titledborder.java

gcc的JAVA模块的源代码

   *         <code>&quot;TitledBorder.font&quot;</code>.
   *
   * @see javax.swing.UIManager#getFont(Object)
   */
  public Font getTitleFont()
  {
    if (titleFont != null)
      return titleFont;

    return UIManager.getFont("TitledBorder.font");
  }


  /**
   * Retrieves the color for displaying the title text. If no color has
   * been set, or if it has been set to<code>null</code>, the current
   * {@link javax.swing.LookAndFeel} will be asked for a color
   * using the key <code>&quot;TitledBorder.titleColor&quot;</code>.
   *
   * @return a color, or <code>null</code> if the current LookAndFeel
   *         does not provide a color for the key
   *         <code>&quot;TitledBorder.titleColor&quot;</code>.
   *
   * @see javax.swing.UIManager#getColor(Object)
   */
  public Color getTitleColor()
  {
    if (titleColor != null)
      return titleColor;

    return UIManager.getColor("TitledBorder.titleColor");
  }


  /**
   * Sets the text of the title.
   *
   * @param title the new title text, or <code>null</code> for displaying
   *        no text at all.
   */
  public void setTitle(String title)
  {
    // Swing borders are not JavaBeans, thus no need to fire an event.
    this.title = title;
  }


  /**
   * Sets the border underneath the title.
   *
   * @param border a border, or <code>null</code> to use the
   *        border that is supplied by the current LookAndFeel.
   *
   * @see #getBorder()
   */
  public void setBorder(Border border)
  {
    // Swing borders are not JavaBeans, thus no need to fire an event.
    this.border = border;
  }


  /**
   * Sets the vertical position of the title text in relation
   * to the border.
   *
   * @param titlePosition one of the values {@link #ABOVE_TOP},
   *        {@link #TOP}, {@link #BELOW_TOP}, {@link #ABOVE_BOTTOM},
   *        {@link #BOTTOM}, {@link #BELOW_BOTTOM},
   *        or {@link #DEFAULT_POSITION}.
   *
   * @throws IllegalArgumentException if an unsupported value is passed
   *         for <code>titlePosition</code>.
   */
  public void setTitlePosition(int titlePosition)
  {
    if ((titlePosition < DEFAULT_POSITION) || (titlePosition > BELOW_BOTTOM))
      throw new IllegalArgumentException();

    // Swing borders are not JavaBeans, thus no need to fire an event.
    this.titlePosition = titlePosition;
  }


  /**
   * Sets the horizontal alignment of the title text in relation to the border.
   *
   * @param titleJustification the new alignment, which must be one of
   *        {@link #LEFT}, {@link #CENTER}, {@link #RIGHT}, {@link #LEADING},
   *        {@link #TRAILING}, or {@link #DEFAULT_JUSTIFICATION}.
   *
   * @throws IllegalArgumentException if an unsupported value is passed
   *         for <code>titleJustification</code>.
   */
  public void setTitleJustification(int titleJustification)
  {
    if ((titleJustification < DEFAULT_JUSTIFICATION)
        || (titleJustification > TRAILING))
      throw new IllegalArgumentException();

    // Swing borders are not JavaBeans, thus no need to fire an event.
    this.titleJustification = titleJustification;
  }


  /**
   * Sets the font for displaying the title text.
   *
   * @param titleFont the font, or <code>null</code> to use the font
   *        provided by the current {@link javax.swing.LookAndFeel}.
   *
   * @see #getTitleFont()
   */
  public void setTitleFont(Font titleFont)
  {
    // Swing borders are not JavaBeans, thus no need to fire an event.
    this.titleFont = titleFont;
  }


  /**
   * Sets the color for displaying the title text.
   *
   * @param titleColor the color, or <code>null</code> to use the color
   *        provided by the current {@link javax.swing.LookAndFeel}.
   *
   * @see #getTitleColor()
   */
  public void setTitleColor(Color titleColor)
  {
    // Swing borders are not JavaBeans, thus no need to fire an event.
    this.titleColor = titleColor;
  }


  /**
   * Calculates the minimum size needed for displaying the border
   * and its title.
   *
   * @param c the Component for which this TitledBorder consitutes
   *        a border.
   */
  public Dimension getMinimumSize(Component c)
  {
    return getMeasurements(c).getMinimumSize();
  }


  /**
   * Returns the font that is used for displaying the title text for
   * a given Component.
   *
   * @param c the Component for which this TitledBorder is the border.
   *
   * @return The font returned by {@link #getTitleFont()}, or a fallback
   *         if {@link #getTitleFont()} returned <code>null</code>.
   */
  protected Font getFont(Component c)
  {
    Font f;

    f = getTitleFont();
    if (f != null)
      return f;

    return new Font("Dialog", Font.PLAIN, 12);
  }


  /**
   * Returns the horizontal alignment of the title text in relation to
   * the border, mapping the component-dependent alignment constants
   * {@link #LEADING}, {@link #TRAILING} and {@link #DEFAULT_JUSTIFICATION}
   * to the correct value according to the embedded component&#x2019;s
   * orientation.
   *
   * @param c the Component for which this TitledBorder is the border.
   *
   * @return one of the values {@link #LEFT}, {@link #CENTER}, or {@link
   *         #RIGHT}.
   */
  private int getRealTitleJustification(Component c)
  {
    switch (titleJustification)
    {
    case DEFAULT_JUSTIFICATION:
    case LEADING:
      if ((c == null) || c.getComponentOrientation().isLeftToRight())
        return LEFT;
      else
        return RIGHT;

    case TRAILING:
      if ((c == null) || c.getComponentOrientation().isLeftToRight())
        return RIGHT;
      else
        return LEFT;

    default:
      return titleJustification;
    }
  }


  /**
   * Performs various measurements for the current state of this TitledBorder
   * and the given Component.
   */
  private Measurements getMeasurements(Component c)
  {
    Measurements m = new Measurements();
    FontMetrics fmet;

    m.font = getFont(c);
    fmet = c.getFontMetrics(m.font);
    m.border = getBorder();
    if (m.border != null)
      m.borderInsets = m.border.getBorderInsets(c);
    else
      m.borderInsets = new Insets(0, 0, 0, 0);

    if (title != null)
    {
      m.trimmedText = title.trim();
      if (m.trimmedText.length() == 0)
        m.trimmedText = null;
    }
    
    m.textAscent = fmet.getAscent();
    m.textDescent = fmet.getDescent();
    if (m.trimmedText != null)
      m.textWidth = fmet.stringWidth(m.trimmedText) + 3;

    m.edgeSpacing = new Insets(EDGE_SPACING, EDGE_SPACING, EDGE_SPACING, EDGE_SPACING);
    m.borderSpacing = new Insets(0, 0, 0, 0);

    switch (titlePosition)
    {
    case ABOVE_TOP:
      m.borderSpacing.top += m.textAscent + m.textDescent + TEXT_SPACING;
      break;

    case BELOW_TOP:
      m.edgeSpacing.top += m.textAscent + m.textDescent + TEXT_SPACING;
      break;

    case ABOVE_BOTTOM:
      m.edgeSpacing.bottom += m.textAscent + m.textDescent + TEXT_SPACING;
      break;

    case BOTTOM:
      m.edgeSpacing.bottom += Math.max(m.textAscent - m.borderInsets.bottom, 0);
      m.borderSpacing.bottom += m.textDescent;
      break;

    case BELOW_BOTTOM:
      m.borderSpacing.bottom += m.textAscent + m.textDescent + TEXT_SPACING;
      break;

    default:
      m.borderSpacing.top += m.textAscent;
    }

    return m;
  }


  /**
   * A private helper class for holding the result of measuring the
   * distances of a TitledBorder.  While it would be possible to cache
   * these objects, it does not seem to be worth the effort. Note that
   * invalidating the cache would be tricky, especially since there is
   * no notification mechanism that would inform the cache when
   * border has changed, so it would return different insets.
   */
  private static class Measurements
  {
    /**
     * The font used for displaying the title text. Note that it can
     * well be that the TitledBorder&#x2019;s font is <code>null</code>,
     * which means that the font is to be retrieved from the current
     * LookAndFeel. In this case, this <code>font</code> field will
     * contain the result of the retrieval. Therefore, it is safe
     * to assume that his <code>font</code> field will never have
     * a <code>null</code> value.
     */
    Font font;


    /**
     * The number of pixels between the base line and the top of the
     * text box.
     */
    int textAscent;


    /**
     * The number of pixels between the base line and the bottom of
     * the text box.
     */
    int textDescent;


    /**
     * The title text after removing leading and trailing white space
     * characters. If the title consists only of white space, the
     * value of <code>trimmedText</code> will be <code>null</code>.
     */
    String trimmedText;


    /**
     * The width of the trimmed title text in pixels.
     */
    int textWidth;


    /**
     * The border that constitues the &quot;interior&quot; border
     * underneath the title text.
     */
    Border border;


    /**
     * The distance between the TitledBorder and the interior border.
     */
    Insets borderSpacing;

    
    /**
     * The width of the interior border, as returned by
     * <code>border.getBorderInsets()</code>.
     */
    Insets borderInsets;

    
    /**
     * The distance between the interior border and the nested
     * Component for which this TitledBorder is a border.
     */
    Insets edgeSpacing;


    /**
     * Determines the insets of the nested component when it has a
     * TitledBorder as its border. Used by {@link
     * TitledBorder#getBorderInsets()}.
     *
     * @param i an Insets object for storing the results into, or
     *        <code>null</code> to cause the creation of a
     *        new instance.
     *
     * @return the <code>i</code> object, or a new Insets object
     *         if <code>null</code> was passed for <code>i</code>.
     */
    public Insets getContentInsets(Insets i)
    {
      if (i == null)
        i = new Insets(0, 0, 0, 0);
      i.left = borderSpacing.left + borderInsets.left + edgeSpacing.left;
      i.right = borderSpacing.right + borderInsets.right + edgeSpacing.right;
      i.top = borderSpacing.top + borderInsets.top + edgeSpacing.top;
      i.bottom = borderSpacing.bottom + borderInsets.bottom + edgeSpacing.bottom;
      return i;
    }


    /**
     * Calculates the minimum size needed for displaying the border
     * and its title. Used by {@link TitledBorder#getMiminumSize()}.
     */
    public Dimension getMinimumSize()
    {
      int width;
      Insets insets;

      insets = getContentInsets(null);
      width = Math.max(insets.left + insets.right, textWidth + 2 * TEXT_INSET_H);
      return new Dimension(width, insets.top + insets.bottom);
    }
  }
}