/***
Copyright (c) 2012 CommonsWare, LLC
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.
From _The Busy Coder's Guide to Advanced Android Development_
http://commonsware.com/AdvAndroid
*/
package com.commonsware.android.cpproxy.provider;
import android.content.ContentProvider;
import android.content.ContentValues;
import android.database.CrossProcessCursor;
import android.database.Cursor;
import android.database.CursorWindow;
import android.database.CursorWrapper;
import android.net.Uri;
public abstract class AbstractCPProxy extends ContentProvider {
abstract protected Uri convertUri(Uri uri);
public AbstractCPProxy() {
super();
}
@Override
public boolean onCreate() {
return(true);
}
@Override
public Cursor query(Uri uri, String[] projection, String selection,
String[] selectionArgs, String sortOrder) {
Cursor result=
getContext().getContentResolver().query(convertUri(uri),
projection, selection,
selectionArgs,
sortOrder);
return(new CrossProcessCursorWrapper(result));
}
@Override
public Uri insert(Uri uri, ContentValues values) {
return(getContext().getContentResolver().insert(convertUri(uri),
values));
}
@Override
public int update(Uri uri, ContentValues values, String selection,
String[] selectionArgs) {
return(getContext().getContentResolver().update(convertUri(uri),
values, selection,
selectionArgs));
}
@Override
public int delete(Uri uri, String selection, String[] selectionArgs) {
return(getContext().getContentResolver().delete(convertUri(uri),
selection,
selectionArgs));
}
@Override
public String getType(Uri uri) {
return(getContext().getContentResolver().getType(convertUri(uri)));
}
// following from
// http://stackoverflow.com/a/5243978/115145
public class CrossProcessCursorWrapper extends CursorWrapper
implements CrossProcessCursor {
public CrossProcessCursorWrapper(Cursor cursor) {
super(cursor);
}
@Override
public CursorWindow getWindow() {
return null;
}
@Override
public void fillWindow(int position, CursorWindow window) {
if (position < 0 || position > getCount()) {
return;
}
window.acquireReference();
try {
moveToPosition(position - 1);
window.clear();
window.setStartPosition(position);
int columnNum=getColumnCount();
window.setNumColumns(columnNum);
while (moveToNext() && window.allocRow()) {
for (int i=0; i < columnNum; i++) {
String field=getString(i);
if (field != null) {
if (!window.putString(field, getPosition(), i)) {
window.freeLastRow();
break;
}
}
else {
if (!window.putNull(getPosition(), i)) {
window.freeLastRow();
break;
}
}
}
}
}
catch (IllegalStateException e) {
// simply ignore it
}
finally {
window.releaseReference();
}
}
@Override
public boolean onMove(int oldPosition, int newPosition) {
return true;
}
}
}