--- /dev/null
+/*
+ * 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 com.android.dexgen.rop.code;
+
+import com.android.dexgen.rop.cst.CstUtf8;
+
+/**
+ * A local variable item: either a name or a signature or both.
+ */
+public class LocalItem implements Comparable<LocalItem> {
+ /** {@code null-ok;} local variable name */
+ private final CstUtf8 name;
+
+ /** {@code null-ok;} local variable signature */
+ private final CstUtf8 signature;
+
+ /**
+ * Make a new item. If both name and signature are null, null is returned.
+ *
+ * TODO: intern these
+ *
+ * @param name {@code null-ok;} local variable name
+ * @param signature {@code null-ok;} local variable signature
+ * @return {@code non-null;} appropriate instance.
+ */
+ public static LocalItem make(CstUtf8 name, CstUtf8 signature) {
+ if (name == null && signature == null) {
+ return null;
+ }
+
+ return new LocalItem (name, signature);
+ }
+
+ /**
+ * Constructs instance.
+ *
+ * @param name {@code null-ok;} local variable name
+ * @param signature {@code null-ok;} local variable signature
+ */
+ private LocalItem(CstUtf8 name, CstUtf8 signature) {
+ this.name = name;
+ this.signature = signature;
+ }
+
+ /** {@inheritDoc} */
+ @Override
+ public boolean equals(Object other) {
+ if (!(other instanceof LocalItem)) {
+ return false;
+ }
+
+ LocalItem local = (LocalItem) other;
+
+ return 0 == compareTo(local);
+ }
+
+ /**
+ * Compares two strings like String.compareTo(), excepts treats a null
+ * as the least-possible string value.
+ *
+ * @return negative integer, zero, or positive integer in accordance
+ * with Comparable.compareTo()
+ */
+ private static int compareHandlesNulls(CstUtf8 a, CstUtf8 b) {
+ if (a == b) {
+ return 0;
+ } else if (a == null) {
+ return -1;
+ } else if (b == null) {
+ return 1;
+ } else {
+ return a.compareTo(b);
+ }
+ }
+
+ /** {@inheritDoc} */
+ public int compareTo(LocalItem local) {
+ int ret;
+
+ ret = compareHandlesNulls(name, local.name);
+
+ if (ret != 0) {
+ return ret;
+ }
+
+ ret = compareHandlesNulls(signature, local.signature);
+
+ return ret;
+ }
+
+
+ /** {@inheritDoc} */
+ @Override
+ public int hashCode() {
+ return (name == null ? 0 : name.hashCode()) * 31
+ + (signature == null ? 0 : signature.hashCode());
+ }
+
+ /** {@inheritDoc} */
+ @Override
+ public String toString() {
+ if (name != null && signature == null) {
+ return name.toQuoted();
+ } else if (name == null && signature == null) {
+ return "";
+ }
+
+ return "[" + (name == null ? "" : name.toQuoted())
+ + "|" + (signature == null ? "" : signature.toQuoted());
+ }
+
+ /**
+ * Gets name.
+ *
+ * @return {@code null-ok;} name
+ */
+ public CstUtf8 getName() {
+ return name;
+ }
+
+ /**
+ * Gets signature.
+ *
+ * @return {@code null-ok;} signature
+ */
+ public CstUtf8 getSignature() {
+ return signature;
+ }
+}