Feature/panlock: add PanLock button to TitleBar

src/gui/MainWindow.cpp

@@ -3461,6 +3461,11 @@ MainWindow::MainWindow(QWidget* parent)
     // Overlay-menu antenna wiring is now per-pan in wirePanadapter() (#1260).
     // Antenna list and S-meter are now wired per-widget in onSliceAdded.
 
+    // ── Title bar: Pan Follow ────────────────────────────────────────────────
+    connect(m_titleBar, &TitleBar::panFollowToggled,
+            this, &MainWindow::setPanFollow);
+    if (m_titleBar->isPanFollowChecked()) setPanFollow(true);
+
     // ── Title bar: PC Audio, master volume, headphone volume ────────────────
     // The remote_audio_rx stream controls the radio's audio routing:
     // stream exists → audio to PC; stream removed → audio to radio speakers.
@@ -19059,4 +19064,52 @@ void MainWindow::onSpectrumReadyForSHistory(quint32 streamId, const QVector<floa
     }
 }
 
+// ─── Pan Follow ───────────────────────────────────────────────────────────────
+
+void MainWindow::setPanFollow(bool on)
+{
+    disconnect(m_panFollowConn);
+    disconnect(m_panFollowSliceConn);
+
+    if (!on) return;
+
+    // Re-attach helper: wires frequency tracking to whichever slice 0
+    // is currently live. Called on activation and whenever slice 0 is
+    // recreated (radio reconnect, slice re-assignment, etc.).
+    auto attachToSlice0 = [this]() {
+        disconnect(m_panFollowConn);
+
+        auto* s = m_radioModel.slice(0);
+        if (!s) {
+            // No slice yet — uncheck the button so UI matches reality.
+            if (m_titleBar) m_titleBar->setPanFollowChecked(false);
+            return;
+        }
+
+        auto centerPan = [this, s]() {
+            const QString panId = s->panId();
+            if (panId.isEmpty()) return;
+            const double freq = s->frequency();
+            auto* pan = m_radioModel.panadapter(panId);
+            if (pan && qFuzzyCompare(pan->centerMhz(), freq)) return;
+            const QString freqStr = QString::number(freq, 'f', 6);
+            if (pan) pan->applyPanStatus({{"center", freqStr}});
+            m_radioModel.sendCommand(
+                QString("display pan set %1 center=%2").arg(panId, freqStr));
+        };
+
+        centerPan();
+        m_panFollowConn = connect(s, &SliceModel::frequencyChanged,
+                                  this, [centerPan](double) { centerPan(); });
+    };
+
+    attachToSlice0();
+
+    // Re-attach whenever a new slice 0 appears (reconnect / re-assignment).
+    m_panFollowSliceConn = connect(&m_radioModel, &RadioModel::sliceAdded,
+        this, [this, attachToSlice0](SliceModel* s) {
+            if (s && s->sliceId() == 0) attachToSlice0();
+        });
+}
+
 } // namespace AetherSDR

src/gui/MainWindow.h

@@ -924,6 +924,11 @@ private slots:
     void onFdvMetersChanged();
 #endif
 
+    // Pan Follow — keeps the panadapter centered on Slice A frequency
+    QMetaObject::Connection m_panFollowConn;
+    QMetaObject::Connection m_panFollowSliceConn;
+    void setPanFollow(bool on);
+
 #if defined(Q_OS_MAC) || defined(HAVE_PIPEWIRE)
     DaxBridge* m_daxBridge{nullptr};
     QString m_savedMicSelection;  // restore on stopDax

src/gui/TitleBar.cpp

@@ -11,6 +11,7 @@
 #include <QMouseEvent>
 #include <QPointer>
 #include <QPushButton>
+#include <QSignalBlocker>
 #include <QSizePolicy>
 #include <QSlider>
 #include <QLabel>
@@ -219,6 +220,38 @@ TitleBar::TitleBar(QWidget* parent)
     // ── PC Audio + Master Vol + HP Vol ──────────────────────────────────────
     auto& s = AppSettings::instance();
 
+    // Pan Follow toggle — keeps the panadapter centered on Slice A frequency
+    m_panFollowBtn = new QPushButton("Pan Lock");
+    m_panFollowBtn->setCheckable(true);
+    bool panLockOn = s.value("PanLockEnabled", "False").toString() == "True";
+    m_panFollowBtn->setChecked(panLockOn);
+    m_panFollowBtn->setFixedHeight(22);
+    m_panFollowBtn->setFixedWidth(70);
+    m_panFollowBtn->setAccessibleName("Pan follow slice");
+    m_panFollowBtn->setAccessibleDescription("Keep panadapter centered on Slice A frequency");
+    m_panFollowBtn->setToolTip("Pan Lock — keeps the panadapter centered on Slice A frequency (e.g. for Doppler tracking)");
+
+    auto updatePanFollowStyle = [this]() {
+        m_panFollowBtn->setStyleSheet(m_panFollowBtn->isChecked()
+            ? "QPushButton { background: #1e4a8a; color: #b0e8ff; border: 1px solid #4090d0; "
+              "border-radius: 3px; font-size: 10px; font-weight: bold; }"
+              "QPushButton:hover { background: #2558a0; }"
+            : "QPushButton { background: #1a2a3a; color: #607080; border: 1px solid #304050; "
+              "border-radius: 3px; font-size: 10px; font-weight: bold; }"
+              "QPushButton:hover { background: #243848; }");
+    };
+    updatePanFollowStyle();
+
+    connect(m_panFollowBtn, &QPushButton::toggled, this, [this, updatePanFollowStyle](bool on) {
+        updatePanFollowStyle();
+        auto& ss = AppSettings::instance();
+        ss.setValue("PanLockEnabled", on ? "True" : "False");
+        ss.save();
+        emit panFollowToggled(on);
+    });
+    m_hbox->addWidget(m_panFollowBtn);
+    m_hbox->addSpacing(4);
+
     // PC Audio toggle
     m_pcBtn = new QPushButton("PC Audio");
     m_pcBtn->setCheckable(true);
@@ -459,6 +492,18 @@ bool TitleBar::isDragHandle(QObject* obj) const
     return obj && obj->property(kTitleDragHandleProperty).toBool();
 }
 
+bool TitleBar::isPanFollowChecked() const
+{
+    return m_panFollowBtn && m_panFollowBtn->isChecked();
+}
+
+void TitleBar::setPanFollowChecked(bool on)
+{
+    if (!m_panFollowBtn) return;
+    QSignalBlocker block(m_panFollowBtn);
+    m_panFollowBtn->setChecked(on);
+}
+
 bool TitleBar::isSystemMoveAreaAt(const QPoint& globalPos) const
 {
     const QPoint localPos = mapFromGlobal(globalPos);

src/gui/TitleBar.h

@@ -51,7 +51,13 @@ class TitleBar : public QWidget {
     // as caption drag zones while keeping controls interactive.
     bool isSystemMoveAreaAt(const QPoint& globalPos) const;
 
+    // Pan Lock accessors. Out-of-line so the header doesn't need to pull in
+    // <QPushButton>; defined alongside the button's setup in TitleBar.cpp.
+    bool isPanFollowChecked() const;
+    void setPanFollowChecked(bool on);
+
 signals:
+    void panFollowToggled(bool on);
     void pcAudioToggled(bool on);
     void masterVolumeChanged(int pct);
     void headphoneVolumeChanged(int pct);
@@ -87,6 +93,7 @@ class TitleBar : public QWidget {
     QLabel*      m_appNameLabel{nullptr};
     QLabel*      m_otherTxLabel{nullptr};
     QPushButton* m_mfBtn{nullptr};
+    QPushButton* m_panFollowBtn{nullptr};
     QPushButton* m_pcBtn{nullptr};
     QPushButton* m_speakerBtn{nullptr};
     QPushButton* m_headphoneBtn{nullptr};