Add StorIOContentResolver get().numberOfResults()!

storio-content-resolver/src/main/java/com/pushtorefresh/storio/contentresolver/operations/get/PreparedGet.java

@@ -3,6 +3,7 @@
 import android.support.annotation.NonNull;
 
 import com.pushtorefresh.storio.contentresolver.StorIOContentResolver;
+import com.pushtorefresh.storio.contentresolver.queries.Query;
 import com.pushtorefresh.storio.operations.PreparedOperation;
 
 /**
@@ -15,8 +16,12 @@ public abstract class PreparedGet<Result> implements PreparedOperation<Result> {
     @NonNull
     protected final StorIOContentResolver storIOContentResolver;
 
-    PreparedGet(@NonNull StorIOContentResolver storIOContentResolver) {
+    @NonNull
+    protected final Query query;
+
+    PreparedGet(@NonNull StorIOContentResolver storIOContentResolver, @NonNull Query query) {
         this.storIOContentResolver = storIOContentResolver;
+        this.query = query;
     }
 
     /**
@@ -52,5 +57,15 @@ public PreparedGetCursor.Builder cursor() {
         public <T> PreparedGetListOfObjects.Builder<T> listOfObjects(@NonNull Class<T> type) {
             return new PreparedGetListOfObjects.Builder<T>(storIOContentResolver, type);
         }
+
+        /**
+        * Returns builder for Get Operation that returns number of results.
+        *
+        * @return builder for Get Operation that returns number of results.
+        */
+        @NonNull
+        public PreparedGetNumberOfResults.Builder numberOfResults() {
+            return new PreparedGetNumberOfResults.Builder(storIOContentResolver);
+        }
     }
 }

storio-content-resolver/src/main/java/com/pushtorefresh/storio/contentresolver/operations/get/PreparedGetCursor.java

@@ -25,17 +25,13 @@
  */
 public final class PreparedGetCursor extends PreparedGet<Cursor> {
 
-    @NonNull
-    private final Query query;
-
     @NonNull
     private final GetResolver<Cursor> getResolver;
 
     PreparedGetCursor(@NonNull StorIOContentResolver storIOContentResolver,
                       @NonNull GetResolver<Cursor> getResolver,
                       @NonNull Query query) {
-        super(storIOContentResolver);
-        this.query = query;
+        super(storIOContentResolver, query);
         this.getResolver = getResolver;
     }
 

storio-content-resolver/src/main/java/com/pushtorefresh/storio/contentresolver/operations/get/PreparedGetListOfObjects.java

@@ -36,19 +36,15 @@ public final class PreparedGetListOfObjects<T> extends PreparedGet<List<T>> {
     @NonNull
     private final Class<T> type;
 
-    @NonNull
-    private final Query query;
-
     @Nullable
     private final GetResolver<T> explicitGetResolver;
 
     PreparedGetListOfObjects(@NonNull StorIOContentResolver storIOContentResolver,
                              @NonNull Class<T> type,
                              @NonNull Query query,
                              @Nullable GetResolver<T> explicitGetResolver) {
-        super(storIOContentResolver);
+        super(storIOContentResolver, query);
         this.type = type;
-        this.query = query;
         this.explicitGetResolver = explicitGetResolver;
     }
 
@@ -140,7 +136,7 @@ public Observable<List<T>> createObservable() {
     }
 
     /**
-     * Compile-time safe part of builder for {@link PreparedGetListOfObjects}.
+     * Builder for {@link PreparedGetListOfObjects}.
      *
      * @param <T> type of objects for query.
      */

storio-content-resolver/src/main/java/com/pushtorefresh/storio/contentresolver/operations/get/PreparedGetNumberOfResults.java

@@ -0,0 +1,175 @@
+package com.pushtorefresh.storio.contentresolver.operations.get;
+
+import android.database.Cursor;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+import android.support.annotation.WorkerThread;
+
+import com.pushtorefresh.storio.StorIOException;
+import com.pushtorefresh.storio.contentresolver.StorIOContentResolver;
+import com.pushtorefresh.storio.contentresolver.queries.Query;
+import com.pushtorefresh.storio.operations.internal.MapSomethingToExecuteAsBlocking;
+import com.pushtorefresh.storio.operations.internal.OnSubscribeExecuteAsBlocking;
+
+import rx.Observable;
+import rx.schedulers.Schedulers;
+
+import static com.pushtorefresh.storio.internal.Checks.checkNotNull;
+import static com.pushtorefresh.storio.internal.Environment.throwExceptionIfRxJavaIsNotAvailable;
+
+public class PreparedGetNumberOfResults extends PreparedGet<Integer> {
+
+    @NonNull
+    private final GetResolver<Integer> getResolver;
+
+    PreparedGetNumberOfResults(@NonNull StorIOContentResolver storIOContentResolver, @NonNull Query query, @NonNull GetResolver<Integer> getResolver) {
+        super(storIOContentResolver, query);
+        this.getResolver = getResolver;
+    }
+
+    /**
+     * Executes Get Operation immediately in current thread.
+     * <p>
+     * Notice: This is blocking I/O operation that should not be executed on the Main Thread,
+     * it can cause ANR (Activity Not Responding dialog), block the UI and drop animations frames.
+     * So please, call this method on some background thread. See {@link WorkerThread}.
+     *
+     * @return non-null {@link Integer} with number of results of the query.
+     */
+    @WorkerThread
+    @NonNull
+    @Override
+    public Integer executeAsBlocking() {
+        final Cursor cursor;
+
+        try {
+            cursor = getResolver.performGet(storIOContentResolver, query);
+            try {
+                return getResolver.mapFromCursor(cursor);
+            } finally {
+                cursor.close();
+            }
+        } catch (Exception exception) {
+            throw new StorIOException(exception);
+        }
+    }
+
+    /**
+     * Creates "Hot" {@link Observable} which will be subscribed to changes of tables from query
+     * and will emit result each time change occurs.
+     * <p>
+     * First result will be emitted immediately after subscription,
+     * other emissions will occur only if changes of tables from query will occur during lifetime of
+     * the {@link Observable}.
+     * <dl>
+     * <dt><b>Scheduler:</b></dt>
+     * <dd>Operates on {@link Schedulers#io()}.</dd>
+     * </dl>
+     * <p>
+     * Please don't forget to unsubscribe from this {@link Observable} because
+     * it's "Hot" and endless.
+     *
+     * @return non-null {@link Observable} which will emit non-null
+     * number of results of the executed query and will be subscribed to changes of tables from query.
+     */
+    @NonNull
+    @Override
+    public Observable<Integer> createObservable() {
+        throwExceptionIfRxJavaIsNotAvailable("createObservable()");
+
+        return storIOContentResolver
+                .observeChangesOfUri(query.uri()) // each change triggers executeAsBlocking
+                .map(MapSomethingToExecuteAsBlocking.newInstance(this))
+                .startWith(Observable.create(OnSubscribeExecuteAsBlocking.newInstance(this))) // start stream with first query result
+                .subscribeOn(Schedulers.io());
+    }
+
+    /**
+     * Builder for {@link PreparedGetNumberOfResults}.
+     */
+     public static final class Builder {
+
+        @NonNull
+        private final StorIOContentResolver storIOContentResolver;
+
+        Builder(@NonNull StorIOContentResolver storIOContentResolver) {
+            this.storIOContentResolver = storIOContentResolver;
+        }
+
+        /**
+         * Required: Specifies query which will be passed to {@link StorIOContentResolver}
+         * to get list of objects.
+         *
+         * @param query non-null query.
+         * @return builder.
+         * @see Query
+         */
+        @NonNull
+        public CompleteBuilder withQuery(@NonNull Query query) {
+            checkNotNull(query, "Please specify query");
+            return new CompleteBuilder(storIOContentResolver, query);
+        }
+    }
+
+    /**
+     * Compile-time safe part of builder for {@link PreparedGetNumberOfResults}.
+     */
+    public static final class CompleteBuilder {
+
+        @NonNull
+        static final GetResolver<Integer> STANDARD_GET_RESOLVER = new DefaultGetResolver<Integer>() {
+            @NonNull
+            @Override
+            public Integer mapFromCursor(@NonNull Cursor cursor) {
+                return cursor.getCount();
+            }
+        };
+
+        @NonNull
+        private final StorIOContentResolver storIOContentResolver;
+
+        @NonNull
+        private final Query query;
+
+        @Nullable
+        private GetResolver<Integer> getResolver;
+
+        CompleteBuilder(@NonNull StorIOContentResolver storIOContentResolver, @NonNull Query query) {
+            this.storIOContentResolver = storIOContentResolver;
+            this.query = query;
+        }
+
+        /**
+         * Optional: Specifies resolver for Get Operation which can be used
+         * to provide custom behavior of Get Operation.
+         * <p>
+         *
+         * @param getResolver nullable resolver for Get Operation.
+         * @return builder.
+         */
+        @NonNull
+        public CompleteBuilder withGetResolver(@Nullable GetResolver<Integer> getResolver) {
+            this.getResolver = getResolver;
+            return this;
+        }
+
+        /**
+         * Builds new instance of {@link PreparedGetNumberOfResults}.
+         *
+         * @return new instance of {@link PreparedGetNumberOfResults}.
+         */
+        @NonNull
+        public PreparedGetNumberOfResults prepare() {
+            if (getResolver == null) {
+                getResolver = STANDARD_GET_RESOLVER;
+            }
+
+            return new PreparedGetNumberOfResults(
+                    storIOContentResolver,
+                    query,
+                    getResolver
+            );
+        }
+    }
+
+}

storio-content-resolver/src/test/java/com/pushtorefresh/storio/contentresolver/integration/GetOperationTest.java

@@ -1,5 +1,6 @@
 package com.pushtorefresh.storio.contentresolver.integration;
 
+import android.content.ContentValues;
 import android.database.Cursor;
 
 import com.pushtorefresh.storio.contentresolver.BuildConfig;
@@ -165,4 +166,38 @@ public void getListOfObjectsAsObservableOnlyInitialValue() {
         changesTestSubscriber.assertNoErrors();
         changesTestSubscriber.assertValues(Changes.newInstance(TestItem.CONTENT_URI));
     }
+
+    @Test
+    public void getNumberOfResults() {
+        TestSubscriber<Changes> changesTestSubscriber = new TestSubscriber<Changes>();
+
+        storIOContentResolver
+                .observeChangesOfUri(TestItem.CONTENT_URI)
+                .take(1)
+                .subscribe(changesTestSubscriber);
+
+        final int testItemsQuantity = 8;
+
+        ContentValues[] contentValues = new ContentValues[testItemsQuantity];
+        for (int i = 0; i < testItemsQuantity; ++i) {
+            TestItem testItemToInsert = TestItem.create(null, "value");
+            contentValues[i] = testItemToInsert.toContentValues();
+        }
+        contentResolver.bulkInsert(TestItem.CONTENT_URI, contentValues);
+
+        Integer numberOfResults = storIOContentResolver
+                .get()
+                .numberOfResults()
+                .withQuery(Query.builder()
+                        .uri(TestItem.CONTENT_URI)
+                        .build())
+                .prepare()
+                .executeAsBlocking();
+
+        assertThat(numberOfResults).isEqualTo(testItemsQuantity);
+
+        changesTestSubscriber.awaitTerminalEvent(60, SECONDS);
+        changesTestSubscriber.assertNoErrors();
+        changesTestSubscriber.assertValue(Changes.newInstance(TestItem.CONTENT_URI));
+    }
 }

storio-content-resolver/src/test/java/com/pushtorefresh/storio/contentresolver/integration/IntegrationContentProvider.java

@@ -4,6 +4,7 @@
 import android.content.ContentValues;
 import android.content.UriMatcher;
 import android.database.Cursor;
+import android.database.sqlite.SQLiteDatabase;
 import android.database.sqlite.SQLiteOpenHelper;
 import android.net.Uri;
 import android.support.annotation.NonNull;
@@ -81,6 +82,32 @@ public Uri insert(@NonNull Uri uri, @NonNull ContentValues values) {
         throw new IllegalArgumentException("Unknown uri = " + uri);
     }
 
+    @Override
+    public int bulkInsert(@NonNull Uri uri, @NonNull ContentValues[] values) {
+        switch (uriMatcher.match(uri)) {
+            case CODE_TEST_ITEM_MATCH:
+                SQLiteDatabase sqLiteDatabase = sqLiteOpenHelper.getWritableDatabase();
+                try {
+                    sqLiteDatabase.beginTransaction();
+
+                    for (ContentValues value : values) {
+                        sqLiteDatabase.insert(
+                                IntegrationSQLiteOpenHelper.TABLE_TEST_ITEMS,
+                                null,
+                                value);
+                    }
+                    sqLiteDatabase.setTransactionSuccessful();
+                } finally {
+                    sqLiteDatabase.endTransaction();
+                }
+
+                getContext().getContentResolver().notifyChange(uri, null);
+
+                return values.length;
+        }
+        throw new IllegalArgumentException("Unknown uri = " + uri);
+    }
+
     @Override
     public int update(@NonNull Uri uri, @NonNull ContentValues values, @Nullable String selection,
                       @Nullable String[] selectionArgs) {