Rendering SVGs in wxPython

test.py

import wx
import rsvg
import numpy

try:
    import wx.lib.wxcairo
    import cairo
    haveCairo = True
except ImportError:
    haveCairo = False

class ComponentFrame(wx.Frame):
    def __init__(self, parent, id, title, pos, size):
        wx.Frame.__init__(self, parent, id, title, pos, size)

        self.panel = wx.Panel(self)
        vbox = wx.BoxSizer(wx.HORIZONTAL)
        component = SvgComponent(self.panel)
        vbox.Add(component, 1, wx.EXPAND | wx.ALL, 10)
        self.panel.SetSizer(vbox)

        self.Show(True)

class SvgComponent(wx.PyControl):
    def __init__(self, parent, label="",
                 id=wx.ID_ANY,
                 pos=wx.DefaultPosition,
                 size=wx.DefaultSize, style=wx.NO_BORDER, validator=wx.DefaultValidator,
                 name="CustomMeter"):

        wx.PyControl.__init__(self, parent, id, pos, size, style, validator, name)

        self.Bind(wx.EVT_PAINT, self.OnPaint)
        self.Bind(wx.EVT_SIZE, self.OnSize)
        self.Bind(wx.EVT_ERASE_BACKGROUND, self.OnEraseBackground)

        if not haveCairo or not wx.GraphicsRenderer.GetCairoRenderer():
            print "Cairo unavailable!"

    def OnPaint(self, event):
        dc = wx.BufferedPaintDC(self)
        self.Draw(dc)

    def Draw(self, dc):
        width, height = self.GetClientSize()
        if not width or not height:
            return

        imgW = width
        imgH = height
        brga = numpy.ndarray(shape=(imgH, imgW, 4), dtype=numpy.uint8)
        brga[:, :, 0].fill(180)  # blue
        brga[:, :, 1].fill(180)  # green
        brga[:, :, 2].fill(180)  # red
        rgba = numpy.ndarray(shape=(imgH, imgW, 4), dtype=numpy.uint8)
        data24 = numpy.ndarray(shape=(imgH, imgW, 3), dtype=numpy.uint8)
        stride = imgW * 4

        surface = cairo.ImageSurface.create_for_data(brga,
                                                     cairo.FORMAT_ARGB32,
                                                     imgW,
                                                     imgH,
                                                     stride)
        ctx = cairo.Context(surface)
        rsvg.set_default_dpi(900)
        svg = rsvg.Handle('tiger.svg')
        svg.render_cairo(ctx)

        rgba[:, :, 0] = brga[:, :, 2]
        rgba[:, :, 1] = brga[:, :, 1]
        rgba[:, :, 2] = brga[:, :, 0]
        rgba[:, :, 3] = brga[:, :, 3]

        data24[:, :, 0] = brga[:, :, 2]
        data24[:, :, 1] = brga[:, :, 1]
        data24[:, :, 2] = brga[:, :, 0]

        #img = wx.ImageFromData(imgW, imgH, data24)
        #bmp = wx.BitmapFromImage(img)
        bmp = wx.BitmapFromBufferRGBA(imgW, imgH, rgba)  # wxPython 2.8

        wx.StaticBitmap(self, bitmap=bmp, size=wx.Size(width, height))

    def OnSize(self, event):
        self.Refresh(False)

    def OnEraseBackground(self, event):
        pass

    def DoGetBestSize(self):
        """
        Overridden base class virtual.  Determines the best size of the control
        based on the label size, the bitmap size and the current font.
        """
        best = wx.Size(400, 400)
        self.CacheBestSize(best)
        return best

if __name__ == '__main__':
        app = wx.App()
        frame = ComponentFrame(None, wx.ID_ANY, 'test rsvg', (200, 200), (800, 800))
        app.MainLoop()

test_directly_to_dc.py

import wx
import rsvg
import numpy

try:
    import wx.lib.wxcairo
    import cairo
    haveCairo = True
except ImportError:
    haveCairo = False

class ComponentFrame(wx.Frame):
    def __init__(self, parent, id, title, pos, size):
        wx.Frame.__init__(self, parent, id, title, pos, size)

        self.panel = wx.Panel(self)
        vbox = wx.BoxSizer(wx.HORIZONTAL)
        component = SvgComponent(self.panel)
        vbox.Add(component, 1, wx.EXPAND | wx.ALL, 10)
        self.panel.SetSizer(vbox)

        self.Show(True)

class SvgComponent(wx.PyControl):
    def __init__(self, parent, label="",
                 id=wx.ID_ANY,
                 pos=wx.DefaultPosition,
                 size=wx.DefaultSize, style=wx.NO_BORDER, validator=wx.DefaultValidator,
                 name="CustomMeter"):

        wx.PyControl.__init__(self, parent, id, pos, size, style, validator, name)

        self.Bind(wx.EVT_PAINT, self.OnPaint)
        self.Bind(wx.EVT_SIZE, self.OnSize)
        self.Bind(wx.EVT_ERASE_BACKGROUND, self.OnEraseBackground)

        if not haveCairo or not wx.GraphicsRenderer.GetCairoRenderer():
            print "Cairo unavailable!"

    def OnPaint(self, event):
        dc = wx.BufferedPaintDC(self)
        self.Draw(dc)

    def Draw(self, dc):
        width, height = self.GetClientSize()
        if not width or not height:
            return

        ctx = wx.lib.wxcairo.ContextFromDC(dc)

        with open('demo.svg', 'r') as content_file:
            xml_data = content_file.read()

        svg = rsvg.Handle(data=xml_data)
        svg.render_cairo(ctx)

    def OnSize(self, event):
        self.Refresh(True)

    def OnEraseBackground(self, event):
        pass

    def DoGetBestSize(self):
        """
        Overridden base class virtual.  Determines the best size of the control
        based on the label size, the bitmap size and the current font.
        """
        best = wx.Size(400, 400)
        self.CacheBestSize(best)
        return best

if __name__ == '__main__':
        app = wx.App()
        frame = ComponentFrame(None, wx.ID_ANY, 'test rsvg', (200, 200), (400, 400))
        app.MainLoop()