ProjectStatus.h

Go to the documentation of this file.

/**********************************************************************
 
Audacity: A Digital Audio Editor
 
ProjectStatus.h
 
Paul Licameli
 
**********************************************************************/
 
#ifndef __AUDACITY_PROJECT_STATUS__
#define __AUDACITY_PROJECT_STATUS__
#endif
 
#include <utility>
#include <unordered_map>
#include <vector>
#include "ClientData.h" // to inherit
#include "Prefs.h"
#include "Observer.h"
#include "Registry.h"
 
class AudacityProject;
class wxWindow;
 
using StatusBarField = Identifier;
 
PROJECT_API StatusBarField StateStatusBarField();
PROJECT_API StatusBarField MainStatusBarField();
PROJECT_API StatusBarField RateStatusBarField();
 
class PROJECT_API StatusBarFieldItem /* not final */
    : public Registry::SingleItem
{
public:
   explicit StatusBarFieldItem(StatusBarField identifier);
   virtual ~StatusBarFieldItem();
 
   virtual int GetDefaultWidth(const AudacityProject& project) const = 0;
 
   virtual void OnSize(AudacityProject& project);
 
   virtual void SetText(AudacityProject& project, const TranslatableString& msg) = 0;
   virtual TranslatableString GetText(const AudacityProject& project) const = 0;
 
   virtual bool IsVisible(const AudacityProject& project) const = 0;
 
protected:
   void DispatchFieldChanged(const AudacityProject& project);
};
 
struct PROJECT_API StatusBarFieldRegistryTraits final
   : Registry::DefaultTraits
{
   using LeafTypes = List<StatusBarFieldItem>;
};
 
using StatusBarFieldRegistryVisitor = Registry::VisitorFunctions<StatusBarFieldRegistryTraits>;
 
struct PROJECT_API ProjectStatusFieldsRegistry final
{
   static Registry::GroupItem<StatusBarFieldRegistryTraits>& Registry();
   static void Visit(const StatusBarFieldRegistryVisitor& visitor);
   static std::size_t Count(const AudacityProject* project);
   static StatusBarFieldItem* Get(const StatusBarField& identifier);
   static int GetFieldIndex(
      const AudacityProject& project, const StatusBarField& identifier);
   static void OnSize(AudacityProject& project);
 
   static Observer::Subscription
   Subscribe(std::function<void(const AudacityProject&, const StatusBarField&)>
                handler);
};
 
using StatusBarFieldItemRegistrator =
   Registry::RegisteredItem<ProjectStatusFieldsRegistry>;
 
class PROJECT_API ProjectStatus final
   : public ClientData::Base
   , public PrefsListener
   , public Observer::Publisher<StatusBarField>
{
public:
   static ProjectStatus &Get( AudacityProject &project );
   static const ProjectStatus &Get( const AudacityProject &project );
 
   explicit ProjectStatus( AudacityProject &project );
   ProjectStatus( const ProjectStatus & ) = delete;
   ProjectStatus &operator= ( const ProjectStatus & ) = delete;
   ~ProjectStatus() override;
 
   // Type of a function to report translatable strings, and also report an extra
   // margin, to request that the corresponding field of the status bar should
   // be wide enough to contain any of those strings plus the margin.
   using StatusWidthResult = std::pair< std::vector<TranslatableString>, unsigned >;
   using StatusWidthFunction = std::function<
      StatusWidthResult( const AudacityProject &, StatusBarField )
   >;
   using StatusWidthFunctions = std::vector< StatusWidthFunction >;
 
   // Typically a static instance of this struct is used.
   struct PROJECT_API RegisteredStatusWidthFunction
   {
      explicit
      RegisteredStatusWidthFunction( const StatusWidthFunction &function );
   };
 
   static const StatusWidthFunctions &GetStatusWidthFunctions();
 
   TranslatableString Get( StatusBarField field = MainStatusBarField() ) const;
   void Set(const TranslatableString &msg,
      StatusBarField field = MainStatusBarField());
 
   // PrefsListener implementation
   void UpdatePrefs() override;
 
private:
   class ProjectStatusTextField;
   static struct DefaultFieldsRegistrator final
   {
      DefaultFieldsRegistrator();
   } sDefaultFieldsRegistrator;
 
   AudacityProject &mProject;
   std::unordered_map<StatusBarField, TranslatableString> mCurrentStatus;
   Observer::Subscription mFieldChangedSubscription;
};