Prima::ImageViewer(3)

NAME
Prima::ImageViewer - standard image, icon, and bitmap viewer class.

DESCRIPTION
The module contains "Prima::ImageViewer" class, which provides image displaying functionality, including different zoom levels.

"Prima::ImageViewer" is a descendant of "Prima::ScrollWidget" and inherits its document scrolling behavior and programming interface. See Prima::ScrollWidget for details.

API

  Properties

alignment INTEGER
    One of the following "ta::XXX" constants:

       ta::Left
       ta::Center
       ta::Right

    Selects the horizontal image alignment.

    Default value: "ta::Left"

image OBJECT
    Selects the image object to be displayed. OBJECT can be an instance of "Prima::Image", "Prima::Icon", or "Prima::DeviceBitmap" class.

imageFile FILE
    Set the image FILE to be loaded and displayed. Is rarely used since does not return a loading success flag.

quality BOOLEAN
    A boolean flag, selecting if the palette of "image" is to be copied into the widget palette, providing higher visual quality on paletted displays. See also "palette" in Prima::Widget.

    Default value: 1

valignment INTEGER
    One of the following "ta::XXX" constants:

       ta::Top
       ta::Middle or ta::Center
       ta::Bottom

    Selects the vertical image alignment.

    NB: "ta::Middle" value is not equal to "ta::Center"'s, however the both constants produce equal effect here.

    Default value: "ta::Bottom"

zoom FLOAT
    Selects zoom level for image display. The acceptable value range is between 0.02 and 100. The zoom value is rounded to fiftieth and twentieth fractional values - .02, .04, .05, .06, .08, and 0.1 .

    Default value: 1

  Methods

screen2point X, Y, [ X, Y, ... ]
    Performs translation of integer pairs integers as (X,Y)-points from widget coordinates to pixel offset in image coordinates. Takes in account zoom level, image alignments, and offsets. Returns array of same length as the input.

    Useful for determining correspondence, for example, of a mouse event to a image point.

    The reverse function is "point2screen".

point2screen   X, Y, [ X, Y, ... ]
    Performs translation of integer pairs as (X,Y)-points from image pixel offset to widget image coordinates. Takes in account zoom level, image alignments, and offsets. Returns array of same length as the input.

    Useful for determining a screen location of an image point.

    The reverse function is "screen2point".

AUTHOR
Dmitry Karasik, <dmitry@karasik.eu.org>.

SEE ALSO
Prima, Prima::Image, Prima::ScrollWidget, examples/iv.pl.