debugger/swing_utils/src/main/com/thesett/aima/logic/fol/wam/debugger/swing/JTextGrid.java
private void initializeFontMetrics()
    {
        if (!fontMetricsInitialized)
        {
            FontMetrics fontMetrics = getFontMetrics(getFont());
            charWidth = fontMetrics.charWidth(' ');
            charHeight = fontMetrics.getHeight();
            descent = fontMetrics.getDescent();
            fontMetricsInitialized = true;
        }
    }
private void initializeFontMetrics()
    {
        if (!fontMetricsInitialized)
        {
            FontMetrics fontMetrics = getFontMetrics(getFont());
            charWidth = fontMetrics.charWidth(' ');
            charHeight = fontMetrics.getHeight();
            descent = fontMetrics.getDescent();
            fontMetricsInitialized = true;
        }
    }
Sets up metrics relating to the size of the font used to display the text grid. This only needs to be done once
but this method can be called many times as it is guarded by an initialization flag to prevent these being
calculated many times.