qt: Introduce runtime theme changes

src/qt/bitcoingui.cpp

@@ -125,8 +125,6 @@ BitcoinGUI::BitcoinGUI(const PlatformStyle *_platformStyle, const NetworkStyle *
     spinnerFrame(0),
     platformStyle(_platformStyle)
 {
-    GUIUtil::loadStyleSheet(this);
-
     QSettings settings;
     if (!restoreGeometry(settings.value("MainWindowGeometry").toByteArray())) {
         // Restore failed (perhaps missing setting), center the window
@@ -844,6 +842,7 @@ void BitcoinGUI::optionsClicked()
 
     OptionsDialog dlg(this, enableWallet);
     dlg.setModel(clientModel->getOptionsModel());
+    connect(&dlg, &OptionsDialog::themeChanged, [=]() { GUIUtil::loadTheme(); });
     dlg.exec();
 }
 

src/qt/dash.cpp

@@ -395,6 +395,8 @@ void BitcoinApplication::createWindow(const NetworkStyle *networkStyle)
 {
     window = new BitcoinGUI(platformStyle, networkStyle, 0);
 
+    GUIUtil::loadTheme(window);
+
     pollShutdownTimer = new QTimer(window);
     connect(pollShutdownTimer, SIGNAL(timeout()), window, SLOT(detectShutdown()));
 }

src/qt/guiutil.cpp

@@ -132,6 +132,11 @@ static std::set<QWidget*> setFixedPitchFontUpdates;
 // Contains all widgets where a non-default fontsize has been seet with GUIUtil::setFont
 static std::map<QWidget*, int> mapFontSizeUpdates;
 
+#ifdef Q_OS_MAC
+// Contains all widgets where the macOS focus rect has been disabled.
+static std::set<QWidget*> setRectsDisabled;
+#endif
+
 static const std::map<ThemedColor, QColor> themedColors = {
     { ThemedColor::DEFAULT, QColor(85, 85, 85) },
     { ThemedColor::UNCONFIRMED, QColor(128, 128, 128) },
@@ -1025,7 +1030,12 @@ const std::vector<QString> listThemes()
     return vecThemes;
 }
 
-void loadStyleSheet(QWidget* widget, bool fDebugWidget)
+const QString getDefaultTheme()
+{
+    return defaultTheme;
+}
+
+void loadStyleSheet(QWidget* widget, bool fForceUpdate)
 {
     AssertLockNotHeld(cs_css);
     LOCK(cs_css);
@@ -1036,7 +1046,7 @@ void loadStyleSheet(QWidget* widget, bool fDebugWidget)
     bool fDebugCustomStyleSheets = gArgs.GetBoolArg("-debug-ui", false) && isStyleSheetDirectoryCustom();
     bool fStyleSheetChanged = false;
 
-    if (stylesheet == nullptr || fDebugCustomStyleSheets) {
+    if (stylesheet == nullptr || fForceUpdate || fDebugCustomStyleSheets) {
         auto hasModified = [](const std::vector<QString>& vecFiles) -> bool {
             static std::map<const QString, QDateTime> mapLastModified;
 
@@ -1053,7 +1063,7 @@ void loadStyleSheet(QWidget* widget, bool fDebugWidget)
         };
 
         auto loadFiles = [&](const std::vector<QString>& vecFiles) -> bool {
-            if (fDebugCustomStyleSheets && !hasModified(vecFiles)) {
+            if (!fForceUpdate && fDebugCustomStyleSheets && !hasModified(vecFiles)) {
                 return false;
             }
 
@@ -1086,29 +1096,27 @@ void loadStyleSheet(QWidget* widget, bool fDebugWidget)
         fStyleSheetChanged = loadFiles(vecFiles);
     }
 
-    bool fUpdateStyleSheet = fDebugCustomStyleSheets && fStyleSheetChanged;
+    bool fUpdateStyleSheet = fForceUpdate || (fDebugCustomStyleSheets && fStyleSheetChanged);
 
-    if (fDebugWidget) {
+    if (widget) {
         setWidgets.insert(widget);
-        QWidgetList allWidgets = QApplication::allWidgets();
-        auto it = setWidgets.begin();
-        while (it != setWidgets.end()) {
-            if (!allWidgets.contains(*it)) {
-                it = setWidgets.erase(it);
-                continue;
-            }
-            if (fUpdateStyleSheet && *it != widget) {
-                (*it)->setStyleSheet(*stylesheet);
-            }
-            ++it;
-        }
+        widget->setStyleSheet(*stylesheet);
     }
 
-    if (widget) {
-        widget->setStyleSheet(*stylesheet);
+    QWidgetList allWidgets = QApplication::allWidgets();
+    auto it = setWidgets.begin();
+    while (it != setWidgets.end()) {
+        if (!allWidgets.contains(*it)) {
+            it = setWidgets.erase(it);
+            continue;
+        }
+        if (fUpdateStyleSheet && *it != widget) {
+            (*it)->setStyleSheet(*stylesheet);
+        }
+        ++it;
     }
 
-    if (!ShutdownRequested() && fDebugCustomStyleSheets) {
+    if (!ShutdownRequested() && fDebugCustomStyleSheets && !fForceUpdate) {
         QTimer::singleShot(200, [] { loadStyleSheet(); });
     }
 }
@@ -1517,12 +1525,36 @@ bool dashThemeActive()
     return theme != traditionalTheme;
 }
 
+void loadTheme(QWidget* widget, bool fForce)
+{
+    loadStyleSheet(widget, fForce);
+    updateFonts();
+    updateMacFocusRects();
+}
+
 void disableMacFocusRect(const QWidget* w)
 {
 #ifdef Q_OS_MAC
     for (const auto& c : w->findChildren<QWidget*>()) {
         if (c->testAttribute(Qt::WA_MacShowFocusRect)) {
             c->setAttribute(Qt::WA_MacShowFocusRect, !dashThemeActive());
+            setRectsDisabled.emplace(c);
+        }
+    }
+#endif
+}
+
+void updateMacFocusRects()
+{
+#ifdef Q_OS_MAC
+    QWidgetList allWidgets = QApplication::allWidgets();
+    auto it = setRectsDisabled.begin();
+    while (it != setRectsDisabled.end()) {
+        if (allWidgets.contains(*it)) {
+            (*it)->setAttribute(Qt::WA_MacShowFocusRect, !dashThemeActive());
+            ++it;
+        } else {
+            it = setRectsDisabled.erase(it);
         }
     }
 #endif

src/qt/guiutil.h

@@ -253,10 +253,13 @@ namespace GUIUtil
     /** Return a list of all theme css files */
     const std::vector<QString> listThemes();
 
-    /** Updates the widgets stylesheet and adds it to the list of ui debug elements
-        if fDebugWidget is true. Beeing on that list means the stylesheet of the
-        widget gets updated if the related css files has been changed if -debug-ui mode is active. */
-    void loadStyleSheet(QWidget* widget = nullptr, bool fDebugWidget = true);
+    /** Return the name of the default theme `*/
+    const QString getDefaultTheme();
+
+    /** Updates the widgets stylesheet and adds it to the list of ui debug elements.
+    Beeing on that list means the stylesheet of the widget gets updated if the
+    related css files has been changed if -debug-ui mode is active. */
+    void loadStyleSheet(QWidget* widget = nullptr, bool fForceUpdate = false);
 
     enum class FontFamily {
         SystemDefault,
@@ -335,10 +338,16 @@ namespace GUIUtil
     /** Check if a dash specific theme is activated (light/dark).*/
     bool dashThemeActive();
 
+    /** Load the theme and update all UI elements according to the appearance settings. */
+    void loadTheme(QWidget* widget = nullptr, bool fForce = true);
+
     /** Disable the OS default focus rect for macOS because we have custom focus rects
      * set in the css files */
     void disableMacFocusRect(const QWidget* w);
 
+    /** Enable/Disable the macOS focus rects depending on the current theme. */
+    void updateMacFocusRects();
+
     /* Convert QString to OS specific boost path through UTF-8 */
     fs::path qstringToBoostPath(const QString &path);
 

src/qt/optionsdialog.cpp

@@ -26,6 +26,7 @@
 #include <QIntValidator>
 #include <QLocale>
 #include <QMessageBox>
+#include <QSettings>
 #include <QTimer>
 
 OptionsDialog::OptionsDialog(QWidget *parent, bool enableWallet) :
@@ -36,6 +37,8 @@ OptionsDialog::OptionsDialog(QWidget *parent, bool enableWallet) :
 {
     ui->setupUi(this);
 
+    previousTheme = GUIUtil::getActiveTheme();
+
     GUIUtil::setFont({ui->statusLabel}, GUIUtil::FontWeight::Bold, 16);
 
     GUIUtil::updateFonts();
@@ -104,6 +107,7 @@ OptionsDialog::OptionsDialog(QWidget *parent, bool enableWallet) :
     for (const QString& entry : GUIUtil::listThemes()) {
         ui->theme->addItem(entry, QVariant(entry));
     }
+    connect(ui->theme, SIGNAL(valueChanged()), this, SLOT(updateTheme()));
 
     /* Language selector */
     QDir translations(":translations");
@@ -188,7 +192,6 @@ void OptionsDialog::setModel(OptionsModel *_model)
     connect(ui->connectSocksTor, SIGNAL(clicked(bool)), this, SLOT(showRestartWarning()));
     /* Display */
     connect(ui->digits, SIGNAL(valueChanged()), this, SLOT(showRestartWarning()));
-    connect(ui->theme, SIGNAL(valueChanged()), this, SLOT(showRestartWarning()));
     connect(ui->lang, SIGNAL(valueChanged()), this, SLOT(showRestartWarning()));
     connect(ui->thirdPartyTxUrls, SIGNAL(textChanged(const QString &)), this, SLOT(showRestartWarning()));
 }
@@ -293,6 +296,9 @@ void OptionsDialog::on_okButton_clicked()
 
 void OptionsDialog::on_cancelButton_clicked()
 {
+    if (previousTheme != GUIUtil::getActiveTheme()) {
+        updateTheme(previousTheme);
+    }
     reject();
 }
 
@@ -373,6 +379,16 @@ void OptionsDialog::updateDefaultProxyNets()
     (strProxy == strDefaultProxyGUI.toStdString()) ? ui->proxyReachTor->setChecked(true) : ui->proxyReachTor->setChecked(false);
 }
 
+void OptionsDialog::updateTheme(const QString& theme)
+{
+    QString newValue = theme.isEmpty() ? ui->theme->value().toString() : theme;
+    if (GUIUtil::getActiveTheme() != newValue) {
+        QSettings().setValue("theme", newValue);
+        QSettings().sync();
+        Q_EMIT themeChanged();
+    }
+}
+
 ProxyAddressValidator::ProxyAddressValidator(QObject *parent) :
 QValidator(parent)
 {

src/qt/optionsdialog.h

@@ -60,15 +60,18 @@ private Q_SLOTS:
     void updateProxyValidationState();
     /* query the networks, for which the default proxy is used */
     void updateDefaultProxyNets();
+    void updateTheme(const QString& toTheme = QString());
 
 Q_SIGNALS:
     void proxyIpChecks(QValidatedLineEdit *pUiProxyIp, int nProxyPort);
+    void themeChanged();
 
 private:
     Ui::OptionsDialog *ui;
     OptionsModel *model;
     QDataWidgetMapper *mapper;
     QButtonGroup pageButtons;
+    QString previousTheme;
 };
 
 #endif // BITCOIN_QT_OPTIONSDIALOG_H

src/qt/optionsmodel.cpp

@@ -85,7 +85,7 @@ void OptionsModel::Init(bool resetSettings)
     strThirdPartyTxUrls = settings.value("strThirdPartyTxUrls", "").toString();
 
     if (!settings.contains("theme"))
-        settings.setValue("theme", "");
+        settings.setValue("theme", GUIUtil::getDefaultTheme());
 
 #ifdef ENABLE_WALLET
     if (!settings.contains("fCoinControlFeatures"))
@@ -510,10 +510,8 @@ bool OptionsModel::setData(const QModelIndex & index, const QVariant & value, in
             break;
 #endif // ENABLE_WALLET
         case Theme:
-            if (settings.value("theme") != value) {
-                settings.setValue("theme", value);
-                setRestartRequired(true);
-            }
+            // Set in OptionsDialog::updateTheme slot now
+            // to allow instant theme changes.
             break;
         case Language:
             if (settings.value("language") != value) {

src/qt/rpcconsole.cpp

@@ -1263,6 +1263,16 @@ void RPCConsole::hideEvent(QHideEvent *event)
     clientModel->getPeerTableModel()->stopAutoRefresh();
 }
 
+void RPCConsole::changeEvent(QEvent* e)
+{
+    if (e->type() == QEvent::StyleChange) {
+        clear();
+        ui->promptIcon->setHidden(GUIUtil::dashThemeActive());
+    }
+
+    QWidget::changeEvent(e);
+}
+
 void RPCConsole::showPeersTableContextMenu(const QPoint& point)
 {
     QModelIndex index = ui->peerWidget->indexAt(point);

src/qt/rpcconsole.h

@@ -79,6 +79,7 @@ private Q_SLOTS:
     void resizeEvent(QResizeEvent *event);
     void showEvent(QShowEvent *event);
     void hideEvent(QHideEvent *event);
+    void changeEvent(QEvent* e);
     /** Show custom context menu on Peers tab */
     void showPeersTableContextMenu(const QPoint& point);
     /** Show custom context menu on Bans tab */

src/qt/utilitydialog.cpp

@@ -211,7 +211,7 @@ ShutdownWindow::ShutdownWindow(QWidget *parent, Qt::WindowFlags f):
 {
     setObjectName("ShutdownWindow");
 
-    GUIUtil::loadStyleSheet(this, false);
+    GUIUtil::loadStyleSheet(this);
 
     QVBoxLayout *layout = new QVBoxLayout();
     layout->addWidget(new QLabel(