Small cleanup in order to improve toc change detection within insets.

[lyx.git] / src / Cursor.cpp

/**
 * \file Cursor.cpp
 * This file is part of LyX, the document processor.
 * Licence details can be found in the file COPYING.
 *
 * \author Alejandro Aguilar Sierra
 * \author Alfredo Braunstein
 * \author Dov Feldstern
 * \author André Pönitz
 * \author Stefan Schimanski
 *
 * Full author contact details are available in file CREDITS.
 */

#include <config.h>

#include "Bidi.h"
#include "Buffer.h"
#include "BufferView.h"
#include "CoordCache.h"
#include "Cursor.h"
#include "CutAndPaste.h"
#include "DispatchResult.h"
#include "Encoding.h"
#include "Font.h"
#include "FuncCode.h"
#include "FuncRequest.h"
#include "Language.h"
#include "LyXFunc.h" // only for setMessage()
#include "LyXRC.h"
#include "paragraph_funcs.h"
#include "Paragraph.h"
#include "ParIterator.h"
#include "Row.h"
#include "Text.h"
#include "TextMetrics.h"
#include "TocBackend.h"

#include "support/lassert.h"
#include "support/debug.h"
#include "support/docstream.h"

#include "insets/InsetTabular.h"
#include "insets/InsetText.h"

#include "mathed/InsetMath.h"
#include "mathed/InsetMathBrace.h"
#include "mathed/InsetMathScript.h"
#include "mathed/MacroTable.h"
#include "mathed/MathData.h"
#include "mathed/MathMacro.h"

#include <boost/bind.hpp>

#include <sstream>
#include <limits>
#include <map>

using namespace std;

namespace lyx {

namespace {

bool positionable(DocIterator const & cursor, DocIterator const & anchor)
{
        // avoid deeper nested insets when selecting
        if (cursor.depth() > anchor.depth())
                return false;

        // anchor might be deeper, should have same path then
        for (size_t i = 0; i < cursor.depth(); ++i)
                if (&cursor[i].inset() != &anchor[i].inset())
                        return false;

        // position should be ok.
        return true;
}


// Find position closest to (x, y) in cell given by iter.
// Used only in mathed
DocIterator bruteFind2(Cursor const & c, int x, int y)
{
        double best_dist = numeric_limits<double>::max();

        DocIterator result;

        DocIterator it = c;
        it.top().pos() = 0;
        DocIterator et = c;
        et.top().pos() = et.top().asInsetMath()->cell(et.top().idx()).size();
        for (size_t i = 0;; ++i) {
                int xo;
                int yo;
                Inset const * inset = &it.inset();
                map<Inset const *, Geometry> const & data =
                        c.bv().coordCache().getInsets().getData();
                map<Inset const *, Geometry>::const_iterator I = data.find(inset);

                // FIXME: in the case where the inset is not in the cache, this
                // means that no part of it is visible on screen. In this case
                // we don't do elaborate search and we just return the forwarded
                // DocIterator at its beginning.
                if (I == data.end()) {
                        it.top().pos() = 0;
                        return it;
                }

                Point o = I->second.pos;
                inset->cursorPos(c.bv(), it.top(), c.boundary(), xo, yo);
                // Convert to absolute
                xo += o.x_;
                yo += o.y_;
                double d = (x - xo) * (x - xo) + (y - yo) * (y - yo);
                // '<=' in order to take the last possible position
                // this is important for clicking behind \sum in e.g. '\sum_i a'
                LYXERR(Debug::DEBUG, "i: " << i << " d: " << d
                        << " best: " << best_dist);
                if (d <= best_dist) {
                        best_dist = d;
                        result = it;
                }
                if (it == et)
                        break;
                it.forwardPos();
        }
        return result;
}


/*
/// moves position closest to (x, y) in given box
bool bruteFind(Cursor & cursor,
        int x, int y, int xlow, int xhigh, int ylow, int yhigh)
{
        LASSERT(!cursor.empty(), return false);
        Inset & inset = cursor[0].inset();
        BufferView & bv = cursor.bv();

        CoordCache::InnerParPosCache const & cache =
                bv.coordCache().getParPos().find(cursor.bottom().text())->second;
        // Get an iterator on the first paragraph in the cache
        DocIterator it(inset);
        it.push_back(CursorSlice(inset));
        it.pit() = cache.begin()->first;
        // Get an iterator after the last paragraph in the cache
        DocIterator et(inset);
        et.push_back(CursorSlice(inset));
        et.pit() = boost::prior(cache.end())->first;
        if (et.pit() >= et.lastpit())
                et = doc_iterator_end(inset);
        else
                ++et.pit();

        double best_dist = numeric_limits<double>::max();;
        DocIterator best_cursor = et;

        for ( ; it != et; it.forwardPos(true)) {
                // avoid invalid nesting when selecting
                if (!cursor.selection() || positionable(it, cursor.anchor_)) {
                        Point p = bv.getPos(it, false);
                        int xo = p.x_;
                        int yo = p.y_;
                        if (xlow <= xo && xo <= xhigh && ylow <= yo && yo <= yhigh) {
                                double const dx = xo - x;
                                double const dy = yo - y;
                                double const d = dx * dx + dy * dy;
                                // '<=' in order to take the last possible position
                                // this is important for clicking behind \sum in e.g. '\sum_i a'
                                if (d <= best_dist) {
                                        //      lyxerr << "*" << endl;
                                        best_dist   = d;
                                        best_cursor = it;
                                }
                        }
                }
        }

        if (best_cursor != et) {
                cursor.setCursor(best_cursor);
                return true;
        }

        return false;
}
*/


/// moves position closest to (x, y) in given box
bool bruteFind3(Cursor & cur, int x, int y, bool up)
{
        BufferView & bv = cur.bv();
        int ylow  = up ? 0 : y + 1;
        int yhigh = up ? y - 1 : bv.workHeight();
        int xlow = 0;
        int xhigh = bv.workWidth();

// FIXME: bit more work needed to get 'from' and 'to' right.
        pit_type from = cur.bottom().pit();
        //pit_type to = cur.bottom().pit();
        //lyxerr << "Pit start: " << from << endl;

        //lyxerr << "bruteFind3: x: " << x << " y: " << y
        //      << " xlow: " << xlow << " xhigh: " << xhigh
        //      << " ylow: " << ylow << " yhigh: " << yhigh
        //      << endl;
        Inset & inset = bv.buffer().inset();
        DocIterator it = doc_iterator_begin(inset);
        it.pit() = from;
        DocIterator et = doc_iterator_end(inset);

        double best_dist = numeric_limits<double>::max();
        DocIterator best_cursor = et;

        for ( ; it != et; it.forwardPos()) {
                // avoid invalid nesting when selecting
                if (bv.cursorStatus(it) == CUR_INSIDE
                                && (!cur.selection() || positionable(it, cur.anchor_))) {
                        Point p = bv.getPos(it, false);
                        int xo = p.x_;
                        int yo = p.y_;
                        if (xlow <= xo && xo <= xhigh && ylow <= yo && yo <= yhigh) {
                                double const dx = xo - x;
                                double const dy = yo - y;
                                double const d = dx * dx + dy * dy;
                                //lyxerr << "itx: " << xo << " ity: " << yo << " d: " << d
                                //      << " dx: " << dx << " dy: " << dy
                                //      << " idx: " << it.idx() << " pos: " << it.pos()
                                //      << " it:\n" << it
                                //      << endl;
                                // '<=' in order to take the last possible position
                                // this is important for clicking behind \sum in e.g. '\sum_i a'
                                if (d <= best_dist) {
                                        //lyxerr << "*" << endl;
                                        best_dist   = d;
                                        best_cursor = it;
                                }
                        }
                }
        }

        //lyxerr << "best_dist: " << best_dist << " cur:\n" << best_cursor << endl;
        if (best_cursor == et)
                return false;
        cur.setCursor(best_cursor);
        return true;
}

docstring parbreak(Paragraph const & par)
{
        odocstringstream os;
        os << '\n';
        // only add blank line if we're not in an ERT or Listings inset
        if (par.ownerCode() != ERT_CODE
                        && par.ownerCode() != LISTINGS_CODE)
                os << '\n';
        return os.str();
}

} // namespace anon


// be careful: this is called from the bv's constructor, too, so
// bv functions are not yet available!
Cursor::Cursor(BufferView & bv)
        : DocIterator(), bv_(&bv), anchor_(), x_target_(-1), textTargetOffset_(0),
          selection_(false), mark_(false), logicalpos_(false),
          current_font(inherit_font)
{}


void Cursor::reset(Inset & inset)
{
        clear();
        push_back(CursorSlice(inset));
        anchor_ = doc_iterator_begin(inset);
        anchor_.clear();
        clearTargetX();
        selection_ = false;
        mark_ = false;
}


// this (intentionally) does neither touch anchor nor selection status
void Cursor::setCursor(DocIterator const & cur)
{
        DocIterator::operator=(cur);
}


void Cursor::dispatch(FuncRequest const & cmd0)
{
        LYXERR(Debug::DEBUG, "cmd: " << cmd0 << '\n' << *this);
        if (empty())
                return;

        fixIfBroken();
        FuncRequest cmd = cmd0;
        Cursor safe = *this;
        
        // store some values to be used inside of the handlers
        beforeDispatchCursor_ = *this;
        for (; depth(); pop(), boundary(false)) {
                LYXERR(Debug::DEBUG, "Cursor::dispatch: cmd: "
                        << cmd0 << endl << *this);
                LASSERT(pos() <= lastpos(), /**/);
                LASSERT(idx() <= lastidx(), /**/);
                LASSERT(pit() <= lastpit(), /**/);

                // The common case is 'LFUN handled, need update', so make the
                // LFUN handler's life easier by assuming this as default value.
                // The handler can reset the update and val flags if necessary.
                disp_.update(Update::FitCursor | Update::Force);
                disp_.dispatched(true);
                inset().dispatch(*this, cmd);
                if (disp_.dispatched())
                        break;
        }
        
        // it completely to get a 'bomb early' behaviour in case this
        // object will be used again.
        if (!disp_.dispatched()) {
                LYXERR(Debug::DEBUG, "RESTORING OLD CURSOR!");
                operator=(safe);
                disp_.update(Update::None);
                disp_.dispatched(false);
        } else {
                // restore the previous one because nested Cursor::dispatch calls
                // are possible which would change it
                beforeDispatchCursor_ = safe.beforeDispatchCursor_;
        }
}


DispatchResult Cursor::result() const
{
        return disp_;
}


BufferView & Cursor::bv() const
{
        LASSERT(bv_, /**/);
        return *bv_;
}


Buffer & Cursor::buffer() const
{
        LASSERT(bv_, /**/);
        return bv_->buffer();
}


void Cursor::pop()
{
        LASSERT(depth() >= 1, /**/);
        pop_back();
}


void Cursor::push(Inset & p)
{
        push_back(CursorSlice(p));
        p.setBuffer(bv_->buffer());
}


void Cursor::pushBackward(Inset & p)
{
        LASSERT(!empty(), /**/);
        //lyxerr << "Entering inset " << t << " front" << endl;
        push(p);
        p.idxFirst(*this);
}


bool Cursor::popBackward()
{
        LASSERT(!empty(), /**/);
        if (depth() == 1)
                return false;
        pop();
        return true;
}


bool Cursor::popForward()
{
        LASSERT(!empty(), /**/);
        //lyxerr << "Leaving inset from in back" << endl;
        const pos_type lp = (depth() > 1) ? (*this)[depth() - 2].lastpos() : 0;
        if (depth() == 1)
                return false;
        pop();
        pos() += lastpos() - lp + 1;
        return true;
}


int Cursor::currentMode()
{
        LASSERT(!empty(), /**/);
        for (int i = depth() - 1; i >= 0; --i) {
                int res = operator[](i).inset().currentMode();
                if (res != Inset::UNDECIDED_MODE)
                        return res;
        }
        return Inset::TEXT_MODE;
}


void Cursor::getPos(int & x, int & y) const
{
        Point p = bv().getPos(*this, boundary());
        x = p.x_;
        y = p.y_;
}


Row const & Cursor::textRow() const
{
        CursorSlice const & cs = innerTextSlice();
        ParagraphMetrics const & pm = bv().parMetrics(cs.text(), cs.pit());
        LASSERT(!pm.rows().empty(), /**/);
        return pm.getRow(pos(), boundary());
}


void Cursor::resetAnchor()
{
        anchor_ = *this;
}



bool Cursor::posBackward()
{
        if (pos() == 0)
                return false;
        --pos();
        return true;
}


bool Cursor::posForward()
{
        if (pos() == lastpos())
                return false;
        ++pos();
        return true;
}


bool Cursor::posVisRight(bool skip_inset)
{
        Cursor new_cur = *this; // where we will move to
        pos_type left_pos; // position visually left of current cursor
        pos_type right_pos; // position visually right of current cursor
        bool new_pos_is_RTL; // is new position we're moving to RTL?

        getSurroundingPos(left_pos, right_pos);

        LYXERR(Debug::RTL, left_pos <<"|"<< right_pos << " (pos: "<< pos() <<")");

        // Are we at an inset?
        new_cur.pos() = right_pos;
        new_cur.boundary(false);
        if (!skip_inset &&
                text()->checkAndActivateInsetVisual(new_cur, right_pos >= pos(), false)) {
                // we actually move the cursor at the end of this function, for now
                // we just keep track of the new position in new_cur...
                LYXERR(Debug::RTL, "entering inset at: " << new_cur.pos());
        }

        // Are we already at rightmost pos in row?
        else if (text()->empty() || right_pos == -1) {
                
                new_cur = *this;
                if (!new_cur.posVisToNewRow(false)) {
                        LYXERR(Debug::RTL, "not moving!");
                        return false;
                }
                
                // we actually move the cursor at the end of this function, for now 
                // just keep track of the new position in new_cur...
                LYXERR(Debug::RTL, "right edge, moving: " << int(new_cur.pit()) << "," 
                        << int(new_cur.pos()) << "," << (new_cur.boundary() ? 1 : 0));

        }
        // normal movement to the right
        else {
                new_cur = *this;
                // Recall, if the cursor is at position 'x', that means *before* 
                // the character at position 'x'. In RTL, "before" means "to the 
                // right of", in LTR, "to the left of". So currently our situation
                // is this: the position to our right is 'right_pos' (i.e., we're 
                // currently to the left of 'right_pos'). In order to move to the 
                // right, it depends whether or not the character at 'right_pos' is RTL.
                new_pos_is_RTL = paragraph().getFontSettings(
                        bv().buffer().params(), right_pos).isVisibleRightToLeft();
                // If the character at 'right_pos' *is* LTR, then in order to move to
                // the right of it, we need to be *after* 'right_pos', i.e., move to
                // position 'right_pos' + 1.
                if (!new_pos_is_RTL) {
                        new_cur.pos() = right_pos + 1;
                        // set the boundary to true in two situations:
                        if (
                        // 1. if new_pos is now lastpos (which means that we're moving 
                        // right to the end of an LTR chunk which is at the end of an
                        // RTL paragraph);
                                new_cur.pos() == lastpos()
                        // 2. if the position *after* right_pos is RTL (we want to be 
                        // *after* right_pos, not before right_pos + 1!)
                                || paragraph().getFontSettings(bv().buffer().params(),
                                                new_cur.pos()).isVisibleRightToLeft()
                        )
                                new_cur.boundary(true);
                        else // set the boundary to false
                                new_cur.boundary(false);
                }
                // Otherwise (if the character at position 'right_pos' is RTL), then
                // moving to the right of it is as easy as setting the new position
                // to 'right_pos'.
                else {
                        new_cur.pos() = right_pos;
                        new_cur.boundary(false);
                }
        
        }

        bool moved = (new_cur.pos() != pos()
                                  || new_cur.pit() != pit()
                                  || new_cur.boundary() != boundary());
        
        if (moved) {
                LYXERR(Debug::RTL, "moving to: " << new_cur.pos() 
                        << (new_cur.boundary() ? " (boundary)" : ""));
                *this = new_cur;
        }

        return moved;
}


bool Cursor::posVisLeft(bool skip_inset)
{
        Cursor new_cur = *this; // where we will move to
        pos_type left_pos; // position visually left of current cursor
        pos_type right_pos; // position visually right of current cursor
        bool new_pos_is_RTL; // is new position we're moving to RTL?

        getSurroundingPos(left_pos, right_pos);

        LYXERR(Debug::RTL, left_pos <<"|"<< right_pos << " (pos: "<< pos() <<")");

        // Are we at an inset?
        new_cur.pos() = left_pos;
        new_cur.boundary(false);
        if (!skip_inset && 
                text()->checkAndActivateInsetVisual(new_cur, left_pos >= pos(), true)) {
                // we actually move the cursor at the end of this function, for now 
                // we just keep track of the new position in new_cur...
                LYXERR(Debug::RTL, "entering inset at: " << new_cur.pos());
        }

        // Are we already at leftmost pos in row?
        else if (text()->empty() || left_pos == -1) {
                
                new_cur = *this;
                if (!new_cur.posVisToNewRow(true)) {
                        LYXERR(Debug::RTL, "not moving!");
                        return false;
                }
                
                // we actually move the cursor at the end of this function, for now 
                // just keep track of the new position in new_cur...
                LYXERR(Debug::RTL, "left edge, moving: " << int(new_cur.pit()) << "," 
                        << int(new_cur.pos()) << "," << (new_cur.boundary() ? 1 : 0));

        }
        // normal movement to the left
        else {
                new_cur = *this;
                // Recall, if the cursor is at position 'x', that means *before* 
                // the character at position 'x'. In RTL, "before" means "to the 
                // right of", in LTR, "to the left of". So currently our situation
                // is this: the position to our left is 'left_pos' (i.e., we're 
                // currently to the right of 'left_pos'). In order to move to the 
                // left, it depends whether or not the character at 'left_pos' is RTL.
                new_pos_is_RTL = paragraph().getFontSettings(
                        bv().buffer().params(), left_pos).isVisibleRightToLeft();
                // If the character at 'left_pos' *is* RTL, then in order to move to
                // the left of it, we need to be *after* 'left_pos', i.e., move to
                // position 'left_pos' + 1.
                if (new_pos_is_RTL) {
                        new_cur.pos() = left_pos + 1;
                        // set the boundary to true in two situations:
                        if (
                        // 1. if new_pos is now lastpos (which means that we're moving left
                        // to the end of an RTL chunk which is at the end of an LTR 
                        // paragraph);
                                new_cur.pos() == lastpos()
                        // 2. if the position *after* left_pos is not RTL (we want to be 
                        // *after* left_pos, not before left_pos + 1!)
                                || !paragraph().getFontSettings(bv().buffer().params(),
                                                new_cur.pos()).isVisibleRightToLeft()
                        )
                                new_cur.boundary(true);
                        else // set the boundary to false
                                new_cur.boundary(false);
                }
                // Otherwise (if the character at position 'left_pos' is LTR), then
                // moving to the left of it is as easy as setting the new position
                // to 'left_pos'.
                else {
                        new_cur.pos() = left_pos;
                        new_cur.boundary(false);
                }
        
        }

        bool moved = (new_cur.pos() != pos() 
                                  || new_cur.pit() != pit()
                                  || new_cur.boundary() != boundary());

        if (moved) {
                LYXERR(Debug::RTL, "moving to: " << new_cur.pos() 
                        << (new_cur.boundary() ? " (boundary)" : ""));
                *this = new_cur;
        }
                
        return moved;
}


void Cursor::getSurroundingPos(pos_type & left_pos, pos_type & right_pos)
{
        // preparing bidi tables
        Paragraph const & par = paragraph();
        Buffer const & buf = buffer();
        Row const & row = textRow();
        Bidi bidi;
        bidi.computeTables(par, buf, row);

        LYXERR(Debug::RTL, "bidi: " << row.pos() << "--" << row.endpos());

        // The cursor is painted *before* the character at pos(), or, if 'boundary'
        // is true, *after* the character at (pos() - 1). So we already have one
        // known position around the cursor:
        pos_type known_pos = boundary() ? pos() - 1 : pos();
        
        // edge case: if we're at the end of the paragraph, things are a little 
        // different (because lastpos is a position which does not really "exist" 
        // --- there's no character there yet).
        if (known_pos == lastpos()) {
                if (par.isRTL(buf.params())) {
                        left_pos = -1;
                        right_pos = bidi.vis2log(row.pos());
                }
                else { // LTR paragraph
                        right_pos = -1;
                        left_pos = bidi.vis2log(row.endpos() - 1);
                }
                return;
        }
        
        // Whether 'known_pos' is to the left or to the right of the cursor depends
        // on whether it is an RTL or LTR character...
        bool const cur_is_RTL = 
                par.getFontSettings(buf.params(), known_pos).isVisibleRightToLeft();
        // ... in the following manner:
        // For an RTL character, "before" means "to the right" and "after" means
        // "to the left"; and for LTR, it's the reverse. So, 'known_pos' is to the
        // right of the cursor if (RTL && boundary) or (!RTL && !boundary):
        bool known_pos_on_right = (cur_is_RTL == boundary());

        // So we now know one of the positions surrounding the cursor. Let's 
        // determine the other one:
        
        if (known_pos_on_right) {
                right_pos = known_pos;
                // *visual* position of 'left_pos':
                pos_type v_left_pos = bidi.log2vis(right_pos) - 1;
                // If the position we just identified as 'left_pos' is a "skipped 
                // separator" (a separator which is at the logical end of a row,
                // except for the last row in a paragraph; such separators are not
                // painted, so they "are not really there"; note that in bidi text,
                // such a separator could appear visually in the middle of a row),
                // set 'left_pos' to the *next* position to the left.
                if (bidi.inRange(v_left_pos) 
                                && bidi.vis2log(v_left_pos) + 1 == row.endpos() 
                                && row.endpos() < lastpos()
                                && par.isSeparator(bidi.vis2log(v_left_pos))) {
                        --v_left_pos;
                }
                // calculate the logical position of 'left_pos', if in row
                if (!bidi.inRange(v_left_pos))
                        left_pos = -1;
                else
                        left_pos = bidi.vis2log(v_left_pos);
                // If the position we identified as 'right_pos' is a "skipped 
                // separator", set 'right_pos' to the *next* position to the right.
                if (right_pos + 1 == row.endpos() && row.endpos() < lastpos() 
                                && par.isSeparator(right_pos)) {
                        pos_type v_right_pos = bidi.log2vis(right_pos) + 1;
                        if (!bidi.inRange(v_right_pos))
                                right_pos = -1;
                        else
                                right_pos = bidi.vis2log(v_right_pos);
                }
        } 
        else { // known_pos is on the left
                left_pos = known_pos;
                // *visual* position of 'right_pos'
                pos_type v_right_pos = bidi.log2vis(left_pos) + 1;
                // If the position we just identified as 'right_pos' is a "skipped 
                // separator", set 'right_pos' to the *next* position to the right.
                if (bidi.inRange(v_right_pos) 
                                && bidi.vis2log(v_right_pos) + 1 == row.endpos() 
                                && row.endpos() < lastpos()
                                && par.isSeparator(bidi.vis2log(v_right_pos))) {
                        ++v_right_pos;
                }
                // calculate the logical position of 'right_pos', if in row
                if (!bidi.inRange(v_right_pos)) 
                        right_pos = -1;
                else
                        right_pos = bidi.vis2log(v_right_pos);
                // If the position we identified as 'left_pos' is a "skipped 
                // separator", set 'left_pos' to the *next* position to the left.
                if (left_pos + 1 == row.endpos() && row.endpos() < lastpos() 
                                && par.isSeparator(left_pos)) {
                        pos_type v_left_pos = bidi.log2vis(left_pos) - 1;
                        if (!bidi.inRange(v_left_pos))
                                left_pos = -1;
                        else
                                left_pos = bidi.vis2log(v_left_pos);
                }
        }
        return;
}


bool Cursor::posVisToNewRow(bool movingLeft)
{
        Paragraph const & par = paragraph();
        Buffer const & buf = buffer();
        Row const & row = textRow();
        bool par_is_LTR = !par.isRTL(buf.params());

        // Inside a table, determining whether to move to the next or previous row
        // should be done based on the table's direction. 
        int s = depth() - 1;
        if (s >= 1 && (*this)[s].inset().asInsetTabular()) {
                par_is_LTR = !(*this)[s].inset().asInsetTabular()->isRightToLeft(*this);
                LYXERR(Debug::RTL, "Inside table! par_is_LTR=" << (par_is_LTR ? 1 : 0));
        }
        
        // if moving left in an LTR paragraph or moving right in an RTL one, 
        // move to previous row
        if (par_is_LTR == movingLeft) {
                if (row.pos() == 0) { // we're at first row in paragraph
                        if (pit() == 0) // no previous paragraph! don't move
                                return false;
                        // move to last pos in previous par
                        --pit();
                        pos() = lastpos();
                        boundary(false);
                } else { // move to previous row in this par
                        pos() = row.pos() - 1; // this is guaranteed to be in previous row
                        boundary(false);
                }
        }
        // if moving left in an RTL paragraph or moving right in an LTR one, 
        // move to next row
        else {
                if (row.endpos() == lastpos()) { // we're at last row in paragraph
                        if (pit() == lastpit()) // last paragraph! don't move
                                return false;
                        // move to first row in next par
                        ++pit();
                        pos() = 0;
                        boundary(false);
                } else { // move to next row in this par
                        pos() = row.endpos();
                        boundary(false);
                }
        }
        
        // make sure we're at left-/right-most pos in new row
        posVisToRowExtremity(!movingLeft);

        return true;
}


void Cursor::posVisToRowExtremity(bool left)  
{
        // prepare bidi tables
        Paragraph const & par = paragraph();
        Buffer const & buf = buffer();
        Row const & row = textRow();
        Bidi bidi;
        bidi.computeTables(par, buf, row);

        LYXERR(Debug::RTL, "entering extremity: " << pit() << "," << pos() << ","
                << (boundary() ? 1 : 0));

        if (left) { // move to leftmost position
                // if this is an RTL paragraph, and we're at the last row in the
                // paragraph, move to lastpos
                if (par.isRTL(buf.params()) && row.endpos() == lastpos())
                        pos() = lastpos();
                else {
                        pos() = bidi.vis2log(row.pos());

                        // Moving to the leftmost position in the row, the cursor should
                        // normally be placed to the *left* of the leftmost position.
                        // A very common exception, though, is if the leftmost character 
                        // also happens to be the separator at the (logical) end of the row
                        // --- in this case, the separator is positioned beyond the left 
                        // margin, and we don't want to move the cursor there (moving to 
                        // the left of the separator is equivalent to moving to the next
                        // line). So, in this case we actually want to place the cursor 
                        // to the *right* of the leftmost position (the separator). 
                        // Another exception is if we're moving to the logically last 
                        // position in the row, which is *not* a separator: this means
                        // that the entire row has no separators (if there were any, the 
                        // row would have been broken there); and therefore in this case
                        // we also move to the *right* of the last position (this indicates
                        // to the user that there is no space after this position, and is 
                        // consistent with the behavior in the middle of a row --- moving
                        // right or left moves to the next/previous character; if we were
                        // to move to the *left* of this position, that would simulate 
                        // a separator which is not really there!). 
                        // Finally, there is an exception to the previous exception: if 
                        // this non-separator-but-last-position-in-row is an inset, then
                        // we *do* want to stay to the left of it anyway: this is the 
                        // "boundary" which we simulate at insets.
                        
                        bool right_of_pos = false; // do we want to be to the right of pos?

                        // as explained above, if at last pos in row, stay to the right
                        if ((pos() == row.endpos() - 1) && !par.isInset(pos()))
                                right_of_pos = true;

                        // Now we know if we want to be to the left or to the right of pos,
                        // let's make sure we are where we want to be.
                        bool new_pos_is_RTL = 
                                par.getFontSettings(buf.params(), pos()).isVisibleRightToLeft();

                        if (new_pos_is_RTL == !right_of_pos) {
                                ++pos();
                                boundary(true);
                        }
                        
                }
        }
        else { // move to rightmost position
                // if this is an LTR paragraph, and we're at the last row in the
                // paragraph, move to lastpos
                if (!par.isRTL(buf.params()) && row.endpos() == lastpos())
                        pos() = lastpos();
                else {
                        pos() = bidi.vis2log(row.endpos() - 1);

                        // Moving to the rightmost position in the row, the cursor should
                        // normally be placed to the *right* of the rightmost position.
                        // A very common exception, though, is if the rightmost character 
                        // also happens to be the separator at the (logical) end of the row
                        // --- in this case, the separator is positioned beyond the right 
                        // margin, and we don't want to move the cursor there (moving to 
                        // the right of the separator is equivalent to moving to the next
                        // line). So, in this case we actually want to place the cursor 
                        // to the *left* of the rightmost position (the separator). 
                        // Another exception is if we're moving to the logically last 
                        // position in the row, which is *not* a separator: this means
                        // that the entire row has no separators (if there were any, the 
                        // row would have been broken there); and therefore in this case
                        // we also move to the *left* of the last position (this indicates
                        // to the user that there is no space after this position, and is 
                        // consistent with the behavior in the middle of a row --- moving
                        // right or left moves to the next/previous character; if we were
                        // to move to the *right* of this position, that would simulate 
                        // a separator which is not really there!). 
                        // Finally, there is an exception to the previous exception: if 
                        // this non-separator-but-last-position-in-row is an inset, then
                        // we *do* want to stay to the right of it anyway: this is the 
                        // "boundary" which we simulate at insets.
                        
                        bool left_of_pos = false; // do we want to be to the left of pos?

                        // as explained above, if at last pos in row, stay to the left
                        if ((pos() == row.endpos() - 1) && !par.isInset(pos()))
                                left_of_pos = true;

                        // Now we know if we want to be to the left or to the right of pos,
                        // let's make sure we are where we want to be.
                        bool new_pos_is_RTL = 
                                par.getFontSettings(buf.params(), pos()).isVisibleRightToLeft();

                        if (new_pos_is_RTL == left_of_pos) {
                                ++pos();
                                boundary(true);
                        }
                }
        }
        LYXERR(Debug::RTL, "leaving extremity: " << pit() << "," << pos() << ","
                << (boundary() ? 1 : 0));
}


CursorSlice Cursor::anchor() const
{
        LASSERT(anchor_.depth() >= depth(), /**/);
        CursorSlice normal = anchor_[depth() - 1];
        if (depth() < anchor_.depth() && top() <= normal) {
                // anchor is behind cursor -> move anchor behind the inset
                ++normal.pos();
        }
        return normal;
}


CursorSlice Cursor::selBegin() const
{
        if (!selection())
                return top();
        return anchor() < top() ? anchor() : top();
}


CursorSlice Cursor::selEnd() const
{
        if (!selection())
                return top();
        return anchor() > top() ? anchor() : top();
}


DocIterator Cursor::selectionBegin() const
{
        if (!selection())
                return *this;

        DocIterator di;
        // FIXME: This is a work-around for the problem that
        // CursorSlice doesn't keep track of the boundary.
        if (anchor() == top())
                di = anchor_.boundary() > boundary() ? anchor_ : *this;
        else
                di = anchor() < top() ? anchor_ : *this;
        di.resize(depth());
        return di;
}


DocIterator Cursor::selectionEnd() const
{
        if (!selection())
                return *this;

        DocIterator di;
        // FIXME: This is a work-around for the problem that
        // CursorSlice doesn't keep track of the boundary.
        if (anchor() == top())
                di = anchor_.boundary() < boundary() ? anchor_ : *this;
        else
                di = anchor() > top() ? anchor_ : *this;

        if (di.depth() > depth()) {
                di.resize(depth());
                ++di.pos();
        }
        return di;
}


void Cursor::setSelection()
{
        setSelection(true);
        // A selection with no contents is not a selection
        // FIXME: doesnt look ok
        if (idx() == anchor().idx() && 
            pit() == anchor().pit() && 
            pos() == anchor().pos())
                setSelection(false);
}


void Cursor::setSelection(DocIterator const & where, int n)
{
        setCursor(where);
        setSelection(true);
        anchor_ = where;
        pos() += n;
}


void Cursor::clearSelection()
{
        setSelection(false);
        setMark(false);
        resetAnchor();
}


void Cursor::setTargetX(int x)
{
        x_target_ = x;
        textTargetOffset_ = 0;
}


int Cursor::x_target() const
{
        return x_target_;
}


void Cursor::clearTargetX()
{
        x_target_ = -1;
        textTargetOffset_ = 0;
}


void Cursor::updateTextTargetOffset()
{
        int x;
        int y;
        getPos(x, y);
        textTargetOffset_ = x - x_target_;
}


void Cursor::info(odocstream & os) const
{
        for (int i = 1, n = depth(); i < n; ++i) {
                operator[](i).inset().infoize(os);
                os << "  ";
        }
        if (pos() != 0) {
                Inset const * inset = prevInset();
                // prevInset() can return 0 in certain case.
                if (inset)
                        prevInset()->infoize2(os);
        }
        // overwite old message
        os << "                    ";
}


bool Cursor::selHandle(bool sel)
{
        //lyxerr << "Cursor::selHandle" << endl;
        if (mark())
                sel = true;
        if (sel == selection())
                return false;

        if (!sel)
                cap::saveSelection(*this);

        resetAnchor();
        setSelection(sel);
        return true;
}


ostream & operator<<(ostream & os, Cursor const & cur)
{
        os << "\n cursor:                                | anchor:\n";
        for (size_t i = 0, n = cur.depth(); i != n; ++i) {
                os << " " << cur[i] << " | ";
                if (i < cur.anchor_.depth())
                        os << cur.anchor_[i];
                else
                        os << "-------------------------------";
                os << "\n";
        }
        for (size_t i = cur.depth(), n = cur.anchor_.depth(); i < n; ++i) {
                os << "------------------------------- | " << cur.anchor_[i] << "\n";
        }
        os << " selection: " << cur.selection_
           << " x_target: " << cur.x_target_ << endl;
        return os;
}


LyXErr & operator<<(LyXErr & os, Cursor const & cur)
{
        os.stream() << cur;
        return os;
}


} // namespace lyx


///////////////////////////////////////////////////////////////////
//
// FIXME: Look here
// The part below is the non-integrated rest of the original math
// cursor. This should be either generalized for texted or moved
// back to mathed (in most cases to InsetMathNest).
//
///////////////////////////////////////////////////////////////////

#include "mathed/InsetMathChar.h"
#include "mathed/InsetMathGrid.h"
#include "mathed/InsetMathScript.h"
#include "mathed/InsetMathUnknown.h"
#include "mathed/MathFactory.h"
#include "mathed/MathStream.h"
#include "mathed/MathSupport.h"


namespace lyx {

//#define FILEDEBUG 1


bool Cursor::isInside(Inset const * p) const
{
        for (size_t i = 0; i != depth(); ++i)
                if (&operator[](i).inset() == p)
                        return true;
        return false;
}


void Cursor::leaveInset(Inset const & inset)
{
        for (size_t i = 0; i != depth(); ++i) {
                if (&operator[](i).inset() == &inset) {
                        resize(i);
                        return;
                }
        }
}


bool Cursor::openable(MathAtom const & t) const
{
        if (!t->isActive())
                return false;

        if (t->lock())
                return false;

        if (!selection())
                return true;

        // we can't move into anything new during selection
        if (depth() >= anchor_.depth())
                return false;
        if (t.nucleus() != &anchor_[depth()].inset())
                return false;

        return true;
}


void Cursor::setScreenPos(int x, int /*y*/)
{
        setTargetX(x);
        //bruteFind(*this, x, y, 0, bv().workWidth(), 0, bv().workHeight());
}



void Cursor::plainErase()
{
        cell().erase(pos());
}


void Cursor::markInsert()
{
        insert(char_type(0));
}


void Cursor::markErase()
{
        cell().erase(pos());
}


void Cursor::plainInsert(MathAtom const & t)
{
        cell().insert(pos(), t);
        ++pos();
        inset().setBuffer(bv_->buffer());
        inset().initView();
}


void Cursor::insert(docstring const & str)
{
        for_each(str.begin(), str.end(),
                 boost::bind(static_cast<void(Cursor::*)(char_type)>
                             (&Cursor::insert), this, _1));
}


void Cursor::insert(char_type c)
{
        //lyxerr << "Cursor::insert char '" << c << "'" << endl;
        LASSERT(!empty(), /**/);
        if (inMathed()) {
                cap::selClearOrDel(*this);
                insert(new InsetMathChar(c));
        } else {
                text()->insertChar(*this, c);
        }
}


void Cursor::insert(MathAtom const & t)
{
        //lyxerr << "Cursor::insert MathAtom '" << t << "'" << endl;
        macroModeClose();
        cap::selClearOrDel(*this);
        plainInsert(t);
}


void Cursor::insert(Inset * inset0)
{
        LASSERT(inset0, /**/);
        if (inMathed())
                insert(MathAtom(inset0));
        else {
                text()->insertInset(*this, inset0);
                inset0->setBuffer(bv_->buffer());
                inset0->initView();
        }
}


void Cursor::niceInsert(docstring const & t)
{
        MathData ar;
        asArray(t, ar);
        if (ar.size() == 1)
                niceInsert(ar[0]);
        else
                insert(ar);
}


void Cursor::niceInsert(MathAtom const & t)
{
        macroModeClose();
        docstring const safe = cap::grabAndEraseSelection(*this);
        plainInsert(t);
        // enter the new inset and move the contents of the selection if possible
        if (t->isActive()) {
                posBackward();
                // be careful here: don't use 'pushBackward(t)' as this we need to
                // push the clone, not the original
                pushBackward(*nextInset());
                // We may not use niceInsert here (recursion)
                MathData ar;
                asArray(safe, ar);
                insert(ar);
        }
}


void Cursor::insert(MathData const & ar)
{
        macroModeClose();
        if (selection())
                cap::eraseSelection(*this);
        cell().insert(pos(), ar);
        pos() += ar.size();
}


bool Cursor::backspace()
{
        autocorrect() = false;

        if (selection()) {
                cap::eraseSelection(*this);
                return true;
        }

        if (pos() == 0) {
                // If empty cell, and not part of a big cell
                if (lastpos() == 0 && inset().nargs() == 1) {
                        popBackward();
                        // Directly delete empty cell: [|[]] => [|]
                        if (inMathed()) {
                                plainErase();
                                resetAnchor();
                                return true;
                        }
                        // [|], can not delete from inside
                        return false;
                } else {
                        if (inMathed())
                                pullArg();
                        else
                                popBackward();
                        return true;
                }
        }

        if (inMacroMode()) {
                InsetMathUnknown * p = activeMacro();
                if (p->name().size() > 1) {
                        p->setName(p->name().substr(0, p->name().size() - 1));
                        return true;
                }
        }

        if (pos() != 0 && prevAtom()->nargs() > 0) {
                // let's require two backspaces for 'big stuff' and
                // highlight on the first
                resetAnchor();
                setSelection(true);
                --pos();
        } else {
                --pos();
                plainErase();
        }
        return true;
}


bool Cursor::erase()
{
        autocorrect() = false;
        if (inMacroMode())
                return true;

        if (selection()) {
                cap::eraseSelection(*this);
                return true;
        }

        // delete empty cells if possible
        if (pos() == lastpos() && inset().idxDelete(idx()))
                return true;

        // special behaviour when in last position of cell
        if (pos() == lastpos()) {
                bool one_cell = inset().nargs() == 1;
                if (one_cell && lastpos() == 0) {
                        popBackward();
                        // Directly delete empty cell: [|[]] => [|]
                        if (inMathed()) {
                                plainErase();
                                resetAnchor();
                                return true;
                        }
                        // [|], can not delete from inside
                        return false;
                }
                // remove markup
                if (!one_cell)
                        inset().idxGlue(idx());
                return true;
        }

        // 'clever' UI hack: only erase large items if previously slected
        if (pos() != lastpos() && nextAtom()->nargs() > 0) {
                resetAnchor();
                setSelection(true);
                ++pos();
        } else {
                plainErase();
        }

        return true;
}


bool Cursor::up()
{
        macroModeClose();
        DocIterator save = *this;
        FuncRequest cmd(selection() ? LFUN_UP_SELECT : LFUN_UP, docstring());
        this->dispatch(cmd);
        if (disp_.dispatched())
                return true;
        setCursor(save);
        autocorrect() = false;
        return false;
}


bool Cursor::down()
{
        macroModeClose();
        DocIterator save = *this;
        FuncRequest cmd(selection() ? LFUN_DOWN_SELECT : LFUN_DOWN, docstring());
        this->dispatch(cmd);
        if (disp_.dispatched())
                return true;
        setCursor(save);
        autocorrect() = false;
        return false;
}


bool Cursor::macroModeClose()
{
        if (!inMacroMode())
                return false;
        InsetMathUnknown * p = activeMacro();
        p->finalize();
        MathData selection;
        asArray(p->selection(), selection);
        docstring const s = p->name();
        --pos();
        cell().erase(pos());

        // do nothing if the macro name is empty
        if (s == "\\")
                return false;

        // trigger updates of macros, at least, if no full
        // updates take place anyway
        updateFlags(Update::Force);

        docstring const name = s.substr(1);
        InsetMathNest * const in = inset().asInsetMath()->asNestInset();
        if (in && in->interpretString(*this, s))
                return true;
        MathAtom atom = createInsetMath(name);

        // try to put argument into macro, if we just inserted a macro
        bool macroArg = false;
        MathMacro * atomAsMacro = atom.nucleus()->asMacro();
        if (atomAsMacro) {
                // macros here are still unfolded (in init mode in fact). So
                // we have to resolve the macro here manually and check its arity
                // to put the selection behind it if arity > 0.
                MacroData const * data = buffer().getMacro(atomAsMacro->name());
                if (selection.size() > 0 && data && data->numargs() - data->optionals() > 0) {
                        macroArg = true;
                        atomAsMacro->setDisplayMode(MathMacro::DISPLAY_INTERACTIVE_INIT, 1);
                } else
                        // non-greedy case. Do not touch the arguments behind
                        atomAsMacro->setDisplayMode(MathMacro::DISPLAY_INTERACTIVE_INIT, 0);
        }

        // insert remembered selection into first argument of a non-macro
        else if (atom.nucleus()->nargs() > 0)
                atom.nucleus()->cell(0).append(selection);
        
        plainInsert(atom);

        // finally put the macro argument behind, if needed
        if (macroArg) {
                if (selection.size() > 1)
                        plainInsert(MathAtom(new InsetMathBrace(selection)));
                else
                        insert(selection);
        }
        
        return true;
}


docstring Cursor::macroName()
{
        return inMacroMode() ? activeMacro()->name() : docstring();
}


void Cursor::handleNest(MathAtom const & a, int c)
{
        //lyxerr << "Cursor::handleNest: " << c << endl;
        MathAtom t = a;
        asArray(cap::grabAndEraseSelection(*this), t.nucleus()->cell(c));
        insert(t);
        posBackward();
        pushBackward(*nextInset());
}


int Cursor::targetX() const
{
        if (x_target() != -1)
                return x_target();
        int x = 0;
        int y = 0;
        getPos(x, y);
        return x;
}


int Cursor::textTargetOffset() const
{
        return textTargetOffset_;
}


void Cursor::setTargetX()
{
        int x;
        int y;
        getPos(x, y);
        setTargetX(x);
}


bool Cursor::inMacroMode() const
{
        if (!inMathed())
                return false;
        if (pos() == 0)
                return false;
        InsetMathUnknown const * p = prevAtom()->asUnknownInset();
        return p && !p->final();
}


InsetMathUnknown * Cursor::activeMacro()
{
        return inMacroMode() ? prevAtom().nucleus()->asUnknownInset() : 0;
}


InsetMathUnknown const * Cursor::activeMacro() const
{
        return inMacroMode() ? prevAtom().nucleus()->asUnknownInset() : 0;
}


void Cursor::pullArg()
{
        // FIXME: Look here
        MathData ar = cell();
        if (popBackward() && inMathed()) {
                plainErase();
                cell().insert(pos(), ar);
                resetAnchor();
        } else {
                //formula()->mutateToText();
        }
}


void Cursor::touch()
{
        // FIXME: look here
#if 0
        DocIterator::const_iterator it = begin();
        DocIterator::const_iterator et = end();
        for ( ; it != et; ++it)
                it->cell().touch();
#endif
}


void Cursor::normalize()
{
        if (idx() > lastidx()) {
                lyxerr << "this should not really happen - 1: "
                       << idx() << ' ' << nargs()
                       << " in: " << &inset() << endl;
                idx() = lastidx();
        }

        if (pos() > lastpos()) {
                lyxerr << "this should not really happen - 2: "
                        << pos() << ' ' << lastpos() <<  " in idx: " << idx()
                       << " in atom: '";
                odocstringstream os;
                WriteStream wi(os, false, true, false);
                inset().asInsetMath()->write(wi);
                lyxerr << to_utf8(os.str()) << endl;
                pos() = lastpos();
        }
}


bool Cursor::upDownInMath(bool up)
{
        // Be warned: The 'logic' implemented in this function is highly
        // fragile. A distance of one pixel or a '<' vs '<=' _really
        // matters. So fiddle around with it only if you think you know
        // what you are doing!
        int xo = 0;
        int yo = 0;
        getPos(xo, yo);
        xo = theLyXFunc().cursorBeforeDispatchX();
        
        // check if we had something else in mind, if not, this is the future
        // target
        if (x_target_ == -1)
                setTargetX(xo);
        else if (inset().asInsetText() && xo - textTargetOffset() != x_target()) {
                // In text mode inside the line (not left or right) possibly set a new target_x,
                // but only if we are somewhere else than the previous target-offset.
                
                // We want to keep the x-target on subsequent up/down movements
                // that cross beyond the end of short lines. Thus a special
                // handling when the cursor is at the end of line: Use the new
                // x-target only if the old one was before the end of line
                // or the old one was after the beginning of the line
                bool inRTL = isWithinRtlParagraph(*this);
                bool left;
                bool right;
                if (inRTL) {
                        left = pos() == textRow().endpos();
                        right = pos() == textRow().pos();
                } else {
                        left = pos() == textRow().pos();
                        right = pos() == textRow().endpos();
                }
                if ((!left && !right) ||
                                (left && !right && xo < x_target_) ||
                                (!left && right && x_target_ < xo))
                        setTargetX(xo);
                else
                        xo = targetX();
        } else
                xo = targetX();

        // try neigbouring script insets
        Cursor old = *this;
        if (inMathed() && !selection()) {
                // try left
                if (pos() != 0) {
                        InsetMathScript const * p = prevAtom()->asScriptInset();
                        if (p && p->has(up)) {
                                --pos();
                                push(*const_cast<InsetMathScript*>(p));
                                idx() = p->idxOfScript(up);
                                pos() = lastpos();
                                
                                // we went in the right direction? Otherwise don't jump into the script
                                int x;
                                int y;
                                getPos(x, y);
                                int oy = theLyXFunc().cursorBeforeDispatchY();
                                if ((!up && y <= oy) ||
                                                (up && y >= oy))
                                        operator=(old);
                                else
                                        return true;
                        }
                }
                
                // try right
                if (pos() != lastpos()) {
                        InsetMathScript const * p = nextAtom()->asScriptInset();
                        if (p && p->has(up)) {
                                push(*const_cast<InsetMathScript*>(p));
                                idx() = p->idxOfScript(up);
                                pos() = 0;
                                
                                // we went in the right direction? Otherwise don't jump into the script
                                int x;
                                int y;
                                getPos(x, y);
                                int oy = theLyXFunc().cursorBeforeDispatchY();
                                if ((!up && y <= oy) ||
                                                (up && y >= oy))
                                        operator=(old);
                                else
                                        return true;
                        }
                }
        }
                
        // try to find an inset that knows better then we,
        if (inset().idxUpDown(*this, up)) {
                //lyxerr << "idxUpDown triggered" << endl;
                // try to find best position within this inset
                if (!selection())
                        setCursor(bruteFind2(*this, xo, yo));
                return true;
        }
        
        // any improvement going just out of inset?
        if (popBackward() && inMathed()) {
                //lyxerr << "updown: popBackward succeeded" << endl;
                int xnew;
                int ynew;
                int yold = theLyXFunc().cursorBeforeDispatchY();
                getPos(xnew, ynew);
                if (up ? ynew < yold : ynew > yold)
                        return true;
        }
        
        // no success, we are probably at the document top or bottom
        operator=(old);
        return false;
}


bool Cursor::upDownInText(bool up, bool & updateNeeded)
{
        LASSERT(text(), /**/);

        // where are we?
        int xo = 0;
        int yo = 0;
        getPos(xo, yo);
        xo = theLyXFunc().cursorBeforeDispatchX();

        // update the targetX - this is here before the "return false"
        // to set a new target which can be used by InsetTexts above
        // if we cannot move up/down inside this inset anymore
        if (x_target_ == -1)
                setTargetX(xo);
        else if (xo - textTargetOffset() != x_target() &&
                                         depth() == beforeDispatchCursor_.depth()) {
                // In text mode inside the line (not left or right) possibly set a new target_x,
                // but only if we are somewhere else than the previous target-offset.
                
                // We want to keep the x-target on subsequent up/down movements
                // that cross beyond the end of short lines. Thus a special
                // handling when the cursor is at the end of line: Use the new
                // x-target only if the old one was before the end of line
                // or the old one was after the beginning of the line
                bool inRTL = isWithinRtlParagraph(*this);
                bool left;
                bool right;
                if (inRTL) {
                        left = pos() == textRow().endpos();
                        right = pos() == textRow().pos();
                } else {
                        left = pos() == textRow().pos();
                        right = pos() == textRow().endpos();
                }
                if ((!left && !right) ||
                                (left && !right && xo < x_target_) ||
                                (!left && right && x_target_ < xo))
                        setTargetX(xo);
                else
                        xo = targetX();
        } else
                xo = targetX();
                
        // first get the current line
        TextMetrics & tm = bv_->textMetrics(text());
        ParagraphMetrics const & pm = tm.parMetrics(pit());
        int row;
        if (pos() && boundary())
                row = pm.pos2row(pos() - 1);
        else
                row = pm.pos2row(pos());
                
        // are we not at the start or end?
        if (up) {
                if (pit() == 0 && row == 0)
                        return false;
        } else {
                if (pit() + 1 >= int(text()->paragraphs().size()) &&
                                row + 1 >= int(pm.rows().size()))
                        return false;
        }

        // with and without selection are handled differently
        if (!selection()) {
                int yo = bv().getPos(*this, boundary()).y_;
                Cursor old = *this;
                // To next/previous row
                if (up)
                        tm.editXY(*this, xo, yo - textRow().ascent() - 1);
                else
                        tm.editXY(*this, xo, yo + textRow().descent() + 1);
                clearSelection();
                
                // This happens when you move out of an inset.
                // And to give the DEPM the possibility of doing
                // something we must provide it with two different
                // cursors. (Lgb)
                Cursor dummy = *this;
                if (dummy == old)
                        ++dummy.pos();
                if (bv().checkDepm(dummy, old)) {
                        updateNeeded = true;
                        // Make sure that cur gets back whatever happened to dummy(Lgb)
                        operator=(dummy);
                }
        } else {
                // if there is a selection, we stay out of any inset, and just jump to the right position:
                Cursor old = *this;
                if (up) {
                        if (row > 0) {
                                top().pos() = min(tm.x2pos(pit(), row - 1, xo), top().lastpos());
                        } else if (pit() > 0) {
                                --pit();
                                TextMetrics & tm = bv_->textMetrics(text());
                                if (!tm.contains(pit()))
                                        tm.newParMetricsUp();
                                ParagraphMetrics const & pmcur = tm.parMetrics(pit());
                                top().pos() = min(tm.x2pos(pit(), pmcur.rows().size() - 1, xo), top().lastpos());
                        }
                } else {
                        if (row + 1 < int(pm.rows().size())) {
                                top().pos() = min(tm.x2pos(pit(), row + 1, xo), top().lastpos());
                        } else if (pit() + 1 < int(text()->paragraphs().size())) {
                                ++pit();
                                TextMetrics & tm = bv_->textMetrics(text());
                                if (!tm.contains(pit()))
                                        tm.newParMetricsDown();
                                top().pos() = min(tm.x2pos(pit(), 0, xo), top().lastpos());
                        }
                }

                updateNeeded |= bv().checkDepm(*this, old);
        }

        updateTextTargetOffset();
        return true;
}       


void Cursor::handleFont(string const & font)
{
        LYXERR(Debug::DEBUG, font);
        docstring safe;
        if (selection()) {
                macroModeClose();
                safe = cap::grabAndEraseSelection(*this);
        }

        recordUndoInset();

        if (lastpos() != 0) {
                // something left in the cell
                if (pos() == 0) {
                        // cursor in first position
                        popBackward();
                } else if (pos() == lastpos()) {
                        // cursor in last position
                        popForward();
                } else {
                        // cursor in between. split cell
                        MathData::iterator bt = cell().begin();
                        MathAtom at = createInsetMath(from_utf8(font));
                        at.nucleus()->cell(0) = MathData(bt, bt + pos());
                        cell().erase(bt, bt + pos());
                        popBackward();
                        plainInsert(at);
                }
        } else {
                // nothing left in the cell
                popBackward();
                plainErase();
                resetAnchor();
        }
        insert(safe);
}


void Cursor::message(docstring const & msg) const
{
        theLyXFunc().setMessage(msg);
}


void Cursor::errorMessage(docstring const & msg) const
{
        theLyXFunc().setErrorMessage(msg);
}


docstring Cursor::selectionAsString(bool with_label) const
{
        if (!selection())
                return docstring();

        int const label = with_label
                ? AS_STR_LABEL | AS_STR_INSETS : AS_STR_INSETS;

        if (inTexted()) {
                idx_type const startidx = selBegin().idx();
                idx_type const endidx = selEnd().idx();
                if (startidx != endidx) {
                        // multicell selection
                        InsetTabular * table = inset().asInsetTabular();
                        LASSERT(table, return docstring());
                        return table->asString(startidx, endidx);
                }
                
                ParagraphList const & pars = text()->paragraphs();

                pit_type const startpit = selBegin().pit();
                pit_type const endpit = selEnd().pit();
                size_t const startpos = selBegin().pos();
                size_t const endpos = selEnd().pos();

                if (startpit == endpit)
                        return pars[startpit].asString(startpos, endpos, label);

                // First paragraph in selection
                docstring result = pars[startpit].
                        asString(startpos, pars[startpit].size(), label)
                                 + parbreak(pars[startpit]);

                // The paragraphs in between (if any)
                for (pit_type pit = startpit + 1; pit != endpit; ++pit) {
                        Paragraph const & par = pars[pit];
                        result += par.asString(0, par.size(), label)
                                  + parbreak(pars[pit]);
                }

                // Last paragraph in selection
                result += pars[endpit].asString(0, endpos, label);

                return result;
        }

        if (inMathed())
                return cap::grabSelection(*this);

        return docstring();
}


docstring Cursor::currentState() const
{
        if (inMathed()) {
                odocstringstream os;
                info(os);
                return os.str();
        }

        if (inTexted())
                return text()->currentState(*this);

        return docstring();
}


docstring Cursor::getPossibleLabel() const
{
        return inMathed() ? from_ascii("eq:") : text()->getPossibleLabel(*this);
}


Encoding const * Cursor::getEncoding() const
{
        if (empty())
                return 0;
        CursorSlice const & sl = innerTextSlice();
        Text const & text = *sl.text();
        Font font = text.getPar(sl.pit()).getFont(
                bv().buffer().params(), sl.pos(), outerFont(sl.pit(), text.paragraphs()));
        return font.language()->encoding();
}


void Cursor::undispatched()
{
        disp_.dispatched(false);
}


void Cursor::dispatched()
{
        disp_.dispatched(true);
}


void Cursor::updateFlags(Update::flags f)
{
        disp_.update(f);
}


void Cursor::noUpdate()
{
        disp_.update(Update::None);
}


Font Cursor::getFont() const
{
        // The logic here should more or less match to the Cursor::setCurrentFont
        // logic, i.e. the cursor height should give a hint what will happen
        // if a character is entered.
        
        // HACK. far from being perfect...

        CursorSlice const & sl = innerTextSlice();
        Text const & text = *sl.text();
        Paragraph const & par = text.getPar(sl.pit());
        
        // on boundary, so we are really at the character before
        pos_type pos = sl.pos();
        if (pos > 0 && boundary())
                --pos;
        
        // on space? Take the font before (only for RTL boundary stay)
        if (pos > 0) {
                TextMetrics const & tm = bv().textMetrics(&text);
                if (pos == sl.lastpos()
                        || (par.isSeparator(pos) 
                        && !tm.isRTLBoundary(sl.pit(), pos)))
                        --pos;
        }
        
        // get font at the position
        Font font = par.getFont(bv().buffer().params(), pos,
                outerFont(sl.pit(), text.paragraphs()));

        return font;
}


bool Cursor::fixIfBroken()
{
        if (DocIterator::fixIfBroken()) {
                        clearSelection();
                        return true;
        }
        return false;
}


bool notifyCursorLeaves(Cursor const & old, Cursor & cur)
{
        // find inset in common
        size_type i;
        for (i = 0; i < old.depth() && i < cur.depth(); ++i) {
                if (&old[i].inset() != &cur[i].inset())
                        break;
        }

        // update words if we just moved to another paragraph
        if (i == old.depth() && i == cur.depth()
            && !cur.buffer().isClean()
            && cur.inTexted() && old.inTexted()
            && cur.pit() != old.pit()) {
                old.paragraph().updateWords(old.top());
                return false;
        }
        
        // notify everything on top of the common part in old cursor,
        // but stop if the inset claims the cursor to be invalid now
        for (; i < old.depth(); ++i) {
                Cursor insetPos = old;
                insetPos.cutOff(i);
                if (old[i].inset().notifyCursorLeaves(insetPos, cur))
                        return true;
        }
        
        return false;
}


void Cursor::setCurrentFont()
{
        CursorSlice const & cs = innerTextSlice();
        Paragraph const & par = cs.paragraph();
        pos_type cpit = cs.pit();
        pos_type cpos = cs.pos();
        Text const & ctext = *cs.text();
        TextMetrics const & tm = bv().textMetrics(&ctext);

        // are we behind previous char in fact? -> go to that char
        if (cpos > 0 && boundary())
                --cpos;

        // find position to take the font from
        if (cpos != 0) {
                // paragraph end? -> font of last char
                if (cpos == lastpos())
                        --cpos;
                // on space? -> look at the words in front of space
                else if (cpos > 0 && par.isSeparator(cpos))     {
                        // abc| def -> font of c
                        // abc |[WERBEH], i.e. boundary==true -> font of c
                        // abc [WERBEH]| def, font of the space
                        if (!tm.isRTLBoundary(cpit, cpos))
                                --cpos;
                }
        }

        // get font
        BufferParams const & bufparams = buffer().params();
        current_font = par.getFontSettings(bufparams, cpos);
        real_current_font = tm.displayFont(cpit, cpos);

        // special case for paragraph end
        if (cs.pos() == lastpos()
            && tm.isRTLBoundary(cpit, cs.pos())
            && !boundary()) {
                Language const * lang = par.getParLanguage(bufparams);
                current_font.setLanguage(lang);
                current_font.fontInfo().setNumber(FONT_OFF);
                real_current_font.setLanguage(lang);
                real_current_font.fontInfo().setNumber(FONT_OFF);
        }
}


bool Cursor::textUndo()
{
        DocIterator dit = *this;
        // Undo::textUndo() will modify dit.
        if (!bv_->buffer().undo().textUndo(dit))
                return false;
        // Set cursor
        setCursor(dit);
        clearSelection();
        fixIfBroken();
        return true;
}


bool Cursor::textRedo()
{
        DocIterator dit = *this;
        // Undo::textRedo() will modify dit.
        if (!bv_->buffer().undo().textRedo(dit))
                return false;
        // Set cursor
        setCursor(dit);
        clearSelection();
        fixIfBroken();
        return true;
}


void Cursor::finishUndo() const
{
        bv_->buffer().undo().finishUndo();
}


void Cursor::beginUndoGroup() const
{
        bv_->buffer().undo().beginUndoGroup();
}


void Cursor::endUndoGroup() const
{
        bv_->buffer().undo().endUndoGroup();
}


void Cursor::recordUndo(UndoKind kind, pit_type from, pit_type to) const
{
        bv_->buffer().undo().recordUndo(*this, kind, from, to);
}


void Cursor::recordUndo(UndoKind kind, pit_type from) const
{
        bv_->buffer().undo().recordUndo(*this, kind, from);
}


void Cursor::recordUndo(UndoKind kind) const
{
        bv_->buffer().undo().recordUndo(*this, kind);
}


void Cursor::recordUndoInset(UndoKind kind) const
{
        bv_->buffer().undo().recordUndoInset(*this, kind);
}


void Cursor::recordUndoFullDocument() const
{
        bv_->buffer().undo().recordUndoFullDocument(*this);
}


void Cursor::recordUndoSelection() const
{
        if (inMathed()) {
                if (cap::multipleCellsSelected(*this))
                        recordUndoInset();
                else
                        recordUndo();
        } else
                bv_->buffer().undo().recordUndo(*this, ATOMIC_UNDO,
                        selBegin().pit(), selEnd().pit());
}


void Cursor::checkBufferStructure()
{
        Buffer const * master = buffer().masterBuffer();
        if (master->tocBackend().updateItem(*this))
                master->structureChanged();
}


} // namespace lyx