sprite module files

This commit is contained in:
Scott Davis 2011-06-12 00:15:23 -04:00
parent 5999c7ba6c
commit 21a5a2ae3d
2 changed files with 158 additions and 0 deletions

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module Compass
module SassExtensions
module Sprites
module ImageMethods
# Fetches the Sprite::Image object for the supplied name
def image_for(name)
@images.detect { |img| img.name == name}
end
# Returns true if the image name has a hover selector image
def has_hover?(name)
!image_for("#{name}_hover").nil?
end
# Returns true if the image name has a target selector image
def has_target?(name)
!image_for("#{name}_target").nil?
end
# Returns true if the image name has an active selector image
def has_active?(name)
!image_for("#{name}_active").nil?
end
# Return and array of image names that make up this sprite
def sprite_names
image_names.map { |f| File.basename(f, '.png') }
end
end
end
end
end

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module Compass
module SassExtensions
module Sprites
module SpriteMethods
# Changing this string will invalidate all previously generated sprite images.
# We should do so only when the packing algorithm changes
SPRITE_VERSION = "1"
# Calculates the overal image dimensions
# collects image sizes and input parameters for each sprite
# Calculates the height
def compute_image_metadata!
@width = 0
init_images
compute_image_positions!
@height = @images.last.top + @images.last.height
end
# Creates the Sprite::Image objects for each image and calculates the width
def init_images
@images = image_names.collect do |relative_file|
image = Compass::SassExtensions::Sprites::Image.new(self, relative_file, kwargs)
@width = [ @width, image.width + image.offset ].max
image
end
end
# Calculates the overal image dimensions
# collects image sizes and input parameters for each sprite
def compute_image_positions!
@images.each_with_index do |image, index|
image.left = image.position.unit_str == "%" ? (@width - image.width) * (image.position.value / 100) : image.position.value
next if index == 0
last_image = @images[index-1]
image.top = last_image.top + last_image.height + [image.spacing, last_image.spacing].max
end
end
# Validates that the sprite_names are valid sass
def validate!
for sprite_name in sprite_names
unless sprite_name =~ /\A#{Sass::SCSS::RX::IDENT}\Z/
raise Sass::SyntaxError, "#{sprite_name} must be a legal css identifier"
end
end
end
# The on-the-disk filename of the sprite
def filename
File.join(Compass.configuration.images_path, "#{path}-s#{uniqueness_hash}.png")
end
# Generate a sprite image if necessary
def generate
if generation_required?
if kwargs.get_var('cleanup').value
cleanup_old_sprites
end
sprite_data = construct_sprite
save!(sprite_data)
Compass.configuration.run_callback(:sprite_generated, sprite_data)
end
end
def cleanup_old_sprites
Dir[File.join(Compass.configuration.images_path, "#{path}-*.png")].each do |file|
FileUtils.rm file
end
end
# Does this sprite need to be generated
def generation_required?
!File.exists?(filename) || outdated?
end
# Returns the uniqueness hash for this sprite object
def uniqueness_hash
@uniqueness_hash ||= begin
sum = Digest::MD5.new
sum << SPRITE_VERSION
sum << path
images.each do |image|
[:relative_file, :height, :width, :repeat, :spacing, :position, :digest].each do |attr|
sum << image.send(attr).to_s
end
end
sum.hexdigest[0...10]
end
@uniqueness_hash
end
# Saves the sprite engine
def save!(output_png)
saved = output_png.save filename
Compass.configuration.run_callback(:sprite_saved, filename)
saved
end
# All the full-path filenames involved in this sprite
def image_filenames
@images.map(&:file)
end
# Checks whether this sprite is outdated
def outdated?
if File.exists?(filename)
return @images.map(&:mtime).any? { |imtime| imtime.to_i > self.mtime.to_i }
end
true
end
# Mtime of the sprite file
def mtime
@mtime ||= File.mtime(filename)
end
# Calculate the size of the sprite
def size
[width, height]
end
end
end
end
end