canvas::gradient - Variations on a canvas

[ Tklib Home | Main Table Of Contents | Table Of Contents | Keyword Index | Categories | Modules | Applications ]

# canvas::gradient(n) 0.2 tklib "Variations on a canvas"

## Name

canvas::gradient - Canvas with a gradient background

## Synopsis

- package require Tcl 8.5
- package require Tk 8.5
- package require canvas::gradient ?0.2?

- ::canvas::gradient pathName ?options?...

## Description

This package provides a command to set background gradients on canvases.

NOTE! This package reserves the canvas tag canvas::gradient for its use.

## API

::canvas::gradient pathName ?options?...

  Creates a background gradient on the canvas pathName. An existing gradient is replaced by the new definition.

  The set of available options is decribed below, in section Options.

### Options

-direction direction

  The value for this option specifies the direction of the gradient. If not specified the system defaults to x, a horizontal gradient. The package supports five directions:

  x

    for a horizontal gradient (default). Color changes along the x-axis, with the start color at the left.

  y

    for a vertical gradient. Color changes along the y-axis, with the start color at the top.

  d1

    for a diagonal gradient from left+top to bottom+right. Color changes along the diagonal. with the start color at left+top.

  d2

    for a diagonal gradient from left+bottom to top+right. Color changes along the diagonal. with the start color at left+bottom.

  r

    for a radial gradient around the center of the viewport Color changes from the center outward, with the start color at the center.

-color1 color

  The value for this option specifies the starting color of the gradient. If not specified it defaults to red.

-color2 color

  The value for this option specifies the ending color of the gradient. If not specified it defaults to green.

-type type

  The value for this option specifies how the gradient is calculated. The package currently supports on ly one method, which is the default, naturally:

  linear

    for linear interpolation between the start and end colors (default).

## Example

    	package require canvas::gradient
    	canvas .c
    	canvas::gradient .c -direction x -color1 yellow -color2 blue
    	pack .c -fill both -expand 1

## Bugs, Ideas, Feedback

This document, and the package it describes, will undoubtedly contain bugs and other problems. Please report such in the category canvas of the Tklib Trackers. Please also report any ideas for enhancements you may have for either package and/or documentation.

## Keywords

background, canvas, color gradient, gradients, image, widget background

## Copyright

Copyright © 2013 Jarek Lewandowski, MaxJarek
Copyright © Origin http://wiki.tcl.tk/6100
Copyright © Origin http://wiki.tcl.tk/37242
Copyright © Origin http://wiki.tcl.tk/9079