fix: hover invisible when theme.hover == background, remove CSS on QMenuBar

Move hover color fixup into Theme::fromJson so all consumers get a
visible hover automatically. Remove duplicate lighter(130) fallback
from applyGlobalTheme. Replace QMenuBar CSS with QPalette so
MenuBarStyle QProxyStyle is not bypassed. Add PE_PanelMenuBar and
CE_MenuBarEmptyArea suppression so Fusion never paints over the
title bar background.

src/main.cpp

@@ -251,6 +251,9 @@ public:
         // Kill the 1px frame margin Fusion reserves around QMenu contents
         if (metric == PM_MenuPanelWidth)
             return 0;
+        // Kill the separator between dock widgets / central widget
+        if (metric == PM_DockWidgetSeparatorExtent)
+            return 0;
         return QProxyStyle::pixelMetric(metric, opt, w);
     }
     void drawPrimitive(PrimitiveElement elem, const QStyleOption* opt,
@@ -261,18 +264,28 @@ public:
         // Kill the status bar item frame and panel border
         if (elem == PE_FrameStatusBarItem || elem == PE_PanelStatusBar)
             return;
+        // Transparent menu bar background (no CSS needed)
+        if (elem == PE_PanelMenuBar)
+            return;
         QProxyStyle::drawPrimitive(elem, opt, p, w);
     }
     void drawControl(ControlElement element, const QStyleOption* opt,
                      QPainter* p, const QWidget* w) const override {
-        // Menu bar items (File, Edit, View…) — direct paint, Fusion ignores palette
+        // Suppress Fusion's CE_MenuBarEmptyArea — it fills with palette.window()
+        // bypassing PE_PanelMenuBar.  TitleBarWidget paints the background.
+        if (element == CE_MenuBarEmptyArea)
+            return;
+        // Menu bar items (File, Edit, View…) — hover bg + amber text, no CSS
         if (element == CE_MenuBarItem) {
             if (auto* mi = qstyleoption_cast<const QStyleOptionMenuItem*>(opt)) {
                 if (mi->state & (State_Selected | State_Sunken)) {
+                    // Draw hover background
+                    p->fillRect(mi->rect, mi->palette.color(QPalette::Mid));
+                    // Draw text with amber color, no highlight state
                     QStyleOptionMenuItem patched = *mi;
                     patched.state &= ~(State_Selected | State_Sunken);
                     patched.palette.setColor(QPalette::ButtonText,
-                        mi->palette.color(QPalette::Link));          // amber text only
+                        mi->palette.color(QPalette::Link));          // amber text
                     QProxyStyle::drawControl(element, &patched, p, w);
                     return;
                 }
@@ -285,7 +298,7 @@ public:
                     && mi->menuItemType != QStyleOptionMenuItem::Separator) {
                     QStyleOptionMenuItem patched = *mi;
                     patched.palette.setColor(QPalette::Highlight,
-                        mi->palette.color(QPalette::Mid));           // theme.border
+                        mi->palette.color(QPalette::Mid));           // theme.hover
                     patched.palette.setColor(QPalette::HighlightedText,
                         mi->palette.color(QPalette::Link));          // theme.indHoverSpan
                     QProxyStyle::drawControl(element, &patched, p, w);
@@ -1352,8 +1365,7 @@ void MainWindow::toggleMcp() {
 void MainWindow::applyTheme(const Theme& theme) {
     applyGlobalTheme(theme);
 
-    // Kill the 1px separator line between central widget and status bar
-    setStyleSheet("QMainWindow::separator { height: 0px; width: 0px; }");
+    // Separator killed via PM_DockWidgetSeparatorExtent in MenuBarStyle
 
     // Custom title bar
     m_titleBar->applyTheme(theme);
@@ -2280,8 +2292,16 @@ void MainWindow::populateSourceMenu() {
         {QStringLiteral("reclass.netcompatlayer"), QStringLiteral(":/vsicons/plug.svg")},
     };
 
-    m_sourceMenu->addAction(QIcon(QStringLiteral(":/vsicons/file-binary.svg")),
-                            QStringLiteral("File"), this, [this]() {
+    auto addSourceAction = [this](const QString& text, const QIcon& icon, auto&& slot) {
+        auto* act = m_sourceMenu->addAction(icon, text);
+        act->setIconVisibleInMenu(true);
+        connect(act, &QAction::triggered, this, std::forward<decltype(slot)>(slot));
+        return act;
+    };
+
+    addSourceAction(QStringLiteral("File"),
+                    makeIcon(QStringLiteral(":/vsicons/file-binary.svg")),
+                    [this]() {
         if (auto* c = activeController()) c->selectSource(QStringLiteral("File"));
     });
 
@@ -2289,14 +2309,14 @@ void MainWindow::populateSourceMenu() {
     for (const auto& prov : providers) {
         QString name = prov.name;
         auto it = s_providerIcons.constFind(prov.identifier);
-        QIcon icon(it != s_providerIcons.constEnd() ? *it
-                                                     : QStringLiteral(":/vsicons/extensions.svg"));
+        QIcon icon = makeIcon(it != s_providerIcons.constEnd() ? *it
+                              : QStringLiteral(":/vsicons/extensions.svg"));
 
         QString label = prov.dllFileName.isEmpty()
             ? name
             : QStringLiteral("%1  (%2)").arg(name, prov.dllFileName);
 
-        m_sourceMenu->addAction(icon, label, this, [this, name]() {
+        addSourceAction(label, icon, [this, name]() {
             if (auto* c = activeController()) c->selectSource(name);
         });
     }
@@ -2306,18 +2326,20 @@ void MainWindow::populateSourceMenu() {
         for (int i = 0; i < ctrl->savedSources().size(); i++) {
             const auto& e = ctrl->savedSources()[i];
             auto* act = m_sourceMenu->addAction(
-                QStringLiteral("%1 '%2'").arg(e.kind, e.displayName),
-                this, [this, i]() {
-                    if (auto* c = activeController()) c->switchSource(i);
-                });
+                QStringLiteral("%1 '%2'").arg(e.kind, e.displayName));
             act->setCheckable(true);
             act->setChecked(i == ctrl->activeSourceIndex());
+            connect(act, &QAction::triggered, this, [this, i]() {
+                if (auto* c = activeController()) c->switchSource(i);
+            });
         }
         m_sourceMenu->addSeparator();
-        m_sourceMenu->addAction(QIcon(QStringLiteral(":/vsicons/clear-all.svg")),
-                                QStringLiteral("Clear All"), this, [this]() {
+        auto* clearAct = addSourceAction(QStringLiteral("Clear All"),
+                        makeIcon(QStringLiteral(":/vsicons/clear-all.svg")),
+                        [this]() {
             if (auto* c = activeController()) c->clearSources();
         });
+        Q_UNUSED(clearAct);
     }
 }
 

src/themes/theme.cpp

@@ -1,4 +1,5 @@
 #include "theme.h"
+#include <QtGlobal>
 #include <type_traits>
 
 namespace rcx {
@@ -61,6 +62,15 @@ Theme Theme::fromJson(const QJsonObject& o) {
         t.indHeatWarm = t.indHoverSpan.isValid() ? t.indHoverSpan : t.syntaxString;
     if (!t.indHeatHot.isValid())
         t.indHeatHot = t.markerPtr;
+
+    // Ensure hover is visually distinct from background
+    if (t.hover.isValid() && t.background.isValid()) {
+        int dist = qAbs(t.hover.red() - t.background.red())
+                 + qAbs(t.hover.green() - t.background.green())
+                 + qAbs(t.hover.blue() - t.background.blue());
+        if (dist < 20)
+            t.hover = t.background.lighter(130);
+    }
     return t;
 }
 

src/titlebar.cpp

@@ -76,14 +76,16 @@ void TitleBarWidget::applyTheme(const Theme& theme) {
         QStringLiteral("QLabel { color: %1; font-size: 12px; font-weight: bold; }")
             .arg(theme.textDim.name()));
 
-    // Menu bar styling — transparent background, themed text
-    m_menuBar->setStyleSheet(
-        QStringLiteral(
-            "QMenuBar { background: transparent; border: none; }"
-            "QMenuBar::item { background: transparent; color: %1; padding: 8px 8px 4px 8px; }"
-            "QMenuBar::item:selected { background: %2; }"
-            "QMenuBar::item:pressed { background: %2; }")
-            .arg(theme.textDim.name(), theme.hover.name()));
+    // Menu bar palette — hover/bg handled by MenuBarStyle QProxyStyle.
+    // Set Window + Button to background so Fusion never paints a foreign color.
+    {
+        QPalette mbPal = m_menuBar->palette();
+        mbPal.setColor(QPalette::Window, theme.background);
+        mbPal.setColor(QPalette::Button, theme.background);
+        mbPal.setColor(QPalette::ButtonText, theme.textDim);
+        m_menuBar->setPalette(mbPal);
+        m_menuBar->setAutoFillBackground(false);
+    }
 
     // Chrome buttons
     QString btnStyle = QStringLiteral(

tools/test_hover.py

@@ -0,0 +1,159 @@
+"""
+Structural hover test: validate that all themes produce visible hover colors
+and that the QProxyStyle code handles the required control elements.
+
+No pixel sampling — checks theme JSON values and source code patterns.
+"""
+import json
+import os
+import re
+import sys
+
+
+def hex_to_rgb(h):
+    h = h.lstrip('#')
+    return tuple(int(h[i:i+2], 16) for i in (0, 2, 4))
+
+
+def color_dist(c1, c2):
+    return sum(abs(a - b) for a, b in zip(c1, c2))
+
+
+def lighter_130(rgb):
+    """Approximate Qt's QColor::lighter(130) for dark grays."""
+    r, g, b = rgb
+    return (min(255, int(r * 1.3) + 1),
+            min(255, int(g * 1.3) + 1),
+            min(255, int(b * 1.3) + 1))
+
+
+def load_themes():
+    themes = {}
+    theme_dir = os.path.join(os.path.dirname(__file__),
+                             '..', 'src', 'themes', 'defaults')
+    if not os.path.isdir(theme_dir):
+        return themes
+    for name in os.listdir(theme_dir):
+        if name.endswith('.json'):
+            with open(os.path.join(theme_dir, name)) as f:
+                themes[name] = json.load(f)
+    return themes
+
+
+def test_hover_visibility(themes):
+    """Every theme must have hover visually distinct from background.
+    If raw values are identical, Theme::fromJson applies lighter(130)."""
+    ok = True
+    for name, data in sorted(themes.items()):
+        bg = hex_to_rgb(data['background'])
+        hover = hex_to_rgb(data['hover'])
+        dist = color_dist(bg, hover)
+
+        if dist < 20:
+            # fromJson will fix this — verify the fix produces sufficient contrast
+            fixed = lighter_130(bg)
+            fixed_dist = color_dist(bg, fixed)
+            if fixed_dist < 15:
+                print(f"  FAIL: {name}: hover==bg and lighter(130) still too close "
+                      f"(dist={fixed_dist})")
+                ok = False
+            else:
+                print(f"  OK:   {name}: hover==bg, fromJson fixup -> "
+                      f"dist {dist}->{fixed_dist}")
+        else:
+            print(f"  OK:   {name}: hover distinct (dist={dist})")
+    return ok
+
+
+def test_proxystyle_handlers():
+    """Verify MenuBarStyle handles CE_MenuBarItem, CE_MenuItem, CE_MenuBarEmptyArea."""
+    src = os.path.join(os.path.dirname(__file__), '..', 'src', 'main.cpp')
+    with open(src) as f:
+        code = f.read()
+
+    required = {
+        'CE_MenuBarItem':      r'element\s*==\s*CE_MenuBarItem',
+        'CE_MenuItem':         r'element\s*==\s*CE_MenuItem',
+        'CE_MenuBarEmptyArea': r'element\s*==\s*CE_MenuBarEmptyArea',
+        'State_Selected':      r'State_Selected',
+        'QPalette::Mid':       r'QPalette::Mid',
+    }
+
+    ok = True
+    for label, pattern in required.items():
+        if re.search(pattern, code):
+            print(f"  OK:   MenuBarStyle handles {label}")
+        else:
+            print(f"  FAIL: MenuBarStyle missing {label}")
+            ok = False
+    return ok
+
+
+def test_no_menubar_css():
+    """Verify no CSS stylesheet is set on QMenuBar (would bypass QProxyStyle)."""
+    src_dir = os.path.join(os.path.dirname(__file__), '..', 'src')
+    ok = True
+    for root, _, files in os.walk(src_dir):
+        for fname in files:
+            if not fname.endswith('.cpp'):
+                continue
+            path = os.path.join(root, fname)
+            with open(path, encoding='utf-8', errors='replace') as f:
+                for i, line in enumerate(f, 1):
+                    # Check for menuBar/m_menuBar stylesheet calls
+                    if ('menuBar' in line or 'm_menuBar' in line) and \
+                       'setStyleSheet' in line:
+                        print(f"  FAIL: CSS on QMenuBar at {fname}:{i}: "
+                              f"{line.strip()}")
+                        ok = False
+    if ok:
+        print("  OK:   No CSS on QMenuBar")
+    return ok
+
+
+def test_hover_fixup_in_fromjson():
+    """Verify Theme::fromJson applies the hover fixup."""
+    src = os.path.join(os.path.dirname(__file__),
+                       '..', 'src', 'themes', 'theme.cpp')
+    with open(src) as f:
+        code = f.read()
+
+    if 'lighter(130)' in code and 't.hover' in code:
+        print("  OK:   Theme::fromJson has hover fixup")
+        return True
+    else:
+        print("  FAIL: Theme::fromJson missing hover fixup")
+        return False
+
+
+def main():
+    themes = load_themes()
+    if not themes:
+        print("FAIL: No theme files found")
+        return 1
+
+    all_ok = True
+
+    print("--- Test 1: Hover visibility across themes ---")
+    all_ok &= test_hover_visibility(themes)
+
+    print("\n--- Test 2: QProxyStyle handles required elements ---")
+    all_ok &= test_proxystyle_handlers()
+
+    print("\n--- Test 3: No CSS on QMenuBar ---")
+    all_ok &= test_no_menubar_css()
+
+    print("\n--- Test 4: Theme::fromJson hover fixup ---")
+    all_ok &= test_hover_fixup_in_fromjson()
+
+    print(f"\n{'='*50}")
+    if all_ok:
+        print("ALL HOVER TESTS PASSED")
+        return 0
+    else:
+        print("SOME HOVER TESTS FAILED")
+        return 1
+
+
+if __name__ == '__main__':
+    sys.exit(main())