composable ViewPropertyAnimator

package com.hackthenorth.android.util;

import android.animation.Animator;
import android.animation.TimeInterpolator;
import android.animation.ValueAnimator;
import android.annotation.SuppressLint;
import android.view.View;

/**
 * "Because, honestly, why isn't android.animation.ViewPropertyAnimator an Animator in
 * the first place?"
 *
 * Benefits of ViewPropertyAnimator being an Animator:
 * - they're easily composed with android.animation.AnimatorSet
 * - they're easily composed with android.animation.AnimatorSet
 * - they're easily composed with android.animation.AnimatorSet
 * - they're easily composed with android.animation.AnimatorSet
 * - they're easily composed with android.animation.AnimatorSet
 *
 * You can use this class the same way as android.animation.ViewPropertyAnimator, except for a
 * few things:
 *
 * 1. Rather than view.animate().foo(x).bar(y), you must construct the animator by doing new
 * ViewPropertyAnimator(view).foo(x).bar(y).
 *
 * 2. The start() method is mandatory, rather than optional.
 *
 * 3. The setDuration, setStartDelay, and setInterpolator abstract Animator methods have
 * equivalent methods setVPADuration, setVPAStartDelay, and setVPAInterpolator methods which
 * return a reference to the ViewPropertyAnimator for chained method calls.
 */
public class ViewPropertyAnimator extends Animator {
    private static final String TAG = "ViewPropertyAnimator";

    /**
     * This is the target view for the ViewPropertyAnimation. Note that the actual
     * android.animation.ViewPropertyAnimation isn't created until the start() method is called.
     */
    View mView;

    // state constants
    final long ALPHA_SET = 1;
    final long ALPHA_BY_SET = 1 << 1;
    final long ROTATION_SET = 1 << 2;
    final long ROTATION_BY_SET = 1 << 3;
    final long ROTATION_X_SET = 1 << 4;
    final long ROTATION_X_BY_SET = 1 << 5;
    final long ROTATION_Y_SET = 1 << 6;
    final long ROTATION_Y_BY_SET = 1 << 7;
    final long SCALE_X_SET = 1 << 8;
    final long SCALE_X_BY_SET = 1 << 9;
    final long SCALE_Y_SET = 1 << 10;
    final long SCALE_Y_BY_SET = 1 << 11;
    final long DURATION_SET = 1 << 12;
    final long INTERPOLATOR_SET = 1 << 13;
    final long LISTENER_SET = 1 << 14;
    final long START_DELAY_SET = 1 << 15;
    final long UPDATE_LISTENER_SET = 1 << 16;
    final long TRANSLATION_X_SET = 1 << 17;
    final long TRANSLATION_X_BY_SET = 1 << 18;
    final long TRANSLATION_Y_SET = 1 << 19;
    final long TRANSLATION_Y_BY_SET = 1 << 20;
    final long END_ACTION_SET = 1 << 21;
    final long WITH_LAYER_CALLED = 1 << 22;
    final long START_ACTION_SET = 1 << 23;
    final long X_SET = 1 << 24;
    final long X_BY_SET = 1 << 25;
    final long Y_SET = 1 << 26;
    final long Y_BY_SET = 1 << 27;

    long mState = 0;

    // Mirror all the settings that you can pass to android.animation.ViewPropertyAnimator.
    float mAlpha;
    float mAlphaBy;
    float mRotation;
    float mRotationBy;
    float mRotationX;
    float mRotationXBy;
    float mRotationY;
    float mRotationYBy;
    float mScaleX;
    float mScaleXBy;
    float mScaleY;
    float mScaleYBy;
    long mDuration;
    TimeInterpolator mInterpolator;
    AnimatorListener mListener;
    long mStartDelay;
    ValueAnimator.AnimatorUpdateListener mUpdateListener;
    float mTranslationX;
    float mTranslationXBy;
    float mTranslationY;
    float mTranslationYBy;
    Runnable mEndAction;
    Runnable mStartAction;
    float mX;
    float mXBy;
    float mY;
    float mYBy;

    public ViewPropertyAnimator(View view) {
        mView = view;
    }

    // Animator methods

    @Override
    public long getStartDelay() {
        return mStartDelay;
    }

    @Override
    public void setStartDelay(long startDelay) {
        mState |= START_DELAY_SET;
        mStartDelay = startDelay;
    }

    @Override
    public Animator setDuration(long duration) {
        mState |= DURATION_SET;
        mDuration = duration;
        return this;
    }

    @Override
    public long getDuration() {
        return mDuration;
    }

    @Override
    public void setInterpolator(TimeInterpolator value) {
        mState |= INTERPOLATOR_SET;
        mInterpolator = value;
    }

    /**
     * Unsupported
     * @return false
     */
    @Deprecated
    @Override
    public boolean isRunning() { return false; }

    @SuppressLint("NewApi")
    @Override
    public void start() {
        android.view.ViewPropertyAnimator anim = mView.animate();
        if ((mState & ALPHA_SET) != 0) anim.alpha(mAlpha);
        if ((mState & ALPHA_BY_SET) != 0) anim.alphaBy(mAlphaBy);
        if ((mState & ROTATION_SET) != 0) anim.rotation(mRotation);
        if ((mState & ROTATION_BY_SET) != 0) anim.rotationBy(mRotationBy);
        if ((mState & ROTATION_X_SET) != 0) anim.rotationX(mRotationX);
        if ((mState & ROTATION_X_BY_SET) != 0) anim.rotationXBy(mRotationXBy);
        if ((mState & ROTATION_Y_SET) != 0) anim.rotationY(mRotationY);
        if ((mState & ROTATION_Y_BY_SET) != 0) anim.rotationYBy(mRotationYBy);
        if ((mState & SCALE_X_SET) != 0) anim.scaleX(mScaleX);
        if ((mState & SCALE_X_BY_SET) != 0) anim.scaleXBy(mScaleXBy);
        if ((mState & SCALE_Y_SET) != 0) anim.scaleY(mScaleY);
        if ((mState & SCALE_Y_BY_SET) != 0) anim.scaleYBy(mScaleYBy);
        if ((mState & DURATION_SET) != 0) anim.setDuration(mDuration);
        if ((mState & INTERPOLATOR_SET) != 0) anim.setInterpolator(mInterpolator);
        if ((mState & LISTENER_SET) != 0) anim.setListener(mListener);
        if ((mState & START_DELAY_SET) != 0) anim.setStartDelay(mStartDelay);
        if ((mState & UPDATE_LISTENER_SET) != 0) anim.setUpdateListener(mUpdateListener);
        if ((mState & TRANSLATION_X_SET) != 0) anim.translationX(mTranslationX);
        if ((mState & TRANSLATION_X_BY_SET) != 0) anim.translationXBy(mTranslationXBy);
        if ((mState & TRANSLATION_Y_SET) != 0) anim.translationY(mTranslationY);
        if ((mState & TRANSLATION_Y_BY_SET) != 0) anim.translationYBy(mTranslationYBy);
        if ((mState & END_ACTION_SET) != 0) anim.withEndAction(mEndAction);
        if ((mState & WITH_LAYER_CALLED) != 0) anim.withLayer();
        if ((mState & START_ACTION_SET) != 0) anim.withStartAction(mStartAction);
        if ((mState & X_SET) != 0) anim.x(mX);
        if ((mState & X_BY_SET) != 0) anim.xBy(mXBy);
        if ((mState & Y_SET) != 0) anim.y(mY);
        if ((mState & Y_BY_SET) != 0) anim.yBy(mYBy);
        anim.start();
    }

    // ViewPropertyAnimator cloned methods
    public ViewPropertyAnimator alpha(float value) {
        mState |= ALPHA_SET;
        mAlpha = value;
        return this;
    }
    public ViewPropertyAnimator alphaBy(float value) {
        mState |= ALPHA_BY_SET;
        mAlphaBy = value;
        return this;
    }
    public ViewPropertyAnimator rotation(float value) {
        mState |= ROTATION_SET;
        mRotation = value;
        return this;
    }
    public ViewPropertyAnimator rotationBy(float value) {
        mState |= ROTATION_BY_SET;
        mRotation = value;
        return this;
    }
    public ViewPropertyAnimator rotationX(float value) {
        mState |= ROTATION_X_SET;
        mRotationX = value;
        return this;
    }
    public ViewPropertyAnimator rotationXBy(float value) {
        mState |= ROTATION_X_BY_SET;
        mRotationXBy = value;
        return this;
    }
    public ViewPropertyAnimator rotationY(float value) {
        mState |= ROTATION_Y_SET;
        mRotationY = value;
        return this;
    }
    public ViewPropertyAnimator rotationYBy(float value) {
        mState |= ROTATION_Y_BY_SET;
        mRotationYBy = value;
        return this;
    }
    public ViewPropertyAnimator scaleX(float value) {
        mState |= SCALE_X_SET;
        mScaleX = value;
        return this;
    }
    public ViewPropertyAnimator scaleXBy(float value) {
        mState |= SCALE_X_BY_SET;
        mScaleXBy = value;
        return this;
    }
    public ViewPropertyAnimator scaleY(float value) {
        mState |= SCALE_Y_SET;
        mScaleY = value;
        return this;
    }
    public ViewPropertyAnimator scaleYBy(float value) {
        mState |= SCALE_Y_BY_SET;
        mScaleYBy = value;
        return this;
    }

    // these methods can't be mirrored exactly, as they conflict with the abstract methods from
    // Animator that we have to implement. so an appropriate substitute method name is given.
    public ViewPropertyAnimator setVPADuration(long duration) {
        mState |= DURATION_SET;
        mDuration = duration;
        return this;
    }
    public ViewPropertyAnimator setVPAInterpolator(TimeInterpolator interpolator) {
        mState |= INTERPOLATOR_SET;
        mInterpolator = interpolator;
        return this;
    }

    public ViewPropertyAnimator setListener(AnimatorListener listener) {
        mState |= LISTENER_SET;
        mListener = listener;
        return this;
    }

    // same as with setVPADuration
    public ViewPropertyAnimator setVPAStartDelay(long startDelay) {
        mState |= START_DELAY_SET;
        mStartDelay = startDelay;
        return this;
    }

    public ViewPropertyAnimator setUpdateListener(ValueAnimator.AnimatorUpdateListener listener) {
        mState |= UPDATE_LISTENER_SET;
        mUpdateListener = listener;
        return this;
    }
    public ViewPropertyAnimator translationX(float value) {
        mState |= TRANSLATION_X_SET;
        mTranslationX = value;
        return this;
    }
    public ViewPropertyAnimator translationXBy(float value) {
        mState |= TRANSLATION_X_BY_SET;
        mTranslationXBy = value;
        return this;
    }
    public ViewPropertyAnimator translationY(float value) {
        mState |= TRANSLATION_Y_SET;
        mTranslationY = value;
        return this;
    }
    public ViewPropertyAnimator translationYBy(float value) {
        mState |= TRANSLATION_Y_BY_SET;
        mTranslationYBy = value;
        return this;
    }
    public ViewPropertyAnimator withEndAction(Runnable runnable) {
        mState |= END_ACTION_SET;
        mEndAction = runnable;
        return this;
    }
    public ViewPropertyAnimator withStartAction(Runnable runnable) {
        mState |= START_ACTION_SET;
        mStartAction = runnable;
        return this;
    }
    public ViewPropertyAnimator x(float value) {
        mState |= X_SET;
        mX = value;
        return this;
    }
    public ViewPropertyAnimator xBy(float value) {
        mState |= X_BY_SET;
        mXBy = value;
        return this;
    }
    public ViewPropertyAnimator y(float value) {
        mState |= Y_SET;
        mY = value;
        return this;
    }
    public ViewPropertyAnimator yBy(float value) {
        mState |= Y_BY_SET;
        mYBy = value;
        return this;
    }
}