python - 困惑搞乱动画

Question

Clutter 没有完成完整的动画。

这是我当前的代码:

from gi.repository import Clutter, Gtk
import sys

def onClick(actor, event):
    actor.animatev(Clutter.AnimationMode.LINEAR, 1000, ["x"], [280])  # clutter does not seem to be running this line
    actor.animatev(Clutter.AnimationMode.LINEAR, 1000, ["x"], [20])

def main():
    Clutter.init(sys.argv)

    # Colors
    red = Clutter.Color().new(255, 0, 0, 255)
    black = Clutter.Color().new(0, 0, 0, 255)

    # Create Stage
    stage = Clutter.Stage()
    stage.set_title("Basic Usage")
    stage.set_size(400, 200)
    stage.set_color(black)

    # Rectangle Actor
    actor = Clutter.Rectangle()
    actor.set_size(100, 50)
    actor.set_position(150, 100)
    actor.set_color(red)
    actor.set_reactive(True)
    actor.connect("button-press-event", onClick)

    # Add Actor to the Stage
    stage.add_actor(actor)
    stage.connect("destroy", lambda w:  Clutter.main_quit())
    stage.show_all()

    Clutter.main()

if __name__ == '__main__':
    main()

看看我的问题的这个例子:

对于那些不喜欢 gif 的人，这是我用文字描述的问题:我想让 Actor 从中间向右移动，然后一直向左移动。相反，它只是从中间直接向左移动。

是什么原因造成的，我该如何解决？

Answer 1

就像 ClutterActor.animate() 的文档说的那样:

Calling this function on an actor that is already being animated will cause the current animation to change with the new final values, the new easing mode and the new duration https://developer.gnome.org/clutter/stable/clutter-Implicit-Animations.html#clutter-actor-animate

这意味着下面的代码:

actor.animatev(Clutter.AnimationMode.LINEAR, 1000, ["x"], [280])
actor.animatev(Clutter.AnimationMode.LINEAR, 1000, ["x"], [20])

完全等同于:

actor.animatev(Clutter.AnimationMode.LINEAR, 1000, ["x"], [20])

这就是您所看到的。

如果你想链接两个动画，你必须连接到 ClutterAnimation 的 completed 信号，使用 connect_after 函数，这样杂乱可以创建一个新的动画:

def moveLeft (animation, actor):
    actor.animatev(Clutter.AnimationMode.LINEAR, 1000, ["x"], [20])

actor.animatev(Clutter.AnimationMode.LINEAR, 1000, ["x"], [280]).connect_after('completed', moveLeft)

我想指出 animatev() 和 ClutterAnimation 已弃用；它们可以通过使用显式 Clutter.KeyframeTransition 或隐式转换来替换，例如:

from gi.repository import Clutter

Clutter.init(None)

stage = Clutter.Stage()
stage.connect('destroy', lambda x: Clutter.main_quit())

actor = Clutter.Actor()
actor.set_background_color(Clutter.Color.get_static(Clutter.StaticColor.RED))
actor.set_reactive(True)
actor.set_size(32, 32)
stage.add_child(actor)
actor.set_position(82, 82)

def moveLeft(actor):
    actor.set_x(20)

def moveRight(actor):

    actor.set_easing_duration(1000)
    actor.set_easing_mode(Clutter.AnimationMode.LINEAR)
    actor.set_x(280)
    actor.connect('transition-stopped::x', lambda a, n, t: moveLeft(actor))

actor.connect('button-press-event', lambda a, e: moveRight(actor))

stage.show()
Clutter.main()

它可以比这更复杂；您还需要记住断开 transition-stopped::x 信号处理程序，并恢复缓动状态以避免每次更改 actor 的状态时都创建隐式动画，但我将其保留为给读者练习。