I have found a couple of unusual behaviors of drawing with cairo in
Pygtk and was wondering if there were solutions or if they needed to
be reported as bugs.
The first is that a sub-class of a GtkDrawingArea widget renders
correctly on its own in a window, but if placed in a box with another
widget, only renders if it's the first of only two widgets in the
container. It does not render at all hen placed in a GtkTable. This
behavior is demonstrated in test.py.
The second is that when sub-classing GtkDrawingArea,
self.get_allocation returns a GdkRectangle with the right x, height
and width values but the wrong y value. This behavior is demonstrated
in deka.py. There are 5 rows of polygons in each column. If you
can't see them, make your window taller until the fifth row comes into
view. This is the problem.
Cheers,
Adam Schreiber
#!/usr/bin/env python
import gtk
import math
class Bar(gtk.DrawingArea):
def __init__(self):
gtk.DrawingArea.__init__(self)
self.connect("expose_event", self.expose)
def expose(self, widget, event):
self.context = widget.window.cairo_create()
# set a clip region for the expose event
self.context.rectangle(event.area.x, event.area.y,
event.area.width, event.area.height)
self.context.clip()
self.draw(self.context)
return False
def draw(self, context):
rect = self.get_allocation()
print "width = {0}, height = {1}, x = {2}, y = {3}".format(rect.width,rect.height, rect.x, rect.y)
context.rectangle(gtk.gdk.Rectangle(rect.x + rect.width/3,
rect.y + 5,
rect.width/3,
rect.height - 10))
context.set_source_rgba(0.0, 0.0, 0.0, 0.25)
context.fill_preserve()
context.set_source_rgba(0.0, 0.0, 0.0, 1.0)
context.stroke()
def main():
window = gtk.Window()
window.set_default_size(200, 200)
vbox = gtk.VBox()
hbox = gtk.HBox()
button = gtk.Button()
bar = Bar()
hbox.add(bar)
hbox.add(button)
vbox.add(hbox)
window.add(vbox)
window.connect("destroy", gtk.main_quit)
window.show_all()
window = gtk.Window()
window.set_default_size(200, 200)
vbox = gtk.VBox()
hbox = gtk.HBox()
button = gtk.Button()
bar = Bar()
hbox.add(button)
hbox.add(bar)
vbox.add(hbox)
window.add(vbox)
window.connect("destroy", gtk.main_quit)
window.show_all()
gtk.main()
if __name__ == "__main__":
main()
#!/usr/bin/env python
"""
Copyright 2009 Adam Schreiber <[email protected]>
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 3 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, see <http://www.gnu.org/licenses/>.
"""
import gtk
import math
class DrawShapesArea(gtk.DrawingArea):
def __init__(self):
gtk.DrawingArea.__init__(self)
self.connect_after("expose_event", self.expose)
self.ones = 0
self.tens = 0
self.hundreds = 0
self.thousands = 0
self.tenthousands = 0
self.hundredthousands = 0
def expose(self, widget, event):
#print widget.window
self.context = widget.window.cairo_create()
#print self.context
# set a clip region for the expose event
self.context.rectangle(event.area.x, event.area.y,
event.area.width, event.area.height)
self.context.clip()
self.draw(self.context)
return False
def draw (self, context):
rect = self.get_allocation()
context.set_source_rgba(0.0, 0.0, 0.0, 1.0)
context.move_to (rect.x+rect.width/6, rect.y)
context.line_to (rect.x+rect.width/6, rect.y + rect.height)
context.move_to (rect.x+2*rect.width/6, rect.y)
context.line_to (rect.x+2*rect.width/6, rect.y + rect.height)
context.move_to (rect.x+3*rect.width/6, rect.y)
context.line_to (rect.x+3*rect.width/6, rect.y + rect.height)
context.move_to (rect.x+4*rect.width/6, rect.y)
context.line_to (rect.x+4*rect.width/6, rect.y + rect.height)
context.move_to (rect.x+5*rect.width/6, rect.y)
context.line_to (rect.x+5*rect.width/6, rect.y + rect.height)
context.stroke()
for m in range (0,5):
for n in range (0,2):
if (((5-m) + ((n+1)%2)*5) <= self.ones):
opacity = 1
else:
opacity = 0.25
self.drawBar (context, rect.x + 5*rect.width/6 + n*rect.width/12,
rect.y + m*rect.height/6, rect.width/12, rect.height/6, opacity)
for m in range (0,5):
for n in range (0,2):
if (((5-m) + ((n+1)%2)*5) <= self.tens):
opacity = 1
else:
opacity = 0.25
self.drawCircle (context, rect.x + 4*rect.width/6 + n*rect.width/12,
rect.y + m*rect.height/6, rect.width/12, rect.height/6, opacity)
for m in range (0,5):
for n in range (0,2):
if (((5-m) + ((n+1)%2)*5) <= self.hundreds):
opacity = 1
else:
opacity = 0.25
self.drawTriangle (context, rect.x + 3*rect.width/6 + n*rect.width/12,
rect.y + m*rect.height/6, rect.width/12, rect.height/6, opacity)
for m in range (0,5):
for n in range (0,2):
if (((5-m) + ((n+1)%2)*5) <= self.thousands):
opacity = 1
else:
opacity = 0.25
self.drawSquare (context, rect.x + 2*rect.width/6 + n*rect.width/12,
rect.y + m*rect.height/6, rect.width/12, rect.height/6, opacity)
for m in range (0,5):
for n in range (0,2):
if (((5-m) + ((n+1)%2)*5) <= self.tenthousands):
opacity = 1
else:
opacity = 0.25
self.drawPentagon (context, rect.x + 1*rect.width/6 + n*rect.width/12,
rect.y + m*rect.height/6, rect.width/12, rect.height/6, opacity)
for m in range (0,5):
for n in range (0,2):
if (((5-m) + ((n+1)%2)*5) <= self.hundredthousands):
opacity = 1
else:
opacity = 0.25
self.drawHexagon (context, rect.x + 0*rect.width/6 + n*rect.width/12,
rect.y + m*rect.height/6, rect.width/12, rect.height/6, opacity)
def set_count (self, count):
val = int(count)
self.hundredthousands = int(math.floor(val/math.pow(10,5)))
self.tenthousands = int(math.floor(math.fmod(val,math.pow(10,5))/math.pow(10,4)))
self.thousands = int(math.floor(math.fmod(val,math.pow(10,4))/math.pow(10,3)))
self.hundreds = int(math.floor(math.fmod(val,math.pow(10,3))/math.pow(10,2)))
self.tens = int(math.floor(math.fmod(val,math.pow(10,2))/math.pow(10,1)))
self.ones = int(math.floor(math.fmod(val,math.pow(10,1))))
self.queue_draw ()
def get_count ():
return (self.hundredthousands * 10**5 + self.tenthousands * 10**4
+ self.thousands * 10**3 + self.hundreds * 10**2
+ self.tens * 10 + self.ones)
def drawBar (self, context, x, y, width, height, opacity):
context.rectangle(gtk.gdk.Rectangle(x + width/3,
y+height/6,
width/3,
height*2/3))
context.set_source_rgba(0.933, 0.510, 0.933, opacity)
context.fill_preserve()
context.set_source_rgba(0.933, 0.510, 0.933, 1.0)
context.stroke()
def drawCircle (self, context, x, y, width, height, opacity):
x = x + width / 2
y = y + height / 2
radius = min(width / 2, height / 2) - 5
context.arc(x, y, radius, 0, 2 * math.pi)
context.set_source_rgba(0, 0, 1, opacity)
context.fill_preserve()
context.set_source_rgb(0, 0, 1)
context.stroke()
def drawTriangle (self, context, x, y, width, height, opacity):
x = x + width / 2
y = y + height / 2
radius = min(width / 2, height / 2) - 5
context.move_to (x, y - radius)
context.line_to (x+radius*math.cos(-30.0/180.0*math.pi), y - radius*math.sin(-30.0/180.0*math.pi))
context.line_to (x-radius*math.cos(-30.0/180.0*math.pi), y - radius*math.sin(-30.0/180.0*math.pi))
context.line_to (x, y - radius)
context.set_source_rgba(0.0, 1.0, 0.0, opacity)
context.fill_preserve()
context.set_source_rgba(0.0, 1.0, 0.0, 1.0)
context.stroke()
def drawSquare (self, context, x, y, width, height, opacity):
x = x + width / 2
y = y + height / 2
radius = min(width / 2, height / 2) - 5
context.rectangle (gtk.gdk.Rectangle (int(x-.5*radius*math.sqrt(2.0)),
int(y-.5*radius*math.sqrt(2.0)),
int(radius*math.sqrt(2.0)),
int(radius*math.sqrt(2.0))))
context.set_source_rgba(1.0, 1.0, 0.0, opacity)
context.fill_preserve()
context.set_source_rgba(1.0, 1.0, 0.0, 1.0)
context.stroke()
def drawPentagon (self, context, x, y, width, height, opacity):
x = x + width / 2
y = y + height / 2
radius = min(width / 2, height / 2) - 5
context.move_to (x, y - radius)
context.line_to (x+radius*math.cos(13.0/180.0*math.pi), y - radius*math.sin(13.0/180.0*math.pi))
context.line_to (x+radius*math.cos(54.0/180.0*math.pi), y + radius*math.sin(54.0/180.0*math.pi))
context.line_to (x-radius*math.cos(54.0/180.0*math.pi), y + radius*math.sin(54.0/180.0*math.pi))
context.line_to (x-radius*math.cos(13.0/180.0*math.pi), y - radius*math.sin(13.0/180.0*math.pi))
context.line_to (x, y - radius)
context.set_source_rgba(1.0, 0.647, 0.0, opacity)
context.fill_preserve()
context.set_source_rgba(1.0, 0.647, 0.0, 1.0)
context.stroke()
def drawHexagon (self, context, x, y, width, height, opacity):
x = x + width / 2
y = y + height / 2
radius = min(width / 2, height / 2) - 5
context.move_to (x+radius*math.cos(60.0/180.0*math.pi), y - radius*math.sin(60.0/180.0*math.pi))
context.line_to (x+radius, y)
context.line_to (x+radius*math.cos(60.0/180.0*math.pi), y + radius*math.sin(60.0/180.0*math.pi))
context.line_to (x-radius*math.cos(60.0/180.0*math.pi), y + radius*math.sin(60.0/180.0*math.pi))
context.line_to (x-radius, y)
context.line_to (x - radius*math.cos(60.0/180.0*math.pi), y - radius*math.sin(60.0/180.0*math.pi))
context.line_to (x+radius*math.cos(60.0/180.0*math.pi), y - radius*math.sin(60.0/180.0*math.pi))
context.set_source_rgba(1.0, 0.0, 0.0, opacity)
context.fill_preserve()
context.set_source_rgba(1.0, 0.0, 0.0, 1.0)
context.stroke()
def main():
window = gtk.Window(gtk.WINDOW_TOPLEVEL)
window.connect("delete_event", delete_event)
window.connect("destroy", gtk.main_quit)
window.set_border_width(10)
window.set_default_size(640, 480)
window.set_title("Deka")
vbox = gtk.VBox (False, 10)
window.add(vbox)
# Scrollbar Value Label
hbox = gtk.HBox()
spinbut = gtk.SpinButton()
spinbut.set_range(0,999999)
spinbut.set_increments(1,100)
spinbut.set_numeric(True)
hbox.pack_start(spinbut, True, False)
vbox.pack_start(hbox, False)
# Scrollbar
hscrollbar = gtk.HScrollbar()
hscrollbar.set_range(0,999999)
hscrollbar.set_increments(1,100)
vbox.pack_start(hscrollbar, False)
# Equivalent Label
equivlab = gtk.Label("0 * 100000 + 0 * 10000 + 0 * 1000 + 0 * 100 + 0 * 10 + 0 * 1 = 0")
vbox.pack_start(equivlab, False)
# Power of 10 Equivalent Label
powequivlab = gtk.Label("0 * 10<sup>5</sup> + 0 * 10<sup>4</sup> + 0 * 10<sup>3</sup> + 0 * 10<sup>2</sup> + 0 * 10<sup>1</sup> + 0 * 10<sup>0</sup> = 0")
powequivlab.set_use_markup(True)
vbox.pack_start(powequivlab, False)
# Start Figure Box
drawshapesarea = DrawShapesArea()
vbox.add(drawshapesarea)
spinbut.connect("value-changed", scrollbar_changed, [spinbut, hscrollbar, equivlab, powequivlab, drawshapesarea])
hscrollbar.connect("value-changed", scrollbar_changed, [spinbut, hscrollbar, equivlab, powequivlab, drawshapesarea])
window.show_all()
gtk.main()
def scrollbar_changed(range, data=None):
spinbut = data[0]
hscrollbar = data[1]
equivlab = data[2]
powequivlab = data[3]
drawshapesarea = data[4]
val = round(range.get_value())
if abs(val) < abs(1e-2):
val = 0
val = int(val)
val5 = int(math.floor(val/math.pow(10,5)))
val4 = int(math.floor(math.fmod(val,math.pow(10,5))/math.pow(10,4)))
val3 = int(math.floor(math.fmod(val,math.pow(10,4))/math.pow(10,3)))
val2 = int(math.floor(math.fmod(val,math.pow(10,3))/math.pow(10,2)))
val1 = int(math.floor(math.fmod(val,math.pow(10,2))/math.pow(10,1)))
val0 = int(math.floor(math.fmod(val,math.pow(10,1))))
spinbut.set_value(int(val))
hscrollbar.set_value(int(val))
equivlab.set_text("{0} * 100000 + {1} * 10000 + {2} * 1000 + {3} * 100 + {4} * 10 + {5} * 1 = {6}".format(val5, val4, val3, val2, val1, val0, val))
powequivlab.set_markup("{0} * 10<sup>5</sup> + {1} * 10<sup>4</sup> + {2} * 10<sup>3</sup> + {3} * 10<sup>2</sup> + {4} * 10<sup>1</sup> + {5} * 10<sup>0</sup> = {6}".format(val5, val4, val3, val2, val1, val0, val))
drawshapesarea.set_count (val)
def delete_event(widget, event, data=None):
return False
if __name__ == "__main__":
main()
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