How do I create an expanding field editor in a LiveCode DataGrid?

Question

I need to create a field editor in a LiveCode DataGrid that grows as the user types to fit the formattedHeight of the field. The rest of the underlying row control needs to resize too along with shifting any subsequent row controls down.

Answer 1

Answering my own question as it may be useful to others.

Copy the field editor behavior button from the revDataGridLibrary stack to the card with the row template on it.

Edit the script of the field to be edited as follows (note you will need to fix the behavior button reference to be the long id of your new field edtior behaviour):

on preOpenFieldEditor pEditor
   set the behavior of pEditor to the long id of button id 1023 of card id 1010 of stack "Data Grid Templates 1362091650635"
   set the uRowControl of pEditor to the long id of the owner of me
end preOpenFieldEditor

Edit the field editor behavior script adding the following:

local sHeight,sRowControl

setProp uRowControl pRowControl
   put pRowControl into sRowControl
end uRowControl

on openField
   put the formattedHeight of me into sHeight
   pass openField
end openField

on textChanged
   local tHeight,tRect
   lock screen
   put the formattedHeight of me into tHeight
   if sHeight <> tHeight then
      put the rect of me into tRect
      put item 2 of tRect+ tHeight into item 4 of tRect
      set the rect of me to tRect
      put tHeight into sHeight
      dispatch "UpdateRow" to sRowControl with the long id of me
   end if 
   unlock screen
   pass textChanged
end textChanged

Now edit the row template behaviour adding the following handler (Note that in this case the field being edited is named "note" so you will want to change that for your use case):

on UpdateRow pFieldEditor
   set the rect of graphic "Background" of me to the rect of pFieldEditor
   set the rect of fld "note" of me to the rect of pFieldEditor
   set the rect of me to the formattedRect of me
   put the uScriptLocal["sTableObjectsA"] of me into tTableObjectsA
   repeat for each line tControl in tTableObjectsA["all row controls"]
      delete word -2 to -1 of tControl -- of me
      put tControl into tControlA[the dgIndex of tControl]
   end repeat
   put the bottomLeft of me into tTopLeft
   repeat for each item tIndex in tTableObjectsA["current"]["indexes"]
      if tIndex > the dgIndex of me then
         set the topLeft of tControlA[tIndex] to tTopLeft
         put the bottomLeft of tControlA[tIndex] into tTopLeft
      end if
   end repeat
end UpdateRow