internal void DrawString(DrawStringCache.Entry c, PointF offset)
{
// TODO: Consider units
// First we call the brush with a fill of false so the brush can setup the stroke color
// that the text will be using.
// For LinearGradientBrush this will setup a TransparentLayer so the gradient can
// be filled at the end. See comments.
var savedSmoothingMode = SmoothingMode;
SmoothingMode = SmoothingMode.Default;
c.brush.Setup(this, false); // Stroke
if ((c.format.FormatFlags & StringFormatFlags.NoClip) == 0 && c.layoutAvailable)
{
context.SaveState();
if ((c.format.FormatFlags & StringFormatFlags.DirectionVertical) == StringFormatFlags.DirectionVertical)
{
context.ClipToRect(new CGRect(offset.X, offset.Y, c.boundsHeight, c.boundsWidth));
}
else
{
context.ClipToRect(new CGRect(offset.X, offset.Y, c.boundsWidth, c.boundsHeight));
}
}
if ((c.format.FormatFlags & StringFormatFlags.DirectionVertical) == StringFormatFlags.DirectionVertical)
{
c.verticalMatrix = CGAffineTransform.MakeTranslation(-offset.X, -offset.Y);
c.verticalMatrix.Rotate((float)NMath.PI * 0.5f);
c.verticalMatrix.Translate(offset.X, offset.Y);
if (c.layoutAvailable)
{
c.verticalMatrix.Translate(c.layoutRectangle.Width, 0);
}
else
{
c.verticalMatrix.Translate((c.lines.Count * c.lineHeight), 0);
}
context.ConcatCTM(c.verticalMatrix);
}
var textPosition = new PointF(c.textPosition.X + offset.X, c.textPosition.Y + offset.Y); // Let's not change pre-calculated value
foreach (var line in c.lines)
{
// Make sure that the line still exists, it may be null if it's too small to render any text and wants StringTrimming
if (line != null)
{
nfloat ascent, descent, leading;
var lineWidth = line.GetTypographicBounds(out ascent, out descent, out leading);
// Calculate the string format if need be
nfloat x = textPosition.X;
if (c.layoutAvailable)
{
if (c.format.Alignment == StringAlignment.Far)
{
x += (float)line.GetPenOffsetForFlush(1.0f, c.boundsWidth);
}
else if (c.format.Alignment == StringAlignment.Center)
{
x += (float)line.GetPenOffsetForFlush(0.5f, c.boundsWidth);
}
if ((c.format.FormatFlags & StringFormatFlags.MeasureTrailingSpaces) != 0)
{
if (c.format.Alignment == StringAlignment.Far)
{
x -= (float)line.TrailingWhitespaceWidth;
}
else if (c.format.Alignment == StringAlignment.Center)
{
x -= (float)line.TrailingWhitespaceWidth * 0.5f;
}
}
}
else
{
// We were only passed in a point so we need to format based on the point.
if ((c.format.FormatFlags & StringFormatFlags.MeasureTrailingSpaces) != 0)
{
lineWidth += line.TrailingWhitespaceWidth;
}
if (c.format.Alignment == StringAlignment.Far)
{
x -= (float)lineWidth;
}
else if (c.format.Alignment == StringAlignment.Center)
{
x -= (float)lineWidth / 2.0f;
}
}
// initialize our Text Matrix or we could get trash in here
context.TextMatrix = new CGAffineTransform(1, 0, 0, -1, x, textPosition.Y + c.font.nativeFont.AscentMetric);
line.Draw(context);
//line.Dispose ();
// Currently we support strikethrough only at the font level (for a whole text, not for ranges). It seems CoreText does not handle it for us.
if (c.font.Strikeout)
{
var sy = textPosition.Y + ascent - c.font.nativeFont.XHeightMetric / (nfloat)2.0;
context.MoveTo(x, sy);
context.AddLineToPoint(x + (nfloat)lineWidth, sy);
context.SetStrokeColor(lastBrushColor.ToCGColor());
context.SetLineWidth(1);
context.StrokePath();
}
}
// Move the index beyond the line break.
textPosition.Y += c.lineHeight;
}
if ((c.format.FormatFlags & StringFormatFlags.NoClip) == 0 && c.layoutAvailable)
{
context.RestoreState();
}
else if ((c.format.FormatFlags & StringFormatFlags.DirectionVertical) == StringFormatFlags.DirectionVertical)
{
context.ConcatCTM(c.verticalMatrix.Invert());
}
// Now we call the brush with a fill of true so the brush can do the fill if need be
// For LinearGradientBrush this will draw the Gradient and end the TransparentLayer.
// See comments.
c.brush.Setup(this, true); // Fill
SmoothingMode = savedSmoothingMode;
}
internal DrawStringCache.Entry CreateCacheEntry(string s, Font font, Brush brush, RectangleF layoutRectangle, StringFormat format)
{
if (font == null)
{
throw new ArgumentNullException(nameof(font));
}
if (brush == null)
{
throw new ArgumentNullException(nameof(brush));
}
layoutRectangle.Location = PointF.Empty;
var c = new DrawStringCache.Entry(s, font, brush, layoutRectangle, format);
brush.Setup(this, false); // Stroke
var attributedString = buildAttributedString(s, font, format, lastBrushColor);
// Work out the geometry
c.layoutAvailable = true;
var insetBounds = layoutRectangle;
if (insetBounds.Size == SizeF.Empty)
{
insetBounds.Width = float.MaxValue;
insetBounds.Height = float.MaxValue;
c.layoutAvailable = false;
}
c.lineHeight = font.nativeFont.GetLineHeight();
c.lines = new List <CTLine>();
c.verticalMatrix = default(CGAffineTransform);
// Calculate the lines
// If we are drawing vertical direction then we need to rotate our context transform by 90 degrees
if ((format.FormatFlags & StringFormatFlags.DirectionVertical) == StringFormatFlags.DirectionVertical)
{
// Swap out the width and height and calculate the lines
c.lines = CreateLines(font, attributedString, new SizeF(insetBounds.Height, insetBounds.Width), format, c.lineHeight);
c.boundsWidth = insetBounds.Height;
c.boundsHeight = insetBounds.Width;
}
else
{
c.lines = CreateLines(font, attributedString, insetBounds.Size, format, c.lineHeight);
c.boundsWidth = insetBounds.Width;
c.boundsHeight = insetBounds.Height;
}
c.textPosition = new PointF(insetBounds.X + .5f, insetBounds.Y + .5f);
if (c.layoutAvailable)
{
if (format.LineAlignment == StringAlignment.Far)
{
c.textPosition.Y += c.boundsHeight - (c.lines.Count * c.lineHeight);
}
else if (format.LineAlignment == StringAlignment.Center)
{
c.textPosition.Y += (c.boundsHeight - (c.lines.Count * c.lineHeight)) / 2;
}
}
else
{
// Precalculate maximum width to allow for aligning lines
if (format.Alignment != StringAlignment.Near)
{
float maxLineWidth = 0;
foreach (var line in c.lines)
{
if (line != null)
{
nfloat ascent, descent, leading;
var lineWidth = line.GetTypographicBounds(out ascent, out descent, out leading);
if ((format.FormatFlags & StringFormatFlags.MeasureTrailingSpaces) != 0)
{
lineWidth += line.TrailingWhitespaceWidth;
}
maxLineWidth = Math.Max(maxLineWidth, (float)NMath.Ceiling((float)lineWidth));
}
}
c.boundsWidth = maxLineWidth;
}
if (format.LineAlignment == StringAlignment.Far)
{
c.textPosition.Y -= c.lineHeight * c.lines.Count;
}
else if (format.LineAlignment == StringAlignment.Center)
{
c.textPosition.Y -= (c.lineHeight * c.lines.Count) / 2;
}
}
return(c);
}
