Undo/redo changes in images

In This Topic

SDK has the open architecture for undo/redo changes in images, annotations and user defined objects.

Architecture contains 3 main classes:

UndoAction - base class that stores information about changes in object.
UndoManager - stores information about changes in object(s) and allows to undo/redo changes in object(s).
UndoMonitor - base class that monitors changes in object.

Class UndoAction allows to:

Determine logic of undo operation by overriding the UndoAction.Undo method.
Describe change in object using the UndoAction.ToString method.

Class UndoManager allows to:

Add information about change in object to the history using the UndoManager.AddAction method.
Undo several changes in object(s) using the UndoManager.Undo method.
Redo several changes in object(s) using the UndoManager.Redo method.
Get an information about changes in object(s) using the UndoManager.GetActions method and restore object to the necessary state using the UndoManager.CurrentAction property.
Clear information about changes in object(s) using the UndoManager.Clear method.
Get or set the maximum number of undo levels using the UndoManager.UndoLevel property.

Here is a list of standard undo monitors:

ImageProcessingUndoMonitor - class that monitors changes in image which are made by image processing command.
VisualToolUndoMonitor - class that monitors changes in image which are made by visual tool.
AnnotationViewUndoMonitor - class that monitors changes in annotation view.
AnnotationViewCollectionUndoMonitor - class that monitors changes in annotation view collection.

Here is C#/VB.NET code that demonstrates how to process an image and undo changes in image:

/// <summary>
/// This example demonstrates how to process an image and undo changes in image.
/// </summary>
public static void ImageUndoManagerExample()
{
    // create an image collection
    Vintasoft.Imaging.ImageCollection images =
        new Vintasoft.Imaging.ImageCollection();
    // add image to the image collection
    images.Add(@"..\..\Resources\Image.png");

    Vintasoft.Imaging.VintasoftImage image = images[0];

    // show information about image
    ShowInfo(image);


    // create an instance of undo manager
    Vintasoft.Imaging.Undo.UndoManager undoManager =
        new Vintasoft.Imaging.Undo.UndoManager();

    // create the image resize command
    Vintasoft.Imaging.ImageProcessing.ResizeCommand resizeCommand =
        new Vintasoft.Imaging.ImageProcessing.ResizeCommand();
    // create the undo monitor for the image resize command
    using (Vintasoft.Imaging.Undo.UndoMonitor resizeCommandUndoMonitor =
        new Vintasoft.Imaging.Undo.ImageProcessingUndoMonitor(undoManager, resizeCommand))
    {
        // create the image change pixel format command
        Vintasoft.Imaging.ImageProcessing.ChangePixelFormatCommand changePixelFormatCommand =
            new Vintasoft.Imaging.ImageProcessing.ChangePixelFormatCommand();
        // create the undo manager for image change pixel format command
        using (Vintasoft.Imaging.Undo.UndoMonitor changePixelFormatCommandUndoMonitor =
            new Vintasoft.Imaging.Undo.ImageProcessingUndoMonitor(undoManager, changePixelFormatCommand))
        {
            // Step 1: change pixel format to grayscale
            changePixelFormatCommand.PixelFormat = Vintasoft.Imaging.PixelFormat.Gray8;
            changePixelFormatCommand.ExecuteInPlace(image);

            // show information about image
            ShowInfo(image);

            // undo one step (Step 1)
            undoManager.Undo(1);

            // show information about image
            ShowInfo(image);


            // Step 2: resize image
            resizeCommand.Width = 750;
            resizeCommand.Height = 350;
            resizeCommand.ExecuteInPlace(image);

            // show information about image
            ShowInfo(image);


            // Step 3: change pixel format to Bgr48
            changePixelFormatCommand.PixelFormat = Vintasoft.Imaging.PixelFormat.Bgr48;
            changePixelFormatCommand.ExecuteInPlace(image);

            // show information about image
            ShowInfo(image);

            // undo two steps (Step 3 and Step 2)
            undoManager.Undo(2);

            // show information about image
            ShowInfo(image);

            // redo one step (Step 2)
            undoManager.Redo(1);

            // show information about image
            ShowInfo(image);
        }
    }
}

/// <summary>
/// Shows information about image.
/// </summary>
/// <param name="image">Image.</param>
public static void ShowInfo(
    Vintasoft.Imaging.VintasoftImage image)
{
    // show information about image
    System.Console.WriteLine("Image: {0}x{1} PixelFormat:{2}", image.Width, image.Height, image.PixelFormat);
}

/* This code example produces the following output:

Image: 500x534 PixelFormat:Bgr24
Image: 500x534 PixelFormat:Gray8
Image: 500x534 PixelFormat:Bgr24
Image: 750x350 PixelFormat:Bgr24
Image: 750x350 PixelFormat:Bgr48
Image: 500x534 PixelFormat:Bgr24
Image: 750x350 PixelFormat:Bgr24
*/

VB.NET

        ''' <summary>
        ''' This example demonstrates how to process an image and undo changes in image.
        ''' </summary>
        Public Shared Sub ImageUndoManagerExample()
            ' create an image collection
            Dim images As New Vintasoft.Imaging.ImageCollection()
            ' add image to the image collection
            images.Add("..\..\Resources\Image.png")

            Dim image As Vintasoft.Imaging.VintasoftImage = images(0)

            ' show information about image
            ShowInfo(image)


            ' create an instance of undo manager
            Dim undoManager As New Vintasoft.Imaging.Undo.UndoManager()

            ' create the image resize command
            Dim resizeCommand As New Vintasoft.Imaging.ImageProcessing.ResizeCommand()
            ' create the undo monitor for the image resize command
            Using resizeCommandUndoMonitor As Vintasoft.Imaging.Undo.UndoMonitor = New Vintasoft.Imaging.Undo.ImageProcessingUndoMonitor(undoManager, resizeCommand)
                ' create the image change pixel format command
                Dim changePixelFormatCommand As New Vintasoft.Imaging.ImageProcessing.ChangePixelFormatCommand()
                ' create the undo manager for image change pixel format command
                Using changePixelFormatCommandUndoMonitor As Vintasoft.Imaging.Undo.UndoMonitor = New Vintasoft.Imaging.Undo.ImageProcessingUndoMonitor(undoManager, changePixelFormatCommand)
                    ' Step 1: change pixel format to grayscale
                    changePixelFormatCommand.PixelFormat = Vintasoft.Imaging.PixelFormat.Gray8
                    changePixelFormatCommand.ExecuteInPlace(image)

                    ' show information about image
                    ShowInfo(image)

                    ' undo one step (Step 1)
                    undoManager.Undo(1)

                    ' show information about image
                    ShowInfo(image)


                    ' Step 2: resize image
                    resizeCommand.Width = 750
                    resizeCommand.Height = 350
                    resizeCommand.ExecuteInPlace(image)

                    ' show information about image
                    ShowInfo(image)


                    ' Step 3: change pixel format to Bgr48
                    changePixelFormatCommand.PixelFormat = Vintasoft.Imaging.PixelFormat.Bgr48
                    changePixelFormatCommand.ExecuteInPlace(image)

                    ' show information about image
                    ShowInfo(image)

                    ' undo two steps (Step 3 and Step 2)
                    undoManager.Undo(2)

                    ' show information about image
                    ShowInfo(image)

                    ' redo one step (Step 2)
                    undoManager.Redo(1)

                    ' show information about image
                    ShowInfo(image)
                End Using
            End Using
        End Sub

        ''' <summary>
        ''' Shows information about image.
        ''' </summary>
        ''' <param name="image">Image.</param>
        Public Shared Sub ShowInfo(image As Vintasoft.Imaging.VintasoftImage)
            ' show information about image
            System.Console.WriteLine("Image: {0}x{1} PixelFormat:{2}", image.Width, image.Height, image.PixelFormat)
        End Sub

        ' This code example produces the following output:
'
'        Image: 500x534 PixelFormat:Bgr24
'        Image: 500x534 PixelFormat:Gray8
'        Image: 500x534 PixelFormat:Bgr24
'        Image: 750x350 PixelFormat:Bgr24
'        Image: 750x350 PixelFormat:Bgr48
'        Image: 500x534 PixelFormat:Bgr24
'        Image: 750x350 PixelFormat:Bgr24
'

Here is C#/VB.NET code that demonstrates how to process an image with annotations and undo changes in image and annotations:

/// <summary>
/// This example demonstrates how to process an image with annotations and undo changes in image and annotations.
/// </summary>
public void ImageAndAnnotationsUndoManagerExample()
{
    // create an image collection
    Vintasoft.Imaging.ImageCollection images =
        new Vintasoft.Imaging.ImageCollection();
    // add image to the image collection
    images.Add(@"..\..\Resources\Image.png");

    Vintasoft.Imaging.VintasoftImage image = images[0];

    // create the annotation data controller for image collection
    Vintasoft.Imaging.Annotation.AnnotationDataController annotationDataController =
        new Vintasoft.Imaging.Annotation.AnnotationDataController(images);

    // get reference to the annotation data collection of image
    Vintasoft.Imaging.Annotation.AnnotationDataCollection annotationDataCollection =
        annotationDataController.GetAnnotations(image);
    // get reference to the annotation view collection of image
    Vintasoft.Imaging.Annotation.UI.AnnotationViewCollection annotationViewCollection =
        new Vintasoft.Imaging.Annotation.UI.AnnotationViewCollection(annotationDataCollection);

    // show information about image and annotations
    ShowInfo(image, annotationDataCollection);


    // create an instance of undo manager
    Vintasoft.Imaging.Undo.UndoManager undoManager =
        new Vintasoft.Imaging.Undo.UndoManager();

    // create the image resize command
    Vintasoft.Imaging.ImageProcessing.ResizeCommand resizeCommand =
        new Vintasoft.Imaging.ImageProcessing.ResizeCommand();
    // create the undo monitor for the image resize command
    using (Vintasoft.Imaging.Undo.UndoMonitor resizeCommandUndoMonitor =
        new Vintasoft.Imaging.Undo.ImageProcessingUndoMonitor(undoManager, resizeCommand))
    {
        // create the undo monitor for annotations
        using (Vintasoft.Imaging.Undo.UndoMonitor annotationUndoMonitor =
            new Vintasoft.Imaging.Annotation.UI.Undo.AnnotationViewCollectionUndoMonitor(
                undoManager, annotationViewCollection))
        {
            // Step 1

            // create a rectangle annotation
            Vintasoft.Imaging.Annotation.RectangleAnnotationData rectangleAnnotationData =
                new Vintasoft.Imaging.Annotation.RectangleAnnotationData();
            rectangleAnnotationData.Location = new System.Drawing.PointF(60, 110);
            rectangleAnnotationData.Size = new System.Drawing.SizeF(100, 38);
            // add the rectangle annotation to the image
            annotationDataCollection.Add(rectangleAnnotationData);

            // show information about image and annotations
            ShowInfo(image, annotationDataCollection);

            // undo one step (Step 1)
            undoManager.Undo(1);

            // show information about image and annotations
            ShowInfo(image, annotationDataCollection);


            // Step 2: resize image
            resizeCommand.Width = 550;
            resizeCommand.Height = 450;
            resizeCommand.ExecuteInPlace(image);

            // show information about image and annotations
            ShowInfo(image, annotationDataCollection);


            // Step 3

            // change an existing annotation
            Vintasoft.Imaging.Annotation.AnnotationData annotationData = annotationDataCollection[0];
            annotationData.Location = new System.Drawing.PointF(15, 10);

            // show information about image and annotations
            ShowInfo(image, annotationDataCollection);

            // undo two steps (Step 3 and Step 2)
            undoManager.Undo(2);

            // show information about image and annotations
            ShowInfo(image, annotationDataCollection);


            // redo one step (Step 2)
            undoManager.Redo(1);

            // show information about image and annotations
            ShowInfo(image, annotationDataCollection);
        }
    }
}

/// <summary>
/// Shows information about image and annotations.
/// </summary>
/// <param name="image">Image.</param>
/// <param name="annotationDataCollection">Annotation data collection.</param>
public void ShowInfo(
    Vintasoft.Imaging.VintasoftImage image,
    Vintasoft.Imaging.Annotation.AnnotationDataCollection annotationDataCollection)
{
    // show information about image
    System.Console.WriteLine("Image: {0}x{1} PixelFormat:{2}", image.Width, image.Height, image.PixelFormat);

    // show information about annotations
    System.Console.WriteLine("Annotation count: {0}", annotationDataCollection.Count);
    foreach (Vintasoft.Imaging.Annotation.AnnotationData annotationData in annotationDataCollection)
    {
        System.Type annotationDataType = annotationData.GetType();
        System.Console.WriteLine("\tType:{0} Location:{1} Size:{2}", annotationDataType.Name,
            annotationData.Location, annotationData.Size);
    }
}

/* This code example produces the following output:

Image: 500x418 PixelFormat:Bgr24
Annotations count: 2
        Type:PolygonAnnotationData Location:{X=26,00019, Y=22,55438} Size:{Width=60,77151, Height=61,08478}
        Type:LineAnnotationData Location:{X=114,9647, Y=15,34951} Size:{Width=0, Height=104,6273}
Image: 500x418 PixelFormat:Bgr24
Annotations count: 3
        Type:PolygonAnnotationData Location:{X=26,00019, Y=22,55438} Size:{Width=60,77151, Height=61,08478}
        Type:LineAnnotationData Location:{X=114,9647, Y=15,34951} Size:{Width=0, Height=104,6273}
        Type:RectangleAnnotationData Location:{X=60, Y=110} Size:{Width=100, Height=38}
Image: 500x418 PixelFormat:Bgr24
Annotations count: 2
        Type:PolygonAnnotationData Location:{X=26,00019, Y=22,55438} Size:{Width=60,77151, Height=61,08478}
        Type:LineAnnotationData Location:{X=114,9647, Y=15,34951} Size:{Width=0, Height=104,6273}
Image: 550x450 PixelFormat:Bgr24
Annotations count: 2
        Type:PolygonAnnotationData Location:{X=26,00019, Y=22,55438} Size:{Width=60,77151, Height=61,08478}
        Type:LineAnnotationData Location:{X=114,9647, Y=15,34951} Size:{Width=0, Height=104,6273}
Image: 500x418 PixelFormat:Bgr24
Annotations count: 2
        Type:PolygonAnnotationData Location:{X=26,00019, Y=22,55438} Size:{Width=60,77151, Height=61,08478}
        Type:LineAnnotationData Location:{X=114,9647, Y=15,34951} Size:{Width=0, Height=104,6273}
Image: 550x450 PixelFormat:Bgr24
Annotations count: 2
        Type:PolygonAnnotationData Location:{X=26,00019, Y=22,55438} Size:{Width=60,77151, Height=61,08478}
        Type:LineAnnotationData Location:{X=114,9647, Y=15,34951} Size:{Width=0, Height=104,6273}
*/

VB.NET

        ''' <summary>
        ''' This example demonstrates how to process an image with annotations and undo changes in image and annotations.
        ''' </summary>
        Public Sub ImageAndAnnotationsUndoManagerExample()
            ' create an image collection
            Dim images As New Vintasoft.Imaging.ImageCollection()
            ' add image to the image collection
            images.Add("..\..\Resources\Image.png")

            Dim image As Vintasoft.Imaging.VintasoftImage = images(0)

            ' create the annotation data controller for image collection
            Dim annotationDataController As New Vintasoft.Imaging.Annotation.AnnotationDataController(images)

            ' get reference to the annotation data collection of image
            Dim annotationDataCollection As Vintasoft.Imaging.Annotation.AnnotationDataCollection = annotationDataController.GetAnnotations(image)
            ' get reference to the annotation view collection of image
            Dim annotationViewCollection As New Vintasoft.Imaging.Annotation.UI.AnnotationViewCollection(annotationDataCollection)

            ' show information about image and annotations
            ShowInfo(image, annotationDataCollection)


            ' create an instance of undo manager
            Dim undoManager As New Vintasoft.Imaging.Undo.UndoManager()

            ' create the image resize command
            Dim resizeCommand As New Vintasoft.Imaging.ImageProcessing.ResizeCommand()
            ' create the undo monitor for the image resize command
            Using resizeCommandUndoMonitor As Vintasoft.Imaging.Undo.UndoMonitor = New Vintasoft.Imaging.Undo.ImageProcessingUndoMonitor(undoManager, resizeCommand)
                ' create the undo monitor for annotations
                Using annotationUndoMonitor As Vintasoft.Imaging.Undo.UndoMonitor = New Vintasoft.Imaging.Annotation.UI.Undo.AnnotationViewCollectionUndoMonitor(undoManager, annotationViewCollection)
                    ' Step 1

                    ' create a rectangle annotation
                    Dim rectangleAnnotationData As New Vintasoft.Imaging.Annotation.RectangleAnnotationData()
                    rectangleAnnotationData.Location = New System.Drawing.PointF(60, 110)
                    rectangleAnnotationData.Size = New System.Drawing.SizeF(100, 38)
                    ' add the rectangle annotation to the image
                    annotationDataCollection.Add(rectangleAnnotationData)

                    ' show information about image and annotations
                    ShowInfo(image, annotationDataCollection)

                    ' undo one step (Step 1)
                    undoManager.Undo(1)

                    ' show information about image and annotations
                    ShowInfo(image, annotationDataCollection)


                    ' Step 2: resize image
                    resizeCommand.Width = 550
                    resizeCommand.Height = 450
                    resizeCommand.ExecuteInPlace(image)

                    ' show information about image and annotations
                    ShowInfo(image, annotationDataCollection)


                    ' Step 3

                    ' change an existing annotation
                    Dim annotationData As Vintasoft.Imaging.Annotation.AnnotationData = annotationDataCollection(0)
                    annotationData.Location = New System.Drawing.PointF(15, 10)

                    ' show information about image and annotations
                    ShowInfo(image, annotationDataCollection)

                    ' undo two steps (Step 3 and Step 2)
                    undoManager.Undo(2)

                    ' show information about image and annotations
                    ShowInfo(image, annotationDataCollection)


                    ' redo one step (Step 2)
                    undoManager.Redo(1)

                    ' show information about image and annotations
                    ShowInfo(image, annotationDataCollection)
                End Using
            End Using
        End Sub

        ''' <summary>
        ''' Shows information about image and annotations.
        ''' </summary>
        ''' <param name="image">Image.</param>
        ''' <param name="annotationDataCollection">Annotation data collection.</param>
        Public Sub ShowInfo(image As Vintasoft.Imaging.VintasoftImage, annotationDataCollection As Vintasoft.Imaging.Annotation.AnnotationDataCollection)
            ' show information about image
            System.Console.WriteLine("Image: {0}x{1} PixelFormat:{2}", image.Width, image.Height, image.PixelFormat)

            ' show information about annotations
            System.Console.WriteLine("Annotation count: {0}", annotationDataCollection.Count)
            For Each annotationData As Vintasoft.Imaging.Annotation.AnnotationData In annotationDataCollection
                Dim annotationDataType As System.Type = annotationData.[GetType]()
                System.Console.WriteLine(vbTab & "Type:{0} Location:{1} Size:{2}", annotationDataType.Name, annotationData.Location, annotationData.Size)
            Next
        End Sub

        ' This code example produces the following output:
'
'        Image: 500x418 PixelFormat:Bgr24
'        Annotations count: 2
'                Type:PolygonAnnotationData Location:{X=26,00019, Y=22,55438} Size:{Width=60,77151, Height=61,08478}
'                Type:LineAnnotationData Location:{X=114,9647, Y=15,34951} Size:{Width=0, Height=104,6273}
'        Image: 500x418 PixelFormat:Bgr24
'        Annotations count: 3
'                Type:PolygonAnnotationData Location:{X=26,00019, Y=22,55438} Size:{Width=60,77151, Height=61,08478}
'                Type:LineAnnotationData Location:{X=114,9647, Y=15,34951} Size:{Width=0, Height=104,6273}
'                Type:RectangleAnnotationData Location:{X=60, Y=110} Size:{Width=100, Height=38}
'        Image: 500x418 PixelFormat:Bgr24
'        Annotations count: 2
'                Type:PolygonAnnotationData Location:{X=26,00019, Y=22,55438} Size:{Width=60,77151, Height=61,08478}
'                Type:LineAnnotationData Location:{X=114,9647, Y=15,34951} Size:{Width=0, Height=104,6273}
'        Image: 550x450 PixelFormat:Bgr24
'        Annotations count: 2
'                Type:PolygonAnnotationData Location:{X=26,00019, Y=22,55438} Size:{Width=60,77151, Height=61,08478}
'                Type:LineAnnotationData Location:{X=114,9647, Y=15,34951} Size:{Width=0, Height=104,6273}
'        Image: 500x418 PixelFormat:Bgr24
'        Annotations count: 2
'                Type:PolygonAnnotationData Location:{X=26,00019, Y=22,55438} Size:{Width=60,77151, Height=61,08478}
'                Type:LineAnnotationData Location:{X=114,9647, Y=15,34951} Size:{Width=0, Height=104,6273}
'        Image: 550x450 PixelFormat:Bgr24
'        Annotations count: 2
'                Type:PolygonAnnotationData Location:{X=26,00019, Y=22,55438} Size:{Width=60,77151, Height=61,08478}
'                Type:LineAnnotationData Location:{X=114,9647, Y=15,34951} Size:{Width=0, Height=104,6273}
'

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