source: branches/PersistentDataStructures/HeuristicLab.ExtLibs/HeuristicLab.Netron/3.0.2672.12446/Netron.Diagramming.Core-3.0.2672.12446/Tools/ConnectorMoverTool.cs

using System;
using System.Drawing;
using System.Windows.Forms;

namespace Netron.Diagramming.Core {
  /// <summary>
  /// This tool implement the action of moving shape connectors on the canvas.     
  /// </summary>
  class ConnectorMoverTool : AbstractTool, IMouseListener {

    #region Fields
    /// <summary>
    /// the location of the mouse when the motion starts
    /// </summary>
    private Point initialPoint;
    /// <summary>
    /// the intermediate location of the mouse during the motion
    /// </summary>
    private Point lastPoint;
    /// <summary>
    /// the connector being moved
    /// </summary>
    private IConnector fetchedConnector;
    /// <summary>
    /// whether we are currently moving something
    /// </summary>
    private bool motionStarted;

    #endregion

    #region Constructor
    /// <summary>
    /// Initializes a new instance of the <see cref="T:ConnectorMoverTool"/> class.
    /// </summary>
    /// <param name="name">The name of the tool.</param>
    public ConnectorMoverTool(string name)
      : base(name) {
    }
    #endregion

    #region Methods

    /// <summary>
    /// Called when the tool is activated.
    /// </summary>
    protected override void OnActivateTool() {
      Controller.View.CurrentCursor = CursorPalette.Select;
      motionStarted = false;
      fetchedConnector = null;
    }

    /// <summary>
    /// Handles the mouse down event
    /// </summary>
    /// <param name="e">The <see cref="T:System.Windows.Forms.MouseEventArgs"/> instance containing the event data.</param>
    public bool MouseDown(MouseEventArgs e) {
      if (e == null)
        throw new ArgumentNullException("The argument object is 'null'");
      if (e.Button == MouseButtons.Left && Enabled && !IsSuspended) {
        fetchedConnector = this.Controller.Model.Selection.FindShapeConnector(e.Location);
        if (fetchedConnector != null) {

          initialPoint = e.Location;
          lastPoint = initialPoint;
          motionStarted = true;
          return true;
        }
      }
      return false;
    }

    /// <summary>
    /// Handles the mouse move event
    /// </summary>
    /// <param name="e">The <see cref="T:System.Windows.Forms.MouseEventArgs"/> instance containing the event data.</param>
    public void MouseMove(MouseEventArgs e) {
      if (e == null)
        throw new ArgumentNullException("The argument object is 'null'");
      Point point = e.Location;
      if (IsActive && motionStarted) {

        fetchedConnector.MoveBy(new Point(point.X - lastPoint.X, point.Y - lastPoint.Y));

        lastPoint = point;
      }
    }
    /// <summary>
    /// Handles the mouse up event
    /// </summary>
    /// <param name="e">The <see cref="T:System.Windows.Forms.MouseEventArgs"/> instance containing the event data.</param>
    public void MouseUp(MouseEventArgs e) {
      if (IsActive) {
        DeactivateTool();
        if (fetchedConnector == null)
          return;
        Bundle bundle = new Bundle(Controller.Model);
        bundle.Entities.Add(fetchedConnector);
        MoveCommand cmd = new MoveCommand(this.Controller, bundle, new Point(lastPoint.X - initialPoint.X, lastPoint.Y - initialPoint.Y));
        Controller.UndoManager.AddUndoCommand(cmd);
        //not necessary to perform the Redo action of the command since the mouse-move already moved the bundle!
      }
    }
    #endregion
  }

}