Daniel Grunwald
14 years ago
3 changed files with 8 additions and 210 deletions
@ -1,171 +0,0 @@
@@ -1,171 +0,0 @@
|
||||
// Copyright (c) AlphaSierraPapa for the SharpDevelop Team (for details please see \doc\copyright.txt)
|
||||
// This code is distributed under the GNU LGPL (for details please see \doc\license.txt)
|
||||
|
||||
using System; |
||||
using System.Collections.Generic; |
||||
using System.Diagnostics; |
||||
using System.Linq; |
||||
using ICSharpCode.AvalonEdit.Utils; |
||||
using ICSharpCode.NRefactory.Editor; |
||||
|
||||
namespace ICSharpCode.AvalonEdit.Document |
||||
{ |
||||
/// <summary>
|
||||
/// <para>A checkpoint that allows tracking changes to a TextDocument.</para>
|
||||
/// <para>
|
||||
/// Use <see cref="TextDocument.CreateSnapshot(out ChangeTrackingCheckpoint)"/> to create a checkpoint.
|
||||
/// </para>
|
||||
/// </summary>
|
||||
/// <remarks>
|
||||
/// <para>The <see cref="ChangeTrackingCheckpoint"/> class allows tracking document changes, even from background threads.</para>
|
||||
/// <para>Once you have two checkpoints, you can call <see cref="ChangeTrackingCheckpoint.GetChangesTo"/> to retrieve the complete list
|
||||
/// of document changes that happened between those versions of the document.</para>
|
||||
/// </remarks>
|
||||
public sealed class ChangeTrackingCheckpoint : ITextSourceVersion |
||||
{ |
||||
static readonly ChangeTrackingCheckpoint checkpointBelongsToNoDocument = new ChangeTrackingCheckpoint(null); |
||||
|
||||
// Object that is unique per document.
|
||||
// Used to determine if two checkpoints belong to the same document.
|
||||
// We don't use a reference to the document itself to allow the GC to reclaim the document memory
|
||||
// even if there are still references to checkpoints.
|
||||
readonly object documentIdentifier; |
||||
|
||||
// 'value' is the change from the previous checkpoint to this checkpoint
|
||||
// TODO: store the change in the older checkpoint instead - if only a reference to the
|
||||
// newest document version exists, the GC should be able to collect all DocumentChangeEventArgs.
|
||||
readonly DocumentChangeEventArgs value; |
||||
readonly int id; |
||||
ChangeTrackingCheckpoint next; |
||||
|
||||
internal ChangeTrackingCheckpoint(object documentIdentifier) |
||||
{ |
||||
this.documentIdentifier = documentIdentifier; |
||||
} |
||||
|
||||
internal ChangeTrackingCheckpoint(object documentIdentifier, DocumentChangeEventArgs value, int id) |
||||
{ |
||||
this.documentIdentifier = documentIdentifier; |
||||
this.value = value; |
||||
this.id = id; |
||||
} |
||||
|
||||
internal ChangeTrackingCheckpoint Append(DocumentChangeEventArgs change) |
||||
{ |
||||
Debug.Assert(this.next == null); |
||||
this.next = new ChangeTrackingCheckpoint(this.documentIdentifier, change, unchecked( this.id + 1 )); |
||||
return this.next; |
||||
} |
||||
|
||||
/// <summary>
|
||||
/// Creates a change tracking checkpoint for the specified document.
|
||||
/// This method is thread-safe.
|
||||
/// If you need a ChangeTrackingCheckpoint that's consistent with a snapshot of the document,
|
||||
/// use <see cref="TextDocument.CreateSnapshot(out ChangeTrackingCheckpoint)"/>.
|
||||
/// </summary>
|
||||
public static ChangeTrackingCheckpoint Create(TextDocument document) |
||||
{ |
||||
if (document == null) |
||||
throw new ArgumentNullException("document"); |
||||
return document.CreateChangeTrackingCheckpoint(); |
||||
} |
||||
|
||||
/// <summary>
|
||||
/// Gets whether this checkpoint belongs to the same document as the other checkpoint.
|
||||
/// </summary>
|
||||
public bool BelongsToSameDocumentAs(ChangeTrackingCheckpoint other) |
||||
{ |
||||
if (other == null) |
||||
throw new ArgumentNullException("other"); |
||||
return documentIdentifier == other.documentIdentifier; |
||||
} |
||||
|
||||
/// <summary>
|
||||
/// Compares the age of this checkpoint to the other checkpoint.
|
||||
/// </summary>
|
||||
/// <remarks>This method is thread-safe.</remarks>
|
||||
/// <exception cref="ArgumentException">Raised if 'other' belongs to a different document than this checkpoint.</exception>
|
||||
/// <returns>-1 if this checkpoint is older than <paramref name="other"/>.
|
||||
/// 0 if <c>this</c>==<paramref name="other"/>.
|
||||
/// 1 if this checkpoint is newer than <paramref name="other"/>.</returns>
|
||||
public int CompareAge(ChangeTrackingCheckpoint other) |
||||
{ |
||||
if (other == null) |
||||
throw new ArgumentNullException("other"); |
||||
if (other.documentIdentifier != this.documentIdentifier) |
||||
throw new ArgumentException("Checkpoints do not belong to the same document."); |
||||
// We will allow overflows, but assume that the maximum distance between checkpoints is 2^31-1.
|
||||
// This is guaranteed on x86 because so many checkpoints don't fit into memory.
|
||||
return Math.Sign(unchecked( this.id - other.id )); |
||||
} |
||||
|
||||
/// <summary>
|
||||
/// Gets the changes from this checkpoint to the other checkpoint.
|
||||
/// If 'other' is older than this checkpoint, reverse changes are calculated.
|
||||
/// </summary>
|
||||
/// <remarks>This method is thread-safe.</remarks>
|
||||
/// <exception cref="ArgumentException">Raised if 'other' belongs to a different document than this checkpoint.</exception>
|
||||
public IEnumerable<DocumentChangeEventArgs> GetChangesTo(ChangeTrackingCheckpoint other) |
||||
{ |
||||
int result = CompareAge(other); |
||||
if (result < 0) |
||||
return GetForwardChanges(other); |
||||
else if (result > 0) |
||||
return other.GetForwardChanges(this).Reverse().Select(change => change.Invert()); |
||||
else |
||||
return Empty<DocumentChangeEventArgs>.Array; |
||||
} |
||||
|
||||
IEnumerable<DocumentChangeEventArgs> GetForwardChanges(ChangeTrackingCheckpoint other) |
||||
{ |
||||
// Return changes from this(exclusive) to other(inclusive).
|
||||
ChangeTrackingCheckpoint node = this; |
||||
do { |
||||
node = node.next; |
||||
yield return node.value; |
||||
} while (node != other); |
||||
} |
||||
|
||||
/// <summary>
|
||||
/// Calculates where the offset has moved in the other buffer version.
|
||||
/// </summary>
|
||||
/// <remarks>This method is thread-safe.</remarks>
|
||||
/// <exception cref="ArgumentException">Raised if 'other' belongs to a different document than this checkpoint.</exception>
|
||||
public int MoveOffsetTo(ChangeTrackingCheckpoint other, int oldOffset, AnchorMovementType movement) |
||||
{ |
||||
int offset = oldOffset; |
||||
foreach (DocumentChangeEventArgs e in GetChangesTo(other)) { |
||||
offset = e.GetNewOffset(offset, movement); |
||||
} |
||||
return offset; |
||||
} |
||||
|
||||
static ChangeTrackingCheckpoint GetCheckPoint(ITextSourceVersion version) |
||||
{ |
||||
if (version == null) |
||||
return null; |
||||
else |
||||
return version as ChangeTrackingCheckpoint ?? checkpointBelongsToNoDocument; |
||||
} |
||||
|
||||
bool ITextSourceVersion.BelongsToSameDocumentAs(ITextSourceVersion other) |
||||
{ |
||||
return BelongsToSameDocumentAs(GetCheckPoint(other)); |
||||
} |
||||
|
||||
int ITextSourceVersion.CompareAge(ITextSourceVersion other) |
||||
{ |
||||
return CompareAge(GetCheckPoint(other)); |
||||
} |
||||
|
||||
IEnumerable<TextChangeEventArgs> ITextSourceVersion.GetChangesTo(ITextSourceVersion other) |
||||
{ |
||||
return GetChangesTo(GetCheckPoint(other)); |
||||
} |
||||
|
||||
int ITextSourceVersion.MoveOffsetTo(ITextSourceVersion other, int oldOffset, AnchorMovementType movement) |
||||
{ |
||||
return MoveOffsetTo(GetCheckPoint(other), oldOffset, movement); |
||||
} |
||||
} |
||||
} |
||||
Loading…
Reference in new issue