/// <summary>
/// Initializes a new instance of a <see cref="NormalizedSnapshotSpanCollection"/> from a list of <see cref="SnapshotSpan"/> objects.
/// </summary>
/// <param name="snapshotSpans">An arbitrary set of <see cref="SnapshotSpan"/> objects.</param>
/// <exception cref="ArgumentNullException"><paramref name="snapshotSpans"/> is null.</exception>
/// <exception cref="ArgumentException">A <see cref="SnapshotSpan"/> is uninitialized, or it
/// does not refer to the same <see cref="ITextSnapshot"/> as the other snapshot spans, or it refers to an uninitialized <see cref="ITextSnapshot"/>.</exception>
public NormalizedSnapshotSpanCollection(IList <SnapshotSpan> snapshotSpans)
{
// TODO: possibly eliminate based on slight usage?
if (snapshotSpans == null)
{
throw new ArgumentNullException(nameof(snapshotSpans));
}
if (snapshotSpans.Count == 0)
{
// empty collection
}
else
{
this.snapshot = snapshotSpans[0].Snapshot;
if (this.snapshot == null)
{
throw new ArgumentException(Strings.UninitializedSnapshotSpan);
}
if (snapshotSpans.Count == 1)
{
// length one
this.span = snapshotSpans[0].Span;
}
else
{
// length at least two
bool alreadyNormalized = true;
List <Span> spans = new List <Span>(snapshotSpans.Count);
Span currentSpan = snapshotSpans[0].Span;
spans.Add(currentSpan);
int lastEnd = currentSpan.End;
for (int s = 1; s < snapshotSpans.Count; ++s)
{
if (snapshotSpans[s].Snapshot != this.snapshot)
{
if (snapshotSpans[s].Snapshot == null)
{
throw new ArgumentException(Strings.UninitializedSnapshotSpan);
}
else
{
throw new ArgumentException(Strings.InvalidSnapshot);
}
}
currentSpan = snapshotSpans[s].Span;
spans.Add(currentSpan);
if (currentSpan.Start <= lastEnd)
{
alreadyNormalized = false;
}
lastEnd = currentSpan.End;
}
this.spans = alreadyNormalized
? NormalizedSpanCollection.CreateFromNormalizedSpans(spans)
: new NormalizedSpanCollection(spans);
}
}
}
/// <summary>
/// Initializes a new instance of a <see cref="NormalizedSnapshotSpanCollection"/> from a list of <see cref="SnapshotSpan"/> objects.
/// </summary>
/// <param name="snapshotSpans">An arbitrary set of <see cref="SnapshotSpan"/> objects.</param>
/// <exception cref="ArgumentNullException"><paramref name="snapshotSpans"/> is null.</exception>
/// <exception cref="ArgumentException">A <see cref="SnapshotSpan"/> is uninitialized, or it
/// does not refer to the same <see cref="ITextSnapshot"/> as the other snapshot spans, or it refers to an uninitialized <see cref="ITextSnapshot"/>.</exception>
public NormalizedSnapshotSpanCollection(IEnumerable <SnapshotSpan> snapshotSpans)
{
if (snapshotSpans == null)
{
throw new ArgumentNullException(nameof(snapshotSpans));
}
using (IEnumerator <SnapshotSpan> spanEnumerator = snapshotSpans.GetEnumerator())
{
if (!spanEnumerator.MoveNext())
{
// empty
}
else
{
SnapshotSpan firstSpan = spanEnumerator.Current;
this.snapshot = firstSpan.Snapshot;
if (!spanEnumerator.MoveNext())
{
// length one
this.span = firstSpan.Span;
}
else
{
// length at least two
bool alreadyNormalized = true;
List <Span> spans = new List <Span>();
Span currentSpan = firstSpan.Span;
spans.Add(currentSpan);
int lastEnd = currentSpan.End;
do
{
SnapshotSpan snapshotSpan = spanEnumerator.Current;
if (snapshotSpan.Snapshot != this.snapshot)
{
if (snapshotSpan.Snapshot == null)
{
throw new ArgumentException(Strings.UninitializedSnapshotSpan);
}
else
{
throw new ArgumentException(Strings.InvalidSnapshot);
}
}
currentSpan = snapshotSpan.Span;
spans.Add(currentSpan);
if (currentSpan.Start <= lastEnd)
{
alreadyNormalized = false;
}
lastEnd = currentSpan.End;
} while (spanEnumerator.MoveNext());
this.spans = alreadyNormalized
? NormalizedSpanCollection.CreateFromNormalizedSpans(spans)
: new NormalizedSpanCollection(spans);
}
}
}
}