CODEWITHSUNDEEP
javaswing
user16666
user16666

Reputation: 47

Draw multiple polygons on a JLabel Java Swing

I have around 10 sets of coordinates for 10 polygons that I need to draw on an image Label. This is what I have coded so far:

But since I cannot call paintComponent separately , I am calling it while instantiating the JLabel and that leads to the problem. At the end , I am just getting the last Polygon drawn on the image because everytime the new jLabel is created. Can someone point out how can this be improved so that I could draw multiple polygons on the same JLabel.

private void setMapImage()
{
    Queries queries = new Queries(dbConnection, connection);
    List<ArrayList<Integer>> allGeo = queries.getBuilding();

    for(int i = 0; i < allGeo.size(); i++)
    {
        int[] xPoly = queries.separateCoordinates(allGeo.get(i),0);
        int[] yPoly = queries.separateCoordinates(allGeo.get(i),1);
        poly = new Polygon(xPoly, yPoly, xPoly.length);

        poly = new Polygon(xPoly, yPoly, xPoly.length);
        background=new JLabel(new ImageIcon("image.JPG"),SwingConstants.LEFT)
        {
            @Override
            protected void paintComponent(Graphics g) {
                super.paintComponent(g);
                g.setColor(Color.YELLOW);
                g.drawPolygon(poly);

            }
            @Override
            public Dimension getPreferredSize() {
                return new Dimension(820, 580);
            }
        };
    }
    background.setVerticalAlignment(SwingConstants.TOP);
    frame.add(background);
    background.setLayout(new FlowLayout());
    frame.setVisible(true);
}

Upvotes: 0

Views: 599

Answers (1)

rafalopez79
rafalopez79

Reputation: 2076

I think you have to iterate through the polygons you have in the paintComponent method of the JLabel. Before that you have to add all the poligons to a list.

For instance:

private void setMapImage()
{
    Queries queries = new Queries(dbConnection, connection);
    List<ArrayList<Integer>> allGeo = queries.getBuilding();
    List<Polygon> polyList = new ArrayList<Polygon>();
    for(int i = 0; i < allGeo.size(); i++)
    {
        int[] xPoly = queries.separateCoordinates(allGeo.get(i),0);
        int[] yPoly = queries.separateCoordinates(allGeo.get(i),1);
        poly = new Polygon(xPoly, yPoly, xPoly.length);
        polyList.add(poly);
    }   
    background=new JLabel(new ImageIcon("image.JPG"),SwingConstants.LEFT)
    {
        @Override
        protected void paintComponent(Graphics g) {
            super.paintComponent(g);
            g.setColor(Color.YELLOW);
            for(final Polygon poly : polyList){
                g.drawPolygon(poly);
            }
        }
        @Override
        public Dimension getPreferredSize() {
            return new Dimension(820, 580);
        }
    };

    background.setVerticalAlignment(SwingConstants.TOP);
    frame.add(background);
    background.setLayout(new FlowLayout());
    frame.setVisible(true);
}

Upvotes: 0

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