MDI is a Java framework for building scientific desktop applications with:
- Interactive plotting
- Simulation engines
- Multi-view modular architecture
- Extensible tools and layered drawing
- Distribution via Maven Central
It is built on pure Swing for long-term JVM stability and zero external runtime dependencies.
Scientific desktop applications have different needs than typical GUI apps:
- Long-running simulations
- Real-time data visualization
- Multi-document workflows
- Precise rendering control
- Stability across Java versions
MDI provides architectural infrastructure for these use cases.
It is not just a widget toolkit.
It is a foundation for building complete scientific applications.
Each window (“view”) operates independently while sharing:
- Messaging infrastructure
- Common models
- Simulation engine integration
- Extensible toolbars
- Layered drawing support
The built-in plotting module provides:
- Thread-safe curve updates
- Swing EDT-safe rendering
- Curve fitting
- Lock-free staging queues for background updates
- Coalesced repaint events
Plots can safely receive data from worker threads without repaint storms.
MDI includes:
- Step-based simulation engines
- Cancel support
- Reset hooks
- Coordinated view refresh
- Background execution integration
Ideal for:
- Physics demonstrations
- Optimization visualizations
- Network simulations
- Educational tools
Views support:
- Items
- Layers
- Mouse interaction
- Selection tools
- Virtual desktop behavior
This makes it easy to build:
- Network graphs
- Geometric editors
- Data overlays
- Interactive teaching tools
MDI is available on Maven Central:
<dependency>
<groupId>io.github.heddle</groupId>
<artifactId>mdi</artifactId>
<version>1.0.0</version>
</dependency>The following minimal example creates an MDI application with a single DrawingView:
This example demonstrates:
- Creating an MDI application by extending
BaseMDIApplication - Configuring a
DrawingViewusing key–value properties - Adding initial content once the virtual desktop is ready
public class HelloMDI extends BaseMDIApplication {
private final DrawingView drawingView; //only view
public HelloMDI(Object... keyVals) {
super(keyVals);
// set to a fraction of screen
Dimension d = WindowPlacement.screenFraction(0.4);
// specify (bitwise) what will be on the toolbar
long toolBits = ToolBits.STATUS | ToolBits.DRAWINGTOOLS | ToolBits.ZOOMTOOLS | ToolBits.PAN;
drawingView = new DrawingView(
PropertyUtils.WORLDSYSTEM, new Rectangle2D.Double(0, 0, d.width, d.height),
PropertyUtils.WIDTH, d.width,
PropertyUtils.HEIGHT, d.height,
PropertyUtils.TOOLBARBITS, toolBits,
PropertyUtils.VISIBLE, true,
PropertyUtils.BACKGROUND, Color.white,
PropertyUtils.INFOBUTTON, true,
PropertyUtils.TITLE,"Drawing View");
}
// Runs once after the outer frame is showing and Swing layout has stabilized.
@Override
protected void onVirtualDesktopReady() {
// desktop ready, safe to apply default placements and add content.
drawingView.center();
//lets add some initial content to the drawing view
Layer layer = drawingView.getContainer().getAnnotationLayer();
CreationSupport.createRectangleItem(layer, new Rectangle(50, 50, 100, 100));
}
// Main method to launch the application.
public static void main(String[] args) {
BaseMDIApplication.launch(() ->
new HelloMDI(
PropertyUtils.TITLE, "Hello MDI",
PropertyUtils.FRACTION, 0.8
)
);
}
}The repository includes a full-featured DemoApp showcasing:
- DrawingView
- PlotView (splot integration)
- Network layout demo
- Traveling Salesperson simulation
- 2D map view
- Simulation framework examples
To run the demo from the project source:
mvn clean package
mvn exec:java -Dexec.mainClass="edu.cnu.mdi.app.DemoApp"Here is one of the views running inside the DemoApp:
