/// <summary>
/// Analyzes the given htmlElement expecting it to be converted
/// into some of xaml Block elements and adds the converted block
/// to the children collection of xamlParentElement.
/// Analyzes the given XmlElement htmlElement, recognizes it as some HTML element
/// and adds it as a child to a xamlParentElement.
/// In some cases several following siblings of the given htmlElement
/// will be consumed too (e.g. LIs encountered without wrapping UL/OL,
/// which must be collected together and wrapped into one implicit List element).
/// </summary>
/// <param name="xamlParentElement">
/// Parent xaml element, to which new converted element will be added
/// </param>
/// <param name="htmlNode"></param>
/// <param name="inheritedProperties">
/// Properties inherited from an outer context.
/// </param>
/// <param name="stylesheet"></param>
/// <param name="sourceContext"></param>
/// <returns>
/// Last processed html node. Normally it should be the same htmlElement
/// as was passed as a paramater, but in some irregular cases
/// it could one of its following siblings.
/// The caller must use this node to get to next sibling from it.
/// </returns>
private static XmlNode AddBlock(
XmlElement xamlParentElement,
XmlNode htmlNode,
Hashtable inheritedProperties,
CssStylesheet stylesheet,
List<XmlElement> sourceContext)
{
var node = htmlNode as XmlComment;
if (node != null)
{
DefineInlineFragmentParent(node, /*xamlParentElement:*/null);
}
else if (htmlNode is XmlText)
{
htmlNode = AddImplicitParagraph
(
xamlParentElement,
htmlNode,
inheritedProperties,
stylesheet,
sourceContext);
}
else if (htmlNode is XmlElement)
{
// Identify element name
var htmlElement = (XmlElement) htmlNode;
string htmlElementName = htmlElement.LocalName; // Keep the name case-sensitive to check xml names
string htmlElementNamespace = htmlElement.NamespaceURI;
if (htmlElementNamespace == HtmlParser.XhtmlNamespace)
{
sourceContext.Add(htmlElement);
// Convert the name to lowercase, because html elements are case-insensitive
htmlElementName = htmlElementName.ToLower();
// Switch to an appropriate kind of processing depending on html element name
switch (htmlElementName)
{
// Sections:
case "html":
case "body":
case "div":
case "form": // not a block according to xhtml spec
case "pre": // Renders text in a fixed-width font
case "blockquote":
case "caption":
case "center":
case "cite":
AddSection
(
xamlParentElement,
htmlElement,
inheritedProperties,
stylesheet,
sourceContext);
break;
// Paragraphs:
case "p":
case "h1":
case "h2":
case "h3":
case "h4":
case "h5":
case "h6":
case "nsrtitle":
case "textarea":
case "dd": // ???
case "dl": // ???
case "dt": // ???
case "tt": // ???
AddParagraph
(
xamlParentElement,
htmlElement,
inheritedProperties,
stylesheet,
sourceContext);
break;
case "ol":
case "ul":
case "dir": // treat as UL element
case "menu": // treat as UL element
// List element conversion
AddList
(
xamlParentElement,
htmlElement,
inheritedProperties,
stylesheet,
sourceContext);
break;
case "li":
// LI outside of OL/UL
// Collect all sibling LIs, wrap them into a List and then proceed with the element following the last of LIs
htmlNode = AddOrphanListItems
(
xamlParentElement,
htmlElement,
inheritedProperties,
stylesheet,
sourceContext);
break;
case "img":
// TODO: Add image processing
AddImage
(
xamlParentElement,
htmlElement,
inheritedProperties,
stylesheet,
sourceContext);
break;
case "table":
// hand off to table parsing function which will perform special table syntax checks
AddTable
(
xamlParentElement,
htmlElement,
inheritedProperties,
stylesheet,
sourceContext);
break;
case "tbody":
case "tfoot":
case "thead":
case "tr":
case "td":
case "th":
// Table stuff without table wrapper
// TODO: add special-case processing here for elements that should be within tables when the
// parent element is NOT a table. If the parent element is a table they can be processed normally.
// we need to compare against the parent element here, we can't just break on a switch
goto default; // Thus we will skip this element as unknown, but still recurse into it.
case "style": // We already pre-processed all style elements. Ignore it now
case "meta":
case "head":
case "title":
case "script":
// Ignore these elements
break;
default:
// Wrap a sequence of inlines into an implicit paragraph
htmlNode = AddImplicitParagraph
(
xamlParentElement,
htmlElement,
inheritedProperties,
stylesheet,
sourceContext);
break;
}
// Remove the element from the stack
Debug.Assert(sourceContext.Count > 0 && sourceContext[sourceContext.Count - 1] == htmlElement);
sourceContext.RemoveAt(sourceContext.Count - 1);
}
else
{
// Non-html element. skip it
// Isn't it too agressive? What if this is just an error in html tag name?
// TODO: Consider skipping just a wparrer in recursing into the element tree,
// which may produce some garbage though coming from xml fragments.
return htmlElement;
}
// Put source element to the stack
}
// Return last processed node
return htmlNode;
}
/// <summary>
/// Performs a parsing pass over a tbody to read information about column width and rowspan attributes. Information
/// read about width
/// attributes is stored in the reference ArrayList parameter columnStarts, which contains a list of all starting
/// positions of all columns in the table, ordered from left to right. Row spans are taken into consideration when
/// computing column starts
/// </summary>
/// <param name="htmlTbodyElement">
/// XmlElement representing Html tbody whose structure is to be analyzed
/// </param>
/// <param name="columnStarts">
/// ArrayList of type double which contains the function output. If analysis fails, this parameter is set to null
/// </param>
/// <param name="activeRowSpans"></param>
/// <param name="stylesheet"></param>
/// <returns>
/// Calculated width of a tbody.
/// In case of non-analizable column width structure return 0;
/// </returns>
private static double AnalyzeTbodyStructure(
XmlNode htmlTbodyElement,
ArrayList columnStarts,
ArrayList activeRowSpans,
CssStylesheet stylesheet)
{
// Parameter validation
Debug.Assert(htmlTbodyElement.LocalName.ToLower() == "tbody");
Debug.Assert(columnStarts != null);
double tbodyWidth = 0;
bool columnWidthsAvailable = true;
if (!htmlTbodyElement.HasChildNodes)
{
return tbodyWidth;
}
// Set active row spans to 0 - thus ignoring row spans crossing tbody boundaries
ClearActiveRowSpans(activeRowSpans);
XmlNode htmlChildNode = htmlTbodyElement.FirstChild;
// Analyze tr elements
while (htmlChildNode != null && columnWidthsAvailable)
{
switch (htmlChildNode.LocalName.ToLower())
{
case "tr":
double trWidth = AnalyzeTrStructure
(
htmlChildNode,
columnStarts,
activeRowSpans,
stylesheet);
if (trWidth > tbodyWidth)
{
tbodyWidth = trWidth;
}
break;
case "td":
columnWidthsAvailable = false; // interrupt the analisys
break;
}
htmlChildNode = htmlChildNode.NextSibling;
}
// Set active row spans to 0 - thus ignoring row spans crossing tbody boundaries
ClearActiveRowSpans(activeRowSpans);
return columnWidthsAvailable
? tbodyWidth
: 0;
}
/// <summary>
/// Performs a parsing pass over a tr element to read information about column width and rowspan attributes.
/// </summary>
/// <param name="htmlTrElement">
/// XmlElement representing Html tr element whose structure is to be analyzed
/// </param>
/// <param name="columnStarts">
/// ArrayList of type double which contains the function output. If analysis is successful, this ArrayList contains
/// all the points which are the starting position of any column in the tr, ordered from left to right. If analysis
/// fails,
/// the ArrayList is set to null
/// </param>
/// <param name="activeRowSpans">
/// ArrayList representing all columns currently spanned by an earlier row span attribute. These columns should
/// not be used for data in this row. The ArrayList actually contains notation for all columns in the table, if the
/// active row span is set to 0 that column is not presently spanned but if it is > 0 the column is presently spanned
/// </param>
/// <param name="stylesheet"></param>
private static double AnalyzeTrStructure(
XmlNode htmlTrElement,
ArrayList columnStarts,
ArrayList activeRowSpans,
CssStylesheet stylesheet)
{
if (stylesheet == null)
{
throw new ArgumentNullException("stylesheet");
}
// Parameter validation
Debug.Assert(htmlTrElement.LocalName.ToLower() == "tr");
Debug.Assert(columnStarts != null);
Debug.Assert(activeRowSpans != null);
Debug.Assert(columnStarts.Count == activeRowSpans.Count);
if (!htmlTrElement.HasChildNodes)
{
return 0;
}
bool columnWidthsAvailable = true;
double columnStart = 0; // starting position of current column
XmlNode htmlChildNode = htmlTrElement.FirstChild;
int columnIndex = 0;
// Skip spanned columns to get to real column start
if (columnIndex < activeRowSpans.Count)
{
Debug.Assert((double) columnStarts[columnIndex] >= columnStart);
const double epsilon = 0;
if (Math.Abs((double) columnStarts[columnIndex] - columnStart) < epsilon)
{
// The new column may be in a spanned area
while (columnIndex < activeRowSpans.Count && (int) activeRowSpans[columnIndex] > 0)
{
activeRowSpans[columnIndex] = (int) activeRowSpans[columnIndex] - 1;
Debug.Assert((int) activeRowSpans[columnIndex] >= 0);
columnIndex++;
columnStart = (double) columnStarts[columnIndex];
}
}
}
while (htmlChildNode != null && columnWidthsAvailable)
{
Debug.Assert(columnStarts.Count == activeRowSpans.Count);
VerifyColumnStartsAscendingOrder(columnStarts);
switch (htmlChildNode.LocalName.ToLower())
{
case "td":
Debug.Assert(columnIndex <= columnStarts.Count);
if (columnIndex < columnStarts.Count)
{
Debug.Assert(columnStart <= (double) columnStarts[columnIndex]);
if (columnStart < (double) columnStarts[columnIndex])
{
columnStarts.Insert
(
columnIndex,
columnStart);
// There can be no row spans now - the column data will appear here
// Row spans may appear only during the column analysis
activeRowSpans.Insert
(
columnIndex,
0);
}
}
else
{
// Column start is greater than all previous starts. Row span must still be 0 because
// we are either adding after another column of the same row, in which case it should not inherit
// the previous column's span. Otherwise we are adding after the last column of some previous
// row, and assuming the table widths line up, we should not be spanned by it. If there is
// an incorrect tbale structure where a columns starts in the middle of a row span, we do not
// guarantee correct output
columnStarts.Add(columnStart);
activeRowSpans.Add(0);
}
double columnWidth = GetColumnWidth((XmlElement) htmlChildNode);
const double epsilon = 0;
if (Math.Abs(columnWidth - -1) > epsilon)
{
int rowSpan = GetRowSpan((XmlElement) htmlChildNode);
int nextColumnIndex = GetNextColumnIndex
(
columnIndex,
columnWidth,
columnStarts,
activeRowSpans);
if (nextColumnIndex != -1)
{
// Entire column width can be processed without hitting conflicting row span. This means that
// column widths line up and we can process them
Debug.Assert(nextColumnIndex <= columnStarts.Count);
// Apply row span to affected columns
for (int spannedColumnIndex = columnIndex;
spannedColumnIndex < nextColumnIndex;
spannedColumnIndex++)
{
activeRowSpans[spannedColumnIndex] = rowSpan - 1;
Debug.Assert((int) activeRowSpans[spannedColumnIndex] >= 0);
}
columnIndex = nextColumnIndex;
// Calculate columnsStart for the next cell
columnStart = columnStart + columnWidth;
if (columnIndex < activeRowSpans.Count)
{
Debug.Assert((double) columnStarts[columnIndex] >= columnStart);
if (Math.Abs((double) columnStarts[columnIndex] - columnStart) < epsilon)
{
// The new column may be in a spanned area
while (columnIndex < activeRowSpans.Count &&
(int) activeRowSpans[columnIndex] > 0)
{
activeRowSpans[columnIndex] = (int) activeRowSpans[columnIndex] - 1;
Debug.Assert((int) activeRowSpans[columnIndex] >= 0);
columnIndex++;
columnStart = (double) columnStarts[columnIndex];
}
}
// else: the new column does not start at the same time as a pre existing column
// so we don't have to check it for active row spans, it starts in the middle
// of another column which has been checked already by the GetNextColumnIndex function
}
}
else
{
// Full column width cannot be processed without a pre existing row span.
// We cannot analyze widths
columnWidthsAvailable = false;
}
}
else
{
// Incorrect column width, stop processing
columnWidthsAvailable = false;
}
break;
}
htmlChildNode = htmlChildNode.NextSibling;
}
// The width of the tr element is the position at which it's last td element ends, which is calculated in
// the columnStart value after each td element is processed
double trWidth = columnWidthsAvailable
? columnStart
: 0;
return trWidth;
}
// .............................................................
//
// Inline Elements
//
// .............................................................
private static void AddInline(
XmlElement xamlParentElement,
XmlNode htmlNode,
Hashtable inheritedProperties,
CssStylesheet stylesheet,
List<XmlElement> sourceContext)
{
var node = htmlNode as XmlComment;
if (node != null)
{
DefineInlineFragmentParent
(
node,
xamlParentElement);
}
else if (htmlNode is XmlText)
{
AddTextRun
(
xamlParentElement,
htmlNode.Value);
}
else
{
var element = htmlNode as XmlElement;
if (element != null)
{
XmlElement htmlElement = element;
// Check whether this is an html element
if (htmlElement.NamespaceURI != HtmlParser.XhtmlNamespace)
{
return; // Skip non-html elements
}
// Identify element name
string htmlElementName = htmlElement.LocalName.ToLower();
// Put source element to the stack
sourceContext.Add(htmlElement);
switch (htmlElementName)
{
case "a":
AddHyperlink
(
xamlParentElement,
htmlElement,
inheritedProperties,
stylesheet,
sourceContext);
break;
case "img":
AddImage
(
xamlParentElement,
htmlElement,
inheritedProperties,
stylesheet,
sourceContext);
break;
case "br":
case "SelectHR":
AddBreak
(
xamlParentElement,
htmlElementName);
break;
default:
if (HtmlSchema.IsInlineElement(htmlElementName) ||
HtmlSchema.IsBlockElement(htmlElementName))
{
// Note: actually we do not expect block elements here,
// but if it happens to be here, we will treat it as a Span.
AddSpanOrRun
(
xamlParentElement,
htmlElement,
inheritedProperties,
stylesheet,
sourceContext);
}
break;
}
// Ignore all other elements non-(block/inline/image)
// Remove the element from the stack
Debug.Assert(sourceContext.Count > 0 && sourceContext[sourceContext.Count - 1] == htmlElement);
sourceContext.RemoveAt(sourceContext.Count - 1);
}
}
}
/// <summary>
/// If li items are found without a parent ul/ol element in Html string, creates xamlListElement as their parent and
/// adds
/// them to it. If the previously added node to the same xamlParentElement was a List, adds the elements to that list.
/// Otherwise, we create a new xamlListElement and add them to it. Elements are added as long as li elements appear
/// sequentially.
/// The first non-li or text node stops the addition.
/// </summary>
/// <param name="xamlParentElement">
/// Parent element for the list
/// </param>
/// <param name="htmlLiElement">
/// Start Html li element without parent list
/// </param>
/// <param name="inheritedProperties">
/// Properties inherited from parent context
/// </param>
/// <param name="stylesheet"></param>
/// <param name="sourceContext"></param>
/// <returns>
/// XmlNode representing the first non-li node in the input after one or more li's have been processed.
/// </returns>
private static XmlElement AddOrphanListItems(
XmlNode xamlParentElement,
XmlNode htmlLiElement,
Hashtable inheritedProperties,
CssStylesheet stylesheet,
List<XmlElement> sourceContext)
{
Debug.Assert(htmlLiElement.LocalName.ToLower() == "li");
XmlElement lastProcessedListItemElement = null;
// Find out the last element attached to the xamlParentElement, which is the previous sibling of this node
XmlNode xamlListItemElementPreviousSibling = xamlParentElement.LastChild;
XmlElement xamlListElement = null;
if (xamlListItemElementPreviousSibling != null && xamlListItemElementPreviousSibling.LocalName == XamlList)
{
// Previously added Xaml element was a list. We will add the new li to it
xamlListElement = (XmlElement) xamlListItemElementPreviousSibling;
}
else
{
// No list element near. Create our own.
if (xamlParentElement.OwnerDocument != null)
{
xamlListElement = xamlParentElement.OwnerDocument.CreateElement
(
null,
XamlList,
XamlNamespace);
}
if (xamlListElement != null)
{
xamlParentElement.AppendChild(xamlListElement);
}
}
XmlNode htmlChildNode = htmlLiElement;
string htmlChildNodeName = htmlChildNode.LocalName.ToLower();
// Current element properties missed here.
//currentProperties = GetElementProperties(htmlLIElement, inheritedProperties, out localProperties, stylesheet);
// Add li elements to the parent xamlListElement we created as long as they appear sequentially
// Use properties inherited from xamlParentElement for context
while (htmlChildNode != null && htmlChildNodeName == "li")
{
AddListItem
(
xamlListElement,
(XmlElement) htmlChildNode,
inheritedProperties,
stylesheet,
sourceContext);
lastProcessedListItemElement = (XmlElement) htmlChildNode;
htmlChildNode = htmlChildNode.NextSibling;
htmlChildNodeName = htmlChildNode == null
? null
: htmlChildNode.LocalName.ToLower();
}
return lastProcessedListItemElement;
}
/// <summary>
/// adds table cell data to xamlTableCellElement
/// </summary>
/// <param name="xamlTableCellElement">
/// XmlElement representing Xaml TableCell element to which the converted data should be added
/// </param>
/// <param name="htmlDataStartNode">
/// XmlElement representing the start element of data to be added to xamlTableCellElement
/// </param>
/// <param name="currentProperties">
/// Current properties for the html td/th element corresponding to xamlTableCellElement
/// </param>
/// <param name="stylesheet"></param>
/// <param name="sourceContext"></param>
private static void AddDataToTableCell(
XmlElement xamlTableCellElement,
XmlNode htmlDataStartNode,
Hashtable currentProperties,
CssStylesheet stylesheet,
List<XmlElement> sourceContext)
{
// Parameter validation
Debug.Assert(xamlTableCellElement.LocalName == XamlTableCell);
Debug.Assert(currentProperties != null);
for (XmlNode htmlChildNode = htmlDataStartNode;
htmlChildNode != null;
htmlChildNode = htmlChildNode != null
? htmlChildNode.NextSibling
: null)
{
// Process a new html element and add it to the td element
htmlChildNode = AddBlock
(
xamlTableCellElement,
htmlChildNode,
currentProperties,
stylesheet,
sourceContext);
}
}
// .............................................................
//
// Images
//
// .............................................................
private static void AddImage(
XmlElement xamlParentElement,
XmlElement htmlElement,
Hashtable inheritedProperties,
CssStylesheet stylesheet,
List<XmlElement> sourceContext)
{
if (xamlParentElement == null)
{
throw new ArgumentNullException("xamlParentElement");
}
if (htmlElement == null)
{
throw new ArgumentNullException("htmlElement");
}
if (inheritedProperties == null)
{
throw new ArgumentNullException("inheritedProperties");
}
if (stylesheet == null)
{
throw new ArgumentNullException("stylesheet");
}
if (sourceContext == null)
{
throw new ArgumentNullException("sourceContext");
}
// Implement images
}
/// <summary>
/// Adds TableCell elements to xamlTableRowElement.
/// </summary>
/// <param name="xamlTableRowElement">
/// XmlElement representing Xaml TableRow element to which the converted cells should be added
/// </param>
/// <param name="htmlTdStartNode">
/// XmlElement representing the child of tr or tbody element from which we should start adding td elements
/// </param>
/// <param name="currentProperties">
/// properties of the current html tr element to which cells are to be added
/// </param>
/// <param name="columnStarts"></param>
/// <param name="activeRowSpans"></param>
/// <param name="stylesheet"></param>
/// <param name="sourceContext"></param>
/// <returns>
/// XmlElement representing the current position of the iterator among the children of the parent Html tbody/tr element
/// </returns>
private static XmlNode AddTableCellsToTableRow(
XmlNode xamlTableRowElement,
XmlNode htmlTdStartNode,
Hashtable currentProperties,
ArrayList columnStarts,
IList activeRowSpans,
CssStylesheet stylesheet,
List<XmlElement> sourceContext)
{
if (xamlTableRowElement == null)
{
throw new ArgumentNullException("xamlTableRowElement");
}
// parameter validation
Debug.Assert(xamlTableRowElement.LocalName == XamlTableRow);
Debug.Assert(currentProperties != null);
if (columnStarts != null)
{
Debug.Assert(activeRowSpans.Count == columnStarts.Count);
}
XmlNode htmlChildNode = htmlTdStartNode;
int columnIndex = 0;
while (htmlChildNode != null && htmlChildNode.LocalName.ToLower() != "tr" &&
htmlChildNode.LocalName.ToLower() != "tbody" && htmlChildNode.LocalName.ToLower() != "thead" &&
htmlChildNode.LocalName.ToLower() != "tfoot")
{
if (htmlChildNode.LocalName.ToLower() == "td" || htmlChildNode.LocalName.ToLower() == "th")
{
if (xamlTableRowElement.OwnerDocument != null)
{
XmlElement xamlTableCellElement = xamlTableRowElement.OwnerDocument.CreateElement
(
null,
XamlTableCell,
XamlNamespace);
sourceContext.Add((XmlElement) htmlChildNode);
Hashtable tdElementLocalProperties;
Hashtable tdElementCurrentProperties = GetElementProperties
(
(XmlElement) htmlChildNode,
currentProperties,
out tdElementLocalProperties,
stylesheet,
sourceContext);
// TODO: determine if localProperties can be used instead of htmlChildNode in this call, and if they can,
// make necessary changes and use them instead.
ApplyPropertiesToTableCellElement
(
(XmlElement) htmlChildNode,
xamlTableCellElement);
if (columnStarts != null)
{
Debug.Assert(columnIndex < columnStarts.Count - 1);
while (columnIndex < activeRowSpans.Count && (int) activeRowSpans[columnIndex] > 0)
{
activeRowSpans[columnIndex] = (int) activeRowSpans[columnIndex] - 1;
Debug.Assert((int) activeRowSpans[columnIndex] >= 0);
columnIndex++;
}
Debug.Assert(columnIndex < columnStarts.Count - 1);
double columnWidth = GetColumnWidth((XmlElement) htmlChildNode);
int columnSpan = CalculateColumnSpan
(
columnIndex,
columnWidth,
columnStarts);
int rowSpan = GetRowSpan((XmlElement) htmlChildNode);
// Column cannot have no span
Debug.Assert(columnSpan > 0);
Debug.Assert(columnIndex + columnSpan < columnStarts.Count);
xamlTableCellElement.SetAttribute
(
XamlTableCellColumnSpan,
columnSpan.ToString(CultureInfo.InvariantCulture));
// Apply row span
for (int spannedColumnIndex = columnIndex;
spannedColumnIndex < columnIndex + columnSpan;
spannedColumnIndex++)
{
Debug.Assert(spannedColumnIndex < activeRowSpans.Count);
activeRowSpans[spannedColumnIndex] = (rowSpan - 1);
Debug.Assert((int) activeRowSpans[spannedColumnIndex] >= 0);
}
columnIndex = columnIndex + columnSpan;
}
AddDataToTableCell
(
xamlTableCellElement,
htmlChildNode.FirstChild,
tdElementCurrentProperties,
stylesheet,
sourceContext);
if (xamlTableCellElement.HasChildNodes)
{
xamlTableRowElement.AppendChild(xamlTableCellElement);
}
}
Debug.Assert(sourceContext.Count > 0 && sourceContext[sourceContext.Count - 1] == htmlChildNode);
sourceContext.RemoveAt(sourceContext.Count - 1);
htmlChildNode = htmlChildNode.NextSibling;
}
else
{
// Not td element. Ignore it.
// TODO: Consider better recovery
htmlChildNode = htmlChildNode.NextSibling;
}
}
return htmlChildNode;
}
/// <summary>
/// Converts htmlColElement into Xaml TableColumn element, and appends it to the parent
/// xamlTableColumnGroupElement
/// </summary>
/// <param name="xamlTableElement"></param>
/// <param name="htmlColElement">
/// XmlElement representing Html col element to be converted
/// </param>
/// <param name="inheritedProperties">
/// properties inherited from parent context
/// </param>
/// <param name="stylesheet"></param>
/// <param name="sourceContext"></param>
private static void AddTableColumn(
XmlNode xamlTableElement,
XmlElement htmlColElement,
Hashtable inheritedProperties,
CssStylesheet stylesheet,
List<XmlElement> sourceContext)
{
Hashtable localProperties;
Hashtable currentProperties = GetElementProperties
(
htmlColElement,
inheritedProperties,
out localProperties,
stylesheet,
sourceContext);
if (xamlTableElement.OwnerDocument == null)
{
return;
}
XmlElement xamlTableColumnElement = xamlTableElement.OwnerDocument.CreateElement
(
null,
XamlTableColumn,
XamlNamespace);
// TODO: process local properties for TableColumn element
// Col is an empty element, with no subtree
xamlTableElement.AppendChild(xamlTableColumnElement);
}
private static void AddSpanOrRun(
XmlNode xamlParentElement,
XmlElement htmlElement,
Hashtable inheritedProperties,
CssStylesheet stylesheet,
List<XmlElement> sourceContext)
{
// Decide what XAML element to use for this inline element.
// Check whether it contains any nested inlines
bool elementHasChildren = false;
for (XmlNode htmlNode = htmlElement.FirstChild;
htmlNode != null;
htmlNode = htmlNode.NextSibling)
{
if (!(htmlNode is XmlElement))
{
continue;
}
string htmlChildName = (htmlNode).LocalName.ToLower();
if (!HtmlSchema.IsInlineElement(htmlChildName) && !HtmlSchema.IsBlockElement(htmlChildName) &&
htmlChildName != "img" && htmlChildName != "br" && htmlChildName != "SelectHR")
{
continue;
}
elementHasChildren = true;
break;
}
string xamlElementName = elementHasChildren
? XamlSpan
: XamlRun;
// Create currentProperties as a compilation of local and inheritedProperties, set localProperties
Hashtable localProperties;
Hashtable currentProperties = GetElementProperties
(
htmlElement,
inheritedProperties,
out localProperties,
stylesheet,
sourceContext);
// Create a XAML element corresponding to this html element
if (xamlParentElement.OwnerDocument == null)
{
return;
}
XmlElement xamlElement = xamlParentElement.OwnerDocument.CreateElement
(
/*prefix:*/
null, /*localName:*/xamlElementName,
XamlNamespace);
ApplyLocalProperties
(
xamlElement,
localProperties, /*isBlock:*/false);
// Recurse into element subtree
for (XmlNode htmlChildNode = htmlElement.FirstChild;
htmlChildNode != null;
htmlChildNode = htmlChildNode.NextSibling)
{
AddInline
(
xamlElement,
htmlChildNode,
currentProperties,
stylesheet,
sourceContext);
}
// Add the new element to the parent.
xamlParentElement.AppendChild(xamlElement);
}
// .............................................................
//
// Tables
//
// .............................................................
/// <summary>
/// Converts htmlTableElement to a Xaml Table element. Adds tbody elements if they are missing so
/// that a resulting Xaml Table element is properly formed.
/// </summary>
/// <param name="xamlParentElement">
/// Parent xaml element to which a converted table must be added.
/// </param>
/// <param name="htmlTableElement">
/// XmlElement reprsenting the Html table element to be converted
/// </param>
/// <param name="inheritedProperties">
/// Hashtable representing properties inherited from parent context.
/// </param>
/// <param name="stylesheet"></param>
/// <param name="sourceContext"></param>
private static void AddTable(
XmlElement xamlParentElement,
XmlElement htmlTableElement,
Hashtable inheritedProperties,
CssStylesheet stylesheet,
List<XmlElement> sourceContext)
{
// Parameter validation
Debug.Assert(htmlTableElement.LocalName.ToLower() == "table");
Debug.Assert(xamlParentElement != null);
Debug.Assert(inheritedProperties != null);
// Create current properties to be used by children as inherited properties, set local properties
Hashtable localProperties;
Hashtable currentProperties = GetElementProperties
(
htmlTableElement,
inheritedProperties,
out localProperties,
stylesheet,
sourceContext);
// TODO: process localProperties for tables to override defaults, decide cell spacing defaults
// Check if the table contains only one cell - we want to take only its content
XmlElement singleCell = GetCellFromSingleCellTable(htmlTableElement);
if (singleCell != null)
{
// Need to push skipped table elements onto sourceContext
sourceContext.Add(singleCell);
// Add the cell's content directly to parent
for (XmlNode htmlChildNode = singleCell.FirstChild;
htmlChildNode != null;
htmlChildNode = htmlChildNode != null
? htmlChildNode.NextSibling
: null)
{
htmlChildNode = AddBlock
(
xamlParentElement,
htmlChildNode,
currentProperties,
stylesheet,
sourceContext);
}
Debug.Assert(sourceContext.Count > 0 && sourceContext[sourceContext.Count - 1] == singleCell);
sourceContext.RemoveAt(sourceContext.Count - 1);
}
else
{
// Create xamlTableElement
if (xamlParentElement.OwnerDocument != null)
{
XmlElement xamlTableElement = xamlParentElement.OwnerDocument.CreateElement
(
null,
XamlTable,
XamlNamespace);
// Analyze table structure for column widths and rowspan attributes
ArrayList columnStarts = AnalyzeTableStructure
(
htmlTableElement,
stylesheet);
// Process COLGROUP & COL elements
AddColumnInformation
(
htmlTableElement,
xamlTableElement,
columnStarts,
currentProperties,
stylesheet,
sourceContext);
// Process table body - TBODY and TR elements
XmlNode htmlChildNode = htmlTableElement.FirstChild;
while (htmlChildNode != null)
{
string htmlChildName = htmlChildNode.LocalName.ToLower();
// Process the element
switch (htmlChildName)
{
case "tfoot":
case "thead":
case "tbody":
{
// Add more special processing for TableHeader and TableFooter
if (xamlTableElement.OwnerDocument != null)
{
XmlElement xamlTableBodyElement = xamlTableElement.OwnerDocument.CreateElement
(
null,
XamlTableRowGroup,
XamlNamespace);
xamlTableElement.AppendChild(xamlTableBodyElement);
sourceContext.Add((XmlElement) htmlChildNode);
// Get properties of Html tbody element
Hashtable tbodyElementLocalProperties;
Hashtable tbodyElementCurrentProperties =
GetElementProperties
(
(XmlElement) htmlChildNode,
currentProperties,
out tbodyElementLocalProperties,
stylesheet,
sourceContext);
// TODO: apply local properties for tbody
// Process children of htmlChildNode, which is tbody, for tr elements
AddTableRowsToTableBody
(
xamlTableBodyElement,
htmlChildNode.FirstChild,
tbodyElementCurrentProperties,
columnStarts,
stylesheet,
sourceContext);
if (xamlTableBodyElement.HasChildNodes)
{
xamlTableElement.AppendChild(xamlTableBodyElement);
// else: if there is no TRs in this TBody, we simply ignore it
}
}
Debug.Assert
(
sourceContext.Count > 0 &&
sourceContext[sourceContext.Count - 1] == htmlChildNode);
sourceContext.RemoveAt(sourceContext.Count - 1);
htmlChildNode = htmlChildNode.NextSibling;
}
break;
case "tr":
{
// Tbody is not present, but tr element is present. Tr is wrapped in tbody
if (xamlTableElement.OwnerDocument != null)
{
XmlElement xamlTableBodyElement = xamlTableElement.OwnerDocument.CreateElement
(
null,
XamlTableRowGroup,
XamlNamespace);
// We use currentProperties of xamlTableElement when adding rows since the tbody element is artificially created and has
// no properties of its own
htmlChildNode = AddTableRowsToTableBody
(
xamlTableBodyElement,
htmlChildNode,
currentProperties,
columnStarts,
stylesheet,
sourceContext);
if (xamlTableBodyElement.HasChildNodes)
{
xamlTableElement.AppendChild(xamlTableBodyElement);
}
}
}
break;
default:
htmlChildNode = htmlChildNode.NextSibling;
break;
}
}
if (xamlTableElement.HasChildNodes)
{
xamlParentElement.AppendChild(xamlTableElement);
}
}
}
}
// .............................................................
//
// Text Flow Elements
//
// .............................................................
/// <summary>
/// Generates Section or Paragraph element from DIV depending whether it contains any block elements or not
/// </summary>
/// <param name="xamlParentElement">
/// XmlElement representing Xaml parent to which the converted element should be added
/// </param>
/// <param name="htmlElement">
/// XmlElement representing Html element to be converted
/// </param>
/// <param name="inheritedProperties">
/// properties inherited from parent context
/// </param>
/// <param name="stylesheet"></param>
/// <param name="sourceContext"></param>
/// true indicates that a content added by this call contains at least one block element
private static void AddSection(
XmlElement xamlParentElement,
XmlElement htmlElement,
Hashtable inheritedProperties,
CssStylesheet stylesheet,
List<XmlElement> sourceContext)
{
// Analyze the content of htmlElement to decide what xaml element to choose - Section or Paragraph.
// If this Div has at least one block child then we need to use Section, otherwise use Paragraph
bool htmlElementContainsBlocks = false;
for (XmlNode htmlChildNode = htmlElement.FirstChild;
htmlChildNode != null;
htmlChildNode = htmlChildNode.NextSibling)
{
if (!(htmlChildNode is XmlElement))
{
continue;
}
string htmlChildName = (htmlChildNode).LocalName.ToLower();
if (!HtmlSchema.IsBlockElement(htmlChildName))
{
continue;
}
htmlElementContainsBlocks = true;
break;
}
if (!htmlElementContainsBlocks)
{
// The Div does not contain any block elements, so we can treat it as a Paragraph
AddParagraph
(
xamlParentElement,
htmlElement,
inheritedProperties,
stylesheet,
sourceContext);
}
else
{
// The Div has some nested blocks, so we treat it as a Section
// Create currentProperties as a compilation of local and inheritedProperties, set localProperties
Hashtable localProperties;
Hashtable currentProperties = GetElementProperties
(
htmlElement,
inheritedProperties,
out localProperties,
stylesheet,
sourceContext);
// Create a XAML element corresponding to this html element
if (xamlParentElement.OwnerDocument != null)
{
XmlElement xamlElement = xamlParentElement.OwnerDocument.CreateElement
(
/*prefix:*/
null, /*localName:*/XamlSection,
XamlNamespace);
ApplyLocalProperties
(
xamlElement,
localProperties, /*isBlock:*/true);
// Decide whether we can unwrap this element as not having any formatting significance.
if (!xamlElement.HasAttributes)
{
// This elements is a group of block elements whitout any additional formatting.
// We can add blocks directly to xamlParentElement and avoid
// creating unnecessary Sections nesting.
xamlElement = xamlParentElement;
}
// Recurse into element subtree
for (XmlNode htmlChildNode = htmlElement.FirstChild;
htmlChildNode != null;
htmlChildNode = htmlChildNode != null
? htmlChildNode.NextSibling
: null)
{
htmlChildNode = AddBlock
(
xamlElement,
htmlChildNode,
currentProperties,
stylesheet,
sourceContext);
}
// Add the new element to the parent.
if (xamlElement != xamlParentElement)
{
xamlParentElement.AppendChild(xamlElement);
}
}
}
}
/// <summary>
/// Converts an html string into xaml string.
/// </summary>
/// <param name="htmlString">
/// Input html which may be badly formated xml.
/// </param>
/// <param name="asFlowDocument">
/// true indicates that we need a FlowDocument as a root element;
/// false means that Section or Span elements will be used
/// dependeing on StartFragment/EndFragment comments locations.
/// </param>
/// <returns>
/// Well-formed xml representing XAML equivalent for the input html string.
/// </returns>
public static string ConvertHtmlToXaml(
string htmlString,
bool asFlowDocument)
{
// Create well-formed Xml from Html string
XmlElement htmlElement = HtmlParser.ParseHtml(htmlString);
// Decide what name to use as a root
string rootElementName = asFlowDocument
? XamlFlowDocument
: XamlSection;
// Create an XmlDocument for generated xaml
var xamlTree = new XmlDocument();
XmlElement xamlFlowDocumentElement = xamlTree.CreateElement
(
null,
rootElementName,
XamlNamespace);
// Extract style definitions from all STYLE elements in the document
var stylesheet = new CssStylesheet(htmlElement);
// Source context is a stack of all elements - ancestors of a parentElement
var sourceContext = new List<XmlElement>(10);
// Clear fragment parent
_inlineFragmentParentElement = null;
// convert root html element
AddBlock
(
xamlFlowDocumentElement,
htmlElement,
new Hashtable(),
stylesheet,
sourceContext);
// In case if the selected fragment is inline, extract it into a separate Span wrapper
if (!asFlowDocument)
{
xamlFlowDocumentElement = ExtractInlineFragment(xamlFlowDocumentElement);
}
// Return a string representing resulting Xaml
xamlFlowDocumentElement.SetAttribute
(
"xml:space",
"preserve");
string xaml = xamlFlowDocumentElement.OuterXml;
return xaml;
}
/// <summary>
/// Generates Paragraph element from P, H1-H7, Center etc.
/// </summary>
/// <param name="xamlParentElement">
/// XmlElement representing Xaml parent to which the converted element should be added
/// </param>
/// <param name="htmlElement">
/// XmlElement representing Html element to be converted
/// </param>
/// <param name="inheritedProperties">
/// properties inherited from parent context
/// </param>
/// <param name="stylesheet"></param>
/// <param name="sourceContext"></param>
/// true indicates that a content added by this call contains at least one block element
private static void AddParagraph(
XmlNode xamlParentElement,
XmlElement htmlElement,
Hashtable inheritedProperties,
CssStylesheet stylesheet,
List<XmlElement> sourceContext)
{
// Create currentProperties as a compilation of local and inheritedProperties, set localProperties
Hashtable localProperties;
Hashtable currentProperties = GetElementProperties
(
htmlElement,
inheritedProperties,
out localProperties,
stylesheet,
sourceContext);
// Create a XAML element corresponding to this html element
if (xamlParentElement.OwnerDocument == null)
{
return;
}
XmlElement xamlElement = xamlParentElement.OwnerDocument.CreateElement
(
/*prefix:*/
null, /*localName:*/XamlParagraph,
XamlNamespace);
ApplyLocalProperties
(
xamlElement,
localProperties, /*isBlock:*/true);
// Recurse into element subtree
for (XmlNode htmlChildNode = htmlElement.FirstChild;
htmlChildNode != null;
htmlChildNode = htmlChildNode.NextSibling)
{
AddInline
(
xamlElement,
htmlChildNode,
currentProperties,
stylesheet,
sourceContext);
}
// Add the new element to the parent.
xamlParentElement.AppendChild(xamlElement);
}
/// <summary>
/// Analyzes the tag of the htmlElement and infers its associated formatted properties.
/// After that parses style attribute and adds all inline css styles.
/// The resulting style attributes are collected in output parameter localProperties.
/// </summary>
/// <param name="htmlElement">
/// </param>
/// <param name="inheritedProperties">
/// set of properties inherited from ancestor elements. Currently not used in the code. Reserved for the future
/// development.
/// </param>
/// <param name="localProperties">
/// returns all formatting properties defined by this element - implied by its tag, its attributes, or its css inline
/// style
/// </param>
/// <param name="stylesheet"></param>
/// <param name="sourceContext"></param>
/// <returns>
/// returns a combination of previous context with local set of properties.
/// This value is not used in the current code - inntended for the future development.
/// </returns>
private static Hashtable GetElementProperties(
XmlElement htmlElement,
IDictionary inheritedProperties,
out Hashtable localProperties,
CssStylesheet stylesheet,
List<XmlElement> sourceContext)
{
// Start with context formatting properties
var currentProperties = new Hashtable();
IDictionaryEnumerator propertyEnumerator = inheritedProperties.GetEnumerator();
while (propertyEnumerator.MoveNext())
{
currentProperties[propertyEnumerator.Key] = propertyEnumerator.Value;
}
// Identify element name
string elementName = htmlElement.LocalName.ToLower();
// update current formatting properties depending on element tag
localProperties = new Hashtable();
switch (elementName)
{
// Character formatting
case "i":
case "italic":
case "em":
localProperties["font-style"] = "italic";
break;
case "b":
case "bold":
case "strong":
case "dfn":
localProperties["font-weight"] = "bold";
break;
case "u":
case "underline":
localProperties["text-decoration-underline"] = "true";
break;
case "font":
string attributeValue = GetAttribute
(
htmlElement,
"face");
if (attributeValue != null)
{
localProperties["font-family"] = attributeValue;
}
attributeValue = GetAttribute
(
htmlElement,
"size");
if (attributeValue != null)
{
double fontSize = double.Parse(attributeValue)*(12.0/3.0);
if (fontSize < 1.0)
{
fontSize = 1.0;
}
else if (fontSize > 1000.0)
{
fontSize = 1000.0;
}
localProperties["font-size"] = fontSize.ToString(CultureInfo.InvariantCulture);
}
attributeValue = GetAttribute
(
htmlElement,
"color");
if (attributeValue != null)
{
localProperties["color"] = attributeValue;
}
break;
case "samp":
localProperties["font-family"] = "Courier New"; // code CodePanel
localProperties["font-size"] = XamlFontSizeXxSmall;
localProperties["text-align"] = "Left";
break;
case "sub":
break;
case "sup":
break;
// Hyperlinks
case "a": // href, hreflang, urn, methods, rel, rev, title
// Set default hyperlink properties
break;
case "acronym":
break;
// Paragraph formatting:
case "p":
// Set default paragraph properties
break;
case "div":
// Set default div properties
break;
case "pre":
localProperties["font-family"] = "Courier New"; // renders text in a fixed-width font
localProperties["font-size"] = XamlFontSizeXxSmall;
localProperties["text-align"] = "Left";
break;
case "blockquote":
localProperties["margin-left"] = "16";
break;
case "h1":
localProperties["font-size"] = XamlFontSizeXxLarge;
break;
case "h2":
localProperties["font-size"] = XamlFontSizeXLarge;
break;
case "h3":
localProperties["font-size"] = XamlFontSizeLarge;
break;
case "h4":
localProperties["font-size"] = XamlFontSizeMedium;
break;
case "h5":
localProperties["font-size"] = XamlFontSizeSmall;
break;
case "h6":
localProperties["font-size"] = XamlFontSizeXSmall;
break;
// List properties
case "ul":
localProperties["list-style-type"] = "diStockControl";
break;
case "ol":
localProperties["list-style-type"] = "decimal";
break;
case "table":
case "body":
case "html":
break;
}
// Override html defaults by css attributes - from stylesheets and inline settings
HtmlCssParser.GetElementPropertiesFromCssAttributes
(
htmlElement,
elementName,
stylesheet,
localProperties,
sourceContext);
// Combine local properties with context to create new current properties
propertyEnumerator = localProperties.GetEnumerator();
while (propertyEnumerator.MoveNext())
{
currentProperties[propertyEnumerator.Key] = propertyEnumerator.Value;
}
return currentProperties;
}
/// <summary>
/// Converts htmlColgroupElement into Xaml TableColumnGroup element, and appends it to the parent
/// xamlTableElement
/// </summary>
/// <param name="xamlTableElement">
/// XmlElement representing Xaml Table element to which the converted column group should be added
/// </param>
/// <param name="htmlColgroupElement" />
/// XmlElement representing Html colgroup element to be converted
/// <param name="inheritedProperties">
/// Properties inherited from parent context
/// </param>
/// <param name="stylesheet"></param>
/// <param name="sourceContext"></param>
private static void AddTableColumnGroup(
XmlElement xamlTableElement,
XmlElement htmlColgroupElement,
Hashtable inheritedProperties,
CssStylesheet stylesheet,
List<XmlElement> sourceContext)
{
Hashtable localProperties;
Hashtable currentProperties = GetElementProperties
(
htmlColgroupElement,
inheritedProperties,
out localProperties,
stylesheet,
sourceContext);
// TODO: process local properties for colgroup
// Process children of colgroup. Colgroup may contain only col elements.
for (XmlNode htmlNode = htmlColgroupElement.FirstChild;
htmlNode != null;
htmlNode = htmlNode.NextSibling)
{
if (htmlNode is XmlElement && htmlNode.LocalName.ToLower() == "col")
{
AddTableColumn
(
xamlTableElement,
(XmlElement) htmlNode,
currentProperties,
stylesheet,
sourceContext);
}
}
}
/// <summary>
/// Processes the information about table columns - COLGROUP and COL html elements.
/// </summary>
/// <param name="htmlTableElement">
/// XmlElement representing a source html table.
/// </param>
/// <param name="xamlTableElement">
/// XmlElement repesenting a resulting xaml table.
/// </param>
/// <param name="columnStartsAllRows">
/// Array of doubles - column start coordinates.
/// Can be null, which means that column size information is not available
/// and we must use source colgroup/col information.
/// In case wneh it's not null, we will ignore source colgroup/col information.
/// </param>
/// <param name="currentProperties"></param>
/// <param name="stylesheet"></param>
/// <param name="sourceContext"></param>
private static void AddColumnInformation(
XmlNode htmlTableElement,
XmlElement xamlTableElement,
IList columnStartsAllRows,
Hashtable currentProperties,
CssStylesheet stylesheet,
List<XmlElement> sourceContext)
{
// Add column information
if (columnStartsAllRows != null)
{
// We have consistent information derived from table cells; use it
// The last element in columnStarts represents the end of the table
for (int columnIndex = 0;
columnIndex < columnStartsAllRows.Count - 1;
columnIndex++)
{
if (xamlTableElement.OwnerDocument == null)
{
continue;
}
XmlElement xamlColumnElement = xamlTableElement.OwnerDocument.CreateElement
(
null,
XamlTableColumn,
XamlNamespace);
xamlColumnElement.SetAttribute
(
XamlWidth,
((double) columnStartsAllRows[columnIndex + 1] -
(double) columnStartsAllRows[columnIndex]).ToString
(
CultureInfo.InvariantCulture));
xamlTableElement.AppendChild(xamlColumnElement);
}
}
else
{
// We do not have consistent information from table cells;
// Translate blindly colgroups from html.
for (XmlNode htmlChildNode = htmlTableElement.FirstChild;
htmlChildNode != null;
htmlChildNode = htmlChildNode.NextSibling)
{
if (htmlChildNode.LocalName.ToLower() == "colgroup")
{
// TODO: add column width information to this function as a parameter and process it
AddTableColumnGroup
(
xamlTableElement,
(XmlElement) htmlChildNode,
currentProperties,
stylesheet,
sourceContext);
}
else if (htmlChildNode.LocalName.ToLower() == "col")
{
AddTableColumn
(
xamlTableElement,
(XmlElement) htmlChildNode,
currentProperties,
stylesheet,
sourceContext);
}
else if (htmlChildNode is XmlElement)
{
// Some element which belongs to table body. Stop column loop.
break;
}
}
}
}
/// <summary>
/// Adds TableRow elements to xamlTableBodyElement. The rows are converted from Html tr elements that
/// may be the children of an Html tbody element or an Html table element with tbody missing
/// </summary>
/// <param name="xamlTableBodyElement">
/// XmlElement representing Xaml TableRowGroup element to which the converted rows should be added
/// </param>
/// <param name="htmlTrStartNode">
/// XmlElement representing the first tr child of the tbody element to be read
/// </param>
/// <param name="currentProperties">
/// Hashtable representing current properties of the tbody element that are generated and applied in the
/// AddTable function; to be used as inheritedProperties when adding tr elements
/// </param>
/// <param name="columnStarts"></param>
/// <param name="stylesheet"></param>
/// <param name="sourceContext"></param>
/// <returns>
/// XmlNode representing the current position of the iterator among tr elements
/// </returns>
private static XmlNode AddTableRowsToTableBody(
XmlNode xamlTableBodyElement,
XmlNode htmlTrStartNode,
Hashtable currentProperties,
ArrayList columnStarts,
CssStylesheet stylesheet,
List<XmlElement> sourceContext)
{
// Parameter validation
Debug.Assert(xamlTableBodyElement.LocalName == XamlTableRowGroup);
Debug.Assert(currentProperties != null);
// Initialize child node for iteratimg through children to the first tr element
XmlNode htmlChildNode = htmlTrStartNode;
ArrayList activeRowSpans = null;
if (columnStarts != null)
{
activeRowSpans = new ArrayList();
InitializeActiveRowSpans
(
activeRowSpans,
columnStarts.Count);
}
while (htmlChildNode != null && htmlChildNode.LocalName.ToLower() != "tbody")
{
switch (htmlChildNode.LocalName.ToLower())
{
case "tr":
{
if (xamlTableBodyElement.OwnerDocument != null)
{
XmlElement xamlTableRowElement = xamlTableBodyElement.OwnerDocument.CreateElement
(
null,
XamlTableRow,
XamlNamespace);
sourceContext.Add((XmlElement) htmlChildNode);
// Get tr element properties
Hashtable trElementLocalProperties;
Hashtable trElementCurrentProperties = GetElementProperties
(
(XmlElement) htmlChildNode,
currentProperties,
out trElementLocalProperties,
stylesheet,
sourceContext);
// TODO: apply local properties to tr element
AddTableCellsToTableRow
(
xamlTableRowElement,
htmlChildNode.FirstChild,
trElementCurrentProperties,
columnStarts,
activeRowSpans,
stylesheet,
sourceContext);
if (xamlTableRowElement.HasChildNodes)
{
xamlTableBodyElement.AppendChild(xamlTableRowElement);
}
}
Debug.Assert(sourceContext.Count > 0 && sourceContext[sourceContext.Count - 1] == htmlChildNode);
sourceContext.RemoveAt(sourceContext.Count - 1);
// Advance
htmlChildNode = htmlChildNode.NextSibling;
}
break;
case "td":
{
// Tr element is not present. We create one and add td elements to it
if (xamlTableBodyElement.OwnerDocument != null)
{
XmlElement xamlTableRowElement = xamlTableBodyElement.OwnerDocument.CreateElement
(
null,
XamlTableRow,
XamlNamespace);
// This is incorrect formatting and the column starts should not be set in this case
Debug.Assert(columnStarts == null);
htmlChildNode = AddTableCellsToTableRow
(
xamlTableRowElement,
htmlChildNode,
currentProperties,
null,
null,
stylesheet,
sourceContext);
if (xamlTableRowElement.HasChildNodes)
{
xamlTableBodyElement.AppendChild(xamlTableRowElement);
}
}
}
break;
default:
htmlChildNode = htmlChildNode.NextSibling;
break;
}
}
return htmlChildNode;
}
private static void AddHyperlink(
XmlNode xamlParentElement,
XmlElement htmlElement,
Hashtable inheritedProperties,
CssStylesheet stylesheet,
List<XmlElement> sourceContext)
{
// Convert href attribute into NavigateUri and TargetName
string href = GetAttribute
(
htmlElement,
"href");
if (href == null)
{
// When href attribute is missing - ignore the hyperlink
AddSpanOrRun
(
xamlParentElement,
htmlElement,
inheritedProperties,
stylesheet,
sourceContext);
}
else
{
// Create currentProperties as a compilation of local and inheritedProperties, set localProperties
Hashtable localProperties;
Hashtable currentProperties = GetElementProperties
(
htmlElement,
inheritedProperties,
out localProperties,
stylesheet,
sourceContext);
// Create a XAML element corresponding to this html element
if (xamlParentElement.OwnerDocument != null)
{
XmlElement xamlElement = xamlParentElement.OwnerDocument.CreateElement
(
/*prefix:*/
null, /*localName:*/XamlHyperlink,
XamlNamespace);
ApplyLocalProperties
(
xamlElement,
localProperties, /*isBlock:*/false);
string[] hrefParts = href.Split('#');
if (hrefParts.Length > 0 && hrefParts[0].Trim()
.Length > 0)
{
xamlElement.SetAttribute
(
XamlHyperlinkNavigateUri,
hrefParts[0].Trim());
}
if (hrefParts.Length == 2 && hrefParts[1].Trim()
.Length > 0)
{
xamlElement.SetAttribute
(
XamlHyperlinkTargetName,
hrefParts[1].Trim());
}
// Recurse into element subtree
for (XmlNode htmlChildNode = htmlElement.FirstChild;
htmlChildNode != null;
htmlChildNode = htmlChildNode.NextSibling)
{
AddInline
(
xamlElement,
htmlChildNode,
currentProperties,
stylesheet,
sourceContext);
}
// Add the new element to the parent.
xamlParentElement.AppendChild(xamlElement);
}
}
}
// ReSharper restore FunctionRecursiveOnAllPaths
/// <summary>
/// Performs a parsing pass over a table to read information about column width and rowspan attributes. This
/// information
/// is used to determine the starting point of each column.
/// </summary>
/// <param name="htmlTableElement"></param>
/// <param name="stylesheet"></param>
/// <returns>
/// ArrayList of type double which contains the function output. If analysis is successful, this ArrayList contains
/// all the points which are the starting position of any column in the table, ordered from left to right.
/// In case if analisys was impossible we return null.
/// </returns>
// ReSharper disable FunctionRecursiveOnAllPaths
private static ArrayList AnalyzeTableStructure(
object htmlTableElement,
CssStylesheet stylesheet)
{
try
{
if (htmlTableElement == null)
{
throw new ArgumentNullException("htmlTableElement");
}
if (stylesheet == null)
{
throw new ArgumentNullException("stylesheet");
}
return AnalyzeTableStructure
(
null,
stylesheet);
}
catch (Exception)
{
return null;
}
}
/// <summary>
/// Creates a Paragraph element and adds all nodes starting from htmlNode
/// converted to appropriate Inlines.
/// </summary>
/// <param name="xamlParentElement">
/// XmlElement representing Xaml parent to which the converted element should be added
/// </param>
/// <param name="htmlNode">
/// XmlNode starting a collection of implicitly wrapped inlines.
/// </param>
/// <param name="inheritedProperties">
/// properties inherited from parent context
/// </param>
/// <param name="stylesheet"></param>
/// <param name="sourceContext"></param>
/// true indicates that a content added by this call contains at least one block element
/// <returns>
/// The last htmlNode added to the implicit paragraph
/// </returns>
private static XmlNode AddImplicitParagraph(
XmlNode xamlParentElement,
XmlNode htmlNode,
Hashtable inheritedProperties,
CssStylesheet stylesheet,
List<XmlElement> sourceContext)
{
// Collect all non-block elements and wrap them into implicit Paragraph
if (xamlParentElement.OwnerDocument != null)
{
XmlElement xamlParagraph = xamlParentElement.OwnerDocument.CreateElement
(
/*prefix:*/
null, /*localName:*/XamlParagraph,
XamlNamespace);
XmlNode lastNodeProcessed = null;
while (htmlNode != null)
{
var node = htmlNode as XmlComment;
if (node != null)
{
DefineInlineFragmentParent(node, /*xamlParentElement:*/null);
}
else if (htmlNode is XmlText)
{
if (htmlNode.Value.Trim()
.Length > 0)
{
AddTextRun
(
xamlParagraph,
htmlNode.Value);
}
}
else if (htmlNode is XmlElement)
{
string htmlChildName = (htmlNode).LocalName.ToLower();
if (HtmlSchema.IsBlockElement(htmlChildName))
{
// The sequence of non-blocked inlines ended. Stop implicit loop here.
break;
}
AddInline
(
xamlParagraph,
htmlNode,
inheritedProperties,
stylesheet,
sourceContext);
}
// Store last processed node to return it at the end
lastNodeProcessed = htmlNode;
htmlNode = htmlNode.NextSibling;
}
// Add the Paragraph to the parent
// If only whitespaces and commens have been encountered,
// then we have nothing to add in implicit paragraph; forget it.
if (xamlParagraph.FirstChild != null)
{
xamlParentElement.AppendChild(xamlParagraph);
}
// Need to return last processed node
return lastNodeProcessed;
}
return null;
}
/// <summary>
/// Performs a parsing pass over a table to read information about column width and rowspan attributes. This
/// information
/// is used to determine the starting point of each column.
/// </summary>
/// <param name="htmlTableElement">
/// XmlElement representing Html table whose structure is to be analyzed
/// </param>
/// <param name="stylesheet"></param>
/// <param name="epsilon"></param>
/// <returns>
/// ArrayList of type double which contains the function output. If analysis is successful, this ArrayList contains
/// all the points which are the starting position of any column in the table, ordered from left to right.
/// In case if analisys was impossible we return null.
/// </returns>
private static ArrayList AnalyzeTableStructure(
XmlNode htmlTableElement,
CssStylesheet stylesheet,
double epsilon)
{
if (htmlTableElement == null)
{
throw new ArgumentNullException("htmlTableElement");
}
// Parameter validation
Debug.Assert(htmlTableElement.LocalName.ToLower() == "table");
if (!htmlTableElement.HasChildNodes)
{
return null;
}
bool columnWidthsAvailable = true;
var columnStarts = new ArrayList();
var activeRowSpans = new ArrayList();
Debug.Assert(columnStarts.Count == activeRowSpans.Count);
XmlNode htmlChildNode = htmlTableElement.FirstChild;
double tableWidth = 0; // Keep track of table width which is the width of its widest row
// Analyze tbody and tr elements
while (htmlChildNode != null && columnWidthsAvailable)
{
Debug.Assert(columnStarts.Count == activeRowSpans.Count);
switch (htmlChildNode.LocalName.ToLower())
{
case "tbody":
// Tbody element, we should analyze its children for trows
double tbodyWidth = AnalyzeTbodyStructure
(
htmlChildNode,
columnStarts,
activeRowSpans,
stylesheet);
if (tbodyWidth > tableWidth)
{
// Table width must be increased to supported newly added wide row
tableWidth = tbodyWidth;
}
else if (Math.Abs(tbodyWidth - 0) < epsilon)
{
// Tbody analysis may return 0, probably due to unprocessable format.
// We should also fail.
columnWidthsAvailable = false; // interrupt the analisys
}
break;
case "tr":
// Table row. Analyze column structure within row directly
double trWidth = AnalyzeTrStructure
(
htmlChildNode,
columnStarts,
activeRowSpans,
stylesheet);
if (trWidth > tableWidth)
{
tableWidth = trWidth;
}
else if (Math.Abs(trWidth - 0) < epsilon)
{
columnWidthsAvailable = false; // interrupt the analisys
}
break;
case "td":
// Incorrect formatting, too deep to analyze at this level. Return null.
// TODO: implement analysis at this level, possibly by creating a new tr
columnWidthsAvailable = false; // interrupt the analisys
break;
// Element should not occur directly in table. Ignore it.
}
htmlChildNode = htmlChildNode.NextSibling;
}
if (columnWidthsAvailable)
{
// Add an item for whole table width
columnStarts.Add(tableWidth);
VerifyColumnStartsAscendingOrder(columnStarts);
}
else
{
columnStarts = null;
}
return columnStarts;
}
// .............................................................
//
// Lists
//
// .............................................................
/// <summary>
/// Converts Html ul or ol element into Xaml list element. During conversion if the ul/ol element has any children
/// that are not li elements, they are ignored and not added to the list element
/// </summary>
/// <param name="xamlParentElement">
/// XmlElement representing Xaml parent to which the converted element should be added
/// </param>
/// <param name="htmlListElement">
/// XmlElement representing Html ul/ol element to be converted
/// </param>
/// <param name="inheritedProperties">
/// properties inherited from parent context
/// </param>
/// <param name="stylesheet"></param>
/// <param name="sourceContext"></param>
private static void AddList(
XmlNode xamlParentElement,
XmlElement htmlListElement,
Hashtable inheritedProperties,
CssStylesheet stylesheet,
List<XmlElement> sourceContext)
{
string htmlListElementName = htmlListElement.LocalName.ToLower();
Hashtable localProperties;
Hashtable currentProperties = GetElementProperties
(
htmlListElement,
inheritedProperties,
out localProperties,
stylesheet,
sourceContext);
// Create Xaml List element
if (xamlParentElement.OwnerDocument == null)
{
return;
}
XmlElement xamlListElement = xamlParentElement.OwnerDocument.CreateElement
(
null,
XamlList,
XamlNamespace);
// Set default list markers
xamlListElement.SetAttribute
(
XamlListMarkerStyle,
htmlListElementName == "ol"
? XamlListMarkerStyleDecimal
: XamlListMarkerStyleDisc);
// Apply local properties to list to set marker attribute if specified
// TODO: Should we have separate list attribute processing function?
ApplyLocalProperties
(
xamlListElement,
localProperties, /*isBlock:*/true);
// Recurse into list subtree
for (XmlNode htmlChildNode = htmlListElement.FirstChild;
htmlChildNode != null;
htmlChildNode = htmlChildNode.NextSibling)
{
if (!(htmlChildNode is XmlElement) || htmlChildNode.LocalName.ToLower() != "li")
{
// Not an li element. Add it to previous ListBoxItem
// We need to append the content to the end
// of a previous list item.
}
else
{
sourceContext.Add((XmlElement) htmlChildNode);
AddListItem
(
xamlListElement,
(XmlElement) htmlChildNode,
currentProperties,
stylesheet,
sourceContext);
Debug.Assert(sourceContext.Count > 0 && sourceContext[sourceContext.Count - 1] == htmlChildNode);
sourceContext.RemoveAt(sourceContext.Count - 1);
}
}
// Add the List element to xaml tree - if it is not empty
if (xamlListElement.HasChildNodes)
{
xamlParentElement.AppendChild(xamlListElement);
}
}
/// <summary>
/// Converts htmlLIElement into Xaml ListItem element, and appends it to the parent xamlListElement
/// </summary>
/// <param name="xamlListElement">
/// XmlElement representing Xaml List element to which the converted td/th should be added
/// </param>
/// <param name="htmlLiElement">
/// XmlElement representing Html li element to be converted
/// </param>
/// <param name="inheritedProperties">
/// Properties inherited from parent context
/// </param>
/// <param name="stylesheet"></param>
/// <param name="sourceContext"></param>
private static void AddListItem(
XmlNode xamlListElement,
XmlElement htmlLiElement,
Hashtable inheritedProperties,
CssStylesheet stylesheet,
List<XmlElement> sourceContext)
{
// Parameter validation
Debug.Assert(xamlListElement != null);
Debug.Assert(xamlListElement.LocalName == XamlList);
Debug.Assert(htmlLiElement != null);
Debug.Assert(htmlLiElement.LocalName.ToLower() == "li");
Debug.Assert(inheritedProperties != null);
Hashtable localProperties;
Hashtable currentProperties = GetElementProperties
(
htmlLiElement,
inheritedProperties,
out localProperties,
stylesheet,
sourceContext);
if (xamlListElement.OwnerDocument == null)
{
return;
}
XmlElement xamlListItemElement = xamlListElement.OwnerDocument.CreateElement
(
null,
XamlListItem,
XamlNamespace);
// TODO: process local properties for li element
// Process children of the ListItem
for (XmlNode htmlChildNode = htmlLiElement.FirstChild;
htmlChildNode != null;
htmlChildNode = htmlChildNode != null
? htmlChildNode.NextSibling
: null)
{
htmlChildNode = AddBlock
(
xamlListItemElement,
htmlChildNode,
currentProperties,
stylesheet,
sourceContext);
}
// Add resulting ListBoxItem to a xaml parent
xamlListElement.AppendChild(xamlListItemElement);
}
