Initial changes to allow collections in widgets.

Change-Id: I3cfa899bae88cd252912cecebc12e93c27a3b7c9

1 files changed, 140 insertions, 0 deletions

diff --git a/core/java/android/widget/RemoteViewsService.java b/core/java/android/widget/RemoteViewsService.java
new file mode 100644
index 0000000..7c9d7ff
--- /dev/null
+++ b/core/java/android/widget/RemoteViewsService.java
@@ -0,0 +1,140 @@
+/*
+ * 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 android.widget;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import android.app.Service;
+import android.content.Intent;
+import android.os.IBinder;
+import android.util.Pair;
+
+import com.android.internal.widget.IRemoteViewsFactory;
+
+/**
+ * The service to be connected to for a remote adapter to request RemoteViews.  Users should
+ * extend the RemoteViewsService to provide the appropriate RemoteViewsFactory's used to
+ * populate the remote collection view (ListView, GridView, etc).
+ */
+public abstract class RemoteViewsService extends Service {
+
+    private static final String LOG_TAG = "RemoteViewsService";
+
+    // multimap implementation for reference counting
+    private HashMap<Intent, Pair<RemoteViewsFactory, Integer>> mRemoteViewFactories;
+    private final Object mLock = new Object();
+
+    /**
+     * An interface for an adapter between a remote collection view (ListView, GridView, etc) and
+     * the underlying data for that view.  The implementor is responsible for making a RemoteView
+     * for each item in the data set.
+     */
+    public interface RemoteViewsFactory {
+        public void onCreate();
+        public void onDestroy();
+
+        public int getCount();
+        public RemoteViews getViewAt(int position);
+        public RemoteViews getLoadingView();
+        public int getViewTypeCount();
+        public long getItemId(int position);
+        public boolean hasStableIds();
+    }
+
+    /**
+     * A private proxy class for the private IRemoteViewsFactory interface through the
+     * public RemoteViewsFactory interface.
+     */
+    private class RemoteViewsFactoryAdapter extends IRemoteViewsFactory.Stub {
+        public RemoteViewsFactoryAdapter(RemoteViewsFactory factory) {
+            mFactory = factory;
+        }
+
+        public int getCount() {
+            return mFactory.getCount();
+        }
+        public RemoteViews getViewAt(int position) {
+            return mFactory.getViewAt(position);
+        }
+        public RemoteViews getLoadingView() {
+            return mFactory.getLoadingView();
+        }
+        public int getViewTypeCount() {
+            return mFactory.getViewTypeCount();
+        }
+        public long getItemId(int position) {
+            return mFactory.getItemId(position);
+        }
+        public boolean hasStableIds() {
+            return mFactory.hasStableIds();
+        }
+
+        private RemoteViewsFactory mFactory;
+    }
+
+    public RemoteViewsService() {
+        mRemoteViewFactories = new HashMap<Intent, Pair<RemoteViewsFactory, Integer>>();
+    }
+
+    @Override
+    public IBinder onBind(Intent intent) {
+        synchronized (mLock) {
+            // increment the reference count to the particular factory associated with this intent
+            Pair<RemoteViewsFactory, Integer> factoryRef = null;
+            RemoteViewsFactory factory = null;
+            if (!mRemoteViewFactories.containsKey(intent)) {
+                factory = onGetViewFactory(intent);
+                factoryRef = new Pair<RemoteViewsFactory, Integer>(factory, 1);
+                mRemoteViewFactories.put(intent, factoryRef);
+                factory.onCreate();
+            } else {
+                Pair<RemoteViewsFactory, Integer> oldFactoryRef = mRemoteViewFactories.get(intent);
+                factory = oldFactoryRef.first;
+                int newRefCount = oldFactoryRef.second.intValue() + 1;
+                factoryRef = new Pair<RemoteViewsFactory, Integer>(oldFactoryRef.first, newRefCount);
+                mRemoteViewFactories.put(intent, factoryRef);
+            }
+            return new RemoteViewsFactoryAdapter(factory);
+        }
+    }
+
+    @Override
+    public boolean onUnbind(Intent intent) {
+        synchronized (mLock) {
+            if (mRemoteViewFactories.containsKey(intent)) {
+                // this alleviates the user's responsibility of having to clear all factories
+                Pair<RemoteViewsFactory, Integer> oldFactoryRef = mRemoteViewFactories.get(intent);
+                int newRefCount = oldFactoryRef.second.intValue() - 1;
+                if (newRefCount <= 0) {
+                    oldFactoryRef.first.onDestroy();
+                    mRemoteViewFactories.remove(intent);
+                } else {
+                    Pair<RemoteViewsFactory, Integer> factoryRef = new Pair<RemoteViewsFactory, Integer>(oldFactoryRef.first, newRefCount);
+                    mRemoteViewFactories.put(intent, factoryRef);
+                }
+            }
+        }
+        return super.onUnbind(intent);
+    }
+
+    /**
+     * To be implemented by the derived service to generate appropriate factories for
+     * the data.
+     */
+    public abstract RemoteViewsFactory onGetViewFactory(Intent intent);
+}