pdf_signature/lib/ui/features/pdf/widgets/pdf_screen.dart

641 lines
21 KiB
Dart

import 'dart:math' as math;
import 'dart:typed_data';
import 'package:file_selector/file_selector.dart' as fs;
import 'package:flutter/foundation.dart' show kIsWeb;
import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:pdfrx/pdfrx.dart';
import 'package:printing/printing.dart' as printing;
import '../../../../data/model/model.dart';
import '../../../../data/services/providers.dart';
import '../view_model/view_model.dart';
import 'draw_canvas.dart';
import '../../preferences/widgets/settings_screen.dart';
class PdfSignatureHomePage extends ConsumerStatefulWidget {
const PdfSignatureHomePage({super.key});
@override
ConsumerState<PdfSignatureHomePage> createState() =>
_PdfSignatureHomePageState();
}
class _PdfSignatureHomePageState extends ConsumerState<PdfSignatureHomePage> {
static const Size _pageSize = SignatureController.pageSize;
final GlobalKey _captureKey = GlobalKey();
// Exposed for tests to trigger the invalid-file SnackBar without UI.
@visibleForTesting
void debugShowInvalidSignatureSnackBar() {
ref.read(signatureProvider.notifier).setInvalidSelected(context);
}
Future<void> _pickPdf() async {
final typeGroup = const fs.XTypeGroup(label: 'PDF', extensions: ['pdf']);
final file = await fs.openFile(acceptedTypeGroups: [typeGroup]);
if (file != null) {
Uint8List? bytes;
try {
bytes = await file.readAsBytes();
} catch (_) {
bytes = null;
}
ref.read(pdfProvider.notifier).openPicked(path: file.path, bytes: bytes);
ref.read(signatureProvider.notifier).resetForNewPage();
}
}
void _jumpToPage(int page) {
ref.read(pdfProvider.notifier).jumpTo(page);
}
void _toggleMarkForSigning() {
ref.read(pdfProvider.notifier).toggleMark();
}
Future<void> _loadSignatureFromFile() async {
final pdf = ref.read(pdfProvider);
if (!pdf.markedForSigning) return;
final typeGroup = const fs.XTypeGroup(
label: 'Image',
extensions: ['png', 'jpg', 'jpeg', 'webp'],
);
final file = await fs.openFile(acceptedTypeGroups: [typeGroup]);
if (file == null) return;
final bytes = await file.readAsBytes();
final sig = ref.read(signatureProvider.notifier);
sig.setImageBytes(bytes);
}
void _onDragSignature(Offset delta) {
ref.read(signatureProvider.notifier).drag(delta);
}
void _onResizeSignature(Offset delta) {
ref.read(signatureProvider.notifier).resize(delta);
}
Future<void> _openDrawCanvas() async {
final pdf = ref.read(pdfProvider);
if (!pdf.markedForSigning) return;
final result = await showModalBottomSheet<Uint8List>(
context: context,
isScrollControlled: true,
enableDrag: false,
builder: (_) => const DrawCanvas(),
);
if (result != null && result.isNotEmpty) {
// Use the drawn image as signature content
ref.read(signatureProvider.notifier).setImageBytes(result);
}
}
Future<void> _saveSignedPdf() async {
// Set exporting state to show loading overlay and block interactions
ref.read(exportingProvider.notifier).state = true;
try {
final pdf = ref.read(pdfProvider);
final sig = ref.read(signatureProvider);
// Cache messenger before any awaits to avoid using BuildContext across async gaps.
final messenger = ScaffoldMessenger.of(context);
if (!pdf.loaded || sig.rect == null) {
messenger.showSnackBar(
const SnackBar(
content: Text('Nothing to save yet'),
), // guard per use-case
);
return;
}
final exporter = ref.read(exportServiceProvider);
final targetDpi = ref.read(exportDpiProvider);
final useMock = ref.read(useMockViewerProvider);
bool ok = false;
String? savedPath;
if (kIsWeb) {
// Web: prefer using picked bytes; share via Printing
Uint8List? src = pdf.pickedPdfBytes;
if (src == null) {
ok = false;
} else {
final processed = ref.read(processedSignatureImageProvider);
final bytes = await exporter.exportSignedPdfFromBytes(
srcBytes: src,
signedPage: pdf.signedPage,
signatureRectUi: sig.rect,
uiPageSize: SignatureController.pageSize,
signatureImageBytes: processed ?? sig.imageBytes,
targetDpi: targetDpi,
);
if (bytes != null) {
try {
await printing.Printing.sharePdf(
bytes: bytes,
filename: 'signed.pdf',
);
ok = true;
} catch (_) {
ok = false;
}
} else {
ok = false;
}
}
} else {
// Desktop/mobile: choose between bytes or file-based export
final pick = ref.read(savePathPickerProvider);
final path = await pick();
if (path == null || path.trim().isEmpty) return;
final fullPath = _ensurePdfExtension(path.trim());
savedPath = fullPath;
if (pdf.pickedPdfBytes != null) {
final processed = ref.read(processedSignatureImageProvider);
final out = await exporter.exportSignedPdfFromBytes(
srcBytes: pdf.pickedPdfBytes!,
signedPage: pdf.signedPage,
signatureRectUi: sig.rect,
uiPageSize: SignatureController.pageSize,
signatureImageBytes: processed ?? sig.imageBytes,
targetDpi: targetDpi,
);
if (useMock) {
// In mock mode for tests, simulate success without file IO
ok = out != null;
} else if (out != null) {
ok = await exporter.saveBytesToFile(
bytes: out,
outputPath: fullPath,
);
} else {
ok = false;
}
} else if (pdf.pickedPdfPath != null) {
if (useMock) {
// Simulate success in mock
ok = true;
} else {
final processed = ref.read(processedSignatureImageProvider);
ok = await exporter.exportSignedPdfFromFile(
inputPath: pdf.pickedPdfPath!,
outputPath: fullPath,
signedPage: pdf.signedPage,
signatureRectUi: sig.rect,
uiPageSize: SignatureController.pageSize,
signatureImageBytes: processed ?? sig.imageBytes,
targetDpi: targetDpi,
);
}
} else {
ok = false;
}
}
if (!kIsWeb) {
// Desktop/mobile: we had a concrete path
if (ok) {
messenger.showSnackBar(
SnackBar(content: Text('Saved: ${savedPath ?? ''}')),
);
} else {
messenger.showSnackBar(
const SnackBar(content: Text('Failed to save PDF')),
);
}
} else {
// Web: indicate whether we triggered a download dialog
if (ok) {
messenger.showSnackBar(
const SnackBar(content: Text('Download started')),
);
} else {
messenger.showSnackBar(
const SnackBar(content: Text('Failed to generate PDF')),
);
}
}
} finally {
// Clear exporting state when finished or on error
ref.read(exportingProvider.notifier).state = false;
}
}
String _ensurePdfExtension(String name) {
if (!name.toLowerCase().endsWith('.pdf')) return '$name.pdf';
return name;
}
@override
Widget build(BuildContext context) {
final pdf = ref.watch(pdfProvider);
final isExporting = ref.watch(exportingProvider);
return Scaffold(
appBar: AppBar(title: const Text('PDF Signature')),
body: Padding(
padding: const EdgeInsets.all(12),
child: Stack(
children: [
Column(
children: [
_buildToolbar(pdf, disabled: isExporting),
const SizedBox(height: 8),
Expanded(
child: AbsorbPointer(
absorbing: isExporting,
child: _buildPageArea(pdf),
),
),
Consumer(
builder: (context, ref, _) {
final sig = ref.watch(signatureProvider);
return sig.rect != null
? AbsorbPointer(
absorbing: isExporting,
child: _buildAdjustmentsPanel(sig),
)
: const SizedBox.shrink();
},
),
],
),
if (isExporting)
Positioned.fill(
child: Container(
color: Colors.black45,
child: const Center(
child: Column(
mainAxisSize: MainAxisSize.min,
children: [
CircularProgressIndicator(),
SizedBox(height: 12),
Text(
'Exporting... Please wait',
style: TextStyle(color: Colors.white),
),
],
),
),
),
),
],
),
),
);
}
Widget _buildToolbar(PdfState pdf, {bool disabled = false}) {
final dpi = ref.watch(exportDpiProvider);
final pageInfo = 'Page ${pdf.currentPage}/${pdf.pageCount}';
return Wrap(
spacing: 8,
runSpacing: 8,
crossAxisAlignment: WrapCrossAlignment.center,
children: [
OutlinedButton(
key: const Key('btn_open_settings'),
onPressed:
disabled
? null
: () {
Navigator.of(context).push(
MaterialPageRoute(builder: (_) => const SettingsScreen()),
);
},
child: const Text('Settings'),
),
OutlinedButton(
key: const Key('btn_open_pdf_picker'),
onPressed: disabled ? null : _pickPdf,
child: const Text('Open PDF...'),
),
if (pdf.loaded) ...[
Row(
mainAxisSize: MainAxisSize.min,
children: [
IconButton(
key: const Key('btn_prev'),
onPressed:
disabled ? null : () => _jumpToPage(pdf.currentPage - 1),
icon: const Icon(Icons.chevron_left),
tooltip: 'Prev',
),
Text(pageInfo, key: const Key('lbl_page_info')),
IconButton(
key: const Key('btn_next'),
onPressed:
disabled ? null : () => _jumpToPage(pdf.currentPage + 1),
icon: const Icon(Icons.chevron_right),
tooltip: 'Next',
),
],
),
Row(
mainAxisSize: MainAxisSize.min,
children: [
const Text('Go to:'),
SizedBox(
width: 60,
child: TextField(
key: const Key('txt_goto'),
keyboardType: TextInputType.number,
enabled: !disabled,
onSubmitted: (v) {
final n = int.tryParse(v);
if (n != null) _jumpToPage(n);
},
),
),
],
),
Row(
mainAxisSize: MainAxisSize.min,
children: [
const Text('DPI:'),
const SizedBox(width: 8),
DropdownButton<double>(
key: const Key('ddl_export_dpi'),
value: dpi,
items:
const [96.0, 144.0, 200.0, 300.0]
.map(
(v) => DropdownMenuItem(
value: v,
child: Text(v.toStringAsFixed(0)),
),
)
.toList(),
onChanged:
disabled
? null
: (v) {
if (v != null) {
ref.read(exportDpiProvider.notifier).state = v;
}
},
),
],
),
ElevatedButton(
key: const Key('btn_mark_signing'),
onPressed: disabled ? null : _toggleMarkForSigning,
child: Text(
pdf.markedForSigning ? 'Unmark Signing' : 'Mark for Signing',
),
),
if (pdf.loaded)
ElevatedButton(
key: const Key('btn_save_pdf'),
onPressed: disabled ? null : _saveSignedPdf,
child: const Text('Save Signed PDF'),
),
if (pdf.markedForSigning) ...[
OutlinedButton(
key: const Key('btn_load_signature_picker'),
onPressed: disabled ? null : _loadSignatureFromFile,
child: const Text('Load Signature from file'),
),
ElevatedButton(
key: const Key('btn_draw_signature'),
onPressed: disabled ? null : _openDrawCanvas,
child: const Text('Draw Signature'),
),
],
],
],
);
}
Widget _buildPageArea(PdfState pdf) {
if (!pdf.loaded) {
return const Center(child: Text('No PDF loaded'));
}
final useMock = ref.watch(useMockViewerProvider);
if (useMock) {
return Center(
child: AspectRatio(
aspectRatio: _pageSize.width / _pageSize.height,
child: RepaintBoundary(
key: _captureKey,
child: Stack(
key: const Key('page_stack'),
children: [
Container(
key: const Key('pdf_page'),
color: Colors.grey.shade200,
child: Center(
child: Text(
'Page ${pdf.currentPage}/${pdf.pageCount}',
style: const TextStyle(
fontSize: 24,
color: Colors.black54,
),
),
),
),
Consumer(
builder: (context, ref, _) {
final sig = ref.watch(signatureProvider);
final visible = ref.watch(signatureVisibilityProvider);
return sig.rect != null && visible
? _buildSignatureOverlay(sig)
: const SizedBox.shrink();
},
),
],
),
),
),
);
}
// If a real PDF path is selected, show actual viewer. Otherwise, keep mock sample.
if (pdf.pickedPdfPath != null) {
return PdfDocumentViewBuilder.file(
pdf.pickedPdfPath!,
builder: (context, document) {
if (document == null) {
return const Center(child: CircularProgressIndicator());
}
final pages = document.pages;
final pageNum = pdf.currentPage.clamp(1, pages.length);
final page = pages[pageNum - 1];
final aspect = page.width / page.height;
// Update page count in state if needed (post-frame to avoid build loop)
if (pdf.pageCount != pages.length) {
WidgetsBinding.instance.addPostFrameCallback((_) {
if (mounted) {
ref.read(pdfProvider.notifier).setPageCount(pages.length);
}
});
}
return Center(
child: AspectRatio(
aspectRatio: aspect,
child: RepaintBoundary(
key: _captureKey,
child: Stack(
key: const Key('page_stack'),
children: [
PdfPageView(
document: document,
pageNumber: pageNum,
alignment: Alignment.center,
),
Consumer(
builder: (context, ref, _) {
final sig = ref.watch(signatureProvider);
final visible = ref.watch(signatureVisibilityProvider);
return sig.rect != null && visible
? _buildSignatureOverlay(sig)
: const SizedBox.shrink();
},
),
],
),
),
),
);
},
);
}
// Fallback should not occur when not using mock; still return empty view
return const SizedBox.shrink();
}
Widget _buildSignatureOverlay(SignatureState sig) {
final r = sig.rect!;
return LayoutBuilder(
builder: (context, constraints) {
final scaleX = constraints.maxWidth / _pageSize.width;
final scaleY = constraints.maxHeight / _pageSize.height;
final left = r.left * scaleX;
final top = r.top * scaleY;
final width = r.width * scaleX;
final height = r.height * scaleY;
return Stack(
children: [
Positioned(
left: left,
top: top,
width: width,
height: height,
child: GestureDetector(
key: const Key('signature_overlay'),
behavior: HitTestBehavior.opaque,
onPanStart: (_) {},
onPanUpdate:
(d) => _onDragSignature(
Offset(d.delta.dx / scaleX, d.delta.dy / scaleY),
),
child: DecoratedBox(
decoration: BoxDecoration(
color: Color.fromRGBO(
0,
0,
0,
0.05 + math.min(0.25, (sig.contrast - 1.0).abs()),
),
border: Border.all(color: Colors.indigo, width: 2),
),
child: Stack(
children: [
Consumer(
builder: (context, ref, _) {
final processed = ref.watch(
processedSignatureImageProvider,
);
final bytes = processed ?? sig.imageBytes;
if (bytes == null) {
return const Center(child: Text('Signature'));
}
return Image.memory(bytes, fit: BoxFit.contain);
},
),
Positioned(
right: 0,
bottom: 0,
child: GestureDetector(
key: const Key('signature_handle'),
behavior: HitTestBehavior.opaque,
onPanUpdate:
(d) => _onResizeSignature(
Offset(
d.delta.dx / scaleX,
d.delta.dy / scaleY,
),
),
child: const Icon(Icons.open_in_full, size: 20),
),
),
],
),
),
),
),
],
);
},
);
}
Widget _buildAdjustmentsPanel(SignatureState sig) {
return Column(
key: const Key('adjustments_panel'),
children: [
Row(
children: [
Checkbox(
key: const Key('chk_aspect_lock'),
value: sig.aspectLocked,
onChanged:
(v) => ref
.read(signatureProvider.notifier)
.toggleAspect(v ?? false),
),
const Text('Lock aspect ratio'),
const SizedBox(width: 16),
Switch(
key: const Key('swt_bg_removal'),
value: sig.bgRemoval,
onChanged:
(v) => ref.read(signatureProvider.notifier).setBgRemoval(v),
),
const Text('Background removal'),
],
),
Row(
children: [
const Text('Contrast'),
Expanded(
child: Slider(
key: const Key('sld_contrast'),
min: 0.0,
max: 2.0,
value: sig.contrast,
onChanged:
(v) => ref.read(signatureProvider.notifier).setContrast(v),
),
),
Text(sig.contrast.toStringAsFixed(2)),
],
),
Row(
children: [
const Text('Brightness'),
Expanded(
child: Slider(
key: const Key('sld_brightness'),
min: -1.0,
max: 1.0,
value: sig.brightness,
onChanged:
(v) =>
ref.read(signatureProvider.notifier).setBrightness(v),
),
),
Text(sig.brightness.toStringAsFixed(2)),
],
),
],
);
}
}