我有一个自定义的NSLayoutManager
子类我正用它来绘制药丸形状的代币。我使用自定义属性(TokenAttribute
)为子字符串绘制这些标记。我没有问题。
但是,我需要在我的TokenAttribute
范围内添加一些“填充”(以便令牌的圆角矩形背景不会与文本相交)。
在上图中,我正在用橙色绘制我的令牌背景,但我想在469
周围添加额外的填充,因此背景不会正好对着文本。
我不确定该怎么做。我尝试重写-boundingRectForGlyphRange:inTextContainer:
以返回带有更多水平填充的边界矩形,但看起来字形的布局实际上并未受此影响。
如何围绕某些字形/字形范围提供更多间距?
这是我用来绘制背景的代码,在我的布局管理器子类中:
- (void)drawGlyphsForGlyphRange:(NSRange)glyphsToShow atPoint:(CGPoint)origin {
NSTextStorage *textStorage = self.textStorage;
NSRange glyphRange = glyphsToShow;
while (glyphRange.length > 0) {
NSRange characterRange = [self characterRangeForGlyphRange:glyphRange actualGlyphRange:NULL];
NSRange attributeCharacterRange;
NSRange attributeGlyphRange;
id attribute = [textStorage attribute:LAYScrubbableParameterAttributeName
atIndex:characterRange.location
longestEffectiveRange:&attributeCharacterRange
inRange:characterRange];
attributeGlyphRange = [self glyphRangeForCharacterRange:attributeCharacterRange
actualCharacterRange:NULL];
attributeGlyphRange = NSIntersectionRange(attributeGlyphRange, glyphRange);
if (attribute != nil) {
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSaveGState(context);
UIColor *backgroundColor = [UIColor orangeColor];
NSTextContainer *textContainer = self.textContainers[0];
CGRect boundingRect = [self boundingRectForGlyphRange:attributeGlyphRange inTextContainer:textContainer];
// Offset this bounding rect by the `origin` passed in above
// `origin` is the origin of the text container!
// if we don't do this, then bounding rect is incorrectly placed (too high, in my case).
boundingRect.origin.x += origin.x;
boundingRect.origin.y += origin.y;
[backgroundColor setFill];
UIBezierPath *path = [UIBezierPath bezierPathWithRoundedRect:boundingRect cornerRadius:boundingRect.size.height / 2.0];
[path fill];
[super drawGlyphsForGlyphRange:attributeGlyphRange atPoint:origin];
CGContextRestoreGState(context);
} else {
[super drawGlyphsForGlyphRange:glyphsToShow atPoint:origin];
}
glyphRange.length = NSMaxRange(glyphRange) - NSMaxRange(attributeGlyphRange);
glyphRange.location = NSMaxRange(attributeGlyphRange);
}
}
答案 0 :(得分:1)
NSLayoutManagerDelegate中定义了一些方法,这些方法可用作基于字形的自定义点。
使用
func layoutManager(_ layoutManager: NSLayoutManager, shouldGenerateGlyphs glyphs: UnsafePointer<CGGlyph>, properties props: UnsafePointer<NSLayoutManager.GlyphProperty>, characterIndexes charIndexes: UnsafePointer<Int>, font aFont: NSFont, forGlyphRange glyphRange: NSRange) -> Int
识别与关注范围周围的空白相关联的字形,并通过将它们在 props 数组中的值更改为 NSLayoutManager.GlyphProperty.controlCharacter 来标记它们。 然后将更改后的数组传递给
NSLayoutManager.setGlyphs(_:properties:characterIndexes:font:forGlyphRange:)
之后,您可以实施
func layoutManager(_ layoutManager: NSLayoutManager, shouldUse action: NSLayoutManager.ControlCharacterAction, forControlCharacterAt charIndex: Int) -> NSLayoutManager.ControlCharacterAction
再次标识感兴趣的字形并返回预定义的操作:
NSLayoutManager.ControlCharacterAction.whitespace
最后,这使您可以实现
func layoutManager(_ layoutManager: NSLayoutManager, boundingBoxForControlGlyphAt glyphIndex: Int, for textContainer: NSTextContainer, proposedLineFragment proposedRect: NSRect, glyphPosition: NSPoint, characterIndex charIndex: Int) -> NSRect
更改用于字形的边框。只需返回适当的尺寸。这将影响以下布局机制。
祝你好运!