public override Size GetSize(object backend)
{
LayoutInfo li = (LayoutInfo)backend;
using (CTFrame frame = CreateFrame(li)) {
if (frame == null)
{
return(Size.Zero);
}
Size result = Size.Zero;
CTLine [] lines = frame.GetLines();
float lineHeight = li.Font.Ascender - li.Font.Descender + li.Font.Leading;
// try to approximate Pango's layout
foreach (var line in lines)
{
result.Width = Math.Max(result.Width, line.GetTypographicBounds());
result.Height += lineHeight;
// clean up after ourselves as we go
line.Dispose();
}
// CoreText throws away trailing line breaks..
if (li.Text.EndsWith("\n"))
{
result.Height += lineHeight;
}
result.Width = Math.Ceiling(result.Width);
result.Height = Math.Ceiling(result.Height);
return(result);
}
}
public static RectangleF GetTextSize(CTFrame frame)
{
var minY = float.MaxValue;
var maxY = float.MinValue;
float width = 0;
var lines = frame.GetLines();
var origins = new CGPoint[lines.Length];
frame.GetLineOrigins(new NSRange(0, 0), origins);
for (var i = 0; i < lines.Length; i++)
{
var line = lines[i];
var lineWidth = (float)line.GetTypographicBounds(out var ascent, out var descent, out var leading);
if (lineWidth > width)
{
width = lineWidth;
}
var origin = origins[i];
minY = (float)Math.Min(minY, origin.Y - ascent);
maxY = (float)Math.Max(maxY, origin.Y + descent);
lines[i].Dispose();
}
return(new RectangleF(0f, minY, width, Math.Max(0, maxY - minY)));
}
// Helper method for drawing the current selection range (as a simple filled rect)
void DrawRangeAsSelection(NSRange selectionRange)
{
// If not in editing mode, we do not draw selection rects
if (!IsEditing)
{
return;
}
// If selection range empty, do not draw
if (selectionRange.Length == 0 || selectionRange.Location == NSRange.NotFound)
{
return;
}
// set the fill color to the selection color
SelectionColor.SetFill();
// Iterate over the lines in our CTFrame, looking for lines that intersect
// with the given selection range, and draw a selection rect for each intersection
var lines = frame.GetLines();
for (int i = 0; i < lines.Length; i++)
{
CTLine line = lines [i];
NSRange lineRange = line.StringRange;
NSRange range = new NSRange(lineRange.Location, lineRange.Length);
NSRange intersection = RangeIntersection(range, selectionRange);
if (intersection.Location != NSRange.NotFound && intersection.Length > 0)
{
// The text range for this line intersects our selection range
nfloat xStart = line.GetOffsetForStringIndex(intersection.Location);
nfloat xEnd = line.GetOffsetForStringIndex(intersection.Location + intersection.Length);
var origin = new CGPoint [lines.Length];
// Get coordinate and bounds information for the intersection text range
frame.GetLineOrigins(new NSRange(i, 0), origin);
nfloat ascent, descent, leading;
line.GetTypographicBounds(out ascent, out descent, out leading);
// Create a rect for the intersection and draw it with selection color
CGRect selectionRect = new CGRect(xStart, origin [0].Y - descent, xEnd - xStart, ascent + descent);
UIGraphics.RectFill(selectionRect);
}
}
}
public override Size GetSize(object backend)
{
LayoutInfo li = (LayoutInfo)backend;
using (CTFrame frame = CreateFrame(li)) {
if (frame == null)
{
return(Size.Zero);
}
Size result = Size.Zero;
CTLine [] lines = frame.GetLines();
nfloat lineHeight = li.Font.Ascender - li.Font.Descender + li.Font.Leading;
CTLine ellipsis = null;
bool ellipsize = li.Width.HasValue && li.TextTrimming == TextTrimming.WordElipsis;
if (ellipsize)
{
ellipsis = new CTLine(CreateAttributedString(li, "..."));
}
// try to approximate Pango's layout
foreach (var line in lines)
{
var l = line;
if (ellipsize) // we need to create a new CTLine here because the framesetter already truncated the text for the line
{
l = new CTLine(CreateAttributedString(li, li.Text.Substring((int)line.StringRange.Location)))
.GetTruncatedLine(li.Width.Value, CTLineTruncation.End, ellipsis);
line.Dispose();
}
result.Width = Math.Max(result.Width, l.GetTypographicBounds());
result.Height += lineHeight;
// clean up after ourselves as we go
l.Dispose();
}
// CoreText throws away trailing line breaks..
if (li.Text.EndsWith("\n"))
{
result.Height += lineHeight;
}
result.Width = Math.Ceiling(result.Width);
result.Height = Math.Ceiling(result.Height);
return(result);
}
}
internal static void Draw(CGContext ctx, object layout, double x, double y)
{
LayoutInfo li = (LayoutInfo)layout;
using (CTFrame frame = CreateFrame(li)) {
if (frame == null)
{
return;
}
CTLine ellipsis = null;
bool ellipsize = li.Width.HasValue && li.TextTrimming == TextTrimming.WordElipsis;
if (ellipsize)
{
ellipsis = new CTLine(CreateAttributedString(li, "..."));
}
nfloat lineHeight = li.Font.Ascender - li.Font.Descender + li.Font.Leading;
ctx.SaveState();
ctx.TextMatrix = CGAffineTransform.MakeScale(1f, -1f);
ctx.TranslateCTM((float)x, (float)y + li.Font.Ascender);
foreach (var line in frame.GetLines())
{
ctx.TextPosition = CGPoint.Empty;
// Determine final line
var ln = line;
if (ellipsize)
{
// we need to create a new CTLine here because the framesetter already truncated the text for the line
ln = new CTLine(CreateAttributedString(li, li.Text.Substring((int)line.StringRange.Location)))
.GetTruncatedLine(li.Width.Value, CTLineTruncation.End, ellipsis);
line.Dispose();
}
else if (li.Width.HasValue && li.TextAlignment != Alignment.Start)
{
var tx = li.Width.Value - GetLineWidth(ln);
if (li.TextAlignment == Alignment.Center)
{
tx /= 2d;
}
ctx.TextPosition = new CGPoint((nfloat)tx, 0);
}
ln.Draw(ctx);
ctx.TranslateCTM(0, lineHeight);
ln.Dispose();
}
ctx.RestoreState();
}
}