Implement BQP Android UI using QR codes

briar-android/src/org/briarproject/android/util/QrCodeUtils.java

@@ -0,0 +1,51 @@
+package org.briarproject.android.util;
+
+import android.app.Activity;
+import android.graphics.Bitmap;
+import android.graphics.Color;
+import android.util.DisplayMetrics;
+
+import com.google.zxing.BarcodeFormat;
+import com.google.zxing.WriterException;
+import com.google.zxing.common.BitMatrix;
+import com.google.zxing.qrcode.QRCodeWriter;
+
+import java.util.logging.Logger;
+
+import static java.util.logging.Level.WARNING;
+
+public class QrCodeUtils {
+
+	private static final Logger LOG =
+			Logger.getLogger(QrCodeUtils.class.getName());
+
+	public static Bitmap createQrCode(Activity activity, String input) {
+		// Get narrowest screen dimension
+		DisplayMetrics dm = new DisplayMetrics();
+		activity.getWindowManager().getDefaultDisplay().getMetrics(dm);
+		int smallestDimen = Math.min(dm.widthPixels, dm.heightPixels);
+		try {
+			// Generate QR code
+			final BitMatrix encoded = new QRCodeWriter().encode(
+					input, BarcodeFormat.QR_CODE, smallestDimen, smallestDimen);
+			// Convert QR code to Bitmap
+			int width = encoded.getWidth();
+			int height = encoded.getHeight();
+			int[] pixels = new int[width * height];
+			for (int x = 0; x < width; x++) {
+				for (int y = 0; y < height; y++) {
+					pixels[y * width + x] =
+							encoded.get(x, y) ? Color.BLACK : Color.WHITE;
+				}
+			}
+			Bitmap qr = Bitmap.createBitmap(width, height,
+					Bitmap.Config.ARGB_8888);
+			qr.setPixels(pixels, 0, width, 0, 0, width, height);
+			return qr;
+		} catch (WriterException e) {
+			if (LOG.isLoggable(WARNING))
+				LOG.log(WARNING, e.toString(), e);
+			return null;
+		}
+	}
+}