/*
* DBeaver - Universal Database Manager
* Copyright (C) 2010-2017 Serge Rider (serge@jkiss.org)
*
* 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 org.jkiss.dbeaver.ui.dnd;
import org.eclipse.swt.dnd.ByteArrayTransfer;
import org.eclipse.swt.dnd.TransferData;
import java.nio.charset.Charset;
/**
* This Transfer will only work when dragging within the same instance of Eclipse.
* Subclasses should maintain a
* single instance of their Transfer and provide a static method to obtain that
* instance.
*/
public abstract class LocalObjectTransfer<OBJECT_TYPE> extends ByteArrayTransfer {
private OBJECT_TYPE object;
private long startTime;
/**
* Returns the Object.
*
* @return The Object
*/
public OBJECT_TYPE getObject() {
return object;
}
/**
* The data object is not converted to bytes. It is held onto in a field.
* Instead, a checksum is written out to prevent unwanted drags across
* multiple running copies of Eclipse.
*
* @see org.eclipse.swt.dnd.Transfer#javaToNative(Object, org.eclipse.swt.dnd.TransferData)
*/
@Override
public void javaToNative(Object object, TransferData transferData) {
setObject((OBJECT_TYPE)object);
startTime = System.currentTimeMillis();
if (transferData != null)
super.javaToNative(String.valueOf(startTime).getBytes(Charset.defaultCharset()),
transferData);
}
/**
* The data object is not converted to bytes. It is held onto in a field.
* Instead, a checksum is written out to prevent unwanted drags across
* mulitple running. copies of Eclipse.
*
* @see org.eclipse.swt.dnd.Transfer#nativeToJava(org.eclipse.swt.dnd.TransferData)
*/
@Override
public Object nativeToJava(TransferData transferData) {
byte bytes[] = (byte[]) super.nativeToJava(transferData);
if (bytes == null) {
return null;
}
long startTime = Long.parseLong(new String(bytes));
return (this.startTime == startTime) ? getObject() : null;
}
/**
* Sets the Object.
*
* @param obj
* The Object
*/
public void setObject(OBJECT_TYPE obj) {
object = obj;
}
}