/// <summary>
/// Build a new layout tree, deferring layout calculations.
/// </summary>
/// <param name="rootNode">A <see cref="xavierHTML.DOM.Document"/>'s root <see cref="StyledNode"/>.</param>
/// <returns>Fully built layout tree.</returns>
/// <exception cref="InvalidOperationException">
/// Thrown when given a <see cref="StyledNode"/> with display property set to none.
/// </exception>
public static Box FromStyledNode(StyledNode rootNode)
{
if (rootNode.Display == Display.None)
{
throw new InvalidOperationException("Root node has display: none.");
}
var nodes = rootNode.Children
// Skip nodes with `display: none;`
.Where(node => node.Display != Display.None)
.Select(FromStyledNode).ToList();
// If a block-level node has only inline children, return just this block-level box with
// the inline children.
if (rootNode.Display == Display.Block &&
nodes.TrueForAll(box => box.Display == Display.Inline))
{
return(new NodeBox(nodes.AsReadOnly(), rootNode));
}
// TODO: Handle case where an inline node contains a block-level child
// CSS2 box generation algorithm
// http://www.w3.org/TR/CSS2/visuren.html#box-gen
// If a block node contains an inline child, create an anonymous block box to contain it.
// If there are several inline children in a row, put them all in the same anonymous container.
var children = new List <Box>();
nodes.ForEach(box =>
{
if (box.Display != Display.Inline)
{
children.Add(box);
}
var anonymousBox = children.LastOrDefault(b => !(b is NodeBox));
if (anonymousBox != null)
{
children.Add(new Box(anonymousBox.Children.Append(box).ToList().AsReadOnly()));
}
children.Add(new Box(new List <Box> {
box
}.AsReadOnly()));
});
return(new NodeBox(children.AsReadOnly(), rootNode));
}
public NodeBox(ReadOnlyCollection <Box> children, StyledNode style) : base(children)
{
Style = style;
}
