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用QTextBrowser实现的Web浏览器 [复制链接]

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离线hikarisama
新手上路
 
只看楼主 倒序阅读 楼主  发表于: 2016-04-19
— 本帖被 XChinux 执行加亮操作(2016-04-20) —
qt5.6上的webEngine暂时无法用gcc编译，也没法用在android上，用了很多办法都没法用jni来调用android java的webview，无奈之下用QTextBrowser实现一个最简单的仅支持HTML4子集的Web浏览器，QTextBrowser是没有网络读取功能的，我添加一个网络下载函数，用QtConcurrent异步加载，再用正则表达式解析img标签，然后signal把QTextDocument呈现出来。

这是原型代码，写得比较草率，有兴趣的可以扩展一下QTextBrowser/QTextDocument的源代码得到更多的HTML/CSS渲染效果


复制代码
  1. #ifndef QHTMLBROWSER_H
  2. #define QHTMLBROWSER_H
  4. //** for more information, please refer to http://www.one-lab.net
  6. #include <QtConcurrent>
  7. #include <QtNetwork/QtNetwork>
  8. #include <QTextBrowser>
  9. #include <QTextDocument>
  10. #include <QMap>
  11. #include <QRegExp>
  12. #include <QCryptographicHash>
  13. #include <QApplication>
  15. class QHtmlBrowser : public QObject
  16. {
  17.     Q_OBJECT
  18.     
  19. private:
  20.     QTextBrowser* mBrowser;
  21.     QString mUrl;
  22.     QMap<QString, QByteArray> mResources;
  24. signals:
  25.     void loadFinished();
  27. public slots:
  28.     void onLoadFinished();
  29.     void onRequestUrl(const QUrl& url);
  31. public:
  32.     ~QHtmlBrowser();
  33.     explicit QHtmlBrowser(QTextBrowser* browser);
  34.     void load(const QString& url);
  35.     void addResource(const QString& key, const QByteArray& bytes);
  36. };
  38. #endif // QHTMLBROWSER_H

复制代码
  1. #include "qhtmlbrowser.h"
  3. //** for more information, please refer to http://www.one-lab.net
  5. #define hit_ext(p) \
  6.     else if (src.endsWith(#p, Qt::CaseInsensitive)) \
  7.         ext = #p
  8. #define index_tag   "index"
  9. #define images_tag   "images://"
  11. QString setUrl(QUrl& parentUrl, const QString& path)
  12. {
  13.     QString srcUrl;
  14.     QString hostPath = parentUrl.host();
  15.     if (parentUrl.port() != 80)
  16.         hostPath += ":" + QString::number(parentUrl.port());
  17.     hostPath += parentUrl.path();
  18.     int pos = hostPath.lastIndexOf('/');
  19.     if (pos > -1)
  20.         hostPath = hostPath.left(pos);
  21.     srcUrl = hostPath + "/" + path;
  22.     while (srcUrl.contains("//"))
  23.         srcUrl.replace("//", "/");
  24.     srcUrl = "http://" + srcUrl;
  25.     return srcUrl;
  26. }
  28. void downloadHtml(QHtmlBrowser* browser, const QString& urlPath, int timeoutSeconds)
  29. {
  30.     QNetworkAccessManager network;
  31.     QNetworkRequest request;
  32.     QUrl url(urlPath);
  33.     request.setUrl(url);
  34.     QByteArray requestContent = urlPath.toUtf8();
  35.     request.setHeader(QNetworkRequest::ContentLengthHeader, requestContent.length());
  36.     bool timeout = false;
  37.     if (QNetworkReply* reply = network.get(request))
  38.     {
  39.         QDateTime stamp = QDateTime::currentDateTime();
  40.         while (reply->isRunning())
  41.         {
  42.             QApplication::processEvents();
  43.             if (stamp.secsTo(QDateTime::currentDateTime()) > timeoutSeconds)
  44.             {
  45.                 reply->abort();
  46.                 timeout = true;
  47.                 break;
  48.             }
  49.         }
  50.         if (!timeout)
  51.         {
  52.             QString content = QString::fromUtf8(reply->readAll());
  53.             QRegExp imgTagRegex("\\<img[^\\>]*src\\s*=\\s*\"([^\"]*)\"[^\\>]*\\>", Qt::CaseInsensitive);
  54.             imgTagRegex.setMinimal(true);
  55.             QStringList imgSrcList;
  56.             QStringList imgTagList;
  57.             int offset = 0;
  58.             while( (offset = imgTagRegex.indexIn(content, offset)) != -1){
  59.                 offset += imgTagRegex.matchedLength();
  60.                 imgTagList.append(imgTagRegex.cap(0));
  61.                 imgSrcList.append(imgTagRegex.cap(1));
  62.             }
  63.             QString srcUrl;
  64.             QString resourcePrefix(images_tag);
  65.             QString ext;
  66.             int index = -1;
  67.             foreach(QString src, imgSrcList)
  68.             {
  69.                 index++;
  70.                 srcUrl.clear();
  71.                 if (src.startsWith("http://", Qt::CaseInsensitive))
  72.                     srcUrl = src;
  73.                 else
  74.                 {
  75.                     if (0){}
  76.                     hit_ext(.png);
  77.                     hit_ext(.jpeg);
  78.                     hit_ext(.jpg);
  79.                     hit_ext(.gif);
  80.                     else continue;
  81.                     if (src.startsWith("://") || src.startsWith("file://", Qt::CaseInsensitive)) continue;
  82.                     srcUrl = setUrl(url, src);
  83.                     request.setUrl(srcUrl);
  84.                     requestContent = srcUrl.toUtf8();
  85.                     request.setHeader(QNetworkRequest::ContentLengthHeader, requestContent.length());
  86.                     QCryptographicHash hash(QCryptographicHash::Md5);
  87.                     if (QNetworkReply* itemReply = network.get(request))
  88.                     {
  89.                         timeout = false;
  90.                         stamp = QDateTime::currentDateTime();
  91.                         while (itemReply->isRunning())
  92.                         {
  93.                             QApplication::processEvents();
  94.                             if (stamp.secsTo(QDateTime::currentDateTime()) > timeoutSeconds)
  95.                             {
  96.                                 itemReply->abort();
  97.                                 timeout = true;
  98.                                 break;
  99.                             }
  100.                         }
  101.                         if (timeout)
  102.                         {
  103.                             delete itemReply;
  104.                             continue;
  105.                         }
  106.                         QString imgFile = resourcePrefix + "/";
  107.                         hash.addData(srcUrl.toUtf8());
  108.                         foreach(char c, hash.result())
  109.                         {
  110.                             int cInt = (int)c;
  111.                             if (cInt < 10)
  112.                                 imgFile += "0" + QString::number(cInt, 16).left(1);
  113.                             else
  114.                                 imgFile += QString::number(cInt, 16).left(2);
  115.                         }
  116.                         imgFile += ext;
  117.                         QString target = imgTagList[index];
  118.                         target.replace(src, imgFile);
  119.                         browser->addResource(imgFile, itemReply->readAll());
  120.                         content.replace(imgTagList[index], target);
  121.                         delete itemReply;
  122.                     }
  123.                 }
  124.             }
  125.             browser->addResource(index_tag, content.toUtf8());
  126.         }
  127.         delete reply;
  128.         emit browser->loadFinished();
  129.     }
  130. }
  132. void QHtmlBrowser::onLoadFinished()
  133. {
  134.     QTextDocument* document = new QTextDocument(mBrowser);
  135.     if (mResources.contains(index_tag))
  136.     {
  137.         foreach(QString key, mResources.keys())
  138.         {
  139.             if (key.startsWith(images_tag))
  140.                 document->addResource(QTextDocument::ImageResource, key, QVariant(mResources[key]));
  141.         }
  142.         document->setHtml(QString::fromUtf8(mResources[index_tag]));
  143.         mBrowser->setDocument(document);
  144.     }
  145. }
  147. QHtmlBrowser::~QHtmlBrowser()
  148. {
  149. }
  151. QHtmlBrowser::QHtmlBrowser(QTextBrowser* browser) : QObject(browser)
  152. {
  153.     mBrowser = browser;
  154.     mBrowser->setReadOnly(true);
  155.     mBrowser->setContextMenuPolicy(Qt::NoContextMenu);
  156.     mBrowser->setAcceptRichText(true);
  157.     mBrowser->setAutoFormatting(QTextEdit::AutoAll);
  158.     connect(this, SIGNAL(loadFinished()), SLOT(onLoadFinished()));
  159.     connect(mBrowser, SIGNAL(anchorClicked(QUrl)), SLOT(onRequestUrl(QUrl)));
  160. }
  162. void QHtmlBrowser::onRequestUrl(const QUrl& url)
  163. {
  164.     QUrl currentUrl(mUrl);
  165.     QString requestingUrl = setUrl(currentUrl, url.toString());
  166.     load(requestingUrl);
  167. }
  169. void QHtmlBrowser::load(const QString &url)
  170. {
  171.     mUrl = url;
  172.     QtConcurrent::run(downloadHtml, this, url, 30);
  173. }
  175. void QHtmlBrowser::addResource(const QString &key, const QByteArray &bytes)
  176. {
  177.     if (mResources.contains(key))
  178.         mResources[key] = bytes;
  179.     else
  180.         mResources.insert(key, bytes);
  181. }
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离线nigoole
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只看该作者 1楼 发表于: 2016-04-19
   挺有创意的！
有句话说得好：好好学习，天天向上。加油~~！有上船的朋友联系企鹅393320854
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离线新手崛起
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只看该作者 2楼 发表于: 2016-10-31
楼主你这个能获取到网页源码吗？
只有想不到，没有做不到的
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