Tk::Bitmap3pm

Usage

Overview

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.

Creating bitmaps

Bitmaps are created using $widget->Bitmap. 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).

Image methods

When a bitmap image is created, Tk also creates a new object. This object supports the configure and cget methods described in Tk::options which can be used to enquire and modify the options described above.

Keywords

bitmap, image