Class: Buttonize::Button

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

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(options) ⇒ Button

Returns a new instance of Button.



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# File 'lib/buttonize/button.rb', line 5

def initialize(options)
  @options = {
    :width => nil, 
    :template_base => "button",
    :template_path => File.dirname(__FILE__) + "/../../examples/default",        
    :font => "Arial",#File.dirname(__FILE__) + "/fonts/verdanab.ttf", 
    :font_size => 9,       
    :font_antialias => true, 
    :text_color => "#fff",
    :text_offset => {:x => 0, :y => 0},
    :text_align => :center,
    :padding => {:left => 10, :right => 10},       
    :target_path => Dir.pwd
  }.update(options)
  @options[:template_images] ||=  ["_left","_middle","_right"].map{|p| options[:template_base] + p + ".gif" }
  
  # Validation
  @options[:template_images].each{|i| raise "Missing template_image #{i}" unless File.exist?(File.join(options[:template_path],i)) }
end

Instance Attribute Details

#options ⇒ Object (readonly)

Returns the value of attribute options.



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# File 'lib/buttonize/button.rb', line 3

def options
  @options
end

Instance Method Details

#add_extension(filename, extension) ⇒ Object 



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# File 'lib/buttonize/button.rb', line 90

def add_extension(filename,extension)
  if filename =~ /\.#{extension}$/
    filename
  else
    filename + "." + extension
  end
end

#generate(text, filename = nil) ⇒ Object 



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# File 'lib/buttonize/button.rb', line 29

def generate(text, filename = nil)
  filename ||= self.text_to_filename(text)
  filename = add_extension(filename,"gif")
  padding = options[:padding]

  # Load the images
  left,mid,right = options[:template_images].map{|p| Image.read(File.join(options[:template_path],p)).first }  

  draw = Draw.new
  draw.pointsize = options[:font_size]
  draw.fill = options[:text_color]
  draw.gravity = self.gravity_from_alignment(options[:text_align])
  draw.font = options[:font]
  draw.font_weight = Magick::AnyWeight
  draw.text_antialias = options[:font_antialias] || false
  
  # Measure the text first
  metrics = draw.get_type_metrics(text)
  target_width = metrics.width + padding[:left] + padding[:right]

  target_width = options[:width] if options[:width] && options[:width] > target_width

  self.log "Generating image with text \"#{text}\" and width #{target_width}px and height #{left.rows}px"
  dst = Image.new(target_width,left.rows) { self.background_color = "transparent"}

  # Place left
  dst.composite!(left,0,0,Magick::OverCompositeOp)

  # Fill up the middle
  pos = left.columns
  while pos < (target_width - right.columns) do
    if pos + mid.columns >= (target_width - right.columns)
      leftover = target_width - pos - right.columns
      dst.composite!(mid,(pos - (mid.columns - leftover)),0,Magick::OverCompositeOp)
      pos = pos - (mid.columns - leftover) +  mid.columns
    else
      dst.composite!(mid,pos,0,Magick::OverCompositeOp)
      pos += mid.columns  
    end

  end

  # Place right
  dst.composite!(right,pos,0,Magick::OverCompositeOp)
  
  # Draw text
  left = options[:text_offset][:x] || 0
  left += padding[:left] unless options[:text_align] == :center
  draw.annotate(dst,0,0,left,options[:text_offset][:y],text)
  
  # Write file
  dst.write(File.join(options[:target_path],filename))
  dst.destroy!
  
  filename      
end

#gravity_from_alignment(alignment) ⇒ Object 



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# File 'lib/buttonize/button.rb', line 98

def gravity_from_alignment(alignment)
  case alignment
  when :left then Magick::WestGravity
  when :right then Magick::EastGravity
  else Magick::CenterGravity      
  end
end

#log(text) ⇒ Object 



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# File 'lib/buttonize/button.rb', line 25

def log(text)
  puts text
end

#text_to_filename(text) ⇒ Object 



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# File 'lib/buttonize/button.rb', line 86

def text_to_filename(text)
  text.to_s.downcase.gsub(/[^a-z0-9]/,"_").squeeze("_").gsub(/_$/,"") 
end