StylusPlugIn.OnStylusUpProcessed(Object, Boolean) Method
Definition
Important
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Occurs on the application UI (user interface) thread when the user lifts the tablet pen from the digitizer.
protected:
virtual void OnStylusUpProcessed(System::Object ^ callbackData, bool targetVerified);protected virtual void OnStylusUpProcessed (object callbackData, bool targetVerified);abstract member OnStylusUpProcessed : obj * bool -> unit
override this.OnStylusUpProcessed : obj * bool -> unitProtected Overridable Sub OnStylusUpProcessed (callbackData As Object, targetVerified As Boolean)Parameters
- callbackData
- Object
The object that the application passed to the NotifyWhenProcessed(Object) method.
- targetVerified
- Boolean
true if the pen's input was correctly routed to the StylusPlugIn; otherwise, false.
Examples
The following example creates a StylusPlugIn that checks for the Down gesture. The StylusPlugIn checks for the gesture in the OnStylusUpProcessed method, which is called from the application UI thread.
class RecognizerPlugin : StylusPlugIn
{
GestureRecognizer recognizer;
// StylusPointCollection that contains the stylus points of the current
// stroke.
StylusPointCollection points;
// Keeps track of the stylus to check whether two styluses are used on the
// digitizer.
int currentStylus;
public RecognizerPlugin()
: base()
{
recognizer = new GestureRecognizer();
}
// Collect the points as the user draws the stroke.
protected override void OnStylusDown(RawStylusInput rawStylusInput)
{
// If points is not null, there is already a stroke taking place
// on the digitizer, so don't create a new StylusPointsCollection.
if (points == null)
{
points = new StylusPointCollection(rawStylusInput.GetStylusPoints().Description);
points.Add(rawStylusInput.GetStylusPoints());
currentStylus = rawStylusInput.StylusDeviceId;
}
}
// Collect the points as the user draws the stroke.
protected override void OnStylusMove(RawStylusInput rawStylusInput)
{
// Check whether the stylus that started the stroke is the same, and
// that the element hasn't lost focus since the stroke began.
if (points != null && currentStylus == rawStylusInput.StylusDeviceId)
{
points.Add(rawStylusInput.GetStylusPoints());
}
}
// Collect the points as the user draws the stroke.
protected override void OnStylusUp(RawStylusInput rawStylusInput)
{
// Check whether the stylus that started the stroke is the same, and
// that the element hasn't lost focus since the stroke began.
if (points != null && currentStylus == rawStylusInput.StylusDeviceId)
{
points.Add(rawStylusInput.GetStylusPoints());
// Subscribe to the OnStylusUpProcessed method.
rawStylusInput.NotifyWhenProcessed(points);
}
points = null;
currentStylus = 0;
}
// If the element loses focus, stop collecting the points and don't
// perform gesture recognition.
protected override void OnStylusLeave(RawStylusInput rawStylusInput, bool confirmed)
{
if (confirmed)
{
// Clear the StylusPointCollection
points = null;
currentStylus = 0;
}
}
// This method is called on the application thread.
protected override void OnStylusUpProcessed(object callbackData, bool targetVerified)
{
// Check that the element actually receive the OnStylusUp input.
if (targetVerified && recognizer.IsRecognizerAvailable)
{
StylusPointCollection strokePoints = callbackData as StylusPointCollection;
if (strokePoints == null)
{
return;
}
// Create a StrokeCollection to pass to the GestureRecognizer.
Stroke newStroke = new Stroke(strokePoints);
StrokeCollection strokes = new StrokeCollection();
strokes.Add(newStroke);
ReadOnlyCollection<GestureRecognitionResult> results = recognizer.Recognize(strokes);
// If the GestureRecognizer recognizes the stroke as a Down
// gesture with strong confidence, raise an event.
if (results[0].ApplicationGesture == ApplicationGesture.Down &&
results[0].RecognitionConfidence == RecognitionConfidence.Strong)
{
//raise event
}
}
}
}
Class RecognizerPlugin
Inherits StylusPlugIn
Private recognizer As GestureRecognizer
' StylusPointCollection that contains the stylus points of the current
' stroke.
Private points As StylusPointCollection
' Keeps track of the stylus to check whether two styluses are used on the
' digitizer.
Private currentStylus As Integer
Public Sub New()
recognizer = New GestureRecognizer()
End Sub
' Collect the points as the user draws the stroke.
Protected Overrides Sub OnStylusDown(ByVal rawStylusInput As RawStylusInput)
' If points is not null, there is already a stroke taking place
' on the digitizer, so don't create a new StylusPointsCollection.
If points Is Nothing Then
points = New StylusPointCollection(rawStylusInput.GetStylusPoints().Description)
points.Add(rawStylusInput.GetStylusPoints())
currentStylus = rawStylusInput.StylusDeviceId
End If
End Sub
' Collect the points as the user draws the stroke.
Protected Overrides Sub OnStylusMove(ByVal rawStylusInput As RawStylusInput)
' Check whether the stylus that started the stroke is the same, and
' that the element hasn't lost focus since the stroke began.
If Not (points Is Nothing) AndAlso currentStylus = rawStylusInput.StylusDeviceId Then
points.Add(rawStylusInput.GetStylusPoints())
End If
End Sub
' Collect the points as the user draws the stroke.
Protected Overrides Sub OnStylusUp(ByVal rawStylusInput As RawStylusInput)
' Check whether the stylus that started the stroke is the same, and
' that the element hasn't lost focus since the stroke began.
If Not (points Is Nothing) AndAlso currentStylus = rawStylusInput.StylusDeviceId Then
points.Add(rawStylusInput.GetStylusPoints())
' Subscribe to the OnStylusUpProcessed method.
rawStylusInput.NotifyWhenProcessed(points)
End If
points = Nothing
currentStylus = 0
End Sub
' If the element loses focus, stop collecting the points and don't
' perform gesture recognition.
Protected Overrides Sub OnStylusLeave(ByVal rawStylusInput As RawStylusInput, ByVal confirmed As Boolean)
If confirmed Then
' Clear the StylusPointCollection
points = Nothing
currentStylus = 0
End If
End Sub
' This method is called on the application thread.
Protected Overrides Sub OnStylusUpProcessed(ByVal callbackData As Object, ByVal targetVerified As Boolean)
' Check that the element actually receive the OnStylusUp input.
If targetVerified AndAlso recognizer.IsRecognizerAvailable Then
Dim strokePoints As StylusPointCollection = callbackData
If strokePoints Is Nothing Then
Return
End If
' Create a StrokeCollection to pass to the GestureRecognizer.
Dim newStroke As New Stroke(strokePoints)
Dim strokes As New StrokeCollection()
strokes.Add(newStroke)
Dim results As ReadOnlyCollection(Of GestureRecognitionResult) = recognizer.Recognize(strokes)
' If the GestureRecognizer recognizes the stroke as a Down
' gesture with strong confidence, raise an event.
If results(0).ApplicationGesture = ApplicationGesture.Down AndAlso _
results(0).RecognitionConfidence = RecognitionConfidence.Strong Then
'raise event
End If
End If
End Sub
End Class
Remarks
To subscribe to this method, call NotifyWhenProcessed in the OnStylusUp method
