Window.softinput_mode/TextInput - Window moves up/down when switching softinput_mode to 'below_target'/'resize'

[ghost]

When the Window's softinput_mode is set to 'below_target' or 'resize', the Window size and position is not correct after requesting keyboard with textinput/restartting the app after first launch.

Example app code:

https://gist.github.com/rafalo1333/5484ebdba49203074114

App UI on initial launch:

App UI when keyboard was requested (look at the bar under the TextInput widget:

App UI after hiding keyboard/resetting the app (look at the bar under the TextInput):

With the Window.softinput_mode set to 'resize', things are going even uglier.

It could be related to #483 PR.

It should be fixed as right now Kivy TextInputs are unusable on Android.

[inclement]

According to the other issues linked, this should be fixed in master.