ColorUtil.java

/*
 * Created by LuaView.
 * Copyright (c) 2017, Alibaba Group. All rights reserved.
 *
 * This source code is licensed under the MIT.
 * For the full copyright and license information,please view the LICENSE file in the root directory of this source tree.
 */

package com.taobao.luaview.util;

import android.graphics.Color;

import org.luaj.vm2.LuaValue;

/**
 * 颜色解析
 *
 * @author song
 * @date 15/10/27
 */
public class ColorUtil {
    private static final int MAX_COLOR_VALUE = 16777216;//16^6，6位的

    /**
     * parse a color value
     *
     * @param colorValue
     * @return
     */
    public static Integer parse(LuaValue colorValue) {
        return parse(colorValue, null);
    }

    public static Integer parse(LuaValue colorValue, Integer defaultValue) {
        if (LuaUtil.isNumber(colorValue)) {
            return parse(colorValue.toint(), defaultValue);
        }
        return defaultValue;//黑色
    }

    /**
     * parse a color value
     *
     * @param color
     * @return
     */
    public static Integer parse(Integer color) {
        return parse(color, null);
    }

    public static Integer parse(Integer color, Integer defaultColor) {
        if (color != null) {
            if (color < MAX_COLOR_VALUE) {
                return Color.argb(255, Color.red(color), Color.green(color), Color.blue(color));//去除alpha信息，alpha信息由函数传入
            } else {//8位的
                return Color.argb(Color.alpha(color), Color.red(color), Color.green(color), Color.blue(color));
            }
             /*if (LuaUtil.isString(colorValue)) {//TODO 支持字符串
                try {
                    return Color.parseColor(colorValue.toString());
                } catch (Exception e) {
                    e.printStackTrace();
                    return -1;
                }
            }*/
        }
        return defaultColor;
    }

    /**
     * convert a color to hex string
     *
     * @param color
     * @return
     */
    public static Integer getHexColor(Integer color) {
        if (color != null) {
            int red = Color.red(color);
            int green = Color.green(color);
            int blue = Color.blue(color);
            return (red / 16) * 1048576 + (red % 16) * 65536 + (green / 16) * 4096 + (green % 16) * 256 + (blue / 16) * 16 + (blue % 16);
        }
        return 0;
    }

    /**
     * get alpha of given color
     *
     * @param color
     * @return
     */
    public static double getAlpha(Integer color) {
        if (color != null) {
            int hexColor = getHexAlpha(color);
            return hexColor / 255.0f;
        } else {
            return 1.0f;
        }
    }

    /**
     * get alpha of given color
     *
     * @param color
     * @return
     */
    public static int getHexAlpha(Integer color) {
        if (color == null || color < MAX_COLOR_VALUE) {
            return 255;
        } else {
            return Color.alpha(color);
        }
    }
}