def wheelEvent(self, evt: QtGui.QWheelEvent) -> None:
self.__mouse_pos = evt.pos()
measure_editor = self.track.measureEditorAt(evt.pos())
if isinstance(measure_editor, MeasureEditor):
measure_evt = QtGui.QWheelEvent(
evt.pos() - measure_editor.topLeft(), evt.globalPos(),
evt.pixelDelta(), evt.angleDelta(), 0, Qt.Horizontal,
evt.buttons(), evt.modifiers(), evt.phase(), evt.source())
measure_evt.setAccepted(False)
self.wheelMeasureEvent(measure_editor, measure_evt)
evt.setAccepted(measure_evt.isAccepted())
class ScrollArea(QScrollArea):
""" 一个可以平滑滚动的区域 """
def __init__(self, parent=None):
super().__init__(parent)
self.fps = 60
self.duration = 400
self.stepsTotal = 0
self.stepRatio = 1.5
self.acceleration = 1
self.lastWheelEvent = None
self.scrollStamps = deque()
self.stepsLeftQueue = deque()
self.smoothMoveTimer = QTimer(self)
self.smoothMode = SmoothMode(SmoothMode.COSINE)
self.smoothMoveTimer.timeout.connect(self.smoothMove)
def setSMoothMode(self, smoothMode):
""" 设置滚动模式 """
self.smoothMode = smoothMode
def wheelEvent(self, e: QWheelEvent):
""" 实现平滑滚动效果 """
if self.smoothMode == SmoothMode.NO_SMOOTH:
super().wheelEvent(e)
return
# 将当前时间点插入队尾
now = QDateTime.currentDateTime().toMSecsSinceEpoch()
self.scrollStamps.append(now)
while now - self.scrollStamps[0] > 500:
self.scrollStamps.popleft()
# 根据未处理完的事件调整移动速率增益
accerationRatio = min(len(self.scrollStamps) / 15, 1)
if not self.lastWheelEvent:
self.lastWheelEvent = QWheelEvent(e)
else:
self.lastWheelEvent = e
# 计算步数
self.stepsTotal = self.fps * self.duration / 1000
# 计算每一个事件对应的移动距离
delta = e.angleDelta().y() * self.stepRatio
if self.acceleration > 0:
delta += delta * self.acceleration * accerationRatio
# 将移动距离和步数组成列表，插入队列等待处理
self.stepsLeftQueue.append([delta, self.stepsTotal])
# 定时器的溢出时间t=1000ms/帧数
self.smoothMoveTimer.start(1000 / self.fps)
def smoothMove(self):
""" 计时器溢出时进行平滑滚动 """
totalDelta = 0
# 计算所有未处理完事件的滚动距离，定时器每溢出一次就将步数-1
for i in self.stepsLeftQueue:
totalDelta += self.subDelta(i[0], i[1])
i[1] -= 1
# 如果事件已处理完，就将其移出队列
while self.stepsLeftQueue and self.stepsLeftQueue[0][1] == 0:
self.stepsLeftQueue.popleft()
# 构造滚轮事件
e = QWheelEvent(self.lastWheelEvent.pos(),
self.lastWheelEvent.globalPos(),
self.lastWheelEvent.pos(),
self.lastWheelEvent.globalPos(),
round(totalDelta),
Qt.Vertical,
self.lastWheelEvent.buttons(),
Qt.NoModifier)
# 将构造出来的滚轮事件发送给app处理
QApplication.sendEvent(self.verticalScrollBar(), e)
# 如果队列已空，停止滚动
if not self.stepsLeftQueue:
self.smoothMoveTimer.stop()
def subDelta(self, delta, stepsLeft):
""" 计算每一步的插值 """
m = self.stepsTotal / 2
x = abs(self.stepsTotal - stepsLeft - m)
# 根据滚动模式计算插值
res = 0
if self.smoothMode == SmoothMode.NO_SMOOTH:
res = 0
elif self.smoothMode == SmoothMode.CONSTANT:
res = delta / self.stepsTotal
elif self.smoothMode == SmoothMode.LINEAR:
res = 2 * delta / self.stepsTotal * (m - x) / m
elif self.smoothMode == SmoothMode.QUADRATI:
res = 3 / 4 / m * (1 - x * x / m / m) * delta
elif self.smoothMode == SmoothMode.COSINE:
res = (cos(x * pi / m) + 1) / (2 * m) * delta
return res
def wheelEvent(self, evt: QtGui.QWheelEvent) -> None:
evt = QtGui.QWheelEvent(evt.pos() + self.offset(), evt.globalPos(),
evt.pixelDelta(), evt.angleDelta(), 0,
Qt.Horizontal, evt.buttons(), evt.modifiers(),
evt.phase(), evt.source())
self.__toolbox.wheelEvent(evt)
def on_wheel(self, event: QWheelEvent):
self.invoke_event(CustomEvent.MouseWheelEvent,
global_pos=event.globalPos(),
num_steps=self.get_wheel_rotated_steps(event))
