Fix Mac tabbing to sliders and meters, analogously to buttons...

... And make sure they don't steal focus when clicked or double clicked

src/Menus.cpp

@@ -137,6 +137,8 @@ simplifies construction of menu items.
 #include "tracks/ui/Scrubbing.h"
 #include "prefs/TracksPrefs.h"
 
+#include "widgets/Meter.h"
+
 enum {
    kAlignStartZero = 0,
    kAlignStartSelStart,
@@ -2752,10 +2754,12 @@ void AudacityProject::OnSetRightSelection()
 void AudacityProject::NextOrPrevFrame(bool forward)
 {
    // Focus won't take in a dock unless at least one descendant window
-   // accepts focus.  Tell all AButtons to take focus for the duration of this
+   // accepts focus.  Tell controls to take focus for the duration of this
    // function, only.  Outside of this, they won't steal the focus when
    // clicked.
-   auto temp = AButton::TemporarilyAllowFocus();
+   auto temp1 = AButton::TemporarilyAllowFocus();
+   auto temp2 = ASlider::TemporarilyAllowFocus();
+   auto temp3 = Meter::TemporarilyAllowFocus();
 
 
    // Define the set of windows we rotate among.

src/widgets/AButton.cpp

@@ -247,7 +247,7 @@ void AButton::UseDisabledAsDownHiliteImage(bool flag)
 // this bypasses that limitation
 void AButton::SetFocusFromKbd()
 {
-   auto temp = AButton::TemporarilyAllowFocus();
+   auto temp = TemporarilyAllowFocus();
    SetFocus();
 }
 
@@ -574,6 +574,11 @@ void AButton::SetControl(bool control)
    mWasControlDown = control;
 }
 
+auto AButton::TemporarilyAllowFocus() -> TempAllowFocus {
+   s_AcceptsFocus = true;
+   return std::move(TempAllowFocus{ &s_AcceptsFocus });
+}
+
 #if wxUSE_ACCESSIBILITY
 
 AButtonAx::AButtonAx( wxWindow *window ):

src/widgets/AButton.h

@@ -144,10 +144,7 @@ class AButton final : public wxWindow {
    using TempAllowFocus = std::unique_ptr<bool, Resetter>;
 
  public:
-   static TempAllowFocus TemporarilyAllowFocus() {
-      s_AcceptsFocus = true;
-      return std::move(TempAllowFocus{ &s_AcceptsFocus });
-   }
+   static TempAllowFocus TemporarilyAllowFocus();
 
  private:
 

src/widgets/ASlider.cpp

@@ -1783,6 +1783,22 @@ bool ASlider::IsEnabled() const
    return mLWSlider->GetEnabled();
 }
 
+bool ASlider::s_AcceptsFocus{ false };
+
+auto ASlider::TemporarilyAllowFocus() -> TempAllowFocus {
+   s_AcceptsFocus = true;
+   return std::move(TempAllowFocus{ &s_AcceptsFocus });
+}
+
+// This compensates for a but in wxWidgets 3.0.2 for mac:
+// Couldn't set focus from keyboard when AcceptsFocus returns false;
+// this bypasses that limitation
+void ASlider::SetFocusFromKbd()
+{
+   auto temp = TemporarilyAllowFocus();
+   SetFocus();
+}
+
 #if wxUSE_ACCESSIBILITY
 
 ASliderAx::ASliderAx( wxWindow * window ) :

src/widgets/ASlider.h

@@ -15,6 +15,7 @@
 
 #include "../Experimental.h"
 
+#include "../MemoryX.h"
 #include <wx/defs.h>
 #include <wx/window.h>
 #include <wx/dialog.h>
@@ -264,7 +265,10 @@ class ASlider /* not final */ : public wxPanel
             int orientation = wxHORIZONTAL);
    virtual ~ASlider();
 
-   bool AcceptsFocus() const override { return false; }
+   bool AcceptsFocus() const override { return s_AcceptsFocus; }
+   bool AcceptsFocusFromKeyboard() const override { return true; }
+
+   void SetFocusFromKbd() override;
 
    void GetScroll(float & line, float & page);
    void SetScroll(float line, float page);
@@ -298,6 +302,14 @@ class ASlider /* not final */ : public wxPanel
    bool Enable(bool enable = true);
    bool IsEnabled() const;
 
+private:
+   static bool s_AcceptsFocus;
+   struct Resetter { void operator () (bool *p) const { if(p) *p = false; } };
+   using TempAllowFocus = std::unique_ptr<bool, Resetter>;
+
+public:
+   static TempAllowFocus TemporarilyAllowFocus();
+
  private:
    LWSlider *mLWSlider;
    bool mSliderIsFocused;

src/widgets/Meter.cpp

@@ -2083,6 +2083,23 @@ wxString Meter::Key(const wxString & key) const
    return wxT("/Meter/Output/") + key;
 }
 
+bool Meter::s_AcceptsFocus{ false };
+
+auto Meter::TemporarilyAllowFocus() -> TempAllowFocus {
+   s_AcceptsFocus = true;
+   return std::move(TempAllowFocus{ &s_AcceptsFocus });
+}
+
+// This compensates for a but in wxWidgets 3.0.2 for mac:
+// Couldn't set focus from keyboard when AcceptsFocus returns false;
+// this bypasses that limitation
+void Meter::SetFocusFromKbd()
+{
+   auto temp = TemporarilyAllowFocus();
+   SetFocus();
+}
+
+
 #if wxUSE_ACCESSIBILITY
 
 MeterAx::MeterAx(wxWindow *window):

src/widgets/Meter.h

@@ -113,8 +113,10 @@ class Meter final : public wxPanel
 
    ~Meter();
 
-   bool AcceptsFocus() const override { return false; };
-   bool AcceptsFocusFromKeyboard() const override { return true; };
+   bool AcceptsFocus() const override { return s_AcceptsFocus; }
+   bool AcceptsFocusFromKeyboard() const override { return true; }
+
+   void SetFocusFromKbd() override;
 
    void UpdatePrefs();
    void Clear();
@@ -179,6 +181,14 @@ class Meter final : public wxPanel
    void *SaveState();
    void RestoreState(void *state);
 
+ private:
+   static bool s_AcceptsFocus;
+   struct Resetter { void operator () (bool *p) const { if(p) *p = false; } };
+   using TempAllowFocus = std::unique_ptr<bool, Resetter>;
+
+ public:
+   static TempAllowFocus TemporarilyAllowFocus();
+
  private:
    //
    // Event handlers