ch9p1_cdplayer.cpp

游戏音频程序设计-Beginning.Game.Audio.Programming

// Ch9p1_CDPlayer.cpp : Defines the entry point for the application.
//

#include <windows.h>
#include <string>
#include <vector>
#include <sstream>

#include "resource.h"
#include "cdplayer.h"

using namespace AudioEngine;
using namespace std;

CCDPlayer g_CDPlayer;

int g_CurTrack = 1;
bool g_cdindrive = false;

void RefreshGUI(HWND hDlg)
{
  // gray out buttons if no CD is in drive
  EnableWindow(GetDlgItem(hDlg, IDC_PREVIOUSTRACK), g_cdindrive);
  EnableWindow(GetDlgItem(hDlg, IDC_PLAY), g_cdindrive);
  EnableWindow(GetDlgItem(hDlg, IDC_STOP), g_cdindrive);
  EnableWindow(GetDlgItem(hDlg, IDC_NEXTTRACK), g_cdindrive);

  // put current track/time into LCD label
  HWND label = GetDlgItem(hDlg, IDC_LCD);

  char buf[32] = { 0 };
  
  if (g_cdindrive) {
    // ask the cd player what the current position is
    CTrackMinSecFrame pos = g_CDPlayer.GetCurrentPos();

    // if we get a blank pos back, fill in the last track we played
    // just to make the GUI look better.
    if (pos == CTrackMinSecFrame()) {
      pos.m_Track = g_CurTrack;
    }

    _snprintf(buf, sizeof(buf), "%02d - %02d:%02d", pos.m_Track, pos.m_Minute, pos.m_Second);

    // set g_CurTrack in case they stop then play later
    g_CurTrack = pos.m_Track;

    // set label on play button
    if (g_CDPlayer.IsPlaying()) {
      SendMessage(GetDlgItem(hDlg, IDC_PLAY), WM_SETTEXT, 0, (LPARAM)"Pause");
    }
    else if (g_CDPlayer.IsPaused()) {
      SendMessage(GetDlgItem(hDlg, IDC_PLAY), WM_SETTEXT, 0, (LPARAM)"Resume");
    }
    else {
      SendMessage(GetDlgItem(hDlg, IDC_PLAY), WM_SETTEXT, 0, (LPARAM)"Play");
    }
  }
  SendMessage(label, WM_SETTEXT, 0, (LPARAM)buf); 
}

void OnComboBoxChange(HWND hDlg, HWND hcombobox)
{
  int ndx = SendMessage(hcombobox, CB_GETCURSEL, 0, 0);
  if (ndx != CB_ERR) {

    // uninit any device we may already be using
    g_CDPlayer.UnInit();

    // get drive letter (hidden in combo box item userdata)
    char drive = (char)SendMessage(hcombobox, CB_GETITEMDATA, ndx, 0);

    // initialize the CD player for this drive
    g_CDPlayer.Init(hDlg, drive); 
    g_cdindrive = g_CDPlayer.IsCDInDrive();
  }
  RefreshGUI(hDlg);
}

void PutAvailableDevicesInComboBox(HWND hDlg, UINT comboboxid)
{
  vector<CCDDeviceInfo> devices = CCDPlayer::GetAvailableDevices();

  HWND hcombobox = GetDlgItem(hDlg, comboboxid);
  if (!hcombobox) return;

  // clear contents of combo box
  SendMessage(hcombobox, CB_RESETCONTENT, 0, 0);

  // add devices
  for (vector<CCDDeviceInfo>::iterator iter = devices.begin(); iter != devices.end(); ++iter) {
    stringstream stream;
    stream << "<" << iter->m_DriveLetter << ":\\>  " << iter->m_Description << "  (";
    
    if (iter->m_CDProductCode.size() > 2) {
      stream << "UPC: " << iter->m_CDProductCode << ")";
    }
    else {
      stream << "ID: " <<  iter->m_CDProductCode << ")";
    }

    string desc = stream.str();
    int ndx = SendMessage(hcombobox, CB_ADDSTRING, 0, (LPARAM)desc.c_str());
    SendMessage(hcombobox, CB_SETITEMDATA, (WPARAM)ndx, (LPARAM)iter->m_DriveLetter); 
  }
  SendMessage(GetDlgItem(hDlg, comboboxid), CB_SETCURSEL, 0, 0);
  OnComboBoxChange(hDlg, (HWND)hcombobox);
}

void OnNextTrack(HWND hDlg)
{
  g_CurTrack++;
  if (g_CurTrack > g_CDPlayer.GetNumTracks()) g_CurTrack = 1;
  if (g_CDPlayer.IsPlaying()) {
    g_CDPlayer.Play(g_CurTrack);
  }
  RefreshGUI(hDlg);
}

void OnPrevTrack(HWND hDlg)
{
  g_CurTrack--;
  if (g_CurTrack < 1) g_CurTrack = 1;
  if (g_CDPlayer.IsPlaying()) {
    g_CDPlayer.Play(g_CurTrack);
  }
}

void OnPlay(HWND hDlg)
{
  if (g_CDPlayer.IsPaused()) {
    g_CDPlayer.Resume();  
  }
  else {
    if (g_CDPlayer.IsPlaying()) {
      g_CDPlayer.Pause();  
    }
    else {
      g_CDPlayer.Play(g_CurTrack);
    }
  }
  RefreshGUI(hDlg);
}

INT_PTR CALLBACK MainDlgProc( HWND hDlg, UINT msg, WPARAM wParam, LPARAM lParam )
{
  try {
    switch( msg ) 
    {
      case WM_DEVICECHANGE:
        g_cdindrive = g_CDPlayer.IsCDInDrive();
        RefreshGUI(hDlg);
        break;

      case MM_MCINOTIFY:
        // a track has completed... goto the next one
        if (wParam == MCI_NOTIFY_SUCCESSFUL) {
          OnNextTrack(hDlg);
          OnPlay(hDlg);
        }
        break;

      case WM_INITDIALOG:
        {
          // create display update timer
          SetTimer(hDlg, 1, 1000, NULL);
          PutAvailableDevicesInComboBox(hDlg, IDC_DEVICES);
          g_cdindrive = g_CDPlayer.IsCDInDrive();
          
          RefreshGUI(hDlg);
        }
        break;

      case WM_TIMER:
        // update track display
        RefreshGUI(hDlg);
        break;
      case WM_COMMAND:
        switch(HIWORD(wParam)) {
          case CBN_SELCHANGE:
          {
            // user has selected a new drive in the combo box
            OnComboBoxChange(hDlg, (HWND)lParam);
          

          }
          break;

          case BN_CLICKED:
          {
            // a button was clicked... which one?
            switch(LOWORD(wParam)) {
             
              case IDC_EJECT:
                g_CDPlayer.OpenCDDoor();
                RefreshGUI(hDlg);
                break;

              case IDC_NEXTTRACK:
                OnNextTrack(hDlg);
                break;

              case IDC_PREVIOUSTRACK:
                OnPrevTrack(hDlg);
                break;

              case IDC_PLAY:
                OnPlay(hDlg);
                break;
          
              case IDC_STOP:
                g_CDPlayer.Stop();
                RefreshGUI(hDlg);
                break;

            } // switch LOWORD(wParam)
          }
          break;

        } // notification code
        break;

      case WM_CLOSE:
        ShowWindow(hDlg, SW_HIDE);
        g_CDPlayer.UnInit();
        KillTimer(hDlg, 1);
        PostQuitMessage(0);
        break;

      case WM_DESTROY:
        break; 

      default:
        return FALSE; // Didn't handle message
    }
  } 
  catch(char *err) {
    MessageBox(hDlg, err, "Ch9p1_CDPlayer MCI Error Message", MB_OK);
    return(FALSE);

  }
  return TRUE; // Handled message
}

int APIENTRY WinMain(HINSTANCE hInstance,
                     HINSTANCE hPrevInstance,
                     LPSTR     lpCmdLine,
                     int       nCmdShow)
{
 	HWND    hDlg = NULL;
  MSG     msg;

  try {

    // Display the main dialog box.
    hDlg = CreateDialog( hInstance, MAKEINTRESOURCE(IDD_CDPLAYER), 
                         NULL, MainDlgProc );
    
    ShowWindow(hDlg, SW_SHOW);

    while(1) 
    { 
      // Windows messages are available
      if(GetMessage(&msg, NULL, 0, 0)) 
      { 
        if(!IsDialogMessage(hDlg, &msg))  
        {
          TranslateMessage(&msg); 
          DispatchMessage(&msg); 
        }

        
      }
      else {
        DestroyWindow(hDlg);
        return(msg.wParam);
      }
    }

  }
  catch(...) {
    // TODO
  }

	return 0;
}