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performance tuning - Scaling Dynamic widgets up


The serious flaw of Dynamic is a combination of facts:




  • it is triggered/refreshed by any kind of mutation of a symbol,





  • careful metaprogramming/construction of symbols is really cumbersome




An example is worth a thousand words so:


{ Dynamic@x[[1]], Dynamic@x[[2]]}

You can't trigger one without other one being affected even if the value didn't change. And writing:


{ Dynamic @ x1, Dynamic @ x2 }


will be tough to automatically scale/maintain for regular users. A real world example can be found here:


Allow multiple GUI elements to react dynamically to interaction with a single element


The code in the answer is not something you'd love to write on daily basis:


DynamicModule[{}, Graphics[{
   ( ToExpression[
      "{sA:=state" <> ToString[#] <> ", sB:=state" <> ToString[#2] <> "}",
      StandardForm, 
      Hold
    ] /. Hold[spec_] :> With[spec, 

       {  Dynamic @ If[TrueQ[sA || sB], Red, Black], 
          Line[{pts[#1], pts[#2]}]
       }
    ]
   ) & @@@ edges
   ,
   PointSize[0.025],
   (
    ToExpression[
      "{sA:=state" <> ToString[#] <> "}", 

      StandardForm, 
      Hold
    ] /. Hold[spec_] :> With[spec, 
       { Dynamic @ If[TrueQ[sA], Red, Black], 
         EventHandler[ Point @ pts[#], 
           {"MouseEntered" :> (sA = True), "MouseExited" :> (sA = False)}
         ]
       }
    ]
   ) & /@ names

  }, 
  ImageSize -> Large]
 ]

Very often a smart, specific solution can be applied but it would be nice to be able to do mindless things and not be limited by syntax/design issues but real limitations of how much FrontEnd can handle.


What can we do to make programming of idioms presented in the linked question more approachable?



Related topic: How to track Part of Symbol or How to symbolize Parts of Symbol without copying data




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