ObservableColorMatrix.java

/*
 * Copyright 2015 Google Inc.
 *
 * 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.github.takahirom.materialelement.animation;

import android.graphics.ColorMatrix;
import android.util.Property;

/**
 * An extension to {@link ColorMatrix} which caches the saturation value for animation purposes.
 */
public class ObservableColorMatrix extends ColorMatrix {

    private float saturation = 1f;

    public ObservableColorMatrix() {
        super();
    }

    public float getSaturation() {
        return saturation;
    }

    @Override
    public void setSaturation(float saturation) {
        this.saturation = saturation;
        super.setSaturation(saturation);
    }

    public static final Property<ObservableColorMatrix, Float> SATURATION
            = new FloatProperty<ObservableColorMatrix>("saturation") {

        @Override
        public void setValue(ObservableColorMatrix cm, float value) {
            cm.setSaturation(value);
        }

        @Override
        public Float get(ObservableColorMatrix cm) {
            return cm.getSaturation();
        }
    };


    /**
     * An implementation of {@link android.util.Property} to be used specifically with fields of
     * type
     * <code>float</code>. This type-specific subclass enables performance benefit by allowing
     * calls to a {@link #set(Object, Float) set()} function that takes the primitive
     * <code>float</code> type and avoids autoboxing and other overhead associated with the
     * <code>Float</code> class.
     *
     * @param <T> The class on which the Property is declared.
     **/
    public static abstract class FloatProperty<T> extends Property<T, Float> {
        public FloatProperty(String name) {
            super(Float.class, name);
        }

        /**
         * A type-specific override of the {@link #set(Object, Float)} that is faster when dealing
         * with fields of type <code>float</code>.
         */
        public abstract void setValue(T object, float value);

        @Override
        final public void set(T object, Float value) {
            setValue(object, value);
        }
    }
}