libreoffice/svx/source/accessibility/AccessibleParaManager.hxx

/*************************************************************************
 *
 *  OpenOffice.org - a multi-platform office productivity suite
 *
 *  $RCSfile: AccessibleParaManager.hxx,v $
 *
 *  $Revision: 1.10 $
 *
 *  last change: $Author: rt $ $Date: 2006-01-13 17:18:08 $
 *
 *  The Contents of this file are made available subject to
 *  the terms of GNU Lesser General Public License Version 2.1.
 *
 *
 *    GNU Lesser General Public License Version 2.1
 *    =============================================
 *    Copyright 2005 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
 *
 ************************************************************************/

#ifndef _SVX_ACCESSIBLE_PARA_MANAGER_HXX
#define _SVX_ACCESSIBLE_PARA_MANAGER_HXX

#include <vector>
#include <algorithm>
#include <functional>
#include <utility>

#ifndef _SV_GEN_HXX
#include <tools/gen.hxx>
#endif

#ifndef _COM_SUN_STAR_AWT_RECTANGLE_HPP_
#include <com/sun/star/awt/Rectangle.hpp>
#endif

#ifndef _COM_SUN_STAR_UNO_REFERENCE_HXX_
#include <com/sun/star/uno/Reference.hxx>
#endif
#ifndef _CPPUHELPER_WEAKREF_HXX_
#include <cppuhelper/weakref.hxx>
#endif

#ifndef _COM_SUN_STAR_ACCESSIBILITY_XACCESSIBLECONTEXT_HPP_
#include <com/sun/star/accessibility/XAccessibleContext.hpp>
#endif

class SvxEditSourceAdapter;

namespace accessibility
{
    class AccessibleEditableTextPara;

    /** Helper class for WeakCppRef

        This class is returned by WeakChild::get() and contains a hard
        reference and a reference to the c++ object. This combination
        prevents the c++ object from destruction during usage. Hold
        this object only as long as absolutely necessary, prevents
        referenced object from vanishing otherwise
    */
    template < class UnoType, class CppType > class HardCppRef
    {
    public:

        typedef UnoType UnoInterfaceType;
        typedef CppType InterfaceType;

        HardCppRef( const ::com::sun::star::uno::WeakReference< UnoInterfaceType >& xRef, InterfaceType* rImpl ) :
            mxRef( xRef ),
            mpImpl( rImpl )
        {
        }

        /** Query whether the reference is still valid.

            Hands off also from the implementation pointer if this
            returns sal_False!
         */
        sal_Bool is() const { return mxRef.is(); }
        InterfaceType* operator->() const { return mpImpl; }
        InterfaceType& operator*() const { return *mpImpl; }
        ::com::sun::star::uno::Reference< UnoInterfaceType >& getRef() { return mxRef; }
        const ::com::sun::star::uno::Reference< UnoInterfaceType >& getRef() const { return mxRef; }

        // default copy constructor and assignment will do
        // HardCppRef( const HardCppRef& );
        // HardCppRef& operator= ( const HardCppRef& );

    private:

        // the interface, hard reference to prevent object from vanishing
        ::com::sun::star::uno::Reference< UnoInterfaceType >    mxRef;

        // the c++ object, for our internal stuff
        InterfaceType*                                          mpImpl;

    };

    /** Helper class for weak object references plus implementation

        This class combines a weak reference (to facilitate automatic
        object disposal if user drops last reference) and hard
        reference to the c++ class (for fast access and bypassing of
        the UNO interface)
    */
    template < class UnoType, class CppType > class WeakCppRef
    {
    public:

        typedef UnoType UnoInterfaceType;
        typedef CppType InterfaceType;
        typedef HardCppRef< UnoInterfaceType, InterfaceType >  HardRefType;

        WeakCppRef() : maWeakRef(), maUnsafeRef( NULL ) {}
        WeakCppRef( InterfaceType& rImpl ) :
            maWeakRef( ::com::sun::star::uno::Reference< UnoInterfaceType >( rImpl, ::com::sun::star::uno::UNO_QUERY ) ),
            maUnsafeRef( &rImpl )
        {
        }

        WeakCppRef( HardRefType& rImpl ) :
            maWeakRef( rImpl.getRef() ),
            maUnsafeRef( rImpl.operator->() )
        {
        }

        // get object with c++ object and hard reference (which
        // prevents the c++ object from destruction during use)
        HardRefType get() const { return HardRefType( maWeakRef, maUnsafeRef ); }

        // default copy constructor and assignment will do
        // WeakCppRef( const WeakCppRef& );
        // WeakCppRef& operator= ( const WeakCppRef& );

    private:

        // the interface, hold weakly
        ::com::sun::star::uno::WeakReference< UnoInterfaceType >    maWeakRef;

        // hard ref to c++ class, _only_ valid if maWeakRef.is() is true
        InterfaceType*                                              maUnsafeRef;
    };


    /** This class manages the paragraphs of an AccessibleTextHelper

        To facilitate automatic deletion of paragraphs no longer used,
        this class uses the WeakCppRef helper to hold the objects weakly.
     */
    class AccessibleParaManager
    {
    public:
        typedef WeakCppRef < ::com::sun::star::accessibility::XAccessible, AccessibleEditableTextPara > WeakPara;
        typedef ::std::pair< WeakPara, ::com::sun::star::awt::Rectangle > WeakChild;
        typedef ::std::pair< ::com::sun::star::uno::Reference<
            ::com::sun::star::accessibility::XAccessible > , ::com::sun::star::awt::Rectangle > Child;
        typedef ::std::vector< WeakChild > VectorOfChildren;
        typedef ::std::vector< sal_Int16 > VectorOfStates;

        AccessibleParaManager();
        ~AccessibleParaManager();

        /** Sets a vector of additional accessible states.

            The states are passed to every created child object
            (text paragraph). The state values are defined in
            com::sun::star::accessibility::AccessibleStateType.
         */
        void SetAdditionalChildStates( const VectorOfStates& rChildStates );

        /** Returns the additional accessible states for children.
         */
        const VectorOfStates& GetAdditionalChildStates() const;

        /** Set the number of paragraphs

            @param nNumPara
            The total number of paragraphs the EditEngine currently
            has (_not_ the number of currently visible children)
         */
        void SetNum( sal_uInt32 nNumParas );

        /** Get the number of paragraphs currently possible */
        sal_uInt32 GetNum() const;

        // iterators
        VectorOfChildren::iterator begin();
        VectorOfChildren::iterator end();
        VectorOfChildren::const_iterator begin() const;
        VectorOfChildren::const_iterator end() const;

        // dealing with single paragraphs (release reference, return reference etc)
        void Release( sal_uInt32 nPara );
        /// Set focus to given child
        void SetFocus( sal_Int32 nChild );

        void FireEvent( sal_uInt32 nPara,
                        const sal_Int16 nEventId,
                        const ::com::sun::star::uno::Any& rNewValue = ::com::sun::star::uno::Any(),
                        const ::com::sun::star::uno::Any& rOldValue = ::com::sun::star::uno::Any() ) const;

        static sal_Bool IsReferencable( WeakPara::HardRefType aChild );
        sal_Bool IsReferencable( sal_uInt32 nChild ) const;
        static void ShutdownPara( const WeakChild& rChild );

        Child CreateChild( sal_Int32                                                                                        nChild,
                           const ::com::sun::star::uno::Reference< ::com::sun::star::accessibility::XAccessible >& xFrontEnd,
                           SvxEditSourceAdapter&                                                                            rEditSource,
                           sal_uInt32                                                                                       nParagraphIndex );

        WeakChild GetChild( sal_uInt32 nParagraphIndex ) const;

        // forwarder to all paragraphs
        /// Make all children active and editable (or off)
        void SetActive( sal_Bool bActive = sal_True );
        /// Set state of all children
        void SetState( const sal_Int16 nStateId );
        /// Unset state of all children
        void UnSetState( const sal_Int16 nStateId );
        /// Set offset to edit engine for all children
        void SetEEOffset        ( const Point& rOffset );
        /// Change edit source on all living children
        void SetEditSource      ( SvxEditSourceAdapter* pEditSource );
        /// Dispose all living children
        void Dispose            ();

        // forwarder to given paragraphs
        //------------------------------------------------------------------------
        /** Release the given range of paragraphs

            All ranges have the meaning [start,end), similar to STL

            @param nStartPara
            Index of paragraph to start with releasing

            @param nEndPara
            Index of first paragraph to stop with releasing
         */
        void Release( sal_uInt32 nStartPara, sal_uInt32 nEndPara );

        /** Fire event for the given range of paragraphs

            All ranges have the meaning [start,end), similar to STL

            @param nStartPara
            Index of paragraph to start with event firing

            @param nEndPara
            Index of first paragraph to stop with event firing
         */
        void FireEvent( sal_uInt32 nStartPara,
                        sal_uInt32 nEndPara,
                        const sal_Int16 nEventId,
                        const ::com::sun::star::uno::Any& rNewValue = ::com::sun::star::uno::Any(),
                        const ::com::sun::star::uno::Any& rOldValue = ::com::sun::star::uno::Any() ) const;

        /** Functor adapter for ForEach template

            Adapts giving functor such that only the paragraph objects
            are accessed and the fact that our children are held
            weakly is hidden

            The functor must provide the following method:
            void operator() ( AccessibleEditablePara& )

        */
        template < typename Functor > class WeakChildAdapter : public ::std::unary_function< const WeakChild&, void >
        {
        public:
            WeakChildAdapter( Functor& rFunctor ) : mrFunctor(rFunctor) {}
            void operator()( const WeakChild& rPara )
            {
                // retrieve hard reference from weak one
                WeakPara::HardRefType aHardRef( rPara.first.get() );

                if( aHardRef.is() )
                    mrFunctor( *aHardRef );
            }

        private:
            Functor& mrFunctor;
        };

        /** Adapter for unary member functions

            Since STL's binder don't work with const& arguments (and
            BOOST's neither, at least on MSVC), have to provide our
            own adapter for unary member functions.

            Create with pointer to member function of
            AccessibleEditableTextPara and the corresponding argument.
         */
        template < typename Argument > class MemFunAdapter : public ::std::unary_function< const WeakChild&, void >
        {
        public:
            typedef void (::accessibility::AccessibleEditableTextPara::*FunctionPointer)( Argument );

            MemFunAdapter( FunctionPointer aFunPtr, Argument aArg ) : maFunPtr(aFunPtr), maArg(aArg) {}
            void operator()( const WeakChild& rPara )
            {
                // retrieve hard reference from weak one
                WeakPara::HardRefType aHardRef( rPara.first.get() );

                if( aHardRef.is() )
                    (*aHardRef.*maFunPtr)( maArg );
            }

        private:
            FunctionPointer maFunPtr;
            Argument maArg;
        };

        /** Generic algorithm on given paragraphs

            Convenience method, that already adapts the given functor with WeakChildAdapter
        */
        template < typename Functor > void ForEach( Functor& rFunctor )
        {
            ::std::for_each( begin(), end(), WeakChildAdapter< Functor >(rFunctor) );
        }

    private:
        /// Set state on given child
        void SetState( sal_Int32 nChild, const sal_Int16 nStateId );
        /// Unset state on given child
        void UnSetState( sal_Int32 nChild, const sal_Int16 nStateId );
        /// Init child with default state (as stored in previous SetFocus and SetActive calls)
        void InitChild( AccessibleEditableTextPara&     rChild,
                        SvxEditSourceAdapter&           rEditSource,
                        sal_Int32                       nChild,
                        sal_uInt32                      nParagraphIndex ) const;

        // vector the size of the paragraph number of the underlying EditEngine
        VectorOfChildren maChildren;

        /// Additional states that will be set at every created child object.
        VectorOfStates maChildStates;

        // cache EE offset for child creation
        Point maEEOffset;

        // which child currently has the focus (-1 for none)
        sal_Int32 mnFocusedChild;

        // whether children are active and editable
        sal_Bool mbActive;
    };

} // end of namespace accessibility

#endif