shellcalccomposite.java

mywork是rcp开发的很好的例子

package net.sf.pim.calc;

import net.sf.util.StringUtil;

import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.BusyIndicator;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.layout.RowLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Text;

import bsh.Interpreter;

/**
 * 计算组件，对用户的文本输入，实现如下三种计算
 * 1.列求和，常用于周报中时间汇种
 * 2.表达式求值，也可替代计算器的功能
 * 3.groovy代码片段执行
 * 其中，2,3均采用groovy实现
 * 因为beanshell的性能比groovy好，而且更小巧，用beanshell替代groovy
 * @author levin
 *
 */
public class ShellCalcComposite extends Composite{
	//输入
	private Text input;
	//输出，只读
	private Text output;

	public ShellCalcComposite(Composite parent, int style) {
		super(parent, style);
		create();
	}

	private void create(){
		final GridLayout gridLayout = new GridLayout();
		gridLayout.numColumns=3;
		setLayout(gridLayout);

		input = new Text(this,SWT.WRAP | SWT.V_SCROLL);
		GridData gridData = new GridData(GridData.FILL_BOTH);
		gridData.verticalSpan=3;
		input.setLayoutData(gridData);
		
		Composite group=new Composite(this,SWT.NULL);
		RowLayout rowLayout=new RowLayout(SWT.VERTICAL);
		rowLayout.spacing = 5;
		group.setLayout(rowLayout);
		
		Button sum=new Button(group,SWT.FLAT);
		sum.setText("求和");
		sum.addSelectionListener(new SelectionAdapter(){
			public void widgetSelected(SelectionEvent e) {
				if(input.getText().equals("")) return ;
				try{
					String[] ss=StringUtil.toArray(input.getText(), "\r\n");
					double total=0.0;
					for(int i=0;i<ss.length;i++)
						total += StringUtil.parseDouble(convert(ss[i]));
					output.setText(String.valueOf(total));
				}catch(Exception ex){
					output.setText("求和失败!"+ex);
				}
			}});
		
		Button eval=new Button(group,SWT.FLAT);
		eval.setText("运算");
		eval.addSelectionListener(new SelectionAdapter(){
			public void widgetSelected(SelectionEvent e) {
				if(input.getText().equals("")) return ;
				BusyIndicator.showWhile(Display.getCurrent(), new Runnable() {
					public void run() {
						try {
							Interpreter shell = new Interpreter();
							Object value = shell.eval(input.getText());
							output.setText(String.valueOf(value));
						} catch (Exception ex) {
							output.setText("运算失败!" + ex);
						}
					}
				});
			}
		});
		
		Button run=new Button(group,SWT.FLAT);
		run.setText("执行");
		run.setEnabled(false);
		
		Button clear=new Button(group,SWT.FLAT);
		clear.setText("清除");
		clear.addSelectionListener(new SelectionAdapter(){
			public void widgetSelected(SelectionEvent e) {
				output.setText("");	
			}});
		
		output = new Text(this,SWT.WRAP | SWT.V_SCROLL|SWT.READ_ONLY);
		output.setLayoutData(gridData);
		output.setBackground(Display.getCurrent().getSystemColor(SWT.COLOR_WHITE));
	}

	//对字符串进行处理
	private static String convert(String string) {
		String str=string;
		if(StringUtil.isNull(string)) 
			str="";
		//去掉前或后问号
		String mask="?？%％";
		if(mask.indexOf(string.charAt(0)) != -1)
			str=string.substring(1);
		if(mask.indexOf(string.charAt(string.length()-1)) != -1)
			str=string.substring(0,string.length()-1);
		return str;
	}
}