Synchronous API for creating instances and Hot-reload fix

DeveloperNotes.md

@@ -57,3 +57,20 @@ Some files in the project are generated to maintain sync between
   Generated file paths are configured as values in `bin/codegen.dart` for `toGenerate` Map
 
 [Read about generation of platform specific constant files](bin/README.md)
+
+
+## Static plugin code analyzer
+
+The new flutter analyzer does a great job at analyzing complete flutter package.
+
+Running `flutter analyze` in project root will analyze dart files in complete project,
+ i.e., plugin code and example code
+
+
+Or, use the good old dart analyzer
+
+```bash
+dartanalyzer --fatal-warnings lib/**/*.dart
+
+dartanalyzer --fatal-warnings example/lib/**/*.dart
+```

README.md

@@ -41,12 +41,6 @@ site to discuss privately.
 import 'package:ably_flutter_plugin/ably.dart' as ably;
 ```
 
-##### Create an Ably instance
-
-```dart
-final ably.Ably ablyPlugin = ably.Ably();
-```
-
 ##### create a ClientOptions
 
 ```dart
@@ -57,7 +51,7 @@ clientOptions.logLevel = ably.LogLevel.verbose; //optional
 ##### Rest API
 
 ```dart
-ably.Rest rest = await ablyPlugin.createRest(options: clientOptions);
+ably.Rest rest = ably.Rest(options: clientOptions);
 ```
 
 Getting a channel instance
@@ -69,20 +63,24 @@ ably.RestChannel channel = rest.channels.get('test');
 Publish rest messages
 
 ```dart
-//passing both name and data
-await channel.publish(name: "Hello", data: "Ably");
-//passing just name
-await channel.publish(name: "Hello");
-//passing just data
-await channel.publish(data: "Ably");
-//publishing an empty message
-await channel.publish();
+void publishMessages() async {
+    //passing both name and data
+    await channel.publish(name: "Hello", data: "Ably");
+    //passing just name
+    await channel.publish(name: "Hello");
+    //passing just data
+    await channel.publish(data: "Ably");
+    //publishing an empty message
+    await channel.publish();
+}
+
+publishMessages();
 ```
 
 ##### Realtime API
 
 ```dart
-ably.Realtime realtime = await ablyPlugin.createRealtime(options: clientOptions);
+ably.Realtime realtime = ably.Realtime(options: clientOptions);
 ```
 
 Listen to connection state change event

android/src/main/java/io/ably/flutter/plugin/AblyEventStreamHandler.java

@@ -4,7 +4,6 @@
 import android.os.Looper;
 
 import io.ably.flutter.plugin.generated.PlatformConstants;
-import io.ably.lib.realtime.ChannelStateListener;
 import io.ably.lib.realtime.ConnectionStateListener;
 import io.flutter.plugin.common.EventChannel;
 
@@ -16,15 +15,13 @@
  * ref: https://api.flutter.dev/javadoc/io/flutter/plugin/common/EventChannel.StreamHandler.html
  * */
 public class AblyEventStreamHandler implements EventChannel.StreamHandler {
-    private final AblyMethodCallHandler methodCallHandler;
 
     /**
-     * Constructor requiring methodCallHandler, as it is a singleton and has all instances stored
-     * Event listening can be started on an instance picked from the stored instances
+     * Creating an ablyLibrary instance.
+     * As ablyLibrary is a singleton,
+     * all ably object instance will be accessible
      * */
-    AblyEventStreamHandler(AblyMethodCallHandler methodCallHandler){
-        this.methodCallHandler = methodCallHandler;
-    }
+    private final AblyLibrary ablyLibrary = AblyLibrary.getInstance();
 
     /**
      * Refer to the comments on AblyMethodCallHandler.MethodResultWrapper
@@ -62,26 +59,35 @@ private class Listener{
     }
 
     private class PluginConnectionStateListener extends Listener implements ConnectionStateListener {
-        PluginConnectionStateListener(EventChannel.EventSink eventSink){super(eventSink);}
+
+        PluginConnectionStateListener(EventChannel.EventSink eventSink){
+            super(eventSink);
+        }
+
         public void onConnectionStateChanged(ConnectionStateChange stateChange){
             eventSink.success(stateChange);
         }
+
+    }
+
+    // Casting stream creation arguments from `Object` into `AblyMessage`
+    private AblyFlutterMessage<String> getMessage(Object message){
+        return ((AblyFlutterMessage<AblyFlutterMessage<String>>)message).message;
     }
 
     @Override
     public void onListen(Object object, EventChannel.EventSink uiThreadEventSink) {
         MainThreadEventSink eventSink = new MainThreadEventSink(uiThreadEventSink);
-        methodCallHandler.<AblyFlutterMessage<String>>ablyDo((AblyFlutterMessage)object, (ablyLibrary, message) -> {
-            String eventName = message.message;
-            switch(eventName) {
-                case PlatformConstants.PlatformMethod.onRealtimeConnectionStateChanged:
-                    connectionStateListener = new PluginConnectionStateListener(eventSink);
-                    ablyLibrary.getRealtime(message.handle).connection.on(connectionStateListener);
-                    return;
-                default:
-                    eventSink.error("unhandled event", null, null);
-            }
-        });
+        AblyFlutterMessage<String> message = getMessage(object);
+        String eventName = message.message;
+        switch(eventName) {
+            case PlatformConstants.PlatformMethod.onRealtimeConnectionStateChanged:
+                connectionStateListener = new PluginConnectionStateListener(eventSink);
+                ablyLibrary.getRealtime(message.handle).connection.on(connectionStateListener);
+                return;
+            default:
+                eventSink.error("unhandled event", null, null);
+        }
     }
 
     @Override
@@ -90,15 +96,12 @@ public void onCancel(Object object) {
             System.out.println("Cannot process null input on cancel");
             return;
         }
-        methodCallHandler.<AblyFlutterMessage<String>>ablyDo((AblyFlutterMessage)object, (ablyLibrary, message) -> {
-            String eventName = message.message;
-            switch (eventName) {
-                case PlatformConstants.PlatformMethod.onRealtimeConnectionStateChanged:
-                    ablyLibrary.getRealtime(message.handle).connection.off(connectionStateListener);
-                case PlatformConstants.PlatformMethod.onRealtimeChannelStateChanged:
-                    // ablyLibrary.getRealtime(handle).connection.off(connectionStateListener);
-            }
-        });
+        AblyFlutterMessage<String> message = getMessage(object);
+        String eventName = message.message;
+        switch (eventName) {
+            case PlatformConstants.PlatformMethod.onRealtimeConnectionStateChanged:
+                ablyLibrary.getRealtime(message.handle).connection.off(connectionStateListener);
+        }
     }
 
 }

android/src/main/java/io/ably/flutter/plugin/AblyFlutterMessage.java

@@ -4,10 +4,7 @@ class AblyFlutterMessage<T> {
     final Long handle;
     final T message;
 
-    AblyFlutterMessage(final Long handle, final T message) {
-        if (null == handle) {
-            throw new NullPointerException("handle cannot be null.");
-        }
+    AblyFlutterMessage(final T message, final Long handle) {
         if (null == message) {
             throw new NullPointerException("message cannot be null.");
         }

android/src/main/java/io/ably/flutter/plugin/AblyFlutterPlugin.java

@@ -2,7 +2,6 @@
 
 import androidx.annotation.NonNull;
 
-import app.loup.streams_channel.StreamsChannel;
 import io.flutter.embedding.engine.plugins.FlutterPlugin;
 import io.flutter.plugin.common.BinaryMessenger;
 import io.flutter.plugin.common.MethodChannel;
@@ -35,14 +34,17 @@ public static void registerWith(Registrar registrar) {
 
     private static void setupChannels(BinaryMessenger messenger){
         MethodCodec codec = createCodec();
-        AblyMethodCallHandler methodCallHandler = AblyMethodCallHandler.getInstance();
-
-        final MethodChannel channel = new MethodChannel(messenger, "io.ably.flutter.plugin", codec);
-        channel.setMethodCallHandler(methodCallHandler);
 
         final StreamsChannel streamsChannel = new StreamsChannel(messenger, "io.ably.flutter.stream", codec);
-        streamsChannel.setStreamHandlerFactory(arguments -> new AblyEventStreamHandler(methodCallHandler));
+        streamsChannel.setStreamHandlerFactory(arguments -> new AblyEventStreamHandler());
 
+        AblyMethodCallHandler methodCallHandler = AblyMethodCallHandler.getInstance(
+                // Streams channel will be created on `register` method call
+                // and also on every hot-reload
+                streamsChannel::reset
+        );
+        final MethodChannel channel = new MethodChannel(messenger, "io.ably.flutter.plugin", codec);
+        channel.setMethodCallHandler(methodCallHandler);
     }
 
     @Override

android/src/main/java/io/ably/flutter/plugin/AblyLibrary.java

@@ -8,53 +8,46 @@
 import io.ably.lib.types.ClientOptions;
 
 class AblyLibrary {
-    private boolean _disposed = false;
+
+    private static AblyLibrary _instance;
     private long _nextHandle = 1;
 
+    // privatizing default constructor to enforce usage of getInstance
+    private AblyLibrary(){}
+
+    static synchronized AblyLibrary getInstance() {
+        if (null == _instance) {
+            _instance = new AblyLibrary();
+        }
+        return _instance;
+    }
+
     //    using LongSparseArray as suggested by Studio
     //    and as per this answer https://stackoverflow.com/a/31413003
     private final LongSparseArray<AblyRest> _restInstances = new LongSparseArray<>();
     private final LongSparseArray<AblyRealtime> _realtimeInstances = new LongSparseArray<>();
 
-    private void assertNotDisposed() {
-        if (_disposed) {
-            throw new IllegalStateException("Instance disposed.");
-        }
-    }
-
     long createRealtime(final ClientOptions clientOptions) throws AblyException {
-        assertNotDisposed();
-
         final AblyRealtime realtime = new AblyRealtime(clientOptions);
         _realtimeInstances.put(_nextHandle, realtime);
         return _nextHandle++;
     }
 
     long createRest(final ClientOptions clientOptions) throws AblyException {
-        assertNotDisposed();
-
         final AblyRest rest = new AblyRest(clientOptions);
         _restInstances.put(_nextHandle, rest);
         return _nextHandle++;
     }
 
     AblyRealtime getRealtime(final long handle) {
-        assertNotDisposed();
-
         return _realtimeInstances.get(handle);
     }
 
     AblyRest getRest(final long handle){
-        assertNotDisposed();
-
         return _restInstances.get(handle);
     }
 
     void dispose() {
-        assertNotDisposed();
-
-        _disposed = true;
-
         for(int i=0; i<_realtimeInstances.size(); i++){
             long key = _realtimeInstances.keyAt(i);
             AblyRealtime r = _realtimeInstances.get(key);

android/src/main/java/io/ably/flutter/plugin/AblyMessageCodec.java

@@ -137,7 +137,7 @@ private AblyFlutterMessage readAblyFlutterMessage(Map<String, Object> jsonMap) {
         if(type!=null){
             message = codecMap.get((byte)(int)type).decode((Map<String, Object>)message);
         }
-        return new AblyFlutterMessage<>(handle, message);
+        return new AblyFlutterMessage<>(message, handle);
     }
 
     private ClientOptions readClientOptions(Map<String, Object> jsonMap) {