Add parts of zxing library to generate qr codes

OpenPGP-Keychain/src/com/google/zxing/qrcode/detector/AlignmentPattern.java

@@ -0,0 +1,48 @@
+/*
+ * Copyright 2007 ZXing authors
+ *
+ * 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.google.zxing.qrcode.detector;
+
+import com.google.zxing.ResultPoint;
+
+/**
+ * <p>Encapsulates an alignment pattern, which are the smaller square patterns found in
+ * all but the simplest QR Codes.</p>
+ *
+ * @author Sean Owen
+ */
+public final class AlignmentPattern extends ResultPoint {
+
+  private final float estimatedModuleSize;
+
+  AlignmentPattern(float posX, float posY, float estimatedModuleSize) {
+    super(posX, posY);
+    this.estimatedModuleSize = estimatedModuleSize;
+  }
+
+  /**
+   * <p>Determines if this alignment pattern "about equals" an alignment pattern at the stated
+   * position and size -- meaning, it is at nearly the same center with nearly the same size.</p>
+   */
+  boolean aboutEquals(float moduleSize, float i, float j) {
+    if (Math.abs(i - getY()) <= moduleSize && Math.abs(j - getX()) <= moduleSize) {
+      float moduleSizeDiff = Math.abs(moduleSize - estimatedModuleSize);
+      return moduleSizeDiff <= 1.0f || moduleSizeDiff / estimatedModuleSize <= 1.0f;
+    }
+    return false;
+  }
+
+}