Hi,<br><br>I'm trying to make the background of a Desktop Widget semi-transparent using the cairo graphics library. The widget is written in Python and the only examples of this I've found are using C (I don't know much C -- I wasn't even able to apply the examples to Python).<br>
<br>This is the current code (that doesn't work -- the background appears as a black box)<br><br><br> def __init__(self):<br> hildondesktop.HomePluginItem.__init__(self)<br>...<br> self.connect("screen-changed", self.screen_changed)<br>
self.connect("expose-event", self.expose)<br clear="all"><br><br> def expose(self, widget, event):<br> cr = self.window.cairo_create()<br> cr.set_source_rgba(1.0, 1.0, 1.0, 0.0) # Transparent<br>
<br> # Draw the background<br> cr.set_operator(cairo.OPERATOR_SOURCE)<br> cr.paint()<br><br> # draw rounded rect<br> width, height = self.allocation[2], self.allocation[3]<br><br> #/* a custom shape, that could be wrapped in a function */<br>
x0 = 0 #/*< parameters like cairo_rectangle */<br> y0 = 0<br><br> radius = min(15, width/2, height/2) #/*< and an approximate curvature radius */<br><br> x1 = x0 + width<br> y1 = y0 + height<br>
<br> cr.move_to (x0, y0 + radius)<br> cr.arc (x0 + radius, y0 + radius, radius, 3.14, 1.5 * 3.14)<br> cr.line_to (x1 - radius, y0)<br> cr.arc (x1 - radius, y0 + radius, radius, 1.5 * 3.14, 0.0)<br> cr.line_to (x1 , y1 - radius)<br>
cr.arc (x1 - radius, y1 - radius, radius, 0.0, 0.5 * 3.14)<br> cr.line_to (x0 + radius, y1)<br> cr.arc (x0 + radius, y1 - radius, radius, 0.5 * 3.14, 3.14)<br><br> cr.close_path ()<br><br> bg_color=gtk.gdk.color_parse("#000000")<br>
<br> cr.set_source_rgba (bg_color.red / 65535.0, bg_color.green/65535.0, bg_color.blue/65535.0, float(32767/65535.0))<br> cr.fill_preserve ()<br> # cr.set_source_rgba (0.5, 0.5, 1.0, 0.8)<br> # cr.stroke ()<br>
<br> def screen_changed(self, widget):<br> screen = self.get_screen()<br> colormap = screen.get_rgba_colormap()<br> self.set_colormap(colormap)<br><br> return False<br><br><br>What I'm trying to do is have the widget appear semi-transparent with rounded corners (like most widgets look) but the above code does not work at all. I do not know much about cairo and got most of that code from Khertan's HomeIP widget for Diablo/Chinook and only modified it a little to work with Maemo 5.<br>
<br>Any help would be greatly appreciated. I've been "banging my head against a wall" for a while with this one.<br><br>-- <br>Best Regards,<br><br>Brent Chiodo<br>