// Unity C# reference source

// Copyright (c) Unity Technologies. For terms of use, see

// https://unity3d.com/legal/licenses/Unity_Reference_Only_License

using System;

using System.Collections.Generic;

namespace UnityEngine.UIElements.StyleSheets

{

// Utility class to abstract away the concerne of traversing the visual tree

internal abstract class HierarchyTraversal

{

public virtual void Traverse(VisualElement element)

{

TraverseRecursive(element, 0);

}

// Subclasses are responsible for calling Recurse() on the element

public abstract void TraverseRecursive(VisualElement element, int depth);

protected void Recurse(VisualElement element, int depth)

{

int i = 0;

while (i < element.hierarchy.childCount)

{

var child = element.hierarchy[i];

TraverseRecursive(child, depth + 1);

// if the child has been moved to another parent, which happens when its parent has changed, then do not increment the iterator

if (child.hierarchy.parent != element)

continue;

i++;

}

}

}

}