Loop: beatloop_activate adopts rolling loop and quits slip mode

src/engine/controls/loopingcontrol.cpp

@@ -1309,6 +1309,15 @@ void LoopingControl::slotBeatLoopDeactivate(BeatLoopingControl* pBeatLoopControl
 
 void LoopingControl::slotBeatLoopDeactivateRoll(BeatLoopingControl* pBeatLoopControl) {
     pBeatLoopControl->deactivate();
+
+    if (!m_bLoopRollActive) {
+        // beatloop_activate was pressed while rolling and slotBeatLoopToggle()
+        // did already reset roll status (m_activeLoopRolls, m_bLoopRollActive)
+        // and EngineBuffer quit slip mode (but didn't seek).
+        // So nothing to do here, just leave the adopted loop active.
+        return;
+    }
+
     const double size = pBeatLoopControl->getSize();
     // clang-tidy wants auto to be auto* because QStack inherits from QVector
     // and QVector::iterator is a pointer type in Qt5, but QStack inherits
@@ -1325,18 +1334,15 @@ void LoopingControl::slotBeatLoopDeactivateRoll(BeatLoopingControl* pBeatLoopCon
 
     // Make sure slip mode is not turned off if it was turned on
     // by something that was not a rolling beatloop.
-    if (m_bLoopRollActive && m_activeLoopRolls.empty()) {
+    if (m_activeLoopRolls.empty()) {
         setLoopingEnabled(false);
         m_pSlipEnabled->set(0);
         m_bLoopRollActive = false;
-    }
-
-    // Return to the previous beatlooproll if necessary.
-    // Else previous regular beatloop if no rolling loops are active.
-    if (!m_activeLoopRolls.empty()) {
-        slotBeatLoop(m_activeLoopRolls.top(), m_bLoopRollActive, true);
-    } else {
         restoreLoopInfo();
+    } else {
+        // Return to the previous beatlooproll if necessary.
+        // Else previous regular beatloop if no rolling loops are active.
+        slotBeatLoop(m_activeLoopRolls.top(), m_bLoopRollActive, true);
     }
 }
 
@@ -1694,14 +1700,25 @@ void LoopingControl::slotBeatLoopSizeChangeRequest(double beats) {
 }
 
 void LoopingControl::slotBeatLoopToggle(double pressed) {
-    if (pressed > 0) {
-        if (m_bLoopingEnabled) {
+    if (pressed <= 0) {
+        return;
+    }
+
+    if (m_bLoopingEnabled) {
+        // If we're in a rolling loop, quit slip mode and adopt it as regular loop.
+        // Use case is to have a looproll button pressed, then press loop_activate
+        // and nothing should happen when releasing the looproll button.
+        if (m_bLoopRollActive) {
+            m_bLoopRollActive = false;
+            m_activeLoopRolls.clear();
+            getEngineBuffer()->slipQuitAndAdopt();
+        } else {
             // Deactivate the loop if we're already looping
             setLoopingEnabled(false);
-        } else {
-            // Create a loop at current position
-            slotBeatLoop(m_pCOBeatLoopSize->get());
         }
+    } else {
+        // Create a loop at current position
+        slotBeatLoop(m_pCOBeatLoopSize->get());
     }
 }
 
@@ -1723,6 +1740,14 @@ void LoopingControl::slotBeatLoopRollActivate(double pressed) {
             m_bLoopRollActive = true;
         }
     } else {
+        if (!m_bLoopRollActive) {
+            // beatloop_activate was pressed while rolling and slotBeatLoopToggle()
+            // did already reset roll status (m_activeLoopRolls, m_bLoopRollActive)
+            // and EngineBuffer quit slip mode (but didn't seek).
+            // So nothing to do here, just leave the adopted loop active.
+            return;
+        }
+
         setLoopingEnabled(false);
         // Make sure slip mode is not turned off if it was turned on
         // by something that was not a rolling beatloop.

src/engine/enginebuffer.cpp

@@ -90,6 +90,7 @@ EngineBuffer::EngineBuffer(const QString& group,
           m_iSeekPhaseQueued(0),
           m_iEnableSyncQueued(SYNC_REQUEST_NONE),
           m_iSyncModeQueued(static_cast<int>(SyncMode::Invalid)),
+          m_slipQuitAndAdopt(0),
           m_bPlayAfterLoading(false),
           m_channelCount(mixxx::kEngineChannelOutputCount),
           m_pCrossfadeBuffer(SampleUtil::alloc(
@@ -864,6 +865,11 @@ void EngineBuffer::slotKeylockEngineChanged(double dIndex) {
     }
 }
 
+void EngineBuffer::slipQuitAndAdopt() {
+    m_slipQuitAndAdopt.storeRelease(1);
+    m_pSlipButton->set(0);
+}
+
 void EngineBuffer::processTrackLocked(
         CSAMPLE* pOutput, const std::size_t bufferSize, mixxx::audio::SampleRate sampleRate) {
     ScopedTimer t(QStringLiteral("EngineBuffer::process_pauselock"));
@@ -1257,8 +1263,12 @@ void EngineBuffer::processSlip(std::size_t bufferSize) {
             m_slipPos = m_playPos;
             m_dSlipRate = m_rate_old;
         } else {
-            // TODO(owen) assuming that looping will get canceled properly
-            seekExact(m_slipPos.toNearestFrameBoundary());
+            // If m_slipQuitAndAdopt is 1 we've already quit slip mode
+            // but we don't seek in that case.
+            if (m_slipQuitAndAdopt.fetchAndStoreAcquire(0) == 0) {
+                // TODO(owen) assuming that looping will get canceled properly
+                seekExact(m_slipPos.toNearestFrameBoundary());
+            }
             m_slipPos = mixxx::audio::kStartFramePos;
         }
     }

src/engine/enginebuffer.h

@@ -236,6 +236,8 @@ class EngineBuffer : public EngineObject {
 
     void verifyPlay();
 
+    void slipQuitAndAdopt();
+
   public slots:
     void slotControlPlayRequest(double);
     void slotControlPlayFromStart(double);
@@ -466,6 +468,7 @@ class EngineBuffer : public EngineObject {
     ControlValueAtomic<QueuedSeek> m_queuedSeek;
     bool m_previousBufferSeek = false;
 
+    QAtomicInt m_slipQuitAndAdopt;
     /// Indicates that no seek is queued
     static constexpr QueuedSeek kNoQueuedSeek = {mixxx::audio::kInvalidFramePos, SEEK_NONE};
     /// indicates a clone seek on a bosition from another deck