public override void DrawInContext(CoreGraphics.CGContext ctx)
        {
            base.DrawInContext (ctx);

            var knobFrame = CGRect.Inflate(PaintFrame, -2.0f, -2.0f);

            UIBezierPath knobPath = UIBezierPath.FromRoundedRect((CGRect)knobFrame, (nfloat)knobFrame.Height * Slider.Curvaceousness / 2.0f);

            // 1) fill - with a subtle shadow
            ctx.SetShadow(new CGSize(0, 1), 1.0f, UIColor.Gray.CGColor);
            ctx.SetFillColor( Slider.KnobColor.CGColor);
            ctx.AddPath( knobPath.CGPath);
            ctx.FillPath ();

            // 2) outline
            ctx.SetStrokeColor(UIColor.Gray.CGColor);
            ctx.SetLineWidth((nfloat)0.5f);
            ctx.AddPath(knobPath.CGPath);
            ctx.StrokePath ();

            // 3) inner gradient
            var rect = CGRect.Inflate(knobFrame, -2.0f, -2.0f);
            var clipPath = UIBezierPath.FromRoundedRect ((CGRect)rect, (nfloat)rect.Height * Slider.Curvaceousness / 2.0f);

            CGGradient myGradient;
            CGColorSpace myColorspace;

            nfloat[] locations = { 0.0f, 1.0f };
            nfloat[] components = { 0.0f, 0.0f, 0.0f , 0.15f,  // Start color
                0.0f, 0.0f, 0.0f, 0.05f }; // End color

            myColorspace = CGColorSpace.CreateDeviceRGB (); // CGColorSpaceCreateDeviceRGB();
            myGradient = new CGGradient( myColorspace, components, locations);

            CGPoint startPoint = new CGPoint((float)rect.GetMidX(), (float)rect.GetMinY());
            CGPoint endPoint = new CGPoint((float)rect.GetMidX(), (float)rect.GetMaxY());

            ctx.SaveState ();
            ctx.AddPath( clipPath.CGPath);
            ctx.Clip ();
            ctx.DrawLinearGradient( (CGGradient)myGradient, (CGPoint)startPoint, (CGPoint)endPoint, (CGGradientDrawingOptions)0);

            myGradient.Dispose ();
            myColorspace.Dispose();
            ctx.RestoreState();

            // 4) highlight
            if (Highlighted)
            {
                // fill
                ctx.SetFillColor(UIColor.FromWhiteAlpha((nfloat)0.0f, (nfloat)0.1f).CGColor);
                ctx.AddPath( knobPath.CGPath);
                ctx.FillPath();
            }
        }
Esempio n. 2
0
			public override void DrawInContext (CoreGraphics.CGContext ctx)
			{
				CGRect rect = this.BoundsRect();
				CGColorSpace colorSpace = CGColorSpace.CreateDeviceRGB ();
				nfloat [] colors = new nfloat[] {
					0.42f, 0.66f, 0.31f, 1.0f,
					0.95f, 0.76f, 0.20f, 1.0f,
					0.80f, 0.25f, 0.15f, 1.0f
				};

				CGGradient gradient = new CGGradient (colorSpace, colors, null);

				nuint tickSpaces = this.Axis.MajorTickCount - 1;
				nuint pointsCount = 5;
				if (this.Chart.Frame.Size.Height < this.Chart.Frame.Size.Width) {
					pointsCount = 3;
				}

				nfloat diameter = 8;
				nfloat spaceHeight = rect.Size.Height / tickSpaces;
				nfloat spacing = (spaceHeight - (pointsCount * diameter)) / (pointsCount + 1);
				nuint allPointsCount = pointsCount * tickSpaces;
				CGPath multipleCirclePath = new CGPath ();
				double y = rect.GetMinY() +  diameter / 2.0f  + spacing;

				for (uint i = 1; i <= allPointsCount; i++) {
					CGPoint center = new CGPoint (rect.GetMidX (), y);
					CGPath path = new CGPath ();
					path.AddArc (center.X, center.Y, (nfloat)diameter/2.0f, 0, (nfloat)Math.PI * 2, true);
					multipleCirclePath.AddPath (path);
					y += spacing + diameter;
					if (i % pointsCount == 0) {
						y += spacing;
					}
				}

				ctx.SaveState ();
				ctx.AddPath (multipleCirclePath);
				ctx.Clip ();
				CGPoint startPoint = new CGPoint (rect.GetMidX (), rect.GetMinY ());
				CGPoint endPoint = new CGPoint (rect.GetMidX (), rect.GetMaxY());
				ctx.DrawLinearGradient (gradient, startPoint, endPoint, 0);
				ctx.RestoreState ();

				base.DrawInContext (ctx);
			}