#include <htmlbrowser.h>

Inheritance diagram for HtmlBrowser:

Collaboration diagram for HtmlBrowser:

Public Member Functions
	HtmlBrowser (QWidget *parent=nullptr)

	~HtmlBrowser ()

QVariant	loadResource (int type, const QUrl &name) override

Protected Slots
void	resourceLoaded (QNetworkReply *reply)

Protected Attributes
QNetworkAccessManager *	m_netManager

QNetworkDiskCache *	m_diskCache

QHash< QUrl, bool >	m_activeRequests

Detailed Description

Definition at line 38 of file htmlbrowser.h.

Constructor & Destructor Documentation

◆ HtmlBrowser()

HtmlBrowser::HtmlBrowser ( QWidget * parent = nullptr )

explicit

Definition at line 43 of file htmlbrowser.cpp.

     : QTextBrowser(parent)
 {
     m_netManager = new QNetworkAccessManager(this);
     m_diskCache = new QNetworkDiskCache(this);
     m_diskCache->setCacheDirectory(QDir::cleanPath(specialFolderLocation(SpecialFolder::Cache) + "/rss"));
     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, &QNetworkAccessManager::finished, this, &HtmlBrowser::resourceLoaded);
 }

References Cache, m_diskCache, m_netManager, resourceLoaded(), and specialFolderLocation().

Here is the call graph for this function:

◆ ~HtmlBrowser()

HtmlBrowser::~HtmlBrowser ( )

Definition at line 56 of file htmlbrowser.cpp.

57 {

58 }

Member Function Documentation

◆ loadResource()

QVariant HtmlBrowser::loadResource	(	int	type,
		const QUrl &	name
	)

override

Definition at line 60 of file htmlbrowser.cpp.

 {
     if (type == QTextDocument::ImageResource)
     {
         QUrl url(name);
         if (url.scheme().isEmpty())
             url.setScheme("http");
  
         QIODevice *dev = m_diskCache->data(url);
         if (dev)
         {
             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 {};
     }
  
     return QTextBrowser::loadResource(type, name);
 }

References m_activeRequests, m_diskCache, and m_netManager.

◆ resourceLoaded

void HtmlBrowser::resourceLoaded ( QNetworkReply * reply )

protectedslot

Definition at line 92 of file htmlbrowser.cpp.

 {
     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);
 }