Class: GradientView

Inherits:
UIView
  • Object
show all
Defined in:
lib/gradient-view/version.rb,
lib/gradient-view/gradient_view.rb

Constant Summary collapse

Version = 
'0.1.3'

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#angle ⇒ Object

for linear gradient:



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# File 'lib/gradient-view/gradient_view.rb', line 7

def angle
  @angle
end

#finalColor ⇒ Object

Returns the value of attribute finalColor.



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# File 'lib/gradient-view/gradient_view.rb', line 3

def finalColor
  @finalColor
end

#gradientCenter ⇒ Object

for radial gradient:



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# File 'lib/gradient-view/gradient_view.rb', line 9

def gradientCenter
  @gradientCenter
end

#startColor ⇒ Object

Returns the value of attribute startColor.



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# File 'lib/gradient-view/gradient_view.rb', line 2

def startColor
  @startColor
end

#type ⇒ Object

:linear, :radial



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# File 'lib/gradient-view/gradient_view.rb', line 4

def type
  @type
end

Instance Method Details

#drawLinearGradient ⇒ Object 



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# File 'lib/gradient-view/gradient_view.rb', line 30

def drawLinearGradient
  w = CGRectGetWidth(self.frame)
  h = CGRectGetHeight(self.frame)
  if w == 0 or h == 0
    return
  end

  context = UIGraphicsGetCurrentContext()
  color_space = CGColorSpaceCreateDeviceRGB()

  the_start_color = self.startColor
  the_final_color = self.finalColor
  angle = self.angle
  angle %= 2 * Math::PI
  if angle > Math::PI
    angle = Math::PI - angle % Math::PI
    the_start_color, the_final_color = the_final_color, the_start_color
  end

  radius = Math.hypot(w/2, h/2)
  r_angle = Math.atan2(h/2, w/2)
  inner_angle = self.angle - r_angle
  l = radius * Math.cos(inner_angle)

  center = CGPoint.new(w/2, h/2)
  start_point = center + CGPoint.new(l * Math.cos(angle - Math::PI),
                                     l * Math.sin(angle - Math::PI))
  final_point = center + CGPoint.new(l * Math.cos(angle),
                                     l * Math.sin(angle))
  start_color = self.startColor
  start_color = start_color.uicolor unless start_color.is_a? UIColor

  final_color = self.finalColor
  final_color = final_color.uicolor unless final_color.is_a? UIColor

  gradient = CGGradientCreateWithColors(color_space, [start_color.CGColor, final_color.CGColor],
                                                 [0, 1].to_pointer(:float))
  CGContextDrawLinearGradient(context, gradient, start_point, final_point, 0)
end

#drawRadialGradient ⇒ Object 



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# File 'lib/gradient-view/gradient_view.rb', line 70

def drawRadialGradient
end

#drawRect(rect) ⇒ Object 



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# File 'lib/gradient-view/gradient_view.rb', line 21

def drawRect(rect)
  case self.type
  when :linear
    drawLinearGradient
  when :radial
    drawRadialGradient
  end
end

#initWithFrame(frame) ⇒ Object 



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# File 'lib/gradient-view/gradient_view.rb', line 11

def initWithFrame(frame)
  super.tap do
    self.startColor = :white
    self.finalColor = :black
    self.angle = Math::PI / 2
    self.type = :linear
    self.backgroundColor = UIColor.clearColor
  end
end