Issue #99: Icons for dark mode

Pdf4QtDocDiff/mainwindow.cpp

@@ -28,6 +28,7 @@
 #include "pdfdocumentmanipulator.h"
 #include "pdfdocumentbuilder.h"
 #include "pdfdocumentwriter.h"
+#include "pdfwidgetutils.h"
 
 #include <QToolBar>
 #include <QDesktopServices>
@@ -164,6 +165,11 @@ MainWindow::MainWindow(QWidget* parent) :
         }
     }
 
+    if (pdf::PDFWidgetUtils::isDarkTheme())
+    {
+        pdf::PDFWidgetUtils::convertActionsForDarkTheme(actions, iconSize, qGuiApp->devicePixelRatio());
+    }
+
     connect(m_progress, &pdf::PDFProgress::progressStarted, this, &MainWindow::onProgressStarted);
     connect(m_progress, &pdf::PDFProgress::progressStep, this, &MainWindow::onProgressStep);
     connect(m_progress, &pdf::PDFProgress::progressFinished, this, &MainWindow::onProgressFinished);

Pdf4QtDocPageOrganizer/mainwindow.cpp

@@ -192,6 +192,11 @@ MainWindow::MainWindow(QWidget* parent) :
         }
     }
 
+    if (pdf::PDFWidgetUtils::isDarkTheme())
+    {
+        pdf::PDFWidgetUtils::convertActionsForDarkTheme(actions, iconSize, qGuiApp->devicePixelRatio());
+    }
+
     // Initialize pixmap cache size
     const int depth = 4; // 4 bytes (ARGB)
     const int reserveSize = 2; // Caching of two screens

Pdf4QtLib/sources/pdfwidgetutils.cpp

@@ -16,11 +16,15 @@
 //    along with PDF4QT.  If not, see <https://www.gnu.org/licenses/>.
 
 #include "pdfwidgetutils.h"
+#include "pdfcolorconvertor.h"
 #include "pdfdbgheap.h"
 
 #include <QDialog>
 #include <QLayout>
+#include <QPainter>
+#include <QPixmap>
 #include <QGroupBox>
+#include <QApplication>
 
 #ifdef Q_OS_MAC
 int qt_default_dpi_x() { return 72; }
@@ -161,4 +165,48 @@ void PDFWidgetUtils::style(QWidget* widget)
     }
 }
 
+bool PDFWidgetUtils::isDarkTheme()
+{
+    QPalette palette = QApplication::palette();
+    QColor backgroundColor = palette.color(QPalette::Window);
+    QColor textColor = palette.color(QPalette::WindowText);
+
+    return backgroundColor.lightness() < textColor.lightness();
+}
+
+void PDFWidgetUtils::convertActionForDarkTheme(QAction* action, QSize iconSize, qreal devicePixelRatioF)
+{
+    if (!action)
+    {
+        return;
+    }
+
+    QIcon icon = action->icon();
+    if (!icon.isNull())
+    {
+        icon = pdf::PDFWidgetUtils::convertIconForDarkTheme(icon, iconSize, devicePixelRatioF);
+        action->setIcon(icon);
+    }
+}
+
+QIcon PDFWidgetUtils::convertIconForDarkTheme(QIcon icon, QSize iconSize, qreal devicePixelRatioF)
+{
+    QPixmap pixmap(iconSize * devicePixelRatioF);
+    pixmap.setDevicePixelRatio(devicePixelRatioF);
+    pixmap.fill(Qt::transparent);
+
+    QPainter painter(&pixmap);
+    icon.paint(&painter, QRect(0, 0, iconSize.width(), iconSize.height()));
+    painter.end();
+
+    PDFColorConvertor convertor;
+    convertor.setMode(PDFColorConvertor::Mode::InvertedColors);
+
+    QImage image = pixmap.toImage();
+    image = convertor.convert(image);
+    pixmap = QPixmap::fromImage(image);
+
+    return QIcon(pixmap);
+}
+
 } // namespace pdf

Pdf4QtLib/sources/pdfwidgetutils.h

@@ -20,6 +20,7 @@
 
 #include "pdfglobal.h"
 
+#include <QIcon>
 #include <QWidget>
 
 namespace pdf
@@ -57,6 +58,35 @@ public:
 
     /// Apply style to the widget
     static void style(QWidget* widget);
+
+    /// Vrátí true, pokud je aktuálně nastavená dark theme
+    /// pro aplikaci.
+    static bool isDarkTheme();
+
+    /// Converts an action's icon for use in a dark theme.
+    /// \param action Pointer to the QAction to be converted.
+    /// \param iconSize The size of the action's icon.
+    /// \param devicePixelRatioF The device pixel ratio factor.
+    static void convertActionForDarkTheme(QAction* action, QSize iconSize, qreal devicePixelRatioF);
+
+    /// Converts an icon for use in a dark theme.
+    /// \param icon The icon to be converted.
+    /// \param iconSize The size of the icon.
+    /// \param devicePixelRatioF The device pixel ratio factor.
+    static QIcon convertIconForDarkTheme(QIcon icon, QSize iconSize, qreal devicePixelRatioF);
+
+    /// Converts an action's icon for use in a dark theme.
+    /// \param action Pointer to the QAction to be converted.
+    /// \param iconSize The size of the action's icon.
+    /// \param devicePixelRatioF The device pixel ratio factor.
+    template<typename Container>
+    static void convertActionsForDarkTheme(const Container& actions, QSize iconSize, qreal devicePixelRatioF)
+    {
+        for (QAction* action : actions)
+        {
+            convertActionForDarkTheme(action, iconSize, devicePixelRatioF);
+        }
+    }
 };
 
 } // namespace pdf

Pdf4QtViewer/pdfprogramcontroller.cpp

@@ -27,6 +27,7 @@
 #include "pdfdocumentbuilder.h"
 #include "pdfdbgheap.h"
 #include "pdfcertificatemanagerdialog.h"
+#include "pdfwidgetutils.h"
 
 #include "pdfviewersettings.h"
 #include "pdfundoredomanager.h"
@@ -292,6 +293,20 @@ void PDFActionManager::initActions(QSize iconSize, bool initializeStampActions)
         createCreateStampAction(CreateStampSold, pdf::Stamp::Sold);
         createCreateStampAction(CreateStampTopSecret, pdf::Stamp::TopSecret);
     }
+
+    m_iconSize = iconSize;
+}
+
+void PDFActionManager::styleActions()
+{
+    if (pdf::PDFWidgetUtils::isDarkTheme())
+    {
+        qreal devicePixelRatio = qGuiApp->devicePixelRatio();
+
+        // Convert icons to dark theme icons
+        pdf::PDFWidgetUtils::convertActionsForDarkTheme(m_actions, m_iconSize, devicePixelRatio);
+        pdf::PDFWidgetUtils::convertActionsForDarkTheme(m_additionalActions, m_iconSize, devicePixelRatio);
+    }
 }
 
 bool PDFActionManager::hasActions(const std::initializer_list<Action>& actionTypes) const

Pdf4QtViewer/pdfprogramcontroller.h

@@ -230,6 +230,7 @@ public:
     void addAdditionalAction(QAction* action);
 
     void initActions(QSize iconSize, bool initializeStampActions);
+    void styleActions();
 
 private:
     bool hasActions(const std::initializer_list<Action>& actionTypes) const;
@@ -238,6 +239,7 @@ private:
     std::array<QAction*, LastAction> m_actions;
     std::array<QActionGroup*, LastActionGroup> m_actionGroups;
     std::vector<QAction*> m_additionalActions;
+    QSize m_iconSize;
 };
 
 class PDF4QTVIEWERLIBSHARED_EXPORT PDFProgramController : public QObject, public pdf::IPluginDataExchange

Pdf4QtViewer/pdfviewermainwindow.cpp

@@ -301,6 +301,8 @@ PDFViewerMainWindow::PDFViewerMainWindow(QWidget* parent) :
     {
         connect(toolManager, &pdf::PDFToolManager::messageDisplayRequest, statusBar(), &QStatusBar::showMessage);
     }
+
+    m_actionManager->styleActions();
 }
 
 PDFViewerMainWindow::~PDFViewerMainWindow()

Pdf4QtViewer/pdfviewermainwindowlite.cpp

@@ -218,6 +218,8 @@ PDFViewerMainWindowLite::PDFViewerMainWindowLite(QWidget* parent) :
     {
         connect(toolManager, &pdf::PDFToolManager::messageDisplayRequest, statusBar(), &QStatusBar::showMessage);
     }
+
+    m_actionManager->styleActions();
 }
 
 PDFViewerMainWindowLite::~PDFViewerMainWindowLite()