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//---------------------------------------------------------------------------
//
// File: ValidationHelper.cs
//
// Copyright (C) Microsoft Corporation. All rights reserved.
//
// Description: Helpers for TOM parameter validation.
//
//---------------------------------------------------------------------------
namespace System.Windows.Documents
{
using MS.Internal; // Invariant.Assert
using System.ComponentModel;
using System.Windows;
using System.Windows.Media;
internal static class ValidationHelper
{
//------------------------------------------------------
//
// Internal Methods
//
//------------------------------------------------------
#region Internal Methods
// Verifies a TextPointer is non-null and
// is associated with a given TextContainer.
//
// Throws an appropriate exception if a test fails.
internal static void VerifyPosition(ITextContainer tree, ITextPointer position)
{
VerifyPosition(tree, position, "position");
}
// Verifies a TextPointer is non-null and is associated with a given TextContainer.
//
// Throws an appropriate exception if a test fails.
internal static void VerifyPosition(ITextContainer container, ITextPointer position, string paramName)
{
if (position == null)
{
throw new ArgumentNullException(paramName);
}
if (position.TextContainer != container)
{
throw new ArgumentException(SR.Get(SRID.NotInAssociatedTree, paramName));
}
}
// Verifies two positions are safe to use as a logical text span.
//
// Throws ArgumentNullException if startPosition == null || endPosition == null
// ArgumentException if startPosition.TextContainer != endPosition.TextContainer or
// startPosition > endPosition
internal static void VerifyPositionPair(ITextPointer startPosition, ITextPointer endPosition)
{
if (startPosition == null)
{
throw new ArgumentNullException("startPosition");
}
if (endPosition == null)
{
throw new ArgumentNullException("endPosition");
}
if (startPosition.TextContainer != endPosition.TextContainer)
{
throw new ArgumentException(SR.Get(SRID.InDifferentTextContainers, "startPosition", "endPosition"));
}
if (startPosition.CompareTo(endPosition) > 0)
{
throw new ArgumentException(SR.Get(SRID.BadTextPositionOrder, "startPosition", "endPosition"));
}
}
// Throws an ArgumentException if direction is not a valid enum.
internal static void VerifyDirection(LogicalDirection direction, string argumentName)
{
if (direction != LogicalDirection.Forward &&
direction != LogicalDirection.Backward)
{
throw new InvalidEnumArgumentException(argumentName, (int)direction, typeof(LogicalDirection));
}
}
// Throws an ArgumentException if edge is not a valid enum.
internal static void VerifyElementEdge(ElementEdge edge, string param)
{
if (edge != ElementEdge.BeforeStart &&
edge != ElementEdge.AfterStart &&
edge != ElementEdge.BeforeEnd &&
edge != ElementEdge.AfterEnd)
{
throw new InvalidEnumArgumentException(param, (int)edge, typeof(ElementEdge));
}
}
// ...............................................................
//
// TextSchema Validation
//
// ...............................................................
// Checks whether it is valid to insert the child object at passed position.
internal static void ValidateChild(TextPointer position, object child, string paramName)
{
Invariant.Assert(position != null);
if (child == null)
{
throw new ArgumentNullException(paramName);
}
if (!TextSchema.IsValidChild(/*position:*/position, /*childType:*/child.GetType()))
{
throw new ArgumentException(SR.Get(SRID.TextSchema_ChildTypeIsInvalid, position.Parent.GetType().Name, child.GetType().Name));
}
// The new child should not be currently in other text tree
if (child is TextElement)
{
if (((TextElement)child).Parent != null)
{
throw new ArgumentException(SR.Get(SRID.TextSchema_TheChildElementBelongsToAnotherTreeAlready, child.GetType().Name));
}
}
else
{
Invariant.Assert(child is UIElement);
// Cannot call UIElement.Parent across assembly boundary. So skip this part of validation. This condition will be checked elsewhere anyway.
//if (((UIElement)child).Parent != null)
//{
// throw new ArgumentException(SR.Get(SRID.TextSchema_TheChildElementBelongsToAnotherTreeAlready, child.GetType().Name));
//}
}
}
#endregion Internal methods
}
}
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