compositeview.java

gcc的组建

   *         model location
   */
  public int getViewIndex(int pos, Position.Bias b)
  {
    // FIXME: Handle bias somehow.
    return getViewIndexAtPosition(pos);
  }

  /**
   * Returns <code>true</code> if the specified point lies before the
   * given <code>Rectangle</code>, <code>false</code> otherwise.
   *
   * &quot;Before&quot; is typically defined as being to the left or above.
   *
   * @param x the X coordinate of the point
   * @param y the Y coordinate of the point
   * @param r the rectangle to test the point against
   *
   * @return <code>true</code> if the specified point lies before the
   *         given <code>Rectangle</code>, <code>false</code> otherwise
   */
  protected abstract boolean isBefore(int x, int y, Rectangle r);

  /**
   * Returns <code>true</code> if the specified point lies after the
   * given <code>Rectangle</code>, <code>false</code> otherwise.
   *
   * &quot;After&quot; is typically defined as being to the right or below.
   *
   * @param x the X coordinate of the point
   * @param y the Y coordinate of the point
   * @param r the rectangle to test the point against
   *
   * @return <code>true</code> if the specified point lies after the
   *         given <code>Rectangle</code>, <code>false</code> otherwise
   */
  protected abstract boolean isAfter(int x, int y, Rectangle r);

  /**
   * Returns the child <code>View</code> at the specified location.
   *
   * @param x the X coordinate
   * @param y the Y coordinate
   * @param r the inner allocation of this <code>BoxView</code> on entry,
   *        the allocation of the found child on exit
   *
   * @return the child <code>View</code> at the specified location
   */
  protected abstract View getViewAtPoint(int x, int y, Rectangle r);

  /**
   * Computes the allocation for a child <code>View</code>. The parameter
   * <code>a</code> stores the allocation of this <code>CompositeView</code>
   * and is then adjusted to hold the allocation of the child view.
   *
   * @param index the index of the child <code>View</code>
   * @param a the allocation of this <code>CompositeView</code> before the
   *        call, the allocation of the child on exit
   */
  protected abstract void childAllocation(int index, Rectangle a);

  /**
   * Returns the child <code>View</code> that contains the given model
   * position. The given <code>Rectangle</code> gives the parent's allocation
   * and is changed to the child's allocation on exit.
   *
   * @param pos the model position to query the child <code>View</code> for
   * @param a the parent allocation on entry and the child allocation on exit
   *
   * @return the child view at the given model position
   */
  protected View getViewAtPosition(int pos, Rectangle a)
  {
    int i = getViewIndexAtPosition(pos);
    View view = children[i];
    childAllocation(i, a);
    return view;
  }

  /**
   * Returns the index of the child <code>View</code> for the given model
   * position.
   *
   * @param pos the model position for whicht the child <code>View</code> is
   *        queried
   *
   * @return the index of the child <code>View</code> for the given model
   *         position
   */
  protected int getViewIndexAtPosition(int pos)
  {
    int index = -1;
    for (int i = 0; i < children.length; i++)
      {
        if (children[i].getStartOffset() <= pos
            && children[i].getEndOffset() > pos)
          {
            index = i;
            break;
          }
      }
    return index;
  }

  /**
   * Returns the allocation that is given to this <code>CompositeView</code>
   * minus this <code>CompositeView</code>'s insets.
   *
   * Also this translates from an immutable allocation to a mutable allocation
   * that is typically reused and further narrowed, like in
   * {@link #childAllocation}.
   *
   * @param a the allocation given to this <code>CompositeView</code>
   *
   * @return the allocation that is given to this <code>CompositeView</code>
   *         minus this <code>CompositeView</code>'s insets or
   *         <code>null</code> if a was <code>null</code>
   */
  protected Rectangle getInsideAllocation(Shape a)
  {
    if (a == null)
      return null;

    Rectangle alloc = a.getBounds();
    // Initialize the inside allocation rectangle. This is done inside
    // a synchronized block in order to avoid multiple threads creating
    // this instance simultanously.
    Rectangle inside;
    synchronized(this)
      {
        inside = insideAllocation;
        if (inside == null)
          {
            inside = new Rectangle();
            insideAllocation = inside;
          }
      }
    inside.x = alloc.x + insets.left;
    inside.y = alloc.y + insets.top;
    inside.width = alloc.width - insets.left - insets.right;
    inside.height = alloc.height - insets.top - insets.bottom;
    return inside;
  }

  /**
   * Sets the insets defined by attributes in <code>attributes</code>. This
   * queries the attribute keys {@link StyleConstants#SpaceAbove},
   * {@link StyleConstants#SpaceBelow}, {@link StyleConstants#LeftIndent} and
   * {@link StyleConstants#RightIndent} and calls {@link #setInsets} to
   * actually set the insets on this <code>CompositeView</code>.
   *
   * @param attributes the attributes from which to query the insets
   */
  protected void setParagraphInsets(AttributeSet attributes)
  {
    Float l = (Float) attributes.getAttribute(StyleConstants.LeftIndent);
    short left = 0;
    if (l != null)
      left = l.shortValue();
    Float r = (Float) attributes.getAttribute(StyleConstants.RightIndent);
    short right = 0;
    if (r != null)
      right = r.shortValue();
    Float t = (Float) attributes.getAttribute(StyleConstants.SpaceAbove);
    short top = 0;
    if (t != null)
      top = t.shortValue();
    Float b = (Float) attributes.getAttribute(StyleConstants.SpaceBelow);
    short bottom = 0;
    if (b != null)
      bottom = b.shortValue();
    setInsets(top, left, bottom, right);
  }

  /**
   * Sets the insets of this <code>CompositeView</code>.
   *
   * @param top the top inset
   * @param left the left inset
   * @param bottom the bottom inset
   * @param right the right inset
   */
  protected void setInsets(short top, short left, short bottom, short right)
  {
    insets.top = top;
    insets.left = left;
    insets.bottom = bottom;
    insets.right = right;
  }

  /**
   * Returns the left inset of this <code>CompositeView</code>.
   *
   * @return the left inset of this <code>CompositeView</code>
   */
  protected short getLeftInset()
  {
    return (short) insets.left;
  }

  /**
   * Returns the right inset of this <code>CompositeView</code>.
   *
   * @return the right inset of this <code>CompositeView</code>
   */
  protected short getRightInset()
  {
    return (short) insets.right;
  }

  /**
   * Returns the top inset of this <code>CompositeView</code>.
   *
   * @return the top inset of this <code>CompositeView</code>
   */
  protected short getTopInset()
  {
    return (short) insets.top;
  }

  /**
   * Returns the bottom inset of this <code>CompositeView</code>.
   *
   * @return the bottom inset of this <code>CompositeView</code>
   */
  protected short getBottomInset()
  {
    return (short) insets.bottom;
  }

  /**
   * Returns the next model location that is visible in north or south
   * direction.
   * This is used to determine the
   * placement of the caret when navigating around the document with
   * the arrow keys.
   *
   * @param pos the model position to start search from
   * @param b the bias for <code>pos</code>
   * @param a the allocated region for this view
   * @param direction the direction from the current position, can be one of
   *        the following:
   *        <ul>
   *        <li>{@link SwingConstants#NORTH}</li>
   *        <li>{@link SwingConstants#SOUTH}</li>
   *        </ul>
   * @param biasRet the bias of the return value gets stored here
   *
   * @return the position inside the model that represents the next visual
   *         location
   *
   * @throws BadLocationException if <code>pos</code> is not a valid location
   *         inside the document model
   * @throws IllegalArgumentException if <code>direction</code> is invalid
   */
  protected int getNextNorthSouthVisualPositionFrom(int pos, Position.Bias b,
                                                    Shape a, int direction,
                                                    Position.Bias[] biasRet)
    throws BadLocationException
  {
    // FIXME: Implement this correctly.
    return pos;
  }

  /**
   * Returns the next model location that is visible in east or west
   * direction.
   * This is used to determine the
   * placement of the caret when navigating around the document with
   * the arrow keys.
   *
   * @param pos the model position to start search from
   * @param b the bias for <code>pos</code>
   * @param a the allocated region for this view
   * @param direction the direction from the current position, can be one of
   *        the following:
   *        <ul>
   *        <li>{@link SwingConstants#EAST}</li>
   *        <li>{@link SwingConstants#WEST}</li>
   *        </ul>
   * @param biasRet the bias of the return value gets stored here
   *
   * @return the position inside the model that represents the next visual
   *         location
   *
   * @throws BadLocationException if <code>pos</code> is not a valid location
   *         inside the document model
   * @throws IllegalArgumentException if <code>direction</code> is invalid
   */
  protected int getNextEastWestVisualPositionFrom(int pos, Position.Bias b,
                                                  Shape a, int direction,
                                                  Position.Bias[] biasRet)
    throws BadLocationException
  {
    // FIXME: Implement this correctly.
    return pos;
  }

  /**
   * Determines if the next view in horinzontal direction is located to
   * the east or west of the view at position <code>pos</code>. Usually
   * the <code>View</code>s are laid out from the east to the west, so
   * we unconditionally return <code>false</code> here. Subclasses that
   * support bidirectional text may wish to override this method.
   *
   * @param pos the position in the document
   * @param bias the bias to be applied to <code>pos</code>
   *
   * @return <code>true</code> if the next <code>View</code> is located
   *         to the EAST, <code>false</code> otherwise
   */
  protected boolean flipEastAndWestAtEnds(int pos, Position.Bias bias)
  {
    return false;
  }

  /**
   * Returns the document position that is (visually) nearest to the given
   * document position <code>pos</code> in the given direction <code>d</code>.
   *
   * @param c the text component
   * @param pos the document position
   * @param b the bias for <code>pos</code>
   * @param d the direction, must be either {@link SwingConstants#NORTH},
   *        {@link SwingConstants#SOUTH}, {@link SwingConstants#WEST} or
   *        {@link SwingConstants#EAST}
   * @param biasRet an array of {@link Position.Bias} that can hold at least
   *        one element, which is filled with the bias of the return position
   *        on method exit
   *
   * @return the document position that is (visually) nearest to the given
   *         document position <code>pos</code> in the given direction
   *         <code>d</code>
   *
   * @throws BadLocationException if <code>pos</code> is not a valid offset in
   *         the document model
   */
  public int getNextVisualPositionFrom(JTextComponent c, int pos,
                                       Position.Bias b, int d,
                                       Position.Bias[] biasRet)
    throws BadLocationException
  {
    // TODO: Implement this properly.
    throw new AssertionError("Not implemented yet.");
  }
}