Refactor: Add EngineBuffer::setPlaybackSpeedFromBpm

src/engine/controls/bpm/bpmtapcontrol.cpp

@@ -128,9 +128,5 @@ void BpmTapControl::slotTempoTapFilter(double averageLength, int numSamples) {
     }
 
     auto averageBpm = averageBpmRoundedWithinRange(averageLength, 1.0);
-    m_pEngineBpm->set(averageBpm.value());
-    // NOTE(ronso0) When setting the control, m_pEngineBpm->valueChanged()
-    // is not emitted (with Qt6) (it is when setting via a ControlProxy),
-    // so call the slot directly.
-    slotUpdateRateSlider(0.0 /* value is actually ignored */);
+    getEngineBuffer()->setPlaybackSpeedFromBpm(averageBpm);
 }

src/engine/controls/bpmcontrol.cpp

@@ -217,6 +217,14 @@ mixxx::Bpm BpmControl::getBpm() const {
     return mixxx::Bpm(m_pEngineBpm->get());
 }
 
+void BpmControl::setPlaybackSpeedFromBpm(mixxx::Bpm desiredBpm) {
+    m_pEngineBpm->set(desiredBpm.value());
+    // NOTE(ronso0) When setting the control, m_pEngineBpm->valueChanged()
+    // is not emitted (with Qt6) (it is when setting via a ControlProxy),
+    // so call the slot directly.
+    slotUpdateRateSlider(desiredBpm.value());
+}
+
 void BpmControl::adjustBeatsBpm(double deltaBpm) {
     const TrackPointer pTrack = getEngineBuffer()->getLoadedTrack();
     if (!pTrack) {

src/engine/controls/bpmcontrol.h

@@ -27,6 +27,9 @@ class BpmControl : public EngineControl {
         return m_pLocalBpm ? mixxx::Bpm(m_pLocalBpm->get()) : mixxx::Bpm();
     }
 
+    /// Sets the playback rate based on the desired BPM (not thread-safe)
+    void setPlaybackSpeedFromBpm(double desiredBpm);
+
     // When in sync lock mode, ratecontrol calls calcSyncedRate to figure out
     // how fast the track should play back.  The returned rate is usually just
     // the correct pitch to match bpms.  The usertweak argument represents

src/engine/enginebuffer.cpp

@@ -378,6 +378,10 @@ mixxx::Bpm EngineBuffer::getLocalBpm() const {
     return m_pBpmControl->getLocalBpm();
 }
 
+void EngineBuffer::setPlaybackSpeedFromBpm(mixxx::Bpm desiredBpm) {
+    m_pBpmControl->setPlaybackSpeedFromBpm(desiredBpm);
+}
+
 void EngineBuffer::setBeatLoop(mixxx::audio::FramePos startPosition, bool enabled) {
     m_pLoopingControl->setBeatLoop(startPosition, enabled);
 }

src/engine/enginebuffer.h

@@ -121,6 +121,8 @@ class EngineBuffer : public EngineObject {
     mixxx::Bpm getBpm() const;
     /// Returns the BPM of the loaded track around the current position (not thread-safe)
     mixxx::Bpm getLocalBpm() const;
+    /// Sets the playback rate based on the desired BPM (not thread-safe)
+    void setPlaybackSpeedFromBpm(mixxx::Bpm desiredBpm);
     /// Sets a beatloop for the loaded track (not thread safe)
     void setBeatLoop(mixxx::audio::FramePos startPosition, bool enabled);
     /// Sets a loop for the loaded track (not thread safe)