ShapeTool.java

package gis2.scenario;

import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;
import java.awt.Color;
import java.awt.Point;
import java.awt.Insets;

import maps.gml.view.FilledShapeDecorator;
import maps.gml.GMLRoad;
import maps.gml.GMLBuilding;
import maps.gml.GMLSpace;
import maps.gml.GMLShape;
import maps.gml.GMLCoordinates;

/**
   Abstract base class for tools that operate on GML shapes.
*/
public abstract class ShapeTool extends AbstractTool {
    private static final Color HIGHLIGHT_COLOUR = new Color(0, 0, 255, 128);

    private Listener listener;
    private FilledShapeDecorator highlight;

    private GMLShape highlightShape;

    /**
       Construct a ShapeTool.
       @param editor The editor instance.
    */
    public ShapeTool(ScenarioEditor editor) {
        super(editor);
        listener = new Listener();
        highlight = new FilledShapeDecorator(HIGHLIGHT_COLOUR, HIGHLIGHT_COLOUR, HIGHLIGHT_COLOUR);
    }

    @Override
    public void activate() {
        editor.getViewer().addMouseListener(listener);
        editor.getViewer().addMouseMotionListener(listener);
        highlightShape = null;
    }

    @Override
    public void deactivate() {
        editor.getViewer().removeMouseListener(listener);
        editor.getViewer().removeMouseMotionListener(listener);
        editor.getViewer().clearAllBuildingDecorators();
        editor.getViewer().clearAllRoadDecorators();
        editor.getViewer().clearAllSpaceDecorators();
        editor.getViewer().repaint();
    }

    /**
       Handle a click on a shape.
       @param shape The shape that was clicked.
    */
    protected abstract void processClick(GMLShape shape);

    /**
       Find out if a shape should be highlighted or not. Only highlighted shapes can be clicked.
       @param shape The shape to check.
       @return True if the shape should be highlighted, false otherwise.
    */
    protected abstract boolean shouldHighlight(GMLShape shape);

    private void highlight(GMLShape newShape) {
        if (!shouldHighlight(newShape)) {
            return;
        }
        if (highlightShape == newShape) {
            return;
        }
        if (highlightShape != null) {
            if (highlightShape instanceof GMLBuilding) {
                editor.getViewer().clearBuildingDecorator((GMLBuilding)highlightShape);
            }
            if (highlightShape instanceof GMLRoad) {
                editor.getViewer().clearRoadDecorator((GMLRoad)highlightShape);
            }
            if (highlightShape instanceof GMLSpace) {
                editor.getViewer().clearSpaceDecorator((GMLSpace)highlightShape);
            }
        }
        highlightShape = newShape;
        if (highlightShape != null) {
            if (highlightShape instanceof GMLBuilding) {
                editor.getViewer().setBuildingDecorator(highlight, (GMLBuilding)highlightShape);
            }
            if (highlightShape instanceof GMLRoad) {
                editor.getViewer().setRoadDecorator(highlight, (GMLRoad)highlightShape);
            }
            if (highlightShape instanceof GMLSpace) {
                editor.getViewer().setSpaceDecorator(highlight, (GMLSpace)highlightShape);
            }
        }
        editor.getViewer().repaint();
    }

    private class Listener implements MouseListener, MouseMotionListener {
        @Override
        public void mouseClicked(MouseEvent e) {
            if (highlightShape != null && e.getButton() == MouseEvent.BUTTON1) {
                processClick(highlightShape);
            }
        }

        @Override
        public void mouseMoved(MouseEvent e) {
            Point p = fixEventPoint(e.getPoint());
            GMLCoordinates c = editor.getViewer().getCoordinatesAtPoint(p.x, p.y);
            highlight(editor.getMap().findShapeUnder(c.getX(), c.getY()));
        }

        @Override
        public void mousePressed(MouseEvent e) {
        }
        @Override
        public void mouseReleased(MouseEvent e) {
        }
        @Override
        public void mouseDragged(MouseEvent e) {
        }
        @Override
        public void mouseEntered(MouseEvent e) {
        }
        @Override
        public void mouseExited(MouseEvent e) {
        }

        private Point fixEventPoint(Point p) {
            Insets insets = editor.getViewer().getInsets();
            return new Point(p.x - insets.left, p.y - insets.top);
        }
    }
}