Flutter:- paint using Float32Int and drawRawPoints
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2
I am trying to paint using Float32Int and drawRawPoints but, it's showing that
bad state element.
I have created one list type of Float32Int and in Float32Int var, and then I am storing offset on by on in the list. in paint method using for loop, I am trying to paint. but it shwoing bad state of element in the console
library painter;
import 'package:flutter/widgets.dart' hide Image;
import 'dart:ui';
import 'dart:async';
import 'dart:typed_data';
class Painter extends StatefulWidget {
final PainterController painterController;
Painter(PainterController painterController)
: this.painterController = painterController,
super(key: new ValueKey<PainterController>(painterController));
@override
_PainterState createState() => new _PainterState();
}
class _PainterState extends State<Painter> {
bool _finished;
@override
void initState() {
super.initState();
_finished = false;
widget.painterController._widgetFinish = _finish;
}
Size _finish() {
setState(() {
_finished = true;
});
return context.size;
}
@override
Widget build(BuildContext context) {
Widget child = new CustomPaint(
willChange: true,
painter: new _PainterPainter(widget.painterController._pathHistory,
repaint: widget.painterController),
);
child = new ClipRect(child: child);
if (!_finished) {
child = new GestureDetector(
child: child,
onPanStart: _onPanStart,
onPanUpdate: _onPanUpdate,
onPanEnd: _onPanEnd,
);
}
return new Container(
child: child,
width: double.infinity,
height: double.infinity,
);
}
void _onPanStart(DragStartDetails start) {
Offset pos = (context.findRenderObject() as RenderBox)
.globalToLocal(start.globalPosition);
widget.painterController._pathHistory.add(pos);
widget.painterController._notifyListeners();
}
void _onPanUpdate(DragUpdateDetails update) {
Offset pos = (context.findRenderObject() as RenderBox)
.globalToLocal(update.globalPosition);
widget.painterController._pathHistory.updateCurrent(pos);
widget.painterController._notifyListeners();
}
void _onPanEnd(DragEndDetails end) {
widget.painterController._pathHistory.endCurrent();
widget.painterController._notifyListeners();
}
}
class _PainterPainter extends CustomPainter {
final _PathHistory _path;
_PainterPainter(this._path, {Listenable repaint}) : super(repaint: repaint);
@override
void paint(Canvas canvas, Size size) {
_path.draw(canvas, size);
}
@override
bool shouldRepaint(_PainterPainter oldDelegate) {
return true;
}
}
class _PathHistory {
List<MapEntry<Path, Paint>> _paths;
Paint currentPaint;
Paint _backgroundPaint;
bool _inDrag;
_PathHistory() {
_paths = new List<MapEntry<Path, Paint>>();
_inDrag = false;
_backgroundPaint = new Paint();
}
void setBackgroundColor(Color backgroundColor) {
_backgroundPaint.color = backgroundColor;
}
void undo() {
if (!_inDrag) {
_paths.removeLast();
}
}
void clear() {
if (!_inDrag) {
_paths.clear();
}
}
static List<Float32List> list = ;
Float32List float32list;
// Float32List floatPoints = Float32List.fromList(list);
void add(Offset startPoint) {
if (!_inDrag) {
_inDrag = true;
Path path = new Path();
// path.moveTo(startPoint.dx, startPoint.dy);
// _paths.add(new MapEntry<Path, Paint>(path, currentPaint));
float32list.addAll([startPoint.dx, startPoint.dy]);
}
}
void updateCurrent(Offset nextPoint) {
if (_inDrag) {
// path.lineTo(nextPoint.dx, nextPoint.dy);
float32list.addAll([nextPoint.dx, nextPoint.dy]);
}
}
void endCurrent() {
_inDrag = false;
list.add(float32list);
}
void draw(Canvas canvas, Size size) {
Paint p = new Paint();
p.strokeCap = StrokeCap.round;
p.strokeWidth = 20.0;
canvas.drawRect(
new Rect.fromLTWH(0.0, 0.0, size.width, size.height), _backgroundPaint);
for (int i = 0; i < list.length; i++) {
if (list.isNotEmpty) canvas.drawRawPoints(PointMode.lines, list[i], p);
}
}
}
typedef PictureDetails PictureCallback();
class PictureDetails {
final Picture picture;
final int width;
final int height;
const PictureDetails(this.picture, this.width, this.height);
Image toImage() {
return picture.toImage(width, height);
}
Future<Uint8List> toPNG() async {
return (await toImage().toByteData(format: ImageByteFormat.png))
.buffer
.asUint8List();
}
}
class PainterController extends ChangeNotifier {
Color _drawColor = new Color.fromARGB(255, 0, 0, 0);
Color _backgroundColor = new Color.fromARGB(255, 255, 255, 255);
double _thickness = 1.0;
PictureDetails _cached;
_PathHistory _pathHistory;
ValueGetter<Size> _widgetFinish;
PainterController() {
_pathHistory = new _PathHistory();
}
Color get drawColor => _drawColor;
set drawColor(Color color) {
_drawColor = color;
_updatePaint();
}
Color get backgroundColor => _backgroundColor;
set backgroundColor(Color color) {
_backgroundColor = color;
_updatePaint();
}
double get thickness => _thickness;
set thickness(double t) {
_thickness = t;
_updatePaint();
}
void _updatePaint() {
Paint paint = new Paint();
paint.color = drawColor;
paint.style = PaintingStyle.stroke;
paint.strokeWidth = thickness;
_pathHistory.currentPaint = paint;
_pathHistory.setBackgroundColor(backgroundColor);
notifyListeners();
}
void undo() {
if (!isFinished()) {
_pathHistory.undo();
notifyListeners();
}
}
void _notifyListeners() {
notifyListeners();
}
void clear() {
if (!isFinished()) {
_pathHistory.clear();
notifyListeners();
}
}
PictureDetails finish() {
if (!isFinished()) {
_cached = _render(_widgetFinish());
}
return _cached;
}
PictureDetails _render(Size size) {
PictureRecorder recorder = new PictureRecorder();
Canvas canvas = new Canvas(recorder);
_pathHistory.draw(canvas, size);
return new PictureDetails(
recorder.endRecording(), size.width.floor(), size.height.floor());
}
bool isFinished() {
return _cached != null;
}
}
══╡ EXCEPTION CAUGHT BY GESTURE ╞═══════════════════════════════════════════════════════════════════
I/flutter (17993): The following NoSuchMethodError was thrown while handling a gesture:
I/flutter (17993): The method 'addAll' was called on null.
I/flutter (17993): Receiver: null
I/flutter (17993): Tried calling: addAll(Instance(length:2) of '_GrowableList')
I/flutter (17993):
I/flutter (17993): When the exception was thrown, this was the stack:
I/flutter (17993): #0 Object.noSuchMethod (dart:core/runtime/libobject_patch.dart:50:5)
I/flutter (17993): #1 _PathHistory.add (package:painter/painter.dart:133:19)
I/flutter (17993): #2 _PainterState._onPanStart (package:painter/painter.dart:62:43)
I/flutter (17993): #3 DragGestureRecognizer.acceptGesture.<anonymous closure> (package:flutter/src/gestures/monodrag.dart:169:47)
I/flutter (17993): #4 GestureRecognizer.invokeCallback (package:flutter/src/gestures/recognizer.dart:102:24)
I/flutter (17993): #5 DragGestureRecognizer.acceptGesture (package:flutter/src/gestures/monodrag.dart:169:9)
I/flutter (17993): #6 GestureArenaManager._resolveByDefault (package:flutter/src/gestures/arena.dart:250:25)
I/flutter (17993): #7 GestureArenaManager._tryToResolveArena.<anonymous closure> (package:flutter/src/gestures/arena.dart:231:31)
I/flutter (17993): (elided 2 frames from package dart:async)
I/flutter (17993):
I/flutter (17993): Handler: onStart
I/flutter (17993): Recognizer:
I/flutter (17993): PanGestureRecognizer#80c77(debugOwner: GestureDetector)
I/flutter (17993): ════════════════════════════════════════════════════════════════════════════════════════════════════
I/flutter (17993): Another exception was thrown: NoSuchMethodError: The method 'addAll' was called on null.
I/flutter (17993): Another exception was thrown: NoSuchMethodError: The method 'addAll' was called on null.
Stack Trace:
[ERROR:flutter/shell/common/shell.cc(184)] Dart Error: Unhandled exception:
E/flutter (11464): oh no!
E/flutter (11464): package:painter/painter.dart 39:5 _PainterState.runAsync
E/flutter (11464): package:painter/painter.dart 35:62 _PainterState.scheduleAsync.<fn>
E/flutter (11464): package:stack_trace/src/stack_zone_specification.dart 129:26 StackZoneSpecification._registerUnaryCallback.<fn>.<fn>
E/flutter (11464): package:stack_trace/src/stack_zone_specification.dart 209:15 StackZoneSpecification._run
E/flutter (11464): package:stack_trace/src/stack_zone_specification.dart 129:14 StackZoneSpecification._registerUnaryCallback.<fn>
E/flutter (11464): dart:async/zone.dart 1132:38 _rootRunUnary
E/flutter (11464): dart:async/zone.dart 1029:19 _CustomZone.runUnary
E/flutter (11464): dart:async/future_impl.dart 129:18 _FutureListener.handleValue
E/flutter (11464): dart:async/future_impl.dart 642:45 Future._propagateToListeners.handleValueCallback
E/flutter (11464): dart:async/future_impl.dart 671:32 Future._propagateToListeners
E/flutter (11464): dart:async/future_impl.dart 476:7 Future._complete
E/flutter (11464): dart:async/future.dart 316:16 new Future.delayed.<fn> E/flutter (11464): package:stack_trace/src/stack_zone_specification.dart 209:15 StackZoneSpecification._run
E/flutter (11464): package:stack_trace/src/stack_zone_specification.dart 119:48 StackZoneSpecification._registerCallback.<fn>
android dart 
flutter edited Nov 26 '18 at 6:21
Günter Zöchbauer
336k721022949
asked Nov 23 '18 at 11:25
satishsatish
133115
add a comment |
2
I am trying to paint using Float32Int and drawRawPoints but, it's showing that
bad state element.
I have created one list type of Float32Int and in Float32Int var, and then I am storing offset on by on in the list. in paint method using for loop, I am trying to paint. but it shwoing bad state of element in the console
library painter;
import 'package:flutter/widgets.dart' hide Image;
import 'dart:ui';
import 'dart:async';
import 'dart:typed_data';
class Painter extends StatefulWidget {
final PainterController painterController;
Painter(PainterController painterController)
: this.painterController = painterController,
super(key: new ValueKey<PainterController>(painterController));
@override
_PainterState createState() => new _PainterState();
}
class _PainterState extends State<Painter> {
bool _finished;
@override
void initState() {
super.initState();
_finished = false;
widget.painterController._widgetFinish = _finish;
}
Size _finish() {
setState(() {
_finished = true;
});
return context.size;
}
@override
Widget build(BuildContext context) {
Widget child = new CustomPaint(
willChange: true,
painter: new _PainterPainter(widget.painterController._pathHistory,
repaint: widget.painterController),
);
child = new ClipRect(child: child);
if (!_finished) {
child = new GestureDetector(
child: child,
onPanStart: _onPanStart,
onPanUpdate: _onPanUpdate,
onPanEnd: _onPanEnd,
);
}
return new Container(
child: child,
width: double.infinity,
height: double.infinity,
);
}
void _onPanStart(DragStartDetails start) {
Offset pos = (context.findRenderObject() as RenderBox)
.globalToLocal(start.globalPosition);
widget.painterController._pathHistory.add(pos);
widget.painterController._notifyListeners();
}
void _onPanUpdate(DragUpdateDetails update) {
Offset pos = (context.findRenderObject() as RenderBox)
.globalToLocal(update.globalPosition);
widget.painterController._pathHistory.updateCurrent(pos);
widget.painterController._notifyListeners();
}
void _onPanEnd(DragEndDetails end) {
widget.painterController._pathHistory.endCurrent();
widget.painterController._notifyListeners();
}
}
class _PainterPainter extends CustomPainter {
final _PathHistory _path;
_PainterPainter(this._path, {Listenable repaint}) : super(repaint: repaint);
@override
void paint(Canvas canvas, Size size) {
_path.draw(canvas, size);
}
@override
bool shouldRepaint(_PainterPainter oldDelegate) {
return true;
}
}
class _PathHistory {
List<MapEntry<Path, Paint>> _paths;
Paint currentPaint;
Paint _backgroundPaint;
bool _inDrag;
_PathHistory() {
_paths = new List<MapEntry<Path, Paint>>();
_inDrag = false;
_backgroundPaint = new Paint();
}
void setBackgroundColor(Color backgroundColor) {
_backgroundPaint.color = backgroundColor;
}
void undo() {
if (!_inDrag) {
_paths.removeLast();
}
}
void clear() {
if (!_inDrag) {
_paths.clear();
}
}
static List<Float32List> list = ;
Float32List float32list;
// Float32List floatPoints = Float32List.fromList(list);
void add(Offset startPoint) {
if (!_inDrag) {
_inDrag = true;
Path path = new Path();
// path.moveTo(startPoint.dx, startPoint.dy);
// _paths.add(new MapEntry<Path, Paint>(path, currentPaint));
float32list.addAll([startPoint.dx, startPoint.dy]);
}
}
void updateCurrent(Offset nextPoint) {
if (_inDrag) {
// path.lineTo(nextPoint.dx, nextPoint.dy);
float32list.addAll([nextPoint.dx, nextPoint.dy]);
}
}
void endCurrent() {
_inDrag = false;
list.add(float32list);
}
void draw(Canvas canvas, Size size) {
Paint p = new Paint();
p.strokeCap = StrokeCap.round;
p.strokeWidth = 20.0;
canvas.drawRect(
new Rect.fromLTWH(0.0, 0.0, size.width, size.height), _backgroundPaint);
for (int i = 0; i < list.length; i++) {
if (list.isNotEmpty) canvas.drawRawPoints(PointMode.lines, list[i], p);
}
}
}
typedef PictureDetails PictureCallback();
class PictureDetails {
final Picture picture;
final int width;
final int height;
const PictureDetails(this.picture, this.width, this.height);
Image toImage() {
return picture.toImage(width, height);
}
Future<Uint8List> toPNG() async {
return (await toImage().toByteData(format: ImageByteFormat.png))
.buffer
.asUint8List();
}
}
class PainterController extends ChangeNotifier {
Color _drawColor = new Color.fromARGB(255, 0, 0, 0);
Color _backgroundColor = new Color.fromARGB(255, 255, 255, 255);
double _thickness = 1.0;
PictureDetails _cached;
_PathHistory _pathHistory;
ValueGetter<Size> _widgetFinish;
PainterController() {
_pathHistory = new _PathHistory();
}
Color get drawColor => _drawColor;
set drawColor(Color color) {
_drawColor = color;
_updatePaint();
}
Color get backgroundColor => _backgroundColor;
set backgroundColor(Color color) {
_backgroundColor = color;
_updatePaint();
}
double get thickness => _thickness;
set thickness(double t) {
_thickness = t;
_updatePaint();
}
void _updatePaint() {
Paint paint = new Paint();
paint.color = drawColor;
paint.style = PaintingStyle.stroke;
paint.strokeWidth = thickness;
_pathHistory.currentPaint = paint;
_pathHistory.setBackgroundColor(backgroundColor);
notifyListeners();
}
void undo() {
if (!isFinished()) {
_pathHistory.undo();
notifyListeners();
}
}
void _notifyListeners() {
notifyListeners();
}
void clear() {
if (!isFinished()) {
_pathHistory.clear();
notifyListeners();
}
}
PictureDetails finish() {
if (!isFinished()) {
_cached = _render(_widgetFinish());
}
return _cached;
}
PictureDetails _render(Size size) {
PictureRecorder recorder = new PictureRecorder();
Canvas canvas = new Canvas(recorder);
_pathHistory.draw(canvas, size);
return new PictureDetails(
recorder.endRecording(), size.width.floor(), size.height.floor());
}
bool isFinished() {
return _cached != null;
}
}
══╡ EXCEPTION CAUGHT BY GESTURE ╞═══════════════════════════════════════════════════════════════════
I/flutter (17993): The following NoSuchMethodError was thrown while handling a gesture:
I/flutter (17993): The method 'addAll' was called on null.
I/flutter (17993): Receiver: null
I/flutter (17993): Tried calling: addAll(Instance(length:2) of '_GrowableList')
I/flutter (17993):
I/flutter (17993): When the exception was thrown, this was the stack:
I/flutter (17993): #0 Object.noSuchMethod (dart:core/runtime/libobject_patch.dart:50:5)
I/flutter (17993): #1 _PathHistory.add (package:painter/painter.dart:133:19)
I/flutter (17993): #2 _PainterState._onPanStart (package:painter/painter.dart:62:43)
I/flutter (17993): #3 DragGestureRecognizer.acceptGesture.<anonymous closure> (package:flutter/src/gestures/monodrag.dart:169:47)
I/flutter (17993): #4 GestureRecognizer.invokeCallback (package:flutter/src/gestures/recognizer.dart:102:24)
I/flutter (17993): #5 DragGestureRecognizer.acceptGesture (package:flutter/src/gestures/monodrag.dart:169:9)
I/flutter (17993): #6 GestureArenaManager._resolveByDefault (package:flutter/src/gestures/arena.dart:250:25)
I/flutter (17993): #7 GestureArenaManager._tryToResolveArena.<anonymous closure> (package:flutter/src/gestures/arena.dart:231:31)
I/flutter (17993): (elided 2 frames from package dart:async)
I/flutter (17993):
I/flutter (17993): Handler: onStart
I/flutter (17993): Recognizer:
I/flutter (17993): PanGestureRecognizer#80c77(debugOwner: GestureDetector)
I/flutter (17993): ════════════════════════════════════════════════════════════════════════════════════════════════════
I/flutter (17993): Another exception was thrown: NoSuchMethodError: The method 'addAll' was called on null.
I/flutter (17993): Another exception was thrown: NoSuchMethodError: The method 'addAll' was called on null.
Stack Trace:
[ERROR:flutter/shell/common/shell.cc(184)] Dart Error: Unhandled exception:
E/flutter (11464): oh no!
E/flutter (11464): package:painter/painter.dart 39:5 _PainterState.runAsync
E/flutter (11464): package:painter/painter.dart 35:62 _PainterState.scheduleAsync.<fn>
E/flutter (11464): package:stack_trace/src/stack_zone_specification.dart 129:26 StackZoneSpecification._registerUnaryCallback.<fn>.<fn>
E/flutter (11464): package:stack_trace/src/stack_zone_specification.dart 209:15 StackZoneSpecification._run
E/flutter (11464): package:stack_trace/src/stack_zone_specification.dart 129:14 StackZoneSpecification._registerUnaryCallback.<fn>
E/flutter (11464): dart:async/zone.dart 1132:38 _rootRunUnary
E/flutter (11464): dart:async/zone.dart 1029:19 _CustomZone.runUnary
E/flutter (11464): dart:async/future_impl.dart 129:18 _FutureListener.handleValue
E/flutter (11464): dart:async/future_impl.dart 642:45 Future._propagateToListeners.handleValueCallback
E/flutter (11464): dart:async/future_impl.dart 671:32 Future._propagateToListeners
E/flutter (11464): dart:async/future_impl.dart 476:7 Future._complete
E/flutter (11464): dart:async/future.dart 316:16 new Future.delayed.<fn> E/flutter (11464): package:stack_trace/src/stack_zone_specification.dart 209:15 StackZoneSpecification._run
E/flutter (11464): package:stack_trace/src/stack_zone_specification.dart 119:48 StackZoneSpecification._registerCallback.<fn>
edited Nov 26 '18 at 6:21
Günter Zöchbauer
336k721022949
asked Nov 23 '18 at 11:25
satishsatish
133115
post 4-6 top frames from the stacktrace
– pskink
Nov 24 '18 at 7:07
Whatever I am getting the error in console, I added at end of my code.
– satish
Nov 26 '18 at 6:05
in the end, the stack is also given.
– satish
Nov 26 '18 at 6:13
add a comment |
2
2
2
I am trying to paint using Float32Int and drawRawPoints but, it's showing that
bad state element.
I have created one list type of Float32Int and in Float32Int var, and then I am storing offset on by on in the list. in paint method using for loop, I am trying to paint. but it shwoing bad state of element in the console
library painter;
import 'package:flutter/widgets.dart' hide Image;
import 'dart:ui';
import 'dart:async';
import 'dart:typed_data';
class Painter extends StatefulWidget {
final PainterController painterController;
Painter(PainterController painterController)
: this.painterController = painterController,
super(key: new ValueKey<PainterController>(painterController));
@override
_PainterState createState() => new _PainterState();
}
class _PainterState extends State<Painter> {
bool _finished;
@override
void initState() {
super.initState();
_finished = false;
widget.painterController._widgetFinish = _finish;
}
Size _finish() {
setState(() {
_finished = true;
});
return context.size;
}
@override
Widget build(BuildContext context) {
Widget child = new CustomPaint(
willChange: true,
painter: new _PainterPainter(widget.painterController._pathHistory,
repaint: widget.painterController),
);
child = new ClipRect(child: child);
if (!_finished) {
child = new GestureDetector(
child: child,
onPanStart: _onPanStart,
onPanUpdate: _onPanUpdate,
onPanEnd: _onPanEnd,
);
}
return new Container(
child: child,
width: double.infinity,
height: double.infinity,
);
}
void _onPanStart(DragStartDetails start) {
Offset pos = (context.findRenderObject() as RenderBox)
.globalToLocal(start.globalPosition);
widget.painterController._pathHistory.add(pos);
widget.painterController._notifyListeners();
}
void _onPanUpdate(DragUpdateDetails update) {
Offset pos = (context.findRenderObject() as RenderBox)
.globalToLocal(update.globalPosition);
widget.painterController._pathHistory.updateCurrent(pos);
widget.painterController._notifyListeners();
}
void _onPanEnd(DragEndDetails end) {
widget.painterController._pathHistory.endCurrent();
widget.painterController._notifyListeners();
}
}
class _PainterPainter extends CustomPainter {
final _PathHistory _path;
_PainterPainter(this._path, {Listenable repaint}) : super(repaint: repaint);
@override
void paint(Canvas canvas, Size size) {
_path.draw(canvas, size);
}
@override
bool shouldRepaint(_PainterPainter oldDelegate) {
return true;
}
}
class _PathHistory {
List<MapEntry<Path, Paint>> _paths;
Paint currentPaint;
Paint _backgroundPaint;
bool _inDrag;
_PathHistory() {
_paths = new List<MapEntry<Path, Paint>>();
_inDrag = false;
_backgroundPaint = new Paint();
}
void setBackgroundColor(Color backgroundColor) {
_backgroundPaint.color = backgroundColor;
}
void undo() {
if (!_inDrag) {
_paths.removeLast();
}
}
void clear() {
if (!_inDrag) {
_paths.clear();
}
}
static List<Float32List> list = ;
Float32List float32list;
// Float32List floatPoints = Float32List.fromList(list);
void add(Offset startPoint) {
if (!_inDrag) {
_inDrag = true;
Path path = new Path();
// path.moveTo(startPoint.dx, startPoint.dy);
// _paths.add(new MapEntry<Path, Paint>(path, currentPaint));
float32list.addAll([startPoint.dx, startPoint.dy]);
}
}
void updateCurrent(Offset nextPoint) {
if (_inDrag) {
// path.lineTo(nextPoint.dx, nextPoint.dy);
float32list.addAll([nextPoint.dx, nextPoint.dy]);
}
}
void endCurrent() {
_inDrag = false;
list.add(float32list);
}
void draw(Canvas canvas, Size size) {
Paint p = new Paint();
p.strokeCap = StrokeCap.round;
p.strokeWidth = 20.0;
canvas.drawRect(
new Rect.fromLTWH(0.0, 0.0, size.width, size.height), _backgroundPaint);
for (int i = 0; i < list.length; i++) {
if (list.isNotEmpty) canvas.drawRawPoints(PointMode.lines, list[i], p);
}
}
}
typedef PictureDetails PictureCallback();
class PictureDetails {
final Picture picture;
final int width;
final int height;
const PictureDetails(this.picture, this.width, this.height);
Image toImage() {
return picture.toImage(width, height);
}
Future<Uint8List> toPNG() async {
return (await toImage().toByteData(format: ImageByteFormat.png))
.buffer
.asUint8List();
}
}
class PainterController extends ChangeNotifier {
Color _drawColor = new Color.fromARGB(255, 0, 0, 0);
Color _backgroundColor = new Color.fromARGB(255, 255, 255, 255);
double _thickness = 1.0;
PictureDetails _cached;
_PathHistory _pathHistory;
ValueGetter<Size> _widgetFinish;
PainterController() {
_pathHistory = new _PathHistory();
}
Color get drawColor => _drawColor;
set drawColor(Color color) {
_drawColor = color;
_updatePaint();
}
Color get backgroundColor => _backgroundColor;
set backgroundColor(Color color) {
_backgroundColor = color;
_updatePaint();
}
double get thickness => _thickness;
set thickness(double t) {
_thickness = t;
_updatePaint();
}
void _updatePaint() {
Paint paint = new Paint();
paint.color = drawColor;
paint.style = PaintingStyle.stroke;
paint.strokeWidth = thickness;
_pathHistory.currentPaint = paint;
_pathHistory.setBackgroundColor(backgroundColor);
notifyListeners();
}
void undo() {
if (!isFinished()) {
_pathHistory.undo();
notifyListeners();
}
}
void _notifyListeners() {
notifyListeners();
}
void clear() {
if (!isFinished()) {
_pathHistory.clear();
notifyListeners();
}
}
PictureDetails finish() {
if (!isFinished()) {
_cached = _render(_widgetFinish());
}
return _cached;
}
PictureDetails _render(Size size) {
PictureRecorder recorder = new PictureRecorder();
Canvas canvas = new Canvas(recorder);
_pathHistory.draw(canvas, size);
return new PictureDetails(
recorder.endRecording(), size.width.floor(), size.height.floor());
}
bool isFinished() {
return _cached != null;
}
}
══╡ EXCEPTION CAUGHT BY GESTURE ╞═══════════════════════════════════════════════════════════════════
I/flutter (17993): The following NoSuchMethodError was thrown while handling a gesture:
I/flutter (17993): The method 'addAll' was called on null.
I/flutter (17993): Receiver: null
I/flutter (17993): Tried calling: addAll(Instance(length:2) of '_GrowableList')
I/flutter (17993):
I/flutter (17993): When the exception was thrown, this was the stack:
I/flutter (17993): #0 Object.noSuchMethod (dart:core/runtime/libobject_patch.dart:50:5)
I/flutter (17993): #1 _PathHistory.add (package:painter/painter.dart:133:19)
I/flutter (17993): #2 _PainterState._onPanStart (package:painter/painter.dart:62:43)
I/flutter (17993): #3 DragGestureRecognizer.acceptGesture.<anonymous closure> (package:flutter/src/gestures/monodrag.dart:169:47)
I/flutter (17993): #4 GestureRecognizer.invokeCallback (package:flutter/src/gestures/recognizer.dart:102:24)
I/flutter (17993): #5 DragGestureRecognizer.acceptGesture (package:flutter/src/gestures/monodrag.dart:169:9)
I/flutter (17993): #6 GestureArenaManager._resolveByDefault (package:flutter/src/gestures/arena.dart:250:25)
I/flutter (17993): #7 GestureArenaManager._tryToResolveArena.<anonymous closure> (package:flutter/src/gestures/arena.dart:231:31)
I/flutter (17993): (elided 2 frames from package dart:async)
I/flutter (17993):
I/flutter (17993): Handler: onStart
I/flutter (17993): Recognizer:
I/flutter (17993): PanGestureRecognizer#80c77(debugOwner: GestureDetector)
I/flutter (17993): ════════════════════════════════════════════════════════════════════════════════════════════════════
I/flutter (17993): Another exception was thrown: NoSuchMethodError: The method 'addAll' was called on null.
I/flutter (17993): Another exception was thrown: NoSuchMethodError: The method 'addAll' was called on null.
Stack Trace:
[ERROR:flutter/shell/common/shell.cc(184)] Dart Error: Unhandled exception:
E/flutter (11464): oh no!
E/flutter (11464): package:painter/painter.dart 39:5 _PainterState.runAsync
E/flutter (11464): package:painter/painter.dart 35:62 _PainterState.scheduleAsync.<fn>
E/flutter (11464): package:stack_trace/src/stack_zone_specification.dart 129:26 StackZoneSpecification._registerUnaryCallback.<fn>.<fn>
E/flutter (11464): package:stack_trace/src/stack_zone_specification.dart 209:15 StackZoneSpecification._run
E/flutter (11464): package:stack_trace/src/stack_zone_specification.dart 129:14 StackZoneSpecification._registerUnaryCallback.<fn>
E/flutter (11464): dart:async/zone.dart 1132:38 _rootRunUnary
E/flutter (11464): dart:async/zone.dart 1029:19 _CustomZone.runUnary
E/flutter (11464): dart:async/future_impl.dart 129:18 _FutureListener.handleValue
E/flutter (11464): dart:async/future_impl.dart 642:45 Future._propagateToListeners.handleValueCallback
E/flutter (11464): dart:async/future_impl.dart 671:32 Future._propagateToListeners
E/flutter (11464): dart:async/future_impl.dart 476:7 Future._complete
E/flutter (11464): dart:async/future.dart 316:16 new Future.delayed.<fn> E/flutter (11464): package:stack_trace/src/stack_zone_specification.dart 209:15 StackZoneSpecification._run
E/flutter (11464): package:stack_trace/src/stack_zone_specification.dart 119:48 StackZoneSpecification._registerCallback.<fn>
edited Nov 26 '18 at 6:21
Günter Zöchbauer
336k721022949
asked Nov 23 '18 at 11:25
satishsatish
133115
I am trying to paint using Float32Int and drawRawPoints but, it's showing that
bad state element.
I have created one list type of Float32Int and in Float32Int var, and then I am storing offset on by on in the list. in paint method using for loop, I am trying to paint. but it shwoing bad state of element in the console
library painter;
import 'package:flutter/widgets.dart' hide Image;
import 'dart:ui';
import 'dart:async';
import 'dart:typed_data';
class Painter extends StatefulWidget {
final PainterController painterController;
Painter(PainterController painterController)
: this.painterController = painterController,
super(key: new ValueKey<PainterController>(painterController));
@override
_PainterState createState() => new _PainterState();
}
class _PainterState extends State<Painter> {
bool _finished;
@override
void initState() {
super.initState();
_finished = false;
widget.painterController._widgetFinish = _finish;
}
Size _finish() {
setState(() {
_finished = true;
});
return context.size;
}
@override
Widget build(BuildContext context) {
Widget child = new CustomPaint(
willChange: true,
painter: new _PainterPainter(widget.painterController._pathHistory,
repaint: widget.painterController),
);
child = new ClipRect(child: child);
if (!_finished) {
child = new GestureDetector(
child: child,
onPanStart: _onPanStart,
onPanUpdate: _onPanUpdate,
onPanEnd: _onPanEnd,
);
}
return new Container(
child: child,
width: double.infinity,
height: double.infinity,
);
}
void _onPanStart(DragStartDetails start) {
Offset pos = (context.findRenderObject() as RenderBox)
.globalToLocal(start.globalPosition);
widget.painterController._pathHistory.add(pos);
widget.painterController._notifyListeners();
}
void _onPanUpdate(DragUpdateDetails update) {
Offset pos = (context.findRenderObject() as RenderBox)
.globalToLocal(update.globalPosition);
widget.painterController._pathHistory.updateCurrent(pos);
widget.painterController._notifyListeners();
}
void _onPanEnd(DragEndDetails end) {
widget.painterController._pathHistory.endCurrent();
widget.painterController._notifyListeners();
}
}
class _PainterPainter extends CustomPainter {
final _PathHistory _path;
_PainterPainter(this._path, {Listenable repaint}) : super(repaint: repaint);
@override
void paint(Canvas canvas, Size size) {
_path.draw(canvas, size);
}
@override
bool shouldRepaint(_PainterPainter oldDelegate) {
return true;
}
}
class _PathHistory {
List<MapEntry<Path, Paint>> _paths;
Paint currentPaint;
Paint _backgroundPaint;
bool _inDrag;
_PathHistory() {
_paths = new List<MapEntry<Path, Paint>>();
_inDrag = false;
_backgroundPaint = new Paint();
}
void setBackgroundColor(Color backgroundColor) {
_backgroundPaint.color = backgroundColor;
}
void undo() {
if (!_inDrag) {
_paths.removeLast();
}
}
void clear() {
if (!_inDrag) {
_paths.clear();
}
}
static List<Float32List> list = ;
Float32List float32list;
// Float32List floatPoints = Float32List.fromList(list);
void add(Offset startPoint) {
if (!_inDrag) {
_inDrag = true;
Path path = new Path();
// path.moveTo(startPoint.dx, startPoint.dy);
// _paths.add(new MapEntry<Path, Paint>(path, currentPaint));
float32list.addAll([startPoint.dx, startPoint.dy]);
}
}
void updateCurrent(Offset nextPoint) {
if (_inDrag) {
// path.lineTo(nextPoint.dx, nextPoint.dy);
float32list.addAll([nextPoint.dx, nextPoint.dy]);
}
}
void endCurrent() {
_inDrag = false;
list.add(float32list);
}
void draw(Canvas canvas, Size size) {
Paint p = new Paint();
p.strokeCap = StrokeCap.round;
p.strokeWidth = 20.0;
canvas.drawRect(
new Rect.fromLTWH(0.0, 0.0, size.width, size.height), _backgroundPaint);
for (int i = 0; i < list.length; i++) {
if (list.isNotEmpty) canvas.drawRawPoints(PointMode.lines, list[i], p);
}
}
}
typedef PictureDetails PictureCallback();
class PictureDetails {
final Picture picture;
final int width;
final int height;
const PictureDetails(this.picture, this.width, this.height);
Image toImage() {
return picture.toImage(width, height);
}
Future<Uint8List> toPNG() async {
return (await toImage().toByteData(format: ImageByteFormat.png))
.buffer
.asUint8List();
}
}
class PainterController extends ChangeNotifier {
Color _drawColor = new Color.fromARGB(255, 0, 0, 0);
Color _backgroundColor = new Color.fromARGB(255, 255, 255, 255);
double _thickness = 1.0;
PictureDetails _cached;
_PathHistory _pathHistory;
ValueGetter<Size> _widgetFinish;
PainterController() {
_pathHistory = new _PathHistory();
}
Color get drawColor => _drawColor;
set drawColor(Color color) {
_drawColor = color;
_updatePaint();
}
Color get backgroundColor => _backgroundColor;
set backgroundColor(Color color) {
_backgroundColor = color;
_updatePaint();
}
double get thickness => _thickness;
set thickness(double t) {
_thickness = t;
_updatePaint();
}
void _updatePaint() {
Paint paint = new Paint();
paint.color = drawColor;
paint.style = PaintingStyle.stroke;
paint.strokeWidth = thickness;
_pathHistory.currentPaint = paint;
_pathHistory.setBackgroundColor(backgroundColor);
notifyListeners();
}
void undo() {
if (!isFinished()) {
_pathHistory.undo();
notifyListeners();
}
}
void _notifyListeners() {
notifyListeners();
}
void clear() {
if (!isFinished()) {
_pathHistory.clear();
notifyListeners();
}
}
PictureDetails finish() {
if (!isFinished()) {
_cached = _render(_widgetFinish());
}
return _cached;
}
PictureDetails _render(Size size) {
PictureRecorder recorder = new PictureRecorder();
Canvas canvas = new Canvas(recorder);
_pathHistory.draw(canvas, size);
return new PictureDetails(
recorder.endRecording(), size.width.floor(), size.height.floor());
}
bool isFinished() {
return _cached != null;
}
}
══╡ EXCEPTION CAUGHT BY GESTURE ╞═══════════════════════════════════════════════════════════════════
I/flutter (17993): The following NoSuchMethodError was thrown while handling a gesture:
I/flutter (17993): The method 'addAll' was called on null.
I/flutter (17993): Receiver: null
I/flutter (17993): Tried calling: addAll(Instance(length:2) of '_GrowableList')
I/flutter (17993):
I/flutter (17993): When the exception was thrown, this was the stack:
I/flutter (17993): #0 Object.noSuchMethod (dart:core/runtime/libobject_patch.dart:50:5)
I/flutter (17993): #1 _PathHistory.add (package:painter/painter.dart:133:19)
I/flutter (17993): #2 _PainterState._onPanStart (package:painter/painter.dart:62:43)
I/flutter (17993): #3 DragGestureRecognizer.acceptGesture.<anonymous closure> (package:flutter/src/gestures/monodrag.dart:169:47)
I/flutter (17993): #4 GestureRecognizer.invokeCallback (package:flutter/src/gestures/recognizer.dart:102:24)
I/flutter (17993): #5 DragGestureRecognizer.acceptGesture (package:flutter/src/gestures/monodrag.dart:169:9)
I/flutter (17993): #6 GestureArenaManager._resolveByDefault (package:flutter/src/gestures/arena.dart:250:25)
I/flutter (17993): #7 GestureArenaManager._tryToResolveArena.<anonymous closure> (package:flutter/src/gestures/arena.dart:231:31)
I/flutter (17993): (elided 2 frames from package dart:async)
I/flutter (17993):
I/flutter (17993): Handler: onStart
I/flutter (17993): Recognizer:
I/flutter (17993): PanGestureRecognizer#80c77(debugOwner: GestureDetector)
I/flutter (17993): ════════════════════════════════════════════════════════════════════════════════════════════════════
I/flutter (17993): Another exception was thrown: NoSuchMethodError: The method 'addAll' was called on null.
I/flutter (17993): Another exception was thrown: NoSuchMethodError: The method 'addAll' was called on null.
Stack Trace:
[ERROR:flutter/shell/common/shell.cc(184)] Dart Error: Unhandled exception:
E/flutter (11464): oh no!
E/flutter (11464): package:painter/painter.dart 39:5 _PainterState.runAsync
E/flutter (11464): package:painter/painter.dart 35:62 _PainterState.scheduleAsync.<fn>
E/flutter (11464): package:stack_trace/src/stack_zone_specification.dart 129:26 StackZoneSpecification._registerUnaryCallback.<fn>.<fn>
E/flutter (11464): package:stack_trace/src/stack_zone_specification.dart 209:15 StackZoneSpecification._run
E/flutter (11464): package:stack_trace/src/stack_zone_specification.dart 129:14 StackZoneSpecification._registerUnaryCallback.<fn>
E/flutter (11464): dart:async/zone.dart 1132:38 _rootRunUnary
E/flutter (11464): dart:async/zone.dart 1029:19 _CustomZone.runUnary
E/flutter (11464): dart:async/future_impl.dart 129:18 _FutureListener.handleValue
E/flutter (11464): dart:async/future_impl.dart 642:45 Future._propagateToListeners.handleValueCallback
E/flutter (11464): dart:async/future_impl.dart 671:32 Future._propagateToListeners
E/flutter (11464): dart:async/future_impl.dart 476:7 Future._complete
E/flutter (11464): dart:async/future.dart 316:16 new Future.delayed.<fn> E/flutter (11464): package:stack_trace/src/stack_zone_specification.dart 209:15 StackZoneSpecification._run
E/flutter (11464): package:stack_trace/src/stack_zone_specification.dart 119:48 StackZoneSpecification._registerCallback.<fn>
edited Nov 26 '18 at 6:21
Günter Zöchbauer
336k721022949
asked Nov 23 '18 at 11:25
satishsatish
133115
edited Nov 26 '18 at 6:21
Günter Zöchbauer
336k721022949
asked Nov 23 '18 at 11:25
satishsatish
133115
edited Nov 26 '18 at 6:21
Günter Zöchbauer
336k721022949
edited Nov 26 '18 at 6:21
Günter Zöchbauer
336k721022949
edited Nov 26 '18 at 6:21
Günter Zöchbauer
336k721022949
336k721022949
asked Nov 23 '18 at 11:25
satishsatish
133115
asked Nov 23 '18 at 11:25
satishsatish
133115
asked Nov 23 '18 at 11:25
satishsatish
133115
133115
post 4-6 top frames from the stacktrace
– pskink
Nov 24 '18 at 7:07
Whatever I am getting the error in console, I added at end of my code.
– satish
Nov 26 '18 at 6:05
in the end, the stack is also given.
– satish
Nov 26 '18 at 6:13
add a comment |
post 4-6 top frames from the stacktrace
– pskink
Nov 24 '18 at 7:07
Whatever I am getting the error in console, I added at end of my code.
– satish
Nov 26 '18 at 6:05
in the end, the stack is also given.
– satish
Nov 26 '18 at 6:13
post 4-6 top frames from the stacktrace
– pskink
Nov 24 '18 at 7:07
post 4-6 top frames from the stacktrace
– pskink
Nov 24 '18 at 7:07
Whatever I am getting the error in console, I added at end of my code.
– satish
Nov 26 '18 at 6:05
Whatever I am getting the error in console, I added at end of my code.
– satish
Nov 26 '18 at 6:05
in the end, the stack is also given.
– satish
Nov 26 '18 at 6:13
in the end, the stack is also given.
– satish
Nov 26 '18 at 6:13
add a comment |
1 Answer
1
active
oldest
votes
0
Your exception comes from
float32list.addAll([startPoint.dx, startPoint.dy]);
being called when float32list is null as the exception output points out.
Float32List float32list;
should be
Float32List float32list = Float32List.fromList(list);
or float32list be initialized by other means.
answered Nov 26 '18 at 6:26
Günter ZöchbauerGünter Zöchbauer
336k721022949
add a comment |
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1 Answer
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0
Your exception comes from
float32list.addAll([startPoint.dx, startPoint.dy]);
being called when float32list is null as the exception output points out.
Float32List float32list;
should be
Float32List float32list = Float32List.fromList(list);
or float32list be initialized by other means.
answered Nov 26 '18 at 6:26
Günter ZöchbauerGünter Zöchbauer
336k721022949
add a comment |
0
Your exception comes from
float32list.addAll([startPoint.dx, startPoint.dy]);
being called when float32list is null as the exception output points out.
Float32List float32list;
should be
Float32List float32list = Float32List.fromList(list);
or float32list be initialized by other means.
answered Nov 26 '18 at 6:26
Günter ZöchbauerGünter Zöchbauer
336k721022949
add a comment |
0
0
0
Your exception comes from
float32list.addAll([startPoint.dx, startPoint.dy]);
being called when float32list is null as the exception output points out.
Float32List float32list;
should be
Float32List float32list = Float32List.fromList(list);
or float32list be initialized by other means.
answered Nov 26 '18 at 6:26
Günter ZöchbauerGünter Zöchbauer
336k721022949
Your exception comes from
float32list.addAll([startPoint.dx, startPoint.dy]);
being called when float32list is null as the exception output points out.
Float32List float32list;
should be
Float32List float32list = Float32List.fromList(list);
or float32list be initialized by other means.
answered Nov 26 '18 at 6:26
Günter ZöchbauerGünter Zöchbauer
336k721022949
answered Nov 26 '18 at 6:26
Günter ZöchbauerGünter Zöchbauer
336k721022949
answered Nov 26 '18 at 6:26
Günter ZöchbauerGünter Zöchbauer
336k721022949
answered Nov 26 '18 at 6:26
Günter ZöchbauerGünter Zöchbauer
336k721022949
336k721022949
add a comment |
add a comment |
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post 4-6 top frames from the stacktrace
– pskink
Nov 24 '18 at 7:07
Whatever I am getting the error in console, I added at end of my code.
– satish
Nov 26 '18 at 6:05
in the end, the stack is also given.
– satish
Nov 26 '18 at 6:13