From 630b6da8995eeff7aeeed02cb4f2a8fed5910675 Mon Sep 17 00:00:00 2001
From: Lukas Waslowski <cr7pt0gr4ph7@gmail.com>
Date: Sat, 27 Apr 2024 19:34:01 +0000
Subject: [PATCH] AutoDJProcessor: Trigger recalculation of the remaining play
 time when relevant

The following data points are used as inputs for the "remaining time"
calculation, and should therefore trigger a recalculation:

* The list of tracks in the Auto DJ playlist (both
  the set of tracks and their order are important).

  We subscribe to PlaylistTableModel::tracksChanged
  to receive the relevant notifications.

* The AutoDJ transition mode and transition time settings.
  We will be notified via ::setTransitionMode
  and ::setTransitionTime, respectively.

* The Intro, Outro & N60dBSound cues of all tracks
  that are contained in the Auto DJ queue.

  We subscribe to TrackCollection::tracksChanged
  and TrackCollection::multipleTracksChanged to
  receive notifications about possible changes.

  As of now, we do not filter the notifications,
  and simply trigger a recalculation when ANY
  track has changed.
---
 src/library/autodj/autodjprocessor.cpp | 55 ++++++++++++++++++++++++++
 src/library/autodj/autodjprocessor.h   |  4 ++
 2 files changed, 59 insertions(+)

diff --git a/src/library/autodj/autodjprocessor.cpp b/src/library/autodj/autodjprocessor.cpp
index c2110e68080..ef121f30c8e 100644
--- a/src/library/autodj/autodjprocessor.cpp
+++ b/src/library/autodj/autodjprocessor.cpp
@@ -4,6 +4,8 @@
 #include "control/controlpushbutton.h"
 #include "engine/channels/enginedeck.h"
 #include "library/playlisttablemodel.h"
+#include "library/trackcollection.h"
+#include "library/trackcollectionmanager.h"
 #include "mixer/basetrackplayer.h"
 #include "mixer/playermanager.h"
 #include "moc_autodjprocessor.cpp"
@@ -235,6 +237,14 @@ AutoDJProcessor::AutoDJProcessor(
             &PlaylistTableModel::tracksChanged,
             this,
             &AutoDJProcessor::playlistTracksChanged);
+    connect(pTrackCollectionManager->internalCollection(),
+            &TrackCollection::tracksChanged,
+            this,
+            &AutoDJProcessor::tracksChanged);
+    connect(pTrackCollectionManager->internalCollection(),
+            &TrackCollection::multipleTracksChanged,
+            this,
+            &AutoDJProcessor::multipleTracksChanged);
 
     // TODO(rryan) listen to signals from PlayerManager and add/remove as decks
     // are created.
@@ -299,6 +309,43 @@ void AutoDJProcessor::setCrossfader(double value) {
 
 void AutoDJProcessor::playlistTracksChanged() {
     m_pTracksRemaining->set(m_pAutoDJTableModel->rowCount());
+    updateRemainingTime();
+}
+
+void AutoDJProcessor::tracksChanged(const QSet<TrackId>& tracks) {
+    Q_UNUSED(tracks);
+    updateRemainingTime();
+}
+
+void AutoDJProcessor::multipleTracksChanged() {
+    updateRemainingTime();
+}
+
+void AutoDJProcessor::updateRemainingTime() {
+    // The following data points are used as inputs for the "remaining time"
+    // calculation, and should therefore trigger a recalculation:
+    //
+    //     * The list of tracks in the Auto DJ playlist (both
+    //       the set of tracks and their order are important).
+    //
+    //       We subscribe to PlaylistTableModel::tracksChanged
+    //       to receive the relevant notifications.
+    //
+    //     * The AutoDJ transition mode and transition time settings.
+    //       We will be notified via ::setTransitionMode
+    //       and ::setTransitionTime, respectively.
+    //
+    //     * The Intro, Outro & N60dBSound cues of all tracks
+    //       that are contained in the Auto DJ queue.
+    //
+    //       We subscribe to TrackCollection::tracksChanged
+    //       and TrackCollection::multipleTracksChanged to
+    //       receive notifications about possible changes.
+    //
+    //       As of now, we do not filter the notifications,
+    //       and simply trigger a recalculation when ANY
+    //       track has changed.
+    //
     m_pTimeRemaining->set(calculateRemainingTime().toDoubleSeconds());
 }
 
@@ -1856,6 +1903,10 @@ void AutoDJProcessor::setTransitionTime(int time) {
             calculateTransition(pRightDeck, pLeftDeck, false);
         }
     }
+
+    // Recalculate the duration of the Auto DJ playlist,
+    // which may have been affected by the transition time change
+    updateRemainingTime();
 }
 
 void AutoDJProcessor::setTransitionMode(TransitionMode newMode) {
@@ -1897,6 +1948,10 @@ void AutoDJProcessor::setTransitionMode(TransitionMode newMode) {
         // user has manually started the other deck or stopped both.
         // don't know what to do.
     }
+
+    // Recalculate the duration of the Auto DJ playlist,
+    // which may have been affected by the transition mode change
+    updateRemainingTime();
 }
 
 DeckAttributes* AutoDJProcessor::getLeftDeck() {
diff --git a/src/library/autodj/autodjprocessor.h b/src/library/autodj/autodjprocessor.h
index e50f46b70e8..bd9e7ff2d0b 100644
--- a/src/library/autodj/autodjprocessor.h
+++ b/src/library/autodj/autodjprocessor.h
@@ -8,6 +8,7 @@
 #include "engine/channels/enginechannel.h"
 #include "preferences/usersettings.h"
 #include "track/track_decl.h"
+#include "track/trackid.h"
 #include "util/class.h"
 #include "util/duration.h"
 
@@ -277,6 +278,9 @@ class AutoDJProcessor : public QObject {
     void playerRateChanged(DeckAttributes* pDeck);
 
     void playlistTracksChanged();
+    void tracksChanged(const QSet<TrackId>& tracks);
+    void multipleTracksChanged();
+    void updateRemainingTime();
 
     void controlEnableChangeRequest(double value);
     void controlFadeNow(double value);