Pdf view (#2312)

* Draft: feature/pdf_view (#2268)

* build base code

* simple run successful

* add save session

* add pdfjs resource

* simple pdf viewer

Co-authored-by: chendapao <feloxx@163.com>

src/core/buffer/buffer.pri

@@ -6,8 +6,11 @@ SOURCES += \
     $$PWD/markdownbufferfactory.cpp \
     $$PWD/filetypehelper.cpp \
     $$PWD/nodebufferprovider.cpp \
+    $$PWD/pdfbuffer.cpp \
+    $$PWD/pdfbufferfactory.cpp \
     $$PWD/textbuffer.cpp \
-    $$PWD/textbufferfactory.cpp
+    $$PWD/textbufferfactory.cpp \
+    $$PWD/urlbasedbufferprovider.cpp
 
 HEADERS += \
     $$PWD/bufferprovider.h \
@@ -18,5 +21,8 @@ HEADERS += \
     $$PWD/markdownbufferfactory.h \
     $$PWD/filetypehelper.h \
     $$PWD/nodebufferprovider.h \
+    $$PWD/pdfbuffer.h \
+    $$PWD/pdfbufferfactory.h \
     $$PWD/textbuffer.h \
-    $$PWD/textbufferfactory.h
+    $$PWD/textbufferfactory.h \
+    $$PWD/urlbasedbufferprovider.h

src/core/buffer/bufferprovider.cpp

@@ -16,6 +16,7 @@ QDateTime BufferProvider::getLastModifiedFromFile() const
 
 bool BufferProvider::checkFileChangedOutside() const
 {
+    // TODO: support non-local URLs.
     QFileInfo info(getContentPath());
     if (!info.exists() || m_lastModified != info.lastModified()) {
         return true;

src/core/buffer/filetypehelper.cpp

@@ -75,6 +75,22 @@ void FileTypeHelper::setupBuiltInTypes()
         m_fileTypes.push_back(type);
     }
 
+    {
+        FileType type;
+        type.m_type = FileType::Pdf;
+        type.m_typeName = QStringLiteral("PDF");
+        type.m_displayName = Buffer::tr("Portable Document Format");
+
+        auto suffixes = coreConfig.findFileTypeSuffix(type.m_typeName);
+        if (suffixes && !suffixes->isEmpty()) {
+            type.m_suffixes = *suffixes;
+        } else {
+            type.m_suffixes << QStringLiteral("pdf");
+        }
+
+        m_fileTypes.push_back(type);
+    }
+
     {
         FileType type;
         type.m_type = FileType::Others;

src/core/buffer/filetypehelper.h

@@ -15,6 +15,7 @@ namespace vnotex
         {
             Markdown = 0,
             Text,
+            Pdf,
             Others
         };
 

src/core/buffer/pdfbuffer.cpp

@@ -0,0 +1,17 @@
+#include "pdfbuffer.h"
+
+#include <widgets/pdfviewwindow.h>
+
+using namespace vnotex;
+
+PdfBuffer::PdfBuffer(const BufferParameters &p_parameters,
+                     QObject *p_parent)
+    : Buffer(p_parameters, p_parent)
+{
+}
+
+ViewWindow *PdfBuffer::createViewWindowInternal(const QSharedPointer<FileOpenParameters> &p_paras, QWidget *p_parent)
+{
+    Q_UNUSED(p_paras);
+    return new PdfViewWindow(p_parent);
+}

src/core/buffer/pdfbuffer.h

@@ -0,0 +1,22 @@
+#ifndef PDFBUFFER_H
+#define PDFBUFFER_H
+
+#include "buffer.h"
+
+namespace vnotex
+{
+    class PdfBuffer : public Buffer
+    {
+        Q_OBJECT
+    public:
+        PdfBuffer(const BufferParameters &p_parameters,
+                  QObject *p_parent = nullptr);
+
+    protected:
+        ViewWindow *createViewWindowInternal(const QSharedPointer<FileOpenParameters> &p_paras,
+                                             QWidget *p_parent) Q_DECL_OVERRIDE;
+
+    };
+} // ns vnotex
+
+#endif // PDFBUFFER_H

src/core/buffer/pdfbufferfactory.cpp

@@ -0,0 +1,19 @@
+#include "pdfbufferfactory.h"
+
+#include "pdfbuffer.h"
+#include "urlbasedbufferprovider.h"
+
+using namespace vnotex;
+
+Buffer *PdfBufferFactory::createBuffer(const BufferParameters &p_parameters,
+                                        QObject *p_parent)
+{
+    BufferParameters paras;
+    paras.m_provider = QSharedPointer<UrlBasedBufferProvider>::create(p_parameters.m_provider);
+    return new PdfBuffer(paras, p_parent);
+}
+
+bool PdfBufferFactory::isBufferCreatedByFactory(const Buffer *p_buffer) const
+{
+    return dynamic_cast<const PdfBuffer *>(p_buffer) != nullptr;
+}

src/core/buffer/pdfbufferfactory.h

@@ -0,0 +1,19 @@
+#ifndef PDFBUFFERFACTORY_H
+#define PDFBUFFERFACTORY_H
+
+#include "ibufferfactory.h"
+
+namespace vnotex
+{
+    // Buffer factory for Pdf file.
+    class PdfBufferFactory : public IBufferFactory
+    {
+    public:
+        Buffer *createBuffer(const BufferParameters &p_parameters,
+                             QObject *p_parent) Q_DECL_OVERRIDE;
+
+        bool isBufferCreatedByFactory(const Buffer *p_buffer) const Q_DECL_OVERRIDE;
+    };
+} // vnotex
+
+#endif // PDFBUFFERFACTORY_H

src/core/buffer/urlbasedbufferprovider.cpp

@@ -0,0 +1,3 @@
+#include "urlbasedbufferprovider.h"
+
+using namespace vnotex;

src/core/buffer/urlbasedbufferprovider.h

@@ -0,0 +1,132 @@
+#ifndef URLBASEDBUFFERPROVIDER_H
+#define URLBASEDBUFFERPROVIDER_H
+
+#include "bufferprovider.h"
+
+#include <QSharedPointer>
+
+namespace vnotex
+{
+    // A wrapper provider to provide URL-based buffer (instead of content-based).
+    class UrlBasedBufferProvider : public BufferProvider
+    {
+        Q_OBJECT
+    public:
+        // Will own @p_provider.
+        UrlBasedBufferProvider(const QSharedPointer<BufferProvider> &p_provider, QObject *p_parent = nullptr)
+            : BufferProvider(p_parent),
+              m_provider(p_provider)
+        {
+        }
+
+        Buffer::ProviderType getType() const Q_DECL_OVERRIDE {
+            return m_provider->getType();
+        }
+
+        bool match(const Node *p_node) const Q_DECL_OVERRIDE {
+            return m_provider->match(p_node);
+        }
+
+        bool match(const QString &p_filePath) const Q_DECL_OVERRIDE {
+            return m_provider->match(p_filePath);
+        }
+
+        QString getName() const Q_DECL_OVERRIDE {
+            return m_provider->getName();
+        }
+
+        QString getPath() const Q_DECL_OVERRIDE {
+            return m_provider->getPath();
+        }
+
+        QString getContentPath() const Q_DECL_OVERRIDE {
+            return m_provider->getContentPath();
+        }
+
+        QString getResourcePath() const Q_DECL_OVERRIDE {
+            return m_provider->getResourcePath();
+        }
+
+        void write(const QString &p_content) Q_DECL_OVERRIDE {
+            Q_UNUSED(p_content);
+        }
+
+        QString read() const Q_DECL_OVERRIDE {
+            const_cast<UrlBasedBufferProvider *>(this)->m_lastModified = getLastModifiedFromFile();
+            return QString();
+        }
+
+        QString fetchImageFolderPath() Q_DECL_OVERRIDE {
+            return m_provider->fetchImageFolderPath();
+        }
+
+        bool isChildOf(const Node *p_node) const Q_DECL_OVERRIDE {
+            return m_provider->isChildOf(p_node);
+        }
+
+        Node *getNode() const Q_DECL_OVERRIDE {
+            return m_provider->getNode();
+        }
+
+        QString getAttachmentFolder() const Q_DECL_OVERRIDE {
+            return m_provider->getAttachmentFolder();
+        }
+
+        QString fetchAttachmentFolderPath() Q_DECL_OVERRIDE {
+            return m_provider->fetchAttachmentFolderPath();
+        }
+
+        QStringList addAttachment(const QString &p_destFolderPath, const QStringList &p_files) Q_DECL_OVERRIDE {
+            return m_provider->addAttachment(p_destFolderPath, p_files);
+        }
+
+        QString newAttachmentFile(const QString &p_destFolderPath, const QString &p_name) Q_DECL_OVERRIDE {
+            return m_provider->newAttachmentFile(p_destFolderPath, p_name);
+        }
+
+        QString newAttachmentFolder(const QString &p_destFolderPath, const QString &p_name) Q_DECL_OVERRIDE {
+            return m_provider->newAttachmentFolder(p_destFolderPath, p_name);
+        }
+
+        QString renameAttachment(const QString &p_path, const QString &p_name) Q_DECL_OVERRIDE {
+            return m_provider->renameAttachment(p_path, p_name);
+        }
+
+        void removeAttachment(const QStringList &p_paths) Q_DECL_OVERRIDE {
+            m_provider->removeAttachment(p_paths);
+        }
+
+        QString insertImage(const QString &p_srcImagePath, const QString &p_imageFileName) Q_DECL_OVERRIDE {
+            return m_provider->insertImage(p_srcImagePath, p_imageFileName);
+        }
+
+        QString insertImage(const QImage &p_image, const QString &p_imageFileName) Q_DECL_OVERRIDE {
+            return m_provider->insertImage(p_image, p_imageFileName);
+        }
+
+        void removeImage(const QString &p_imagePath) Q_DECL_OVERRIDE {
+            m_provider->removeImage(p_imagePath);
+        }
+
+        bool isAttachmentSupported() const Q_DECL_OVERRIDE {
+            return m_provider->isAttachmentSupported();
+        }
+
+        bool isTagSupported() const Q_DECL_OVERRIDE {
+            return m_provider->isTagSupported();
+        }
+
+        bool isReadOnly() const Q_DECL_OVERRIDE {
+            return true;
+        }
+
+        QSharedPointer<File> getFile() const Q_DECL_OVERRIDE {
+            return m_provider->getFile();
+        }
+
+    private:
+        QSharedPointer<BufferProvider> m_provider;
+    };
+}
+
+#endif // URLBASEDBUFFERPROVIDER_H

src/core/buffermgr.cpp

@@ -7,6 +7,7 @@
 #include <buffer/filetypehelper.h>
 #include <buffer/markdownbufferfactory.h>
 #include <buffer/textbufferfactory.h>
+#include <buffer/pdfbufferfactory.h>
 #include <buffer/buffer.h>
 #include <buffer/nodebufferprovider.h>
 #include <buffer/filebufferprovider.h>
@@ -52,6 +53,10 @@ void BufferMgr::initBufferServer()
     // Text.
     auto textFactory = QSharedPointer<TextBufferFactory>::create();
     m_bufferServer->registerItem(helper.getFileType(FileType::Text).m_typeName, textFactory);
+
+    // Pdf.
+    auto pdfFactory = QSharedPointer<PdfBufferFactory>::create();
+    m_bufferServer->registerItem(helper.getFileType(FileType::Pdf).m_typeName, pdfFactory);
 }
 
 void BufferMgr::open(Node *p_node, const QSharedPointer<FileOpenParameters> &p_paras)

src/core/configmgr.cpp

@@ -25,7 +25,7 @@
 using namespace vnotex;
 
 #ifndef QT_NO_DEBUG
-    // #define VX_DEBUG_WEB
+#define VX_DEBUG_WEB
 #endif
 
 const QString ConfigMgr::c_orgName = "VNote";

src/core/core.pri

@@ -24,6 +24,7 @@ SOURCES += \
     $$PWD/logger.cpp \
     $$PWD/mainconfig.cpp \
     $$PWD/markdowneditorconfig.cpp \
+    $$PWD/pdfviewerconfig.cpp \
     $$PWD/quickaccesshelper.cpp \
     $$PWD/singleinstanceguard.cpp \
     $$PWD/templatemgr.cpp \
@@ -54,6 +55,7 @@ HEADERS += \
     $$PWD/mainconfig.h \
     $$PWD/markdowneditorconfig.h \
     $$PWD/noncopyable.h \
+    $$PWD/pdfviewerconfig.h \
     $$PWD/quickaccesshelper.h \
     $$PWD/singleinstanceguard.h \
     $$PWD/iconfig.h \

src/core/editorconfig.cpp

@@ -5,6 +5,7 @@
 
 #include "texteditorconfig.h"
 #include "markdowneditorconfig.h"
+#include "pdfviewerconfig.h"
 
 #include <vtextedit/viconfig.h>
 
@@ -41,7 +42,8 @@ QJsonObject EditorConfig::ImageHostItem::toJson() const
 EditorConfig::EditorConfig(ConfigMgr *p_mgr, IConfig *p_topConfig)
     : IConfig(p_mgr, p_topConfig),
       m_textEditorConfig(new TextEditorConfig(p_mgr, p_topConfig)),
-      m_markdownEditorConfig(new MarkdownEditorConfig(p_mgr, p_topConfig, m_textEditorConfig))
+      m_markdownEditorConfig(new MarkdownEditorConfig(p_mgr, p_topConfig, m_textEditorConfig)),
+      m_pdfViewerConfig(new PdfViewerConfig(p_mgr, p_topConfig))
 {
     m_sessionName = QStringLiteral("editor");
 }
@@ -65,6 +67,7 @@ void EditorConfig::init(const QJsonObject &p_app,
 
     m_textEditorConfig->init(appObj, userObj);
     m_markdownEditorConfig->init(appObj, userObj);
+    m_pdfViewerConfig->init(appObj, userObj);
 }
 
 void EditorConfig::loadCore(const QJsonObject &p_app, const QJsonObject &p_user)
@@ -148,6 +151,7 @@ QJsonObject EditorConfig::toJson() const
     QJsonObject obj;
     obj[m_textEditorConfig->getSessionName()] = m_textEditorConfig->toJson();
     obj[m_markdownEditorConfig->getSessionName()] = m_markdownEditorConfig->toJson();
+    obj[m_pdfViewerConfig->getSessionName()] = m_pdfViewerConfig->toJson();
     obj[QStringLiteral("core")] = saveCore();
     obj[QStringLiteral("image_host")] = saveImageHost();
 
@@ -178,6 +182,16 @@ const MarkdownEditorConfig &EditorConfig::getMarkdownEditorConfig() const
     return *m_markdownEditorConfig;
 }
 
+PdfViewerConfig &EditorConfig::getPdfViewerConfig()
+{
+    return *m_pdfViewerConfig;
+}
+
+const PdfViewerConfig &EditorConfig::getPdfViewerConfig() const
+{
+    return *m_pdfViewerConfig;
+}
+
 int EditorConfig::getToolBarIconSize() const
 {
     return m_toolBarIconSize;

src/core/editorconfig.h

@@ -19,6 +19,7 @@ namespace vnotex
 {
     class TextEditorConfig;
     class MarkdownEditorConfig;
+    class PdfViewerConfig;
 
     class EditorConfig : public IConfig
     {
@@ -105,6 +106,9 @@ namespace vnotex
         MarkdownEditorConfig &getMarkdownEditorConfig();
         const MarkdownEditorConfig &getMarkdownEditorConfig() const;
 
+        PdfViewerConfig &getPdfViewerConfig();
+        const PdfViewerConfig &getPdfViewerConfig() const;
+
         void init(const QJsonObject &p_app, const QJsonObject &p_user) Q_DECL_OVERRIDE;
 
         QJsonObject toJson() const Q_DECL_OVERRIDE;
@@ -176,6 +180,8 @@ namespace vnotex
 
         QScopedPointer<MarkdownEditorConfig> m_markdownEditorConfig;
 
+        QScopedPointer<PdfViewerConfig> m_pdfViewerConfig;
+
         bool m_spellCheckAutoDetectLanguageEnabled = false;
 
         QString m_spellCheckDefaultDictionary;

src/core/htmltemplatehelper.cpp

@@ -3,6 +3,7 @@
 #include <QDebug>
 
 #include <core/markdowneditorconfig.h>
+#include <core/pdfviewerconfig.h>
 #include <core/configmgr.h>
 #include <utils/utils.h>
 #include <utils/fileutils.h>
@@ -16,7 +17,9 @@ using namespace vnotex;
 
 HtmlTemplateHelper::Template HtmlTemplateHelper::s_markdownViewerTemplate;
 
-QString WebGlobalOptions::toJavascriptObject() const
+HtmlTemplateHelper::Template HtmlTemplateHelper::s_pdfViewerTemplate;
+
+QString MarkdownWebGlobalOptions::toJavascriptObject() const
 {
     return QStringLiteral("window.vxOptions = {\n")
            + QString("webPlantUml: %1,\n").arg(Utils::boolToString(m_webPlantUml))
@@ -101,7 +104,7 @@ static void fillThemeStyles(QString &p_template, const QString &p_webStyleSheetF
     }
 }
 
-static void fillGlobalOptions(QString &p_template, const WebGlobalOptions &p_opts)
+static void fillGlobalOptions(QString &p_template, const MarkdownWebGlobalOptions &p_opts)
 {
     p_template.replace(QStringLiteral("/* VX_GLOBAL_OPTIONS_PLACEHOLDER */"),
                        p_opts.toJavascriptObject());
@@ -187,7 +190,7 @@ void HtmlTemplateHelper::updateMarkdownViewerTemplate(const MarkdownEditorConfig
 
     s_markdownViewerTemplate.m_revision = p_config.revision();
 
-    Paras paras;
+    MarkdownParas paras;
     const auto &themeMgr = VNoteX::getInst().getThemeMgr();
     paras.m_webStyleSheetFile = themeMgr.getFile(Theme::File::WebStyleSheet);
     paras.m_highlightStyleSheetFile = themeMgr.getFile(Theme::File::HighlightStyleSheet);
@@ -195,7 +198,8 @@ void HtmlTemplateHelper::updateMarkdownViewerTemplate(const MarkdownEditorConfig
     s_markdownViewerTemplate.m_template = generateMarkdownViewerTemplate(p_config, paras);
 }
 
-QString HtmlTemplateHelper::generateMarkdownViewerTemplate(const MarkdownEditorConfig &p_config, const Paras &p_paras)
+QString HtmlTemplateHelper::generateMarkdownViewerTemplate(const MarkdownEditorConfig &p_config,
+                                                           const MarkdownParas &p_paras)
 {
     const auto &viewerResource = p_config.getViewerResource();
     const auto templateFile = ConfigMgr::getInst().getUserOrAppFile(viewerResource.m_template);
@@ -212,7 +216,7 @@ QString HtmlTemplateHelper::generateMarkdownViewerTemplate(const MarkdownEditorC
     fillThemeStyles(htmlTemplate, p_paras.m_webStyleSheetFile, p_paras.m_highlightStyleSheetFile);
 
     {
-        WebGlobalOptions opts;
+        MarkdownWebGlobalOptions opts;
         opts.m_webPlantUml = p_config.getWebPlantUml();
         opts.m_plantUmlWebService = p_config.getPlantUmlWebService();
         opts.m_webGraphviz = p_config.getWebGraphviz();
@@ -242,8 +246,8 @@ QString HtmlTemplateHelper::generateMarkdownViewerTemplate(const MarkdownEditorC
     return htmlTemplate;
 }
 
-QString HtmlTemplateHelper::generateExportTemplate(const MarkdownEditorConfig &p_config,
+QString HtmlTemplateHelper::generateMarkdownExportTemplate(const MarkdownEditorConfig &p_config,
-                                                   bool p_addOutlinePanel)
+                                                           bool p_addOutlinePanel)
 {
     auto exportResource = p_config.getExportResource();
     const auto templateFile = ConfigMgr::getInst().getUserOrAppFile(exportResource.m_template);
@@ -251,7 +255,7 @@ QString HtmlTemplateHelper::generateExportTemplate(const MarkdownEditorConfig &p
     try {
         htmlTemplate = FileUtils::readTextFile(templateFile);
     } catch (Exception &p_e) {
-        qWarning() << "failed to read export HTML template" << templateFile << p_e.what();
+        qWarning() << "failed to read Markdown export HTML template" << templateFile << p_e.what();
         return errorPage();
     }
 
@@ -322,3 +326,38 @@ QString HtmlTemplateHelper::errorPage()
     return VNoteX::tr("Failed to load HTML template. Check the logs for details. "
                       "Try deleting the user configuration file and the default configuration file.");
 }
+
+const QString &HtmlTemplateHelper::getPdfViewerTemplate()
+{
+    return s_pdfViewerTemplate.m_template;
+}
+
+const QString &HtmlTemplateHelper::getPdfViewerTemplatePath()
+{
+    return s_pdfViewerTemplate.m_templatePath;
+}
+
+void HtmlTemplateHelper::updatePdfViewerTemplate(const PdfViewerConfig &p_config, bool p_force)
+{
+    if (!p_force && p_config.revision() == s_markdownViewerTemplate.m_revision) {
+        return;
+    }
+
+    s_pdfViewerTemplate.m_revision = p_config.revision();
+    generatePdfViewerTemplate(p_config, s_pdfViewerTemplate);
+}
+
+void HtmlTemplateHelper::generatePdfViewerTemplate(const PdfViewerConfig &p_config, Template& p_template)
+{
+    const auto &viewerResource = p_config.getViewerResource();
+    p_template.m_templatePath = ConfigMgr::getInst().getUserOrAppFile(viewerResource.m_template);
+    try {
+        p_template.m_template = FileUtils::readTextFile(p_template.m_templatePath);
+    } catch (Exception &p_e) {
+        qWarning() << "failed to read HTML template" << p_template.m_templatePath << p_e.what();
+        p_template.m_template = errorPage();
+        return;
+    }
+
+    fillResources(p_template.m_template, viewerResource);
+}

src/core/htmltemplatehelper.h

@@ -6,10 +6,11 @@
 namespace vnotex
 {
     class MarkdownEditorConfig;
+    class PdfViewerConfig;
     struct WebResource;
 
-    // Global options to be passed to Web side at the very beginning.
+    // Global options to be passed to Web side at the very beginning for Markdown.
-    struct WebGlobalOptions
+    struct MarkdownWebGlobalOptions
     {
         bool m_webPlantUml = true;
 
@@ -67,7 +68,7 @@ namespace vnotex
     class HtmlTemplateHelper
     {
     public:
-        struct Paras
+        struct MarkdownParas
         {
             QString m_webStyleSheetFile;
 
@@ -90,14 +91,16 @@ namespace vnotex
 
         HtmlTemplateHelper() = delete;
 
+        // For Markdown.
         static const QString &getMarkdownViewerTemplate();
         static void updateMarkdownViewerTemplate(const MarkdownEditorConfig &p_config, bool p_force = false);
 
-        static QString generateMarkdownViewerTemplate(const MarkdownEditorConfig &p_config, const Paras &p_paras);
+        static QString generateMarkdownViewerTemplate(const MarkdownEditorConfig &p_config, const MarkdownParas &p_paras);
 
-        static QString generateExportTemplate(const MarkdownEditorConfig &p_config,
+        static QString generateMarkdownExportTemplate(const MarkdownEditorConfig &p_config,
-                                              bool p_addOutlinePanel);
+                                                      bool p_addOutlinePanel);
 
+        // For common HTML content manipulation.
         static void fillTitle(QString &p_template, const QString &p_title);
 
         static void fillStyleContent(QString &p_template, const QString &p_styles);
@@ -110,17 +113,27 @@ namespace vnotex
 
         static void fillOutlinePanel(QString &p_template, WebResource &p_exportResource, bool p_addOutlinePanel);
 
-    private:
+        // For PdfViewer.
-        static QString errorPage();
+        static const QString &getPdfViewerTemplate();
+        static void updatePdfViewerTemplate(const PdfViewerConfig &p_config, bool p_force = false);
 
+        static const QString &getPdfViewerTemplatePath();
+
+    private:
         struct Template
         {
             int m_revision = -1;
             QString m_template;
+            QString m_templatePath;
         };
 
-        // Template for MarkdownViewer.
+        static QString errorPage();
+
+        static void generatePdfViewerTemplate(const PdfViewerConfig &p_config, Template& p_template);
+
         static Template s_markdownViewerTemplate;
+
+        static Template s_pdfViewerTemplate;
     };
 }
 

src/core/pdfviewerconfig.cpp

@@ -0,0 +1,61 @@
+#include "pdfviewerconfig.h"
+
+#include "mainconfig.h"
+
+#define READSTR(key) readString(appObj, userObj, (key))
+#define READBOOL(key) readBool(appObj, userObj, (key))
+#define READINT(key) readInt(appObj, userObj, (key))
+
+using namespace vnotex;
+
+PdfViewerConfig::PdfViewerConfig(ConfigMgr *p_mgr, IConfig *p_topConfig)
+    : IConfig(p_mgr, p_topConfig)
+{
+    m_sessionName = QStringLiteral("pdf_viewer");
+}
+
+void PdfViewerConfig::init(const QJsonObject &p_app,
+                           const QJsonObject &p_user)
+{
+    const auto appObj = p_app.value(m_sessionName).toObject();
+    const auto userObj = p_user.value(m_sessionName).toObject();
+
+    loadViewerResource(appObj, userObj);
+}
+
+QJsonObject PdfViewerConfig::toJson() const
+{
+    QJsonObject obj;
+    obj[QStringLiteral("viewer_resource")] = saveViewerResource();
+    return obj;
+}
+
+void PdfViewerConfig::loadViewerResource(const QJsonObject &p_app, const QJsonObject &p_user)
+{
+    const QString name(QStringLiteral("viewer_resource"));
+
+    if (MainConfig::isVersionChanged()) {
+        bool needOverride = p_app[QStringLiteral("override_viewer_resource")].toBool();
+        if (needOverride) {
+            qInfo() << "override \"viewer_resource\" in user configuration due to version change";
+            m_viewerResource.init(p_app[name].toObject());
+            return;
+        }
+    }
+
+    if (p_user.contains(name)) {
+        m_viewerResource.init(p_user[name].toObject());
+    } else {
+        m_viewerResource.init(p_app[name].toObject());
+    }
+}
+
+QJsonObject PdfViewerConfig::saveViewerResource() const
+{
+    return m_viewerResource.toJson();
+}
+
+const WebResource &PdfViewerConfig::getViewerResource() const
+{
+    return m_viewerResource;
+}

src/core/pdfviewerconfig.h

@@ -0,0 +1,31 @@
+#ifndef PDFVIEWERCONFIG_H
+#define PDFVIEWERCONFIG_H
+
+#include "iconfig.h"
+
+#include "webresource.h"
+
+namespace vnotex
+{
+    class PdfViewerConfig : public IConfig
+    {
+    public:
+        PdfViewerConfig(ConfigMgr *p_mgr, IConfig *p_topConfig);
+
+        void init(const QJsonObject &p_app, const QJsonObject &p_user) Q_DECL_OVERRIDE;
+
+        QJsonObject toJson() const Q_DECL_OVERRIDE;
+
+        const WebResource &getViewerResource() const;
+
+    private:
+        friend class MainConfig;
+
+        void loadViewerResource(const QJsonObject &p_app, const QJsonObject &p_user);
+        QJsonObject saveViewerResource() const;
+
+        WebResource m_viewerResource;
+    };
+}
+
+#endif // PDFVIEWERCONFIG_H

src/data/core/vnotex.json

@@ -88,6 +88,12 @@
                     "text",
                     "log"
                 ]
+            },
+            {
+                "name" : "PDF",
+                "suffixes" : [
+                    "pdf"
+                ]
             }
         ],
         "shortcut_leader_key" : "Ctrl+G",
@@ -268,12 +274,13 @@
                         "scripts" : [
                             "web/js/qwebchannel.js",
                             "web/js/eventemitter.js",
+                            "web/js/vxcore.js",
                             "web/js/utils.js",
                             "web/js/nodelinemapper.js",
                             "web/js/lrucache.js",
                             "web/js/graphcache.js",
                             "web/js/graphpreviewer.js",
-                            "web/js/vnotex.js",
+                            "web/js/markdownviewercore.js",
                             "web/js/vxworker.js",
                             "web/js/graphrenderer.js",
                             "web/js/svg-to-image.js",
@@ -472,6 +479,43 @@
             "edit_view_mode" : "editonly",
             "rich_paste_by_default" : true
         },
+        "pdf_viewer" : {
+            "override_viewer_resource" : true,
+            "viewer_resource" : {
+                "template" : "web/pdf-viewer-template.html",
+                "resources" : [
+                    {
+                        "name" : "built_in",
+                        "enabled" : true,
+                        "scripts" : [
+                            "web/js/qwebchannel.js",
+                            "web/js/eventemitter.js",
+                            "web/js/utils.js",
+                            "web/js/vxcore.js",
+                            "web/js/pdfviewercore.js"
+                        ]
+                    },
+                    {
+                        "name" : "pdf.js",
+                        "enabled" : true,
+                        "scripts" : [
+                            "web/js/pdf.js/pdf.min.js",
+                            "web/js/pdf.js/pdf_viewer.js"
+                        ],
+                        "styles" : [
+                            "web/js/pdf.js/pdf_viewer.css"
+                        ]
+                    },
+                    {
+                        "name" : "pdf_viewer",
+                        "enabled" : true,
+                        "scripts" : [
+                            "web/js/pdfviewer.js"
+                        ]
+                    }
+                ]
+            }
+        },
         "image_host" : {
             "hosts" : [
             ],

src/data/extra/extra.qrc

@@ -16,6 +16,7 @@
         <file>docs/zh_CN/features_tips.txt</file>
         <file>web/markdown-viewer-template.html</file>
         <file>web/markdown-export-template.html</file>
+        <file>web/pdf-viewer-template.html</file>
         <file>web/css/user.css</file>
         <file>web/css/globalstyles.css</file>
         <file>web/css/markdownit.css</file>
@@ -29,7 +30,9 @@
         <file>web/js/lrucache.js</file>
         <file>web/js/graphcache.js</file>
         <file>web/js/graphpreviewer.js</file>
-        <file>web/js/vnotex.js</file>
+        <file>web/js/markdownviewercore.js</file>
+        <file>web/js/pdfviewercore.js</file>
+        <file>web/js/vxcore.js</file>
         <file>web/js/vxworker.js</file>
         <file>web/js/graphrenderer.js</file>
         <file>web/js/markdownviewer.js</file>
@@ -80,6 +83,13 @@
         <file>web/js/markjs.js</file>
         <file>web/js/mind-elixir/MindElixir.min.js</file>
         <file>web/js/mind-elixir/painter.js</file>
+        <file>web/js/pdf.js/pdf.worker.min.js</file>
+        <file>web/js/pdf.js/pdf.min.js</file>
+        <file>web/js/pdf.js/pdf_viewer.js</file>
+        <file>web/js/pdf.js/pdf_viewer.css</file>
+        <file>web/js/pdf.js/images/shadow.png</file>
+        <file>web/js/pdf.js/images/loading-icon.gif</file>
+        <file>web/js/pdfviewer.js</file>
         <file>dicts/en_US.aff</file>
         <file>dicts/en_US.dic</file>
         <file>themes/native/text-editor.theme</file>

src/data/extra/web/js/crosscopy.js

@@ -213,7 +213,7 @@ class CrossCopy {
 
             // Check if we need to fix the encoding.
             // Win needs only space-encoded.
-            if (window.vnotex.os === "Windows") {
+            if (window.vxcore.os === "Windows") {
                 let decodedUrl = decodeURI(img.src);
                 if (decodedUrl.length != img.src.length) {
                     // May need other encoding.

src/data/extra/web/js/easyaccess.js

@@ -12,7 +12,7 @@ class EasyAccess {
         // The repeat token from user input.
         this.repeatToken =  0;
 
-        window.vnotex.on('ready', () => {
+        window.vxcore.on('ready', () => {
             this.setupMouseMove();
             this.setupViNavigation();
             this.setupZoomOnWheel();
@@ -22,7 +22,7 @@ class EasyAccess {
     setupMouseMove() {
         window.addEventListener('mousedown', (e) => {
             e = e || window.event;
-            let isCtrl = window.vnotex.os === 'Mac' ? e.metaKey : e.ctrlKey;
+            let isCtrl = window.vxcore.os === 'Mac' ? e.metaKey : e.ctrlKey;
             // Left button and Ctrl key.
             if (e.buttons == 1
                 && isCtrl
@@ -99,7 +99,7 @@ class EasyAccess {
             shift = !!e.shiftKey;
             ctrl = !!e.ctrlKey;
             meta = !!e.metaKey;
-            let isCtrl = window.vnotex.os === 'Mac' ? e.metaKey : e.ctrlKey;
+            let isCtrl = window.vxcore.os === 'Mac' ? e.metaKey : e.ctrlKey;
             switch (key) {
             // Skip Ctrl, Shift, Alt, Supper.
             case 16:
@@ -332,7 +332,7 @@ class EasyAccess {
             if (accepted) {
                 e.preventDefault();
             } else {
-                window.vnotex.setKeyPress(key, ctrl, shift, meta);
+                window.vxcore.setKeyPress(key, ctrl, shift, meta);
             }
         });
     }
@@ -342,12 +342,12 @@ class EasyAccess {
     //                 negative value for upper level;
     //                 positive value is ignored.
     jumpTitle(forward, relativeLevel, repeat) {
-        let headings = window.vnotex.nodeLineMapper.headingNodes;
+        let headings = window.vxcore.nodeLineMapper.headingNodes;
         if (headings.length == 0) {
             return;
         }
 
-        let currentHeadingIdx = window.vnotex.nodeLineMapper.currentHeadingIndex();
+        let currentHeadingIdx = window.vxcore.nodeLineMapper.currentHeadingIndex();
         if (currentHeadingIdx == -1) {
             // At the beginning, before any headings.
             if (relativeLevel < 0 || !forward) {
@@ -403,19 +403,19 @@ class EasyAccess {
             return;
         }
 
-        window.vnotex.nodeLineMapper.scrollToNode(headings[targetIdx], false, false);
+        window.vxcore.nodeLineMapper.scrollToNode(headings[targetIdx], false, false);
         window.setTimeout(function() {
-            window.vnotex.nodeLineMapper.updateCurrentHeading();
+            window.vxcore.nodeLineMapper.updateCurrentHeading();
         }, 1000);
     };
 
     setupZoomOnWheel() {
         window.addEventListener('wheel', (e) => {
             e = e || window.event;
-            let isCtrl = window.vnotex.os === 'Mac' ? e.metaKey : e.ctrlKey;
+            let isCtrl = window.vxcore.os === 'Mac' ? e.metaKey : e.ctrlKey;
             if (isCtrl) {
                 if (e.deltaY != 0) {
-                    window.vnotex.zoom(e.deltaY < 0);
+                    window.vxcore.zoom(e.deltaY < 0);
                 }
                 e.preventDefault();
             }

src/data/extra/web/js/flowchartjs.js

@@ -110,4 +110,4 @@ class FlowchartJs extends GraphRenderer {
     }
 }
 
-window.vnotex.registerWorker(new FlowchartJs());
+window.vxcore.registerWorker(new FlowchartJs());

src/data/extra/web/js/graphpreviewer.js

@@ -1,6 +1,6 @@
 class GraphPreviewer {
-    constructor(p_vnotex, p_container) {
+    constructor(p_vxcore, p_container) {
-        this.vnotex = p_vnotex;
+        this.vxcore = p_vxcore;
 
         // Preview will take place here.
         this.container = p_container;
@@ -36,21 +36,21 @@ class GraphPreviewer {
         this.initOnFirstPreview();
 
         if (p_lang === 'flow' || p_lang === 'flowchart') {
-            this.vnotex.getWorker('flowchartjs').renderText(this.container,
+            this.vxcore.getWorker('flowchartjs').renderText(this.container,
                 p_text,
                 this.flowchartJsIdx++,
                 (graphDiv) => {
                     this.processGraph(p_id, p_timeStamp, graphDiv);
                 });
         } else if (p_lang === 'wavedrom') {
-            this.vnotex.getWorker('wavedrom').renderText(this.container,
+            this.vxcore.getWorker('wavedrom').renderText(this.container,
                 p_text,
                 this.waveDromIdx++,
                 (graphDiv) => {
                     this.processGraph(p_id, p_timeStamp, graphDiv);
                 });
         } else if (p_lang === 'mermaid') {
-            this.vnotex.getWorker('mermaid').renderText(this.container,
+            this.vxcore.getWorker('mermaid').renderText(this.container,
                 p_text,
                 this.mermaidIdx++,
                 (graphDiv) => {
@@ -66,7 +66,7 @@ class GraphPreviewer {
                     previewer.setGraphPreviewData(id, timeStamp, p_format, p_data, false, true);
                 };
             };
-            this.vnotex.getWorker('plantuml').renderText(p_text, func(this, p_id, p_timeStamp));
+            this.vxcore.getWorker('plantuml').renderText(p_text, func(this, p_id, p_timeStamp));
             return;
         } else if (p_lang === 'dot' || p_lang === 'graphviz') {
             let func = function(p_previewer, p_id, p_timeStamp) {
@@ -77,7 +77,7 @@ class GraphPreviewer {
                     previewer.setGraphPreviewData(id, timeStamp, 'svg', p_svgNode.outerHTML, false, true);
                 };
             };
-            this.vnotex.getWorker('graphviz').renderText(p_text, func(this, p_id, p_timeStamp));
+            this.vxcore.getWorker('graphviz').renderText(p_text, func(this, p_id, p_timeStamp));
             return;
         } else if (p_lang === 'mathjax') {
             this.renderMath(p_id, p_timeStamp, p_text, null);
@@ -104,7 +104,7 @@ class GraphPreviewer {
         if (this.firstPreview) {
             this.firstPreview = false;
 
-            let contentStyle = window.getComputedStyle(this.vnotex.contentContainer);
+            let contentStyle = window.getComputedStyle(this.vxcore.contentContainer);
             this.currentColor = contentStyle.getPropertyValue('color');
             console.log('currentColor', this.currentColor);
         }
@@ -121,7 +121,7 @@ class GraphPreviewer {
                 previewer.processSvgAsPng(id, timeStamp, p_svgNode, p_dataSetter);
             };
         };
-        this.vnotex.getWorker('mathjax').renderText(this.container,
+        this.vxcore.getWorker('mathjax').renderText(this.container,
                                                     p_text,
                                                     func(this, p_id, p_timeStamp));
     }
@@ -237,7 +237,7 @@ class GraphPreviewer {
             base64: p_base64,
             needScale: p_needScale
         };
-        this.vnotex.setGraphPreviewData(previewData);
+        this.vxcore.setGraphPreviewData(previewData);
     }
 
     setMathPreviewData(p_id, p_timeStamp, p_format = '', p_data = '', p_base64 = false, p_needScale = false) {
@@ -249,6 +249,6 @@ class GraphPreviewer {
             base64: p_base64,
             needScale: p_needScale
         };
-        this.vnotex.setMathPreviewData(previewData);
+        this.vxcore.setMathPreviewData(previewData);
     }
 }

src/data/extra/web/js/graphrenderer.js

@@ -28,12 +28,12 @@ class GraphRenderer extends VxWorker {
     }
 
     registerInternal() {
-        this.vnotex.on('basicMarkdownRendered', () => {
+        this.vxcore.on('basicMarkdownRendered', () => {
             this.reset();
             this.renderCodeNodes();
         });
 
-        this.vnotex.getWorker('markdownit').addLangsToSkipHighlight(this.langs);
+        this.vxcore.getWorker('markdownit').addLangsToSkipHighlight(this.langs);
     }
 
     // Return ture if we could continue.
@@ -79,7 +79,7 @@ class GraphRenderer extends VxWorker {
     // Interface 2.
     // Get code nodes from markdownIt directly.
     renderCodeNodes() {
-        this.nodesToRender = this.vnotex.getWorker('markdownit').getCodeNodes(this.langs);
+        this.nodesToRender = this.vxcore.getWorker('markdownit').getCodeNodes(this.langs);
         this.numOfRenderedNodes = 0;
         this.doRender();
     }

src/data/extra/web/js/graphviz.js

@@ -21,12 +21,12 @@ class Graphviz extends GraphRenderer {
     }
 
     registerInternal() {
-        this.vnotex.on('basicMarkdownRendered', () => {
+        this.vxcore.on('basicMarkdownRendered', () => {
             this.reset();
             this.renderCodeNodes(window.vxOptions.transformSvgToPngEnabled ? 'png' : 'svg');
         });
 
-        this.vnotex.getWorker('markdownit').addLangsToSkipHighlight(this.langs);
+        this.vxcore.getWorker('markdownit').addLangsToSkipHighlight(this.langs);
         this.useWeb = window.vxOptions.webGraphviz;
         if (!this.useWeb) {
             this.extraScripts = [];
@@ -138,7 +138,7 @@ class Graphviz extends GraphRenderer {
         };
 
         let callback = func(this, p_node);
-        this.vnotex.renderGraph(this.id,
+        this.vxcore.renderGraph(this.id,
             this.nextLocalGraphIndex++,
             this.format,
             'dot',
@@ -174,4 +174,4 @@ class Graphviz extends GraphRenderer {
     }
 }
 
-window.vnotex.registerWorker(new Graphviz());
+window.vxcore.registerWorker(new Graphviz());

src/data/extra/web/js/imageviewer.js

@@ -4,7 +4,7 @@ class ImageViewer {
         this.viewBoxOffsetToMouse = { x: 0, y: 0 }
         this.viewImageClass = 'vx-image-view-image';
 
-        window.vnotex.on('ready', () => {
+        window.vxcore.on('ready', () => {
             this.viewBoxContainer = document.getElementById('vx-image-view-box');
             this.viewBox = document.getElementById('vx-image-view');
             this.closeButton = document.getElementById('vx-image-view-close');

src/data/extra/web/js/markdownit.js

@@ -244,10 +244,10 @@ class MarkdownIt extends VxWorker {
     }
 
     registerInternal() {
-        this.vnotex.on('markdownTextUpdated', (p_text) => {
+        this.vxcore.on('markdownTextUpdated', (p_text) => {
-            this.render(this.vnotex.contentContainer,
+            this.render(this.vxcore.contentContainer,
                         p_text,
-                        'window.vnotex.getWorker(\'markdownit\').markdownRenderFinished();');
+                        'window.vxcore.getWorker(\'markdownit\').markdownRenderFinished();');
         });
     }
 
@@ -307,7 +307,7 @@ class MarkdownIt extends VxWorker {
     // Will be called when basic markdown is rendered.
     markdownRenderFinished() {
         window.vxImageViewer.setupForAllImages(this.lastContainerNode);
-        this.vnotex.setBasicMarkdownRendered();
+        this.vxcore.setBasicMarkdownRendered();
     }
 
     getCodeNodes(p_langs) {
@@ -342,4 +342,4 @@ class MarkdownIt extends VxWorker {
     }
 }
 
-window.vnotex.registerWorker(new MarkdownIt(null));
+window.vxcore.registerWorker(new MarkdownIt(null));

src/data/extra/web/js/markdownviewer.js

@@ -8,65 +8,65 @@ new QWebChannel(qt.webChannelTransport,
 
         // Connect signals from CPP side.
         adapter.textUpdated.connect(function(p_text) {
-            window.vnotex.setMarkdownText(p_text);
+            window.vxcore.setMarkdownText(p_text);
         });
 
         adapter.editLineNumberUpdated.connect(function(p_lineNumber) {
-            window.vnotex.scrollToLine(p_lineNumber);
+            window.vxcore.scrollToLine(p_lineNumber);
         });
 
         adapter.anchorScrollRequested.connect(function(p_anchor) {
-            window.vnotex.scrollToAnchor(p_anchor);
+            window.vxcore.scrollToAnchor(p_anchor);
         });
 
         adapter.graphPreviewRequested.connect(function(p_id, p_timeStamp, p_lang, p_text) {
-            window.vnotex.previewGraph(p_id, p_timeStamp, p_lang, p_text);
+            window.vxcore.previewGraph(p_id, p_timeStamp, p_lang, p_text);
         });
 
         adapter.mathPreviewRequested.connect(function(p_id, p_timeStamp, p_text) {
-            window.vnotex.previewMath(p_id, p_timeStamp, p_text);
+            window.vxcore.previewMath(p_id, p_timeStamp, p_text);
         });
 
         adapter.scrollRequested.connect(function(p_up) {
-            window.vnotex.scroll(p_up);
+            window.vxcore.scroll(p_up);
         });
 
         adapter.htmlToMarkdownRequested.connect(function(p_id, p_timeStamp, p_html) {
-            window.vnotex.htmlToMarkdown(p_id, p_timeStamp, p_html);
+            window.vxcore.htmlToMarkdown(p_id, p_timeStamp, p_html);
         });
 
         adapter.highlightCodeBlockRequested.connect(function(p_idx, p_timeStamp, p_text) {
-            window.vnotex.highlightCodeBlock(p_idx, p_timeStamp, p_text);
+            window.vxcore.highlightCodeBlock(p_idx, p_timeStamp, p_text);
         });
 
         adapter.parseStyleSheetRequested.connect(function(p_id, p_styleSheet) {
-            window.vnotex.parseStyleSheet(p_id, p_styleSheet);
+            window.vxcore.parseStyleSheet(p_id, p_styleSheet);
         });
 
         adapter.crossCopyRequested.connect(function(p_id, p_timeStamp, p_target, p_baseUrl, p_html) {
-            window.vnotex.crossCopy(p_id, p_timeStamp, p_target, p_baseUrl, p_html);
+            window.vxcore.crossCopy(p_id, p_timeStamp, p_target, p_baseUrl, p_html);
         });
 
         adapter.findTextRequested.connect(function(p_texts, p_options, p_currentMatchLine) {
-            window.vnotex.findText(p_texts, p_options, p_currentMatchLine);
+            window.vxcore.findText(p_texts, p_options, p_currentMatchLine);
         });
 
         adapter.contentRequested.connect(function() {
-            window.vnotex.saveContent();
+            window.vxcore.saveContent();
         });
 
         adapter.graphRenderDataReady.connect(function(p_id, p_index, p_format, p_data) {
-            window.vnotex.graphRenderDataReady(p_id, p_index, p_format, p_data);
+            window.vxcore.graphRenderDataReady(p_id, p_index, p_format, p_data);
         });
 
         console.log('QWebChannel has been set up');
-        if (window.vnotex.initialized) {
+        if (window.vxcore.initialized) {
-            window.vnotex.kickOffMarkdown();
+            window.vxcore.kickOffMarkdown();
         }
     });
 
-window.vnotex.on('ready', function() {
+window.vxcore.on('ready', function() {
     if (window.vxMarkdownAdapter) {
-        window.vnotex.kickOffMarkdown();
+        window.vxcore.kickOffMarkdown();
     }
 });

src/data/extra/web/js/markdownviewercore.js

@@ -1,25 +1,13 @@
 /*
-    The main object that will be provided to all scripts in VNoteX.
+    Markdown events:
-    Maintain a list of workers for different tasks.
-
-    Main:
-        - initialized()
-        - ready()
-
-    Markdown scenario:
         - markdownTextUpdated(p_text)
         - basicMarkdownRendered()
         - fullMarkdownRendered()
 */
-class VNoteX extends EventEmitter {
+class MarkdownViewerCore extends VXCore {
     constructor() {
         super();
 
-        this.kickedOff = false;
-
-        this.initialized = false;
-
-        // Registered workers.
         // name -> worker.
         this.workers = new Map();
 
@@ -33,58 +21,48 @@ class VNoteX extends EventEmitter {
 
         this.numOfMuteScroll = 0;
 
-        this.os = VNoteX.detectOS();
-
         this.turndown = null;
 
         this.sectionNumberBaseLevel = 2;
 
         // Dict mapping from {id, index} to callback for renderGraph().
         this.renderGraphCallbacks = {}
+    }
 
-        window.addEventListener('load', () => {
+    initOnLoad() {
-            console.log('window load finished');
+        // Init DOM nodes.
+        this.contentContainer = document.getElementById('vx-content');
+        this.inplacePreviewContainer = document.getElementById('vx-inplace-preview');
 
-            // Init DOM nodes.
+        this.nodeLineMapper = new NodeLineMapper(this, this.contentContainer);
-            this.contentContainer = document.getElementById('vx-content');
-            this.inplacePreviewContainer = document.getElementById('vx-inplace-preview');
 
-            this.nodeLineMapper = new NodeLineMapper(this, this.contentContainer);
+        this.graphPreviewer = new GraphPreviewer(this, this.inplacePreviewContainer);
 
-            this.graphPreviewer = new GraphPreviewer(this, this.inplacePreviewContainer);
+        this.crossCopyer = new CrossCopy(this);
 
-            this.crossCopyer = new CrossCopy(this);
+        this.searcher = new MarkJs(this, this.contentContainer);
 
-            this.searcher = new MarkJs(this, this.contentContainer);
+        this.sectionNumberBaseLevel = window.vxOptions.sectionNumberBaseLevel;
+        if (this.sectionNumberBaseLevel > 3) {
+            console.warn('only support section number base level less than 3', this.sectionNumberBaseLevel);
+            this.sectionNumberBaseLevel = 3;
+        }
 
-            this.sectionNumberBaseLevel = window.vxOptions.sectionNumberBaseLevel;
+        this.setContentContainerOption('vx-constrain-image-width',
-            if (this.sectionNumberBaseLevel > 3) {
+                                       window.vxOptions.constrainImageWidthEnabled || !window.vxOptions.scrollable);
-                console.warn('only support section number base level less than 3', this.sectionNumberBaseLevel);
+        this.setContentContainerOption('vx-image-align-center',
-                this.sectionNumberBaseLevel = 3;
+                                       window.vxOptions.imageAlignCenterEnabled);
-            }
+        this.setContentContainerOption('vx-indent-first-line',
+                                       window.vxOptions.indentFirstLineEnabled);
+        this.setContentContainerOption('line-numbers',
+                                       window.vxOptions.codeBlockLineNumberEnabled);
+        this.setBodyOption('vx-transparent-background',
+                           window.vxOptions.transparentBackgroundEnabled);
+        this.setContentContainerOption('vx-nonscrollable',
+                                       !window.vxOptions.scrollable);
 
-            this.setContentContainerOption('vx-constrain-image-width',
+        this.setBodySize(window.vxOptions.bodyWidth, window.vxOptions.bodyHeight);
-                                           window.vxOptions.constrainImageWidthEnabled || !window.vxOptions.scrollable);
+        document.body.style.height = '800';
-            this.setContentContainerOption('vx-image-align-center',
-                                           window.vxOptions.imageAlignCenterEnabled);
-            this.setContentContainerOption('vx-indent-first-line',
-                                           window.vxOptions.indentFirstLineEnabled);
-            this.setContentContainerOption('line-numbers',
-                                           window.vxOptions.codeBlockLineNumberEnabled);
-            this.setBodyOption('vx-transparent-background',
-                               window.vxOptions.transparentBackgroundEnabled);
-            this.setContentContainerOption('vx-nonscrollable',
-                                           !window.vxOptions.scrollable);
-
-            this.setBodySize(window.vxOptions.bodyWidth, window.vxOptions.bodyHeight);
-            document.body.style.height = '800';
-
-            this.initialized = true;
-
-            // Signal out.
-            this.emit('initialized');
-            this.emit('ready');
-        });
     }
 
     setContentContainerOption(p_class, p_enabled) {
@@ -369,20 +347,6 @@ class VNoteX extends EventEmitter {
             delete this.renderGraphCallbacks[key];
         }
     }
-
-    static detectOS() {
-        let osName="Unknown OS";
-        if (navigator.appVersion.indexOf("Win")!=-1) {
-            osName="Windows";
-        } else if (navigator.appVersion.indexOf("Mac")!=-1) {
-            osName="MacOS";
-        } else if (navigator.appVersion.indexOf("X11")!=-1) {
-            osName="UNIX";
-        } else if (navigator.appVersion.indexOf("Linux")!=-1) {
-            osName="Linux";
-        }
-        return osName
-    }
 }
 
-window.vnotex = new VNoteX();
+window.vxcore = new MarkdownViewerCore();

src/data/extra/web/js/mathjax.js

@@ -12,7 +12,7 @@ window.MathJax = {
         ready: function() {
             MathJax.startup.defaultReady();
             MathJax.startup.promise.then(() => {
-                window.vnotex.getWorker('mathjax').setMathJaxReady();
+                window.vxcore.getWorker('mathjax').setMathJaxReady();
             });
         }
     },
@@ -42,11 +42,11 @@ class MathJaxRenderer extends VxWorker {
     }
 
     registerInternal() {
-        this.vnotex.on('basicMarkdownRendered', () => {
+        this.vxcore.on('basicMarkdownRendered', () => {
-            this.render(this.vnotex.contentContainer, 'tex-to-render');
+            this.render(this.vxcore.contentContainer, 'tex-to-render');
         });
 
-        this.vnotex.getWorker('markdownit').addLangsToSkipHighlight(this.langs);
+        this.vxcore.getWorker('markdownit').addLangsToSkipHighlight(this.langs);
     }
 
     initialize(p_callback) {
@@ -74,7 +74,7 @@ class MathJaxRenderer extends VxWorker {
         this.nodesToRender = [];
 
         // Transform extra class nodes.
-        let extraNodes = this.vnotex.getWorker('markdownit').getCodeNodes(this.langs);
+        let extraNodes = this.vxcore.getWorker('markdownit').getCodeNodes(this.langs);
         this.transformExtraNodes(p_node, p_className, extraNodes);
 
         // Collect nodes to render.
@@ -192,4 +192,4 @@ class MathJaxRenderer extends VxWorker {
     }
 }
 
-window.vnotex.registerWorker(new MathJaxRenderer());
+window.vxcore.registerWorker(new MathJaxRenderer());

src/data/extra/web/js/mermaid.js

@@ -122,4 +122,4 @@ class Mermaid extends GraphRenderer {
     }
 }
 
-window.vnotex.registerWorker(new Mermaid());
+window.vxcore.registerWorker(new Mermaid());

src/data/extra/web/js/pdf.js/README.md

@@ -0,0 +1,3 @@
+https://github.com/mozilla/pdf.js
+Legacy version: https://unpkg.com/pdfjs-dist/
+v3.1.81

src/data/extra/web/js/pdfviewer.js

@@ -0,0 +1,27 @@
+/* Main script file for PdfViewer. */
+
+new QWebChannel(qt.webChannelTransport,
+    function(p_channel) {
+        let adapter = p_channel.objects.vxAdapter;
+        // Export the adapter globally.
+        window.vxAdapter = adapter;
+
+        // Connect signals from CPP side.
+        adapter.urlUpdated.connect(function(p_url) {
+            window.vxcore.loadPdf(p_url);
+        });
+
+        console.log('QWebChannel has been set up');
+
+        if (window.vxcore.initialized) {
+            window.vxAdapter.setReady(true);
+        }
+    });
+
+pdfjsLib.GlobalWorkerOptions.workerSrc = window.vxcore.workerSrc;
+
+window.vxcore.on('ready', function() {
+    if (window.vxAdapter) {
+        window.vxAdapter.setReady(true);
+    }
+});

src/data/extra/web/js/pdfviewercore.js

@@ -0,0 +1,55 @@
+class PdfViewerCore extends VXCore {
+    constructor() {
+        super();
+
+        const scriptFolderPath = Utils.parentFolder(document.currentScript.src);
+        this.workerSrc = scriptFolderPath + '/pdf.js/pdf.worker.min.js';
+    }
+
+    initOnLoad() {
+        this.container = document.getElementById('vx-viewer-container');
+    }
+
+    loadPdf(p_url) {
+        const eventBus = new pdfjsViewer.EventBus();
+
+        // (Optionally) enable hyperlinks within PDF files.
+        const pdfLinkService = new pdfjsViewer.PDFLinkService({
+            eventBus,
+        });
+
+        // (Optionally) enable find controller.
+        const pdfFindController = new pdfjsViewer.PDFFindController({
+            eventBus,
+            linkService: pdfLinkService,
+        });
+
+        const pdfViewer = new pdfjsViewer.PDFViewer({
+            container: this.container,
+            eventBus,
+            linkService: pdfLinkService,
+            findController: pdfFindController,
+        });
+        pdfLinkService.setViewer(pdfViewer);
+
+        eventBus.on("pagesinit", function () {
+            // We can use pdfViewer now, e.g. let's change default scale.
+            pdfViewer.currentScaleValue = "page-width";
+        });
+
+        // Loading document.
+        const loadingTask = pdfjsLib.getDocument({
+            url: p_url,
+            enableXfa: true,
+        });
+        (async function () {
+            const pdfDocument = await loadingTask.promise;
+            // Document loaded, specifying document for the viewer and
+            // the (optional) linkService.
+            pdfViewer.setDocument(pdfDocument);
+            pdfLinkService.setDocument(pdfDocument, null);
+        })();
+    }
+}
+
+window.vxcore = new PdfViewerCore();

src/data/extra/web/js/plantuml.js

@@ -21,12 +21,12 @@ class PlantUml extends GraphRenderer {
     }
 
     registerInternal() {
-        this.vnotex.on('basicMarkdownRendered', () => {
+        this.vxcore.on('basicMarkdownRendered', () => {
             this.reset();
             this.renderCodeNodes(window.vxOptions.transformSvgToPngEnabled ? 'png' : 'svg');
         });
 
-        this.vnotex.getWorker('markdownit').addLangsToSkipHighlight(this.langs);
+        this.vxcore.getWorker('markdownit').addLangsToSkipHighlight(this.langs);
 
         this.useWeb = window.vxOptions.webPlantUml;
         if (!this.useWeb) {
@@ -139,7 +139,7 @@ class PlantUml extends GraphRenderer {
 
     // A helper function to render PlantUml via local JAR.
     renderLocal(p_format, p_text, p_callback) {
-        this.vnotex.renderGraph(this.id,
+        this.vxcore.renderGraph(this.id,
             this.nextLocalGraphIndex++,
             p_format,
             'puml',
@@ -175,4 +175,4 @@ class PlantUml extends GraphRenderer {
     }
 }
 
-window.vnotex.registerWorker(new PlantUml());
+window.vxcore.registerWorker(new PlantUml());

src/data/extra/web/js/prism.js

@@ -18,8 +18,8 @@ class PrismRenderer extends VxWorker {
     }
 
     registerInternal() {
-        this.vnotex.on('basicMarkdownRendered', () => {
+        this.vxcore.on('basicMarkdownRendered', () => {
-            this.renderCodeNodes(this.vnotex.contentContainer);
+            this.renderCodeNodes(this.vxcore.contentContainer);
         });
     }
 
@@ -30,7 +30,7 @@ class PrismRenderer extends VxWorker {
 
         this.initialized = true;
 
-        let markdownIt = this.vnotex.getWorker('markdownit');
+        let markdownIt = this.vxcore.getWorker('markdownit');
         Prism.plugins.filterHighlightAll.add((p_env) => {
             return !markdownIt.langsToSkipHighlight.has(p_env.language);
         });
@@ -58,7 +58,7 @@ class PrismRenderer extends VxWorker {
     renderCodeNodes(p_node) {
         this.initialize();
 
-        let codeNodes = this.vnotex.getWorker('markdownit').getCodeNodes(null);
+        let codeNodes = this.vxcore.getWorker('markdownit').getCodeNodes(null);
         this.doRender(p_node, codeNodes);
     }
 
@@ -104,4 +104,4 @@ class PrismRenderer extends VxWorker {
     }
 }
 
-window.vnotex.registerWorker(new PrismRenderer());
+window.vxcore.registerWorker(new PrismRenderer());

src/data/extra/web/js/vxcore.js

@@ -0,0 +1,46 @@
+/*
+    The main object that will be provided to all scripts in VNoteX.
+    TODO: Maintain a list of workers.
+
+    Events:
+        - initialized()
+        - ready()
+*/
+
+class VXCore extends EventEmitter {
+    constructor() {
+        super();
+
+        this.kickedOff = false;
+
+        this.initialized = false;
+
+        this.os = VXCore.detectOS();
+
+        window.addEventListener('load', () => {
+            console.log('window load finished');
+
+            this.initOnLoad();
+
+            this.initialized = true;
+
+            // Signal out.
+            this.emit('initialized');
+            this.emit('ready');
+        });
+    }
+
+    static detectOS() {
+        let osName="Unknown OS";
+        if (navigator.appVersion.indexOf("Win")!=-1) {
+            osName="Windows";
+        } else if (navigator.appVersion.indexOf("Mac")!=-1) {
+            osName="MacOS";
+        } else if (navigator.appVersion.indexOf("X11")!=-1) {
+            osName="UNIX";
+        } else if (navigator.appVersion.indexOf("Linux")!=-1) {
+            osName="Linux";
+        }
+        return osName
+    }
+}

src/data/extra/web/js/vxworker.js

@@ -2,7 +2,7 @@
 class VxWorker {
     constructor() {
         this.name = '';
-        this.vnotex = null;
+        this.vxcore = null;
 
         if (!window.vxWorkerId) {
             window.vxWorkerId = 1;
@@ -11,8 +11,8 @@ class VxWorker {
     }
 
     // Called when registering this worker.
-    register(p_vnotex) {
+    register(p_vxcore) {
-        this.vnotex = p_vnotex;
+        this.vxcore = p_vxcore;
 
         this.registerInternal();
     }
@@ -23,6 +23,6 @@ class VxWorker {
 
     finishWork() {
         console.log('worker finished', this.name);
-        this.vnotex.finishWorker(this.name);
+        this.vxcore.finishWorker(this.name);
     }
 }

src/data/extra/web/js/wavedrom.js

@@ -77,4 +77,4 @@ class WaveDromRenderer extends GraphRenderer {
     }
 }
 
-window.vnotex.registerWorker(new WaveDromRenderer());
+window.vxcore.registerWorker(new WaveDromRenderer());

src/data/extra/web/pdf-viewer-template.html

@@ -0,0 +1,33 @@
+<!DOCTYPE html>
+<html>
+<head>
+    <meta charset="utf-8">
+    <title>VNoteX PDF Viewer</title>
+
+    <!-- VX_STYLES_PLACEHOLDER -->
+
+    <style>
+        body {
+            margin: 0;
+            padding: 0;
+        }
+        #vx-viewer-container {
+          overflow: auto;
+          position: absolute;
+          width: 100%;
+          height: 100%;
+        }
+    </style>
+
+    <script type="text/javascript">
+        /* VX_GLOBAL_OPTIONS_PLACEHOLDER */
+    </script>
+
+    <!-- VX_SCRIPTS_PLACEHOLDER -->
+</head>
+<body>
+    <div id="vx-viewer-container">
+        <div id="vx-viewer" class="pdfViewer"></div>
+    </div>
+</body>
+</html>

src/export/webviewexporter.cpp

@@ -285,7 +285,7 @@ void WebViewExporter::prepare(const ExportOption &p_option)
 
     qDebug() << "export page body size" << pageBodySize;
 
-    HtmlTemplateHelper::Paras paras;
+    HtmlTemplateHelper::MarkdownParas paras;
     paras.m_webStyleSheetFile = p_option.m_renderingStyleFile;
     paras.m_highlightStyleSheetFile = p_option.m_syntaxHighlightStyleFile;
     paras.m_transparentBackgroundEnabled = p_option.m_useTransparentBg;
@@ -300,7 +300,7 @@ void WebViewExporter::prepare(const ExportOption &p_option)
 
     {
         const bool addOutlinePanel = p_option.m_targetFormat == ExportFormat::HTML && p_option.m_htmlOption.m_addOutlinePanel;
-        m_exportHtmlTemplate = HtmlTemplateHelper::generateExportTemplate(config, addOutlinePanel);
+        m_exportHtmlTemplate = HtmlTemplateHelper::generateMarkdownExportTemplate(config, addOutlinePanel);
     }
 
     if (useWkhtmltopdf) {

src/widgets/editors/editormarkdownvieweradapter.cpp

@@ -1,17 +0,0 @@
-#include "editormarkdownvieweradapter.h"
-
-#include <buffer/buffer.h>
-
-using namespace vnotex;
-
-EditorMarkdownViewerAdapter::EditorMarkdownViewerAdapter(Buffer *p_buffer,
-                                                         QObject *p_parent)
-    : MarkdownViewerAdapter(p_parent),
-      m_buffer(p_buffer)
-{
-}
-
-void EditorMarkdownViewerAdapter::setBuffer(Buffer *p_buffer)
-{
-    m_buffer = p_buffer;
-}

src/widgets/editors/editormarkdownvieweradapter.h

@@ -1,25 +0,0 @@
-#ifndef EDITORMARKDOWNVIEWERADAPTER_H
-#define EDITORMARKDOWNVIEWERADAPTER_H
-
-#include "markdownvieweradapter.h"
-
-namespace vnotex
-{
-    class Buffer;
-
-    class EditorMarkdownViewerAdapter : public MarkdownViewerAdapter
-    {
-        Q_OBJECT
-    public:
-        EditorMarkdownViewerAdapter(Buffer *p_buffer, QObject *p_parent = nullptr);
-
-        void setBuffer(Buffer *p_buffer);
-
-    public slots:
-
-    private:
-        Buffer *m_buffer = nullptr;
-    };
-}
-
-#endif // EDITORMARKDOWNVIEWERADAPTER_H

src/widgets/editors/pdfviewer.cpp

@@ -0,0 +1,28 @@
+#include "pdfviewer.h"
+
+#include <QWebChannel>
+
+#include "pdfvieweradapter.h"
+#include "previewhelper.h"
+
+using namespace vnotex;
+
+PdfViewer::PdfViewer(PdfViewerAdapter *p_adapter,
+                     const QColor &p_background,
+                     qreal p_zoomFactor,
+                     QWidget *p_parent)
+    : WebViewer(p_background, p_zoomFactor, p_parent),
+      m_adapter(p_adapter)
+{
+    m_adapter->setParent(this);
+
+    auto channel = new QWebChannel(this);
+    channel->registerObject(QStringLiteral("vxAdapter"), m_adapter);
+
+    page()->setWebChannel(channel);
+}
+
+PdfViewerAdapter *PdfViewer::adapter() const
+{
+    return m_adapter;
+}

src/widgets/editors/pdfviewer.h

@@ -0,0 +1,27 @@
+#ifndef PDFVIEWER_H
+#define PDFVIEWER_H
+
+#include "../webviewer.h"
+
+namespace vnotex
+{
+    class PdfViewerAdapter;
+
+    class PdfViewer : public WebViewer
+    {
+        Q_OBJECT
+    public:
+        PdfViewer(PdfViewerAdapter *p_adapter,
+                  const QColor &p_background,
+                  qreal p_zoomFactor,
+                  QWidget *p_parent = nullptr);
+
+        PdfViewerAdapter *adapter() const;
+
+    private:
+        // Managed by QObject.
+        PdfViewerAdapter *m_adapter = nullptr;
+    };
+}
+
+#endif // PDFVIEWER_H

src/widgets/editors/pdfvieweradapter.cpp

@@ -0,0 +1,34 @@
+#include "pdfvieweradapter.h"
+
+using namespace vnotex;
+
+PdfViewerAdapter::PdfViewerAdapter(QObject *p_parent)
+    : QObject(p_parent)
+{
+}
+
+void PdfViewerAdapter::setUrl(const QString &p_url)
+{
+    if (m_viewerReady) {
+        emit urlUpdated(p_url);
+    } else {
+        m_pendingActions.append([this, p_url]() {
+            emit urlUpdated(p_url);
+        });
+    }
+}
+
+void PdfViewerAdapter::setReady(bool p_ready)
+{
+    if (m_viewerReady == p_ready) {
+        return;
+    }
+
+    m_viewerReady = p_ready;
+    if (m_viewerReady) {
+        for (auto &act : m_pendingActions) {
+            act();
+        }
+        m_pendingActions.clear();
+    }
+}

src/widgets/editors/pdfvieweradapter.h

@@ -0,0 +1,40 @@
+#ifndef PDFVIEWERADAPTER_H
+#define PDFVIEWERADAPTER_H
+
+#include <QObject>
+#include <QString>
+#include <QJsonObject>
+
+#include <core/global.h>
+
+namespace vnotex
+{
+    // Adapter and interface between CPP and JS for PDF.
+    class PdfViewerAdapter : public QObject
+    {
+        Q_OBJECT
+    public:
+        explicit PdfViewerAdapter(QObject *p_parent = nullptr);
+
+        ~PdfViewerAdapter() = default;
+
+        void setUrl(const QString &p_url);
+
+        // Functions to be called from web side.
+    public slots:
+        void setReady(bool p_ready);
+
+        // Signals to be connected at web side.
+    signals:
+        void urlUpdated(const QString &p_url);
+
+    private:
+        // Whether web side viewer is ready to handle url update.
+        bool m_viewerReady = false;
+
+        // Pending actions for the viewer once it is ready.
+        QVector<std::function<void()>> m_pendingActions;
+    };
+}
+
+#endif // PDFVIEWERADAPTER_H

src/widgets/markdownviewwindow.cpp

@@ -34,7 +34,7 @@
 #include "editors/markdowneditor.h"
 #include "textviewwindowhelper.h"
 #include "editors/markdownviewer.h"
-#include "editors/editormarkdownvieweradapter.h"
+#include "editors/markdownvieweradapter.h"
 #include "editors/previewhelper.h"
 #include "dialogs/deleteconfirmdialog.h"
 #include "outlineprovider.h"
@@ -193,10 +193,10 @@ void MarkdownViewWindow::setModified(bool p_modified)
 
 void MarkdownViewWindow::handleEditorConfigChange()
 {
-    const auto &editorConfig = ConfigMgr::getInst().getEditorConfig();
-    const auto &markdownEditorConfig = editorConfig.getMarkdownEditorConfig();
-
     if (updateConfigRevision()) {
+        const auto &editorConfig = ConfigMgr::getInst().getEditorConfig();
+        const auto &markdownEditorConfig = editorConfig.getMarkdownEditorConfig();
+
         updatePreviewHelperFromConfig(markdownEditorConfig);
 
         HtmlTemplateHelper::updateMarkdownViewerTemplate(markdownEditorConfig);
@@ -439,7 +439,7 @@ void MarkdownViewWindow::setupViewer()
 
     HtmlTemplateHelper::updateMarkdownViewerTemplate(markdownEditorConfig);
 
-    auto adapter = new EditorMarkdownViewerAdapter(nullptr, this);
+    auto adapter = new MarkdownViewerAdapter(this);
     m_viewer = new MarkdownViewer(adapter,
                                   this,
                                   VNoteX::getInst().getThemeMgr().getBaseBackground(),
@@ -544,7 +544,6 @@ void MarkdownViewWindow::syncViewerFromBuffer(bool p_syncPositionFromEditMode)
     }
 
     auto buffer = getBuffer();
-    adapter()->setBuffer(buffer);
     if (buffer) {
         int lineNumber = -1;
         if (p_syncPositionFromEditMode) {
@@ -624,10 +623,10 @@ void MarkdownViewWindow::setBufferRevisionAfterInvalidation(int p_bufferRevision
     }
 }
 
-EditorMarkdownViewerAdapter *MarkdownViewWindow::adapter() const
+MarkdownViewerAdapter *MarkdownViewWindow::adapter() const
 {
     if (m_viewer) {
-        return dynamic_cast<EditorMarkdownViewerAdapter *>(m_viewer->adapter());
+        return m_viewer->adapter();
     }
 
     return nullptr;

src/widgets/markdownviewwindow.h

@@ -23,7 +23,7 @@ namespace vnotex
 {
     class MarkdownEditor;
     class MarkdownViewer;
-    class EditorMarkdownViewerAdapter;
+    class MarkdownViewerAdapter;
     class PreviewHelper;
     struct Outline;
     class EditorConfig;
@@ -141,7 +141,7 @@ namespace vnotex
         // call this function to tell us now the latest buffer revision.
         void setBufferRevisionAfterInvalidation(int p_bufferRevision);
 
-        EditorMarkdownViewerAdapter *adapter() const;
+        MarkdownViewerAdapter *adapter() const;
 
         // Get the position to sync from editor.
         // Return -1 for an invalid position.

src/widgets/pdfviewwindow.cpp

@@ -0,0 +1,166 @@
+#include "pdfviewwindow.h"
+
+#include <core/vnotex.h>
+#include <core/thememgr.h>
+#include <core/htmltemplatehelper.h>
+#include <core/configmgr.h>
+#include <core/editorconfig.h>
+#include <core/pdfviewerconfig.h>
+#include <utils/pathutils.h>
+
+#include "editors/pdfviewer.h"
+#include "editors/pdfvieweradapter.h"
+
+using namespace vnotex;
+
+PdfViewWindow::PdfViewWindow(QWidget *p_parent)
+    : ViewWindow(p_parent)
+{
+    m_mode = ViewWindowMode::Read;
+    setupUI();
+}
+
+void PdfViewWindow::setupUI()
+{
+    setupViewer();
+    setCentralWidget(m_viewer);
+}
+
+void PdfViewWindow::setupViewer()
+{
+    Q_ASSERT(!m_viewer);
+
+    const auto &editorConfig = ConfigMgr::getInst().getEditorConfig();
+    const auto &pdfViewerConfig = editorConfig.getPdfViewerConfig();
+
+    updateConfigRevision();
+
+    HtmlTemplateHelper::updatePdfViewerTemplate(pdfViewerConfig);
+
+    auto adapter = new PdfViewerAdapter(nullptr);
+    m_viewer = new PdfViewer(adapter,
+                             VNoteX::getInst().getThemeMgr().getBaseBackground(),
+                             1.0,
+                             this);
+}
+
+QString PdfViewWindow::getLatestContent() const
+{
+    return NULL;
+}
+
+QString PdfViewWindow::selectedText() const
+{
+    return QString();
+}
+
+void PdfViewWindow::setMode(ViewWindowMode p_mode)
+{
+    Q_UNUSED(p_mode);
+    Q_ASSERT(false);
+}
+
+void PdfViewWindow::openTwice(const QSharedPointer<FileOpenParameters> &p_paras)
+{
+    Q_UNUSED(p_paras);
+}
+
+ViewWindowSession PdfViewWindow::saveSession() const
+{
+    auto session = ViewWindow::saveSession();
+    session.m_lineNumber = 1;
+    return session;
+}
+
+void PdfViewWindow::applySnippet(const QString &p_name)
+{
+    Q_UNUSED(p_name);
+}
+
+void PdfViewWindow::applySnippet()
+{
+}
+
+void PdfViewWindow::fetchWordCountInfo(const std::function<void(const WordCountInfo &)> &p_callback) const
+{
+    Q_UNUSED(p_callback);
+}
+
+void PdfViewWindow::handleEditorConfigChange()
+{
+    if (updateConfigRevision()) {
+        const auto &editorConfig = ConfigMgr::getInst().getEditorConfig();
+        const auto &pdfViewerConfig = editorConfig.getPdfViewerConfig();
+
+        HtmlTemplateHelper::updatePdfViewerTemplate(pdfViewerConfig);
+    }
+}
+
+void PdfViewWindow::setModified(bool p_modified)
+{
+    Q_UNUSED(p_modified);
+}
+
+void PdfViewWindow::print()
+{
+}
+
+void PdfViewWindow::syncEditorFromBuffer()
+{
+    auto buffer = getBuffer();
+    if (buffer) {
+        m_viewer->setHtml(HtmlTemplateHelper::getPdfViewerTemplate(),
+                          PathUtils::pathToUrl(HtmlTemplateHelper::getPdfViewerTemplatePath()));
+
+        const auto url = PathUtils::pathToUrl(buffer->getContentPath());
+        adapter()->setUrl(url.toString(QUrl::EncodeSpaces));
+    } else {
+        m_viewer->setHtml("");
+        adapter()->setUrl("");
+    }
+}
+
+void PdfViewWindow::syncEditorFromBufferContent()
+{
+}
+
+void PdfViewWindow::scrollUp()
+{
+}
+
+void PdfViewWindow::scrollDown()
+{
+}
+
+void PdfViewWindow::zoom(bool p_zoomIn)
+{
+    Q_UNUSED(p_zoomIn);
+}
+
+PdfViewerAdapter *PdfViewWindow::adapter() const
+{
+    if (m_viewer) {
+        return dynamic_cast<PdfViewerAdapter *>(m_viewer->adapter());
+    }
+
+    return nullptr;
+}
+
+bool PdfViewWindow::updateConfigRevision()
+{
+    bool changed = false;
+
+    const auto &editorConfig = ConfigMgr::getInst().getEditorConfig();
+
+    if (m_editorConfigRevision != editorConfig.revision()) {
+        changed = true;
+        m_editorConfigRevision = editorConfig.revision();
+    }
+
+    if (m_viewerConfigRevision != editorConfig.getPdfViewerConfig().revision()) {
+        changed = true;
+        m_viewerConfigRevision = editorConfig.getPdfViewerConfig().revision();
+    }
+
+    return changed;
+}

src/widgets/pdfviewwindow.h

@@ -0,0 +1,73 @@
+#ifndef PDFVIEWWINDOW_H
+#define PDFVIEWWINDOW_H
+
+#include "viewwindow.h"
+
+#include <QScopedPointer>
+
+class QWebEngineView;
+
+namespace vnotex
+{
+    class PdfViewer;
+    class PdfViewerAdapter;
+    class EditorConfig;
+
+    class PdfViewWindow : public ViewWindow
+    {
+        Q_OBJECT
+    public:
+        explicit PdfViewWindow(QWidget *p_parent = nullptr);
+
+        QString getLatestContent() const Q_DECL_OVERRIDE;
+
+        QString selectedText() const Q_DECL_OVERRIDE;
+
+        void setMode(ViewWindowMode p_mode) Q_DECL_OVERRIDE;
+
+        void openTwice(const QSharedPointer<FileOpenParameters> &p_paras) Q_DECL_OVERRIDE;
+
+        ViewWindowSession saveSession() const Q_DECL_OVERRIDE;
+
+        void applySnippet(const QString &p_name) Q_DECL_OVERRIDE;
+
+        void applySnippet() Q_DECL_OVERRIDE;
+
+        void fetchWordCountInfo(const std::function<void(const WordCountInfo &)> &p_callback) const Q_DECL_OVERRIDE;
+
+    public slots:
+        void handleEditorConfigChange() Q_DECL_OVERRIDE;
+
+    protected slots:
+        void setModified(bool p_modified) Q_DECL_OVERRIDE;
+
+        void print() Q_DECL_OVERRIDE;
+
+    protected:
+        void syncEditorFromBuffer() Q_DECL_OVERRIDE;
+
+        void syncEditorFromBufferContent() Q_DECL_OVERRIDE;
+
+        void scrollUp() Q_DECL_OVERRIDE;
+
+        void scrollDown() Q_DECL_OVERRIDE;
+
+        void zoom(bool p_zoomIn) Q_DECL_OVERRIDE;
+
+    private:
+        void setupUI();
+
+        void setupViewer();
+
+        PdfViewerAdapter *adapter() const;
+
+        bool updateConfigRevision();
+
+        // Managed by QObject.
+        PdfViewer *m_viewer = nullptr;
+
+        int m_viewerConfigRevision = 0;
+    };
+}
+
+#endif // PDFVIEWWINDOW_H

src/widgets/textviewwindow.cpp

@@ -135,10 +135,10 @@ void TextViewWindow::setModified(bool p_modified)
 
 void TextViewWindow::handleEditorConfigChange()
 {
-    const auto &editorConfig = ConfigMgr::getInst().getEditorConfig();
-    const auto &textEditorConfig = editorConfig.getTextEditorConfig();
-
     if (updateConfigRevision()) {
+        const auto &editorConfig = ConfigMgr::getInst().getEditorConfig();
+        const auto &textEditorConfig = editorConfig.getTextEditorConfig();
+
         auto config = createTextEditorConfig(editorConfig, textEditorConfig);
         m_editor->setConfig(config);
 

src/widgets/viewwindow.cpp

@@ -156,6 +156,12 @@ void ViewWindow::handleBufferChanged(const QSharedPointer<FileOpenParameters> &p
     emit bufferChanged();
 }
 
+void ViewWindow::handleBufferChangedInternal(const QSharedPointer<FileOpenParameters> &p_paras)
+{
+    Q_UNUSED(p_paras);
+    syncEditorFromBuffer();
+}
+
 void ViewWindow::attachToBuffer(Buffer *p_buffer, const QSharedPointer<FileOpenParameters> &p_paras)
 {
     Q_ASSERT(p_buffer);

src/widgets/viewwindow.h

@@ -167,7 +167,7 @@ namespace vnotex
 
     protected slots:
         // Handle current buffer change.
-        virtual void handleBufferChangedInternal(const QSharedPointer<FileOpenParameters> &p_paras) = 0;
+        virtual void handleBufferChangedInternal(const QSharedPointer<FileOpenParameters> &p_paras);
 
         // Handle all kinds of type action.
         virtual void handleTypeAction(TypeAction p_action);

src/widgets/widgets.pri

@@ -44,7 +44,6 @@ SOURCES += \
     $$PWD/dialogs/viewtagsdialog.cpp \
     $$PWD/dockwidgethelper.cpp \
     $$PWD/dragdropareaindicator.cpp \
-    $$PWD/editors/editormarkdownvieweradapter.cpp \
     $$PWD/editors/graphhelper.cpp \
     $$PWD/editors/graphvizhelper.cpp \
     $$PWD/editors/markdowneditor.cpp \
@@ -52,6 +51,8 @@ SOURCES += \
     $$PWD/editors/markdowntablehelper.cpp \
     $$PWD/editors/markdownviewer.cpp \
     $$PWD/editors/markdownvieweradapter.cpp \
+    $$PWD/editors/pdfviewer.cpp \
+    $$PWD/editors/pdfvieweradapter.cpp \
     $$PWD/editors/plantumlhelper.cpp \
     $$PWD/editors/previewhelper.cpp \
     $$PWD/editors/statuswidget.cpp \
@@ -81,6 +82,7 @@ SOURCES += \
     $$PWD/outlinepopup.cpp \
     $$PWD/outlineprovider.cpp \
     $$PWD/outlineviewer.cpp \
+    $$PWD/pdfviewwindow.cpp \
     $$PWD/propertydefs.cpp \
     $$PWD/quickselector.cpp \
     $$PWD/searchinfoprovider.cpp \
@@ -177,7 +179,6 @@ HEADERS += \
     $$PWD/dialogs/viewtagsdialog.h \
     $$PWD/dockwidgethelper.h \
     $$PWD/dragdropareaindicator.h \
-    $$PWD/editors/editormarkdownvieweradapter.h \
     $$PWD/editors/graphhelper.h \
     $$PWD/editors/graphvizhelper.h \
     $$PWD/editors/markdowneditor.h \
@@ -185,6 +186,8 @@ HEADERS += \
     $$PWD/editors/markdowntablehelper.h \
     $$PWD/editors/markdownviewer.h \
     $$PWD/editors/markdownvieweradapter.h \
+    $$PWD/editors/pdfviewer.h \
+    $$PWD/editors/pdfvieweradapter.h \
     $$PWD/editors/plantumlhelper.h \
     $$PWD/editors/previewhelper.h \
     $$PWD/editors/statuswidget.h \
@@ -216,6 +219,7 @@ HEADERS += \
     $$PWD/outlinepopup.h \
     $$PWD/outlineprovider.h \
     $$PWD/outlineviewer.h \
+    $$PWD/pdfviewwindow.h \
     $$PWD/propertydefs.h \
     $$PWD/quickselector.h \
     $$PWD/searchinfoprovider.h \