Initial checkin of the Java OfflineContentProvider

components/offline_items_collection/core/android/java/src/org/chromium/components/offline_items_collection/OfflineContentAggregatorBridge.java

Index: components/offline_items_collection/core/android/java/src/org/chromium/components/offline_items_collection/OfflineContentAggregatorBridge.java
diff --git a/components/offline_items_collection/core/android/java/src/org/chromium/components/offline_items_collection/OfflineContentAggregatorBridge.java b/components/offline_items_collection/core/android/java/src/org/chromium/components/offline_items_collection/OfflineContentAggregatorBridge.java
new file mode 100644
index 0000000000000000000000000000000000000000..f14368f8158cde1e83e3283a11069bce6132581d
--- /dev/null
+++ b/components/offline_items_collection/core/android/java/src/org/chromium/components/offline_items_collection/OfflineContentAggregatorBridge.java
@@ -0,0 +1,166 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.components.offline_items_collection;
+
+import org.chromium.base.ObserverList;
+import org.chromium.base.annotations.CalledByNative;
+import org.chromium.base.annotations.JNINamespace;
+
+import java.util.ArrayList;
+
+/**
+ * A helper class responsible for exposing the C++ OfflineContentAggregator
+ * (components/offline_items_collection/core/offline_content_aggregator.h) class to Java.  This
+ * class is created and owned by it's C++ counterpart OfflineContentAggregatorBridge
+ * (components/offline_items_collection/core/android/offline_content_aggregator_bridge.h).
+ */
+@JNINamespace("offline_items_collection::android")
+public class OfflineContentAggregatorBridge implements OfflineContentProvider {
+    private long mNativeOfflineContentAggregatorBridge;
+    private ObserverList<OfflineContentProvider.Observer> mObservers;
+    private boolean mItemsAvailable;
+
+    /**
+     * A private constructor meant to be called by the C++ OfflineContentAggregatorBridge.
+     * @param nativeOfflineContentAggregatorBridge A C++ pointer to the
+     * OfflineContentAggregatorBridge.
+     */
+    private OfflineContentAggregatorBridge(long nativeOfflineContentAggregatorBridge) {
+        mNativeOfflineContentAggregatorBridge = nativeOfflineContentAggregatorBridge;
+        mItemsAvailable = false;
+        mObservers = new ObserverList<OfflineContentProvider.Observer>();
+    }
+
+    // OfflineContentProvider implementation.
+    @Override
+    public boolean areItemsAvailable() {
+        return mItemsAvailable;
+    }
+
+    @Override
+    public void openItem(ContentId id) {
+        if (mNativeOfflineContentAggregatorBridge == 0) return;
+        nativeOpenItem(mNativeOfflineContentAggregatorBridge, id.namespace, id.id);
+    }
+
+    @Override
+    public void removeItem(ContentId id) {
+        if (mNativeOfflineContentAggregatorBridge == 0) return;
+        nativeRemoveItem(mNativeOfflineContentAggregatorBridge, id.namespace, id.id);
+    }
+
+    @Override
+    public void cancelDownload(ContentId id) {
+        if (mNativeOfflineContentAggregatorBridge == 0) return;
+        nativeCancelDownload(mNativeOfflineContentAggregatorBridge, id.namespace, id.id);
+    }
+
+    @Override
+    public void pauseDownload(ContentId id) {
+        if (mNativeOfflineContentAggregatorBridge == 0) return;
+        nativePauseDownload(mNativeOfflineContentAggregatorBridge, id.namespace, id.id);
+    }
+
+    @Override
+    public void resumeDownload(ContentId id) {
+        if (mNativeOfflineContentAggregatorBridge == 0) return;
+        nativeResumeDownload(mNativeOfflineContentAggregatorBridge, id.namespace, id.id);
+    }
+
+    @Override
+    public OfflineItem getItemById(ContentId id) {
+        if (mNativeOfflineContentAggregatorBridge == 0) return null;
+        return nativeGetItemById(mNativeOfflineContentAggregatorBridge, id.namespace, id.id);
+    }
+
+    @Override
+    public ArrayList<OfflineItem> getAllItems() {
+        if (mNativeOfflineContentAggregatorBridge == 0) return null;
+        return nativeGetAllItems(mNativeOfflineContentAggregatorBridge);
+    }
+
+    @Override
+    public void addObserver(OfflineContentProvider.Observer observer) {
+        mObservers.addObserver(observer);
+    }
+
+    @Override
+    public void removeObserver(OfflineContentProvider.Observer observer) {
+        mObservers.removeObserver(observer);
+    }
+
+    // Methods called from C++ via JNI.
+    @CalledByNative
+    private void onItemsAvailable() {
+        mItemsAvailable = true;
+
+        for (Observer observer : mObservers) {
+            observer.onItemsAvailable();
+        }
+    }
+
+    @CalledByNative
+    private void onItemsAdded(ArrayList<OfflineItem> items) {
+        if (items.size() == 0) return;
+
+        for (Observer observer : mObservers) {
+            observer.onItemsAdded(items);
+        }
+    }
+
+    @CalledByNative
+    private void onItemRemoved(String nameSpace, String id) {
+        ContentId contentId = new ContentId(nameSpace, id);
+
+        for (Observer observer : mObservers) {
+            observer.onItemRemoved(contentId);
+        }
+    }
+
+    @CalledByNative
+    private void onItemUpdated(OfflineItem item) {
+        for (Observer observer : mObservers) {
+            observer.onItemUpdated(item);
+        }
+    }
+
+    /**
+     * Called when the C++ OfflineContentAggregatorBridge is destroyed.  This tears down the Java
+     * component of the JNI bridge so that this class, which may live due to other references, no
+     * longer attempts to access the C++ side of the bridge.
+     */
+    @CalledByNative
+    private void onNativeDestroyed() {
+        mNativeOfflineContentAggregatorBridge = 0;
+    }
+
+    /**
+     * A private static factory method meant to be called by the C++ OfflineContentAggregatorBridge.
+     * @param nativeOfflineContentAggregatorBridge A C++ pointer to the
+     * OfflineContentAggregatorBridge.
+     * @return A new instance of this OfflineContentAggregatorBridge.
+     */
+    @CalledByNative
+    private static OfflineContentAggregatorBridge create(
+            long nativeOfflineContentAggregatorBridge) {
+        return new OfflineContentAggregatorBridge(nativeOfflineContentAggregatorBridge);
+    }
+
+    // Methods called to C++ via JNI.
+    private native void nativeOpenItem(
+            long nativeOfflineContentAggregatorBridge, String nameSpace, String id);
+    private native void nativeRemoveItem(
+            long nativeOfflineContentAggregatorBridge, String nameSpace, String id);
+    private native void nativeCancelDownload(
+            long nativeOfflineContentAggregatorBridge, String nameSpace, String id);
+    private native void nativePauseDownload(
+            long nativeOfflineContentAggregatorBridge, String nameSpace, String id);
+    private native void nativeResumeDownload(
+            long nativeOfflineContentAggregatorBridge, String nameSpace, String id);
+    private native OfflineItem nativeGetItemById(
+            long nativeOfflineContentAggregatorBridge, String nameSpace, String id);
+    private native ArrayList<OfflineItem> nativeGetAllItems(
+            long nativeOfflineContentAggregatorBridge);
+}