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
command. 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 command
whose name is the same as the image. This command 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 command.
The following commands 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 command.
- 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 command 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 command modifies the
given option(s) to have the given value(s); in this case the command
returns an empty string. Option may have any of the values accepted
by the image create bitmap command.