// Copyright (c) 2014 AlphaSierraPapa for the SharpDevelop Team
//
// Permission is hereby granted, free of charge, to any person obtaining a copy of this
// software and associated documentation files (the "Software"), to deal in the Software
// without restriction, including without limitation the rights to use, copy, modify, merge,
// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
// to whom the Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all copies or
// substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Diagnostics;
using System.Diagnostics.CodeAnalysis;
using System.Globalization;
using System.IO;
using System.Threading;
using Unity.CodeEditor.Utils;
namespace Unity.CodeEditor.Document
{
/// <summary>
/// This class is the main class of the text model. Basically, it is a <see cref="System.Text.StringBuilder"/> with events.
/// </summary>
/// <remarks>
/// <b>Thread safety:</b>
/// <inheritdoc cref="VerifyAccess"/>
/// <para>However, there is a single method that is thread-safe: <see cref="CreateSnapshot()"/> (and its overloads).</para>
/// </remarks>
internal sealed class TextDocument : IDocument, INotifyPropertyChanged
{
#region Thread ownership
private readonly object _lockObject = new object();
#endregion
#region Fields + Constructor
private readonly Rope<char> _rope;
private readonly DocumentLineTree _lineTree;
private readonly LineManager _lineManager;
private readonly TextAnchorTree _anchorTree;
private readonly TextSourceVersionProvider _versionProvider = new TextSourceVersionProvider();
/// <summary>
/// Create an empty text document.
/// </summary>
internal TextDocument()
: this(string.Empty.ToCharArray())
{
}
/// <summary>
/// Create a new text document with the specified initial text.
/// </summary>
internal TextDocument(IEnumerable<char> initialText)
{
if (initialText == null)
throw new ArgumentNullException(nameof(initialText));
_rope = new Rope<char>(initialText);
_lineTree = new DocumentLineTree(this);
_lineManager = new LineManager(_lineTree, this);
_lineTrackers.CollectionChanged += delegate
{
_lineManager.UpdateListOfLineTrackers();
};
_anchorTree = new TextAnchorTree(this);
_undoStack = new UndoStack();
FireChangeEvents();
}
/// <summary>
/// Create a new text document with the specified initial text.
/// </summary>
internal TextDocument(ITextSource initialText)
: this(GetTextFromTextSource(initialText))
{
}
// gets the text from a text source, directly retrieving the underlying rope where possible
private static IEnumerable<char> GetTextFromTextSource(ITextSource textSource)
{
if (textSource == null)
throw new ArgumentNullException(nameof(textSource));
if (textSource is RopeTextSource rts)
{
return rts.GetRope();
}
if (textSource is TextDocument doc)
{
return doc._rope;
}
return textSource.Text.ToCharArray();
}
#endregion
#region Text
private void ThrowIfRangeInvalid(int offset, int length)
{
if (offset < 0 || offset > _rope.Length)
{
throw new ArgumentOutOfRangeException(nameof(offset), offset, "0 <= offset <= " + _rope.Length.ToString(CultureInfo.InvariantCulture));
}
if (length < 0 || offset + length > _rope.Length)
{
throw new ArgumentOutOfRangeException(nameof(length), length, "0 <= length, offset(" + offset + ")+length <= " + _rope.Length.ToString(CultureInfo.InvariantCulture));
}
}
/// <inheritdoc/>
public string GetText(int offset, int length)
{
VerifyAccess();
return _rope.ToString(offset, length);
}
/// <inheritdoc/>
public ReadOnlyMemory<char> GetTextAsMemory(int offset, int length)
{
VerifyAccess();
return _rope.GetMemory(offset, length);
}
private Thread ownerThread = Thread.CurrentThread;
/// <summary>
/// Transfers ownership of the document to another thread.
/// </summary>
/// <remarks>
/// <para>
/// The owner can be set to null, which means that no thread can access the document. But, if the document
/// has no owner thread, any thread may take ownership by calling <see cref="SetOwnerThread"/>.
/// </para>
/// </remarks>
internal void SetOwnerThread(Thread newOwner)
{
// We need to lock here to ensure that in the null owner case,
// only one thread succeeds in taking ownership.
lock (_lockObject) {
if (ownerThread != null) {
VerifyAccess();
}
ownerThread = newOwner;
}
}
private void VerifyAccess()
{
if(Thread.CurrentThread != ownerThread)
{
throw new InvalidOperationException("Call from invalid thread.");
}
}
/// <summary>
/// Retrieves the text for a portion of the document.
/// </summary>
public string GetText(ISegment segment)
{
if (segment == null)
throw new ArgumentNullException(nameof(segment));
return GetText(segment.Offset, segment.Length);
}
/// <inheritdoc/>
public int IndexOf(char c, int startIndex, int count)
{
DebugVerifyAccess();
return _rope.IndexOf(c, startIndex, count);
}
/// <inheritdoc/>
public int LastIndexOf(char c, int startIndex, int count)
{
DebugVerifyAccess();
return _rope.LastIndexOf(c, startIndex, count);
}
/// <inheritdoc/>
public int IndexOfAny(char[] anyOf, int startIndex, int count)
{
DebugVerifyAccess(); // frequently called (NewLineFinder), so must be fast in release builds
return _rope.IndexOfAny(anyOf, startIndex, count);
}
/// <inheritdoc/>
public int IndexOf(string searchText, int startIndex, int count, StringComparison comparisonType)
{
DebugVerifyAccess();
return _rope.IndexOf(searchText, startIndex, count, comparisonType);
}
/// <inheritdoc/>
public int LastIndexOf(string searchText, int startIndex, int count, StringComparison comparisonType)
{
DebugVerifyAccess();
return _rope.LastIndexOf(searchText, startIndex, count, comparisonType);
}
/// <inheritdoc/>
public char GetCharAt(int offset)
{
DebugVerifyAccess(); // frequently called, so must be fast in release builds
return _rope[offset];
}
private WeakReference _cachedText;
/// <summary>
/// Gets/Sets the text of the whole document.
/// </summary>
public string Text
{
get
{
VerifyAccess();
var completeText = _cachedText?.Target as string;
if (completeText == null)
{
completeText = _rope.ToString();
_cachedText = new WeakReference(completeText);
}
return completeText;
}
set
{
VerifyAccess();
if (value == null)
throw new ArgumentNullException(nameof(value));
Replace(0, _rope.Length, value);
}
}
/// <summary>
/// This event is called after a group of changes is completed.
/// </summary>
/// <remarks><inheritdoc cref="Changing"/></remarks>
public event EventHandler TextChanged;
event EventHandler IDocument.ChangeCompleted
{
add => TextChanged += value;
remove => TextChanged -= value;
}
/// <inheritdoc/>
public int TextLength
{
get
{
VerifyAccess();
return _rope.Length;
}
}
/// <summary>
/// Is raised when the TextLength property changes.
/// </summary>
/// <remarks><inheritdoc cref="Changing"/></remarks>
internal event EventHandler TextLengthChanged;
/// <summary>
/// Is raised before the document changes.
/// </summary>
/// <remarks>
/// <para>Here is the order in which events are raised during a document update:</para>
/// <list type="bullet">
/// <item><description><b><see cref="BeginUpdate">BeginUpdate()</see></b></description>
/// <list type="bullet">
/// <item><description>Start of change group (on undo stack)</description></item>
/// <item><description><see cref="UpdateStarted"/> event is raised</description></item>
/// </list></item>
/// <item><description><b><see cref="Insert(int,string)">Insert()</see> / <see cref="Remove(int,int)">Remove()</see> / <see cref="Replace(int,int,string)">Replace()</see></b></description>
/// <list type="bullet">
/// <item><description><see cref="Changing"/> event is raised</description></item>
/// <item><description>The document is changed</description></item>
/// <item><description><see cref="TextAnchor.Deleted">TextAnchor.Deleted</see> event is raised if anchors were
/// in the deleted text portion</description></item>
/// <item><description><see cref="Changed"/> event is raised</description></item>
/// </list></item>
/// <item><description><b><see cref="EndUpdate">EndUpdate()</see></b></description>
/// <list type="bullet">
/// <item><description><see cref="TextChanged"/> event is raised</description></item>
/// <item><description><see cref="PropertyChanged"/> event is raised (for the Text, TextLength, LineCount properties, in that order)</description></item>
/// <item><description>End of change group (on undo stack)</description></item>
/// <item><description><see cref="UpdateFinished"/> event is raised</description></item>
/// </list></item>
/// </list>
/// <para>
/// If the insert/remove/replace methods are called without a call to <c>BeginUpdate()</c>,
/// they will call <c>BeginUpdate()</c> and <c>EndUpdate()</c> to ensure no change happens outside of <c>UpdateStarted</c>/<c>UpdateFinished</c>.
/// </para><para>
/// There can be multiple document changes between the <c>BeginUpdate()</c> and <c>EndUpdate()</c> calls.
/// In this case, the events associated with EndUpdate will be raised only once after the whole document update is done.
/// </para><para>
/// The <see cref="UndoStack"/> listens to the <c>UpdateStarted</c> and <c>UpdateFinished</c> events to group all changes into a single undo step.
/// </para>
/// </remarks>
internal event EventHandler<DocumentChangeEventArgs> Changing;
// Unfortunately EventHandler<T> is invariant, so we have to use two separate events
private event EventHandler<TextChangeEventArgs> TextChangingInternal;
event EventHandler<TextChangeEventArgs> IDocument.TextChanging
{
add => TextChangingInternal += value;
remove => TextChangingInternal -= value;
}
/// <summary>
/// Is raised after the document has changed.
/// </summary>
/// <remarks><inheritdoc cref="Changing"/></remarks>
internal event EventHandler<DocumentChangeEventArgs> Changed;
private event EventHandler<TextChangeEventArgs> TextChangedInternal;
event EventHandler<TextChangeEventArgs> IDocument.TextChanged
{
add => TextChangedInternal += value;
remove => TextChangedInternal -= value;
}
/// <summary>
/// Creates a snapshot of the current text.
/// </summary>
/// <remarks>
/// <para>This method returns an immutable snapshot of the document, and may be safely called even when
/// the document's owner thread is concurrently modifying the document.
/// </para><para>
/// This special thread-safety guarantee is valid only for TextDocument.CreateSnapshot(), not necessarily for other
/// classes implementing ITextSource.CreateSnapshot().
/// </para><para>
/// </para>
/// </remarks>
public ITextSource CreateSnapshot()
{
lock (_lockObject)
{
return new RopeTextSource(_rope, _versionProvider.CurrentVersion);
}
}
/// <summary>
/// Creates a snapshot of a part of the current text.
/// </summary>
/// <remarks><inheritdoc cref="CreateSnapshot()"/></remarks>
public ITextSource CreateSnapshot(int offset, int length)
{
lock (_lockObject)
{
return new RopeTextSource(_rope.GetRange(offset, length));
}
}
/// <inheritdoc/>
public ITextSourceVersion Version => _versionProvider.CurrentVersion;
/// <inheritdoc/>
public TextReader CreateReader()
{
lock (_lockObject)
{
return new RopeTextReader(_rope);
}
}
/// <inheritdoc/>
public TextReader CreateReader(int offset, int length)
{
lock (_lockObject)
{
return new RopeTextReader(_rope.GetRange(offset, length));
}
}
/// <inheritdoc/>
public void WriteTextTo(TextWriter writer)
{
VerifyAccess();
_rope.WriteTo(writer, 0, _rope.Length);
}
/// <inheritdoc/>
public void WriteTextTo(TextWriter writer, int offset, int length)
{
VerifyAccess();
_rope.WriteTo(writer, offset, length);
}
private void OnPropertyChanged(string propertyName)
{
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
public event PropertyChangedEventHandler PropertyChanged;
#endregion
#region BeginUpdate / EndUpdate
private int _beginUpdateCount;
/// <summary>
/// Gets if an update is running.
/// </summary>
/// <remarks><inheritdoc cref="BeginUpdate"/></remarks>
internal bool IsInUpdate
{
get
{
VerifyAccess();
return _beginUpdateCount > 0;
}
}
/// <summary>
/// Immediately calls <see cref="BeginUpdate()"/>,
/// and returns an IDisposable that calls <see cref="EndUpdate()"/>.
/// </summary>
/// <remarks><inheritdoc cref="BeginUpdate"/></remarks>
internal IDisposable RunUpdate()
{
BeginUpdate();
return new CallbackOnDispose(EndUpdate);
}
/// <summary>
/// <para>Begins a group of document changes.</para>
/// <para>Some events are suspended until EndUpdate is called, and the <see cref="UndoStack"/> will
/// group all changes into a single action.</para>
/// <para>Calling BeginUpdate several times increments a counter, only after the appropriate number
/// of EndUpdate calls the events resume their work.</para>
/// </summary>
/// <remarks><inheritdoc cref="Changing"/></remarks>
internal void BeginUpdate()
{
VerifyAccess();
if (InDocumentChanging)
throw new InvalidOperationException("Cannot change document within another document change.");
_beginUpdateCount++;
if (_beginUpdateCount == 1)
{
_undoStack.StartUndoGroup();
UpdateStarted?.Invoke(this, EventArgs.Empty);
}
}
/// <summary>
/// Ends a group of document changes.
/// </summary>
/// <remarks><inheritdoc cref="Changing"/></remarks>
internal void EndUpdate()
{
VerifyAccess();
if (InDocumentChanging)
throw new InvalidOperationException("Cannot end update within document change.");
if (_beginUpdateCount == 0)
throw new InvalidOperationException("No update is active.");
if (_beginUpdateCount == 1)
{
// fire change events inside the change group - event handlers might add additional
// document changes to the change group
FireChangeEvents();
_undoStack.EndUndoGroup();
_beginUpdateCount = 0;
UpdateFinished?.Invoke(this, EventArgs.Empty);
}
else
{
_beginUpdateCount -= 1;
}
}
/// <summary>
/// Occurs when a document change starts.
/// </summary>
/// <remarks><inheritdoc cref="Changing"/></remarks>
internal event EventHandler UpdateStarted;
/// <summary>
/// Occurs when a document change is finished.
/// </summary>
/// <remarks><inheritdoc cref="Changing"/></remarks>
internal event EventHandler UpdateFinished;
void IDocument.StartUndoableAction()
{
BeginUpdate();
}
void IDocument.EndUndoableAction()
{
EndUpdate();
}
IDisposable IDocument.OpenUndoGroup()
{
return RunUpdate();
}
#endregion
#region Fire events after update
private int _oldTextLength;
private int _oldLineCount;
private bool _fireTextChanged;
/// <summary>
/// Fires TextChanged, TextLengthChanged, LineCountChanged if required.
/// </summary>
internal void FireChangeEvents()
{
// it may be necessary to fire the event multiple times if the document is changed
// from inside the event handlers
while (_fireTextChanged)
{
_fireTextChanged = false;
TextChanged?.Invoke(this, EventArgs.Empty);
OnPropertyChanged("Text");
var textLength = _rope.Length;
if (textLength != _oldTextLength)
{
_oldTextLength = textLength;
TextLengthChanged?.Invoke(this, EventArgs.Empty);
OnPropertyChanged("TextLength");
}
var lineCount = _lineTree.LineCount;
if (lineCount != _oldLineCount)
{
_oldLineCount = lineCount;
LineCountChanged?.Invoke(this, EventArgs.Empty);
OnPropertyChanged("LineCount");
}
}
}
#endregion
#region Insert / Remove / Replace
/// <summary>
/// Inserts text.
/// </summary>
/// <param name="offset">The offset at which the text is inserted.</param>
/// <param name="text">The new text.</param>
/// <remarks>
/// Anchors positioned exactly at the insertion offset will move according to their movement type.
/// For AnchorMovementType.Default, they will move behind the inserted text.
/// The caret will also move behind the inserted text.
/// </remarks>
public void Insert(int offset, string text)
{
Replace(offset, 0, new StringTextSource(text), null);
}
/// <summary>
/// Inserts text.
/// </summary>
/// <param name="offset">The offset at which the text is inserted.</param>
/// <param name="text">The new text.</param>
/// <remarks>
/// Anchors positioned exactly at the insertion offset will move according to their movement type.
/// For AnchorMovementType.Default, they will move behind the inserted text.
/// The caret will also move behind the inserted text.
/// </remarks>
public void Insert(int offset, ITextSource text)
{
Replace(offset, 0, text, null);
}
/// <summary>
/// Inserts text.
/// </summary>
/// <param name="offset">The offset at which the text is inserted.</param>
/// <param name="text">The new text.</param>
/// <param name="defaultAnchorMovementType">
/// Anchors positioned exactly at the insertion offset will move according to the anchor's movement type.
/// For AnchorMovementType.Default, they will move according to the movement type specified by this parameter.
/// The caret will also move according to the <paramref name="defaultAnchorMovementType"/> parameter.
/// </param>
public void Insert(int offset, string text, AnchorMovementType defaultAnchorMovementType)
{
if (defaultAnchorMovementType == AnchorMovementType.BeforeInsertion)
{
Replace(offset, 0, new StringTextSource(text), OffsetChangeMappingType.KeepAnchorBeforeInsertion);
}
else
{
Replace(offset, 0, new StringTextSource(text), null);
}
}
/// <summary>
/// Inserts text.
/// </summary>
/// <param name="offset">The offset at which the text is inserted.</param>
/// <param name="text">The new text.</param>
/// <param name="defaultAnchorMovementType">
/// Anchors positioned exactly at the insertion offset will move according to the anchor's movement type.
/// For AnchorMovementType.Default, they will move according to the movement type specified by this parameter.
/// The caret will also move according to the <paramref name="defaultAnchorMovementType"/> parameter.
/// </param>
public void Insert(int offset, ITextSource text, AnchorMovementType defaultAnchorMovementType)
{
if (defaultAnchorMovementType == AnchorMovementType.BeforeInsertion)
{
Replace(offset, 0, text, OffsetChangeMappingType.KeepAnchorBeforeInsertion);
}
else
{
Replace(offset, 0, text, null);
}
}
/// <summary>
/// Removes text.
/// </summary>
public void Remove(ISegment segment)
{
Replace(segment, string.Empty);
}
/// <summary>
/// Removes text.
/// </summary>
/// <param name="offset">Starting offset of the text to be removed.</param>
/// <param name="length">Length of the text to be removed.</param>
public void Remove(int offset, int length)
{
Replace(offset, length, StringTextSource.Empty);
}
internal bool InDocumentChanging;
/// <summary>
/// Replaces text.
/// </summary>
public void Replace(ISegment segment, string text)
{
if (segment == null)
throw new ArgumentNullException(nameof(segment));
Replace(segment.Offset, segment.Length, new StringTextSource(text), null);
}
/// <summary>
/// Replaces text.
/// </summary>
public void Replace(ISegment segment, ITextSource text)
{
if (segment == null)
throw new ArgumentNullException(nameof(segment));
Replace(segment.Offset, segment.Length, text, null);
}
/// <summary>
/// Replaces text.
/// </summary>
/// <param name="offset">The starting offset of the text to be replaced.</param>
/// <param name="length">The length of the text to be replaced.</param>
/// <param name="text">The new text.</param>
public void Replace(int offset, int length, string text)
{
Replace(offset, length, new StringTextSource(text), null);
}
/// <summary>
/// Replaces text.
/// </summary>
/// <param name="offset">The starting offset of the text to be replaced.</param>
/// <param name="length">The length of the text to be replaced.</param>
/// <param name="text">The new text.</param>
public void Replace(int offset, int length, ITextSource text)
{
Replace(offset, length, text, null);
}
/// <summary>
/// Replaces text.
/// </summary>
/// <param name="offset">The starting offset of the text to be replaced.</param>
/// <param name="length">The length of the text to be replaced.</param>
/// <param name="text">The new text.</param>
/// <param name="offsetChangeMappingType">The offsetChangeMappingType determines how offsets inside the old text are mapped to the new text.
/// This affects how the anchors and segments inside the replaced region behave.</param>
public void Replace(int offset, int length, string text, OffsetChangeMappingType offsetChangeMappingType)
{
Replace(offset, length, new StringTextSource(text), offsetChangeMappingType);
}
/// <summary>
/// Replaces text.
/// </summary>
/// <param name="offset">The starting offset of the text to be replaced.</param>
/// <param name="length">The length of the text to be replaced.</param>
/// <param name="text">The new text.</param>
/// <param name="offsetChangeMappingType">The offsetChangeMappingType determines how offsets inside the old text are mapped to the new text.
/// This affects how the anchors and segments inside the replaced region behave.</param>
public void Replace(int offset, int length, ITextSource text, OffsetChangeMappingType offsetChangeMappingType)
{
if (text == null)
throw new ArgumentNullException(nameof(text));
// Please see OffsetChangeMappingType XML comments for details on how these modes work.
switch (offsetChangeMappingType)
{
case OffsetChangeMappingType.Normal:
Replace(offset, length, text, null);
break;
case OffsetChangeMappingType.KeepAnchorBeforeInsertion:
Replace(offset, length, text, OffsetChangeMap.FromSingleElement(
new OffsetChangeMapEntry(offset, length, text.TextLength, false, true)));
break;
case OffsetChangeMappingType.RemoveAndInsert:
if (length == 0 || text.TextLength == 0)
{
// only insertion or only removal?
// OffsetChangeMappingType doesn't matter, just use Normal.
Replace(offset, length, text, null);
}
else
{
var map = new OffsetChangeMap(2)
{
new OffsetChangeMapEntry(offset, length, 0),
new OffsetChangeMapEntry(offset, 0, text.TextLength)
};
map.Freeze();
Replace(offset, length, text, map);
}
break;
case OffsetChangeMappingType.CharacterReplace:
if (length == 0 || text.TextLength == 0)
{
// only insertion or only removal?
// OffsetChangeMappingType doesn't matter, just use Normal.
Replace(offset, length, text, null);
}
else if (text.TextLength > length)
{
// look at OffsetChangeMappingType.CharacterReplace XML comments on why we need to replace
// the last character
var entry = new OffsetChangeMapEntry(offset + length - 1, 1, 1 + text.TextLength - length);
Replace(offset, length, text, OffsetChangeMap.FromSingleElement(entry));
}
else if (text.TextLength < length)
{
var entry = new OffsetChangeMapEntry(offset + text.TextLength, length - text.TextLength, 0, true, false);
Replace(offset, length, text, OffsetChangeMap.FromSingleElement(entry));
}
else
{
Replace(offset, length, text, OffsetChangeMap.Empty);
}
break;
default:
throw new ArgumentOutOfRangeException(nameof(offsetChangeMappingType), offsetChangeMappingType, "Invalid enum value");
}
}
/// <summary>
/// Replaces text.
/// </summary>
/// <param name="offset">The starting offset of the text to be replaced.</param>
/// <param name="length">The length of the text to be replaced.</param>
/// <param name="text">The new text.</param>
/// <param name="offsetChangeMap">The offsetChangeMap determines how offsets inside the old text are mapped to the new text.
/// This affects how the anchors and segments inside the replaced region behave.
/// If you pass null (the default when using one of the other overloads), the offsets are changed as
/// in OffsetChangeMappingType.Normal mode.
/// If you pass OffsetChangeMap.Empty, then everything will stay in its old place (OffsetChangeMappingType.CharacterReplace mode).
/// The offsetChangeMap must be a valid 'explanation' for the document change. See <see cref="OffsetChangeMap.IsValidForDocumentChange"/>.
/// Passing an OffsetChangeMap to the Replace method will automatically freeze it to ensure the thread safety of the resulting
/// DocumentChangeEventArgs instance.
/// </param>
public void Replace(int offset, int length, string text, OffsetChangeMap offsetChangeMap)
{
Replace(offset, length, new StringTextSource(text), offsetChangeMap);
}
/// <summary>
/// Replaces text.
/// </summary>
/// <param name="offset">The starting offset of the text to be replaced.</param>
/// <param name="length">The length of the text to be replaced.</param>
/// <param name="text">The new text.</param>
/// <param name="offsetChangeMap">The offsetChangeMap determines how offsets inside the old text are mapped to the new text.
/// This affects how the anchors and segments inside the replaced region behave.
/// If you pass null (the default when using one of the other overloads), the offsets are changed as
/// in OffsetChangeMappingType.Normal mode.
/// If you pass OffsetChangeMap.Empty, then everything will stay in its old place (OffsetChangeMappingType.CharacterReplace mode).
/// The offsetChangeMap must be a valid 'explanation' for the document change. See <see cref="OffsetChangeMap.IsValidForDocumentChange"/>.
/// Passing an OffsetChangeMap to the Replace method will automatically freeze it to ensure the thread safety of the resulting
/// DocumentChangeEventArgs instance.
/// </param>
public void Replace(int offset, int length, ITextSource text, OffsetChangeMap offsetChangeMap)
{
text = text?.CreateSnapshot() ?? throw new ArgumentNullException(nameof(text));
offsetChangeMap?.Freeze();
// Ensure that all changes take place inside an update group.
// Will also take care of throwing an exception if inDocumentChanging is set.
BeginUpdate();
try
{
// protect document change against corruption by other changes inside the event handlers
InDocumentChanging = true;
try
{
// The range verification must wait until after the BeginUpdate() call because the document
// might be modified inside the UpdateStarted event.
ThrowIfRangeInvalid(offset, length);
DoReplace(offset, length, text, offsetChangeMap);
}
finally
{
InDocumentChanging = false;
}
}
finally
{
EndUpdate();
}
}
private void DoReplace(int offset, int length, ITextSource newText, OffsetChangeMap offsetChangeMap)
{
if (length == 0 && newText.TextLength == 0)
return;
// trying to replace a single character in 'Normal' mode?
// for single characters, 'CharacterReplace' mode is equivalent, but more performant
// (we don't have to touch the anchorTree at all in 'CharacterReplace' mode)
if (length == 1 && newText.TextLength == 1 && offsetChangeMap == null)
offsetChangeMap = OffsetChangeMap.Empty;
ITextSource removedText;
if (length == 0)
{
removedText = StringTextSource.Empty;
}
else if (length < 100)
{
removedText = new StringTextSource(_rope.ToString(offset, length));
}
else
{
// use a rope if the removed string is long
removedText = new RopeTextSource(_rope.GetRange(offset, length));
}
var args = new DocumentChangeEventArgs(offset, removedText, newText, offsetChangeMap);
// fire DocumentChanging event
Changing?.Invoke(this, args);
TextChangingInternal?.Invoke(this, args);
_undoStack.Push(this, args);
_cachedText = null; // reset cache of complete document text
_fireTextChanged = true;
var delayedEvents = new DelayedEvents();
lock (_lockObject)
{
// create linked list of checkpoints
_versionProvider.AppendChange(args);
// now update the textBuffer and lineTree
if (offset == 0 && length == _rope.Length)
{
// optimize replacing the whole document
_rope.Clear();
if (newText is RopeTextSource newRopeTextSource)
_rope.InsertRange(0, newRopeTextSource.GetRope());
else
_rope.InsertText(0, newText.Text);
_lineManager.Rebuild();
}
else
{
_rope.RemoveRange(offset, length);
_lineManager.Remove(offset, length);
#if DEBUG
_lineTree.CheckProperties();
#endif
if (newText is RopeTextSource newRopeTextSource)
_rope.InsertRange(offset, newRopeTextSource.GetRope());
else
_rope.InsertText(offset, newText.Text);
_lineManager.Insert(offset, newText);
#if DEBUG
_lineTree.CheckProperties();
#endif
}
}
// update text anchors
if (offsetChangeMap == null)
{
_anchorTree.HandleTextChange(args.CreateSingleChangeMapEntry(), delayedEvents);
}
else
{
foreach (var entry in offsetChangeMap)
{
_anchorTree.HandleTextChange(entry, delayedEvents);
}
}
_lineManager.ChangeComplete(args);
// raise delayed events after our data structures are consistent again
delayedEvents.RaiseEvents();
// fire DocumentChanged event
Changed?.Invoke(this, args);
TextChangedInternal?.Invoke(this, args);
}
#endregion
#region GetLineBy...
/// <summary>
/// Gets a read-only list of lines.
/// </summary>
/// <remarks><inheritdoc cref="DocumentLine"/></remarks>
internal IList<DocumentLine> Lines => _lineTree;
/// <summary>
/// Gets a line by the line number: O(log n)
/// </summary>
public DocumentLine GetLineByNumber(int number)
{
VerifyAccess();
if (number < 1 || number > _lineTree.LineCount)
throw new ArgumentOutOfRangeException(nameof(number), number, "Value must be between 1 and " + _lineTree.LineCount);
return _lineTree.GetByNumber(number);
}
IDocumentLine IDocument.GetLineByNumber(int lineNumber)
{
return GetLineByNumber(lineNumber);
}
/// <summary>
/// Gets a document lines by offset.
/// Runtime: O(log n)
/// </summary>
[SuppressMessage("Microsoft.Globalization", "CA1305:SpecifyIFormatProvider", MessageId = "System.Int32.ToString")]
public DocumentLine GetLineByOffset(int offset)
{
VerifyAccess();
if (offset < 0 || offset > _rope.Length)
{
throw new ArgumentOutOfRangeException(nameof(offset), offset, "0 <= offset <= " + _rope.Length);
}
return _lineTree.GetByOffset(offset);
}
IDocumentLine IDocument.GetLineByOffset(int offset)
{
return GetLineByOffset(offset);
}
#endregion
#region GetOffset / GetLocation
/// <summary>
/// Gets the offset from a text location.
/// </summary>
/// <seealso cref="GetLocation"/>
public int GetOffset(TextLocation location)
{
return GetOffset(location.Line, location.Column);
}
/// <summary>
/// Gets the offset from a text location.
/// </summary>
/// <seealso cref="GetLocation"/>
public int GetOffset(int line, int column)
{
var docLine = GetLineByNumber(line);
if (column <= 0)
return docLine.Offset;
if (column > docLine.Length)
return docLine.EndOffset;
return docLine.Offset + column - 1;
}
/// <summary>
/// Gets the location from an offset.
/// </summary>
/// <seealso cref="GetOffset(TextLocation)"/>
public TextLocation GetLocation(int offset)
{
var line = GetLineByOffset(offset);
return new TextLocation(line.LineNumber, offset - line.Offset + 1);
}
#endregion
#region Line Trackers
private readonly ObservableCollection<ILineTracker> _lineTrackers = new ObservableCollection<ILineTracker>();
/// <summary>
/// Gets the list of <see cref="ILineTracker"/>s attached to this document.
/// You can add custom line trackers to this list.
/// </summary>
internal IList<ILineTracker> LineTrackers
{
get
{
VerifyAccess();
return _lineTrackers;
}
}
#endregion
#region UndoStack
internal UndoStack _undoStack;
/// <summary>
/// Gets the <see cref="UndoStack"/> of the document.
/// </summary>
/// <remarks>This property can also be used to set the undo stack, e.g. for sharing a common undo stack between multiple documents.</remarks>
internal UndoStack UndoStack
{
get => _undoStack;
set
{
if (value == null)
throw new ArgumentNullException();
if (value != _undoStack)
{
_undoStack.ClearAll(); // first clear old undo stack, so that it can't be used to perform unexpected changes on this document
// ClearAll() will also throw an exception when it's not safe to replace the undo stack (e.g. update is currently in progress)
_undoStack = value;
OnPropertyChanged("UndoStack");
}
}
}
#endregion
#region CreateAnchor
/// <summary>
/// Creates a new <see cref="TextAnchor"/> at the specified offset.
/// </summary>
/// <inheritdoc cref="TextAnchor" select="remarks|example"/>
public TextAnchor CreateAnchor(int offset)
{
VerifyAccess();
if (offset < 0 || offset > _rope.Length)
{
throw new ArgumentOutOfRangeException(nameof(offset), offset, "0 <= offset <= " + _rope.Length.ToString(CultureInfo.InvariantCulture));
}
return _anchorTree.CreateAnchor(offset);
}
ITextAnchor IDocument.CreateAnchor(int offset)
{
return CreateAnchor(offset);
}
#endregion
#region LineCount
/// <summary>
/// Gets the total number of lines in the document.
/// Runtime: O(1).
/// </summary>
public int LineCount
{
get
{
VerifyAccess();
return _lineTree.LineCount;
}
}
/// <summary>
/// Is raised when the LineCount property changes.
/// </summary>
internal event EventHandler LineCountChanged;
#endregion
#region Debugging
[Conditional("DEBUG")]
internal void DebugVerifyAccess()
{
VerifyAccess();
}
/// <summary>
/// Gets the document lines tree in string form.
/// </summary>
[SuppressMessage("Microsoft.Performance", "CA1811:AvoidUncalledPrivateCode")]
[SuppressMessage("Microsoft.Design", "CA1024:UsePropertiesWhereAppropriate")]
internal string GetLineTreeAsString()
{
#if DEBUG
return _lineTree.GetTreeAsString();
#else
return "Not available in release build.";
#endif
}
/// <summary>
/// Gets the text anchor tree in string form.
/// </summary>
[SuppressMessage("Microsoft.Performance", "CA1811:AvoidUncalledPrivateCode")]
[SuppressMessage("Microsoft.Design", "CA1024:UsePropertiesWhereAppropriate")]
internal string GetTextAnchorTreeAsString()
{
#if DEBUG
return _anchorTree.GetTreeAsString();
#else
return "Not available in release build.";
#endif
}
#endregion
#region Service Provider
private IServiceProvider _serviceProvider;
internal IServiceProvider ServiceProvider
{
get
{
VerifyAccess();
if (_serviceProvider == null)
{
var container = new ServiceContainer();
container.AddService(this);
container.AddService<IDocument>(this);
_serviceProvider = container;
}
return _serviceProvider;
}
set
{
VerifyAccess();
_serviceProvider = value ?? throw new ArgumentNullException(nameof(value));
}
}
object IServiceProvider.GetService(Type serviceType)
{
return ServiceProvider.GetService(serviceType);
}
#endregion
#region FileName
private string _fileName;
/// <inheritdoc/>
public event EventHandler FileNameChanged;
private void OnFileNameChanged(EventArgs e)
{
FileNameChanged?.Invoke(this, e);
}
/// <inheritdoc/>
public string FileName
{
get { return _fileName; }
set
{
if (_fileName != value)
{
_fileName = value;
OnFileNameChanged(EventArgs.Empty);
}
}
}
#endregion
}
}