Swing/TabSize のバックアップ(No.14)

textpane.setFont(new Font(Font.MONOSPACED, Font.PLAIN, 12));
FontMetrics fm = textpane.getFontMetrics(textpane.getFont());
int charWidth = fm.charWidth('m');
int tabLength = charWidth * 4;
TabStop[] tabs = new TabStop[10];
for(int j=0;j<tabs.length;j++) {
  tabs[j] = new TabStop((j+1)*tabLength);
}
TabSet tabSet = new TabSet(tabs);
SimpleAttributeSet attrs = new SimpleAttributeSet();
StyleConstants.setTabSet(attrs, tabSet);
int l = textpane.getDocument().getLength();
textpane.getStyledDocument().setParagraphAttributes(0, l, attrs, false);