18 files changed, 386 insertions, 313 deletions

diff --git a/src/engine/controls/bpmcontrol.cpp b/src/engine/controls/bpmcontrol.cpp
index 20285ca89f..52370da16d 100644
--- a/src/engine/controls/bpmcontrol.cpp
+++ b/src/engine/controls/bpmcontrol.cpp
@@ -40,7 +40,7 @@ constexpr int kLocalBpmSpan = 4;
 constexpr SINT kSamplesPerFrame = 2;
 }
 
-BpmControl::BpmControl(QString group,
+BpmControl::BpmControl(const QString& group,
         UserSettingsPointer pConfig)
         : EngineControl(group, pConfig),
           m_tapFilter(this, kBpmTapFilterLength, kBpmTapMaxInterval),
diff --git a/src/engine/controls/bpmcontrol.h b/src/engine/controls/bpmcontrol.h
index 4257595dc5..156fdca700 100644
--- a/src/engine/controls/bpmcontrol.h
+++ b/src/engine/controls/bpmcontrol.h
@@ -22,7 +22,7 @@ class BpmControl : public EngineControl {
     Q_OBJECT
 
   public:
-    BpmControl(QString group, UserSettingsPointer pConfig);
+    BpmControl(const QString& group, UserSettingsPointer pConfig);
     ~BpmControl() override;
 
     double getBpm() const;
diff --git a/src/engine/controls/clockcontrol.cpp b/src/engine/controls/clockcontrol.cpp
index 2a374aa1b4..f48660bb4c 100644
--- a/src/engine/controls/clockcontrol.cpp
+++ b/src/engine/controls/clockcontrol.cpp
@@ -6,7 +6,7 @@
 #include "preferences/usersettings.h"
 #include "track/track.h"
 
-ClockControl::ClockControl(QString group, UserSettingsPointer pConfig)
+ClockControl::ClockControl(const QString& group, UserSettingsPointer pConfig)
         : EngineControl(group, pConfig) {
     m_pCOBeatActive = new ControlObject(ConfigKey(group, "beat_active"));
     m_pCOBeatActive->set(0.0);
diff --git a/src/engine/controls/clockcontrol.h b/src/engine/controls/clockcontrol.h
index 1a26d30d8c..87667db443 100644
--- a/src/engine/controls/clockcontrol.h
+++ b/src/engine/controls/clockcontrol.h
@@ -11,8 +11,8 @@ class ControlObject;
 class ClockControl: public EngineControl {
     Q_OBJECT
   public:
-    ClockControl(QString group,
-                 UserSettingsPointer pConfig);
+    ClockControl(const QString& group,
+            UserSettingsPointer pConfig);
 
     ~ClockControl() override;
 
diff --git a/src/engine/controls/cuecontrol.cpp b/src/engine/controls/cuecontrol.cpp
index 3a92609105..f8ac0c8e20 100644
--- a/src/engine/controls/cuecontrol.cpp
+++ b/src/engine/controls/cuecontrol.cpp
@@ -26,6 +26,7 @@ constexpr double CUE_MODE_CUP = 5.0;
 
 /// This is the position of a fresh loaded tack without any seek
 constexpr double kDefaultLoadPosition = 0.0;
+constexpr int kNoHotCueNumber = 0;
 
 // Helper function to convert control values (i.e. doubles) into RgbColor
 // instances (or nullopt if value < 0). This happens by using the integer
@@ -41,9 +42,37 @@ inline mixxx::RgbColor::optional_t doubleToRgbColor(double value) {
     return mixxx::RgbColor::optional(colorCode);
 }
 
+/// Convert hot cue index to 1-based number
+///
+/// Works independent of if the hot cue index is either 0-based
+/// or 1..n-based.
+inline int hotcueIndexToHotcueNumber(int hotcueIndex) {
+    if (hotcueIndex >= Cue::kFirstHotCue) {
+        DEBUG_ASSERT(hotcueIndex != Cue::kNoHotCue);
+        return (hotcueIndex - Cue::kFirstHotCue) + 1; // to 1-based numbering
+    } else {
+        DEBUG_ASSERT(hotcueIndex == Cue::kNoHotCue);
+        return kNoHotCueNumber;
+    }
+}
+
+/// Convert 1-based hot cue number to hot cue index.
+///
+/// Works independent of if the hot cue index is either 0-based
+/// or 1..n-based.
+inline int hotcueNumberToHotcueIndex(int hotcueNumber) {
+    if (hotcueNumber >= 1) {
+        DEBUG_ASSERT(hotcueNumber != kNoHotCueNumber);
+        return Cue::kFirstHotCue + (hotcueNumber - 1); // from 1-based numbering
+    } else {
+        DEBUG_ASSERT(hotcueNumber == kNoHotCueNumber);
+        return Cue::kNoHotCue;
+    }
+}
+
 } // namespace
 
-CueControl::CueControl(QString group,
+CueControl::CueControl(const QString& group,
         UserSettingsPointer pConfig)
         : EngineControl(group, pConfig),
           m_pConfig(pConfig),
@@ -132,6 +161,9 @@ CueControl::CueControl(QString group,
     m_pCueIndicator = new ControlIndicator(ConfigKey(group, "cue_indicator"));
     m_pPlayIndicator = new ControlIndicator(ConfigKey(group, "play_indicator"));
 
+    m_pPlayLatched = new ControlObject(ConfigKey(group, "play_latched"));
+    m_pPlayLatched->setReadOnly();
+
     m_pIntroStartPosition = new ControlObject(ConfigKey(group, "intro_start_position"));
     m_pIntroStartPosition->set(Cue::kNoPosition);
 
@@ -220,7 +252,7 @@ CueControl::CueControl(QString group,
     m_pVinylControlMode = new ControlProxy(group, "vinylcontrol_mode");
 
     m_pHotcueFocus = new ControlObject(ConfigKey(group, "hotcue_focus"));
-    m_pHotcueFocus->set(Cue::kNoHotCue);
+    setHotcueFocusIndex(Cue::kNoHotCue);
 
     m_pHotcueFocusColorPrev = new ControlObject(ConfigKey(group, "hotcue_focus_color_prev"));
     connect(m_pHotcueFocusColorPrev,
@@ -252,6 +284,7 @@ CueControl::~CueControl() {
     delete m_pPlayStutter;
     delete m_pCueIndicator;
     delete m_pPlayIndicator;
+    delete m_pPlayLatched;
     delete m_pIntroStartPosition;
     delete m_pIntroStartEnabled;
     delete m_pIntroStartSet;
@@ -313,7 +346,7 @@ void CueControl::createControls() {
     }
 }
 
-void CueControl::attachCue(CuePointer pCue, HotcueControl* pControl) {
+void CueControl::attachCue(const CuePointer& pCue, HotcueControl* pControl) {
     VERIFY_OR_DEBUG_ASSERT(pControl) {
         return;
     }
@@ -355,7 +388,7 @@ void CueControl::trackLoaded(TrackPointer pNewTrack) {
         m_pOutroStartEnabled->forceSet(0.0);
         m_pOutroEndPosition->set(Cue::kNoPosition);
         m_pOutroEndEnabled->forceSet(0.0);
-        m_pHotcueFocus->set(Cue::kNoHotCue);
+        setHotcueFocusIndex(Cue::kNoHotCue);
         m_pLoadedTrack.reset();
         m_usedSeekOnLoadPosition.setValue(kDefaultLoadPosition);
     }
@@ -644,15 +677,16 @@ void CueControl::quantizeChanged(double v) {
 void CueControl::hotcueSet(HotcueControl* pControl, double value) {
     //qDebug() << "CueControl::hotcueSet" << value;
 
-    if (value == 0) {
+    if (value <= 0) {
         return;
     }
 
     QMutexLocker lock(&m_mutex);
-    if (!m_pLoadedTrack)
+    if (!m_pLoadedTrack) {
         return;
+    }
 
-    int hotcue = pControl->getHotcueNumber();
+    int hotcueIndex = pControl->getHotcueIndex();
     // Note: the cue is just detached from the hotcue control
     // It remains in the database for later use
     // TODO: find a rule, that allows us to delete the cue as well
@@ -662,14 +696,14 @@ void CueControl::hotcueSet(HotcueControl* pControl, double value) {
     CuePointer pCue(m_pLoadedTrack->createAndAddCue());
     double cuePosition = getQuantizedCurrentPosition();
     pCue->setStartPosition(cuePosition);
-    pCue->setHotCue(hotcue);
+    pCue->setHotCue(hotcueIndex);
     pCue->setLabel();
     pCue->setType(mixxx::CueType::HotCue);
 
     const ColorPalette hotcueColorPalette =
             m_colorPaletteSettings.getHotcueColorPalette();
     if (getConfig()->getValue(ConfigKey("[Controls]", "auto_hotcue_colors"), false)) {
-        pCue->setColor(hotcueColorPalette.colorForHotcueIndex(hotcue));
+        pCue->setColor(hotcueColorPalette.colorForHotcueIndex(hotcueIndex));
     } else {
         int hotcueDefaultColorIndex = m_pConfig->getValue(ConfigKey("[Controls]", "HotcueDefaultColorIndex"), -1);
         if (hotcueDefaultColorIndex < 0 || hotcueDefaultColorIndex >= hotcueColorPalette.size()) {
@@ -693,7 +727,7 @@ void CueControl::hotcueSet(HotcueControl* pControl, double value) {
 }
 
 void CueControl::hotcueGoto(HotcueControl* pControl, double value) {
-    if (value == 0) {
+    if (value <= 0) {
         return;
     }
 
@@ -716,7 +750,7 @@ void CueControl::hotcueGoto(HotcueControl* pControl, double value) {
 }
 
 void CueControl::hotcueGotoAndStop(HotcueControl* pControl, double value) {
-    if (value == 0) {
+    if (value <= 0) {
         return;
     }
 
@@ -732,14 +766,19 @@ void CueControl::hotcueGotoAndStop(HotcueControl* pControl, double value) {
     if (pCue) {
         double position = pCue->getPosition();
         if (position != Cue::kNoPosition) {
-            m_pPlay->set(0.0);
-            seekExact(position);
+            if (!m_iCurrentlyPreviewingHotcues && !m_bPreviewing) {
+                m_pPlay->set(0.0);
+                seekExact(position);
+            } else {
+                // this becomes a play latch command if we are previewing
+                m_pPlay->set(0.0);
+            }
         }
     }
 }
 
 void CueControl::hotcueGotoAndPlay(HotcueControl* pControl, double value) {
-    if (value == 0) {
+    if (value <= 0) {
         return;
     }
 
@@ -784,7 +823,7 @@ void CueControl::hotcueActivate(HotcueControl* pControl, double value) {
     lock.unlock();
 
     if (pCue) {
-        if (value != 0) {
+        if (value > 0) {
             if (pCue->getPosition() == Cue::kNoPosition) {
                 hotcueSet(pControl, value);
             } else {
@@ -801,7 +840,7 @@ void CueControl::hotcueActivate(HotcueControl* pControl, double value) {
         }
     } else {
         // The cue is non-existent ...
-        if (value != 0) {
+        if (value > 0) {
             // set it to the current position
             hotcueSet(pControl, value);
         } else if (m_iCurrentlyPreviewingHotcues) {
@@ -813,7 +852,7 @@ void CueControl::hotcueActivate(HotcueControl* pControl, double value) {
         }
     }
 
-    m_pHotcueFocus->set(pControl->getHotcueNumber());
+    setHotcueFocusIndex(pControl->getHotcueIndex());
 }
 
 void CueControl::hotcueActivatePreview(HotcueControl* pControl, double value) {
@@ -823,8 +862,8 @@ void CueControl::hotcueActivatePreview(HotcueControl* pControl, double value) {
     }
     CuePointer pCue(pControl->getCue());
 
-    if (value != 0) {
-        if (pCue && pCue->getPosition() != Cue::kNoPosition) {
+    if (value > 0) {
+        if (pCue && pCue->getPosition() != Cue::kNoPosition && !pControl->isPreviewing()) {
             m_iCurrentlyPreviewingHotcues++;
             double position = pCue->getPosition();
             m_bypassCueSetByPlay = true;
@@ -858,7 +897,7 @@ void CueControl::hotcueActivatePreview(HotcueControl* pControl, double value) {
 }
 
 void CueControl::hotcueClear(HotcueControl* pControl, double value) {
-    if (value == 0) {
+    if (value <= 0) {
         return;
     }
 
@@ -873,7 +912,7 @@ void CueControl::hotcueClear(HotcueControl* pControl, double value) {
     }
     detachCue(pControl);
     m_pLoadedTrack->removeCue(pCue);
-    m_pHotcueFocus->set(Cue::kNoHotCue);
+    setHotcueFocusIndex(Cue::kNoHotCue);
 }
 
 void CueControl::hotcuePositionChanged(HotcueControl* pControl, double newPosition) {
@@ -919,7 +958,7 @@ void CueControl::hintReader(HintVector* pHintList) {
 // Moves the cue point to current position or to closest beat in case
 // quantize is enabled
 void CueControl::cueSet(double value) {
-    if (value == 0) {
+    if (value <= 0) {
         return;
     }
 
@@ -937,7 +976,7 @@ void CueControl::cueSet(double value) {
 }
 
 void CueControl::cueClear(double value) {
-    if (value == 0) {
+    if (value <= 0) {
         return;
     }
 
@@ -952,7 +991,7 @@ void CueControl::cueClear(double value) {
 }
 
 void CueControl::cueGoto(double value) {
-    if (value == 0) {
+    if (value <= 0) {
         return;
     }
 
@@ -967,7 +1006,7 @@ void CueControl::cueGoto(double value) {
 }
 
 void CueControl::cueGotoAndPlay(double value) {
-    if (value == 0) {
+    if (value <= 0) {
         return;
     }
 
@@ -985,27 +1024,30 @@ void CueControl::cueGotoAndPlay(double value) {
 }
 
 void CueControl::cueGotoAndStop(double value) {
-    if (value == 0) {
+    if (value <= 0) {
         return;
     }
 
-    QMutexLocker lock(&m_mutex);
-    m_pPlay->set(0.0);
-    double cuePoint = m_pCuePoint->get();
-
-    // Need to unlock before emitting any signals to prevent deadlock.
-    lock.unlock();
-
-    seekExact(cuePoint);
+    if (!m_iCurrentlyPreviewingHotcues && !m_bPreviewing) {
+        m_pPlay->set(0.0);
+        double position = m_pCuePoint->get();
+        seekExact(position);
+    } else {
+        // this becomes a play latch command if we are previewing
+        m_pPlay->set(0.0);
+    }
 }
 
 void CueControl::cuePreview(double value) {
+    //qDebug() << "CueControl::cuePreview" << value;
     QMutexLocker lock(&m_mutex);
 
-    if (value != 0) {
-        m_bPreviewing = true;
-        m_bypassCueSetByPlay = true;
-        m_pPlay->set(1.0);
+    if (value > 0) {
+        if (!m_bPreviewing) {
+            m_bPreviewing = true;
+            m_bypassCueSetByPlay = true;
+            m_pPlay->set(1.0);
+        }
     } else if (m_bPreviewing) {
         m_bPreviewing = false;
         if (m_iCurrentlyPreviewingHotcues) {
@@ -1033,8 +1075,11 @@ void CueControl::cueCDJ(double value) {
     const auto freely_playing = m_pPlay->toBool() && !getEngineBuffer()->getScratching();
     TrackAt trackAt = getTrackAt();
 
-    if (value != 0) {
-        if (m_iCurrentlyPreviewingHotcues) {
+    if (value > 0) {
+        if (m_bPreviewing) {
+            // already previewing, do nothing
+            return;
+        } else if (m_iCurrentlyPreviewingHotcues) {
             // we are already previewing by hotcues
             // just jump to cue point and continue previewing
             m_bPreviewing = true;
@@ -1058,9 +1103,6 @@ void CueControl::cueCDJ(double value) {
         } else {
             // Pause not at cue point and not at end position
             cueSet(value);
-            // Just in case.
-            m_bPreviewing = false;
-            m_pPlay->set(0.0);
 
             // If quantize is enabled, jump to the cue point since it's not
             // necessarily where we currently are
@@ -1100,8 +1142,11 @@ void CueControl::cueDenon(double value) {
     bool playing = (m_pPlay->toBool());
     TrackAt trackAt = getTrackAt();
 
-    if (value != 0) {
-        if (m_iCurrentlyPreviewingHotcues) {
+    if (value > 0) {
+        if (m_bPreviewing) {
+            // already previewing, do nothing
+            return;
+        } else if (m_iCurrentlyPreviewingHotcues) {
             // we are already previewing by hotcues
             // just jump to cue point and continue previewing
             m_bPreviewing = true;
@@ -1112,13 +1157,8 @@ void CueControl::cueDenon(double value) {
             m_bPreviewing = true;
             m_pPlay->set(1.0);
         } else {
-            // Just in case.
-            m_bPreviewing = false;
-            m_pPlay->set(0.0);
-
             // Need to unlock before emitting any signals to prevent deadlock.
             lock.unlock();
-
             seekAbs(m_pCuePoint->get());
         }
     } else if (m_bPreviewing) {
@@ -1146,7 +1186,7 @@ void CueControl::cuePlay(double value) {
     TrackAt trackAt = getTrackAt();
 
     // pressed
-    if (value != 0) {
+    if (value > 0) {
         if (freely_playing) {
             m_bPreviewing = false;
             m_pPlay->set(0.0);
@@ -1212,7 +1252,7 @@ void CueControl::playStutter(double v) {
 }
 
 void CueControl::introStartSet(double value) {
-    if (value == 0) {
+    if (value <= 0) {
         return;
     }
 
@@ -1253,7 +1293,7 @@ void CueControl::introStartSet(double value) {
 }
 
 void CueControl::introStartClear(double value) {
-    if (value == 0) {
+    if (value <= 0) {
         return;
     }
 
@@ -1290,7 +1330,7 @@ void CueControl::introStartActivate(double value) {
 }
 
 void CueControl::introEndSet(double value) {
-    if (value == 0) {
+    if (value <= 0) {
         return;
     }
 
@@ -1331,7 +1371,7 @@ void CueControl::introEndSet(double value) {
 }
 
 void CueControl::introEndClear(double value) {
-    if (value == 0) {
+    if (value <= 0) {
         return;
     }
 
@@ -1368,7 +1408,7 @@ void CueControl::introEndActivate(double value) {
 }
 
 void CueControl::outroStartSet(double value) {
-    if (value == 0) {
+    if (value <= 0) {
         return;
     }
 
@@ -1409,7 +1449,7 @@ void CueControl::outroStartSet(double value) {
 }
 
 void CueControl::outroStartClear(double value) {
-    if (value == 0) {
+    if (value <= 0) {
         return;
     }
 
@@ -1430,7 +1470,7 @@ void CueControl::outroStartClear(double value) {
 }
 
 void CueControl::outroStartActivate(double value) {
-    if (value == 0) {
+    if (value <= 0) {
         return;
     }
 
@@ -1446,7 +1486,7 @@ void CueControl::outroStartActivate(double value) {
 }
 
 void CueControl::outroEndSet(double value) {
-    if (value == 0) {
+    if (value <= 0) {
         return;
     }
 
@@ -1487,7 +1527,7 @@ void CueControl::outroEndSet(double value) {
 }
 
 void CueControl::outroEndClear(double value) {
-    if (value == 0) {
+    if (value <= 0) {
         return;
     }
 
@@ -1508,7 +1548,7 @@ void CueControl::outroEndClear(double value) {
 }
 
 void CueControl::outroEndActivate(double value) {
-    if (value == 0) {
+    if (value <= 0) {
         return;
     }
 
@@ -1546,8 +1586,10 @@ bool CueControl::updateIndicatorsAndModifyPlay(bool newPlay, bool oldPlay, bool
             m_bPreviewing = false;
             m_iCurrentlyPreviewingHotcues = 0;
             newPlay = true;
+            m_pPlayLatched->forceSet(1.0);
         } else {
             previewing = true;
+            m_pPlayLatched->forceSet(0.0);
         }
     }
 
@@ -1558,13 +1600,16 @@ bool CueControl::updateIndicatorsAndModifyPlay(bool newPlay, bool oldPlay, bool
         newPlay = false;
         m_pPlayIndicator->setBlinkValue(ControlIndicator::OFF);
         m_pStopButton->set(0.0);
+        m_pPlayLatched->forceSet(0.0);
     } else if (newPlay && !previewing) {
         // Play: Indicates a latched Play
         m_pPlayIndicator->setBlinkValue(ControlIndicator::ON);
         m_pStopButton->set(0.0);
+        m_pPlayLatched->forceSet(1.0);
     } else {
         // Pause:
         m_pStopButton->set(1.0);
+        m_pPlayLatched->forceSet(0.0);
         if (cueMode == CueMode::Denon) {
             if (trackAt == TrackAt::Cue || previewing) {
                 m_pPlayIndicator->setBlinkValue(ControlIndicator::OFF);
@@ -1757,16 +1802,16 @@ SeekOnLoadMode CueControl::getSeekOnLoadPreference() {
 }
 
 void CueControl::hotcueFocusColorPrev(double value) {
-    if (value == 0) {
+    if (value <= 0) {
         return;
     }
 
-    int hotcueNumber = static_cast<int>(m_pHotcueFocus->get());
-    if (hotcueNumber < 0 || hotcueNumber >= m_hotcueControls.size()) {
+    int hotcueIndex = getHotcueFocusIndex();
+    if (hotcueIndex < 0 || hotcueIndex >= m_hotcueControls.size()) {
         return;
     }
 
-    HotcueControl* pControl = m_hotcueControls.at(hotcueNumber);
+    HotcueControl* pControl = m_hotcueControls.at(hotcueIndex);
     if (!pControl) {
         return;
     }
@@ -1786,16 +1831,16 @@ void CueControl::hotcueFocusColorPrev(double value) {
 }
 
 void CueControl::hotcueFocusColorNext(double value) {
-    if (value == 0) {
+    if (value <= 0) {
         return;
     }
 
-    int hotcueNumber = static_cast<int>(m_pHotcueFocus->get());
-    if (hotcueNumber < 0 || hotcueNumber >= m_hotcueControls.size()) {
+    int hotcueIndex = getHotcueFocusIndex();
+    if (hotcueIndex < 0 || hotcueIndex >= m_hotcueControls.size()) {
         return;
     }
 
-    HotcueControl* pControl = m_hotcueControls.at(hotcueNumber);
+    HotcueControl* pControl = m_hotcueControls.at(hotcueIndex);
     if (!pControl) {
         return;
     }
@@ -1814,89 +1859,108 @@ void CueControl::hotcueFocusColorNext(double value) {
     pCue->setColor(colorPalette.nextColor(*color));
 }
 
-ConfigKey HotcueControl::keyForControl(int hotcue, const char* name) {
+void CueControl::setHotcueFocusIndex(int hotcueIndex) {
+    m_pHotcueFocus->set(hotcueIndexToHotcueNumber(hotcueIndex));
+}
+
+int CueControl::getHotcueFocusIndex() const {
+    return hotcueNumberToHotcueIndex(static_cast<int>(m_pHotcueFocus->get()));
+}
+
+ConfigKey HotcueControl::keyForControl(const QString& name) {
     ConfigKey key;
     key.group = m_group;
     // Add one to hotcue so that we don't have a hotcue_0
-    key.item = QLatin1String("hotcue_") % QString::number(hotcue+1) % "_" % name;
+    key.item = QStringLiteral("hotcue_") +
+            QString::number(hotcueIndexToHotcueNumber(m_hotcueIndex)) +
+            QChar('_') + name;
     return key;
 }
 
-HotcueControl::HotcueControl(QString group, int i)
+HotcueControl::HotcueControl(const QString& group, int hotcueIndex)
         : m_group(group),
-          m_iHotcueNumber(i),
-          m_pCue(NULL),
+          m_hotcueIndex(hotcueIndex),
+          m_pCue(nullptr),
           m_bPreviewing(false),
           m_previewingPosition(-1) {
-    m_hotcuePosition = new ControlObject(keyForControl(i, "position"));
-    connect(m_hotcuePosition, &ControlObject::valueChanged,
-            this, &HotcueControl::slotHotcuePositionChanged,
+    m_hotcuePosition = std::make_unique<ControlObject>(keyForControl(QStringLiteral("position")));
+    connect(m_hotcuePosition.get(),
+            &ControlObject::valueChanged,
+            this,
+            &HotcueControl::slotHotcuePositionChanged,
             Qt::DirectConnection);
     m_hotcuePosition->set(Cue::kNoPosition);
 
-    m_hotcueEnabled = new ControlObject(keyForControl(i, "enabled"));
+    m_hotcueEnabled = std::make_unique<ControlObject>(keyForControl(QStringLiteral("enabled")));
     m_hotcueEnabled->setReadOnly();
 
     // The rgba value  of the color assigned to this color.
-    m_hotcueColor = new ControlObject(keyForControl(i, "color"));
+    m_hotcueColor = std::make_unique<ControlObject>(keyForControl(QStringLiteral("color")));
     m_hotcueColor->connectValueChangeRequest(
             this,
             &HotcueControl::slotHotcueColorChangeRequest,
             Qt::DirectConnection);
-    connect(m_hotcueColor,
+    connect(m_hotcueColor.get(),
             &ControlObject::valueChanged,
             this,
             &HotcueControl::slotHotcueColorChanged,
             Qt::DirectConnection);
 
-    m_hotcueSet = new ControlPushButton(keyForControl(i, "set"));
-    connect(m_hotcueSet, &ControlObject::valueChanged,
-            this, &HotcueControl::slotHotcueSet,
+    m_hotcueSet = std::make_unique<ControlPushButton>(keyForControl(QStringLiteral("set")));
+    connect(m_hotcueSet.get(),
+            &ControlObject::valueChanged,
+            this,
+            &HotcueControl::slotHotcueSet,
             Qt::DirectConnection);
 
-    m_hotcueGoto = new ControlPushButton(keyForControl(i, "goto"));
-    connect(m_hotcueGoto, &ControlObject::valueChanged,
-            this, &HotcueControl::slotHotcueGoto,
+    m_hotcueGoto = std::make_unique<ControlPushButton>(keyForControl(QStringLiteral("goto")));
+    connect(m_hotcueGoto.get(),
+            &ControlObject::valueChanged,
+            this,
+            &HotcueControl::slotHotcueGoto,
             Qt::DirectConnection);
 
-    m_hotcueGotoAndPlay = new ControlPushButton(keyForControl(i, "gotoandplay"));
-    connect(m_hotcueGotoAndPlay, &ControlObject::valueChanged,
-            this, &HotcueControl::slotHotcueGotoAndPlay,
+    m_hotcueGotoAndPlay = std::make_unique<ControlPushButton>(
+            keyForControl(QStringLiteral("gotoandplay")));
+    connect(m_hotcueGotoAndPlay.get(),
+            &ControlObject::valueChanged,
+            this,
+            &HotcueControl::slotHotcueGotoAndPlay,
             Qt::DirectConnection);
 
-    m_hotcueGotoAndStop = new ControlPushButton(keyForControl(i, "gotoandstop"));
-    connect(m_hotcueGotoAndStop, &ControlObject::valueChanged,
-            this, &HotcueControl::slotHotcueGotoAndStop,
+    m_hotcueGotoAndStop = std::make_unique<ControlPushButton>(
+            keyForControl(QStringLiteral("gotoandstop")));
+    connect(m_hotcueGotoAndStop.get(),
+            &ControlObject::valueChanged,
+            this,
+            &HotcueControl::slotHotcueGotoAndStop,
             Qt::DirectConnection);
 
-    m_hotcueActivate = new ControlPushButton(keyForControl(i, "activate"));
-    connect(m_hotcueActivate, &ControlObject::valueChanged,
-            this, &HotcueControl::slotHotcueActivate,
+    m_hotcueActivate = std::make_unique<ControlPushButton>(
+            keyForControl(QStringLiteral("activate")));
+    connect(m_hotcueActivate.get(),
+            &ControlObject::valueChanged,
+            this,
+            &HotcueControl::slotHotcueActivate,
             Qt::DirectConnection);
 
-    m_hotcueActivatePreview = new ControlPushButton(keyForControl(i, "activate_preview"));
-    connect(m_hotcueActivatePreview, &ControlObject::valueChanged,
-            this, &HotcueControl::slotHotcueActivatePreview,
+    m_hotcueActivatePreview = std::make_unique<ControlPushButton>(
+            keyForControl(QStringLiteral("activate_preview")));
+    connect(m_hotcueActivatePreview.get(),
+            &ControlObject::valueChanged,
+            this,
+            &HotcueControl::slotHotcueActivatePreview,
             Qt::DirectConnection);
 
-    m_hotcueClear = new ControlPushButton(keyForControl(i, "clear"));
-    connect(m_hotcueClear, &ControlObject::valueChanged,
-            this, &HotcueControl::slotHotcueClear,
+    m_hotcueClear = std::make_unique<ControlPushButton>(keyForControl(QStringLiteral("clear")));
+    connect(m_hotcueClear.get(),
+            &ControlObject::valueChanged,
+            this,
+            &HotcueControl::slotHotcueClear,
             Qt::DirectConnection);
 }
 
-HotcueControl::~HotcueControl() {
-    delete m_hotcuePosition;
-    delete m_hotcueEnabled;
-    delete m_hotcueColor;
-    delete m_hotcueSet;
-    delete m_hotcueGoto;
-    delete m_hotcueGotoAndPlay;
-    delete m_hotcueGotoAndStop;
-    delete m_hotcueActivate;
-    delete m_hotcueActivatePreview;
-    delete m_hotcueClear;
-}
+HotcueControl::~HotcueControl() = default;
 
 void HotcueControl::slotHotcueSet(double v) {
     emit hotcueSet(this, v);
@@ -1957,7 +2021,7 @@ double HotcueControl::getPosition() const {
     return m_hotcuePosition->get();
 }
 
-void HotcueControl::setCue(CuePointer pCue) {
+void HotcueControl::setCue(const CuePointer& pCue) {
     setPosition(pCue->getPosition());
     setColor(pCue->getColor());
     // set pCue only if all other data is in place
diff --git a/src/engine/controls/cuecontrol.h b/src/engine/controls/cuecontrol.h
index 8cd217569d..e71de0123a 100644
--- a/src/engine/controls/cuecontrol.h
+++ b/src/engine/controls/cuecontrol.h
@@ -39,29 +39,34 @@ inline SeekOnLoadMode seekOnLoadModeFromDouble(double value) {
 class HotcueControl : public QObject {
     Q_OBJECT
   public:
-    HotcueControl(QString group, int hotcueNumber);
+    HotcueControl(const QString& group, int hotcueIndex);
     ~HotcueControl() override;
 
-    inline int getHotcueNumber() { return m_iHotcueNumber; }
-    inline CuePointer getCue() { return m_pCue; }
+    int getHotcueIndex() const {
+        return m_hotcueIndex;
+    }
+
+    CuePointer getCue() const {
+        return m_pCue;
+    }
     double getPosition() const;
-    void setCue(CuePointer pCue);
+    void setCue(const CuePointer& pCue);
     void resetCue();
     void setPosition(double position);
     void setColor(mixxx::RgbColor::optional_t newColor);
     mixxx::RgbColor::optional_t getColor() const;
 
     // Used for caching the preview state of this hotcue control.
-    inline bool isPreviewing() {
+    bool isPreviewing() const {
         return m_bPreviewing;
     }
-    inline void setPreviewing(bool bPreviewing) {
+    void setPreviewing(bool bPreviewing) {
         m_bPreviewing = bPreviewing;
     }
-    inline double getPreviewingPosition() {
+    double getPreviewingPosition() const {
         return m_previewingPosition;
     }
-    inline void setPreviewingPosition(double position) {
+    void setPreviewingPosition(double position) {
         m_previewingPosition = position;
     }
 
@@ -90,24 +95,24 @@ class HotcueControl : public QObject {
     void hotcuePlay(double v);
 
   private:
-    ConfigKey keyForControl(int hotcue, const char* name);
+    ConfigKey keyForControl(const QString& name);
 
     const QString m_group;
-    int m_iHotcueNumber;
+    const int m_hotcueIndex;
     CuePointer m_pCue;
 
     // Hotcue state controls
-    ControlObject* m_hotcuePosition;
-    ControlObject* m_hotcueEnabled;
-    ControlObject* m_hotcueColor;
+    std::unique_ptr<ControlObject> m_hotcuePosition;
+    std::unique_ptr<ControlObject> m_hotcueEnabled;
+    std::unique_ptr<ControlObject> m_hotcueColor;
     // Hotcue button controls
-    ControlObject* m_hotcueSet;
-    ControlObject* m_hotcueGoto;
-    ControlObject* m_hotcueGotoAndPlay;
-    ControlObject* m_hotcueGotoAndStop;
-    ControlObject* m_hotcueActivate;
-    ControlObject* m_hotcueActivatePreview;
-    ControlObject* m_hotcueClear;
+    std::unique_ptr<ControlPushButton> m_hotcueSet;
+    std::unique_ptr<ControlPushButton> m_hotcueGoto;
+    std::unique_ptr<ControlPushButton> m_hotcueGotoAndPlay;
+    std::unique_ptr<ControlPushButton> m_hotcueGotoAndStop;
+    std::unique_ptr<ControlPushButton> m_hotcueActivate;
+    std::unique_ptr<ControlPushButton> m_hotcueActivatePreview;
+    std::unique_ptr<ControlPushButton> m_hotcueClear;
 
     bool m_bPreviewing;
     double m_previewingPosition;
@@ -116,8 +121,8 @@ class HotcueControl : public QObject {
 class CueControl : public EngineControl {
     Q_OBJECT
   public:
-    CueControl(QString group,
-               UserSettingsPointer pConfig);
+    CueControl(const QString& group,
+            UserSettingsPointer pConfig);
     ~CueControl() override;
 
     void hintReader(HintVector* pHintList) override;
@@ -184,13 +189,15 @@ class CueControl : public EngineControl {
 
     // These methods are not thread safe, only call them when the lock is held.
     void createControls();
-    void attachCue(CuePointer pCue, HotcueControl* pControl);
+    void attachCue(const CuePointer& pCue, HotcueControl* pControl);
     void detachCue(HotcueControl* pControl);
     void loadCuesFromTrack();
     double quantizeCuePoint(double position);
     double getQuantizedCurrentPosition();
     TrackAt getTrackAt() const;
     void seekOnLoad(double seekOnLoadPosition);
+    void setHotcueFocusIndex(int hotcueIndex);
+    int getHotcueFocusIndex() const;
 
     UserSettingsPointer m_pConfig;
     ColorPaletteSettings m_colorPaletteSettings;
@@ -216,6 +223,7 @@ class CueControl : public EngineControl {
     ControlPushButton* m_pPlayStutter;
     ControlIndicator* m_pCueIndicator;
     ControlIndicator* m_pPlayIndicator;
+    ControlObject* m_pPlayLatched;
     ControlPushButton* m_pCueGoto;
     ControlPushButton* m_pCueGotoAndPlay;
     ControlPushButton* m_pCuePlay;
diff --