SWT工具栏菜单的实现

弹出菜单要定义为SWT.POP_UP

带有下拉按钮的工具栏按钮要设置为SWT.DROP_DOWN

判断是否是单击下拉按钮事件的方法代码：

if(event.detail == SWT.ARROW)

显示菜单时，要先计算出菜单所要出现的位置，然后通过setLocation(x,y)方法定位菜单，最后使用setVisible(true)方法将菜单显示出来。

package com.layotech.www.toolbar;

import org.eclipse.swt.SWT;

import org.eclipse.swt.graphics.Point;

import org.eclipse.swt.graphics.Rectangle;

import org.eclipse.swt.layout.GridData;

import org.eclipse.swt.layout.GridLayout;

import org.eclipse.swt.widgets.Composite;

import org.eclipse.swt.widgets.Display;

import org.eclipse.swt.widgets.Event;

import org.eclipse.swt.widgets.Listener;

import org.eclipse.swt.widgets.Menu;

import org.eclipse.swt.widgets.MenuItem;

import org.eclipse.swt.widgets.Shell;

import org.eclipse.swt.widgets.Text;

import org.eclipse.swt.widgets.ToolBar;

import org.eclipse.swt.widgets.ToolItem;

import com.layotech.www.facory.ImageFactory;

public class ToolBarSample {

public static void main(String[] args) {

Display display = new Display();

Shell shell = new Shell(display);

shell.setText("ToolBar");

shell.setLayout(new GridLayout());

Composite tool = new Composite(shell, SWT.NONE);

tool.setLayoutData(new GridData(SWT.LEFT, SWT.TOP,true,false));

//创建工具栏对象

final ToolBar toolBar = new ToolBar(tool, SWT.FLAT);

//创建打开按钮

ToolItem openItem = new ToolItem(toolBar, SWT.NONE);

openItem.setImage(ImageFactory.loadImage(display, ImageFactory.OPEN_IMAGE));

openItem.setText("打开");

openItem.setToolTipText("打开");

final ToolItem helpItem = new ToolItem(toolBar, SWT.DROP_DOWN);

helpItem.setImage(ImageFactory.loadImage(display, ImageFactory.PREVIEW_IMAGE));

helpItem.setText("帮助");

helpItem.setToolTipText("帮助");

final Menu helpMenu = new Menu(shell,SWT.POP_UP);

MenuItem welcomeItem = new MenuItem(helpMenu, SWT.PUSH);

welcomeItem.setText("欢迎");

new MenuItem(helpMenu, SWT.SEPARATOR);

MenuItem updateItem = new MenuItem(helpMenu, SWT.PUSH);

updateItem.setText("在线更新");

MenuItem aboutItem = new MenuItem(helpMenu, SWT.PUSH);

aboutItem.setText("关于我们");

helpItem.addListener(SWT.Selection, new Listener() {

@Override

public void handleEvent(Event event) {

if(event.detail == SWT.ARROW){

//获得帮助按钮所在的坐标位置和大小

Rectangle rec = helpItem.getBounds();

//计算出菜单出现的起始位置

Point point = new Point(rec.x, rec.y+rec.height);

//将该店转化为与屏幕相对的点

point = toolBar.toDisplay(point);

//设置菜单的位置

helpMenu.setLocation(point.x,point.y);

helpMenu.setVisible(true);

}

}

});

toolBar.pack();

Text content = new Text(shell, SWT.MULTI);

content.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true));

shell.setSize(200,150);

shell.open();

while(!shell.isDisposed()){

if(!display.readAndDispatch()){

display.sleep();

}

}

ImageFactory.dispose();

display.dispose();

}

}