/// <summary>
/// Attempts to parse a markdown link e.g. "[](http://www.reddit.com)".
/// </summary>
/// <param name="markdown"> The markdown text. </param>
/// <param name="start"> The location to start parsing. </param>
/// <param name="maxEnd"> The location to stop parsing. </param>
/// <returns> A parsed markdown link, or <c>null</c> if this is not a markdown link. </returns>
internal static Common.InlineParseResult Parse(string markdown, int start, int maxEnd)
{
// Expect a '[' character.
if (start == maxEnd || markdown[start] != '[')
return null;
// Find the ']' character, keeping in mind that [test [0-9]](http://www.test.com) is allowed.
int linkTextOpen = start + 1;
int pos = linkTextOpen;
int linkTextClose;
int openSquareBracketCount = 0;
while (true)
{
linkTextClose = markdown.IndexOfAny(new char[] { '[', ']' }, pos, maxEnd - pos);
if (linkTextClose == -1)
return null;
if (markdown[linkTextClose] == '[')
openSquareBracketCount++;
else if (openSquareBracketCount > 0)
openSquareBracketCount--;
else
break;
pos = linkTextClose + 1;
}
// Skip whitespace.
pos = linkTextClose + 1;
while (pos < maxEnd && Common.IsWhiteSpace(markdown[pos]))
pos++;
if (pos == maxEnd)
return null;
// Expect the '(' character or the '[' character.
int linkOpen = pos;
if (markdown[pos] == '(')
{
// Skip whitespace.
linkOpen++;
while (linkOpen < maxEnd && Common.IsWhiteSpace(markdown[linkOpen]))
linkOpen++;
// Find the ')' character.
pos = linkOpen;
int linkClose = -1;
while (pos < maxEnd)
{
linkClose = Common.IndexOf(markdown, ')', pos, maxEnd);
if (linkClose == -1)
return null;
if (markdown[linkClose - 1] != '\\')
break;
pos = linkClose + 1;
}
if (pos >= maxEnd)
return null;
int end = linkClose + 1;
// Skip whitespace backwards.
while (linkClose > linkOpen && Common.IsWhiteSpace(markdown[linkClose - 1]))
linkClose--;
// If there is no text whatsoever, then this is not a valid link.
if (linkOpen == linkClose)
return null;
// Check if there is tooltip text.
string url;
string tooltip = null;
bool lastUrlCharIsDoubleQuote = markdown[linkClose - 1] == '"';
int tooltipStart = Common.IndexOf(markdown, " \"", linkOpen, linkClose - 1);
if (tooltipStart == linkOpen)
return null;
if (lastUrlCharIsDoubleQuote && tooltipStart != -1)
{
// Extract the URL (resolving any escape sequences).
url = TextRunInline.ResolveEscapeSequences(markdown, linkOpen, tooltipStart).TrimEnd(' ', '\t', '\r', '\n');
tooltip = markdown.Substring(tooltipStart + 2, (linkClose - 1) - (tooltipStart + 2));
}
else
{
// Extract the URL (resolving any escape sequences).
url = TextRunInline.ResolveEscapeSequences(markdown, linkOpen, linkClose);
}
// Check the URL is okay.
if (!IsUrlValid(url))
return null;
// We found a regular stand-alone link.
var result = new MarkdownLinkInline();
result.Inlines = Common.ParseInlineChildren(markdown, linkTextOpen, linkTextClose, ignoreLinks: true);
result.Url = url.Replace(" ", "%20");
result.Tooltip = tooltip;
return new Common.InlineParseResult(result, start, end);
}
else if (markdown[pos] == '[')
{
// Find the ']' character.
int linkClose = Common.IndexOf(markdown, ']', pos + 1, maxEnd);
if (linkClose == -1)
return null;
// We found a reference-style link.
var result = new MarkdownLinkInline();
result.Inlines = Common.ParseInlineChildren(markdown, linkTextOpen, linkTextClose, ignoreLinks: true);
result.ReferenceId = markdown.Substring(linkOpen + 1, linkClose - (linkOpen + 1));
if (result.ReferenceId == string.Empty)
result.ReferenceId = markdown.Substring(linkTextOpen, linkTextClose - linkTextOpen);
return new Common.InlineParseResult(result, start, linkClose + 1);
}
return null;
}
/// <summary>
/// Renders a link element
/// </summary>
/// <param name="inlineCollection"> The list to add to. </param>
/// <param name="element"> The parsed inline element to render. </param>
/// <param name="parent"> The container element. </param>
/// <param name="context"> Persistent state. </param>
private void RenderMarkdownLink(InlineCollection inlineCollection, MarkdownLinkInline element, TextElement parent, RenderContext context)
{
// Avoid crash when link text is empty.
if (element.Inlines.Count == 0)
return;
// Attempt to resolve references.
element.ResolveReference(this.document);
if (element.Url == null)
{
// The element couldn't be resolved, just render it as text.
RenderInlineChildren(inlineCollection, element.Inlines, parent, context);
return;
}
// HACK: Superscript is not allowed within a hyperlink. But if we switch it around, so
// that the superscript is outside the hyperlink, then it will render correctly.
// This assumes that the entire hyperlink is to be rendered as superscript.
if (AllTextIsSuperscript(element) == false)
{
// Regular ol' hyperlink.
var link = new Hyperlink();
// Register the link
this.linkRegister.RegisterNewHyperLink(link, element.Url);
// Remove superscripts.
RemoveSuperscriptRuns(element, insertCaret: true);
// Render the children into the link inline.
var childContext = context.Clone();
childContext.WithinHyperlink = true;
RenderInlineChildren(link.Inlines, element.Inlines, link, childContext);
context.TrimLeadingWhitespace = childContext.TrimLeadingWhitespace;
// Add it to the current inlines
inlineCollection.Add(link);
}
else
{
// THE HACK IS ON!
// Create a fake superscript element.
var fakeSuperscript = new SuperscriptTextInline();
fakeSuperscript.Inlines = new List<MarkdownInline> { element };
// Remove superscripts.
RemoveSuperscriptRuns(element, insertCaret: false);
// Now render it.
RenderSuperscriptRun(inlineCollection, fakeSuperscript, parent, context);
}
}
/// <summary>
/// Attempts to parse a markdown link e.g. "[](http://www.reddit.com)".
/// </summary>
/// <param name="markdown"> The markdown text. </param>
/// <param name="start"> The location to start parsing. </param>
/// <param name="maxEnd"> The location to stop parsing. </param>
/// <returns> A parsed markdown link, or <c>null</c> if this is not a markdown link. </returns>
internal static Common.InlineParseResult Parse(string markdown, int start, int maxEnd)
{
// Expect a '[' character.
if (start == maxEnd || markdown[start] != '[')
{
return(null);
}
// Find the ']' character, keeping in mind that [test [0-9]](http://www.test.com) is allowed.
int linkTextOpen = start + 1;
int pos = linkTextOpen;
int linkTextClose;
int openSquareBracketCount = 0;
while (true)
{
linkTextClose = markdown.IndexOfAny(new char[] { '[', ']' }, pos, maxEnd - pos);
if (linkTextClose == -1)
{
return(null);
}
if (markdown[linkTextClose] == '[')
{
openSquareBracketCount++;
}
else if (openSquareBracketCount > 0)
{
openSquareBracketCount--;
}
else
{
break;
}
pos = linkTextClose + 1;
}
// Skip whitespace.
pos = linkTextClose + 1;
while (pos < maxEnd && Common.IsWhiteSpace(markdown[pos]))
{
pos++;
}
if (pos == maxEnd)
{
return(null);
}
// Expect the '(' character or the '[' character.
int linkOpen = pos;
if (markdown[pos] == '(')
{
// Skip whitespace.
linkOpen++;
while (linkOpen < maxEnd && Common.IsWhiteSpace(markdown[linkOpen]))
{
linkOpen++;
}
// Find the ')' character.
pos = linkOpen;
int linkClose = -1;
while (pos < maxEnd)
{
linkClose = Common.IndexOf(markdown, ')', pos, maxEnd);
if (linkClose == -1)
{
return(null);
}
if (markdown[linkClose - 1] != '\\')
{
break;
}
pos = linkClose + 1;
}
if (pos >= maxEnd)
{
return(null);
}
int end = linkClose + 1;
// Skip whitespace backwards.
while (linkClose > linkOpen && Common.IsWhiteSpace(markdown[linkClose - 1]))
{
linkClose--;
}
// If there is no text whatsoever, then this is not a valid link.
if (linkOpen == linkClose)
{
return(null);
}
// Check if there is tooltip text.
string url;
string tooltip = null;
bool lastUrlCharIsDoubleQuote = markdown[linkClose - 1] == '"';
int tooltipStart = Common.IndexOf(markdown, " \"", linkOpen, linkClose - 1);
if (tooltipStart == linkOpen)
{
return(null);
}
if (lastUrlCharIsDoubleQuote && tooltipStart != -1)
{
// Extract the URL (resolving any escape sequences).
url = TextRunInline.ResolveEscapeSequences(markdown, linkOpen, tooltipStart).TrimEnd(' ', '\t', '\r', '\n');
tooltip = markdown.Substring(tooltipStart + 2, (linkClose - 1) - (tooltipStart + 2));
}
else
{
// Extract the URL (resolving any escape sequences).
url = TextRunInline.ResolveEscapeSequences(markdown, linkOpen, linkClose);
}
// Check the URL is okay.
if (!IsUrlValid(url))
{
return(null);
}
// We found a regular stand-alone link.
var result = new MarkdownLinkInline();
result.Inlines = Common.ParseInlineChildren(markdown, linkTextOpen, linkTextClose, ignoreLinks: true);
result.Url = url.Replace(" ", "%20");
result.Tooltip = tooltip;
return(new Common.InlineParseResult(result, start, end));
}
else if (markdown[pos] == '[')
{
// Find the ']' character.
int linkClose = Common.IndexOf(markdown, ']', pos + 1, maxEnd);
if (linkClose == -1)
{
return(null);
}
// We found a reference-style link.
var result = new MarkdownLinkInline();
result.Inlines = Common.ParseInlineChildren(markdown, linkTextOpen, linkTextClose, ignoreLinks: true);
result.ReferenceId = markdown.Substring(linkOpen + 1, linkClose - (linkOpen + 1));
if (result.ReferenceId == string.Empty)
{
result.ReferenceId = markdown.Substring(linkTextOpen, linkTextClose - linkTextOpen);
}
return(new Common.InlineParseResult(result, start, linkClose + 1));
}
return(null);
}
/// <summary>
/// Renders a link element
/// </summary>
/// <param name="element"></param>
/// <param name="currentInlines"></param>
/// <param name="trimTextStart">If true this element should trin the start of the text and set to fales.</param>
private void RenderMarkdownLink(MarkdownLinkInline element, InlineCollection currentInlines, ref bool trimTextStart)
{
// Create the text run
Hyperlink link = new Hyperlink();
// Register the link
m_linkRegister.RegisterNewHyperLink(link, element.Url);
// Render the children into the link inline.
RenderInlineChildren(element, link.Inlines, ref trimTextStart);
// Add it to the current inlines
currentInlines.Add(link);
}
