bitmap
Images that display two colors
(image 'create 'bitmap ?name? ?options?)
A bitmap is an image whose pixels can display either of two colors
or be transparent.
A bitmap image is defined by four things: a background color,
a foreground color, and two bitmaps, called the source
and the mask.
Each of the bitmaps specifies 0/1 values for a rectangular
array of pixels, and the two bitmaps must have the same
dimensions.
For pixels where the mask is zero, the image displays nothing,
producing a transparent effect.
For other pixels, the image displays the foreground color if
the source data is one and the background color if the source
data is zero.
Like all images, bitmaps are created using the image create
procedure.
Bitmaps support the following options:
- :background color
-
Specifies a background color for the image in any of the standard
ways accepted by Tk. If this option is set to an empty string
then the background pixels will be transparent. This effect
is achieved by using the source bitmap as the mask bitmap, ignoring
any :maskdata or :maskfile options.
- :data string
-
Specifies the contents of the source bitmap as a string.
The string must adhere to X11 bitmap format (e.g., as generated
by the bitmap program).
If both the :data and :file options are specified,
the :data option takes precedence.
- :file name
-
name gives the name of a file whose contents define the
source bitmap.
The file must adhere to X11 bitmap format (e.g., as generated
by the bitmap program).
- :foreground color
-
Specifies a foreground color for the image in any of the standard
ways accepted by Tk.
- :maskdata string
-
Specifies the contents of the mask as a string.
The string must adhere to X11 bitmap format (e.g., as generated
by the bitmap program).
If both the :maskdata and :maskfile options are specified,
the :maskdata option takes precedence.
- :maskfile name
-
name gives the name of a file whose contents define the
mask.
The file must adhere to X11 bitmap format (e.g., as generated
by the bitmap program).
When a bitmap image is created, Tk also creates a new procedure
whose name is the same as the image.
This procedure may be used to invoke various operations
on the image.
It has the following general form:
(imageName option ?arg arg ...?)
Option and the args
determine the exact behavior of the procedure. The following
procedures are possible for bitmap images:
- (imageName cget option)
-
Returns the current value of the configuration option given
by option.
Option may have any of the values accepted by the
image create bitmap procedure.
- (imageName configure ?option? ?value option value ...?)
-
Query or modify the configuration options for the image.
If no option is specified, returns a list describing all of
the available options for imageName (see Tk_ConfigureInfo for
information on the format of this list). If option is specified
with no value, then the procedure returns a list describing the
one named option (this list will be identical to the corresponding
sublist of the value returned if no option is specified). If
one or more option-value pairs are specified, then the procedure
modifies the given option(s) to have the given value(s); in
this case the procedure returns an empty string.
Option may have any of the values accepted by the
image create bitmap procedure.
make-image, image, jpeg, photo, pixmap
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