using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;

namespace org.mmakers.controls {

    /// <summary>
    /// Custom tab control that allows its tab pages to be enabled/disabled
    /// </summary>
    public class CustomTabControl : TabControl {

        /// <summary>
        /// Default constructor
        /// </summary>
        public CustomTabControl() : base() {
            // Set the draw mode property to owner draw
            DrawMode = TabDrawMode.OwnerDrawFixed;
        }

        /// <summary>
        /// Called whenever the control is going to be drawn
        /// </summary>
        /// <param name="e">The event arguments</param>
        protected override void OnDrawItem(DrawItemEventArgs e) {
            base.OnDrawItem(e);

            TabPage tabPage = TabPages[e.Index];
            Rectangle tabRectangle = GetTabRect(e.Index);

            if (Alignment == TabAlignment.Left || Alignment == TabAlignment.Right) {
                float rotateAngle = 90;
                if (Alignment == TabAlignment.Left) {rotateAngle = 270;}
                PointF cp = new PointF(tabRectangle.Left + (tabRectangle.Width / 2),tabRectangle.Top + (tabRectangle.Height / 2));
                e.Graphics.TranslateTransform(cp.X,cp.Y);
                e.Graphics.RotateTransform(rotateAngle);
                tabRectangle = new Rectangle(-(tabRectangle.Height / 2),-(tabRectangle.Width / 2),tabRectangle.Height,tabRectangle.Width);
            }
            using (SolidBrush foreBrush = new SolidBrush(tabPage.ForeColor)) {
                using (SolidBrush backBrush = new SolidBrush(tabPage.BackColor)) {
                    if (!tabPage.Enabled) {foreBrush.Color = SystemColors.GrayText;}
                    e.Graphics.FillRectangle(backBrush,tabRectangle);
                    using (StringFormat stringFormat = new StringFormat()) {
                        stringFormat.Alignment = StringAlignment.Center;
                        stringFormat.LineAlignment = StringAlignment.Center;
                        e.Graphics.DrawString(tabPage.Text,e.Font,foreBrush,tabRectangle,stringFormat);
                    }
                }
            }
            e.Graphics.ResetTransform();
        }

        /// <summary>
        /// Called whenever a tab page is going to be selected
        /// </summary>
        /// <param name="e">The event arguments</param>
        protected override void OnSelecting(TabControlCancelEventArgs e) {
            base.OnSelecting(e);

            // If tab page is disabled, cancel the event
            if (!e.TabPage.Enabled) {e.Cancel = true;}
        }

        /// <summary>
        /// Called whenever a tab page is added to the tab control
        /// </summary>
        /// <param name="e">The event arguments</param>
        protected override void OnControlAdded(ControlEventArgs e) {
            // Add a enabled-changed listener to the tab page so we can repaint the tab control
            TabPage tabPage = e.Control as TabPage;
            if (tabPage != null) {tabPage.EnabledChanged += new EventHandler(tabPage_EnabledChanged);}
            base.OnControlAdded(e);
        }

        /// <summary>
        /// Called whenever a tab page is removed from the tab control
        /// </summary>
        /// <param name="e">The event arguments</param>
        protected override void OnControlRemoved(ControlEventArgs e) {
            // Remove the enabled-changed listener
            TabPage tabPage = e.Control as TabPage;
            if (tabPage != null) {tabPage.EnabledChanged -= new EventHandler(tabPage_EnabledChanged);}
            base.OnControlRemoved(e);
        }

        /// <summary>
        /// Called whenever the enabled property of a tab page changes
        /// </summary>
        /// <param name="sender">The event sender object</param>
        /// <param name="e">The event arguments</param>
        private void tabPage_EnabledChanged(object sender,EventArgs e) {
            // Invalidate the tab page title so it's redrawn again
            TabPage tabPage = sender as TabPage;
            TabControl tabControl = tabPage.Parent as TabControl;
            tabControl.Invalidate(tabPage.ClientRectangle);
        }

    }
}