Creating a Simple Map Application

Developing with design tools > Using the Map Builder > Writing an application > Creating a Simple Map Application

The application example given in this section is the JViews Maps application provided in <installdir> /jviews-maps/samples/buildmap/index.html as part of the Rogue Wave® JViews Maps demonstration software.

The application:

Creates a map GUI.

Loads a shape file, an image file (a raster), and two data sources.

To create the application:

1. Import the following Java™ packages and classes:

import ilog.views.*;

import ilog.views.maps.*;

import ilog.views.maps.beans.*;

import ilog.views.maps.datasource.*;

import ilog.views.maps.format.image.IlvRasterBasicImageReader;

import ilog.views.maps.graphic.style.IlvPolylineStyle;

import ilog.views.maps.raster.datasource.IlvRasterDataSourceFactory;

import ilog.views.maps.srs.coordsys.IlvCoordinateSystem;

import ilog.views.maps.srs.coordsys.IlvGeographicCoordinateSystem;

import ilog.views.swing.IlvJManagerViewControlBar;

import ilog.views.swing.IlvJScrollManagerView;

import java.awt.*;

import java.beans.PropertyChangeEvent;

import java.beans.PropertyChangeListener;

import java.io.File;

import java.net.URL;

import javax.swing.JFrame;

import javax.swing.JTabbedPane;

2. Declare the public class BuildMapDemo, which defines the basic building blocks of the Map Builder:

public class BuildMapDemo extends JFrame {

IlvManagerView view;// Map View

IlvJScrollManagerView viewScroll;// scroll around the Map View

IlvJManagerViewControlBar viewToolbar; // zoom & selection toolbar

IlvLayerTreePanel layerTreePanel = new IlvLayerTreePanel(); // layer

visibility and properties control

IlvJCoordinateSystemEditorPanel csPanel;// coordinate system choice.

IlvJMouseCoordinateViewer locator;// coordinate information

3. Create a main frame and set it to exit when the Close button is pressed:

public BuildMapDemo() {

super();

setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

4. Create the main components of this example and set them up:

view=new IlvManagerView();

view.setManager(new IlvGrapher());

viewScroll=new IlvJScrollManagerView(view);

viewToolbar = new IlvJManagerViewControlBar();

csPanel=new IlvJCoordinateSystemEditorPanel();

viewToolbar.setView(view);

locator=new IlvJMouseCoordinateViewer();

locator.setView(view);

viewToolbar.add(locator);

view.setKeepingAspectRatio(true);

view.setBackground(new Color(80, 180, 240));

view.setAntialiasing(false);

view.setSize(new Dimension(900, 450));

viewScroll.setPreferredSize(view.getSize());

layerTreePanel.setView(view);

5. Georeference the view:

view.getManager().setNamedProperty(new

IlvCoordinateSystemProperty(IlvGeographicCoordinateSystem.WGS84));

6. Set up the Coordinate System panel to change projection according to panel selection and to reload the map data:

csPanel.setCoordinateSystem(IlvCoordinateSystemProperty.GetCoordinateSystem

(view.getManager()));

csPanel.addCoordinateSystemChangeListener(new PropertyChangeListener(){

public void propertyChange(PropertyChangeEvent evt) {

IlvCoordinateSystem system = (IlvCoordinateSystem) evt.getNewValue();

view.getManager().setNamedProperty(new IlvCoordinateSystemProperty(system));

clearManager();

loadData();

}

});

7. Build the map and configure the main window:

loadData();

getContentPane().add(viewToolbar,BorderLayout.NORTH);

getContentPane().add(viewScroll,BorderLayout.CENTER);

JTabbedPane tabPane=new JTabbedPane();

tabPane.addTab("Map layers",layerTreePanel);

tabPane.addTab("Coordinate System",csPanel);

getContentPane().add(tabPane,BorderLayout.LINE_START);

getContentPane().add(locator,BorderLayout.SOUTH);

}

8. Load the sample map data into the application:

private void loadData() {

URL shpFile = findURL("data/world.shp");

URL gifFile = findURL("data/world.gif");

try {

// Create a data source for the shape file.

IlvShapeDataSource shpDataSource = new

IlvShapeDataSource(shpFile.getFile(), true);

shpDataSource.setCoordinateSystem(IlvGeographicCoordinateSystem.WGS84);

// Create a raster reader for the .gif file (necessary to create the

datasource that follows).

IlvRasterBasicImageReader imageReader = new

IlvRasterBasicImageReader();

imageReader.loadImage(gifFile.getFile());

// Georeference this image (it covers the whole earth).

imageReader.setImageBounds(0,-Math.PI,Math.PI/2,Math.PI,-Math.PI/2);

// Create a datasource for the .gif file.

IlvMapDataSource imageDataSource =

IlvRasterDataSourceFactory.buildImageDataSource(

view.getManager(),imageReader,true,true,true,null);

// Insert it in the data source tree of the manager.

IlvMapDataSourceModel dataSourceModel =

IlvMapDataSourceProperty.GetMapDataSourceModel(view.getManager());

dataSourceModel.insert(shpDataSource);

dataSourceModel.insert(imageDataSource);

// Start reading the model (recursively start all data sources of this

model).

dataSourceModel.start();

// Get the shape map layer used to display the data source.

IlvMapLayer shpLayer = shpDataSource.getInsertionLayer();

shpLayer.setName("ESRI layer (world.shp)");

IlvMapLayer imageLayer = imageDataSource.getInsertionLayer();

// Insert it in the Map layer tree of the manager.

IlvMapLayerTreeModel ltm =

IlvMapLayerTreeProperty.GetMapLayerTreeModel(view.getManager());

ltm.addChild(null, shpLayer);

ltm.addChild(null, imageLayer);

// Set up the shape layer style.

shpLayer.getStyle().setAttribute(IlvPolylineStyle.FOREGROUND,Color.

black);

shpLayer.getStyle().setAttribute(IlvPolylineStyle.BACKGROUND,new

Color(1,1,1,0.25f));

imageLayer.setName("Image layer (world.gif)");

} catch (Exception e1) {

e1.printStackTrace();

}

9. Fit the data source to the size of the application view:

view.fitTransformerToContent();

view.repaint();

}

10. Write the main method:

static public void main(String args[]) {

javax.swing.SwingUtilities.invokeLater(

new Runnable() {

public void run() {

final JFrame frame = new BuildMapDemo();

frame.setTitle("Simple map building demo");

frame.pack();

frame.setVisible(true);

}

);

}

11. Remove all the layers from the manager and clear the associated model when the coordinate system changes:

private void clearManager() {

IlvManager manager = view.getManager();

IlvMapLayerTreeModel model =

IlvMapLayerTreeProperty.GetMapLayerTreeModel(manager);

model.clearAllObjects();

while (manager.getLayersCount() > 0) {

IlvManagerLayer layer = manager.getManagerLayer(0);

manager.removeLayer(0, false);

}

manager.removeNamedProperty(IlvMapLayerTreeProperty.NAME);

manager.removeNamedProperty(IlvMapDataSourceProperty.NAME);

manager.removeNamedProperty(IlvAreasOfInterestProperty.NAME);

}