/******************************************************************************
* Copyright (c) 2011 GitHub Inc.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* Kevin Sawicki (GitHub Inc.) - initial API and implementation
*****************************************************************************/
package org.eclipse.egit.ui.internal.handler;
import java.util.LinkedList;
import java.util.List;
import org.eclipse.core.commands.AbstractHandler;
import org.eclipse.core.commands.ExecutionEvent;
import org.eclipse.core.commands.ExecutionException;
import org.eclipse.egit.core.AdapterUtils;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.StructuredSelection;
import org.eclipse.ui.IWorkbenchPart;
import org.eclipse.ui.handlers.HandlerUtil;
/**
* Base handler with helpers for working with selections
*/
public abstract class SelectionHandler extends AbstractHandler {
/**
* Get structured selection for event
*
* @param event
* @return selection, never null
*/
protected IStructuredSelection getSelection(final ExecutionEvent event) {
ISelection selection = HandlerUtil.getCurrentSelection(event);
if (selection == null || selection.isEmpty())
selection = HandlerUtil.getActiveMenuSelection(event);
if (selection instanceof IStructuredSelection)
return (IStructuredSelection) selection;
return StructuredSelection.EMPTY;
}
/**
* Get current selection as target item class
*
* @param itemClass
* @param event
* @param <V> type of itemClass
* @return non-null but possibly empty list
*/
protected <V> V getSelectedItem(final Class<V> itemClass,
final ExecutionEvent event) {
final Object selected = getSelection(event).getFirstElement();
return AdapterUtils.adapt(selected, itemClass);
}
/**
* Get current selection as list of target item class objects
*
* @param itemClass
* @param event
* @param <V> type of itemClass
* @return non-null but possibly empty list
*/
protected <V> List<V> getSelectedItems(Class<V> itemClass,
ExecutionEvent event) {
final List<V> items = new LinkedList<>();
for (Object selected : getSelection(event).toArray()) {
V adapted = AdapterUtils.adapt(selected, itemClass);
if (adapted != null)
items.add(adapted);
}
return items;
}
/**
* Get workbench part for event
*
* @param event
* @return part
* @throws ExecutionException
*/
protected IWorkbenchPart getPart(ExecutionEvent event)
throws ExecutionException {
return HandlerUtil.getActivePartChecked(event);
}
}