Heavyweight version of SelectedRegion stored in ViewInfo emits events

src/LabelTrack.h

@@ -21,6 +21,7 @@ class wxTextFile;
 
 class AudacityProject;
 class DirManager;
+class NotifyingSelectedRegion;
 class TimeWarper;
 
 struct LabelTrackHit;

src/ProjectSelectionManager.cpp

@@ -58,7 +58,7 @@ bool ProjectSelectionManager::SnapSelection()
    auto snapTo = settings.GetSnapTo();
    if (snapTo != SNAP_OFF) {
       auto &viewInfo = ViewInfo::Get( project );
-      SelectedRegion &selectedRegion = viewInfo.selectedRegion;
+      auto &selectedRegion = viewInfo.selectedRegion;
       NumericConverter nc(NumericConverter::TIME,
          settings.GetSelectionFormat(), 0, settings.GetRate());
       const bool nearest = (snapTo == SNAP_NEAREST);

src/TrackArtist.h

@@ -128,7 +128,7 @@ public:
    bool findNotesQuantizeOld;
 #endif
 
-   SelectedRegion *pSelectedRegion{};
+   const SelectedRegion *pSelectedRegion{};
    ZoomInfo *pZoomInfo{};
 
    bool drawEnvelope{ false };

src/TrackPanel.cpp

@@ -851,7 +851,8 @@ void TrackPanel::DrawTracks(wxDC * dc)
 
    const wxRect clip = GetRect();
 
-   mTrackArtist->pSelectedRegion = &mViewInfo->selectedRegion;
+   const SelectedRegion &sr = mViewInfo->selectedRegion;
+   mTrackArtist->pSelectedRegion = &sr;
    mTrackArtist->pZoomInfo = mViewInfo;
    TrackPanelDrawingContext context {
       *dc, Target(), mLastMouseState, mTrackArtist.get()

src/ViewInfo.cpp

@@ -21,6 +21,119 @@ Paul Licameli
 #include "prefs/TracksBehaviorsPrefs.h"
 #include "xml/XMLWriter.h"
 
+wxDEFINE_EVENT( EVT_SELECTED_REGION_CHANGE, SelectedRegionEvent );
+
+SelectedRegionEvent::SelectedRegionEvent(
+   wxEventType commandType, NotifyingSelectedRegion *pReg )
+: wxEvent{ 0, commandType }
+, pRegion{ pReg }
+{}
+
+wxEvent *SelectedRegionEvent::Clone() const
+{
+   return safenew SelectedRegionEvent{ *this };
+}
+
+NotifyingSelectedRegion& NotifyingSelectedRegion::operator =
+( const SelectedRegion &other )
+{
+   if ( mRegion != other ) {
+      mRegion = other;
+      Notify();
+   }
+   return *this;
+}
+
+bool NotifyingSelectedRegion::setTimes(double t0, double t1)
+{
+   bool result = false;
+   if ( mRegion.t0() != t0 || mRegion.t1() != t1 ) {
+      result = mRegion.setTimes( t0, t1 );
+      Notify();
+   }
+   return result;
+}
+
+bool NotifyingSelectedRegion::setT0(double t, bool maySwap)
+{
+   bool result = false;
+   if ( mRegion.t0() != t ) {
+      result = mRegion.setT0( t, maySwap );
+      Notify();
+   }
+   return result;
+}
+
+bool NotifyingSelectedRegion::setT1(double t, bool maySwap)
+{
+   bool result = false;
+   if ( mRegion.t1() != t ) {
+      result = mRegion.setT1( t, maySwap );
+      Notify();
+   }
+   return result;
+}
+
+void NotifyingSelectedRegion::collapseToT0()
+{
+   if ( mRegion.t0() !=  mRegion.t1() ) {
+      mRegion.collapseToT0();
+      Notify();
+   }
+}
+
+void NotifyingSelectedRegion::collapseToT1()
+{
+   if ( mRegion.t0() !=  mRegion.t1() ) {
+      mRegion.collapseToT1();
+      Notify();
+   }
+}
+
+void NotifyingSelectedRegion::move(double delta)
+{
+   if (delta != 0) {
+      mRegion.move( delta );
+      Notify();
+   }
+}
+
+bool NotifyingSelectedRegion::setFrequencies(double f0, double f1)
+{
+   bool result = false;
+   if ( mRegion.f0() != f0 || mRegion.f1() != f1 ) {
+      result = mRegion.setFrequencies( f0, f1 );
+      Notify();
+   }
+   return result;
+}
+
+bool NotifyingSelectedRegion::setF0(double f, bool maySwap)
+{
+   bool result = false;
+   if ( mRegion.f0() != f ) {
+      result = mRegion.setF0( f, maySwap );
+      Notify();
+   }
+   return result;
+}
+
+bool NotifyingSelectedRegion::setF1(double f, bool maySwap)
+{
+   bool result = false;
+   if ( mRegion.f1() != f ) {
+      result = mRegion.setF1( f, maySwap );
+      Notify();
+   }
+   return result;
+}
+
+void NotifyingSelectedRegion::Notify()
+{
+   SelectedRegionEvent evt{ EVT_SELECTED_REGION_CHANGE, this };
+   ProcessEvent( evt );
+}
+
 static const AudacityProject::AttachedObjects::RegisteredFactory key{
    []( AudacityProject &project ) {
       auto result =

src/ViewInfo.h

@@ -14,11 +14,92 @@
 #include <utility>
 #include <vector>
 #include <wx/event.h> // inherit wxEvtHandler
+#include <wx/weakref.h> // member variable
 #include "SelectedRegion.h"
 #include "MemoryX.h"
 #include "ZoomInfo.h" // to inherit
 
 
+class NotifyingSelectedRegion;
+
+struct SelectedRegionEvent : public wxEvent
+{
+   SelectedRegionEvent( wxEventType commandType,
+                       NotifyingSelectedRegion *pRegion );
+
+   wxEvent *Clone() const override;
+
+   wxWeakRef< NotifyingSelectedRegion > pRegion;
+};
+
+// To do:  distinguish time changes from frequency changes perhaps?
+wxDECLARE_EXPORTED_EVENT( AUDACITY_DLL_API,
+                          EVT_SELECTED_REGION_CHANGE, SelectedRegionEvent );
+
+// This heavyweight wrapper of the SelectedRegion structure emits events
+// on mutating operations, that other classes can listen for.
+class NotifyingSelectedRegion : public wxEvtHandler
+{
+public:
+   // Expose SelectedRegion's const accessors
+   double t0 () const { return mRegion.t0(); }
+   double t1 () const { return mRegion.t1(); }
+   double f0 () const { return mRegion.f0(); }
+   double f1 () const { return mRegion.f1(); }
+   double fc () const { return mRegion.fc(); }
+   bool isPoint() const { return mRegion.isPoint(); }
+   double duration() const { return mRegion.duration(); }
+
+   // Writing and reading of persistent fields -- the read is mutating but
+   // does not emit events
+   void WriteXMLAttributes
+      (XMLWriter &xmlFile,
+       const wxChar *legacyT0Name, const wxChar *legacyT1Name) const
+   { mRegion.WriteXMLAttributes(xmlFile, legacyT0Name, legacyT1Name); }
+
+   bool HandleXMLAttribute
+      (const wxChar *attr, const wxChar *value,
+       const wxChar *legacyT0Name, const wxChar *legacyT1Name)
+   { return mRegion.HandleXMLAttribute(
+      attr, value, legacyT0Name, legacyT1Name ); }
+
+   // const-only access allows assignment from this into a SelectedRegion
+   // or otherwise passing it into a function taking const SelectedRegion&
+   operator const SelectedRegion & () const { return mRegion; }
+
+   // These are the event-emitting operations
+   NotifyingSelectedRegion& operator = ( const SelectedRegion &other );
+   
+   // Returns true iff the bounds got swapped
+   bool setTimes(double t0, double t1);
+
+   // Returns true iff the bounds got swapped
+   bool setT0(double t, bool maySwap = true);
+
+   // Returns true iff the bounds got swapped
+   bool setT1(double t, bool maySwap = true);
+
+   void collapseToT0();
+
+   void collapseToT1();
+
+   void move(double delta);
+
+   // Returns true iff the bounds got swapped
+   bool setFrequencies(double f0, double f1);
+
+   // Returns true iff the bounds got swapped
+   bool setF0(double f, bool maySwap = true);
+
+   // Returns true iff the bounds got swapped
+   bool setF1(double f, bool maySwap = true);
+
+private:
+   void Notify();
+
+   SelectedRegion mRegion;
+};
+
 // See big pictorial comment in TrackPanel.cpp for explanation of these numbers
 enum : int {
    // constants related to y coordinates in the track panel
@@ -117,7 +198,7 @@ public:
 
    // Current selection
 
-   SelectedRegion selectedRegion;
+   NotifyingSelectedRegion selectedRegion;
    PlayRegion playRegion;
 
    // Scroll info

src/effects/Effect.cpp

@@ -1171,14 +1171,14 @@ bool Effect::DoEffect(wxWindow *parent,
                       double projectRate,
                       TrackList *list,
                       TrackFactory *factory,
-                      SelectedRegion *selectedRegion,
+                      NotifyingSelectedRegion &selectedRegion,
                       bool shouldPrompt /* = true */)
 {
-   wxASSERT(selectedRegion->duration() >= 0.0);
+   wxASSERT(selectedRegion.duration() >= 0.0);
 
    mOutputTracks.reset();
 
-   mpSelectedRegion = selectedRegion;
+   mpSelectedRegion = &selectedRegion;
    mFactory = factory;
    mProjectRate = projectRate;
    mTracks = list;
@@ -1218,8 +1218,8 @@ bool Effect::DoEffect(wxWindow *parent,
       newTrack->SetSelected(true);
    }
 
-   mT0 = selectedRegion->t0();
-   mT1 = selectedRegion->t1();
+   mT0 = selectedRegion.t0();
+   mT1 = selectedRegion.t1();
    if (mT1 > mT0)
    {
       // there is a selection: let's fit in there...
@@ -1237,8 +1237,8 @@ bool Effect::DoEffect(wxWindow *parent,
       : NumericConverter::DefaultSelectionFormat();
 
 #ifdef EXPERIMENTAL_SPECTRAL_EDITING
-   mF0 = selectedRegion->f0();
-   mF1 = selectedRegion->f1();
+   mF0 = selectedRegion.f0();
+   mF1 = selectedRegion.f1();
    wxArrayString Names;
    if( mF0 != SelectedRegion::UndefinedFrequency )
       Names.push_back(wxT("control-f0"));
@@ -1280,7 +1280,7 @@ bool Effect::DoEffect(wxWindow *parent,
 
    if (returnVal && (mT1 >= mT0 ))
    {
-      selectedRegion->setTimes(mT0, mT1);
+      selectedRegion.setTimes(mT0, mT1);
    }
 
    success = returnVal;
@@ -1289,10 +1289,11 @@ bool Effect::DoEffect(wxWindow *parent,
 
 bool Effect::Delegate( Effect &delegate, wxWindow *parent, bool shouldPrompt)
 {
-   SelectedRegion region{ mT0, mT1 };
+   NotifyingSelectedRegion region;
+   region.setTimes( mT0, mT1 );
 
    return delegate.DoEffect( parent, mProjectRate, mTracks, mFactory,
-      &region, shouldPrompt );
+      region, shouldPrompt );
 }
 
 // All legacy effects should have this overridden

src/effects/Effect.h

@@ -43,6 +43,7 @@ class AudacityCommand;
 
 class AudacityProject;
 class LabelTrack;
+class NotifyingSelectedRegion;
 class ProgressDialog;
 class SelectedRegion;
 class EffectUIHost;
@@ -257,7 +258,7 @@ class AUDACITY_DLL_API Effect /* not final */ : public wxEvtHandler,
    // have the "selected" flag set to true, which is consistent with
    // Audacity's standard UI.
    /* not virtual */ bool DoEffect(wxWindow *parent, double projectRate, TrackList *list,
-                 TrackFactory *factory, SelectedRegion *selectedRegion,
+                 TrackFactory *factory, NotifyingSelectedRegion &selectedRegion,
                  bool shouldPrompt = true);
 
    bool Delegate( Effect &delegate, wxWindow *parent, bool shouldPrompt);
@@ -459,7 +460,7 @@ protected:
    double         mProjectRate; // Sample rate of the project - NEW tracks should
                                // be created with this rate...
    double         mSampleRate;
-   SelectedRegion *mpSelectedRegion{};
+   wxWeakRef<NotifyingSelectedRegion> mpSelectedRegion{};
    TrackFactory   *mFactory;
    const TrackList *inputTracks() const { return mTracks; }
    std::shared_ptr<TrackList> mOutputTracks; // used only if CopyInputTracks() is called.

src/effects/EffectManager.cpp

@@ -166,7 +166,7 @@ void EffectManager::UnregisterEffect(const PluginID & ID)
    EffectManager & em = EffectManager::Get();
 
    success = em.DoEffect(ID, &window, rate,
-      &tracks, &trackFactory, &selectedRegion,
+      &tracks, &trackFactory, selectedRegion,
       (flags & EffectManager::kConfigured) == 0);
 
    if (!success)
@@ -239,7 +239,7 @@ bool EffectManager::DoEffect(const PluginID & ID,
                              double projectRate,
                              TrackList *list,
                              TrackFactory *factory,
-                             SelectedRegion *selectedRegion,
+                             NotifyingSelectedRegion &selectedRegion,
                              bool shouldPrompt /* = true */)
 
 {

src/effects/EffectManager.h

@@ -41,6 +41,8 @@ class EffectRack;
 class AudacityCommand;
 
 
+class NotifyingSelectedRegion;
+
 class AUDACITY_DLL_API EffectManager
 {
 public:
@@ -88,7 +90,7 @@ public:
                  double projectRate,
                  TrackList *list,
                  TrackFactory *factory,
-                 SelectedRegion *selectedRegion,
+                 NotifyingSelectedRegion &selectedRegion,
                  bool shouldPrompt = true);
 
    wxString GetEffectFamilyName(const PluginID & ID);

src/tracks/labeltrack/ui/LabelGlyphHandle.cpp

@@ -124,7 +124,7 @@ LabelGlyphHandle::~LabelGlyphHandle()
 void LabelGlyphHandle::HandleGlyphClick
 (LabelTrackHit &hit, const wxMouseEvent & evt,
  const wxRect & r, const ZoomInfo &zoomInfo,
- SelectedRegion *WXUNUSED(newSel))
+ NotifyingSelectedRegion &WXUNUSED(newSel))
 {
    if (evt.ButtonDown())
    {
@@ -188,7 +188,7 @@ UIHandle::Result LabelGlyphHandle::Click
 
    auto &viewInfo = ViewInfo::Get( *pProject );
    HandleGlyphClick(
-      *mpHit, event, mRect, viewInfo, &viewInfo.selectedRegion);
+      *mpHit, event, mRect, viewInfo, viewInfo.selectedRegion);
 
    if (! mpHit->mIsAdjustingLabel )
    {
@@ -278,7 +278,7 @@ bool LabelGlyphHandle::HandleGlyphDragRelease
 (AudacityProject &project,
  LabelTrackHit &hit, const wxMouseEvent & evt,
  wxRect & r, const ZoomInfo &zoomInfo,
- SelectedRegion *newSel)
+ NotifyingSelectedRegion &newSel)
 {
    const auto pTrack = mpLT;
    const auto &mLabels = pTrack->GetLabels();
@@ -340,7 +340,7 @@ bool LabelGlyphHandle::HandleGlyphDragRelease
          auto selIndex = view.GetSelectedIndex( project );
          //Set the selection region to be equal to
          //the NEW size of the label.
-         *newSel = mLabels[ selIndex ].selectedRegion;
+         newSel = mLabels[ selIndex ].selectedRegion;
       }
       pTrack->SortLabels();
    }
@@ -356,7 +356,7 @@ UIHandle::Result LabelGlyphHandle::Drag
    const wxMouseEvent &event = evt.event;
    auto &viewInfo = ViewInfo::Get( *pProject );
    HandleGlyphDragRelease(
-      *pProject, *mpHit, event, mRect, viewInfo, &viewInfo.selectedRegion);
+      *pProject, *mpHit, event, mRect, viewInfo, viewInfo.selectedRegion);
 
    // Refresh all so that the change of selection is redrawn in all tracks
    return result | RefreshCode::RefreshAll | RefreshCode::DrawOverlays;
@@ -377,7 +377,7 @@ UIHandle::Result LabelGlyphHandle::Release
    const wxMouseEvent &event = evt.event;
    auto &viewInfo = ViewInfo::Get( *pProject );
    if (HandleGlyphDragRelease(
-         *pProject, *mpHit, event, mRect, viewInfo, &viewInfo.selectedRegion)) {
+         *pProject, *mpHit, event, mRect, viewInfo, viewInfo.selectedRegion)) {
       ProjectHistory::Get( *pProject ).PushState(_("Modified Label"),
          _("Label Edit"),
          UndoPush::CONSOLIDATE);

src/tracks/labeltrack/ui/LabelGlyphHandle.h

@@ -16,7 +16,7 @@ Paul Licameli split from TrackPanel.cpp
 class wxMouseState;
 class LabelTrack;
 class LabelTrackEvent;
-class SelectedRegion;
+class NotifyingSelectedRegion;
 class ZoomInfo;
 
 /// mEdge:
@@ -92,12 +92,12 @@ private:
    void HandleGlyphClick
       (LabelTrackHit &hit,
        const wxMouseEvent & evt, const wxRect & r, const ZoomInfo &zoomInfo,
-       SelectedRegion *newSel);
+       NotifyingSelectedRegion &newSel);
    bool HandleGlyphDragRelease
       (AudacityProject &project,
        LabelTrackHit &hit,
        const wxMouseEvent & evt, wxRect & r, const ZoomInfo &zoomInfo,
-       SelectedRegion *newSel);
+       NotifyingSelectedRegion &newSel);
 
    void MayAdjustLabel
       ( LabelTrackHit &hit,

src/tracks/labeltrack/ui/LabelTextHandle.cpp

@@ -78,7 +78,7 @@ void LabelTextHandle::HandleTextClick(AudacityProject &
                                                               ,
    const wxMouseEvent & evt,
    const wxRect & r, const ZoomInfo &zoomInfo,
-   SelectedRegion *newSel)
+   NotifyingSelectedRegion &newSel)
 {
    auto pTrack = mpLT.lock();
    if (!pTrack)
@@ -94,7 +94,7 @@ void LabelTextHandle::HandleTextClick(AudacityProject &
       if ( selIndex != -1 ) {
          const auto &mLabels = pTrack->GetLabels();
          const auto &labelStruct = mLabels[ selIndex ];
-         *newSel = labelStruct.selectedRegion;
+         newSel = labelStruct.selectedRegion;
 
          if (evt.LeftDown()) {
             // Find the NEW drag end
@@ -135,7 +135,7 @@ void LabelTextHandle::HandleTextClick(AudacityProject &
             if (!LabelTrackView::OverTextBox(&labelStruct, evt.m_x, evt.m_y))
                view.SetSelectedIndex( -1 );
             double t = zoomInfo.PositionToTime(evt.m_x, r.x);
-            *newSel = SelectedRegion(t, t);
+            newSel = SelectedRegion(t, t);
          }
 #endif
       }
@@ -143,7 +143,7 @@ void LabelTextHandle::HandleTextClick(AudacityProject &
       if (evt.MiddleDown()) {
          // Paste text, making a NEW label if none is selected.
          wxTheClipboard->UsePrimarySelection(true);
-         view.PasteSelectedText(project, newSel->t0(), newSel->t1());
+         view.PasteSelectedText(project, newSel.t0(), newSel.t1());
          wxTheClipboard->UsePrimarySelection(false);
       }
 #endif
@@ -169,7 +169,7 @@ UIHandle::Result LabelTextHandle::Click
 
    mSelectedRegion = viewInfo.selectedRegion;
    HandleTextClick( *pProject,
-      event, evt.rect, viewInfo, &viewInfo.selectedRegion );
+      event, evt.rect, viewInfo, viewInfo.selectedRegion );
 
    {
       // IF the user clicked a label, THEN select all other tracks by Label

src/tracks/labeltrack/ui/LabelTextHandle.h

@@ -16,6 +16,7 @@ Paul Licameli split from TrackPanel.cpp
 
 class wxMouseState;
 class LabelTrack;
+class NotifyingSelectedRegion;
 class SelectionStateChanger;
 class ZoomInfo;
 
@@ -59,7 +60,7 @@ private:
    void HandleTextClick
       (AudacityProject &project,
        const wxMouseEvent & evt, const wxRect & r, const ZoomInfo &zoomInfo,
-       SelectedRegion *newSel);
+       NotifyingSelectedRegion &newSel);
    void HandleTextDragRelease(
       AudacityProject &project, const wxMouseEvent & evt);
 

src/tracks/labeltrack/ui/LabelTrackView.cpp

@@ -1336,7 +1336,7 @@ unsigned LabelTrackView::Char(
 
 /// KeyEvent is called for every keypress when over the label track.
 bool LabelTrackView::DoKeyDown(
-   AudacityProject &project, SelectedRegion &newSel, wxKeyEvent & event)
+   AudacityProject &project, NotifyingSelectedRegion &newSel, wxKeyEvent & event)
 {
    // Only track true changes to the label
    bool updated = false;
@@ -1564,7 +1564,7 @@ bool LabelTrackView::DoKeyDown(
 /// OnChar is called for incoming characters -- that's any keypress not handled
 /// by OnKeyDown.
 bool LabelTrackView::DoChar(
-   AudacityProject &project, SelectedRegion &WXUNUSED(newSel),
+   AudacityProject &project, NotifyingSelectedRegion &WXUNUSED(newSel),
    wxKeyEvent & event)
 {
    // Check for modifiers and only allow shift.

src/tracks/labeltrack/ui/LabelTrackView.h

@@ -20,6 +20,7 @@ class LabelStruct;
 class LabelTrack;
 struct LabelTrackEvent;
 struct LabelTrackHit;
+class NotifyingSelectedRegion;
 class SelectedRegion;
 struct TrackPanelDrawingContext;
 class ZoomInfo;
@@ -54,9 +55,9 @@ public:
 
    bool DoCaptureKey( AudacityProject &project, wxKeyEvent &event );
    bool DoKeyDown(
-      AudacityProject &project, SelectedRegion &sel, wxKeyEvent & event);
+      AudacityProject &project, NotifyingSelectedRegion &sel, wxKeyEvent & event);
    bool DoChar(
-      AudacityProject &project, SelectedRegion &sel, wxKeyEvent & event);
+      AudacityProject &project, NotifyingSelectedRegion &sel, wxKeyEvent & event);
 
    //This returns the index of the label we just added.
    int AddLabel(const SelectedRegion &region,