// 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 ICSharpCode.AvalonEdit.Utils;
using System;
using System.IO;
namespace ICSharpCode.AvalonEdit.Document
{
/// <summary>
/// Interface for read-only access to a text source.
/// </summary>
/// <seealso cref="TextDocument"/>
/// <seealso cref="StringTextSource"/>
public interface ITextSource
{
/// <summary>
/// Gets the whole text as string.
/// </summary>
[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Naming", "CA1721:PropertyNamesShouldNotMatchGetMethods")]
string Text { get; }
/// <summary>
/// Is raised when the Text property changes.
/// </summary>
event EventHandler TextChanged;
/// <summary>
/// Gets the total text length.
/// </summary>
/// <returns>The length of the text, in characters.</returns>
/// <remarks>This is the same as Text.Length, but is more efficient because
/// it doesn't require creating a String object.</remarks>
int TextLength { get; }
/// <summary>
/// Gets a character at the specified position in the document.
/// </summary>
/// <paramref name="offset">The index of the character to get.</paramref>
/// <exception cref="ArgumentOutOfRangeException">Offset is outside the valid range (0 to TextLength-1).</exception>
/// <returns>The character at the specified position.</returns>
/// <remarks>This is the same as Text[offset], but is more efficient because
/// it doesn't require creating a String object.</remarks>
char GetCharAt(int offset);
/// <summary>
/// Gets the index of the first occurrence of any character in the specified array.
/// </summary>
/// <param name="anyOf"></param>
/// <param name="startIndex">Start index of the search.</param>
/// <param name="count">Length of the area to search.</param>
/// <returns>The first index where any character was found; or -1 if no occurrence was found.</returns>
int IndexOfAny(char[] anyOf, int startIndex, int count);
/// <summary>
/// Retrieves the text for a portion of the document.
/// </summary>
/// <exception cref="ArgumentOutOfRangeException">offset or length is outside the valid range.</exception>
/// <remarks>This is the same as Text.Substring, but is more efficient because
/// it doesn't require creating a String object for the whole document.</remarks>
string GetText(int offset, int length);
/// <summary>
/// Creates a snapshot of the current text.
/// </summary>
/// <remarks>
/// This method is generally not thread-safe when called on a mutable text buffer, but the resulting text buffer is immutable and thread-safe.
/// However, some implementing classes may provide additional thread-safety guarantees, see <see cref="TextDocument.CreateSnapshot()">TextDocument.CreateSnapshot</see>.
/// </remarks>
ITextSource CreateSnapshot();
/// <summary>
/// Creates a snapshot of a part of the current text.
/// </summary>
/// <remarks>
/// This method is generally not thread-safe when called on a mutable text buffer, but the resulting text buffer is immutable and thread-safe.
/// However, some implementing classes may provide additional thread-safety guarantees, see <see cref="TextDocument.CreateSnapshot()">TextDocument.CreateSnapshot</see>.
/// </remarks>
ITextSource CreateSnapshot(int offset, int length);
/// <summary>
/// Creates a text reader.
/// If the text is changed while a reader is active, the reader will continue to read from the old text version.
/// </summary>
TextReader CreateReader();
}
/// <summary>
/// Implements the ITextSource interface by wrapping another TextSource
/// and viewing only a part of the text.
/// </summary>
[Obsolete("This class will be removed in a future version of AvalonEdit")]
public sealed class TextSourceView : ITextSource
{
readonly ITextSource baseTextSource;
readonly ISegment viewedSegment;
/// <summary>
/// Creates a new TextSourceView object.
/// </summary>
/// <param name="baseTextSource">The base text source.</param>
/// <param name="viewedSegment">A text segment from the base text source</param>
public TextSourceView(ITextSource baseTextSource, ISegment viewedSegment)
{
if (baseTextSource == null)
throw new ArgumentNullException("baseTextSource");
if (viewedSegment == null)
throw new ArgumentNullException("viewedSegment");
this.baseTextSource = baseTextSource;
this.viewedSegment = viewedSegment;
}
/// <inheritdoc/>
public event EventHandler TextChanged {
add { baseTextSource.TextChanged += value; }
remove { baseTextSource.TextChanged -= value; }
}
/// <inheritdoc/>
public string Text {
get {
return baseTextSource.GetText(viewedSegment.Offset, viewedSegment.Length);
}
}
/// <inheritdoc/>
public int TextLength {
get { return viewedSegment.Length; }
}
/// <inheritdoc/>
public char GetCharAt(int offset)
{
return baseTextSource.GetCharAt(viewedSegment.Offset + offset);
}
/// <inheritdoc/>
public string GetText(int offset, int length)
{
return baseTextSource.GetText(viewedSegment.Offset + offset, length);
}
/// <inheritdoc/>
public ITextSource CreateSnapshot()
{
return baseTextSource.CreateSnapshot(viewedSegment.Offset, viewedSegment.Length);
}
/// <inheritdoc/>
public ITextSource CreateSnapshot(int offset, int length)
{
return baseTextSource.CreateSnapshot(viewedSegment.Offset + offset, length);
}
/// <inheritdoc/>
public TextReader CreateReader()
{
return CreateSnapshot().CreateReader();
}
/// <inheritdoc/>
public int IndexOfAny(char[] anyOf, int startIndex, int count)
{
int offset = viewedSegment.Offset;
int result = baseTextSource.IndexOfAny(anyOf, startIndex + offset, count);
return result >= 0 ? result - offset : result;
}
}
/// <summary>
/// Implements the ITextSource interface using a string.
/// </summary>
public sealed class StringTextSource : ITextSource
{
readonly string text;
/// <summary>
/// Creates a new StringTextSource.
/// </summary>
public StringTextSource(string text)
{
if (text == null)
throw new ArgumentNullException("text");
this.text = text;
}
// Text can never change
event EventHandler ITextSource.TextChanged { add {} remove {} }
/// <inheritdoc/>
public string Text {
get { return text; }
}
/// <inheritdoc/>
public int TextLength {
get { return text.Length; }
}
/// <inheritdoc/>
public char GetCharAt(int offset)
{
// GetCharAt must throw ArgumentOutOfRangeException, not IndexOutOfRangeException
if (offset < 0 || offset >= text.Length)
throw new ArgumentOutOfRangeException("offset", offset, "offset must be between 0 and " + (text.Length - 1));
return text[offset];
}
/// <inheritdoc/>
public string GetText(int offset, int length)
{
return text.Substring(offset, length);
}
/// <inheritdoc/>
public TextReader CreateReader()
{
return new StringReader(text);
}
/// <inheritdoc/>
public ITextSource CreateSnapshot()
{
return this; // StringTextSource already is immutable
}
/// <inheritdoc/>
public ITextSource CreateSnapshot(int offset, int length)
{
return new StringTextSource(text.Substring(offset, length));
}
/// <inheritdoc/>
public int IndexOfAny(char[] anyOf, int startIndex, int count)
{
return text.IndexOfAny(anyOf, startIndex, count);
}
}
/// <summary>
/// Implements the ITextSource interface using a rope.
/// </summary>
public sealed class RopeTextSource : ITextSource
{
readonly Rope<char> rope;
/// <summary>
/// Creates a new RopeTextSource.
/// </summary>
public RopeTextSource(Rope<char> rope)
{
if (rope == null)
throw new ArgumentNullException("rope");
this.rope = rope;
}
/// <summary>
/// Returns a clone of the rope used for this text source.
/// </summary>
/// <remarks>
/// RopeTextSource only publishes a copy of the contained rope to ensure that the underlying rope cannot be modified.
/// Unless the creator of the RopeTextSource still has a reference on the rope, RopeTextSource is immutable.
/// </remarks>
[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Design", "CA1024:UsePropertiesWhereAppropriate", Justification="Not a property because it creates a clone")]
public Rope<char> GetRope()
{
return rope.Clone();
}
// Change event is not supported
event EventHandler ITextSource.TextChanged { add {} remove {} }
/// <inheritdoc/>
public string Text {
get { return rope.ToString(); }
}
/// <inheritdoc/>
public int TextLength {
get { return rope.Length; }
}
/// <inheritdoc/>
public char GetCharAt(int offset)
{
return rope[offset];
}
/// <inheritdoc/>
public string GetText(int offset, int length)
{
return rope.ToString(offset, length);
}
/// <inheritdoc/>
public TextReader CreateReader()
{
return new RopeTextReader(rope);
}
/// <inheritdoc/>
public ITextSource CreateSnapshot()
{
// we clone the underlying rope because the creator of the RopeTextSource might be modifying it
return new RopeTextSource(rope.Clone());
}
/// <inheritdoc/>
public ITextSource CreateSnapshot(int offset, int length)
{
return new RopeTextSource(rope.GetRange(offset, length));
}
/// <inheritdoc/>
public int IndexOfAny(char[] anyOf, int startIndex, int count)
{
return rope.IndexOfAny(anyOf, startIndex, count);
}
}
}