from PyQt4 import QtGui, QtCore, QtSvg

import sys
from xml import FileToTree, TreeToFile, NS_MAP

from PIL import Image

class SVG2PNG_View(QtGui.QGraphicsView):
    """
        Uses a graphics view to render an svg image.
    """
    def __init__(self, svgfile, pngfile, manipulate=None):
        ''' read a svg file and store it in rasterized form as a png image
        @param manipulate: callable that can manipulate the xml tree
        @type manipulate: callable
        '''
        QtGui.QGraphicsView.__init__(self)
        
        if manipulate is not None:
            tree = FileToTree(svgfile)
            manipulate(tree)
            TreeToFile(tree, svgfile + '.svg')
            item = QtSvg.QGraphicsSvgItem(svgfile + '.svg')
        else:
            item = QtSvg.QGraphicsSvgItem(svgfile)
        
        self.scene = QtGui.QGraphicsScene(self)
        item.setPos(QtCore.QPointF(0, 0))
        self.scene.addItem(item)

        self.setScene(self.scene)
        
        self.saveImage(pngfile)
        
        #~ img = Image.open(pngfile)
        #~ img = img.resize((int(img.size[0] * 0.5), int(img.size[1] * 0.5)))
        #~ img.save(pngfile)
        
    def saveImage(self, pngfile):
        """create a QImage and render graphics scene to it.
        """
        isize = self.scene.sceneRect().size().toSize()
        self.qimage = QtGui.QImage(isize, QtGui.QImage.Format_ARGB32)
        painter = QtGui.QPainter(self.qimage)
        self.scene.render(painter)    
        self.qimage.save(pngfile)

def svg2png(svgfile, pngfile, manipulate=None):
    SVG2PNG_View(svgfile, pngfile, manipulate=manipulate)
    
def stripLayers(layername):
    def _inner(tree):
        for e in tree.xpath('//svg:g[not(@id="layer3")]', namespaces=NS_MAP):
            e.getparent().remove(e)
    return _inner
    p = tree.xpath('//svg:g/svg:path', namespaces=NS_MAP)[0]
    p.attrib['style'] = 'fill:#FFFFFF;'

if __name__ == '__main__':
    app = QtGui.QApplication(sys.argv)
    svg2png('umic.svg', 'out.png', manipulate=stripLayers('asd'))