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TkPhotoImage documentation #9

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TkPhotoImage documentation #9

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a78da05
added documentation to TkPhotoImage
lkdjiin Feb 11, 2011
e756629
remove commented code
lkdjiin Feb 11, 2011
847bb54
renamed st to state
lkdjiin Feb 11, 2011
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122 changes: 118 additions & 4 deletions ext/tk/lib/tk/image.rb
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Original file line number Diff line number Diff line change
Expand Up @@ -72,7 +72,6 @@ def initialize(keys=nil)
end
unless @path
Tk_Image_ID.mutex.synchronize{
# @path = Tk_Image_ID.join('')
@path = Tk_Image_ID.join(TkCore::INTERP._ip_id_)
Tk_Image_ID[1].succ!
}
Expand Down Expand Up @@ -128,6 +127,12 @@ def initialize(*args)
end
end

# A photo is an image whose pixels can display any color or be transparent.
# At present, only GIF and PPM/PGM formats are supported, but an interface
# exists to allow additional image file formats to be added easily.
#
# This class documentation is a copy from the original Tcl/Tk at
# http://www.tcl.tk/man/tcl8.5/TkCmd/photo.htm with some rewrited parts.
class TkPhotoImage<TkImage
NullArgOptionKeys = [ "shrink", "grayscale" ]

Expand All @@ -146,11 +151,49 @@ def _photo_hash_kv(keys)
end
private :_photo_hash_kv

# Create a new image with the given options.
# == Examples of use :
# === Create an empty image of 300x200 pixels
#
# image = TkPhotoImage.new(:height => 200, :width => 300)
#
# === Create an image from a file
#
# image = TkPhotoImage.new(:file: => 'my_image.gif')
#
# == Options
# Photos support the following options:
# * :data
# Specifies the contents of the image as a string.
# * :format
# Specifies the name of the file format for the data.
# * :file
# Gives the name of a file that is to be read to supply data for the image.
# * :gamma
# Specifies that the colors allocated for displaying this image in a window
# should be corrected for a non-linear display with the specified gamma
# exponent value.
# * height
# Specifies the height of the image, in pixels. This option is useful
# primarily in situations where the user wishes to build up the contents of
# the image piece by piece. A value of zero (the default) allows the image
# to expand or shrink vertically to fit the data stored in it.
# * palette
# Specifies the resolution of the color cube to be allocated for displaying
# this image.
# * width
# Specifies the width of the image, in pixels. This option is useful
# primarily in situations where the user wishes to build up the contents of
# the image piece by piece. A value of zero (the default) allows the image
# to expand or shrink horizontally to fit the data stored in it.
def initialize(*args)
@type = 'photo'
super(*args)
end

# Blank the image; that is, set the entire image to have no data, so it will
# be displayed as transparent, and the background of whatever window it is
# displayed in will show through.
def blank
tk_send_without_enc('blank')
self
Expand All @@ -164,6 +207,10 @@ def cget_strict(option)
tk_tcl2ruby(tk_send('cget', '-' << option.to_s))
end
end

# Returns the current value of the configuration option given by option.
# Example, display name of the file from which <tt>image</tt> was created:
# puts image.cget :file
def cget(option)
unless TkConfigMethod.__IGNORE_UNKNOWN_CONFIGURE_OPTION__
cget_strict(option)
Expand All @@ -182,6 +229,50 @@ def cget(option)
end
end

# Copies a region from the image called source to the image called destination,
# possibly with pixel zooming and/or subsampling. If no options are specified,
# this method copies the whole of source into destination, starting at
# coordinates (0,0) in destination. The following options may be specified:
#
# * :from [x1, y1, x2, y2]
# Specifies a rectangular sub-region of the source image to be copied.
# (x1,y1) and (x2,y2) specify diagonally opposite corners of the rectangle.
# If x2 and y2 are not specified, the default value is the bottom-right corner
# of the source image. The pixels copied will include the left and top edges
# of the specified rectangle but not the bottom or right edges. If the :from
# option is not given, the default is the whole source image.
# * :to [x1, y1, x2, y2]
# Specifies a rectangular sub-region of the destination image to be affected.
# (x1,y1) and (x2,y2) specify diagonally opposite corners of the rectangle.
# If x2 and y2 are not specified, the default value is (x1,y1) plus the size of
# the source region (after subsampling and zooming, if specified). If x2 and
# y2 are specified, the source region will be replicated if necessary to fill
# the destination region in a tiled fashion.
# * :shrink
# Specifies that the size of the destination image should be reduced, if
# necessary, so that the region being copied into is at the bottom-right
# corner of the image. This option will not affect the width or height of
# the image if the user has specified a non-zero value for the :width or
# :height configuration option, respectively.
# * :zoom [x, y]
# Specifies that the source region should be magnified by a factor of x
# in the X direction and y in the Y direction. If y is not given, the default
# value is the same as x. With this option, each pixel in the source image will
# be expanded into a block of x x y pixels in the destination image, all the
# same color. x and y must be greater than 0.
# * :subsample [x, y]
# Specifies that the source image should be reduced in size by using only
# every xth pixel in the X direction and yth pixel in the Y direction.
# Negative values will cause the image to be flipped about the Y or X axes,
# respectively. If y is not given, the default value is the same as x.
# * :compositingrule rule
# Specifies how transparent pixels in the source image are combined with
# the destination image. When a compositing rule of <tt>overlay</tt> is set, the old
# contents of the destination image are visible, as if the source image were
# printed on a piece of transparent film and placed over the top of the
# destination. When a compositing rule of <tt>set</tt> is set, the old contents of
# the destination image are discarded and the source image is used as-is.
# The default compositing rule is <tt>overlay</tt>.
def copy(src, *opts)
if opts.size == 0
tk_send('copy', src)
Expand All @@ -201,11 +292,31 @@ def copy(src, *opts)
self
end

# Returns image data in the form of a string. The following options may be specified:
# * :background color
# If the color is specified, the data will not contain any transparency information.
# In all transparent pixels the color will be replaced by the specified color.
# * :format format-name
# Specifies the name of the image file format handler to be used. Specifically,
# this subcommand searches for the first handler whose name matches an initial
# substring of format-name and which has the capability to read this image data.
# If this option is not given, this subcommand uses the first handler that has
# the capability to read the image data.
# * :from [x1, y1, x2, y2]
# Specifies a rectangular region of imageName to be returned. If only x1 and y1
# are specified, the region extends from (x1,y1) to the bottom-right corner of
# imageName. If all four coordinates are given, they specify diagonally opposite
# corners of the rectangular region, including x1,y1 and excluding x2,y2.
# The default, if this option is not given, is the whole image.
# * :grayscale
# If this options is specified, the data will not contain color information.
# All pixel data will be transformed into grayscale.
def data(keys={})
#tk_send('data', *_photo_hash_kv(keys))
tk_split_list(tk_send('data', *_photo_hash_kv(keys)))
end

# Returns the color of the pixel at coordinates (x,y) in the image as a list
# of three integers between 0 and 255, representing the red, green and blue components respectively.
def get(x, y)
tk_send('get', x, y).split.collect{|n| n.to_i}
end
Expand Down Expand Up @@ -246,11 +357,14 @@ def redither
self
end

# Returns a boolean indicating if the pixel at (x,y) is transparent.
def get_transparency(x, y)
bool(tk_send('transparency', 'get', x, y))
end
def set_transparency(x, y, st)
tk_send('transparency', 'set', x, y, st)

# Makes the pixel at (x,y) transparent if <tt>state</tt> is true, and makes that pixel opaque otherwise.
def set_transparency(x, y, state)
tk_send('transparency', 'set', x, y, state)
self
end

Expand Down