/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
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 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * This file incorporates work covered by the following license notice:
 *
 *   Licensed to the Apache Software Foundation (ASF) under one or more
 *   contributor license agreements. See the NOTICE file distributed
 *   with this work for additional information regarding copyright
 *   ownership. The ASF licenses this file to you under the Apache
 *   License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0 .
 */

#pragma once

#include "ShellFactory.hxx"
#include <o3tl/deleter.hxx>
#include <memory>
#include <utility>

class FmFormShell;
class SfxShell;

namespace sd
{
class ViewShell;
class ViewShellBase;

/** The ViewShellManager has the responsibility to manage the view shells
    and sub shells on the SFX shell stack.  They form a two level hierarchy
    (the underlying ViewShellBase, the only true SfxViewShell descendant,
    forms a third level.)  On the first level there are the view shells
    (what formerly was called view shell, anyway; nowadays they are derived
    from SfxShell) and shells for panes. On the second level there are sub
    shells (also derived from SfxShell) that usually are tool bars.

    <p>On the SFX shell stack the regular sub shells are placed above their
    view shells.  The FormShell is a special case.  With the SetFormShell()
    method it can be placed directly above or below one of the view
    shells.</p>

    <p>Shells managed by this class are created by factories or are given
    directly to Activate... methods.  For the sub shells there is one
    factory for every view shell.  Factories are added or removed via the
    (Add|Remove)SubShellFactory() methods.  The FormShell is managed with the
    factory of its view shell.</p>
*/
class ViewShellManager
{
public:
    typedef std::shared_ptr<ShellFactory<SfxShell>> SharedShellFactory;

    ViewShellManager(ViewShellBase& rBase);

    /** Before the destructor is called the method Shutdown() has to have
        been called.
    */
    ~ViewShellManager();

    /** Tell a ViewShellManager object to prepare to be deleted, i.e. to
        destroy all of its resources and to ignore all following calls.
        Use this when the owner of the view shell manager is about being
        destroyed but the view shell manager itself can not yet be deleted.
    */
    void Shutdown();

    /** Set the factory for sub shells of the specified view shell.
    */
    void AddSubShellFactory(ViewShell const* pViewShell, const SharedShellFactory& rpFactory);
    void RemoveSubShellFactory(ViewShell const* pViewShell, const SharedShellFactory& rpFactory);

    /** Activate the given view shell.
    */
    void ActivateViewShell(ViewShell* pViewShell);

    void RemoveOverridingMainShell();
    void SetOverridingMainShell(const std::shared_ptr<ViewShell>& pViewShell);
    std::shared_ptr<ViewShell> GetOverridingMainShell();

    /** Activate the given shell, putting it at the bottom of the stack instead of
        the top.
     */
    void ActivateLowPriorityShell(SfxShell* pShell);

    /** Deactivate the specified shell, i.e. take it and all of its
        object bars from the shell stack.
        @param pShell
            The shell to deactivate.
    */
    void DeactivateViewShell(const ViewShell* pShell);

    /** Deactivate the specified shell.  The shell is not destroyed.
    */
    void DeactivateShell(const SfxShell* pShell);

    /** Associate the form shell with a view shell and their relative
        position.  This method does not change the shell stack, it just
        stores the given values for the next shell stack update.
        @param pParentShell
            The view shell of the form shell.
        @param pFormShell
            The form shell.
        @param bAbove
            When <TRUE/> then the form shell will be placed directly above
            pViewShell on the SFX shell stack.  Otherwise the form shell is
            placed directly below the view shell.
    */
    void SetFormShell(const ViewShell* pParentShell, FmFormShell* pFormShell, bool bAbove);

    /** Activate the specified shell as sub shell for the given view shell.
        The sub shell factory associated with the view shell is used to
        create the sub shell.
        @param rParentShell
            The new sub shell will be placed above this view shell.
        @param nId
            This id is used only with the factory registered for the parent
            view shell.
    */
    void ActivateSubShell(const ViewShell& rParentShell, ShellId nId);

    /** Deactivate the specified sub shell.
    */
    void DeactivateSubShell(const ViewShell& rParentShell, ShellId nId);

    /** Send all sub shells of the specified view shell an Invalidate()
        call.  This does not modify the shell stack.
    */
    void InvalidateAllSubShells(ViewShell const* pViewShell);

    /** Move the specified view shell to the top most position on the stack
        of view shells in relation to the other view shells.  After this the
        only shells that are higher on the stack are its object bars.

        Call this method after a focus change to bring a view mode view
        shell and is associated tool bar shells to the top of the
        stack.

        The mbKeepMainViewShellOnTop flag is not obeyed.

        @param nId
            The id of the shell to move to the top.
    */
    void MoveToTop(const ViewShell& rShell);

    /** Return the first, i.e. top most, view shell that has been activated
        under the given id.
        @param nId
            The id of the shell for which to return a pointer.
        @return
            When the specified shell is currently not active then NULL is
            returned.
    */
    SAL_RET_MAYBENULL SfxShell* GetShell(ShellId nId) const;

    /** Return the top-most shell on the SFX shell stack regardless of
        whether that is a view shell or a sub shell.
    */
    SAL_RET_MAYBENULL SfxShell* GetTopShell() const;

    /** Return the top-most active view shell on the internal shell stack.
    */
    SAL_RET_MAYBENULL SfxShell* GetTopViewShell() const;

    /** Use this class to safely lock updates of the view shell stack.
    */
    class UpdateLock
    {
    public:
        UpdateLock(std::shared_ptr<ViewShellManager> pManager)
            : mpManager(std::move(pManager))
        {
            mpManager->LockUpdate();
        }
        ~UpdateLock() COVERITY_NOEXCEPT_FALSE { mpManager->UnlockUpdate(); }

    private:
        std::shared_ptr<ViewShellManager> mpManager;
    };
    friend class UpdateLock;

private:
    class Implementation;
    std::unique_ptr<ViewShellManager::Implementation,
                    o3tl::default_delete<ViewShellManager::Implementation>>
        mpImpl;
    bool mbValid;

    void LockUpdate();
    void UnlockUpdate();
};

} // end of namespace sd

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