PointFAnimator.java

/*
 * Copyright (C) 2015 Andrey Kulikov (andkulikov@gmail.com)
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.transitionseverywhere.utils;

import android.annotation.TargetApi;
import android.graphics.PointF;
import android.os.Build;

/**
 * Created by Andrey Kulikov on 17.08.15.
 */
@TargetApi(Build.VERSION_CODES.ICE_CREAM_SANDWICH)
public class PointFAnimator extends BasePointFAnimator {

    private float mStartTop, mStartLeft, mEndTop, mEndLeft;

    protected PointFAnimator(Object target, PointFProperty pointFProperty) {
        super(target, pointFProperty);
    }

    public static <T> PointFAnimator ofPointF(T target, PointFProperty<T> property, float startLeft,
                                              float startTop, float endLeft, float endTop) {
        PointFAnimator animator = null;
        if (target != null && property != null) {
            animator = new PointFAnimator(target, property);
            animator.mStartLeft = startLeft;
            animator.mStartTop = startTop;
            animator.mEndLeft = endLeft;
            animator.mEndTop = endTop;
        }
        return animator;
    }

    protected void applyAnimatedFraction(PointF holder, float fraction) {
        holder.x = interpolate(fraction, mStartLeft, mEndLeft);
        holder.y = interpolate(fraction, mStartTop, mEndTop);
    }

    protected static float interpolate(float fraction, float startValue, float endValue) {
        float diff = endValue - startValue;
        return startValue + (diff * fraction);
    }

}