// 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.Diagnostics;
using System.Globalization;
using System.IO;
using System.Text;
using System.Windows;
using ICSharpCode.AvalonEdit.Document;
namespace ICSharpCode.AvalonEdit.Highlighting
{
/// <summary>
/// Allows copying HTML text to the clipboard.
/// </summary>
public static class HtmlClipboard
{
/// <summary>
/// Builds a header for the CF_HTML clipboard format.
/// </summary>
static string BuildHeader(int startHTML, int endHTML, int startFragment, int endFragment)
{
StringBuilder b = new StringBuilder();
b.AppendLine("Version:0.9");
b.AppendLine("StartHTML:" + startHTML.ToString("d8", CultureInfo.InvariantCulture));
b.AppendLine("EndHTML:" + endHTML.ToString("d8", CultureInfo.InvariantCulture));
b.AppendLine("StartFragment:" + startFragment.ToString("d8", CultureInfo.InvariantCulture));
b.AppendLine("EndFragment:" + endFragment.ToString("d8", CultureInfo.InvariantCulture));
return b.ToString();
}
/// <summary>
/// Sets the TextDataFormat.Html on the data object to the specified html fragment.
/// This helper methods takes care of creating the necessary CF_HTML header.
/// </summary>
public static void SetHtml(DataObject dataObject, string htmlFragment)
{
if (dataObject == null)
throw new ArgumentNullException("dataObject");
if (htmlFragment == null)
throw new ArgumentNullException("htmlFragment");
string htmlStart = @"<!DOCTYPE HTML PUBLIC ""-//W3C//DTD HTML 4.0 Transitional//EN"">" + Environment.NewLine
+ "<HTML>" + Environment.NewLine
+ "<BODY>" + Environment.NewLine
+ "<!--StartFragment-->" + Environment.NewLine;
string htmlEnd = "<!--EndFragment-->" + Environment.NewLine + "</BODY>" + Environment.NewLine + "</HTML>" + Environment.NewLine;
string dummyHeader = BuildHeader(0, 0, 0, 0);
// the offsets are stored as UTF-8 bytes (see CF_HTML documentation)
int startHTML = dummyHeader.Length;
int startFragment = startHTML + htmlStart.Length;
int endFragment = startFragment + Encoding.UTF8.GetByteCount(htmlFragment);
int endHTML = endFragment + htmlEnd.Length;
string cf_html = BuildHeader(startHTML, endHTML, startFragment, endFragment) + htmlStart + htmlFragment + htmlEnd;
Debug.WriteLine(cf_html);
dataObject.SetText(cf_html, TextDataFormat.Html);
}
/// <summary>
/// Creates a HTML fragment from a part of a document.
/// </summary>
/// <param name="document">The document to create HTML from.</param>
/// <param name="highlighter">The highlighter used to highlight the document. <c>null</c> is valid and will create HTML without any highlighting.</param>
/// <param name="segment">The part of the document to create HTML for. You can pass <c>null</c> to create HTML for the whole document.</param>
/// <param name="options">The options for the HTML creation.</param>
/// <returns>HTML code for the document part.</returns>
public static string CreateHtmlFragment(TextDocument document, IHighlighter highlighter, ISegment segment, HtmlOptions options)
{
if (document == null)
throw new ArgumentNullException("document");
if (options == null)
throw new ArgumentNullException("options");
if (highlighter != null && highlighter.Document != document)
throw new ArgumentException("Highlighter does not belong to the specified document.");
if (segment == null)
segment = new SimpleSegment(0, document.TextLength);
StringBuilder html = new StringBuilder();
int segmentEndOffset = segment.EndOffset;
DocumentLine line = document.GetLineByOffset(segment.Offset);
while (line != null && line.Offset < segmentEndOffset) {
HighlightedLine highlightedLine;
if (highlighter != null)
highlightedLine = highlighter.HighlightLine(line.LineNumber);
else
highlightedLine = new HighlightedLine(document, line);
SimpleSegment s = segment.GetOverlap(line);
if (html.Length > 0)
html.AppendLine("<br>");
html.Append(highlightedLine.ToHtml(s.Offset, s.EndOffset, options));
line = line.NextLine;
}
return html.ToString();
}
/// <summary>
/// Escapes text and writes the result to the StringBuilder.
/// </summary>
internal static void EscapeHtml(StringWriter w, string text, HtmlOptions options)
{
int spaceCount = -1;
foreach (char c in text) {
if (c == ' ') {
if (spaceCount < 0)
w.Write(" ");
else
spaceCount++;
} else if (c == '\t') {
if (spaceCount < 0)
spaceCount = 0;
spaceCount += options.TabSize;
} else {
if (spaceCount == 1) {
w.Write(' ');
} else if (spaceCount >= 1) {
for (int i = 0; i < spaceCount; i++) {
w.Write(" ");
}
}
spaceCount = 0;
switch (c) {
case '<':
w.Write("<");
break;
case '>':
w.Write(">");
break;
case '&':
w.Write("&");
break;
case '"':
w.Write(""");
break;
default:
w.Write(c);
break;
}
}
}
for (int i = 0; i < spaceCount; i++) {
w.Write(" ");
}
}
}
/// <summary>
/// Holds options for converting text to HTML.
/// </summary>
public class HtmlOptions
{
/// <summary>
/// Creates a default HtmlOptions instance.
/// </summary>
public HtmlOptions()
{
this.TabSize = 4;
}
/// <summary>
/// Creates a new HtmlOptions instance that copies applicable options from the <see cref="TextEditorOptions"/>.
/// </summary>
public HtmlOptions(TextEditorOptions options)
: this()
{
if (options == null)
throw new ArgumentNullException("options");
this.TabSize = options.IndentationSize;
}
/// <summary>
/// The amount of spaces a tab gets converted to.
/// </summary>
public int TabSize { get; set; }
/// <summary>
/// Writes the HTML attribute for the style to the text writer.
/// </summary>
public virtual void WriteStyleAttributeForColor(TextWriter writer, HighlightingColor color)
{
if (writer == null)
throw new ArgumentNullException("writer");
if (color == null)
throw new ArgumentNullException("color");
writer.Write(" style=\"");
writer.Write(color.ToCss());
writer.Write("\"");
}
/// <summary>
/// Gets whether the color needs to be written out to HTML.
/// </summary>
public virtual bool ColorNeedsSpanForStyling(HighlightingColor color)
{
if (color == null)
throw new ArgumentNullException("color");
return !string.IsNullOrEmpty(color.ToCss());
}
}
}
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