Correct lookup of Explorer-specific file association information.

The code added in r52154 never worked because it was looking for the Progid
value in a wrong place, look for it under UserChoice subkey where it really
is.

Also add a way to look up the command to open files with the given extension
to the exec sample.

Closes #12302.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@73106 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

samples/exec/exec.cpp

@@ -55,6 +55,7 @@
 #include "wx/numdlg.h"
 #include "wx/textdlg.h"
 #include "wx/ffile.h"
+#include "wx/scopedptr.h"
 #include "wx/stopwatch.h"
 
 #include "wx/process.h"
@@ -122,6 +123,7 @@ public:
     void OnFileExec(wxCommandEvent& event);
     void OnFileLaunch(wxCommandEvent& event);
     void OnOpenURL(wxCommandEvent& event);
+    void OnShowCommandForExt(wxCommandEvent& event);
 
     void OnAbout(wxCommandEvent& event);
 
@@ -321,6 +323,7 @@ enum
     Exec_Shell,
     Exec_POpen,
     Exec_OpenFile,
+    Exec_ShowCommandForExt,
     Exec_LaunchFile,
     Exec_OpenURL,
     Exec_DDEExec,
@@ -365,6 +368,7 @@ BEGIN_EVENT_TABLE(MyFrame, wxFrame)
     EVT_MENU(Exec_POpen, MyFrame::OnPOpen)
 
     EVT_MENU(Exec_OpenFile, MyFrame::OnFileExec)
+    EVT_MENU(Exec_ShowCommandForExt, MyFrame::OnShowCommandForExt)
     EVT_MENU(Exec_LaunchFile, MyFrame::OnFileLaunch)
     EVT_MENU(Exec_OpenURL, MyFrame::OnOpenURL)
 
@@ -459,6 +463,9 @@ MyFrame::MyFrame(const wxString& title, const wxPoint& pos, const wxSize& size)
     menuFile->AppendSeparator();
     menuFile->Append(Exec_OpenFile, wxT("Open &file...\tCtrl-F"),
                      wxT("Launch the command to open this kind of files"));
+    menuFile->Append(Exec_ShowCommandForExt,
+                     "Show association for extension...\tShift-Ctrl-A",
+                     "Show the command associated with the given extension");
     menuFile->Append(Exec_LaunchFile, wxT("La&unch file...\tShift-Ctrl-F"),
                      wxT("Launch the default application associated with the file"));
     menuFile->Append(Exec_OpenURL, wxT("Open &URL...\tCtrl-U"),
@@ -1098,6 +1105,41 @@ void MyFrame::OnFileExec(wxCommandEvent& WXUNUSED(event))
     DoAsyncExec(cmd);
 }
 
+void MyFrame::OnShowCommandForExt(wxCommandEvent& WXUNUSED(event))
+{
+    static wxString s_ext;
+
+    wxString ext = wxGetTextFromUser
+                   (
+                    "Enter the extension without leading dot",
+                    "Exec sample",
+                    s_ext,
+                    this
+                   );
+    if ( ext.empty() )
+        return;
+
+    s_ext = ext;
+
+    wxScopedPtr<wxFileType>
+        ft(wxTheMimeTypesManager->GetFileTypeFromExtension(ext));
+    if ( !ft )
+    {
+        wxLogError("Information for extension \"%s\" not found", ext);
+        return;
+    }
+
+    const wxString cmd = ft->GetOpenCommand("file." + ext);
+    if ( cmd.empty() )
+    {
+        wxLogWarning("Open command for extension \"%s\" not defined.", ext);
+        return;
+    }
+
+    wxLogMessage("Open command for files of extension \"%s\" is\n%s",
+                 ext, cmd);
+}
+
 void MyFrame::OnFileLaunch(wxCommandEvent& WXUNUSED(event))
 {
     if ( !AskUserForFileName() )

src/msw/mimetype.cpp

@@ -227,19 +227,38 @@ wxString wxFileTypeImpl::GetCommand(const wxString& verb) const
     wxLogNull nolog;
     wxString strKey;
 
+    // Since Windows Vista the association used by Explorer is different from
+    // the association information stored in the traditional part of the
+    // registry. Unfortunately the new schema doesn't seem to be documented
+    // anywhere so using it involves a bit of guesswork:
+    //
+    // The information is stored under Explorer-specific key whose path is
+    // below. The interesting part is UserChoice subkey which is the only one
+    // we use so far but there is also OpenWithProgids subkey which can exist
+    // even if UserChoice doesn't. However in practice there doesn't seem to be
+    // any cases when OpenWithProgids values for the given extension are
+    // different from those found directly under HKCR\.ext, so for now we don't
+    // bother to use this, apparently the programs registering their file type
+    // associations do it in both places. We do use UserChoice because when the
+    // association is manually changed by the user it's only recorded there and
+    // so must override whatever value was created under HKCR by the setup
+    // program.
+
     {
-        wxRegKey explorerKey(wxRegKey::HKCU, wxT("Software\\Microsoft\\Windows\\CurrentVersion\\Explorer\\FileExts\\") + m_ext);
-        if (explorerKey.Exists())
-        {
-            if (explorerKey.Open(wxRegKey::Read))
-            {
-                if (explorerKey.QueryValue(wxT("Progid"), strKey))
+        wxRegKey explorerKey
+                 (
+                    wxRegKey::HKCU,
+                    wxT("Software\\Microsoft\\Windows\\CurrentVersion\\")
+                    wxT("Explorer\\FileExts\\") +
+                    m_ext +
+                    wxT("\\UserChoice")
+                 );
+        if ( explorerKey.Open(wxRegKey::Read) &&
+                explorerKey.QueryValue(wxT("Progid"), strKey) )
         {
             strKey = wxFileTypeImplGetCurVer(strKey);
         }
     }
-        }
-    }
 
     if (!strKey && wxRegKey(wxRegKey::HKCR, m_ext + wxT("\\shell")).Exists())
         strKey = m_ext;