flutter_painter 0.2.0 
flutter_painter: ^0.2.0 copied to clipboard
A Flutter widget to draw scribbles, text and shapes on a background image or color
import 'dart:typed_data';
import 'dart:ui';
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter_painter/flutter_painter.dart';
import 'dart:ui' as ui;
import 'package:phosphor_flutter/phosphor_flutter.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
const MyApp({Key? key}) : super(key: key);
@override
Widget build(BuildContext context) {
return MaterialApp(
debugShowCheckedModeBanner: false,
title: "Flutter Painter Example",
theme: ThemeData(
primaryColor: Colors.brown, accentColor: Colors.amberAccent),
home: FlutterPainterExample(),
);
}
}
class FlutterPainterExample extends StatefulWidget {
const FlutterPainterExample({Key? key}) : super(key: key);
@override
_FlutterPainterExampleState createState() => _FlutterPainterExampleState();
}
class _FlutterPainterExampleState extends State<FlutterPainterExample> {
static const Color red = Color(0xFFFF0000);
FocusNode textFocusNode = FocusNode();
late PainterController controller;
ui.Image? backgroundImage;
Paint shapePaint = Paint()
..strokeWidth = 5
..color = Colors.red
..style = PaintingStyle.stroke
..strokeCap = StrokeCap.round;
@override
void initState() {
super.initState();
controller = PainterController(
settings: PainterSettings(
text: TextSettings(
focusNode: textFocusNode,
textStyle: TextStyle(
fontWeight: FontWeight.bold, color: red, fontSize: 18),
),
freeStyle: FreeStyleSettings(
enabled: false,
color: red,
strokeWidth: 5,
),
shape: ShapeSettings(
paint: shapePaint,
)));
// Listen to focus events of the text field
textFocusNode.addListener(onFocus);
// Initialize background
initBackground();
}
/// Fetches image from an [ImageProvider] (in this example, [NetworkImage])
/// to use it as a background
void initBackground() async {
// Extension getter (.image) to get [ui.Image] from [ImageProvider]
final image = await NetworkImage('https://picsum.photos/1920/1080/').image;
setState(() {
backgroundImage = image;
controller.background = image.backgroundDrawable;
});
}
/// Updates UI when the focus changes
void onFocus() {
setState(() {});
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text("Flutter Painter Example"),
actions: [
IconButton(
icon: Icon(
PhosphorIcons.arrowCounterClockwise,
),
onPressed: removeLastDrawable,
),
IconButton(
icon: Icon(
PhosphorIcons.scribbleLoop,
color: controller.freeStyleSettings.enabled
? Theme.of(context).accentColor
: null,
),
onPressed: toggleFreeStyle,
),
IconButton(
icon: Icon(
PhosphorIcons.textT,
color:
textFocusNode.hasFocus ? Theme.of(context).accentColor : null,
),
onPressed: addText,
),
PopupMenuButton<ShapeFactory?>(
itemBuilder: (context) => [
PopupMenuItem(
value: LineFactory(),
child: Row(
mainAxisAlignment: MainAxisAlignment.start,
children: [
Icon(
PhosphorIcons.lineSegment,
color: Colors.black,
),
Text(" Line")
],
)),
PopupMenuItem(
value: ArrowFactory(),
child: Row(
mainAxisAlignment: MainAxisAlignment.start,
children: [
Icon(
PhosphorIcons.arrowUpRight,
color: Colors.black,
),
Text(" Arrow")
],
)),
PopupMenuItem(
value: RectangleFactory(),
child: Row(
mainAxisAlignment: MainAxisAlignment.start,
children: [
Icon(
PhosphorIcons.rectangle,
color: Colors.black,
),
Text(" Rectangle")
],
)),
PopupMenuItem(
value: OvalFactory(),
child: Row(
mainAxisAlignment: MainAxisAlignment.start,
children: [
Icon(
PhosphorIcons.circle,
color: Colors.black,
),
Text(" Oval")
],
)),
],
onSelected: selectShape,
child: Padding(
padding: const EdgeInsets.all(8.0),
child: Icon(
controller.shapeSettings.factory is LineFactory
? PhosphorIcons.lineSegment
: controller.shapeSettings.factory is ArrowFactory
? PhosphorIcons.arrowUpRight
: controller.shapeSettings.factory is RectangleFactory
? PhosphorIcons.rectangle
: controller.shapeSettings.factory is OvalFactory
? PhosphorIcons.circle
: PhosphorIcons.polygon,
color: controller.shapeSettings.factory != null
? Theme.of(context).accentColor
: null,
),
),
),
],
),
floatingActionButton: FloatingActionButton(
child: Icon(
PhosphorIcons.imageFill,
),
onPressed: renderAndDisplayImage,
),
body: Stack(
children: [
if (backgroundImage != null)
// Enforces constraints
Positioned.fill(
child: Center(
child: AspectRatio(
aspectRatio: backgroundImage!.width / backgroundImage!.height,
child: FlutterPainter(
onPainterSettingsChanged: (_) => setState(() {}),
controller: controller,
),
),
),
),
Positioned(
bottom: 0,
right: 0,
left: 0,
child: Row(
mainAxisAlignment: MainAxisAlignment.center,
children: [
Flexible(
child: Container(
constraints: BoxConstraints(
maxWidth: 400,
),
padding: const EdgeInsets.symmetric(horizontal: 15),
decoration: BoxDecoration(
borderRadius:
BorderRadius.vertical(top: Radius.circular(20)),
color: Colors.white54,
),
child: Column(
mainAxisSize: MainAxisSize.min,
children: [
if (controller.freeStyleSettings.enabled) ...[
Divider(),
Text("Free Style Drawing Settings"),
// Control free style stroke width
Row(
children: [
Expanded(flex: 1, child: Text("Stroke Width")),
Expanded(
flex: 3,
child: Slider.adaptive(
min: 2,
max: 25,
value: controller
.freeStyleSettings.strokeWidth,
onChanged: setFreeStyleStrokeWidth),
),
],
),
Row(
children: [
Expanded(flex: 1, child: Text("Color")),
// Control free style color hue
Expanded(
flex: 3,
child: Slider.adaptive(
min: 0,
max: 359.99,
value: HSVColor.fromColor(
controller.freeStyleSettings.color)
.hue,
activeColor:
controller.freeStyleSettings.color,
onChanged: setFreeStyleColor),
),
],
),
],
if (textFocusNode.hasFocus) ...[
Divider(),
Text("Text settings"),
// Control text font size
Row(
children: [
Expanded(flex: 1, child: Text("Font Size")),
Expanded(
flex: 3,
child: Slider.adaptive(
min: 8,
max: 96,
value: controller
.textSettings.textStyle.fontSize ??
14,
onChanged: setTextFontSize),
),
],
),
// Control text color hue
Row(
children: [
Expanded(flex: 1, child: Text("Color")),
Expanded(
flex: 3,
child: Slider.adaptive(
min: 0,
max: 359.99,
value: HSVColor.fromColor(controller
.textSettings.textStyle.color ??
red)
.hue,
activeColor:
controller.textSettings.textStyle.color,
onChanged: setTextColor),
),
],
),
],
if (controller.shapeSettings.factory != null) ...[
Divider(),
Text("Shape Settings"),
// Control text color hue
Row(
children: [
Expanded(flex: 1, child: Text("Stroke Width")),
Expanded(
flex: 3,
child: Slider.adaptive(
min: 2,
max: 25,
value: controller
.shapeSettings.paint?.strokeWidth ??
shapePaint.strokeWidth,
onChanged: (value) => setShapeFactoryPaint(
(controller.shapeSettings.paint ??
shapePaint)
.copyWith(
strokeWidth: value,
))),
),
],
),
// Control shape color hue
Row(
children: [
Expanded(flex: 1, child: Text("Color")),
Expanded(
flex: 3,
child: Slider.adaptive(
min: 0,
max: 359.99,
value: HSVColor.fromColor(
(controller.shapeSettings.paint ??
shapePaint)
.color)
.hue,
activeColor:
(controller.shapeSettings.paint ??
shapePaint)
.color,
onChanged: (hue) => setShapeFactoryPaint(
(controller.shapeSettings.paint ??
shapePaint)
.copyWith(
color: HSVColor.fromAHSV(1, hue, 1, 1)
.toColor(),
))),
),
],
),
Row(
children: [
Expanded(flex: 1, child: Text("Fill shape")),
Expanded(
flex: 3,
child: Center(
child: Switch(
value: (controller.shapeSettings.paint ??
shapePaint)
.style ==
PaintingStyle.fill,
onChanged: (value) =>
setShapeFactoryPaint(
(controller.shapeSettings.paint ??
shapePaint)
.copyWith(
style: value
? PaintingStyle.fill
: PaintingStyle.stroke,
))),
),
),
],
),
]
],
),
),
),
],
),
)
],
),
);
}
void removeLastDrawable() {
controller.removeLastDrawable();
}
void toggleFreeStyle() {
// Set state is just to update the current UI, the [FlutterPainter] UI updates without it
setState(() {
controller.freeStyleSettings = controller.freeStyleSettings
.copyWith(enabled: !controller.freeStyleSettings.enabled);
});
}
void addText() {
if (controller.freeStyleSettings.enabled) toggleFreeStyle();
controller.addText();
}
void setFreeStyleStrokeWidth(double value) {
// Set state is just to update the current UI, the [FlutterPainter] UI updates without it
setState(() {
controller.freeStyleSettings =
controller.freeStyleSettings.copyWith(strokeWidth: value);
});
}
void setFreeStyleColor(double hue) {
// Set state is just to update the current UI, the [FlutterPainter] UI updates without it
setState(() {
controller.freeStyleSettings = controller.freeStyleSettings.copyWith(
color: HSVColor.fromAHSV(1, hue, 1, 1).toColor(),
);
});
}
void setTextFontSize(double size) {
// Set state is just to update the current UI, the [FlutterPainter] UI updates without it
setState(() {
controller.textSettings = controller.textSettings.copyWith(
textStyle:
controller.textSettings.textStyle.copyWith(fontSize: size));
});
}
void setShapeFactoryPaint(Paint paint) {
// Set state is just to update the current UI, the [FlutterPainter] UI updates without it
setState(() {
controller.shapeSettings =
controller.shapeSettings.copyWith(paint: paint);
});
}
void setTextColor(double hue) {
// Set state is just to update the current UI, the [FlutterPainter] UI updates without it
setState(() {
controller.textSettings = controller.textSettings.copyWith(
textStyle: controller.textSettings.textStyle.copyWith(
color: HSVColor.fromAHSV(1, hue, 1, 1).toColor(),
));
});
}
void selectShape(ShapeFactory? factory) {
setState(() {
controller.shapeSettings = controller.shapeSettings.copyWith(
factory:
factory.runtimeType == controller.shapeSettings.factory.runtimeType
? null
: factory,
);
});
}
void renderAndDisplayImage() {
if (backgroundImage == null) return;
final backgroundImageSize = Size(
backgroundImage!.width.toDouble(), backgroundImage!.height.toDouble());
// Render the image
// Returns a [ui.Image] object, convert to to byte data and then to Uint8List
final imageFuture = controller
.renderImage(backgroundImageSize)
.then<Uint8List?>((ui.Image image) => image.pngBytes);
// From here, you can write the PNG image data a file or do whatever you want with it
// For example:
// ```dart
// final file = File('${(await getTemporaryDirectory()).path}/img.png');
// await file.writeAsBytes(byteData.buffer.asUint8List(byteData.offsetInBytes, byteData.lengthInBytes));
// ```
// I am going to display it using Image.memory
// Show a dialog with the image
showDialog(
context: context,
builder: (context) => RenderedImageDialog(imageFuture: imageFuture));
}
}
class RenderedImageDialog extends StatelessWidget {
final Future<Uint8List?> imageFuture;
const RenderedImageDialog({Key? key, required this.imageFuture})
: super(key: key);
@override
Widget build(BuildContext context) {
return AlertDialog(
title: Text("Rendered Image"),
content: FutureBuilder<Uint8List?>(
future: imageFuture,
builder: (context, snapshot) {
if (snapshot.connectionState != ConnectionState.done)
return SizedBox(
height: 50,
child: Center(child: CircularProgressIndicator.adaptive()),
);
if (!snapshot.hasData || snapshot.data == null) return SizedBox();
return InteractiveViewer(
maxScale: 10, child: Image.memory(snapshot.data!));
},
),
);
}
}Metadata
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Metadata
A Flutter widget to draw scribbles, text and shapes on a background image or color
Repository (GitHub)
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License
unknown (LICENSE)
