Pluggable Renderers & Editors - Swing defines several renderer and editor classes that are used for its UI components such as tree, table or list. FlexGantt does the same and defines renderers for tree table cells, column headers, popups, dateline models, timeline objects, eventline objects. Editors are available for tree table cells and timeline objects. A timeline object editor gets displayed in a transparent window within the right-hand side of the Gantt chart (in-place editing, see picture below)

Paging - If a scheduling application needs to deal with a large amount of timeline objects then it often makes sense to divide the timeline horizon into several pages / time spans. This way the data gets broken into smaller chunks that the Gantt chart can deal with more easily. The paging model manages the individual pages. It can be queried for the current page, the previous page, the next page, the first page, and the last page. The user interface provides a control that can be used to select individual pages.

Popups / Annotations - A bar underneath a timeline is a nice representation for an activity but it can only carry a limited number of information due to space restrictions. Popups / annotations that show up when the mouse cursor hovers over such a bar is a nice feature that can display a wealth of additional information that the planner might need to make a scheduling decision. FlexGantt's popups can be customized in the same way that any Swing component can be customized. Different renderers can be mapped to different types of popup objects. The popup objects are looked up from a specialized popup policy. The image below shows the default popup renderer that displays popup objects in its serialized form.

Printing - A plan shown in a Gantt chart is a document and every document needs to be printable. The built-in printing support for FlexGantt lets the user specify a time span and a granularity to be printed (see picture below). The resulting chart can be printed on several pages wide and high.

Command Framework - FlexGantt provides a small but powerful command framework. It is used to support editing operations that can be undone and redone. The framework consists of commands, a command stack, a command stack listener and a progress monitor. Commands are executed, undone and redone via the Gantt chart, which internally uses a replaceable command stack. Commands are executed in their own thread in order to keep the user interface responsive. Command stack events are issued during the execution of the command. Progress monitors are used to display the progress made by a command. Sub-progress monitors are used for compound commands that consist of several other commands. Once a command has finished execution it will be added to the command stack‘s list of undoable commands. This list will be cleared when a command gets executed that can not be undone. The command framework uses a high level of abstraction so that an already existing command infrastructure (legacy code) can be reused.

Multiline - The multiline feature enables a Gantt chart to display timeline objects within the same row but above and below each other. This way timeline objects that would otherwise overlap each other can be displayed without problems.

Variable Row Heights - Each row in a FlexGantt chart can have its own height. This feature is very useful when the nodes in the tree table represent different types of objects or if a quantity is associted with each node. In this case the row height can reflect this quantity (e.g. the capacity of a resource).

Multi-Column Sorting - The tree table on the left-hand side of the Gantt chart supports multi-column sorting, which means that the user can select several tree table columns at the same time and the data in the table will be sorted based on this selection. FlexGantt uses a quicksort algorithm for fast sorting and supports ascending and descending sorting.

Calendar Model - The calendar model provides data for the Gantt chart related to weekends, holidays, or any other kind of special time span. Entries in the calendar model are rendered across the entire height of the layer container (right-hand side). The most prominent example for the use of the calendar model is the definition of those days that are considered weekend. The background of weekend days will grayed out.

Autoscrolling - If a FlexGantt chart updates its 'time now / system time' frequently then it sometimes makes sense to make the application focus on this time. When autoscrolling is enabled then the time now cursor (a vertical dashed line) will remain in the center of the layer container even when time progresses. This is a very useful feature when an application has more of a monitoring function then an interactive scheduling function.

Customizable Timeline - Each application has its own requirements for the timeline. Some require the week of the year to be shown next to the date, others want to show the number of the day in the year (for example 'day 241'). The timeline has been designed with flexibility in mind. Its model can be replaced, its renderers can be replaced, even the entire timeline can be substituted with a custom subclass.