ItemProviderDelegate.java

// Copyright 2015 The Project Buendia Authors
//
// 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 distrib-
// uted 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
// specific language governing permissions and limitations under the License.

package org.projectbuendia.client.providers;

import android.content.ContentResolver;
import android.content.ContentValues;
import android.database.Cursor;
import android.net.Uri;

import org.projectbuendia.client.sync.Database;
import org.projectbuendia.client.sync.QueryBuilder;

/**
 * A {@link ProviderDelegate} that provides query, delete, and update access to a single item
 * provided directly from the database.
 */
public class ItemProviderDelegate implements ProviderDelegate<Database> {

    protected final String mName;
    protected final Contracts.Table mTable;
    protected final String mType;
    protected final String mIdColumn;

    /** Creates an instance of {@link ItemProviderDelegate}. */
    public ItemProviderDelegate(String name, Contracts.Table table, String idColumn) {
        mName = name;
        mTable = table;
        mIdColumn = idColumn;
        mType = ContentResolver.CURSOR_ITEM_BASE_TYPE + TYPE_PACKAGE_PREFIX + mName;
    }

    @Override public String getType() {
        return mType;
    }

    @Override public Cursor query(
        Database dbHelper, ContentResolver contentResolver, Uri uri,
        String[] projection, String selection, String[] selectionArgs, String sortOrder) {
        Cursor cursor = new QueryBuilder(mTable)
            .where(mIdColumn + "=?", uri.getLastPathSegment())
            .where(selection, selectionArgs)
            .orderBy(sortOrder)
            .select(dbHelper.getReadableDatabase(), projection);
        cursor.setNotificationUri(contentResolver, uri);
        return cursor;
    }

    @Override public Uri insert(
        Database dbHelper, ContentResolver contentResolver, Uri uri,
        ContentValues values) {
        throw new UnsupportedOperationException("Insert is not supported for URI '" + uri + "'.");
    }

    @Override public int bulkInsert(
        Database dbHelper, ContentResolver contentResolver, Uri uri,
        ContentValues[] allValues) {
        throw new UnsupportedOperationException(
            "Bulk insert is not supported for URI '" + uri + "'.");
    }

    @Override public int delete(
        Database dbHelper, ContentResolver contentResolver, Uri uri,
        String selection, String[] selectionArgs) {
        int count = new QueryBuilder(mTable)
            .where(mIdColumn + "=?", uri.getLastPathSegment())
            .where(selection, selectionArgs)
            .delete(dbHelper.getWritableDatabase());
        contentResolver.notifyChange(uri, null, false);
        return count;
    }

    @Override public int update(
        Database dbHelper, ContentResolver contentResolver, Uri uri,
        ContentValues values, String selection, String[] selectionArgs) {
        int count = new QueryBuilder(mTable)
            .where(mIdColumn + "=?", uri.getLastPathSegment())
            .where(selection, selectionArgs)
            .update(dbHelper.getWritableDatabase(), values);
        contentResolver.notifyChange(uri, null, false);
        return count;
    }
}