Clean up some issues with Effect abstract classes, primarily that the progress dialog had Stop and Cancel buttons that produced exactly the same results, i.e., Cancel, so I removed the Stop button.

src/effects/Effect.cpp

@@ -26,7 +26,6 @@ greater use in future.
 #include <wx/defs.h>
 #include <wx/string.h>
 #include <wx/msgdlg.h>
-#include <wx/progdlg.h>
 #include <wx/sizer.h>
 #include <wx/timer.h>
 #include <wx/hashmap.h>
@@ -140,7 +139,8 @@ bool Effect::DoEffect(wxWindow *parent, int flags,
    bool skipFlag = CheckWhetherSkipEffect();
    if (skipFlag == false) {
       mProgress = new ProgressDialog(StripAmpersand(GetEffectName()),
-                                     GetEffectAction());
+                                     GetEffectAction(), 
+                                     pdlgHideStopButton);
       returnVal = Process();
       delete mProgress;
    }
@@ -163,25 +163,19 @@ bool Effect::DoEffect(wxWindow *parent, int flags,
 bool Effect::TotalProgress(double frac)
 {
    int updateResult = mProgress->Update(frac);
-   if (updateResult == eProgressSuccess)
-     return false;
-   return true;
+   return (updateResult != eProgressSuccess);
 }
 
 bool Effect::TrackProgress(int whichTrack, double frac)
 {
    int updateResult = mProgress->Update(whichTrack + frac, (double) mNumTracks);
-   if (updateResult == eProgressSuccess)
-     return false;
-   return true;
+   return (updateResult != eProgressSuccess);
 }
 
 bool Effect::TrackGroupProgress(int whichGroup, double frac)
 {
    int updateResult = mProgress->Update(whichGroup + frac, (double) mNumGroups);
-   if (updateResult == eProgressSuccess)
-     return false;
-   return true;
+   return (updateResult != eProgressSuccess);
 }
 
 void Effect::GetSamples(WaveTrack *track, sampleCount *start, sampleCount *len)
@@ -472,7 +466,8 @@ void Effect::Preview()
    // again, so the state is exactly the way it was before Preview
    // was called.
    mProgress = new ProgressDialog(StripAmpersand(GetEffectName()),
-                                  _("Preparing preview"));
+                                  _("Preparing preview"), 
+                                  pdlgHideCancelButton); // Have only "Stop" button.
    bool bSuccess = Process();
    delete mProgress;
    End();

src/effects/Effect.h

@@ -14,7 +14,6 @@
 
 #include <set>
 
-#include <wx/button.h>
 #include <wx/dynarray.h>
 #include <wx/intl.h> 
 #include <wx/string.h>
@@ -135,6 +134,10 @@ class AUDACITY_DLL_API Effect {
 
    wxString GetPreviewName();
 
+   //ANSWER-ME: Isn't this pointless?
+   //    None of the built-in functions has an ampersand in the result of 
+   //    GetEffectName(), the only strings on which this method is used. 
+   //    In fact, the example 'E&qualizer' does not exist in the code!
    // Strip ampersand ('&' char) from string. This effectively removes the
    // shortcut from the string ('E&qualizer' becomes 'Equalizer'). This is
    // important for sorting.
@@ -147,11 +150,10 @@ class AUDACITY_DLL_API Effect {
  // do its processing.
  //
  protected:
-   // The constructor.  Called once at the beginning of the program.
+   // The constructor is called once by each subclass at the beginning of the program.
    // Avoid allocating memory or doing time-consuming processing here.
    Effect();
 
-   //The destructor.
    virtual ~Effect();
  
    // Called once each time an effect is called.  Perform any initialization;

src/effects/EffectManager.cpp

@@ -62,7 +62,7 @@ void EffectManager::RegisterEffect(Effect *f, int NewFlags)
    int i;
    for(i=0; i<len; i++)
       if (name.CmpNoCase(Effect::StripAmpersand(mEffects[i]->GetEffectName())) < 0) {
-	 mEffects.Insert(f, i);
+         mEffects.Insert(f, i);
          break;
       }
    if (i==len)

src/effects/Generator.cpp

@@ -46,9 +46,9 @@ bool Generator::Process()
          //if we can't move clips, and we're generating into an empty space,
          //make sure there's room.
          if (!editClipCanMove &&
-	     track->IsEmpty(mT0, mT1+1.0/track->GetRate()) &&
+	          track->IsEmpty(mT0, mT1+1.0/track->GetRate()) &&
              !track->IsEmpty(mT0, mT0+mDuration-(mT1-mT0)-1.0/track->GetRate()))
-	 {
+	      {
              wxMessageBox(
                _("There is not enough room available to generate the audio"),
                _("Error"), wxICON_STOP);