GWT Highcharts - Quick Guide

GWT Highcharts - Overview

GWT Highcharts is a open source java based library to provides an elegant and feature rich Highcharts visualizations within a GWT application and can be used along with GWT widget libraries.

Features

• Compatible - All modern browsers are supported along with iPhone/iPad browsers and Internet Explorer 6 onwards. Modern browsers use SVG for the graphics rendering and in legacy Internet Explorer graphics are drawn using VML.

• Pure Java - No JavaScript is required as complete Highcharts API is available in Java methods.

• No Flash - No requirement of client side plug-ins like Flash player or Java as Highcharts is uses native browser technologies and charts can run without modification on modern mobile devices.

• Clean Syntax - Most of the methods are chainable thus configuration options of the chart can be managed using syntax as tight as JSON.

• Dynamic - Series and points can be added dynamically any time after chart creation. Event hooks supported. Server interactions are supported.

• Documented - Highcharts APIs are thoroughly documented with numerous code and syntax examples.

GWT Highcharts - Environment Setup

This tutorial will guide you on how to prepare a development environment to start your work with Highcharts and GWT Framework. This tutorial will also teach you how to setup JDK, Tomcat and Eclipse on your machine before you setup GWT Framework −

System Requirement

GWT requires JDK 1.6 or higher so the very first requirement is to have JDK installed in your machine.

Follow the given steps to setup your environment to start with GWT application development.

Step 1 - Verify Java Installation on your Machine

Now open console and execute the following java command.

Let's verify the output for all the operating systems

Step 2 - Setup Java Development Kit (JDK)

If you do not have Java installed then you can install the Java Software Development Kit (SDK) from Oracle's Java site: Java SE Downloads. You will find instructions for installing JDK in downloaded files, follow the given instructions to install and configure the setup. Finally set PATH and JAVA_HOME environment variables to refer to the directory that contains java and javac, typically java_install_dir/bin and java_install_dir respectively.

Set the JAVA_HOME environment variable to point to the base directory location where Java is installed on your machine. For example

Append Java compiler location to System Path.

Alternatively, if you use an Integrated Development Environment (IDE) like Borland JBuilder, Eclipse, IntelliJ IDEA, or Sun ONE Studio, compile and run a simple program to confirm that the IDE knows where you installed Java, otherwise do proper setup as given document of the IDE.

Step 3 - Setup Eclipse IDE

All the examples in this tutorial have been written using Eclipse IDE. So I would suggest you should have latest version of Eclipse installed on your machine based on your operating system.

To install Eclipse IDE, download the latest Eclipse binaries from https://www.eclipse.org/downloads/. Once you downloaded the installation, unpack the binary distribution into a convenient location. For example in C:\eclipse on windows, or /usr/local/eclipse on Linux/Unix and finally set PATH variable appropriately.

Eclipse can be started by executing the following commands on windows machine, or you can simply double click on eclipse.exe

%C:\eclipse\eclipse.exe

Eclipse can be started by executing the following commands on Unix (Solaris, Linux, etc.) machine −

$/usr/local/eclipse/eclipse

After a successful startup, if everything is fine then it should display following result −

Step 4: Install GWT SDK & Plugin for Eclipse

Follow the instructions given at the link Plugin for Eclipse (incl. SDKs) to install GWT SDK & Plugin for Eclipse version installed on your machine.

After a successful setup for the GWT plugin, if everything is fine then it should display following screen with Google icon marked with red rectangle as shown below −

Step 5: Install Highcharts

Download the latest Highcharts jar from its Downloadpage and add it to project's classpath.

Add the following entry in <project-name>.gwt.xml file

<inherits name="org.moxieapps.gwt.highcharts.Highcharts"/>

Add the following entry in <project-name>.html file

<script src = "https://ajax.googleapis.com/ajax/libs/jquery/2.1.3/jquery.min.js"/>
<script src = "https://code.highcharts.com/highcharts.js"/>
<script type="text/javascript" src="https://code.highcharts.com/highcharts-3d.js" />
<script type="text/javascript" src="https://code.highcharts.com/highcharts-more.js" />
<script src = "https://code.highcharts.com/modules/heatmap.js" />
<script src = "https://code.highcharts.com/modules/treemap.js" />

GWT Highcharts - Configuration Syntax

In this chapter, we will showcase the configuration required to draw a chart using the Highcharts API in GWT.

Step 1: Create GWT Application

Follow the following steps to update the GWT application we created in GWT - Create Application chapter −

Following is the content of the modified module descriptor src/com.howcodex/HelloWorld.gwt.xml.

<?xml version = "1.0" encoding = "UTF-8"?>
<module rename-to = 'helloworld'>
   <inherits name = 'com.google.gwt.user.User'/>
   <inherits name = 'com.google.gwt.user.theme.clean.Clean'/>
   <entry-point class = 'com.howcodex.client.HelloWorld'/>
   <inherits name="org.moxieapps.gwt.highcharts.Highcharts"/>
   <source path = 'client'/>
   <source path = 'shared'/>
</module>

Following is the content of the modified HTML host file war/HelloWorld.html.

<html>
   <head>
      <title>GWT Highcharts Showcase</title>
      <link rel = "stylesheet" href = "HelloWorld.css"/>
      <script language = "javascript" src = "helloworld/helloworld.nocache.js">
         <script src = "https://ajax.googleapis.com/ajax/libs/jquery/2.1.3/jquery.min.js" />
         <script src = "https://code.highcharts.com/highcharts.js" />
      </script>
   </head>
   <body>    
   </body>
</html>

We'll see the updated HelloWorld.java in the end after understanding configurations.

Step 2: Create Configurations

Create Chart

Configure the type, title and sub-title of the chart.

Chart chart = new Chart()
   .setType(Type.SPLINE)
   .setChartTitleText("Monthly Average Temperature")
   .setChartSubtitleText("Source: WorldClimate.com");

xAxis

Configure the ticker to be displayed on the X-Axis.

XAxis xAxis = chart.getXAxis();
xAxis.setCategories("Jan", "Feb", "Mar", "Apr", "May", "Jun",
   "Jul", "Aug", "Sep", "Oct", "Nov", "Dec");

yAxis

Configure the title, plot lines to be displayed on the Y-Axis.

YAxis yAxis = chart.getYAxis();
yAxis.setAxisTitleText("Temperature °C");
yAxis.createPlotLine()
   .setValue(0)
   .setWidth(1)
   .setColor("#808080");  

tooltip

Configure the tooltip. Put suffix to be added after value (y-axis).

ToolTip toolTip = new ToolTip();
toolTip.setValueSuffix("°C");
chart.setToolTip(toolTip);

legend

Configure the legend to be displayed on the right side of the chart along with other properties.

legend.setLayout(Legend.Layout.VERTICAL)
   .setAlign(Legend.Align.RIGHT)
   .setVerticalAlign(Legend.VerticalAlign.TOP)
   .setX(-10)
   .setY(100)
   .setBorderWidth(0);
chart.setLegend(legend);

series

Configure the data to be displayed on the chart. Series is an array where each element of this array represents a single line on the chart.

chart.addSeries(chart.createSeries()
   .setName("Tokyo")
   .setPoints(new Number[] {
      7.0, 6.9, 9.5, 14.5, 18.2, 21.5, 25.2,
      26.5, 23.3, 18.3, 13.9, 9.6
   })
);

chart.addSeries(chart.createSeries()
   .setName("New York")
   .setPoints(new Number[] {
      -0.2, 0.8, 5.7, 11.3, 17.0, 22.0, 24.8, 
      24.1, 20.1, 14.1, 8.6, 2.5
   })
);

chart.addSeries(chart.createSeries()
   .setName("Berlin")
   .setPoints(new Number[] {
      -0.9, 0.6, 3.5, 8.4, 13.5, 17.0, 18.6,
      17.9, 14.3, 9.0, 3.9, 1.0
   })
);

chart.addSeries(chart.createSeries()
   .setName("London")
   .setPoints(new Number[] {
      3.9, 4.2, 5.7, 8.5, 11.9, 15.2, 17.0, 
      16.6, 14.2, 10.3, 6.6, 4.8
   })
);

Step 3: Add the chart to parent panel.

We're adding the chart to root panel.

RootPanel.get().add(chart);

Example

Consider the following example to further understand the Configuration Syntax −

HelloWorld.java

package com.howcodex.client;

import org.moxieapps.gwt.highcharts.client.Chart;
import org.moxieapps.gwt.highcharts.client.Legend;
import org.moxieapps.gwt.highcharts.client.Series.Type;
import org.moxieapps.gwt.highcharts.client.ToolTip;
import org.moxieapps.gwt.highcharts.client.XAxis;
import org.moxieapps.gwt.highcharts.client.YAxis;

import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.user.client.ui.RootPanel;

public class HelloWorld implements EntryPoint {
   public void onModuleLoad() {
      Chart chart = new Chart()
         .setType(Type.SPLINE)
         .setChartTitleText("Monthly Average Temperature")
         .setChartSubtitleText("Source: WorldClimate.com");

      XAxis xAxis = chart.getXAxis();
      xAxis.setCategories("Jan", "Feb", "Mar", "Apr", "May", "Jun",
         "Jul", "Aug", "Sep", "Oct", "Nov", "Dec");

      YAxis yAxis = chart.getYAxis();
      yAxis.setAxisTitleText("Temperature °C");
      yAxis.createPlotLine()
         .setValue(0)
         .setWidth(1)
         .setColor("#808080");

      ToolTip toolTip = new ToolTip();
      toolTip.setValueSuffix("°C");
      chart.setToolTip(toolTip);

      Legend legend = new Legend();
      legend.setLayout(Legend.Layout.VERTICAL)
         .setAlign(Legend.Align.RIGHT)
         .setVerticalAlign(Legend.VerticalAlign.TOP)
         .setX(-10)
         .setY(100)
         .setBorderWidth(0);
      chart.setLegend(legend);

      chart.addSeries(chart.createSeries()
         .setName("Tokyo")
         .setPoints(new Number[] {
            7.0, 6.9, 9.5, 14.5, 18.2, 21.5, 25.2,
            26.5, 23.3, 18.3, 13.9, 9.6
         })
      );

      chart.addSeries(chart.createSeries()
         .setName("New York")
         .setPoints(new Number[] {
            -0.2, 0.8, 5.7, 11.3, 17.0, 22.0, 24.8, 
            24.1, 20.1, 14.1, 8.6, 2.5
         })
      );

      chart.addSeries(chart.createSeries()
         .setName("Berlin")
         .setPoints(new Number[] {
            -0.9, 0.6, 3.5, 8.4, 13.5, 17.0, 18.6,
            17.9, 14.3, 9.0, 3.9, 1.0
         })
      );

      chart.addSeries(chart.createSeries()
         .setName("London")
         .setPoints(new Number[] {
            3.9, 4.2, 5.7, 8.5, 11.9, 15.2, 17.0, 
            16.6, 14.2, 10.3, 6.6, 4.8
         })
      );
      RootPanel.get().add(chart);
   }
}

Result

Verify the result.

GWT Highcharts - Line Charts

Line charts are used to draw line/spline based charts. In this section, we will discuss the different types of line and spline based charts.

GWT Highcharts - Area Charts

Area charts are used to draw area based charts. In this section, we will discuss the different types of area based charts.

GWT Highcharts - Bar Charts

Bar charts are used to draw bar based charts. In this section, we will discuss the different types of bar based charts.

GWT Highcharts - Column Charts

Column charts are used to draw column based charts. In this section, we will discuss the different types of column based charts.

GWT Highcharts - Pie Charts

Pie charts are used to draw pie based charts. In this section, we will discuss the different types of pie based charts.

GWT Highcharts - Scatter Chart

Following is an example of a basic scatter chart.

We have already seen the configuration used to draw a chart in Highcharts Configuration Syntax chapter.

An example of a basic scatter chart is given below.

Configurations

Let us now see the additional configurations/steps taken.

series

Configure the chart type to be scatter based. series.type decides the series type for the chart. Here, the default value is "line".

chart.addSeries(chart.createSeries()  
   .setName("Observations")  
   .setType(Type.SCATTER)  
   .setPoints(new Number[] {  
      1, 1.5, 2.8, 3.5, 3.9, 4.2  
   })  
);  

Example

HelloWorld.java

package com.howcodex.client;

import org.moxieapps.gwt.highcharts.client.Chart;
import org.moxieapps.gwt.highcharts.client.Series.Type;

import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.user.client.ui.RootPanel;

public class HelloWorld implements EntryPoint {
   public void onModuleLoad() {
      final Chart chart = new Chart()  
         .setChartTitleText("Scatter plot");  

      chart.getXAxis()  
         .setMin(-0.5)  
         .setMax(5.5);  

      chart.getYAxis()  
         .setMin(0);  

      chart.addSeries(chart.createSeries()  
         .setName("Observations")  
         .setType(Type.SCATTER)  
         .setPoints(new Number[] {  
            1, 1.5, 2.8, 3.5, 3.9, 4.2  
         })  
      );  
      RootPanel.get().add(chart);
   }
}

Result

Verify the result.

GWT Highcharts - Dynamic Charts

Dynamic charts are used to draw data based charts where data can change after rendering of chart. In this section, we will discuss the different types of dynamic chart.

GWT Highcharts - Combination Charts

Combination charts are used to draw mixed charts; for example, bar chart with pie chart. In this section, we will discuss the different types of combinations charts.

GWT Highcharts - 3D Charts

3D charts are used to draw 3-dimensional charts. In this section, we will discuss the different types of 3D charts.

GWT Highcharts - Map Charts

Map charts are used to draw heat map or Tree map charts. In this section, we will discuss the different types of Map charts.