from PyQt4.QtCore import *
from PyQt4.QtGui import *
from qgis.core import *
from qgis.gui import *
import sys
import os
# Import our GUI
from shapeviewer_gui import Ui_MainWindow

# Environment variable QGISHOME must be set to the install directory
# before running the application
qgis_prefix = "/usr"


class ShapeViewer(QMainWindow, Ui_MainWindow):

  def __init__(self):
    QMainWindow.__init__(self)

    # Required by Qt4 to initialize the UI
    self.setupUi(self)

    # Set the title for the app
    self.setWindowTitle("ShapeViewer")

    # Create the map canvas
    self.canvas = QgsMapCanvas()
    self.canvas.useImageToRender(False)
    self.canvas.show()

    # Lay our widgets out in the main window using a 
    # vertical box layout
    self.layout = QVBoxLayout(self.frame)
    self.layout.addWidget(self.canvas)



    layer = QgsVectorLayer("greece.shp", "greece", "ogr")

    if not layer.isValid():
        print 'not valid layer'
        return
        
    # Add layer to the registry
    QgsMapLayerRegistry.instance().addMapLayer(layer);
    
    if layer.isUsingRendererV2():
        rendererV2 = layer.rendererV2()
        symbols = layer.rendererV2().symbols()
        symbol = symbols[0]
        symbol.setColor(QColor.fromRgb(192,192,192))
        symbol.setAlpha(0.7)
    else:
        renderer = layer.renderer()
        
    if not hasattr(layer, 'isUsingRendererV2'):
        print "You have an old version of QGIS"
    
    
    
    # Set extent to the extent of our layer
    self.canvas.setExtent(layer.extent())

    
    # Set up the map canvas layer set

    cl=QgsMapCanvasLayer(layer)
    self.layers = []
    self.layers.insert( 0, QgsMapCanvasLayer(cl) )
    self.canvas.setLayerSet( self.layers )
        
    self.canvas.setCanvasColor(QColor(213,235,255))

       
    

def main(argv):
  # create Qt application
  app = QApplication(argv)

  # Initialize qgis libraries
  QgsApplication.setPrefixPath(qgis_prefix, True)
  QgsApplication.initQgis()

  # create main window
  wnd = ShapeViewer()
  # Move the app window to upper left
  wnd.move(100,100)
  wnd.show()

  # run!
  retval = app.exec_()
  
  # exit
  QgsApplication.exitQgis()
  sys.exit(retval)


if __name__ == "__main__":
  main(sys.argv)