feat: 支持启动时识别 DTK 主题颜色，判断网页是否需要显示为深色模式（切换 DTK 主题后重启生效，不支持实时生效）

https://github.com/qutebrowser/qutebrowser/issues/4840
启动时判断 DTK 主题颜色，QTWEBENGINE_CHROMIUM_FLAGS 环境变量添加 --blink-settings=preferredColorScheme=0 启用深色模式（或 --force-dark-mode）（Qt >= 5.14，当前仅 Deepin 支持）

Log: 支持启动时识别 DTK 主题颜色，判断网页是否需要显示为深色模式

spark-webapp-runtime/main.cpp

@@ -4,10 +4,11 @@
  */
 #include "application.h"
 #include "mainwindow.h"
-#include "globaldefine.h"
+#include "webengineview.h"
 #include "httpd.h"
 
 #include <DSysInfo>
+#include <DApplicationSettings>
 
 #include <QCommandLineParser>
 #include <QCommandLineOption>
@@ -50,6 +51,9 @@ int main(int argc, char *argv[])
     }
     Application a(fakeArgc, fakeArgv.data());
 
+    // 保存 DTK 主题
+    DApplicationSettings settings;
+
     // 解析命令行启动参数
     QCommandLineParser parser;
 
@@ -255,12 +259,14 @@ int main(int argc, char *argv[])
         toUseGPU = parser.value(useGPU).toUInt();
     }
     if (toUseGPU == true) {
-        qputenv("QTWEBENGINE_CHROMIUM_FLAGS", "--ignore-gpu-blocklist --enable-gpu-rasterization --enable-native-gpu-memory-buffers --enable-accelerated-video-decode --blink-settings=darkMode=4,darkModeImagePolicy=2");
+        qputenv("QTWEBENGINE_CHROMIUM_FLAGS", "--ignore-gpu-blocklist --enable-gpu-rasterization --enable-native-gpu-memory-buffers --enable-accelerated-video-decode");
 #ifdef __sw_64__
-        qputenv("QTWEBENGINE_CHROMIUM_FLAGS", "--ignore-gpu-blocklist --enable-gpu-rasterization --enable-native-gpu-memory-buffers --enable-accelerated-video-decode --blink-settings=darkMode=4,darkModeImagePolicy=2 --no-sandbox");
+        qputenv("QTWEBENGINE_CHROMIUM_FLAGS", "--ignore-gpu-blocklist --enable-gpu-rasterization --enable-native-gpu-memory-buffers --enable-accelerated-video-decode --no-sandbox");
 #endif
         qDebug() << "Setting GPU to True.";
     }
+    // 初始化 QtWebEngine 深色模式环境变量
+    WebEngineView::handleChromiumFlags();
 
 #if SSL_SERVER
     if (parser.isSet(optSSLPort)) {

spark-webapp-runtime/webengineview.cpp

@@ -1,20 +1,53 @@
 #include "webengineview.h"
 //#include "webengineurlrequestinterceptor.h"
 
+#include <DGuiApplicationHelper>
+
 #include <QWebEngineSettings>
 #include <QWebEngineProfile>
 #include <QLocale>
 
+DGUI_USE_NAMESPACE
+
 WebEngineView::WebEngineView(QWidget *parent)
     : QWebEngineView(parent)
 //    , interceptor(new WebEngineUrlRequestInterceptor(this))
 {
-    //    page()->profile()->setHttpUserAgent(page()->profile()->httpUserAgent() + " MediaFeature/prefers-color-scheme:dark");
-
     connect(this, &WebEngineView::urlChanged, this, [=]() {
         //        page()->setUrlRequestInterceptor(interceptor);
         //        page()->settings()->setAttribute(QWebEngineSettings::WebAttribute::LocalContentCanAccessRemoteUrls, true);
         page()->profile()->setHttpAcceptLanguage(QLocale::system().name());
-        //        qInfo() << "User Agent:" << page()->profile()->httpUserAgent();
     });
 }
+
+void WebEngineView::handleChromiumFlags()
+{
+    DGuiApplicationHelper::ColorType themeType = DGuiApplicationHelper::instance()->themeType();
+
+    QString env = qgetenv("QTWEBENGINE_CHROMIUM_FLAGS");
+    QStringList flags = env.split(" ", QString::SkipEmptyParts);
+
+    /**
+     * --blink-settings=preferredColorScheme=0 强制 prefers-color-scheme=dark (>= 5.14)
+     * --blink-settings=darkModeEnabled=true,darkModeInversionAlgorithm=4 强制反转网页颜色 (>= 5.14 && < 5.15)
+     * --blink-settings=forceDarkModeEnabled=true,darkModeInversionAlgorithm=4 强制反转网页颜色 (>= 5.15)
+     * --force-dark-mode 强制 prefers-color-scheme=dark (>= 5.14)
+     */
+    foreach (const QString &flag, flags) {
+        if (flag == "--force-dark-mode") {
+            flags.removeAll(flag);
+        }
+        if (flag.startsWith("--blink-settings")) {
+            flags.removeAll(flag);
+        }
+    }
+
+    if (themeType == DGuiApplicationHelper::DarkType) {
+        flags.append("--blink-settings=preferredColorScheme=0");
+    } else {
+        flags.append("--blink-settings=preferredColorScheme=1");
+    }
+    qputenv("QTWEBENGINE_CHROMIUM_FLAGS", flags.join(" ").toUtf8());
+
+    qDebug() << Q_FUNC_INFO << "QTWEBENGINE_CHROMIUM_FLAGS=" + qgetenv("QTWEBENGINE_CHROMIUM_FLAGS");
+}

spark-webapp-runtime/webengineview.h

@@ -11,6 +11,8 @@ class WebEngineView : public QWebEngineView
 public:
     explicit WebEngineView(QWidget *parent = nullptr);
 
+    static void handleChromiumFlags();
+
 private:
     //    WebEngineUrlRequestInterceptor *interceptor = nullptr;
 };

spark-webapp-runtime/widget.cpp

@@ -13,37 +13,8 @@ Widget::Widget(QString szUrl, QWidget *parent)
     , mainLayout(new QStackedLayout(this))
     , m_szUrl(szUrl)
 {
-    m_spinner->setFixedSize(96, 96);
-
-    m_webEngineView->setObjectName(QStringLiteral("webEngineView"));
-    m_webEngineView->setEnabled(true);
-    m_webEngineView->setAutoFillBackground(false);
-
-    DApplication *dApp = qobject_cast<DApplication *>(qApp);
-    m_webEngineView->setZoomFactor(dApp->devicePixelRatio());
-
-    WebEnginePage *page = new WebEnginePage(m_webEngineView);
-    m_webEngineView->setPage(page);
-
-    page->setUrl(QUrl());
-    if (!m_szUrl.isEmpty()) {
-        page->setUrl(QUrl(m_szUrl));
-    }
-
-    QWidget *spinnerWidget = new QWidget(this);
-    QHBoxLayout *spinnerLayout = new QHBoxLayout(spinnerWidget);
-    spinnerLayout->setMargin(0);
-    spinnerLayout->setSpacing(0);
-    spinnerLayout->setAlignment(Qt::AlignCenter);
-    spinnerLayout->addStretch();
-    spinnerLayout->addWidget(m_spinner);
-    spinnerLayout->addStretch();
-
-    mainLayout->addWidget(spinnerWidget);
-    mainLayout->addWidget(m_webEngineView);
-
-    connect(m_webEngineView, &QWebEngineView::loadStarted, this, &Widget::on_loadStarted);
-    connect(m_webEngineView, &QWebEngineView::loadFinished, this, &Widget::on_loadFinished);
+    initUI();
+    initConnections();
 }
 
 Widget::~Widget()
@@ -70,6 +41,63 @@ void Widget::refresh()
     m_webEngineView->reload();
 }
 
+void Widget::initUI()
+{
+    m_spinner->setFixedSize(96, 96);
+
+    DApplication *dApp = qobject_cast<DApplication *>(qApp);
+    m_webEngineView->setZoomFactor(dApp->devicePixelRatio());
+
+    WebEnginePage *page = new WebEnginePage(m_webEngineView);
+    m_webEngineView->setPage(page);
+
+    page->setUrl(QUrl());
+    if (!m_szUrl.isEmpty()) {
+        page->setUrl(QUrl(m_szUrl));
+    }
+
+    QWidget *spinnerWidget = new QWidget(this);
+    QHBoxLayout *spinnerLayout = new QHBoxLayout(spinnerWidget);
+    spinnerLayout->setMargin(0);
+    spinnerLayout->setSpacing(0);
+    spinnerLayout->setAlignment(Qt::AlignCenter);
+    spinnerLayout->addStretch();
+    spinnerLayout->addWidget(m_spinner);
+    spinnerLayout->addStretch();
+
+    mainLayout->addWidget(spinnerWidget);
+    mainLayout->addWidget(m_webEngineView);
+}
+
+void Widget::initConnections()
+{
+    connect(m_webEngineView, &QWebEngineView::loadStarted, this, &Widget::on_loadStarted, Qt::UniqueConnection);
+    connect(m_webEngineView, &QWebEngineView::loadFinished, this, &Widget::on_loadFinished, Qt::UniqueConnection);
+
+    // FIXME: DTK 主题切换时，动态修改 QtWebEngine prefers-color-scheme
+    //    connect(DGuiApplicationHelper::instance(), &DGuiApplicationHelper::paletteTypeChanged, this, &Widget::slotPaletteTypeChanged, Qt::UniqueConnection);
+}
+
+void Widget::updateLayout()
+{
+    on_loadStarted();
+
+    mainLayout->removeWidget(m_webEngineView);
+    QUrl url = m_webEngineView->url();
+    m_webEngineView->deleteLater();
+
+    m_webEngineView = new WebEngineView(this);
+    mainLayout->addWidget(m_webEngineView);
+    initConnections();
+
+    DApplication *dApp = qobject_cast<DApplication *>(qApp);
+    m_webEngineView->setZoomFactor(dApp->devicePixelRatio());
+
+    WebEnginePage *page = new WebEnginePage(m_webEngineView);
+    m_webEngineView->setPage(page);
+    page->setUrl(url);
+}
+
 void Widget::on_loadStarted()
 {
     mainLayout->setCurrentIndex(0);
@@ -81,3 +109,13 @@ void Widget::on_loadFinished()
     m_spinner->stop();
     mainLayout->setCurrentIndex(1);
 }
+
+void Widget::slotPaletteTypeChanged(DGuiApplicationHelper::ColorType paletteType)
+{
+    Q_UNUSED(paletteType)
+
+    WebEngineView::handleChromiumFlags();
+    if (m_webEngineView) {
+        updateLayout();
+    }
+}

spark-webapp-runtime/widget.h

@@ -2,12 +2,14 @@
 #define WIDGET_H
 
 #include <DSpinner>
+#include <DGuiApplicationHelper>
 
 #include <QWidget>
 #include <QWebEnginePage>
 #include <QStackedLayout>
 
 DWIDGET_USE_NAMESPACE
+DGUI_USE_NAMESPACE
 
 class WebEngineView;
 class Widget : public QWidget
@@ -23,10 +25,17 @@ public:
     void goForward();
     void refresh();
 
+private:
+    void initUI();
+    void initConnections();
+    void updateLayout();
+
 private slots:
     void on_loadStarted();
     void on_loadFinished();
 
+    void slotPaletteTypeChanged(DGuiApplicationHelper::ColorType paletteType);
+
 private:
     WebEngineView *m_webEngineView = nullptr;
     DSpinner *m_spinner = nullptr;