Reputation: 73

Type 'ui.ViewConfiguration' not found error while building iOS app in Flutter

Error: Type 'ui.ViewConfiguration' not found.

While running my flutter project, I am getting this error and the build fails. It runs fine on android but issue is only found while running in ios.

Failed to build iOS app Error (Xcode): ../../../../.pub-cache/hosted/pub.dev/printing-5.9.3/lib/src/widget_wrapper.dart:234:9: Error: Type 'ui.ViewConfiguration' not found. ../…/src/widget_wrapper.dart:234

Could not build the application for the simulator. Error launching application on iPhone 14. Exited

This is the code where the error has occured. This is a .pubcache file.

import 'dart:async';
import 'dart:typed_data';
import 'dart:ui' as ui;

import 'package:flutter/material.dart';
import 'package:flutter/rendering.dart';
import 'package:flutter/widgets.dart';
import 'package:pdf/pdf.dart';
import 'package:pdf/widgets.dart' as pw;

/// ImageProvider that draws a Flutter Widget on a PDF document
class WidgetWraper extends pw.ImageProvider {
  WidgetWraper._(
    this.bytes,
    int width,
    int height,
    PdfImageOrientation orientation,
    double? dpi,
  ) : super(width, height, orientation, dpi);

  /// Wrap a Flutter Widget identified by a GlobalKey to an ImageProvider.
  ///
  /// Use it with a RepaintBoundary:
  /// 
  /// final rb = GlobalKey();
  ///
  /// @override
  /// Widget build(BuildContext context) {
  ///   return RepaintBoundary(
  ///       key: rb,
  ///       child: FlutterLogo()
  ///   );
  /// }
  ///
  /// Future<Uint8List> _generatePdf(PdfPageFormat format) async {
  ///   final pdf = pw.Document();
  ///
  ///   final image = await WidgetWraper.fromKey(key: rb);
  ///
  ///   pdf.addPage(
  ///     pw.Page(
  ///       build: (context) {
  ///         return pw.Center(
  ///           child: pw.Image(image),
  ///         );
  ///       },
  ///     ),
  ///   );
  ///
  ///   return pdf.save();
  /// }
  /// 
  static Future<WidgetWraper> fromKey({
    required GlobalKey key,
    int? width,
    int? height,
    double pixelRatio = 1.0,
    PdfImageOrientation? orientation,
    double? dpi,
  }) async {
    assert(pixelRatio > 0);

    final wrappedWidget =
        key.currentContext!.findRenderObject() as RenderRepaintBoundary;
    final image = await wrappedWidget.toImage(pixelRatio: pixelRatio);
    final byteData = await image.toByteData(format: ui.ImageByteFormat.rawRgba);

    if (byteData == null) {
      return WidgetWraper._(
        Uint8List(0),
        0,
        0,
        PdfImageOrientation.topLeft,
        dpi,
      );
    }

    final imageData = byteData.buffer.asUint8List();
    return WidgetWraper._(
      imageData,
      image.width,
      image.height,
      orientation ?? PdfImageOrientation.topLeft,
      dpi,
    );
  }

  /// Wrap a Flutter Widget to an ImageProvider.
  ///
  /// 
  /// final wrapped = await WidgetWraper.fromWidget(
  ///   widget: Container(
  ///     color: Colors.white,
  ///     child: Text(
  ///       'Hello world !',
  ///       style: TextStyle(color: Colors.amber),
  ///     ),
  ///   ),
  ///   constraints: BoxConstraints(maxWidth: 100, maxHeight: 400),
  ///   pixelRatio: 3,
  /// );
  ///
  /// pdf.addPage(
  ///   pw.Page(
  ///     pageFormat: format,
  ///     build: (context) {
  ///       return pw.Image(wrapped, width: 100);
  ///     },
  ///   ),
  /// );
  /// 
  static Future<WidgetWraper> fromWidget({
    required Widget widget,
    required BoxConstraints constraints,
    double pixelRatio = 1.0,
    PdfImageOrientation? orientation,
    double? dpi,
  }) async {
    assert(pixelRatio > 0);

    if (!constraints.hasBoundedHeight || !constraints.hasBoundedHeight) {
      throw Exception(
          'Unable to convert an unbounded widget. Add maxWidth and maxHeight to the constraints.');
    }

    widget = ConstrainedBox(
      constraints: constraints,
      child: widget,
    );

    final _properties = DiagnosticPropertiesBuilder();
    widget.debugFillProperties(_properties);

    if (_properties.properties.isEmpty) {
      throw ErrorDescription('Unable to get the widget properties');
    }

    final _constraints = _properties.properties
        .whereType<DiagnosticsProperty<BoxConstraints>>()
        .first
        .value;

    if (_constraints == null ||
        !_constraints.hasBoundedWidth ||
        !_constraints.hasBoundedWidth) {
      throw Exception('Unable to convert an unbounded widget.');
    }

    final _repaintBoundary = RenderRepaintBoundary();

    final renderView = RenderView(
      child: RenderPositionedBox(
          alignment: Alignment.center, child: _repaintBoundary),
      configuration: ViewConfiguration(
          size: Size(_constraints.maxWidth, _constraints.maxHeight),
          devicePixelRatio: ui.window.devicePixelRatio),
      window: _FlutterView(
        configuration: ui.ViewConfiguration(
          devicePixelRatio: ui.window.devicePixelRatio,
        ),
      ),
    );

    final pipelineOwner = PipelineOwner()..rootNode = renderView;
    renderView.prepareInitialFrame();

    final buildOwner = BuildOwner(focusManager: FocusManager());
    final _rootElement = RenderObjectToWidgetAdapter<RenderBox>(
      container: _repaintBoundary,
      child: Directionality(
        textDirection: TextDirection.ltr,
        child: IntrinsicHeight(child: IntrinsicWidth(child: widget)),
      ),
    ).attachToRenderTree(buildOwner);

    buildOwner
      ..buildScope(_rootElement)
      ..finalizeTree();

    pipelineOwner
      ..flushLayout()
      ..flushCompositingBits()
      ..flushPaint();

    final image = await _repaintBoundary.toImage(pixelRatio: pixelRatio);
    final bytes = await image.toByteData(format: ui.ImageByteFormat.rawRgba);
    if (bytes == null) {
      throw Exception('Unable to read image data');
    }

    return WidgetWraper._(
      bytes.buffer.asUint8List(),
      image.width,
      image.height,
      orientation ?? PdfImageOrientation.topLeft,
      dpi,
    );
  }

  /// The image data
  final Uint8List bytes;

  @override
  PdfImage buildImage(pw.Context context, {int? width, int? height}) {
    return PdfImage(
      context.document,
      image: bytes,
      width: width ?? this.width!,
      height: height ?? this.height!,
      orientation: orientation,
    );
  }
}

class _FlutterView extends ui.FlutterView {
  _FlutterView({required this.configuration});

  final ui.ViewConfiguration configuration;

  @override
  ui.PlatformDispatcher get platformDispatcher =>
      ui.PlatformDispatcher.instance;

  @override
  ui.ViewConfiguration get viewConfiguration => configuration;
}

This particular part is giving the error

final ui.ViewConfiguration configuration;

  @override
  ui.PlatformDispatcher get platformDispatcher =>
      ui.PlatformDispatcher.instance;

  @override
  ui.ViewConfiguration get viewConfiguration => configuration;

Upvotes: 7