Warn user about dangers of aliased files and ask which type of import to proceed with.

Also adds a preference in the warnings that defaults to true.

src/import/ImportPCM.cpp

@@ -182,6 +182,72 @@ int PCMImportFileHandle::GetFileUncompressedBytes()
    return mInfo.frames * mInfo.channels * SAMPLE_SIZE(mFormat);
 }
 
+// returns "copy" or "edit" (aliased) as the user selects.
+// if the cancel button is hit then "cancel" is returned.
+static wxString AskCopyOrEdit()
+{
+   wxString oldCopyPref = gPrefs->Read(wxT("/FileFormats/CopyOrEditUncompressedData"), wxT("copy"));
+   bool oldAskPref      = gPrefs->Read(wxT("/Warnings/CopyOrEditUncompressedDataAsk"), true);
+
+   // check the current preferences for whether or not we should ask the user about this.
+   if (oldAskPref) {
+      wxString newCopyPref = wxT("copy");
+      wxDialog dialog(NULL, -1, _("Importing Uncompressed Audio Files"));
+
+      wxBoxSizer *vbox = new wxBoxSizer(wxVERTICAL);
+      dialog.SetSizer(vbox);
+
+      wxStaticText *message = new wxStaticText(&dialog, -1, wxString::Format(_("You can import uncompressed audio files by copying them into the project, \
+or by reading them directly from their current location (without copying).\n\n\
+Your current preference is set to %s.\n\n\
+\
+Reading the files directly allows you to play or edit them almost immediately.\n\
+It is less safe than copying in, because you must retain the files with their\
+original names in their original location.\n\
+File > Check Dependencies will show the original names and location of any files that you are reading directly.\n\n\
+\
+How do you want to import The current file(s)?"), oldCopyPref == wxT("copy") ? _("copy in") : _("read directly")));
+      message->Wrap(500);
+                               
+      vbox->Add(message, 1, wxALL | wxEXPAND, 10);
+
+      wxRadioButton *copyRadio  = new wxRadioButton(&dialog, -1, _("Make a copy of the files before editing (safer)"), wxDefaultPosition, wxDefaultSize, wxRB_GROUP);
+      vbox->Add(copyRadio, 0, wxALL);
+
+      wxRadioButton *aliasRadio = new wxRadioButton(&dialog, -1, _("Read the files directly from the original (faster)"));
+      vbox->Add(aliasRadio, 0, wxALL);
+
+      wxCheckBox *dontAskNextTimeBox = new wxCheckBox(&dialog, -1, _("Don't ask again and always use my choice above"));
+      vbox->Add(dontAskNextTimeBox, 0, wxALL);
+
+      wxRadioButton *prefsRadio = oldCopyPref == wxT("copy") ? copyRadio : aliasRadio;
+      prefsRadio->SetValue(true);
+
+      wxSizer *buttonSizer = dialog.CreateButtonSizer(wxOK | wxCANCEL);
+      vbox->Add(buttonSizer, 0, wxALL | wxEXPAND);
+      dialog.SetSize(dialog.GetBestSize());
+      dialog.Layout();
+
+      if (dialog.ShowModal() == wxID_OK) {
+         if (aliasRadio->GetValue()) {
+            newCopyPref = wxT("edit");
+         }
+         if (dontAskNextTimeBox->IsChecked()) {
+            gPrefs->Write(wxT("/Warnings/CopyOrEditUncompressedDataAsk"), (long) false);
+         }
+      } else {
+         return wxT("cancel");
+      }
+
+      // if the preference changed, save it.
+      if (newCopyPref != oldCopyPref) {
+         gPrefs->Write(wxT("/FileFormats/CopyOrEditUncompressedData"), newCopyPref);
+      }
+      oldCopyPref = newCopyPref;
+   }
+   return oldCopyPref;
+}
+
 int PCMImportFileHandle::Import(TrackFactory *trackFactory,
                                 Track ***outTracks,
                                 int *outNumTracks,
@@ -189,6 +255,18 @@ int PCMImportFileHandle::Import(TrackFactory *trackFactory,
 {
    wxASSERT(mFile);
 
+   // Get the preference / warn the user about aliased files.
+   wxString copyEdit = AskCopyOrEdit();
+
+   if (copyEdit == wxT("cancel"))
+      return eProgressCancelled;
+
+   // Fall back to "copy" if it doesn't match anything else, since it is safer
+   bool doEdit = false;
+   if (copyEdit.IsSameAs(wxT("edit"), false))
+      doEdit = true;
+      
+
    CreateProgress();
 
    WaveTrack **channels = new WaveTrack *[mInfo.channels];
@@ -218,14 +296,6 @@ int PCMImportFileHandle::Import(TrackFactory *trackFactory,
    sampleCount maxBlockSize = channels[0]->GetMaxBlockSize();
    int updateResult = false;
    
-   wxString copyEdit =
-       gPrefs->Read(wxT("/FileFormats/CopyOrEditUncompressedData"), wxT("edit"));
-
-   // Fall back to "edit" if it doesn't match anything else
-   bool doEdit = true;          
-   if (copyEdit.IsSameAs(wxT("copy"), false))
-      doEdit = false;
-      
    // If the format is not seekable, we must use 'copy' mode,
    // because 'edit' mode depends on the ability to seek to an
    // arbitrary location in the file.

src/prefs/ImportExportPrefs.cpp

@@ -52,7 +52,7 @@ void ImportExportPrefs::PopulateOrExchange(ShuttleGui & S)
 
    S.StartStatic(_("When importing audio files"));
    {
-      S.StartRadioButtonGroup(wxT("/FileFormats/CopyOrEditUncompressedData"), wxT("edit"));
+      S.StartRadioButtonGroup(wxT("/FileFormats/CopyOrEditUncompressedData"), wxT("copy"));
       {
          S.TieRadioButton(_("&Make a copy of uncompressed audio files before editing (safer)"),
                           wxT("copy"));

src/prefs/WarningsPrefs.cpp

@@ -69,6 +69,9 @@ void WarningsPrefs::PopulateOrExchange(ShuttleGui & S)
       S.TieCheckBox(_("Mixing down to &mono during export"),
                     wxT("/Warnings/MixMono"),
                     true);
+      S.TieCheckBox(_("Warn when &importing uncompressed files"),
+                    wxT("/Warnings/CopyOrEditUncompressedDataAsk"),
+                    true);
    }
    S.EndStatic();
 }