/*************************************************************************
 *
 *  $RCSfile: UpdateLockManager.cxx,v $
 *
 *  $Revision: 1.3 $
 *
 *  last change: $Author: obo $ $Date: 2005-04-18 11:16:42 $
 *
 *  The Contents of this file are made available subject to the terms of
 *  either of the following licenses
 *
 *         - GNU Lesser General Public License Version 2.1
 *         - Sun Industry Standards Source License Version 1.1
 *
 *  Sun Microsystems Inc., October, 2000
 *
 *  GNU Lesser General Public License Version 2.1
 *  =============================================
 *  Copyright 2000 by Sun Microsystems, Inc.
 *  901 San Antonio Road, Palo Alto, CA 94303, USA
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License version 2.1, as published by the Free Software Foundation.
 *
 *  This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 *  MA  02111-1307  USA
 *
 *
 *  Sun Industry Standards Source License Version 1.1
 *  =================================================
 *  The contents of this file are subject to the Sun Industry Standards
 *  Source License Version 1.1 (the "License"); You may not use this file
 *  except in compliance with the License. You may obtain a copy of the
 *  License at http://www.openoffice.org/license.html.
 *
 *  Software provided under this License is provided on an "AS IS" basis,
 *  WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING,
 *  WITHOUT LIMITATION, WARRANTIES THAT THE SOFTWARE IS FREE OF DEFECTS,
 *  MERCHANTABLE, FIT FOR A PARTICULAR PURPOSE, OR NON-INFRINGING.
 *  See the License for the specific provisions governing your rights and
 *  obligations concerning the Software.
 *
 *  The Initial Developer of the Original Code is: Sun Microsystems, Inc.
 *
 *  Copyright: 2000 by Sun Microsystems, Inc.
 *
 *  All Rights Reserved.
 *
 *  Contributor(s): _______________________________________
 *
 *
 ************************************************************************/

#include "UpdateLockManager.hxx"

#include "MutexOwner.hxx"
#include "ViewShellBase.hxx"

#ifndef _COM_SUN_STAR_FRAME_XLAYOUTMANAGER_HPP_
#include <com/sun/star/frame/XLayoutManager.hpp>
#endif
#ifndef _COM_SUN_STAR_FRAME_XLAYOUTMANAGEREVENTBROADCASTER_HPP_
#include <com/sun/star/frame/XLayoutManagerEventBroadcaster.hpp>
#endif
#ifndef _COM_SUN_STAR_FRAME_LAYOUTMANAGEREVENTS_HPP_
#include <com/sun/star/frame/LayoutManagerEvents.hpp>
#endif
#ifndef _COM_SUN_STAR_BEANS_XPROPERTYSET_HPP_
#include <com/sun/star/beans/XPropertySet.hpp>
#endif

#ifndef _CPPUHELPER_COMPBASE1_HXX_
#include <cppuhelper/compbase1.hxx>
#endif

#include <vcl/timer.hxx>
#include <sfx2/viewfrm.hxx>

using namespace ::com::sun::star::uno;
using namespace ::com::sun::star;
using namespace ::rtl;

namespace {
typedef cppu::WeakComponentImplHelper1<frame::XLayoutManagerListener> InterfaceBase;
}

namespace sd {


/** This implementation class not only implements the Lock() and Unlock()
    methods but as well listens for the right combination of events to call
    Unlock() when all is ready after the PaneManager has switched (some of)
    its view shells.
*/

class UpdateLockManager::Implementation
    : protected MutexOwner,
      public InterfaceBase
{
public:
    Implementation (ViewShellBase& rBase);
    virtual ~Implementation (void);

    void Lock (void);
    void Unlock (void);
    bool IsLocked (void) const;

    /** Unlock regardless of the current lock level.
    */
    void ForceUnlock (void);

private:
    ViewShellBase& mrBase;
    /// A lock level greater than 0 indicates that the ViewShellBase is locked.
    sal_Int32 mnLockDepth;
    /// The emergency timer to unlock the ViewShellBase when all else fails.
    Timer maTimer;
    /// Remember when to unlock after a layout event from frame::XLayoutManager
    bool mbUnlockOnNextLayout;
    /// Remember whether we are listening to the frame::XLayoutManager
    bool mbListenerIsRegistered;
    /// Remember whether the frame::XLayoutManager is locked.
    bool mbLayouterIsLocked;
    /** We hold a weak reference to the layout manager in order to have
        access to it even when the ViewShellBase object is not valid anymore
        and can not be used to obtain the layout manager.
    */
    WeakReference<frame::XLayoutManager> mxLayoutManager;

    //=====  frame::XLayoutEventListener  =====================================

    /** The event of the layouter are observed to find the best moment for
        unlocking.  This is the first layout after the lock level of the
        layouter drops to one (we hold a lock to it ourselves which we
        release when unlocking).
    */
    virtual void SAL_CALL layoutEvent (
        const lang::EventObject& xSource,
        sal_Int16 eLayoutEvent,
        const Any& rInfo)
        throw (uno::RuntimeException);

    //=====  lang::XEventListener  ============================================
    virtual void SAL_CALL
        disposing (const lang::EventObject& rEventObject)
        throw (::com::sun::star::uno::RuntimeException);

    virtual void SAL_CALL disposing (void);

    /** This is only a fallback to make the office usable when for some
        reason the intended way of unlocking it failed.
    */
    DECL_LINK(Timeout, void*);

    /** Convenience method that finds the layout manager associated with the
        frame that shows the ViewShellBase.
    */
    Reference<frame::XLayoutManager> GetLayoutManager (void);

    Implementation (const Implementation&); // Not implemented.
    Implementation& operator= (const Implementation&); // Not implemented.
};




//===== UpdateLockManager =====================================================

UpdateLockManager::UpdateLockManager (ViewShellBase& rBase)
    : mpImpl(new Implementation(rBase))
{
    mpImpl->acquire();
}



UpdateLockManager::~UpdateLockManager (void)
{
    if (mpImpl != NULL)
    {
        mpImpl->ForceUnlock();
        mpImpl->release();
    }
}




void UpdateLockManager::Disable (void)
{
    if (mpImpl != NULL)
    {
        mpImpl->ForceUnlock();
        mpImpl->release();
        mpImpl = NULL;
    }
}




void UpdateLockManager::Lock (void)
{
    if (mpImpl != NULL)
        mpImpl->Lock();
}




void UpdateLockManager::Unlock (void)
{
    if (mpImpl != NULL)
        mpImpl->Unlock();
}




bool UpdateLockManager::IsLocked (void) const
{
    if (mpImpl != NULL)
        return mpImpl->IsLocked();
    else
        return false;
}



//===== UpdateLock::Implementation ============================================

UpdateLockManager::Implementation::Implementation (ViewShellBase& rBase)
    : InterfaceBase(maMutex),
      mrBase(rBase),
      mnLockDepth(0),
      maTimer(),
      mbUnlockOnNextLayout(false),
      mbListenerIsRegistered(false),
      mbLayouterIsLocked(false)
{
}




UpdateLockManager::Implementation::~Implementation (void)
{
    OSL_ASSERT(mnLockDepth==0);
    ForceUnlock();
}




void UpdateLockManager::Implementation::Lock (void)
{
    ++mnLockDepth;
    if (mnLockDepth == 1)
    {
        Reference<frame::XLayoutManager> xLayouter (GetLayoutManager());
        if (xLayouter.is())
        {
            // Register as event listener.
            Reference<frame::XLayoutManagerEventBroadcaster> xBroadcaster (
                xLayouter, UNO_QUERY);
            if (xBroadcaster.is())
            {
                mbListenerIsRegistered = true;
                xBroadcaster->addLayoutManagerEventListener(
                    Reference<frame::XLayoutManagerListener> (
                        static_cast<XWeak*>(this), UNO_QUERY) );
            }

            // Lock the layout manager.
            mbLayouterIsLocked = true;
            xLayouter->lock();
        }

        // As a fallback, when the notification mechanism does not work (or is
        // incorrectly used) we use a timer that will unlock us eventually.
        maTimer.SetTimeout(5000 /*ms*/);
        maTimer.SetTimeoutHdl(LINK(this,UpdateLockManager::Implementation,Timeout));
        maTimer.Start();
    }
}




void UpdateLockManager::Implementation::Unlock (void)
{
    --mnLockDepth;

    if (mnLockDepth == 0)
    {
        // Stop the timer.  We don't need it anymore.
        maTimer.Stop();

        try
        {
            Reference<frame::XLayoutManager> xLayouter (GetLayoutManager());
            if (xLayouter.is())
            {
                // Detach from the layouter.
                if (mbListenerIsRegistered)
                {
                    Reference<frame::XLayoutManagerEventBroadcaster> xBroadcaster (
                        xLayouter, UNO_QUERY);
                    if (xBroadcaster.is())
                    {
                        mbListenerIsRegistered = false;
                        xBroadcaster->removeLayoutManagerEventListener(
                            Reference<frame::XLayoutManagerListener> (
                                static_cast<XWeak*>(this), UNO_QUERY) );
                    }
                }

                // Unlock the layouter.
                if (mbLayouterIsLocked)
                {
                    mbLayouterIsLocked = false;
                    xLayouter->unlock();
                }
            }
        }
        catch (RuntimeException)
        { }

        // Force a rearrangement of the UI elements of the views.
        mrBase.Rearrange();
    }
}




bool UpdateLockManager::Implementation::IsLocked (void) const
{
    return (mnLockDepth > 0);
}




void UpdateLockManager::Implementation::ForceUnlock (void)
{
    while (IsLocked())
        Unlock();
}




void SAL_CALL UpdateLockManager::Implementation::layoutEvent (
    const lang::EventObject& xSource,
    sal_Int16 eLayoutEvent,
    const Any& rInfo)
    throw (uno::RuntimeException)
{
    switch (eLayoutEvent)
    {
        case frame::LayoutManagerEvents::LOCK:
        {
            sal_Int32 nLockCount;
            rInfo >>= nLockCount;
        }
        break;

        case frame::LayoutManagerEvents::UNLOCK:
        {
            sal_Int32 nLockCount;
            rInfo >>= nLockCount;
            if (nLockCount == 1)
            {
                // The lock count dropped to one.  This means that we are
                // the only one that still holds a lock to the layout
                // manager.  We unlock the layout manager now and the
                // ViewShellBase on the next layout of the layout manager.
                mbUnlockOnNextLayout = true;
                Reference<frame::XLayoutManager> xLayouter (GetLayoutManager());
                if (xLayouter.is() && mbLayouterIsLocked)
                {
                    mbLayouterIsLocked = false;
                    xLayouter->unlock();
                }
            }
        }
        break;

        case frame::LayoutManagerEvents::LAYOUT:
            // Unlock when the layout manager is not still locked.
            if (mbUnlockOnNextLayout)
                Unlock();
            break;
    }
}




void SAL_CALL UpdateLockManager::Implementation::disposing (const lang::EventObject& rEventObject)
    throw (::com::sun::star::uno::RuntimeException)
{
}




void SAL_CALL UpdateLockManager::Implementation::disposing (void)
{
}




IMPL_LINK(UpdateLockManager::Implementation, Timeout, void*, unused)
{
    // This method is only called when all else failed.  We unlock
    // regardless of how deep the lock depth.
    while (mnLockDepth > 0)
        Unlock();
    return 1;
}




Reference< ::com::sun::star::frame::XLayoutManager>
    UpdateLockManager::Implementation::GetLayoutManager (void)
{
    Reference<frame::XLayoutManager> xLayoutManager;

    if (mxLayoutManager.get() == NULL)
    {
        if (mrBase.GetViewFrame()!=NULL
            && mrBase.GetViewFrame()->GetFrame()!=NULL)
        {
            Reference<beans::XPropertySet> xFrameProperties (
                mrBase.GetViewFrame()->GetFrame()->GetFrameInterface(),
                UNO_QUERY);
            if (xFrameProperties.is())
            {
                try
                {
                    Any aValue (xFrameProperties->getPropertyValue(
                        ::rtl::OUString::createFromAscii("LayoutManager")));
                    aValue >>= xLayoutManager;
                }
                catch (const beans::UnknownPropertyException& rException)
                {
                    (void)rException;
                }
            }
            mxLayoutManager = xLayoutManager;
        }
    }
    else
        xLayoutManager = mxLayoutManager;

    return xLayoutManager;
}




} // end of anonymous namespace