import android.graphics.Bitmap;
import android.graphics.Matrix;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.WriterException;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.qrcode.QRCodeWriter;

import java.util.Hashtable;

/**
 * Created by xiaolei on 2017/4/26.
 */

public class QRCodeUtil
{
    // 生成QR图
    public static Bitmap createImage(String text, int w, int h, Bitmap logo)
    {
        try
        {
            Bitmap scaleLogo = getScaleLogo(logo, w, h);
            int offsetX = (w - scaleLogo.getWidth()) / 2;
            int offsetY = (h - scaleLogo.getHeight()) / 2;
            Hashtable<EncodeHintType, Object> hints = new Hashtable<>();
            hints.put(EncodeHintType.CHARACTER_SET, "utf-8");
            hints.put(EncodeHintType.MARGIN, 0);
            BitMatrix bitMatrix = new QRCodeWriter().encode(text,
                    BarcodeFormat.QR_CODE, w, h, hints);
            int[] pixels = new int[w * h];
            for (int y = 0; y < h; y++)
            {
                for (int x = 0; x < w; x++)
                {
                    if (x >= offsetX && x < offsetX + scaleLogo.getWidth() && y >= offsetY && y < offsetY + scaleLogo.getHeight())
                    {
                        int pixel = scaleLogo.getPixel(x - offsetX, y - offsetY);
                        if (pixel == 0)
                        {
                            if (bitMatrix.get(x, y))
                            {
                                pixel = 0xff000000;
                            } else
                            {
                                pixel = 0xffffffff;
                            }
                        }
                        pixels[y * w + x] = pixel;
                    } else
                    {
                        if (bitMatrix.get(x, y))
                        {
                            pixels[y * w + x] = 0xff000000;
                        } else
                        {
                            pixels[y * w + x] = 0xffffffff;
                        }
                    }
                }
            }
            Bitmap bitmap = Bitmap.createBitmap(w, h,
                    Bitmap.Config.ARGB_8888);
            bitmap.setPixels(pixels, 0, w, 0, 0, w, h);
            return bitmap;
        } catch (WriterException e)
        {
            e.printStackTrace();
        }
        return null;
    }

    private static Bitmap getScaleLogo(Bitmap logo, int w, int h)
    {
        if (logo == null) return null;
        Matrix matrix = new Matrix();
        float scaleFactor = Math.min(w * 1.0f / 5 / logo.getWidth(), h * 1.0f / 5 / logo.getHeight());
        matrix.postScale(scaleFactor, scaleFactor);
        Bitmap result = Bitmap.createBitmap(logo, 0, 0, logo.getWidth(), logo.getHeight(), matrix, true);
        return result;
    }
}