Add OptionPageWidget with `paletteChanged()` signal

settingsdialog/optionpage.cpp

@@ -1,11 +1,14 @@
 #include "./optionpage.h"
 
 #include <QCheckBox>
+#include <QEvent>
 #include <QGroupBox>
 #include <QLabel>
 #include <QPushButton>
 #include <QRadioButton>
 
+#include <utility>
+
 namespace QtUtilities {
 
 /*!
@@ -81,12 +84,26 @@ bool OptionPage::matches(const QString &searchKeyWord)
             m_keywords << groupBox->title();
         m_keywordsInitialized = true;
     }
-    for (const QString &keyword : m_keywords)
+    for (const QString &keyword : std::as_const(m_keywords))
         if (keyword.contains(searchKeyWord, Qt::CaseInsensitive))
             return true;
     return false;
 }
 
+/*!
+ * \brief Emits the paletteChanged() signal.
+ */
+bool OptionPageWidget::event(QEvent *event)
+{
+    switch (event->type()) {
+    case QEvent::PaletteChange:
+        emit paletteChanged();
+        break;
+    default:;
+    }
+    return QWidget::event(event);
+}
+
 /*!
  * \fn OptionPage::apply()
  * \brief Applies altered settings.

settingsdialog/optionpage.h

@@ -12,6 +12,24 @@ namespace QtUtilities {
 
 class SettingsDialog;
 
+class QT_UTILITIES_EXPORT OptionPageWidget : public QWidget {
+    Q_OBJECT
+
+public:
+    explicit OptionPageWidget(QWidget *parent = nullptr, Qt::WindowFlags f = Qt::WindowFlags());
+
+Q_SIGNALS:
+    void paletteChanged();
+
+protected:
+    bool event(QEvent *) override;
+};
+
+inline OptionPageWidget::OptionPageWidget(QWidget *parent, Qt::WindowFlags f)
+    : QWidget(parent, f)
+{
+}
+
 class QT_UTILITIES_EXPORT OptionPage {
     friend class SettingsDialog;
 
@@ -125,7 +143,7 @@ template <class UiClass> UiFileBasedOptionPage<UiClass>::~UiFileBasedOptionPage(
  */
 template <class UiClass> QWidget *UiFileBasedOptionPage<UiClass>::setupWidget()
 {
-    QWidget *widget = new QWidget();
+    QWidget *widget = new OptionPageWidget();
     if (!m_ui) {
         m_ui.reset(new UiClass);
     }