old_contents: #!/usr/bin/env python
  
  # To run this example, you need to set the GI_TYPELIB_PATH environment
  # variable to point to the gir directory:
  #
  # export GI_TYPELIB_PATH=$GI_TYPELIB_PATH:/usr/local/lib/girepository-1.0/
  
  from gi.repository import GtkClutter
  from gi.repository import GObject, Gtk, Gdk, GtkChamplain 
  
  class KeyboardMapping:
  
      def __init__(self):
          GtkClutter.init([])
  
          window = Gtk.Window(type=Gtk.WindowType.TOPLEVEL)
          window.connect("destroy", Gtk.main_quit)
          window.connect("key-press-event", self.on_key_press)
  
          self.widget = GtkChamplain.Embed()
          self.widget.set_size_request(640, 480)
          self.view = self.widget.get_view()
  
          window.add(self.widget)
          window.show_all()
  
      def on_key_press(self, widget, ev):
          delta = self.widget.get_allocation().width / 4
          if ev.keyval == Gdk.KEY_Left: 
              self.scroll(-delta, 0)
          elif ev.keyval == Gdk.KEY_Right: 
              self.scroll(delta, 0)
          elif ev.keyval == Gdk.KEY_Up: 
              self.scroll(0, -delta)
          elif ev.keyval == Gdk.KEY_Down: 
              self.scroll(0, delta)
          elif ev.keyval == Gdk.KEY_plus or ev.keyval == Gdk.KEY_KP_Add:
              self.view.zoom_in()
          elif ev.keyval == Gdk.KEY_minus or ev.keyval == Gdk.KEY_KP_Subtract: 
              self.view.zoom_out()
          else:
              return False
          return True
  
      def scroll(self, deltax, deltay):
          lat = self.view.get_center_latitude()
          lon = self.view.get_center_longitude()
          
          x = self.view.longitude_to_x(lon) + deltax
          y = self.view.latitude_to_y(lat) + deltay
          
          lon = self.view.x_to_longitude(x)
          lat = self.view.y_to_latitude(y)
        
          self.view.center_on(lat, lon)
          #self.view.go_to(lat, lon)
  
  if __name__ == "__main__":
      KeyboardMapping()
      Gtk.main()
  
new_contents: #!/usr/bin/env python
  
  # To run this example, you need to set the GI_TYPELIB_PATH environment
  # variable to point to the gir directory:
  #
  # export GI_TYPELIB_PATH=$GI_TYPELIB_PATH:/usr/local/lib/girepository-1.0/
  
  from gi.repository import GtkClutter
  from gi.repository import GObject, Gtk, Gdk, GtkChamplain 
  
  class KeyboardMapping:
  
      def __init__(self):
          GtkClutter.init([])
  
          window = Gtk.Window(type=Gtk.WindowType.TOPLEVEL)
          window.connect("destroy", Gtk.main_quit)
          window.connect("key-press-event", self.on_key_press)
  
          self.widget = GtkChamplain.Embed()
          self.widget.set_size_request(640, 480)
          self.view = self.widget.get_view()
  
          window.add(self.widget)
          window.show_all()
  
      def on_key_press(self, widget, ev):
          deltax = self.widget.get_allocation().width / 4
          deltay = self.widget.get_allocation().height / 4
          if ev.keyval == Gdk.KEY_Left: 
              self.scroll(-deltax, 0)
          elif ev.keyval == Gdk.KEY_Right: 
              self.scroll(deltax, 0)
          elif ev.keyval == Gdk.KEY_Up: 
              self.scroll(0, -deltay)
          elif ev.keyval == Gdk.KEY_Down: 
              self.scroll(0, deltay)
          elif ev.keyval == Gdk.KEY_plus or ev.keyval == Gdk.KEY_KP_Add:
              self.view.zoom_in()
          elif ev.keyval == Gdk.KEY_minus or ev.keyval == Gdk.KEY_KP_Subtract: 
              self.view.zoom_out()
          else:
              return False
          return True
  
      def scroll(self, deltax, deltay):
          lat = self.view.get_center_latitude()
          lon = self.view.get_center_longitude()
          
          x = self.view.longitude_to_x(lon) + deltax
          y = self.view.latitude_to_y(lat) + deltay
          
          lon = self.view.x_to_longitude(x)
          lat = self.view.y_to_latitude(y)
        
          self.view.center_on(lat, lon)
          #self.view.go_to(lat, lon)
  
  if __name__ == "__main__":
      KeyboardMapping()
      Gtk.main()
  
subject: Use view height for computing y delta in the keyboard mapping demo