//-------------------------------------------------------------------
//
// Private Methods
//
//-------------------------------------------------------------------
#region Private Methods
// Worker for OnAdd and Add(string).
// If returnIndex == true, uses the more costly IList.Add
// to calculate and return the index of the newly inserted
// Run, otherwise returns -1.
private int AddText(string text, bool returnIndex)
{
if (text == null)
{
throw new ArgumentNullException("text");
}
// Special case for TextBlock - to keep its simple content in simple state
if (this.Parent is TextBlock)
{
TextBlock textBlock = (TextBlock)this.Parent;
if (!textBlock.HasComplexContent)
{
textBlock.Text = textBlock.Text + text;
return(0); // There's always one implicit Run with simple content, at index 0.
}
}
this.TextContainer.BeginChange();
try
{
Run implicitRun = Run.CreateImplicitRun(this.Parent);
int index;
if (returnIndex)
{
index = base.OnAdd(implicitRun);
}
else
{
this.Add(implicitRun);
index = -1;
}
// Set the Text property after inserting the Run to avoid allocating
// a temporary TextContainer.
implicitRun.Text = text;
return(index);
}
finally
{
this.TextContainer.EndChange();
}
}