CoreText的认识（三）

1.CoreText的图片点击

* 根据绘制图片时获取到图片的frame
* 判断是否点击了图片

// 坐标转换
    let location = CGPoint(x: point.x, y: self.bounds.size.height - point.y)
    
    if imageFrame.contains(location) {
        print("点击了图片")
        return
    }

2.CoreText的文字点击

• 遍历CTLine，获取每一个CTLine的frame，判断点击了哪一行
• 获取CTLine对应的range，根据range获取到点击对应的CTRun
• CTRunGetTypographicBounds获取descent,ascent等
• 转换坐标，判断是否在点击范围中

    guard let frame = ctFrame else { return }
    
    let lines = CTFrameGetLines(frame) as Array
    
    var origins = [CGPoint](repeating: CGPoint.zero, count: lines.count)
    CTFrameGetLineOrigins(frame, CFRange(location: 0, length: 0), &origins)
    
    var ranges = [CFRange](repeating: CFRange(location: 0, length: 0), count: lines.count)
    
    var lineAscent: CGFloat = 0
    var lineDescent: CGFloat = 0
    
    for i in 0..<lines.count {
        
        let line = lines[i] as! CTLine
        let range = CTLineGetStringRange(line)
        ranges[i] = range
        
        // 点击的某一行的Frame[翻转坐标后的frame]
        CTLineGetTypographicBounds(line, &lineAscent, &lineDescent, nil)
        let lineFrame = CGRect(x: origins[i].x, y: self.bounds.size.height - origins[i].y - (lineAscent + lineDescent), width: CTLineGetOffsetForStringIndex(line, 100000, nil), height: lineAscent + lineDescent)

        if lineFrame.contains(point) {
            
            for j in range.location..<(range.location + range.length) {
                
                let runFrame = frameForCTRunWithIndex(index: j, line: line, origin: origins[i])
                
                let finalFrame = CGRect(x: runFrame.origin.x, y: self.bounds.height - runFrame.origin.y - runFrame.height, width: runFrame.width, height: runFrame.height)
                
                if finalFrame.contains(point) {
                    print("点击了\(i)行, 第\(j - range.location)个元素")
                    break
                }
            }
            break
        }
    }
    
    
    
    
    func frameForCTRunWithIndex(index: Int, line: CTLine, origin: CGPoint) -> CGRect {
    var offsetX = CTLineGetOffsetForStringIndex(line, index, nil)
    var offsetX2 = CTLineGetOffsetForStringIndex(line, index + 1, nil)
    
    offsetX += origin.x
    offsetX2 += origin.x
    
    let offsetY = origin.y
    var lineAscent: CGFloat = 0
    var lineDescent: CGFloat = 0
    var runs = CTLineGetGlyphRuns(line) as Array
    var currentRun: CTRun?
    for k in 0..<runs.count {
        let run = runs[k] as! CTRun
        let range = NSRange(location: CTRunGetStringRange(run).location, length: CTRunGetStringRange(run).length)
        if index <= (range.location + range.length - 1) && (index >= range.location) {
            currentRun = run
            break
        }
    }
    if let currentRun = currentRun {
        CTRunGetTypographicBounds(currentRun, CFRange(location: 0, length: 0), &lineAscent, &lineDescent, nil)
        let height = lineDescent + lineAscent
        return CGRect(x: offsetX, y: offsetY, width: offsetX2 - offsetX, height: height)
    }
    return CGRect.zero
    }