PageView itembuilder reset after some page

Question

Steps to reproduce

Created enum for pageview pages. Created pageview controller and store in provider for accessing in to pageview's pages. When I trying to go next page in page 15 , pageview builder index reproduce value to 16 and after 0. You can see pageview index values in logs. When I trying to next page at page15 , item builder was print index 16 as correctly but after it that change it to 0. I cant see page 16.

Im using context.read().questionPageController in two pages explicitly, I even tried to remove controller from these pages and just used in QuestionView but there is no change. Other than that, I don't interfere with the controller object from anywhere else anyway.

When I opened a project from scratch and created an 18-page pageview just like mine, I didn't encounter a problem. Thank you.

Expected results

PageView itembuilder should give to item index 16

Actual results

PageView itembuilder giving item index 16 and 0

Code sample and log

// My Onboard Pages---------------------------------------------

enum QuestionPagesEnum {
  questionStart,
  gender,
  heightWeightAge,
  focusParts,
  target,
  desiredMetrics,
  desiredMetricsGoal,
  desiredMetricsWeightGoal,
  targetBasedBenefit,
  injury,
  equipment,
  wearable,
  dayCountAvailable,
  daysAvailable,
  analyzingYourData,
  fitTest,
  fitnessLevel,
  daysAvaiableAfterLoadPage,
}

extension XQuestionPagesEnum on QuestionPagesEnum {
  Widget toPage() {
    switch (this) {
      case QuestionPagesEnum.questionStart:
        return const QuestionStartPage();
      case QuestionPagesEnum.gender:
        return const QuestionGenderPage();
      case QuestionPagesEnum.heightWeightAge:
        return const HeightWeightAgePage();
      case QuestionPagesEnum.focusParts:
        return const FocusPartsPage();
      case QuestionPagesEnum.target:
        return const TargetPage();
      case QuestionPagesEnum.desiredMetrics:
        return const DesiredMetricsPage();
      case QuestionPagesEnum.desiredMetricsGoal:
        return const DesiredMetricsGoalPage();
      case QuestionPagesEnum.desiredMetricsWeightGoal:
        return const DesiredMetricsWeightGoalPage();
      case QuestionPagesEnum.targetBasedBenefit:
        return const TargetBasedBenefitPage();
      case QuestionPagesEnum.fitnessLevel:
        return const FitnessLevelPage();
      case QuestionPagesEnum.injury:
        return const InjuryPage();
      case QuestionPagesEnum.equipment:
        return const EquipmentPage();
      case QuestionPagesEnum.wearable:
        return const WearablePage();
      case QuestionPagesEnum.analyzingYourData:
        return const AnalyzingDataPage();
      case QuestionPagesEnum.dayCountAvailable:
        return const DayCountAvailablePage();
      case QuestionPagesEnum.daysAvailable:
        return const DaysAvailablePage();
      case QuestionPagesEnum.daysAvaiableAfterLoadPage:
        return const DaysAvaiableAfterLoadPage();
      case QuestionPagesEnum.fitTest:
        return const FitTestPage();
      default:
        return const QuestionStartPage();
    }
  }
}

// My Onboard View--------------------------------------------------------

class QuestionsView extends StatefulWidget {
  const QuestionsView({super.key});

  @override
  State<QuestionsView> createState() => _QuestionsViewState();
}

class _QuestionsViewState extends State<QuestionsView> {
 
  @override
  Widget build(BuildContext context) {
    ColorConstant.setDefaultUIOverlayStyle();

    return Selector<OnBoardViewModel, int>(
      selector: (p0, p1) => p1.questionsPageIndex,
      shouldRebuild: (previous, next) => true,
      builder: (context, index, _) {
        return AppScaffold(
          child: SafeArea(
            child: Selector<OnBoardViewModel, bool>(
                selector: (p0, p1) => p1.isRouteForCompleteOnboard,
                builder: (context, isRouteForCompleteOnboard, _) {
                  return Column(
                    children: [
                      const Expanded(child: _PageView()),
                      Visibility(
                        visible: index == QuestionPagesEnum.daysAvailable.index,
                        child: _daysAvailableBottomText(context),
                      ),
                      Visibility(
                        visible: isVisibleNextButton(index),
                        child: _nextPageButton(index),
                      ),
                      if (index != QuestionPagesEnum.fitTest.index) ...{
                        SizedBox(height: MediaQuery.of(context).viewPadding.bottom == 0 ? 16 : 0),
                      },
                    ],
                  );
                }),
          ),
        );
      },
    );

 // Next Page Button
  Widget _nextPageButton(int index) {
    return Consumer<OnBoardViewModel>(
      builder: (context, viewmodel, child) {
        return Padding(
          padding: const EdgeInsets.symmetric(horizontal: 16.0),
          child: ButtonPrimary(
            width: double.maxFinite,
            onPressed: _isContinue(viewmodel)
                ? () async {
                    FocusManager.instance.primaryFocus?.unfocus();
                    if (viewmodel.heightWeightFormKey.currentState?.validate() == false) return;
                    if (viewmodel.desiredMetricsGoalWeightFormKey.currentState?.validate() == false) return;

                    viewmodel.questionsPageController!.nextPage(
                      duration: const Duration(milliseconds: 200),
                      curve: Curves.linear,
                    );
                  }
                : null,
          ),
        );
      },
    );
  }

  }


// My Page View--------------------------------------------------------

class _PageView extends StatefulWidget {
  const _PageView();

  @override
  State<_PageView> createState() => _PageViewState();
}

class _PageViewState extends State<_PageView> {
  final controller = PageController();

  @override
  void initState() {
    super.initState();
    context.read<OnBoardViewModel>().questionsPageController = controller;
  }

  @override
  void dispose() {
    controller.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return PageView.builder(
        controller: controller,
        physics: const NeverScrollableScrollPhysics(),
        itemCount: QuestionPagesEnum.values.length,
        onPageChanged: (value) {
          print('onPageChanged $value');
          context.read<OnBoardViewModel>().setQuestionsPageIndex(value);
        },
        itemBuilder: (context, index) {
          print('itemBuilder $index');
          return QuestionPagesEnum.values[index].toPage();
        });
  }
}


### Logs

    Launching lib\main.dart on sdk gphone64 x86 64 in debug mode...
√  Built build\app\outputs\flutter-apk\app-debug.apk.
D/FlutterGeolocator( 5437): Attaching Geolocator to activity
I/TextToSpeech( 5437): Connected to TTS engine
D/HostConnection( 5437): createUnique: call
D/HostConnection( 5437): HostConnection::get() New Host Connection established 0x72b870fa3ed0, tid 5607
D/HostConnection( 5437): HostComposition ext ANDROID_EMU_CHECKSUM_HELPER_v1 ANDROID_EMU_native_sync_v2 ANDROID_EMU_dma_v1 ANDROID_EMU_direct_mem ANDROID_EMU_YUV_Cache ANDROID_EMU_has_shared_slots_host_memory_allocator ANDROID_EMU_sync_buffer_data ANDROID_EMU_read_color_buffer_dma GL_OES_vertex_array_object GL_KHR_texture_compression_astc_ldr ANDROID_EMU_host_side_tracing ANDROID_EMU_gles_max_version_2
W/OpenGLRenderer( 5437): Failed to initialize 101010-2 format, error = EGL_SUCCESS
D/EGL_emulation( 5437): eglCreateContext: 0x72b870fa3b10: maj 2 min 0 rcv 2
D/EGL_emulation( 5437): eglMakeCurrent: 0x72b870fa3b10: ver 2 0 (tinfo 0x72ba8ae88180) (first time)
I/Gralloc4( 5437): mapper 4.x is not supported
I/TextToSpeech( 5437): Setting up the connection to TTS engine...
D/HostConnection( 5437): createUnique: call
D/HostConnection( 5437): HostConnection::get() New Host Connection established 0x72b870fa4f50, tid 5636
D/goldfish-address-space( 5437): allocate: Ask for block of size 0x100
D/goldfish-address-space( 5437): allocate: ioctl allocate returned offset 0x3edffc000 size 0x2000
W/Gralloc4( 5437): allocator 4.x is not supported
D/HostConnection( 5437): HostComposition ext ANDROID_EMU_CHECKSUM_HELPER_v1 ANDROID_EMU_native_sync_v2 ANDROID_EMU_dma_v1 ANDROID_EMU_direct_mem ANDROID_EMU_YUV_Cache ANDROID_EMU_has_shared_slots_host_memory_allocator ANDROID_EMU_sync_buffer_data ANDROID_EMU_read_color_buffer_dma GL_OES_vertex_array_object GL_KHR_texture_compression_astc_ldr ANDROID_EMU_host_side_tracing ANDROID_EMU_gles_max_version_2
D/HostConnection( 5437): createUnique: call
D/HostConnection( 5437): HostConnection::get() New Host Connection established 0x72b870fa3450, tid 5636
D/HostConnection( 5437): HostComposition ext ANDROID_EMU_CHECKSUM_HELPER_v1 ANDROID_EMU_native_sync_v2 ANDROID_EMU_dma_v1 ANDROID_EMU_direct_mem ANDROID_EMU_YUV_Cache ANDROID_EMU_has_shared_slots_host_memory_allocator ANDROID_EMU_sync_buffer_data ANDROID_EMU_read_color_buffer_dma GL_OES_vertex_array_object GL_KHR_texture_compression_astc_ldr ANDROID_EMU_host_side_tracing ANDROID_EMU_gles_max_version_2
D/EGL_emulation( 5437): eglMakeCurrent: 0x72b870fa2850: ver 2 0 (tinfo 0x72ba8ae88200) (first time)
D/EGL_emulation( 5437): eglCreateContext: 0x72b870fa3390: maj 2 min 0 rcv 2
D/FlutterGeolocator( 5437): Creating service.
D/FlutterGeolocator( 5437): Binding to location service.
D/FlutterGeolocator( 5437): Geolocator foreground service connected
D/FlutterGeolocator( 5437): Initializing Geolocator services
D/FlutterGeolocator( 5437): Flutter engine connected. Connected engine count 1
Connecting to VM Service at ws://127.0.0.1:52520/7Uq3vzWR_PI=/ws
W/FlutterJNI( 5437): FlutterJNI.loadLibrary called more than once
I/ResourceExtractor( 5437): Found extracted resources res_timestamp-133-1689879497352
W/FlutterJNI( 5437): FlutterJNI.prefetchDefaultFontManager called more than once
W/FlutterJNI( 5437): FlutterJNI.init called more than once
I/FLTFireBGExecutor( 5437): Creating background FlutterEngine instance, with args: [--start-paused, --enable-dart-profiling]
D/EGL_emulation( 5437): eglCreateContext: 0x72b870fa3d50: maj 2 min 0 rcv 2
D/EGL_emulation( 5437): eglCreateContext: 0x72b870fa4890: maj 2 min 0 rcv 2
D/HostConnection( 5437): createUnique: call
D/HostConnection( 5437): HostConnection::get() New Host Connection established 0x72b870f9ff10, tid 5741
D/HostConnection( 5437): HostComposition ext ANDROID_EMU_CHECKSUM_HELPER_v1 ANDROID_EMU_native_sync_v2 ANDROID_EMU_dma_v1 ANDROID_EMU_direct_mem ANDROID_EMU_YUV_Cache ANDROID_EMU_has_shared_slots_host_memory_allocator ANDROID_EMU_sync_buffer_data ANDROID_EMU_read_color_buffer_dma GL_OES_vertex_array_object GL_KHR_texture_compression_astc_ldr ANDROID_EMU_host_side_tracing ANDROID_EMU_gles_max_version_2
D/EGL_emulation( 5437): eglMakeCurrent: 0x72b870fa4890: ver 2 0 (tinfo 0x72ba8ae88280) (first time)
I/TextToSpeech( 5437): Sucessfully bound to com.google.android.tts
I/TextToSpeech( 5437): Connected to TTS engine
I/TextToSpeech( 5437): Setting up the connection to TTS engine...
W/SQLiteLog( 5437): (28) double-quoted string literal: "notification"
D/FlutterGeolocator( 5437): Geolocator foreground service connected
D/FlutterGeolocator( 5437): Initializing Geolocator services
D/FlutterGeolocator( 5437): Flutter engine connected. Connected engine count 2
D/EGL_emulation( 5437): app_time_stats: avg=478.81ms min=71.38ms max=1673.68ms count=4
I/flutter ( 5437): onPageChanged 1
I/flutter ( 5437): itemBuilder 1
D/EGL_emulation( 5437): app_time_stats: avg=265.48ms min=23.54ms max=1355.86ms count=7
D/EGL_emulation( 5437): app_time_stats: avg=146.04ms min=31.44ms max=1115.07ms count=10
I/flutter ( 5437): itemBuilder 2
I/flutter ( 5437): onPageChanged 2
I/flutter ( 5437): itemBuilder 3
I/flutter ( 5437): onPageChanged 3
D/EGL_emulation( 5437): app_time_stats: avg=55.15ms min=18.90ms max=258.53ms count=18
D/EGL_emulation( 5437): app_time_stats: avg=91.16ms min=22.30ms max=710.96ms count=12
I/flutter ( 5437): itemBuilder 4
I/flutter ( 5437): onPageChanged 4
D/EGL_emulation( 5437): app_time_stats: avg=50.04ms min=16.93ms max=503.90ms count=28
I/flutter ( 5437): itemBuilder 5
I/flutter ( 5437): onPageChanged 5
D/EGL_emulation( 5437): app_time_stats: avg=50.49ms min=19.49ms max=246.47ms count=21
I/flutter ( 5437): itemBuilder 6
I/flutter ( 5437): onPageChanged 6
D/EGL_emulation( 5437): app_time_stats: avg=50.42ms min=15.42ms max=441.49ms count=20
I/flutter ( 5437): itemBuilder 7
I/flutter ( 5437): onPageChanged 7
I/flutter ( 5437): itemBuilder 8
I/flutter ( 5437): onPageChanged 8
D/EGL_emulation( 5437): app_time_stats: avg=82.53ms min=18.27ms max=360.83ms count=14
I/flutter ( 5437): itemBuilder 9
I/flutter ( 5437): onPageChanged 9
D/EGL_emulation( 5437): app_time_stats: avg=31.93ms min=16.46ms max=59.25ms count=31
I/flutter ( 5437): itemBuilder 10
I/flutter ( 5437): onPageChanged 10
D/EGL_emulation( 5437): app_time_stats: avg=37.92ms min=15.08ms max=177.90ms count=27
I/flutter ( 5437): itemBuilder 11
I/flutter ( 5437): onPageChanged 11
D/EGL_emulation( 5437): app_time_stats: avg=49.81ms min=17.58ms max=456.65ms count=20
I/flutter ( 5437): itemBuilder 12
I/flutter ( 5437): onPageChanged 12
I/flutter ( 5437): itemBuilder 13
I/flutter ( 5437): onPageChanged 13
D/EGL_emulation( 5437): app_time_stats: avg=36.46ms min=15.46ms max=146.37ms count=27
D/EGL_emulation( 5437): app_time_stats: avg=49.67ms min=15.77ms max=438.82ms count=20
D/EGL_emulation( 5437): app_time_stats: avg=105.22ms min=19.10ms max=1083.31ms count=14
I/flutter ( 5437): itemBuilder 14
I/flutter ( 5437): onPageChanged 14
D/EGL_emulation( 5437): app_time_stats: avg=28.37ms min=15.43ms max=62.76ms count=34
D/EGL_emulation( 5437): app_time_stats: avg=26.62ms min=14.73ms max=38.46ms count=36
D/EGL_emulation( 5437): app_time_stats: avg=26.15ms min=14.88ms max=38.08ms count=36
D/EGL_emulation( 5437): app_time_stats: avg=26.83ms min=15.34ms max=67.52ms count=34
D/EGL_emulation( 5437): app_time_stats: avg=26.21ms min=14.47ms max=38.58ms count=37
D/EGL_emulation( 5437): app_time_stats: avg=53.53ms min=17.50ms max=354.10ms count=19
D/EGL_emulation( 5437): app_time_stats: avg=39.92ms min=24.09ms max=139.54ms count=25
D/EGL_emulation( 5437): app_time_stats: avg=34.88ms min=20.18ms max=75.62ms count=29
D/EGL_emulation( 5437): app_time_stats: avg=33.20ms min=20.06ms max=40.76ms count=30
D/EGL_emulation( 5437): app_time_stats: avg=34.26ms min=24.73ms max=51.62ms count=30
I/flutter ( 5437): itemBuilder 15
I/flutter ( 5437): onPageChanged 15
I/flutter ( 5437): itemBuilder 16
D/EGL_emulation( 5437): app_time_stats: avg=200.45ms min=22.77ms max=2003.17ms count=12
I/flutter ( 5437): onPageChanged 16
I/flutter ( 5437): itemBuilder 0

samedhrmn · Answer 1 · 2023-07-20T21:38:28.213

0

Update: Okey , when I remove this line in my code , issue is gone.

if (index != QuestionPagesEnum.fitTest.index) ...{
                    SizedBox(height: MediaQuery.of(context).viewPadding.bottom == 0 ? 16 : 0),},

Ok. I've noticed this. When I compare the index value from the selector with the if-statement of the QuestionPageEnum index value, the PageView builder behaves unstable. I am trying to test the same scenario in the project I opened from scratch, but I do not get the same error.

edited Jul 20 '23 at 21:38

answered Jul 20 '23 at 20:46

samedhrmn

85
1
5

you can mark as answer – Md. Yeasin Sheikh Jul 20 '23 at 21:42

PageView itembuilder reset after some page

Steps to reproduce

Expected results

Actual results

Code sample and log

1 Answers1