// Searches for a navigable element starting from currentFocusable and scanning along the specified direction.
// If no elements are found, wraps around from the other side of the panel and scan along the same direction
// up to currentFocusable. If still no elements are found, returns currentFocusable.
//
// Though search order is hierarchy-based, the "best candidate" selection process is intended to be independent
// from any hierarchy consideration. Scanned elements are validated using an intersection test between their
// worldBound and a scanning validation rect, currentFocusable's worldBound extended to the panel's limits in
// the direction of the search (or from the other side during the second "wrap-around" scan).
//
// The best candidate is the element whose border is "least advanced" in the scanning direction, using the
// element's worldBound border opposite from scanning direction, left border when scanning right, right border
// for scanning left, etc. See FocusableHierarchyTraversal for more details and how further ties are resolved.
Focusable GetNextFocusable2D(Focusable currentFocusable, ChangeDirection direction)
{
if (!(currentFocusable is VisualElement ve))
{
ve = m_Root;
}
Rect panelBounds = m_Root.worldBoundingBox;
Rect panelRect = new Rect(panelBounds.position - Vector2.one, panelBounds.size + Vector2.one * 2);
Rect rect = ve.worldBound;
Rect validRect = new Rect(rect.position - Vector2.one, rect.size + Vector2.one * 2);
if (direction == Up)
{
validRect.yMin = panelRect.yMin;
}
else if (direction == Down)
{
validRect.yMax = panelRect.yMax;
}
else if (direction == Left)
{
validRect.xMin = panelRect.xMin;
}
else if (direction == Right)
{
validRect.xMax = panelRect.xMax;
}
Focusable best = new FocusableHierarchyTraversal
{
currentFocusable = ve,
direction = direction,
validRect = validRect,
firstPass = true
}.GetBestOverall(m_Root);
if (best != null)
{
return(best);
}
validRect = new Rect(rect.position - Vector2.one, rect.size + Vector2.one * 2);
if (direction == Down)
{
validRect.yMin = panelRect.yMin;
}
else if (direction == Up)
{
validRect.yMax = panelRect.yMax;
}
else if (direction == Right)
{
validRect.xMin = panelRect.xMin;
}
else if (direction == Left)
{
validRect.xMax = panelRect.xMax;
}
best = new FocusableHierarchyTraversal
{
currentFocusable = ve,
direction = direction,
validRect = validRect,
firstPass = false
}.GetBestOverall(m_Root);
if (best != null)
{
return(best);
}
return(currentFocusable);
}
Focusable GetNextFocusable2D(Focusable currentFocusable, ChangeDirection direction)
{
if (!(currentFocusable is VisualElement ve))
{
ve = m_Root;
}
ve = GetRootFocusable(ve);
Rect rect = ve.worldBound;
Rect validRect = new Rect(rect.position - Vector2.one, rect.size + Vector2.one * 2);
if (direction == Up)
{
validRect.yMin = 0;
}
else if (direction == Down)
{
validRect.yMax = Screen.height;
}
else if (direction == Left)
{
validRect.xMin = 0;
}
else if (direction == Right)
{
validRect.xMax = Screen.width;
}
var best = new FocusableHierarchyTraversal
{
currentFocusable = ve,
direction = direction,
validRect = validRect,
firstPass = true
}.GetBestOverall(m_Root);
if (best != null)
{
return(GetLeafFocusable(best));
}
validRect = new Rect(rect.position - Vector2.one, rect.size + Vector2.one * 2);
if (direction == Down)
{
validRect.yMin = 0;
}
else if (direction == Up)
{
validRect.yMax = Screen.height;
}
else if (direction == Right)
{
validRect.xMin = 0;
}
else if (direction == Left)
{
validRect.xMax = Screen.height;
}
best = new FocusableHierarchyTraversal
{
currentFocusable = ve,
direction = direction,
validRect = validRect,
firstPass = false
}.GetBestOverall(m_Root);
if (best != null)
{
return(GetLeafFocusable(best));
}
return(currentFocusable);
}
