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Implementing User-Defined Objects With LEADTOOLS Annotations

You can easily create your own annotation objects with LEADTOOLS Annotations framework. This secion shows you how to create two new annotations objects and how to write the required designer for them to plug these objects into the LEADTOOLS Annotations Automation framework.

Start by creating a new Windows Application project.

Add references to the following DLL's:

  • Leadtools.dll
  • Leadtools.WinForms.dll
  • Leadtools.Codecs.dll
  • Leadtools.Annotations.dll

The first object we are going to create is a simple triangle object. This object will have three points for the end points of the triangle and it will support a pen to stroke the triangle edges and a brush to fill the interior.

Add a new class to your project, name this class MyTriangleObject. Following is the source code for this class:

[Visual Basic]


Imports System
Imports System.Drawing
Imports System.Drawing.Drawing2D
Imports System.Runtime.Serialization
Imports Leadtools.Annotations
'
' Triangle annotation object class
' This class will have a 3 points for a triangle objects that can be stroked with a pen and filled with a brush
'
' our class must be serializable to play well with the annotation load/save and undo/redo features
<Serializable()> _
Public Class MyTriangleObject
   Inherits AnnObject    ' must derive from AnnObject or one of its derived classes
   '
   ' our private variables
   '
   ' the three points that define our triangle
   <NonSerialized()> Private _firstPoint As AnnPoint
   <NonSerialized()> Private _secondPoint As AnnPoint
   <NonSerialized()> Private _thirdPoint As AnnPoint
   '
   ' constructor
   '
   Public Sub New()
      ' supportsPen = yes, supportsBrush = yes, supportsFont = no
      MyBase.New( _
         True, _
         True, _
         False)
      ' initialize the points
      _firstPoint = AnnPoint.Empty
      _secondPoint = AnnPoint.Empty
      _thirdPoint = AnnPoint.Empty
   End Sub
   '
   ' ISerializable implementation
   '
   Protected Sub New(ByVal info As SerializationInfo, ByVal context As StreamingContext)
      MyBase.New(info, context)    ' do not forget to call the base class version
      ' we need to deserialize our private variables here
      _firstPoint = DirectCast(info.GetValue("FirstPointName", GetType(AnnPoint)), AnnPoint)
      _secondPoint = DirectCast(info.GetValue("SecondPointName", GetType(AnnPoint)), AnnPoint)
      _thirdPoint = DirectCast(info.GetValue("ThirdPointName", GetType(AnnPoint)), AnnPoint)
   End Sub
   Public Overrides Sub GetObjectData(ByVal info As SerializationInfo, ByVal context As StreamingContext)
      ' we need to serialize our private variables here
      ' call the base class version
      MyBase.GetObjectData(info, context)
      ' serialize the points
      info.AddValue("FirstPointName", _firstPoint, GetType(AnnPoint))
      info.AddValue("SecondPointName", _secondPoint, GetType(AnnPoint))
      info.AddValue("ThirdPointName", _thirdPoint, GetType(AnnPoint))
   End Sub
   '
   ' accessors to the points
   '
   Public Property FirstPoint() As AnnPoint
      Get
         Return _firstPoint
      End Get
      Set(ByVal Value As AnnPoint)
         _firstPoint = Value
      End Set
   End Property
   Public Property SecondPoint() As AnnPoint
      Get
         Return _secondPoint
      End Get
      Set(ByVal Value As AnnPoint)
         _secondPoint = Value
      End Set
   End Property
   Public Property ThirdPoint() As AnnPoint
      Get
         Return _thirdPoint
      End Get
         Set(ByVal Value As AnnPoint)
         _thirdPoint = Value
      End Set
   End Property
   '
   ' AnnObject overrides
   '
   Protected Overrides Function Create() As AnnObject
      ' must return a new instance of our class
      Return New MyTriangleObject
   End Function
   Public Overrides Function Clone() As Object
      ' override the clone method
      ' first call the base implementation
      Dim obj As MyTriangleObject = DirectCast(MyBase.Clone(), MyTriangleObject)
      ' next, copy the points
      obj.FirstPoint = FirstPoint
      obj.SecondPoint = SecondPoint
      obj.ThirdPoint = ThirdPoint
      Return obj
   End Function
   Public Overrides Function GetGraphicsPath(ByVal mode As AnnGetGraphicsPathMode) As GraphicsPath
      ' must a return a graphics path representation of our object
      ' Note: this object does not require us to override AnnObject.DrawObject since we can
      ' use a graphics path to represents the object completely.
      ' create a new graphics path
      Dim path As New GraphicsPath
      ' add the triangle points as a series of lines
      ' convert the points to pixels PointF
      Dim pts() As PointF = _
      { _
         FirstPoint.ConvertTo(UnitConverter, AnnUnit.Pixel).ToPointF(), _
         SecondPoint.ConvertTo(UnitConverter, AnnUnit.Pixel).ToPointF(), _
         ThirdPoint.ConvertTo(UnitConverter, AnnUnit.Pixel).ToPointF() _
      }
      path.AddLines(pts)
      path.CloseFigure()
      Return path
   End Function
End Class

[C#]


using System;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Runtime.Serialization;
using Leadtools.Annotations;
namespace MyNamespace
{
   //
   // Triangle annotation object class
   // This class will have a 3 points for a triangle objects that can be stroked with a pen and filled with a brush
   //
   [Serializable] // our class must be serializable to play well with the annotation load/save and undo/redo features
   public class MyTriangleObject:
      AnnObject    // must derive from AnnObject or one of its derived classes
   {
      //
      // our private variables
      //
      // the three points that define our triangle
      [NonSerialized()] private AnnPoint _firstPoint;
      [NonSerialized()] private AnnPoint _secondPoint;
      [NonSerialized()] private AnnPoint _thirdPoint;
      //
      // constructor
      //
      public MyTriangleObject() :
         base(
         true,    // yes, we require a pen
         true,    // yes, we require a brush
         false)    // no, we do not require a font
      {
         // initialize the points
         _firstPoint = AnnPoint.Empty;
         _secondPoint = AnnPoint.Empty;
         _thirdPoint = AnnPoint.Empty;
      }
      //
      // ISerializable implementation
      //
      protected MyTriangleObject(SerializationInfo info, StreamingContext context) :
         base(info, context)    // do not forget to call the base class version
      {
         // we need to deserialize our private variables here
         _firstPoint = (AnnPoint)info.GetValue("FirstPointName", typeof(AnnPoint));
         _secondPoint = (AnnPoint)info.GetValue("SecondPointName", typeof(AnnPoint));
         _thirdPoint = (AnnPoint)info.GetValue("ThirdPointName", typeof(AnnPoint));
      }
      public override void GetObjectData(SerializationInfo info, StreamingContext context)
      {
         // we need to serialize our private variables here
         // call the base class version
         base.GetObjectData(info, context);
         // serialize the points
         info.AddValue("FirstPointName", _firstPoint, typeof(AnnPoint));
         info.AddValue("SecondPointName", _secondPoint, typeof(AnnPoint));
         info.AddValue("ThirdPointName", _thirdPoint, typeof(AnnPoint));
      }
      //
      // accessors to the points
      //
      public AnnPoint FirstPoint
      {
         get
         {
            return _firstPoint;
         }
         set
         {
            _firstPoint = value;
         }
      }
      public AnnPoint SecondPoint
      {
         get
         {
            return _secondPoint;
         }
         set
         {
            _secondPoint = value;
         }
      }
      public AnnPoint ThirdPoint
      {
         get
         {
            return _thirdPoint;
         }
         set
         {
            _thirdPoint = value;
         }
      }
      //
      // AnnObject overrides
      //
      protected override AnnObject Create()
      {
         // must return a new instance of our class
         return new MyTriangleObject();
      }
      public override object Clone()
      {
         // override the clone method
         // first call the base implementation
         MyTriangleObject obj = base.Clone() as MyTriangleObject;
         // next, copy the points
         obj.FirstPoint = FirstPoint;
         obj.SecondPoint = SecondPoint;
         obj.ThirdPoint = ThirdPoint;
         return obj;
      }
      public override GraphicsPath GetGraphicsPath(AnnGetGraphicsPathMode mode)
      {
         // must a return a graphics path representation of our object
         // Note: this object does not require us to override AnnObject.DrawObject since we can
         // use a graphics path to represent the object completely.
         // create a new graphics path
         GraphicsPath path = new GraphicsPath();
         // add the triangle points as a series of lines
         // convert the points to pixels PointF
         PointF[] pts =
         {
            FirstPoint.ConvertTo(UnitConverter, AnnUnit.Pixel).ToPointF(),
            SecondPoint.ConvertTo(UnitConverter, AnnUnit.Pixel).ToPointF(),
            ThirdPoint.ConvertTo(UnitConverter, AnnUnit.Pixel).ToPointF()
         };
      path.AddLines(pts);
      path.CloseFigure();
      return path;
      }
   }
}

This enough to manually add, remove, load, save and draw this object to an annotation container. However, we want to be able to draw and edit this object using the annotation designers. Since we cannot find a suitable draw and edit designer to use with this class, we need to create our own.

First, the draw designer, add a new class to your project, name this class "MyTriangleObjectDrawDesigner" and add the following code:

[Visual Basic]


Imports System
Imports System.Drawing
Imports System.Windows.Forms
Imports Leadtools.Annotations
'
' MyTriangleObject draw designer
' Will require the user to click 3 times once for each point
'
Public Class MyTriangleObjectDrawDesigner
   Inherits AnnDrawDesigner    ' must derive from AnnDrawDesigner or one of its derived classes
   '
   ' private variables
   '
   ' we need to keep track on next point to add
   Private _clickCount As Integer
   '
   ' constructor
   '
   Public Sub New()
      _clickCount = 0
   End Sub
   '
   ' AnnDrawDesigner overrides
   '
   Public Overrides Function MouseDown(ByVal e As MouseEventArgs) As Boolean
      Dim handled As Boolean = False
      ' only process left button clicks
      If (e.Button = MouseButtons.Left) Then
         ' check if we have not started drawing yet, DrawObject will be null
         If (IsNothing(DrawObject)) Then
            ' yes, create a new MyTriangleObject from ObjectTemplate
            Dim obj As MyTriangleObject = DirectCast(ObjectTemplate.Clone(), MyTriangleObject)
            ' setup the points
            Dim pt As AnnPoint = GetLogicalAnnPoint(e.X, e.Y, obj.FirstPoint.Unit)
            obj.FirstPoint = pt
            obj.SecondPoint = pt
            obj.ThirdPoint = pt
            ' start drawing this new object
            StartWorking(obj)
            handled = True
            ' we processed first click
            _clickCount = _clickCount + 1
         Else
            ' an object is already being drawn, so process next click
            ' get our object and assign next point to it
            Dim obj As MyTriangleObject = DirectCast(DrawObject, MyTriangleObject)
            Dim pt As AnnPoint = GetLogicalAnnPoint(e.X, e.Y, obj.FirstPoint.Unit)
            If (_clickCount = 1) Then
               ' second point
               obj.SecondPoint = pt
               _clickCount = _clickCount + 1
            ElseIf (_clickCount = 2) Then
               ' third point
               obj.ThirdPoint = pt
               ' we are done!
               EndWorking()
            End If
         End If
      Else
         ' we want to cancel the drawing if any other button has been clicked
         If (Not IsNothing(DrawObject)) Then
            Cancel()
            handled = True
         End If
      End If
      Return handled
   End Function
   Public Overrides Function MouseMove(ByVal e As MouseEventArgs) As Boolean
      Dim handled As Boolean = False
      ' check if we are already drawing an object
      If (Not IsNothing(DrawObject)) Then
         ' yes, get this object and assign the next point
         ' first, save the old invalid rectangle
         Dim rcOld As Rectangle = DrawObject.InvalidRectangle
         ' get out object and assign the point
         Dim obj As MyTriangleObject = DirectCast(DrawObject, MyTriangleObject)
         Dim pt As AnnPoint = GetLogicalAnnPoint(e.X, e.Y, obj.FirstPoint.Unit)
         If (_clickCount = 1) Then
            obj.SecondPoint = pt
         ElseIf (_clickCount = 2) Then
            obj.ThirdPoint = pt
         End If
         ' get the new invalid rectangle
         Dim rcNew As Rectangle = DrawObject.InvalidRectangle
         ' continue drawing this object
         Working(Rectangle.Union(rcOld, rcNew))
         handled = True
      End If
      Return handled
   End Function
   Public Overrides Function MouseUp(ByVal e As MouseEventArgs) As Boolean
      ' we do not need to do anything special on mouse up.
      ' so just see if we are drawing to return true (we handled it)
      Dim handled As Boolean = False
      If (IsNothing(DrawObject)) Then
         handled = True
      End If
      Return handled
   End Function
End Class

[C#]


using System;
using System.Drawing;
using System.Windows.Forms;
using Leadtools.Annotations;
namespace MyNamespace
{
   //
   // MyTriangleObject draw designer
   // Will require the user to click 3 times once for each point
   //
   public class MyTriangleObjectDrawDesigner :
      AnnDrawDesigner    // must derive from AnnDrawDesigner or one of its derived classes
   {
      // private variables
      //
      // we need to keep track on next point to add
      private int _clickCount;
      //
      // constructor
      //
      public MyTriangleObjectDrawDesigner()
      {
            _clickCount = 0;
      }
      //
      // AnnDrawDesigner overrides
      //
      public override bool MouseDown(MouseEventArgs e)
      {
         bool handled = false;
         // only process left button clicks
         if(e.Button == MouseButtons.Left)
         {
            // check if we have not started drawing yet, DrawObject will be null
            if(DrawObject == null)
            {
               // yes, create a new MyTriangleObject from ObjectTemplate
               MyTriangleObject obj = ObjectTemplate.Clone() as MyTriangleObject;
               // setup the points
               AnnPoint pt = GetLogicalAnnPoint(e.X, e.Y, obj.FirstPoint.Unit);
               obj.FirstPoint = pt;
               obj.SecondPoint = pt;
               obj.ThirdPoint = pt;
               // start drawing this new object
               StartWorking(obj);
               handled = true;
               // we processed first click
               _clickCount++;
            }
            else
            {
               // an object is already being drawn, so process next click
               // get our object and assign next point to it
               MyTriangleObject obj = DrawObject as MyTriangleObject;
               AnnPoint pt = GetLogicalAnnPoint(e.X, e.Y, obj.FirstPoint.Unit);
               if(_clickCount == 1)
               {
                  // second point
                  obj.SecondPoint = pt;
                  _clickCount++;
               }
               else if(_clickCount == 2)
               {
                  // third point
                  obj.ThirdPoint = pt;
                  // we are done!
                  EndWorking();
               }
            }
         }
         else
         {
            // we want to cancel the drawing if any other button has been clicked
            if(DrawObject != null)
            {
               Cancel();
               handled = true;
            }
         }
         return handled;
      }
      public override bool MouseMove(MouseEventArgs e)
      {
         bool handled = false;
         // check if we are already drawing an object
         if(DrawObject != null)
         {
            // yes, get this object and assign the next point
            // first, save the old invalid rectangle
            Rectangle rcOld = DrawObject.InvalidRectangle;
            // get out object and assign the point
            MyTriangleObject obj = DrawObject as MyTriangleObject;
            AnnPoint pt = GetLogicalAnnPoint(e.X, e.Y, obj.FirstPoint.Unit);
            if(_clickCount == 1)
               obj.SecondPoint = pt;
            else if(_clickCount == 2)
               obj.ThirdPoint = pt;
            // get the new invalid rectangle
            Rectangle rcNew = DrawObject.InvalidRectangle;
            // continue drawing this object
            Working(Rectangle.Union(rcOld, rcNew));
            handled = true;
         }
         return handled;
      }
      public override bool MouseUp(MouseEventArgs e)
      {
         // we do not need to do anything special on mouse up.
         // so just see if we are drawing to return true (we handled it)
         bool handled = false;
         if(DrawObject == null)
            handled = true;
         return handled;
      }
   }
}

Next, the edit designer, add a new class to your project, name this class "MyTriangleObjectEditDesigner" and add the following code:

[Visual Basic]


Imports System
Imports System.Drawing
Imports Leadtools.Annotations
'
' MyTriangleObject edit designer
' User can click on any of the points and move them around as well as clicking and dragging the object itself.
'
Public Class MyTriangleObjectEditDesigner
   Inherits AnnEditDesigner    ' must derive from AnnEditDesigner or one of its derived classes
   '
   ' constructor
   '
   Public Sub New()
   End Sub
   '
   ' AnnEditDesigner overrides
   '
   Public Overrides ReadOnly Property ControlPointCount() As Integer
      Get
         ' return the number of control points we need
         ' in this case 3, one for each point in our triangle
         Return 3
      End Get
   End Property
   Public Overrides Function GetControlPointsLocation() As AnnPoint()
      ' return the position of these control points
      ' in this case, same as the points from our object
      Dim obj As MyTriangleObject = DirectCast(EditObject, MyTriangleObject)
      Return New AnnPoint() _
      { _
         obj.FirstPoint, _
         obj.SecondPoint, _
         obj.ThirdPoint() _
      }
   End Property
   Protected Overrides Sub MoveControlPoint(ByVal controlPointIndex As Integer, ByVal pt As AnnPoint)
      ' user has clicked and moved a point.
      ' based on the index, we can tell if the user dragged the first, second or third point
      Dim obj As MyTriangleObject = DirectCast(EditObject, MyTriangleObject)
      Select Case (controlPointIndex)
         Case 0
            ' first point
            obj.FirstPoint = pt.ConvertTo(Container.UnitConverter, obj.FirstPoint.Unit)
         Case 1
            ' second point
            obj.SecondPoint = pt.ConvertTo(Container.UnitConverter, obj.SecondPoint.Unit)
         Case 2
            ' third point
            obj.ThirdPoint = pt.ConvertTo(Container.UnitConverter, obj.ThirdPoint.Unit)
      End Select
   End Sub
   ' Note, we will not override Move or MoveName since the default implementation is good enough for our object
End Class

[C#]


using System;
using System.Drawing;
using Leadtools.Annotations;
namespace MyNamespace
{
   //
   // MyTriangleObject edit designer
   // The user can click on any of the points and move them around, as well as clicking and dragging the object itself.
   //
   public class MyTriangleObjectEditDesigner :
      AnnEditDesigner    // must derive from AnnEditDesigner or one of its derived classes
   {
      //
      // constructor
      //
      public MyTriangleObjectEditDesigner()
      {
      }
      //
      // AnnEditDesigner overrides
      //
      public override int ControlPointCount
      {
         get
         {
            // return the number of control points we need
            // in this case 3, one for each point in our triangle
            return 3;
         }
      }
      public override AnnPoint[] GetControlPointsLocation()
      {
         // return the position of these control points
         // in this case, same as the points from our object
         MyTriangleObject obj = EditObject as MyTriangleObject;
         return new AnnPoint[]
         {
            obj.FirstPoint,
            obj.SecondPoint,
            obj.ThirdPoint
         };
      }
      protected override void MoveControlPoint(int controlPointIndex, AnnPoint pt)
      {
         // user has clicked and moved a point.
         // based on the index, we can tell if the user dragged the first, second or third point
         MyTriangleObject obj = EditObject as MyTriangleObject;
         switch(controlPointIndex)
         {
            case 0:
               // first point
               obj.FirstPoint = pt.ConvertTo(Container.UnitConverter, obj.FirstPoint.Unit);
               break;
            case 1:
               // second point
               obj.SecondPoint = pt.ConvertTo(Container.UnitConverter, obj.SecondPoint.Unit);
               break;
            case 2:
               // third point
               obj.ThirdPoint = pt.ConvertTo(Container.UnitConverter, obj.ThirdPoint.Unit);
               break;
         }
      }
      // Note, we will not override Move or MoveName since the default implementation is good enough for our object
   }
}

Now we are going to add another object. The CheckBox class will use the ControlPaint class to draw a check box along with a text string. Our class will not support a pen, but a brush and a text. We will use the AnnTextObject as the base class for our CheckBox class.

Start by adding a new class to your project, name this class MyCheckBoxObject. The following is the source code for this class:

[Visual Basic]


Imports System
Imports System.Drawing
Imports System.Drawing.Drawing2D
Imports System.Windows.Forms
Imports System.Runtime.Serialization
Imports Leadtools.Annotations
'
' CheckBox annotation object class
' our class will use the ControlPaint class to draw a check box along with text.
' our class will not support a pen, but a brush and a text
'
' our class must be serializable to play well with the annotation load/save and undo/redo features
<Serializable()> _
Public Class MyCheckBoxObject
   Inherits AnnTextObject    ' We will derive from AnnTextObject so we already have the text
   '
   ' our private variables
   '
   ' the checkbox state
   <NonSerialized()> Private _checked As Boolean
   '
   ' constructor
   '
   Public Sub New()
      ' supportsPen = no, supportsBrush = yes, supportsFont = yes
      MyBase.New( _
         False, _
         True, _
         True)
      ' initialize the state
      _checked = False
   End Sub
   '
   ' ISerializable implementation
   '
   Protected Sub New(ByVal info As SerializationInfo, ByVal context As StreamingContext)
      MyBase.New(info, context)    ' do not forget to call the base class version
      ' we need to deserialize our private variables here
      _checked = info.GetBoolean("Checked")
   End Sub
   Public Overrides Sub GetObjectData(ByVal info As SerializationInfo, ByVal context As StreamingContext)
      ' we need to serialize our private variables here
      ' call the base class version
      MyBase.GetObjectData(info, context)
      ' serialize the state
      info.AddValue("Checked", _checked)
   End Sub
   '
   ' accessors
   '
   Public Property Checked() As Boolean
      Get
         Return _checked
      End Get
      Set(ByVal Value As Boolean)
         _checked = Value
      End Set
   End Property
   '
   ' AnnObject overrides
   '
   Protected Overrides Function Create() As AnnObject
      ' must return a new instance of our class
      Return New MyCheckBoxObject
   End Function
   Public Overrides Function Clone() As Object
      ' override the clone method
      ' first call the base implementation
      Dim obj As MyCheckBoxObject = DirectCast(MyBase.Clone(), MyCheckBoxObject)
      Return obj
   End Function
   ' we will not override GetGraphicsPath, the base class version is
   ' suitable for hittesting and finding the object bounding rectangle.
   ' however, we will override DrawObject to manually paint the object
   Protected Overrides Sub DrawObject(ByVal g As Graphics)
      ' begin the drawing
      Dim gState As GraphicsState = BeginDraw(g)
      If (Not gState Is Nothing) Then
         ' get the bounding rectangle in pixels
         Dim boundsPixels As RectangleF = Bounds.ConvertTo(UnitConverter, AnnUnit.Pixel).ToRectangleF()
         ' first, see if we have a brush, if so, fill this rectangle
         If (HasBrush) Then
            Dim br As Brush = Brush.Create(UnitConverter, Bounds)
            g.FillRectangle(br, boundsPixels)
            br.Dispose()
         End If
         If (IsNonEmptyRectangle(boundsPixels)) Then
            ' use the ControlPaint class to paint the check box on the left of the object
            Dim rc As Rectangle = Rectangle.Round(boundsPixels)
            If (IsNonEmptyRectangle(rc)) Then
               Dim checkBoxRectangle As New Rectangle(rc.Left, rc.Top, rc.Height, rc.Height)
               If (Checked) Then
                  ControlPaint.DrawCheckBox(g, checkBoxRectangle, ButtonState.Checked)
               Else
                  ControlPaint.DrawCheckBox(g, checkBoxRectangle, ButtonState.Normal)
               End If
               ' update the bounds rectangle
               boundsPixels = RectangleF.FromLTRB(checkBoxRectangle.Right, checkBoxRectangle.Top, boundsPixels.Right, boundsPixels.Bottom)
            End If
         End If
         ' get the edge margin in pixels
         Dim edgeMarginPixels As Single = EdgeMargin.Converted(UnitConverter, AnnUnit.Pixel)
         boundsPixels.Inflate(-edgeMarginPixels, -edgeMarginPixels)
         ' finally draw the text
         If (HasFont AndAlso Not IsNothing(Text) AndAlso Text <> String.Empty AndAlso Text.Length > 0 AndAlso IsNonEmptyRectangle(boundsPixels)) Then
            Dim sf As StringFormat = DirectCast(StringFormat.GenericDefault.Clone(), StringFormat)
            sf.Alignment = Alignment
            sf.LineAlignment = LineAlignment
            Dim fnt As Font = Font.Create(g, UnitConverter)
            Dim br As New SolidBrush(TextColor)
            g.DrawString(Text, fnt, br, boundsPixels, sf)
            br.Dispose()
            fnt.Dispose()
            sf.Dispose()
         End If
         EndDraw(g, gState)
      End If
   End Sub
  Shared Function FixRectangle(ByVal rc As RectangleF) As RectangleF
     If (rc.Left > rc.Right OrElse rc.Top > rc.Bottom) Then
        Return RectangleF.FromLTRB( _
           Math.Min(rc.Left, rc.Right), _
           Math.Min(rc.Top, rc.Bottom), _
           Math.Max(rc.Left, rc.Right), _
           Math.Max(rc.Top, rc.Bottom))
     Else
        Return rc
     End If
  End Function
  Shared Function IsNonEmptyRectangle(ByVal rc As RectangleF) As Boolean
     Return rc.Width <> 0 AndAlso rc.Height <> 0
  End Function
End Class

[C#]


using System;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Windows.Forms;
using System.Runtime.Serialization;
using Leadtools.Annotations;
namespace MyNamespace
{
   //
   // CheckBox annotation object class
   // our class will use the ControlPaint class to draw a check box along with text.
   // our class will not support a pen, but a brush and a text
   //
   [Serializable] // our class must be serializable to play well with the annotation load/save and undo/redo features
   public class MyCheckBoxObject :
      AnnTextObject    // We will derive from AnnTextObject so we already have the text
   {
      //
      // our private variables
      //
      // the checkbox state
      [NonSerialized()] private bool _checked;
      //
      // constructor
      //
      public MyCheckBoxObject() :
         base(
         false,    // no, we do not require a pen
         true,    // we require a brush
         true)    // we require a font
      {
         // initialize the state
         _checked = false;
      }
      //
      // ISerializable implementation
      //
      protected MyCheckBoxObject(SerializationInfo info, StreamingContext context) :
      base(info, context)    // do not forget to call the base class version
      {
         // we need to deserialize our private variables here
         _checked = info.GetBoolean("Checked");
      }
      public override void GetObjectData(SerializationInfo info, StreamingContext context)
      {
         // we need to serialize our private variables here
         // call the base class version
         base.GetObjectData(info, context);
         // serialize the state
         info.AddValue("Checked", _checked);
      }
      //
      // accessors
      //
      public bool Checked
      {
         get
         {
            return _checked;
         }
         set
         {
            _checked = value;
         }
      }
      //
      // AnnObject overrides
      //
      protected override AnnObject Create()
      {
         // must return a new instance of our class
         return new MyCheckBoxObject();
      }
      public override object Clone()
      {
         // override the clone method
         // first call the base implementation
         MyCheckBoxObject obj = base.Clone() as MyCheckBoxObject;
         return obj;
      }
      // we will not override GetGraphicsPath, the base class version is
      // suitable for hittesting and finding the object bounding rectangle.
      // however, we will override DrawObject to manually paint the object
      protected override void DrawObject(Graphics g)
      {
         // begin the drawing
         GraphicsState gState = BeginDraw(g);
         if(gState != null)
         {
            // get the bounding rectangle in pixels
            RectangleF boundsPixels = Bounds.ConvertTo(UnitConverter, AnnUnit.Pixel).ToRectangleF();
            // first, see if we have a brush, if so, fill this rectangle
            if(HasBrush)
            {
               using(Brush br = Brush.Create(UnitConverter, Bounds))
               g.FillRectangle(br, boundsPixels);
            }
            if(IsNonEmptyRectangle(boundsPixels))
            {
               // use the ControlPaint class to paint the check box on the left of the object
               Rectangle rc = Rectangle.Round(boundsPixels);
               if(IsNonEmptyRectangle(rc))
               {
                  Rectangle checkBoxRectangle = new Rectangle(rc.Left, rc.Top, rc.Height, rc.Height);
                  ControlPaint.DrawCheckBox(g, checkBoxRectangle, Checked ? ButtonState.Checked: ButtonState.Normal);
                  // update the bounds rectangle
                  boundsPixels = RectangleF.FromLTRB(checkBoxRectangle.Right, checkBoxRectangle.Top, boundsPixels.Right, boundsPixels.Bottom);
               }
            }
            // get the edge margin in pixels
            float edgeMarginPixels = EdgeMargin.Converted(UnitConverter, AnnUnit.Pixel);
            boundsPixels.Inflate(-edgeMarginPixels, -edgeMarginPixels);
            // finally draw the text
            if(HasFont && Text != null && Text != string.Empty && Text.Length > 0 && IsNonEmptyRectangle(boundsPixels))
            {
               using(StringFormat sf = StringFormat.GenericDefault.Clone() as StringFormat)
               {
                  sf.Alignment = Alignment;
                  sf.LineAlignment = LineAlignment;
                  using(Font font = Font.Create(g, UnitConverter))
                  {
                     using(Brush brush = new SolidBrush(TextColor))
                     g.DrawString(Text, font, brush, boundsPixels, sf);
                  }
               }
            }
            EndDraw(g, gState);
         }
      }
      static RectangleF FixRectangle(RectangleF rc)
      {
         if(rc.Left > rc.Right || rc.Top > rc.Bottom)
            return RectangleF.FromLTRB(
               Math.Min(rc.Left, rc.Right),
               Math.Min(rc.Top, rc.Bottom),
               Math.Max(rc.Left, rc.Right),
               Math.Max(rc.Top, rc.Bottom));
         else
            return rc;
      }
      static bool IsNonEmptyRectangle(RectangleF rc)
      {
         return rc.Width != 0 && rc.Height != 0;
      }
   }
}

We will use the AnnRectangleDrawDesigner and AnnRectangleEditDesigner to draw and edit this class. However, we will add a custom run designer to handle the runtime behavor of this class. At runtime, we want the user to be able to click the CheckBox class and change the checked state.

Add a new class to your project, name this class "MyCheckBoxRunDesigner" and add the following code:

[Visual Basic]


Imports System
Imports System.Drawing
Imports System.Windows.Forms
Imports Leadtools.Annotations
'
' MyCheckBoxObject run designer
' When the user clicks the object, flip the Checked state
'
Public Class MyCheckBoxObjectRunDesigner
   Inherits AnnRunDesigner    ' must derive from AnnRunDesigner or one of its derived classes
   '
   ' constructor
   '
   Public Sub New()
   End Sub
   '
   ' AnnRunDesigner overrides
   '
   Protected Overrides Sub OnRun(ByVal e As AnnRunDesignerEventArgs)
      ' OnRun gets called while the user is running the object
      ' check the state
      If (e.OperationStatus = AnnDesignerOperationStatus.End) Then
         ' End is when the user clicks the object by default, flip the Checked state
         Dim obj As MyCheckBoxObject = DirectCast(e.Object, MyCheckBoxObject)
         obj.Checked = Not obj.Checked
         ' repaint this object
         Owner.Invalidate(obj.InvalidRectangle)
         ' we chose to ignore the default run for this object
         ' not setting e.Cancel to true will play the hyperlink
         e.Cancel = True
      End If
      MyBase.OnRun(e)
   End Sub
End Class

[C#]


using System;
using System.Drawing;
using System.Windows.Forms;
using Leadtools.Annotations;
namespace MyNamespace
{
   //
   // MyCheckBoxObject run designer
   // When the user clicks the object, flip the Checked state
   //
   public class MyCheckBoxObjectRunDesigner :
   AnnRunDesigner    // must derive from AnnRunDesigner or one of its derived classes
   {
      //
      // constructor
      //
      public MyCheckBoxObjectRunDesigner()
      {
      }
      //
      // AnnRunDesigner overrides
      //
      protected override void OnRun(AnnRunDesignerEventArgs e)
      {
         // OnRun gets called while the user is running the object
         // check the state
         if(e.OperationStatus == AnnDesignerOperationStatus.End)
         {
            // End is when the user clicks the object by default, flip the Checked state
            MyCheckBoxObject obj = e.Object as MyCheckBoxObject;
            obj.Checked = !obj.Checked;
            // repaint this object
            Owner.Invalidate(obj.InvalidRectangle);
            // we chose to ignore the default run for this object
            // not setting e.Cancel to true will play the hyperlink
            e.Cancel = true;
         }
         base.OnRun(e);
      }
   }
}

Now let us test these new objects. Add a new RasterImageViewer control to your main form along with four buttons (Text = "Save", "Load", "Clear" and "Run/Design".

At the top of the Form1 class, add the following:

[Visual Basic]


Imports System.IO
Imports Leadtools
Imports Leadtools.Codecs
Imports Leadtools.WinForms
Imports Leadtools.Annotations

[C#]


using System.IO;
using Leadtools;
using Leadtools.Codecs;
using Leadtools.WinForms;
using Leadtools.Annotations;
using MyNamespace;

Add a new handler for Form1 Load event and add the following code:

[Visual Basic]


Private theManager As AnnAutomationManager
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
   ' load an image into the viewer
   RasterCodecs.Startup()
   Dim codecs As New RasterCodecs
   RasterImageViewer1.Image = codecs.Load("C:\Program Files\LEAD Technologies\LEADTOOLS 15\Images\Sample1.cmp")
   RasterCodecs.Shutdown()
   ' create and setup the automation manager
   theManager = New AnnAutomationManager
   ' Create the default (all) automation objects.
   theManager.CreateDefaultObjects()
   ' add our own Triangle and CheckBox as automation objects
   AddMyTriangleAutomationObject(theManager)
   AddMyCheckBoxAutomationObject(theManager)
   ' create the toolbar and add it to the form
   theManager.CreateToolBar()
   Controls.Add(theManager.ToolBar)
   theManager.ToolBar.BringToFront()
   ' setup the automation (will create the container as well)
   Dim automation As New AnnAutomation(theManager, RasterImageViewer1)
   ' setup this automation as the active one
   automation.Active = True
End Sub
Private Sub AddMyTriangleAutomationObject(ByVal manager As AnnAutomationManager)
   Dim autObj As New AnnAutomationObject
   ' setup the ID
   autObj.Id = AnnAutomationManager.UserObjectId
   ' give it a friendly name
   autObj.Name = "Triangle"
   ' setup the object template
   ' this the object that will be used when drawing new MyTriangleObject.    so, setup the pen and brush as desired
   Dim obj As New MyTriangleObject
   obj.Pen = New AnnPen(Color.Blue, New AnnLength(2, AnnUnit.Pixel))
   obj.Brush = New AnnSolidBrush(Color.Yellow)
   autObj.Object = obj
   ' setup the draw, edit and run designers type
   autObj.DrawDesignerType = GetType(MyTriangleObjectDrawDesigner)
   autObj.EditDesignerType = GetType(MyTriangleObjectEditDesigner)
   ' we will use the default run designer for this object
   autObj.RunDesignerType = GetType(AnnRunDesigner)
   ' we need a toolbar image, so create one
   Dim btmp As New Bitmap(16, 16)
   Dim g As Graphics = Graphics.FromImage(btmp)
   g.FillRectangle(Brushes.Magenta, 0, 0, 16, 16)
   g.DrawLine(Pens.Black, 8, 2, 14, 14)
   g.DrawLine(Pens.Black, 14, 14, 2, 14)
   g.DrawLine(Pens.Black, 2, 14, 8, 2)
   g.Dispose()
   autObj.ToolBarImage = btmp
   ' setup the toolbar button tooltip text
   autObj.ToolBarToolTipText = "Triangle"
   ' setup the cursor used when drawing this object
   autObj.DrawCursor = Cursors.Cross
   ' setup the context menu for this object
   ' we will use the default context menu
   autObj.ContextMenu = AnnAutomationManager.CreateDefaultObjectContextMenu(autObj.Id)
   ' finally add this object to the automation objects of the manager
   manager.Objects.Add(autObj)
End Sub
Private Sub AddMyCheckBoxAutomationObject(ByVal manager As AnnAutomationManager)
   Dim autObj As New AnnAutomationObject
   ' setup the ID
   autObj.Id = AnnAutomationManager.UserObjectId + 1
   ' give it a friendly name
   autObj.Name = "CheckBox"
   ' setup the object template
   ' this the object that will be used when drawing new MyCheckBoxObject.    so, setup the brush, font and text
   Dim obj As New MyCheckBoxObject
   obj.Checked = False
   obj.Brush = New AnnSolidBrush(SystemColors.Control)
   obj.Text = "CheckBox"
   obj.TextColor = SystemColors.ControlText
   obj.Font = New AnnFont("Arial", New AnnLength(8, AnnUnit.Point), FontStyle.Regular)
   obj.Alignment = StringAlignment.Near
   obj.LineAlignment = StringAlignment.Center
   autObj.Object = obj
   ' setup the draw, edit and run designers type
   ' note, MyCheckBoxObject will use the default rectangle draw and edit designers
   autObj.DrawDesignerType = GetType(AnnRectangleDrawDesigner)
   autObj.EditDesignerType = GetType(AnnRectangleEditDesigner)
   ' use our run designer
   autObj.RunDesignerType = GetType(MyCheckBoxObjectRunDesigner)
   ' we need a toolbar image, so create one
   Dim btmp As New Bitmap(16, 16)
   Dim g As Graphics = Graphics.FromImage(btmp)
   g.FillRectangle(Brushes.Magenta, 0, 0, 16, 16)
   ControlPaint.DrawCheckBox(g, 0, 0, 16, 16, ButtonState.Flat Or ButtonState.Checked)
   g.Dispose()
   autObj.ToolBarImage = btmp
   ' setup the toolbar button tooltip text
   autObj.ToolBarToolTipText = "CheckBox"
   ' setup the cursor used when drawing this object
   autObj.DrawCursor = Cursors.Cross
   ' setup the context menu for this object
   ' we will insert a new menu item for "Checked" before the properties menu item
   Dim cm As ContextMenu = AnnAutomationManager.CreateDefaultObjectContextMenu(autObj.Id)
   ' add a handler for the Popup event so we can check/uncheck our new menu item
   AddHandler cm.Popup, AddressOf checkedMenuItem_Popup
   ' first a new seperator 2 items from the end
   cm.MenuItems.Add(cm.MenuItems.Count - 2, New MenuItem("-"))
   ' and our menu item
   Dim checkedMenuItem As New MenuItem("Checked")
   AddHandler checkedMenuItem.Click, AddressOf checkedMenuItem_Click
   cm.MenuItems.Add(cm.MenuItems.Count - 2, checkedMenuItem)
   autObj.ContextMenu = cm
   ' finally add this object to the automation objects of the manager
   manager.Objects.Add(autObj)
End Sub
Private Sub checkedMenuItem_Popup(ByVal sender As Object, ByVal e As EventArgs)
   ' check/uncheck the Checked menu item depending on the object state
   Dim cm As ContextMenu = DirectCast(sender, ContextMenu)
   Dim automation As AnnAutomation = theManager.Automations(0)
   Dim obj As MyCheckBoxObject = DirectCast(automation.CurrentEditObject, MyCheckBoxObject)
   cm.MenuItems(cm.MenuItems.Count - 3).Checked = obj.Checked
End Sub
Private Sub checkedMenuItem_Click(ByVal sender As Object, ByVal e As EventArgs)
   ' check/uncheck the object
   ' do not forget to add an undo node
   Dim automation As AnnAutomation = theManager.Automations(0)
   Dim obj As MyCheckBoxObject = DirectCast(automation.CurrentEditObject, MyCheckBoxObject)
   automation.BeginUndo()
   obj.Checked = Not obj.Checked
   automation.EndUndo()
   automation.Viewer.Invalidate(obj.InvalidRectangle)
End Sub

[C#]


private AnnAutomationManager theManager;
private void Form1_Load(object sender, System.EventArgs e)
{
   // load an image into the viewer
   RasterCodecs.Startup();
   RasterCodecs codecs = new RasterCodecs();
   rasterImageViewer1.Image = codecs.Load(@"C:\Program Files\LEAD Technologies\LEADTOOLS 15\Images\Sample1.cmp");
   RasterCodecs.Shutdown();
   // create and setup the automation manager
   theManager = new AnnAutomationManager();
   // Create the default (all) automation objects.
   theManager.CreateDefaultObjects();
   // add our own Triangle and CheckBox as automation objects
   AddMyTriangleAutomationObject(theManager);
   AddMyCheckBoxAutomationObject(theManager);
   // create the toolbar and add it to the form
   theManager.CreateToolBar();
   Controls.Add(theManager.ToolBar);
   theManager.ToolBar.BringToFront();
   // setup the automation (will create the container as well)
   AnnAutomation automation = new AnnAutomation(theManager, rasterImageViewer1);
   // setup this automation as the active one
   automation.Active = true;
}
private void AddMyTriangleAutomationObject(AnnAutomationManager manager)
{
   AnnAutomationObject autObj = new AnnAutomationObject();
   // setup the ID
   autObj.Id = AnnAutomationManager.UserObjectId;
   // give it a friendly name
   autObj.Name = "Triangle";
   // setup the object template
   // this the object that will be used when drawing new MyTriangleObject.    so, setup the pen and brush as desired
   MyTriangleObject obj = new MyTriangleObject();
   obj.Pen = new AnnPen(Color.Blue, new AnnLength(2, AnnUnit.Pixel));
   obj.Brush = new AnnSolidBrush(Color.Yellow);
   autObj.Object = obj;
   // setup the draw, edit and run designers type
   autObj.DrawDesignerType = typeof(MyTriangleObjectDrawDesigner);
   autObj.EditDesignerType = typeof(MyTriangleObjectEditDesigner);
   // we will use the default run designer for this object
   autObj.RunDesignerType = typeof(AnnRunDesigner);
   // we need a toolbar image, so create one
   Bitmap btmp = new Bitmap(16, 16);
   using(Graphics g = Graphics.FromImage(btmp))
   {
      g.FillRectangle(Brushes.Magenta, 0, 0, 16, 16);
      g.DrawLine(Pens.Black, 8, 2, 14, 14);
      g.DrawLine(Pens.Black, 14, 14, 2, 14);
      g.DrawLine(Pens.Black, 2, 14, 8, 2);
   }
   autObj.ToolBarImage = btmp;
   // setup the toolbar button tooltip text
   autObj.ToolBarToolTipText = "Triangle";
   // setup the cursor used when drawing this object
   autObj.DrawCursor = Cursors.Cross;
   // setup the context menu for this object
   // we will use the default context menu
   autObj.ContextMenu = AnnAutomationManager.CreateDefaultObjectContextMenu(autObj.Id);
   // finally add this object to the automation objects of the manager
   manager.Objects.Add(autObj);
}
private void AddMyCheckBoxAutomationObject(AnnAutomationManager manager)
{
   AnnAutomationObject autObj = new AnnAutomationObject();
   // setup the ID
   autObj.Id = AnnAutomationManager.UserObjectId + 1;
   // give it a friendly name
   autObj.Name = "CheckBox";
   // setup the object template
   // this the object that will be used when drawing new MyCheckBoxObject.    so, setup the brush, font and text
   MyCheckBoxObject obj = new MyCheckBoxObject();
   obj.Checked = false;
   obj.Brush = new AnnSolidBrush(SystemColors.Control);
   obj.Text = "CheckBox";
   obj.TextColor = SystemColors.ControlText;
   obj.Font = new AnnFont("Arial", new AnnLength(8, AnnUnit.Point), FontStyle.Regular);
   obj.Alignment = StringAlignment.Near;
   obj.LineAlignment = StringAlignment.Center;
   autObj.Object = obj;
   // setup the draw, edit and run designers type
   // note, MyCheckBoxObject will use the default rectangle draw and edit designers
   autObj.DrawDesignerType = typeof(AnnRectangleDrawDesigner);
   autObj.EditDesignerType = typeof(AnnRectangleEditDesigner);
   // use our run designer
   autObj.RunDesignerType = typeof(MyCheckBoxObjectRunDesigner);
   // we need a toolbar image, so create one
   Bitmap btmp = new Bitmap(16, 16);
   using(Graphics g = Graphics.FromImage(btmp))
   {
      g.FillRectangle(Brushes.Magenta, 0, 0, 16, 16);
      ControlPaint.DrawCheckBox(g, 0, 0, 16, 16, ButtonState.Flat | ButtonState.Checked);
   }
   autObj.ToolBarImage = btmp;
   // setup the toolbar button tooltip text
   autObj.ToolBarToolTipText = "CheckBox";
   // setup the cursor used when drawing this object
   autObj.DrawCursor = Cursors.Cross;
   // setup the context menu for this object
   // we will insert a new menu item for "Checked" before the properties menu item
   ContextMenu cm = AnnAutomationManager.CreateDefaultObjectContextMenu(autObj.Id);
   // add a handler for the Popup event so we can check/uncheck our new menu item
   cm.Popup += new EventHandler(checkedMenuItem_Popup);
   // first a new seperator 2 items from the end
   cm.MenuItems.Add(cm.MenuItems.Count - 2, new MenuItem("-"));
   // and our menu item
   MenuItem checkedMenuItem = new MenuItem("Checked");
   checkedMenuItem.Click += new EventHandler(checkedMenuItem_Click);
   cm.MenuItems.Add(cm.MenuItems.Count - 2, checkedMenuItem);
   autObj.ContextMenu = cm;
   // finally add this object to the automation objects of the manager
   manager.Objects.Add(autObj);
}
private void checkedMenuItem_Popup(object sender, EventArgs e)
{
   // check/uncheck the Checked menu item depending on the object state
   ContextMenu cm = sender as ContextMenu;
   AnnAutomation automation = theManager.Automations[0];
   MyCheckBoxObject obj = automation.CurrentEditObject as MyCheckBoxObject;
   cm.MenuItems[cm.MenuItems.Count - 3].Checked = obj.Checked;
}
private void checkedMenuItem_Click(object sender, EventArgs e)
{
   // check/uncheck the object
   // do not forget to add an undo node
   AnnAutomation automation = theManager.Automations[0];
   MyCheckBoxObject obj = automation.CurrentEditObject as MyCheckBoxObject;
   automation.BeginUndo();
   obj.Checked = !obj.Checked;
   automation.EndUndo();
   automation.Viewer.Invalidate(obj.InvalidRectangle);
}

Add event handlers for Button1, Button2, Button3 and Button3 and add the following code:

[Visual Basic]


Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
   ' Save button clicked
   Dim codecs As New AnnCodecs
   codecs.Save("C:\Test.ann", theManager.Automations(0).Container, AnnCodecsFormat.Serialize, 1, AnnCodecsSavePageMode.Overwrite)
   RasterImageViewer1.Invalidate()
End Sub
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
   ' Load button clicked
   Dim codecs As New AnnCodecs
   theManager.Automations(0).Container.Objects.Clear()
   codecs.Load("C:\Test.ann", theManager.Automations(0).Container, 1)
   RasterImageViewer1.Invalidate()
End Sub
Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
   ' Clear button clicked
   theManager.Automations(0).Container.Objects.Clear()
   RasterImageViewer1.Invalidate()
End Sub
Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button4.Click
   ' Run/Design button clicked
   If (theManager.UserMode = AnnUserMode.Design) Then
      theManager.UserMode = AnnUserMode.Run
   Else
      theManager.UserMode = AnnUserMode.Design
   End If
End Sub

[C#]


private void button1_Click(object sender, System.EventArgs e)
{
   // Save button clicked
   AnnCodecs codecs = new AnnCodecs();
   codecs.Save(@"C:\Test.ann", theManager.Automations[0].Container, AnnCodecsFormat.Serialize, 1, AnnCodecsSavePageMode.Overwrite);
   rasterImageViewer1.Invalidate();
}
private void button2_Click(object sender, System.EventArgs e)
{
   // Load button clicked
   AnnCodecs codecs = new AnnCodecs();
   theManager.Automations[0].Container.Objects.Clear();
   codecs.Load(@"C:\Test.ann", theManager.Automations[0].Container, 1);
   rasterImageViewer1.Invalidate();
}
private void button3_Click(object sender, System.EventArgs e)
{
   // Clear button clicked
   theManager.Automations[0].Container.Objects.Clear();
   rasterImageViewer1.Invalidate();
}
private void button4_Click(object sender, System.EventArgs e)
{
   // Run/Design button clicked
   theManager.UserMode = theManager.UserMode == AnnUserMode.Design ? AnnUserMode.Run : AnnUserMode.Design;
}

Build and run the application to test it.