3b1b-manim/manimlib/event_handler/event_dispatcher.py
2022-04-12 19:19:59 +08:00

95 lines
3.8 KiB
Python

from __future__ import annotations
import numpy as np
from manimlib.event_handler.event_listner import EventListner
from manimlib.event_handler.event_type import EventType
class EventDispatcher(object):
def __init__(self):
self.event_listners: dict[
EventType, list[EventListner]
] = {
event_type: []
for event_type in EventType
}
self.mouse_point = np.array((0., 0., 0.))
self.mouse_drag_point = np.array((0., 0., 0.))
self.pressed_keys: set[int] = set()
self.draggable_object_listners: list[EventListner] = []
def add_listner(self, event_listner: EventListner):
assert(isinstance(event_listner, EventListner))
self.event_listners[event_listner.event_type].append(event_listner)
return self
def remove_listner(self, event_listner: EventListner):
assert(isinstance(event_listner, EventListner))
try:
while event_listner in self.event_listners[event_listner.event_type]:
self.event_listners[event_listner.event_type].remove(event_listner)
except:
# raise ValueError("Handler is not handling this event, so cannot remove it.")
pass
return self
def dispatch(self, event_type: EventType, **event_data):
if event_type == EventType.MouseMotionEvent:
self.mouse_point = event_data["point"]
elif event_type == EventType.MouseDragEvent:
self.mouse_drag_point = event_data["point"]
elif event_type == EventType.KeyPressEvent:
self.pressed_keys.add(event_data["symbol"]) # Modifiers?
elif event_type == EventType.KeyReleaseEvent:
self.pressed_keys.difference_update({event_data["symbol"]}) # Modifiers?
elif event_type == EventType.MousePressEvent:
self.draggable_object_listners = [
listner
for listner in self.event_listners[EventType.MouseDragEvent]
if listner.mobject.is_point_touching(self.mouse_point)
]
elif event_type == EventType.MouseReleaseEvent:
self.draggable_object_listners = []
propagate_event = None
if event_type == EventType.MouseDragEvent:
for listner in self.draggable_object_listners:
assert(isinstance(listner, EventListner))
propagate_event = listner.callback(listner.mobject, event_data)
if propagate_event is not None and propagate_event is False:
return propagate_event
elif event_type.value.startswith('mouse'):
for listner in self.event_listners[event_type]:
if listner.mobject.is_point_touching(self.mouse_point):
propagate_event = listner.callback(
listner.mobject, event_data)
if propagate_event is not None and propagate_event is False:
return propagate_event
elif event_type.value.startswith('key'):
for listner in self.event_listners[event_type]:
propagate_event = listner.callback(listner.mobject, event_data)
if propagate_event is not None and propagate_event is False:
return propagate_event
return propagate_event
def get_listners_count(self) -> int:
return sum([len(value) for key, value in self.event_listners.items()])
def get_mouse_point(self) -> np.ndarray:
return self.mouse_point
def get_mouse_drag_point(self) -> np.ndarray:
return self.mouse_drag_point
def is_key_pressed(self, symbol: int) -> bool:
return (symbol in self.pressed_keys)
__iadd__ = add_listner
__isub__ = remove_listner
__call__ = dispatch
__len__ = get_listners_count