org.eclipse.jface.util.LocalSelectionTransfer Maven / Gradle / Ivy
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/*******************************************************************************
* Copyright (c) 2005, 2015 IBM Corporation and others.
*
* This program and the accompanying materials
* are made available under the terms of the Eclipse Public License 2.0
* which accompanies this distribution, and is available at
* https://www.eclipse.org/legal/epl-2.0/
*
* SPDX-License-Identifier: EPL-2.0
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.jface.util;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.jface.resource.JFaceResources;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.swt.dnd.ByteArrayTransfer;
import org.eclipse.swt.dnd.TransferData;
/**
* A LocalSelectionTransfer may be used for drag and drop operations
* within the same instance of Eclipse.
* The selection is made available directly for use in the DropTargetListener.
* dropAccept method. The DropTargetEvent passed to dropAccept does not contain
* the drop data. The selection may be used for validation purposes so that the
* drop can be aborted if appropriate.
*
* This class is not intended to be subclassed.
*
* @since 3.2
*/
public class LocalSelectionTransfer extends ByteArrayTransfer {
// First attempt to create a UUID for the type name to make sure that
// different Eclipse applications use different "types" of
// LocalSelectionTransfer
private static final String TYPE_NAME = "local-selection-transfer-format" + System.currentTimeMillis(); //$NON-NLS-1$ ;
private static final int TYPEID = registerType(TYPE_NAME);
private static final LocalSelectionTransfer INSTANCE = new LocalSelectionTransfer();
private ISelection selection;
private long selectionSetTime;
/**
* Only the singleton instance of this class may be used.
*/
protected LocalSelectionTransfer() {
// do nothing
}
/**
* Returns the singleton.
*
* @return the singleton
*/
public static LocalSelectionTransfer getTransfer() {
return INSTANCE;
}
/**
* Returns the local transfer data.
*
* @return the local transfer data
*/
public ISelection getSelection() {
return selection;
}
/**
* Tests whether native drop data matches this transfer type.
*
* @param result result of converting the native drop data to Java
* @return true if the native drop data does not match this transfer type.
* false otherwise.
*/
private boolean isInvalidNativeType(Object result) {
return !(result instanceof byte[])
|| !TYPE_NAME.equals(new String((byte[]) result));
}
/**
* Returns the type id used to identify this transfer.
*
* @return the type id used to identify this transfer.
*/
@Override
protected int[] getTypeIds() {
return new int[] { TYPEID };
}
/**
* Returns the type name used to identify this transfer.
*
* @return the type name used to identify this transfer.
*/
@Override
protected String[] getTypeNames() {
return new String[] { TYPE_NAME };
}
/**
* Overrides org.eclipse.swt.dnd.ByteArrayTransfer#javaToNative(Object,
* TransferData).
* Only encode the transfer type name since the selection is read and
* written in the same process.
*
* @see org.eclipse.swt.dnd.ByteArrayTransfer#javaToNative(java.lang.Object, org.eclipse.swt.dnd.TransferData)
*/
@Override
public void javaToNative(Object object, TransferData transferData) {
byte[] check = TYPE_NAME.getBytes();
super.javaToNative(check, transferData);
}
/**
* Overrides org.eclipse.swt.dnd.ByteArrayTransfer#nativeToJava(TransferData).
* Test if the native drop data matches this transfer type.
*
* @see org.eclipse.swt.dnd.ByteArrayTransfer#nativeToJava(TransferData)
*/
@Override
public Object nativeToJava(TransferData transferData) {
Object result = super.nativeToJava(transferData);
if (result != null && isInvalidNativeType(result)) {
Policy.getLog().log(new Status(
IStatus.ERROR,
Policy.JFACE,
IStatus.ERROR,
JFaceResources.getString("LocalSelectionTransfer.errorMessage"), null)); //$NON-NLS-1$
}
return selection;
}
/**
* Sets the transfer data for local use.
*
* @param s the transfer data
*/
public void setSelection(ISelection s) {
selection = s;
}
/**
* Returns the time when the selection operation
* this transfer is associated with was started.
*
* @return the time when the selection operation has started
*
* @see org.eclipse.swt.events.TypedEvent#time
*/
public long getSelectionSetTime() {
return selectionSetTime;
}
/**
* Sets the time when the selection operation this transfer is associated with
* was started. If assigning this from an SWT event, be sure to use
* setSelectionTime(event.time & 0xFFFF)
*
* @param time the time when the selection operation was started
*
* @see org.eclipse.swt.events.TypedEvent#time
*/
public void setSelectionSetTime(long time) {
selectionSetTime = time;
}
}