Make Recent root know contents changed

Add ContentObserver on each cursor return from different providers
to make Recent root observe files are downloaded or photos are taken.

Fix: 139446177
Test: manual
Test: atest DocumentsUIGoogleTests
Change-Id: I158d99a480ef25b9b52ce2e050d4a2a1ff3085d1

7 files changed, 138 insertions, 32 deletions

diff --git a/src/com/android/documentsui/AbstractActionHandler.java b/src/com/android/documentsui/AbstractActionHandler.java
index 423565d78..824d2090e 100644
--- a/src/com/android/documentsui/AbstractActionHandler.java
+++ b/src/com/android/documentsui/AbstractActionHandler.java
@@ -576,11 +576,15 @@ public abstract class AbstractActionHandler<T extends FragmentActivity & CommonA
             Context context = mActivity;
 
             if (mState.stack.isRecents()) {
+                final LockingContentObserver observer = new LockingContentObserver(
+                        mContentLock, AbstractActionHandler.this::loadDocumentsForCurrentStack);
+                MultiRootDocumentsLoader loader;
+
                 if (mSearchMgr.isSearching()) {
                     if (DEBUG) {
                         Log.d(TAG, "Creating new GlobalSearchLoader.");
                     }
-                    return new GlobalSearchLoader(
+                    loader = new GlobalSearchLoader(
                             context,
                             mProviders,
                             mState,
@@ -591,13 +595,15 @@ public abstract class AbstractActionHandler<T extends FragmentActivity & CommonA
                     if (DEBUG) {
                         Log.d(TAG, "Creating new loader recents.");
                     }
-                    return new RecentsLoader(
+                    loader =  new RecentsLoader(
                             context,
                             mProviders,
                             mState,
                             mExecutors,
                             mInjector.fileTypeLookup);
                 }
+                loader.setObserver(observer);
+                return loader;
             } else {
                 Uri contentsUri = mSearchMgr.isSearching()
                         ? DocumentsContract.buildSearchDocumentsUri(
diff --git a/src/com/android/documentsui/DirectoryLoader.java b/src/com/android/documentsui/DirectoryLoader.java
index d65b4c353..63c3bf66a 100644
--- a/src/com/android/documentsui/DirectoryLoader.java
+++ b/src/com/android/documentsui/DirectoryLoader.java
@@ -16,20 +16,16 @@
 
 package com.android.documentsui;
 
-import static com.android.documentsui.base.SharedMinimal.DEBUG;
 import static com.android.documentsui.base.SharedMinimal.VERBOSE;
 
 import android.content.ContentProviderClient;
 import android.content.ContentResolver;
 import android.content.Context;
-import android.database.ContentObserver;
 import android.database.Cursor;
 import android.net.Uri;
 import android.os.Bundle;
 import android.os.CancellationSignal;
 import android.os.FileUtils;
-import android.os.Handler;
-import android.os.Looper;
 import android.os.OperationCanceledException;
 import android.os.RemoteException;
 import android.provider.DocumentsContract.Document;
@@ -241,28 +237,4 @@ public class DirectoryLoader extends AsyncTaskLoader<DirectoryResult> {
 
         getContext().getContentResolver().unregisterContentObserver(mObserver);
     }
-
-    private static final class LockingContentObserver extends ContentObserver {
-        private final ContentLock mLock;
-        private final Runnable mContentChangedCallback;
-
-        public LockingContentObserver(ContentLock lock, Runnable contentChangedCallback) {
-            super(new Handler(Looper.getMainLooper()));
-            mLock = lock;
-            mContentChangedCallback = contentChangedCallback;
-        }
-
-        @Override
-        public boolean deliverSelfNotifications() {
-            return true;
-        }
-
-        @Override
-        public void onChange(boolean selfChange) {
-            if (DEBUG) {
-                Log.d(TAG, "Directory content updated.");
-            }
-            mLock.runWhenUnlocked(mContentChangedCallback);
-        }
-    }
 }
diff --git a/src/com/android/documentsui/LockingContentObserver.java b/src/com/android/documentsui/LockingContentObserver.java
new file mode 100644
index 000000000..bbd7a98cd
--- /dev/null
+++ b/src/com/android/documentsui/LockingContentObserver.java
@@ -0,0 +1,53 @@
+/*
+ * Copyright (C) 2019 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.documentsui;
+
+import static com.android.documentsui.base.SharedMinimal.DEBUG;
+import static com.android.documentsui.base.SharedMinimal.TAG;
+
+import android.database.ContentObserver;
+import android.os.Handler;
+import android.os.Looper;
+import android.util.Log;
+
+/**
+ * A custom {@link ContentObserver} which constructed by a {@link ContentLock}
+ * and a {@link Runnable} callback. It will callback when it's onChange and ContentLock is unlock.
+ */
+public final class LockingContentObserver extends ContentObserver {
+    private final ContentLock mLock;
+    private final Runnable mContentChangedCallback;
+
+    public LockingContentObserver(ContentLock lock, Runnable contentChangedCallback) {
+        super(new Handler(Looper.getMainLooper()));
+        mLock = lock;
+        mContentChangedCallback = contentChangedCallback;
+    }
+
+    @Override
+    public boolean deliverSelfNotifications() {
+        return true;
+    }
+
+    @Override
+    public void onChange(boolean selfChange) {
+        if (DEBUG) {
+            Log.d(TAG, "Content updated.");
+        }
+        mLock.runWhenUnlocked(mContentChangedCallback);
+    }
+}
diff --git a/src/com/android/documentsui/MultiRootDocumentsLoader.java b/src/com/android/documentsui/MultiRootDocumentsLoader.java
index 777efe0b6..11208c16b 100644
--- a/src/com/android/documentsui/MultiRootDocumentsLoader.java
+++ b/src/com/android/documentsui/MultiRootDocumentsLoader.java
@@ -17,7 +17,6 @@
 package com.android.documentsui;
 
 import static com.android.documentsui.base.SharedMinimal.DEBUG;
-import static com.android.documentsui.base.SharedMinimal.TAG;
 
 import android.app.ActivityManager;
 import android.content.ContentProviderClient;
@@ -65,6 +64,9 @@ import java.util.concurrent.TimeUnit;
  * and return the combined result.
  */
 public abstract class MultiRootDocumentsLoader extends AsyncTaskLoader<DirectoryResult> {
+
+    private static final String TAG = "MultiRootDocsLoader";
+
     // TODO: clean up cursor ownership so background thread doesn't traverse
     // previously returned cursors for filtering/sorting; this currently races
     // with the UI thread.
@@ -83,6 +85,7 @@ public abstract class MultiRootDocumentsLoader extends AsyncTaskLoader<Directory
     private final ProvidersAccess mProviders;
     private final Lookup<String, Executor> mExecutors;
     private final Lookup<String, String> mFileTypeMap;
+    private LockingContentObserver mObserver;
 
     @GuardedBy("mTasks")
     /** A authority -> QueryTask map */
@@ -101,6 +104,8 @@ public abstract class MultiRootDocumentsLoader extends AsyncTaskLoader<Directory
      * @param state current state
      * @param executors the executors of authorities
      * @param fileTypeMap the map of mime types and file types.
+     * @param lock the selection lock
+     * @param contentChangedCallback callback when content changed
      */
     public MultiRootDocumentsLoader(Context context, ProvidersAccess providers, State state,
             Lookup<String, Executor> executors, Lookup<String, String> fileTypeMap) {
@@ -126,6 +131,10 @@ public abstract class MultiRootDocumentsLoader extends AsyncTaskLoader<Directory
         }
     }
 
+    public void setObserver(LockingContentObserver observer) {
+        mObserver = observer;
+    }
+
     private DirectoryResult loadInBackgroundLocked() {
         if (mFirstPassLatch == null) {
             // First time through we kick off all the recent tasks, and wait
@@ -322,6 +331,10 @@ public abstract class MultiRootDocumentsLoader extends AsyncTaskLoader<Directory
 
         FileUtils.closeQuietly(mResult);
         mResult = null;
+
+        if (mObserver != null) {
+            getContext().getContentResolver().unregisterContentObserver(mObserver);
+        }
     }
 
     // TODO: create better transfer of ownership around cursor to ensure its
@@ -406,6 +419,9 @@ public abstract class MultiRootDocumentsLoader extends AsyncTaskLoader<Directory
                         mState.sortModel.addQuerySortArgs(queryArgs);
                         addQueryArgs(queryArgs);
                         res[i] = client.query(uri, null, queryArgs, null);
+                        if (mObserver != null) {
+                            res[i].registerContentObserver(mObserver);
+                        }
                         mCursors[i] = generateResultCursor(rootInfos.get(i), res[i]);
                     } catch (Exception e) {
                         Log.w(TAG, "Failed to load " + authority + ", " + rootInfos.get(i).rootId,
diff --git a/tests/common/com/android/documentsui/testing/TestCursor.java b/tests/common/com/android/documentsui/testing/TestCursor.java
new file mode 100644
index 000000000..56f42695a
--- /dev/null
+++ b/tests/common/com/android/documentsui/testing/TestCursor.java
@@ -0,0 +1,30 @@
+/*
+ * Copyright (C) 2019 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.documentsui.testing;
+
+import android.database.MatrixCursor;
+
+public class TestCursor extends MatrixCursor {
+
+    public TestCursor(String[] columnNames) {
+        super(columnNames);
+    }
+
+    public void mockOnChange() {
+        onChange(false);
+    }
+}
diff --git a/tests/common/com/android/documentsui/testing/TestDocumentsProvider.java b/tests/common/com/android/documentsui/testing/TestDocumentsProvider.java
index 794d1c9fe..3e4dffd49 100644
--- a/tests/common/com/android/documentsui/testing/TestDocumentsProvider.java
+++ b/tests/common/com/android/documentsui/testing/TestDocumentsProvider.java
@@ -117,7 +117,7 @@ public class TestDocumentsProvider extends DocumentsProvider {
     }
 
     private Cursor createDocumentsCursor(DocumentInfo... docs) {
-        MatrixCursor cursor = new MatrixCursor(DOCUMENTS_PROJECTION);
+        TestCursor cursor = new TestCursor(DOCUMENTS_PROJECTION);
         for (DocumentInfo doc : docs) {
             cursor.newRow()
                     .add(Document.COLUMN_DOCUMENT_ID, doc.documentId)
diff --git a/tests/unit/com/android/documentsui/RecentsLoaderTests.java b/tests/unit/com/android/documentsui/RecentsLoaderTests.java
index f044b92e1..73ba36f3c 100644
--- a/tests/unit/com/android/documentsui/RecentsLoaderTests.java
+++ b/tests/unit/com/android/documentsui/RecentsLoaderTests.java
@@ -29,6 +29,7 @@ import androidx.test.runner.AndroidJUnit4;
 import com.android.documentsui.base.DocumentInfo;
 import com.android.documentsui.base.State;
 import com.android.documentsui.testing.ActivityManagers;
+import com.android.documentsui.testing.TestCursor;
 import com.android.documentsui.testing.TestEnv;
 import com.android.documentsui.testing.TestFileTypeLookup;
 import com.android.documentsui.testing.TestImmediateExecutor;
@@ -38,6 +39,9 @@ import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+
 @RunWith(AndroidJUnit4.class)
 @MediumTest
 public class RecentsLoaderTests {
@@ -45,6 +49,7 @@ public class RecentsLoaderTests {
     private TestEnv mEnv;
     private TestActivity mActivity;
     private RecentsLoader mLoader;
+    private boolean mContentChanged;
 
     @Before
     public void setUp() {
@@ -105,4 +110,28 @@ public class RecentsLoaderTests {
             assertEquals(0, flags & Document.FLAG_SUPPORTS_MOVE);
         }
     }
+
+    @Test
+    public void testContentsUpdate_observable() throws Exception {
+        CountDownLatch latch = new CountDownLatch(1);
+        Runnable callback = () -> {
+            latch.countDown();
+            mContentChanged = true;
+        };
+        mLoader.setObserver(new LockingContentObserver(new ContentLock(), callback));
+
+        final DocumentInfo doc = mEnv.model.createFile("freddy.jpg");
+        doc.lastModified = System.currentTimeMillis();
+        mEnv.mockProviders.get(TestProvidersAccess.HOME.authority)
+                .setNextRecentDocumentsReturns(doc);
+
+        mLoader.loadInBackground();
+
+        TestCursor c = (TestCursor) mEnv.mockProviders.get(TestProvidersAccess.HOME.authority)
+                .queryRecentDocuments(null, null);
+        c.mockOnChange();
+
+        latch.await(1, TimeUnit.SECONDS);
+        assertTrue(mContentChanged);
+    }
 }