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examples/SysLibs/TaskSchedulerExample/taskscheduler.cpp

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// Copyright (c) 2007-2009 Nokia Corporation and/or its subsidiary(-ies).
// All rights reserved.
// This component and the accompanying materials are made available
// under the terms of "Eclipse Public License v1.0"
// which accompanies this distribution, and is available
// at the URL "http://www.eclipse.org/legal/epl-v10.html".
//
// Initial Contributors:
// Nokia Corporation - initial contribution.
//
// Contributors:
//
// Description:
// This is simple example code that demonstrates the use of task scheduler. 
// The code demonstrates how to,
// 1) Connect and register with the task scheduler
// 2) Create a persistent schedule
// 3) Add tasks to it
// 4) Execute the schedule
// 5) Delete the schedules and the tasks associated with them after
// verifying that they are the schedules created by us.
// 6) Create a transient schedule
// 7) Add task to the transient schedule, edit the schedule and execute it
//



#include "taskscheduler.h"
#include <e32std.h>
#include <schinfo.h>
#include <e32base.h>

_LIT(KTaskName,"MyTaskName\n");

_LIT(KTitle, "Task Scheduler example");
_LIT(KTextPressAKey, "\nPress any key to step through the example\n");
_LIT(KExit,"\nPress any key to exit the application");
_LIT(KPressAKey,"\nPress any key to continue\n");

_LIT(KConnect, "\nConnecting the client to the task scheduler server");
_LIT(KRegisterClient,"\nRegistering the client\n");
_LIT(KCreateSchedule,"Creating a persistent schedule\n");
_LIT(KCreateTask,"Creating task for the schedule\n");

_LIT(KPersistentWait,"Waiting for the persistent task to complete. This will take 20 seconds\n");
_LIT(KDone,"Task complete \n");
_LIT(KTransientSchedule,"A transient schedule");
_LIT(KTransientWait,"Waiting for the transient task to complete. This will take 20 seconds\n");

_LIT(KCreateTransient,"\nCreating a transient schedule with non-repeating task\n");
_LIT(KDeleteAllTasks,"\nDeleting all the persistent tasks scheduled by this exe");
_LIT(KDeleteAllSchedules,"\nDeleting all schedules created by this exe\n");
_LIT(KTask, "Number of task(s) scheduled by us is(are) %d\n");
_LIT(KExists, "The tasks scheduled exist\n");
_LIT(KOtherTask,"Error! Unexpected schedules not scheduled by this exe exist\n");

CTaskSchedule* CTaskSchedule::NewLC()
        {
        CTaskSchedule* schedule = new(ELeave) CTaskSchedule();
        CleanupStack::PushL(schedule);
        schedule->ConstructL();
        return schedule;
        }
        
CTaskSchedule::CTaskSchedule()
        {
        }       

void CTaskSchedule::ConstructL()
        {       
        iConsole = Console::NewL(KTitle,TSize(KConsFullScreen,KConsFullScreen));
        iConsole->Printf (KTextPressAKey);
        iConsole->Getch ();
        }

CTaskSchedule::~CTaskSchedule()
        {
        iScheduler.Close();
        iConsole->Printf(KExit);
        iConsole->Getch();
        
        delete iConsole;
        }

void CTaskSchedule::ConnectAndRegisterL()
        {
        
        // Connect to the scheduler server
        iConsole->Printf(KConnect);
        User::LeaveIfError(iScheduler.Connect());
        
        _LIT(KTaskExec,"Taskexecutor");
        TFileName filename;
        filename.Append(KTaskExec);
        
        // Register with the scheduler
        iConsole->Printf(KRegisterClient);
        
        // A priority value
        const TInt priority = 3;
        User::LeaveIfError(iScheduler.Register(filename, priority));
        
        }

void CTaskSchedule::PersistentScheduleL()
        {
        
        iConsole->Printf(KCreateSchedule);              
        TSchedulerItemRef scheduleHandle;
        TTime time;
        time.UniversalTime();
        
        // Assign an offset of 20 seconds. TTimeIntervalMinutes, 
        // TTimeIntervalHours etc can be used for longer offsets.
        time += TTimeIntervalSeconds(20);// 20 secs in future

        TTsTime time2 (time, ETrue);

        iConsole->Printf(KCreateTask);
        CreatePersistentScheduleL(scheduleHandle,time2);

        // Create the task to be scheduled
        TTaskInfo taskInfo;
        
        const TInt priority = 2; 
        const TInt numberOfRepeats = 2;
        // Name of the task
        taskInfo.iName = KTaskName;
        
        // Task priority set by the client. 
        // If the client has two tasks with different priorities, 
        // the task with the higher priority will be executed first.
        taskInfo.iPriority = priority;
        
        // Task repeats twice
        taskInfo.iRepeat = numberOfRepeats;
        
        _LIT(KScheduleType," persistent schedule");
        const TDesC* persistent = &KScheduleType;
        HBufC* data = persistent->AllocLC();
        
        // Add the task
        User::LeaveIfError(iScheduler.ScheduleTask(taskInfo, *data, scheduleHandle.iHandle));
                                
        // Wait for the entry to fire
        iConsole->Printf(KPersistentWait);
        const TInt twentySecs = 20000000;
        User::After(twentySecs); // pause for 20 seconds
        
        // Delete all the persistent schedules created
        DeleteSchedulesL(scheduleHandle, EAllSchedules);

        CleanupStack::PopAndDestroy(1); // data
        
        }

        
void CTaskSchedule::CreatePersistentScheduleL(TSchedulerItemRef& aRef, const TTsTime& aStartTime)
        {
        CArrayFixFlat<TScheduleEntryInfo2>* cSchEntryInfoArray; 
        cSchEntryInfoArray = new CArrayFixFlat<TScheduleEntryInfo2>(1);
        CleanupStack::PushL(cSchEntryInfoArray);

        // Create an hourly schedule with StartTime of aStartTime
        TScheduleEntryInfo2 entry1;
        
        // Set the first instance when the entry will 
        // cause the execution of tasks. 
        entry1.SetStartTime(aStartTime);
        
        // Set the type of interval used between due times 
        // for the scheduled entry
        entry1.SetIntervalType(TIntervalType(EHourly));
        
        // Set the period for which the entry is valid. After 8 hours the 
        // tasks associated with the entry will not be eligible for execution.
        const TInt eightHours = 480; // in minutes 
        entry1.SetValidityPeriod(TTimeIntervalMinutes (eightHours));
        
        // Set the interval between execution of tasks
        // Here the interval is 1 hour because the interval type is hourly.
        const TInt interval = 1;
        entry1.SetInterval(interval);

        cSchEntryInfoArray->AppendL(entry1);
        
        User::LeaveIfError(iScheduler.CreatePersistentSchedule(aRef, *cSchEntryInfoArray));
        CleanupStack::PopAndDestroy(cSchEntryInfoArray);
        
        }
        

void CTaskSchedule::CreateTransientScheduleL()
        {
        iConsole->ClearScreen();

        TSchedulerItemRef ref;
        CArrayFixFlat<TScheduleEntryInfo2>* cSchEntryInfoArray;
        cSchEntryInfoArray = new CArrayFixFlat<TScheduleEntryInfo2>(1);
        
        CleanupStack::PushL(cSchEntryInfoArray);
        ref.iName = KTransientSchedule;
        iConsole->Printf(KCreateTransient);
        
        // Create a schedule entry
        TScheduleEntryInfo2 entry;      
        TTime now;
        
        //      Set the date and time of this TTime to the universal time. 
        now.UniversalTime();
        
        // Assign an offset of 15 seconds. TTimeIntervalMinutes, 
        // TTimeIntervalHours etc can be used for longer offsets.
        TInt offset = 15;
        now += TTimeIntervalSeconds(offset);
        
        // Constructs a TTsTime with a TTime object. 
        // ETrue indicates that TTsTime is UTC based time
        TTsTime time (now, ETrue);
        
        // Set the above time as the first time at which 
        // the entry will cause execution of tasks. 
        entry.SetStartTime(time);
        
        // Set the type of interval used between due times for scheduled entry
        entry.SetIntervalType(TIntervalType(EHourly));
        
        // Set the period for which the entry is valid. 
        // After 2 hours the tasks associated with the entry will not be eligible for execution 
        TInt validity = 120;
        entry.SetValidityPeriod(TTimeIntervalMinutes (validity));
        
        // Set the interval between execution of tasks
        // Here the interval is 1 hour because the interval type is hourly.
        entry.SetInterval(1);
        cSchEntryInfoArray->AppendL(entry);
        
        // Create a transient task to be scheduled
        TTaskInfo taskInfo;
        // Name of the task
        taskInfo.iName = KTransientSchedule;
        // Task id
        const TInt tId = 0;
        taskInfo.iTaskId = tId;
        
        // The task repeats just once
        const TInt numberOfRepeats = 1;
        taskInfo.iRepeat = numberOfRepeats;
        
        // Task priority set by the client. 
        // Where a client has two tasks with different priorities, 
        // the task with the higher priority will be executed first.
        const TInt priority = 2; 
        taskInfo.iPriority = priority;
        
        _LIT(KScheduleType," transient schedule");
        const TDesC* transient = &KScheduleType;
        HBufC* data = transient->AllocLC();
                
        // Schedule the item
        User::LeaveIfError(iScheduler.ScheduleTask(taskInfo, *data, ref, *cSchEntryInfoArray));
        
        // Change the start time and validity duration for the schedule
        offset = 19; // 19 seconds in future
        now += TTimeIntervalSeconds(offset);
        TTsTime newTime (now, ETrue);
        entry.SetStartTime(newTime);
        validity = 300;
        entry.SetValidityPeriod(TTimeIntervalMinutes (validity));
        cSchEntryInfoArray->AppendL(entry);
        
        // Change the transient time based schedule
    User::LeaveIfError(iScheduler.EditSchedule(ref.iHandle, *cSchEntryInfoArray));
        
        CleanupStack::PopAndDestroy(2); // data, CSchEntryInfoArray

        // Check if the tasks scheduled exist
        TBool exists;
        DoesScheduledItemExistL(ref, exists);
        if(!exists)
                {
                User::Leave(KErrNotFound);
                }
        // Wait for the task to fire and complete
        iConsole->Printf(KTransientWait);
        const TInt twentySecs = 20000000;
        User::After(twentySecs); // pause for 20 seconds
        
        iConsole->Printf(KDone);        

        // Transient schedules are deleted automatically once they are executed
        // i.e check for count to be zero in the function being called
        DoesScheduledItemExistL(ref, exists);
        if(exists)
                {
                User::Leave(KErrGeneral);
                }
        }

 void CTaskSchedule::DoesScheduledItemExistL(TSchedulerItemRef &aRef, TBool& aExists)
        // Extract schedule references from the schedule server based on a filter.
        {
        aExists = EFalse;
        CArrayFixFlat<TSchedulerItemRef>* CSchItemRefArray;
        
        CSchItemRefArray = new CArrayFixFlat<TSchedulerItemRef>(3);
        CleanupStack::PushL(CSchItemRefArray);
        
        User::LeaveIfError(iScheduler.GetScheduleRefsL(*CSchItemRefArray, EAllSchedules));
        
        TInt count = CSchItemRefArray->Count();
        for(TInt i = 0; i < count; i++)
                {
                // Get a list of schedules created by this executable
                if(aRef.iHandle == (*CSchItemRefArray)[i].iHandle)
                        {
                        aExists = ETrue;
                        iConsole->Printf(KExists);
                        iConsole->Printf(KTask, count);
                        }
                else
                        {
                        iConsole->Printf(KOtherTask);
                        }
                }

        CleanupStack::PopAndDestroy(); // CSchItemRefArray

        }

void CTaskSchedule::DeleteSchedulesL(TSchedulerItemRef &aRef, TScheduleFilter aFilter)
        {
        CArrayFixFlat<TSchedulerItemRef>* CSchItemRefArray;
        
        CSchItemRefArray = new CArrayFixFlat<TSchedulerItemRef>(3);
        CleanupStack::PushL(CSchItemRefArray);
        
        User::LeaveIfError(iScheduler.GetScheduleRefsL(*CSchItemRefArray, aFilter));
        
        TInt count = CSchItemRefArray->Count();
        iConsole->Printf(KTask, count);
        
        for(TInt i = 0; i < count; i++)
                {
                // Check if the schedules are created by this exe or
                // some other exe
                if(aRef.iHandle == (*CSchItemRefArray)[i].iHandle)
                        {       
                        // Delete the tasks scheduled by us (this exe)
                        iConsole->Printf(KDeleteAllTasks);
                        User::LeaveIfError(iScheduler.DeleteTask(aRef.iHandle));
                        // Delete the schedules created by us (this exe)
                        iConsole->Printf(KDeleteAllSchedules);
                        User::LeaveIfError(iScheduler.DeleteSchedule(aRef.iHandle));
                        
                        iConsole->Printf(KPressAKey);
                        iConsole->Getch();
                                        
                        }
                else
                        {
                        // Not deleting the tasks or schedules as,
                        // they are not created by this exe
                        iConsole->Printf(KOtherTask);
                        }
                }
        CleanupStack::PopAndDestroy(); // CSchItemRefArray
        
        }
        
void MainL()
        {
        // Create an Active Scheduler to handle asychronous calls
        CActiveScheduler* scheduler = new (ELeave) CActiveScheduler;
        CleanupStack::PushL(scheduler);

        // Install the active scheduler
        CActiveScheduler::Install( scheduler );
        CTaskSchedule* app = CTaskSchedule::NewLC();
        
        // Connect and register with the task scheduler
        app->ConnectAndRegisterL();
        
        // Create a persistent schedule and add tasks to it
        app->PersistentScheduleL();
                
        // Create a transient schedule and add tasks to it
        app->CreateTransientScheduleL();
        
        CleanupStack::PopAndDestroy(2); // app, scheduler

        }

TInt E32Main()
        {
    __UHEAP_MARK;
    CTrapCleanup* cleanup = CTrapCleanup::New();
    if(cleanup == NULL)
        {
        return KErrNoMemory;
        }
        
    TRAPD(err, MainL());
        if(err != KErrNone)
                {
                User::Panic(_L("Failed to complete"),err);
                }
    delete cleanup;
  
    __UHEAP_MARKEND;
    return KErrNone;
        }

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Copyright ©2010 Nokia Corporation and/or its subsidiary(-ies).
All rights reserved. Unless otherwise stated, these materials are provided under the terms of the Eclipse Public License v1.0.