1 files changed, 120 insertions, 0 deletions
diff --git a/java/com/android/voicemailomtp/mail/store/imap/ImapElement.java b/java/com/android/voicemailomtp/mail/store/imap/ImapElement.java
new file mode 100644
index 000000000..9f272e31c
--- /dev/null
+++ b/java/com/android/voicemailomtp/mail/store/imap/ImapElement.java
@@ -0,0 +1,120 @@
+/*
+ * Copyright (C) 2015 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.voicemailomtp.mail.store.imap;
+
+/**
+ * Class representing "element"s in IMAP responses.
+ *
+ * <p>Class hierarchy:
+ * <pre>
+ * ImapElement
+ *   |
+ *   |-- ImapElement.NONE (for 'index out of range')
+ *   |
+ *   |-- ImapList (isList() == true)
+ *   |   |
+ *   |   |-- ImapList.EMPTY
+ *   |   |
+ *   |   --- ImapResponse
+ *   |
+ *   --- ImapString (isString() == true)
+ *       |
+ *       |-- ImapString.EMPTY
+ *       |
+ *       |-- ImapSimpleString
+ *       |
+ *       |-- ImapMemoryLiteral
+ *       |
+ *       --- ImapTempFileLiteral
+ * </pre>
+ */
+public abstract class ImapElement {
+    /**
+     * An element that is returned by {@link ImapList#getElementOrNone} to indicate an index
+     * is out of range.
+     */
+    public static final ImapElement NONE = new ImapElement() {
+        @Override public void destroy() {
+            // Don't call super.destroy().
+            // It's a shared object.  We don't want the mDestroyed to be set on this.
+        }
+
+        @Override public boolean isList() {
+            return false;
+        }
+
+        @Override public boolean isString() {
+            return false;
+        }
+
+        @Override public String toString() {
+            return "[NO ELEMENT]";
+        }
+
+        @Override
+        public boolean equalsForTest(ImapElement that) {
+            return super.equalsForTest(that);
+        }
+    };
+
+    private boolean mDestroyed = false;
+
+    public abstract boolean isList();
+
+    public abstract boolean isString();
+
+    protected boolean isDestroyed() {
+        return mDestroyed;
+    }
+
+    /**
+     * Clean up the resources used by the instance.
+     * It's for removing a temp file used by {@link ImapTempFileLiteral}.
+     */
+    public void destroy() {
+        mDestroyed = true;
+    }
+
+    /**
+     * Throws {@link RuntimeException} if it's already destroyed.
+     */
+    protected final void checkNotDestroyed() {
+        if (mDestroyed) {
+            throw new RuntimeException("Already destroyed");
+        }
+    }
+
+    /**
+     * Return a string that represents this object; it's purely for the debug purpose.  Don't
+     * mistake it for {@link ImapString#getString}.
+     *
+     * Abstract to force subclasses to implement it.
+     */
+    @Override
+    public abstract String toString();
+
+    /**
+     * The equals implementation that is intended to be used only for unit testing.
+     * (Because it may be heavy and has a special sense of "equal" for testing.)
+     */
+    public boolean equalsForTest(ImapElement that) {
+        if (that == null) {
+            return false;
+        }
+        return this.getClass() == that.getClass(); // Has to be the same class.
+    }
+}
+\ No newline at end of file