Reference

canvas::gradient(3tk)

Canvas with a gradient background


        
    

    
        

            
                
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 [http://core.tcl.tk/tklib/reportlist]. 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 (c) 2013 Jarek Lewandowski, MaxJarek
Copyright (c) Origin http://wiki.tcl.tk/6100
Copyright (c) Origin http://wiki.tcl.tk/37242
Copyright (c) Origin http://wiki.tcl.tk/9079



        
    


        

    



        
            

                
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