Upstream ResourceManager

ui/android/java/src/org/chromium/ui/resources/dynamics/DynamicResourceLoader.java

Index: ui/android/java/src/org/chromium/ui/resources/dynamics/DynamicResourceLoader.java
diff --git a/ui/android/java/src/org/chromium/ui/resources/dynamics/DynamicResourceLoader.java b/ui/android/java/src/org/chromium/ui/resources/dynamics/DynamicResourceLoader.java
new file mode 100644
index 0000000000000000000000000000000000000000..6145cae461ea8e7769e32e8b4aa0d19a1b86ac76
--- /dev/null
+++ b/ui/android/java/src/org/chromium/ui/resources/dynamics/DynamicResourceLoader.java
@@ -0,0 +1,69 @@
+// Copyright 2014 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.ui.resources.dynamics;
+
+import android.util.SparseArray;
+
+import org.chromium.ui.resources.ResourceLoader;
+
+/**
+ * Handles managing dynamic resources.  This is basically a list of dynamic resources that checks
+ * {@link DynamicResource#isDirty()} before notifying the {@link ResourceLoaderCallback}.
+ */
+public class DynamicResourceLoader extends ResourceLoader {
+    private final SparseArray<DynamicResource> mDynamicResources =
+            new SparseArray<DynamicResource>();
+
+    /**
+     * Builds a {@link DynamicResourceLoader} instance.
+     * @param resourceType The resource type this loader is responsible for loading.
+     * @param callback     A {@link ResourceLoaderCallback} to be notified when the dynamic resource
+     *                     has changed.  The callback will only be notified if
+     *                     {@link #loadResource(int)} is called.
+     */
+    public DynamicResourceLoader(int resourceType, ResourceLoaderCallback callback) {
+        super(resourceType, callback);
+    }
+
+    /**
+     * Registers a {@link DynamicResource} to be tracked and exposed by this class.
+     * @param resId    The Android id to use.  This should be an actual Android id (R.id.some_id).
+     * @param resource The {@link DynamicResource} to track and expose.
+     */
+    public void registerResource(int resId, DynamicResource resource) {
+        assert mDynamicResources.get(resId) == null;
+        mDynamicResources.put(resId, resource);
+    }
+
+    /**
+     * Unregisters a {@link DynamicResource} specified by {@code resId}.
+     * @param resId The Android id representing the {@link DynamicResource}.
+     */
+    public void unregisterResource(int resId) {
+        mDynamicResources.remove(resId);
+    }
+
+    /**
+     * Called when a {@link DynamicResource} was requested.  This will notify the
+     * {@link ResourceLoaderCallback} if the resource has new contents.
+     * @param resId The Android id representing the {@link DynamicResource}.
+     */
+    @Override
+    public void loadResource(int resId) {
+        DynamicResource resource = mDynamicResources.get(resId);
+        if (resource == null) return;
+
+        if (resource.isDirty()) notifyLoadFinished(resId, resource);
+    }
+
+    /**
+     * Since this class relies solely on registration it does not support preloading resources.
+     */
+    @Override
+    public void preloadResource(int resId) {
+        // Not implemented.
+        assert false : "Preloading dynamic resources isn't supported.";
+    }
+}