function data = updateConstantLine(obj,plotIndex)

%-AXIS INDEX-%

axIndex = obj.getAxisIndex(obj.State.Plot(plotIndex).AssociatedAxis);

%-PLOT DATA STRUCTURE- %

plotData = obj.State.Plot(plotIndex).Handle;

%-CHECK FOR MULTIPLE AXES-%

[xsource, ysource] = findSourceAxis(obj, axIndex);

data.xaxis = "x" + xsource;

data.yaxis = "y" + ysource;

data.type = "scatter";

data.visible = plotData.Visible == "on";

xaxis = obj.layout.("xaxis" + xsource);

yaxis = obj.layout.("yaxis" + ysource);

value = [plotData.Value plotData.Value];

if plotData.InterceptAxis == "y"

data.x = xaxis.range;

data.y = value;

else

data.x = value;

data.y = yaxis.range;

end

if ~isempty(plotData.Label)

annotation = struct();

annotation.showarrow = false;

annotation.xref = "x" + xsource;

annotation.yref = "y" + ysource;

if plotData.InterceptAxis == "x"

annotation.textangle = -90;

end

annotation.xanchor = plotData.LabelHorizontalAlignment;

switch plotData.LabelVerticalAlignment

case {"top", "cap"}

annotation.yanchor = "top";

case "middle"

annotation.yanchor = "middle";

case {"baseline","bottom"}

annotation.yanchor = "bottom";

end

annotation.text = parseString( ...

plotData.Label, plotData.Interpreter);

annotation.text = "<b>" + join( ...

string(annotation.text), "<br>") + "</b>";

if plotData.InterceptAxis == "x"

annotation.x = plotData.Value;

annotation.y = yaxis.range(2);

else

annotation.x = xaxis.range(2);

annotation.y = plotData.Value;

end

col = round(255*plotData.LabelColor);

annotation.font.color = getStringColor(col);

annotation.font.family = matlab2plotlyfont(plotData.FontName);

annotation.font.size = plotData.FontSize;

switch plotData.FontWeight

case {"bold","demi"}

annotation.text = "<b>" + annotation.text + "</b>";

otherwise

end

if plotData.LabelHorizontalAlignment == "center"

if plotData.InterceptAxis == "x"

ylim = plotData.Parent.YLim;

textWidth = text(0,0,plotData.Label,units="normalized", ...

rotation=90,Visible="off").Extent(4);

textWidth = textWidth * (ylim(2) - ylim(1));

data.y(2) = data.y(2) - textWidth;

else

xlim = plotData.Parent.XLim;

textWidth = text(0,0,plotData.Label,units="normalized", ...

Visible="off").Extent(3);

textWidth = textWidth * (xlim(2) - xlim(1));

data.x(2) = data.x(2) - textWidth;

end

end

obj.layout.annotations{end+1} = annotation;

end

%-For 3D plots-%

obj.PlotOptions.is3d = false; % by default

if isfield(plotData,"ZData")

numbset = unique(plotData.ZData);

if any(plotData.ZData) && length(numbset)>1

data.z = plotData.ZData;

data.type = "scatter3d";

%-flag to manage 3d plots-%

obj.PlotOptions.is3d = true;

end

end

data.name = plotData.DisplayName;

if plotData.Type ~= "constantline" ...

&& lower(plotData.Marker) ~= "none" ...

&& lower(plotData.LineStyle) ~= "none"

mode = "lines+markers";

elseif plotData.Type ~= "constantline" ...

&& lower(plotData.Marker) ~= "none"

mode = "markers";

elseif lower(plotData.LineStyle) ~= "none"

mode = "lines";

else

mode = "none";

end

data.mode = mode;

data.line = extractLineLine(plotData);

if plotData.Type ~= "constantline"

data.marker = extractLineMarker(plotData);

end

data.showlegend = getShowLegend(plotData);