I cannot see the hidden portion of JPanel when adding to JScrollPane then a JTabbedPane

[Jacky Luk]

I know I am doing something wrong here. But I don't know how
I want to stack up the charts (JFreeChart) one after the other,
because the charts are big, so that I need it to scroll vertically or horizontally
when the viewport is not large enough.
You may assume GradientPanel is a JPanel with Database support.
Here I cannot scroll and the charts are not moving
Thanks
Jack

public class DisplayChart extends GradientPanel {

     public DisplayChart( Database _db) throws SQLException {
        super(_db);
        
        Dimension dim = new Dimension (600,600);
        JTabbedPane jTabbedPane1 = new JTabbedPane();
        
        GradientPanel chartPanel1 = new GradientPanel();
        GradientPanel chartPanel2 = new GradientPanel();
        
        chartPanel1.setPreferredSize(new Dimension (600,600));
        chartPanel1.setLayout(new FlowLayout());
        
        AgeDistributionChart ageDisChart
            = new AgeDistributionChart("Age Distribution", "Age", "No of Persons");
        
        JPanel agePanel = ageDisChart.createPanel(db.getAgeDistribution(2), 0);
        agePanel.setPreferredSize(dim);
        
        ProductChart productChart =
           new ProductChart("Product Distribution", "Product Name", "Sales Volume");
        JPanel productPanel = productChart.createPanel(db.getProductDistribution(), 0);
        productPanel.setPreferredSize(dim);
         
        /////////////////////
        // todo within product id
        GenderDistributionChart genderChart = 
           new GenderDistributionChart("Gender Distribution", "Gender", "Percentage");
        
        
        JPanel genderPanel = genderChart.createPanel(db.getGenderDistribution(), 1);
        genderPanel.setPreferredSize(dim);
        
         
        OccupationDistributionChart occupatDistChart = 
            new OccupationDistributionChart("Occupation Distribution", "Occupation", "No of Persons");
        
        JPanel occupationPanel = occupatDistChart.createPanel(db.getOccupationDistribution(), 0);
        occupationPanel.setPreferredSize(dim);
        
        chartPanel1.add(agePanel);
        chartPanel1.add(genderPanel);
        chartPanel1.add(occupationPanel);
        chartPanel1.add(productPanel);
        
         
        
        //////////////////
         
        IncomeDistributionChart  incomeDistChart = 
            new IncomeDistributionChart("Income Distribution Chart", "Income Range", "No of Persons");
        
        JPanel incomePanel = i
             ncomeDistChart.createPanel(db.getIncomeRangeDistribution(db.getIncomeRange()), 0);
        incomePanel.setPreferredSize(dim);
        
         
        AddressDistributionChart addDistChart = 
             new AddressDistributionChart("Address Distribution Chart", "Address", "No of Persons");
        
        // a better method
        JPanel addPanel = addDistChart.createPanel(_db.getAddressDist(),0);
        addPanel.setPreferredSize(dim);
        
        chartPanel2.add(incomePanel);
        chartPanel2.add(addPanel);
        
        JScrollPane sp1 = new JScrollPane(chartPanel1);
        JScrollPane sp2 = new JScrollPane(chartPanel2);
         
         sp1.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
         sp1.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);         
         sp2.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
         sp2.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);         
        
         
        jTabbedPane1.add(sp1, "Chart 1");
        jTabbedPane1.add(sp2, "Chart 2");
        
         
        
        this.add(jTabbedPane1);
        
    }
 }

[Rob Camick]

You may assume GradientPanel is a JPanel with Database support.

No, I can't assume that. Maybe the GradientPanel is the cause of the problem.

Here I cannot scroll and the charts are not moving

//chartPanel1.setPreferredSize(new Dimension (600,600));  
chartPanel1.setLayout(new FlowLayout());  

Never set the preferred size of a component. That is the job of the layout manager. Scrollbars appear when the preferred size of the component added to the scrollpane is greater than the size of the scrollpane.

If you need more help then post a proper SSCCE.