Load image from sharedPreferences to pdf in Flutter - image

Question

I'm need to load a image from sharedPreferences to a pdf document.
The image loads normally when in normal use, but i don't know how to make it load in the pdf.
When I try to load it like a normal image I get "Unhandled Exception: type 'Image' is not a subtype of type 'PdfImage'"
This is how I use it normally.
import 'package:flutter/material.dart';
import 'package:flutter_settings_screens/flutter_settings_screens.dart';
import 'package:image_picker/image_picker.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'package:MyApp/SharedPrefUtility.dart';
Future<void> initSettings() async {
await Settings.init(
cacheProvider: SharePreferenceCache(),
);
}
class ProfilePage extends StatefulWidget {
#override
_ProfilePageState createState() => _ProfilePageState();
}
class _ProfilePageState extends State<ProfilePage> {
Image logo;
pickImage(ImageSource source) async {
final _image = await ImagePicker.pickImage(source: ImageSource.gallery);
if (_image != null) {
setState(() {
logo = Image.file(_image);
});
ImageSharedPrefs.saveImageToPrefs(
ImageSharedPrefs.base64String(_image.readAsBytesSync()));
} else {
print('Error picking image!');
}
}
loadImageFromPrefs() async {
SharedPreferences prefs = await SharedPreferences.getInstance();
final imageKeyValue = prefs.getString(IMAGE_KEY);
if (imageKeyValue != null) {
final imageString = await ImageSharedPrefs.loadImageFromPrefs();
setState(() {
logo = ImageSharedPrefs.imageFrom64BaseString(imageString);
});
}
}
#override
void initState() {
super.initState();
loadImageFromPrefs();
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
backgroundColor: Colors.red,
title: Text('Profile Settings'),
),
body: Center(
child: ListView(
children: [
Column(
crossAxisAlignment: CrossAxisAlignment.center,
mainAxisAlignment: MainAxisAlignment.start,
children: <Widget>[
ClipRect(
child: Container(
width: 300,
height: 300,
child: logo == null ? Text('No image selected.') : logo,
),
),
RaisedButton(
onPressed: () {
pickImage(ImageSource.gallery);
},
child: Text('Pick Company Logo'),
),
],
),
],
),
),
);
}
}
With SharedPrefUtility.dart
import 'dart:convert';
import 'dart:typed_data';
import 'package:flutter/widgets.dart';
import 'package:shared_preferences/shared_preferences.dart';
const IMAGE_KEY = 'IMAGE_KEY';
class ImageSharedPrefs {
static Future<bool> saveImageToPrefs(String value) async {
SharedPreferences prefs = await SharedPreferences.getInstance();
return await prefs.setString(IMAGE_KEY, value);
}
static Future<String> loadImageFromPrefs() async {
SharedPreferences prefs = await SharedPreferences.getInstance();
return prefs.getString(IMAGE_KEY);
}
static String base64String(Uint8List data) {
return base64Encode(data);
}
static imageFrom64BaseString(String base64String) {
return Image.memory(
base64Decode(base64String),
fit: BoxFit.contain,
);
}
}
Any Suggestions would be great.

Answer 1

davey06 gave the answer on gitHub
final imageString = await ImageSharedPrefs.loadImageFromPrefs();
// Create a PDF document.
final document = pw.Document();
// Add page to the PDF
document.addPage(pw.Page(build: (context) {
return pw.Center(
child: pw.Image(
PdfImage.file(document.document, bytes: base64Decode(imageString)),
),
);
}));
// Return the PDF file content
return document.save();
https://github.com/DavBfr/dart_pdf/issues/477

Answer 2

"Unhandled Exception: type 'Image' is not a subtype of type 'PdfImage'" - it says you need to convert Image to PdfImage
import 'package:pdf/pdf.dart';
import 'package:pdf/widgets.dart ' as pw;
pdf = pw.Document();
PdfImage pdfImage = PdfImage.fromImage(pdf.document, image: logo);
pdf.addPage(
pw.Page(
pageFormat: PdfPageFormat.a4,
build: (context) {
return pw.Image(arcPdfImage, fit: pw.BoxFit.contain);
},
),
);

Answer 3

I'm using images taken from my assets to create PDF in this way:
PdfImage _logo = PdfImage.file(
doc.document,
bytes: (await rootBundle.load('assets/client-logo.png')).buffer.asUint8List(),
);
//later, during widget tree creation
pw.Image(_logo, width: 180);
It's not exactly what you're doing, but I think it's close enough. The PdfImage class can take as input any Uint8List for the bytes argument, so you should be able to use the same input you're using for the base64String method you defined for ImageSharedPrefs