/*******************************************************************************
 * Copyright (c) 2003, 2010 IBM Corporation and others.
 * 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:
 * *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.gef.internal.ui.rulers;

import java.util.List;

import org.eclipse.swt.accessibility.AccessibleEvent;

import org.eclipse.draw2d.IFigure;

import org.eclipse.gef.AccessibleEditPart;
import org.eclipse.gef.DragTracker;
import org.eclipse.gef.EditPart;
import org.eclipse.gef.EditPolicy;
import org.eclipse.gef.GraphicalViewer;
import org.eclipse.gef.LayerConstants;
import org.eclipse.gef.Request;
import org.eclipse.gef.editparts.AbstractGraphicalEditPart;
import org.eclipse.gef.editparts.LayerManager;
import org.eclipse.gef.editparts.ZoomManager;
import org.eclipse.gef.editpolicies.SelectionEditPolicy;
import org.eclipse.gef.internal.GEFMessages;
import org.eclipse.gef.requests.SelectionRequest;
import org.eclipse.gef.rulers.RulerChangeListener;
import org.eclipse.gef.rulers.RulerProvider;

/**
 * @author Pratik Shah
 * @since 3.0
 */
public class RulerEditPart extends AbstractGraphicalEditPart {

	protected GraphicalViewer diagramViewer;
	private AccessibleEditPart accPart;
	private RulerProvider rulerProvider;
	private boolean horizontal;
	private RulerChangeListener listener = new RulerChangeListener.Stub() {
		public void notifyGuideReparented(Object guide) {
			handleGuideReparented(guide);
		}

		public void notifyUnitsChanged(int newUnit) {
			handleUnitsChanged(newUnit);
		}
	};

	public RulerEditPart(Object model) {
		setModel(model);
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.gef.editparts.AbstractGraphicalEditPart#activate()
	 */
	public void activate() {
		getRulerProvider().addRulerChangeListener(listener);
		getRulerFigure().setZoomManager(getZoomManager());
		super.activate();
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.gef.editparts.AbstractEditPart#createEditPolicies()
	 */
	protected void createEditPolicies() {
		/*
		 * @TODO:Pratik the right way of creating guides and figuring out the
		 * target edit part is by installing an edit policy with container role.
		 * talk to randy about how this should work. would isMove() in
		 * GuideEditPart's drag tracker still have to return true all the time?
		 */
		// installEditPolicy(EditPolicy.CONTAINER_ROLE, );
		installEditPolicy(EditPolicy.SELECTION_FEEDBACK_ROLE,
				new RulerSelectionPolicy());
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.gef.editparts.AbstractGraphicalEditPart#createFigure()
	 */
	protected IFigure createFigure() {
		RulerFigure ruler = new RulerFigure(isHorizontal(), getRulerProvider()
				.getUnit());
		if (ruler.getUnit() == RulerProvider.UNIT_PIXELS)
			ruler.setInterval(100, 2);
		return ruler;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.gef.editparts.AbstractGraphicalEditPart#deactivate()
	 */
	public void deactivate() {
		super.deactivate();
		getRulerProvider().removeRulerChangeListener(listener);
		rulerProvider = null;
		getRulerFigure().setZoomManager(null);
	}

	protected AccessibleEditPart getAccessibleEditPart() {
		if (accPart == null)
			accPart = new AccessibleGraphicalEditPart() {
				public void getName(AccessibleEvent e) {
					e.result = isHorizontal() ? GEFMessages.Ruler_Horizontal_Label
							: GEFMessages.Ruler_Vertical_Label;
				}

				public void getDescription(AccessibleEvent e) {
					e.result = GEFMessages.Ruler_Desc;
				}
			};
		return accPart;
	}

	/**
	 * Returns the GraphicalViewer associated with the diagram.
	 * 
	 * @return graphical viewer associated with the diagram.
	 */
	protected GraphicalViewer getDiagramViewer() {
		return diagramViewer;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see
	 * org.eclipse.gef.editparts.AbstractGraphicalEditPart#getDragTracker(org
	 * .eclipse.gef.Request)
	 */
	public DragTracker getDragTracker(Request request) {
		if (request.getType().equals(REQ_SELECTION)
				&& ((SelectionRequest) request).getLastButtonPressed() != 1) {
			return null;
		}
		return new RulerDragTracker(this);
	}

	public IFigure getGuideLayer() {
		LayerManager lm = (LayerManager) diagramViewer.getEditPartRegistry()
				.get(LayerManager.ID);
		if (lm != null)
			return lm.getLayer(LayerConstants.GUIDE_LAYER);
		return null;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.gef.editparts.AbstractEditPart#getModelChildren()
	 */
	protected List getModelChildren() {
		return getRulerProvider().getGuides();
	}

	protected RulerFigure getRulerFigure() {
		return (RulerFigure) getFigure();
	}

	public RulerProvider getRulerProvider() {
		return rulerProvider;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.gef.EditPart#getTargetEditPart(org.eclipse.gef.Request)
	 */
	public EditPart getTargetEditPart(Request request) {
		if (request.getType().equals(REQ_MOVE)) {
			return this;
		} else {
			return super.getTargetEditPart(request);
		}
	}

	public ZoomManager getZoomManager() {
		return (ZoomManager) diagramViewer.getProperty(ZoomManager.class
				.toString());
	}

	public void handleGuideReparented(Object guide) {
		refreshChildren();
		EditPart guidePart = (EditPart) getViewer().getEditPartRegistry().get(
				guide);
		if (guidePart != null) {
			getViewer().select(guidePart);
		}
	}

	public void handleUnitsChanged(int newUnit) {
		getRulerFigure().setUnit(newUnit);
		if (newUnit == RulerProvider.UNIT_PIXELS)
			getRulerFigure().setInterval(100, 2);
		else
			getRulerFigure().setInterval(0, 0);
	}

	public boolean isHorizontal() {
		return horizontal;
	}

	public void setParent(EditPart parent) {
		super.setParent(parent);
		if (getParent() != null && diagramViewer == null) {
			diagramViewer = (GraphicalViewer) getViewer().getProperty(
					GraphicalViewer.class.toString());
			RulerProvider hProvider = (RulerProvider) diagramViewer
					.getProperty(RulerProvider.PROPERTY_HORIZONTAL_RULER);
			if (hProvider != null && hProvider.getRuler() == getModel()) {
				rulerProvider = hProvider;
				horizontal = true;
			} else {
				rulerProvider = (RulerProvider) diagramViewer
						.getProperty(RulerProvider.PROPERTY_VERTICAL_RULER);
			}
		}
	}

	public static class RulerSelectionPolicy extends SelectionEditPolicy {
		protected void hideFocus() {
			((RulerFigure) getHostFigure()).setDrawFocus(false);
		}

		protected void hideSelection() {
			((RulerFigure) getHostFigure()).setDrawFocus(false);
		}

		protected void showFocus() {
			((RulerFigure) getHostFigure()).setDrawFocus(true);
		}

		protected void showSelection() {
			((RulerFigure) getHostFigure()).setDrawFocus(true);
		}
	}

}
