From b0e5c3001b5422e84177ff65caff8a51baffadf3 Mon Sep 17 00:00:00 2001
From: Jakub Melka <Mgr.Jakub.Melka@gmail.com>
Date: Sat, 19 Oct 2024 19:53:36 +0200
Subject: [PATCH] Issue #200: Icons under dark theme on Arch/KDE is broken

---
 Pdf4QtEditor/main.cpp                       | 15 +++++++++++++++
 Pdf4QtLibWidgets/sources/pdfwidgetutils.cpp | 11 ++---------
 Pdf4QtLibWidgets/sources/pdfwidgetutils.h   |  2 +-
 Pdf4QtViewer/main.cpp                       | 15 +++++++++++++++
 4 files changed, 33 insertions(+), 10 deletions(-)

diff --git a/Pdf4QtEditor/main.cpp b/Pdf4QtEditor/main.cpp
index 55f2c40..9825250 100644
--- a/Pdf4QtEditor/main.cpp
+++ b/Pdf4QtEditor/main.cpp
@@ -18,6 +18,7 @@
 #include "pdfeditormainwindow.h"
 #include "pdfconstants.h"
 #include "pdfsecurityhandler.h"
+#include "pdfwidgetutils.h"
 
 #include <QApplication>
 #include <QCommandLineParser>
@@ -39,10 +40,14 @@ int main(int argc, char *argv[])
     QApplication::setApplicationDisplayName(QApplication::translate("Application", "PDF4QT Editor"));
 
     QCommandLineOption noDrm("no-drm", "Disable DRM settings of documents.");
+    QCommandLineOption lightGui("theme-light", "Use a light theme for the GUI.");
+    QCommandLineOption darkGui("theme-dark", "Use a dark theme for the GUI.");
 
     QCommandLineParser parser;
     parser.setApplicationDescription(QCoreApplication::applicationName());
     parser.addOption(noDrm);
+    parser.addOption(lightGui);
+    parser.addOption(darkGui);
     parser.addHelpOption();
     parser.addVersionOption();
     parser.addPositionalArgument("file", "The PDF file to open.");
@@ -53,6 +58,16 @@ int main(int argc, char *argv[])
         pdf::PDFSecurityHandler::setNoDRMMode();
     }
 
+    if (parser.isSet(lightGui))
+    {
+        pdf::PDFWidgetUtils::setDarkTheme(false);
+    }
+
+    if (parser.isSet(darkGui))
+    {
+        pdf::PDFWidgetUtils::setDarkTheme(true);
+    }
+
     QIcon appIcon(":/app-icon.svg");
     QApplication::setWindowIcon(appIcon);
 
diff --git a/Pdf4QtLibWidgets/sources/pdfwidgetutils.cpp b/Pdf4QtLibWidgets/sources/pdfwidgetutils.cpp
index dc934e5..67f15d7 100644
--- a/Pdf4QtLibWidgets/sources/pdfwidgetutils.cpp
+++ b/Pdf4QtLibWidgets/sources/pdfwidgetutils.cpp
@@ -46,8 +46,6 @@ int qt_default_dpi_y() { return 96; }
 namespace pdf
 {
 
-std::optional<bool> s_isDarkThemeOverride;
-
 static constexpr bool isScalingNeeded()
 {
     return QT_VERSION_MAJOR < 6;
@@ -176,18 +174,13 @@ void PDFWidgetUtils::style(QWidget* widget)
     }
 }
 
-void PDFWidgetUtils::overrideDarkTheme(bool isDarkTheme)
+void PDFWidgetUtils::setDarkTheme(bool isDarkTheme)
 {
-    s_isDarkThemeOverride = isDarkTheme;
+    QApplication::styleHints()->setColorScheme(isDarkTheme ? Qt::ColorScheme::Dark : Qt::ColorScheme::Light);
 }
 
 bool PDFWidgetUtils::isDarkTheme()
 {
-    if (s_isDarkThemeOverride.has_value())
-    {
-        return s_isDarkThemeOverride.value();
-    }
-
     Qt::ColorScheme colorScheme = QApplication::styleHints()->colorScheme();
     return colorScheme == Qt::ColorScheme::Dark;
 }
diff --git a/Pdf4QtLibWidgets/sources/pdfwidgetutils.h b/Pdf4QtLibWidgets/sources/pdfwidgetutils.h
index b539b6f..bfa296e 100644
--- a/Pdf4QtLibWidgets/sources/pdfwidgetutils.h
+++ b/Pdf4QtLibWidgets/sources/pdfwidgetutils.h
@@ -61,7 +61,7 @@ public:
     static void style(QWidget* widget);
 
     /// Overrides automatically detected dark theme / light theme settings
-    static void overrideDarkTheme(bool isDarkTheme);
+    static void setDarkTheme(bool isDarkTheme);
 
     /// Returns true if the dark theme is currently set for the application.
     static bool isDarkTheme();
diff --git a/Pdf4QtViewer/main.cpp b/Pdf4QtViewer/main.cpp
index 62a7cbe..a22ef72 100644
--- a/Pdf4QtViewer/main.cpp
+++ b/Pdf4QtViewer/main.cpp
@@ -18,6 +18,7 @@
 #include "pdfviewermainwindow.h"
 #include "pdfconstants.h"
 #include "pdfsecurityhandler.h"
+#include "pdfwidgetutils.h"
 
 #include <QApplication>
 #include <QCommandLineParser>
@@ -33,10 +34,14 @@ int main(int argc, char *argv[])
     QApplication::setApplicationDisplayName(QApplication::translate("Application", "PDF4QT Viewer"));
 
     QCommandLineOption noDrm("no-drm", "Disable DRM settings of documents.");
+    QCommandLineOption lightGui("theme-light", "Use a light theme for the GUI.");
+    QCommandLineOption darkGui("theme-dark", "Use a dark theme for the GUI.");
 
     QCommandLineParser parser;
     parser.setApplicationDescription(QCoreApplication::applicationName());
     parser.addOption(noDrm);
+    parser.addOption(lightGui);
+    parser.addOption(darkGui);
     parser.addHelpOption();
     parser.addVersionOption();
     parser.addPositionalArgument("file", "The PDF file to open.");
@@ -47,6 +52,16 @@ int main(int argc, char *argv[])
         pdf::PDFSecurityHandler::setNoDRMMode();
     }
 
+    if (parser.isSet(lightGui))
+    {
+        pdf::PDFWidgetUtils::setDarkTheme(false);
+    }
+
+    if (parser.isSet(darkGui))
+    {
+        pdf::PDFWidgetUtils::setDarkTheme(true);
+    }
+
     QIcon appIcon(":/app-icon.svg");
     QApplication::setWindowIcon(appIcon);