = [[SCIChartModifierCollection alloc] initWithChildModifiers:@[pzm, zem, zpm]];
    [surface setChartModifiers: gm];
    
    [self setupAnnotations];
    
    [surface invalidateElement];
}

-(void) setupAnnotations {
    
    SCIAnnotationCollection *annotationCollection = [SCIAnnotationCollection new];
    
    // Watermark
    SCITextFormattingStyle *textStyle = [SCITextFormattingStyle new];
    [textStyle setFontSize:42];
    [self buildTextAnnotation:annotationCollection
                             :0.5 :0.5
                             :SCIHorizontalAnchorPoint_Center
                             :SCIVerticalAnchorPoint_Center
                             :textStyle
                             :SCIAnnotationCoordinate_Relative
                             :@"Create \n Watermarks" :0x22FFFFFF];
    
    // Text annotations
    textStyle = [SCITextFormattingStyle new];
    [textStyle setFontSize:24];
    [self buildTextAnnotation:annotationCollection
                             :0.3 :9.7
                             :SCIHorizontalAnchorPoint_Left
                             :SCIVerticalAnchorPoint_Top
                             :textStyle
                             :SCIAnnotationCoordinate_Absolute
                             :@"Annotations are Easy!" :0xFFFFFFFF];
    
    textStyle = [SCITextFormattingStyle new];
    [textStyle setColor: [UIColor whiteColor]];
    [textStyle setFontSize:10];
    [self buildTextAnnotation:annotationCollection
                             :1.0 :9.0
                             :SCIHorizontalAnchorPoint_Left
                             :SCIVerticalAnchorPoint_Top
                             :textStyle
                             :SCIAnnotationCoordinate_Absolute
                             :@"You can create text" :0xFFFFFFFF];
    
    [self buildTextAnnotation:annotationCollection
                             :5.0 :8.0
                             :SCIHorizontalAnchorPoint_Center
                             :SCIVerticalAnchorPoint_Bottom
                             :textStyle
                             :SCIAnnotationCoordinate_Absolute
                             :@"Anchor Center" :0xFFFFFFFF];
    
    [self buildTextAnnotation:annotationCollection
                             :5.0 :8.0
                             :SCIHorizontalAnchorPoint_Right
                             :SCIVerticalAnchorPoint_Top
                             :textStyle
                             :SCIAnnotationCoordinate_Absolute
                             :@"Anchor Right" :0xFFFFFFFF];
    
    [self buildTextAnnotation:annotationCollection
                             :5.0 :8.0
                             :SCIHorizontalAnchorPoint_Left
                             :SCIVerticalAnchorPoint_Top
                             :textStyle
                             :SCIAnnotationCoordinate_Absolute
                             :@"or anchor Left" :0xFFFFFFFF];
    
    // Line and line arrow annotations
    textStyle = [SCITextFormattingStyle new];
    [textStyle setColor: [UIColor whiteColor]];
    [textStyle setFontSize:12];
    
    [self buildTextAnnotation:annotationCollection
                             :0.3 :6.1
                             :SCIHorizontalAnchorPoint_Left
                             :SCIVerticalAnchorPoint_Bottom
                             :textStyle
                             :SCIAnnotationCoordinate_Absolute
                             :@"Draw Lines \nAnnotations" :0xFFFFFFFF];
    
    [self buildLineAnnotation:annotationCollection
                             :1.0 :4.0
                             :2.0 :6.0
                             :0xFF555555 :2.0];
    
    // Box annotations
    [self buildTextAnnotation:annotationCollection
                             :3.5 :6.1
                             :SCIHorizontalAnchorPoint_Left
                             :SCIVerticalAnchorPoint_Bottom
                             :textStyle
                             :SCIAnnotationCoordinate_Absolute
                             :@"Draw Boxes" :0xFFFFFFFF];
    
    [self buildBoxAnnotation:annotationCollection
                            :3.5 :4.0 :5.0 :5.0
                            :[[SCILinearGradientBrushStyle alloc]initWithColorStart:[UIColor fromARGBColorCode:0x550000FF] finish:[UIColor fromARGBColorCode:0x55FFFF00] direction:SCILinearGradientDirection_Vertical]
                            :[[SCISolidPenStyle alloc]initWithColorCode:0xFF279B27 withThickness:1.0] ];
    
    [self buildBoxAnnotation:annotationCollection
                            :4.0 :4.5 :5.5 :5.5
                            :[[SCISolidBrushStyle alloc]initWithColorCode:0x55FF1919]
                            :[[SCISolidPenStyle alloc]initWithColorCode:0xFFFF1919 withThickness:1.0] ];
    
    [self buildBoxAnnotation:annotationCollection
                            :4.5 :5.0 :6.0 :6.0
                            :[[SCISolidBrushStyle alloc]initWithColorCode:0x55279B27]
                            :[[SCISolidPenStyle alloc]initWithColorCode:0xFF279B27 withThickness:1.0] ];
    
    // Custom shapes
    [self buildTextAnnotation:annotationCollection
                             :7.0 :6.1
                             :SCIHorizontalAnchorPoint_Left
                             :SCIVerticalAnchorPoint_Bottom
                             :textStyle
                             :SCIAnnotationCoordinate_Absolute
                             :@"Or Custom Shapes" :0xFFFFFFFF];
    
    
    SCICustomAnnotation * customAnnotationGreen = [[SCICustomAnnotation alloc]init];
    [customAnnotationGreen setCustomView:[[UIImageView alloc]initWithImage:[UIImage imageNamed:@"GreenArrow"]]];
    [customAnnotationGreen setX1:SCIGeneric(8)];
    [customAnnotationGreen setY1:SCIGeneric(5.5)];
    [annotationCollection add:customAnnotationGreen];
    
    SCICustomAnnotation * customAnnotationRed = [[SCICustomAnnotation alloc]init];
    [customAnnotationRed setCustomView:[[UIImageView alloc]initWithImage:[UIImage imageNamed:@"RedArrow"]]];
    [customAnnotationRed setX1:SCIGeneric(7.5)];
    [customAnnotationRed setY1:SCIGeneric(5)];
    [annotationCollection add:customAnnotationRed];
    
    
    // Horizontal Line Annotations
    SCIHorizontalLineAnnotation * horizontalLine = [[SCIHorizontalLineAnnotation alloc] init];
    horizontalLine.coordinateMode = SCIAnnotationCoordinate_Absolute;
    horizontalLine.x1 = SCIGeneric(5.0);
    horizontalLine.y1 = SCIGeneric(3.2);
    horizontalLine.horizontalAlignment = SCIHorizontalLineAnnotationAlignment_Right;
    horizontalLine.style.linePen = [[SCISolidPenStyle alloc] initWithColor: [UIColor orangeColor] withThickness:2];
    [horizontalLine addLabel: [self buildLineAnnotationLabelWithText:@"Right Aligned, with text on left" andAlignment:SCILabelPlacement_TopLeft andColor:[UIColor orangeColor] andBackColor:[UIColor clearColor]]];
    [annotationCollection add:horizontalLine];
    
    SCIHorizontalLineAnnotation * horizontalLine1 = [[SCIHorizontalLineAnnotation alloc] init];
    horizontalLine1.coordinateMode = SCIAnnotationCoordinate_Absolute;
    horizontalLine1.horizontalAlignment = SCIHorizontalLineAnnotationAlignment_Stretch;
    horizontalLine1.y1 = SCIGeneric(2.8);
    [horizontalLine1 addLabel: [self buildLineAnnotationLabelWithText:@"" andAlignment:SCILabelPlacement_Axis andColor:[UIColor blackColor] andBackColor:[UIColor orangeColor]]];
    horizontalLine1.style.linePen = [[SCISolidPenStyle alloc] initWithColor: [UIColor orangeColor] withThickness:2];
    [annotationCollection add:horizontalLine1];
    
    // Vertical Line annotations
    SCIVerticalLineAnnotation * verticalLine = [[SCIVerticalLineAnnotation alloc] init];
    verticalLine.coordinateMode = SCIAnnotationCoordinate_Absolute;
    verticalLine.x1 = SCIGeneric(9.0);
    verticalLine.y1 = SCIGeneric(4.0);
    verticalLine.verticalAlignment = SCIVerticalLineAnnotationAlignment_Bottom;
    verticalLine.style.linePen = [[SCISolidPenStyle alloc] initWithColorCode: 0xFFA52A2A withThickness:2];
    [annotationCollection add:verticalLine];
    
    SCIVerticalLineAnnotation * verticalLine1 = [[SCIVerticalLineAnnotation alloc] init];
    verticalLine1.coordinateMode = SCIAnnotationCoordinate_Absolute;
    verticalLine1.x1 = SCIGeneric(9.5);
    verticalLine1.y1 = SCIGeneric(3.0);
    verticalLine1.verticalAlignment = SCIVerticalLineAnnotationAlignment_Bottom;
    verticalLine1.style.linePen = [[SCISolidPenStyle alloc] initWithColorCode: 0xFFA52A2A withThickness:2];
    [annotationCollection add:verticalLine1];
    surface.annotations = annotationCollection;
}

-(SCILineAnnotationLabel *)buildLineAnnotationLabelWithText: (NSString*)text andAlignment:(SCILabelPlacement)labelPlacement andColor:(UIColor*)color andBackColor:(UIColor*)backColor{
    SCILineAnnotationLabel * lineAnnotationLabel = [SCILineAnnotationLabel new];
    lineAnnotationLabel.text = text;
    lineAnnotationLabel.style.backgroundColor = backColor;
    lineAnnotationLabel.style.labelPlacement = labelPlacement;
    lineAnnotationLabel.style.textStyle.color = color;
    return lineAnnotationLabel;
}

-(void)buildTextAnnotation:(SCIAnnotationCollection*)annotationCollection
                          :(double)x :(double)y
                          :(SCIHorizontalAnchorPoint)horizontalAnchorPoint
                          :(SCIVerticalAnchorPoint)verticalAnchorPoint
                          :(SCITextFormattingStyle*)textStyle
                          :(SCIAnnotationCoordinateMode)coordMode
                          :(NSString*)text :(uint)color{
    
    SCITextAnnotation * textAnnotation = [[SCITextAnnotation alloc] init];
    textAnnotation.coordinateMode = coordMode;
    textAnnotation.x1 = SCIGeneric(x);
    textAnnotation.y1 = SCIGeneric(y);
    textAnnotation.horizontalAnchorPoint = horizontalAnchorPoint;
    textAnnotation.verticalAnchorPoint = verticalAnchorPoint;
    textAnnotation.text = text;
    textAnnotation.style.textStyle = textStyle;
    textAnnotation.style.textColor = [UIColor fromARGBColorCode:color];
    textAnnotation.style.backgroundColor = [UIColor clearColor];
    [annotationCollection add:textAnnotation];
}

-(void)buildLineAnnotation:(SCIAnnotationCollection*)annotationCollection
                          :(double)x1 :(double)y1
                          :(double)x2 :(double)y2
                          :(uint)color :(double)strokeThickness{
    
    SCILineAnnotation * lineAnnotationRelative = [SCILineAnnotation new];
    lineAnnotationRelative.coordinateMode = SCIAnnotationCoordinate_Absolute;
    lineAnnotationRelative.x1 = SCIGeneric(x1);
    lineAnnotationRelative.y1 = SCIGeneric(y1);
    lineAnnotationRelative.x2 = SCIGeneric(x2);
    lineAnnotationRelative.y2 = SCIGeneric(y2);
    lineAnnotationRelative.style.linePen = [[SCISolidPenStyle alloc] initWithColorCode:color withThickness:strokeThickness];
    [annotationCollection add:lineAnnotationRelative];
}

-(void)buildBoxAnnotation:(SCIAnnotationCollection*)annotationCollection
                         :(double)x1 :(double)y1
                         :(double)x2 :(double)y2
                         :(SCIBrushStyle*)brush
                         :(SCISolidPenStyle*)pen{
    
    SCIBoxAnnotation * boxAnnotation = [[SCIBoxAnnotation alloc] init];
    boxAnnotation.coordinateMode = SCIAnnotationCoordinate_Absolute;
    boxAnnotation.x1 = SCIGeneric(x1);
    boxAnnotation.y1 = SCIGeneric(y1);
    boxAnnotation.x2 = SCIGeneric(x2);
    boxAnnotation.y2 = SCIGeneric(y2);
    boxAnnotation.style.fillBrush = brush;
    boxAnnotation.style.borderPen = pen;
    [annotationCollection add:boxAnnotation];
}

@end

// SCSAnnotationsChartView.swift

//
//  SCSAnnotationsView.swift
//  SciChartSwiftDemo
//
//  Created by Mykola Hrybeniuk on 6/6/16.
//  Copyright © 2016 SciChart Ltd. All rights reserved.
//

import Foundation
import SciChart

class SCSAnnotationsChartView: UIView {
    let surface = SCIChartSurface()
    
    override init(frame: CGRect) {
        super.init(frame: frame)
        completeConfiguration()
    }
    
    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        completeConfiguration()
    }
    
    // MARK: initialize surface
    fileprivate func addSurface() {
        surface.translatesAutoresizingMaskIntoConstraints = true
        surface.frame = bounds
        surface.autoresizingMask = [.flexibleHeight, .flexibleWidth]
        addSubview(surface)
    }
    
    // MARK: Overrided Functions
    
    func completeConfiguration() {
        addSurface()
        addAxis()
        addDefaultModifiers()
        setupAnnotations()
    }
    
    // MARK: Private Functions
    
    fileprivate func addAxis() {
        surface.xAxes.add(SCINumericAxis())
        surface.yAxes.add(SCINumericAxis())
    }
    
    func addDefaultModifiers() {
        
        let xAxisDragmodifier = SCIXAxisDragModifier()
        xAxisDragmodifier.dragMode = .scale
        xAxisDragmodifier.clipModeX = .none
        
        let yAxisDragmodifier = SCIYAxisDragModifier()
        yAxisDragmodifier.dragMode = .pan
        
        let extendZoomModifier = SCIZoomExtentsModifier()
        
        let pinchZoomModifier = SCIPinchZoomModifier()
        
        let zoomPanModifier = SCIZoomPanModifier()
        zoomPanModifier.clipModeX = .none;
        
        let groupModifier = SCIChartModifierCollection(childModifiers: [xAxisDragmodifier, yAxisDragmodifier, pinchZoomModifier, extendZoomModifier, zoomPanModifier])
        
        surface.chartModifiers = groupModifier
    }
    
    fileprivate func setupAnnotations() {
        let annotationGroup = SCIAnnotationCollection()
        
        // Watermark
        var textStyle = SCITextFormattingStyle()
        textStyle.fontSize=42
        buildTextAnnotation(annotations: annotationGroup,x: 0.5,y: 0.5,horizontalAnchorPoint: .center,verticalAnchorPoint: .center,textStyle: textStyle,coordMode: .relative,text: "Create \n Watermarks",color: 0x22FFFFFF)
        
        // Text annotations
        textStyle = SCITextFormattingStyle()
        textStyle.fontSize=24
        buildTextAnnotation(annotations: annotationGroup,x: 0.3,y: 9.7,horizontalAnchorPoint: .left,verticalAnchorPoint: .top,textStyle: textStyle,coordMode: .absolute,text: "Annotations are Easy!",color: 0xFFFFFFFF)
        
        textStyle = SCITextFormattingStyle()
        textStyle.fontSize=10
        buildTextAnnotation(annotations: annotationGroup,x: 1.0,y: 9.0,horizontalAnchorPoint: .left,verticalAnchorPoint: .top,textStyle: textStyle,coordMode: .absolute,text: "You can create text",color: 0xFFFFFFFF)
        
        buildTextAnnotation(annotations: annotationGroup,x: 5.0,y: 8.0,horizontalAnchorPoint: .center,verticalAnchorPoint: .bottom,textStyle: textStyle,coordMode: .absolute,text: "Anchor Center",color: 0xFFFFFFFF)
        buildTextAnnotation(annotations: annotationGroup,x: 5.0,y: 8.0,horizontalAnchorPoint: .right,verticalAnchorPoint: .top,textStyle: textStyle,coordMode: .absolute,text: "Anchor Left",color: 0xFFFFFFFF)
        buildTextAnnotation(annotations: annotationGroup,x: 5.0,y: 8.0,horizontalAnchorPoint: .left,verticalAnchorPoint: .top,textStyle: textStyle,coordMode: .absolute,text: "or anchor Right",color: 0xFFFFFFFF)
        
        // Line and line arrow annotations
        
        textStyle = SCITextFormattingStyle()
        textStyle.fontSize=12
        buildTextAnnotation(annotations: annotationGroup,
                            x: 0.3, y: 6.1,
                            horizontalAnchorPoint: .left,
                            verticalAnchorPoint: .bottom,
                            textStyle: textStyle,
                            coordMode: .absolute,
                            text: "Draw Lines \nAnnotations",
                            color: 0xFFFFFFFF)
        
        buildLineAnnotation(annotations: annotationGroup,
                            x1: 1.0, y1: 4.0,
                            x2: 2.0, y2: 6.0,
                            color: 0xFF555555,
                            strokeThickness: 2.0)
        
        // Box annotations
        buildTextAnnotation(annotations: annotationGroup,
                            x: 3.5,y: 6.1,
                            horizontalAnchorPoint: .left,
                            verticalAnchorPoint: .bottom,
                            textStyle: textStyle,
                            coordMode: .absolute,
                            text: "Draw Boxes", color: 0xFFFFFFFF)
        
        buildBoxAnnotation(annotations: annotationGroup,
                           x1: 3.5, y1: 4.0,
                           x2: 5.0, y2: 5.0,
                           brush: SCILinearGradientBrushStyle.init(colorStart: UIColor.fromARGBColorCode(0x550000FF), finish: UIColor.fromARGBColorCode(0x55FFFF00), direction: .vertical),
                           pen: SCISolidPenStyle.init(color: UIColor.fromARGBColorCode(0xFF279B27), withThickness: 1.0))
        
        buildBoxAnnotation(annotations: annotationGroup,
                           x1: 4.0, y1: 4.5,
                           x2: 5.5, y2: 5.5,
                           brush: SCISolidBrushStyle.init(color: UIColor.fromARGBColorCode(0x55FF1919)),
                           pen: SCISolidPenStyle.init(color: UIColor.fromARGBColorCode(0xFFFF1919), withThickness: 1.0))
        
        buildBoxAnnotation(annotations: annotationGroup,
                           x1: 4.5, y1: 5.0,
                           x2: 6.0, y2: 6.0,
                           brush: SCISolidBrushStyle.init(color: UIColor.fromARGBColorCode(0x55279B27)),
                           pen: SCISolidPenStyle.init(color: UIColor.fromARGBColorCode(0xFF279B27), withThickness: 1.0))
        
        // Custom shapes
        buildTextAnnotation(annotations: annotationGroup,
                            x: 7.0,y: 6.1,
                            horizontalAnchorPoint: .left,
                            verticalAnchorPoint: .bottom,
                            textStyle: textStyle, coordMode: .absolute,
                            text: "Or Custom Shapes",color: 0xFFFFFFFF)
        
        let customAnnotationGreen = SCICustomAnnotation()
        customAnnotationGreen.customView = UIImageView.init(image: UIImage.init(named: "GreenArrow"))
        customAnnotationGreen.x1=SCIGeneric(8)
        customAnnotationGreen.y1=SCIGeneric(5.5)
        annotationGroup.add(customAnnotationGreen)
        
        let customAnnotationRed = SCICustomAnnotation()
        customAnnotationRed.customView = UIImageView.init(image: UIImage.init(named: "RedArrow"))
        customAnnotationRed.x1=SCIGeneric(7.5)
        customAnnotationRed.y1=SCIGeneric(5.0)
        annotationGroup.add(customAnnotationRed)
        
        // Horizontal Line Annotations
        let horizontalLine = SCIHorizontalLineAnnotation()
        horizontalLine.coordinateMode = .absolute;
        horizontalLine.x1 = SCIGeneric(5.0);
        horizontalLine.y1 = SCIGeneric(3.2);
        horizontalLine.horizontalAlignment = .right
        horizontalLine.style.linePen = SCISolidPenStyle.init(color: UIColor.orange, withThickness:2)
        horizontalLine.add(self.buildLineTextLabel("Right Aligned, with text on left", alignment: .topLeft, backColor: UIColor.clear, textColor: UIColor.orange))
        annotationGroup.add(horizontalLine)
        
        let horizontalLine1 = SCIHorizontalLineAnnotation()
        horizontalLine1.coordinateMode = .absolute;
        horizontalLine1.y1 = SCIGeneric(2.8);
        horizontalLine1.horizontalAlignment = .stretch
        horizontalLine1.add(self.buildLineTextLabel("", alignment: .axis, backColor: UIColor.orange, textColor: UIColor.white))
        horizontalLine1.style.linePen = SCISolidPenStyle.init(color: UIColor.orange, withThickness:2)
        annotationGroup.add(horizontalLine1)
        
        // Vertical Line annotations
        let verticalLine = SCIVerticalLineAnnotation()
        verticalLine.coordinateMode = .absolute;
        verticalLine.x1 = SCIGeneric(9.0);
        verticalLine.y1 = SCIGeneric(4.0);
        verticalLine.verticalAlignment = .bottom
        verticalLine.add(self.buildLineTextLabel("", alignment: .axis, backColor: UIColor.fromARGBColorCode(0xFFA52A2A), textColor: UIColor.white))
        verticalLine.style.linePen = SCISolidPenStyle.init(colorCode: 0xFFA52A2A, withThickness:2)
        annotationGroup.add(verticalLine)
        
        let verticalLine1 = SCIVerticalLineAnnotation()
        verticalLine1.coordinateMode = .absolute;
        verticalLine1.x1 = SCIGeneric(9.5);
        verticalLine1.y1 = SCIGeneric(3.0);
        verticalLine.verticalAlignment = .bottom
        verticalLine1.style.linePen = SCISolidPenStyle.init(colorCode: 0xFFA52A2A, withThickness:2)
        verticalLine1.add(self.buildLineTextLabel("", alignment: .axis, backColor: UIColor.fromARGBColorCode(0xFFA52A2A), textColor: UIColor.white))
        annotationGroup.add(verticalLine1)
        
        surface.annotations = annotationGroup
    }
    
    private func buildLineTextLabel(_ text: String, alignment: SCILabelPlacement, backColor: UIColor, textColor: UIColor) -> SCILineAnnotationLabel {
        let lineText = SCILineAnnotationLabel()
        lineText.text = text
        lineText.style.labelPlacement = alignment
        lineText.style.backgroundColor = backColor
        lineText.style.textStyle.color = textColor
        return lineText
    }
    
    private func buildTextAnnotation(annotations:SCIAnnotationCollection, x:Double, y:Double, horizontalAnchorPoint:SCIHorizontalAnchorPoint, verticalAnchorPoint:SCIVerticalAnchorPoint, textStyle:SCITextFormattingStyle, coordMode:SCIAnnotationCoordinateMode, text:String, color:uint){
        
        let textAnnotation = SCITextAnnotation()
        textAnnotation.coordinateMode = coordMode;
        textAnnotation.x1 = SCIGeneric(x);
        textAnnotation.y1 = SCIGeneric(y);
        textAnnotation.horizontalAnchorPoint = horizontalAnchorPoint;
        textAnnotation.verticalAnchorPoint = verticalAnchorPoint;
        textAnnotation.text = text;
        textAnnotation.style.textStyle = textStyle;
        textAnnotation.style.textColor = UIColor.fromARGBColorCode(color);
        textAnnotation.style.backgroundColor = UIColor.clear
        
        annotations.add(textAnnotation);
    }
    
    private func buildLineAnnotation(annotations:SCIAnnotationCollection, x1:(Double), y1:(Double), x2:(Double), y2:(Double), color:(uint), strokeThickness:Double){
        
        let lineAnnotationRelative = SCILineAnnotation();
        lineAnnotationRelative.coordinateMode = .absolute;
        lineAnnotationRelative.x1 = SCIGeneric(x1);
        lineAnnotationRelative.y1 = SCIGeneric(y1);
        lineAnnotationRelative.x2 = SCIGeneric(x2);
        lineAnnotationRelative.y2 = SCIGeneric(y2);
        lineAnnotationRelative.style.linePen = SCISolidPenStyle.init(colorCode:color, withThickness:Float(strokeThickness));
        
        annotations.add(lineAnnotationRelative);
    }
    
    private func buildBoxAnnotation(annotations:SCIAnnotationCollection, x1:Double, y1:Double, x2:Double, y2:Double, brush:SCIBrushStyle, pen:SCISolidPenStyle){
        
        let boxAnnotation = SCIBoxAnnotation()
        boxAnnotation.coordinateMode = .absolute;
        boxAnnotation.x1 = SCIGeneric(x1);
        boxAnnotation.y1 = SCIGeneric(y1);
        boxAnnotation.x2 = SCIGeneric(x2);
        boxAnnotation.y2 = SCIGeneric(y2);
        boxAnnotation.style.fillBrush = brush;
        boxAnnotation.style.borderPen = pen;
        
        annotations.add(boxAnnotation);
    }
    
}

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