net.sf.versiontree.ui.TreeSelection.java Source code

Introduction

Here is the source code for net.sf.versiontree.ui.TreeSelection.java

Source

/*******************************************************************************
 * Copyright (c) 2003 Jan Karstens, Andr Langhorst.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 *
 * Contributors:
 *     Jan Karstens <jan.karstens@web.de> - initial implementation
 *******************************************************************************/
package net.sf.versiontree.ui;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import net.sf.versiontree.data.IRevision;

import org.eclipse.jface.viewers.IStructuredSelection;

/**
 * @author Jan
 * Instances of the class can manage selections of tree elements in
 * a tree view.
 */
public class TreeSelection implements IStructuredSelection {

    /**
     * Delegate that holds all selected elements.
     */
    private ArrayList<IRevision> selection;

    /**
     * The element that was selected last.
     */
    private Object lastSelectedElement;

    /**
     * Creates an empty TreeSelection.
     */
    protected TreeSelection() {
        selection = new ArrayList<IRevision>();
        lastSelectedElement = null;
    }

    /**
     * Clears the selection, adds an element to the selection
     * and sets the last selected element.
     * @param element
     */
    public void setSelectedElement(IRevision element) {
        selection.clear();
        selection.add(element);
        lastSelectedElement = element;
    }

    /**
     * Clears the selection and adds the elements to the selection.
     * The first element in the list will be set as the last selected element.
     * @param element
     */
    public void setSelectedElements(List<IRevision> elements) {
        selection.clear();
        if (elements.isEmpty()) {
            lastSelectedElement = null;
        } else {
            selection.addAll(elements);
            lastSelectedElement = elements.get(0);
        }
    }

    /**
     * Adds an element to the selection
     * and sets the last selected element.
     * @param element
     */
    public void addSelectedElement(IRevision element) {
        selection.add(element);
        lastSelectedElement = element;
    }

    /**
     * Adds a set of elements to the selection and sets the first element
     * as the last selected element.
     * @param elements
     */
    public void addSelectedElements(List<IRevision> elements) {
        if (!elements.isEmpty()) {
            selection.addAll(elements);
            lastSelectedElement = elements.get(0);
        }
    }

    /**
     * Removes an element from the selection if it is contained in it
     * and sets it as the last selected element.
     * @param element
     */
    public void removeSelectedElement(Object element) {
        if (selection.contains(element)) {
            selection.remove(element);
            lastSelectedElement = element;
        }
    }

    /**
     * Returns true if the element is in the selection.
     * @param element
     * @return
     */
    public boolean contains(Object element) {
        return selection.contains(element);
    }

    /**
     * Removes all elements from the selection.
     *
     */
    public void clear() {
        selection.clear();
    }

    public Object getFirstElement() {
        if (selection.isEmpty()) {
            return null;
        } else {
            return selection.get(0);
        }
    }

    public Iterator<IRevision> iterator() {
        return selection.iterator();
    }

    public int size() {
        return selection.size();
    }

    public Object[] toArray() {
        return selection.toArray();
    }

    @SuppressWarnings("unchecked")
    public List<IRevision> toList() {
        return (List<IRevision>) selection.clone();
    }

    public boolean isEmpty() {
        return selection.isEmpty();
    }

    public Object getLastSelectedElement() {
        return lastSelectedElement;
    }

}