diff --git a/src/stage/model/canvas-hook.hpp b/src/stage/model/canvas-hook.hpp
index 4d3978f36..7b5d6d5ff 100644
--- a/src/stage/model/canvas-hook.hpp
+++ b/src/stage/model/canvas-hook.hpp
@@ -64,6 +64,7 @@ namespace model {
   
   using lib::time::Time;
   using lib::time::TimeValue;
+  using lib::time::TimeSpan;
   
   
   
@@ -82,8 +83,11 @@ namespace model {
     public:
       virtual ~DisplayMetric() { }    ///< this is an interface
       
+      /** the overall time Duration covered by this timeline canvas */
+      virtual TimeSpan coveredTime()  const                =0;
+      
       /** extension point for time axis zoom management. */
-      virtual int translateTimeToPixels (TimeValue)  const      =0;
+      virtual int translateTimeToPixels (TimeValue)  const =0;
     };
   
   
@@ -101,7 +105,6 @@ namespace model {
    */
   template<class WID>
   class CanvasHook
-    : public DisplayMetric
     {
     public:
       virtual ~CanvasHook() { }    ///< this is an interface
@@ -110,6 +113,9 @@ namespace model {
       virtual void move   (WID& widget, int xPos, int yPos)  =0;
       virtual void remove (WID& widget)                      =0;
 
+      /** access the component to handle layout metric */
+      virtual DisplayMetric& getMetric()  const              =0;
+      
       /** Anchor point to build chains of related View Hooks */
       virtual CanvasHook<WID>&
       getAnchorHook()  noexcept
@@ -137,7 +143,7 @@ namespace model {
       Pos
       hookedAt (Time start, int downshift=0)
         {
-          return hookedAt (translateTimeToPixels (start), downshift);
+          return hookedAt (getMetric().translateTimeToPixels (start), downshift);
         }
     };
   
diff --git a/src/stage/timeline/body-canvas-widget.cpp b/src/stage/timeline/body-canvas-widget.cpp
index eb9fe80a6..fd2872d27 100644
--- a/src/stage/timeline/body-canvas-widget.cpp
+++ b/src/stage/timeline/body-canvas-widget.cpp
@@ -84,10 +84,6 @@ namespace timeline {
   using CairoC = PCairoContext const&;
   using StyleC = PStyleContext const&;
   
-  namespace {   /////////////////////////////////////////////////////TICKET #1213 : use proper zoom handling instead of dummy constants!!
-    const int TODO_px_per_second = 25;
-  }             /////////////////////////////////////////////////////TICKET #1213 : (END) get rid of these dummy constants!!
-  
   namespace { // details of track background painting
     
     const int INITIAL_TIMERULER_HEIGHT_px = 30;
@@ -576,10 +572,10 @@ namespace timeline {
     getCanvas(yPos).move (widget, xPos, yPos);
   }
   
-  int
-  BodyCanvasWidget::translateTimeToPixels (TimeValue startTimePoint)  const
+  model::DisplayMetric&
+  BodyCanvasWidget::getMetric()  const
   {
-    return _raw(startTimePoint) * TODO_px_per_second / Time::SCALE;   //////////TICKET #1213 : delegate zoom handling to the display manager (field #layout_) !!
+    return layout_;
   }
   
   /** respond to the DisplayEvaluation pass.
diff --git a/src/stage/timeline/body-canvas-widget.hpp b/src/stage/timeline/body-canvas-widget.hpp
index 3030bdc0a..2c6996ad8 100644
--- a/src/stage/timeline/body-canvas-widget.hpp
+++ b/src/stage/timeline/body-canvas-widget.hpp
@@ -176,8 +176,8 @@ namespace timeline {
       void hook (Gtk::Widget&, int xPos=0, int yPos=0) override;
       void move (Gtk::Widget&, int xPos, int yPos)     override;
       void remove (Gtk::Widget&)                       override;
-      
-      int translateTimeToPixels (TimeValue)  const     override;
+
+      model::DisplayMetric& getMetric()  const         override;
       
     protected: /* ==== Interface: LayoutElement ===== */
       
diff --git a/src/stage/timeline/clip-widget.cpp b/src/stage/timeline/clip-widget.cpp
index aacbfd295..bfade0673 100644
--- a/src/stage/timeline/clip-widget.cpp
+++ b/src/stage/timeline/clip-widget.cpp
@@ -327,7 +327,7 @@ namespace timeline {
         void
         establishHorizontalExtension()
           {
-            int hSize = getCanvas().translateTimeToPixels (getLen());
+            int hSize = getCanvas().getMetric().translateTimeToPixels (getLen());
             set_size_request (hSize, -1);
 //            queue_resize();
           }
@@ -349,7 +349,7 @@ namespace timeline {
         void
         get_preferred_width_vfunc(int& minimum_width, int& natural_width)  const override
           {
-            minimum_width = natural_width = getCanvas().translateTimeToPixels (getLen());
+            minimum_width = natural_width = getCanvas().getMetric().translateTimeToPixels (getLen());
           }
         
         
diff --git a/src/stage/timeline/display-manager.hpp b/src/stage/timeline/display-manager.hpp
index 7cb17a132..13909c9ef 100644
--- a/src/stage/timeline/display-manager.hpp
+++ b/src/stage/timeline/display-manager.hpp
@@ -146,11 +146,11 @@ namespace timeline {
       virtual int hookAdjX (int xPos)  =0;
       virtual int hookAdjY (int yPos)  =0;
       
-      /** delegating default implementation for timeline zoom */
-      int
-      translateTimeToPixels (TimeValue startTimePoint)  const override
+      /** delegating layout metric to the root canvas */
+      model::DisplayMetric&
+      getMetric()  const override
         {
-          return refHook_.translateTimeToPixels (startTimePoint);
+          return refHook_.getMetric();
         }
       
     public:
@@ -215,15 +215,13 @@ namespace timeline {
   class DisplayManager
     : util::NonCopyable
     , public DisplayViewHooks
+    , public model::DisplayMetric
     {
       
       
     public:
       virtual ~DisplayManager();    ///< this is an interface
       
-      /** the overall horizontal pixel span to cover by this timeline */
-      virtual PixSpan getPixSpan()         =0;
-      
       /** cause a re-allocation of the complete layout */
       virtual void triggerDisplayEvaluation() =0;
       
@@ -235,6 +233,16 @@ namespace timeline {
        * arrangement of the timeline layout.
        */
       SignalStructureChange signalStructureChange_;
+
+
+      /** the overall horizontal pixel span to cover by this timeline */
+      PixSpan
+      getPixSpan()
+        {
+          return {translateTimeToPixels (coveredTime().start())
+                 ,translateTimeToPixels (coveredTime().end())
+                 };
+        }
       
       
     private:/* ===== Internals ===== */
diff --git a/src/stage/timeline/timeline-layout.cpp b/src/stage/timeline/timeline-layout.cpp
index c3b9ca6ec..7d54a2243 100644
--- a/src/stage/timeline/timeline-layout.cpp
+++ b/src/stage/timeline/timeline-layout.cpp
@@ -40,6 +40,7 @@
 
 #include "common/advice.hpp"
 //#include "lib/util.hpp"
+#include "lib/time/timevalue.hpp"
 
 //#include <algorithm>
 //#include <vector>
@@ -53,11 +54,19 @@
 //using sigc::ptr_fun;
 //using std::cout;
 //using std::endl;
+using lib::time::Time;
+using lib::time::FSecs;
+//using lib::time::Duration;
+using lib::time::TimeSpan;
 
 
 namespace stage {
 namespace timeline {
   
+  namespace {   /////////////////////////////////////////////////////TICKET #1213 : use proper zoom handling instead of dummy constants!!
+    const int TODO_px_per_second = 25;
+  }             /////////////////////////////////////////////////////TICKET #1213 : (END) get rid of these dummy constants!!
+  
   
   
   
@@ -108,14 +117,19 @@ namespace timeline {
   
   
   
-  /* ==== Interface: LayoutManager===== */
+  /* ==== Interface: DisplayManager===== */
   
-  PixSpan
-  TimelineLayout::getPixSpan()
+  TimeSpan
+  TimelineLayout::coveredTime() const
+  {                                        /////////////////////////////////////TICKET #1019 : need a "ZoomWindow" here to manage the visible area
+                                           /////////////////////////////////////TICKET #1039 : "somehow" wire with the TimelineController to find out the covered span
+    return TimeSpan {Time::ZERO, FSecs{23}}; ////////////////Lalala Lalü
+  }
+  
+  int
+  TimelineLayout::translateTimeToPixels (TimeValue startTimePoint)  const
   {
-                                           ////////////////////////////////////////////////////////TICKET #1019 : need a "ZoomWindow" here to manage the visible area
-                                           ////////////////////////////////////////////////////////TICKET #1039 : "somehow" wire with the TimelineController to find out the covered span
-    return PixSpan {0, 248}; ////////////////Lalala Lalü
+    return _raw(startTimePoint) * TODO_px_per_second / Time::SCALE;   //////////TICKET #1213 : delegate zoom handling to the display manager (field #layout_) !!
   }
   
   
diff --git a/src/stage/timeline/timeline-layout.hpp b/src/stage/timeline/timeline-layout.hpp
index b8387be18..4bdfeb4d9 100644
--- a/src/stage/timeline/timeline-layout.hpp
+++ b/src/stage/timeline/timeline-layout.hpp
@@ -137,9 +137,14 @@ namespace timeline {
       
     protected: /* ==== Interface: LayoutManager===== */
       
-      PixSpan getPixSpan()  override;
       void triggerDisplayEvaluation()  override;
       
+      /////////////////////////////////////////////////////////////////////////////////////////////TICKET 1218 : better extract into a sub component when providing a non-dummy implementation
+      virtual lib::time::TimeSpan coveredTime()     const override;
+      virtual int translateTimeToPixels (TimeValue) const override;
+      /////////////////////////////////////////////////////////////////////////////////////////////TICKET 1218 : better extract into a sub component when providing a non-dummy implementation
+      
+      
     protected: /* ==== Interface: DisplayViewHooks===== */
       
       model::ViewHook<TrackHeadWidget>& getHeadHook()  override { return *this;       };
diff --git a/tests/stage/model/canvas-hook-test.cpp b/tests/stage/model/canvas-hook-test.cpp
index 66b93ca7a..c223427a9 100644
--- a/tests/stage/model/canvas-hook-test.cpp
+++ b/tests/stage/model/canvas-hook-test.cpp
@@ -151,11 +151,10 @@ namespace test {
           }
         
       protected:
-        int
-        translateTimeToPixels (TimeValue)  const override
+        DisplayMetric&
+        getMetric()  const override
           {
             NOTREACHED ("Time to pixel translation not covered in this unit test");
-            return -1;
           }
       };
   }
diff --git a/wiki/thinkPad.ichthyo.mm b/wiki/thinkPad.ichthyo.mm
index 19e4a798b..dd141e861 100644
--- a/wiki/thinkPad.ichthyo.mm
+++ b/wiki/thinkPad.ichthyo.mm
@@ -33099,7 +33099,7 @@
 </html></richcontent>
 </node>
 </node>
-<node BACKGROUND_COLOR="#eee5c3" COLOR="#990000" CREATED="1619697245422" ID="ID_1061197338" MODIFIED="1619697783176" TEXT="Forwarding &#xfc;ber mehrere Schritte">
+<node COLOR="#435e98" CREATED="1619697245422" ID="ID_1061197338" MODIFIED="1619804310109" TEXT="Forwarding &#xfc;ber mehrere Schritte">
 <richcontent TYPE="NOTE"><html>
   <head>
     
@@ -33123,8 +33123,8 @@
 </html></richcontent>
 <icon BUILTIN="messagebox_warning"/>
 <node CREATED="1619697735697" ID="ID_1610716398" MODIFIED="1619697746057" TEXT="effektiv 2-Schritt-Forwarding f&#xfc;r jeden Aufruf"/>
-<node BACKGROUND_COLOR="#eee5c3" COLOR="#990000" CREATED="1619697793583" ID="ID_800939749" MODIFIED="1619697865895" TEXT="kann man (opaque) direkt aufrufen?">
-<icon BUILTIN="flag-yellow"/>
+<node COLOR="#338800" CREATED="1619697793583" FOLDED="true" ID="ID_800939749" MODIFIED="1619804558065" TEXT="kann man (opaque) direkt aufrufen?">
+<icon BUILTIN="button_ok"/>
 <node CREATED="1619698100329" ID="ID_1983859376" MODIFIED="1619698109360" TEXT="ja: wenn es ein VTable-Slot ist">
 <node CREATED="1619698280744" ID="ID_1197467052" MODIFIED="1619698299342" TEXT="dazu m&#xfc;&#xdf;te das Delegate ein Sub-Interface implementieren"/>
 <node CREATED="1619698300242" ID="ID_498514293" MODIFIED="1619698315566" TEXT="und der Wrapper ebenfalls"/>
@@ -33164,14 +33164,14 @@
       das Platzieren auf den Canvas ist <b>keine</b>&#160;high-Performance-Operation;<br />vielmehr ist es sogar <i>vernachl&#228;ssigbar im Vergleich </i>zum Aufwand der Zeichen-Operationen; und letztere werden eben genau aus Performance-Gr&#252;nden gebatcht und geb&#252;ndelt....
     </p>
   </body>
-</html>
-</richcontent>
+</html></richcontent>
 <linktarget COLOR="#6775b4" DESTINATION="ID_1522870458" ENDARROW="Default" ENDINCLINATION="125;10;" ID="Arrow_ID_565826448" SOURCE="ID_1388699771" STARTARROW="None" STARTINCLINATION="290;14;"/>
 <icon BUILTIN="yes"/>
 </node>
 </node>
 </node>
-<node CREATED="1619698512378" ID="ID_333159714" MODIFIED="1619698546465" TEXT="Metrik-&#xdc;bersetzung">
+<node COLOR="#435e98" CREATED="1619698512378" ID="ID_333159714" MODIFIED="1619804302859" TEXT="Metrik-&#xdc;bersetzung">
+<icon BUILTIN="forward"/>
 <node CREATED="1619698551205" ID="ID_994295604" MODIFIED="1619698871778" TEXT="sieht nach einem isolierten Belang aus">
 <arrowlink COLOR="#fef4ac" DESTINATION="ID_560285819" ENDARROW="Default" ENDINCLINATION="150;-12;" ID="Arrow_ID_514924311" STARTARROW="None" STARTINCLINATION="-370;27;"/>
 </node>
@@ -33192,14 +33192,13 @@
       im Gegensatz zum CanvasHook ist <i>das hier durchaus relevant</i>
     </p>
   </body>
-</html>
-</richcontent>
+</html></richcontent>
 <arrowlink COLOR="#6775b4" DESTINATION="ID_1522870458" ENDARROW="Default" ENDINCLINATION="125;10;" ID="Arrow_ID_565826448" STARTARROW="None" STARTINCLINATION="290;14;"/>
 </node>
 </node>
 </node>
-<node BACKGROUND_COLOR="#eee5c3" COLOR="#990000" CREATED="1619698607118" ID="ID_239118181" MODIFIED="1619698618056" TEXT="Umbau sehr w&#xfc;nschenswert">
-<icon BUILTIN="flag-yellow"/>
+<node COLOR="#338800" CREATED="1619698607118" ID="ID_239118181" MODIFIED="1619804296540" TEXT="Umbau sehr w&#xfc;nschenswert">
+<icon BUILTIN="button_ok"/>
 </node>
 </node>
 </node>
@@ -33214,7 +33213,8 @@
 <node CREATED="1619132510942" ID="ID_1513485460" MODIFIED="1619132510942" TEXT="applyScreenDelta(TimeValue, deltaPx)"/>
 <node CREATED="1619132513720" ID="ID_718240764" MODIFIED="1619132619351" TEXT="translateScreenDeltaToTime(deltaPx)"/>
 </node>
-<node CREATED="1619698634099" ID="ID_1185723124" MODIFIED="1619698643209" TEXT="Sub-Interface einf&#xfc;hren">
+<node COLOR="#338800" CREATED="1619698634099" ID="ID_1185723124" MODIFIED="1619804547408" TEXT="Sub-Interface einf&#xfc;hren">
+<icon BUILTIN="button_ok"/>
 <node CREATED="1619698644218" ID="ID_560285819" MODIFIED="1619698871778" TEXT="es ist ein komplett isolierter Belang">
 <linktarget COLOR="#fef4ac" DESTINATION="ID_560285819" ENDARROW="Default" ENDINCLINATION="150;-12;" ID="Arrow_ID_514924311" SOURCE="ID_994295604" STARTARROW="None" STARTINCLINATION="-370;27;"/>
 <icon BUILTIN="idea"/>
@@ -33232,11 +33232,15 @@
 </html></richcontent>
 <icon BUILTIN="forward"/>
 </node>
-<node BACKGROUND_COLOR="#eee5c3" COLOR="#990000" CREATED="1619698722008" ID="ID_755674225" MODIFIED="1619698813353" TEXT="wird (parametrisierbare) Komponente im LayoutManager">
-<icon BUILTIN="flag-yellow"/>
+<node BACKGROUND_COLOR="#eee5c3" COLOR="#990000" CREATED="1619698722008" FOLDED="true" ID="ID_755674225" MODIFIED="1619804539751" TEXT="wird (parametrisierbare) Komponente im LayoutManager">
+<icon BUILTIN="bell"/>
+<node CREATED="1619804516182" ID="ID_303795305" MODIFIED="1619804534566" TEXT="vorl&#xe4;ufige Dummy-Implementierung">
+<icon BUILTIN="idea"/>
 </node>
-<node BACKGROUND_COLOR="#eee5c3" COLOR="#990000" CREATED="1619698793375" ID="ID_127168366" MODIFIED="1619698814669" TEXT="und Mix-In f&#xfc;r die CanvasHook-Hierarchie">
-<icon BUILTIN="flag-yellow"/>
+<node COLOR="#435e98" CREATED="1619804525392" ID="ID_1563089049" MODIFIED="1619804538286" TEXT="in timeline-layout.cpp, Zeile 123"/>
+</node>
+<node COLOR="#338800" CREATED="1619698793375" ID="ID_127168366" MODIFIED="1619804320757" TEXT="und Mix-In f&#xfc;r die CanvasHook-Hierarchie">
+<icon BUILTIN="button_ok"/>
 </node>
 </node>
 </node>