plApplication Class Reference

Base class to be used by applications based on plEngine. More...

#include <Application.h>

Inheritance diagram for plApplication:

Public Types
enum class	Execution { Continue , Quit }
	Defines the possible return values for the plApplication::Run() function. More...

Public Member Functions
	plApplication (plStringView sAppName)
	Constructor.
virtual	~plApplication ()
	Virtual destructor.
void	SetApplicationName (plStringView sAppName)
	Changes the application name.
const plString &	GetApplicationName () const
	Returns the application name.
virtual plResult	BeforeCoreSystemsStartup ()
	This function is called before any kind of engine initialization is done.
virtual void	AfterCoreSystemsStartup ()
	This function is called after basic engine initialization has been done.
virtual void	BeforeHighLevelSystemsShutdown ()
	This function is called after the application main loop has run for the last time, before engine deinitialization.
virtual void	AfterHighLevelSystemsShutdown ()
	Called after plStartup::ShutdownHighLevelSystems() has been executed.
virtual void	BeforeCoreSystemsShutdown ()
	This function is called after the application main loop has run for the last time, before engine deinitialization.
virtual void	AfterCoreSystemsShutdown ()
	This function is called after plStartup::ShutdownCoreSystems() has been called.
virtual void	BeforeEnterBackground ()
	This function is called when an application is moved to the background.
virtual void	BeforeEnterForeground ()
	This function is called whenever an application is resumed from background mode.
virtual Execution	Run ()=0
	Main run function which is called periodically. This function must be overridden.
void	SetReturnCode (plInt32 iReturnCode)
	Sets the value that the application will return to the OS. You can call this function at any point during execution to update the return value of the application. Default is zero.
plInt32	GetReturnCode () const
	Returns the currently set value that the application will return to the OS.
virtual const char *	TranslateReturnCode () const
	If the return code is not zero, this function might be called to get a string to print the error code in human readable form.
void	SetCommandLineArguments (plUInt32 uiArgumentCount, const char **pArguments)
	Will set the command line arguments that were passed to the app by the OS. This is automatically called by PL_APPLICATION_ENTRY_POINT() and PL_CONSOLEAPP_ENTRY_POINT().
plUInt32	GetArgumentCount () const
	Returns the number of command line arguments that were passed to the application.
const char *	GetArgument (plUInt32 uiArgument) const
	Returns one of the command line arguments that was passed to the application.
const char **	GetArgumentsArray () const
	Returns the complete array of command line arguments that were passed to the application.
void	EnableMemoryLeakReporting (bool bEnable)
bool	IsMemoryLeakReportingEnabled () const
virtual void	RequestQuit ()
	Calling this function requests that the application quits after the current invocation of Run() finishes.
PL_ALWAYS_INLINE bool	WasQuitRequested () const
	Returns whether RequestQuit() was called.

Static Public Member Functions
static plApplication *	GetApplicationInstance ()
	Returns the one instance of plApplication that is available.

Protected Attributes
bool	m_bWasQuitRequested = false

Friends
PL_FOUNDATION_DLL_FRIEND void	plRun (plApplication *pApplicationInstance)
	Platform independent run function for main loop based systems (e.g. Win32, ..)
PL_FOUNDATION_DLL_FRIEND plResult	plRun_Startup (plApplication *pApplicationInstance)
	[internal] Called by plRun()
PL_FOUNDATION_DLL_FRIEND void	plRun_MainLoop (plApplication *pApplicationInstance)
	[internal] Called by plRun()
PL_FOUNDATION_DLL_FRIEND void	plRun_Shutdown (plApplication *pApplicationInstance)
	[internal] Called by plRun()

Detailed Description

Base class to be used by applications based on plEngine.

The platform abstraction layer will ensure that the correct functions are called independent of the basic main loop structure (traditional or event-based). Derive an application specific class from plApplication and implement at least the abstract Run() function. Additional virtual functions allow to hook into specific events to run application specific code at the correct times.

Finally pass the name of your derived class to one of the macros PL_APPLICATION_ENTRY_POINT() or PL_CONSOLEAPP_ENTRY_POINT(). Those are used to abstract away the platform specific code to run an application.

A simple example how to get started is as follows:

class plSampleApp : public plApplication
{
public:
 
  virtual void AfterCoreSystemsStartup() override
  {
    // Setup Filesystem, Logging, etc.
  }
 
  virtual void BeforeCoreSystemsShutdown() override
  {
    // Close log file, etc.
  }
 
  virtual plApplication::Execution Run() override
  {
    // Either run a one-time application (e.g. console script) and return plApplication::Quit
    // Or run one update (frame) of your game loop and return plApplication::Continue
 
    return plApplication::Quit;
  }
};
 
PL_APPLICATION_ENTRY_POINT(plSampleApp);

Member Enumeration Documentation

Execution

enum class plApplication::Execution

strong

Defines the possible return values for the plApplication::Run() function.

Enumerator
Continue	The 'Run' function should return this to keep the application running.
Quit	The 'Run' function should return this to quit the application.

Member Function Documentation

AfterCoreSystemsShutdown()

virtual void plApplication::AfterCoreSystemsShutdown ( )

inlinevirtual

This function is called after plStartup::ShutdownCoreSystems() has been called.

It is unlikely that there is any kind of deinitialization left, that can still be run at this point.

AfterCoreSystemsStartup()

virtual void plApplication::AfterCoreSystemsStartup ( )

inlinevirtual

This function is called after basic engine initialization has been done.

plApplication will automatically call plStartup::StartupCoreSystems() to initialize the application. This function can be overridden to do additional application specific initialization. To startup entire subsystems, you should however use the features provided by plStartup and plSubSystem.

Reimplemented in plEngineProcessGameApplication, plFileserverApp, plGameApplicationBase, plPlayerApplication, plShaderCompilerApplication, and plTexConv.

BeforeCoreSystemsShutdown()

virtual void plApplication::BeforeCoreSystemsShutdown ( )

inlinevirtual

This function is called after the application main loop has run for the last time, before engine deinitialization.

Override this function to do application specific deinitialization that still requires a running engine. After this function returns plStartup::ShutdownCoreSystems() is called and thus everything, including allocators, is shut down. To shut down entire subsystems, you should, however, use the features provided by plStartup and plSubSystem.

Reimplemented in plEngineProcessGameApplication, plFileserverApp, plGameApplicationBase, and plTexConv.

BeforeCoreSystemsStartup()

plResult plApplication::BeforeCoreSystemsStartup ( )

virtual

This function is called before any kind of engine initialization is done.

Override this function to be able to configure subsystems, before they are initialized. After this function returns, plStartup::StartupCoreSystems() is automatically called. If you need to set up custom allocators, this is the place to do this.

Reimplemented in plEngineProcessGameApplication, plFileserverApp, plGameApplicationBase, plPlayerApplication, plShaderCompilerApplication, and plTexConv.

BeforeEnterBackground()

virtual void plApplication::BeforeEnterBackground ( )

inlinevirtual

This function is called when an application is moved to the background.

On Windows that might simply mean that the main window lost the focus. On other devices this might mean that the application is not visible at all anymore and might even get shut down later. Override this function to be able to put the application into a proper sleep mode.

BeforeEnterForeground()

virtual void plApplication::BeforeEnterForeground ( )

inlinevirtual

This function is called whenever an application is resumed from background mode.

On Windows that might simply mean that the main window received focus again. On other devices this might mean that the application was suspended and is now active again. Override this function to reload the apps state or other resources, etc.

BeforeHighLevelSystemsShutdown()

virtual void plApplication::BeforeHighLevelSystemsShutdown ( )

inlinevirtual

This function is called after the application main loop has run for the last time, before engine deinitialization.

After this function call, plApplication executes plStartup::ShutdownHighLevelSystems().

Note

plApplication does NOT call plStartup::StartupHighLevelSystems() as it may be a window-less application. This is left to plGameApplicationBase to do. However, it does make sure to shut down the high-level systems, in case they were started.

Reimplemented in plGameApplicationBase.

GetArgumentCount()

plUInt32 plApplication::GetArgumentCount ( ) const

inline

Returns the number of command line arguments that were passed to the application.

Note that the very first command line argument is typically the path to the application itself.

RequestQuit()

void plApplication::RequestQuit ( )

virtual

Calling this function requests that the application quits after the current invocation of Run() finishes.

Sets the m_bWasQuitRequested to true as an indicator for derived application objects to engage shutdown procedures. Can be overridden to implement custom behavior. There is no other logic associated with this function and flag so the respective derived application class has to implement logic to perform the actual quit when this function is called or m_bWasQuitRequested is set to true.

Run()

virtual Execution plApplication::Run ( )

pure virtual

Main run function which is called periodically. This function must be overridden.

Return Execution::Quit when the application should quit. You may set a return code via SetReturnCode() beforehand.

Implemented in plEngineProcessGameApplication, plFileserverApp, plGameApplicationBase, plShaderCompilerApplication, and plTexConv.

Friends And Related Symbol Documentation

plRun

PL_FOUNDATION_DLL_FRIEND void plRun ( plApplication * pApplicationInstance )

friend

Platform independent run function for main loop based systems (e.g. Win32, ..)

This is automatically called by PL_APPLICATION_ENTRY_POINT() and PL_CONSOLEAPP_ENTRY_POINT().

plRun simply calls plRun_Startup(), plRun_MainLoop() and plRun_Shutdown().

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The documentation for this class was generated from the following files:

• Code/Engine/Foundation/Application/Application.h
• Code/Engine/Foundation/Application/Implementation/Application.cpp