/*******************************************************************************
 * <copyright>
 *
 * Copyright (c) 2005, 2010 SAP AG.
 * 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:
 *    SAP AG - initial API, implementation and documentation
 *
 * </copyright>
 *
 *******************************************************************************/
/*
 * Created on 06.07.2005
 */
package org.eclipse.graphiti.features.impl;

import org.eclipse.graphiti.datatypes.IDimension;
import org.eclipse.graphiti.features.IFeatureProvider;
import org.eclipse.graphiti.features.IMoveAnchorFeature;
import org.eclipse.graphiti.features.context.IContext;
import org.eclipse.graphiti.features.context.IMoveAnchorContext;
import org.eclipse.graphiti.internal.Messages;
import org.eclipse.graphiti.mm.algorithms.GraphicsAlgorithm;
import org.eclipse.graphiti.mm.pictograms.AdvancedAnchor;
import org.eclipse.graphiti.mm.pictograms.Anchor;
import org.eclipse.graphiti.mm.pictograms.AnchorContainer;
import org.eclipse.graphiti.mm.pictograms.BoxRelativeAnchor;
import org.eclipse.graphiti.mm.pictograms.FixPointAnchor;
import org.eclipse.graphiti.services.Graphiti;

/**
 * The Class DefaultMoveAnchorFeature.
 */
public class DefaultMoveAnchorFeature extends AbstractFeature implements IMoveAnchorFeature {

	/**
	 * Creates a new {@link DefaultMoveAnchorFeature}.
	 * 
	 * @param fp
	 *            the feature provider
	 */
	public DefaultMoveAnchorFeature(IFeatureProvider fp) {
		super(fp);
	}

	public boolean canMoveAnchor(IMoveAnchorContext context) {
		Anchor anchor = context.getAnchor();
		return (anchor instanceof FixPointAnchor || anchor instanceof BoxRelativeAnchor);
	}

	public void moveAnchor(IMoveAnchorContext context) {
		if (!getUserDecision()) {
			return;
		}
		int posX = context.getX();
		int posY = context.getY();

		moveAnchor(context.getAnchor(), posX, posY);
	}

	public void preMoveAnchor(IMoveAnchorContext context) {
	}

	public void postMoveAnchor(IMoveAnchorContext context) {
	}

	/**
	 * Move anchor.
	 * 
	 * @param anchor
	 *            the anchor
	 * @param posX
	 *            the pos x
	 * @param posY
	 *            the pos y
	 */
	protected void moveAnchor(Anchor anchor, int posX, int posY) {

		if (anchor instanceof AdvancedAnchor) {
			posX -= anchor.getGraphicsAlgorithm().getX();
			posY -= anchor.getGraphicsAlgorithm().getY();
		}

		if (anchor instanceof FixPointAnchor) {
			FixPointAnchor fpAnchor = (FixPointAnchor) anchor;
			fpAnchor.setLocation(Graphiti.getGaCreateService().createPoint(posX, posY));
		} else if (anchor instanceof BoxRelativeAnchor) {
			BoxRelativeAnchor brAnchor = (BoxRelativeAnchor) anchor;
			AnchorContainer anchorContainer = brAnchor.getParent();
			GraphicsAlgorithm anchorContainerGa = anchorContainer.getGraphicsAlgorithm();
			IDimension sizeOfGraphicsAlgorithm = Graphiti.getGaService().calculateSize(anchorContainerGa, false);
			int width = sizeOfGraphicsAlgorithm.getWidth();
			double newRelativeX = 1d * posX / width;
			brAnchor.setRelativeWidth(newRelativeX);
			int height = sizeOfGraphicsAlgorithm.getHeight();
			double newRelativeY = 1d * posY / height;
			brAnchor.setRelativeHeight(newRelativeY);
		}
	}

	public boolean canExecute(IContext context) {
		boolean ret = false;
		if (context instanceof IMoveAnchorContext) {
			ret = canMoveAnchor((IMoveAnchorContext) context);
		}
		return ret;
	}

	public void execute(IContext context) {
		if (context instanceof IMoveAnchorContext) {
			moveAnchor((IMoveAnchorContext) context);
		}
	}

	@Override
	public String getName() {
		return NAME;
	}

	private static final String NAME = Messages.DefaultMoveAnchorFeature_0_xfld;
}