Q:

Why am I unable to change page in PageView.builder inside Future builder? 

Hello stackoverflow! 
I Have been having trouble using the pageview.builder inside a future builder.  the items it is paging through are cards, I did have this previously working but while implimenting logic to get notes and things I went to using a future builder and moved this NoteSet into it's own class.  I persume I made a breaking change somewhere but I am not sure.  The weird thing is, I can build and see the cards.  The enclosing gesturedetector works fine aswell, but I cannot page through my pageview.builder. 
Any help is greatly appreciated! 
class NoteSet extends StatefulWidget {
  VoidCallback callback;
  final Category category;

  NoteSet(this.category, this.callback);

  @override
  _NoteSetState createState() => _NoteSetState();
}

class _NoteSetState extends State<NoteSet> {
  List<NoteEntry> sortedNotes = [];
  double currentPage;
  bool largeCards = false;

  SortMethod currentSortMethod = SortMethod. CreatedDescending;

  Future<List<NoteEntry>> getNotes() async {
    return await readCategoryNotes(widget.category);
  }

  void sortNotes(){...}

  refresh() {...}

  deleteCategory() async {
    deleteCategoryDialog(context, widget.category, refresh);
  }

  void toggleModifiedSort(){
    currentSortMethod == SortMethod. ModifiedDescending ?  currentSortMethod = SortMethod. ModifiedAscending : currentSortMethod = SortMethod. ModifiedDescending;
    refresh();
  }

  void toggleCreatedSort(){
    currentSortMethod == SortMethod. CreatedDescending ?  currentSortMethod = SortMethod. CreatedAscending : currentSortMethod = SortMethod. CreatedDescending;
    refresh();
  }

  void toggleCardSize(){
    largeCards = ! largeCards;
    refresh();
  }

  void moveThisCategoryUp() async {
    await moveCategoryUp(widget.category);
    refresh();
  }

  void moveThisCategoryDown() async {
    await moveCategoryDown(widget.category);
    refresh();
  }

  @override
  Widget build(BuildContext context) {
    PageController controller = PageController();
    currentPage = (sortedNotes.length - 1).roundToDouble();
    return Column(
      children: <Widget>[
        Padding(
          padding: EdgeInsets.symmetric(horizontal: 10.0),
          child: Row(
            mainAxisAlignment: MainAxisAlignment.spaceBetween,
            children: <Widget>[
              Text(widget.category.toString().split(". ").last,
                style: TextStyle(
                  color: Colors.white,
                  fontSize: 46.0,
                  fontWeight: FontWeight.bold,
                  letterSpacing: 1.0,
                )
              ),
              PopupMenuButton<VoidCallback>(...),
            ],
          ),
        ),
        FutureBuilder(
          future: getNotes(),
          builder: (context, snapshot){
            if(snapshot.hasData){
              sortedNotes = snapshot.data;
              sortNotes();
              controller.addListener(() {
                setState(() {
                  currentPage = controller.page;
                });
              });
              return Column(
                children: <Widget>[
                  Padding(
                    padding: const EdgeInsets.only(left: 15.0),
                    child: Row(
                      children: <Widget>[
                        Text("${sortedNotes.length} Entries",
                            style: TextStyle(color: Colors.tealAccent[200]))
                      ],
                    ),
                  ),
                  Stack(
                    children: <Widget>[
                      CardScrollWidget(currentPage, sortedNotes, largeCards ?  0.8 : 1.2),
                      Positioned.fill(
                        child: GestureDetector(
                          onTap: () {
                            editNoteDialog(context, sortedNotes[currentPage.round()], refresh);
                          },
                          onLongPress: () {
                            deleteNoteDialog(context, sortedNotes[currentPage.round()], refresh);
                          },
                          child: ScrollConfiguration(
                            behavior: PageScrollBehavior(),
                            child: PageView.builder(
                              itemCount: sortedNotes.length,
                              controller: controller,
                              reverse: true,
                              itemBuilder: (context, index) {
                                return Container();
                              },
                            ),
                          ),
                        ),
                      )
                    ],
                  ),
                ],
              );
            }
            else{
              return Padding(
                padding: const EdgeInsets.all(20.0),
                child: Center(
                  child: SpinKitPulse(
                    color: Colors.tealAccent,
                    size: 60.0,
                  ),
                ),
              );
            }
          },
        ),
        SizedBox(height: 15,),
      ],
    );
  }
}

A:

Ok so I found my issue, everytime NoteSet was building, it was setting the currentPage variable to the initial page.  I also removed the future builder and instead call the future on init, then refresh when data is found.  Here is my corrected code:
class NoteSet extends StatefulWidget {
  VoidCallback callback;
  final Category category;

  NoteSet(this.category, this.callback);

  @override
  _NoteSetState createState() => _NoteSetState();
}

class _NoteSetState extends State<NoteSet> {
  List<NoteEntry> sortedNotes = [];
  double currentPage = 0;
  bool largeCards = false;
  bool dataReady = false;

  SortMethod currentSortMethod = SortMethod. CreatedDescending;

  Future getNotes() async {
    dataReady = false;
    refresh();
    sortedNotes = await readCategoryNotes(widget.category);
    currentPage = (sortedNotes.length - 1).roundToDouble();
    dataReady = true;
    refresh();
  }

  void sortNotes(){...}

  refresh() {
    widget.callback();
    this.setState((){});
    sortNotes();
  }

...

  @override
  void initState() {
    getNotes();
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return Column(
      children: <Widget>[
        Padding(
          padding: EdgeInsets.symmetric(horizontal: 10.0),
          child: Row(
            mainAxisAlignment: MainAxisAlignment.spaceBetween,
            children: <Widget>[
              Text(widget.category.toString().split(". ").last,
                style: TextStyle(
                  color: Colors.white,
                  fontSize: 46.0,
                  fontWeight: FontWeight.bold,
                  letterSpacing: 1.0,
                )
              ),
              PopupMenuButton<VoidCallback>(
                onSelected: (VoidCallback value){
                  value();
                },
                icon: Icon(
                  Icons.more_horiz,
                  size: 30.0,
                  color: Colors.white,
                ),
                itemBuilder: (BuildContext context) => <PopupMenuEntry<VoidCallback>>[...],
              ),
            ],
          ),
        ),
        ((){
            if(dataReady){
              PageController controller = PageController(initialPage: sortedNotes.length - 1);
              controller.addListener(() {
                setState(() {
                  currentPage = controller.page;
                });
              });
              return Column(
                children: <Widget>[
                  Padding(
                    padding: const EdgeInsets.only(left: 15.0),
                    child: Row(
                      children: <Widget>[
                        Text("${sortedNotes.length} Entries",
                            style: TextStyle(color: Colors.tealAccent[200]))
                      ],
                    ),
                  ),
                  Stack(
                    children: <Widget>[
                      CardScrollWidget(currentPage, sortedNotes, largeCards ?  0.8 : 1.2),
                      Positioned.fill(
                        child: GestureDetector(
                          onTap: () {
                            editNoteDialog(context, sortedNotes[currentPage.round()], refresh);
                          },
                          onLongPress: () {
                            deleteNoteDialog(context, sortedNotes[currentPage.round()], refresh);
                          },
                          child: ScrollConfiguration(
                            behavior: PageScrollBehavior(),
                            child: PageView.builder(
                              itemCount: sortedNotes.length,
                              controller: controller,
                              reverse: true,
                              itemBuilder: (context, index) {
                                return Container();
                              },
                            ),
                          ),
                        ),
                      )
                    ],
                  ),
                ],
              );
            }
            else{
              return Padding(
                padding: const EdgeInsets.all(20.0),
                child: Center(
                  child: SpinKitPulse(
                    color: Colors.tealAccent,
                    size: 60.0,
                  ),
                ),
              );
            }
          }()),
        SizedBox(height: 15,),
      ],
    );
  }
}

