using System;
using System.Collections.Generic;
using System.Text;
using System.Windows.Forms;
using System.Drawing;

namespace Core.StlMes.Client.SaleBase
{ 
    public class TreeComboBox : ComboBox
	{
		#region 自定义成员变量

		private TextBox m_TextBox;
		private TreeView m_TreeView;
		private Button m_DropdownButton;
		private int m_MaxDropDownItems = 8;
		//是否正在显示下拉列表
		private bool b_Dropdown = false;
		//使能
        private bool b_Enabled = true;
		//事件
		public event EventHandler DropDown;
		public event EventHandler DropDownClosed;
		public event EventHandler EnableChanged;
		public event TreeViewCancelEventHandler BeforeExpand;
		public event TreeViewCancelEventHandler BeforeCollapse;
		public event TreeViewEventHandler AfterExpand;
		public event TreeViewEventHandler AfterCollapse;  
		#endregion

		/// <summary>
		/// 构造函数
		/// </summary>
		public TreeComboBox()
		{
			this.InitControls();
			this.LayoutControls();   
		}

		#region 内部辅助方法
		/// <summary>
		/// 创建并初始化所有控件，包括添加事件处理函数
		/// </summary>
		private void InitControls()
		{
			//TextBox
			this.m_TextBox = new TextBox();
			this.m_TextBox.KeyDown += new KeyEventHandler(m_TextBox_KeyDown);
			this.m_TextBox.Parent = this;
            this.m_TextBox.ReadOnly = true; 
			//Button
			this.m_DropdownButton = new Button();
			//Assembly asm = Assembly.GetExecutingAssembly();
			//System.IO.Stream stream = asm.GetManifestResourceStream(asm.GetName().Name + ".BM_dropdown.bmp");
			Bitmap bm = new Bitmap(this.GetType(), "BM_dropdown.bmp");
			this.m_DropdownButton.Image = bm;
			this.m_DropdownButton.Width = 16;
			this.m_DropdownButton.Height = this.m_TextBox.Height-2;
			this.m_DropdownButton.Location = new Point(this.m_TextBox.Right-18, 1);
			this.m_DropdownButton.Click += new EventHandler(m_DropdownButton_Click);
            this.m_DropdownButton.TextChanged += new EventHandler(m_DropdownButton_TextChanged);
			this.m_DropdownButton.FlatStyle = FlatStyle.Flat;
			this.m_DropdownButton.Parent = this;
			this.m_DropdownButton.BringToFront();

			//TreeView
			this.m_TreeView = new TreeView();
			this.m_TreeView.Visible = false;
			this.m_TreeView.DoubleClick += new EventHandler(m_TreeView_DoubleClick);
			this.m_TreeView.KeyDown += new KeyEventHandler(m_TreeView_KeyDown);
			this.m_TreeView.LostFocus += new EventHandler(m_TreeView_LostFocus);
			this.m_TreeView.BeforeExpand += new TreeViewCancelEventHandler(m_TreeView_BeforeExpand);
			this.m_TreeView.BeforeCollapse += new TreeViewCancelEventHandler(TreeComboBox_BeforeCollapse);
			this.m_TreeView.AfterExpand += new TreeViewEventHandler(m_TreeView_AfterExpand);
			this.m_TreeView.AfterCollapse += new TreeViewEventHandler(TreeComboBox_AfterCollapse);
			this.m_TreeView.Location = new Point(0, 0);
			this.m_TreeView.Parent = null;

			this.LostFocus += new EventHandler(TreeComboBox_LostFocus);
		} 

		/// <summary>
		/// 布局所有控件，让TextBox尺寸适应容器尺寸
		/// </summary>
		private void LayoutControls()
		{
			this.m_TextBox.Width = this.Width;
			this.Height = this.m_TextBox.Height;
			this.m_DropdownButton.Left = this.m_TextBox.Right - 18;
			this.m_DropdownButton.Height = this.m_TextBox.Height - 2;
			this.m_TreeView.Width = this.Width * 2;
			this.m_TreeView.Height = (int)((this.Font.Height+3) * this.m_MaxDropDownItems);
		}

		/// <summary>
		/// 显示下拉列表
		/// </summary>
		private void ShowDropDown()
		{
			if (this.Parent == null)
				return;

			// 智能计算显示的位置，尝试在下方显示，如果没有足够空间，则在上方显示
			// 尝试在下方的位置（现在只是相对父窗口的相对位置）
			Point pos = new Point(this.Left, this.Bottom-1);

			// 把位置映射到顶层窗口,获取父窗口的屏幕坐标
			Point parentPos = this.Parent.PointToScreen(this.Parent.Location);
			// 获取顶层窗口的屏幕坐标
			Point topParentPos = this.TopLevelControl.PointToScreen(this.Parent.Location);
			// 把相对父窗口的位置变换为相对顶级窗口的位置，因为popup的父是顶级窗口
			pos.Offset(parentPos.X - topParentPos.X, parentPos.Y - topParentPos.Y);

			// 检查是否有足够空间用于在label下方显示day picker
			if ((pos.Y + this.m_TreeView.Height) > this.TopLevelControl.ClientRectangle.Height)
			{
				// 没有足够的空间（超出了顶级窗口客户区），尝试在上方显示将Y方向，向上平移
				pos.Y -= (this.Height + this.m_TreeView.Height);
				if (pos.Y < 0)
				{
					// 如果上方仍然没有空间显示，则显示在顶级窗口的底部
					pos.Y = (this.TopLevelControl.ClientRectangle.Height -this.m_TreeView.Height);
				}
			}

			// 尝试停靠,如果右边超过顶级窗口的客户区，则将控件向左移动，并紧靠在顶级窗口右侧
			if ((pos.X + this.m_TreeView.Width) > this.TopLevelControl.ClientRectangle.Width)
				pos.X = (this.TopLevelControl.ClientRectangle.Width - this.m_TreeView.Width);	

			this.m_TreeView.Location = pos;// this.Parent.PointToScreen(pt);
			this.m_TreeView.Visible = true;
			this.m_TreeView.Parent = this.TopLevelControl;
			this.m_TreeView.BringToFront();
			this.b_Dropdown = true;
			//raise event
			if (this.DropDown != null)
				this.DropDown(this, EventArgs.Empty);
			this.m_TreeView.Focus();
		}

		/// <summary>
		/// 隐藏下拉列表
		/// </summary>
		private void HideDropDown()
		{
			if (this.DropDownClosed != null)
				this.DropDownClosed(this,EventArgs.Empty);
			this.m_TreeView.Parent = null;
			this.m_TreeView.Visible = false;
			this.b_Dropdown = false;
		}
		#endregion

		#region 事件处理 - TextBox
		/// <summary>
		/// 在编辑框中按下按键
		/// </summary>
		/// <param name="sender"></param>
		/// <param name="e"></param>
		private void m_TextBox_KeyDown(object sender, KeyEventArgs e)
		{
			if (e.KeyCode == Keys.Enter)
			{
				if (this.b_Dropdown)
					this.HideDropDown();
				else
					this.ShowDropDown();
			}
			else if (e.KeyCode == Keys.Down)
			{
				this.ShowDropDown();
				this.m_TreeView.Focus();
			}
		}
       /// <summary>
       /// 在编辑框改变Text
       /// </summary>
       /// <param name="sender"></param>
       /// <param name="e"></param>
        private void m_DropdownButton_TextChanged(object sender, EventArgs e)
        {
            throw new NotImplementedException();
        }
		#endregion

		#region 事件处理 - TreeView
		/// <summary>
		/// 在下拉列表中选择了一个节点的事件处理！
		/// </summary>
		/// <param name="sender"></param>
		/// <param name="e"></param>
		private void m_TreeView_KeyDown(object sender, KeyEventArgs e)
		{
			//如果按下回车表示要选中当前节点
			if (e.KeyCode == Keys.Enter)
			{
				this.m_TreeView_DoubleClick(sender, EventArgs.Empty);
			}
		}

		/// <summary>
		/// 失去焦点时，如果不是被下拉按钮夺取的焦点，则隐藏它！
		/// </summary>
		/// <param name="sender"></param>
		/// <param name="e"></param>
		void m_TreeView_LostFocus(object sender, EventArgs e)
		{
			if(!this.m_DropdownButton.Focused)
				this.HideDropDown();
		}

		/// <summary>
		/// 在下拉列表中双击
		/// </summary>
		/// <param name="sender"></param>
		/// <param name="e"></param>
		private void m_TreeView_DoubleClick(object sender, EventArgs e)
		{
			TreeNode node = this.m_TreeView.SelectedNode;
			if (node != null)
				this.m_TextBox.Text = node.Text;

			if (this.b_Dropdown)
			{
				this.HideDropDown();
			}
		}

		void TreeComboBox_AfterCollapse(object sender, TreeViewEventArgs e)
		{
			if (this.AfterCollapse != null)
				this.AfterCollapse(this, e);
		}

		void TreeComboBox_BeforeCollapse(object sender, TreeViewCancelEventArgs e)
		{
			if (this.BeforeCollapse != null)
				this.BeforeCollapse(this, e);
		}

		void m_TreeView_AfterExpand(object sender, TreeViewEventArgs e)
		{
			if (this.AfterExpand != null)
				this.AfterExpand(this,e);
		}

		void m_TreeView_BeforeExpand(object sender, TreeViewCancelEventArgs e)
		{
			if (this.BeforeExpand != null)
				this.BeforeExpand(this, e);
		}


		#endregion

		#region 事件处理 - Button
		private void m_DropdownButton_Click(object sender, EventArgs e)
		{
			//throw new Exception("The method or operation is not implemented.");
			if (this.b_Dropdown)
				this.HideDropDown();
			else
				this.ShowDropDown();
		}
		#endregion

		#region 事件处理 - 自身
		/// <summary>
		/// 失去焦点
		/// </summary>
		/// <param name="sender"></param>
		/// <param name="e"></param>
		private void TreeComboBox_LostFocus(object sender, EventArgs e)
		{
			if (this.b_Dropdown)
				this.HideDropDown();
		}

		/// <summary>
		/// 重设尺寸
		/// </summary>
		/// <param name="e"></param>
		protected override void OnResize(EventArgs e)
		{
			base.OnResize(e);
			this.LayoutControls();
		}

		protected override void OnSizeChanged(EventArgs e)
		{
			base.OnSizeChanged(e);
			this.LayoutControls();
		}

		#endregion

		#region 外部属性封装

		/// <summary>
		/// 获取节点集合
		/// </summary>
		public TreeNodeCollection Nodes
		{
			get { return this.m_TreeView.Nodes; }
		}

		/// <summary>
		/// 设置或者获取节点的图片列表
		/// </summary>
		public ImageList ImageList
		{
			get
			{
				return this.m_TreeView.ImageList;
			}
			set
			{
				this.m_TreeView.ImageList = value;
			}
		}

		/// <summary>
		/// 重写enabled属性
		/// </summary>
		public new bool Enabled
		{
			get { return this.b_Enabled; }
			set
			{
				if (this.b_Enabled != value)
				{
					this.b_Enabled = value;
					this.m_DropdownButton.Enabled = value;
					this.b_Enabled = value;
					//当灰掉时，隐藏下拉列表
					if (!this.b_Enabled && this.b_Dropdown)
						this.HideDropDown();
					if (this.EnableChanged != null)
						this.EnableChanged(this, EventArgs.Empty);
				}
			}
		}

		/// <summary>
		/// 字体
		/// </summary>
		public override Font Font
		{
			get
			{
				return base.Font;
			}
			set
			{
				base.Font = value;
				this.m_TextBox.Font = value;
				this.m_TreeView.Font = value;
				//调整布局
				this.LayoutControls();
			}
		}

		/// <summary>
		/// 重写Text
		/// </summary>
		public override string Text
		{
			get
			{
				return this.m_TextBox.Text;
			}
			set
			{
				if (this.Text != value)
				{
					this.m_TextBox.Text = value;
				}
			}
		}

		/// <summary>
		/// 是否显示lines
		/// </summary>
		public bool ShowLines
		{
			get { return this.m_TreeView.ShowLines; }
			set { this.m_TreeView.ShowLines = value; }
		}

		/// <summary>
		/// 是否显示+ -按钮
		/// </summary>
		public bool ShowPlusMinus
		{
			get { return this.m_TreeView.ShowPlusMinus; }
			set { this.m_TreeView.ShowPlusMinus = value; }
		}

		/// <summary>
		/// 是否显示root lines
		/// </summary>
		public bool ShowRootLines 
		{
			get { return this.m_TreeView.ShowRootLines; }
			set { this.m_TreeView.ShowRootLines = value; }
		}

		/// <summary>
		/// 是否显示root lines
		/// </summary>
		public bool ShowNodeToolTips
		{
			get { return this.m_TreeView.ShowNodeToolTips; }
			set { this.m_TreeView.ShowNodeToolTips = value; }
		}

		/// <summary>
		/// 获取或者设置选中的节点！
		/// </summary>
		public TreeNode SelectedNode
		{
			get
			{
				return this.m_TreeView.SelectedNode;
			}
			set
			{
				this.m_TreeView.SelectedNode = value;
				if (value != null)
					this.Text = value.Text;
			}
		}

		public int MaxDropDownItems
		{
			get
			{
				return this.m_MaxDropDownItems;
			}
			set
			{
				if (this.m_MaxDropDownItems != value)
				{
					this.m_MaxDropDownItems = value;
					this.m_TreeView.Height = this.m_TextBox.Height * value;
				}
			}
		}

		#endregion

	}
}