jlabel.java

gcc的组建

   * This method is used primarily for debugging purposes and returns a string
   * that can be used to represent this label.
   *
   * @return A string to represent this label.
   */
  protected String paramString()
  {
    return "JLabel";
  }

  /**
   * This method returns the label text.
   *
   * @return The label text.
   */
  public String getText()
  {
    return text;
  }

  /**
   * This method changes the "text" property. The given text will be painted
   * in the label.
   *
   * @param newText The label's text.
   */
  public void setText(String newText)
  {
    if (text != newText)
      {
        String oldText = text;
        text = newText;
        firePropertyChange("text", oldText, newText);

        if (text != null && text.length() <= displayedMnemonicIndex)
          setDisplayedMnemonicIndex(text.length() - 1);
        revalidate();
        repaint();
      }
  }

  /**
   * This method returns the active icon. The active icon is painted when the
   * label is enabled.
   *
   * @return The active icon.
   */
  public Icon getIcon()
  {
    return icon;
  }

  /**
   * This method changes the "icon" property. This icon (the active icon) will
   * be the one displayed when the label is enabled.
   *
   * @param newIcon The active icon.
   */
  public void setIcon(Icon newIcon)
  {
    if (icon != newIcon)
      {
	Icon oldIcon = icon;
	icon = newIcon;
	firePropertyChange("icon", oldIcon, newIcon);
      }
  }

  /**
   * This method returns the disabled icon. The disabled icon is painted when
   * the label is disabled. If the disabled icon is null and the active icon
   * is an ImageIcon, this method returns a grayed version of the icon. The
   * grayed  version of the icon becomes the disabledIcon.
   *
   * @return The disabled icon.
   */
  public Icon getDisabledIcon()
  {
    if (disabledIcon == null && icon instanceof ImageIcon)
      disabledIcon = new ImageIcon(GrayFilter.createDisabledImage(((ImageIcon) icon)
                                                                  .getImage()));

    return disabledIcon;
  }

  /**
   * This method changes the "disabledIcon" property. This icon (the disabled
   * icon) will be the one displayed when the label is disabled.
   *
   * @param newIcon The disabled icon.
   */
  public void setDisabledIcon(Icon newIcon)
  {
    if (disabledIcon != newIcon)
      {
	Icon oldIcon = disabledIcon;
	disabledIcon = newIcon;
	firePropertyChange("disabledIcon", oldIcon, newIcon);
      }
  }

  /**
   * This method sets the keycode that will be the label's mnemonic. If the
   * label is used as a label for another component, the label will give
   * focus to that component when the mnemonic is activated.
   *
   * @param mnemonic The keycode to use for the mnemonic.
   */
  public void setDisplayedMnemonic(int mnemonic)
  {
    if (displayedMnemonic != mnemonic)
      {
	firePropertyChange("displayedMnemonic",
	                   displayedMnemonic, mnemonic);
	displayedMnemonic = mnemonic;

	if (text != null)
	  setDisplayedMnemonicIndex(text.toUpperCase().indexOf(mnemonic));
      }
  }

  /**
   * This method sets the character that will be the mnemonic used. If the
   * label is used as a label for another component, the label will give
   * focus to that component when the mnemonic is activated.
   *
   * @param mnemonic The character to use for the mnemonic.
   */
  public void setDisplayedMnemonic(char mnemonic)
  {
    setDisplayedMnemonic((int) Character.toUpperCase(mnemonic));
  }

  /**
   * This method returns the keycode that is used for the label's mnemonic.
   *
   * @return The keycode that is used for the label's mnemonic.
   */
  public int getDisplayedMnemonic()
  {
    return (int) displayedMnemonic;
  }

  /**
   * This method sets which character in the text will be the underlined
   * character. If the given index is -1, then this indicates  that there is
   * no mnemonic. If the index is less than -1 or if the index is equal to
   * the length, this method will throw an IllegalArgumentException.
   *
   * @param newIndex The index of the character to underline.
   *
   * @throws IllegalArgumentException If index less than -1 or index equals
   *         length.
   */
  public void setDisplayedMnemonicIndex(int newIndex)
    throws IllegalArgumentException
  {
    if (newIndex < -1 || (text != null && newIndex >= text.length()))
      throw new IllegalArgumentException();

    if (newIndex == -1
        || text == null
	|| text.charAt(newIndex) != displayedMnemonic)
      newIndex = -1;

    if (newIndex != displayedMnemonicIndex)
      {
	int oldIndex = displayedMnemonicIndex;
	displayedMnemonicIndex = newIndex;
	firePropertyChange("displayedMnemonicIndex",
	                   oldIndex, newIndex);
      }
  }

  /**
   * This method returns which character in the text will be  the underlined
   * character.
   *
   * @return The index of the character that will be underlined.
   */
  public int getDisplayedMnemonicIndex()
  {
    return displayedMnemonicIndex;
  }

  /**
   * This method ensures that the key is valid as a horizontal alignment.
   * Valid keys are: LEFT, CENTER, RIGHT, LEADING, TRAILING
   *
   * @param key The key to check.
   * @param message The message of the exception to be thrown if the key is
   *        invalid.
   *
   * @return The key if it's valid.
   *
   * @throws IllegalArgumentException If the key is invalid.
   */
  protected int checkHorizontalKey(int key, String message)
  {
    if (key != LEFT && key != CENTER && key != RIGHT && key != LEADING
        && key != TRAILING)
      throw new IllegalArgumentException(message);
    else
      return key;
  }

  /**
   * This method ensures that the key is valid as a  vertical alignment. Valid
   * keys are: TOP, CENTER, and BOTTOM.
   *
   * @param key The key to check.
   * @param message The message of the exception to be thrown if the key is
   *        invalid.
   *
   * @return The key if it's valid.
   *
   * @throws IllegalArgumentException If the key is invalid.
   */
  protected int checkVerticalKey(int key, String message)
  {
    if (key != TOP && key != BOTTOM && key != CENTER)
      throw new IllegalArgumentException(message);
    else
      return key;
  }

  /**
   * This method returns the gap between the icon and the text.
   *
   * @return The gap between the icon and the text.
   */
  public int getIconTextGap()
  {
    return iconTextGap;
  }

  /**
   * This method changes the "iconTextGap" property. The iconTextGap
   * determines how much space there is between the icon and the text.
   *
   * @param newGap The gap between the icon and the text.
   */
  public void setIconTextGap(int newGap)
  {
    if (iconTextGap != newGap)
      {
	firePropertyChange("iconTextGap", iconTextGap, newGap);
	iconTextGap = newGap;
      }
  }

  /**
   * This method returns the vertical alignment of the label.
   *
   * @return The vertical alignment of the label.
   */
  public int getVerticalAlignment()
  {
    return verticalAlignment;
  }

  /**
   * This method changes the "verticalAlignment" property of the label. The
   * vertical alignment determines how where the label will be placed
   * vertically. If the alignment is not valid, it will default to the
   * center.
   *
   * @param alignment The vertical alignment of the label.
   */
  public void setVerticalAlignment(int alignment)
  {
    if (alignment == verticalAlignment)
      return;

    int oldAlignment = verticalAlignment;
    verticalAlignment = checkVerticalKey(alignment, "verticalAlignment");
    firePropertyChange("verticalAlignment", oldAlignment, verticalAlignment);
  }

  /**
   * This method returns the horziontal alignment of the label.
   *
   * @return The horizontal alignment of the label.
   */
  public int getHorizontalAlignment()
  {
    return horizontalAlignment;
  }

  /**
   * This method changes the "horizontalAlignment" property. The horizontal
   * alignment determines where the label will be placed horizontally.
   *
   * @param alignment The horizontal alignment of the label.
   */
  public void setHorizontalAlignment(int alignment)
  {
    if (horizontalAlignment == alignment)
      return;
    
    int oldAlignment = horizontalAlignment;
    horizontalAlignment = checkHorizontalKey(alignment, "horizontalAlignment");
    firePropertyChange("horizontalAlignment", oldAlignment,
                       horizontalAlignment);
  }

  /**
   * This method returns the vertical text position of the label.
   *
   * @return The vertical text position of the label.
   */
  public int getVerticalTextPosition()
  {
    return verticalTextPosition;
  }

  /**
   * This method changes the "verticalTextPosition" property of the label. The
   * vertical text position determines where the text will be placed
   * vertically relative to the icon.
   *
   * @param textPosition The vertical text position.
   */
  public void setVerticalTextPosition(int textPosition)
  {
    if (textPosition != verticalTextPosition)
      {
	int oldPos = verticalTextPosition;
	verticalTextPosition = checkVerticalKey(textPosition,
	                                        "verticalTextPosition");
	firePropertyChange("verticalTextPosition", oldPos,
	                   verticalTextPosition);
      }
  }

  /**
   * This method returns the horizontal text position of the label.
   *
   * @return The horizontal text position.
   */
  public int getHorizontalTextPosition()
  {
    return horizontalTextPosition;
  }

  /**
   * This method changes the "horizontalTextPosition" property of the label.
   * The horizontal text position determines where the text will be placed
   * horizontally relative to the icon.
   *
   * @param textPosition The horizontal text position.
   */
  public void setHorizontalTextPosition(int textPosition)
  {
    if (textPosition != horizontalTextPosition)
      {
	int oldPos = horizontalTextPosition;
	horizontalTextPosition = checkHorizontalKey(textPosition,
	                                            "horizontalTextPosition");
	firePropertyChange("horizontalTextPosition", oldPos,
	                   horizontalTextPosition);
      }
  }

  /**
   * This method simply returns false if the current icon image (current  icon
   * will depend on whether the label is enabled) is not equal to the passed
   * in image.
   *
   * @param img The image to check.
   * @param infoflags The bitwise inclusive OR of ABORT, ALLBITS, ERROR,
   *        FRAMEBITS, HEIGHT, PROPERTIES, SOMEBITS, and WIDTH
   * @param x The x position
   * @param y The y position
   * @param w The width
   * @param h The height
   *
   * @return Whether the current icon image is equal to the image given.
   */
  public boolean imageUpdate(Image img, int infoflags, int x, int y, int w,
                             int h)
  {
    Icon currIcon = isEnabled() ? icon : disabledIcon;

    // XXX: Is this the correct way to check for image equality?
    if (currIcon != null && currIcon instanceof ImageIcon)
      return (((ImageIcon) currIcon).getImage() == img);

    return false;
  }

  /**
   * This method returns the component that the label gives focus to  when the
   * mnemonic is activated.
   *
   * @return The component that gets focus when the label's mnemonic is
   *         activated.
   */
  public Component getLabelFor()
  {
    return labelFor;
  }

  /**
   * This method changes the "labelFor" property. The component that the label
   * is acting as a label for will request focus when the label's  mnemonic
   * is activated.
   *
   * @param c The component that gets focus when the label's mnemonic is
   *        activated.
   */
  public void setLabelFor(Component c)
  {
    if (c != labelFor)
      {
	Component oldLabelFor = labelFor;
	labelFor = c;
	firePropertyChange("labelFor", oldLabelFor, labelFor);
      }
  }

  /**
   * This method overrides setFont so that we can call for a repaint after the
   * font is changed.
   *
   * @param f The font for this label.
   */
  public void setFont(Font f)
  {
    super.setFont(f);
    repaint();
  }

  /**
   * DOCUMENT ME!
   *
   * @return The accessible context.
   */
  public AccessibleContext getAccessibleContext()
  {
    if (accessibleContext == null)
      accessibleContext = new AccessibleJLabel();
    return accessibleContext;
  }
}