Gantt Charts with JFreeChart

If you have ever tried to draw gantt charts with JFreeChart you have already noticed that it’s a very simplistic implementation - it doesn’t have the facility to display dependency lines or milestones.

Gantt chart demo from JFreeChart samples:

In a recent project I needed some additional features like:

1. Summary tasks
2. Milestones/deliverables
3. Dependencies between task and milestones/deliverables

So I modified BarRenderer.java, GanttRenderer.java, GanttCategoryDataset.java, Task.java, and TaskSeriesCollection.java appropriately and also created my own class called LineAndShapeGanttRenderer.java.

Gantt chart with JFreeChart after files modification:

The base version of JFreeChart was 1.0.2, and the modified files were:

• BarRenderer.java
• GanttRenderer.java
• GanttCategoryDataset.java
• Task.java
• TaskSeriesCollection.java
• LineAndShapeGanttRenderer.java (New)