KiCad 8 python API changes and porting guides

[adamws]

Hello, I started looking at KiCad 8 release candidate. I expect that many plugins will break due to major API changes. I’m creating this topic for sharing findings/porting efforts.

Let me start:

• pcbnew.PAD.GetParent() no longer returns FOOTPRINT (returns BOARD_ITEM_CONTAINER) - to call FOOTPRINT methods ( in my case it was pad.GetParent().GetOrientationDegrees()) the additional cast is required: pcbnew.Cast_to_FOOTPRINT(parent)

• NETINFO_LIST object has no attribute AppendNet

  • I was using AppendNet for generating board objects, like this:

    board = pcbnew.CreateEmptyBoard()
    ...
    add_nets(board, netnames)
    ...
    def add_nets(board, netnames):
        net_info = board.GetNetInfo()
        net_count = board.GetNetCount()
        for i, n in enumerate(netnames):
            net = pcbnew.NETINFO_ITEM(board, n, net_count + i)
            net_info.AppendNet(net)
            board.Add(net)
    

    Looks like net_info can be ignored when using KiCad8?

• Loading footprints does not work for me anymore. The part of my ‘generate board from scratch’ flow was adding footprints:

  def add_diode_footprint(board, footprint, request):
      library = get_footprints_dir(request)
      f = pcbnew.FootprintLoad(str(library), footprint)
      f.SetReference("D1")
      board.Add(f)
      return f
  

  which now fails with following error:

  tests/test_board_modifier.py:37: in add_diode_footprint
      f = pcbnew.FootprintLoad(str(library), footprint)
  /usr/lib/kicad-nightly/local/lib/python3.11/dist-packages/pcbnew.py:19001: in FootprintLoad
      plug = GetPluginForPath(libname)
  _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
  
  libname = '/home/aws/git/kicad-kbplacer/tests/data/footprints/tests.pretty'
  
      def GetPluginForPath(libname):
  >       plugin_type = IO_MGR.GuessPluginTypeFromLibPath( libname );
  E       NameError: name 'IO_MGR' is not defined
  
  /usr/lib/kicad-nightly/local/lib/python3.11/dist-packages/pcbnew.py:18993: NameError
  

  This might be either wrong usage or perhaps bug in KiCad, did not figure out that one yet (looks more like the latter).

[adamws]

I have quick update on my IO_MGR issue.
I opened pcbnew.py and changed this:

def GetPluginForPath(libname):
    plugin_type = IO_MGR.GuessPluginTypeFromLibPath( libname );
    return IO_MGR.PluginFind(plugin_type)

to this

def GetPluginForPath(libname):
    plugin_type = PCB_IO_MGR.GuessPluginTypeFromLibPath( libname );
    return PCB_IO_MGR.PluginFind(plugin_type)

ant it works. Something went wrong with generation of this file (occurs for both ubuntu nightly and windows builds)

[adamws]

IO_MGR problem has been fixed, if plugin used pcbnew.IO_MGR then it’s called pcbnew.PCB_IO_MGR now. The pcbnew.FootprintLoad works as expected.