// Copyright (c) 1996-2009 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:

//

// Window server redraw queue handling

//

#include <e32std.h>

#include "server.h"

#include "rootwin.h"

#include "windowgroup.h"

#include "walkwindowtree.h"

#include "EVQUEUE.H"

#include "panics.h"

#include "wstop.h"

const TInt KGranularity = 10;

void TWsRedrawEvent::SetHandle(TUint aHandle)

	{

	iHandle=aHandle;

	}

void TWsRedrawEvent::SetRect(TRect aRect)

	{

	iRect=aRect;

	}

TWsRedrawEvent CRedrawQueue::iNullRedrawEvent;

CRedrawQueue::CRedrawQueue(CWsClient *aOwner) : CEventBase(aOwner)

	{

	__DECLARE_NAME(_S("CRedrawQueue"));

	}

void CRedrawQueue::ConstructL()

	{

	iRedrawTrigger=EFalse;

	iRedraws=new(ELeave) CArrayFixSeg<TRedraw>(KGranularity);

	iKeyPriority=new(ELeave) TKeyArrayFix(_FOFF(TRedraw,iPriority),ECmpTUint32);

	iKeyWindow=new(ELeave) TKeyArrayFix(_FOFF(TRedraw,iRedraw),ECmpTUint32);

	Mem::FillZ(&iNullRedrawEvent,sizeof(iNullRedrawEvent));

	}

CRedrawQueue::~CRedrawQueue()

	{

	delete iRedraws;

	delete iKeyPriority;

	delete iKeyWindow;

	}

void CRedrawQueue::ReCalcOrder()

	{

	const TInt redrawsCount=iRedraws->Count();

	for(TInt index=0;index<redrawsCount;index++)

		{

		TRedraw *redraw=&iRedraws->At(index);

		redraw->iPriority=static_cast<CWsClientWindow*>(redraw->iRedraw->WsWin())->RedrawPriority();

		}

	iRedraws->Sort(*iKeyPriority);

	}

void CRedrawQueue::AddInvalid(CWsWindowRedraw *aRedrawWin) 

//

// Add a window to the update list.

//

	{

	TInt index;

	TRedraw redraw;

	redraw.iRedraw=aRedrawWin;

	if (iRedraws->Find(redraw,*iKeyWindow,index)!=0)

		{

		redraw.iPriority=static_cast<CWsClientWindow*>(aRedrawWin->WsWin())->RedrawPriority();

		TRAPD(err,iRedraws->InsertIsqAllowDuplicatesL(redraw,*iKeyPriority));

		if (err!=KErrNone)

			{

			WS_ASSERT_DEBUG(err==KErrNoMemory,EWsPanicRedrawQueueError);

			iAllocError=ETrue;

			}

		iRedrawTrigger=ETrue;

		}

	}

void CRedrawQueue::DeleteFromQueue(TInt aIndex)

	{

	iRedraws->Delete(aIndex,1);

	//We are certain we will need iRedraws again, so it would be silly to compress away the last KGranularity slots.

	const TInt count = iRedraws->Count();

	if((count >= KGranularity) && (count % KGranularity == 0))

		{

		iRedraws->Compress();

		}

	}

void CRedrawQueue::RemoveInvalid(CWsWindowRedraw *aRedrawWin)

//

// remove the window from the invalid window list.

// harmless to call if the window is not in the list.

//

	{

	TInt index;

	TRedraw redraw;

	redraw.iRedraw=aRedrawWin;

	redraw.iPriority=0;

	if ((iRedraws->Find(redraw,*iKeyWindow,index))==KErrNone)

		DeleteFromQueue(index);

	}

TBool CRedrawQueue::TriggerRedraw()

//

// Trigger any pending redraw messages in the queue

// Returns ETrue if a redraw was sent, EFalse if not.

//

	{

	TBool ret=EFalse;

	if (iRedrawTrigger)

		{

		iRedrawTrigger=EFalse;

		if (!iEventMsg.IsNull() && (iRedraws->Count()>0 || iAllocError))

			{

			SignalEvent();

			ret=ETrue;

			}

		}

	return(ret);

	}

void CRedrawQueue::EventReady(const RMessagePtr2& aEventMsg)

//

// Queue a read of an event from the queue

//

	{

	CEventBase::EventReady(aEventMsg);

	iRedrawTrigger=ETrue;

	TriggerRedraw();

	}

TBool CRedrawQueue::FindOutstandingRedrawEvent(CWsWindowRedraw& aRedraw, TWsRedrawEvent& aEvent)

	{

	TRect rect;

	if (aRedraw.GetRedrawRect(rect))

		{

		aEvent.SetRect(rect);

		aEvent.SetHandle(aRedraw.WsWin()->ClientHandle());

		CEventBase::GetData(&aEvent,sizeof(aEvent));

		return ETrue;

		}

	return EFalse;

	}

TBool CRedrawQueue::FindWindowNeedingRedrawEvent(TWsRedrawEvent& aEvent)

	{

#if defined(_DEBUG)

	CWsWindowRedraw* previousRedraw = NULL;

#endif

	// search all screens

	TInt invalidWindows = 0;

	for (TInt screenNo = 0; screenNo < CWsTop::NumberOfScreens(); ++screenNo)

		{

		const CScreen* screen = CWsTop::Screen(screenNo);

		WS_ASSERT_ALWAYS(screen, EWsPanicNoScreen);

		CWsRootWindow* rootWindow = screen->RootWindow();

		for (CWsWindowGroup *groupWin = rootWindow->Child(); groupWin; groupWin = groupWin->NextSibling())

			{

			if (groupWin->WsOwner() == iWsOwner)

				{

				CWsWindowRedraw* redrawWin = NULL;

				// use a window tree walk that can be resumed to find windows with an invalid region

				TResumableWalkWindowTreeFindInvalid wwt(&redrawWin);

				groupWin->WalkWindowTree(wwt, EWalkChildren, EFalse);

				while (redrawWin != NULL)

					{

					WS_ASSERT_DEBUG(redrawWin != previousRedraw, EWsPanicRedrawQueueError);

					// (the window may not actually need the client to redraw it, e.g. a CWsBlankWindow can redraw itself)

					if (FindOutstandingRedrawEvent(*redrawWin, aEvent))

						{

						return ETrue;

						}

					else

						{ // continue the Tree Walk

#if defined(_DEBUG)

						previousRedraw = redrawWin;

#endif

						if (redrawWin->NeedsRedraw())

							{ // needs to be redrawn later?

							++invalidWindows;

							}

						redrawWin = NULL;

						groupWin->WalkWindowTree(wwt, EWalkChildren, ETrue);

						}

					}

				}

			}

		}

	if (invalidWindows == 0)

		{ // error recovery is complete

		iAllocError = 0;

		}

	return EFalse;

	}

void CRedrawQueue::GetData()

//

// If there is an outstanding redraw event in the queue, reply with it's data

//

	{

	CWsWindowRedraw *redraw;

	TWsRedrawEvent event;

	while (iRedraws->Count()>0)

		{

		redraw=(*iRedraws)[0].iRedraw;

		if (FindOutstandingRedrawEvent(*redraw,event))

			{

			return;

			}

		TInt toDelete=0;

		if (redraw!=(*iRedraws)[0].iRedraw)

			{		//In low memory conditions calls to FindOutstandingRedrawEvent can cause extra entries to be added to the array

			TRedraw redrawFind;

			redrawFind.iRedraw=redraw;

			iRedraws->Find(redrawFind,*iKeyWindow,toDelete);

			}

		DeleteFromQueue(toDelete);

		}

	if (iAllocError && FindWindowNeedingRedrawEvent(event))

		{

		return;

		}

	CEventBase::GetData(&iNullRedrawEvent,sizeof(iNullRedrawEvent));

	}

TUint CRedrawQueue::RedrawPriority(CWsWindowRedraw *aRedrawWin)

	{

	TInt index;

	TRedraw redraw;

	TUint priority=0;

	redraw.iRedraw=aRedrawWin;

	if ((iRedraws->Find(redraw,*iKeyWindow,index))==KErrNone)

		{

		priority=iRedraws->At(index).iPriority;

		}

	return priority;

	}