// ---------------------------------------------------------------------
//
// Internal Methods
//
// ---------------------------------------------------------------------
#region Internal Methods
/// <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 ? HtmlToXamlConverter.Xaml_FlowDocument : HtmlToXamlConverter.Xaml_Section;
// Create an XmlDocument for generated xaml
XmlDocument xamlTree = new XmlDocument();
XmlElement xamlFlowDocumentElement = xamlTree.CreateElement(null, rootElementName, _xamlNamespace);
// Extract style definitions from all STYLE elements in the document
CssStylesheet stylesheet = new CssStylesheet(htmlElement);
// Source context is a stack of all elements - ancestors of a parentElement
List<XmlElement> 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;
}
// .............................................................
//
// Inline Elements
//
// .............................................................
private static void AddInline(XmlElement xamlParentElement, XmlNode htmlNode, Hashtable inheritedProperties, CssStylesheet stylesheet, List<XmlElement> sourceContext)
{
if (htmlNode is XmlComment)
{
DefineInlineFragmentParent((XmlComment)htmlNode, xamlParentElement);
}
else if (htmlNode is XmlText)
{
AddTextRun(xamlParentElement, htmlNode.Value);
}
else if (htmlNode is XmlElement)
{
XmlElement htmlElement = (XmlElement)htmlNode;
// 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 "hr":
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>
/// 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
/// </param>
/// <returns>
/// The last htmlNode added to the implicit paragraph
/// </returns>
private static XmlNode AddImplicitParagraph(XmlElement xamlParentElement, XmlNode htmlNode, Hashtable inheritedProperties, CssStylesheet stylesheet, List<XmlElement> sourceContext)
{
// Collect all non-block elements and wrap them into implicit Paragraph
XmlElement xamlParagraph = xamlParentElement.OwnerDocument.CreateElement(/*prefix:*/null, /*localName:*/HtmlToXamlConverter.Xaml_Paragraph, _xamlNamespace);
XmlNode lastNodeProcessed = null;
while (htmlNode != null)
{
if (htmlNode is XmlComment)
{
DefineInlineFragmentParent((XmlComment)htmlNode, /*xamlParentElement:*/null);
}
else if (htmlNode is XmlText)
{
if (htmlNode.Value.Trim().Length > 0)
{
AddTextRun(xamlParagraph, htmlNode.Value);
}
}
else if (htmlNode is XmlElement)
{
string htmlChildName = ((XmlElement)htmlNode).LocalName.ToLower();
if (HtmlSchema.IsBlockElement(htmlChildName))
{
// The sequence of non-blocked inlines ended. Stop implicit loop here.
break;
}
else
{
AddInline(xamlParagraph, (XmlElement)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;
}
/// <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
/// </param>
private static void AddParagraph(XmlElement 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
XmlElement xamlElement = xamlParentElement.OwnerDocument.CreateElement(/*prefix:*/null, /*localName:*/HtmlToXamlConverter.Xaml_Paragraph, _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>
/// 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(XmlElement htmlTableElement, XmlElement xamlTableElement, ArrayList 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++)
{
XmlElement xamlColumnElement;
xamlColumnElement = xamlTableElement.OwnerDocument.CreateElement(null, Xaml_TableColumn, _xamlNamespace);
xamlColumnElement.SetAttribute(Xaml_Width, ((double)columnStartsAllRows[columnIndex + 1] - (double)columnStartsAllRows[columnIndex]).ToString());
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>
/// 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>
private static void AddListItem(XmlElement xamlListElement, XmlElement htmlLIElement, Hashtable inheritedProperties, CssStylesheet stylesheet, List<XmlElement> sourceContext)
{
// Parameter validation
Debug.Assert(xamlListElement != null);
Debug.Assert(xamlListElement.LocalName == Xaml_List);
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);
XmlElement xamlListItemElement = xamlListElement.OwnerDocument.CreateElement(null, Xaml_ListItem, _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);
}
// .............................................................
//
// 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(XmlElement 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
XmlElement xamlListElement = xamlParentElement.OwnerDocument.CreateElement(null, Xaml_List, _xamlNamespace);
// Set default list markers
if (htmlListElementName == "ol")
{
// Ordered list
xamlListElement.SetAttribute(HtmlToXamlConverter.Xaml_List_MarkerStyle, Xaml_List_MarkerStyle_Decimal);
}
else
{
// Unordered list - all elements other than OL treated as unordered lists
xamlListElement.SetAttribute(HtmlToXamlConverter.Xaml_List_MarkerStyle, Xaml_List_MarkerStyle_Disc);
}
// 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")
{
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);
}
else
{
// Not an li element. Add it to previous ListBoxItem
// We need to append the content to the end
// of a previous list item.
}
}
// Add the List element to xaml tree - if it is not empty
if (xamlListElement.HasChildNodes)
{
xamlParentElement.AppendChild(xamlListElement);
}
}
private static void AddHyperlink(XmlElement 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
XmlElement xamlElement = xamlParentElement.OwnerDocument.CreateElement(/*prefix:*/null, /*localName:*/HtmlToXamlConverter.Xaml_Hyperlink, _xamlNamespace);
ApplyLocalProperties(xamlElement, localProperties, /*isBlock:*/false);
string[] hrefParts = href.Split(new char[] { '#' });
if (hrefParts.Length > 0 && hrefParts[0].Trim().Length > 0)
{
xamlElement.SetAttribute(HtmlToXamlConverter.Xaml_Hyperlink_NavigateUri, hrefParts[0].Trim());
}
if (hrefParts.Length == 2 && hrefParts[1].Trim().Length > 0)
{
xamlElement.SetAttribute(HtmlToXamlConverter.Xaml_Hyperlink_TargetName, 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);
}
}
/// <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="tableWidth">
/// Current width of the table. This is used to determine if a new column when added to the end of table should
/// come after the last column in the table or is actually splitting the last column in two. If it is only splitting
/// the last column it should inherit row span for that column
/// </param>
/// <returns>
/// Calculated width of a tbody.
/// In case of non-analizable column width structure return 0;
/// </returns>
private static double AnalyzeTbodyStructure(XmlElement htmlTbodyElement, ArrayList columnStarts, ArrayList activeRowSpans, double tableWidth, 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((XmlElement)htmlChildNode, columnStarts, activeRowSpans, tbodyWidth, stylesheet);
if (trWidth > tbodyWidth)
{
tbodyWidth = trWidth;
}
break;
case "td":
columnWidthsAvailable = false; // interrupt the analisys
break;
default:
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 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>
/// <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(XmlElement htmlTableElement, CssStylesheet stylesheet)
{
// Parameter validation
Debug.Assert(htmlTableElement.LocalName.ToLower() == "table");
if (!htmlTableElement.HasChildNodes)
{
return null;
}
bool columnWidthsAvailable = true;
ArrayList columnStarts = new ArrayList();
ArrayList 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((XmlElement)htmlChildNode, columnStarts, activeRowSpans, tableWidth, stylesheet);
if (tbodyWidth > tableWidth)
{
// Table width must be increased to supported newly added wide row
tableWidth = tbodyWidth;
}
else if (tbodyWidth == 0)
{
// 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((XmlElement)htmlChildNode, columnStarts, activeRowSpans, tableWidth, stylesheet);
if (trWidth > tableWidth)
{
tableWidth = trWidth;
}
else if (trWidth == 0)
{
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;
default:
// Element should not occur directly in table. Ignore it.
break;
}
htmlChildNode = htmlChildNode.NextSibling;
}
if (columnWidthsAvailable)
{
// Add an item for whole table width
columnStarts.Add(tableWidth);
VerifyColumnStartsAscendingOrder(columnStarts);
}
else
{
columnStarts = null;
}
return columnStarts;
}
/// <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>
private static void AddDataToTableCell(XmlElement xamlTableCellElement, XmlNode htmlDataStartNode, Hashtable currentProperties, CssStylesheet stylesheet, List<XmlElement> sourceContext)
{
// Parameter validation
Debug.Assert(xamlTableCellElement.LocalName == Xaml_TableCell);
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);
}
}
/// <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>
/// <returns>
/// XmlElement representing the current position of the iterator among the children of the parent Html tbody/tr element
/// </returns>
private static XmlNode AddTableCellsToTableRow(XmlElement xamlTableRowElement, XmlNode htmlTDStartNode, Hashtable currentProperties, ArrayList columnStarts, ArrayList activeRowSpans, CssStylesheet stylesheet, List<XmlElement> sourceContext)
{
// parameter validation
Debug.Assert(xamlTableRowElement.LocalName == Xaml_TableRow);
Debug.Assert(currentProperties != null);
if (columnStarts != null)
{
Debug.Assert(activeRowSpans.Count == columnStarts.Count);
}
XmlNode htmlChildNode = htmlTDStartNode;
double columnStart = 0;
double columnWidth = 0;
int columnIndex = 0;
int columnSpan = 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")
{
XmlElement xamlTableCellElement = xamlTableRowElement.OwnerDocument.CreateElement(null, Xaml_TableCell, _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);
columnStart = (double)columnStarts[columnIndex];
columnWidth = GetColumnWidth((XmlElement)htmlChildNode);
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(Xaml_TableCell_ColumnSpan, columnSpan.ToString());
// 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>
/// 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(XmlElement xamlTableBodyElement, XmlNode htmlTRStartNode, Hashtable currentProperties, ArrayList columnStarts, CssStylesheet stylesheet, List<XmlElement> sourceContext)
{
// Parameter validation
Debug.Assert(xamlTableBodyElement.LocalName == Xaml_TableRowGroup);
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")
{
if (htmlChildNode.LocalName.ToLower() == "tr")
{
XmlElement xamlTableRowElement = xamlTableBodyElement.OwnerDocument.CreateElement(null, Xaml_TableRow, _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;
}
else if (htmlChildNode.LocalName.ToLower() == "td")
{
// Tr element is not present. We create one and add td elements to it
XmlElement xamlTableRowElement = xamlTableBodyElement.OwnerDocument.CreateElement(null, Xaml_TableRow, _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, columnStarts, activeRowSpans, stylesheet, sourceContext);
if (xamlTableRowElement.HasChildNodes)
{
xamlTableBodyElement.AppendChild(xamlTableRowElement);
}
}
else
{
// Not a tr or td element. Ignore it.
// TODO: consider better recovery here
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(XmlElement xamlTableElement, XmlElement htmlColElement, Hashtable inheritedProperties, CssStylesheet stylesheet, List<XmlElement> sourceContext)
{
Hashtable localProperties;
Hashtable currentProperties = GetElementProperties(htmlColElement, inheritedProperties, out localProperties, stylesheet, sourceContext);
XmlElement xamlTableColumnElement = xamlTableElement.OwnerDocument.CreateElement(null, Xaml_TableColumn, _xamlNamespace);
// TODO: process local properties for TableColumn element
// Col is an empty element, with no subtree
xamlTableElement.AppendChild(xamlTableColumnElement);
}
/// <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>
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>
/// 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="tableWidth">
/// Double value representing the current width of the table.
/// Return 0 if analisys was insuccessful.
/// </param>
private static double AnalyzeTRStructure(XmlElement htmlTRElement, ArrayList columnStarts, ArrayList activeRowSpans, double tableWidth, CssStylesheet stylesheet)
{
double columnWidth;
// 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;
double trWidth = 0;
// Skip spanned columns to get to real column start
if (columnIndex < activeRowSpans.Count)
{
Debug.Assert((double)columnStarts[columnIndex] >= columnStart);
if ((double)columnStarts[columnIndex] == columnStart)
{
// 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);
}
columnWidth = GetColumnWidth((XmlElement)htmlChildNode);
if (columnWidth != -1)
{
int nextColumnIndex;
int rowSpan = GetRowSpan((XmlElement)htmlChildNode);
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 ((double)columnStarts[columnIndex] == columnStart)
{
// 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;
default:
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
if (columnWidthsAvailable)
{
trWidth = columnStart;
}
else
{
trWidth = 0;
}
return trWidth;
}
private static void AddSpanOrRun(XmlElement 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)
{
string htmlChildName = ((XmlElement)htmlNode).LocalName.ToLower();
if (HtmlSchema.IsInlineElement(htmlChildName) || HtmlSchema.IsBlockElement(htmlChildName) ||
htmlChildName == "img" || htmlChildName == "br" || htmlChildName == "hr")
{
elementHasChildren = true;
break;
}
}
}
string xamlElementName = elementHasChildren ? HtmlToXamlConverter.Xaml_Span : HtmlToXamlConverter.Xaml_Run;
// 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
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);
}
// ---------------------------------------------------------------------
//
// Private Methods
//
// ---------------------------------------------------------------------
#region Private Methods
/// <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="htmlElement">
/// Source html element subject to convert to xaml.
/// </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)
{
if (htmlNode is XmlComment)
{
DefineInlineFragmentParent((XmlComment)htmlNode, /*xamlParentElement:*/null);
}
else if (htmlNode is XmlText)
{
htmlNode = AddImplicitParagraph(xamlParentElement, htmlNode, inheritedProperties, stylesheet, sourceContext);
}
else if (htmlNode is XmlElement)
{
// Identify element name
XmlElement htmlElement = (XmlElement)htmlNode;
string htmlElementName = htmlElement.LocalName; // Keep the name case-sensitive to check xml names
string htmlElementNamespace = htmlElement.NamespaceURI;
if (htmlElementNamespace != HtmlParser.XhtmlNamespace)
{
// 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
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);
}
// Return last processed node
return htmlNode;
}
// .............................................................
//
// Images
//
// .............................................................
private static void AddImage(XmlElement xamlParentElement, XmlElement htmlElement, Hashtable inheritedProperties, CssStylesheet stylesheet, List<XmlElement> sourceContext)
{
// Implement images
}
/// <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, Hashtable inheritedProperties, out Hashtable localProperties, CssStylesheet stylesheet, List<XmlElement> sourceContext)
{
// Start with context formatting properties
Hashtable currentProperties = new Hashtable();
IDictionaryEnumerator propertyEnumerator = inheritedProperties.GetEnumerator();
while (propertyEnumerator.MoveNext())
{
currentProperties[propertyEnumerator.Key] = propertyEnumerator.Value;
}
// Identify element name
string elementName = htmlElement.LocalName.ToLower();
string elementNamespace = htmlElement.NamespaceURI;
// 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();
}
attributeValue = GetAttribute(htmlElement, "color");
if (attributeValue != null)
{
localProperties["color"] = attributeValue;
}
break;
case "samp":
localProperties["font-family"] = "Courier New"; // code sample
localProperties["font-size"] = Xaml_FontSize_XXSmall;
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"] = Xaml_FontSize_XXSmall;
localProperties["text-align"] = "Left";
break;
case "blockquote":
localProperties["margin-left"] = "16";
break;
case "h1":
localProperties["font-size"] = Xaml_FontSize_XXLarge;
break;
case "h2":
localProperties["font-size"] = Xaml_FontSize_XLarge;
break;
case "h3":
localProperties["font-size"] = Xaml_FontSize_Large;
break;
case "h4":
localProperties["font-size"] = Xaml_FontSize_Medium;
break;
case "h5":
localProperties["font-size"] = Xaml_FontSize_Small;
break;
case "h6":
localProperties["font-size"] = Xaml_FontSize_XSmall;
break;
// List properties
case "ul":
localProperties["list-style-type"] = "disc";
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>
/// 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>
/// <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(XmlElement xamlParentElement, XmlElement 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;
if (xamlListItemElementPreviousSibling != null && xamlListItemElementPreviousSibling.LocalName == Xaml_List)
{
// 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.
xamlListElement = xamlParentElement.OwnerDocument.CreateElement(null, Xaml_List, _xamlNamespace);
xamlParentElement.AppendChild(xamlListElement);
}
XmlNode htmlChildNode = htmlLIElement;
string htmlChildNodeName = htmlChildNode == null ? null : 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;
}
// .............................................................
//
// 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
/// </param>
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)
{
string htmlChildName = ((XmlElement)htmlChildNode).LocalName.ToLower();
if (HtmlSchema.IsBlockElement(htmlChildName))
{
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
XmlElement xamlElement = xamlParentElement.OwnerDocument.CreateElement(/*prefix:*/null, /*localName:*/HtmlToXamlConverter.Xaml_Section, _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);
}
}
}
// .............................................................
//
// 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>
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
XmlElement xamlTableElement = xamlParentElement.OwnerDocument.CreateElement(null, Xaml_Table, _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
if (htmlChildName == "tbody" || htmlChildName == "thead" || htmlChildName == "tfoot")
{
// Add more special processing for TableHeader and TableFooter
XmlElement xamlTableBodyElement = xamlTableElement.OwnerDocument.CreateElement(null, Xaml_TableRowGroup, _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;
}
else if (htmlChildName == "tr")
{
// Tbody is not present, but tr element is present. Tr is wrapped in tbody
XmlElement xamlTableBodyElement = xamlTableElement.OwnerDocument.CreateElement(null, Xaml_TableRowGroup, _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);
}
}
else
{
// Element is not tbody or tr. Ignore it.
// TODO: add processing for thead, tfoot elements and recovery for td elements
htmlChildNode = htmlChildNode.NextSibling;
}
}
if (xamlTableElement.HasChildNodes)
{
xamlParentElement.AppendChild(xamlTableElement);
}
}
}
// .................................................................
//
// Processing CSS Attributes
//
// .................................................................
internal static void GetElementPropertiesFromCssAttributes(XmlElement htmlElement, string elementName, CssStylesheet stylesheet, Hashtable localProperties, List<XmlElement> sourceContext)
{
string styleFromStylesheet = stylesheet.GetStyle(elementName, sourceContext);
string styleInline = HtmlToXamlConverter.GetAttribute(htmlElement, "style");
// Combine styles from stylesheet and from inline attribute.
// The order is important - the latter styles will override the former.
string style = styleFromStylesheet != null ? styleFromStylesheet : null;
if (styleInline != null)
{
style = style == null ? styleInline : (style + ";" + styleInline);
}
// Apply local style to current formatting properties
if (style != null)
{
string[] styleValues = style.Split(';');
for (int i = 0; i < styleValues.Length; i++)
{
string[] styleNameValue;
styleNameValue = styleValues[i].Split(':');
if (styleNameValue.Length == 2)
{
string styleName = styleNameValue[0].Trim().ToLower();
string styleValue = HtmlToXamlConverter.UnQuote(styleNameValue[1].Trim()).ToLower();
int nextIndex = 0;
switch (styleName)
{
case "font":
ParseCssFont(styleValue, localProperties);
break;
case "font-family":
ParseCssFontFamily(styleValue, ref nextIndex, localProperties);
break;
case "font-size":
ParseCssSize(styleValue, ref nextIndex, localProperties, "font-size", /*mustBeNonNegative:*/true);
break;
case "font-style":
ParseCssFontStyle(styleValue, ref nextIndex, localProperties);
break;
case "font-weight":
ParseCssFontWeight(styleValue, ref nextIndex, localProperties);
break;
case "font-variant":
ParseCssFontVariant(styleValue, ref nextIndex, localProperties);
break;
case "line-height":
ParseCssSize(styleValue, ref nextIndex, localProperties, "line-height", /*mustBeNonNegative:*/true);
break;
case "word-spacing":
// Implement word-spacing conversion
break;
case "letter-spacing":
// Implement letter-spacing conversion
break;
case "color":
ParseCssColor(styleValue, ref nextIndex, localProperties, "color");
break;
case "text-decoration":
ParseCssTextDecoration(styleValue, ref nextIndex, localProperties);
break;
case "text-transform":
ParseCssTextTransform(styleValue, ref nextIndex, localProperties);
break;
case "background-color":
ParseCssColor(styleValue, ref nextIndex, localProperties, "background-color");
break;
case "background":
// TODO: need to parse composite background property
ParseCssBackground(styleValue, ref nextIndex, localProperties);
break;
case "text-align":
ParseCssTextAlign(styleValue, ref nextIndex, localProperties);
break;
case "vertical-align":
ParseCssVerticalAlign(styleValue, ref nextIndex, localProperties);
break;
case "text-indent":
ParseCssSize(styleValue, ref nextIndex, localProperties, "text-indent", /*mustBeNonNegative:*/false);
break;
case "width":
case "height":
ParseCssSize(styleValue, ref nextIndex, localProperties, styleName, /*mustBeNonNegative:*/true);
break;
case "margin": // top/right/bottom/left
ParseCssRectangleProperty(styleValue, ref nextIndex, localProperties, styleName);
break;
case "margin-top":
case "margin-right":
case "margin-bottom":
case "margin-left":
ParseCssSize(styleValue, ref nextIndex, localProperties, styleName, /*mustBeNonNegative:*/true);
break;
case "padding":
ParseCssRectangleProperty(styleValue, ref nextIndex, localProperties, styleName);
break;
case "padding-top":
case "padding-right":
case "padding-bottom":
case "padding-left":
ParseCssSize(styleValue, ref nextIndex, localProperties, styleName, /*mustBeNonNegative:*/true);
break;
case "border":
ParseCssBorder(styleValue, ref nextIndex, localProperties);
break;
case "border-style":
case "border-width":
case "border-color":
ParseCssRectangleProperty(styleValue, ref nextIndex, localProperties, styleName);
break;
case "border-top":
case "border-right":
case "border-left":
case "border-bottom":
// Parse css border style
break;
// NOTE: css names for elementary border styles have side indications in the middle (top/bottom/left/right)
// In our internal notation we intentionally put them at the end - to unify processing in ParseCssRectangleProperty method
case "border-top-style":
case "border-right-style":
case "border-left-style":
case "border-bottom-style":
case "border-top-color":
case "border-right-color":
case "border-left-color":
case "border-bottom-color":
case "border-top-width":
case "border-right-width":
case "border-left-width":
case "border-bottom-width":
// Parse css border style
break;
case "display":
// Implement display style conversion
break;
case "float":
ParseCssFloat(styleValue, ref nextIndex, localProperties);
break;
case "clear":
ParseCssClear(styleValue, ref nextIndex, localProperties);
break;
default:
break;
}
}
}
}
}