Class: Stylish::Background

Inherits:
Declaration show all
Defined in:
lib/stylish/background.rb

Overview

The Background class is a specialised kind of Declaration, geared towards dealing with the oddities of the background family of declarations, which can exist in both long- and shorthand forms.

For example, these longhand background declarations

background-color:  #999;
background-image:  url('bg.png');
background-repeat: repeat-x;

could be compressed into a single shorthand declaration

background: #999 url('bg.png') repeat-x;

The Background class allows for easy conversion between these forms. It defaults to the longhand versions, allowing rules with stronger selector weighting to only override specific parts of other rules’ background declarations.

Constant Summary collapse

PROPERTIES = 
[
[:color,      "background-color"],
[:image,      "background-image"],
[:repeat,     "background-repeat"],
[:position,   "background-position"],
[:attachment, "background-attachment"],
[:origin,     "background-origin"],
[:break,      "background-break"],
[:compressed]]
REPEAT_VALUES = 
["repeat-x", "repeat-y", "repeat",
"space", "round", "no-repeat"]
ATTACHMENT_VALUES = 
["scroll", "fixed", "local"]
HORIZONTAL_POSITIONS = 
["left", "center", "right"]
VERTICAL_POSITIONS = 
["top", "center", "bottom"]
ORIGIN_VALUES = 
["border-box", "padding-box", "content-box"]
BREAK_VALUES = 
["bounding-box", "each-box", "continuous"]

Instance Attribute Summary collapse

Attributes included from Formattable

#format

Instance Method Summary collapse

Constructor Details

#initialize(options) ⇒ Background

Create a new Background object with the specified properties.



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# File 'lib/stylish/background.rb', line 50

def initialize(options)
  accept_format(/^\s*%s\s*:\s*%s;\s*$/m, "%s:%s;")
  self.value = options
end

Instance Attribute Details

#attachment ⇒ Object

Returns the value of attribute attachment.



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# File 'lib/stylish/background.rb', line 22

def attachment
  @attachment
end

#break ⇒ Object

Returns the value of attribute break.



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# File 'lib/stylish/background.rb', line 22

def break
  @break
end

#color ⇒ Object

Returns the value of attribute color.



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# File 'lib/stylish/background.rb', line 22

def color
  @color
end

#compressed ⇒ Object

Returns the value of attribute compressed.



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# File 'lib/stylish/background.rb', line 22

def compressed
  @compressed
end

#image ⇒ Object

Returns the value of attribute image.



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# File 'lib/stylish/background.rb', line 22

def image
  @image
end

#origin ⇒ Object

Returns the value of attribute origin.



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# File 'lib/stylish/background.rb', line 22

def origin
  @origin
end

#position ⇒ Object

Returns the value of attribute position.



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# File 'lib/stylish/background.rb', line 22

def position
  @position
end

#repeat ⇒ Object

Returns the value of attribute repeat.



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# File 'lib/stylish/background.rb', line 22

def repeat
  @repeat
end

Instance Method Details

#name ⇒ Object

Override Declaration#name, since it’s not compatible with the internals of this class.



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# File 'lib/stylish/background.rb', line 172

def name
  PROPERTIES.reject {|n, p| p.nil? }.map {|n, p|
    value = self.send(n)
    p.to_s unless value.nil?
  }.compact
end

#name=(val) ⇒ Object

Override Declaration#name=, since it’s not compatible with the internals of this class.

Raises:

  • (NoMethodError) 


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# File 'lib/stylish/background.rb', line 181

def name=(val)
  raise NoMethodError, "name= is not defined for Background."
end

#to_s(symbols = {}) ⇒ Object

Generate a string representation of a Background instance.

There are two kinds of representation, each of which have slightly different CSS semantics. If compressed is set to true, this method will produce a shorthand CSS declaration such as the following:

background: #fff url('bg.png') no-repeat 50% 0;

Otherwise it will produce an unordered list of individual background declarations.



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# File 'lib/stylish/background.rb', line 217

def to_s(symbols = {})
  if @compressed
    "background:#{self.value(true).map {|p, v| v }.compact.join(" ")};"
  else
    self.value(true).map {|p, v| sprintf(@format, p, v.to_s) }.join(" ")
  end
end

#value(name_and_value = false) ⇒ Object

Override Declaration#value, since it’s not compatible with the internals of this class.



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# File 'lib/stylish/background.rb', line 187

def value(name_and_value = false)
  PROPERTIES.reject {|n, p| p.nil? }.map {|n, p|
    value = self.send(n)
    next if value.nil?
    name_and_value ? [p.to_s, value] : value
  }.compact
end

#value=(options) ⇒ Object

Override Declaration#value=, since it’s not compatible with the internals of this class.



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# File 'lib/stylish/background.rb', line 197

def value=(options)
  unless options.is_a? Hash
    raise ArgumentError, "Argument must be a hash of background properties"
  end
  
  PROPERTIES.each do |name, property|
    self.send(:"#{name.to_s}=", options[name]) if options[name]
  end
end