1 files changed, 94 insertions, 0 deletions
diff --git a/src/com/android/messaging/datamodel/binding/Binding.java b/src/com/android/messaging/datamodel/binding/Binding.java
new file mode 100644
index 0000000..3ec01dd
--- /dev/null
+++ b/src/com/android/messaging/datamodel/binding/Binding.java
@@ -0,0 +1,94 @@
+/*
+ * 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.messaging.datamodel.binding;
+
+import java.util.concurrent.atomic.AtomicLong;
+
+public class Binding<T extends BindableData> extends BindingBase<T> {
+    private static AtomicLong sBindingIdx = new AtomicLong(System.currentTimeMillis() * 1000);
+
+    private String mBindingId;
+    private T mData;
+    private final Object mOwner;
+    private boolean mWasBound;
+
+    /**
+     * Initialize a binding instance - the owner is typically the containing class
+     */
+    Binding(final Object owner) {
+        mOwner = owner;
+    }
+
+    @Override
+    public T getData() {
+        ensureBound();
+        return mData;
+    }
+
+    @Override
+    public boolean isBound() {
+        return (mData != null && mData.isBound(mBindingId));
+    }
+
+    @Override
+    public boolean isBound(final T data) {
+        return (isBound() && data == mData);
+    }
+
+    @Override
+    public void ensureBound() {
+        if (!isBound()) {
+            throw new IllegalStateException("not bound; wasBound = " + mWasBound);
+        }
+    }
+
+    @Override
+    public void ensureBound(final T data) {
+        if (!isBound()) {
+            throw new IllegalStateException("not bound; wasBound = " + mWasBound);
+        } else if (data != mData) {
+            throw new IllegalStateException("not bound to correct data " + data + " vs " + mData);
+        }
+    }
+
+    @Override
+    public String getBindingId() {
+        return mBindingId;
+    }
+
+    public void bind(final T data) {
+        // Check both this binding and the data not already bound
+        if (mData != null || data.isBound()) {
+            throw new IllegalStateException("already bound when binding to " + data);
+        }
+        // Generate a unique identifier for this bind call
+        mBindingId = Long.toHexString(sBindingIdx.getAndIncrement());
+        data.bind(mBindingId);
+        mData = data;
+        mWasBound = true;
+    }
+
+    public void unbind() {
+        // Check this binding is bound and that data is bound to this binding
+        if (mData == null || !mData.isBound(mBindingId)) {
+            throw new IllegalStateException("not bound when unbind");
+        }
+        mData.unbind(mBindingId);
+        mData = null;
+        mBindingId = null;
+    }
+}