FloatingActionBarMenu

package com.getbase.floatingactionbutton;

import android.animation.AnimatorSet;
import android.animation.ObjectAnimator;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.drawable.Drawable;
import android.graphics.drawable.LayerDrawable;
import android.os.Parcel;
import android.os.Parcelable;
import android.support.annotation.ColorRes;
import android.support.annotation.NonNull;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.DecelerateInterpolator;
import android.view.animation.Interpolator;
import android.view.animation.OvershootInterpolator;

public class FloatingActionsMenu extends ViewGroup {
    private static final int ANIMATION_DURATION = 300;
    private static final float COLLAPSED_PLUS_ROTATION = 0f;
    private static final float EXPANDED_PLUS_ROTATION = 90f + 45f;

    private int mAddButtonPlusColor;
    private int mAddButtonColorNormal;
    private int mAddButtonColorPressed;

    private int mButtonSpacing;

    private boolean mExpanded;

    private AnimatorSet mExpandAnimation = new AnimatorSet().setDuration(ANIMATION_DURATION);
    private AnimatorSet mCollapseAnimation = new AnimatorSet().setDuration(ANIMATION_DURATION);
    private AddFloatingActionButton mAddButton;
    private RotatingDrawable mRotatingDrawable;

    public FloatingActionsMenu(Context context) {
        this(context, null);
    }

    public FloatingActionsMenu(Context context, AttributeSet attrs) {
        super(context, attrs);
        init(context, attrs);
    }

    public FloatingActionsMenu(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        init(context, attrs);
    }

    private void init(Context context, AttributeSet attributeSet) {
        mAddButtonPlusColor = getColor(android.R.color.white);
        mAddButtonColorNormal = getColor(android.R.color.holo_blue_dark);
        mAddButtonColorPressed = getColor(android.R.color.holo_blue_light);

        mButtonSpacing = (int) (getResources().getDimension(R.dimen.fab_actions_spacing) - getResources().getDimension(R.dimen.fab_shadow_radius) - getResources().getDimension(R.dimen.fab_shadow_offset));

        if (attributeSet != null) {
            TypedArray attr = context.obtainStyledAttributes(attributeSet, R.styleable.FloatingActionsMenu, 0, 0);
            if (attr != null) {
                try {
                    mAddButtonPlusColor = attr.getColor(R.styleable.FloatingActionsMenu_addButtonPlusIconColor, getColor(android.R.color.white));
                    mAddButtonColorNormal = attr.getColor(R.styleable.FloatingActionsMenu_addButtonColorNormal, getColor(android.R.color.holo_blue_dark));
                    mAddButtonColorPressed = attr.getColor(R.styleable.FloatingActionsMenu_addButtonColorPressed, getColor(android.R.color.holo_blue_light));
                } finally {
                    attr.recycle();
                }
            }
        }

        createAddButton(context);
    }

    private static class RotatingDrawable extends LayerDrawable {
        public RotatingDrawable(Drawable drawable) {
            super(new Drawable[]{drawable});
        }

        private float mRotation;

        @SuppressWarnings("UnusedDeclaration")
        public float getRotation() {
            return mRotation;
        }

        @SuppressWarnings("UnusedDeclaration")
        public void setRotation(float rotation) {
            mRotation = rotation;
            invalidateSelf();
        }

        @Override
        public void draw(Canvas canvas) {
            canvas.save();
            canvas.rotate(mRotation, getBounds().centerX(), getBounds().centerY());
            super.draw(canvas);
            canvas.restore();
        }
    }

    private void createAddButton(Context context) {
        mAddButton = new AddFloatingActionButton(context) {
            @Override
            void updateBackground() {
                mPlusColor = mAddButtonPlusColor;
                mColorNormal = mAddButtonColorNormal;
                mColorPressed = mAddButtonColorPressed;
                super.updateBackground();
            }

            @Override
            Drawable getIconDrawable() {
                final RotatingDrawable rotatingDrawable = new RotatingDrawable(super.getIconDrawable());
                mRotatingDrawable = rotatingDrawable;

                final OvershootInterpolator interpolator = new OvershootInterpolator();

                final ObjectAnimator collapseAnimator = ObjectAnimator.ofFloat(rotatingDrawable, "rotation", EXPANDED_PLUS_ROTATION, COLLAPSED_PLUS_ROTATION);
                final ObjectAnimator expandAnimator = ObjectAnimator.ofFloat(rotatingDrawable, "rotation", COLLAPSED_PLUS_ROTATION, EXPANDED_PLUS_ROTATION);

                collapseAnimator.setInterpolator(interpolator);
                expandAnimator.setInterpolator(interpolator);

                mExpandAnimation.play(expandAnimator);
                mCollapseAnimation.play(collapseAnimator);

                return rotatingDrawable;
            }
        };

        mAddButton.setId(R.id.fab_expand_menu_button);
        mAddButton.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                toggle();
            }
        });

        addView(mAddButton, super.generateDefaultLayoutParams());
    }

    private int getColor(@ColorRes int id) {
        return getResources().getColor(id);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        measureChildren(widthMeasureSpec, heightMeasureSpec);

        int width = 0;
        int height = 0;

        for (int i = 0; i < getChildCount(); i++) {
            View child = getChildAt(i);

            width = Math.max(width, child.getMeasuredWidth());
            height += child.getMeasuredHeight();
        }

        height += mButtonSpacing * (getChildCount() - 1);
        height = height * 12 / 10; // for overshoot

        setMeasuredDimension(width, height);
    }

    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        mAddButton.layout(0, 0, mAddButton.getMeasuredWidth(), mAddButton.getMeasuredHeight());

        int bottomY = mButtonSpacing;

        for (int i = getChildCount() - 1; i >= 0; i--) {
            final View child = getChildAt(i);

            if (child == mAddButton) continue;

            int childY = bottomY + child.getMeasuredHeight();
            child.layout(0, 0, child.getMeasuredWidth(), child.getMeasuredHeight());

            float collapsedTranslation = 0f;
            float expandedTranslation = childY;

            child.setTranslationY(mExpanded ? expandedTranslation : collapsedTranslation);
            child.setAlpha(mExpanded ? 1f : 0f);

            LayoutParams params = (LayoutParams) child.getLayoutParams();
            params.mCollapseY.setFloatValues(expandedTranslation, collapsedTranslation);
            params.mExpandY.setFloatValues(collapsedTranslation, expandedTranslation);
            params.setAnimationsTarget(child);

            bottomY = childY + mButtonSpacing;
        }
    }

    @Override
    protected ViewGroup.LayoutParams generateDefaultLayoutParams() {
        return new LayoutParams(super.generateDefaultLayoutParams());
    }

    @Override
    public ViewGroup.LayoutParams generateLayoutParams(AttributeSet attrs) {
        return new LayoutParams(super.generateLayoutParams(attrs));
    }

    @Override
    protected ViewGroup.LayoutParams generateLayoutParams(ViewGroup.LayoutParams p) {
        return new LayoutParams(super.generateLayoutParams(p));
    }

    @Override
    protected boolean checkLayoutParams(ViewGroup.LayoutParams p) {
        return super.checkLayoutParams(p);
    }

    private static Interpolator sExpandInterpolator = new OvershootInterpolator();
    private static Interpolator sCollapseInterpolator = new DecelerateInterpolator(3f);
    private static Interpolator sAlphaExpandInterpolator = new DecelerateInterpolator();

    private class LayoutParams extends ViewGroup.LayoutParams {

        private ObjectAnimator mExpandY = new ObjectAnimator();
        private ObjectAnimator mExpandAlpha = new ObjectAnimator();
        private ObjectAnimator mCollapseY = new ObjectAnimator();
        private ObjectAnimator mCollapseAlpha = new ObjectAnimator();

        public LayoutParams(ViewGroup.LayoutParams source) {
            super(source);

            mExpandY.setInterpolator(sExpandInterpolator);
            mExpandAlpha.setInterpolator(sAlphaExpandInterpolator);
            mCollapseY.setInterpolator(sCollapseInterpolator);
            mCollapseAlpha.setInterpolator(sCollapseInterpolator);

            mCollapseAlpha.setProperty(View.ALPHA);
            mCollapseAlpha.setFloatValues(1f, 0f);

            mExpandAlpha.setProperty(View.ALPHA);
            mExpandAlpha.setFloatValues(0f, 1f);

            mCollapseY.setProperty(View.TRANSLATION_Y);
            mExpandY.setProperty(View.TRANSLATION_Y);

            mExpandAnimation.play(mExpandAlpha);
            mExpandAnimation.play(mExpandY);

            mCollapseAnimation.play(mCollapseAlpha);
            mCollapseAnimation.play(mCollapseY);
        }

        public void setAnimationsTarget(View view) {
            mCollapseAlpha.setTarget(view);
            mCollapseY.setTarget(view);
            mExpandAlpha.setTarget(view);
            mExpandY.setTarget(view);
        }
    }

    @Override
    protected void onFinishInflate() {
        super.onFinishInflate();
        bringChildToFront(mAddButton);
    }

    public void collapse() {
        if (mExpanded) {
            mExpanded = false;
            mCollapseAnimation.start();
            mExpandAnimation.cancel();
        }
    }

    public void toggle() {
        if (mExpanded) {
            collapse();
        } else {
            expand();
        }
    }

    public void expand() {
        if (!mExpanded) {
            mExpanded = true;
            mCollapseAnimation.cancel();
            mExpandAnimation.start();
        }
    }

    @Override
    public Parcelable onSaveInstanceState() {
        Parcelable superState = super.onSaveInstanceState();
        SavedState savedState = new SavedState(superState);
        savedState.mExpanded = mExpanded;

        return savedState;
    }

    @Override
    public void onRestoreInstanceState(Parcelable state) {
        if (state instanceof SavedState) {
            SavedState savedState = (SavedState) state;
            mExpanded = savedState.mExpanded;

            if (mRotatingDrawable != null) {
                mRotatingDrawable.setRotation(mExpanded ? EXPANDED_PLUS_ROTATION : COLLAPSED_PLUS_ROTATION);
            }

            super.onRestoreInstanceState(savedState.getSuperState());
        } else {
            super.onRestoreInstanceState(state);
        }
    }

    public static class SavedState extends BaseSavedState {
        public boolean mExpanded;

        public SavedState(Parcelable parcel) {
            super(parcel);
        }

        private SavedState(Parcel in) {
            super(in);
            mExpanded = in.readInt() == 1;
        }

        @Override
        public void writeToParcel(@NonNull Parcel out, int flags) {
            super.writeToParcel(out, flags);
            out.writeInt(mExpanded ? 1 : 0);
        }

        public static final Creator<SavedState> CREATOR = new Creator<SavedState>() {

            @Override
            public SavedState createFromParcel(Parcel in) {
                return new SavedState(in);
            }

            @Override
            public SavedState[] newArray(int size) {
                return new SavedState[size];
            }
        };
    }
}