We earlier coded the matrix called create_right_button_matrix, which creates a two-dimensional matrix with the number of rows equal to MAX_NUMBER_OF_DRUM_SAMPLES. The number of columns would be decided by multiplying the number of units by the beats per unit values selected by the end user. Its formula can be given as follows:
Number of columns of buttons = Number of units x BPU
This means that every time the user changes the number of units or the beats per unit, the button matrix should be redrawn to change the number of columns. This change should also be reflected in our underlying data structure. Let's add this feature to our drum machine.
We had earlier defined two dummy methods—on_number_of_units_changed() and on_bpu_changed(). We modify them now as follows (see code 3.04.py):
def on_number_of_units_changed(self...
