From 2c6df559e825425b1a45404cb29bc0b3e71f58e6 Mon Sep 17 00:00:00 2001
From: Mladen Milinkovic <max@smoothware.net>
Date: Fri, 22 Nov 2013 21:51:50 +0100
Subject: [PATCH] RSS Feed was not displaying remote images in html
 description. Closes #1119

---
 src/rss/htmlbrowser.cpp | 92 +++++++++++++++++++++++++++++++++++++++++
 src/rss/htmlbrowser.h   | 30 ++++++++++++++
 src/rss/rss.pri         |  6 ++-
 src/rss/rss.ui          | 13 +++++-
 4 files changed, 138 insertions(+), 3 deletions(-)
 create mode 100644 src/rss/htmlbrowser.cpp
 create mode 100644 src/rss/htmlbrowser.h

diff --git a/src/rss/htmlbrowser.cpp b/src/rss/htmlbrowser.cpp
new file mode 100644
index 000000000..8ed92fa67
--- /dev/null
+++ b/src/rss/htmlbrowser.cpp
@@ -0,0 +1,92 @@
+#include "htmlbrowser.h"
+
+#include <QDebug>
+#include <QNetworkRequest>
+#include <QNetworkReply>
+#include <QNetworkDiskCache>
+#include <QStyle>
+#include <QApplication>
+#include <QDir>
+#include <QDateTime>
+#include <QScrollBar>
+
+#include "fs_utils.h"
+
+HtmlBrowser::HtmlBrowser(QWidget* parent)
+	: QTextBrowser(parent)
+{
+	m_netManager = new QNetworkAccessManager(this);
+	m_diskCache = new QNetworkDiskCache(this);
+	m_diskCache->setCacheDirectory(QDir::cleanPath(fsutils::cacheLocation() + "/browser"));
+	m_diskCache->setMaximumCacheSize(50 * 1024 * 1024);
+	qDebug() << "HtmlBrowser  cache path:" << m_diskCache->cacheDirectory() << " max size:" << m_diskCache->maximumCacheSize() / 1024 / 1024 << "MB";
+	m_netManager->setCache(m_diskCache);
+
+	connect(m_netManager, SIGNAL(finished(QNetworkReply *)), this, SLOT(resourceLoaded(QNetworkReply*)));
+}
+
+HtmlBrowser::~HtmlBrowser()
+{
+}
+
+QVariant HtmlBrowser::loadResource(int type, const QUrl &name)
+{
+	if(type == QTextDocument::ImageResource) {
+		QUrl url(name);
+		if(url.scheme().isEmpty())
+			url.setScheme("http");
+
+		QIODevice *dev = m_diskCache->data(url);
+		if(dev != 0) {
+			qDebug() << "HtmlBrowser::loadResource() cache " << url.toString();
+			QByteArray res = dev->readAll();
+			delete dev;
+			return res;
+		}
+
+		if(!m_activeRequests.contains(url)) {
+			m_activeRequests.insert(url, true);
+			qDebug() << "HtmlBrowser::loadResource() get " << url.toString();
+			QNetworkRequest req(url);
+			req.setAttribute(QNetworkRequest::CacheLoadControlAttribute, QNetworkRequest::PreferCache);
+			m_netManager->get(req);
+		}
+
+		return QVariant();
+	}
+
+	return QTextBrowser::loadResource(type, name);
+}
+
+void HtmlBrowser::resourceLoaded(QNetworkReply *reply)
+{
+	m_activeRequests.remove(reply->request().url());
+
+	if(reply->error() == QNetworkReply::NoError && reply->size() > 0) {
+		qDebug() << "HtmlBrowser::resourceLoaded() save " << reply->request().url().toString();
+	} else {
+		// If resource failed to load, replace it with warning icon and store it in cache for 1 day.
+		// Otherwise HTMLBrowser will keep trying to download it every time article is displayed,
+		// since it's not possible to cache error responses.
+		QNetworkCacheMetaData metaData;
+		QNetworkCacheMetaData::AttributesMap atts;
+		metaData.setUrl(reply->request().url());
+		metaData.setSaveToDisk(true);
+		atts[QNetworkRequest::HttpStatusCodeAttribute] = 200;
+		atts[QNetworkRequest::HttpReasonPhraseAttribute] = "Ok";
+		metaData.setAttributes(atts);
+		metaData.setLastModified(QDateTime::currentDateTime());
+		metaData.setExpirationDate(QDateTime::currentDateTime().addDays(1));
+		QIODevice *dev = m_diskCache->prepare(metaData);
+		if(!dev)
+			return;
+		QApplication::style()->standardIcon(QStyle::SP_MessageBoxWarning).pixmap(32, 32).save(dev, "PNG");
+		m_diskCache->insert(dev);
+	}
+	// Refresh the document display and keep scrollbars where they are
+	int sx = horizontalScrollBar()->value();
+	int sy = verticalScrollBar()->value();
+	document()->setHtml(document()->toHtml());
+	horizontalScrollBar()->setValue(sx);
+	verticalScrollBar()->setValue(sy);
+}
diff --git a/src/rss/htmlbrowser.h b/src/rss/htmlbrowser.h
new file mode 100644
index 000000000..7a8ffcea9
--- /dev/null
+++ b/src/rss/htmlbrowser.h
@@ -0,0 +1,30 @@
+#ifndef HTMLBROWSER_H
+#define HTMLBROWSER_H
+
+#include <QTextBrowser>
+#include <QHash>
+
+class QNetworkAccessManager;
+class QNetworkDiskCache;
+class QNetworkReply;
+
+class HtmlBrowser : public QTextBrowser
+{
+	Q_OBJECT
+	
+public:
+	explicit HtmlBrowser(QWidget* parent = 0);
+	~HtmlBrowser();
+
+	virtual QVariant loadResource(int type, const QUrl &name);
+	
+protected:
+	QNetworkAccessManager *m_netManager;
+	QNetworkDiskCache *m_diskCache;
+	QHash<QUrl, bool> m_activeRequests;
+	
+protected slots:
+	void resourceLoaded(QNetworkReply *reply);
+};
+
+#endif // HTMLBROWSER_H
diff --git a/src/rss/rss.pri b/src/rss/rss.pri
index d820d17cd..e4d91389b 100644
--- a/src/rss/rss.pri
+++ b/src/rss/rss.pri
@@ -12,7 +12,8 @@ HEADERS +=    $$PWD/rss_imp.h \
               $$PWD/rssdownloadrule.h \
               $$PWD/rssdownloadrulelist.h \
               $$PWD/cookiesdlg.h \
-              $$PWD/rssparser.h
+              $$PWD/rssparser.h \
+              $$PWD/htmlbrowser.h
 
 SOURCES +=   $$PWD/rss_imp.cpp \
              $$PWD/rsssettingsdlg.cpp \
@@ -26,7 +27,8 @@ SOURCES +=   $$PWD/rss_imp.cpp \
              $$PWD/rssdownloadrulelist.cpp \
              $$PWD/cookiesdlg.cpp \
              $$PWD/rssfile.cpp \
-             $$PWD/rssparser.cpp
+             $$PWD/rssparser.cpp \
+             $$PWD/htmlbrowser.cpp
 
 FORMS +=   $$PWD/rss.ui \
            $$PWD/rsssettingsdlg.ui \
diff --git a/src/rss/rss.ui b/src/rss/rss.ui
index 63bcd9c93..7d0d348bb 100644
--- a/src/rss/rss.ui
+++ b/src/rss/rss.ui
@@ -145,7 +145,11 @@ p, li { white-space: pre-wrap; }
            <enum>QAbstractItemView::SelectItems</enum>
           </property>
          </widget>
-         <widget class="QTextBrowser" name="textBrowser"/>
+         <widget class="HtmlBrowser" name="textBrowser">
+          <property name="openExternalLinks">
+           <bool>true</bool>
+          </property>
+         </widget>
         </widget>
        </item>
       </layout>
@@ -224,6 +228,13 @@ p, li { white-space: pre-wrap; }
    </property>
   </action>
  </widget>
+ <customwidgets>
+  <customwidget>
+   <class>HtmlBrowser</class>
+   <extends>QTextBrowser</extends>
+   <header>htmlbrowser.h</header>
+  </customwidget>
+ </customwidgets>
  <resources/>
  <connections/>
 </ui>