public Stream GetFilledCircleWithCenteredText(int imgSize, string rgbCircleColor, string txt, string rgbTextColor, string fontFamilyName, int fontSize)
{
Stream result = null;
using (UIImage image = new UIImage())
{
UIGraphics.BeginImageContext(new SizeF(imgSize, imgSize));
CGRect rect = new CGRect(0, 0, imgSize, imgSize);
image.Draw(rect);
using (CGContext g = UIGraphics.GetCurrentContext())
{
float x = (float)(rect.X + (rect.Width / 2));
float y = (float)(rect.Y + (rect.Height / 2));
// Draws the circle
UIColor background = FromHexString(rgbCircleColor);
g.SetLineWidth(1);
g.SetFillColor(background.CGColor);
g.SetStrokeColor(background.CGColor);
CGPath path = new CGPath();
path.AddArc(x, y, NMath.Min(rect.Width, rect.Height) / 2 - 1f, 0, 2.0f * (float)Math.PI, true);
g.AddPath(path);
g.DrawPath((CGPathDrawingMode.FillStroke));
// Draws the text
g.SetFillColor(FromHexString(rgbTextColor).CGColor);
var attributedString = new NSAttributedString(txt, new CoreText.CTStringAttributes {
ForegroundColorFromContext = true, Font = new CoreText.CTFont(fontFamilyName, fontSize * 2)
});
using (var textLine = new CoreText.CTLine(attributedString))
{
g.TranslateCTM(x - (textLine.GetBounds(CoreText.CTLineBoundsOptions.UseGlyphPathBounds).Width / 2), y + (textLine.GetBounds(CoreText.CTLineBoundsOptions.UseGlyphPathBounds).Height / 2));
g.ScaleCTM(1, -1);
textLine.Draw(g);
}
}
var resultImage = UIGraphics.GetImageFromCurrentImageContext();
UIGraphics.EndImageContext();
NSData data = resultImage.AsPNG();
result = data.AsStream();
}
return(result);
}
// 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);
}
