title: How do I get size of the screen excluding Unity side panel in GDK
body: <p>I'm trying to make Guake terminal work correctly in Unity. Its window have width that is equal to screen width. But because of Unity left bar window's right border becomes invisible. So, I want to set proper width for window. It must be smaller than actual window size. And the code must work correctly with or without Unity.</p>
  
  <p>This is how Guake determines position and size of its window:</p>
  
  <pre><code>def get_final_window_rect(self):
  
      """Gets the final size of the main window of guake. The height
      is the window_height property, width is window_width and the
      horizontal alignment is given by window_alignment.
      """
      screen = self.window.get_screen()
      height = self.client.get_int(KEY('/general/window_height'))
      width = 100
      halignment = self.client.get_int(KEY('/general/window_halignment'))
  
      # get the rectangle just from the first/default monitor in the
      # future we might create a field to select which monitor you
      # wanna use
      window_rect = screen.get_monitor_geometry(0)
      total_width = window_rect.width
      window_rect.height = window_rect.height * height / 100
      window_rect.width = window_rect.width * width / 100
  
      if width &lt; total_width:
          if halignment == ALIGN_CENTER:
              window_rect.x = (total_width - window_rect.width) / 2
          elif halignment == ALIGN_LEFT:
              window_rect.x = 0
          elif halignment == ALIGN_RIGHT:
              window_rect.x = total_width - window_rect.width
      window_rect.y = 0
      window_rect.width = 250
      return window_rect
  </code></pre>