Class: Cabird::PrettyTextStyle

Inherits:
Object
  • Object
show all
Defined in:
lib/pretty_text_style.rb

Overview

This class represents a style used by the PrettyText class to generate an image. This style includes font properties like the font-file and the font-size, colors and text transformation like upcase.

Possible style attributes are:

format

Can either be :png or :gif, defaults to :png. If :gif is used set the bg_color attribute to get proper antialiasing.

color

The color of the rendered text. Use HTML/CSS style color definitions (eg.: ##fff, ##d2d2d2). Defaults to ##fff.

bg_color

If you choose :gif as format the text will be rendered against the given bg_color and the areas of the background which are not effected by the antialiasing are cut out. This way you get proper antialiasing, although the gif format does not support alpha channels.

size

The size of the rendered font in points

font

The font file to use relative to the font root directory, which is fonts by default

upcase

This flag defines if the text is transformed to uppercase before rendering. This boolean defaults to false.

extra_width

Sometimes Imagemagick will calculate the wrong width for the image. You can add some extra space by setting this value. Defaults to 0. This might be obsolete due to an former error in the implementation.

You can set the atrributes via the constructor:

style = Cabird::PrettyTextStyle.new({:format => :png, :color => '#f00'})

or via the setter methods:

style.color = '#000'

Constant Summary collapse

@@default = 
{:format => :png,
:color => '#000',
:bg_color => '#fff',
:size => 12,
:font => nil,
:upcase => false,
:extra_width => 0,
:xextra => 0,
:xoffset => 0,
:yextra => 0,
:yoffset => 0,
:kerning => 0}

Instance Method Summary collapse

Constructor Details

#initialize(attributes = nil) ⇒ PrettyTextStyle

Sets up a new PrettyTextStyle object. All of the above mentioned attributes can be set here.



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# File 'lib/pretty_text_style.rb', line 69

def initialize(attributes = nil)
  @attributes = attributes || Hash.new
end

Instance Method Details

#alter(attributes = Hash.new) ⇒ Object

Clones this PrettyTextStyle object and returns an altered version of the clone. You can override attributes with the argument.



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# File 'lib/pretty_text_style.rb', line 104

def alter(attributes = Hash.new)
  result = Hash.new
  @@default.keys.each do |key|
    result[key] = (attributes[key]) ? attributes[key] :
                                      @attributes[key]
  end
  return self.class.new(result)
end

#bg_color ⇒ Object

This method overrides the default getter method for the bg_color method.



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# File 'lib/pretty_text_style.rb', line 74

def bg_color
  return "transparent" if self.format == :png
  return @attributes[:bg_color] || @@default[:bg_color]
end

#generate_filename(str) ⇒ Object

This method generates a hashed filename of the style attributes and a given text



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# File 'lib/pretty_text_style.rb', line 97

def generate_filename(str)
  fragments = self.generate_hash(str).scan(/(..)/).flatten
  return File.join(fragments) + "." + self.format.to_s
end

#generate_hash(str = "") ⇒ Object

Generates a hash string of all attributes and a given string. This method is used by the generate_filename method to retrieve the filename for a combilnation of style attributes and a certain text.



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# File 'lib/pretty_text_style.rb', line 88

def generate_hash(str = "")
   to_hash = str
   @@default.keys.each do |key|
     to_hash += self.send(key).to_s
   end
   return  Digest::MD5.hexdigest(to_hash)
end

#process_text(text) ⇒ Object

Applies all text transformations to a given text, which includes only the upcase option at the moment. Returns the transformed text.



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# File 'lib/pretty_text_style.rb', line 81

def process_text(text)
  return (self.upcase == true) ? Unicode::upcase(text) : text
end