Bug 646:

1) Following request from Gale scanning for VSTs will be prompted for every time you start, until it completes successfully OR you ask for it not to happen in preferences.  Also it will happen if the plugns.cfg is empty.
2) UP and DOWN no longer toggle the checkmark too.  SPACE does.

src/effects/VST/VSTEffect.cpp

@@ -77,19 +77,16 @@ void RegisterVSTEffects()
 
    pm.Open();
 
-   bool bScanRequired = false;
+   if ( gPrefs->Read(wxT("/VST/Rescan"), (long)true) != false) {
-   if ( bScanRequired || gPrefs->Read(wxT("/VST/Rescan"), (long)true) != false) {
       pm.PurgeType(VSTPLUGINTYPE);
-      gPrefs->Write(wxT("/VST/Rescan"), false);
-      gPrefs->Flush();
-      bScanRequired = true;
    }
 
    if (!pm.HasType(VSTPLUGINTYPE)) {
       pm.Close();
-      if( bScanRequired) 
+      VSTEffect::Scan();
-         VSTEffect::Scan();
       pm.Open();
+      gPrefs->Write(wxT("/VST/Rescan"), false);
+      gPrefs->Flush();
    }
 
    EffectManager & em = EffectManager::Get();
@@ -122,17 +119,20 @@ class PluginRegistrationDialog:public wxDialog {
    void OnApply(wxCommandEvent & event);
    void OnCancel(wxCommandEvent & event);
    void OnToggleState( wxListEvent & event );
+   void OnChar( wxListEvent & event );
+
    void SetBoldOrRegular( int i );
+   void ToggleItem(int i);
 
    wxButton *mOK;
    wxButton *mCancel;
    wxListCtrl *mPlugins;
+   int miSelected;
    wxArrayString mFiles;
    wxArrayInt miState;
-//   wxListCtrl *mList;
-//   BatchCommands mBatchCommands;
 
    bool mAbort;
+   bool mbNextSelectToggles;
 
    DECLARE_EVENT_TABLE()
 };
@@ -143,7 +143,10 @@ class PluginRegistrationDialog:public wxDialog {
 BEGIN_EVENT_TABLE(PluginRegistrationDialog, wxDialog)
    EVT_BUTTON(wxID_OK, PluginRegistrationDialog::OnApply)
    EVT_BUTTON(wxID_CANCEL, PluginRegistrationDialog::OnCancel)
-   EVT_LIST_ITEM_SELECTED( wxID_ANY, PluginRegistrationDialog::OnToggleState )
+   EVT_LIST_ITEM_SELECTED( PluginListID, PluginRegistrationDialog::OnToggleState )
+   EVT_LIST_ITEM_ACTIVATED( PluginListID, PluginRegistrationDialog::OnToggleState )
+   //EVT_LIST_ITEM_DESELECTED( wxID_ANY, PluginRegistrationDialog::OnToggleState )
+   EVT_LIST_KEY_DOWN( PluginListID, PluginRegistrationDialog::OnChar )
 END_EVENT_TABLE()
 
 PluginRegistrationDialog::PluginRegistrationDialog(wxWindow * parent, const wxArrayString & files):
@@ -152,6 +155,8 @@ PluginRegistrationDialog::PluginRegistrationDialog(wxWindow * parent, const wxAr
             wxDefaultPosition, wxDefaultSize,
             wxDEFAULT_DIALOG_STYLE | wxRESIZE_BORDER)
 {
+   miSelected = 0;
+   mbNextSelectToggles = true;
    SetLabel(_("Install VST Plugins"));         // Provide visual label
    SetName(_("Install VST Plugins"));          // Provide audible label
    Populate();
@@ -190,7 +195,7 @@ void PluginRegistrationDialog::PopulateOrExchange(ShuttleGui &S)
        beside each one.*/
       S.StartStatic(_("&Select Plugins to Install"), true);
       {
-         S.SetStyle(wxSUNKEN_BORDER | wxLC_REPORT | wxLC_HRULES | wxLC_VRULES );
+         S.SetStyle(wxSUNKEN_BORDER | wxLC_REPORT | wxLC_SINGLE_SEL | wxLC_HRULES | wxLC_VRULES );
          mPlugins = S.Id(PluginListID).AddListControlReportMode();
          mPlugins->AssignImageList( pImageList, wxIMAGE_LIST_SMALL );
          mPlugins->InsertColumn(0, _("Plugin File"), wxLIST_FORMAT_LEFT);
@@ -209,16 +214,19 @@ void PluginRegistrationDialog::PopulateOrExchange(ShuttleGui &S)
 
    wxClientDC dc( this );
    
-   int iLen = 100;
+   // The dc is used to compute the text width in pixels.
+   // FIXME: That works fine for PC, but apparently comes out too small for wxMAC.
+   // iLen is minimum width in pixels shown for the file names.  200 is reasonable.
+   int iLen = 200;
    wxSize siz;
    for (int i = 0; i < (int)mFiles.GetCount(); i++) {
-      miState.Add( SHOW_CHECKED ); // 1 is selected.
+      miState.Add( SHOW_CHECKED );
       mPlugins->InsertItem(i, wxString(wxT(" ")) + mFiles[i], SHOW_CHECKED);
-//    SetBoldOrRegular( i );
       siz = dc.GetTextExtent( mFiles[i] );
       if( siz.GetWidth() > iLen )
          iLen = siz.GetWidth();
    }
+   //SetBoldOrRegular( miSelected );
    mPlugins->SetColumnWidth(0, iLen);
    mPlugins->SetSizeHints( iLen, 200 );
    Layout();
@@ -229,6 +237,40 @@ void PluginRegistrationDialog::PopulateOrExchange(ShuttleGui &S)
 
 }
 
+void PluginRegistrationDialog::OnChar( wxListEvent & event  )
+{
+   int iKeyCode = event.GetKeyCode();
+   //int iItem = event.GetIndex(); // Grrr doesn't tell us item for key presses.
+   //use this instead:
+   int iItem = mPlugins->GetNextItem( -1, wxLIST_NEXT_ALL, wxLIST_STATE_FOCUSED);
+   bool bHandleSpecially = iItem != -1;
+
+   if( bHandleSpecially )
+   {
+      // UP and DOWN cause the next item to be selected.
+      // We pre-toggle so that the toggle due to selection 
+      // sets it back!  
+      if( iKeyCode == WXK_UP )
+      {
+         iItem--;
+      }
+      else if( iKeyCode == WXK_DOWN )
+      {
+         iItem++;
+         if( iItem >= (int)mFiles.GetCount())
+            iItem = -1;
+      }
+      else
+      {
+         iItem = -1;
+      }
+      if( iItem >= 0 )
+         ToggleItem(iItem);
+   }
+   event.Skip();
+}
+
+
 void PluginRegistrationDialog::SetBoldOrRegular( int i )
 {
    wxFont Font = mPlugins->GetItemFont( i );
@@ -236,13 +278,26 @@ void PluginRegistrationDialog::SetBoldOrRegular( int i )
    mPlugins->SetItemFont( i, Font );
 }
 
+// We can't capture mouse clicks, only selected and deselected.
+// Clicking on a selected item does not generate any event.
+// Therefore our workaround solution is to NEVER actually select.
+// So whenever the code tries to , we cancel the selection.
+// That way we continue to get events.
+void PluginRegistrationDialog::ToggleItem(int i)
+{
+   miState[ i ] = (miState[ i ]==SHOW_CHECKED) ? SHOW_UNCHECKED : SHOW_CHECKED; // Toggle it.
+   mPlugins->SetItemImage( i, miState[i] );
+   miSelected = i;
+// SetBoldOrRegular( i );
+}
+
+
 void PluginRegistrationDialog::OnToggleState(wxListEvent & event)
 {
    int i = event.GetIndex();
-   miState[ i ] = (miState[ i ]==SHOW_CHECKED) ? SHOW_UNCHECKED : SHOW_CHECKED; // Toggle it.
    mPlugins->SetItemState( i, 0 ,wxLIST_STATE_SELECTED);
-   mPlugins->SetItemImage( i, miState[i] );
+   //miSelected = i;
-// SetBoldOrRegular( i );
+   ToggleItem( i );
 }
 
 void PluginRegistrationDialog::OnApply(wxCommandEvent & WXUNUSED(event))
@@ -251,14 +306,7 @@ void PluginRegistrationDialog::OnApply(wxCommandEvent & WXUNUSED(event))
    size_t cnt = mFiles.GetCount();
    for (size_t i = 0; i < cnt; i++) {
       wxString file = mFiles[i];
-#if 0
+
-      int status = progress->Update(wxLongLong(i),
-                                    wxLongLong(cnt),
-                                    wxString::Format(_("Checking %s"), file.c_str()));
-      if (status != eProgressSuccess) {
-         break;
-      }
-#endif
       mPlugins->EnsureVisible( i );
       if( miState[ i ] == SHOW_CHECKED )
       {