Perforce JViews Gantt Sample: Custom Activity Chart Connection

Description

This sample shows how to create a custom data model implementation that effeciently connects an activity-oriented Gantt chart to a custom data source. The custom data model implements load-on-demand.

How to Use the Sample

• This sample is based on the Gantt Chart XML Data sample in the <installdir>/samples/xmlGantt directory. In this sample, when you open an SDXL data file using the File/Open menu item, scheduling data is read into a standard IlvDefaultGanttModel instance that is then encapsulated inside an GanttModelDBROWrapper in order to simulate read-only back-end scheduling data. An instance of the DBROGanttModel custom data model connects the back-end data to the chart.
• The DBROGanttModel is read-only. Resizing or moving activities in the chart is disabled.
• The File menu contains the following two check boxes that allow you to view the load-on-demand and caching behavior of the DBROGanttModel custom data model and its accesses to the underlying GanttDBRO back-end data:
  • Display Database Queries: Enable this item to log all accesses that the DBROGanttModel data model makes to the underlying back-end data. The log entries will appear in the system console in the following format:
    

    [DB]	Qry child keys of activity:	[20,"Phase II Development"]
    ^	^	^
    the message indicates an access to the back-end data	the log message shows that the back-end data is being queried for the lookup keys of a parent activity's children	the parent activity being queried has a back-end data look-up index of 20 and is named "Phase II Development"

  • Display Data Model: The custom data model instantiates and caches activities, resources, constraints, and reservations upon demand. Enable this item to log the instantiation of the data model entities to the system console in the following format:
    

    [Model]	Creating Activity-19
    ^	^
    the message comes from the custom data model	the log message shows that an instance of IlvActivity is being created from the back-end data look-up key of 19

How to Run the Sample as an Application

This sample can be run as an application. The installation directory contains an executable JAR file, db-gantt.jar, that allows you to execute the sample with a double click from a file browser. Note that if you are using Internet Explorer, you can open the installation directory and execute the JAR file from the browser. This technique may not work in other Web browsers.

Alternatively, you can run the sample application from the command line. First check that the Ant utility is properly configured. If not, see the instructions on how to configure Ant for Perforce JViews.

Then, go to the installation directory of the sample and type:

ant run

Topics Covered

• Design of an efficient custom IlvGanttModel implementation that queries back-end scheduling data as information is needed for display.

Detailed Description

This sample shows how to efficiently connect an activity-oriented Gantt Chart to read-only back-end scheduling data that is stored in tabular format. GanttDBRO defines the read-only interface to the back-end data. For the purposes of this sample, the GanttModelDBROWrapper class simulates the back-end scheduling data by encapsulating an existing Gantt data model that has been parsed from an SDXL data file. DBROGanttModel is the custom data model implementation that connects to the back-end data via the GanttDBRO interface.

Installation Directory

The Custom Activity Chart Connection sample is installed here.

Classes Involved

• ilog.views.gantt.IlvGanttChart

Source Files

• database.GanttDBRO

  An interface that defines read-only access to back-end scheduling information.

• database.GanttModelDBROWrapper

  An implementation of the GanttDBRO interface that simulates back-end scheduling data. The scheduling data is created by encapsulating a standard IlvDefaultGanttModel that has been populated from an SDXL data file.

• database.DBROGanttModel

  A custom read-only IlvGanttModel implementation that connects to back-end scheduling data via the GanttDBRO interface. The data model queries back-end data as it is needed for display.

• database.DBGanttExample

  The main class of the sample.

• database.DBGanttActions

  Swing Actions used in the menus and toolbar.