com.google.gwt.examples.FormPanelExample.java Source code

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Here is the source code for com.google.gwt.examples.FormPanelExample.java

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/*
 * Copyright 2007 Google Inc.
 * 
 * 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.google.gwt.examples;

import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.user.client.Window;
import com.google.gwt.user.client.ui.Button;
import com.google.gwt.user.client.ui.FileUpload;
import com.google.gwt.user.client.ui.FormPanel;
import com.google.gwt.user.client.ui.ListBox;
import com.google.gwt.user.client.ui.RootPanel;
import com.google.gwt.user.client.ui.TextBox;
import com.google.gwt.user.client.ui.VerticalPanel;
import com.google.gwt.user.client.ui.FormPanel.SubmitCompleteEvent;
import com.google.gwt.user.client.ui.FormPanel.SubmitEvent;

public class FormPanelExample implements EntryPoint {

    public void onModuleLoad() {
        // Create a FormPanel and point it at a service.
        final FormPanel form = new FormPanel();
        form.setAction("/myFormHandler");

        // Because we're going to add a FileUpload widget, we'll need to set the
        // form to use the POST method, and multipart MIME encoding.
        form.setEncoding(FormPanel.ENCODING_MULTIPART);
        form.setMethod(FormPanel.METHOD_POST);

        // Create a panel to hold all of the form widgets.
        VerticalPanel panel = new VerticalPanel();
        form.setWidget(panel);

        // Create a TextBox, giving it a name so that it will be submitted.
        final TextBox tb = new TextBox();
        tb.setName("textBoxFormElement");
        panel.add(tb);

        // Create a ListBox, giving it a name and some values to be associated with
        // its options.
        ListBox lb = new ListBox();
        lb.setName("listBoxFormElement");
        lb.addItem("foo", "fooValue");
        lb.addItem("bar", "barValue");
        lb.addItem("baz", "bazValue");
        panel.add(lb);

        // Create a FileUpload widget.
        FileUpload upload = new FileUpload();
        upload.setName("uploadFormElement");
        panel.add(upload);

        // Add a 'submit' button.
        panel.add(new Button("Submit", new ClickHandler() {
            public void onClick(ClickEvent event) {
                form.submit();
            }
        }));

        // Add an event handler to the form.
        form.addSubmitHandler(new FormPanel.SubmitHandler() {
            public void onSubmit(SubmitEvent event) {
                // This event is fired just before the form is submitted. We can take
                // this opportunity to perform validation.
                if (tb.getText().length() == 0) {
                    Window.alert("The text box must not be empty");
                    event.cancel();
                }
            }
        });
        form.addSubmitCompleteHandler(new FormPanel.SubmitCompleteHandler() {
            public void onSubmitComplete(SubmitCompleteEvent event) {
                // When the form submission is successfully completed, this event is
                // fired. Assuming the service returned a response of type text/html,
                // we can get the result text here (see the FormPanel documentation for
                // further explanation).
                Window.alert(event.getResults());
            }
        });

        RootPanel.get().add(form);
    }
}