public static SizeF MeasureText (Graphics g, string text, Font font)
{
// Due to the way the TextBox currently works, it measures each
// character one at a time. And it does this alot. So here we
// are implementing a cache for each font/character combination
// measurement. Since the number of fonts and number of characters
// used tends to be small, this is a good performance gain for
// not too much memory.
if (text.Length == 1) {
// If g.VisibleClipBounds is {X=0, Y=0, Width=1, Height=1}, then some characters
// (in some fonts for some point sizes) return a different width then when the
// VisibleClipBounds has a different (usually but not always more reasonable) value.
// This state of the Graphics object can occur during initialization of text boxes
// with preset Text values. See https://bugzilla.xamarin.com/show_bug.cgi?id=26258
// for more details.
string sep;
var bounds = g.VisibleClipBounds;
if (bounds.Width == 1 && bounds.Height == 1 && bounds.X == 0 && bounds.Y == 0)
sep = "-1x1|";
else
sep = "|";
string key = font.GetHashCode ().ToString () + sep + text;
if (measure_cache.ContainsKey (key)) {
return (SizeF)measure_cache[key];
} else {
SizeF size;
if (!use_textrenderer)
size = g.MeasureString (text, font, 10000, sf_nonprinting);
else
size = TextRenderer.MeasureTextInternal (g, text, font, Size.Empty, TextFormatFlags.NoPadding | TextFormatFlags.NoPrefix, false);
measure_cache[key] = size;
return size;
}
}
if (!use_textrenderer)
return g.MeasureString (text, font, 10000, sf_nonprinting);
else
return TextRenderer.MeasureTextInternal (g, text, font, Size.Empty, TextFormatFlags.NoPadding | TextFormatFlags.NoPrefix, false);
}
public static SizeF MeasureText (Graphics g, string text, Font font)
{
// Due to the way the TextBox currently works, it measures each
// character one at a time. And it does this alot. So here we
// are implementing a cache for each font/character combination
// measurement. Since the number of fonts and number of characters
// used tends to be small, this is a good performance gain for
// not too much memory.
if (text.Length == 1) {
string key = font.GetHashCode ().ToString () + "|" + text;
if (measure_cache.ContainsKey (key)) {
return (SizeF)measure_cache[key];
} else {
SizeF size;
if (!use_textrenderer)
size = g.MeasureString (text, font, 10000, sf_nonprinting);
else
size = TextRenderer.MeasureTextInternal (g, text, font, Size.Empty, TextFormatFlags.NoPadding | TextFormatFlags.NoPrefix, false);
measure_cache[key] = size;
return size;
}
}
if (!use_textrenderer)
return g.MeasureString (text, font, 10000, sf_nonprinting);
else
return TextRenderer.MeasureTextInternal (g, text, font, Size.Empty, TextFormatFlags.NoPadding | TextFormatFlags.NoPrefix, false);
}
public void GetHashCode_NameDiffers_HashesNotEqual()
{
Font f1 = new Font("Arial", 8.25F, GraphicsUnit.Point);
Font f2 = new Font("Courier New", 8.25F, GraphicsUnit.Point);
Assert.IsFalse(f1.GetHashCode() == f2.GetHashCode(),
"Hashcodes should differ if _name member differs");
}
public void GetHashCode_StyleEqualsGdiCharSet_HashesNotEqual()
{
Font f1 = new Font("Arial", 8.25F, FontStyle.Regular, GraphicsUnit.Point, ((byte)(0)));
Font f2 = new Font("Arial", 8.25F, FontStyle.Bold, GraphicsUnit.Point, ((byte)(1)));
Assert.IsFalse(f1.GetHashCode() == f2.GetHashCode(),
"Hashcodes should differ if _style member differs");
}
public void FontUniqueHashCode ()
{
Font f1 = new Font ("Arial", 14);
Font f2 = new Font ("Arial", 12);
Font f3 = new Font (f1, FontStyle.Bold);
Assert.IsFalse (f1.GetHashCode () == f2.GetHashCode (), "1) Fonts with different sizes should have different HashCodes");
Assert.IsFalse (f1.GetHashCode () == f3.GetHashCode (), "2) Fonts with different styles should have different HashCodes");
}