protected override bool OnExposeEvent(Gdk.EventExpose evnt)
{
Cairo.Context cr = Gdk.CairoHelper.Create(evnt.Window);
double step_width = Allocation.Width / (double)steps;
double step_height = Allocation.Height / (double)steps;
double h = 1.0;
double s = 0.0;
for (int xi = 0, i = 0; xi < steps; xi++)
{
for (int yi = 0; yi < steps; yi++, i++)
{
double bg_b = (double)(i / 255.0);
double fg_b = 1.0 - bg_b;
double x = Allocation.X + xi * step_width;
double y = Allocation.Y + yi * step_height;
cr.Rectangle(x, y, step_width, step_height);
cr.SetSourceColor(CairoExtensions.ColorFromHsb(h, s, bg_b));
cr.Fill();
int tw, th;
var layout = new Pango.Layout(PangoContext);
layout.SetText(((int)(bg_b * 255.0)).ToString());
layout.GetPixelSize(out tw, out th);
cr.Translate(0.5, 0.5);
cr.MoveTo(x + (step_width - tw) / 2.0, y + (step_height - th) / 2.0);
cr.SetSourceColor(CairoExtensions.ColorFromHsb(h, s, fg_b));
PangoCairoHelper.ShowLayout(cr, layout);
cr.Translate(-0.5, -0.5);
}
}
CairoExtensions.DisposeContext(cr);
return(true);
}
protected override bool OnDrawn(Cairo.Context cr)
{
double step_width = Allocation.Width / (double)steps;
double step_height = Allocation.Height / (double)steps;
double h = 1.0;
double s = 0.0;
for (int xi = 0, i = 0; xi < steps; xi++)
{
for (int yi = 0; yi < steps; yi++, i++)
{
double bg_b = (double)(i / 255.0);
double fg_b = 1.0 - bg_b;
double x = xi * step_width;
double y = yi * step_height;
cr.Rectangle(x, y, step_width, step_height);
cr.Color = CairoExtensions.ColorFromHsb(h, s, bg_b);
cr.Fill();
int tw, th;
Pango.Layout layout = new Pango.Layout(PangoContext);
layout.SetText(((int)(bg_b * 255.0)).ToString());
layout.GetPixelSize(out tw, out th);
cr.Translate(0.5, 0.5);
cr.MoveTo(x + (step_width - tw) / 2.0, y + (step_height - th) / 2.0);
cr.Color = CairoExtensions.ColorFromHsb(h, s, fg_b);
PangoCairoHelper.ShowLayout(cr, layout);
cr.Translate(-0.5, -0.5);
}
}
return(true);
}