In this example we shall show you how to create a CheckBox example using the Google Web Toolkit, that is an open source set of tools that allows web developers to create and maintain complex JavaScript front-end applications in Java. To create a CheckBox example one should perform the following steps:
- The
CheckBoxExampleclass implements thecom.google.gwt.core.client.EntryPointinterface to allow the class to act as a module entry point. It overrides itsonModuleLoad()method. - Create a new VerticalPanel.
- Create a few instances of CheckBox.
- Add a ClickHandler to the check box and override its
onClick(ClickEvent event)method to handle the click events. - Add the check box to the VerticalPanel.
- Add the VerticalPanel to the
RootPanel, that is the panel to which all other widgets must ultimately be added,
as described in the code snippet below.
01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 | package com.javacodegeeks.snippets.enterprise;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.CheckBox;import com.google.gwt.user.client.ui.RootPanel;import com.google.gwt.user.client.ui.VerticalPanel;public class CheckBoxExample implements EntryPoint { final String[] Items = { "Item0", "Item1", "Item2", "Item3", "Item4", "Item5" }; @Override public void onModuleLoad() { // Create new Instance of vertical panel to align the check boxes VerticalPanel vp = new VerticalPanel(); // Create i Instances of CheckBox() for (int i = 0; i < Items.length; i++) {// Add Item final CheckBox checkBox = new CheckBox(Items[i]);// Add ClickHandler checkBox.addClickHandler(new ClickHandler(){ @Override public void onClick(ClickEvent event) { check(checkBox); } });//Set some checkBoxes disabled by default if (i > 3) checkBox.setEnabled(false);//Add checkBox to Vertical Panel vp.add(checkBox); } //Add Vertical Panel to Root Panel RootPanel.get().add(vp); } // Method that notifies the user whether a checkBox is checked or not public void check(CheckBox checkBox){ boolean checked = checkBox.getValue(); Window.alert(checkBox.getText() + " is " + (checked ? "" : "not ") + "checked"); }} |
This was an example of how to create a CheckBox example using the Google Web Toolkit.
