В документации PyGObject есть некоторая информация о том, как использовать cairo в среде Python 3 + GTK + 3:
https://pygobject.readthedocs.io/en/latest/guide/cairo_integration.html
Я использовал это для адаптации вашего примера.Некоторые изменения с GTK + 2 на GTK + 3:
expose-event сигнал стал draw- Вы не можете
self.window на виджете для доступа к его GdkWindow, используйтеself.get_window()
Я сохраню там код: https://github.com/liberforce/gtk-samples/blob/master/python/gtk3-rotating-square/rotating-square.py
Вот в случае, если вышеприведенная ссылка оборвется:
#!/usr/bin/env python
## cairo demos
##
## Copyright (C) 2007 Donn.C.Ingle <donn.ingle@gmail.com>
## Copyright (C) 2019 Luis Menina <liberforce@freeside.fr>
##
## This program is free software; you can redistribute it and/or modify
## it under the terms of the GNU General Public License as published by
## the Free Software Foundation; either version 2 of the License, or
## (at your option) any later version.
##
## This program is distributed in the hope that it will be useful,
## but WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
## GNU General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with this program; if not, write to the Free Software
## Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
import cairo
import gi
gi.require_version("Gtk", "3.0")
from gi.repository import Gtk, Gdk, GObject
class Screen(Gtk.DrawingArea):
""" This class is a Drawing Area"""
def __init__(self):
super(Screen,self).__init__()
## Connect to the "draw" signal
self.connect("draw", self.on_draw)
## This is what gives the animation life!
GObject.timeout_add(50, self.tick) # Go call tick every 50 whatsits.
def tick(self):
## This invalidates the screen, causing the "draw" event to fire.
rect = self.get_allocation()
self.get_window().invalidate_rect(rect, True)
return True # Causes timeout to tick again.
## When the "draw" event fires, this is run
def on_draw(self, widget, event):
self.cr = self.get_window().cairo_create()
## Call our draw function to do stuff.
geom = self.get_window().get_geometry()
self.draw(geom.width, geom.height)
class MyStuff(Screen):
"""This class is also a Drawing Area, coming from Screen."""
def __init__(self):
Screen.__init__(self)
## x,y is where I'm at
self.x, self.y = 25, -25
## rx,ry is point of rotation
self.rx, self.ry = -10, -25
## rot is angle counter
self.rot = 0
## sx,sy is to mess with scale
self.sx, self.sy = 1, 1
def draw(self, width, height):
## A shortcut
cr = self.cr
## First, let's shift 0,0 to be in the center of page
## This means:
## -y | -y
## -x | +x
## ----0------
## -x | +x
## +y | +y
matrix = cairo.Matrix(1, 0, 0, 1, width/2, height/2)
cr.transform(matrix) # Make it so...
## Now save that situation so that we can mess with it.
## This preserves the last context(the one at 0,0)
## and let's us do new stuff.
cr.save()
## Now attempt to rotate something around a point
## Use a matrix to change the shape's position and rotation.
## First, make a matrix. Don't look at me, I only use this stuff :)
ThingMatrix = cairo.Matrix(1, 0, 0, 1, 0, 0)
## Next, move the drawing to it's x,y
cairo.Matrix.translate(ThingMatrix, self.x, self.y)
cr.transform(ThingMatrix) # Changes the context to reflect that
## Now, change the matrix again to:
cairo.Matrix.translate(ThingMatrix, self.rx, self.ry) # move it all to point of rotation
cairo.Matrix.rotate(ThingMatrix, self.rot) # Do the rotation
cairo.Matrix.translate(ThingMatrix, -self.rx, -self.ry) # move it back again
cairo.Matrix.scale(ThingMatrix, self.sx, self.sy) # Now scale it all
cr.transform(ThingMatrix) # and commit it to the context
## Now, whatever is draw is "under the influence" of the
## context and all that matrix magix we just did.
self.drawCairoStuff(cr)
## Let's inc the angle a little
self.rot += 0.1
## Now mess with scale too
self.sx += 0 # Change to 0 to see if rotation is working...
if self.sx > 4: self.sx=0.5
self.sy = self.sx
## We restore to a clean context, to undo all that hocus-pocus
cr.restore()
## Let's draw a crosshair so we can identify 0,0
## Drawn last to be above the red square.
self.drawcross(cr)
def drawCairoStuff(self, cr):
## Thrillingly, we draw a red rectangle.
## It's drawn such that 0,0 is in it's center.
cr.rectangle(-25, -25, 50, 50)
cr.set_source_rgb(1, 0, 0)
cr.fill()
## Now a visual indicator of the point of rotation
## I have no idea(yet) how to keep this as a
## tiny dot when the entire thing scales.
cr.set_source_rgb(1, 1, 1)
cr.move_to(self.rx, self.ry)
cr.line_to(self.rx+1, self.ry+1)
cr.stroke()
def drawcross(self, ctx):
## Also drawn around 0,0 in the center
ctx.set_source_rgb(0, 0, 0)
ctx.move_to(0,10)
ctx.line_to(0, -10)
ctx.move_to(-10, 0)
ctx.line_to(10, 0)
ctx.stroke()
def run(Widget):
window = Gtk.Window()
window.connect("destroy", Gtk.main_quit)
window.set_size_request(400, 400)
widget = Widget()
widget.show()
window.add(widget)
window.present()
Gtk.main()
run(MyStuff)