After undo, point object SetAllPoints not update

chuanzhen

Hi,
I encountered a problem. When I set the position of an object's point, however, when I undo it and set it again, the object does not refresh in time. Only if I click on the object again and set it again will it be refreshed in time.

This is the video,

This is simple code：



import c4d
import os
import sys
from c4d import gui,bitmaps,plugins,utils,modules


PLUGIN_ID = 10000001


class S_test_Dialog(gui.GeDialog):


    def CreateLayout(self):
        self.SetTitle("test")


        self.GroupBegin(1000,c4d.BFH_SCALEFIT,4,0)

        self.AddStaticText(1003, c4d.BFH_RIGHT, 80, 20, "  Target ")
        bc = c4d.GetCustomDataTypeDefault(c4d.DTYPE_BASELISTLINK)
        self.AddCustomGui(1004, c4d.CUSTOMGUI_LINKBOX, "", c4d.BFH_SCALEFIT, 300, 0, bc)

        self.GroupEnd()

        self.AddButton(1010, c4d.BFH_SCALEFIT, 150, 30, "ChangePoints")



        return True



    def Command(self, id, msg):

        if id == 1010:
            doc = c4d.documents.GetActiveDocument()

            target = self.FindCustomGui(1004, c4d.CUSTOMGUI_LINKBOX).GetData()

            all_p = target.GetAllPoints()
            for id,pos in enumerate(all_p):
                all_p[id] = c4d.Vector(0)

            doc.StartUndo()
            doc.AddUndo(c4d.UNDOTYPE_CHANGE,target)
            target.SetAllPoints(all_p)
            target.Message(c4d.MSG_UPDATE)
            doc.EndUndo()
            c4d.EventAdd()

            return True




        return True






class S_test(plugins.CommandData):

    dialog = None

    def Execute(self,doc):
        # create the dialog
        if self.dialog is None:
            self.dialog = S_test_Dialog()

        return self.dialog.Open(dlgtype=c4d.DLG_TYPE_ASYNC, pluginid=PLUGIN_ID, defaultw=400, defaulth=100)

    def RestoreLayout(self, sec_ref):
        # manage nonmodal dialog
        if self.dialog is None:
            self.dialog = S_test_Dialog()

        return self.dialog.Restore(pluginid=PLUGIN_ID, secret=sec_ref)


# Execute main()
if __name__=='__main__':
    path, fn = os.path.split(__file__)

    plugins.RegisterCommandPlugin(id=PLUGIN_ID,
                                  str="S_test",
                                  info=0,
                                  help="",
                                  dat=S_test(),
                                  icon=None)

Thanks for any help!

ferdinand

Hello @chuanzhen,

Thank you for reaching out to us. The problems you encounter stem from the fact that you use the wrong method to retrieve your link.

When you undo an action, the object will not be the same anymore since the object has been replaced with whatever was found in the undo-stack. You simply must use the correct method c4d.gui.LinkBoxGui.GetLink and things will also work after an undo.

Cheers,
Ferdinand

Code:

def CreateLayout(self):
    self.SetTitle("test")
    self.GroupBegin(1000, c4d.BFH_SCALEFIT, 4, 0)
    self.AddStaticText(1003, c4d.BFH_RIGHT, 80, 20, "  Target ")
    # We store the custom GUI so that we do not have to grab it every time.
    self._link = self.AddCustomGui(
        1004, c4d.CUSTOMGUI_LINKBOX, "", c4d.BFH_SCALEFIT, 300, 0, 
        c4d.GetCustomDataTypeDefault(c4d.DTYPE_BASELISTLINK))
    self.GroupEnd()
    self.AddButton(1010, c4d.BFH_SCALEFIT, 150, 30, "ChangePoints")

    return True

def Command(self, id, msg):

    if id == 1010:
        doc = c4d.documents.GetActiveDocument()
        # This line was problematic because you did use BaseCustomGui.GetData and not 
        # LinkBoxGui.GetLink which has special logic for this type. This can fail.
        # target = self.FindCustomGui(1004, c4d.CUSTOMGUI_LINKBOX).GetData()
        
        # This cannot, it will automatically reattach a dangling link (after an undo for 
        # example). We could also do that ourself with UUIDs but why when we do not have to :)
        target: c4d.BaseObject | None = self._link.GetLink(doc, c4d.Opolygon)
        if not target:
            return True
            
        points: list[c4d.Vector] = [c4d.Vector() for _ in range(target.GetPointCount())]

        doc.StartUndo()
        doc.AddUndo(c4d.UNDOTYPE_CHANGE, target)
        target.SetAllPoints(points)
        target.Message(c4d.MSG_UPDATE)
        doc.EndUndo()
        c4d.EventAdd()
    return True

chuanzhen

@ferdinand Thanks for your help!