A prototypical PocketPC program

#include <windows.h>
#include <aygshell.h> // link against aygshell.lib
#include <doclist.h>  // link against doclist.lib
#include <projects.h> // link against note_prj.lib
#ifndef IDM_NEWMENUMAX
#include <newmenu.h>  // under PPC2000, it was already included in aygshell
#endif
#include <commctrl.h> 
#include <shellapi.h>


HINSTANCE hInstance;
HWND hmain=0;
HWND hcard=0;
HWND hdlc=0;
HWND hmbar=0;
HWND hed=0;
wchar_t dlcfolder[MAX_PATH]={0}; // the full path of the current DLC folder
SHACTIVATEINFO shai={sizeof(SHACTIVATEINFO),0,0,0,0,0};
bool close_on_ok=false;


bool isalphanum(const wchar_t c)
{ if (c>='a' && c<='z') return true;
  if (c>='A' && c<='Z') return true;
  if (c>='0' && c<='9') return true;
  if (c==' ' || c=='-') return true;
  return false;
}

struct TDocument
{ wchar_t fn[MAX_PATH];
  bool open, changed, readonly;
  bool unicode;

  TDocument() : open(false) {*fn=0;}
  void New();
  void Save();
  bool Open(const wchar_t *ofn);
} doc;


void TDocument::New()
{ *fn=0; SetWindowText(hed,L"");
  open=true; changed=false; readonly=false; unicode=true;
}

void TDocument::Save()
{ if (!open || !changed) return;
  int len=GetWindowTextLength(hed); if (len==0) return;
  wchar_t *unc=new wchar_t[len+1];
  GetWindowText(hed,unc,len+1);
  // We may have to construct the filename from the doc's content...
  if (*fn==0)
  { wcscpy(fn,dlcfolder); wchar_t *d=fn+wcslen(fn);
    *d='\\'; d++; bool any=false;
    int i=0; wchar_t *c=unc;
    for (; !isalphanum(*c) && *c!=0 && i<32; i++) {}
    for (; isalphanum(c[i]) && c[i]!=0 && i<32; i++) {*d=c[i]; d++; any=true;}
    if (!any) {wcscpy(d,L"unnamed"); d+=wcslen(d);}
    wcscpy(d,L".txt");
    for (i=1; GetFileAttributes(fn)!=0xFFFFFFFF; i++) wsprintf(d,L" (%i).txt",i);
  }
  // really, if it's being saved on SD, we should use FILE_FLAG_WRITE_THROUGH
  // to hopefully prevent data loss due to buggy SD card filesystems.
  HANDLE hf = CreateFile(fn,GENERIC_WRITE,0,NULL,CREATE_ALWAYS,FILE_ATTRIBUTE_NORMAL,NULL);
  if (unicode)
  { const char byteorder[2]={-1,-2};
    DWORD writ; WriteFile(hf,byteorder,2,&writ,NULL);
    WriteFile(hf,unc,sizeof(wchar_t)*len,&writ,NULL);
  }
  else
  { int size = WideCharToMultiByte(CP_ACP,WC_DEFAULTCHAR,unc,-1,0,0,NULL,NULL);
    char *buf = new char[size];
    WideCharToMultiByte(CP_ACP,WC_DEFAULTCHAR,unc,-1,buf,size,NULL,NULL);
    DWORD writ; WriteFile(hf,buf,size,&writ,NULL);
    delete[] buf;
  }
  CloseHandle(hf);
  delete[] unc;
  changed=false;
}

bool TDocument::Open(const wchar_t *ofn)
{ HANDLE hf = CreateFile(ofn,GENERIC_READ,0,NULL,OPEN_EXISTING,FILE_ATTRIBUTE_NORMAL,NULL);
  if (hf==INVALID_HANDLE_VALUE) return false;
  DWORD size=GetFileSize(hf,0); char *buf=new char[size+2];
  DWORD red; ReadFile(hf,buf,size,&red,NULL); buf[size]=0; buf[size+1]=0;
  CloseHandle(hf);
  // if there's a BOM we'll know it's unicode. If not, we'll guess, based on
  // whether the first 256bytes look ascii-ish or not.
  wchar_t *unc=0;
  if (buf[0]==-1 && buf[1]==-2) unc=(wchar_t*)(buf+2);
  else
  { for (unsigned int i=3; i<256 && i<size && unc==0; i+=2) {if (buf[i]==0) unc=(wchar_t*)buf;}
  }
  unicode = (unc!=0);    
  //
  if (unicode) SetWindowText(hed,unc);
  else
  { unc = new wchar_t[size];
    MultiByteToWideChar(CP_ACP,0,buf,-1,unc,size);
    SetWindowText(hed,unc);
    delete[] unc;
  }
  wcscpy(fn,ofn);
  open=true; changed=false; readonly=true;
  return true;
}






// MakeLayout - this shows/hides the edit/doclist as appropriate,
// resizes according to the SIP, and refreshes the DocList.
//
const DWORD mlShowHide=0, mlRefreshDocList=1, mlResize=2;
//
void MakeLayout(DWORD flags, LPARAM wmsc_lparam=0)
{ ShowWindow(hcard, doc.open?SW_SHOW:SW_HIDE);
  ShowWindow(hdlc, doc.open?SW_HIDE:SW_SHOW);
  // the 'edit' button
  TBBUTTONINFO tbbi; ZeroMemory(&tbbi,sizeof(tbbi)); tbbi.cbSize=sizeof(tbbi);
  tbbi.dwMask=TBIF_STATE; tbbi.fsState= (doc.open&&doc.readonly)?TBSTATE_ENABLED:TBSTATE_HIDDEN;
  SendMessage(hmbar,TB_SETBUTTONINFO,203,(LPARAM)&tbbi);
  // readonly in the card itself
  SendMessage(hed,EM_SETREADONLY,doc.readonly?TRUE:FALSE,0);
  if (doc.open && !doc.readonly) SetFocus(hed);
  // OK/X. When we hide the OK, that lets the X underneath show up
  SHDoneButton(hmain, doc.open?SHDB_SHOW:SHDB_HIDE);
  // Now resize the windows to accommodate SIP. If this is called from
  // WM_SETTINGSCHANGE, then use the same lParam for efficency; otherwise 0
  if (flags&mlResize)
  { SIPINFO si; SHSipInfo(SPI_GETSIPINFO,wmsc_lparam,&si,0);
    int x=si.rcVisibleDesktop.left, y=si.rcVisibleDesktop.top;
    int w=si.rcVisibleDesktop.right-x, h=si.rcVisibleDesktop.bottom-y;
    RECT rc; GetWindowRect(hmbar,&rc); int mh=rc.bottom-rc.top;
    if ((si.fdwFlags&SIPF_ON)) h+=1; else h-=mh-1;
    MoveWindow(hmain,x,y,w,h,FALSE);
    GetClientRect(hmain,&rc);
    MoveWindow(hcard,0,0,rc.right,rc.bottom,FALSE);
    MoveWindow(hdlc,0,0,rc.right,rc.bottom,TRUE);
    MoveWindow(hed,0,0,rc.right,rc.bottom,FALSE);
  }
  // We need to refresh after files have been changed, to reshow their time/size
  if (!doc.open && (flags&mlRefreshDocList)) DocList_Refresh(hdlc);
}




// GetPathForFolder(const wchar_t *folder, wchar_t *path):
// Given a folder name we return its path (assume path>=MAX_PATH).
//   All Folders  -->  \My Documents
//   Business     -->  \My Documents\Business
//   MySdFolder   -->  \Storage Card\MySdFolder
//
struct EnumProjectsInfo {const wchar_t *folder; wchar_t *path;};
//
BOOL CALLBACK EnumCallback(PAstruct *pa, LPARAM lp)
{ wchar_t *fn; 
  if (pa->m_IDtype!=FILE_ID_TYPE_OID) fn=pa->m_szPathname;
  else
  { CEOIDINFO cinf; 
    CeOidGetInfo(pa->m_fileOID,&cinf);
    fn = cinf.infDirectory.szDirName;
  }
  const wchar_t *c=fn, *lastslash=c;
  while (*c!=0) {if (*c=='\\') lastslash=c+1; c++;}
  EnumProjectsInfo *epi = (EnumProjectsInfo*)lp;
  if (wcsicmp(epi->folder,lastslash)!=0) return TRUE; // keep enumerating
  wcscpy(epi->path,fn); return FALSE;
}
//
void GetPathForFolder(const wchar_t *folder, wchar_t *path)
{ // assume 'path' is at least MAX_PATH.
  *path=0;
  EnumProjectsInfo epi; epi.folder=folder; epi.path=path;
  EnumProjectsEx(EnumCallback,0,PRJ_ENUM_ALL_DEVICES,(LPARAM)&epi);
  if (*path==0) SHGetSpecialFolderPath(NULL,epi.path,CSIDL_PERSONAL,FALSE);
}




LRESULT CALLBACK CardWndProc(HWND hwnd,UINT msg,WPARAM wParam,LPARAM lParam)
{ if (msg==WM_COMMAND)
  { int id=LOWORD(wParam), code=HIWORD(wParam);
    if (id==104 && code==EN_CHANGE) doc.changed=true;
  }
  return DefWindowProc(hwnd,msg,wParam,lParam);
}



LRESULT CALLBACK MainWndProc(HWND hwnd,UINT msg,WPARAM wParam,LPARAM lParam)
{
  switch (msg)
  { case WM_CREATE:
    { SHMENUBARINFO mbi; ZeroMemory(&mbi,sizeof(mbi));
      mbi.cbSize=sizeof(mbi);
      mbi.hwndParent = hwnd;
      mbi.nToolBarId = 101;
      mbi.hInstRes = hInstance;
      SHCreateMenuBar(&mbi);
      hmbar=mbi.hwndMB;

      SHGetSpecialFolderPath(hwnd,dlcfolder,CSIDL_PERSONAL,TRUE);
      DOCLISTCREATE dlc; ZeroMemory(&dlc,sizeof(dlc));
      dlc.dwStructSize=sizeof(dlc);
      dlc.hwndParent=hwnd;
      dlc.pstrFilter = L"Text\0*.txt\0";
      dlc.wId=102;
      hdlc = DocList_Create(&dlc);
       
      hcard=CreateWindow(L"LuCardClass",L"",WS_CHILD,0,0,0,0,hwnd,(HMENU)103,hInstance,0);
      hed = CreateWindow(L"CAPEDIT",L"",WS_CHILD|WS_VISIBLE|WS_HSCROLL|WS_VSCROLL|ES_AUTOHSCROLL|ES_AUTOVSCROLL|ES_MULTILINE|WS_TABSTOP,0,0,0,0,hcard,(HMENU)104,hInstance,0);
      CreateWindow(WC_SIPPREF,L"",WS_CHILD,0,0,0,0,hcard,(HMENU)105,hInstance,0);

      MakeLayout(mlShowHide|mlRefreshDocList|mlResize,0);

      int nitems=DocList_GetItemCount(hdlc);
      if (nitems==0) SendMessage(hwnd,WM_COMMAND,IDM_NEWMENUMAX+1,0);
    } return 0;

    case WM_COMMAND:
    { int id=LOWORD(wParam);
      if (id==IDOK && doc.open) // OK button
      { if (doc.open && doc.changed) doc.Save();
        SHSipPreference(hmain,SIP_FORCEDOWN);
        doc.open=false; MakeLayout(mlShowHide|mlRefreshDocList);
        if (close_on_ok) ShowWindow(hwnd,SW_MINIMIZE);
      }
      if (id==301) // tools.exit
      { DestroyWindow(hwnd); 
      }
      else if (id==203) // tools.edit
      { if (doc.open && doc.readonly) {doc.readonly=false; MakeLayout(mlShowHide);} 
      }
      else if (id==IDM_NEWMENUMAX+1) // new.text
      { if (doc.open && doc.changed) doc.Save();
        doc.New(); MakeLayout(mlShowHide);
      }
    } return 0;
 
    case WM_ACTIVATE:
    { SHHandleWMActivate(hwnd, wParam, lParam, &shai, FALSE);
    } return 0;
    case WM_SETTINGCHANGE:
    { SHHandleWMSettingChange(hwnd, wParam, lParam, &shai);
      MakeLayout(mlResize,lParam);
    } return 0;
 
    case WM_HIBERNATE:
    { if (!doc.open) SetWindowText(hed,L"");
    } return 0;

    case WM_DESTROY:
    { if (doc.open && doc.changed) doc.Save();
      CommandBar_Destroy(hmbar);
      PostQuitMessage(0);
    } return 0;

    case WM_APP:
    { // this messages gets sent to activate a previous instance
      close_on_ok=false;
      // maybe have to refresh the doclist.
      if (!doc.open) MakeLayout(mlRefreshDocList);
    } return 0;

    case WM_COPYDATA:
    { // this message gets sent to open a document.
      close_on_ok=true;
      // it might be sent by a new process to an existing one - hence
      // the need for WM_COPYDATA to share data between processes.
      if (doc.open && doc.changed) doc.Save();
      COPYDATASTRUCT *cs = (COPYDATASTRUCT*)lParam;
      doc.Open((wchar_t*)cs->lpData);
      MakeLayout(mlShowHide);
    } return 0;

    case WM_NOTIFY:
    { NMHDR *nmhdr = (NMHDR*)lParam;
      // This first is called by the menubar for the "shared new"
      if (nmhdr->code==NMN_GETAPPREGKEY)
      { NMNEWMENU *nmnew = (NMNEWMENU*)lParam;
        AppendMenu(nmnew->hMenu,MF_ENABLED,IDM_NEWMENUMAX+1,L"Text");
        AppendMenu (nmnew->hMenu, MF_SEPARATOR, 0, 0);
      }
      else if (nmhdr->code==DLN_FOLDER)
      { DLNHDR *dln = (DLNHDR*)lParam;
        GetPathForFolder(dln->pszPath,dlcfolder);
      }
      else if (nmhdr->code==DLN_ITEMACTIVATED)
      { DLNHDR *dln = (DLNHDR*)lParam;
        doc.Open(dln->pszPath);
        MakeLayout(mlShowHide);
      }
    } return 0;
  }
  return DefWindowProc(hwnd,msg,wParam,lParam);
}



int WINAPI WinMain(HINSTANCE h, HINSTANCE, LPTSTR arg, int nCmdShow)
{ hInstance=h;

  hmain = FindWindow(L"LuMainClass",L"My App");
  if (hmain!=0)
  { SetForegroundWindow((HWND)((ULONG)hmain|1)); // the |1 will activate any owned windows
    if (arg!=0 && wcslen(arg)!=0)
    { COPYDATASTRUCT cs; cs.dwData=0; cs.cbData=2+2*wcslen(arg); cs.lpData=arg;
      SendMessage(hmain,WM_COPYDATA,NULL,(LPARAM)&cs);
    }
    else SendMessage(hmain,WM_APP,0,0);
    return 0;
  }


  WNDCLASS wc; ZeroMemory(&wc,sizeof(wc));
  wc.lpfnWndProc = MainWndProc;
  wc.hInstance = hInstance;
  wc.hbrBackground = GetSysColorBrush(COLOR_WINDOW);
  wc.lpszClassName= L"LuMainClass";
  RegisterClass(&wc);
  //
  wc.lpfnWndProc = CardWndProc;
  wc.lpszClassName = L"LuCardClass";
  RegisterClass(&wc);
  //
  SHInitExtraControls();


  hmain = CreateWindow(L"LuMainClass", L"My App", WS_VISIBLE,CW_USEDEFAULT,CW_USEDEFAULT,CW_USEDEFAULT,CW_USEDEFAULT, NULL, NULL, hInstance, NULL);
  ShowWindow(hmain,nCmdShow);
  UpdateWindow(hmain);
  if (arg!=0 && wcslen(arg)!=0)
  { COPYDATASTRUCT cs; cs.dwData=0; cs.cbData=2+2*wcslen(arg); cs.lpData=arg;
    SendMessage(hmain,WM_COPYDATA,NULL,(LPARAM)&cs);
  }


  MSG msg;
  while (GetMessage(&msg,NULL,0,0)) 
  { TranslateMessage(&msg);
    DispatchMessage(&msg);
  }

  return msg.wParam;
}