TB10.1 Example Applications: examples/Base/IPC/Async/Fibonacci1/Fibonacci1.cpp Source File

00001 // Copyright (c) 2000-2009 Nokia Corporation and/or its subsidiary(-ies).
-00002 // All rights reserved.
-00003 // This component and the accompanying materials are made available
-00004 // under the terms of "Eclipse Public License v1.0"
-00005 // which accompanies this distribution, and is available
-00006 // at the URL "http://www.eclipse.org/legal/epl-v10.html".
-00007 //
-00008 // Initial Contributors:
-00009 // Nokia Corporation - initial contribution.
-00010 //
-00011 // Contributors:
-00012 //
-00013 // Description:
-00014 // Example wraps a console in an active object.
-00015 // Calculates Fibonacci number as chosen by the user. Note that, in this
-00016 // example, the calculation is done as part of the console active object's 
-00017 // RunL() and can take a long time to complete. It also means that nothing
-00018 // else can happen (including responding to keyboard events) until the 
-00019 // calculation is complete. 
-00020 //
-00021 
-00022 
-00023 
-00024 #include <e32base.h>
-00025 #include <e32cons.h>
-00026 #include <e32std.h>
-00027 
-00028 
-00029 LOCAL_D CConsoleBase* console;
-00030 
-00031 _LIT(KTxtMainInstructions,"\n\nPress 'F' to start\n      'ESC' to exit.\n");
-00032 
-00034 //
-00035 // -----> CActiveConsole (definition)
-00036 //
-00037 // An abstract class which provides the facility to issue key requests. 
-00038 //
-00040 
-00041 class CActiveConsole : public CActive
-00042         {
-00043 public:
-00044           // Construction
-00045         CActiveConsole(CConsoleBase* aConsole);
-00046         void ConstructL();
-00047 
-00048           // Destruction
-00049         ~CActiveConsole();
-00050 
-00051           // Issue request
-00052         void RequestCharacter();
-00053         
-00054           // Cancel request.
-00055           // Defined as pure virtual by CActive;
-00056           // implementation provided by this class.
-00057         void DoCancel();
-00058 
-00059           // Service completed request.
-00060           // Defined as pure virtual by CActive;
-00061           // implementation provided by this class,
-00062         void RunL();
-00063 
-00064           // Called from RunL() - an implementation must be provided
-00065           // by derived classes to handle the completed request
-00066         virtual void ProcessKeyPress(TChar aChar) = 0; 
-00067           
-00068 protected:
-00069           // Data members defined by this class
-00070         CConsoleBase* iConsole; // A console for reading from
-00071         };
-00072 
-00073 
-00075 //
-00076 // -----> CExampleScheduler (definition)
-00077 //
-00079 
-00080 class CExampleScheduler : public CActiveScheduler
-00081         {
-00082 public:
-00083         void Error (TInt aError) const;
-00084         void WaitForAnyRequest();
-00085         void SetActiveObject(CActiveConsole* aActiveConsole);
-00086 private:
-00087           // data members defined for this class
-00088         CActiveConsole* iActiveConsole;
-00089         };
-00090 
-00091 
-00093 //
-00094 // -----> TFibonacciEngine (definition)
-00095 //
-00096 // This class provides the fibonacci calculation engine
-00097 //
-00099 
-00100 class TFibonacciEngine
-00101         {
-00102 public:
-00103         void Calculate (TInt aTerms) ;
-00104 
-00105         TInt iResult ;
-00106         } ;
-00107 
-00108 
-00110 //
-00111 // -----> CFibonacciApplication (definition)
-00112 //
-00113 // This class encapsulates the fibonacci calculation engine
-00114 //
-00116 
-00117 class CFibonacciApplication : public CActiveConsole
-00118         {
-00119 public:
-00120         CFibonacciApplication(CConsoleBase* aConsole) ;
-00121         void ConstructL();
-00122 
-00123           // Static construction
-00124         static CFibonacciApplication* NewLC(CConsoleBase* aConsole) ;
-00125 
-00126           // service request
-00127         void ProcessKeyPress(TChar aChar) ;
-00128 
-00129 private:
-00130         CConsoleBase* iConsole ;
-00131         TFibonacciEngine iFibonacciEngine ;
-00132         };
-00133 
-00134 
-00136 //
-00137 // -----> CActiveConsole (implementation)
-00138 //
-00140 
-00141 CActiveConsole::CActiveConsole( CConsoleBase* aConsole) 
-00142         : CActive(CActive::EPriorityUserInput)
-00143           // Construct high-priority active object
-00144         {
-00145         iConsole = aConsole;
-00146         __DECLARE_NAME(_S("CActiveConsole"));
-00147 
-00148         }
-00149 
-00150 void CActiveConsole::ConstructL()
-00151         {
-00152           // Add to active scheduler
-00153         CActiveScheduler::Add(this);
-00154         }
-00155 
-00156 CActiveConsole::~CActiveConsole()
-00157         {
-00158         // Make sure we're cancelled
-00159         Cancel();
-00160         }
-00161 
-00162 void  CActiveConsole::DoCancel()
-00163         {
-00164         iConsole->ReadCancel();
-00165         }
-00166 
-00167 void  CActiveConsole::RunL()
-00168         {
-00169           // Handle completed request
-00170         ProcessKeyPress(TChar(iConsole->KeyCode()));
-00171         }
-00172 
-00173 void CActiveConsole::RequestCharacter()
-00174         {
-00175           // A request is issued to the CConsoleBase to accept a
-00176           // character from the keyboard.
-00177         iConsole->Read(iStatus); 
-00178         SetActive();
-00179         }
-00180 
-00181 
-00183 //
-00184 // -----> CExampleScheduler (implementation)
-00185 //
-00187 
-00188 void CExampleScheduler::Error(TInt aError) const
-00189         {
-00190         _LIT(KTxtSchedulerError,"CExampleScheduler - error");
-00191         User::Panic(KTxtSchedulerError,aError);
-00192         }
-00193 
-00194 void CExampleScheduler::WaitForAnyRequest()
-00195         {
-00196         if (!(iActiveConsole->IsActive()))
-00197                 iActiveConsole->RequestCharacter();     
-00198         CActiveScheduler::WaitForAnyRequest();
-00199         }
-00200 
-00201 void CExampleScheduler::SetActiveObject(CActiveConsole* aActiveConsole)
-00202         {
-00203         iActiveConsole = aActiveConsole;
-00204         }
-00205 
-00206 
-00208 // CFibonacciApplication support routine
-00209 //   uses up arrow & down arrow to change number, Enter to select
-00211 
-00212 TInt GetValueFromKeyboard (TInt aInitial, TInt aStep, TInt lowerLimit, TInt upperLimit, const TDesC& aPrompt, CConsoleBase* aConsole)
-00213         {
-00214         TChar input ;
-00215         TInt value = aInitial ;
-00216 
-00217         aConsole->Printf(aPrompt) ;
-00218         do
-00219                 {
-00220                 aConsole->SetPos(0);
-00221                 _LIT(KFormat1,"%d  ");
-00222                 aConsole->Printf(KFormat1, value);
-00223                 input = aConsole->Getch() ;
-00224                 if (input == EKeyUpArrow && value < upperLimit) value = value + aStep ;
-00225                 if (input == EKeyDownArrow && value > lowerLimit) value = value - aStep ;
-00226                 if (input == 'c') value = -1;
-00227                 }
-00228         while (input != EKeyEnter && input != 'c') ;
-00229 
-00230         return value ;
-00231         }
-00232 
-00233 
-00235 //
-00236 // -----> CFibonacciApplication (implementation)
-00237 //
-00239 
-00240 CFibonacciApplication::CFibonacciApplication(CConsoleBase* aConsole )
-00241         : CActiveConsole(aConsole)
-00242           // construct zero-priority active object
-00243         {
-00244         iConsole = aConsole ;
-00245         __DECLARE_NAME(_S("CFibonacciApplication"));
-00246         } 
-00247 
-00248 
-00249 CFibonacciApplication* CFibonacciApplication::NewLC(CConsoleBase* aConsole )
-00250         {
-00251         CFibonacciApplication* self=new (ELeave) CFibonacciApplication(aConsole);
-00252         CleanupStack::PushL(self);
-00253         self->ConstructL();
-00254         return self;
-00255         }
-00256 
-00257 
-00258 void CFibonacciApplication::ConstructL()
-00259         {
-00260           // Add to active scheduler
-00261         CActiveScheduler::Add(this);
-00262           // Make this the active object
-00263         ((CExampleScheduler*)(CActiveScheduler::Current()))->SetActiveObject(this);
-00264         }
-00265 
-00266 
-00267 void CFibonacciApplication::ProcessKeyPress(TChar aChar)
-00268         {
-00269           // if key is ESC 
-00270           //   cancel any outstanding request
-00271           //   stop the scheduler
-00272         if (aChar == EKeyEscape)
-00273                 {
-00274                 CActiveScheduler::Stop();
-00275                 return;
-00276                 }
-00277 
-00278           // If key is "f" or "F"
-00279           //   cancel any outstanding request
-00280           //   issue a fibonacci request.
-00281         if (aChar == 'f' || aChar == 'F') 
-00282                 {
-00283                 _LIT(KTxtStartingFibonacci,"\nStarting Fibonacci....  \n");
-00284                 _LIT(KTxtReturnTermNumber,"\nENTER selects number, and starts calculation\nUP    arrow increases num\nDOWN  arrow decreases num\nC     cancels\n\n");
-00285                 _LIT(KTxtCalculating,"\nCalculating...\n");
-00286                 _LIT(KFormat2,"\nResult : %u \n");
-00287                 _LIT(KTxtCancelled,"Cancelled");
-00288 
-00289                 iConsole->Printf(KTxtStartingFibonacci);
-00290                 
-00291                 TInt iterations = GetValueFromKeyboard(5,1,2,46, KTxtReturnTermNumber, iConsole) ;
-00292                 if (iterations == -1)  // convenient if awkward but allows us to indicate a request to cancel.
-00293                         {
-00294                         iConsole->Printf(KTxtCancelled);
-00295                         iConsole->Printf(KTxtMainInstructions);
-00296                         return;
-00297                         }
-00298 
-00299                 iConsole->Printf(KTxtCalculating);
-00300                 iFibonacciEngine.Calculate(iterations);
-00301                 
-00302                 iConsole->Printf(KFormat2, iFibonacciEngine.iResult) ;
-00303                 iConsole->Printf(KTxtMainInstructions);
-00304                 return;
-00305                 }
-00306 
-00307        // any other key ignore
-00308         _LIT(KTxtNotRecognised,"\nUnwanted key pressed");
-00309         iConsole->Printf(KTxtNotRecognised);
-00310         iConsole->Printf(KTxtMainInstructions);
-00311         }
-00312 
-00314 //
-00315 // -----> TFibonacciEngine (implementation)
-00316 //
-00318 
-00319 void TFibonacciEngine::Calculate (TInt aTerms) 
-00320         {
-00321         TInt iterations = aTerms ;
-00322 
-00323         TInt currentTotal = 1 ;
-00324         TInt previousTotal = 0 ;
-00325         _LIT(KTxtTooManyIterations,"Too many iterations");
-00326         __ASSERT_ALWAYS(iterations<47,User::Panic(KTxtTooManyIterations,iterations));
-00327 
-00328         // if limit not yet reached
-00329         while (iterations-- > 0)        
-00330                 {
-00331                 // calculate next number in series
-00332                 TInt newTotal = currentTotal + previousTotal ;
-00333 
-00334                 // update variables
-00335                 previousTotal = currentTotal ;
-00336                 currentTotal = newTotal ;
-00337 
-00338                 // introduce a delay
-00339                 User::After(1000000) ;
-00340                 }  
-00341 
-00342         iResult = currentTotal ;
-00343 
-00344         } 
-00345 
-00346 
-00348 // This section deals with initialisation and ensuring we have a console active
-00350 
-00351 void doExampleL () ;
-00352 
-00353 void SetupConsoleL();
-00354 
-00355 GLDEF_C TInt E32Main()                          // main function called by E32
-00356     {
-00357         CTrapCleanup* cleanup=CTrapCleanup::New();              // get clean-up stack
-00358         TRAPD(error,SetupConsoleL());                                   // more initialization, then do example
-00359         _LIT(KTxtFibonacciExampleError,"Fibonacci example error");
-00360         __ASSERT_ALWAYS(!error,User::Panic(KTxtFibonacciExampleError,error));
-00361         delete cleanup;                                                                 // destroy clean-up stack
-00362         return 0;                                                                               // and return
-00363     }
-00364 
-00365 void SetupConsoleL()                             // initialize and call example code under cleanup stack
-00366     {
-00367         _LIT(KTxtFibSingActObj,"Single Active Object");
-00368         console=Console::NewL(KTxtFibSingActObj, TSize(KConsFullScreen,KConsFullScreen));
-00369         CleanupStack::PushL(console);
-00370 
-00371         console->Printf(KTxtMainInstructions) ;
-00372         TRAPD(error, doExampleL());                                         // perform example function
-00373         if (error)
-00374                 {
-00375                 _LIT(KFormat3,"failed: leave code=%d");
-00376                 console->Printf(KFormat3, error);
-00377                 }
-00378         _LIT(KTxtPressAnyKey,"[Press any key to exit]");
-00379         console->Printf(KTxtPressAnyKey);
-00380         console->Getch();                                                               // get and ignore character
-00381         CleanupStack::PopAndDestroy();                                  // close console
-00382     }
-00383 
-00384 
-00386 //
-00387 // Do the example
-00388 //
-00390 void doExampleL()
-00391     {
-00392           // Construct and install the active scheduler
-00393         CExampleScheduler*  exampleScheduler = new (ELeave) CExampleScheduler;
-00394 
-00395           // Push onto the cleanup stack
-00396         CleanupStack::PushL(exampleScheduler);
-00397          
-00398           // Install as the active scheduler
-00399         CActiveScheduler::Install(exampleScheduler);
-00400 
-00401           // Create CFibonacciApplication active object.
-00402         CFibonacciApplication* fibonacci = CFibonacciApplication::NewLC(console);
-00403 
-00404           // issue initial request
-00405         fibonacci->RequestCharacter() ;
-00406                         
-00407         // Main part of the program:
-00408         //    wait loop that cycles until ActiveScheduler::Stop called
-00409         CActiveScheduler::Start();
-00410 
-00411         // Remove from the cleanup stack and destroy:
-00412         // 1. the CFibonacciApplication active object.
-00413         // 2. exampleScheduler
-00414         CleanupStack::PopAndDestroy(); 
-00415         CleanupStack::PopAndDestroy(); 
-00416         }
-00417 
-