public void Draw(SKSurface surface, List <IGraphItem> graphItems)
{
SKCanvas canvas = surface.Canvas;
foreach (var item in graphItems)
{
string type = item.GetType().ToString();
int pos = type.LastIndexOf('.');
type = type.Substring(pos + 1);
switch (type)
{
case "GraphClear":
GraphClear graphClear = item as GraphClear;
canvas.Clear(graphClear.Color);
break;
case "GraphLine":
GraphLine graphLine = item as GraphLine;
canvas.DrawLine(graphLine.XPosStart, graphLine.YPosStart, graphLine.XPosEnd, graphLine.YPosEnd, GetLineBrush(graphLine));
break;
case "GraphRectangle":
GraphRectangle graphRectangle = item as GraphRectangle;
var rect = SKRect.Create(graphRectangle.XPos, graphRectangle.YPos, graphRectangle.Width, graphRectangle.Height);
canvas.DrawRect(rect, GetRectangleBrush(graphRectangle));
break;
case "GraphText":
GraphText graphText = item as GraphText;
if (graphText.Rotation == 0)
{
canvas.DrawText(graphText.Text, graphText.XPos, graphText.YPos, GetTextBrush(graphText));
}
else
{
using (new SKAutoCanvasRestore(canvas)) // https://stackoverflow.com/questions/41908497/draw-rotated-text-in-skiasharp
{
// do any transformations
canvas.RotateDegrees(graphText.Rotation, graphText.XPos, graphText.YPos);
// do serious work
canvas.DrawText(graphText.Text, graphText.XPos, graphText.YPos, GetTextBrush(graphText));
// auto restore, even on exceptions or errors
}
}
break;
case "GraphCircle":
GraphCircle graphCircle = item as GraphCircle;
canvas.DrawCircle(graphCircle.XPos, graphCircle.YPos, graphCircle.Radius, GetCircleBrush(graphCircle));
break;
}
}
}
SKPaint GetCircleBrush(GraphCircle graphCircle)
{
SKPaint brush;
string key = $"{graphCircle.Color}{graphCircle.StrokeWidth}{graphCircle.PaintStyle}";
if (lineBrushes.ContainsKey(key))
{
brush = lineBrushes[key];
}
else
{
brush = new SKPaint
{
Style = graphCircle.PaintStyle,
Color = graphCircle.Color,
StrokeWidth = graphCircle.StrokeWidth
};
lineBrushes[key] = brush;
}
return(brush);
}
