Sugar Labs

Changes

Features/GTK3/Porting (view source)

Revision as of 10:05, 14 November 2011

1 byte removed ,  10:05, 14 November 2011
→‎Going from Drawable to Cairo
Line 259: Line 259:     
<pre>
 
<pre>
−
# Map the xlib surface onto a pixmap
+
# create a new 1x1 cairo surface
−
pixmap = gtk.gdk.Pixmap(None, w, h, 24)
+
cs = cairo.ImageSurface(cairo.FORMAT_RGB24, 1, 1);
−
cairo_context = pixmap.cairo_create()
+
cr = cairo.Context(cs)
−
cairo_context.set_source_surface(xlib_surface, 0, 0)
+
# translate surface so that target pixel is at 0, 0
−
cairo_context.paint()
+
cr.set_source_surface(self.tw.turtle_canvas, -x, -y)
−
 
+
cr.rectangle(0,0,1,1)
 +
cr.set_operator(cairo.OPERATOR_SOURCE)
 +
cr.fill()
 +
cs.flush() # ensure all writing is done
 
# Read the pixel
 
# Read the pixel
−
pixel = pixmap.get_image(x, y, 1, 1).get_pixel(0, 0)
+
return (ord(pixels[2]), ord(pixels[1]), ord(pixels[0]), 0)
−
return(int((pixel & 0xFF0000) >> 16), # red
  −
      int((pixel & 0x00FF00) >> 8), # green
  −
      int((pixel & 0x0000FF) >> 0), 0) # blue
   
</pre>
 
</pre>
  
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