From 2cdaa88eae964cc9acfa43162594cd6996a47515 Mon Sep 17 00:00:00 2001
From: Hiroyuki Adachi <hiroxpepe@gmail.com>
Date: Thu, 17 Mar 2022 19:41:06 +0900
Subject: [PATCH] refactor: #13 keeping codes clean.

---
 MidiPlayer.Droid/MainActivity.Component.cs |  16 +++
 MidiPlayer.Droid/MainActivity.cs           |  14 +-
 MidiPlayer.FluidSynth/Synth.cs             |  19 +--
 MidiPlayer/Mixer.cs                        | 154 ++++++++++++++++++---
 4 files changed, 164 insertions(+), 39 deletions(-)

diff --git a/MidiPlayer.Droid/MainActivity.Component.cs b/MidiPlayer.Droid/MainActivity.Component.cs
index bdf8d5f..a412f87 100644
--- a/MidiPlayer.Droid/MainActivity.Component.cs
+++ b/MidiPlayer.Droid/MainActivity.Component.cs
@@ -68,15 +68,31 @@ void initializeComponent() {
             _numberPickerProg = FindViewById<NumberPicker>(Resource.Id.number_picker_prog);
             _numberPickerProg.MinValue = 1;
             _numberPickerProg.MaxValue = 128;
+            _numberPickerProg.ValueChanged += (object sender, NumberPicker.ValueChangeEventArgs e) => {
+                var fader = Mixer.GetCurrent();
+                fader.Program = _numberPickerProg.Value;
+            };
             _numberPickerPan = FindViewById<NumberPicker>(Resource.Id.number_picker_pan);
             _numberPickerPan.MinValue = 1;
             _numberPickerPan.MaxValue = 128;
             _numberPickerPan.Value = 65;
+            _numberPickerPan.ValueChanged += (object sender, NumberPicker.ValueChangeEventArgs e) => {
+                var fader = Mixer.GetCurrent();
+                fader.Pan = _numberPickerPan.Value;
+            };
             _numberPickerVol = FindViewById<NumberPicker>(Resource.Id.number_picker_vol);
             _numberPickerVol.MinValue = 1;
             _numberPickerVol.MaxValue = 128;
             _numberPickerVol.Value = 104;
+            _numberPickerVol.ValueChanged += (object sender, NumberPicker.ValueChangeEventArgs e) => {
+                var fader = Mixer.GetCurrent();
+                fader.Volume = _numberPickerVol.Value;
+            };
             _checkBoxMute = FindViewById<CheckBox>(Resource.Id.check_box_mute);
+            _checkBoxMute.CheckedChange += (object sender, CheckBox.CheckedChangeEventArgs e) => {
+                var fader = Mixer.GetCurrent();
+                fader.Sounds = !_checkBoxMute.Checked;
+            };
             _buttonSendSynth = FindViewById<Button>(Resource.Id.button_send_synth);
             _buttonSendSynth.Click += buttonSendSynth_Click;
 
diff --git a/MidiPlayer.Droid/MainActivity.cs b/MidiPlayer.Droid/MainActivity.cs
index 290bbee..a17fb01 100644
--- a/MidiPlayer.Droid/MainActivity.cs
+++ b/MidiPlayer.Droid/MainActivity.cs
@@ -136,23 +136,21 @@ protected override void OnCreate(Bundle? savedInstanceState) {
             /// add a callback function to be called when the mixer updated.
             /// </summary>
             Mixer.Updated += (object sender, PropertyChangedEventArgs e) => {
-                return;
-                // FIXME:
                 if ((((Mixer.Fader) sender).Index == Mixer.Current)) {
                     if (e.PropertyName is nameof(Mixer.Fader.Name)) {
-                        Log.Debug($"fadar {Mixer.Current}'s Name is updated.");
+                        Log.Debug($"fadar {Mixer.Current} Name is updated.");
                     }
                     if (e.PropertyName is nameof(Mixer.Fader.Bank)) {
-                        Log.Debug($"fadar {Mixer.Current}'s Bank is updated.");
+                        Log.Debug($"fadar {Mixer.Current} Bank is updated.");
                     }
                     if (e.PropertyName is nameof(Mixer.Fader.Program)) {
-                        Log.Debug($"fadar {Mixer.Current}'s Program is updated.");
+                        Log.Debug($"fadar {Mixer.Current} Program is updated.");
                     }
                     if (e.PropertyName is nameof(Mixer.Fader.Volume)) {
-                        Log.Debug($"fadar {Mixer.Current}'s Volume is updated.");
+                        Log.Debug($"fadar {Mixer.Current} Volume is updated.");
                     }
                     if (e.PropertyName is nameof(Mixer.Fader.Pan)) {
-                        Log.Debug($"fadar {Mixer.Current}'s Pan is updated.");
+                        Log.Debug($"fadar {Mixer.Current} Pan is updated.");
                     }
                 }
             };
@@ -391,7 +389,7 @@ void loadFader() {
         void saveFader() {
             var fader = Mixer.GetPrevious();
             if (int.TryParse(_textViewChannel.Text, out int channel)) {
-                fader.Channel = channel;
+                fader.Channel = channel; // MEMO:
                 fader.Program = _numberPickerProg.Value;
                 fader.Pan = _numberPickerPan.Value;
                 fader.Volume = _numberPickerVol.Value;
diff --git a/MidiPlayer.FluidSynth/Synth.cs b/MidiPlayer.FluidSynth/Synth.cs
index 8b7125a..93c1150 100644
--- a/MidiPlayer.FluidSynth/Synth.cs
+++ b/MidiPlayer.FluidSynth/Synth.cs
@@ -208,7 +208,7 @@ public static void Init() {
                 }
                 Multi.StandardMidiFile = _standardMidiFile;
                 Enumerable.Range(MIDI_TRACK_BASE, MIDI_TRACK_COUNT).ToList().ForEach(x => {
-                    Multi.Get(x).PropertyChanged += onPropertyChanged;
+                    Multi.GetBy(x).PropertyChanged += onPropertyChanged;
                 });
                 int result = fluid_player_add(_player, MidiFilePath);
                 if (result == FLUID_FAILED) {
@@ -273,12 +273,12 @@ public static int GetChannel(IntPtr evt) {
         }
 
         public static int GetChannel(int track) {
-            var channel = Multi.Get(track).Channel;
+            var channel = Multi.GetBy(track).Channel;
             return channel;
         }
 
         public static int GetBank(int track) {
-            var bank = Multi.Get(track).Bank;
+            var bank = Multi.GetBy(track).Bank;
             if (bank == -1) { // unset BANK_SELECT_LSB = 32
                 bank = 0;
             }
@@ -286,7 +286,7 @@ public static int GetBank(int track) {
         }
 
         public static int GetProgram(int track) {
-            var program = Multi.Get(track).Program;
+            var program = Multi.GetBy(track).Program;
             return program;
         }
 
@@ -298,12 +298,12 @@ public static string GetVoice(int track) {
         }
 
         public static string GetTrackName(int track) {
-            var name = Multi.Get(track).Name;
+            var name = Multi.GetBy(track).Name;
             return name;
         }
 
         public static bool IsSounded(int channel) {
-            return Multi.Get(channel).Sounds;
+            return Multi.GetBy(channel).Sounds;
         }
 
         ///////////////////////////////////////////////////////////////////////////////////////////////
@@ -425,7 +425,10 @@ public static void ApplyControlChange(int channel, int control, int value) {
                 }
             }
 
-            public static Track Get(int index) {
+            /// <summary>
+            /// get a trak by index.
+            /// </summary>
+            public static Track GetBy(int index) {
                 var track = _trackMap[index];
                 return track;
             }
@@ -470,7 +473,7 @@ public class Track : INotifyPropertyChanged {
             ///////////////////////////////////////////////////////////////////////////////////////////
             // Constructor
 
-            public Track(int index) {
+            internal Track(int index) {
                 _index = index;
             }
 
diff --git a/MidiPlayer/Mixer.cs b/MidiPlayer/Mixer.cs
index c78853b..a5146f9 100644
--- a/MidiPlayer/Mixer.cs
+++ b/MidiPlayer/Mixer.cs
@@ -19,21 +19,43 @@ public static class Mixer {
         ///////////////////////////////////////////////////////////////////////////////////////////////
         // Fields [nouns, noun phrases]
 
+        /// <summary>
+        /// a Dictionary object that holds faders.
+        /// </summary>
         static Map<int, Fader> _mixer;
 
+        /// <summary>
+        /// the current index value of the selected fader.
+        /// </summary>
         static int _current;
 
+        /// <summary>
+        /// the index value of the previously selected fader.
+        /// </summary>
         static int _previous;
 
+        /// <summary>
+        /// func object to be called when a fader is selected.
+        /// </summary>
+        static PropertyChangedEventHandler _onSelected;
+
+        /// <summary>
+        /// func object to be called when a fader is updated.
+        /// </summary>
+        static PropertyChangedEventHandler _onUpdated;
+
         ///////////////////////////////////////////////////////////////////////////////////////////////
         // static Constructor
 
+        /// <summary>
+        /// static constructor.
+        /// </summary>
         static Mixer() {
             _mixer = new();
             _current = 0;
             Enumerable.Range(MIDI_TRACK_BASE, MIDI_TRACK_COUNT).ToList().ForEach(x => {
                 Fader fader = new(x);
-                fader.Updated += Updated;
+                fader.Updated += onUpdate;
                 _mixer.Add(x, fader);
             });
         }
@@ -47,7 +69,10 @@ static Mixer() {
         /// <remarks>
         /// called when Mixer's channel is clicked.<br/>
         /// </remarks>
-        public static event PropertyChangedEventHandler? Selected;
+        public static event PropertyChangedEventHandler? Selected {
+            add => _onSelected += value;
+            remove => _onSelected -= value;
+        }
 
         /// <summary>
         /// updated event handler.
@@ -55,7 +80,10 @@ static Mixer() {
         /// <remarks>
         /// called when Fader's properties change.<br/>
         /// </remarks>
-        public static event PropertyChangedEventHandler? Updated;
+        public static event PropertyChangedEventHandler? Updated {
+            add => _onUpdated += value;
+            remove => _onUpdated -= value;
+        }
 
         ///////////////////////////////////////////////////////////////////////////////////////////////
         // public static Properties [noun, noun phrase, adjective]
@@ -72,7 +100,7 @@ public static int Current {
                 _previous = _current;
                 _current = value;
                 Log.Info($"current: {_current}");
-                Selected?.Invoke(null, new(nameof(Current)));
+                _onSelected(null, new(nameof(Current)));
             }
         }
 
@@ -100,6 +128,19 @@ public static Fader GetBy(int index) {
             return _mixer[index];
         }
 
+        ///////////////////////////////////////////////////////////////////////////////////////////////
+        // private static Methods [verb, verb phrases]
+
+        /// <summary>
+        /// called when a fader value is updated.
+        /// </summary>
+        static void onUpdate(object sender, PropertyChangedEventArgs e) {
+            _onUpdated(sender, e);
+        }
+
+        ///////////////////////////////////////////////////////////////////////////////////////////////
+        // inner Classes
+
         /// <summary>
         /// Fader class.
         /// </summary>
@@ -109,26 +150,53 @@ public class Fader {
             ///////////////////////////////////////////////////////////////////////////////////////////
             // Fields [nouns, noun phrases]
 
+            /// <summary>
+            /// an index value of a fader.
+            /// </summary>
             int _index = -1;
 
-            bool _sounds = true; // mute param.
+            /// <summary>
+            /// a value of whether the fader is on or off.
+            /// </summary>
+            bool _sounds = true; // mute parameter.
 
+            /// <summary>
+            /// a midi channel number of a fader.
+            /// </summary>
             string _name = "undefined";
 
+            /// <summary>
+            /// 
+            /// </summary>
             int _channel = -1;
 
+            /// <summary>
+            /// a midi bank number of a fader.
+            /// </summary>
             int _bank = 0;
 
+            /// <summary>
+            /// a midi program number of a fader.
+            /// </summary>
             int _program = 0;
 
+            /// <summary>
+            /// a midi volume value of a fader.
+            /// </summary>
             int _volume = 104;
 
+            /// <summary>
+            /// a midi pan value of a fader.
+            /// </summary>
             int _pan = 64; // center
 
             ///////////////////////////////////////////////////////////////////////////////////////////
             // Constructor
 
-            public Fader(int index) {
+            /// <summary>
+            /// internal constructor.
+            /// </summary>
+            internal Fader(int index) {
                 _index = index;
             }
 
@@ -138,43 +206,66 @@ public Fader(int index) {
             /// <summary>
             /// updated event handler.
             /// </summary>
-            public event PropertyChangedEventHandler? Updated;
+            internal event PropertyChangedEventHandler? Updated;
 
             ///////////////////////////////////////////////////////////////////////////////////////////
             // Properties [noun, noun phrase, adjective]
 
+            /// <summary>
+            /// an index value of a fader.
+            /// </summary>
             public int Index {
                 get => _index;
                 set {
-                    _index = value; // TODO: Compare if the value is the same value as the previous.
-                    Updated?.Invoke(this, new(nameof(Index))); // FIXME: not Invoke if two values are the same.
+                    if (value != _index) {
+                        _index = value;
+                        Updated?.Invoke(this, new(nameof(Index)));
+                    }
                 }
             }
 
+            /// <summary>
+            /// a value of whether the fader is on or off.
+            /// </summary>
             public bool Sounds {
                 get => _sounds;
                 set {
-                    _sounds = value; // TODO: Compare if the value is the same value as the previous.
-                    Updated?.Invoke(this, new(nameof(Sounds))); // FIXME: not Invoke if two values are the same.
+                    if (value != _sounds) {
+                        _sounds = value;
+                        Updated?.Invoke(this, new(nameof(Sounds)));
+                    }
                 }
             }
 
+            /// <summary>
+            /// a midi track name of a fader.
+            /// </summary>
             public string Name {
                 get => _name;
                 set {
-                    _name = value; // TODO: Compare if the value is the same value as the previous.
-                    Updated?.Invoke(this, new(nameof(Name))); // FIXME: not Invoke if two values are the same.
+                    if (value != _name) {
+                        _name = value;
+                        Updated?.Invoke(this, new(nameof(Name)));
+                    }
                 }
             }
 
+            /// <summary>
+            /// a midi channel number of a fader.
+            /// </summary>
             public int Channel {
                 get => _channel;
                 set {
-                    _channel = value; // TODO: Compare if the value is the same value as the previous.
-                    Updated?.Invoke(this, new(nameof(Channel))); // FIXME: not Invoke if two values are the same.
+                    if (value != _channel) {
+                        _channel = value;
+                        Updated?.Invoke(this, new(nameof(Channel)));
+                    }
                 }
             }
 
+            /// <summary>
+            /// a midi bank number of a fader.
+            /// </summary>
             public int Bank {
                 get {
                     if (_channel == 9 && _bank != 128) {
@@ -183,32 +274,49 @@ public int Bank {
                     return _bank;
                 }
                 set {
-                    _bank = value; // TODO: Compare if the value is the same value as the previous.
-                    Updated?.Invoke(this, new(nameof(Bank))); // FIXME: not Invoke if two values are the same.
+                    if (value != _bank) {
+                        _bank = value;
+                        Updated?.Invoke(this, new(nameof(Bank)));
+                    }
                 }
             }
 
+            /// <summary>
+            /// a midi program number of a fader.
+            /// </summary>
             public int Program {
                 get => _program;
                 set {
-                    _program = value; // TODO: Compare if the value is the same value as the previous.
-                    Updated?.Invoke(this, new(nameof(Program))); // FIXME: not Invoke if two values are the same.
+                    if (value != _program) {
+                        _program = value;
+                        Updated?.Invoke(this, new(nameof(Program)));
+                    }
                 }
             }
 
+            /// <summary>
+            /// a midi volume value of a fader.
+            /// </summary>
             public int Volume {
                 get => _volume;
                 set {
-                    _volume = value; // TODO: Compare if the value is the same value as the previous.
-                    Updated?.Invoke(this, new(nameof(Volume))); // FIXME: not Invoke if two values are the same.
+                    if (value != _volume) {
+                        _volume = value;
+                        Updated?.Invoke(this, new(nameof(Volume)));
+                    }
                 }
             }
 
+            /// <summary>
+            /// a midi pan value of a fader.
+            /// </summary>
             public int Pan {
                 get => _pan;
                 set {
-                    _pan = value; // TODO: Compare if the value is the same value as the previous.
-                    Updated?.Invoke(this, new(nameof(Pan))); // FIXME: not Invoke if two values are the same.
+                    if (value != _pan) {
+                        _pan = value;
+                        Updated?.Invoke(this, new(nameof(Pan)));
+                    }
                 }
             }
         }