feat: update readme

README.md

@@ -3,11 +3,105 @@ Flutter Pluggin for Zebra Multiplatform SDK
 
 ## Getting Started
 
-This project is a starting point for a Flutter
-[plug-in package](https://flutter.dev/developing-packages/),
-a specialized package that includes platform-specific implementation code for
-Android and/or iOS.
-
-For help getting started with Flutter development, view the
-[online documentation](https://flutter.dev/docs), which offers tutorials,
-samples, guidance on mobile development, and a full API reference.
+Add `flutter_zsdk` as a dependency in your `pubspec.yaml` file.
+
+## Project Setup
+
+### Android
+note: tested using `JDK 17.0.2`, `Gradle 8.0`, `AGP 8.1.3`
+
+Tambah / ganti `distributionUrl=https\://services.gradle.org/distributions/gradle-8.0-bin.zip` di android/gradle/wrapper/gradle-wrapper.properties.
+
+Tambah / ganti `id "com.android.application" version "8.1.3" apply false` di android/settings.gradle.
+
+Tambah ke file `gradle.properties`.
+```
+org.gradle.jvmargs=-Xmx4G
+android.useAndroidX=true
+android.enableJetifier=true
+android.jetifier.ignorelist=jackson-core-2.17.2.jar
+```
+
+## Usage
+Contoh lengkap bisa dilihat di `example` folder.  
+
+Pertama buat objek dari plugin
+```
+import 'package:flutter_zsdk/flutter_zsdk.dart';
+
+final _flutterZsdkPlugin = FlutterZsdk();
+
+_flutterZsdk.findBluetoothPrinter();
+// etc
+```
+
+### Discover Bluetooth Device
+Return nilai dari `_flutterZsdkPlugin.findBluetoothPrinter()` itu `Stream<dynamic>` jadi perlu di handle untuk listen ke stream tsb.
+
+Default event:
+- `SOS` : Start of Stream
+- `EOS` : End of Stream (`StreamSubscription` harus di cancel jika tidak diperlukan lagi)
+
+contoh:
+```
+Future<void> discoverBluetoothDevices() async {
+    try {
+      Stream<dynamic> stream = await _flutterZsdkPlugin.findBluetoothPrinters();
+      _bluetoothPrinterSubscription = stream.listen((event) {
+        print(event);
+
+        if (event == 'SOS') {
+          _isDiscovering = true;
+
+        }
+
+        if (event is List) {
+          // add to list logic here...
+
+        }
+
+        if (event == 'EOS') {
+          _isDiscovering = false;
+          showSnackBar('Bluetooth discovery finished, found ${_discoveredBluetoothPrinters.length} printers');
+          _bluetoothPrinterSubscription?.cancel();
+        }
+
+        setState(() {});
+      });
+    
+    } on PlatformException catch (e) {
+      showSnackBar(e.message.toString());
+
+    } on FlutterZsdkException catch (e) { 
+      showSnackBar(e.message);
+
+    } catch (e) {
+      showSnackBar('Unexpected error while discovering bluetooth printers');
+
+    }
+  }
+  ```
+
+
+### Connect to Printer
+Gunakan `_flutterZsdkPlugin.openConnection(<Mac Address>)`, dimana `<Mac Address>` bisa didapatkan dari `.findBluetoothPrinter()`
+
+disarankan `.closeConnection()` sebelum melakukan connect ke printer lain. walaupun sudah dihandle disisi plugin.
+
+### Send ZPL Data to Printer (Print ZPL)
+sebelum print, check dulu koneksi ke printer, utk memastikan printer terkoneksi.
+
+`_flutterZsdkPlugin.isConnected()` utk check koneksi ke printer.
+
+jika sudah terkoneksi, gunakan `_flutterZsdkPlugin.printZplOverBluetooth(<zpl_data>)` untuk mengirim data ZPL ke printer.
+
+
+### Disconnect from Printer
+`_flutterZsdkPlugin.closeConnection()` utk disconnect dari printer.
+
+</br>
+
+
+note: 
+- semua aksi harus dipanggil dalam try-catch block
+- `_flutterZsdkPlugin.isConnected()` hanya harus dipanggil setelah `_flutterZsdkPlugin.openConnection()` jika tidak app bisa crash (tested ANDROID)