sugar3.graphics.animator module

The animator module provides a simple framwork to create animations.

Example

Animate the size of a window:

from gi.repository import Gtk
from sugar3.graphics.animator import Animator, Animation

# Construct a 5 second animator
animator = Animator(5)

# Construct a window to animate
w = Gtk.Window()
w.connect('destroy', Gtk.main_quit)
# Start the animation when the window is shown
w.connect('realize', lambda self: animator.start())
w.show()

# Create an animation subclass to animate the widget
class SizeAnimation(Animation):
    def __init__(self):
        # Tell the animation to give us values between 20 and
        # 420 during the animation
        Animation.__init__(self, 20, 420)

    def next_frame(self, frame):
        size = int(frame)
        w.resize(size, size)
# Add the animation the the animator
animation = SizeAnimation()
animator.add(animation)

# The animation needs to run inside a GObject main loop
Gtk.main()

STABLE.

class sugar3.graphics.animator.Animation(start, end)

Bases: object

The animation class is a base class for creating an animation. It should be subclassed. Subclasses should specify a next_frame function to set the required properties based on the animation progress. The range of the frame value passed to the next_frame function is defined by the start and end values.

Parameters:

• start (float) – the first frame value for the next_frame method
• end (float) – the last frame value for the next_frame method

# Create an animation subclass
class MyAnimation(Animation):
    def __init__(self, thing):
        # Tell the animation to give us values between 0.0 and
        # 1.0 during the animation
        Animation.__init__(self, 0.0, 1.0)
        self._thing = thing

    def next_frame(self, frame):
        # Use the `frame` value to set properties
        self._thing.set_green_value(frame)

do_frame(t, duration, easing)

This method is called by the animtor class every frame. This method calculated the frame value to then call next_frame.

Parameters:

• t (float) – the current time elapsed of the animation in seconds
• duration (float) – the length of the animation in seconds
• easing (int) – the easing mode passed to the animator

next_frame(frame)

This method is called every frame and should be overriden by subclasses.

Parameters:frame (float) – a value between start and end representing the current progress in the animation

class sugar3.graphics.animator.Animator(duration, fps=20, easing=0)

Bases: gi.overrides.GObject.Object

The animator class manages the the timing for calling the animations. The animations can be added using the add function and then started with the start function. If multiple animations are added, then they will be played back at the same time and rate as each other.

The completed signal is emitted upon the completion of the animation and also when the stop function is called.

Parameters:

• duration (float) – the duration of the animation in seconds
• fps (int, optional) – the number of animation callbacks to make per second (frames per second)
• easing (int) – the desired easing mode, either EASE_OUT_EXPO or EASE_IN_EXPO

Note

When creating an animation, take into account the limited cpu power on some devices, such as the XO. Setting the fps too high on can use signifigant cpu usage on the XO.

add(animation)

Add an animation to this animator

Parameters:animation (sugar3.graphics.animator.Animation) – the animation instance to add

remove_all()

Remove all animations and stop this animator

start()

Start the animation running. This will stop and restart the animation if the animation is currently running

stop()

Stop the animation and emit the completed signal