How to set the RowHeight dynamically in a JTable

Question

I want to put a String in a JTable that is longer than the given cell-width. How can I set the rowHeight dynamically so that I can read the whole S

Answer 1

There are several issues when using a JTextArea as rendering component (and most if not all of them already explained in several QA's on this site). Trying to sum them up:

Adjust individual row height to the size requirements of the rendering component

Basically, the way to go is to loop through the cells as needed, then

• configure its renderer with the data
• ask the rendering component for its preferred size
• set the table row height to the pref height

The updateRowHeight method in the OP's edited question is just fine.

JTextArea's calculation of its preferredSize

to get a reasonable sizing hint for one dimension, it needs to be "seeded" with some reasonable size in the other dimension. That is if we want the height it needs a width, and that must be done in each call. In the context of a table, a reasonable width is the current column width:

public Component getTableCellRendererComponent(JTable table,
        Object value, boolean isSelected, boolean hasFocus, int row,
        int column) {
    ... // configure visuals
    setText((String) value);
    setSize(table.getColumnModel().getColumn(column).getWidth(),
            Short.MAX_VALUE);
    return this;
}// getTableCellRendererComponent

Dynamic adjustment of the height

The row height it fully determined in some steady state of the table/column/model. So you set it (call updateRowHeight) once after the initialization is completed and whenever any of the state it depends on is changed.

// TableModelListener
@Override
public void tableChanged(TableModelEvent e) {
    updateRowHeights();
}

// TableColumnModelListener
@Override
public void columnMarginChanged(ChangeEvent e) {
    updateRowHeights();
}

Note

As a general rule, all parameters in the getXXRendererComponent are strictly read-only, implementations must not change any state of the caller. Updating the rowHeight from within the renderer is wrong.