]> git.lyx.org Git - lyx.git/blobdiff - src/Undo.cpp
Update sk.po
[lyx.git] / src / Undo.cpp
index a80c01c701154d6e393f2475759208743d5746b2..4e970df5a03cd4a394a9ef00de7798e6f4f01c1b 100644 (file)
 #include "Undo.h"
 
 #include "Buffer.h"
+#include "BufferList.h"
 #include "BufferParams.h"
-#include "buffer_funcs.h"
-#include "DocIterator.h"
+#include "Cursor.h"
+#include "CutAndPaste.h"
+#include "ErrorList.h"
 #include "Paragraph.h"
 #include "ParagraphList.h"
-#include "ParagraphParameters.h"
 #include "Text.h"
 
-#include "mathed/MathSupport.h"
+#include "mathed/InsetMath.h"
 #include "mathed/MathData.h"
+#include "mathed/MathRow.h"
 
-#include "insets/Inset.h"
+#include "insets/InsetText.h"
 
-#include "support/lassert.h"
 #include "support/debug.h"
+#include "support/lassert.h"
+#include "support/lyxtime.h"
 
 #include <algorithm>
 #include <deque>
+#include <set>
 
 using namespace std;
 using namespace lyx::support;
@@ -61,52 +65,45 @@ structure ('Undo') _before_ it is changed in some edit operation.
 Obviously, the stored range should be as small as possible. However,
 there is a lower limit: The StableDocIterator stored in the undo class
 must be valid after the changes, too, as it will used as a pointer
-where to insert the stored bits when performining undo. 
+where to insert the stored bits when performining undo.
 */
 struct UndoElement
 {
        ///
-       UndoElement(UndoKind kin, StableDocIterator const & cb, 
+       UndoElement(UndoKind kin, CursorData const & cb,
                    StableDocIterator const & cel,
-                   pit_type fro, pit_type en, ParagraphList * pl, 
-                   MathData * ar, BufferParams const & bp, 
-                   bool ifb, bool lc, size_t gid) :
-               kind(kin), cur_before(cb), cell(cel), from(fro), end(en),
-               pars(pl), array(ar), bparams(0), isFullBuffer(ifb),
-               lyx_clean(lc), group_id(gid)
-       {
-               if (isFullBuffer)
-                       bparams = new BufferParams(bp);
-       }
+                   pit_type fro, pit_type en, ParagraphList * pl, MathData * ar,
+                   bool lc, size_t gid) :
+               cur_before(cb), cell(cel), from(fro), end(en),
+               pars(pl), array(ar), bparams(nullptr),
+               group_id(gid), time(current_time()), kind(kin), lyx_clean(lc)
+               {}
        ///
-       UndoElement(UndoElement const & ue)
-       {
-               kind = ue.kind;
-               cur_before = ue.cur_before;
-               cur_after = ue.cur_after;
-               cell = ue.cell;
-               from = ue.from;
-               end = ue.end;
-               pars = ue.pars;
-               array = ue.array;
-               bparams = ue.isFullBuffer
-                       ? new BufferParams(*ue.bparams) : ue.bparams;
-               isFullBuffer = ue.isFullBuffer;
-               lyx_clean = ue.lyx_clean;
-               group_id = ue.group_id;
-       }
+       UndoElement(CursorData const & cb, BufferParams const & bp,
+                               bool lc, size_t gid) :
+               cur_before(cb), cell(), from(0), end(0),
+               pars(nullptr), array(nullptr), bparams(new BufferParams(bp)),
+               group_id(gid), time(current_time()), kind(ATOMIC_UNDO), lyx_clean(lc)
+       {}
+       ///
+       UndoElement(UndoElement const & ue) :
+               cur_before(ue.cur_before), cur_after(ue.cur_after),
+               cell(ue.cell), from(ue.from), end(ue.end),
+               pars(ue.pars), array(ue.array),
+               bparams(ue.bparams ? new BufferParams(*ue.bparams) : nullptr),
+               group_id(ue.group_id), time(current_time()), kind(ue.kind),
+               lyx_clean(ue.lyx_clean)
+               {}
        ///
        ~UndoElement()
        {
-               if (isFullBuffer)
+               if (bparams)
                        delete bparams;
        }
-       /// Which kind of operation are we recording for?
-       UndoKind kind;
        /// the position of the cursor before recordUndo
-       StableDocIterator cur_before;
+       CursorData cur_before;
        /// the position of the cursor at the end of the undo group
-       StableDocIterator cur_after;
+       CursorData cur_after;
        /// the position of the cell described
        StableDocIterator cell;
        /// counted from begin of cell
@@ -117,21 +114,23 @@ struct UndoElement
        ParagraphList * pars;
        /// the contents of the saved MathData (for mathed)
        MathData * array;
-       /// Only used in case of full backups
+       /// Only used in case of params undo
        BufferParams const * bparams;
-       /// Only used in case of full backups
-       bool isFullBuffer;
-       /// Was the buffer clean at this point?
-       bool lyx_clean;
        /// the element's group id
        size_t group_id;
+       /// timestamp
+       time_t time;
+       /// Which kind of operation are we recording for?
+       UndoKind kind;
+       /// Was the buffer clean at this point?
+       bool lyx_clean;
 private:
        /// Protect construction
-       UndoElement();  
+       UndoElement();
 };
 
 
-class UndoElementStack 
+class UndoElementStack
 {
 public:
        /// limit is the maximum size of the stack
@@ -160,20 +159,24 @@ public:
        /// Push an item on to the stack, deleting the bottom group on
        /// overflow.
        void push(UndoElement const & v) {
-               c_.push_front(v);
-               if (c_.size() > limit_) {
+               // Remove some entries if the limit has been reached.
+               // However, if the only group on the stack is the one
+               // we are currently populating, do nothing.
+               if (c_.size() >= limit_
+                   && c_.front().group_id != v.group_id) {
                        // remove a whole group at once.
                        const size_t gid = c_.back().group_id;
                        while (!c_.empty() && c_.back().group_id == gid)
                                c_.pop_back();
                }
+               c_.push_front(v);
        }
 
        /// Mark all the elements of the stack as dirty
        void markDirty() {
                for (size_t i = 0; i != c_.size(); ++i)
                        c_[i].lyx_clean = false;
-       }               
+       }
 
 private:
        /// Internal contents.
@@ -185,30 +188,32 @@ private:
 
 struct Undo::Private
 {
-       Private(Buffer & buffer) : buffer_(buffer), undo_finished_(true), 
-                                  group_id(0), group_level(0) {}
-       
+       Private(Buffer & buffer) : buffer_(buffer),
+               group_id_(0), group_level_(0), undo_finished_(true) {}
+
        // Do one undo/redo step
-       void doTextUndoOrRedo(DocIterator & cur, UndoElementStack & stack, 
+       void doUndoRedoAction(CursorData & cur, UndoElementStack & stack,
                              UndoElementStack & otherStack);
        // Apply one undo/redo group. Returns false if no undo possible.
-       bool textUndoOrRedo(DocIterator & cur, bool isUndoOperation);
+       bool undoRedoAction(CursorData & cur, bool isUndoOperation);
 
        ///
        void doRecordUndo(UndoKind kind,
                DocIterator const & cell,
                pit_type first_pit,
                pit_type last_pit,
-               StableDocIterator const & cur,
-               bool isFullBuffer,
+               CursorData const & cur,
                UndoElementStack & stack);
        ///
        void recordUndo(UndoKind kind,
                DocIterator const & cell,
                pit_type first_pit,
                pit_type last_pit,
-               DocIterator const & cur,
-               bool isFullBuffer);
+               CursorData const & cur);
+       ///
+       void doRecordUndoBufferParams(CursorData const & cur, UndoElementStack & stack);
+       ///
+       void recordUndoBufferParams(CursorData const & cur);
 
        ///
        Buffer & buffer_;
@@ -217,13 +222,16 @@ struct Undo::Private
        /// Redo stack.
        UndoElementStack redostack_;
 
+       /// Current group Id.
+       size_t group_id_;
+       /// Current group nesting nevel.
+       size_t group_level_;
+       /// the position of cursor before the group was created
+       CursorData group_cur_before_;
+
        /// The flag used by Undo::finishUndo().
        bool undo_finished_;
 
-       /// Current group Id.
-       size_t group_id;
-       /// Current group nesting nevel.
-       size_t group_level;
 };
 
 
@@ -250,8 +258,10 @@ void Undo::clear()
        d->undostack_.clear();
        d->redostack_.clear();
        d->undo_finished_ = true;
-       d->group_id = 0;
-       d->group_level = 0;
+       // We used to do that, but I believe it is better to keep
+       // groups (only used in Buffer::reload for now (JMarc)
+       //d->group_id_ = 0;
+       //d->group_level_ = 0;
 }
 
 
@@ -271,7 +281,7 @@ void Undo::markDirty()
 {
        d->undo_finished_ = true;
        d->undostack_.markDirty();
-       d->redostack_.markDirty();      
+       d->redostack_.markDirty();
 }
 
 
@@ -292,13 +302,12 @@ static bool samePar(StableDocIterator const & i1, StableDocIterator const & i2)
 void Undo::Private::doRecordUndo(UndoKind kind,
        DocIterator const & cell,
        pit_type first_pit, pit_type last_pit,
-       StableDocIterator const & cur_before,
-       bool isFullBuffer,
+       CursorData const & cur_before,
        UndoElementStack & stack)
 {
-       if (!group_level) {
+       if (!group_level_) {
                LYXERR0("There is no group open (creating one)");
-               ++group_id;
+               ++group_id_;
        }
 
        if (first_pit > last_pit)
@@ -312,22 +321,25 @@ void Undo::Private::doRecordUndo(UndoKind kind,
        if (!undo_finished_
            && kind != ATOMIC_UNDO
            && !stack.empty()
+           && !stack.top().bparams
            && samePar(stack.top().cell, cell)
            && stack.top().kind == kind
            && stack.top().from == from
-           && stack.top().end == end) {
+           && stack.top().end == end
+           && stack.top().cur_after == cur_before
+           && current_time() - stack.top().time <= 2) {
                // reset cur_after; it will be filled correctly by endUndoGroup.
-               stack.top().cur_after = StableDocIterator();
+               stack.top().cur_after = CursorData();
+               // update the timestamp of the undo element
+               stack.top().time = current_time();
                return;
        }
 
-       if (isFullBuffer)
-               LYXERR(Debug::UNDO, "Create full buffer undo element of group " << group_id);
-       else
-               LYXERR(Debug::UNDO, "Create undo element of group " << group_id);
+       LYXERR(Debug::UNDO, "Create undo element of group " << group_id_);
        // create the position information of the Undo entry
-       UndoElement undo(kind, cur_before, cell, from, end, 0, 0, 
-                        buffer_.params(), isFullBuffer, buffer_.isClean(), group_id);
+       UndoElement undo(kind,
+             group_cur_before_.empty() ? cur_before : group_cur_before_,
+             cell, from, end, nullptr, nullptr, buffer_.isClean(), group_id_);
 
        // fill in the real data to be saved
        if (cell.inMathed()) {
@@ -339,21 +351,12 @@ void Undo::Private::doRecordUndo(UndoKind kind,
                // main Text _is_ the whole document.
                // record the relevant paragraphs
                Text const * text = cell.text();
-               LASSERT(text, /**/);
+               LBUFERR(text);
                ParagraphList const & plist = text->paragraphs();
                ParagraphList::const_iterator first = plist.begin();
                advance(first, first_pit);
                ParagraphList::const_iterator last = plist.begin();
                advance(last, last_pit + 1);
-               // If the paragraphs after the last one have a
-               // non-zero depth and the depth of last paragraph is
-               // decremented, then these paragraphs may be affected
-               // (ticket #8159). We guard against that by saving
-               // these extra paragraphs.
-               while (last != plist.end() && last->params().depth() > 0) {
-                       ++last;
-                       --undo.end;
-               }
                undo.pars = new ParagraphList(first, last);
        }
 
@@ -366,14 +369,52 @@ void Undo::Private::doRecordUndo(UndoKind kind,
 void Undo::Private::recordUndo(UndoKind kind,
                               DocIterator const & cell,
                               pit_type first_pit, pit_type last_pit,
-                              DocIterator const & cur,
-                              bool isFullBuffer)
+                              CursorData const & cur)
 {
-       LASSERT(first_pit <= cell.lastpit(), /**/);
-       LASSERT(last_pit <= cell.lastpit(), /**/);
+       LASSERT(first_pit <= cell.lastpit(), return);
+       LASSERT(last_pit <= cell.lastpit(), return);
+
+       if (buffer_.isReadonly())
+               return;
 
        doRecordUndo(kind, cell, first_pit, last_pit, cur,
-               isFullBuffer, undostack_);
+               undostack_);
+
+       // next time we'll try again to combine entries if possible
+       undo_finished_ = false;
+
+       // If we ran recordUndo, it means that we plan to change the buffer
+       buffer_.markDirty();
+
+       redostack_.clear();
+}
+
+
+void Undo::Private::doRecordUndoBufferParams(CursorData const & cur_before,
+                                             UndoElementStack & stack)
+{
+       if (!group_level_) {
+               LYXERR0("There is no group open (creating one)");
+               ++group_id_;
+       }
+
+       LYXERR(Debug::UNDO, "Create full buffer undo element of group " << group_id_);
+       // create the position information of the Undo entry
+       UndoElement undo(group_cur_before_.empty() ? cur_before : group_cur_before_,
+                     buffer_.params(), buffer_.isClean(),
+                                        group_id_);
+
+       // push the undo entry to undo stack
+       stack.push(undo);
+}
+
+
+void Undo::Private::recordUndoBufferParams(CursorData const & cur)
+{
+       if (buffer_.isReadonly())
+               return;
+
+       doRecordUndoBufferParams(cur, undostack_);
 
        // next time we'll try again to combine entries if possible
        undo_finished_ = false;
@@ -382,13 +423,10 @@ void Undo::Private::recordUndo(UndoKind kind,
        buffer_.markDirty();
 
        redostack_.clear();
-       //lyxerr << "undostack:\n";
-       //for (size_t i = 0, n = buf.undostack().size(); i != n && i < 6; ++i)
-       //      lyxerr << "  " << i << ": " << buf.undostack()[i] << endl;
 }
 
 
-void Undo::Private::doTextUndoOrRedo(DocIterator & cur, UndoElementStack & stack, UndoElementStack & otherstack)
+void Undo::Private::doUndoRedoAction(CursorData & cur, UndoElementStack & stack, UndoElementStack & otherstack)
 {
        // Adjust undo stack and get hold of current undo data.
        UndoElement & undo = stack.top();
@@ -399,37 +437,42 @@ void Undo::Private::doTextUndoOrRedo(DocIterator & cur, UndoElementStack & stack
        // We will store in otherstack the part of the document under 'undo'
        DocIterator cell_dit = undo.cell.asDocIterator(&buffer_);
 
-       doRecordUndo(ATOMIC_UNDO, cell_dit,
-               undo.from, cell_dit.lastpit() - undo.end, undo.cur_after,
-               undo.isFullBuffer, otherstack);
+       if (undo.bparams)
+               doRecordUndoBufferParams(undo.cur_after, otherstack);
+       else {
+               LATTEST(undo.end <= cell_dit.lastpit());
+               doRecordUndo(ATOMIC_UNDO, cell_dit,
+                                        undo.from, cell_dit.lastpit() - undo.end, undo.cur_after,
+                                        otherstack);
+       }
        otherstack.top().cur_after = undo.cur_before;
 
        // This does the actual undo/redo.
        //LYXERR0("undo, performing: " << undo);
        DocIterator dit = undo.cell.asDocIterator(&buffer_);
-       if (undo.isFullBuffer) {
-               LASSERT(undo.pars, /**/);
-               // This is a full document
+       if (undo.bparams) {
+               // This is a params undo element
                delete otherstack.top().bparams;
                otherstack.top().bparams = new BufferParams(buffer_.params());
+               DocumentClassConstPtr olddc = buffer_.params().documentClassPtr();
                buffer_.params() = *undo.bparams;
-               swap(buffer_.paragraphs(), *undo.pars);
-               delete undo.pars;
-               undo.pars = 0;
+               cap::switchBetweenClasses(olddc, buffer_.params().documentClassPtr(),
+                       static_cast<InsetText &>(buffer_.inset()));
        } else if (dit.inMathed()) {
                // We stored the full cell here as there is not much to be
                // gained by storing just 'a few' paragraphs (most if not
                // all math inset cells have just one paragraph!)
                //LYXERR0("undo.array: " << *undo.array);
-               LASSERT(undo.array, /**/);
+               LBUFERR(undo.array);
                dit.cell().swap(*undo.array);
+               dit.inset().setBuffer(buffer_);
                delete undo.array;
-               undo.array = 0;
+               undo.array = nullptr;
        } else {
                // Some finer machinery is needed here.
                Text * text = dit.text();
-               LASSERT(text, /**/);
-               LASSERT(undo.pars, /**/);
+               LBUFERR(text);
+               LBUFERR(undo.pars);
                ParagraphList & plist = text->paragraphs();
 
                // remove new stuff between first and last
@@ -450,14 +493,25 @@ void Undo::Private::doTextUndoOrRedo(DocIterator & cur, UndoElementStack & stack
                for (; pit != end; ++pit)
                        pit->setInsetOwner(dit.realInset());
                plist.insert(first, undo.pars->begin(), undo.pars->end());
+
+               // set the buffers for insets we created
+               ParagraphList::iterator fpit = plist.begin();
+               advance(fpit, undo.from);
+               ParagraphList::iterator fend = fpit;
+               advance(fend, undo.pars->size());
+               for (; fpit != fend; ++fpit)
+                       fpit->setInsetBuffers(buffer_);
+
                delete undo.pars;
-               undo.pars = 0;
+               undo.pars = nullptr;
        }
-       LASSERT(undo.pars == 0, /**/);
-       LASSERT(undo.array == 0, /**/);
 
-       if (undo.cur_before.size())
-               cur = undo.cur_before.asDocIterator(&buffer_);
+       // We'll clean up in release mode.
+       LASSERT(undo.pars == nullptr, undo.pars = nullptr);
+       LASSERT(undo.array == nullptr, undo.array = nullptr);
+
+       if (!undo.cur_before.empty())
+               cur = undo.cur_before;
        if (undo.lyx_clean)
                buffer_.markClean();
        else
@@ -467,8 +521,11 @@ void Undo::Private::doTextUndoOrRedo(DocIterator & cur, UndoElementStack & stack
 }
 
 
-bool Undo::Private::textUndoOrRedo(DocIterator & cur, bool isUndoOperation)
+bool Undo::Private::undoRedoAction(CursorData & cur, bool isUndoOperation)
 {
+       if (buffer_.isReadonly())
+               return false;
+
        undo_finished_ = true;
 
        UndoElementStack & stack = isUndoOperation ?  undostack_ : redostack_;
@@ -481,10 +538,7 @@ bool Undo::Private::textUndoOrRedo(DocIterator & cur, bool isUndoOperation)
 
        const size_t gid = stack.top().group_id;
        while (!stack.empty() && stack.top().group_id == gid)
-               doTextUndoOrRedo(cur, stack, otherstack);
-
-       // Adapt the new material to current buffer.
-       buffer_.setBuffersForInsets(); // FIXME This shouldn't be here.
+               doUndoRedoAction(cur, stack, otherstack);
        return true;
 }
 
@@ -496,95 +550,151 @@ void Undo::finishUndo()
 }
 
 
-bool Undo::textUndo(DocIterator & cur)
+bool Undo::undoAction(CursorData & cur)
 {
-       return d->textUndoOrRedo(cur, true);
+       return d->undoRedoAction(cur, true);
 }
 
 
-bool Undo::textRedo(DocIterator & cur)
+bool Undo::redoAction(CursorData & cur)
 {
-       return d->textUndoOrRedo(cur, false);
+       return d->undoRedoAction(cur, false);
 }
 
 
 void Undo::beginUndoGroup()
 {
-       if (d->group_level == 0) {
+       if (d->group_level_ == 0) {
                // create a new group
-               ++d->group_id;
-               LYXERR(Debug::UNDO, "+++++++Creating new group " << d->group_id);
+               ++d->group_id_;
+               LYXERR(Debug::UNDO, "+++++++ Creating new group " << d->group_id_
+                      << " for buffer " << &d->buffer_);
        }
-       ++d->group_level;
+       ++d->group_level_;
+}
+
+
+void Undo::beginUndoGroup(CursorData const & cur_before)
+{
+       beginUndoGroup();
+       if (d->group_cur_before_.empty())
+               d->group_cur_before_ = cur_before;
 }
 
 
 void Undo::endUndoGroup()
 {
-       if (d->group_level == 0)
+       if (d->group_level_ == 0) {
                LYXERR0("There is no undo group to end here");
-       --d->group_level;
-       if (d->group_level == 0) {
+               return;
+       }
+       --d->group_level_;
+       if (d->group_level_ == 0) {
                // real end of the group
-               LYXERR(Debug::UNDO, "-------End of group " << d->group_id);
+               d->group_cur_before_ = CursorData();
+               LYXERR(Debug::UNDO, "------- End of group " << d->group_id_
+                      << " of buffer " << &d->buffer_);
        }
 }
 
 
-void Undo::endUndoGroup(DocIterator const & cur)
+void Undo::endUndoGroup(CursorData const & cur_after)
 {
        endUndoGroup();
-       if (!d->undostack_.empty() && !d->undostack_.top().cur_after.size())
-               d->undostack_.top().cur_after = cur;
+       if (!d->undostack_.empty() && d->undostack_.top().cur_after.empty())
+               d->undostack_.top().cur_after = cur_after;
 }
 
 
-// FIXME: remove these convenience functions and make
-// Private::recordUndo public as sole interface. The code in the
-// convenience functions can move to Cursor.cpp.
+void Undo::splitUndoGroup(CursorData const & cur)
+{
+       size_t const level = d->group_level_;
+       d->group_level_ = 1;
+       endUndoGroup(cur);
+       beginUndoGroup(cur);
+       d->group_level_ = level;
+}
+
 
-void Undo::recordUndo(DocIterator const & cur, UndoKind kind)
+bool Undo::activeUndoGroup() const
 {
-       d->recordUndo(kind, cur, cur.pit(), cur.pit(), cur, false);
+       return d->group_level_ > 0
+               && !d->undostack_.empty()
+               && d->undostack_.top().group_id == d->group_id_;
 }
 
 
-void Undo::recordUndoInset(DocIterator const & cur, UndoKind kind,
-                          Inset const * inset)
+void Undo::recordUndo(CursorData const & cur, UndoKind kind)
+{
+       d->recordUndo(kind, cur, cur.pit(), cur.pit(), cur);
+}
+
+
+void Undo::recordUndo(CursorData const & cur, pit_type from, pit_type to)
+{
+       d->recordUndo(ATOMIC_UNDO, cur, from, to, cur);
+}
+
+
+void Undo::recordUndoInset(CursorData const & cur, Inset const * inset)
 {
        if (!inset || inset == &cur.inset()) {
                DocIterator c = cur;
                c.pop_back();
-               d->recordUndo(kind, c, c.pit(), c.pit(), cur, false);
+               d->recordUndo(ATOMIC_UNDO, c, c.pit(), c.pit(), cur);
        } else if (inset == cur.nextInset())
-               recordUndo(cur, kind);
+               recordUndo(cur);
        else
                LYXERR0("Inset not found, no undo stack added.");
 }
 
 
-void Undo::recordUndo(DocIterator const & cur, UndoKind kind, pit_type from)
+void Undo::recordUndoBufferParams(CursorData const & cur)
 {
-       d->recordUndo(kind, cur, cur.pit(), from, cur, false);
+       d->recordUndoBufferParams(cur);
 }
 
 
-void Undo::recordUndo(DocIterator const & cur, UndoKind kind,
-       pit_type from, pit_type to)
-{
-       d->recordUndo(kind, cur, from, to, cur, false);
-}
-
-
-void Undo::recordUndoFullDocument(DocIterator const & cur)
+void Undo::recordUndoFullBuffer(CursorData const & cur)
 {
        // This one may happen outside of the main undo group, so we
        // put it in its own subgroup to avoid complaints.
        beginUndoGroup();
-       d->recordUndo(ATOMIC_UNDO, doc_iterator_begin(&d->buffer_), 
-                     0, d->buffer_.paragraphs().size() - 1, cur, true);
+       d->recordUndo(ATOMIC_UNDO, doc_iterator_begin(&d->buffer_),
+                     0, d->buffer_.paragraphs().size() - 1, cur);
+       d->recordUndoBufferParams(cur);
        endUndoGroup();
 }
 
+/// UndoGroupHelper class stuff
+
+class UndoGroupHelper::Impl {
+       friend class UndoGroupHelper;
+       set<Buffer *> buffers_;
+};
+
+
+UndoGroupHelper::UndoGroupHelper(Buffer * buf) : d(new UndoGroupHelper::Impl)
+{
+       resetBuffer(buf);
+}
+
+
+UndoGroupHelper::~UndoGroupHelper()
+{
+       for (Buffer * buf : d->buffers_)
+               if (theBufferList().isLoaded(buf) || theBufferList().isInternal(buf))
+                       buf->undo().endUndoGroup();
+       delete d;
+}
+
+void UndoGroupHelper::resetBuffer(Buffer * buf)
+{
+       if (buf && d->buffers_.count(buf) == 0) {
+               d->buffers_.insert(buf);
+               buf->undo().beginUndoGroup();
+       }
+}
+
 
 } // namespace lyx