BizDraw framework for .NET

using System;
using System.Collections;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Windows.Forms;
using System.Diagnostics;
using BizDraw.Tools;
using BizDraw.Core;
using BizDraw.Objects;
namespace BizDraw.Controls
{
    [System.Runtime.InteropServices.ComVisible(true)]
	/// <summary>
	/// Working area.
	/// Handles mouse input and draws graphics objects.
	/// </summary>
	public class DrawArea : System.Windows.Forms.UserControl
	{
		/// <summary> 
		/// Required designer variable.
		/// </summary>
		private System.ComponentModel.Container components = null;
        private float _zoom = 1;
        #region Constructor, Dispose

		public DrawArea()
		{
			// This call is required by the Windows.Forms Form Designer.
			InitializeComponent();
            this.KeyDown += new KeyEventHandler(DrawArea_KeyDown);
		}

        void DrawArea_KeyDown(object sender, KeyEventArgs e)
        {
            if (this.Document == null)
                return;
            bool shouldRefresh = false;
            switch (e.KeyData)
            {
                case Keys.Delete :
                    this.Document.DeleteSelection();
                    shouldRefresh = true;
                    break;
                case Keys.Escape :
                    this.Document.Items.UnselectAll();
                    shouldRefresh = true;
                    break;
                case (Keys)( Keys.A | Keys.Control ) :
                    if (e.Control )
                    {
                        this.Document.Items.SelectAll();
                        shouldRefresh = true;
                    }
                    break;


            }
            if (shouldRefresh)
                this.Refresh();
        }

		/// <summary> 
		/// Clean up any resources being used.
		/// </summary>
		protected override void Dispose( bool disposing )
		{
			if( disposing )
			{
				if(components != null)
				{
					components.Dispose();
				}
			}
			base.Dispose( disposing );
		}

        #endregion

		#region Component Designer generated code
		/// <summary> 
		/// Required method for Designer support - do not modify 
		/// the contents of this method with the code editor.
		/// </summary>
		private void InitializeComponent()
		{
            // 
            // DrawArea
            // 
            this.Name = "DrawArea";
            this.MouseUp += new System.Windows.Forms.MouseEventHandler(this.DrawArea_MouseUp);
            this.Paint += new System.Windows.Forms.PaintEventHandler(this.DrawArea_Paint);
            this.MouseMove += new System.Windows.Forms.MouseEventHandler(this.DrawArea_MouseMove);
            this.MouseDown += new System.Windows.Forms.MouseEventHandler(this.DrawArea_MouseDown);
            this.DoubleClick += new EventHandler(DrawArea_DoubleClick);

            Initialize();

        }

        void DrawArea_DoubleClick(object sender, EventArgs e)
        {
            ActiveTool.OnDoubleClick(this,  e);
        }
		#endregion

        #region Members

        private Document document;  

        private Tool  activeTool  ;      // active drawing tool

        // group selection rectangle
        private Rectangle netRectangle;
        private bool drawNetRectangle = false;

        // Information about owner form
        #endregion

        #region Properties
        [Browsable(false)]
        [System.ComponentModel.EditorBrowsable(EditorBrowsableState.Never)]
        /// <summary>
        /// Group selection rectangle. Used for drawing.
        /// </summary>
        public Rectangle NetRectangle
        {
            get
            {
                return netRectangle;
            }
            set
            {
                netRectangle = value;
            }
        }
        [System.ComponentModel.EditorBrowsable(EditorBrowsableState.Never)]
        [Browsable(false)]
        /// <summary>
        /// Flas is set to true if group selection rectangle should be drawn.
        /// </summary>
        public bool DrawNetRectangle
        {
            get
            {
                return drawNetRectangle;
            }
            set
            {
                drawNetRectangle = value;
            }
        }
        [System.ComponentModel.EditorBrowsable(EditorBrowsableState.Never)]
        [Browsable(false)]
        /// <summary>
        /// Active drawing tool.
        /// </summary>
        public Tool  ActiveTool
        {
            get
            {
                return activeTool;
            }
            set
            {
                activeTool = value;
            }
        }
        [System.ComponentModel.ReadOnly(true)]
        [Browsable(false)]
        /// <summary>
        /// List of graphics objects.
        /// </summary>
        public Document  Document
        {
            get
            {
                return document ;
            }
            set
            {
                document = value;
            }
        }
        public float Zoom
        {
            get
            {
                return _zoom;
            }
            set
            {
                _zoom = value;
            }
        }
        #endregion

        #region Event Handlers

        /// <summary>
        /// Draw graphic objects and 
        /// group selection rectangle (optionally)
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void DrawArea_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
        {
            e.Graphics.ScaleTransform(Zoom, Zoom);
            SolidBrush brush = new SolidBrush(Color.FromArgb(255, 255, 255));
            e.Graphics.FillRectangle(brush, 
                this.ClientRectangle);

            if ( this.Document  != null )
            {
                this.document.Items.Draw(e.Graphics);
            }

            DrawNetSelection(e.Graphics);

            brush.Dispose();
        }

        /// <summary>
        /// Mouse down.
        /// Left button down event is passed to active tool.
        /// Right button down event is handled in this class.
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void DrawArea_MouseDown(object sender, System.Windows.Forms.MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)
            {
                ActiveTool.OnMouseDown(this, GetScaledMouseEvent(e));
            }
            else if (e.Button == MouseButtons.Right)
                OnContextMenu(e);
        }

        MouseEventArgs GetScaledMouseEvent( MouseEventArgs e)
        {
            return new MouseEventArgs(e.Button, e.Clicks, Convert.ToInt32(e.X / Zoom), Convert.ToInt32(e.Y / Zoom), Convert.ToInt32(e.Delta / Zoom));
        }
        /// <summary>
        /// Mouse move.
        /// Moving without button pressed or with left button pressed
        /// is passed to active tool.
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void DrawArea_MouseMove(object sender, System.Windows.Forms.MouseEventArgs e)
        {
            if ( e.Button == MouseButtons.Left  ||  e.Button == MouseButtons.None )
                ActiveTool.OnMouseMove(this, GetScaledMouseEvent(e));
            else
                this.Cursor = Cursors.Default;
        }

        /// <summary>
        /// Mouse up event.
        /// Left button up event is passed to active tool.
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void DrawArea_MouseUp(object sender, System.Windows.Forms.MouseEventArgs e)
        {
            if ( e.Button == MouseButtons.Left )
                ActiveTool.OnMouseUp(this, GetScaledMouseEvent(e));
        }

        #endregion

        #region Other Functions

        /// <summary>
        /// Initialization
        /// </summary>
        /// <param name="owner"></param>
        /// <param name="docManager"></param>
        public void Initialize()
        {
            SetStyle(ControlStyles.AllPaintingInWmPaint | 
                ControlStyles.UserPaint | ControlStyles.DoubleBuffer, true);


            // set default tool
            activeTool = new ToolPointer();

            // create list of graphic objects
            document = new Document();

            // create array of drawing tools
           
        }

        /// <summary>
        ///  Draw group selection rectangle
        /// </summary>
        /// <param name="g"></param>
        public void DrawNetSelection(Graphics g)
        {
            if ( ! DrawNetRectangle )
                return;

            ControlPaint.DrawFocusRectangle(g, NetRectangle, Color.Black, Color.Transparent);
        }

        /// <summary>
        /// Right-click handler
        /// </summary>
        /// <param name="e"></param>
        private void OnContextMenu(MouseEventArgs e)
        {
            // Change current selection if necessary

            Point point = new Point(e.X, e.Y);

            int n = this.Document.Items.Count;
            DrawObject o = null;

            for ( int i = 0; i < n; i++ )
            {
                if (this.Document.Items[i].HitTest(point) == 0)
                {
                    o = this.Document.Items[i];
                    break;
                }
            }

            if ( o != null )
            {
                if ( ! o.Selected )
                    this.Document.Items.UnselectAll();

                // Select clicked object
                o.SetSelectedState(true);
            }
            else
            {
                this.Document.Items.UnselectAll();
            }

            Refresh();

        }
        #endregion
	}
}