Google Visualization API Library now available for Google Web Toolkit

DEC 09, 2008
By Uwe Maurer, Google Engineer

We're happy to announce the Google Visualization API Library for Google Web Toolkit (GWT). This has been a requested addition to GWT for some time now on the developer forum and we are excited to make it available.

You can now utilize the visualization and reporting capabilities of the Google Visualization API while writing native Java code for your GWT applications and enjoy the best of both worlds. The library includes wrappers for many of Google's visualizations, such as Bar Chart, Annotated Time Line, Map, Motion Chart, Organizational Chart and many others. We have marked all the visualizations that are currently supported by this library in the Visualization Gallery.

The library also includes classes that enable you to easily wrap any existing Visualization API-compliant visualization in GWT so that you can access it from Java complied by the GWT compiler. So if you want to wrap your own visualization or the nifty Piles of Money visualization, you can easily do so.

Lastly, the library includes a class that makes it easy to write new visualizations in GWT-compiled Java and make it available as JS for general use in the Visualization API. This is cool if you've been itching to contribute new visualizations but prefer coding in Java.

Here is example code that draws the well known Annotated Time Line chart in Java using the new Visualization API Library:

UPDATE: Changed the code font size to fit on one line so you can copy & paste

package com.blogpost.client;

import com.google.gwt.core.client.EntryPoint;
import
      com.google.gwt.user.client.Window;
import
      com.google.gwt.user.client.ui.RootPanel;
import
      com.google.gwt.visualization.client.AjaxLoader;
import
      com.google.gwt.visualization.client.DataTable;
import
      com.google.gwt.visualization.client.Query;
import
      com.google.gwt.visualization.client.QueryResponse;
import
      com.google.gwt.visualization.client.Query.Callback;
import
      com.google.gwt.visualization.client.visualizations.AnnotatedTimeLine;


public class BlogPost implements EntryPoint {
 public void
      onModuleLoad() {
 AjaxLoader.loadVisualizationApi(new Runnable(){

      public void run() {
 Query query = 

      Query.create("http://spreadsheets.google.com/pub?key=pCQbetd-CptH5QNY89vLtAg");

      query.send(new Callback(){
 
 public void onResponse(QueryResponse
      response) {
 if (response.isError()) {
 Window.alert("An error occured:
      " + response.getDetailedMessage());
 }

 DataTable data =
      response.getDataTable();
 AnnotatedTimeLine.Options options =
      AnnotatedTimeLine.Options.create();
 options.setDisplayAnnotations(true);
 RootPanel.get().add(new AnnotatedTimeLine(data, options, "800px", "400px"));

      }
 });
 }}, AnnotatedTimeLine.PACKAGE);
 }
}



This code draws the same visualization that can be seen in the example for Annotated Time Line in the Visualization Gadget Gallery. Both get their data from Google Spreadsheets, only this code does so in Java instead of Javascript or as a Gadget.

Enjoy!
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