/**
* Constructs a new instance of this class given its parent (which must be a <code>Tree</code>)
* and a style value describing its behavior and appearance. The item is added to the end of the
* items maintained by its parent.
*
* <p>The style value is either one of the style constants defined in class <code>SWT</code> which
* is applicable to instances of this class, or must be built by <em>bitwise OR</em>'ing together
* (that is, using the <code>int</code> "|" operator) two or more of those <code>SWT</code> style
* constants. The class description lists the style constants that are applicable to the class.
* Style bits are also inherited from superclasses.
*
* @param parent a composite control which will be the parent of the new instance (cannot be null)
* @param style the style of control to construct
* @exception IllegalArgumentException
* <ul>
* <li>ERROR_NULL_ARGUMENT - if the parent is null
* </ul>
*
* @exception SWTException
* <ul>
* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent
* <li>ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass
* </ul>
*
* @see SWT#LEFT
* @see SWT#RIGHT
* @see SWT#CENTER
* @see Widget#checkSubclass
* @see Widget#getStyle
*/
public TreeColumn(Tree parent, int style) {
super(parent, checkStyle(style));
this.parent = parent;
parent.createItem(this, parent.columnCount);
}
/**
* Constructs a new instance of this class given its parent (which must be a <code>Tree</code>), a
* style value describing its behavior and appearance, and the index at which to place it in the
* items maintained by its parent.
*
* <p>The style value is either one of the style constants defined in class <code>SWT</code> which
* is applicable to instances of this class, or must be built by <em>bitwise OR</em>'ing together
* (that is, using the <code>int</code> "|" operator) two or more of those <code>SWT</code> style
* constants. The class description lists the style constants that are applicable to the class.
* Style bits are also inherited from superclasses.
*
* <p>Note that due to a restriction on some platforms, the first column is always left aligned.
*
* @param parent a composite control which will be the parent of the new instance (cannot be null)
* @param style the style of control to construct
* @param index the zero-relative index to store the receiver in its parent
* @exception IllegalArgumentException
* <ul>
* <li>ERROR_NULL_ARGUMENT - if the parent is null
* <li>ERROR_INVALID_RANGE - if the index is not between 0 and the number of elements in the
* parent (inclusive)
* </ul>
*
* @exception SWTException
* <ul>
* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent
* <li>ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass
* </ul>
*
* @see SWT#LEFT
* @see SWT#RIGHT
* @see SWT#CENTER
* @see Widget#checkSubclass
* @see Widget#getStyle
*/
public TreeColumn(Tree parent, int style, int index) {
super(parent, checkStyle(style));
this.parent = parent;
parent.createItem(this, index);
}