Initial checkin of AOSP Messaging app.

b/23110861

Change-Id: I11db999bd10656801e618f78ab2b2ef74136fff1

src/android/support/v7/mms/pdu/QuotedPrintable.java

@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) 2007 Esmertec AG.
+ * Copyright (C) 2007 The Android Open Source Project
+ *
+ * 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 android.support.v7.mms.pdu;
+
+import java.io.ByteArrayOutputStream;
+
+public class QuotedPrintable {
+    private static byte ESCAPE_CHAR = '=';
+
+    /**
+     * Decodes an array quoted-printable characters into an array of original bytes.
+     * Escaped characters are converted back to their original representation.
+     *
+     * <p>
+     * This function implements a subset of
+     * quoted-printable encoding specification (rule #1 and rule #2)
+     * as defined in RFC 1521.
+     * </p>
+     *
+     * @param bytes array of quoted-printable characters
+     * @return array of original bytes,
+     *         null if quoted-printable decoding is unsuccessful.
+     */
+    public static final byte[] decodeQuotedPrintable(byte[] bytes) {
+        if (bytes == null) {
+            return null;
+        }
+        ByteArrayOutputStream buffer = new ByteArrayOutputStream();
+        for (int i = 0; i < bytes.length; i++) {
+            int b = bytes[i];
+            if (b == ESCAPE_CHAR) {
+                try {
+                    if('\r' == (char)bytes[i + 1] &&
+                            '\n' == (char)bytes[i + 2]) {
+                        i += 2;
+                        continue;
+                    }
+                    int u = Character.digit((char) bytes[++i], 16);
+                    int l = Character.digit((char) bytes[++i], 16);
+                    if (u == -1 || l == -1) {
+                        return null;
+                    }
+                    buffer.write((char) ((u << 4) + l));
+                } catch (ArrayIndexOutOfBoundsException e) {
+                    return null;
+                }
+            } else {
+                buffer.write(b);
+            }
+        }
+        return buffer.toByteArray();
+    }
+}