-- screenshot

README.md

 # screenshot
 
-A new Flutter package project.
+A simple plugin to capture widgets as Images.
+
+This plugin wraps your widgets inside [RenderRepaintBoundary](https://docs.flutter.io/flutter/rendering/RenderRepaintBoundary-class.html)
+
+[Source](https://stackoverflow.com/a/51118088)
 
 ## Getting Started
 
-This project is a starting point for a Dart
-[package](https://flutter.io/developing-packages/),
-a library module containing code that can be shared easily across
-multiple Flutter or Dart projects.
+This handy plugin can be used to capture any Widget including full screen screenshots & individual widgets like Text().
+
+1) Create Instance of Screenshot Controller
+
+```dart
+class _MyHomePageState extends State<MyHomePage> {
+  int _counter = 0;
+  File _imageFile;
+
+  //Create an instance of ScreenshotController
+  ScreenshotController screenshotController = ScreenshotController(); 
+
+  @override
+  void initState() {
+    // TODO: implement initState
+    super.initState();
+  }
+  ...
+}
+```
+2) Wrap the widget that you want to capture inside **Screenshot** Widget. Assign the controller to screenshotController that you have created earlier
+
+```dart
+Screenshot(
+    controller: screenshotController,
+    child: Text("This text will be captured as image"),
+),
+```
+
+3) Take the screenshot by calling capture method. This will return a File
+
+```dart
+screenshotController.capture().then((File image) {
+    //Capture Done
+    setState(() {
+        _imageFile = image;
+    });
+}).catchError((onError) {
+    print(onError);
+});
+```
+
+Example:
+
+```dart
+@override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(
+        title: Text(widget.title),
+      ),
+      body: Container(
+        child: new Center(
+          child: new Column(
+            mainAxisAlignment: MainAxisAlignment.center,
+            children: <Widget>[
+              Screenshot( //Screenshot Widget
+                controller: screenshotController, //asign Controller
+                //wrap the widgets that you want to capture as image
+                child: <Widget>[ 
+                      Text(
+                        'You have pushed the button this many times:' +
+                            _counter.toString(),
+                      ),
+                      FlutterLogo(),
+                    ],
+                ),
+              _imageFile != null ? Image.file(_imageFile) : Container(),
+            ],
+          ),
+        ),
+      ),
+      floatingActionButton: FloatingActionButton(
+        onPressed: () {
+          _incrementCounter();
+          _imageFile = null;
+          screenshotController.capture().then((File image) {
+            setState(() {
+              _imageFile = image;
+            });
+          }).catchError((onError){
+            print(onError);
+          });
+          
+        },
+        tooltip: 'Increment',
+        child: Icon(Icons.add),
+      ),
+    );
+  }
+```
+
+ <img src="assets/screenshot.png" alt="screenshot" width="400"/>
+
+
+By defualt, the captured image will be saved to Application Directory. Custom paths can be set using **path parameter**. Refer [path_provider](https://pub.dartlang.org/packages/path_provider)
+```dart
+final directory = (await getApplicationDocumentsDirectory ()).path; //from path_provide package
+String fileName = DateTime.now().toIso8601String();
+path = '$directory/$fileName.png';
+
+screenshotController.capture(
+    path:path //set path where screenshot will be saved
+);
+```
+
+## Note:
+Captured image may look pixelated. You can overcome this issue by setting value for **pixelRatio** 
+
+>The pixelRatio describes the scale between the logical pixels and the size of the output image. It is independent of the window.devicePixelRatio for the device, so specifying 1.0 (the default) will give you a 1:1 mapping between logical pixels and the output pixels in the image.
+
+
+```dart
+screenshotController.capture(
+    pixelRatio: 1.5
+)
+```
+
+## Known Bugs
+- Image will not be updated if same filename is given multiple times
 
-For help getting started with Flutter, view our 
-[online documentation](https://flutter.io/docs), which offers tutorials, 
-samples, guidance on mobile development, and a full API reference.

example/lib/main.dart

@@ -49,7 +49,16 @@ class MyHomePage extends StatefulWidget {
 class _MyHomePageState extends State<MyHomePage> {
   int _counter = 0;
   File _imageFile;
-  ScreenshotController screenshotController;
+
+  //Create an instance of ScreenshotController
+  ScreenshotController screenshotController = ScreenshotController();
+
+  @override
+  void initState() {
+    // TODO: implement initState
+    super.initState();
+  }
+
   void _incrementCounter() {
     setState(() {
       // This call to setState tells the Flutter framework that something has
@@ -61,13 +70,6 @@ class _MyHomePageState extends State<MyHomePage> {
     });
   }
 
-  @override
-  void initState() {
-    // TODO: implement initState
-    super.initState();
-    screenshotController = new ScreenshotController();
-  }
-
   @override
   Widget build(BuildContext context) {
     // This method is rerun every time setState is called, for instance as done
@@ -88,12 +90,16 @@ class _MyHomePageState extends State<MyHomePage> {
             mainAxisAlignment: MainAxisAlignment.center,
             children: <Widget>[
               Screenshot(
-                controller: screenshotController,
-                child: Text(
-                  'You have pushed the button this many times:' +
-                      _counter.toString(),
-                ),
-              ),
+                  controller: screenshotController,
+                  child: Column(
+                    children: <Widget>[
+                      Text(
+                        'You have pushed the button this many times:' +
+                            _counter.toString(),
+                      ),
+                      FlutterLogo(),
+                    ],
+                  )),
               _imageFile != null ? Image.file(_imageFile) : Container(),
             ],
           ),
@@ -103,15 +109,14 @@ class _MyHomePageState extends State<MyHomePage> {
         onPressed: () {
           _incrementCounter();
           _imageFile = null;
-          screenshotController.capture().then((image) {
+          screenshotController.capture().then((File image) {
             //print("Capture Done");
             setState(() {
               _imageFile = image;
             });
-          }).catchError((onError){
+          }).catchError((onError) {
             print(onError);
           });
-          
         },
         tooltip: 'Increment',
         child: Icon(Icons.add),

lib/screenshot.dart

@@ -10,9 +10,9 @@ import 'package:path_provider/path_provider.dart';
 import 'dart:ui' as ui;
 
 class ScreenshotController {
-  GlobalKey containerKey;
+  GlobalKey _containerKey;
   ScreenshotController() {
-    containerKey = GlobalKey();
+    _containerKey = GlobalKey();
   }
   Future<File> capture({
     String path = "",
@@ -20,7 +20,7 @@ class ScreenshotController {
   }) async {
     try {
       RenderRepaintBoundary boundary =
-          this.containerKey.currentContext.findRenderObject();
+          this._containerKey.currentContext.findRenderObject();
       ui.Image image = await boundary.toImage(pixelRatio: pixelRatio);
       ByteData byteData =
           await image.toByteData(format: ui.ImageByteFormat.png);
@@ -28,7 +28,6 @@ class ScreenshotController {
       if (path == "") {
         final directory = (await getApplicationDocumentsDirectory()).path;
         String fileName = DateTime.now().toIso8601String();
-        //print('Path: $fileName');
         path = '$directory/$fileName.png';
       }
       File imgFile = new File(path);
@@ -69,9 +68,9 @@ class ScreenshotState extends State<Screenshot> with TickerProviderStateMixin {
     super.didUpdateWidget(oldWidget);
 
     if (widget.controller != oldWidget.controller) {
-      widget.controller.containerKey = oldWidget.controller.containerKey;
+      widget.controller._containerKey = oldWidget.controller._containerKey;
       if (oldWidget.controller != null && widget.controller == null)
-        _controller.containerKey = oldWidget.controller.containerKey;
+        _controller._containerKey = oldWidget.controller._containerKey;
       if (widget.controller != null) {
         if (oldWidget.controller == null) {
           _controller = null;
@@ -83,7 +82,7 @@ class ScreenshotState extends State<Screenshot> with TickerProviderStateMixin {
   @override
   Widget build(BuildContext context) {
     return RepaintBoundary(
-      key: _controller.containerKey,
+      key: _controller._containerKey,
       child: widget.child,
     );
   }

pubspec.yaml

 name: screenshot
-description: A new Flutter Screenshot Package
+description: Flutter Screenshot Package (Runtime)
 version: 0.0.1
 author: Sachin Ganesh <sachinganesh@outlook.com>
 homepage: https://github.com/SachinGanesh/screenshot