// using the attributes of SKPaint paint parameter:
//Typeface,
//TextSize,
//TextAlign(Center|Left),
//Style(Fill|Stroke),
//Color,
//StrokeWidth(if Style=Stroke)
public static CGSize DrawTextS(CGContext canvas, string text, SKPoint point, SKPaint paint)
{
// BASIC TEXT DRAWING IN CGContext:
//canvas.SetTextDrawingMode(toCGTextDrawingMode(paint.Style));
//canvas.SetFillColor(CGUtil.toCGColor(paint.Color));
//canvas.SetStrokeColor(CGUtil.toCGColor(paint.Color));
//canvas.SetLineWidth(paint.StrokeWidth);
//canvas.SelectFont("Helvetica", paint.TextSize, CGTextEncoding.MacRoman);
//// upsidedown text: https://stackoverflow.com/questions/44122778/ios-swift-core-graphics-string-is-upside-down
//canvas.SaveState();
//canvas.TranslateCTM(center.X, center.Y); // text should be centered, but isn't
//canvas.ScaleCTM(1, -1);
//canvas.ShowTextAtPoint(0, 0, text);
//canvas.RestoreState();
// TEXT DRAWING IN CoreText to compute text size:
// https://docs.microsoft.com/en-us/dotnet/api/foundation.nsattributedstring?view=xamarin-ios-sdk-12
var typeface = (paint.Typeface == null) ? "Helvetica" : paint.Typeface.FamilyName;
var attributedString = new Foundation.NSAttributedString(text,
new CoreText.CTStringAttributes()
{
ForegroundColor = Color(paint.Color), // ForegroundColor is used (only?) if paint.Style = Fill, and overrides paint.Color
Font = new CoreText.CTFont(typeface, paint.TextSize)
});
var textLine = new CoreText.CTLine(attributedString);
CGSize textSize = attributedString.Size; // maybe we can extract the true baseline origin and return a Rect instead of a Size?
bool centered = paint.TextAlign == SKTextAlign.Center;
CGPoint textStart = (centered) ? new CGPoint(point.X - textSize.Width / 2.0f, point.Y) : Point(point);
canvas.SetTextDrawingMode(CG.TextDrawingMode(paint.Style));
canvas.SetStrokeColor(CG.Color(paint.Color)); // paint.Color is used (only?) if paint.Style = Stroke
canvas.SetLineWidth(paint.StrokeWidth);
// upsidedown text: https://stackoverflow.com/questions/44122778/ios-swift-core-graphics-string-is-upside-down
canvas.SaveState();
canvas.TranslateCTM(textStart.X, textStart.Y);
canvas.ScaleCTM(1, -1);
canvas.TextPosition = new CGPoint(0, 0); // because of the translation
textLine.Draw(canvas);
canvas.RestoreState();
return(textSize);
}
