/*
 * Copyright 2016-2020 MicroEJ Corp. All rights reserved.
 * This library is provided in source code for use, modification and test, subject to license terms.
 * Any modification of the source code will break MicroEJ Corp. warranties on the whole library.
 */
package ej.mwt.style.background;

import ej.annotation.Nullable;
import ej.microui.display.GraphicsContext;

/**
 * Represents the background of the widgets.
 */
public interface Background {

    /**
     * Tells whether or not this background is transparent.
     * <p>
     * A background is considered as transparent if it does not draw every pixel with maximal opacity when it is
     * applied. If a widget has a transparent background, its parent has to be rendered before the widget.
     *
     * @param width
     *            the width of the background.
     * @param height
     *            the height of the background.
     * @return <code>true</code> if the background is transparent, <code>false</code> otherwise.
     */
    boolean isTransparent(int width, int height);

    /**
     * Applies the background on a graphics context.
     *
     * @param g
     *            the graphics context.
     * @param width
     *            the width of the background.
     * @param height
     *            the height of the background.
     */
    void apply(GraphicsContext g, int width, int height);

    @Override
    boolean equals(@Nullable Object obj);

    @Override
    int hashCode();
}