// TODO using Core Text here is going to be a huge problem because we have to
// change the coordinate system for every call to DrawString rather than changing
// it once for all the calls. Not even sure we have enough info (the height of
// the coord system or UIView) to do the transform?
// TODO if we know the text is one-line, we can skip the big transform and just use
// the textmatrix thing.
public void DrawString(string s,
float box_x,
float box_y,
float box_width,
float box_height,
Xamarin.Forms.LineBreakMode lineBreak,
Xamarin.Forms.TextAlignment horizontal_align,
Xamarin.Forms.TextAlignment vertical_align
)
{
_c.SaveState();
// TODO _c.SetTextDrawingMode (CGTextDrawingMode.Fill);
// Core Text uses a different coordinate system.
_c.TranslateCTM(0, _overall_height);
_c.ScaleCTM(1, -1);
var attributedString = new NSAttributedString(s, _ct_attr);
float text_width;
float text_height;
if (
(horizontal_align != TextAlignment.Start) ||
(vertical_align != TextAlignment.Start))
{
// not all of the alignments need the bounding rect. don't
// calculate it if not needed.
var sizeAttr = attributedString.GetBoundingRect(
new SizeF(
(float)box_width,
int.MaxValue),
NSStringDrawingOptions.UsesLineFragmentOrigin | NSStringDrawingOptions.UsesFontLeading,
null
);
text_width = sizeAttr.Width;
//text_height = sizeAttr.Height;
//text_height = sizeAttr.Height + uif.Descender; // descender is negative
text_height = _font_ui.CapHeight;
}
else
{
text_width = 0;
text_height = 0;
}
//Console.WriteLine ("width: {0} height: {1}", text_width, text_height);
float x;
switch (horizontal_align)
{
case Xamarin.Forms.TextAlignment.End:
x = (box_x + box_width) - text_width;
break;
case Xamarin.Forms.TextAlignment.Center:
x = box_x + (box_width - text_width) / 2;
break;
case Xamarin.Forms.TextAlignment.Start:
default:
x = box_x;
break;
}
float y;
switch (vertical_align)
{
case Xamarin.Forms.TextAlignment.End:
y = box_y + text_height;
break;
case Xamarin.Forms.TextAlignment.Center:
y = (box_y + box_height) - (box_height - text_height) / 2;
break;
case Xamarin.Forms.TextAlignment.Start:
default:
y = (box_y + box_height);
break;
}
_c.TextPosition = new PointF((float)x, (float)(_overall_height - y));
// I think that by using CTLine() below, we are preventing multi-line text. :-(
using (var textLine = new CTLine(attributedString)) {
textLine.Draw(_c);
}
//gctx.StrokeRect (new RectangleF(x, height - y, text_width, text_height));
_c.RestoreState();
}
public void DrawString(string s,
float box_x,
float box_y,
float box_width,
float box_height,
Xamarin.Forms.LineBreakMode lineBreak,
Xamarin.Forms.TextAlignment horizontal_align,
Xamarin.Forms.TextAlignment vertical_align
)
{
// TODO
if (string.IsNullOrWhiteSpace(s))
{
return;
}
//SetTextAlign()
float text_width;
float text_height;
if (
(horizontal_align != TextAlignment.Start) ||
(vertical_align != TextAlignment.Start))
{
// not all of the alignments need the bounding rect. don't
// calculate it if not needed.
text_width = _paints.Text.MeasureText(s);
text_height = -(TextFontMetrics.Ascent);
}
else
{
text_width = 0;
text_height = 0;
}
//Console.WriteLine ("width: {0} height: {1}", text_width, text_height);
float x;
switch (horizontal_align)
{
case Xamarin.Forms.TextAlignment.End:
x = (box_x + box_width) - text_width;
break;
case Xamarin.Forms.TextAlignment.Center:
x = box_x + (box_width - text_width) / 2;
break;
case Xamarin.Forms.TextAlignment.Start:
default:
x = box_x;
break;
}
float y;
switch (vertical_align)
{
case Xamarin.Forms.TextAlignment.End:
y = box_y + text_height;
break;
case Xamarin.Forms.TextAlignment.Center:
y = (box_y + box_height) - (box_height - text_height) / 2;
break;
case Xamarin.Forms.TextAlignment.Start:
default:
y = (box_y + box_height);
break;
}
_c.DrawText(s, x, y, _paints.Text);
}
