SVG.Line = function() {
  this.constructor.call(this, SVG.create('line'))
}

// Inherit from SVG.Shape
SVG.Line.prototype = new SVG.Shape

// Add required methods
SVG.extend(SVG.Line, {
  // Move over x-axis
  x: function(x) {
    var b = this.bbox()
    
    return x == null ? b.x : this.attr({
      x1: this.attr('x1') - b.x + x
    , x2: this.attr('x2') - b.x + x
    })
  }
  // Move over y-axis
, y: function(y) {
    var b = this.bbox()
    
    return y == null ? b.y : this.attr({
      y1: this.attr('y1') - b.y + y
    , y2: this.attr('y2') - b.y + y
    })
  }
  // Move by center over x-axis
, cx: function(x) {
    var half = this.bbox().width / 2
    return x == null ? this.x() + half : this.x(x - half)
  }
  // Move by center over y-axis
, cy: function(y) {
    var half = this.bbox().height / 2
    return y == null ? this.y() + half : this.y(y - half)
  }
  // Set line size by width and height
, size: function(width, height) {
    var b = this.bbox()
    
    return this
      .attr(this.attr('x1') < this.attr('x2') ? 'x2' : 'x1', b.x + width)
      .attr(this.attr('y1') < this.attr('y2') ? 'y2' : 'y1', b.y + height)
  }
  // Set path data
, plot: function(x1, y1, x2, y2) {
    return this.attr({
      x1: x1
    , y1: y1
    , x2: x2
    , y2: y2
    })
  }
  
})

//
SVG.extend(SVG.Container, {
  // Create a line element
  line: function(x1, y1, x2, y2) {
    return this.put(new SVG.Line().plot(x1, y1, x2, y2))
  }
  
})