statuslinecontribution.java

基于Eclipse RCP开发的管理工具

 /*  
  * Copyright 2006 Marcel Schoffelmeer 
  * 
  * Licensed under the Apache License, Version 2.0 (the "License"); 
  * you may not use this file except in compliance with the License. 
  * You may obtain a copy of the License at 
  * 
  *    http://www.apache.org/licenses/LICENSE-2.0 
  *    
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS, 
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

package com.s10r.manager;

import org.eclipse.jface.action.ContributionItem;
import org.eclipse.jface.action.IContributionManager;
import org.eclipse.jface.action.StatusLineLayoutData;
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.CLabel;
import org.eclipse.swt.graphics.FontMetrics;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Listener;

// P280 chap 17.7 Adding Contributions to the Status Line

public class StatusLineContribution extends ContributionItem
{

	public final static int DEFAULT_CHAR_WIDTH = 40;

	private CLabel label;

	private Image image;

	// TODO: remove when completed status work
	private String text = ""; //$NON-NLS-1$

	private int widthInChars = -1;


	private Listener listener;

	private int eventType;

	private String tooltip;

	public StatusLineContribution(String id)
	{
		this(id, DEFAULT_CHAR_WIDTH);
	}

	public StatusLineContribution(String id, int charWidth)
	{
		super(id);
		this.widthInChars = charWidth;
		setVisible(true); // no text to start with
	}

	public void fill(Composite parent)
	{
		Label sep = new Label(parent, SWT.SEPARATOR);
		label = new CLabel(parent, SWT.SHADOW_NONE);

		GC gc = new GC(parent);
		gc.setFont(parent.getFont());		
		FontMetrics fm = gc.getFontMetrics();
		
        int widthHint = fm.getAverageCharWidth() * widthInChars;
		int heightHint = fm.getHeight();
		gc.dispose();

		StatusLineLayoutData statusLineLayoutData = new StatusLineLayoutData();
		statusLineLayoutData.widthHint = widthHint;
		// TODO: if we set the heightHint as the RCP book page 281,
		// switching between the properties view and the editor will cause
		// both the status field in increase in width with each switch back
		// to the editor, causing the right field to disappear from the right
		// side of the status bar!
		//
		// statusLineLayoutData.heightHint = heightHint;
		
		label.setLayoutData(statusLineLayoutData);
		label.setText(text);
		label.setImage(image);
		if (listener != null)
		{
			label.addListener(eventType, listener);
		}
		if (tooltip != null)
		{
			label.setToolTipText(tooltip);
		}

		statusLineLayoutData = new StatusLineLayoutData();
		statusLineLayoutData.heightHint = heightHint;
		sep.setLayoutData(statusLineLayoutData);

	}

	public void addListener(int eventType, Listener listener)
	{
		this.eventType = eventType;
		this.listener = listener;
	}

	public String getText()
	{
		return text;
	}

	public void setText(String text)
	{
		
		if (text == null)
		{
			throw new NullPointerException();
		}

		this.text = text;

		if (label != null && !label.isDisposed())
		{
			label.setText(this.text);
		}

		if (this.text.length() == 0)
		{
			if (isVisible())
			{
				setVisible(false);
				IContributionManager contributionManager = getParent();

				if (contributionManager != null)
					contributionManager.update(true);
			}
		}
		else
		{
			if (!isVisible())
			{
				setVisible(true);
				IContributionManager contributionManager = getParent();

				if (contributionManager != null)
					contributionManager.update(true);
			}
		}
	}

	public void setTooltip(String tooltip)
	{
		if (tooltip == null)
		{
			throw new NullPointerException();
		}
		this.tooltip = tooltip;

		if (label != null && !label.isDisposed())
		{
			label.setToolTipText(this.tooltip);
		}
	}

	public void setImage(Image image)
	{
		if (image == null)
			throw new NullPointerException();

		this.image = image;

		if (label != null && !label.isDisposed())
			label.setImage(this.image);

		if (!isVisible())
		{
			setVisible(true);
			IContributionManager contributionManager = getParent();

			if (contributionManager != null)
				contributionManager.update(true);
		}
	}

	
}