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=begin
drawing.rb - Gtk::Drawing sample script.
Copyright (c) 2002-2006 Ruby-GNOME2 Project Team
This program is licenced under the same licence as Ruby-GNOME2.
$Id: drawing.rb,v 1.7 2006/06/17 13:18:12 mutoh Exp $
=end
require 'gtk2'
class Canvas < Gtk::DrawingArea
def initialize
super
signal_connect("expose_event") { |w,e| expose_event(w,e) }
signal_connect("configure_event") { |w, e| configure_event(w,e) }
@buffer = nil
@bgc = nil
end
def expose_event(w,e)
unless @buffer.nil?
rec = e.area
w.window.draw_drawable(@bgc, @buffer, rec.x, rec.y,
rec.x, rec.y, rec.width, rec.height)
end
false
end
def clear(b = @buffer)
return if b.nil?
g = b.size
@bgc = self.style.bg_gc(self.state) if @bgc.nil?
if (g[0] > 0 && g[1] > 0)
b.draw_rectangle(@bgc, true, 0,0, g[0], g[1])
end
end
def configure_event(w,e)
g = w.window.geometry
if (g[2] > 0 && g[3] > 0)
b = Gdk::Pixmap::new(w.window, g[2], g[3], -1)
clear(b)
if not @buffer.nil?
g = @buffer.size
b.draw_drawable(@bgc, @buffer, 0, 0, 0, 0, g[0], g[1])
end
@buffer = b
end
true
end
end
class A < Canvas
def initialize
super
signal_connect("button_press_event") { |w,e| pressed(w,e) }
set_events(Gdk::Event::BUTTON_PRESS_MASK)
end
def pressed(widget, ev)
if not @last.nil?
@buffer.draw_line(widget.style.fg_gc(widget.state),
@last.x, @last.y, ev.x, ev.y)
x1,x2 = if (@last.x < ev.x)
then [@last.x, ev.x]
else [ev.x, @last.x]
end
y1,y2 = if (@last.y < ev.y)
then [@last.y, ev.y]
else [ev.y, @last.y]
end
widget.queue_draw_area(x1, y1, x2 - x1 + 1, y2 - y1 + 1)
end
@last = nil
@last = ev
true
end
end
window = Gtk::Window.new("drawing test")
window.signal_connect("destroy") { Gtk.main_quit }
canvas = A.new
window.add(canvas)
window.show_all
Gtk::main
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