using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Runtime.InteropServices;

namespace TemuKJD.UserComponent
{
    public partial class UcTabControl : TabControl
    {
        public UcTabControl()
        {
            InitializeComponent();

            base.SetStyle(
                ControlStyles.UserPaint |                      // 控件将自行绘制，而不是通过操作系统来绘制
                ControlStyles.OptimizedDoubleBuffer |          // 该控件首先在缓冲区中绘制，而不是直接绘制到屏幕上，这样可以减少闪烁
                ControlStyles.AllPaintingInWmPaint |           // 控件将忽略 WM_ERASEBKGND 窗口消息以减少闪烁
                ControlStyles.ResizeRedraw |                   // 在调整控件大小时重绘控件
                ControlStyles.SupportsTransparentBackColor,    // 控件接受 alpha 组件小于 255 的 BackColor 以模拟透明
                true);                                         // 设置以上值为 true
            base.UpdateStyles();
            //this.SizeMode = TabSizeMode.Fixed;

            this.MouseDown += UcTabControl_MouseDown;
        }

        private void UcTabControl_MouseDown(object sender, MouseEventArgs e)
        {
            if (this.TabCount == 0)
                return;

            if (e.Button == MouseButtons.Left)
            {
                if (!showCloseButton)
                    return;

                int x = e.X, y = e.Y;
                Rectangle rect = this.GetTabRect(this.SelectedIndex);
                Rectangle closeRect = new Rectangle(rect.X + rect.Width - 16, rect.Y + rect.Height / 2 - 4, 8, 8);

                if (x >= closeRect.X && y >= closeRect.Y && x <= closeRect.X + closeRect.Width && y <= closeRect.Y + closeRect.Height)
                {
                    this.TabPages.Remove(this.SelectedTab);
                }
            }
        }

        private Color backgroundColor = Color.FromArgb(251, 251, 251);
        [Browsable(true), Category("自定义分组"), Description("Tab控件背景")]
        public Color BackgroundColor
        {
            get { return backgroundColor; }
            set
            {
                backgroundColor = value;
                this.Invalidate();
            }
        }

        private Color tabSelectColor = Color.Red;
        [Browsable(true), Category("自定义分组"), Description("Tab选中颜色")]
        public Color TabSelectColor
        {
            get { return tabSelectColor; }
            set
            {
                tabSelectColor = value;
                this.Invalidate();
            }
        }

        private Color tabTextColor = Color.Gray;
        [Browsable(true), Category("自定义分组"), Description("Tab选中颜色")]
        public Color TabTextColor
        {
            get { return tabTextColor; }
            set
            {
                tabTextColor = value;
                this.Invalidate();
            }
        }

        private Color tabSelectTextColor = Color.Gray;
        [Browsable(true), Category("自定义分组"), Description("Tab选中颜色")]
        public Color TabSelectTextColor
        {
            get { return tabSelectTextColor; }
            set
            {
                tabSelectTextColor = value;
                this.Invalidate();
            }
        }

        private bool showCloseButton = false;
        [Browsable(true), Category("自定义分组"), Description("显示关闭页面按钮")]
        public bool ShowCloseButton
        {
            get { return showCloseButton; }
            set
            {
                showCloseButton = value;

                if (showCloseButton)
                    this.Padding = new Point(10, this.Padding.Y);
                else
                    this.Padding = new Point(6, this.Padding.Y);
                this.Invalidate();
            }
        }

        #region 去掉或减小TabControl的边框(去掉的话+-3)
        protected override void WndProc(ref Message m)
        {
            if ((m.Msg == TCM_ADJUSTRECT))
            {
                RECT rc = (RECT)m.GetLParam(typeof(RECT));
                //Adjust these values to suit, dependant upon Appearance
                rc.Left -= 2;
                rc.Right += 0;
                rc.Top -= 0;
                rc.Bottom += 0;
                Marshal.StructureToPtr(rc, m.LParam, true);
            }
            base.WndProc(ref m);
        }

        private const Int32 TCM_FIRST = 0x1300;
        private const Int32 TCM_ADJUSTRECT = (TCM_FIRST + 40);
        private struct RECT
        {
            public Int32 Left;
            public Int32 Top;
            public Int32 Right;
            public Int32 Bottom;
        }
        #endregion

        Size oldSize = new Size();
        protected override void OnPaint(PaintEventArgs e)
        {
            if (TabPages.Count > 0 && oldSize.Width != this.Size.Width && this.SizeMode == TabSizeMode.Fixed)
            {
                //this.SizeMode = TabSizeMode.Fixed;
                this.ItemSize = new Size((int)Math.Floor(1.0 * (this.Width - 4) / TabPages.Count), 40);
                oldSize.Width = this.Size.Width;
            }

            // 绘制背景
            e.Graphics.FillRectangle(new SolidBrush(backgroundColor), new RectangleF(0, 0, this.Width, this.Height));

            // 绘制边框
            //e.Graphics.DrawRectangle(new Pen(backgroundColor), 0, 0, this.Width, this.Height);
            //e.Graphics.DrawLine(new Pen(tabSelectColor), 2, this.GetTabRect(0).Bottom, this.Width - 6, this.GetTabRect(0).Bottom);

            // 绘制tab控件
            for (int i = 0; i < this.TabCount; i++)
            {
                // Calculate text position  
                Rectangle bounds = this.GetTabRect(i);
                PointF textPoint = new PointF();
                SizeF textSize = TextRenderer.MeasureText(this.TabPages[i].Text, this.Font);
                // 加上每个标签的左偏移量X  
                textPoint.X = bounds.X + (bounds.Width - textSize.Width) / 2;
                textPoint.Y = bounds.Y + (bounds.Height - textSize.Height) / 2;
                if (showCloseButton)
                    textPoint.X -= 5;
                // 绘制标题
                e.Graphics.TextRenderingHint = System.Drawing.Text.TextRenderingHint.AntiAliasGridFit;
                if (this.SelectedIndex == i)
                    e.Graphics.DrawString(this.TabPages[i].Text, this.Font, new SolidBrush(TabSelectTextColor), textPoint.X, textPoint.Y);
                else
                    e.Graphics.DrawString(this.TabPages[i].Text, this.Font, new SolidBrush(tabTextColor), textPoint.X, textPoint.Y);

                // 绘制tab框
                //e.Graphics.DrawRectangle(Pens.Red, this.GetTabRect(i));
                if (this.SelectedIndex == i)
                {
                    for (int j = 0; j < 2; j++)
                        e.Graphics.DrawLine(new Pen(tabSelectColor),
                            new Point(this.GetTabRect(i).Left + 0, this.GetTabRect(i).Bottom - j),
                            new Point(this.GetTabRect(i).Right - 5, this.GetTabRect(i).Bottom - j));
                }

                // 绘制关闭按钮
                if (showCloseButton)
                {
                    using (Pen pen = new Pen(Color.Gray, 1.4f))
                    {
                        Point p1 = new Point(bounds.X + bounds.Width - 15, bounds.Y + bounds.Height / 2 - 3);
                        Point p2 = new Point(bounds.X + bounds.Width - 9, bounds.Y + bounds.Height / 2 + 3);
                        e.Graphics.DrawLine(pen, p1, p2);

                        Point p3 = new Point(bounds.X + bounds.Width - 9, bounds.Y + bounds.Height / 2 - 3);
                        Point p4 = new Point(bounds.X + bounds.Width - 15, bounds.Y + bounds.Height / 2 + 3);
                        e.Graphics.DrawLine(pen, p3, p4);
                    }
                }
            }
        }
    }
}