TextPointer.GetPointerContext(LogicalDirection) Method

Definition

Namespace:

System.Windows.Documents

Assembly:

PresentationFramework.dll

Returns a category indicator for the content adjacent to the current TextPointer in the specified logical direction.

public:
 System::Windows::Documents::TextPointerContext GetPointerContext(System::Windows::Documents::LogicalDirection direction);

public System.Windows.Documents.TextPointerContext GetPointerContext (System.Windows.Documents.LogicalDirection direction);

member this.GetPointerContext : System.Windows.Documents.LogicalDirection -> System.Windows.Documents.TextPointerContext

Public Function GetPointerContext (direction As LogicalDirection) As TextPointerContext

Parameters

direction

LogicalDirection

One of the LogicalDirection values that specifies the logical direction in which to determine the category for adjacent content.

Returns

TextPointerContext

One of the TextPointerContext values that indicates the category for adjacent content in the specified logical direction.

Examples

The following example demonstrates a use for this method. The example uses the GetPointerContext method to implement an algorithm for calculating the balance of opening and closing element tags between two specified TextPointer positions. Each opening element tag is counted as +1, and each closing element tag is counted as -1.

// Calculate and return the relative balance of opening and closing element tags
// between two specified TextPointers.
int GetElementTagBalance(TextPointer start, TextPointer end)
{
    int balance = 0;
 
    while (start != null && start.CompareTo(end) < 0)
    {
        TextPointerContext forwardContext = start.GetPointerContext(LogicalDirection.Forward);
 
        if (forwardContext == TextPointerContext.ElementStart)     balance++;
        else if (forwardContext == TextPointerContext.ElementEnd)  balance--;
             
        start = start.GetNextContextPosition(LogicalDirection.Forward);
    } // End while.
 
    return balance;
} // End GetElementTagBalance

' Calculate and return the relative balance of opening and closing element tags
' between two specified TextPointers.
Private Function GetElementTagBalance(ByVal start As TextPointer, ByVal [end] As TextPointer) As Integer
    Dim balance As Integer = 0

    Do While start IsNot Nothing AndAlso start.CompareTo([end]) < 0
        Dim forwardContext As TextPointerContext = start.GetPointerContext(LogicalDirection.Forward)

        If forwardContext = TextPointerContext.ElementStart Then
            balance += 1
        ElseIf forwardContext = TextPointerContext.ElementEnd Then
            balance -= 1
        End If

        start = start.GetNextContextPosition(LogicalDirection.Forward)

    Loop ' End while.

    Return balance

End Function ' End GetElementTagBalance