Added Equalizer & EqualizerMode to Dart

lib/dart_vlc.dart

@@ -9,6 +9,7 @@
  */
 
 export 'package:dart_vlc/src/player.dart';
+export 'package:dart_vlc/src/equalizer.dart';
 export 'package:dart_vlc/src/broadcast.dart';
 export 'package:dart_vlc/src/record.dart';
 export 'package:dart_vlc/src/chromecast.dart';
@@ -18,6 +19,7 @@ export 'package:dart_vlc/src/playerState/playerState.dart';
 export 'package:dart_vlc/src/mediaSource/mediaSource.dart';
 export 'package:dart_vlc/src/mediaSource/media.dart';
 export 'package:dart_vlc/src/mediaSource/playlist.dart';
+export 'package:dart_vlc/src/enums/equalizerMode.dart';
 export 'package:dart_vlc/src/enums/mediaSourceType.dart';
 export 'package:dart_vlc/src/enums/mediaType.dart';
 export 'package:dart_vlc/src/enums/playlistMode.dart';

lib/src/enums/equalizerMode.dart

@@ -0,0 +1,23 @@
+
+
+/// Predefined presets for [Equalizer].
+enum EqualizerMode {
+	flat,
+	classical,
+	club,
+	dance,
+	fullBass,
+	fullBassAndTreble,
+	fullTreble,
+	headphones,
+	largeHall,
+	live,
+	party,
+	pop,
+	reggae,
+	rock,
+	ska,
+	soft,
+	softRock,
+	techno
+}

lib/src/equalizer.dart

@@ -0,0 +1,93 @@
+import 'package:dart_vlc/src/channel.dart';
+import 'package:dart_vlc/src/enums/equalizerMode.dart';
+
+
+/// Internally used class to avoid direct creation of the object of a [Equalizer] class.
+class _Equalizer extends Equalizer {}
+
+
+/// Defines an [Equalizer] instance for usage in a [Player].
+/// 
+/// Use [Equalizer.createEmpty] for creating a default equalizer & [Equalizer.createMode] for creating an equalizer using a preset from [EqualizerMode].
+/// 
+/// Example
+/// 
+/// ```dart
+/// Player player = new Player(id: 0);
+/// Equalizer equalizer = Equalizer.createMode(EqualizerMode.party);
+/// player.setEqualizer(equalizer);
+/// ```
+/// 
+class Equalizer {
+  /// Unique Id associated with this [Equalizer].
+  late int id;
+  /// Preamp value of the [Equalizer]. Use [Equalizer.setPreAmp] to change value.
+  double preAmp = 0.0;
+  /// Values of amps of various bands in [Equalizer]. Use [Equalizer.setBandAmp] to change values.
+  Map<double, double> bandAmps = {};
+  /// Preset if [Equalizer] is initialized using [Equalizer.createMode], else `null`.
+  EqualizerMode? mode;
+
+  /// Creates a default [Equalizer] instance with all values set to `0.0`.
+  static Future<Equalizer> createEmpty() async {
+    Equalizer equalizer = new _Equalizer();
+    dynamic _equalizer = await channel.invokeMethod(
+      'Equalizer.createEmpty',
+       {},
+    );
+    equalizer.id = _equalizer['id'];
+    equalizer.preAmp = _equalizer['preAmp'];
+    equalizer.bandAmps = Map<double, double>.from(_equalizer['bandAmps']);
+    return equalizer;
+  }
+
+  /// Creates an [Equalizer] instance with any preset from [EqualizerMode].
+  static Future<Equalizer> createMode(EqualizerMode mode) async {
+    Equalizer equalizer = new _Equalizer();
+    dynamic _equalizer = await channel.invokeMethod(
+      'Equalizer.createMode',
+       {
+         'mode': mode.index,
+       },
+    );
+    equalizer.id = _equalizer['id'];
+    equalizer.mode = mode;
+    equalizer.preAmp = _equalizer['preAmp'];
+    equalizer.bandAmps = Map<double, double>.from(_equalizer['bandAmps']);
+    return equalizer;
+  }
+
+  /// Sets value of [Equalizer.preAmp].
+  /// 
+  /// Constraints:
+  /// `-20.0 < amp < 20.0`
+  /// 
+  Future<void> setPreAmp(double amp) async {
+    await channel.invokeMethod(
+      'Equalizer.setPreAmp',
+       {
+         'id': this.id,
+         'preAmp': amp,
+       },
+    );
+    this.preAmp = amp;
+  }
+
+  /// Sets value of any particular band from [Equalizer.bandAmps].
+  /// Band whose `amp` needs to be changed, must be present in [Equalizer.bandAmps].
+  /// 
+  /// Constraints:
+  /// `-20.0 < amp < 20.0`
+  /// 
+  Future<void> setBandAmp(double band, double amp) async {
+    await channel.invokeMethod(
+      'Equalizer.setBandAmp',
+       {
+         'id': this.id,
+         'band': band,
+         'amp': amp,
+       },
+    );
+    this.bandAmps[band] = amp;
+  }
+}

lib/src/player.dart

@@ -1,6 +1,7 @@
 import 'dart:async';
 import 'package:dart_vlc/dart_vlc.dart';
 import 'package:dart_vlc/src/channel.dart';
+import 'package:dart_vlc/src/equalizer.dart';
 import 'package:dart_vlc/src/playerState/playerState.dart';
 import 'package:dart_vlc/src/mediaSource/media.dart';
 import 'package:dart_vlc/src/mediaSource/mediaSource.dart';
@@ -350,6 +351,18 @@ class Player {
     );
   }
 
+  /// Sets [Equalizer] for the [Player].
+  Future<void> setEqualizer(Equalizer equalizer) async {
+    await this._isInstanceCreated.future;
+    await channel.invokeMethod(
+      'Player.setEqualizer',
+      {
+        'id': this.id,
+        'equalizerId': equalizer.id,
+      },
+    );
+  }
+
   /// Destroys the instance of [Player] & closes all [StreamController]s in it.
   Future<void> dispose() async {
     await this.currentController.close();

windows/dart_vlc_plugin.cpp

@@ -1274,7 +1274,7 @@ namespace {
          * 
         */
         else if (method->name == "Equalizer.setBandAmp") {
-            float id = method->getArgument<float>("id");
+            int id = method->getArgument<int>("id");
             float band = method->getArgument<float>("band");
             float amp = method->getArgument<float>("amp");
             equalizers->get(id)->setBandAmp(band, amp);
@@ -1292,7 +1292,7 @@ namespace {
          * 
         */
         else if (method->name == "Equalizer.setPreAmp") {
-            float id = method->getArgument<float>("id");
+            int id = method->getArgument<int>("id");
             float preAmp = method->getArgument<float>("preAmp");
             equalizers->get(id)->setPreAmp(preAmp);
             return method->returnNull();