basicgraphicsutils.java

gcc的JAVA模块的源代码

   * @param g the graphics into which the rectangle is drawn.
   * @param x the x coordinate of the rectangle.
   * @param y the y coordinate of the rectangle.
   * @param width the width of the rectangle in pixels.
   * @param height the height of the rectangle in pixels.
   *
   * @param shadow the color that will be used for painting
   *        the inner side of the top and left edges.
   *
   * @param darkShadow the color that will be used for painting
   *        the outer side of the top and left edges.
   *
   * @param highlight the color that will be used for painting
   *        the inner side of the bottom and right edges.
   *
   * @param lightHighlight the color that will be used for painting
   *        the outer side of the bottom and right edges.
   */
  public static void drawLoweredBezel(Graphics g,
                                      int x, int y, int width, int height,
                                      Color shadow, Color darkShadow,
                                      Color highlight, Color lightHighlight)
  {
    /* Like drawEtchedRect, but swapping darkShadow and shadow.
     *
     * To understand this, it might be helpful to look at the image
     * "BasicGraphicsUtils-4.png" that is included with the JavaDoc,
     * and to compare it with "BasicGraphicsUtils-1.png" which shows
     * the pixels painted by drawEtchedRect.  These image files are
     * located in the "doc-files" subdirectory.
     */
    drawEtchedRect(g, x, y, width, height,
                   darkShadow, shadow,
                   highlight, lightHighlight);
  }
  
  
  /**
   * Draws a String at the given location, underlining the first
   * occurence of a specified character. The algorithm for determining
   * the underlined position is not sensitive to case. If the
   * character is not part of <code>text</code>, the text will be
   * drawn without underlining. Drawing is performed in the current
   * color and font of <code>g</code>.
   *
   * <p><img src="doc-files/BasicGraphicsUtils-5.png" width="500"
   * height="100" alt="[An illustration showing how to use the
   * method]" />
   *
   * @param g the graphics into which the String is drawn.
   *
   * @param text the String to draw.
   *
   * @param underlinedChar the character whose first occurence in
   *        <code>text</code> will be underlined. It is not clear
   *        why the API specification declares this argument to be
   *        of type <code>int</code> instead of <code>char</code>.
   *        While this would allow to pass Unicode characters outside
   *        Basic Multilingual Plane 0 (U+0000 .. U+FFFE), at least
   *        the GNU Classpath implementation does not underline
   *        anything if <code>underlinedChar</code> is outside
   *        the range of <code>char</code>.
   *        
   * @param x the x coordinate of the text, as it would be passed to
   *        {@link java.awt.Graphics#drawString(java.lang.String,
   *        int, int)}.
   *
   * @param y the y coordinate of the text, as it would be passed to
   *        {@link java.awt.Graphics#drawString(java.lang.String,
   *        int, int)}.
   */
  public static void drawString(Graphics g, String text,
                                int underlinedChar, int x, int y)
  {
    int index = -1;

    /* It is intentional that lower case is used. In some languages,
     * the set of lowercase characters is larger than the set of
     * uppercase ones. Therefore, it is good practice to use lowercase
     * for such comparisons (which really means that the author of this
     * code can vaguely remember having read some Unicode techreport
     * with this recommendation, but is too lazy to look for the URL).
     */
    if ((underlinedChar >= 0) || (underlinedChar <= 0xffff))
      index = text.toLowerCase().indexOf(
        Character.toLowerCase((char) underlinedChar));

    drawStringUnderlineCharAt(g, text, index, x, y);
  }


  /**
   * Draws a String at the given location, underlining the character
   * at the specified index. Drawing is performed in the current color
   * and font of <code>g</code>.
   *
   * <p><img src="doc-files/BasicGraphicsUtils-5.png" width="500"
   * height="100" alt="[An illustration showing how to use the
   * method]" />
   *
   * @param g the graphics into which the String is drawn.
   *
   * @param text the String to draw.
   *
   * @param underlinedIndex the index of the underlined character in
   *        <code>text</code>.  If <code>underlinedIndex</code> falls
   *        outside the range <code>[0, text.length() - 1]</code>, the
   *        text will be drawn without underlining anything.
   *        
   * @param x the x coordinate of the text, as it would be passed to
   *        {@link java.awt.Graphics#drawString(java.lang.String,
   *        int, int)}.
   *
   * @param y the y coordinate of the text, as it would be passed to
   *        {@link java.awt.Graphics#drawString(java.lang.String,
   *        int, int)}.
   *
   * @since 1.4
   */
  public static void drawStringUnderlineCharAt(Graphics g, String text,
                                               int underlinedIndex,
                                               int x, int y)
  {
    Graphics2D g2;
    Rectangle2D.Double underline;
    FontRenderContext frc;
    FontMetrics fmet;
    LineMetrics lineMetrics;
    Font font;
    TextLayout layout;
    double underlineX1, underlineX2;
    boolean drawUnderline;
    int textLength;

    textLength = text.length();
    if (textLength == 0)
      return;

    drawUnderline = (underlinedIndex >= 0) && (underlinedIndex < textLength);

    if (!(g instanceof Graphics2D))
    {
      /* Fall-back. This is likely to produce garbage for any text
       * containing right-to-left (Hebrew or Arabic) characters, even
       * if the underlined character is left-to-right.
       */
      g.drawString(text, x, y);
      if (drawUnderline)
      {
        fmet = g.getFontMetrics();
        g.fillRect(
          /* x */ x + fmet.stringWidth(text.substring(0, underlinedIndex)),
          /* y */ y + fmet.getDescent() - 1,
          /* width */ fmet.charWidth(text.charAt(underlinedIndex)),
          /* height */ 1);
      }

      return;
    }

    g2 = (Graphics2D) g;
    font = g2.getFont();
    frc = g2.getFontRenderContext();
    lineMetrics = font.getLineMetrics(text, frc);
    layout = new TextLayout(text, font, frc);

    /* Draw the text. */
    layout.draw(g2, x, y);
    if (!drawUnderline)
      return;

    underlineX1 = x + layout.getLogicalHighlightShape(
     underlinedIndex, underlinedIndex).getBounds2D().getX();
    underlineX2 = x + layout.getLogicalHighlightShape(
     underlinedIndex + 1, underlinedIndex + 1).getBounds2D().getX();

    underline = new Rectangle2D.Double();
    if (underlineX1 < underlineX2)
    {
      underline.x = underlineX1;
      underline.width = underlineX2 - underlineX1;
    }
    else
    {
      underline.x = underlineX2;
      underline.width = underlineX1 - underlineX2;
    }

    
    underline.height = lineMetrics.getUnderlineThickness();
    underline.y = lineMetrics.getUnderlineOffset();
    if (underline.y == 0)
    {
      /* Some fonts do not specify an underline offset, although they
       * actually should do so. In that case, the result of calling
       * lineMetrics.getUnderlineOffset() will be zero. Since it would
       * look very ugly if the underline was be positioned immediately
       * below the baseline, we check for this and move the underline
       * below the descent, as shown in the following ASCII picture:
       *
       *   #####       ##### #
       *  #     #     #     #
       *  #     #     #     #
       *  #     #     #     #
       *   #####       ######        ---- baseline (0)
       *                    #
       *                    #
       * ------------------###----------- lineMetrics.getDescent()
       */
      underline.y = lineMetrics.getDescent();
    }

    underline.y += y;
    g2.fill(underline);
  }


  /**
   * Draws a rectangle, simulating a dotted stroke by painting only
   * every second pixel along the one-pixel thick edge. The color of
   * those pixels is the current color of the Graphics <code>g</code>.
   * Any other pixels are left unchanged.
   *
   * <p><img src="doc-files/BasicGraphicsUtils-7.png" width="360"
   * height="200" alt="[An illustration that shows which pixels
   * get painted]" />
   *
   * @param g the graphics into which the rectangle is drawn.
   * @param x the x coordinate of the rectangle.
   * @param y the y coordinate of the rectangle.
   * @param width the width of the rectangle in pixels.
   * @param height the height of the rectangle in pixels.
   */
  public static void drawDashedRect(Graphics g,
                                    int x, int y, int width, int height)
  {
    int right = x + width - 1;
    int bottom = y + height - 1;

    /* Draw the top and bottom edge of the dotted rectangle. */
    for (int i = x; i <= right; i += 2)
    {
      g.drawLine(i, y, i, y);
      g.drawLine(i, bottom, i, bottom);
    }

    /* Draw the left and right edge of the dotted rectangle. */
    for (int i = y; i <= bottom; i += 2)
    {
      g.drawLine(x, i, x, i);
      g.drawLine(right, i, right, i);
    }
  }


  /**
   * Determines the preferred width and height of an AbstractButton,
   * given the gap between the button&#x2019;s text and icon.
   *
   * @param b the button whose preferred size is determined.
   *
   * @param textIconGap the gap between the button&#x2019;s text and
   *        icon.
   *
   * @return a <code>Dimension</code> object whose <code>width</code>
   *         and <code>height</code> fields indicate the preferred
   *         extent in pixels.
   *
   * @see javax.swing.SwingUtilities#layoutCompoundLabel
   */
  public static Dimension getPreferredButtonSize(AbstractButton b,
                                                 int textIconGap)
  {
    Rectangle contentRect;
    Rectangle viewRect;
    Rectangle iconRect = new Rectangle();
    Rectangle textRect = new Rectangle();
    Insets insets = b.getInsets();
    
    /* For determining the ideal size, do not assume a size restriction. */
    viewRect = new Rectangle(0, 0,
                             /* width */ Integer.MAX_VALUE,
                             /* height */ Integer.MAX_VALUE);

     /* java.awt.Toolkit.getFontMetrics is deprecated. However, it
     * seems not obvious how to get to the correct FontMetrics object
     * otherwise. The real problem probably is that the method
     * javax.swing.SwingUtilities.layoutCompundLabel should take a
     * LineMetrics, not a FontMetrics argument. But fixing this that
     * would change the public API.
     */
    SwingUtilities.layoutCompoundLabel(
      b, // for the component orientation
      b.getToolkit().getFontMetrics(b.getFont()), // see comment above
      b.getText(),
      b.getIcon(),
      b.getVerticalAlignment(),
      b.getHorizontalAlignment(),
      b.getVerticalTextPosition(),
      b.getHorizontalTextPosition(),
      viewRect, iconRect, textRect,
      textIconGap);


    /*  +------------------------+       +------------------------+
     *  |                        |       |                        |
     *  | ICON                   |       | CONTENTCONTENTCONTENT  |
     *  |          TEXTTEXTTEXT  |  -->  | CONTENTCONTENTCONTENT  |
     *  |          TEXTTEXTTEXT  |       | CONTENTCONTENTCONTENT  |
     *  +------------------------+       +------------------------+
     */
    contentRect = textRect.union(iconRect);

    return new Dimension(insets.left + contentRect.width + insets.right,
                         insets.top + contentRect.height + insets.bottom);
  }
}