--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/taskswitcher/backstepping/src/tsbackstepping.cpp	Mon Sep 13 13:26:33 2010 +0300
@@ -0,0 +1,242 @@
+/*
+* Copyright (c) 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:
+*
+*/
+
+#include "tsbackstepping.h"
+
+#include <w32std.h>// key event
+#include <apgwgnam.h>// for CApaWindowGroupName
+#include <apgtask.h>
+#include <coedef.h>
+#include <e32property.h>
+#include <e32debug.h>
+
+#include <homescreendomainpskeys.h>
+#include <afactivitylauncher.h>
+
+#include "tsbacksteppingfilter.h"
+
+_LIT(KHsActivactionUri, "appto://20022F35?activityname=HsIdleView&activityinbackground=true");
+
+// -----------------------------------------------------------------------------
+/** 
+ *  CTsBackstepping::NewL
+ *  two phase constructor
+ */
+CTsBackstepping* CTsBackstepping::NewL( MTsWindowGroupsMonitor& aMonitor )
+    {
+    CTsBackstepping* self = CTsBackstepping::NewLC( aMonitor );
+    CleanupStack::Pop( self );
+    return self;
+    }
+
+// -----------------------------------------------------------------------------
+/** 
+ *  CTsBackstepping::NewLC
+ *  two phase constructor
+ */
+CTsBackstepping* CTsBackstepping::NewLC( MTsWindowGroupsMonitor& aMonitor )
+    { 
+    CTsBackstepping* self = new (ELeave) CTsBackstepping( aMonitor );
+    CleanupStack::PushL( self );
+    self->ConstructL();
+    return self;
+    }
+
+// -----------------------------------------------------------------------------
+/** 
+ * CTsBackstepping::CTsBackstepping
+ * constructor
+ */
+CTsBackstepping::CTsBackstepping( MTsWindowGroupsMonitor &aMonitor )
+:
+CTsWindowGroupsObserver( aMonitor )
+    {
+    }
+
+// -----------------------------------------------------------------------------
+/** 
+ *  CTsBackstepping::~CTsBackstepping
+ *  deconstructor
+ */
+CTsBackstepping::~CTsBackstepping()
+    {
+    delete iFilter;
+    }
+
+// -----------------------------------------------------------------------------
+/** 
+ *  CTsBackstepping::ConstructL
+ *  two phase constructor
+ */
+void CTsBackstepping::ConstructL ()
+    {
+    BaseConstructL();
+    iFilter = CTsBacksteppingFilter::NewL();
+    }
+
+// -----------------------------------------------------------------------------
+/** 
+ * CTsBackstepping::AnalyseWindowStackL
+ * Analyzes window stack and move homescreen to proper position
+ */
+void CTsBackstepping::HandleWindowGroupChanged( 
+               MTsResourceManager &aResource, 
+               const TArray<RWsSession::TWindowGroupChainInfo> &aWindowGroups )
+    {
+    RDebug::Print(_L("[Backstepping] started"));
+    TRAP_IGNORE( HandleWindowGroupChangedL( aResource, aWindowGroups ) );
+    RDebug::Print(_L("[Backstepping] finished"));
+    }
+
+// -----------------------------------------------------------------------------
+/** 
+ * CTsBackstepping::AnalyseWindowStackL
+ * Analyzes window stack and move homescreen to proper position
+ */
+void CTsBackstepping::HandleWindowGroupChangedL( 
+                MTsResourceManager& aResource,
+                const TArray<RWsSession::TWindowGroupChainInfo>& aWindowGroups )
+    {
+    // calculate the desired position of Homescreen
+    const TInt currentHsOffset( HomescreenOffsetL( aResource, aWindowGroups ) );
+    TInt optimalOffset(1);
+    TInt targetHsOffset(currentHsOffset);
+    for( TInt offset(0); offset < currentHsOffset; ++offset ) 
+        {
+        TUid uid = GetUidFromWindowGroupL( aResource, 
+                                           aWindowGroups[offset].iId );
+        RDebug::Print(_L("[Backstepping] application: %d"), uid.iUid);
+                                           
+        if( TUid::Null() != uid )
+            {
+            if( IsEmbededApp( aWindowGroups[offset] ) )
+                {
+                targetHsOffset = ParentOffsetL( offset, aWindowGroups ) + 1;
+                } 
+            else if (!iFilter->isBlocked(uid))
+                {
+                if(offset + 1 < currentHsOffset && 
+                   GetUidFromWindowGroupL( aResource, aWindowGroups[offset+1].iId) == TUid::Null() ) 
+                    {
+                    ++optimalOffset;
+                    }
+                targetHsOffset = optimalOffset;
+                }
+            break;
+            } 
+        else
+            {
+            ++optimalOffset;
+            }
+        }
+
+    // switch Homescreen to Idle state if Homescreen is not in foreground and is in different state
+    if( 0 != targetHsOffset)
+        {
+        TInt hsState( EHomeScreenIdleState );
+        User::LeaveIfError(RProperty::Get( KHsCategoryUid, 
+                                           KHsCategoryStateKey, 
+                                           hsState ) );
+        if(!(hsState & EHomeScreenWidgetViewActive ) )
+            {
+            RDebug::Print(_L("[Backstepping] about to switch HS activity"));
+            
+            CAfActivityLauncher *activityEnabler = 
+                CAfActivityLauncher::NewLC( aResource.ApaSession(), 
+                                            aResource.WsSession() );
+            activityEnabler->launchActivityL( KHsActivactionUri );
+            CleanupStack::PopAndDestroy( activityEnabler );
+            }
+        }
+    // change windows order if necessary
+    if(targetHsOffset != currentHsOffset)
+        {
+        RDebug::Print(_L("[Backstepping] about to change window groups order"));
+        
+        const TInt hsWindowGroup( aWindowGroups[currentHsOffset].iId );
+        aResource.WsSession().SetWindowGroupOrdinalPosition( hsWindowGroup, 
+                                                             targetHsOffset );
+        }
+    }
+
+// -----------------------------------------------------------------------------
+/** 
+ * CTsBackstepping::HomescreenOffsetL
+ */
+TInt CTsBackstepping::HomescreenOffsetL( 
+        MTsResourceManager& aResource,
+        const TArray<RWsSession::TWindowGroupChainInfo>& aWindowGroups ) const 
+    {
+    TInt offset( KErrNotFound );
+    for( TInt iter(0); KErrNotFound == offset && iter < aWindowGroups.Count(); ++iter )
+        {
+        if( KHsCategoryUid == GetUidFromWindowGroupL( aResource, aWindowGroups[iter].iId ) )
+            {
+            offset = iter;
+            }
+        }
+    User::LeaveIfError( offset );
+    return offset;
+    }
+
+// -----------------------------------------------------------------------------
+/** 
+ * CTsBackstepping::ParentOffsetL
+ */
+TInt CTsBackstepping::ParentOffsetL( 
+        TInt aOffset,
+        const TArray<RWsSession::TWindowGroupChainInfo>& aWindowGroups )const 
+    {
+    for( TInt iter(aOffset + 1); iter < aWindowGroups.Count(); ++iter )
+        {
+        if(aWindowGroups[iter].iId == aWindowGroups[aOffset].iParentId)
+            {
+            return IsEmbededApp( aWindowGroups[iter] ) ? 
+                   ParentOffsetL( iter, aWindowGroups ) : iter; 
+            }
+        }
+    User::Leave( KErrNotFound) ;
+    return KErrNotFound;
+    }
+
+// -----------------------------------------------------------------------------
+/** 
+ * CTsBackstepping::IsEmbededApp
+ */
+TBool CTsBackstepping::IsEmbededApp( 
+            const RWsSession::TWindowGroupChainInfo &aWindowGroupInfo ) const 
+    {
+    return 0 < aWindowGroupInfo.iParentId;
+    }
+
+// -----------------------------------------------------------------------------
+/** 
+ * CTsBackstepping::GetUidFromWindowGroupL
+ */
+TUid CTsBackstepping::GetUidFromWindowGroupL( MTsResourceManager &aResource, 
+                                              TInt aWindowGroupId ) const
+    {
+    TUid retVal(TUid::Null());
+    CApaWindowGroupName *windowGroupName = 
+            CApaWindowGroupName::NewLC( aResource.WsSession() );
+    windowGroupName->ConstructFromWgIdL( aWindowGroupId );
+    retVal = windowGroupName->AppUid();
+    CleanupStack::PopAndDestroy( windowGroupName );
+    return retVal;
+    }
+
+// end of file