When editing a title clip, hide it from timeline so that it doesn't appear on background frame.

Fixes #805

src/bin/bin.cpp

@@ -3656,6 +3656,9 @@ void Bin::showTitleWidget(const std::shared_ptr<ProjectClip> &clip)
     QString path = clip->getProducerProperty(QStringLiteral("resource"));
     QDir titleFolder(m_doc->projectDataFolder() + QStringLiteral("/titles"));
     titleFolder.mkpath(QStringLiteral("."));
+    QList<int> clips = clip->timelineInstances();
+    // Temporarily hide this title clip in timeline so that it does not appear when requesting background frame
+    pCore->temporaryUnplug(clips, true);
     TitleWidget dia_ui(QUrl(), m_doc->timecode(), titleFolder.absolutePath(), pCore->monitorManager()->projectMonitor(), pCore->window());
     QDomDocument doc;
     QString xmldata = clip->getProducerProperty(QStringLiteral("xmldata"));
@@ -3666,8 +3669,9 @@ void Bin::showTitleWidget(const std::shared_ptr<ProjectClip> &clip)
     } else {
         doc.setContent(xmldata);
     }
-    dia_ui.setXml(doc, clip->AbstractProjectItem::clipId());
+    dia_ui.setXml(doc, clip->clipId());
     if (dia_ui.exec() == QDialog::Accepted) {
+        pCore->temporaryUnplug(clips, false);
         QMap<QString, QString> newprops;
         newprops.insert(QStringLiteral("xmldata"), dia_ui.xml().toString());
         if (dia_ui.duration() != clip->duration().frames(pCore->getCurrentFps())) {
@@ -3696,6 +3700,8 @@ void Bin::showTitleWidget(const std::shared_ptr<ProjectClip> &clip)
             }
         }
         slotEditClipCommand(clip->AbstractProjectItem::clipId(), clip->currentProperties(newprops), newprops);
+    } else {
+        pCore->temporaryUnplug(clips, false);
     }
 }
 

src/core.cpp

@@ -921,3 +921,8 @@ void Core::addGuides(QList <int> guides)
     }
     pCore->currentDoc()->getGuideModel()->addMarkers(markers);
 }
+
+void Core::temporaryUnplug(QList<int> clipIds, bool hide)
+{
+    pCore->window()->getMainTimeline()->controller()->temporaryUnplug(clipIds, hide);
+}

src/core.h

@@ -227,6 +227,9 @@ public:
     int audioChannels();
     /** @brief Add guides in the project. */
     void addGuides(QList <int> guides);
+    /** @brief Temporarily un/plug a list of clips in timeline. */
+    void temporaryUnplug(QList<int> clipIds, bool hide);
+    
     KSharedDataCache audioThumbCache;
 
 private:

src/timeline2/model/trackmodel.cpp

@@ -300,6 +300,35 @@ bool TrackModel::requestClipInsertion(int clipId, int position, bool updateView,
     return false;
 }
 
+void TrackModel::temporaryUnplugClip(int clipId)
+{
+    QWriteLocker locker(&m_lock);
+    int clip_position = m_allClips[clipId]->getPosition();
+    auto clip_loc = getClipIndexAt(clip_position);
+    int target_track = clip_loc.first;
+    int target_clip = clip_loc.second;
+    // lock MLT playlist so that we don't end up with invalid frames in monitor
+    m_playlists[target_track].lock();
+    Q_ASSERT(target_clip < m_playlists[target_track].count());
+    Q_ASSERT(!m_playlists[target_track].is_blank(target_clip));
+    std::unique_ptr<Mlt::Producer> prod(m_playlists[target_track].replace_with_blank(target_clip));
+    m_playlists[target_track].unlock();
+}
+
+void TrackModel::temporaryReplugClip(int cid)
+{
+    QWriteLocker locker(&m_lock);
+    int clip_position = m_allClips[cid]->getPosition();
+    int target_track = m_allClips[cid]->getSubPlaylistIndex();
+    m_playlists[target_track].lock();
+    if (auto ptr = m_parent.lock()) {
+        std::shared_ptr<ClipModel> clip = ptr->getClipPtr(cid);
+        m_playlists[target_track].insert_at(clip_position, *clip, 1);
+    }
+    m_playlists[target_track].unlock();
+}
+
+
 void TrackModel::replugClip(int clipId)
 {
     QWriteLocker locker(&m_lock);

src/timeline2/model/trackmodel.hpp

@@ -290,6 +290,8 @@ protected:
     /* @brief This function removes the clip from the mlt object, and then insert it back in the same spot again.
      * This is used when some properties of the clip have changed, and we need this to refresh it */
     void replugClip(int clipId);
+    void temporaryReplugClip(int cid);
+    void temporaryUnplugClip(int clipId);
 
     int trackDuration() const;
 

src/timeline2/view/timelinecontroller.cpp

@@ -3695,3 +3695,18 @@ void TimelineController::mixClip(int cid, int delta)
     m_model->mixClip(cid, delta);
 }
 
+void TimelineController::temporaryUnplug(QList<int> clipIds, bool hide)
+{
+    for (auto &cid : clipIds) {
+        int tid = m_model->getItemTrackId(cid);
+        if (tid == -1) {
+            continue;
+        }
+        if (hide) {
+            m_model->getTrackById_const(tid)->temporaryUnplugClip(cid);
+        } else {
+            m_model->getTrackById_const(tid)->temporaryReplugClip(cid);
+        }
+    }
+}
+

src/timeline2/view/timelinecontroller.h

@@ -564,6 +564,8 @@ public:
     QPoint selectionInOut() const;
     /** @brief Create a mix transition with currently selected clip. If delta = -1, mix with previous clip, +1 with next clip and 0 will check cursor position*/
     Q_INVOKABLE void mixClip(int cid = -1, int delta = 0);
+    /** @brief Temporarily un/plug a list of clips in timeline. */
+    void temporaryUnplug(QList<int> clipIds, bool hide);
 
 public slots:
     void resetView();