JUCE Animator Wrapper

animation.cpp

#pragma once
#include "juce_animation/juce_animation.h"

class Animation
{
public:
    explicit Animation (juce::Component& c) : component (c) {}
    float currentPosition = 0;
    bool isAnimating = false;

    void springTo (const float nextPosition, const int durationMs)
    {
        if (isAnimating)
            return; // debounce

        animator = defaultAnimator (nextPosition, durationMs)
                       .withEasing (juce::Easings::createSpring (juce::SpringEasingOptions().withFrequency (1).withAttenuation (6.0).withExtraAttenuationRange (.85)))
                       .build();

        updater.addAnimator (animator);
        animator.start();
    }

    void easeTo (const float nextPosition, const int durationMs)
    {
        animator = defaultAnimator (nextPosition, durationMs).withEasing (juce::Easings::createEaseOut()).build();
        updater.addAnimator (animator);
        animator.start();
    }

private:
    float lastPosition = 0;
    juce::Component& component;
    juce::VBlankAnimatorUpdater updater { &component };
    juce::Animator animator = juce::ValueAnimatorBuilder {}.build();

    juce::ValueAnimatorBuilder defaultAnimator (float nextPosition, int durationMs)
    {
        return juce::ValueAnimatorBuilder {}
            .withDurationMs (durationMs)
            .withValueChangedCallback ([this, nextPosition] (auto value) {
                isAnimating = true;
                currentPosition = juce::makeAnimationLimits (lastPosition, nextPosition).lerp (value);
                component.repaint();
            })
            .withOnCompleteCallback ([this]() {
                isAnimating = false;
                lastPosition = currentPosition;
            });
    }
};

example.h

class ExampleComponent : public juce::Component
{
public:
    void mouseDown (const juce::MouseEvent& e) override
    {
        animation.springTo (e.x, 250);
    }

    void paint (juce::Graphics& g) override
    {
        g.drawRoundedRectangle (animation.currentPosition, 0.f, 50.f, 50.f, 2, 2);
    }

private:
    Animation animation { *this };
};