From 291d332b56c0b6560ae719662f169a0c0360e1cf Mon Sep 17 00:00:00 2001
From: Nimetu <nimetu@gmail.com>
Date: Sat, 2 Jan 2021 16:45:39 +0200
Subject: [PATCH] Fix css style order when using external css files

---
 code/nel/include/nel/gui/group_html.h  |  7 ++-
 code/nel/include/nel/gui/html_parser.h | 17 ++++--
 code/nel/src/gui/group_html.cpp        | 83 ++++++++++++++++----------
 code/nel/src/gui/html_parser.cpp       | 16 ++---
 4 files changed, 80 insertions(+), 43 deletions(-)

diff --git a/code/nel/include/nel/gui/group_html.h b/code/nel/include/nel/gui/group_html.h
index 8b4a635b9..d04593870 100644
--- a/code/nel/include/nel/gui/group_html.h
+++ b/code/nel/include/nel/gui/group_html.h
@@ -27,6 +27,7 @@
 #include "nel/gui/ctrl_button.h"
 #include "nel/gui/group_table.h"
 #include "nel/gui/html_element.h"
+#include "nel/gui/html_parser.h"
 #include "nel/gui/css_style.h"
 
 // forward declaration
@@ -378,7 +379,9 @@ namespace NLGUI
 		// true if renderer is waiting for css files to finish downloading (link rel=stylesheet)
 		bool			_WaitingForStylesheet;
 		// list of css file urls that are queued up for download
-		std::vector<std::string> _StylesheetQueue;
+		std::vector<CHtmlParser::StyleLink> _StylesheetQueue;
+		// <style> and downloaded <link rel=stylesheet> elements
+		std::vector<std::string> _HtmlStyles;
 
 		// Valid base href was found
 		bool            _IgnoreBaseUrlTag;
@@ -893,7 +896,7 @@ namespace NLGUI
 		std::string localBnpName(const std::string &url);
 
 		// add css file from <link href=".." rel="stylesheet"> to download queue
-		void addStylesheetDownload(std::vector<std::string> links);
+		void addStylesheetDownload(std::vector<CHtmlParser::StyleLink> links);
 
 		// stop all curl downalods (html and data)
 		void releaseDownloads();
diff --git a/code/nel/include/nel/gui/html_parser.h b/code/nel/include/nel/gui/html_parser.h
index 760640234..0c36014da 100644
--- a/code/nel/include/nel/gui/html_parser.h
+++ b/code/nel/include/nel/gui/html_parser.h
@@ -31,14 +31,23 @@ namespace NLGUI
 	class CHtmlParser
 	{
 	public:
+		// <link rel=stylesheet>
+		struct StyleLink
+		{
+			uint Index;
+			std::string Url;
+			StyleLink(uint i, const std::string &url) : Index(i), Url(url)
+			{ }
+		};
+
 		bool parseHtml(std::string htmlString) const;
 
-		// parse html string into DOM, extract <style> tags into styleString, <link stylesheet> urls into links
-		void getDOM(std::string htmlString, CHtmlElement &parent, std::string &styleString, std::vector<std::string> &links) const;
+		// parse html string into DOM, extract <style> and <link stylesheet> urls
+		void getDOM(std::string htmlString, CHtmlElement &parent, std::vector<std::string> &styles, std::vector<StyleLink> &links) const;
 
 	private:
-		// iterate over libxml html tree, build DOM, and join all <style> tags together
-		void parseNode(xmlNode *a_node, CHtmlElement &parent, std::string &styleString, std::vector<std::string> &links) const;
+		// iterate over libxml html tree, build DOM
+		void parseNode(xmlNode *a_node, CHtmlElement &parent, std::vector<std::string> &styles, std::vector<StyleLink> &links) const;
 
 		// read <style> tag and add its content to styleString
 		void parseStyle(xmlNode *a_node, std::string &styleString) const;
diff --git a/code/nel/src/gui/group_html.cpp b/code/nel/src/gui/group_html.cpp
index dd5be59e7..4b9970971 100644
--- a/code/nel/src/gui/group_html.cpp
+++ b/code/nel/src/gui/group_html.cpp
@@ -861,21 +861,16 @@ namespace NLGUI
 			CFile::createDirectory( pathName );
 	}
 
-	void CGroupHTML::addStylesheetDownload(std::vector<std::string> links)
+	void CGroupHTML::addStylesheetDownload(const std::vector<CHtmlParser::StyleLink> links)
 	{
 		for(uint i = 0; i < links.size(); ++i)
 		{
-			std::string url = getAbsoluteUrl(links[i]);
-			std::string local = localImageName(url);
+			_StylesheetQueue.push_back(links[i]);
+			std::string url = getAbsoluteUrl(links[i].Url);
+			_StylesheetQueue.back().Url = url;
 
-			// insert only if url not already downloading
-			std::vector<std::string>::const_iterator it = std::find(_StylesheetQueue.begin(), _StylesheetQueue.end(), url);
-			if (it == _StylesheetQueue.end())
-			{
-				_StylesheetQueue.push_back(url);
-				// push to the front of the queue
-				Curls.push_front(CDataDownload(url, local, StylesheetType, NULL, "", ""));
-			}
+			// push to the front of the queue
+			Curls.push_front(CDataDownload(url, localImageName(url), StylesheetType, NULL, "", ""));
 		}
 		pumpCurlQueue();
 	}
@@ -4211,19 +4206,28 @@ namespace NLGUI
 	// ***************************************************************************
 	void CGroupHTML::cssDownloadFinished(const std::string &url, const std::string &local)
 	{
-		// remove file from download queue
-		std::vector<std::string>::iterator it = std::find(_StylesheetQueue.begin(), _StylesheetQueue.end(), url);
-		if (it != _StylesheetQueue.end())
+		for(std::vector<CHtmlParser::StyleLink>::iterator it = _StylesheetQueue.begin();
+				it != _StylesheetQueue.end(); ++it)
 		{
-			_StylesheetQueue.erase(it);
-		}
+			if (it->Url == url)
+			{
+				// read downloaded file into HtmlStyles
+				if (CFile::fileExists(local) && it->Index < _HtmlStyles.size())
+				{
+					CIFile in;
+					if (in.open(local))
+					{
+						if (!in.readAll(_HtmlStyles[it->Index]))
+						{
+							nlwarning("Failed to read downloaded css file(%s), url(%s)", local.c_str(), url.c_str());
+						}
+					}
+				}
 
-		if (!CFile::fileExists(local))
-		{
-			return;
+				_StylesheetQueue.erase(it);
+				break;
+			}
 		}
-
-		parseStylesheetFile(local);
 	}
 
 	void CGroupHTML::renderDocument()
@@ -4241,6 +4245,16 @@ namespace NLGUI
 		beginBuild();
 		removeContent();
 
+		// process all <style> and <link rel=stylesheet> elements
+		for(uint i = 0; i < _HtmlStyles.size(); ++i)
+		{
+			if (!_HtmlStyles[i].empty())
+			{
+				_Style.parseStylesheet(_HtmlStyles[i]);
+			}
+		}
+		_HtmlStyles.clear();
+
 		std::list<CHtmlElement>::iterator it = _HtmlDOM.Children.begin();
 		while(it != _HtmlDOM.Children.end())
 		{
@@ -4850,9 +4864,6 @@ namespace NLGUI
 	// ***************************************************************************
 	bool CGroupHTML::parseHtml(const std::string &htmlString)
 	{
-		std::vector<std::string> links;
-		std::string styleString;
-
 		CHtmlElement *parsedDOM;
 		if (_CurrentHTMLElement == NULL)
 		{
@@ -4865,16 +4876,28 @@ namespace NLGUI
 			parsedDOM = _CurrentHTMLElement;
 		}
 
+		std::vector<CHtmlParser::StyleLink> links;
+
 		CHtmlParser parser;
-		parser.getDOM(htmlString, *parsedDOM, styleString, links);
+		parser.getDOM(htmlString, *parsedDOM, _HtmlStyles, links);
 
-		if (!styleString.empty())
+		// <link> elements inserted from lua::parseHtml are ignored
+		if (_CurrentHTMLElement == NULL && !links.empty())
 		{
-			_Style.parseStylesheet(styleString);
+			addStylesheetDownload(links);
 		}
-		if (!links.empty())
+		else if (_CurrentHTMLElement != NULL)
 		{
-			addStylesheetDownload(links);
+			// Called from active element (lua)
+			// <style> order is not preserved as document is already being rendered
+			for(uint i = 0; i < _HtmlStyles.size(); ++i)
+			{
+				if (!_HtmlStyles[i].empty())
+				{
+					_Style.parseStylesheet(_HtmlStyles[i]);
+				}
+			}
+			_HtmlStyles.clear();
 		}
 
 		// this should rarely fail as first element should be <html>
@@ -4885,7 +4908,7 @@ namespace NLGUI
 		{
 			if (it->Type == CHtmlElement::ELEMENT_NODE && it->Value == "html")
 			{
-				// more newly parsed childs from <body> into siblings
+				// move newly parsed childs from <body> into siblings
 				if (_CurrentHTMLElement) {
 					std::list<CHtmlElement>::iterator it2 = it->Children.begin();
 					while(it2 != it->Children.end())
diff --git a/code/nel/src/gui/html_parser.cpp b/code/nel/src/gui/html_parser.cpp
index 91c287a7d..f4a611172 100644
--- a/code/nel/src/gui/html_parser.cpp
+++ b/code/nel/src/gui/html_parser.cpp
@@ -57,7 +57,7 @@ namespace NLGUI
 
 	// ***************************************************************************
 	// recursive function to walk html document
-	void CHtmlParser::parseNode(xmlNode *a_node, CHtmlElement &parent, std::string &styleString, std::vector<std::string> &links) const
+	void CHtmlParser::parseNode(xmlNode *a_node, CHtmlElement &parent, std::vector<std::string> &styles, std::vector<StyleLink> &links) const
 	{
 		uint childIndex = 0;
 		uint element_number;
@@ -153,7 +153,9 @@ namespace NLGUI
 
 					if (useStyle)
 					{
-						parseStyle(node->children, styleString);
+						std::string style;
+						parseStyle(node->children, style);
+						styles.push_back(style);
 					}
 					// style tag is kept in dom
 				}
@@ -171,13 +173,14 @@ namespace NLGUI
 
 					if (useStyle)
 					{
-						links.push_back(elm.getAttribute("href"));
+						styles.push_back("");
+						links.push_back(StyleLink(styles.size()-1, elm.getAttribute("href")));
 					}
 					// link tag is kept in dom
 				}
 				else if (node->children)
 				{
-					parseNode(node->children, elm, styleString, links);
+					parseNode(node->children, elm, styles, links);
 
 					// must cleanup nested tags that libxml2 does not fix
 					// dt without end tag: <dl><dt><dt></dl>
@@ -414,7 +417,7 @@ namespace NLGUI
 	}
 
 	// ***************************************************************************
-	void CHtmlParser::getDOM(std::string htmlString, CHtmlElement &dom, std::string &styleString, std::vector<std::string> &links) const
+	void CHtmlParser::getDOM(std::string htmlString, CHtmlElement &dom, std::vector<std::string> &styles, std::vector<StyleLink> &links) const
 	{
 		htmlParserCtxtPtr parser = htmlCreatePushParserCtxt(NULL, NULL, NULL, 0, NULL, XML_CHAR_ENCODING_UTF8);
 		if (!parser)
@@ -436,8 +439,7 @@ namespace NLGUI
 			xmlNode *root = xmlDocGetRootElement(parser->myDoc);
 			if (root)
 			{
-				styleString.clear();
-				parseNode(root, dom, styleString, links);
+				parseNode(root, dom, styles, links);
 			}
 			else
 			{