Scatter – multitouching to drag, rotate, and scale

In the previous chapter you learned how to use events to drag widgets. You learned how to use the on_touch_up, on_touch_move and on_touch_down events. However, the Scatter class already provides that functionality and also lets us scale and rotate using two fingers. All the functionality is included inside the Scatter class, however, we need to apply a few changes to keep our project consistent. In particular, we still want our group mode to work, so that translating, scaling, and rotating can be happening at the same time. Let us implement the changes in four big steps in the comicwidgets.py file:

1. Substitute in the DraggableWidget base class. Let's use Scatter instead of RelativeLayout (line 122 and 125):

   121. # File name: comicwidgets.py
   122. from kivy.uix.scatter import Scatter
   123. from kivy.graphics import Line
   124. 
   125. class DraggableWidget(Scatter):

   Note

   Both, Scatter and RelativeLayout use relative coordinates.

2. Make sure that the on_touch_down...