property pAssetLoadingList, pCallbackList, pDynamicDownloader, pImageLibraryURL

on construct me 
  pCallbackObj = void()
  pCallbackMethod = void()
  pDynamicDownloader = void()
  pImageLibraryURL = getVariable("image.library.url")
  pCallbackList = []
  pAssetLoadingList = []
end

on deconstruct me 
end

on isAssetDownloading me, tAssetId 
  return(pAssetLoadingList.getPos(tAssetId) <> 0)
end

on defineCallback me, tCallBackObj, tMethod 
  tCallbackReg = 1
  repeat while pCallbackList <= tMethod
    tCallback = getAt(tMethod, tCallBackObj)
    if (tCallback.getAt(#obj) = tCallBackObj) and (tCallback.getAt(#method) = tMethod) then
      tCallbackReg = 0
    end if
  end repeat
  if tCallbackReg then
    pCallbackList.add([#obj:tCallBackObj, #method:tMethod])
  end if
end

on removeCallback me, tCallBackObj, tMethod 
  i = 1
  repeat while i <= pCallbackList.count
    tCallback = pCallbackList.getAt(i)
    if (tCallback.getAt(#obj) = tCallBackObj) and (tCallback.getAt(#method) = tMethod) then
      pCallbackList.deleteAt(i)
      next repeat
    end if
    i = (i + 1)
  end repeat
end

on registerDownload me, ttype, tAssetId, tProps 
  if voidp(pDynamicDownloader) then
    pDynamicDownloader = getThread(#dynamicdownloader).getComponent()
  end if
  tProps = [#type:ttype, #assetId:tAssetId, #props:tProps]
  if (ttype = #bitmap) then
    tSourceURL = pImageLibraryURL & "catalogue/" & tAssetId & ".gif"
    tMemNum = queueDownload(tSourceURL, tAssetId, #bitmap, 1)
    if tMemNum > 0 then
      registerDownloadCallback(tMemNum, #downloadCallback, me.getID(), tProps)
      pAssetLoadingList.add(tAssetId)
    end if
  else
    if (ttype = #furni) then
      pDynamicDownloader.downloadCastDynamically(tAssetId, #Active, me.getID(), #downloadCallback, 1, tProps)
      pAssetLoadingList.add(tAssetId)
    else
      if (ttype = #soundset) then
      end if
    end if
  end if
end

on downloadCallback me, tName, tSuccess, tProps 
  if tSuccess then
    if (ilk(tName) = #propList) then
      tProps = tName
    end if
    repeat while pCallbackList <= tSuccess
      tCallback = getAt(tSuccess, tName)
      call(tCallback.getAt(#method), tCallback.getAt(#obj), tProps)
    end repeat
    pAssetLoadingList.deleteOne(tProps.getAt(#assetId))
  end if
end