toppanel.java

ajax例子,Google Web Toolkit 1.0.21

// Copyright 2006 Google Inc. All Rights Reserved.
package com.google.gwt.sample.mail.client;

import com.google.gwt.user.client.Window;
import com.google.gwt.user.client.ui.ClickListener;
import com.google.gwt.user.client.ui.Composite;
import com.google.gwt.user.client.ui.HTML;
import com.google.gwt.user.client.ui.HorizontalPanel;
import com.google.gwt.user.client.ui.VerticalPanel;
import com.google.gwt.user.client.ui.Widget;

/**
 * The top panel, which contains the 'welcome' message and various links.
 */
public class TopPanel extends Composite implements ClickListener {

  private HTML signOutLink = new HTML("<a href='javascript:;'>Sign Out</a>");
  private HTML aboutLink = new HTML("<a href='javascript:;'>About</a>");

  public TopPanel() {
    HorizontalPanel outer = new HorizontalPanel();
    VerticalPanel inner = new VerticalPanel();

    outer.setHorizontalAlignment(HorizontalPanel.ALIGN_RIGHT);
    inner.setHorizontalAlignment(HorizontalPanel.ALIGN_RIGHT);

    HorizontalPanel links = new HorizontalPanel();
    links.setSpacing(4);
    links.add(signOutLink);
    links.add(aboutLink);

    outer.add(inner);
    inner.add(new HTML("<b>Welcome back, [e-mail]</b>"));
    inner.add(links);

    signOutLink.addClickListener(this);
    aboutLink.addClickListener(this);

    setWidget(outer);
    inner.setStyleName("mail-TopPanel");
    links.setStyleName("mail-TopPanelLinks");
  }

  public void onClick(Widget sender) {
    if (sender == signOutLink) {
      Window.alert("If this were implemented, you would be signed out now.");
    } else if (sender == aboutLink) {
      // When the 'About' item is selected, show the AboutDialog.
      // Note that showing a dialog box does not block -- execution continues
      // normally, and the dialog fires an event when it is closed.
      AboutDialog dlg = new AboutDialog();

      // Position it roughly in the middle of the screen.
      int left = (Window.getClientWidth() - 512) / 2;
      int top = (Window.getClientHeight() - 256) / 2;
      dlg.setPopupPosition(left, top);

      dlg.show();
    }
  }
}