From c6c721482696273b9ca67bc0850925c61981b1da Mon Sep 17 00:00:00 2001
From: Ichthyostega <prg@ichthyostega.de>
Date: Mon, 14 Jun 2010 02:08:45 +0200
Subject: [PATCH] try to break the design deadlock with sequence / track
 creation

---
 src/proc/asset/struct-factory-impl.hpp      |  9 ++++-
 src/proc/asset/struct-scheme.hpp            |  4 +--
 src/proc/mobject/session/mobjectfactory.cpp | 11 +++++-
 src/proc/mobject/session/mobjectfactory.hpp |  4 ++-
 src/proc/mobject/session/track.cpp          | 15 ++++++++-
 src/proc/mobject/session/track.hpp          | 25 ++++++++++++--
 wiki/renderengine.html                      | 37 +++++++++++++++++----
 7 files changed, 90 insertions(+), 15 deletions(-)

diff --git a/src/proc/asset/struct-factory-impl.hpp b/src/proc/asset/struct-factory-impl.hpp
index 82050fc5e..bfae323c7 100644
--- a/src/proc/asset/struct-factory-impl.hpp
+++ b/src/proc/asset/struct-factory-impl.hpp
@@ -203,7 +203,14 @@ namespace asset {
       {
         // when we reach this point it is clear a suitable sequence doesn't yet exist in the model
         TODO ("actually extract properties/capabilities from the query...");
-        return new Sequence (createIdent (caps));
+        string trackID = extractID ("track", caps);
+        Query<Track> desiredTrack (isnil (trackID)? "" : "id("+trackID+")");
+//      PTrack track = Session::current->query (desiredTrack);        ///////////////////////////////////TICKET #639
+        // TODO: handle the following cases
+        // - track doesn't exist --> create and root attach it
+        // - track exists and is root attached, but belongs already to a sequence --> throw
+        // - track exists, but isn't root attached ---> what do do here? steal it??
+        return new Sequence (createIdent (caps));  ///////////TODO fed track in here
       }
     
     
diff --git a/src/proc/asset/struct-scheme.hpp b/src/proc/asset/struct-scheme.hpp
index c8e0d09a4..69161ffbc 100644
--- a/src/proc/asset/struct-scheme.hpp
+++ b/src/proc/asset/struct-scheme.hpp
@@ -22,7 +22,7 @@
 
 
 /** @file struct-scheme.hpp
- ** Naming and labelling scheme for structural assets.
+ ** Naming and labeling scheme for structural assets.
  ** Preconfigured traits data for the relevant types encountered in
  ** Lumiera's session data model.
  **
@@ -68,7 +68,7 @@ namespace asset{
     
     
     
-    /* ==== structural asset ID scheme ==== */  /////////////////////////////////////////////TICKET #565 : better organisation of this naming scheme
+    /* ==== structural asset ID scheme ==== */  /////////////////////////////////////////////TICKET #565 : better organization of this naming scheme
     
     template<class STRU>
     struct StructTraits
diff --git a/src/proc/mobject/session/mobjectfactory.cpp b/src/proc/mobject/session/mobjectfactory.cpp
index d08bc7e3a..0b1373710 100644
--- a/src/proc/mobject/session/mobjectfactory.cpp
+++ b/src/proc/mobject/session/mobjectfactory.cpp
@@ -84,12 +84,21 @@ namespace session {
   
   /** */ 
   Placement<Track>
-  MObjectFactory::operator() (PTrackAsset& trackDef)
+  MObjectFactory::operator() (PTrackAsset& trackDef)           /////////////////////TICKET #581 kill kill kill the track-asset
   {
     TODO ("what needs to be registered when creating an Track-MO?");
     return Placement<Track> (*new Track (trackDef), &deleterFunc);
   }
   
+  /** fabricate a new track-MObject, using the given unique ID */ 
+  Placement<Track>
+  MObjectFactory::operator() (TrackID const& id)
+  {
+    TODO ("what needs to be registered when creating an Track-MO?");
+    TODO ("assure the ID is indeed unique and not already used for another track");  //////////TICKET #638
+    return Placement<Track> (*new Track (id), &deleterFunc);
+  }
+  
   /** */ 
   Placement<Effect>
   MObjectFactory::operator() (const asset::Effect& processorDef)
diff --git a/src/proc/mobject/session/mobjectfactory.hpp b/src/proc/mobject/session/mobjectfactory.hpp
index 972bc6628..509975676 100644
--- a/src/proc/mobject/session/mobjectfactory.hpp
+++ b/src/proc/mobject/session/mobjectfactory.hpp
@@ -25,6 +25,7 @@
 #define MOBJECT_SESSION_MOBJECTFACTORY_H
 
 #include "proc/mobject/mobject.hpp"
+#include "proc/asset/entry-id.hpp"
 #include "lib/symbol.hpp"
 
 
@@ -68,7 +69,8 @@ namespace session {
       Placement<Root>   operator() (DefsManager&);
       Placement<Clip>   operator() (asset::Clip const&, asset::Media const&);
       Placement<Clip>   operator() (asset::Clip const&, vector<asset::Media const*>);
-      Placement<Track>  operator() (PTrackAsset&);
+      Placement<Track>  operator() (PTrackAsset&); ////////////////////////////////////////////////////TICKET #581 kill kill kill the track-asset
+      Placement<Track>  operator() (asset::EntryID<Track> const&);                         ////////////TICKET #581 use this one instead
       Placement<Effect> operator() (asset::Effect const&);
       Placement<Label>  operator() (lib::Symbol);
       Placement<Binding>operator() (asset::PSequence const&);
diff --git a/src/proc/mobject/session/track.cpp b/src/proc/mobject/session/track.cpp
index 3ead4e987..f14bdbf12 100644
--- a/src/proc/mobject/session/track.cpp
+++ b/src/proc/mobject/session/track.cpp
@@ -34,7 +34,20 @@ namespace session {
    */
   Track::Track (PTrackAsset& trackDef)
     : start_(0),
-      trackDef_(trackDef)
+      trackDef_(trackDef)    /////////////////////TICKET #581 kill kill kill the track-asset
+  {
+    throwIfInvalid();
+  }
+  
+  
+  /** create a new track-MObject based on the given unique ID.
+   *  Initially, the reference (zero-point) time of this track
+   *  will be set to 0 
+   */
+  Track::Track (TrackID const& trackID)
+    : start_(0),
+      trackDef_()            /////////////////////TICKET #581 kill kill kill the track-asset 
+    , id_(trackID)
   {
     throwIfInvalid();
   }
diff --git a/src/proc/mobject/session/track.hpp b/src/proc/mobject/session/track.hpp
index 7fdd3e345..38550712a 100644
--- a/src/proc/mobject/session/track.hpp
+++ b/src/proc/mobject/session/track.hpp
@@ -25,13 +25,17 @@
 #define MOBJECT_SESSION_TRACK_H
 
 #include "proc/mobject/session/meta.hpp"
+#include "proc/asset/entry-id.hpp"
 
 
 
-namespace asset { class Track; }
+namespace asset { 
+  class Track;           /////////////////////TICKET #581 kill kill kill the track-asset
+  
+}
 
 namespace mobject {
-namespace session {
+namespace session {     //////////////////////////////////////////////////////TICKET #637
     
     using lumiera::P;
     
@@ -40,8 +44,21 @@ namespace session {
     
     typedef P<Track> PTrack;
     typedef P<TrackAsset> PTrackAsset;
+
+}}
     
+namespace asset {       //////////////////////////////////////////////////////TICKET #637
+  
+  typedef EntryID<mobject::session::Track> TrackID;
+}
+
+
+namespace mobject {
+namespace session {
+  
+    using asset::TrackID;
     
+  
     /**
      * A Track is grouping device within the Session.
      * The corresponding Placement by which this Track object is referred
@@ -65,9 +82,11 @@ namespace session {
       {
         Time start_;
         PTrackAsset trackDef_;
+        TrackID id_;
         
       protected:
-        Track (PTrackAsset&);
+        Track (PTrackAsset&);           /////////////////////TICKET #581 kill kill kill the track-asset
+        Track (TrackID const&);
         friend class MObjectFactory;
         
       public:
diff --git a/wiki/renderengine.html b/wiki/renderengine.html
index 9b1beebdf..5c36f50b8 100644
--- a/wiki/renderengine.html
+++ b/wiki/renderengine.html
@@ -2260,6 +2260,15 @@ This Design strives to achieve a StrongSeparation between the low-level Structur
 [img[Classess related to the session|uml/fig128133.png]]
 </pre>
 </div>
+<div title="MagicAttachment" modifier="Ichthyostega" created="201006132135" tags="Model spec draft" changecount="1">
+<pre>The HighLevelModel consists of MObjects, which are attached to one another through their [[Placement]]. While this is a generic scheme to arrange objects in a tree of [[scopes|PlacementScope]], some attachments are handled specifically and may trigger side-effects
+
+{{red{drafted feature as of 6/2010}}}
+
+* a [[binding|BindingMO]] attached to root is linked to a [[Timeline]]
+* a [[Track]] attached to rood corresponds to a [[Sequence]]
+</pre>
+</div>
 <div title="MainMenu" modifier="Ichthyostega" modified="200802031758" created="200706172305" changecount="10">
 <pre>''[[Lumiera|index.html]]''
 [[Proc-Layer|ProcLayer and Engine]]
@@ -2361,7 +2370,7 @@ And, last but not least, doing large scale allocations is the job of the backend
 <div title="Model" modifier="Ichthyostega" modified="201003210021" created="201003210020" tags="overview" changecount="2">
 <pre>Lumiera's Proc-Layer is built around //two interconnected models,// mediated by the [[Builder]]. Basically, the &amp;rarr;[[Session]] is an external interface to the HighLevelModel, while the &amp;rarr;RenderEngine operates the structures of the LowLevelModel.</pre>
 </div>
-<div title="ModelDependencies" modifier="Ichthyostega" modified="201006130130" created="201003020150" tags="SessionLogic operational spec draft img" changecount="32">
+<div title="ModelDependencies" modifier="Ichthyostega" modified="201006140007" created="201003020150" tags="SessionLogic Model operational spec draft img" changecount="35">
 <pre>Our design of the models (both [[high-level|HighLevelModel]] and [[low-level|LowLevelModel]]) relies partially on dependent objects being kept consitently in sync. Currently (2/2010), __ichthyo__'s assessment is to consider this topic not important and pervasive enough to justify building a dedicated solution, like e.g. a central tracking and registration service. An important point to consider with this assesment is the fact that the session implementation is beeing kept mostly single-threaded. Thus, lacking one central place to handle this issue, care has to be taken to capture and treat all the relevant individual dependencies properly at the implementation level.
 
 !known interdependencies
@@ -2390,14 +2399,17 @@ While implemented as StructAsset, additionally we need to assure every instance
 
 ;Sequence
 :is completely dependent on a root-scoped track, can optionally be bound, into one/multiple timelines/VirtualClip, or unbound
-: __created__ &amp;rArr; mandates specification of an track-MO, ({{red{TODO}}}maybe/necessarily??) placed into root scope
-: __destroy__ &amp;rArr; purge the corresponding track from model, including all contents
+: __created__ &amp;rArr; mandates specification of an track-MO, (necessarily) placed into root scope &amp;mdash; {{red{TODO: what to do with non-root tracks?}}}
+: __destroy__ &amp;rArr; destroy any binding using this sequence, purge the corresponding track from model, if applicable, including all contents
 : __querying__ &amp;rArr; forwards to creating a root-placed track, unless the queried sequence exists already
 ;root-placed Track
 :attachment of a track to root scope is detected magically and causes creation of a Sequence
 : __attached__ to root &amp;rArr; invoke sequence creation
-: __detached__ from root &amp;rArr; find and discard corresponding sequence {{red{TODO 3/2010: decide if we want this behaviour}}}
+: __detached__ from root &amp;rArr; find and detach from corresponding sequence, which is then destroyed. //Note:// contents remain unaffected
 : irrespective if the track exists, is empty, or gets purged entirely, only the connection to root scope counts; thus relocating a track by [[Placement]] might cause its scope with all nested contents to become a sequence of its own or become part of another sequence. As sequences aren't required to be bound into a timeline, they may be present in the model as invisible, passive container
+
+!!Magic attachments
+While generally the HighLevelModel allows all kinds of arrangements and attachments, certain connections are [[detected automatically|ScopeTrigger]] and may trigger special actions, like the creation of Timeline or Sequence façade objects as described above. The implementation of such [[magic attachments|MagicAttachment]] relies on the PlacementIndex.
 </pre>
 </div>
 <div title="ModelObjectIdentity" modifier="Ichthyostega" modified="201001072246" created="201001070905" tags="SessionLogic spec draft" changecount="18">
@@ -4104,10 +4116,23 @@ A scope path is a sequence of scopes, where each scope is implemented by a Place
 ** clear a path (reset to default)
 </pre>
 </div>
-<div title="Sequence" modifier="Ichthyostega" modified="201003020521" created="201001252327" tags="def" changecount="13">
+<div title="ScopeTrigger" modifier="Ichthyostega" modified="201006132140" created="201006132139" tags="SessionLogic impl draft" changecount="2">
+<pre>An implementation mechanism used within the PlacementIndex to detect some specific kinds of object connections(&amp;raquoMagicAttachment&amp;laquo;), which then need to trigger a special handling.
+
+{{red{planned feature as of 6/2010)}}}
+
+//It is not clear yet, if that's just an implementation facility, or something which is exposed through the ConfigRules.//
+
+!preliminary requirements
+We need to detect attaching and detaching of
+* root &amp;harr; BindingMO
+* root &amp;harr; [[Track]]
+</pre>
+</div>
+<div title="Sequence" modifier="Ichthyostega" modified="201006132117" created="201001252327" tags="def" changecount="15">
 <pre>A sequence is a collection of media objects, arranged onto a track tree. Sequences are the building blocks within the session. To be visible and editable, a session needs to be bound into a top-level [[Timeline]]. Alternatively, it may be used as a VirtualClip nested within another sequence.
 
-The sequences within the session establish a //logical grouping//, allowing for lots of flexibility. Actually, we can have several sequences within one session, and these sequences can be linked together or not, they may be arranged in temporal order or may constitute a logical grouping of clips used simultaneously in compositional work etc. Multiple sequences can use the same or different tracks, and tracks as well are only an organisational (grouping) device. But at any time, we have exactly one [[Fixture]], derived automatically from all sequences and containing the content actually to be rendered.
+The sequences within the session establish a //logical grouping//, allowing for lots of flexibility. Actually, we can have several sequences within one session, and these sequences can be linked together or not, they may be arranged in temporal order or may constitute a logical grouping of clips used simultaneously in compositional work etc. The data structure comprising a sequence is always a sub-tree of tracks, attached allways directly below root (Sequences at sub-nodes are deliberately disallowed). Through the sequence as frontend, this track tree might be used at various places in the model simultaneously. Tracks in turn are only an organisational (grouping) devices, like folders, so this structure of sequences and track trees referred through them allows to use the contents of such a track or folder at various places within the model. But at any time, we have exactly one [[Fixture]], derived automatically from all sequences and containing the content actually to be rendered.
 &amp;rarr; see considerations about [[the role of Tracks and Pipes in conjunction with the sequences|TrackPipeSequence]]
 
 !!Implementation and lifecycle