plugins/org.eclipse.sirius.diagram.ui/src-diag/org/eclipse/sirius/diagram/ui/tools/internal/palette/ConnectionCreationTool.java

/*******************************************************************************
 * Copyright (c) 2009, 2009 THALES GLOBAL SERVICES.
 * 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:
 *    Obeo - initial API and implementation
 *******************************************************************************/
package org.eclipse.sirius.diagram.ui.tools.internal.palette;

import org.eclipse.gef.commands.Command;
import org.eclipse.gef.requests.CreationFactory;
import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Cursor;

/**
 * ConnectionCreationTool so that the current tool will remain active (locked)
 * if the user is pressing the ctrl key.
 * 
 * @author <a href="mailto:laurent.redor@obeo.fr">Laurent Redor</a>
 */
public class ConnectionCreationTool extends org.eclipse.gef.tools.ConnectionCreationTool {

    /**
     * Default Constructor.
     */
    public ConnectionCreationTool() {
        super();
        setUnloadWhenFinished(true);
    }

    /**
     * Constructs a new ConnectionCreationTool with the given factory.
     * 
     * @param factory
     *            the creation factory
     */
    public ConnectionCreationTool(final CreationFactory factory) {
        super(factory);
        setUnloadWhenFinished(true);
    }

    /**
     * {@inheritDoc}
     * 
     * @see org.eclipse.gef.tools.AbstractConnectionCreationTool#handleMove()
     */
    @Override
    protected boolean handleMove() {
        final boolean bool = super.handleMove();
        if (isInState(STATE_CONNECTION_STARTED)) {
            // Expose the diagram as the user scrolls in the area handled by the
            // autoexpose helper.
            updateAutoexposeHelper();
        }
        return bool;
    }

    /**
     * Overridden so that the current tool will remain active (locked) if the
     * user is pressing the ctrl key (or cmd key for mac users).
     */
    @Override
    protected void handleFinished() {
        if (!getCurrentInput().isModKeyDown(SWT.MOD1)) {
            super.handleFinished();
        } else {
            reactivate();
        }
    }

    /**
     * Overridden to allow feedback with disabled cursor on connection start &
     * end.
     * 
     * {@inheritDoc}
     */
    @Override
    protected Cursor calculateCursor() {
        Command command = getCurrentCommand();
        if (command == null || !command.canExecute()) {
            return getDisabledCursor();
        }
        return super.calculateCursor();
    }

}