private UIStringAttributes GetLineHeightAttributes()
{
var attributes = new UIStringAttributes();
var paragraphStyle = new NSMutableParagraphStyle()
{
MinimumLineHeight = (nfloat)LineHeight,
Alignment = TextAlignment.ToNativeTextAlignment(),
LineBreakMode = GetLineBreakMode(),
};
if (LineStackingStrategy != LineStackingStrategy.MaxHeight)
{
paragraphStyle.MaximumLineHeight = (nfloat)LineHeight;
}
attributes.ParagraphStyle = paragraphStyle;
// BaselineOffset calculation is only required when the text's font size does not take up the entire line height
// Otherwise this calculation will result in invalid values causing the text to be pushed out of the UILabel's rect
if (Font != null && Font.LineHeight < LineHeight)
{
// iOS puts text at the bottom of the line box, whereas Windows puts it at the top. Empirically this offset gives similar positioning to Windows.
// (Note that Descender is typically a negative value.)
var verticalOffset = ((float)LineHeight - (float)Font.LineHeight) * .56f + (float)Font.Descender;
attributes.BaselineOffset = verticalOffset;
}
return(attributes);
}
private void UpdateTextBoxView()
{
if (_contentElement != null)
{
if (_textBoxView is TextBoxView || _textBoxView is SecureTextBoxView)
{
return;
}
if (_isPassword)
{
_textBoxView = new SecureTextBoxView(this)
{
UsesSingleLineMode = true, Alignment = TextAlignment.ToNativeTextAlignment()
};
_revealView = new TextBoxView(this)
{
UsesSingleLineMode = true, Alignment = TextAlignment.ToNativeTextAlignment()
};
_isSecured = true;
}
else
{
var textWrapping = TextWrapping;
var usesSingleLineMode = !(AcceptsReturn || textWrapping != TextWrapping.NoWrap);
_textBoxView = new TextBoxView(this)
{
UsesSingleLineMode = usesSingleLineMode,
LineBreakMode = textWrapping == TextWrapping.WrapWholeWords ? NSLineBreakMode.ByWordWrapping : NSLineBreakMode.CharWrapping,
Alignment = TextAlignment.ToNativeTextAlignment()
};
}
_contentElement.Content = _textBoxView;
_textBoxView.SetTextNative(Text);
InitializeProperties();
}
}
private UIStringAttributes GetAttributes()
{
var attributes = new UIStringAttributes();
var font = UIFontHelper.TryGetFont((float)FontSize, FontWeight, FontStyle, FontFamily);
attributes.Font = font;
attributes.ForegroundColor = (Foreground as SolidColorBrush)?.ColorWithOpacity;
if (TextDecorations != TextDecorations.None)
{
attributes.UnderlineStyle = (TextDecorations & TextDecorations.Underline) == TextDecorations.Underline
? NSUnderlineStyle.Single
: NSUnderlineStyle.None;
attributes.StrikethroughStyle = (TextDecorations & TextDecorations.Strikethrough) == TextDecorations.Strikethrough
? NSUnderlineStyle.Single
: NSUnderlineStyle.None;
}
var paragraphStyle = new NSMutableParagraphStyle()
{
MinimumLineHeight = (nfloat)LineHeight,
Alignment = TextAlignment.ToNativeTextAlignment(),
LineBreakMode = GetLineBreakMode(),
};
// For unknown reasons, the LineBreakMode must be set to WordWrap
// when applied to a NSTextStorage for text to wrap.
if (UseLayoutManager)
{
paragraphStyle.LineBreakMode = UILineBreakMode.WordWrap;
}
if (LineStackingStrategy != LineStackingStrategy.MaxHeight)
{
paragraphStyle.MaximumLineHeight = (nfloat)LineHeight;
}
attributes.ParagraphStyle = paragraphStyle;
if (LineHeight != 0 && font != null)
{
// iOS puts text at the bottom of the line box, whereas Windows puts it at the top.
// Empirically this offset gives similar positioning to Windows.
// Note: Descender is typically a negative value.
var verticalOffset = LineHeight - font.LineHeight + font.Descender;
// Because we're trying to move the text up (toward the top of the line box),
// we only set BaselineOffset to a positive value.
// A negative value indicates that the the text is already bottom-aligned.
attributes.BaselineOffset = Math.Max(0, (float)verticalOffset);
}
if (CharacterSpacing != 0)
{
//CharacterSpacing is in 1/1000 of an em, iOS KerningAdjustment is in points. 1 em = 12 points
attributes.KerningAdjustment = (CharacterSpacing / 1000f) * 12;
}
return(attributes);
}
private UIStringAttributes GetAttributes(NSAttributedStringTarget target)
{
var attributes = new UIStringAttributes();
// We only apply these values to NSTextStorage, as they're already applied to UILabel.
// See: UpdateFont, UpdateTextColor, etc.
if (target == NSAttributedStringTarget.NSTextStorage)
{
attributes.Font = _currentFont;
attributes.ForegroundColor = _currentColor;
}
if (target == NSAttributedStringTarget.NSTextStorage || LineHeight != 0)
{
var paragraphStyle = new NSMutableParagraphStyle()
{
MinimumLineHeight = (nfloat)LineHeight,
Alignment = TextAlignment.ToNativeTextAlignment(),
LineBreakMode = GetLineBreakMode(),
};
// For unknown reasons, the LineBreakMode must be set to WordWrap
// when applied to a NSTextStorage for text to wrap (but not when applied to a UILabel).
if (target == NSAttributedStringTarget.NSTextStorage)
{
paragraphStyle.LineBreakMode = UILineBreakMode.WordWrap;
}
if (LineStackingStrategy != LineStackingStrategy.MaxHeight)
{
paragraphStyle.MaximumLineHeight = (nfloat)LineHeight;
}
attributes.ParagraphStyle = paragraphStyle;
if (Font != null)
{
// iOS puts text at the bottom of the line box, whereas Windows puts it at the top.
// Empirically this offset gives similar positioning to Windows.
// Note: Descender is typically a negative value.
var verticalOffset = LineHeight - Font.LineHeight + Font.Descender;
// For unknown reasons, the verticalOffset must be divided by 2
// when applied to a UILabel (but not when applied to a NSTextStorage).
if (target == NSAttributedStringTarget.UILabel)
{
verticalOffset /= 2;
}
// Because we're trying to move the text up (toward the top of the line box),
// we only set BaselineOffset to a positive value.
// A negative value indicates that the the text is already bottom-aligned.
attributes.BaselineOffset = Math.Max(0, (float)verticalOffset);
}
}
if (CharacterSpacing != 0)
{
//CharacterSpacing is in 1/1000 of an em, iOS KerningAdjustment is in points. 1 em = 12 points
attributes.KerningAdjustment = (CharacterSpacing / 1000f) * 12;
}
return(attributes);
}
private void UpdateTextAlignment()
{
base.TextAlignment = TextAlignment.ToNativeTextAlignment();
}
private NSStringAttributes GetAttributes()
{
var attributes = new NSStringAttributes();
var font = NSFontHelper.TryGetFont((float)FontSize, FontWeight, FontStyle, FontFamily);
attributes.Font = font;
if (TextDecorations != TextDecorations.None)
{
attributes.UnderlineStyle = (int)((TextDecorations & TextDecorations.Underline) == TextDecorations.Underline
? NSUnderlineStyle.Single
: NSUnderlineStyle.None);
attributes.StrikethroughStyle = (int)((TextDecorations & TextDecorations.Strikethrough) == TextDecorations.Strikethrough
? NSUnderlineStyle.Single
: NSUnderlineStyle.None);
}
var paragraphStyle = new NSMutableParagraphStyle()
{
MinimumLineHeight = (nfloat)LineHeight,
Alignment = TextAlignment.ToNativeTextAlignment(),
LineBreakMode = GetLineBreakMode(),
};
// For unknown reasons, the LineBreakMode must be set to WordWrap
// when applied to a NSTextStorage for text to wrap.
if (UseLayoutManager)
{
paragraphStyle.LineBreakMode = NSLineBreakMode.ByWordWrapping;
}
if (LineStackingStrategy != LineStackingStrategy.MaxHeight)
{
paragraphStyle.MaximumLineHeight = (nfloat)LineHeight;
}
attributes.ParagraphStyle = paragraphStyle;
if (LineHeight != 0 && font != null)
{
// iOS puts text at the bottom of the line box, whereas Windows puts it at the top.
// Empirically this offset gives similar positioning to Windows.
// Note: Descender is typically a negative value.
var verticalOffset = LineHeight - font.XHeight /* MACOS TODO XHeight ? */ + font.Descender;
// Because we're trying to move the text up (toward the top of the line box),
// we only set BaselineOffset to a positive value.
// A negative value indicates that the the text is already bottom-aligned.
attributes.BaselineOffset = Math.Max(0, (float)verticalOffset);
}
if (CharacterSpacing != 0)
{
//CharacterSpacing is in 1/1000 of an em, iOS KerningAdjustment is in points. 1 em = 12 points
attributes.KerningAdjustment = (CharacterSpacing / 1000f) * 12;
}
// Foreground checks should be kept at the end since we **may** use the attributes to calculate text size
// for gradient brushes.
// TODO: Support other brushes (e.g. gradients):
if (Brush.TryGetColorWithOpacity(Foreground, out var color))
{
attributes.ForegroundColor = color;
}
else
{
attributes.ForegroundColor = Colors.Transparent;
}
return(attributes);
}
