{ UNIT MIDITest.pas
--------------------------------- MIDITest -----------------------------
 Main unit of kMIDIPlayer project and kMIDIPlayer is a Demo program for TMidiPlayer2.

 Copyright 2011 Silhwan Hyun, All Rights Reserved
 This unit is free. It may be used both in commercial and non-commercial software either in
  original or in modified form.
 This unit can be freely distributed in any way and by any means provided this copyright
  notice is preserved.

 Author : Silhwan Hyun   (e-mail addr : hyunsh@hanafos.com)

 Author's comment : Please let me know if you have any idea to improve or to debug this unit.

 Contibutors
   Emil Weiss : Test & Advice for update/debug

 Revision History
 ------------------------------
  Ver 0.9.6   31 Apr 2013
   - Added "Show Music Sheet" button.
   - Support MidiSheetMusic program which shows music sheet of opened MIDI file.

  Ver 0.9.5    9 Feb 2013
   - Added "Show Channel Window" button.

  Ver 0.9.4    28 May 2012
   - The enabled state of VolumeBar is depends on the VolumeAdjustable property of TMIDIPlayer2
   - Added a sub-form to adjust tempo & pitch.
   - Added a TMemo to display sync lyrics
   - Removed a TCheckBox for mute control (=> it may be not effective if we use a synthesizer
     other than Microsoft MIDI Mapper or Microsoft Wavetable Synth)

  Ver 0.9.3    27 Aug 2011
   - Added a CheckBox to control the Mute state of sound output.
   - Support local language using gnugettext

  Ver 0.9.2    Jul 09 2011
   - Added a EditBox to display the elapsed time at playing MIDI file.
   - Added a Speed control TrackBar.

  Ver 0.9.1    Jul 01 2011
   - Added functions to play MIDI file with MidiPlayer2.

  Ver 0.9.0    Jun 04 2011
   - Initial release
----------------------------------------------------------------------------}

unit MIDITest;

interface

// If you want to use local language for captions of components and messages then
//  activate following conditional compiler directive. (also in the project source)
// You should also prepare your local language file(mo file) to translate captions of
//  components and messages.
{$DEFINE MULTI_LANGUAGE}

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, FileCtrl, ComCtrls,
  MidiPlayer2, MidiFile2, XPMan, Dialogs, StdCtrls, ActnList, CheckLst, StrUtils, ShowMIDILyrics,
  {$IFDEF MULTI_LANGUAGE}gnugettext,{$ENDIF} ExtCtrls, AppEvnts;

const
  WM_InformPlayerStat = WM_USER + 146;
  WM_WaitingURLCheck  = WM_USER + 147;
  Set_ChannelStat     = 1;
  Set_PlayingPos      = 2;
  Set_Title           = 3;
  Set_Lyrics          = 4;

type
  PSyncLyrics = ^TRawLyrics;

  TMainForm = class(TForm)
    btnOpen: TButton;
    OpenDialog1: TOpenDialog;
    btnClose: TButton;
    edTracks: TEdit;
    Label1: TLabel;
    Label2: TLabel;
    edFormat: TEdit;
    edLength: TEdit;
    Label4: TLabel;
    edFile: TEdit;
    Label7: TLabel;
    edCopyright: TEdit;
    Label9: TLabel;
    btnPlay: TButton;
    cbSynthesizer: TComboBox;
    btnStop: TButton;
    PositionBar: TProgressBar;
    Label3: TLabel;
    XPManifest1: TXPManifest;
    btnPause: TButton;
    Label6: TLabel;
    MidiFile: TMidiFile2;
    edTime: TEdit;
    MidiPlayer: TMidiPlayer2;
    tbVolume: TTrackBar;
    PageControl1: TPageControl;
    TrackSheet: TTabSheet;
    TrackList: TCheckListBox;
    PlainLyricsSheet: TTabSheet;
    lbl_Synth: TLabel;
    PlainLyrics: TListBox;
    Button1: TButton;
    TabSheet1: TTabSheet;
    SyncLyricsList: TListBox;
    btnShowLyricsWindow: TButton;
    btnViewChannel: TButton;
    btnShowMusicSheet: TButton;
    Label5: TLabel;
    Label8: TLabel;
    ApplicationEvents1: TApplicationEvents;
    procedure MidiPlayerMidiEvent(Track: integer; Event: PMidiEvent);
    procedure MidiPlayerTrackEnd(Track: Integer);
    procedure MidiPlayerPlayEnd(Sender: TObject);
    procedure MidiPlayerTempoChange(Tempo: Cardinal);
    procedure MidiPlayerPosUpdate(TimePos, TicksPos: Cardinal);
    procedure btnOpenClick(Sender: TObject);
    procedure btnCloseClick(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure FormDestroy(Sender: TObject);
    procedure btnPlayClick(Sender: TObject);
    procedure btnStopClick(Sender: TObject);
    procedure PositionBarMouseDown(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure tbVolumeChange(Sender: TObject);
    procedure btnPauseClick(Sender: TObject);
    procedure cbSynthesizerChange(Sender: TObject);
    procedure TrackListClickCheck(Sender: TObject);
    procedure FormShow(Sender: TObject);
    procedure Button1Click(Sender: TObject);
    procedure MidiPlayerGotLyrics(Track: Integer; Event: PMidiEvent);
    procedure btnShowLyricsWindowClick(Sender: TObject);
    procedure btnViewChannelClick(Sender: TObject);
    procedure btnShowMusicSheetClick(Sender: TObject);
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
    procedure ApplicationEvents1Message(var Msg: tagMSG; var Handled: Boolean);
  private
    { Private declarations }
    FCanvas: TCanvas;
    procedure FillMidiOutDevices;
    function  SendDataW(HServer : THandle; WData: WideString; RequestId : integer): integer;
  public
    { Public declarations }
    procedure WndProc(var Msg : TMessage); override;
  end;

var
  MainForm: TMainForm;

implementation

{$R *.dfm}

uses {$IFDEF UNICODE}ViewChannel{$ELSE}ViewChannel_D7{$ENDIF}, TempoControl;

const
  CMaxVolume = 65535;
  CStepVolume = 3120;

  WM_MIDI_PosUpdate   = WM_USER + 3;

 // Request ID used at controlling MidiSheetMusic
  rqOpenFile = $0001;    // Open MIDI file
  rqCloseFile = $0002;   // Close MIDI file
  rqStop = $0005;        // Stop displaying progress bar
  rqExit = $0044;        // Terminate program
  rqSetHandle = $0099;   // Set the handle to client's window

var
 // MidiFile: TMidiFile2;
 // MidiPlayer: TMidiPlayer2;
  Paused: Boolean = false;
  MIDILyrics: TRawLyrics;
  PassedActivation: boolean = false;
  CurMIDIFile: string;

  hMsg_StartUp: Cardinal;
  hMsg_Terminated: Cardinal;
  MIDIProcessHandle: THandle = 0;
  MIDIThreadId: DWORD;
  MIDIWinHandle: THandle = 0;

  FhServer: cardinal = 0;
  PrevPosMs: DWORD = 0;
  TicksPerMilSec: single = 0;
  MilSecPerTick: single = 0;

procedure TMainForm.WndProc(var Msg : TMessage);
begin
  if (Msg.Msg = WM_SyncLyricsConfig) then
  begin
    if Msg.WParam = SyncLyrics_Shown then
    begin
     //  b_ViewSyncLyrics := true;
       btnShowLyricsWindow.Enabled := false;
    end else
    if Msg.WParam = SyncLyrics_Closed then
    begin
     //  b_ViewSyncLyrics := false;
       btnShowLyricsWindow.Enabled := true;
    end
  end else
  if (Msg.Msg = WM_ViewChannelConfig) then
  begin
    if Msg.WParam = ViewChannel_Shown then
       btnViewChannel.Enabled := false
    else
    if Msg.WParam = ViewChannel_Closed then
       btnViewChannel.Enabled := true;
  end
  {else if (Msg.Msg = WM_QueryEndSession) then
    Msg.Result := 1    // Allow system termination  }
  else
    inherited WndProc(Msg);
end;

procedure TMainForm.FillMidiOutDevices;
var
  iDevice: Integer;
  I: Integer;
begin
  for iDevice := 0 to MidiPlayer.MidiOutDevices - 1 do
    cbSynthesizer.Items.Add(MidiPlayer.MidiOutProductName(iDevice));

  if MidiPlayer.OpenedMidiOut <> '' then
    for I := 0 to cbSynthesizer.Items.Count - 1 do
      if MidiPlayer.OpenedMidiOut = cbSynthesizer.Items[I] then
        cbSynthesizer.ItemIndex := I;
end;

function LookForMIDIWindow(aHandle: HWnd; aThreadId: Longint): BOOL; stdcall;
var
  ClassName: array[0..255] of Char;
  ThreadId: DWORD;
  ProcId: DWORD;
  s: string;
begin
  result := true;

  if GetClassName(aHandle, ClassName, SizeOf(ClassName)) = 0 then
     exit;

  s := string(ClassName);
  if copy(s, 1, 14) <> 'WindowsForms10' then
    exit;

  ThreadId := GetWindowThreadProcessId(aHandle, @ProcId);
  if aThreadId <> 0 then
  begin
     if ThreadId = aThreadId then
     begin
        MIDIWinHandle := aHandle;
        result := false; // exit enumeration loop
     end;
  end else  // aThreadId = 0
  if GetWindowText(aHandle, ClassName, SizeOf(ClassName)) > 0 then
     if StrComp(ClassName, 'Midi Sheet Music') = 0 then
     begin
        MIDIWinHandle := aHandle;
        result := false; // exit enumeration loop
     end;

end;

procedure TMainForm.FormClose(Sender: TObject; var Action: TCloseAction);
begin
 // Check if my launched MidiSheetMusic is running.
 // ( MIDIWinHandle is not 0 if it is running. )
   if MIDIProcessHandle <> 0 then
   begin
      MIDIWinHandle := 0;
      EnumWindows(@LookForMIDIWindow, MIDIThreadId);
      if MIDIWinHandle <> 0 then
        SendDataW(FhServer, 'Exit', rqExit);  // Let MidiSheetMusic terminate
   end;
end;

procedure TMainForm.FormCreate(Sender: TObject);
begin
 {$IFDEF MULTI_LANGUAGE}
  if GetOEMCP = 949 then   // Korean language ?
  begin
    UseLanguage('ko');
    Font.Name := '';
    Font.Size := 9;
    lbl_Synth.Font.Name := 'Tahoma';
    cbSynthesizer.Font.Name := 'Tahoma';
    lbl_Synth.Font.Size := 9;
    cbSynthesizer.Font.Size := 9;
    edTime.Font.Name := 'Arial';
  end;
  if GetOEMCP = 1141 then  // *** Please check and modify if it's wrong.
  begin
    UseLanguage('de');
  end;

  TranslateComponent(self);
 {$ENDIF}

  FCanvas := TControlCanvas.Create;
  TControlCanvas(FCanvas).Control := edFile;
  FCanvas.Font := edFile.Font;

 // You can use following sentences if you want to create the instances of TMidiFile &
 //  TMidiPlayer by code. (i.e., not by placing the components on form at design time.)
 // MidiFile := TMidiFile2.Create(Self);
 // MidiPlayer := TMidiPlayer2.Create(Self);
 // MidiPlayer.MidiFile := MidiFile;
 // MidiPlayer.OnMidiEvent := MidiPlayerMidiEvent;
 // MidiPlayer.OnEndOfTrack := MidiPlayerTrackEnd;
 // MidiPlayer.OnPlayEnd := MidiPlayerPlayEnd;
 // MidiPlayer.OnTempoChange := MidiPlayerTempoChange;
 // MidiPlayer.OnPosUpdate := MidiPlayerPosUpdate;
 // MidiPlayer.OnGotLyrics := MidiPlayerGotLyrics;

  tbVolume.Max := CMaxVolume div CStepVolume;
  FillMidiOutDevices;
  if not MidiPlayer.VolumeAdjustable then
    tbVolume.Enabled := false;

  hMsg_StartUp := RegisterWindowMessage('MIDI Sheet Music Started');
  hMsg_Terminated := RegisterWindowMessage('MIDI Sheet Music Terminated');
  Self.Position := poDesigned;
end;

procedure TMainForm.FormDestroy(Sender: TObject);
begin
  FCanvas.Free;
  if MidiPlayer.Playing then
    MidiPlayer.StopPlaying;

 // You should activate following sentences if the instances of TMidiFile & TMidiPlayer
 //  are created by code.
 // MidiPlayer.Free;
 // MidiFile.Free;
end;


procedure TMainForm.tbVolumeChange(Sender: TObject);
var
  Volume: TVolume;
begin
  Volume.Left := tbVolume.Position * CStepVolume;   // Volume of left side
  Volume.Right := tbVolume.Position * CStepVolume;  // Volume of right side
  MidiPlayer.Volume := Volume;
end;

procedure TMainForm.MidiPlayerGotLyrics(Track: Integer; Event: PMidiEvent);
var
  MidiEvent: TMidiEvent;
  s: string;
  N: integer;
begin
  MidiEvent := Event^;
  s := MidiEvent.Msg;
  if S = '' then
    exit;

  N := SyncLyricsList.Items.Count;
  if (s[Length(s)] = chr(10)) or (s[Length(s)] = chr(13)) then
  begin
    if Length(s) = 1 then
      SyncLyricsList.Items.Add('')
    else begin
      if N > 0 then
      begin
        SyncLyricsList.Items[N-1] := SyncLyricsList.Items[N-1] + copy(s, 1, length(s) - 1);
        SyncLyricsList.Items.Add('');
      end else
        SyncLyricsList.Items.Add('');
    end;
  end else
  if (s[1] = chr(10)) or (s[1] = chr(13)) then  // for MIDI Karaoke files
  begin
    SyncLyricsList.Items.Add('');
    if Length(s) > 1 then
      SyncLyricsList.Items[N] := copy(s, 2, length(s) - 1);
  end else
  begin
    if N > 0 then
      SyncLyricsList.Items[N-1] := SyncLyricsList.Items[N-1] + s
    else
      SyncLyricsList.Items.Add(s);
  end;

// Scroll up the sync lyrics window to show the newly added contents.
  N := SyncLyricsList.Items.Count - (SyncLyricsList.ClientHeight div SyncLyricsList.ItemHeight);
  if N < 0 then N := 0;
  if SyncLyricsList.TopIndex <> N then
    SyncLyricsList.TopIndex := N;
end;

procedure TMainForm.MidiPlayerMidiEvent(Track: integer; Event: PMidiEvent);
var
  MidiEvent: TMidiEvent;
 // s: string;
begin
 // Played a Midi Event

 MidiEvent := Event^;

 // Following code is an example to display Midi Event
 { case (MidiEvent.Event div 16) of
    8: s := 'Note Off';
    9: s := 'Note On';
    $A: s := 'After touch';
    $B: s := 'Control change';
    $C: s := 'Program change';
    $D: s := 'Channel after touch';
    $E: s := 'Pitch wheel change';
    $F: if MidiEvent.Event = $FF then
          s := 'Meta Event'
        else
          s := 'System Event';
   end;
  EventDisplayForm.ListBox1.Items.Add('Position:' + intToStr(MidiEvent.Positon) + ' Track:'
                          + intToStr(Track) + ' ' + s + ' $' + intToHex(MidiEvent.Data1, 2)); }
  MidiEvent := Event^;
  case (MidiEvent.Event div 16) of
    8..$E : ViewChannelForm.GetChannelEvent(MidiEvent);
   { $F: if MidiEvent.Event = $FF then
          s := 'Meta Event'
        else
          s := 'System Event'; }
  end;
end;

procedure TMainForm.MidiPlayerTrackEnd(Track: Integer);
begin
 // A track is ended playing
end;

procedure TMainForm.MidiPlayerPlayEnd(Sender: TObject);
begin
 // Play ended  ( = all tracks are ended playing)
  PostMessage(ShowLyricsForm.Handle, WM_InformPlayerStat, Set_ChannelStat, ord(plmStopped));
end;

procedure TMainForm.MidiPlayerTempoChange(Tempo: Cardinal);
begin
 // Tempo changed
 // Tempo : microseconds per quarter note
end;

procedure TMainForm.MidiPlayerPosUpdate(TimePos, TicksPos: Cardinal);
var
  PlaySec: double;
 // PlayMilSec: double;
begin
  PlaySec := TimePos / (1000 * 24 * 3600);
 // PlayMilSec := MidiFile.Tick2TimePos(round(TicksPos));
 // PlaySec := PlayMilSec / (1000 * 24 * 3600);
  edTime.Text := FormatDateTime ('nn:ss', PlaySec);
  edTime.Update;
 // PositionBar.Position := TicksPos;
  PositionBar.Position := round(TimePos / 100.0);
  PositionBar.Update;
  PostMessage(ShowLyricsForm.Handle, WM_InformPlayerStat, Set_PlayingPos, LPARAM(TicksPos));

  if FhServer <> 0 then
    if TimePos > PrevPosMs then
      if (TimePos - PrevPosMs) >= 100 then
      begin
        PostMessage(FhServer, WM_MIDI_PosUpdate,
                    WPARAM(round(TimePos * TicksPerMilSec)),
                    LPARAM(round(PrevPosMs * TicksPerMilSec)));
        PrevPosMs := TimePos;
      end;
end;

procedure TMainForm.PositionBarMouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
var
   SongPos : DWORD;
begin
  if MidiPlayer.Playing then
  begin
  //  MidiPlayer.CurrentPos := round(PositionBar.Max * (X / PositionBar.Width));
    MidiPlayer.CurrentTime := round(PositionBar.Max * (X / PositionBar.Width) * 100.0);

    if FhServer <> 0 then
    begin
      SongPos := MidiPlayer.CurrentTime;
      PostMessage(FhServer, WM_MIDI_PosUpdate,   //* Remove any highlighted notes
                    WPARAM(-10), LPARAM(round(PrevPosMs * TicksPerMilSec)));
      PrevPosMs := SongPos - 1000;
      PostMessage(FhServer, WM_MIDI_PosUpdate,
                    WPARAM(round(SongPos * TicksPerMilSec)), LPARAM(round(PrevPosMs * TicksPerMilSec)));
    end;
  end;
end;

procedure TMainForm.btnOpenClick(Sender: TObject);
var
  I: integer;
  p: integer;
  S: string;
  S1, S2 : string;
  CurFileName: string;
  {$IFNDEF UNICODE}
  S3: WideString;
  {$ENDIF}
  MidiTrack: TMidiTrack;
  PlayTime: TDateTime;
  pTitle: pWideChar;
begin
  if MidiPlayer.Playing then
  begin
   {$IFDEF MULTI_LANGUAGE}
    S1 := _('Cannot open a MIDI file during playing.');
    S2 := _('Confirm');
    MessageBox(Self.Handle, PChar(S1), PChar(S2), MB_OK);
   {$ELSE}
    MessageBox(Self.Handle, 'Cannot open a MIDI file during playing.', 'Confirm', MB_OK);
   {$ENDIF}
    exit;
  end;
  if not OpenDialog1.Execute then
    exit;

  MidiPlayer.OpenFile(OpenDialog1.FileName);
  if not MidiFile.Valid then
  begin
   {$IFDEF MULTI_LANGUAGE}
    S1 := _('Not a valid MIDI file.');
    S2 := _('Confirm');
    MessageBox(Self.Handle, PChar(S1), PChar(S2), MB_OK);
   {$ELSE}
    MessageBox(Self.Handle, 'Not a valid MIDI file.', 'Confirm', MB_OK);
   {$ENDIF}
    exit;
  end;

  CurMIDIFile := OpenDialog1.FileName;
  if FhServer <> 0 then
    SendDataW(FhServer, CurMIDIFile, rqOpenFile);

  edFile.Text := MinimizeName(OpenDialog1.FileName, FCanvas, edFile.Width);
  case MidiFile.Format of
    0: edFormat.Text := 'single-track, ';
    1: edFormat.Text := 'multiple tracks, synchronous, ';
    2: edFormat.Text := 'multiple tracks, asynchronous, ';
  end;
  case MidiFile.TickUnit of
    0: edFormat.Text := edFormat.Text + intToStr(MidiFile.TicksPerQuarter) + ' Ticks per quarter note';
    1: edFormat.Text := edFormat.Text + intToStr(MidiFile.TicksPerQuarter) + ' Ticks per second';
  end;

//  edCopyright.Text := MidiFileInfo.GetTrack(0);
  MidiTrack := TMidiTrack(MidiFile.GetTrack(0));
  edCopyright.Text := MidiTrack.Copyright;
  PlayTime := MidiFile.Duration / (1000 * 24 * 3600);
  edLength.Text := FormatFloat('#,##0', MidiFile.PlayTicks) + ' Ticks    /   '
                 + FormatFloat('#,##0', MidiFile.Duration) + ' ms'
                 + ' (' + FormatDateTime('nn:ss', PlayTime) + ')';

  edTracks.Text := intToStr(MidiFile.TrackCount);
  TrackList.Clear;
  for I := 0 to (MidiFile.TrackCount - 1) do
  begin
    MidiTrack := TMidiTrack(MidiFile.GetTrack(I));
    TrackList.Items.Add('Track ' + intToStr(I) + ' : ' + MidiTrack.TrackName);
    TrackList.Checked[I] := true;
  end;
  TrackList.ItemEnabled[0] := false;

 // ReloadLyrics(MidiFile.SyncLyrics);
  CurFileName := ExtractFileName(OpenDialog1.FileName);
  {$IFDEF UNICODE}
  pTitle := pChar(CurFileName);
  {$ELSE}
  S3 := CurFileName;
  pTitle := pWideChar(S3);
  {$ENDIF}
  PostMessage(ShowLyricsForm.Handle, WM_InformPlayerStat, Set_Title, LPARAM(pTitle));
  MIDILyrics := MidiFile.SyncLyrics;
  PostMessage(ShowLyricsForm.Handle, WM_InformPlayerStat, Set_Lyrics, LPARAM(@MidiLyrics));

  PlainLyrics.Clear;
  SyncLyricsList.Clear;
  if MidiFile.Lyrics <> '' then
  begin
    S := MidiFile.Lyrics;
  // Replace Line Feed Code to ' ' + Carriage return code
   {$IFDEF UNICODE}
    S := ReplaceStr(S, chr($0A), ' ' + chr($0D));
   {$ELSE}
    S := StringReplace(S, chr($0A), ' ' + chr($0D), [rfReplaceAll]);
   {$ENDIF}
    repeat
      p := pos(chr($0D), S);    // Carriage return code ?
      if P > 0 then
      begin
        PlainLyrics.Items.Add(copy(S, 1, p-1));
        S := copy(S, p + 1, Length(S) - p);
      end else
      begin
        PlainLyrics.Items.Add(S);
        S := '';
      end;
    until S = '';
  end;

 // PositionBar.Max := MidiFile.PlayTicks;
  PositionBar.Max := round(MidiFile.Duration / 100.0);
  PositionBar.Position := 0;
  edTime.Text := '00:00';
  Paused := false;

  TicksPerMilSec := MidiFile.PlayTicks / MidiFile.Duration;
  PrevPosMs := 0;
end;


procedure TMainForm.btnPlayClick(Sender: TObject);
begin
  if MidiPlayer.Playing then exit;
  if not MidiPlayer.ReadyToPlay then exit;

  SyncLyricsList.Clear;
  if Paused then
    MidiPlayer.ResumePlaying
  else
    MidiPlayer.StartPlaying;

  if MidiPlayer.Playing then
  begin
    Paused := false;
    PostMessage(ShowLyricsForm.Handle, WM_InformPlayerStat, Set_ChannelStat, ord(plmPlaying));
  end;
end;

procedure TMainForm.btnPauseClick(Sender: TObject);
begin
  if not MidiPlayer.Playing then
    exit;

  MidiPlayer.StopPlaying;
  Paused := true;
  PostMessage(ShowLyricsForm.Handle, WM_InformPlayerStat, Set_ChannelStat, ord(plmPaused));
end;

procedure TMainForm.btnShowLyricsWindowClick(Sender: TObject);
begin
  ShowLyricsForm.Show;
end;

procedure TMainForm.btnShowMusicSheetClick(Sender: TObject);
var
  {$IFNDEF UNICODE}
   StartUpInfo: TStartUpInfo;
  {$ELSE}
   StartUpInfo: TStartUpInfoA;
  {$ENDIF}
   s: AnsiString;
   ProcessInfo: TProcessInformation;
   ProgDir: string;

begin
 // Check if my launched MidiSheetMusic is running
 // ( MIDIProcessHandle is not 0 if it is running )
   if MIDIProcessHandle <> 0 then
   begin
      MIDIWinHandle := 0;
      EnumWindows(@LookForMIDIWindow, MIDIThreadId);
      if MIDIWinHandle <> 0 then
      begin
        BringWindowToTop(MIDIWinHandle);
        exit;
      end;
   end;

   ProgDir := ExtractFilePath(ParamStr(0));
   if not FileExists(ProgDir + 'MidiSheetMusic.exe') then
   begin
      Application.MessageBox('No MidiSheetMusic.exe in program directory.',
                             'Error', MB_OK or MB_ICONINFORMATION);
      exit;
   end;

   FillChar(StartUpInfo, SizeOf(TStartupInfo), #0);
   FillChar(ProcessInfo, SizeOf(TProcessInformation), #0);
   StartUpInfo.cb := SizeOf(TStartupInfo);
   if CurMIDIFile = '' then
     s := '"' + ProgDir + 'MidiSheetMusic.exe"'
   else
     s := '"' + ProgDir + 'MidiSheetMusic.exe" "' + CurMIDIFile + '"';
  {$IFNDEF UNICODE}
   if CreateProcess(nil, pChar(s), nil, nil, false,
                    NORMAL_PRIORITY_CLASS, nil, nil, StartUpInfo, ProcessInfo) then
  {$ELSE}
   if CreateProcessA(nil, pAnsiChar(s), nil, nil, false,
                    NORMAL_PRIORITY_CLASS, nil, nil, StartUpInfo, ProcessInfo) then
  {$ENDIF}
   begin
      MIDIProcessHandle := ProcessInfo.hProcess;
      MIDIThreadId := ProcessInfo.dwThreadId;
   end;

end;

procedure TMainForm.btnStopClick(Sender: TObject);
begin
  if not MidiPlayer.Playing then
    exit;

  MidiPlayer.StopPlaying;
  PositionBar.Position := 0;
  edTime.Text := '00:00';
  PostMessage(ShowLyricsForm.Handle, WM_InformPlayerStat, Set_ChannelStat, ord(plmStopped));

  // Remove any highlighted notes
  if FhServer <> 0 then
    SendDataW(FhServer, 'Stop', rqStop);

  PrevPosMs := 0;
end;

procedure TMainForm.btnViewChannelClick(Sender: TObject);
begin
  ViewChannelForm.Show;
end;

procedure TMainForm.Button1Click(Sender: TObject);
begin
  TempoControlForm.Show;
end;

procedure TMainForm.cbSynthesizerChange(Sender: TObject);
begin
  MidiPlayer.SelectMidiOut(cbSynthesizer.Text);
  if not MidiPlayer.VolumeAdjustable then
    tbVolume.Enabled := false
  else begin
    tbVolume.Enabled := true;
    tbVolume.Position := (MidiPlayer.Volume.Left) div CStepVolume; // take left volume
  end;
end;

procedure TMainForm.TrackListClickCheck(Sender: TObject);
var
  MidiTrack: TMidiTrack;
  tmpPaused: boolean;

begin
  tmpPaused := false;
  MidiTrack := TMidiTrack(MidiFile.GetTrack(TrackList.ItemIndex));
  if MidiPlayer.Playing then
    if not TrackList.Checked[TrackList.ItemIndex] then  // Inactivate a track ?
    begin
      MidiPlayer.StopPlaying;                           // To avoid a noisy sound.
      tmpPaused := true;
    end;

  MidiTrack.Active := TrackList.Checked[TrackList.ItemIndex];
  if tmpPaused then
    MidiPlayer.ResumePlaying;
end;


procedure TMainForm.FormShow(Sender: TObject);
begin
  if PassedActivation then
      exit;

  ViewChannelForm.ResetFields(true{Reset Device});  // ** Added at 2013-02-12
  if tbVolume.Enabled then
    tbVolume.Position := 16;

 // ViewChannelForm.Show;
  ShowLyricsForm.Show;
  PostMessage(ShowLyricsForm.Handle, WM_InformPlayerStat, Set_ChannelStat, ord(plmStandby));
  PassedActivation := true;

 // TrackList.Items.Assign(Screen.Fonts);
end;

function TMainForm.SendDataW(HServer : THandle; WData: WideString; RequestId : integer): integer;
var
   CopyData : TCopyDataStruct;
   s1 : WideString;
   nLen: integer;
 //  {$IF CompilerVersion < 22}
   dummy : dword;
 //  {$IFEND}
begin
  result := 0;

  if HServer = 0 then
     exit;

  CopyData.dwData := RequestId;

  s1 := WData;
  nLen := (Length(s1) + 1) * SizeOf(WideChar);
  s1 := s1 + chr(0);
  CopyData.cbData := nLen;
  CopyData.lpData := pWideChar(s1);

  {$IF CompilerVersion >= 22}
  result := SendMessageTimeout(HServer, WM_COPYDATA, Self.Handle, LONG_PTR(@CopyData), SMTO_ABORTIFHUNG + SMTO_NORMAL,
                           5000, @dummy);
  {$ELSE}
  result := SendMessageTimeout(HServer, WM_COPYDATA, Self.Handle, LONG_PTR(@CopyData), SMTO_ABORTIFHUNG + SMTO_NORMAL,
                           5000, dummy);
  {$IFEND}
end;

procedure TMainForm.ApplicationEvents1Message(var Msg: tagMSG;
  var Handled: Boolean);
var
  ThreadId : DWORD;
  ProcId : DWORD;
  r : TRect;
  W : integer;
  LeftSided : boolean;

begin
  if (Msg.message = hMsg_StartUp) then
  begin
    Handled := True;

    if (FhServer = 0) then
    begin
      if Msg.lParam <> 1 then  // message comes from MidiSheetMusic ?  (Msg.lParam = 1)
        exit;

      ThreadId := GetWindowThreadProcessId(Msg.wParam, @ProcId);
      if ThreadId = MIDIThreadId then  // It's my launched MidiSheetMusic ?
      begin
        FhServer := Msg.wParam;
       // Reset FhServer if the request to set main window handle is not accepted by MidiSheetMusic.
        if SendDataW(FhServer, intToStr(Self.Handle), rqSetHandle) = 0 then
          FhServer := 0
      end;
    end;
  end else
  if (Msg.message = hMsg_Terminated) then
  begin
    Handled := True;

    if (FhServer <> 0) then   // Previously connected state ?
    begin
      if Msg.lParam <> 1 then  // message comes from MidiSheetMusic ?
        exit;

      if Msg.wParam = FhServer then  // it's my launched MidiSheetMusic ?
        FhServer := 0;
    end;
  end;

end;

procedure TMainForm.btnCloseClick(Sender: TObject);
begin
   Close;
end;

end.