using System;
using System.Collections.Generic;

namespace UnityEngine.Experimental.UIElements
{
	// Token: 0x0200035F RID: 863
	internal class VisualTreeBuilder
	{
		// Token: 0x060034FF RID: 13567 RVA: 0x00056AE4 File Offset: 0x00054CE4
		public VisualTreeBuilder(Recycler r)
		{
			this.m_ElementPool = r;
			this.m_ViewStates = new Stack<VisualTreeBuilder.ViewState>();
			this.m_CurrentContainer = null;
			this.m_CurrentViewState = new VisualTreeBuilder.ViewState(0);
			this.topLevelVisualContainer = null;
			this.verbose = false;
			this.currentScrollView = null;
		}

		// Token: 0x17000C34 RID: 3124
		// (get) Token: 0x06003500 RID: 13568 RVA: 0x00056B34 File Offset: 0x00054D34
		// (set) Token: 0x06003501 RID: 13569 RVA: 0x00056B50 File Offset: 0x00054D50
		public VisualContainer topLevelVisualContainer { get; private set; }

		// Token: 0x17000C35 RID: 3125
		// (get) Token: 0x06003502 RID: 13570 RVA: 0x00056B5C File Offset: 0x00054D5C
		// (set) Token: 0x06003503 RID: 13571 RVA: 0x00056B78 File Offset: 0x00054D78
		public bool verbose { get; set; }

		// Token: 0x17000C36 RID: 3126
		// (get) Token: 0x06003504 RID: 13572 RVA: 0x00056B84 File Offset: 0x00054D84
		// (set) Token: 0x06003505 RID: 13573 RVA: 0x00056BA0 File Offset: 0x00054DA0
		public IMScrollView currentScrollView { get; private set; }

		// Token: 0x06003506 RID: 13574 RVA: 0x00056BAC File Offset: 0x00054DAC
		public void NextView<TType>(out TType view) where TType : IMContainer, new()
		{
			this.NextElement<TType>(out view);
			this.m_CurrentContainer = view;
			this.m_ViewStates.Push(this.m_CurrentViewState);
			this.m_CurrentViewState = new VisualTreeBuilder.ViewState(0);
			IMScrollView imscrollView = this.m_CurrentContainer as IMScrollView;
			if (imscrollView != null)
			{
				this.currentScrollView = imscrollView;
			}
		}

		// Token: 0x06003507 RID: 13575 RVA: 0x00056C0C File Offset: 0x00054E0C
		public void EndView()
		{
			if (this.m_ViewStates.Count < 1)
			{
				Debug.Assert(this.m_CurrentContainer == this.topLevelVisualContainer);
				if (this.verbose)
				{
					Debug.LogError("Unexpected call to EndView()");
				}
			}
			else
			{
				if (this.m_CurrentContainer.childrenCount > this.m_CurrentViewState.childIndex)
				{
					this.RecycleDescendants(this.m_CurrentContainer, this.m_CurrentViewState.childIndex);
				}
				Debug.Assert(this.m_CurrentContainer.parent != null);
				if (this.m_CurrentContainer is IMScrollView)
				{
					VisualContainer visualContainer = this.m_CurrentContainer.parent;
					IMScrollView imscrollView = visualContainer as IMScrollView;
					while (visualContainer != null && imscrollView == null)
					{
						visualContainer = visualContainer.parent;
						imscrollView = visualContainer as IMScrollView;
					}
					this.currentScrollView = imscrollView;
				}
				this.m_CurrentViewState = this.m_ViewStates.Pop();
				this.m_CurrentContainer = this.m_CurrentContainer.parent;
			}
		}

		// Token: 0x06003508 RID: 13576 RVA: 0x00056D14 File Offset: 0x00054F14
		public void BeginGUI(VisualContainer container)
		{
			this.topLevelVisualContainer = container;
			this.m_CurrentContainer = this.topLevelVisualContainer;
			this.m_CurrentViewState = new VisualTreeBuilder.ViewState(0);
			this.m_ViewStates.Clear();
		}

		// Token: 0x06003509 RID: 13577 RVA: 0x00056D44 File Offset: 0x00054F44
		public void EndGUI()
		{
			if (this.topLevelVisualContainer == null)
			{
				Debug.Log("topLevelVisualContainer == null");
			}
			else
			{
				if (this.m_CurrentContainer != this.topLevelVisualContainer)
				{
					if (this.verbose)
					{
						Debug.LogWarning("Non-symmetrical VisualContainer calls to GUI");
					}
					while (this.m_CurrentContainer != this.topLevelVisualContainer)
					{
						this.EndView();
					}
				}
				if (this.topLevelVisualContainer.childrenCount > this.m_CurrentViewState.childIndex)
				{
					this.RecycleDescendants(this.topLevelVisualContainer, this.m_CurrentViewState.childIndex);
				}
				this.topLevelVisualContainer = null;
				this.m_CurrentContainer = null;
			}
		}

		// Token: 0x0600350A RID: 13578 RVA: 0x00056DF8 File Offset: 0x00054FF8
		public void NextElement<TType>(out TType widget) where TType : VisualElement, IOnGUIHandler, new()
		{
			Type typeFromHandle = typeof(TType);
			widget = (TType)((object)null);
			if (this.m_CurrentViewState.childIndex >= this.m_CurrentContainer.childrenCount)
			{
				TType ttype;
				if ((ttype = this.m_ElementPool.TryReuse<TType>()) == null)
				{
					ttype = new TType();
				}
				widget = ttype;
				this.m_CurrentContainer.AddChild(widget);
			}
			else
			{
				VisualElement childAt = this.m_CurrentContainer.GetChildAt(this.m_CurrentViewState.childIndex);
				if (childAt.GetType() == typeFromHandle)
				{
					widget = childAt as TType;
				}
				else
				{
					IOnGUIHandler onGUIHandler = childAt as IOnGUIHandler;
					if (onGUIHandler != null && onGUIHandler.id == 0 && !(onGUIHandler is VisualContainer))
					{
						this.m_CurrentContainer.RemoveChildAt(this.m_CurrentViewState.childIndex);
						this.m_ElementPool.Trash(onGUIHandler);
						this.NextElement<TType>(out widget);
						return;
					}
					TType ttype2;
					if ((ttype2 = this.m_ElementPool.TryReuse<TType>()) == null)
					{
						ttype2 = new TType();
					}
					widget = ttype2;
					this.m_CurrentContainer.InsertChild(this.m_CurrentViewState.childIndex, widget);
				}
			}
			Debug.Assert(widget != null);
			this.m_CurrentViewState = new VisualTreeBuilder.ViewState(this.m_CurrentViewState.childIndex + 1);
		}

		// Token: 0x0600350B RID: 13579 RVA: 0x00056F7C File Offset: 0x0005517C
		private void RecycleDescendants(VisualContainer parent, int startAtIndex)
		{
			while (parent.childrenCount > startAtIndex)
			{
				VisualElement childAt = parent.GetChildAt(startAtIndex);
				VisualContainer visualContainer = childAt as VisualContainer;
				if (visualContainer != null)
				{
					this.RecycleDescendants(visualContainer, 0);
				}
				IOnGUIHandler onGUIHandler = childAt as IOnGUIHandler;
				if (onGUIHandler != null)
				{
					this.m_ElementPool.Trash(onGUIHandler);
					parent.RemoveChild(childAt);
				}
				else
				{
					startAtIndex++;
				}
			}
		}

		// Token: 0x04000B36 RID: 2870
		private Recycler m_ElementPool;

		// Token: 0x04000B37 RID: 2871
		private VisualContainer m_CurrentContainer;

		// Token: 0x04000B38 RID: 2872
		private VisualTreeBuilder.ViewState m_CurrentViewState;

		// Token: 0x04000B39 RID: 2873
		private Stack<VisualTreeBuilder.ViewState> m_ViewStates;

		// Token: 0x02000360 RID: 864
		private struct ViewState
		{
			// Token: 0x0600350C RID: 13580 RVA: 0x00056FEC File Offset: 0x000551EC
			public ViewState(int childIndex)
			{
				this.childIndex = childIndex;
			}

			// Token: 0x04000B3D RID: 2877
			public readonly int childIndex;
		}
	}
}