BugFix Sync Play to Session ready when loading

Add test of session state on Play callback; the play action is then called after all sources are ready, thus starting in sync.

src/SessionCreator.cpp

@@ -1047,7 +1047,7 @@ void SessionLoader::visit (Source& s)
     s.call( new Lock(l) );
     bool p = true;
     sourceNode->QueryBoolAttribute("play", &p);
-    s.call( new Play(p) );
+    s.call( new Play(p, session_) );
 
     xmlCurrent_ = sourceNode->FirstChildElement("Mixing");
     if (xmlCurrent_) s.groupNode(View::MIXING)->accept(*this);

src/SourceCallback.cpp

@@ -494,7 +494,8 @@ void SetDepth::accept(Visitor& v)
     v.visit(*this);
 }
 
-Play::Play(bool on, bool revert) : SourceCallback(), play_(on), bidirectional_(revert)
+Play::Play(bool on, Session *parentsession, bool revert) : SourceCallback(),
+    session_(parentsession), play_(on), bidirectional_(revert)
 {
 }
 
@@ -503,7 +504,8 @@ void Play::update(Source *s, float dt)
     SourceCallback::update(s, dt);
 
     // toggle play status when ready
-    if ( status_ == READY && s->ready() ){
+    if ( status_ == READY && s->ready() &&
+        (session_ ? session_->ready() : true) ){
 
         if (s->playing() != play_)
             // call play function
@@ -516,7 +518,7 @@ void Play::update(Source *s, float dt)
 
 SourceCallback *Play::clone() const
 {
-    return new Play(play_, bidirectional_);
+    return new Play(play_, session_, bidirectional_);
 }
 
 SourceCallback *Play::reverse(Source *s) const

src/SourceCallback.h

@@ -212,11 +212,12 @@ public:
 
 class Play : public SourceCallback
 {
+    class Session *session_;
     bool play_;
     bool bidirectional_;
 
 public:
-    Play (bool on = true, bool revert = false);
+    Play (bool on = true, Session *parentsession = nullptr, bool revert = false);
 
     bool value () const { return play_;}
     void setValue (bool on) { play_ = on; }