Upload painter view interface

MainAppDMT/lib/screens/Painter/painter_view.dart

+import 'package:flutter/material.dart';
+import 'package:painter2/painter2.dart';
+import 'dart:typed_data';
+
+class ExamplePage extends StatefulWidget {
+  @override
+  _ExamplePageState createState() => new _ExamplePageState();
+}
+
+class _ExamplePageState extends State<ExamplePage> {
+  bool _finished;
+  PainterController _controller;
+
+  @override
+  void initState() {
+    super.initState();
+    _finished = false;
+    _controller = newController();
+  }
+
+  PainterController newController() {
+    PainterController controller = PainterController();
+    controller.thickness = 5.0;
+    controller.backgroundColor = Colors.green;
+    controller.backgroundImage = Image.network(
+        'https://cdn-images-1.medium.com/max/1200/1*5-aoK8IBmXve5whBQM90GA.png');
+    return controller;
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    List<Widget> actions;
+    if (_finished) {
+      actions = <Widget>[
+        IconButton(
+          icon: Icon(Icons.content_copy),
+          tooltip: 'New Painting',
+          onPressed: () => setState(() {
+            _finished = false;
+            _controller = newController();
+          }),
+        ),
+      ];
+    } else {
+      actions = <Widget>[
+        IconButton(
+          icon: Icon(Icons.undo),
+          tooltip: 'Undo',
+          onPressed: () {
+            if (_controller.canUndo) _controller.undo();
+          },
+        ),
+        IconButton(
+          icon: Icon(Icons.redo),
+          tooltip: 'Redo',
+          onPressed: () {
+            if (_controller.canRedo) _controller.redo();
+          },
+        ),
+        IconButton(
+          icon: Icon(Icons.delete),
+          tooltip: 'Clear',
+          onPressed: () => _controller.clear(),
+        ),
+        IconButton(
+            icon: Icon(Icons.check),
+            onPressed: () async {
+              setState(() {
+                _finished = true;
+              });
+              Uint8List bytes = await _controller.exportAsPNGBytes();
+              Navigator.of(context)
+                  .push(MaterialPageRoute(builder: (BuildContext context) {
+                return Scaffold(
+                  appBar: AppBar(
+                    title: Text('View your image'),
+                  ),
+                  body: Container(
+                    child: Image.memory(bytes),
+                  ),
+                );
+              }));
+            }),
+      ];
+    }
+    return Scaffold(
+      appBar: AppBar(
+          title: Text('Painter2 Example'),
+          actions: actions,
+          bottom: PreferredSize(
+            child: DrawBar(_controller),
+            preferredSize: Size(MediaQuery.of(context).size.width, 30.0),
+          )),
+      body: Center(
+          child: AspectRatio(aspectRatio: 1.0, child: Painter(_controller))),
+    );
+  }
+}
+
+class DrawBar extends StatelessWidget {
+  final PainterController _controller;
+
+  DrawBar(this._controller);
+
+  @override
+  Widget build(BuildContext context) {
+    return Row(
+      mainAxisAlignment: MainAxisAlignment.center,
+      children: <Widget>[
+        Flexible(child: StatefulBuilder(
+            builder: (BuildContext context, StateSetter setState) {
+          return Container(
+              child: Slider(
+            value: _controller.thickness,
+            onChanged: (value) => setState(() {
+              _controller.thickness = value;
+            }),
+            min: 1.0,
+            max: 20.0,
+            activeColor: Colors.white,
+          ));
+        })),
+        ColorPickerButton(_controller, false),
+        ColorPickerButton(_controller, true),
+      ],
+    );
+  }
+}
+
+class ColorPickerButton extends StatefulWidget {
+  final PainterController _controller;
+  final bool _background;
+
+  ColorPickerButton(this._controller, this._background);
+
+  @override
+  _ColorPickerButtonState createState() => new _ColorPickerButtonState();
+}
+
+class _ColorPickerButtonState extends State<ColorPickerButton> {
+  @override
+  Widget build(BuildContext context) {
+    return IconButton(
+      icon: Icon(_iconData, color: _color),
+      tooltip:
+          widget._background ? 'Change background color' : 'Change draw color',
+      onPressed: () => _pickColor(),
+    );
+  }
+
+  void _pickColor() {
+    Color pickerColor = _color;
+    Navigator.of(context)
+        .push(MaterialPageRoute(
+            fullscreenDialog: true,
+            builder: (BuildContext context) {
+              return Scaffold(
+                  appBar: AppBar(
+                    title: Text('Pick color'),
+                  ),
+                  body: Container());
+            }))
+        .then((_) {
+      setState(() {
+        _color = pickerColor;
+      });
+    });
+  }
+
+  Color get _color => widget._background
+      ? widget._controller.backgroundColor
+      : widget._controller.drawColor;
+
+  IconData get _iconData =>
+      widget._background ? Icons.format_color_fill : Icons.brush;
+
+  set _color(Color color) {
+    if (widget._background) {
+      widget._controller.backgroundColor = color;
+    } else {
+      widget._controller.drawColor = color;
+    }
+  }
+}