Refactor content provider code from ContactsDict

Break contacts binary dictionary into two parts
- one that talks to contacts content provider and maintains
  local state. Includes a manager class and a content observer
- other one that just manages the dict code.

Change-Id: Ie8f89ac9ce174c803ff3168ee0bee5cbe7721d5b

1 files changed, 160 insertions, 0 deletions

diff --git a/java/src/com/android/inputmethod/latin/ContactsManager.java b/java/src/com/android/inputmethod/latin/ContactsManager.java
new file mode 100644
index 000000000..dc5abd955
--- /dev/null
+++ b/java/src/com/android/inputmethod/latin/ContactsManager.java
@@ -0,0 +1,160 @@
+/*
+ * Copyright (C) 2014 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.inputmethod.latin;
+
+import android.content.Context;
+import android.database.Cursor;
+import android.database.sqlite.SQLiteException;
+import android.net.Uri;
+import android.provider.ContactsContract.Contacts;
+import android.util.Log;
+
+import com.android.inputmethod.latin.common.Constants;
+
+import java.util.ArrayList;
+import java.util.concurrent.atomic.AtomicInteger;
+
+/**
+ * Manages all interactions with Contacts DB.
+ *
+ * The manager provides an API for listening to meaning full updates by keeping a
+ * measure of the current state of the content provider.
+ */
+// TODO:Add test
+public class ContactsManager {
+    private static final String TAG = ContactsManager.class.getSimpleName();
+    private static final boolean DEBUG = false;
+
+    /**
+     * Interface to implement for classes interested in getting notified for updates
+     * to Contacts content provider.
+     */
+    public static interface ContactsChangedListener {
+        public void onContactsChange();
+    }
+
+    /**
+     * The number of contacts observed in the most recent instance of
+     * contacts content provider.
+     */
+    private AtomicInteger mContactCountAtLastRebuild = new AtomicInteger(0);
+
+    /**
+     * The hash code of list of valid contacts names in the most recent dictionary
+     * rebuild.
+     */
+    private AtomicInteger mHashCodeAtLastRebuild = new AtomicInteger(0);
+
+    private final Context mContext;
+    private final ContactsContentObserver mObserver;
+
+    public ContactsManager(final Context context) {
+        mContext = context;
+        mObserver = new ContactsContentObserver(this /* ContactsManager */, context);
+    }
+
+    // TODO: This was synchronized in previous version. Why?
+    public void registerForUpdates(final ContactsChangedListener listener) {
+        mObserver.registerObserver(listener);
+    }
+
+    public int getContactCountAtLastRebuild() {
+        return mContactCountAtLastRebuild.get();
+    }
+
+    public int getHashCodeAtLastRebuild() {
+        return mHashCodeAtLastRebuild.get();
+    }
+
+    /**
+     * Returns all the valid names in the Contacts DB. Callers should also
+     * call {@link #updateLocalState(ArrayList)} after they are done with result
+     * so that the manager can cache local state for determining updates.
+     */
+    public ArrayList<String> getValidNames(final Uri uri) {
+        final ArrayList<String> names = new ArrayList<>();
+        // Check all contacts since it's not possible to find out which names have changed.
+        // This is needed because it's possible to receive extraneous onChange events even when no
+        // name has changed.
+        final Cursor cursor = mContext.getContentResolver().query(uri,
+                ContactsDictionaryConstants.PROJECTION, null, null, null);
+        if (cursor != null) {
+            try {
+                if (cursor.moveToFirst()) {
+                    while (!cursor.isAfterLast()) {
+                        final String name = cursor.getString(
+                                ContactsDictionaryConstants.NAME_INDEX);
+                        if (isValidName(name)) {
+                            names.add(name);
+                        }
+                        cursor.moveToNext();
+                    }
+                }
+            } finally {
+                cursor.close();
+            }
+        }
+        return names;
+    }
+
+    /**
+     * Returns the number of contacts in contacts content provider.
+     */
+    public int getContactCount() {
+        // TODO: consider switching to a rawQuery("select count(*)...") on the database if
+        // performance is a bottleneck.
+        Cursor cursor = null;
+        try {
+            cursor = mContext.getContentResolver().query(Contacts.CONTENT_URI,
+                    ContactsDictionaryConstants.PROJECTION_ID_ONLY, null, null, null);
+            if (null == cursor) {
+                return 0;
+            }
+            return cursor.getCount();
+        } catch (final SQLiteException e) {
+            Log.e(TAG, "SQLiteException in the remote Contacts process.", e);
+        } finally {
+            if (null != cursor) {
+                cursor.close();
+            }
+        }
+        return 0;
+    }
+
+    private static boolean isValidName(final String name) {
+        if (name != null && -1 == name.indexOf(Constants.CODE_COMMERCIAL_AT)) {
+            return true;
+        }
+        return false;
+    }
+
+    /**
+     * Updates the local state of the manager. This should be called when the callers
+     * are done with all the updates of the content provider successfully.
+     */
+    public void updateLocalState(final ArrayList<String> names) {
+        mContactCountAtLastRebuild.set(getContactCount());
+        mHashCodeAtLastRebuild.set(names.hashCode());
+    }
+
+    /**
+     * Performs any necessary cleanup.
+     */
+    public void close() {
+        mObserver.unregister();
+    }
+}