Windows 7 Goodies in C++: Jump Lists

// MainDlg.cpp : implementation of the CMainDlg class
/////////////////////////////////////////////////////////////////////////////

#include "stdafx.h"
#include "NaiveAlyViewer.h"
#include "MainDlg.h"
#include "aboutdlg.h"


/////////////////////////////////////////////////////////////////////////////
// Message handlers

BOOL CMainDlg::PreTranslateMessage ( MSG* pMsg )
{
    return CWindow::IsDialogMessage ( pMsg );
}

BOOL CMainDlg::OnInitDialog ( HWND hwndFocus, LPARAM lParam )
{
    // center the dialog on the screen
    CenterWindow();

    // set icons
HICON hIcon = AtlLoadIconImage ( IDR_MAINFRAME, LR_DEFAULTCOLOR, 32, 32 );
HICON hIconSmall = AtlLoadIconImage ( IDR_MAINFRAME, LR_DEFAULTCOLOR, 16, 16 );

    SetIcon(hIcon, TRUE);
    SetIcon(hIconSmall, FALSE);

    // register object for message filtering and idle updates
CMessageLoop* pLoop = _Module.GetMessageLoop();

    ATLASSERT(pLoop != NULL);
    pLoop->AddMessageFilter(this);

    DoDataExchange();

    // Check the command line. If the first argument is a path to an .aly file, open it.
    if ( __argc > 1 )
        {
        LPCTSTR szArg = __targv[1];

        if ( PathMatchSpec ( szArg, _T("*.aly") ) && PathFileExists ( szArg ) )
            ViewAlyFile ( szArg );
        }

    // Let the system set the focus.
    return TRUE;
}

void CMainDlg::OnDestroy()
{
    // unregister message filtering and idle updates
CMessageLoop* pLoop = _Module.GetMessageLoop();

    ATLASSERT(pLoop != NULL);
    pLoop->RemoveMessageFilter(this);
}

void CMainDlg::OnDropFiles ( HDROP hDrop )
{
TCHAR szFilePath[MAX_PATH] = {0};

    // Get the full path of the first dragged file, and check that it's any .aly file.
    if ( DragQueryFile ( hDrop, 0, szFilePath, _countof(szFilePath) ) > 0 &&
         PathMatchSpec ( szFilePath, _T("*.aly") ))
        {
        ViewAlyFile ( szFilePath );
        }

    DragFinish ( hDrop );
}


/////////////////////////////////////////////////////////////////////////////
// Command handlers

void CMainDlg::OnCancel ( UINT nCode, int nID, HWND hwndCtrl )
{
    DestroyWindow();
    PostQuitMessage ( nID );
}

void CMainDlg::OnAppAbout ( UINT nCode, int nID, HWND hwndCtrl )
{
CAboutDlg dlg;

    dlg.DoModal ( m_hWnd );
}

void CMainDlg::OnOpenAlyFile ( UINT uCode, int nID, HWND hwndCtl )
{
const COMDLG_FILTERSPEC aFilters[] =
{
    { L"Aly test files", L"*.aly" },
    { L"All files", L"*.*" }
};
HRESULT hr;
CString sSelectedFilePath;
CShellFileOpenDialog dlg ( L"test1.aly",
                           FOS_FORCEFILESYSTEM | FOS_PATHMUSTEXIST | FOS_FILEMUSTEXIST,
                           L".aly", aFilters, _countof(aFilters) );

    if ( IDOK != dlg.DoModal ( m_hWnd ) )
        return;

    hr = dlg.GetFilePath ( sSelectedFilePath );

    // Show the selected file as the current file. The file open dialog automatically
    // calls SHAddToRecentDocs for us because we didn't use the FOS_DONTADDTORECENT
    // flag. As a result, the file shows up in our jump list.
    if ( SUCCEEDED(hr) )
        ViewAlyFile ( sSelectedFilePath );
}

void CMainDlg::OnRegisterAsHandler ( UINT uCode, int nID, HWND hwndCtl )
{
CString sCaption ( LPCTSTR(IDR_MAINFRAME) );

    // Set this app as the one associated with *.aly files.
    if ( RegisterAsHandler() )
        {
        // That succeeded, so tell the shell that a file association has changed.
        SHChangeNotify ( SHCNE_ASSOCCHANGED, SHCNF_IDLIST, 0, 0 );

        // Create a couple of test files for you to use with this app.
        CreateTestFiles();

        MessageBox ( _T("The file association was created successfully."),
                     sCaption, MB_ICONINFORMATION );

        }
    else
        MessageBox ( _T("Error creating the file association"),
                     sCaption, MB_ICONERROR );
}

void CMainDlg::OnUnregisterAsHandler ( UINT uCode, int nID, HWND hwndCtl )
{
CString sCaption ( LPCTSTR(IDR_MAINFRAME) );

    // Remove the association with *.aly files.
    if ( UnregisterAsHandler() )
        {
        // Delete the test files that were created in OnRegisterAsHandler().
        DeleteTestFiles();

        // Tell the shell that a file association has changed.
        SHChangeNotify ( SHCNE_ASSOCCHANGED, SHCNF_IDLIST, 0, 0 );

        MessageBox ( _T("The file association was removed successfully."),
                     sCaption, MB_ICONINFORMATION );
        }
    else
        MessageBox ( _T("Error removing the file association"),
                     sCaption, MB_ICONERROR );
}


/////////////////////////////////////////////////////////////////////////////
// Other methods

bool WriteRegString ( HKEY hkeyParent, LPCTSTR szSubkey, LPCTSTR szValueName,
                      LPCTSTR szData, HANDLE hTransaction )
{
HKEY hKey;
CRegKey reg;
LONG lRet;

    lRet = RegCreateKeyTransacted (
               hkeyParent, szSubkey, 0, REG_NONE,
               REG_OPTION_NON_VOLATILE, KEY_SET_VALUE, NULL, &hKey, NULL,
               hTransaction, NULL );

    if ( ERROR_SUCCESS != lRet )
        return false;

    reg.Attach ( hKey );

    lRet = reg.SetStringValue ( szValueName, szData );

    return ERROR_SUCCESS == lRet;
}

// This function registers this app as the default handler for *.aly files.
// The association is written to HKEY_CURRENT_USER instead of HKEY_CLASSES_ROOT
// so we can do this without requiring elevation. The jump list would work just
// as well if we did write to HKEY_CLASSES_ROOT, or if we had an installer that
// wrote the association there.
bool CMainDlg::RegisterAsHandler()
{
CHandle hTransaction;
CString sIconPath, sCommandLine;
TCHAR szModulePath[MAX_PATH] = {0};

    GetModuleFileName ( NULL, szModulePath, _countof(szModulePath) );
    sIconPath.Format ( _T("\"%s\",-%d"), szModulePath, IDI_ALY_FILETYPE );

    sCommandLine.Format ( _T("\"%s\" \"%%1\""), szModulePath );

    // Create a transaction for these registry changes.
    hTransaction.Attach ( CreateTransaction ( NULL, 0, TRANSACTION_DO_NOT_PROMOTE,
                          0, 0, 0, NULL ) );

    if ( hTransaction == NULL )
        return false;

struct { LPCTSTR szKey, szValue, szData; } aEntries[] =
{
    { _T("software\\classes\\.aly"), NULL, _T("alyfile") },
    { _T("software\\classes\\alyfile"), NULL, _T("ALY test file type") },
    { _T("software\\classes\\alyfile\\DefaultIcon"), NULL, sIconPath },
    { _T("software\\classes\\alyfile\\shell\\open\\command"), NULL, sCommandLine }
};

    for ( int i = 0; i < _countof(aEntries); i++ )
        {
        if ( !WriteRegString ( HKEY_CURRENT_USER, aEntries[i].szKey, aEntries[i].szValue,
                               aEntries[i].szData, hTransaction ) )
            return false;
        }

    return 0 != CommitTransaction ( hTransaction );
}

// Remove the file association that was created in RegisterAsHandler().
bool CMainDlg::UnregisterAsHandler()
{
CHandle hTransaction;
LONG lRet;
HKEY hKey;
CRegKey rk;

    // Create a transaction for these registry changes.
    hTransaction.Attach ( CreateTransaction ( NULL, 0, TRANSACTION_DO_NOT_PROMOTE,
                          0, 0, 0, NULL ) );

    if ( hTransaction == NULL )
        return false;

    // Delete the .aly key.
    lRet = RegOpenKeyTransacted (
               HKEY_CURRENT_USER, _T("software\\classes"), 0,
               DELETE | KEY_ENUMERATE_SUB_KEYS | KEY_QUERY_VALUE,
               &hKey, hTransaction, NULL );

    if ( ERROR_SUCCESS != lRet )
        return false;

    rk.Attach ( hKey );

    lRet = RegDeleteTree ( rk, _T(".aly") );

    if ( ERROR_SUCCESS != lRet )
        return false;

    // Delete the alyfile key.
    lRet = RegDeleteTree ( rk, _T("alyfile") );

    if ( ERROR_SUCCESS != lRet )
        return false;

    return CommitTransaction ( hTransaction ) != 0;
}

LPWSTR g_awszTestFileNames[] = { L"test1.aly", L"willow.aly", L"buffy.aly" };

// Create some test files in the user's My Documents directory.
void CMainDlg::CreateTestFiles()
{
HRESULT hr;
LPWSTR pwszMyDocsPath = NULL;

    hr = SHGetKnownFolderPath ( FOLDERID_Documents, 0, NULL, &pwszMyDocsPath );

    if ( FAILED(hr) )
        return;

    for ( int i = 0; i < _countof(g_awszTestFileNames); i++ )
        {
        WCHAR wszTestFilePath[MAX_PATH] = {0};
        CHandle hFile;

        PathCombineW ( wszTestFilePath, pwszMyDocsPath, g_awszTestFileNames[i] );

        hFile.Attach ( CreateFileW ( wszTestFilePath, GENERIC_WRITE, 0, NULL,
                                     CREATE_NEW, FILE_ATTRIBUTE_NORMAL, NULL ) );

        if ( hFile != NULL )
            {
            LPCSTR szMsg = "Just a boring ol' test file.";
            DWORD cbyToWrite = strlen ( szMsg ), cbyWritten = 0;

            WriteFile ( hFile, szMsg, cbyToWrite, &cbyWritten, NULL );
            }
        }

    CoTaskMemFree ( pwszMyDocsPath );
}

// Delete the test files that were created in CreateTestFiles().
void CMainDlg::DeleteTestFiles()
{
HRESULT hr;
LPWSTR pwszMyDocsPath = NULL;

    hr = SHGetKnownFolderPath ( FOLDERID_Documents, 0, NULL, &pwszMyDocsPath );

    if ( FAILED(hr) )
        return;

    for ( int i = 0; i < _countof(g_awszTestFileNames); i++ )
        {
        WCHAR wszTestFilePath[MAX_PATH] = {0};

        PathCombineW ( wszTestFilePath, pwszMyDocsPath, g_awszTestFileNames[i] );
        DeleteFileW ( wszTestFilePath );
        }

    CoTaskMemFree ( pwszMyDocsPath );
}

void CMainDlg::ViewAlyFile ( LPCTSTR szFilePath )
{
    // Since this app doesn't do anything with its files, there isn't much here.
    // In a more substantal app, this would be where you open and parse your
    // documents.
    // We'll just check that the file exists, and bail out if not.
    if ( !PathFileExists ( szFilePath ) )
        return;

    // Show the file as the current file.
    m_cCurrFilePath.SetWindowText ( szFilePath );

    // Add it to the recent files list. This also makes Win 7 add it to the
    // app's jump list.
    SHAddToRecentDocs ( SHARD_PATH, szFilePath );
}