de.tub.tfs.muvitor.actions.TrimViewerAction.java Source code

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Here is the source code for de.tub.tfs.muvitor.actions.TrimViewerAction.java

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/*******************************************************************************
 * Copyright (c) 2010-2015 Henshin developers. 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:
 *     TU Berlin, University of Luxembourg, SES S.A.
 *******************************************************************************/
package de.tub.tfs.muvitor.actions;

import java.util.Collection;

import org.eclipse.draw2d.geometry.Point;
import org.eclipse.draw2d.geometry.Rectangle;
import org.eclipse.gef.EditPart;
import org.eclipse.gef.EditPartViewer;
import org.eclipse.gef.GraphicalEditPart;
import org.eclipse.gef.NodeEditPart;
import org.eclipse.gef.RequestConstants;
import org.eclipse.gef.commands.Command;
import org.eclipse.gef.commands.CompoundCommand;
import org.eclipse.gef.requests.ChangeBoundsRequest;
import org.eclipse.gef.ui.actions.SelectionAction;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.ui.IWorkbenchPart;

import de.tub.tfs.muvitor.ui.MuvitorActivator;
import de.tub.tfs.muvitor.ui.MuvitorConstants;

/**
 * This action trims the viewer containing the currently selected
 * GraphicalEditPart. All editparts that return an executable command for a move
 * request will be moved so that the viewers size is minimized but still showing
 * all figures. In short, all figures will be moved by the same amount to the
 * upper-left corner as far as possible.
 * 
 * @author "Tony Modica"
 */
public class TrimViewerAction extends SelectionAction {

    public static final String ID = "TrimViewerAction";

    /**
     * the node's spacing from the viewer's border
     */
    private static final int INSETS = 5;

    /**
     * the viewer containing the currently selected GraphicalEditPart
     */
    private EditPartViewer viewer;

    /**
     * Constructor.
     */
    public TrimViewerAction(final IWorkbenchPart part) {
        super(part);
        setText("Trim viewer");
        setToolTipText("Trim viewer");
        setId(ID);
        setImageDescriptor(MuvitorActivator.getImageDescriptor(MuvitorConstants.ICON_TRIM_16));
    }

    /**
     * 
     */
    @SuppressWarnings("unchecked")
    @Override
    public void run() {
        // when invoking directly, a viewer must be set manually!
        if (viewer == null) {
            return;
        }

        // initialize deltas with maximum values
        int xdelta = Integer.MAX_VALUE, ydelta = Integer.MAX_VALUE;
        // find x and y deltas to move (least x and y of some nodes)
        for (final EditPart editPart : (Collection<EditPart>) viewer.getContents().getChildren()) {
            if (editPart instanceof NodeEditPart) {
                final Rectangle bounds = ((GraphicalEditPart) editPart).getFigure().getBounds();
                xdelta = Math.min(xdelta, bounds.x);
                ydelta = Math.min(ydelta, bounds.y);
            }
        }

        final CompoundCommand compCommand = new CompoundCommand();
        // build commands
        final ChangeBoundsRequest request = new ChangeBoundsRequest(RequestConstants.REQ_MOVE);
        request.setMoveDelta(new Point(-xdelta + INSETS, -ydelta + INSETS));
        for (final EditPart editPart : (Collection<EditPart>) viewer.getContents().getChildren()) {
            final Command command = editPart.getCommand(request);
            // Some editparts may return unexecutable commands
            if (command != null && command.canExecute()) {
                compCommand.add(command);
            }
        }
        // this allows to use this action independently from an editor
        if (getWorkbenchPart() == null || getCommandStack() == null) {
            compCommand.execute();
        } else {
            execute(compCommand);
        }
    }

    /**
     * This setter allows universal usage of this action. Just call the
     * constructor with <code>null</code> and set the viewer to trim manually.
     * 
     * @param viewer
     */
    public void setViewer(final EditPartViewer viewer) {
        this.viewer = viewer;
    }

    /**
     * This action is enabled if some graphical edit part is currently selected
     * from which a viewer can be determined to be trimmed.
     */
    @Override
    protected boolean calculateEnabled() {
        if (getSelection() == null) {
            return false;
        }
        if (getSelection() instanceof IStructuredSelection) {
            final IStructuredSelection selection = (IStructuredSelection) getSelection();
            for (final Object selectedObject : selection.toList()) {
                if (selectedObject instanceof GraphicalEditPart) {
                    viewer = ((GraphicalEditPart) selectedObject).getViewer();
                    return viewer != null;
                }
            }
        }
        return false;
    }

}