1 files changed, 114 insertions, 0 deletions
diff --git a/java/src/com/android/inputmethod/latin/ContactsContentObserver.java b/java/src/com/android/inputmethod/latin/ContactsContentObserver.java
new file mode 100644
index 000000000..5eb9b16d1
--- /dev/null
+++ b/java/src/com/android/inputmethod/latin/ContactsContentObserver.java
@@ -0,0 +1,114 @@
+/*
+ * 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.ContentResolver;
+import android.content.Context;
+import android.database.ContentObserver;
+import android.os.SystemClock;
+import android.provider.ContactsContract.Contacts;
+import android.util.Log;
+
+import com.android.inputmethod.latin.ContactsManager.ContactsChangedListener;
+import com.android.inputmethod.latin.utils.ExecutorUtils;
+
+import java.util.ArrayList;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+/**
+ * A content observer that listens to updates to content provider {@link Contacts#CONTENT_URI}.
+ */
+public class ContactsContentObserver implements Runnable {
+    private static final String TAG = ContactsContentObserver.class.getSimpleName();
+    private static final boolean DEBUG = false;
+    private static AtomicBoolean sRunning = new AtomicBoolean(false);
+
+    private final Context mContext;
+    private final ContactsManager mManager;
+
+    private ContentObserver mContentObserver;
+    private ContactsChangedListener mContactsChangedListener;
+
+    public ContactsContentObserver(final ContactsManager manager, final Context context) {
+        mManager = manager;
+        mContext = context;
+    }
+
+    public void registerObserver(final ContactsChangedListener listener) {
+        if (DEBUG) {
+            Log.d(TAG, "Registered Contacts Content Observer");
+        }
+        mContactsChangedListener = listener;
+        mContentObserver = new ContentObserver(null /* handler */) {
+            @Override
+            public void onChange(boolean self) {
+                ExecutorUtils.getBackgroundExecutor(ExecutorUtils.KEYBOARD)
+                        .execute(ContactsContentObserver.this);
+            }
+        };
+        final ContentResolver contentResolver = mContext.getContentResolver();
+        contentResolver.registerContentObserver(Contacts.CONTENT_URI, true, mContentObserver);
+    }
+
+    @Override
+    public void run() {
+        if (!sRunning.compareAndSet(false /* expect */, true /* update */)) {
+            if (DEBUG) {
+                Log.d(TAG, "run() : Already running. Don't waste time checking again.");
+            }
+            return;
+        }
+        if (haveContentsChanged()) {
+            if (DEBUG) {
+                Log.d(TAG, "run() : Contacts have changed. Notifying listeners.");
+            }
+            mContactsChangedListener.onContactsChange();
+        }
+        sRunning.set(false);
+    }
+
+    boolean haveContentsChanged() {
+        final long startTime = SystemClock.uptimeMillis();
+        final int contactCount = mManager.getContactCount();
+        if (contactCount > ContactsDictionaryConstants.MAX_CONTACT_COUNT) {
+            // If there are too many contacts then return false. In this rare case it is impossible
+            // to include all of them anyways and the cost of rebuilding the dictionary is too high.
+            // TODO: Sort and check only the MAX_CONTACT_COUNT most recent contacts?
+            return false;
+        }
+        if (contactCount != mManager.getContactCountAtLastRebuild()) {
+            if (DEBUG) {
+                Log.d(TAG, "Contact count changed: " + mManager.getContactCountAtLastRebuild()
+                        + " to " + contactCount);
+            }
+            return true;
+        }
+        final ArrayList<String> names = mManager.getValidNames(Contacts.CONTENT_URI);
+        if (names.hashCode() != mManager.getHashCodeAtLastRebuild()) {
+            return true;
+        }
+        if (DEBUG) {
+            Log.d(TAG, "No contacts changed. (runtime = " + (SystemClock.uptimeMillis() - startTime)
+                    + " ms)");
+        }
+        return false;
+    }
+
+    public void unregister() {
+        mContext.getContentResolver().unregisterContentObserver(mContentObserver);
+    }
+}