JTable icon linked to object

Question

I have the following problem: i currently have a few classes representing various plants and animals, which all have base class "Organism", they are part of a world (another class, which contains a "2D" container of Organisms or empty fields - kinda like a 2D map of a world). Only 1 organism can occupy a world slot at the same time.

What i want is to draw a map of this world. In order to do this i have created a JTable, which uses world's 2D container as a data source. Now the problem is, i don't know how to make the JTable use class's own methods in order to draw cells.

Each class has it's method which returns an image representing it:

@Override public ImageIcon drawing(){
    return new ImageIcon("Guarana.png");
}

my table has following components available:

private String[] columnNames;
private Object[][] data;

I've created my own table model (following the tutorial here: https://docs.oracle.com/javase/tutorial/uiswing/components/table.html)

So the creation of table looks like this:

    model = new MyTableModel(testowyString, organizmy);
    JTable table = new JTable(model);

    table.setFillsViewportHeight(true);
    table.setDefaultRenderer(Organizm.class, new IconRenderer());
    JScrollPane scrollPane = new JScrollPane(table);
    scrollPane.setBounds(210, 0, 780, 900);
    add(scrollPane);

As you can see i have tried to create my own IconRenderer (but for some reason the JTable still doesn't draw the icons):

public class IconRenderer extends DefaultTableCellRenderer {

    ImageIcon sheepIcon = new ImageIcon("Owca.png");
    ImageIcon wolfIcon = new ImageIcon("Wilk.png");
    ImageIcon mouseIcon = new ImageIcon("Mysz.png");
    ImageIcon chickenIcon = new ImageIcon("Kurka.png");
    ImageIcon turtleIcon = new ImageIcon("Zolw.png");
    ImageIcon grassIcon = new ImageIcon("Trawa.png");
    ImageIcon guaranaIcon = new ImageIcon("Guarana.png");
    ImageIcon emptyIcon = new ImageIcon("Pusty.png");
public IconRenderer() { super(); }

public void setValue(Organizm organizm) {
    setIcon((organizm == null) ? ikonkaPusty : organizm.rysowanie());
}

}

(yes, the icons here are a part of my old code, when each class didn't return it's icon)

To sum up: i want to make it so when JTable draws a map it draws an icon using an existing method of a class which is linked to cell.

Answer 1

Instead of overriding setValue() you need to override getTableCellRendererComponent() and call setIcon() from there. The value argument will be the Organizm that is the table cell's value, so you can do this:

public Component getTableCellRendererComponent(JTable table,
                                  Object value,
                                  boolean isSelected,
                                  boolean hasFocus,
                                  int row,
                                  int column) {
    Organizm o = (Organizm) value;
    setIcon((organizm == null) ? ikonkaPusty : organizm.rysowanie());
    return this;
}

I'm assuming that organizm.rysowanie() returns the ImageIcon. Although if that's true, then your setValue() implementation probably should have worked. Another thought I have is to change your setValue() signature to public void setValue(Object value) and cast value in the method like in my example above. This would avoid method overloading issues that would result in calling the setValue() method with an Object argument instead of your setValue() method with the Organizm argument.