Returns the node's preferred height for use in layout calculations. If the node is resizable, its parent should treat this value as the node's ideal height within its range. If the node is not resizable, just returns its layoutBounds height, which should be treated as the rigid height of the node.

Layout code which calls this method should first check the content-bias of the node. If the node has a horizontal content-bias, then callers should pass in a width value that the preferred height should be based on. If the node has either a vertical or null content-bias, then the caller should pass in -1.

Node subclasses with a horizontal content-bias should honor the height parameter whether -1 or a positive value. All other subclasses may ignore the height parameter (which will likely be -1).

Parameters:

width the width that should be used if preferred height depends on it

Returns: the preferred height that the node should be resized to during layout The result will never be NaN, nor will it ever be negative.