from ursina import *

class Scrollable():

    def __init__(self, **kwargs):
        super().__init__()
        self.max = inf
        self.min = -inf
        self.scroll_speed = .05
        self.scroll_smoothing = 16
        self.axis = 'y'
        self.target_value = None

        for key, value in kwargs.items():
            setattr(self, key, value)



    def update(self):
        # lerp position
        if self.target_value:
            setattr(self.entity, self.axis, lerp(getattr(self.entity, self.axis), self.target_value, time.dt * self.scroll_smoothing))



    def input(self, key):
        if not mouse.hovered_entity:
            return

        if not self.target_value:
            self.target_value = getattr(self.entity, self.axis)

        if self.entity.hovered or mouse.hovered_entity.has_ancestor(self.entity):
            # print(key)
            if key == 'scroll up':
                self.target_value -= self.scroll_speed
            if key == 'scroll down':
                self.target_value += self.scroll_speed


            self.target_value = max(min(self.target_value, self.max), self.min)


if __name__ == '__main__':
    '''
    This will make target entity move up or down when you hover the entity/its children
    while scrolling the scroll wheel.
    '''

    app = Ursina()
    p = Button(model='quad', scale=(.4, .8), collider='box')
    for i in range(8):
        Button(parent=p , scale_y=.05, text=f'giopwjoigjwr{i}', origin_y=.5, y=.5-(i*.05))

    p.add_script(Scrollable())
    app.run()