How to write a custom DefaultTableCellRenderer to colorize specific cells and "preserve" the color of the others, Java

Question

I'm using netbeans with its gui builder in order to create a desktop application. To colorize special cells in my jTables I have implemented a custom DefaultTableCellRenderer based on example code. So far it works.

My problem is the else case of the overwritten function "getTableCellRendererComponent()". I don't want that a cell which is not in the specified range becomes "white" - I want that these cells appear in the color they already had (e. g. I don't want to change there color to "white" if they have been "red").

I would be happy if somebody could help me on that!!

Thanks a lot in advance.
Steffen

class ColoredTableCellRenderer extends DefaultTableCellRenderer
{

    /** constructor */
    public ColoredTableCellRenderer(int rowToColorizeStart, int rowToColorizeStop, int columnToColorizeStart, int columnToColorizeStop, Color color)
    {
        mRowToColorizeStart = rowToColorizeStart;
        mRowToColorizeStop = rowToColorizeStop;
        mColumnToColorizeStart = columnToColorizeStart;
        mColumnToColorizeStop = columnToColorizeStop;
        mColor = color;
    }

    private int mRowToColorizeStart = 0;
    public void setRowToColorizeStart(int rowToColorizeStart) {
        mRowToColorizeStart = rowToColorizeStart;  
    }
    public int getRowToColorizeStart() {
        return mRowToColorizeStart;  
    }

    private int mRowToColorizeStop = 0;
    public void setRowToColorizeStop(int rowToColorizeStop) {
        mRowToColorizeStop = rowToColorizeStop;  
    }
    public int getRowToColorizeStop() {
        return mRowToColorizeStop;  
    }

        private int mColumnToColorizeStart = 0;
    public void setColumnToColorizeStart(int columnToColorizeStart) {
        mColumnToColorizeStart = columnToColorizeStart;  
    }
    public int getColumnToColorizeStart() {
        return mColumnToColorizeStart;  
    }

    private int mColumnToColorizeStop = 0;
    public void setColumnToColorizeStop(int columnToColorizeStop) {
        mColumnToColorizeStop = columnToColorizeStop;  
    }
    public int getColumnToColorizeStop() {
        return mColumnToColorizeStop;  
    }

    private Color mColor = Color.WHITE;
    public void setColor(Color color) {
        mColor = color;  
    }
    public Color getColor() {
        return mColor;  
    }


    @Override
    public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column) {

        Component cellComponent = super.getTableCellRendererComponent(table, value, isSelected, hasFocus, row, column);    

        if( (row >= getRowToColorizeStart()) && (row <= getRowToColorizeStop()) && (column >= getColumnToColorizeStart()) && (column <= getColumnToColorizeStop()) && (isSelected == false) ) {
            cellComponent.setBackground(getColor());    
        } else {
           cellComponent.setBackground(Color.WHITE);
        }

        return cellComponent;

    }
}

that was waht i thought too, but without the else block, the whole table gets colored... — macktheknife, Oct 15 '12 at 12:09
@Reddy - it _is_ needed, details: http://stackoverflow.com/a/9617446/203657 — kleopatra, Oct 15 '12 at 12:36
i understand that the else case is necessary, but is there an way to preserve the "previous" color of that cells belonging to the else case? — macktheknife, Oct 15 '12 at 12:59
JTable has two dimmension you override only row, maybe then see my (why reinvent the wheel) EDIT — mKorbel, Oct 15 '12 at 14:34

score 4 · Answer 1 · edited May 23 '17 at 12:08

How to write a custom DefaultTableCellRenderer to colorize specific cells “only”, Java

code line

public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column) {

talking about whats happens

if cell is selected or not (boolean isSelected)
if cell is selected and /or has Focus too (boolean hasFocus)
for row in the JTable (int row)
in the Column from JTable (int column)

then there you can to change Font, Border, Color, Icon e.i.

NOTICE ---> don't change Object value in the XxxRenderer, never ever, be sure to try to avoid that

EDIT

JTable has two dimmension there are defined only rows, have look at prepareRenderer
prepareRenderer is designated for row coloring, my question can help you or here, don't forget to override int modelRow = convertRowIndexToModel(row);, in most cases you can lost index model v.s. view, because JTable can be sorted or filtered

score 2 · Answer 2 · answered Oct 15 '12 at 12:12

2

I believe what you are looking for is the following. It uses the table's fg and bg for painting the cell.

else {
    setBackground(table.getBackground());
    setForeground(table.getForeground());
}

answered Oct 15 '12 at 12:12

Devon_C_Miller

16,248
3
45
71

score 0 · Answer 3 · answered Oct 15 '12 at 12:13

0

You should change your else block to

 else if (cellComponent.getBackground != color){
         cellComponent.setBackground(white);
  }

answered Oct 15 '12 at 12:13

Joseph Elcid

887
1
6
21

I changed to:`else if (cellComponent.getBackground() != getColor()) { cellComponent.setBackground(Color.WHITE); }` But the whole table get's the special color now (all cells). – macktheknife Oct 15 '12 at 12:28

How to write a custom DefaultTableCellRenderer to colorize specific cells and "preserve" the color of the others, Java

3 Answers3