ContextNode Class
Represents a node in a tree of objects that are created as part of ink analysis.
Namespace: System.Windows.Ink
Assembly: IAWinFX (in IAWinFX.dll)
Syntax
'Declaration
Public Class ContextNode
'Usage
Dim instance As ContextNode
public class ContextNode
public ref class ContextNode
public class ContextNode
Remarks
After an InkAnalyzer performs an ink analysis, it presents the results as a tree of ContextNode objects. The [T:System.Windows.Ink.RootNode is located at the top of the tree]; the tree presents smaller and smaller collections of strokes further down the tree. These nodes can be groups of words (such as paragraphs or lines), analyzed ink (such as words or drawings), or a variety of other types. (See the ContextNodeType class for a full list.)
You can manually add nodes, such as AnalysisHintNode, ImageNode and TextWordNode objects, to the InkAnalyzer.
In cases of corrupt input, this method throws a ArgumentException exception.
Examples
This example takes an InkAnalyzer named theInkAnalyzer, and uses its ContextNode tree to fill a [System.Windows.Controls.TreeView] named theTreeView. When a node belonging to a tree view is selected, its associated strokes are set to appear in red. The [System.Windows.FrameworkElement.Tag] property is used to map between tree nodes and the context nodes that they represent.
Private Sub BuildTree()
' Remove the old nodes from the TreeView and add the current results.
Me.theResultsTreeView.Items.Clear()
Dim rootNode As New TreeViewItem()
rootNode.Tag = Me.theInkAnalyzer.RootNode
rootNode.Header = theInkAnalyzer.RootNode.ToString()
Me.theResultsTreeView.Items.Add(rootNode)
WalkTree(Me.theInkAnalyzer.RootNode, rootNode)
End Sub 'BuildTree
Private Shared Sub WalkTree(ByVal parentContextNode As ContextNode, ByVal parentTreeNode As TreeViewItem)
parentTreeNode.IsExpanded = True
For Each theContextSubnode As ContextNode In parentContextNode.SubNodes
Dim newTreeNode As New TreeViewItem()
newTreeNode.Header = theContextSubnode.ToString()
If TypeOf theContextSubnode Is InkWordNode Then
newTreeNode.Header += ": " + CType(theContextSubnode, InkWordNode).GetRecognizedString()
ElseIf TypeOf theContextSubnode Is InkDrawingNode Then
newTreeNode.Header += ": " + CType(theContextSubnode, InkDrawingNode).GetShapeName()
End If
' If the context node is confirmed, add a note to the
' tree view item.
If (theContextSubnode.IsConfirmed(ConfirmationType.NodeTypeAndProperties)) Then
newTreeNode.Header += " Confirmed."
End If
' Add the context node as a tag of the tree view item and
' add the new tree view item to the parent node.
newTreeNode.Tag = theContextSubnode
parentTreeNode.Items.Add(newTreeNode)
WalkTree(theContextSubnode, newTreeNode)
Next theContextSubnode
End Sub 'WalkTree
Sub theResultsTreeView_SelectedItemChanged(ByVal sender As Object, _
ByVal e As RoutedPropertyChangedEventArgs(Of Object))
Dim selectedTreeViewItem As TreeViewItem = e.NewValue '
If selectedTreeViewItem Is Nothing Then
Return
End If
' Get the context node
Dim selectedNode As ContextNode = CType(selectedTreeViewItem.Tag, ContextNode)
MarkNodeAsRed(selectedNode)
timeStampLabel.Content = ""
' Show selected results
If Not (selectedNode Is Nothing) Then
If selectedNode.Type = ContextNodeType.WritingRegion Then
Dim writingRegion As WritingRegionNode = CType(selectedNode, WritingRegionNode)
selectedResultsTextBox.Text = writingRegion.GetRecognizedString()
ElseIf selectedNode.Type = ContextNodeType.Paragraph Then
Dim paragraph As ParagraphNode = CType(selectedNode, ParagraphNode)
selectedResultsTextBox.Text = paragraph.GetRecognizedString()
ElseIf selectedNode.Type = ContextNodeType.Line Then
Dim line As LineNode = CType(selectedNode, LineNode)
selectedResultsTextBox.Text = line.GetRecognizedString()
ElseIf selectedNode.Type = ContextNodeType.InkWord Then
Dim inkWord As InkWordNode = CType(selectedNode, InkWordNode)
Dim parentNode As ContextNode = inkWord.ParentNode
If TypeOf parentNode Is LineNode Then
Dim parentLine As LineNode = CType(parentNode, LineNode)
' Put parent line's recognized string into the text box
selectedResultsTextBox.Text = parentLine.GetRecognizedString()
' Select the text that corresponds to the ink word
Dim subNodes As New ContextNodeCollection(theInkAnalyzer)
subNodes.Add(inkWord)
Dim start As Integer
Dim length As Integer
parentLine.GetTextRangeFromNodes(subNodes, start, length)
If start >= 0 AndAlso length > 0 Then
selectedResultsTextBox.Select(start, length)
End If
End If
ElseIf selectedNode.Type = ContextNodeType.InkDrawing Then
Dim drawingNode As InkDrawingNode = CType(selectedNode, InkDrawingNode)
selectedResultsTextBox.Text = drawingNode.GetShapeName()
ElseIf selectedNode.Type = ContextNodeType.InkBullet Then
Dim bulletNode As InkBulletNode = CType(selectedNode, InkBulletNode)
selectedResultsTextBox.Text = bulletNode.GetRecognizedString()
ElseIf selectedNode.Type = ContextNodeType.CustomRecognizer Then
Dim customRecognizer As CustomRecognizerNode = CType(selectedNode, CustomRecognizerNode)
selectedResultsTextBox.Text = customRecognizer.GetRecognizedString()
ElseIf selectedNode.Type = ContextNodeType.Object Then
Dim selectedObject As ObjectNode = CType(selectedNode, ObjectNode)
selectedResultsTextBox.Text = selectedObject.GetRecognizedString()
Else
selectedResultsTextBox.Text = ""
End If
If TypeOf selectedNode Is InkWordNode Then
Dim inkWord As InkWordNode = CType(selectedNode, InkWordNode)
' Show the time stamp
If inkWord.ContainsPropertyData(Me.timeStampGuid) Then
Dim timeStamp As DateTime = CType(inkWord.GetPropertyData(Me.timeStampGuid), DateTime)
timeStampLabel.Content = timeStamp.ToShortTimeString()
End If
' Snippet to demonstrate GetPropertyDataIds
Dim propertyDataIds As Guid() = inkWord.GetPropertyDataIds()
' Snippets to demonstrate loading and saving
Dim data As Byte() = inkWord.SavePropertiesData()
If Not inkWord.LoadPropertiesData(data) Then
MessageBox.Show("Cannot load property data")
End If
End If
End If
PopulateLinksList(selectedNode)
Me.currentNode = selectedNode
End Sub
Private Sub PopulateLinksList(ByVal selectedNode As ContextNode)
linksListBox.Items.Clear()
If selectedNode Is Nothing Then
Return
End If
Dim link As ContextLink
For Each link In selectedNode.Links
linksListBox.Items.Add(link.SourceNode.ToString() + ", " & _
link.DestinationNode.ToString() & ": " & _
link.LinkDirection.ToString())
Next
End Sub
Sub MarkNodeAsRed(ByVal selectedNode As ContextNode)
' Set all node strokes to black, but this one to red
Dim stroke As Stroke
For Each stroke In Me.theInkCanvas.Strokes
If Not (selectedNode Is Nothing) AndAlso selectedNode.Strokes.Contains(stroke) Then
stroke.DrawingAttributes.Color = Colors.Red
Else
stroke.DrawingAttributes.Color = Me.theInkCanvas.DefaultDrawingAttributes.Color
End If
Next stroke
End Sub 'theResultsTreeView_SelectedItemChanged
private void BuildTree()
{
// Remove the old nodes from the TreeView and add the current results.
this.theResultsTreeView.Items.Clear();
TreeViewItem rootNode = new TreeViewItem();
rootNode.Tag = this.theInkAnalyzer.RootNode;
rootNode.Header = theInkAnalyzer.RootNode.ToString();
this.theResultsTreeView.Items.Add(rootNode);
WalkTree(this.theInkAnalyzer.RootNode, rootNode);
}
private static void WalkTree(ContextNode parentContextNode, TreeViewItem parentTreeNode)
{
// Expand the current TreeViewItem.
parentTreeNode.IsExpanded = true;
foreach (ContextNode theContextSubnode
in parentContextNode.SubNodes)
{
TreeViewItem newTreeNode = new TreeViewItem();
newTreeNode.Header = theContextSubnode.ToString();
if (theContextSubnode is InkWordNode)
{
newTreeNode.Header += ": " +
((InkWordNode)theContextSubnode).GetRecognizedString();
}
else if (theContextSubnode is InkDrawingNode)
{
newTreeNode.Header += ": " +
((InkDrawingNode)theContextSubnode).GetShapeName();
}
// If the context node is confirmed, add a note to the
// tree view item.
if (theContextSubnode.IsConfirmed(ConfirmationType.NodeTypeAndProperties))
{
newTreeNode.Header += " Confirmed.";
}
// Add the context node as a tag of the tree view item and
// add the new tree view item to the parent node.
newTreeNode.Tag = theContextSubnode;
parentTreeNode.Items.Add(newTreeNode);
WalkTree(theContextSubnode, newTreeNode);
}
}
void theResultsTreeView_SelectedItemChanged(object sender, RoutedPropertyChangedEventArgs<object> e)
{
TreeViewItem selectedTreeViewItem = e.NewValue as TreeViewItem;
if (selectedTreeViewItem == null)
{
return;
}
// Get the context node
ContextNode selectedNode = (ContextNode)selectedTreeViewItem.Tag;
MarkNodeAsRed(selectedNode);
timeStampLabel.Content = "";
// Show selected results
if (selectedNode != null)
{
if (selectedNode.Type == ContextNodeType.WritingRegion)
{
WritingRegionNode writingRegion = (WritingRegionNode)selectedNode;
selectedResultsTextBox.Text = writingRegion.GetRecognizedString();
}
else if (selectedNode.Type == ContextNodeType.Paragraph)
{
ParagraphNode paragraph = (ParagraphNode)selectedNode;
selectedResultsTextBox.Text = paragraph.GetRecognizedString();
}
else if (selectedNode.Type == ContextNodeType.Line)
{
LineNode line = (LineNode)selectedNode;
selectedResultsTextBox.Text = line.GetRecognizedString();
}
else if (selectedNode.Type == ContextNodeType.InkWord)
{
InkWordNode inkWord = (InkWordNode)selectedNode;
ContextNode parentNode = inkWord.ParentNode;
if (parentNode is LineNode)
{
LineNode parentLine = (LineNode)parentNode;
// Put parent line's recognized string into the text box
selectedResultsTextBox.Text = parentLine.GetRecognizedString();
// Select the text that corresponds to the ink word
ContextNodeCollection subNodes = new ContextNodeCollection(theInkAnalyzer);
subNodes.Add(inkWord);
int start;
int length;
parentLine.GetTextRangeFromNodes(subNodes, out start, out length);
if (start >= 0 && length > 0)
{
selectedResultsTextBox.Select(start, length);
}
}
}
else if (selectedNode.Type == ContextNodeType.InkDrawing)
{
InkDrawingNode drawingNode = (InkDrawingNode)selectedNode;
selectedResultsTextBox.Text = drawingNode.GetShapeName();
}
else if (selectedNode.Type == ContextNodeType.InkBullet)
{
InkBulletNode bulletNode = (InkBulletNode)selectedNode;
selectedResultsTextBox.Text = bulletNode.GetRecognizedString();
}
else if (selectedNode.Type == ContextNodeType.CustomRecognizer)
{
CustomRecognizerNode customRecognizer = (CustomRecognizerNode)selectedNode;
selectedResultsTextBox.Text = customRecognizer.GetRecognizedString();
}
else if (selectedNode.Type == ContextNodeType.Object)
{
ObjectNode selectedObject = (ObjectNode)selectedNode;
selectedResultsTextBox.Text = selectedObject.GetRecognizedString();
}
else
{
selectedResultsTextBox.Text = "";
}
if (selectedNode is InkWordNode)
{
InkWordNode inkWord = (InkWordNode)selectedNode;
// Show the time stamp
if (inkWord.ContainsPropertyData(this.timeStampGuid))
{
DateTime timeStamp =
(DateTime)inkWord.GetPropertyData(this.timeStampGuid);
timeStampLabel.Content = timeStamp.ToShortTimeString();
}
// Snippet to demonstrate GetPropertyDataIds
Guid[] propertyDataIds = inkWord.GetPropertyDataIds();
// Snippets to demonstrate loading and saving
byte[] data = inkWord.SavePropertiesData();
if (!inkWord.LoadPropertiesData(data))
MessageBox.Show("Cannot load property data");
}
}
PopulateLinksList(selectedNode);
this.currentNode = selectedNode;
}
private void PopulateLinksList(ContextNode selectedNode)
{
linksListBox.Items.Clear();
if (selectedNode == null)
{
return;
}
foreach (ContextLink link in selectedNode.Links)
{
linksListBox.Items.Add(link.SourceNode.ToString() + ", " +
link.DestinationNode.ToString() + ": " +
link.LinkDirection.ToString());
}
}
private void MarkNodeAsRed(ContextNode selectedNode)
{
// Set all node strokes to black, but this one to red
foreach (Stroke stroke in this.theInkCanvas.Strokes)
{
if (selectedNode != null &&
selectedNode.Strokes.Contains(stroke))
stroke.DrawingAttributes.Color = Colors.Red;
else
stroke.DrawingAttributes.Color =
this.theInkCanvas.DefaultDrawingAttributes.Color;
}
}
Inheritance Hierarchy
System.Object
System.Windows.Ink.ContextNode
System.Windows.Ink.AnalysisHintNode
System.Windows.Ink.CustomRecognizerNode
System.Windows.Ink.ImageNode
System.Windows.Ink.InkBulletNode
System.Windows.Ink.InkDrawingNode
System.Windows.Ink.InkWordNode
System.Windows.Ink.LineNode
System.Windows.Ink.ObjectNode
System.Windows.Ink.ParagraphNode
System.Windows.Ink.RootNode
System.Windows.Ink.TextWordNode
System.Windows.Ink.UnclassifiedInkNode
System.Windows.Ink.WritingRegionNode
Thread Safety
Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
Platforms
Windows 7, Windows Vista, Windows XP SP2, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
Version Information
.NET Framework
Supported in: 3.0