# Large gnome::canvas problem

**URL:** <https://www.ruby-forum.com/t/large-gnome-canvas-problem/101275>\
**Category:** Ruby\
**Created:** [August 3, 2006, 11:27pm UTC](https://www.ruby-forum.com/t/large-gnome-canvas-problem/101275 "2006-08-03T23:27:27Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![hagi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/h/858c86/32.png) [@hagi](https://www.ruby-forum.com/u/hagi)\
**Post date:** [August 3, 2006, 11:27pm UTC](https://www.ruby-forum.com/t/large-gnome-canvas-problem/101275/1 "2006-08-03T23:27:27Z")

</div>

hi,

I have a little problem with displaying items in ‘big’ canvas, test  
code:

#!/usr/bin/env ruby

require ‘gnomecanvas2’

window = Gtk::Window.new  
window.signal\_connect(“delete\_event”) do |widget, event|  
Gtk::main\_quit  
end

box = Gtk::VBox.new(false, 4)  
window.add(box)

points = [[200, 10], [79800, 190]]

canvas = Gnome::Canvas.new(true)  
canvas.set\_size\_request(500, 200)  
canvas.set\_scroll\_region(0, 0, 80000, 200);  
canvas.center\_scroll\_region = false  
canvas.show  
Gnome::CanvasLine.new(canvas.root,  
{:points =\> points,  
:fill\_color\_rgba =\> 0x00ff00ff,  
:width\_pixels =\> 10.0})  
box.pack\_start(canvas)

scroll = Gtk::HScrollbar.new(canvas.hadjustment)  
scroll.show  
box.pack\_start(scroll)

adj = canvas.hadjustment

canvas = Gnome::Canvas.new(false)  
canvas.set\_size\_request(500, 200)  
canvas.set\_scroll\_region(0, 0, 80000, 200);  
canvas.center\_scroll\_region = false  
canvas.show  
canvas.hadjustment = adj

Gnome::CanvasLine.new(canvas.root,  
{:points =\> points,  
:fill\_color\_rgba =\> 0xff000000,  
:width\_pixels =\> 10.0})  
box.pack\_start(canvas)

box.show  
window.show

Gtk.main

the green line is in ‘antialiased’ canvas and looks good, red which is  
not antialiased looks strange, in fact I,ve got two lines or three  
(different look on different systems)

any idea?

thanks in advance

disclaimer: beginer in ruby and gtk, bad english 😉