tooltipeditpolicy.java

对eclipse gef进行封装,可以生成图形化编辑器

/*******************************************************************************
 * $Header: /cvsroot/EOS6/work_dir/niegy/com.primeton.studio.gef.ui/src/com/primeton/studio/gef/ui/ui/policy/TooltipEditPolicy.java,v 1.1 2006/11/17 03:15:13 niegy Exp $
 * $Revision: 1.1 $
 * $Date: 2006/11/17 03:15:13 $
 *
 *==============================================================================
 *
 * Copyright (c) 2001-2006 Primeton Technologies, Ltd.
 * All rights reserved. 
 * 
 * Created on 2006-9-28
 *******************************************************************************/


package com.primeton.studio.gef.ui.ui.policy;

import org.eclipse.gef.Request;
import org.eclipse.gef.editpolicies.AbstractEditPolicy;
import org.eclipse.gef.requests.LocationRequest;
import org.eclipse.jface.internal.text.link.contentassist.HTMLTextPresenter;
import org.eclipse.jface.text.DefaultInformationControl;
import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.widgets.Display;

import com.primeton.studio.gef.ui.parts.NodeEditPartEx;


/**
 * TODO此处填写 class 信息
 *
 * @author niegy (mailto:[e-mail])
 */
/*
 * 修改历史
 * $Log: TooltipEditPolicy.java,v $
 * Revision 1.1  2006/11/17 03:15:13  niegy
 * create
 * 
 */
public class TooltipEditPolicy extends AbstractEditPolicy {
    public static final String TOOLTIP_ROLE="tooltip_role";
	
	private DefaultInformationControl informationControl = null;

	/* (non-Javadoc)
	 * @see org.eclipse.gef.EditPolicy#eraseTargetFeedback(org.eclipse.gef.Request)
	 */
	public void eraseTargetFeedback(Request request) {
		if (request.getType().equals(REQ_SELECTION_HOVER)) {
			hideToolTip();
		} else
			super.eraseTargetFeedback(request);
	}
	/* (non-Javadoc)
	 * @see org.eclipse.gef.EditPolicy#showTargetFeedback(org.eclipse.gef.Request)
	 */
	public void showTargetFeedback(Request request) {
		if (request.getType().equals(REQ_SELECTION_HOVER)) {
			if(request instanceof LocationRequest){
				Point location=new Point(((LocationRequest)request).getLocation().x,
						((LocationRequest)request).getLocation().y);
				showToolTip(location);
			}
			
		} else
			super.showTargetFeedback(request);
	}
	
	private void showToolTip(Point location){
		if(getGraphicalNodeEditPart().isShowTipOnTop()) return;//tooltip showing on top
		
		String toolTipContent=getGraphicalNodeEditPart().getToolTipContent();
		if(toolTipContent==null) return;//have no tooltip
		
		String statusText=null;
		if(getHost().getViewer().getSelectedEditParts().contains(getHost()))
			statusText="Press \'F2\' for focus";
		
		if(informationControl==null){		
			informationControl = new DefaultInformationControl(null, SWT.NONE, new HTMLTextPresenter(true), statusText);
			informationControl.setSizeConstraints(Integer.MAX_VALUE, Integer.MAX_VALUE);
			informationControl.setInformation(toolTipContent);
	
			Point p=this.getHost().getViewer().getControl().toDisplay(location);
			setHoverLocation(informationControl, p, informationControl.computeSizeHint(), 26);
			informationControl.setVisible(true);
		}
	}
	
	protected NodeEditPartEx getGraphicalNodeEditPart(){
		return (NodeEditPartEx)getHost();
	}
	
	private void hideToolTip(){
		if (informationControl != null) {
			informationControl.setVisible(false);
			informationControl.dispose();
			informationControl = null;
		}
	}
	
	private void setHoverLocation(DefaultInformationControl infoControl, Point p, Point size, int offset) {
		Display display=getHost().getViewer().getControl().getDisplay();
		Rectangle displayBounds = display.getBounds();
		size.x = Math.min(500, size.x);
		size.y = Math.min(350, size.y);

		if (p.x + size.x > displayBounds.width) {
			p.x = displayBounds.width - size.x;
		}
		if (p.y + size.y + offset > displayBounds.height) {
			p.y = p.y - size.y - offset - 16;
		}
		infoControl.setLocation(new Point(p.x, p.y + offset));
		infoControl.setSize(size.x, size.y);
	}
}