feat(browser): introduce centralized web settings management

Additionally fixes a number of regressions from Qt WebEngine migration.

src/libs/browser/CMakeLists.txt

@@ -1,5 +1,6 @@
 add_library(Browser STATIC
     searchtoolbar.cpp
+    settings.cpp
     urlrequestinterceptor.cpp
     webbridge.cpp
     webcontrol.cpp

src/libs/browser/settings.cpp

@@ -0,0 +1,99 @@
+/****************************************************************************
+**
+** Copyright (C) 2020 Oleg Shparber
+** Contact: https://go.zealdocs.org/l/contact
+**
+** This file is part of Zeal.
+**
+** Zeal is free software: you can redistribute it and/or modify
+** it under the terms of the GNU General Public License as published by
+** the Free Software Foundation, either version 3 of the License, or
+** (at your option) any later version.
+**
+** Zeal is distributed in the hope that it will be useful,
+** but WITHOUT ANY WARRANTY; without even the implied warranty of
+** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+** GNU General Public License for more details.
+**
+** You should have received a copy of the GNU General Public License
+** along with Zeal. If not, see <http://www.gnu.org/licenses/>.
+**
+****************************************************************************/
+
+#include "settings.h"
+
+#include "urlrequestinterceptor.h"
+
+#include <core/settings.h>
+
+#include <QFileInfo>
+#include <QWebEngineProfile>
+#include <QWebEngineSettings>
+#include <QWebEngineScript>
+#include <QWebEngineScriptCollection>
+
+namespace {
+constexpr char DarkModeCssUrl[] = "qrc:///browser/assets/css/darkmode.css";
+constexpr char HighlightOnNavigateCssUrl[] = "qrc:///browser/assets/css/highlight.css";
+}
+
+using namespace Zeal::Browser;
+
+Settings::Settings(Core::Settings *appSettings, QObject *parent)
+    : QObject(parent)
+    , m_appSettings(appSettings)
+    , m_webProfile(QWebEngineProfile::defaultProfile())
+{
+    // Setup URL interceptor.
+    m_webProfile->setUrlRequestInterceptor(new UrlRequestInterceptor(this));
+
+    // Disable on-disk cache.
+    m_webProfile->setHttpCacheType(QWebEngineProfile::MemoryHttpCache);
+
+    // Listen to settings changes.
+    connect(m_appSettings, &Core::Settings::updated, this, &Settings::applySettings);
+    applySettings();
+}
+
+void Settings::applySettings()
+{
+    m_webProfile->settings()->setAttribute(QWebEngineSettings::ScrollAnimatorEnabled,
+                                           m_appSettings->isSmoothScrollingEnabled);
+
+    // Apply custom CSS.
+    // TODO: Apply to all open pages.
+    m_webProfile->scripts()->clear(); // Remove all scripts first.
+
+    if (m_appSettings->darkModeEnabled) {
+        setCustomStyleSheet(QStringLiteral("_zeal_darkstylesheet"), DarkModeCssUrl);
+    }
+
+    if (m_appSettings->highlightOnNavigateEnabled) {
+        setCustomStyleSheet(QStringLiteral("_zeal_highlightstylesheet"), HighlightOnNavigateCssUrl);
+    }
+
+    if (QFileInfo::exists(m_appSettings->customCssFile)) {
+        setCustomStyleSheet(QStringLiteral("_zeal_userstylesheet"), m_appSettings->customCssFile);
+    }
+}
+
+void Settings::setCustomStyleSheet(const QString &name, const QString &cssUrl)
+{
+    QString cssInjectCode = QLatin1String("(function() {"
+                "let head = document.getElementsByTagName('head')[0];"
+                "if (!head) { console.error('Cannot set custom stylesheet.'); return; }"
+                "let link = document.createElement('link');"
+                "link.rel = 'stylesheet';"
+                "link.type = 'text/css';"
+                "link.href = '%1';"
+                "link.media = 'all';"
+                "head.appendChild(link);"
+                "})()");
+
+    QWebEngineScript script;
+    script.setName(name);
+    script.setSourceCode(cssInjectCode.arg(cssUrl));
+    script.setInjectionPoint(QWebEngineScript::DocumentReady);
+    script.setRunsOnSubFrames(true);
+    m_webProfile->scripts()->insert(script);
+}

src/libs/browser/settings.h

@@ -0,0 +1,58 @@
+/****************************************************************************
+**
+** Copyright (C) 2020 Oleg Shparber
+** Contact: https://go.zealdocs.org/l/contact
+**
+** This file is part of Zeal.
+**
+** Zeal is free software: you can redistribute it and/or modify
+** it under the terms of the GNU General Public License as published by
+** the Free Software Foundation, either version 3 of the License, or
+** (at your option) any later version.
+**
+** Zeal is distributed in the hope that it will be useful,
+** but WITHOUT ANY WARRANTY; without even the implied warranty of
+** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+** GNU General Public License for more details.
+**
+** You should have received a copy of the GNU General Public License
+** along with Zeal. If not, see <http://www.gnu.org/licenses/>.
+**
+****************************************************************************/
+
+#ifndef ZEAL_BROWSER_SETTINGS_H
+#define ZEAL_BROWSER_SETTINGS_H
+
+#include <QObject>
+
+class QWebEngineProfile;
+
+namespace Zeal {
+
+namespace Core {
+class Settings;
+}
+
+namespace Browser {
+
+class Settings final : public QObject
+{
+    Q_OBJECT
+    Q_DISABLE_COPY(Settings)
+public:
+    explicit Settings(Core::Settings *appSettings, QObject *parent = nullptr);
+
+private slots:
+    void applySettings();
+
+private:
+    void setCustomStyleSheet(const QString &name, const QString &cssUrl);
+
+    Core::Settings *m_appSettings = nullptr;
+    QWebEngineProfile *m_webProfile = nullptr;
+};
+
+} // namespace Browser
+} // namespace Zeal
+
+#endif // ZEAL_BROWSER_SETTINGS_H

src/libs/browser/webpage.cpp

@@ -32,33 +32,12 @@
 #include <QFileInfo>
 #include <QMessageBox>
 #include <QPushButton>
-#include <QWebEngineScript>
-#include <QWebEngineScriptCollection>
-
-namespace {
-constexpr char DarkModeCssUrl[] = "qrc:///browser/assets/css/darkmode.css";
-constexpr char HighlightOnNavigateCssUrl[] = "qrc:///browser/assets/css/highlight.css";
-}
 
 using namespace Zeal::Browser;
 
-WebPage::WebPage(QWebEngineProfile *profile, QObject *parent)
-    : QWebEnginePage (profile, parent)
+WebPage::WebPage(QObject *parent)
+    : QWebEnginePage(parent)
 {
-    auto settings = Core::Application::instance()->settings();
-
-    if (settings->darkModeEnabled) {
-        insertCssWithJS(DarkModeCssUrl);
-        setBackgroundColor(QColor::fromRgb(26, 26, 26));
-    }
-
-    if (settings->highlightOnNavigateEnabled) {
-        insertCssWithJS(HighlightOnNavigateCssUrl);
-    }
-
-    if (QFileInfo::exists(settings->customCssFile)) {
-        insertCssWithJS(settings->customCssFile);
-    }
 }
 
 bool WebPage::acceptNavigationRequest(const QUrl &url, QWebEnginePage::NavigationType type, bool isMainFrame)
@@ -123,20 +102,3 @@ bool WebPage::acceptNavigationRequest(const QUrl &url, QWebEnginePage::Navigatio
 
     return false;
 }
-
-void WebPage::insertCssWithJS(const QString &cssUrl)
-{
-    QString cssInjectCode = QLatin1String(
-                "var head = document.getElementsByTagName('head')[0];"
-                "var link = document.createElement('link');"
-                "link.rel = 'stylesheet';"
-                "link.type = 'text/css';"
-                "link.href = '%1';"
-                "link.media = 'all';"
-                "head.appendChild(link);");
-
-    QWebEngineScript injectCssScript;
-    injectCssScript.setSourceCode(cssInjectCode.arg(cssUrl));
-    injectCssScript.setInjectionPoint(QWebEngineScript::DocumentReady);
-    scripts().insert(injectCssScript);
-}

src/libs/browser/webpage.h

@@ -34,13 +34,10 @@ class WebPage final : public QWebEnginePage
     Q_OBJECT
     Q_DISABLE_COPY(WebPage)
 public:
-    WebPage(QWebEngineProfile *profile, QObject *parent = nullptr);
+    explicit WebPage(QObject *parent = nullptr);
 
 protected:
     bool acceptNavigationRequest(const QUrl &url, NavigationType type, bool isMainFrame) override;
-
-private:
-    void insertCssWithJS(const QString &cssUrl);
 };
 
 } // namespace Browser

src/libs/browser/webview.cpp

@@ -23,7 +23,6 @@
 
 #include "webview.h"
 
-#include "urlrequestinterceptor.h"
 #include "webcontrol.h"
 #include "webpage.h"
 
@@ -49,11 +48,7 @@ using namespace Zeal::Browser;
 WebView::WebView(QWidget *parent)
     : QWebEngineView(parent)
 {
-    UrlRequestInterceptor *requestInterceptor = new UrlRequestInterceptor(this);
-    QWebEngineProfile *profile = new QWebEngineProfile(this);
-    profile->setUrlRequestInterceptor(requestInterceptor);
-    QWebEnginePage *p = new WebPage(profile, this);
-    setPage(p);
+    setPage(new WebPage(this));
     setZoomLevel(defaultZoomLevel());
 
     QApplication::instance()->installEventFilter(this);

src/libs/ui/mainwindow.cpp

@@ -32,6 +32,7 @@
 #include "sidebarviewprovider.h"
 #include <qxtglobalshortcut/qxtglobalshortcut.h>
 
+#include <browser/settings.h>
 #include <browser/webbridge.h>
 #include <browser/webcontrol.h>
 #include <core/application.h>
@@ -47,7 +48,6 @@
 #include <QShortcut>
 #include <QSystemTrayIcon>
 #include <QTabBar>
-#include <QWebEngineSettings>
 
 using namespace Zeal;
 using namespace Zeal::WidgetUi;
@@ -193,6 +193,9 @@ MainWindow::MainWindow(Core::Application *app, QWidget *parent)
     ui->splitter->insertWidget(0, sb);
     ui->splitter->restoreState(m_settings->verticalSplitterGeometry);
 
+    // Setup web settings.
+    auto webSettings = new Browser::Settings(m_settings, this);
+
     // Setup web bridge.
     m_webBridge = new Browser::WebBridge(this);
     connect(m_webBridge, &Browser::WebBridge::actionTriggered, this, [this](const QString &action) {
@@ -524,9 +527,6 @@ void MainWindow::applySettings()
         createTrayIcon();
     else
         removeTrayIcon();
-
-    QWebEngineSettings::globalSettings()->setAttribute(QWebEngineSettings::ScrollAnimatorEnabled,
-                                                       m_settings->isSmoothScrollingEnabled);
 }
 
 void MainWindow::toggleWindow()