Disable auto format detection of Import Raw Data

- Use recent import setting instead of auto detection
- Add Detect button

src/import/ImportRaw.cpp

@@ -61,22 +61,22 @@ and sample size to help you importing data of an unknown format.
 class ImportRawDialog final : public wxDialogWrapper {
 
   public:
-   ImportRawDialog(wxWindow * parent,
-                   int encoding, unsigned channels,
-                   int offset, double rate);
+   ImportRawDialog(wxWindow * parent, const wxString & fileName);
    ~ImportRawDialog();
 
    void OnOK(wxCommandEvent & event);
    void OnCancel(wxCommandEvent & event);
    void OnPlay(wxCommandEvent & event);
+   void OnDetect(wxCommandEvent & event);
    void OnChoice(wxCommandEvent & event);
 
    // in and out
-   int mEncoding;
-   unsigned mChannels;
-   int mOffset;
-   double mRate;
-   double mPercent;
+   // Make static to preserve value for next raw import
+   static int mEncoding;
+   static unsigned mChannels;
+   static int mOffset;
+   static double mRate;
+   static double mPercent;
 
  private:
 
@@ -91,9 +91,19 @@ class ImportRawDialog final : public wxDialogWrapper {
    int         mNumEncodings;
    ArrayOf<int> mEncodingSubtype;
 
+   wxString mFileName;
+
    DECLARE_EVENT_TABLE()
 };
 
+// Initial value for Import Raw dialog
+int ImportRawDialog::mEncoding = SF_FORMAT_RAW | SF_ENDIAN_CPU | SF_FORMAT_PCM_16;
+unsigned ImportRawDialog::mChannels = 1;
+int ImportRawDialog::mOffset = 0;
+double ImportRawDialog::mRate = 0;  // -> project rate
+double ImportRawDialog::mPercent = 100.;
+
+
 // This function leaves outTracks empty as an indication of error,
 // but may also throw FileException to make use of the application's
 // user visible error reporting.
@@ -101,52 +111,27 @@ void ImportRaw(const AudacityProject &project, wxWindow *parent, const wxString
               WaveTrackFactory *trackFactory, TrackHolders &outTracks)
 {
    outTracks.clear();
-   int encoding = 0; // Guess Format
-   sf_count_t offset = 0;
-   double rate = 44100.0;
-   double percent = 100.0;
+
    TrackHolders results;
    auto updateResult = ProgressResult::Success;
 
    {
-      SF_INFO sndInfo;
-      unsigned numChannels = 0;
+      // On first run, set default sample rate from project rate
+      if (ImportRawDialog::mRate < 100.)
+         ImportRawDialog::mRate = ProjectSettings::Get(project).GetRate();
 
-      try {
-         // Yes, FormatClassifier currently handles filenames in UTF8 format only, that's
-         // a TODO ...
-         FormatClassifier theClassifier(fileName.utf8_str());
-         encoding = theClassifier.GetResultFormatLibSndfile();
-         numChannels = theClassifier.GetResultChannels();
-         offset = 0;
-      } catch (...) {
-         // Something went wrong in FormatClassifier, use defaults instead.
-         encoding = 0;
-      }
-
-      if (encoding <= 0) {
-         // Unable to guess.  Use mono, 16-bit samples with CPU endianness
-         // as the default.
-         encoding = SF_FORMAT_RAW | SF_ENDIAN_CPU | SF_FORMAT_PCM_16;
-         numChannels = 1;
-         offset = 0;
-      }
-
-      rate = ProjectSettings::Get( project ).GetRate();
-
-      numChannels = std::max(1u, numChannels);
-      ImportRawDialog dlog(parent, encoding, numChannels, (int)offset, rate);
+      ImportRawDialog dlog(parent, fileName);
       dlog.ShowModal();
       if (!dlog.GetReturnCode())
          return;
 
-      encoding = dlog.mEncoding;
-      numChannels = dlog.mChannels;
-      rate = dlog.mRate;
-      offset = (sf_count_t)dlog.mOffset;
-      percent = dlog.mPercent;
+      int encoding = dlog.mEncoding;
+      unsigned numChannels = dlog.mChannels;
+      double rate = dlog.mRate;
+      sf_count_t offset = (sf_count_t)dlog.mOffset;
+      double percent = dlog.mPercent;
 
-      memset(&sndInfo, 0, sizeof(SF_INFO));
+      SF_INFO sndInfo = { 0 };
       sndInfo.samplerate = (int)rate;
       sndInfo.channels = (int)numChannels;
       sndInfo.format = encoding | SF_FORMAT_RAW;
@@ -289,28 +274,25 @@ void ImportRaw(const AudacityProject &project, wxWindow *parent, const wxString
 
 enum {
    ChoiceID = 9000,
-   PlayID
+   PlayID,
+   DetectID,
 };
 
 BEGIN_EVENT_TABLE(ImportRawDialog, wxDialogWrapper)
    EVT_BUTTON(wxID_OK, ImportRawDialog::OnOK)
    EVT_BUTTON(wxID_CANCEL, ImportRawDialog::OnCancel)
    EVT_BUTTON(PlayID, ImportRawDialog::OnPlay)
+   EVT_BUTTON(DetectID, ImportRawDialog::OnDetect)
    EVT_CHOICE(ChoiceID, ImportRawDialog::OnChoice)
 END_EVENT_TABLE()
 
-ImportRawDialog::ImportRawDialog(wxWindow * parent,
-                                 int encoding, unsigned channels,
-                                 int offset, double rate)
+ImportRawDialog::ImportRawDialog(wxWindow * parent, const wxString & fileName)
 :  wxDialogWrapper(parent, wxID_ANY, XO("Import Raw Data"),
             wxDefaultPosition, wxDefaultSize,
             wxDEFAULT_DIALOG_STYLE | wxRESIZE_BORDER),
-    mEncoding(encoding),
-    mChannels(channels),
-    mOffset(offset),
-    mRate(rate)
+   mFileName(fileName)
 {
-   wxASSERT(channels >= 1);
+   wxASSERT(mChannels >= 1);
 
    SetName();
 
@@ -437,11 +419,20 @@ ImportRawDialog::ImportRawDialog(wxWindow * parent,
       }
       S.EndMultiColumn();
 
-      //
-      // Preview Pane goes here
-      //
+      S.SetBorder(5);
+      S.StartTwoColumn();
+      {
+         /* i18n-hint: Guess format of raw file */
+         S.Id(DetectID).AddButton(XXO("Detect"));
+
+         //
+         // Preview Pane goes here
+         //
+
+         S.AddStandardButtons();
+      }
+      S.EndTwoColumn();
 
-      S.AddStandardButtons();
       // Find the OK button, and change its text to 'Import'.
       // We MUST set mOK because it is used later.
       mOK = (wxButton *)wxWindow::FindWindowById(wxID_OK, this);
@@ -497,6 +488,52 @@ void ImportRawDialog::OnPlay(wxCommandEvent & WXUNUSED(event))
 {
 }
 
+void ImportRawDialog::OnDetect(wxCommandEvent & event)
+{
+   try {
+      // Yes, FormatClassifier currently handles filenames in UTF8 format only, that's a TODO ...
+      FormatClassifier theClassifier(mFileName.utf8_str());
+      mEncoding = theClassifier.GetResultFormatLibSndfile();
+      mChannels = theClassifier.GetResultChannels();
+   } catch (...) {
+      // Something went wrong in FormatClassifier, abort.
+      return;
+   }
+
+   int selection = 0;
+   for (int i = 0; i < mNumEncodings; i++) {
+      int subtype = mEncodingSubtype[i];
+      if ((mEncoding & SF_FORMAT_SUBMASK) == subtype) {
+         selection = i;
+         break;
+      }
+   }
+
+   int endian = 0;
+   switch (mEncoding & SF_FORMAT_ENDMASK)
+   {
+      default:
+      case SF_ENDIAN_FILE:
+         endian = 0;
+         break;
+      case SF_ENDIAN_LITTLE:
+         endian = 1;
+         break;
+      case SF_ENDIAN_BIG:
+         endian = 2;
+         break;
+      case SF_ENDIAN_CPU:
+         endian = 3;
+         break;
+   }
+
+   mEncodingChoice->SetSelection(selection);
+   mEndianChoice->SetSelection(endian);
+   mChannelChoice->SetSelection(mChannels - 1);
+
+   OnChoice(event);
+}
+
 void ImportRawDialog::OnChoice(wxCommandEvent & WXUNUSED(event))
 {
    SF_INFO info;