Class: Pangrid::PNGThumbnail

Inherits:
Plugin
  • Object
show all
Defined in:
lib/pangrid/plugins/png.rb

Constant Summary

Constants inherited from Plugin

Pangrid::Plugin::DESCRIPTION, Pangrid::Plugin::FAILED, Pangrid::Plugin::MISSING_DEPS, Pangrid::Plugin::REGISTRY

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods inherited from Plugin

class_to_name, get, inherited, list_all, load_all, load_plugin

Methods included from PluginUtils

#check

Constructor Details

#initialize(scale = 4, border = [128, 0, 0]) ⇒ PNGThumbnail

Returns a new instance of PNGThumbnail.



8
9
10
11
 
# File 'lib/pangrid/plugins/png.rb', line 8

def initialize(scale = 4, border = [128, 0, 0])
  @scale = scale
  @border = border
end

Instance Attribute Details

#border ⇒ Object (readonly)

Returns the value of attribute border.



6
7
8
 
# File 'lib/pangrid/plugins/png.rb', line 6

def border
  @border
end

#scale ⇒ Object (readonly)

Returns the value of attribute scale.



6
7
8
 
# File 'lib/pangrid/plugins/png.rb', line 6

def scale
  @scale
end

Instance Method Details

#write(xw) ⇒ Object 



13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
 
# File 'lib/pangrid/plugins/png.rb', line 13

def write(xw)
  black = ChunkyPNG::Color::BLACK
  white = ChunkyPNG::Color::WHITE
  grey = ChunkyPNG::Color::rgb(128, 128, 128)
  xdim = xw.width * scale + 2
  ydim = xw.height * scale + 2
  png = ChunkyPNG::Image.new(xdim, ydim, ChunkyPNG::Color::TRANSPARENT)
  xw.each_cell_with_coords do |x, y, cell|
    c = cell.black? ? black : white
    png.rect(
      x * scale, y * scale, (x + 1) * scale, (y + 1) * scale,
      stroke_color = grey, fill_color = c)
  end
  if border
    stroke = ChunkyPNG::Color::rgb(*border)
    png.rect(0, 0, xw.width * scale, xw.height * scale, stroke_color = stroke)
  end
  png.to_blob  
end