VintaSoft Imaging .NET SDK v8.6
In This Topic
    GraphicObjectTool class
    In This Topic

    The visual tool GraphicObjectTool allows to display static graphical objects in image viewer.



    Graphical object.

    GraphicObject class is a base class for static objects and allows to:
    Here is the list of standard static objects:
    Here is an example that demonstrates how to display a grid above the image:
    ' The project, which uses this code, must have references to the following assemblies:
    ' - Vintasoft.Imaging
    
    ''' <summary>
    ''' Displays grid over image in image viewer.
    ''' </summary>
    ''' <param name="viewer">The viewer.</param>
    Public Shared Sub DrawGridOverImageInImageViewer(viewer As Vintasoft.Imaging.UI.ImageViewer)
        ' create visual tool that can display static graphic objects in an image viewer
        Dim tool As New Vintasoft.Imaging.UI.VisualTools.GraphicObjects.GraphicObjectTool()
        ' create graphic object that displays image grid
        Dim grid As New GridGraphicObject(tool)
        ' add graphic object to the visual tool
        tool.GraphicObjectCollection.Add(grid)
        ' set visual tool as current visual tool of image viewer
        viewer.VisualTool = tool
    End Sub
    
    
    ''' <summary>
    ''' Represents an image grid which can be displayed in image viewer.
    ''' </summary>
    Public Class GridGraphicObject
        Inherits Vintasoft.Imaging.UI.VisualTools.GraphicObjects.GraphicObject
    
        #Region "Fields"
    
        Private _tool As Vintasoft.Imaging.UI.VisualTools.VisualTool
    
        #End Region
    
    
    
        #Region "Constructors"
    
        ''' <summary>
        ''' Initializes a new instance of the <see cref="GridGraphicObject"/> class.
        ''' </summary>
        ''' <param name="tool">The visual tool.</param>
        Public Sub New(tool As Vintasoft.Imaging.UI.VisualTools.VisualTool)
            If tool Is Nothing Then
                Throw New System.ArgumentNullException()
            End If
            _tool = tool
            Pen = New System.Drawing.Pen(System.Drawing.Color.FromArgb(128, System.Drawing.Color.Lime), 1)
            PointTransform = New Vintasoft.Imaging.UI.VisualTools.PixelsToImageViewerPointFTransform()
        End Sub
    
        #End Region
    
    
    
        #Region "Properties"
    
        Private _location As System.Drawing.PointF = System.Drawing.PointF.Empty
        ''' <summary>
        ''' Gets or sets the location of grid.
        ''' </summary>
        ''' <value>
        ''' Default value is (0,0).
        ''' </value>
        Public Property Location() As System.Drawing.PointF
            Get
                Return _location
            End Get
            Set
                _location = value
            End Set
        End Property
    
        Private _cellSize As New System.Drawing.SizeF(1, 1)
        ''' <summary>
        ''' Gets or sets the size of the grid cell.
        ''' </summary>
        ''' <value>
        ''' Default value is (1,1).
        ''' </value>
        Public Property CellSize() As System.Drawing.SizeF
            Get
                Return _cellSize
            End Get
            Set
                _cellSize = value
            End Set
        End Property
    
        Private _cellUnitOfMeasure As Vintasoft.Imaging.UnitOfMeasure = Vintasoft.Imaging.UnitOfMeasure.Centimeters
        ''' <summary>
        ''' Gets or sets the unit of measure of the grid cell.
        ''' </summary>
        ''' <value>
        ''' Default value is UnitOfMeasure.Centimeters.
        ''' </value>
        Public Property CellUnitOfMeasure() As Vintasoft.Imaging.UnitOfMeasure
            Get
                Return _cellUnitOfMeasure
            End Get
            Set
                _cellUnitOfMeasure = value
            End Set
        End Property
    
        #End Region
    
    
    
        #Region "Methods"
    
        ''' <summary>
        ''' Determines that point belongs the object.
        ''' </summary>
        ''' <param name="x">X coordinate of point in object space.</param>
        ''' <param name="y">Y coordinate of point in object space.</param>
        ''' <returns>
        ''' true if point belongs the object;
        ''' otherwise, false.
        ''' </returns>
        Public Overrides Function IsPointOnObject(x As Single, y As Single) As Boolean
            If _tool.ImageViewer.Image IsNot Nothing AndAlso (Pen IsNot Nothing OrElse Brush IsNot Nothing) Then
                Dim rect As System.Drawing.RectangleF = GetRectangle(_location, _tool.ImageViewer.Image)
                Return rect.Contains(x, y)
            Else
                Return False
            End If
        End Function
    
        ''' <summary>
        ''' Returns a bounding box of object, in object space.
        ''' </summary>
        ''' <returns>
        ''' Bounding box of object, in object space.
        ''' </returns>
        Public Overrides Function GetBoundingBox() As System.Drawing.RectangleF
            If _tool.ImageViewer.Image IsNot Nothing Then
                Return GetRectangle(_location, _tool.ImageViewer.Image)
            Else
                Return System.Drawing.RectangleF.Empty
            End If
        End Function
    
        ''' <summary>
        ''' Returns a drawing rectangle of object, in object space.
        ''' </summary>
        ''' <param name="viewer">An image viewer.</param>
        ''' <returns>
        ''' Drawing rectangle of object, in object space.
        ''' </returns>
        Public Overrides Function GetDrawingBox(viewer As Vintasoft.Imaging.UI.ImageViewer) As System.Drawing.RectangleF
            If viewer.Image Is Nothing Then
                Return System.Drawing.RectangleF.Empty
            End If
    
            Dim rect As System.Drawing.RectangleF = GetRectangle(_location, viewer.Image)
            If Pen IsNot Nothing Then
                Dim penWidth As Single = Pen.Width / 2F
                rect.Inflate(penWidth, penWidth)
            End If
            Return rect
        End Function
    
        ''' <summary>
        ''' Draws the object on specified <see cref="System.Drawing.Graphics" /> in the object space.
        ''' </summary>
        ''' <param name="viewer">An image viewer.</param>
        ''' <param name="g">A graphics where the object must be drawn.</param>
        ''' <remarks>
        ''' This method draws object after the PointTransform is applied to
        ''' the Graphics, specified by g parameter.

    ''' By default this method does not do anything. ''' </remarks> Public Overrides Sub DrawInObjectSpace(viewer As Vintasoft.Imaging.UI.ImageViewer, g As System.Drawing.Graphics) If viewer.Image Is Nothing Then Return End If Dim rect As System.Drawing.RectangleF = GetRectangle(_location, viewer.Image) If Brush IsNot Nothing Then g.FillRectangle(Brush, rect) End If If Pen IsNot Nothing AndAlso Not CellSize.IsEmpty Then Dim cellHeight As Single = CSng(Vintasoft.Imaging.Utils.UnitOfMeasureConverter.ConvertToPixels(CellSize.Height, CellUnitOfMeasure)) Dim countRow As Integer = CInt(Math.Truncate(System.Math.Ceiling(rect.Height / cellHeight))) Dim cellWidth As Single = CSng(Vintasoft.Imaging.Utils.UnitOfMeasureConverter.ConvertToPixels(CellSize.Width, CellUnitOfMeasure)) Dim countColumn As Integer = CInt(Math.Truncate(System.Math.Ceiling(rect.Width / cellWidth))) If countRow > 0 AndAlso countColumn > 0 Then Dim x1 As Single = rect.X Dim y1 As Single = rect.Y + cellHeight Dim x2 As Single = rect.Right Dim i As Integer i = 1 While i < countRow g.DrawLine(Pen, x1, y1, x2, y1) i += 1 y1 += cellHeight End While x1 += cellWidth y1 = rect.Y Dim y2 As Single = rect.Bottom i = 1 While i < countColumn g.DrawLine(Pen, x1, y1, x1, y2) i += 1 x1 += cellWidth End While End If End If End Sub ''' <summary> ''' Creates a new WpfGridGraphicObject that is a copy of the current instance. ''' </summary> ''' <returns> ''' A new WpfGridGraphicObject that is a copy of this instance. ''' </returns> Public Overrides Function Clone() As Object Dim obj As New GridGraphicObject(_tool) CopyTo(obj) Return obj End Function ''' <summary> ''' Copies current WpfGridGraphicObject to the target WpfGridGraphicObject. ''' </summary> ''' <param name="obj">WpfGridGraphicObject to copy.</param> Public Overrides Sub CopyTo(obj As Vintasoft.Imaging.UI.VisualTools.GraphicObjects.GraphicObject) MyBase.CopyTo(obj) Dim gridObj As GridGraphicObject = TryCast(obj, GridGraphicObject) If gridObj IsNot Nothing Then gridObj.Location = Location gridObj.CellSize = CellSize gridObj.CellUnitOfMeasure = CellUnitOfMeasure End If End Sub ''' <summary> ''' Gets the rectangle of grid. ''' </summary> ''' <param name="location">The location.</param> ''' <param name="image">The image.</param> Private Function GetRectangle(location As System.Drawing.PointF, image As Vintasoft.Imaging.VintasoftImage) As System.Drawing.RectangleF Dim rect As New System.Drawing.RectangleF(_location.X, _location.Y, image.Width - _location.X, image.Height - _location.Y) Return rect End Function #End Region End Class
    // The project, which uses this code, must have references to the following assemblies:
    // - Vintasoft.Imaging
    
    /// <summary>
    /// Displays grid over image in image viewer.
    /// </summary>
    /// <param name="viewer">The viewer.</param>
    public static void DrawGridOverImageInImageViewer(Vintasoft.Imaging.UI.ImageViewer viewer)
    {
        // create visual tool that can display static graphic objects in an image viewer
        Vintasoft.Imaging.UI.VisualTools.GraphicObjects.GraphicObjectTool tool = 
            new Vintasoft.Imaging.UI.VisualTools.GraphicObjects.GraphicObjectTool();
        // create graphic object that displays image grid
        GridGraphicObject grid = new GridGraphicObject(tool);
        // add graphic object to the visual tool
        tool.GraphicObjectCollection.Add(grid);
        // set visual tool as current visual tool of image viewer
        viewer.VisualTool = tool;
    }
    
    
    /// <summary>
    /// Represents an image grid which can be displayed in image viewer.
    /// </summary>
    public class GridGraphicObject : 
        Vintasoft.Imaging.UI.VisualTools.GraphicObjects.GraphicObject
    {
    
        #region Fields
    
        Vintasoft.Imaging.UI.VisualTools.VisualTool _tool;
    
        #endregion
    
    
    
        #region Constructors
    
        /// <summary>
        /// Initializes a new instance of the <see cref="GridGraphicObject"/> class.
        /// </summary>
        /// <param name="tool">The visual tool.</param>
        public GridGraphicObject(Vintasoft.Imaging.UI.VisualTools.VisualTool tool)
        {
            if (tool == null)
                throw new System.ArgumentNullException();
            _tool = tool;
            Pen = new System.Drawing.Pen(
                System.Drawing.Color.FromArgb(128, System.Drawing.Color.Lime), 1);
            PointTransform = 
                new Vintasoft.Imaging.UI.VisualTools.PixelsToImageViewerPointFTransform();
        }
    
        #endregion
    
    
    
        #region Properties
    
        System.Drawing.PointF _location = System.Drawing.PointF.Empty;
        /// <summary>
        /// Gets or sets the location of grid.
        /// </summary>
        /// <value>
        /// Default value is (0,0).
        /// </value>
        public System.Drawing.PointF Location
        {
            get
            {
                return _location;
            }
            set
            {
                _location = value;
            }
        }
    
        System.Drawing.SizeF _cellSize = new System.Drawing.SizeF(1, 1);
        /// <summary>
        /// Gets or sets the size of the grid cell.
        /// </summary>
        /// <value>
        /// Default value is (1,1).
        /// </value>
        public System.Drawing.SizeF CellSize
        {
            get
            {
                return _cellSize;
            }
            set
            {
                _cellSize = value;
            }
        }
    
        Vintasoft.Imaging.UnitOfMeasure _cellUnitOfMeasure = 
            Vintasoft.Imaging.UnitOfMeasure.Centimeters;
        /// <summary>
        /// Gets or sets the unit of measure of the grid cell.
        /// </summary>
        /// <value>
        /// Default value is UnitOfMeasure.Centimeters.
        /// </value>
        public Vintasoft.Imaging.UnitOfMeasure CellUnitOfMeasure
        {
            get
            {
                return _cellUnitOfMeasure;
            }
            set
            {
                _cellUnitOfMeasure = value;
            }
        }
    
        #endregion
    
    
    
        #region Methods
    
        /// <summary>
        /// Determines that point belongs the object.
        /// </summary>
        /// <param name="x">X coordinate of point in object space.</param>
        /// <param name="y">Y coordinate of point in object space.</param>
        /// <returns>
        /// true if point belongs the object;
        /// otherwise, false.
        /// </returns>
        public override bool IsPointOnObject(float x, float y)
        {
            if (_tool.ImageViewer.Image != null &&
                (Pen != null || Brush != null))
            {
                System.Drawing.RectangleF rect = GetRectangle(_location, _tool.ImageViewer.Image);
                return rect.Contains(x, y);
            }
            else
                return false;
        }
    
        /// <summary>
        /// Returns a bounding box of object, in object space.
        /// </summary>
        /// <returns>
        /// Bounding box of object, in object space.
        /// </returns>
        public override System.Drawing.RectangleF GetBoundingBox()
        {
            if (_tool.ImageViewer.Image != null)
                return GetRectangle(_location, _tool.ImageViewer.Image);
            else
                return System.Drawing.RectangleF.Empty;
        }
    
        /// <summary>
        /// Returns a drawing rectangle of object, in object space.
        /// </summary>
        /// <param name="viewer">An image viewer.</param>
        /// <returns>
        /// Drawing rectangle of object, in object space.
        /// </returns>
        public override System.Drawing.RectangleF GetDrawingBox(Vintasoft.Imaging.UI.ImageViewer viewer)
        {
            if (viewer.Image == null)
                return System.Drawing.RectangleF.Empty;
    
            System.Drawing.RectangleF rect = GetRectangle(_location, viewer.Image);
            if (Pen != null)
            {
                float penWidth = Pen.Width / 2.0f;
                rect.Inflate(penWidth, penWidth);
            }
            return rect;
        }
    
        /// <summary>
        /// Draws the object on specified <see cref="System.Drawing.Graphics" /> in the object space.
        /// </summary>
        /// <param name="viewer">An image viewer.</param>
        /// <param name="g">A graphics where the object must be drawn.</param>
        /// <remarks>
        /// This method draws object after the PointTransform is applied to
        /// the Graphics, specified by g parameter.

    /// By default this method does not do anything. /// </remarks> public override void DrawInObjectSpace(Vintasoft.Imaging.UI.ImageViewer viewer, System.Drawing.Graphics g) { if (viewer.Image == null) return; System.Drawing.RectangleF rect = GetRectangle(_location, viewer.Image); if (Brush != null) g.FillRectangle(Brush, rect); if (Pen != null && !CellSize.IsEmpty) { float cellHeight = (float)Vintasoft.Imaging.Utils.UnitOfMeasureConverter.ConvertToPixels(CellSize.Height, CellUnitOfMeasure); int countRow = (int)System.Math.Ceiling(rect.Height / cellHeight); float cellWidth = (float)Vintasoft.Imaging.Utils.UnitOfMeasureConverter.ConvertToPixels(CellSize.Width, CellUnitOfMeasure); int countColumn = (int)System.Math.Ceiling(rect.Width / cellWidth); if (countRow > 0 && countColumn > 0) { float x1 = rect.X; float y1 = rect.Y + cellHeight; float x2 = rect.Right; int i; for (i = 1; i < countRow; i++, y1 += cellHeight) g.DrawLine(Pen, x1, y1, x2, y1); x1 += cellWidth; y1 = rect.Y; float y2 = rect.Bottom; for (i = 1; i < countColumn; i++, x1 += cellWidth) g.DrawLine(Pen, x1, y1, x1, y2); } } } /// <summary> /// Creates a new WpfGridGraphicObject that is a copy of the current instance. /// </summary> /// <returns> /// A new WpfGridGraphicObject that is a copy of this instance. /// </returns> public override object Clone() { GridGraphicObject obj = new GridGraphicObject(_tool); CopyTo(obj); return obj; } /// <summary> /// Copies current WpfGridGraphicObject to the target WpfGridGraphicObject. /// </summary> /// <param name="obj">WpfGridGraphicObject to copy.</param> public override void CopyTo(Vintasoft.Imaging.UI.VisualTools.GraphicObjects.GraphicObject obj) { base.CopyTo(obj); GridGraphicObject gridObj = obj as GridGraphicObject; if (gridObj != null) { gridObj.Location = Location; gridObj.CellSize = CellSize; gridObj.CellUnitOfMeasure = CellUnitOfMeasure; } } /// <summary> /// Gets the rectangle of grid. /// </summary> /// <param name="location">The location.</param> /// <param name="image">The image.</param> private System.Drawing.RectangleF GetRectangle( System.Drawing.PointF location, Vintasoft.Imaging.VintasoftImage image) { System.Drawing.RectangleF rect = new System.Drawing.RectangleF( _location.X, _location.Y, image.Width - _location.X, image.Height - _location.Y); return rect; } #endregion }


    Creating of object appearance.

    VintaSoft Imaging .NET SDK allows to create a custom static object from scratch or modify an existing standard static object.

    The object appearance can be created by overriding one of the following methods:
    Here is an example that demonstrates how to display a rotated text by overriding the GraphicObject.DrawInObjectSpace method:
    ' The project, which uses this code, must have references to the following assemblies:
    ' - Vintasoft.Imaging
    
    ''' <summary>
    ''' Represents a static rotated text which can be displayed in image viewer.
    ''' </summary>
    Public Class RotatedTextGraphicObject
        Inherits Vintasoft.Imaging.UI.VisualTools.GraphicObjects.TextGraphicObject
    
        #Region "Properties"
    
        Private _textRotationAngle As Single = 0F
        ''' <summary>
        ''' Gets or sets the rotation angle, in degrees, of text.
        ''' </summary>
        ''' <value>
        ''' Default value is 0.0.
        ''' </value>
        Public Property TextRotationAngle() As Single
            Get
                Return _textRotationAngle
            End Get
            Set
                _textRotationAngle = value Mod 360F
            End Set
        End Property
    
        #End Region
    
    
    
        #Region "Methods"
    
        ''' <summary>
        ''' Draws the object on specified <see cref="System.Drawing.Graphics" />.
        ''' </summary>
        ''' <param name="viewer">An image viewer.</param>
        ''' <param name="g">A graphics where the object must be drawn.</param>
        ''' <remarks>
        ''' This method draws object after the
        ''' <see cref="Vintasoft.Imaging.UI.VisualTools.GraphicObjects.GraphicObject.PointTransform" /> is applied
        ''' to the Graphics, specified by g parameter.
        ''' </remarks>
        Public Overrides Sub DrawInObjectSpace(viewer As Vintasoft.Imaging.UI.ImageViewer, g As System.Drawing.Graphics)
            ' save matrix of Graphics
            Using m As System.Drawing.Drawing2D.Matrix = g.Transform
                ' create matrix
                Using tmp As New System.Drawing.Drawing2D.Matrix()
                    ' calculate center point of text
                    Dim center As New System.Drawing.PointF(Rectangle.X + Rectangle.Width / 2F, Rectangle.Y + Rectangle.Height / 2F)
                    ' rotate matrix
                    tmp.RotateAt(_textRotationAngle, center)
                    ' multiply matrix
                    g.MultiplyTransform(tmp)
                End Using
    
                ' draw text
                MyBase.DrawInObjectSpace(viewer, g)
    
                ' restore matrix of Graphics
                g.Transform = m
            End Using
        End Sub
    
        #End Region
    
    End Class
                  
    
    // The project, which uses this code, must have references to the following assemblies:
    // - Vintasoft.Imaging
    
    /// <summary>
    /// Represents a static rotated text which can be displayed in image viewer.
    /// </summary>
    public class RotatedTextGraphicObject : 
        Vintasoft.Imaging.UI.VisualTools.GraphicObjects.TextGraphicObject
    {
    
        #region Properties
    
        float _textRotationAngle = 0.0f;
        /// <summary>
        /// Gets or sets the rotation angle, in degrees, of text.
        /// </summary>
        /// <value>
        /// Default value is 0.0.
        /// </value>
        public float TextRotationAngle
        {
            get
            {
                return _textRotationAngle;
            }
            set
            {
                _textRotationAngle = value % 360.0f;
            }
        }
    
        #endregion
    
    
    
        #region Methods
    
        /// <summary>
        /// Draws the object on specified <see cref="System.Drawing.Graphics" />.
        /// </summary>
        /// <param name="viewer">An image viewer.</param>
        /// <param name="g">A graphics where the object must be drawn.</param>
        /// <remarks>
        /// This method draws object after the
        /// <see cref="Vintasoft.Imaging.UI.VisualTools.GraphicObjects.GraphicObject.PointTransform" /> is applied
        /// to the Graphics, specified by g parameter.
        /// </remarks>
        public override void DrawInObjectSpace(Vintasoft.Imaging.UI.ImageViewer viewer, 
            System.Drawing.Graphics g)
        {
            // save matrix of Graphics
            using (System.Drawing.Drawing2D.Matrix m = g.Transform)
            {
                // create matrix
                using (System.Drawing.Drawing2D.Matrix tmp = new System.Drawing.Drawing2D.Matrix())
                {
                    // calculate center point of text
                    System.Drawing.PointF center = new System.Drawing.PointF(
                        Rectangle.X + Rectangle.Width / 2.0f,
                        Rectangle.Y + Rectangle.Height / 2.0f);
                    // rotate matrix
                    tmp.RotateAt(_textRotationAngle, center);
                    // multiply matrix
                    g.MultiplyTransform(tmp);
                }
    
                // draw text
                base.DrawInObjectSpace(viewer, g);
    
                // restore matrix of Graphics
                g.Transform = m;
            }
        }
    
        #endregion
    
    }
                    
    

    Here is an example that demonstrates how to display the name of loaded file, current zoom level and a bounding outline of image in the image viewer. The objects, responsible for displaying of the loaded file name and the zoom level, are located in the coordinate space of viewer, but the object, responsible for displaying of the bounding outline, is located in the coordinate space of image.
    ' The project, which uses this code, must have references to the following assemblies:
    ' - Vintasoft.Imaging
    
    ''' <summary>
    ''' Visual tool that draws static text (filename, current zoom factor) over image in
    ''' image viewer and draws a frame around image in image viewer:
    ''' </summary>
    Public Class GraphicObjectToolExample
        Inherits Vintasoft.Imaging.UI.VisualTools.GraphicObjects.GraphicObjectTool
    
        #Region "Fields"
    
        ''' <summary>
        ''' The graphic object that draws a filename over the image in image viewer.
        ''' </summary>
        Private _fileNameGraphicObject As New Vintasoft.Imaging.UI.VisualTools.GraphicObjects.TextGraphicObject()
    
        ''' <summary>
        ''' The graphic object that draws image zoom factor over the image in image viewer.
        ''' </summary>
        Private _zoomGraphicObject As New Vintasoft.Imaging.UI.VisualTools.GraphicObjects.TextGraphicObject()
    
        ''' <summary>
        ''' The graphic object that draws a frame around image in image viewer.
        ''' </summary>
        Private _borderGraphicObject As New Vintasoft.Imaging.UI.VisualTools.GraphicObjects.RectangularGraphicObject()
    
        #End Region
    
    
    
        #Region "Constructors"
    
        ''' <summary>
        ''' Initializes a new instance of the <see cref="GraphicObjectToolExample"/> class.
        ''' </summary>
        Public Sub New()
            _fileNameGraphicObject.TextAnchor = Vintasoft.Imaging.UI.AnchorType.Top
            _fileNameGraphicObject.FontBrush = System.Drawing.Brushes.Salmon
            _fileNameGraphicObject.Font = New System.Drawing.Font("Arial", 24)
            GraphicObjectCollection.Add(_fileNameGraphicObject)
    
            _zoomGraphicObject.TextAnchor = Vintasoft.Imaging.UI.AnchorType.Bottom Or Vintasoft.Imaging.UI.AnchorType.Right
            _zoomGraphicObject.FontBrush = System.Drawing.Brushes.Lime
            _zoomGraphicObject.Font = New System.Drawing.Font("Arial", 20)
            GraphicObjectCollection.Add(_zoomGraphicObject)
    
            _borderGraphicObject.PointTransform = New Vintasoft.Imaging.UI.VisualTools.PixelsToImageViewerPointFTransform()
            _borderGraphicObject.Pen = New System.Drawing.Pen(System.Drawing.Color.FromArgb(128, System.Drawing.Color.Lime), 10)
            GraphicObjectCollection.Add(_borderGraphicObject)
        End Sub
    
        #End Region
    
    
    
        #Region "Methods"
    
        ''' <summary>
        ''' Raises the <see cref="Vintasoft.Imaging.UI.VisualTools.VisualTool.Activated" /> event.
        ''' </summary>
        Protected Overrides Sub OnActivated(e As System.EventArgs)
            MyBase.OnActivated(e)
            AddHandler ImageViewer.ZoomChanged, New System.EventHandler(Of Vintasoft.Imaging.UI.ZoomChangedEventArgs)(AddressOf ImageViewer_ZoomChanged)
            AddHandler ImageViewer.ClientSizeChanged, New System.EventHandler(AddressOf ImageViewer_ClientSizeChanged)
            AddHandler ImageViewer.ImageLoaded, New System.EventHandler(Of Vintasoft.Imaging.ImageLoadedEventArgs)(AddressOf ImageViewer_ImageLoaded)
    
            UpdateGraphicObjects()
        End Sub
    
        ''' <summary>
        ''' Raises the <see cref="Vintasoft.Imaging.UI.VisualTools.VisualTool.Deactivated" /> event.
        ''' </summary>
        Protected Overrides Sub OnDeactivated(e As System.EventArgs)
            MyBase.OnDeactivated(e)
    
            RemoveHandler ImageViewer.ZoomChanged, AddressOf ImageViewer_ZoomChanged
            RemoveHandler ImageViewer.ClientSizeChanged, AddressOf ImageViewer_ClientSizeChanged
            RemoveHandler ImageViewer.ImageLoaded, AddressOf ImageViewer_ImageLoaded
        End Sub
    
        ''' <summary>
        ''' Updates the graphic objects.
        ''' </summary>
        Private Sub UpdateGraphicObjects()
            _fileNameGraphicObject.Rectangle = ImageViewer.ClientRectangle
            _zoomGraphicObject.Rectangle = ImageViewer.ClientRectangle
            _zoomGraphicObject.Text = String.Format("Zoom: {0}", ImageViewer.Zoom)
    
            Dim image As Vintasoft.Imaging.VintasoftImage = ImageViewer.Image
            If image Is Nothing Then
                _fileNameGraphicObject.Text = String.Empty
                _borderGraphicObject.Rectangle = System.Drawing.Rectangle.Empty
            Else
                Dim info As Vintasoft.Imaging.ImageSourceInfo = image.SourceInfo
                If String.IsNullOrEmpty(info.Filename) Then
                    _fileNameGraphicObject.Text = String.Empty
                Else
                    Dim text As String = System.IO.Path.GetFileName(info.Filename)
                    If info.PageCount > 1 Then
                        text += String.Format(" (Page {0}/{1})", info.PageIndex + 1, info.PageCount)
                    End If
                    _fileNameGraphicObject.Text = text
                End If
    
                _borderGraphicObject.Rectangle = New System.Drawing.RectangleF(0, 0, image.Width, image.Height)
            End If
        End Sub
    
        ''' <summary>
        ''' Handles the ClientSizeChanged event of the ImageViewer control.
        ''' </summary>
        Private Sub ImageViewer_ClientSizeChanged(sender As Object, e As System.EventArgs)
            UpdateGraphicObjects()
        End Sub
    
        ''' <summary>
        ''' Handles the ZoomChanged event of the ImageViewer control.
        ''' </summary>
        Private Sub ImageViewer_ZoomChanged(sender As Object, e As Vintasoft.Imaging.UI.ZoomChangedEventArgs)
            UpdateGraphicObjects()
        End Sub
    
        ''' <summary>
        ''' Handles the ImageLoaded event of the ImageViewer control.
        ''' </summary>
        Private Sub ImageViewer_ImageLoaded(sender As Object, e As Vintasoft.Imaging.ImageLoadedEventArgs)
            UpdateGraphicObjects()
        End Sub
    
        #End Region
    
    End Class
                  
    
    // The project, which uses this code, must have references to the following assemblies:
    // - Vintasoft.Imaging
    
    /// <summary>
    /// Visual tool that draws static text (filename, current zoom factor) over image in
    /// image viewer and draws a frame around image in image viewer:
    /// </summary>
    public class GraphicObjectToolExample : 
        Vintasoft.Imaging.UI.VisualTools.GraphicObjects.GraphicObjectTool
    {
    
        #region Fields
    
        /// <summary>
        /// The graphic object that draws a filename over the image in image viewer.
        /// </summary>
        Vintasoft.Imaging.UI.VisualTools.GraphicObjects.TextGraphicObject _fileNameGraphicObject = 
            new Vintasoft.Imaging.UI.VisualTools.GraphicObjects.TextGraphicObject();
    
        /// <summary>
        /// The graphic object that draws image zoom factor over the image in image viewer.
        /// </summary>
        Vintasoft.Imaging.UI.VisualTools.GraphicObjects.TextGraphicObject _zoomGraphicObject = 
            new Vintasoft.Imaging.UI.VisualTools.GraphicObjects.TextGraphicObject();
    
        /// <summary>
        /// The graphic object that draws a frame around image in image viewer.
        /// </summary>
        Vintasoft.Imaging.UI.VisualTools.GraphicObjects.RectangularGraphicObject _borderGraphicObject = 
            new Vintasoft.Imaging.UI.VisualTools.GraphicObjects.RectangularGraphicObject();
    
        #endregion
    
    
    
        #region Constructors
    
        /// <summary>
        /// Initializes a new instance of the <see cref="GraphicObjectToolExample"/> class.
        /// </summary>
        public GraphicObjectToolExample()
        {
            _fileNameGraphicObject.TextAnchor = Vintasoft.Imaging.UI.AnchorType.Top;
            _fileNameGraphicObject.FontBrush = System.Drawing.Brushes.Salmon;
            _fileNameGraphicObject.Font = new System.Drawing.Font("Arial", 24);
            GraphicObjectCollection.Add(_fileNameGraphicObject);
    
            _zoomGraphicObject.TextAnchor = 
                Vintasoft.Imaging.UI.AnchorType.Bottom | Vintasoft.Imaging.UI.AnchorType.Right;
            _zoomGraphicObject.FontBrush = System.Drawing.Brushes.Lime;
            _zoomGraphicObject.Font = new System.Drawing.Font("Arial", 20);
            GraphicObjectCollection.Add(_zoomGraphicObject);
    
            _borderGraphicObject.PointTransform = 
                new Vintasoft.Imaging.UI.VisualTools.PixelsToImageViewerPointFTransform();
            _borderGraphicObject.Pen = new System.Drawing.Pen(
                System.Drawing.Color.FromArgb(128, System.Drawing.Color.Lime), 10);
            GraphicObjectCollection.Add(_borderGraphicObject);
        }
    
        #endregion
    
    
    
        #region Methods
    
        /// <summary>
        /// Raises the <see cref="Vintasoft.Imaging.UI.VisualTools.VisualTool.Activated" /> event.
        /// </summary>
        protected override void OnActivated(System.EventArgs e)
        {
            base.OnActivated(e);
            ImageViewer.ZoomChanged += 
                new System.EventHandlerZoomChangedEventArgs>(ImageViewer_ZoomChanged);
            ImageViewer.ClientSizeChanged += new System.EventHandler(ImageViewer_ClientSizeChanged);
            ImageViewer.ImageLoaded += 
                new System.EventHandlerImageLoadedEventArgs>(ImageViewer_ImageLoaded);
    
            UpdateGraphicObjects();
        }
    
        /// <summary>
        /// Raises the <see cref="Vintasoft.Imaging.UI.VisualTools.VisualTool.Deactivated" /> event.
        /// </summary>
        protected override void OnDeactivated(System.EventArgs e)
        {
            base.OnDeactivated(e);
    
            ImageViewer.ZoomChanged -= ImageViewer_ZoomChanged;
            ImageViewer.ClientSizeChanged -= ImageViewer_ClientSizeChanged;
            ImageViewer.ImageLoaded -= ImageViewer_ImageLoaded;
        }
    
        /// <summary>
        /// Updates the graphic objects.
        /// </summary>
        void UpdateGraphicObjects()
        {
            _fileNameGraphicObject.Rectangle = ImageViewer.ClientRectangle;
            _zoomGraphicObject.Rectangle = ImageViewer.ClientRectangle;
            _zoomGraphicObject.Text = string.Format("Zoom: {0}", ImageViewer.Zoom);
    
            Vintasoft.Imaging.VintasoftImage image = ImageViewer.Image;
            if (image == null)
            {
                _fileNameGraphicObject.Text = string.Empty;
                _borderGraphicObject.Rectangle = System.Drawing.Rectangle.Empty;
            }
            else
            {
                Vintasoft.Imaging.ImageSourceInfo info = image.SourceInfo;
                if (string.IsNullOrEmpty(info.Filename))
                    _fileNameGraphicObject.Text = string.Empty;
                else
                {
                    string text = System.IO.Path.GetFileName(info.Filename);
                    if (info.PageCount > 1)
                        text += string.Format(" (Page {0}/{1})", info.PageIndex + 1, info.PageCount);
                    _fileNameGraphicObject.Text = text;
                }
    
                _borderGraphicObject.Rectangle = new System.Drawing.RectangleF(0, 0, image.Width, image.Height);
            }
        }
    
        /// <summary>
        /// Handles the ClientSizeChanged event of the ImageViewer control.
        /// </summary>
        void ImageViewer_ClientSizeChanged(object sender, System.EventArgs e)
        {
            UpdateGraphicObjects();
        }
    
        /// <summary>
        /// Handles the ZoomChanged event of the ImageViewer control.
        /// </summary>
        void ImageViewer_ZoomChanged(object sender, Vintasoft.Imaging.UI.ZoomChangedEventArgs e)
        {
            UpdateGraphicObjects();
        }
    
        /// <summary>
        /// Handles the ImageLoaded event of the ImageViewer control.
        /// </summary>
        void ImageViewer_ImageLoaded(object sender, Vintasoft.Imaging.ImageLoadedEventArgs e)
        {
            UpdateGraphicObjects();
        }
    
        #endregion
    
    }