/// <summary>
/// Searches for the closest tab index either before or after the given relative element.
/// Note that relative is expected to be a child of this element.
/// </summary>
/// <param name='forward'>True if you want to search forwards; false for backwards.</param>
private bool SearchRelativeFocusable(HtmlElement relativeTo, bool forward, int search, ref int bestSoFar, ref HtmlElement best)
{
if (childNodes_ == null)
{
return(false);
}
int start = (relativeTo == null) ? -1 : relativeTo.childIndex;
if (forward)
{
for (int i = start + 1; i < childNodes_.length; i++)
{
HtmlElement el = childNodes_[i] as HtmlElement;
// Search in this child node:
if (el != null && el.SearchChildFocusable(null, true, search, ref bestSoFar, ref best))
{
return(true);
}
}
}
else
{
for (int i = start - 1; i >= 0; i--)
{
HtmlElement el = childNodes_[i] as HtmlElement;
// Search in this child node:
if (el != null && el.SearchChildFocusable(null, false, search, ref bestSoFar, ref best))
{
return(true);
}
}
}
return(false);
}
/// <summary>Searches for the closest focusable element with/ without a tabindex. Returns true if it gets a match.</summary>
public bool SearchChildFocusable(HtmlElement stopAt, bool forward, int search, ref int bestSoFar, ref HtmlElement best)
{
if (this == best || this == stopAt)
{
// Terminate
return(true);
}
// It must not declare a tabindex:
if (focusable)
{
if (search == -1 && !hasAttribute("tabindex"))
{
// This is the best one!
best = this;
return(true);
}
else if (search != -1 && hasAttribute("tabindex"))
{
// Is its tabIndex suitable?
int index = tabIndex;
if (index >= 0 && (
(forward && index < bestSoFar && index >= search) ||
(!forward && index > bestSoFar && index <= search)
)
)
{
// This is the best one so far.
best = this;
bestSoFar = index;
if (index == search)
{
// Direct match - stop!
return(true);
}
}
}
}
// Any kids?
if (childNodes_ == null)
{
return(false);
}
if (forward)
{
for (int i = 0; i < childNodes_.length; i++)
{
HtmlElement el = childNodes_[i] as HtmlElement;
// Search in it:
if (el != null && el.SearchChildFocusable(stopAt, true, search, ref bestSoFar, ref best))
{
return(true);
}
}
}
else
{
for (int i = childNodes_.length - 1; i >= 0; i--)
{
HtmlElement el = childNodes_[i] as HtmlElement;
// Search in it:
if (el != null && el.SearchChildFocusable(stopAt, false, search, ref bestSoFar, ref best))
{
return(true);
}
}
}
return(false);
}