Java Swing Tips: Left Clipped JComboBox

2009/05/19

Left Clipped JComboBox

Posted by TERAI Atsuhiro at 00:13

Code

final JButton arrowButton = getArrowButton(combo02);
combo02.setRenderer(new DefaultListCellRenderer() {
  public Component getListCellRendererComponent(JList list, Object value, int index,
                          boolean isSelected, boolean cellHasFocus) {
    super.getListCellRendererComponent(list,value,index,isSelected,cellHasFocus);
    int itb=0, ilr=0;
    Insets insets = getInsets();
    itb+=insets.top+insets.bottom; ilr+=insets.left+insets.right;
    insets = combo02.getInsets();
    itb+=insets.top+insets.bottom; ilr+=insets.left+insets.right;
    int availableWidth = combo02.getWidth()-ilr;
    if(index < 0) {
      //@see BasicComboBoxUI#rectangleForCurrentValue
      int buttonSize = combo02.getHeight()-itb;
      if(arrowButton!=null) {
        buttonSize = arrowButton.getWidth();
      }
      availableWidth -= buttonSize;
      JTextField tf = (JTextField)combo02.getEditor().getEditorComponent();
      insets = tf.getMargin();
      availableWidth -= (insets.left + insets.right);
    }
    String cellText = (value!=null)?value.toString():"";
    //blockquote
    //@cite http://tips4java.wordpress.com/2008/11/12/left-dot-renderer/
    //@title Left Dot Renderer
    //@auther Rob Camick
    FontMetrics fm = getFontMetrics(getFont());
    if(fm.stringWidth(cellText) > availableWidth) {
      String dots = "...";
      int textWidth = fm.stringWidth(dots);
      int nChars = cellText.length() - 1;
      while(nChars > 0) {
        textWidth += fm.charWidth(cellText.charAt(nChars));
        if(textWidth > availableWidth) break;
        nChars--;
      }
      setText(dots+cellText.substring(nChars+1));
    }
    //blockquote
    return this;
  }
});