Problems with Interrupts/ callback functions in Python for an Alarm Clock project

[Henry1]

I recently started programming with Python and now I want to build an appliance with the raspberry pi which is basically an alarm clock. I have a pi, a small OLED display and a rotary encoder which can be turned left/ right or pushed.
Here's the library for the rotary encoder: https://github.com/joan2937/pigpio/blob/...encoder.py
Since there was no support for pushing the rotary encoder, I added the following code to the library:

def _push(self, gpio, level, tick):
    if not self.pushed:
        self.callback("push")
        self.pushed = 1  # debounce 

which works fine.
But when it comes to building my actual appliance and integrating all the things (rotary encoder, oled display, ...) somehow I screw up. Every method in my code should handle one "page" of my appliance, e.g. the methods would be home_menu, alarm_menu, settings_menu, ... I have the following problem: I can't get the navigation through the menus right. After a push from the rotary encoder is detected, I want to display the content of the specific menu element at which the push was detected
Here's an excerpt from my code:

def main_menu_callback(self, cursor, lines = ('Weckzeit: --:--', 'Einstellungen', '01.01.1970')):
        y = 0
        # draw text elements of the main menu
        for line in lines:
            self.draw.text((0,y), line, font = self.sans15, fill=255)
            y += self.textsize_addition(line)[1] + 10
        self.draw.line([0, 43, 128, 43], fill=255)

        # check if rotary encoder was pushed. If so, go to the
        # selected menu point. If it wasn't pushed but turned,
        # display the cursor on the right position.

        if isinstance(cursor, str):

            if self.pos == 0:
                # push detected. move on to the content of the first menu item, which is handled through another method (????)
            else:
                # push detected. move on to the content of the second menu item, which is handled through another method (????)

        elif cursor == -1:
            # rotary encoder was turned left
            self.pos = 0
            self.draw.polygon([(120, 9), (128, 1), (128, 17)], outline=255, fill=255)
            self.draw.polygon([(120, 33), (128, 25), (128, 41)], outline=0, fill=0)
        else:
            # rotary encoder was turned right
            self.pos = 1
            self.draw.polygon([(120, 33), (128, 25), (128, 41)], outline=255, fill=255)
            self.draw.polygon([(120, 9), (128, 1), (128, 17)], outline=0, fill=0)
        self.disp.image(self.image)
        self.disp.display()

To run the code, I called the decoder method of the rotary encoder library and added the above written method (main_menu_callback) to the call, so that main_menu_callback can be used for the callback and get's executed every time the rotary encoder is turned or pushed:

decoder = rotary_encoder.decoder(pi, rotary_CLK, rotary_DT, rotary_SWITCH, main_menu_callback)
print("Test")

One of my many open questions is: How can I make my program to wait until the decoder was canceled (with

decoder.cancel()

)?

Currently it does not wait and the

print("Test")

get's executed right at the start of the program.