// 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.Text.RegularExpressions;
using ICSharpCode.AvalonEdit.Utils;
namespace ICSharpCode.AvalonEdit.Rendering
{
// This class is public because it can be used as a base class for custom links.
/// <summary>
/// Detects hyperlinks and makes them clickable.
/// </summary>
/// <remarks>
/// This element generator can be easily enabled and configured using the
/// <see cref="TextEditorOptions"/>.
/// </remarks>
public class LinkElementGenerator : VisualLineElementGenerator, IBuiltinElementGenerator
{
// a link starts with a protocol (or just with www), followed by 0 or more 'link characters', followed by a link end character
// (this allows accepting punctuation inside links but not at the end)
internal readonly static Regex defaultLinkRegex = new Regex(@"\b(https?://|ftp://|www\.)[\w\d\._/\-~%@()+:?&=#!]*[\w\d/]");
// try to detect email addresses
internal readonly static Regex defaultMailRegex = new Regex(@"\b[\w\d\.\-]+\@[\w\d\.\-]+\.[a-z]{2,6}\b");
readonly Regex linkRegex;
/// <summary>
/// Gets/Sets whether the user needs to press Control to click the link.
/// The default value is true.
/// </summary>
public bool RequireControlModifierForClick { get; set; }
/// <summary>
/// Creates a new LinkElementGenerator.
/// </summary>
public LinkElementGenerator()
{
this.linkRegex = defaultLinkRegex;
this.RequireControlModifierForClick = true;
}
/// <summary>
/// Creates a new LinkElementGenerator using the specified regex.
/// </summary>
protected LinkElementGenerator(Regex regex) : this()
{
if (regex == null)
throw new ArgumentNullException("regex");
this.linkRegex = regex;
}
void IBuiltinElementGenerator.FetchOptions(TextEditorOptions options)
{
this.RequireControlModifierForClick = options.RequireControlModifierForHyperlinkClick;
}
Match GetMatch(int startOffset, out int matchOffset)
{
int endOffset = CurrentContext.VisualLine.LastDocumentLine.EndOffset;
StringSegment relevantText = CurrentContext.GetText(startOffset, endOffset - startOffset);
Match m = linkRegex.Match(relevantText.Text, relevantText.Offset, relevantText.Count);
matchOffset = m.Success ? m.Index - relevantText.Offset + startOffset : -1;
return m;
}
/// <inheritdoc/>
public override int GetFirstInterestedOffset(int startOffset)
{
int matchOffset;
GetMatch(startOffset, out matchOffset);
return matchOffset;
}
/// <inheritdoc/>
public override VisualLineElement ConstructElement(int offset)
{
int matchOffset;
Match m = GetMatch(offset, out matchOffset);
if (m.Success && matchOffset == offset) {
return ConstructElementFromMatch(m);
} else {
return null;
}
}
/// <summary>
/// Constructs a VisualLineElement that replaces the matched text.
/// The default implementation will create a <see cref="VisualLineLinkText"/>
/// based on the URI provided by <see cref="GetUriFromMatch"/>.
/// </summary>
protected virtual VisualLineElement ConstructElementFromMatch(Match m)
{
Uri uri = GetUriFromMatch(m);
if (uri == null)
return null;
VisualLineLinkText linkText = new VisualLineLinkText(CurrentContext.VisualLine, m.Length);
linkText.NavigateUri = uri;
linkText.RequireControlModifierForClick = this.RequireControlModifierForClick;
return linkText;
}
/// <summary>
/// Fetches the URI from the regex match. Returns null if the URI format is invalid.
/// </summary>
protected virtual Uri GetUriFromMatch(Match match)
{
string targetUrl = match.Value;
if (targetUrl.StartsWith("www.", StringComparison.Ordinal))
targetUrl = "http://" + targetUrl;
if (Uri.IsWellFormedUriString(targetUrl, UriKind.Absolute))
return new Uri(targetUrl);
return null;
}
}
// This class is internal because it does not need to be accessed by the user - it can be configured using TextEditorOptions.
/// <summary>
/// Detects e-mail addresses and makes them clickable.
/// </summary>
/// <remarks>
/// This element generator can be easily enabled and configured using the
/// <see cref="TextEditorOptions"/>.
/// </remarks>
sealed class MailLinkElementGenerator : LinkElementGenerator
{
/// <summary>
/// Creates a new MailLinkElementGenerator.
/// </summary>
public MailLinkElementGenerator()
: base(defaultMailRegex)
{
}
protected override Uri GetUriFromMatch(Match match)
{
return new Uri("mailto:" + match.Value);
}
}
}