image_voodoo.rb in image_voodoo-0.8.5

- old
+ new

@@ -1,12 +1,12 @@
 ##
 #
 # = ImageVoodoo
 # == Description
 #
-# ImageVoodoo is an ImageScience-API-compatible image manipulation library for 
-# JRuby.  
+# ImageVoodoo is an ImageScience-API-compatible image manipulation library for
+# JRuby.
 #
 # == Examples
 #
 # === Simple block-based examples
 #
@@ -25,11 +25,11 @@
 # img = ImageVoodoo.with_image(ARGV[0])
 # negative_img = img.negative
 #
 class ImageVoodoo
   attr_accessor :quality
-  
+
   include Java
 
   JFile = java.io.File
 
   ##
@@ -42,12 +42,13 @@
      require 'image_voodoo/gae'
   rescue
      require 'image_voodoo/awt'
   end
 
-  def initialize(src)
+  def initialize(src, format=nil)
     @src = src
+    @format = format
     @quality = nil # nil means no specific quality ever specified
   end
 
   ##
   #
@@ -56,37 +57,37 @@
   #
   def adjust_brightness(scale, offset)
     image = guard { adjust_brightness_impl(scale, offset) }
     block_given? ? yield(image) : image
   end
-  
+
   ##
   #
-  # Converts rgb hex color value to an alpha value an yields/returns the new 
+  # Converts rgb hex color value to an alpha value an yields/returns the new
   # image.
   #
   def alpha(rgb)
     target = guard { alpha_impl(rgb) }
     block_given? ? yield(target) : target
   end
 
   ##
-  # 
+  #
   # Get current image bytes as a String using provided format. Format parameter
   # is the informal name of an image type - for instance,
   # "bmp" or "jpg". If the backend is AWT the types available are listed in
   # javax.imageio.ImageIO.getWriterFormatNames()
-  # 
+  #
   def bytes(format)
     java_bytes = guard { bytes_impl(format) }
     String.from_java_bytes java_bytes
   end
 
   ##
   #
-  # Creates a square thumbnail of the image cropping the longest edge to 
-  # match the shortest edge, resizes to size, and yields/returns the new image. 
+  # Creates a square thumbnail of the image cropping the longest edge to
+  # match the shortest edge, resizes to size, and yields/returns the new image.
   #
   def cropped_thumbnail(size)
     l, t, r, b, half = 0, 0, width, height, (width - height).abs / 2
     l, r = half, half + height if width > height
     t, b = half, half + width if height > width
@@ -112,21 +113,21 @@
     target = guard { flip_vertically_impl }
     block_given? ? yield(target) : target
   end
 
   ##
-  # 
+  #
   # Creates a grayscale version of image and yields/returns the new image.
   #
   def greyscale
     target = guard { greyscale_impl }
     block_given? ? yield(target) : target
   end
   alias_method :grayscale, :greyscale
 
   ##
-  # 
+  #
   # Creates a negative and yields/returns the new image.
   #
   def negative
     target = guard { negative_impl }
     block_given? ? yield(target) : target
@@ -147,24 +148,24 @@
     block_given? ? yield(target) : target
   end
 
   ##
   #
-  # Resizes the image to width and height and yields/returns the new image. 
+  # Resizes the image to width and height and yields/returns the new image.
   #
   def resize(width, height)
     target = guard { resize_impl(width, height) }
     block_given? ? yield(target) : target
   rescue NativeException => ne
     raise ArgumentError, ne.message
   end
 
   ##
-  # 
-  # Saves the image out to path. Changing the file extension will convert 
-  # the file type to the appropriate format. 
   #
+  # Saves the image out to path. Changing the file extension will convert
+  # the file type to the appropriate format.
+  #
   def save(file)
     format = File.extname(file)
     return false if format == ""
     format = format[1..-1].downcase
     guard { save_impl(format, JFile.new(file)) }
@@ -182,40 +183,40 @@
     block_given? ? yield(target) : target
   end
 
   ##
   #
-  # Creates a proportional thumbnail of the image scaled so its longest 
-  # edge is resized to size and yields/returns the new image. 
+  # Creates a proportional thumbnail of the image scaled so its longest
+  # edge is resized to size and yields/returns the new image.
   #
   def thumbnail(size)
     target = scale(size.to_f / (width > height ? width : height))
     block_given? ? yield(target) : target
   end
 
   ##
   #
-  # Crops an image to left, top, right, and bottom and then yields/returns the 
-  # new image. 
+  # Crops an image to left, top, right, and bottom and then yields/returns the
+  # new image.
   #
   def with_crop(left, top, right, bottom)
     image = guard { with_crop_impl(left, top, right, bottom) }
     block_given? ? yield(image) : image
   end
 
   ##
-  # 
+  #
   # A top-level image loader opens path and then yields/returns the image.
   #
   def self.with_image(path)
     raise ArgumentError, "file does not exist" unless File.file?(path)
     image = guard { with_image_impl(JFile.new(path)) }
     image && block_given? ? yield(image) : image
   end
 
   ##
-  # 
+  #
   # A top-level image loader reads bytes and then yields/returns the image.
   #
   def self.with_bytes(bytes)
     bytes = bytes.to_java_bytes if String === bytes
     image = guard { with_bytes_impl(bytes) }
@@ -227,11 +228,11 @@
   end
 
   ##
   #
   # *_impl providers only need provide the implementation if it can
-  # support it.  Otherwise, this method will detect that the method is 
+  # support it.  Otherwise, this method will detect that the method is
   # missing.
   #
   def self.guard(&block)
     begin
       return block.call
@@ -243,19 +244,19 @@
     ImageVoodoo.guard(&block)
   end
 
   ##
   #
-  # Returns the height of the image, in pixels. 
+  # Returns the height of the image, in pixels.
   #
   def height
     @src.height
   end
 
   ##
   #
-  # Returns the width of the image, in pixels. 
+  # Returns the width of the image, in pixels.
   #
   def width
     @src.width
   end
 
@@ -265,7 +266,19 @@
   # Depending on whether you are using AWT or GAE/J you will get a totally
   # different Java class.  So caveat emptor!
   #
   def to_java
     @src
+  end
+
+  ##
+  #
+  # Returns detected image format from binary representation of input data
+  # as upper case string. Eg. JPEG, BMP, PNG. For GWT image representation
+  # compatibility method name is :format. It also accepts block and returns
+  # format as first block argument. When format not detected or not set it
+  # returns nil
+  #
+  def format
+    @format && block_given? ? yield(@format) : @format
   end
 end