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[lyx.git] / src / TextMetrics.cpp

/**
 * \file src/TextMetrics.cpp
 * This file is part of LyX, the document processor.
 * Licence details can be found in the file COPYING.
 *
 * \author Asger Alstrup
 * \author Lars Gullik Bjønnes
 * \author Jean-Marc Lasgouttes
 * \author John Levon
 * \author André Pönitz
 * \author Dekel Tsur
 * \author Jürgen Vigna
 * \author Abdelrazak Younes
 *
 * Full author contact details are available in file CREDITS.
 */

#include <config.h>

#include "TextMetrics.h"

#include "Bidi.h"
#include "Buffer.h"
#include "buffer_funcs.h"
#include "BufferParams.h"
#include "BufferView.h"
#include "Color.h"
#include "CutAndPaste.h"
#include "debug.h"
#include "FontIterator.h"
#include "FuncRequest.h"
#include "InsetList.h"
#include "Layout.h"
#include "Length.h"
#include "LyXRC.h"
#include "MetricsInfo.h"
#include "paragraph_funcs.h"
#include "ParagraphParameters.h"
#include "ParIterator.h"
#include "rowpainter.h"
#include "Text.h"
#include "VSpace.h"

#include "frontends/FontMetrics.h"
#include "frontends/Painter.h"

#include <boost/current_function.hpp>

using std::make_pair;
using std::max;
using std::min;
using std::endl;
using std::pair;

namespace lyx {

using frontend::FontMetrics;

namespace {

int numberOfSeparators(Paragraph const & par, Row const & row)
{
        pos_type const first = max(row.pos(), par.beginOfBody());
        pos_type const last = row.endpos() - 1;
        int n = 0;
        for (pos_type p = first; p < last; ++p) {
                if (par.isSeparator(p))
                        ++n;
        }
        return n;
}


int numberOfLabelHfills(Paragraph const & par, Row const & row)
{
        pos_type last = row.endpos() - 1;
        pos_type first = row.pos();

        // hfill *DO* count at the beginning of paragraphs!
        if (first) {
                while (first < last && par.isHfill(first))
                        ++first;
        }

        last = min(last, par.beginOfBody());
        int n = 0;
        for (pos_type p = first; p < last; ++p) {
                if (par.isHfill(p))
                        ++n;
        }
        return n;
}


int numberOfHfills(Paragraph const & par, Row const & row)
{
        pos_type const last = row.endpos();
        pos_type first = row.pos();

        // hfill *DO* count at the beginning of paragraphs!
        if (first) {
                while (first < last && par.isHfill(first))
                        ++first;
        }

        first = max(first, par.beginOfBody());

        int n = 0;
        for (pos_type p = first; p < last; ++p) {
                if (par.isHfill(p))
                        ++n;
        }
        return n;
}

} // namespace anon

TextMetrics::TextMetrics(BufferView * bv, Text * text)
        : bv_(bv), text_(text)
{
        BOOST_ASSERT(bv_);
        max_width_ = bv_->workWidth();
        dim_.wid = max_width_;
        dim_.asc = 10;
        dim_.des = 10;

        //text_->updateLabels(bv->buffer());
}


bool TextMetrics::has(pit_type pit) const
{
        return par_metrics_.find(pit) != par_metrics_.end();
}


ParagraphMetrics const & TextMetrics::parMetrics(pit_type pit) const
{
        return const_cast<TextMetrics *>(this)->parMetrics(pit, true);
}



pair<pit_type, ParagraphMetrics const *> TextMetrics::first() const
{
        ParMetricsCache::const_iterator it = par_metrics_.begin();
        return make_pair(it->first, &it->second);
}


pair<pit_type, ParagraphMetrics const *> TextMetrics::last() const
{
        ParMetricsCache::const_reverse_iterator it = par_metrics_.rbegin();
        return make_pair(it->first, &it->second);
}


ParagraphMetrics & TextMetrics::parMetrics(pit_type pit,
                bool redo)
{
        ParMetricsCache::iterator pmc_it = par_metrics_.find(pit);
        if (pmc_it == par_metrics_.end()) {
                pmc_it = par_metrics_.insert(
                        make_pair(pit, ParagraphMetrics(text_->getPar(pit)))).first;
        }
        if (pmc_it->second.rows().empty() && redo) {
                redoParagraph(pit);
        }
        return pmc_it->second;
}


int TextMetrics::parPosition(pit_type pit) const
{
        if (pit < par_metrics_.begin()->first)
                return -1000000;
        else if (pit > par_metrics_.rbegin()->first)
                return +1000000;

        return par_metrics_[pit].position();
}


bool TextMetrics::metrics(MetricsInfo & mi, Dimension & dim, int min_width)
{
        BOOST_ASSERT(mi.base.textwidth);
        max_width_ = mi.base.textwidth;
        // backup old dimension.
        Dimension const old_dim = dim_;
        // reset dimension.
        dim_ = Dimension();
        dim_.wid = min_width;
        pit_type const npar = text_->paragraphs().size();
        if (npar > 1)
                // If there is more than one row, expand the text to 
                // the full allowable width.
                dim_.wid = max_width_;

        //lyxerr << "TextMetrics::metrics: width: " << mi.base.textwidth
        //      << " maxWidth: " << max_width_ << "\nfont: " << mi.base.font << endl;

        bool changed = false;
        unsigned int h = 0;
        for (pit_type pit = 0; pit != npar; ++pit) {
                changed |= redoParagraph(pit);
                ParagraphMetrics const & pm = par_metrics_[pit];
                h += pm.height();
                if (dim_.wid < pm.width())
                        dim_.wid = pm.width();
        }

        dim_.asc = par_metrics_[0].ascent();
        dim_.des = h - dim_.asc;
        //lyxerr << "dim_.wid " << dim_.wid << endl;
        //lyxerr << "dim_.asc " << dim_.asc << endl;
        //lyxerr << "dim_.des " << dim_.des << endl;

        changed |= dim_ != old_dim;
        dim = dim_;
        return changed;
}


int TextMetrics::rightMargin(ParagraphMetrics const & pm) const
{
        return main_text_? pm.rightMargin(bv_->buffer()) : 0;
}


int TextMetrics::rightMargin(pit_type const pit) const
{
        return main_text_? par_metrics_[pit].rightMargin(bv_->buffer()) : 0;
}


void TextMetrics::applyOuterFont(Font & font) const
{
        Font lf(font_);
        lf.reduce(bv_->buffer().params().getFont());
        lf.realize(font);
        lf.setLanguage(font.language());
        font = lf;
}


Font TextMetrics::getDisplayFont(pit_type pit, pos_type pos) const
{
        BOOST_ASSERT(pos >= 0);

        ParagraphList const & pars = text_->paragraphs();
        Paragraph const & par = pars[pit];
        LayoutPtr const & layout = par.layout();
        Buffer const & buffer = bv_->buffer();
        // FIXME: broken?
        BufferParams const & params = buffer.params();
        pos_type const body_pos = par.beginOfBody();

        // We specialize the 95% common case:
        if (!par.getDepth()) {
                Font f = par.getFontSettings(params, pos);
                if (!text_->isMainText(buffer))
                        applyOuterFont(f);
                bool lab = layout->labeltype == LABEL_MANUAL && pos < body_pos;

                Font const & lf = lab ? layout->labelfont : layout->font;
                Font rlf = lab ? layout->reslabelfont : layout->resfont;
                
                // In case the default family has been customized
                if (lf.family() == Font::INHERIT_FAMILY)
                        rlf.setFamily(params.getFont().family());
                return f.realize(rlf);
        }

        // The uncommon case need not be optimized as much
        Font const & layoutfont = pos < body_pos ? 
                layout->labelfont : layout->font;

        Font font = par.getFontSettings(params, pos);
        font.realize(layoutfont);

        if (!text_->isMainText(buffer))
                applyOuterFont(font);

        // Realize against environment font information
        // NOTE: the cast to pit_type should be removed when pit_type
        // changes to a unsigned integer.
        if (pit < pit_type(pars.size()))
                font.realize(outerFont(pit, pars));

        // Realize with the fonts of lesser depth.
        font.realize(params.getFont());

        return font;
}


bool TextMetrics::isRTL(CursorSlice const & sl, bool boundary) const
{
        if (!lyxrc.rtl_support || !sl.text())
                return false;

        int correction = 0;
        if (boundary && sl.pos() > 0)
                correction = -1;
                
        return getDisplayFont(sl.pit(), sl.pos() + correction).isVisibleRightToLeft();
}


bool TextMetrics::isRTLBoundary(pit_type pit, pos_type pos) const
{
        if (!lyxrc.rtl_support)
                return false;

        // no RTL boundary at line start
        if (pos == 0)
                return false;

        Paragraph const & par = text_->getPar(pit);

        bool left = getDisplayFont(pit, pos - 1).isVisibleRightToLeft();
        bool right;
        if (pos == par.size())
                right = par.isRTL(bv_->buffer().params());
        else
                right = getDisplayFont(pit, pos).isVisibleRightToLeft();
        return left != right;
}


bool TextMetrics::isRTLBoundary(pit_type pit, pos_type pos,
                Font const & font) const
{
        if (!lyxrc.rtl_support)
                return false;

        Paragraph const & par = text_->getPar(pit);
        bool left = font.isVisibleRightToLeft();
        bool right;
        if (pos == par.size())
                right = par.isRTL(bv_->buffer().params());
        else
                right = getDisplayFont(pit, pos).isVisibleRightToLeft();
        return left != right;
}


bool TextMetrics::redoParagraph(pit_type const pit)
{
        Paragraph & par = text_->getPar(pit);
        // IMPORTANT NOTE: We pass 'false' explicitely in order to not call
        // redoParagraph() recursively inside parMetrics.
        Dimension old_dim = parMetrics(pit, false).dim();
        ParagraphMetrics & pm = par_metrics_[pit];
        pm.reset(par);

        Buffer & buffer = bv_->buffer();
        BufferParams const & bparams = buffer.params();
        main_text_ = (text_ == &buffer.text());
        bool changed = false;

        // FIXME This check ought to be done somewhere else. It is the reason
        // why text_ is not     const. But then, where else to do it?
        // Well, how can you end up with either (a) a biblio environment that
        // has no InsetBibitem or (b) a biblio environment with more than one
        // InsetBibitem? I think the answer is: when paragraphs are merged;
        // when layout is set; when material is pasted.
        int const moveCursor = par.checkBiblio(buffer.params().trackChanges);
        if (moveCursor > 0)
                const_cast<Cursor &>(bv_->cursor()).posRight();
        else if (moveCursor < 0) {
                Cursor & cursor = const_cast<Cursor &>(bv_->cursor());
                if (cursor.pos() >= -moveCursor)
                        cursor.posLeft();
        }

        // Optimisation: this is used in the next two loops
        // so better to calculate that once here.
        int const right_margin = rightMargin(pm);

        // redo insets
        // FIXME: We should always use getFont(), see documentation of
        // noFontChange() in Inset.h.
        Font const bufferfont = buffer.params().getFont();
        InsetList::const_iterator ii = par.insetList().begin();
        InsetList::const_iterator iend = par.insetList().end();
        for (; ii != iend; ++ii) {
                Dimension dim;
                int const w = max_width_ - leftMargin(max_width_, pit, ii->pos)
                        - right_margin;
                Font const & font = ii->inset->noFontChange() ?
                        bufferfont : getDisplayFont(pit, ii->pos);
                MetricsInfo mi(bv_, font, w);
                ii->inset->metrics(mi, dim);
                Dimension const old_dim = pm.insetDimension(ii->inset);
                pm.setInsetDimension(ii->inset, dim);
                changed |= (old_dim != dim);
        }

        Cursor const & cur = bv_->cursor();
        DocIterator sel_beg = cur.selectionBegin();
        DocIterator sel_end = cur.selectionEnd();
        bool selection = cur.selection()
                // This is out text.
                && cur.text() == text_
                // if the anchor is outside, this is not our selection 
                && cur.anchor().text() == text_
                && pit >= sel_beg.pit() && pit <= sel_end.pit();

        // We care only about visible selection.
        if (selection) {
                if (pit != sel_beg.pit()) {
                        sel_beg.pit() = pit;
                        sel_beg.pos() = 0;
                }
                if (pit != sel_end.pit()) {
                        sel_end.pit() = pit;
                        sel_end.pos() = sel_end.lastpos();
                }
        }

        par.setBeginOfBody();
        pos_type first = 0;
        size_t row_index = 0;
        // maximum pixel width of a row
        int width = max_width_ - right_margin; // - leftMargin(max_width_, pit, row);
        do {
                Dimension dim;
                pos_type end = rowBreakPoint(width, pit, first);
                if (row_index || end < par.size())
                        // If there is more than one row, expand the text to 
                        // the full allowable width. This setting here is needed
                        // for the computeRowMetrics() below.
                        dim_.wid = max_width_;

                dim.wid = rowWidth(right_margin, pit, first, end);
                boost::tie(dim.asc, dim.des) = rowHeight(pit, first, end);
                if (row_index == pm.rows().size())
                        pm.rows().push_back(Row());
                Row & row = pm.rows()[row_index];
                row.setChanged(false);
                row.pos(first);
                row.endpos(end);
                if (selection)
                        row.setSelection(sel_beg.pos(), sel_end.pos());
                else
                        row.setSelection(-1, -1);
                row.setDimension(dim);
                int const max_row_width = max(dim_.wid, dim.wid);
                computeRowMetrics(pit, row, max_row_width);
                pm.computeRowSignature(row, bparams);
                first = end;
                ++row_index;

                pm.dim().wid = std::max(pm.dim().wid, dim.wid);
                pm.dim().des += dim.height();
        } while (first < par.size());

        if (row_index < pm.rows().size())
                pm.rows().resize(row_index);

        // Make sure that if a par ends in newline, there is one more row
        // under it
        if (first > 0 && par.isNewline(first - 1)) {
                Dimension dim;
                dim.wid = rowWidth(right_margin, pit, first, first);
                boost::tie(dim.asc, dim.des) = rowHeight(pit, first, first);
                if (row_index == pm.rows().size())
                        pm.rows().push_back(Row());
                Row & row = pm.rows()[row_index];
                row.setChanged(false);
                row.pos(first);
                row.endpos(first);
                row.setDimension(dim);
                int const max_row_width = max(dim_.wid, dim.wid);
                computeRowMetrics(pit, row, max_row_width);
                pm.computeRowSignature(row, bparams);
                pm.dim().des += dim.height();
        }

        pm.dim().asc += pm.rows()[0].ascent();
        pm.dim().des -= pm.rows()[0].ascent();

        changed |= old_dim.height() != pm.dim().height();

        return changed;
}


void TextMetrics::computeRowMetrics(pit_type const pit,
                Row & row, int width) const
{

        row.label_hfill = 0;
        row.hfill = 0;
        row.separator = 0;

        Buffer & buffer = bv_->buffer();
        Paragraph const & par = text_->getPar(pit);

        double w = width - row.width();
        // FIXME: put back this assertion when the crash on new doc is solved.
        //BOOST_ASSERT(w >= 0);

        //lyxerr << "\ndim_.wid " << dim_.wid << endl;
        //lyxerr << "row.width() " << row.width() << endl;
        //lyxerr << "w " << w << endl;

        bool const is_rtl = text_->isRTL(buffer, par);
        if (is_rtl)
                row.x = rightMargin(pit);
        else
                row.x = leftMargin(max_width_, pit, row.pos());

        // is there a manual margin with a manual label
        LayoutPtr const & layout = par.layout();

        if (layout->margintype == MARGIN_MANUAL
            && layout->labeltype == LABEL_MANUAL) {
                /// We might have real hfills in the label part
                int nlh = numberOfLabelHfills(par, row);

                // A manual label par (e.g. List) has an auto-hfill
                // between the label text and the body of the
                // paragraph too.
                // But we don't want to do this auto hfill if the par
                // is empty.
                if (!par.empty())
                        ++nlh;

                if (nlh && !par.getLabelWidthString().empty())
                        row.label_hfill = labelFill(pit, row) / double(nlh);
        }

        // are there any hfills in the row?
        int const nh = numberOfHfills(par, row);

        if (nh) {
                if (w > 0)
                        row.hfill = w / nh;
        // we don't have to look at the alignment if it is ALIGN_LEFT and
        // if the row is already larger then the permitted width as then
        // we force the LEFT_ALIGN'edness!
        } else if (int(row.width()) < max_width_) {
                // is it block, flushleft or flushright?
                // set x how you need it
                int align;
                if (par.params().align() == LYX_ALIGN_LAYOUT)
                        align = layout->align;
                else
                        align = par.params().align();

                // Display-style insets should always be on a centred row
                // The test on par.size() is to catch zero-size pars, which
                // would trigger the assert in Paragraph::getInset().
                //inset = par.size() ? par.getInset(row.pos()) : 0;
                if (row.pos() < par.size()
                    && par.isInset(row.pos()))
                {
                    switch(par.getInset(row.pos())->display()) {
                        case Inset::AlignLeft:
                                align = LYX_ALIGN_BLOCK;
                                break;
                        case Inset::AlignCenter:
                                align = LYX_ALIGN_CENTER;
                                break;
                        case Inset::Inline:
                        case Inset::AlignRight:
                                // unchanged (use align)
                                break;
                    }
                }

                switch (align) {
                case LYX_ALIGN_BLOCK: {
                        int const ns = numberOfSeparators(par, row);
                        bool disp_inset = false;
                        if (row.endpos() < par.size()) {
                                Inset const * in = par.getInset(row.endpos());
                                if (in)
                                        disp_inset = in->display();
                        }
                        // If we have separators, this is not the last row of a
                        // par, does not end in newline, and is not row above a
                        // display inset... then stretch it
                        if (ns
                            && row.endpos() < par.size()
                            && !par.isNewline(row.endpos() - 1)
                            && !disp_inset
                                ) {
                                row.separator = w / ns;
                                //lyxerr << "row.separator " << row.separator << endl;
                                //lyxerr << "ns " << ns << endl;
                        } else if (is_rtl) {
                                row.x += w;
                        }
                        break;
                }
                case LYX_ALIGN_RIGHT:
                        row.x += w;
                        break;
                case LYX_ALIGN_CENTER:
                        row.x += w / 2;
                        break;
                }
        }

        if (is_rtl) {
                pos_type body_pos = par.beginOfBody();
                pos_type end = row.endpos();

                if (body_pos > 0
                    && (body_pos > end || !par.isLineSeparator(body_pos - 1)))
                {
                        row.x += theFontMetrics(text_->getLabelFont(buffer, par)).
                                width(layout->labelsep);
                        if (body_pos <= end)
                                row.x += row.label_hfill;
                }
        }
}


int TextMetrics::labelFill(pit_type const pit, Row const & row) const
{
        Buffer & buffer = bv_->buffer();
        Paragraph const & par = text_->getPar(pit);

        pos_type last = par.beginOfBody();
        BOOST_ASSERT(last > 0);

        // -1 because a label ends with a space that is in the label
        --last;

        // a separator at this end does not count
        if (par.isLineSeparator(last))
                --last;

        int w = 0;
        for (pos_type i = row.pos(); i <= last; ++i)
                w += singleWidth(pit, i);

        docstring const & label = par.params().labelWidthString();
        if (label.empty())
                return 0;

        FontMetrics const & fm
                = theFontMetrics(text_->getLabelFont(buffer, par));

        return max(0, fm.width(label) - w);
}


namespace {

// this needs special handling - only newlines count as a break point
pos_type addressBreakPoint(pos_type i, Paragraph const & par)
{
        pos_type const end = par.size();

        for (; i < end; ++i)
                if (par.isNewline(i))
                        return i + 1;

        return end;
}

};


int TextMetrics::labelEnd(pit_type const pit) const
{
        // labelEnd is only needed if the layout fills a flushleft label.
        if (text_->getPar(pit).layout()->margintype != MARGIN_MANUAL)
                return 0;
        // return the beginning of the body
        return leftMargin(max_width_, pit);
}


pit_type TextMetrics::rowBreakPoint(int width, pit_type const pit,
                pit_type pos) const
{
        Buffer & buffer = bv_->buffer();
        ParagraphMetrics const & pm = par_metrics_[pit];
        Paragraph const & par = text_->getPar(pit);
        pos_type const end = par.size();
        if (pos == end || width < 0)
                return end;

        LayoutPtr const & layout = par.layout();

        if (layout->margintype == MARGIN_RIGHT_ADDRESS_BOX)
                return addressBreakPoint(pos, par);

        pos_type const body_pos = par.beginOfBody();


        // Now we iterate through until we reach the right margin
        // or the end of the par, then choose the possible break
        // nearest that.

        int label_end = labelEnd(pit);
        int const left = leftMargin(max_width_, pit, pos);
        int x = left;

        // pixel width since last breakpoint
        int chunkwidth = 0;

        FontIterator fi = FontIterator(*this, par, pit, pos);
        pos_type point = end;
        pos_type i = pos;
        for ( ; i < end; ++i, ++fi) {
                int thiswidth = pm.singleWidth(i, *fi);

                // add the auto-hfill from label end to the body
                if (body_pos && i == body_pos) {
                        FontMetrics const & fm = theFontMetrics(
                                text_->getLabelFont(buffer, par));
                        int add = fm.width(layout->labelsep);
                        if (par.isLineSeparator(i - 1))
                                add -= singleWidth(pit, i - 1);

                        add = std::max(add, label_end - x);
                        thiswidth += add;
                }

                x += thiswidth;
                chunkwidth += thiswidth;

                // break before a character that will fall off
                // the right of the row
                if (x >= width) {
                        // if no break before, break here
                        if (point == end || chunkwidth >= width - left) {
                                if (i > pos)
                                        point = i;
                                else
                                        point = i + 1;

                        }
                        // exit on last registered breakpoint:
                        break;
                }

                if (par.isNewline(i)) {
                        point = i + 1;
                        break;
                }
                // Break before...
                if (i + 1 < end) {
                        if (par.isInset(i + 1) && par.getInset(i + 1)->display()) {
                                point = i + 1;
                                break;
                        }
                        // ...and after.
                        if (par.isInset(i) && par.getInset(i)->display()) {
                                point = i + 1;
                                break;
                        }
                }

                if (!par.isInset(i) || par.getInset(i)->isChar()) {
                        // some insets are line separators too
                        if (par.isLineSeparator(i)) {
                                // register breakpoint:
                                point = i + 1;
                                chunkwidth = 0;
                        }
                }
        }

        // maybe found one, but the par is short enough.
        if (i == end && x < width)
                point = end;

        // manual labels cannot be broken in LaTeX. But we
        // want to make our on-screen rendering of footnotes
        // etc. still break
        if (body_pos && point < body_pos)
                point = body_pos;

        return point;
}


int TextMetrics::rowWidth(int right_margin, pit_type const pit,
                pos_type const first, pos_type const end) const
{
        Buffer & buffer = bv_->buffer();
        // get the pure distance
        ParagraphMetrics const & pm = par_metrics_[pit];
        Paragraph const & par = text_->getPar(pit);
        int w = leftMargin(max_width_, pit, first);
        int label_end = labelEnd(pit);

        pos_type const body_pos = par.beginOfBody();
        pos_type i = first;

        if (i < end) {
                FontIterator fi = FontIterator(*this, par, pit, i);
                for ( ; i < end; ++i, ++fi) {
                        if (body_pos > 0 && i == body_pos) {
                                FontMetrics const & fm = theFontMetrics(
                                        text_->getLabelFont(buffer, par));
                                w += fm.width(par.layout()->labelsep);
                                if (par.isLineSeparator(i - 1))
                                        w -= singleWidth(pit, i - 1);
                                w = max(w, label_end);
                        }
                        w += pm.singleWidth(i, *fi);
                }
        }

        if (body_pos > 0 && body_pos >= end) {
                FontMetrics const & fm = theFontMetrics(
                        text_->getLabelFont(buffer, par));
                w += fm.width(par.layout()->labelsep);
                if (end > 0 && par.isLineSeparator(end - 1))
                        w -= singleWidth(pit, end - 1);
                w = max(w, label_end);
        }

        return w + right_margin;
}


boost::tuple<int, int> TextMetrics::rowHeight(pit_type const pit, pos_type const first,
                pos_type const end) const
{
        Paragraph const & par = text_->getPar(pit);
        // get the maximum ascent and the maximum descent
        double layoutasc = 0;
        double layoutdesc = 0;
        double const dh = defaultRowHeight();

        // ok, let us initialize the maxasc and maxdesc value.
        // Only the fontsize count. The other properties
        // are taken from the layoutfont. Nicer on the screen :)
        LayoutPtr const & layout = par.layout();

        // as max get the first character of this row then it can
        // increase but not decrease the height. Just some point to
        // start with so we don't have to do the assignment below too
        // often.
        Buffer const & buffer = bv_->buffer();
        Font font = getDisplayFont(pit, first);
        Font::FONT_SIZE const tmpsize = font.size();
        font = text_->getLayoutFont(buffer, pit);
        Font::FONT_SIZE const size = font.size();
        font.setSize(tmpsize);

        Font labelfont = text_->getLabelFont(buffer, par);

        FontMetrics const & labelfont_metrics = theFontMetrics(labelfont);
        FontMetrics const & fontmetrics = theFontMetrics(font);

        // these are minimum values
        double const spacing_val = layout->spacing.getValue()
                * text_->spacing(buffer, par);
        //lyxerr << "spacing_val = " << spacing_val << endl;
        int maxasc  = int(fontmetrics.maxAscent()  * spacing_val);
        int maxdesc = int(fontmetrics.maxDescent() * spacing_val);

        // insets may be taller
        ParagraphMetrics const & pm = par_metrics_[pit];
        InsetList::const_iterator ii = par.insetList().begin();
        InsetList::const_iterator iend = par.insetList().end();
        for ( ; ii != iend; ++ii) {
                Dimension const & dim = pm.insetDimension(ii->inset);
                if (ii->pos >= first && ii->pos < end) {
                        maxasc  = max(maxasc,  dim.ascent());
                        maxdesc = max(maxdesc, dim.descent());
                }
        }

        // Check if any custom fonts are larger (Asger)
        // This is not completely correct, but we can live with the small,
        // cosmetic error for now.
        int labeladdon = 0;

        Font::FONT_SIZE maxsize =
                par.highestFontInRange(first, end, size);
        if (maxsize > font.size()) {
                // use standard paragraph font with the maximal size
                Font maxfont = font;
                maxfont.setSize(maxsize);
                FontMetrics const & maxfontmetrics = theFontMetrics(maxfont);
                maxasc  = max(maxasc,  maxfontmetrics.maxAscent());
                maxdesc = max(maxdesc, maxfontmetrics.maxDescent());
        }

        // This is nicer with box insets:
        ++maxasc;
        ++maxdesc;

        ParagraphList const & pars = text_->paragraphs();

        // is it a top line?
        if (first == 0) {
                BufferParams const & bufparams = buffer.params();
                // some parskips VERY EASY IMPLEMENTATION
                if (bufparams.paragraph_separation
                    == BufferParams::PARSEP_SKIP
                        && par.ownerCode() != ERT_CODE
                        && par.ownerCode() != LISTINGS_CODE
                        && pit > 0
                        && ((layout->isParagraph() && par.getDepth() == 0)
                            || (pars[pit - 1].layout()->isParagraph()
                                && pars[pit - 1].getDepth() == 0)))
                {
                                maxasc += bufparams.getDefSkip().inPixels(*bv_);
                }

                if (par.params().startOfAppendix())
                        maxasc += int(3 * dh);

                // This is special code for the chapter, since the label of this
                // layout is printed in an extra row
                if (layout->counter == "chapter"
                    && !par.params().labelString().empty()) {
                        labeladdon = int(labelfont_metrics.maxHeight()
                                     * layout->spacing.getValue()
                                     * text_->spacing(buffer, par));
                }

                // special code for the top label
                if ((layout->labeltype == LABEL_TOP_ENVIRONMENT
                     || layout->labeltype == LABEL_BIBLIO
                     || layout->labeltype == LABEL_CENTERED_TOP_ENVIRONMENT)
                    && isFirstInSequence(pit, pars)
                    && !par.getLabelstring().empty())
                {
                        labeladdon = int(
                                  labelfont_metrics.maxHeight()
                                        * layout->spacing.getValue()
                                        * text_->spacing(buffer, par)
                                + (layout->topsep + layout->labelbottomsep) * dh);
                }

                // Add the layout spaces, for example before and after
                // a section, or between the items of a itemize or enumerate
                // environment.

                pit_type prev = depthHook(pit, pars, par.getDepth());
                Paragraph const & prevpar = pars[prev];
                if (prev != pit
                    && prevpar.layout() == layout
                    && prevpar.getDepth() == par.getDepth()
                    && prevpar.getLabelWidthString()
                                        == par.getLabelWidthString()) {
                        layoutasc = layout->itemsep * dh;
                } else if (pit != 0 || first != 0) {
                        if (layout->topsep > 0)
                                layoutasc = layout->topsep * dh;
                }

                prev = outerHook(pit, pars);
                if (prev != pit_type(pars.size())) {
                        maxasc += int(pars[prev].layout()->parsep * dh);
                } else if (pit != 0) {
                        Paragraph const & prevpar = pars[pit - 1];
                        if (prevpar.getDepth() != 0 ||
                                        prevpar.layout() == layout) {
                                maxasc += int(layout->parsep * dh);
                        }
                }
        }

        // is it a bottom line?
        if (end >= par.size()) {
                // add the layout spaces, for example before and after
                // a section, or between the items of a itemize or enumerate
                // environment
                pit_type nextpit = pit + 1;
                if (nextpit != pit_type(pars.size())) {
                        pit_type cpit = pit;
                        double usual = 0;
                        double unusual = 0;

                        if (pars[cpit].getDepth() > pars[nextpit].getDepth()) {
                                usual = pars[cpit].layout()->bottomsep * dh;
                                cpit = depthHook(cpit, pars, pars[nextpit].getDepth());
                                if (pars[cpit].layout() != pars[nextpit].layout()
                                        || pars[nextpit].getLabelWidthString() != pars[cpit].getLabelWidthString())
                                {
                                        unusual = pars[cpit].layout()->bottomsep * dh;
                                }
                                layoutdesc = max(unusual, usual);
                        } else if (pars[cpit].getDepth() == pars[nextpit].getDepth()) {
                                if (pars[cpit].layout() != pars[nextpit].layout()
                                        || pars[nextpit].getLabelWidthString() != pars[cpit].getLabelWidthString())
                                        layoutdesc = int(pars[cpit].layout()->bottomsep * dh);
                        }
                }
        }

        // incalculate the layout spaces
        maxasc  += int(layoutasc  * 2 / (2 + pars[pit].getDepth()));
        maxdesc += int(layoutdesc * 2 / (2 + pars[pit].getDepth()));

        // FIXME: the correct way is to do the following is to move the
        // following code in another method specially tailored for the
        // main Text. The following test is thus bogus.
        // Top and bottom margin of the document (only at top-level)
        if (main_text_) {
                if (pit == 0 && first == 0)
                        maxasc += 20;
                if (pit + 1 == pit_type(pars.size()) &&
                    end == par.size() &&
                                !(end > 0 && par.isNewline(end - 1)))
                        maxdesc += 20;
        }

        return boost::make_tuple(maxasc + labeladdon, maxdesc);
}


// x is an absolute screen coord
// returns the column near the specified x-coordinate of the row
// x is set to the real beginning of this column
pos_type TextMetrics::getColumnNearX(pit_type const pit,
                Row const & row, int & x, bool & boundary) const
{
        Buffer const & buffer = bv_->buffer();

        /// For the main Text, it is possible that this pit is not
        /// yet in the CoordCache when moving cursor up.
        /// x Paragraph coordinate is always 0 for main text anyway.
        int const xo = origin_.x_;
        x -= xo;
        Paragraph const & par = text_->getPar(pit);
        ParagraphMetrics const & pm = par_metrics_[pit];
        Bidi bidi;
        bidi.computeTables(par, buffer, row);

        pos_type vc = row.pos();
        pos_type end = row.endpos();
        pos_type c = 0;
        LayoutPtr const & layout = par.layout();

        bool left_side = false;

        pos_type body_pos = par.beginOfBody();

        double tmpx = row.x;
        double last_tmpx = tmpx;

        if (body_pos > 0 &&
            (body_pos > end || !par.isLineSeparator(body_pos - 1)))
                body_pos = 0;

        // check for empty row
        if (vc == end) {
                x = int(tmpx) + xo;
                return 0;
        }

        while (vc < end && tmpx <= x) {
                c = bidi.vis2log(vc);
                last_tmpx = tmpx;
                if (body_pos > 0 && c == body_pos - 1) {
                        FontMetrics const & fm = theFontMetrics(
                                text_->getLabelFont(buffer, par));
                        tmpx += row.label_hfill + fm.width(layout->labelsep);
                        if (par.isLineSeparator(body_pos - 1))
                                tmpx -= singleWidth(pit, body_pos - 1);
                }

                if (pm.hfillExpansion(row, c)) {
                        tmpx += singleWidth(pit, c);
                        if (c >= body_pos)
                                tmpx += row.hfill;
                        else
                                tmpx += row.label_hfill;
                } else if (par.isSeparator(c)) {
                        tmpx += singleWidth(pit, c);
                        if (c >= body_pos)
                                tmpx += row.separator;
                } else {
                        tmpx += singleWidth(pit, c);
                }
                ++vc;
        }

        if ((tmpx + last_tmpx) / 2 > x) {
                tmpx = last_tmpx;
                left_side = true;
        }

        BOOST_ASSERT(vc <= end);  // This shouldn't happen.

        boundary = false;
        // This (rtl_support test) is not needed, but gives
        // some speedup if rtl_support == false
        bool const lastrow = lyxrc.rtl_support && row.endpos() == par.size();

        // If lastrow is false, we don't need to compute
        // the value of rtl.
        bool const rtl = lastrow ? text_->isRTL(buffer, par) : false;
        if (lastrow &&
            ((rtl  &&  left_side && vc == row.pos() && x < tmpx - 5) ||
             (!rtl && !left_side && vc == end  && x > tmpx + 5)))
                c = end;
        else if (vc == row.pos()) {
                c = bidi.vis2log(vc);
                if (bidi.level(c) % 2 == 1)
                        ++c;
        } else {
                c = bidi.vis2log(vc - 1);
                bool const rtl = (bidi.level(c) % 2 == 1);
                if (left_side == rtl) {
                        ++c;
                        boundary = isRTLBoundary(pit, c);
                }
        }

// I believe this code is not needed anymore (Jug 20050717)
#if 0
        // The following code is necessary because the cursor position past
        // the last char in a row is logically equivalent to that before
        // the first char in the next row. That's why insets causing row
        // divisions -- Newline and display-style insets -- must be treated
        // specially, so cursor up/down doesn't get stuck in an air gap -- MV
        // Newline inset, air gap below:
        if (row.pos() < end && c >= end && par.isNewline(end - 1)) {
                if (bidi.level(end -1) % 2 == 0)
                        tmpx -= singleWidth(pit, end - 1);
                else
                        tmpx += singleWidth(pit, end - 1);
                c = end - 1;
        }

        // Air gap above display inset:
        if (row.pos() < end && c >= end && end < par.size()
            && par.isInset(end) && par.getInset(end)->display()) {
                c = end - 1;
        }
        // Air gap below display inset:
        if (row.pos() < end && c >= end && par.isInset(end - 1)
            && par.getInset(end - 1)->display()) {
                c = end - 1;
        }
#endif

        x = int(tmpx) + xo;
        pos_type const col = c - row.pos();

        if (!c || end == par.size())
                return col;

        if (c==end && !par.isLineSeparator(c-1) && !par.isNewline(c-1)) {
                boundary = true;
                return col;
        }

        return min(col, end - 1 - row.pos());
}


pos_type TextMetrics::x2pos(pit_type pit, int row, int x) const
{
        // We play safe and use parMetrics(pit) to make sure the
        // ParagraphMetrics will be redone and OK to use if needed.
        // Otherwise we would use an empty ParagraphMetrics in
        // upDownInText() while in selection mode.
        ParagraphMetrics const & pm = parMetrics(pit);

        BOOST_ASSERT(row < int(pm.rows().size()));
        bool bound = false;
        Row const & r = pm.rows()[row];
        return r.pos() + getColumnNearX(pit, r, x, bound);
}


void TextMetrics::newParMetricsDown()
{
        pair<pit_type, ParagraphMetrics> const & last = *par_metrics_.rbegin();
        pit_type const pit = last.first + 1;
        if (pit == int(text_->paragraphs().size()))
                return;

        // do it and update its position.
        redoParagraph(pit);
        par_metrics_[pit].setPosition(last.second.position()
                + last.second.descent());
}


void TextMetrics::newParMetricsUp()
{
        pair<pit_type, ParagraphMetrics> const & first = *par_metrics_.begin();
        if (first.first == 0)
                return;

        pit_type const pit = first.first - 1;
        // do it and update its position.
        redoParagraph(pit);
        par_metrics_[pit].setPosition(first.second.position()
                - first.second.ascent());
}

// y is screen coordinate
pit_type TextMetrics::getPitNearY(int y)
{
        BOOST_ASSERT(!text_->paragraphs().empty());
        LYXERR(Debug::DEBUG)
                << BOOST_CURRENT_FUNCTION
                << ": y: " << y << " cache size: " << par_metrics_.size()
                << endl;

        // look for highest numbered paragraph with y coordinate less than given y
        pit_type pit = 0;
        int yy = -1;
        ParMetricsCache::const_iterator it = par_metrics_.begin();
        ParMetricsCache::const_iterator et = par_metrics_.end();
        ParMetricsCache::const_iterator last = et; last--;

        ParagraphMetrics const & pm = it->second;

        // If we are off-screen (before the visible part)
        if (y < 0
                // and even before the first paragraph in the cache.
                && y < it->second.position() - int(pm.ascent())) {
                //  and we are not at the first paragraph in the inset.
                if (it->first == 0)
                        return 0;
                // then this is the paragraph we are looking for.
                pit = it->first - 1;
                // rebreak it and update the CoordCache.
                redoParagraph(pit);
                par_metrics_[pit].setPosition(it->second.position() - pm.descent());
                return pit;
        }

        ParagraphMetrics const & pm_last = par_metrics_[last->first];

        // If we are off-screen (after the visible part)
        if (y > bv_->workHeight()
                // and even after the first paragraph in the cache.
                && y >= last->second.position() + int(pm_last.descent())) {
                pit = last->first + 1;
                //  and we are not at the last paragraph in the inset.
                if (pit == int(text_->paragraphs().size()))
                        return last->first;
                // then this is the paragraph we are looking for.
                // rebreak it and update the CoordCache.
                redoParagraph(pit);
                par_metrics_[pit].setPosition(last->second.position() + pm_last.ascent());
                return pit;
        }

        for (; it != et; ++it) {
                LYXERR(Debug::DEBUG)
                        << BOOST_CURRENT_FUNCTION
                        << "  examining: pit: " << it->first
                        << " y: " << it->second.position()
                        << endl;

                ParagraphMetrics const & pm = par_metrics_[it->first];

                if (it->first >= pit && int(it->second.position()) - int(pm.ascent()) <= y) {
                        pit = it->first;
                        yy = it->second.position();
                }
        }

        LYXERR(Debug::DEBUG)
                << BOOST_CURRENT_FUNCTION
                << ": found best y: " << yy << " for pit: " << pit
                << endl;

        return pit;
}


Row const & TextMetrics::getRowNearY(int y, pit_type pit) const
{
        ParagraphMetrics const & pm = par_metrics_[pit];

        int yy = pm.position() - pm.ascent();
        BOOST_ASSERT(!pm.rows().empty());
        RowList::const_iterator rit = pm.rows().begin();
        RowList::const_iterator rlast = pm.rows().end();
        --rlast;
        for (; rit != rlast; yy += rit->height(), ++rit)
                if (yy + rit->height() > y)
                        break;
        return *rit;
}


// x,y are absolute screen coordinates
// sets cursor recursively descending into nested editable insets
Inset * TextMetrics::editXY(Cursor & cur, int x, int y)
{
        if (lyxerr.debugging(Debug::WORKAREA)) {
                lyxerr << "TextMetrics::editXY(cur, " << x << ", " << y << ")" << std::endl;
                cur.bv().coordCache().dump();
        }
        pit_type pit = getPitNearY(y);
        BOOST_ASSERT(pit != -1);

        Row const & row = getRowNearY(y, pit);
        bool bound = false;

        int xx = x; // is modified by getColumnNearX
        pos_type const pos = row.pos()
                + getColumnNearX(pit, row, xx, bound);
        cur.pit() = pit;
        cur.pos() = pos;
        cur.boundary(bound);
        cur.setTargetX(x);

        // try to descend into nested insets
        Inset * inset = checkInsetHit(x, y);
        //lyxerr << "inset " << inset << " hit at x: " << x << " y: " << y << endl;
        if (!inset) {
                // Either we deconst editXY or better we move current_font
                // and real_current_font to Cursor
                // FIXME: what is needed now that current_font and real_current_font
                // are transferred?
                cur.setCurrentFont();
                return 0;
        }

        ParagraphList const & pars = text_->paragraphs();
        Inset const * insetBefore = pos? pars[pit].getInset(pos - 1): 0;
        //Inset * insetBehind = pars[pit].getInset(pos);

        // This should be just before or just behind the
        // cursor position set above.
        BOOST_ASSERT((pos != 0 && inset == insetBefore)
                || inset == pars[pit].getInset(pos));

        // Make sure the cursor points to the position before
        // this inset.
        if (inset == insetBefore) {
                --cur.pos();
                cur.boundary(false);
        }

        // Try to descend recursively inside the inset.
        inset = inset->editXY(cur, x, y);

        if (cur.top().text() == text_)
                cur.setCurrentFont();
        return inset;
}


void TextMetrics::setCursorFromCoordinates(Cursor & cur, int const x, int const y)
{
        BOOST_ASSERT(text_ == cur.text());
        pit_type pit = getPitNearY(y);

        ParagraphMetrics const & pm = par_metrics_[pit];

        int yy = pm.position() - pm.ascent();
        LYXERR(Debug::DEBUG)
                << BOOST_CURRENT_FUNCTION
                << ": x: " << x
                << " y: " << y
                << " pit: " << pit
                << " yy: " << yy << endl;

        int r = 0;
        BOOST_ASSERT(pm.rows().size());
        for (; r < int(pm.rows().size()) - 1; ++r) {
                Row const & row = pm.rows()[r];
                if (int(yy + row.height()) > y)
                        break;
                yy += row.height();
        }

        Row const & row = pm.rows()[r];

        LYXERR(Debug::DEBUG)
                << BOOST_CURRENT_FUNCTION
                << ": row " << r
                << " from pos: " << row.pos()
                << endl;

        bool bound = false;
        int xx = x;
        pos_type const pos = row.pos() + getColumnNearX(pit, row, xx, bound);

        LYXERR(Debug::DEBUG)
                << BOOST_CURRENT_FUNCTION
                << ": setting cursor pit: " << pit
                << " pos: " << pos
                << endl;

        text_->setCursor(cur, pit, pos, true, bound);
        // remember new position.
        cur.setTargetX();
}


//takes screen x,y coordinates
Inset * TextMetrics::checkInsetHit(int x, int y)
{
        pit_type pit = getPitNearY(y);
        BOOST_ASSERT(pit != -1);

        Paragraph const & par = text_->paragraphs()[pit];
        ParagraphMetrics const & pm = par_metrics_[pit];

        LYXERR(Debug::DEBUG)
                << BOOST_CURRENT_FUNCTION
                << ": x: " << x
                << " y: " << y
                << "  pit: " << pit
                << endl;
        InsetList::const_iterator iit = par.insetList().begin();
        InsetList::const_iterator iend = par.insetList().end();
        for (; iit != iend; ++iit) {
                Inset * inset = iit->inset;

                LYXERR(Debug::DEBUG)
                        << BOOST_CURRENT_FUNCTION
                        << ": examining inset " << inset << endl;

                if (!bv_->coordCache().getInsets().has(inset)) {
                        LYXERR(Debug::DEBUG)
                                << BOOST_CURRENT_FUNCTION
                                << ": inset has no cached position" << endl;
                        return 0;
                }

                Dimension const & dim = pm.insetDimension(inset);
                Point p = bv_->coordCache().getInsets().xy(inset);

                LYXERR(Debug::DEBUG)
                        << BOOST_CURRENT_FUNCTION
                        << ": xo: " << p.x_ << "..." << p.x_ + dim.wid
                        << " yo: " << p.y_ - dim.asc << "..." << p.y_ + dim.des
                        << endl;

                if (x >= p.x_
                        && x <= p.x_ + dim.wid
                        && y >= p.y_ - dim.asc
                        && y <= p.y_ + dim.des) {
                        LYXERR(Debug::DEBUG)
                                << BOOST_CURRENT_FUNCTION
                                << ": Hit inset: " << inset << endl;
                        return inset;
                }
        }

        LYXERR(Debug::DEBUG)
                << BOOST_CURRENT_FUNCTION
                << ": No inset hit. " << endl;
        return 0;
}


int TextMetrics::cursorX(CursorSlice const & sl,
                bool boundary) const
{
        BOOST_ASSERT(sl.text() == text_);
        pit_type const pit = sl.pit();
        Paragraph const & par = text_->paragraphs()[pit];
        ParagraphMetrics const & pm = par_metrics_[pit];
        if (pm.rows().empty())
                return 0;

        pos_type ppos = sl.pos();
        // Correct position in front of big insets
        bool const boundary_correction = ppos != 0 && boundary;
        if (boundary_correction)
                --ppos;

        Row const & row = pm.getRow(sl.pos(), boundary);

        pos_type cursor_vpos = 0;

        Buffer const & buffer = bv_->buffer();
        double x = row.x;
        Bidi bidi;
        bidi.computeTables(par, buffer, row);

        pos_type const row_pos  = row.pos();
        pos_type const end      = row.endpos();
        // Spaces at logical line breaks in bidi text must be skipped during 
        // cursor positioning. However, they may appear visually in the middle
        // of a row; they must be skipped, wherever they are...
        // * logically "abc_[HEBREW_\nHEBREW]"
        // * visually "abc_[_WERBEH\nWERBEH]"
        pos_type skipped_sep_vpos = -1;

        if (end <= row_pos)
                cursor_vpos = row_pos;
        else if (ppos >= end)
                cursor_vpos = text_->isRTL(buffer, par) ? row_pos : end;
        else if (ppos > row_pos && ppos >= end)
                // Place cursor after char at (logical) position pos - 1
                cursor_vpos = (bidi.level(ppos - 1) % 2 == 0)
                        ? bidi.log2vis(ppos - 1) + 1 : bidi.log2vis(ppos - 1);
        else
                // Place cursor before char at (logical) position ppos
                cursor_vpos = (bidi.level(ppos) % 2 == 0)
                        ? bidi.log2vis(ppos) : bidi.log2vis(ppos) + 1;

        pos_type body_pos = par.beginOfBody();
        if (body_pos > 0 &&
            (body_pos > end || !par.isLineSeparator(body_pos - 1)))
                body_pos = 0;

        // Use font span to speed things up, see below
        FontSpan font_span;
        Font font;

        // If the last logical character is a separator, skip it, unless
        // it's in the last row of a paragraph; see skipped_sep_vpos declaration
        if (end > 0 && end < par.size() && par.isSeparator(end - 1))
                skipped_sep_vpos = bidi.log2vis(end - 1);
        
        for (pos_type vpos = row_pos; vpos < cursor_vpos; ++vpos) {
                // Skip the separator which is at the logical end of the row
                if (vpos == skipped_sep_vpos)
                        continue;
                pos_type pos = bidi.vis2log(vpos);
                if (body_pos > 0 && pos == body_pos - 1) {
                        FontMetrics const & labelfm = theFontMetrics(
                                text_->getLabelFont(buffer, par));
                        x += row.label_hfill + labelfm.width(par.layout()->labelsep);
                        if (par.isLineSeparator(body_pos - 1))
                                x -= singleWidth(pit, body_pos - 1);
                }

                // Use font span to speed things up, see above
                if (pos < font_span.first || pos > font_span.last) {
                        font_span = par.fontSpan(pos);
                        font = getDisplayFont(pit, pos);
                }

                x += pm.singleWidth(pos, font);

                if (pm.hfillExpansion(row, pos))
                        x += (pos >= body_pos) ? row.hfill : row.label_hfill;
                else if (par.isSeparator(pos) && pos >= body_pos)
                        x += row.separator;
        }

        // see correction above
        if (boundary_correction) {
                if (isRTL(sl, boundary))
                        x -= singleWidth(pit, ppos);
                else
                        x += singleWidth(pit, ppos);
        }

        return int(x);
}


int TextMetrics::cursorY(CursorSlice const & sl, bool boundary) const
{
        //lyxerr << "TextMetrics::cursorY: boundary: " << boundary << std::endl;
        ParagraphMetrics const & pm = par_metrics_[sl.pit()];
        if (pm.rows().empty())
                return 0;

        int h = 0;
        h -= par_metrics_[0].rows()[0].ascent();
        for (pit_type pit = 0; pit < sl.pit(); ++pit) {
                h += par_metrics_[pit].height();
        }
        int pos = sl.pos();
        if (pos && boundary)
                --pos;
        size_t const rend = pm.pos2row(pos);
        for (size_t rit = 0; rit != rend; ++rit)
                h += pm.rows()[rit].height();
        h += pm.rows()[rend].ascent();
        return h;
}


void TextMetrics::cursorPrevious(Cursor & cur)
{
        pos_type cpos = cur.pos();
        pit_type cpar = cur.pit();

        int x = cur.x_target();
        setCursorFromCoordinates(cur, x, 0);
        cur.dispatch(FuncRequest(cur.selection()? LFUN_UP_SELECT: LFUN_UP));

        if (cpar == cur.pit() && cpos == cur.pos())
                // we have a row which is taller than the workarea. The
                // simplest solution is to move to the previous row instead.
                cur.dispatch(FuncRequest(cur.selection()? LFUN_UP_SELECT: LFUN_UP));

        cur.finishUndo();
        cur.updateFlags(Update::Force | Update::FitCursor);
}


void TextMetrics::cursorNext(Cursor & cur)
{
        pos_type cpos = cur.pos();
        pit_type cpar = cur.pit();

        int x = cur.x_target();
        setCursorFromCoordinates(cur, x, cur.bv().workHeight() - 1);
        cur.dispatch(FuncRequest(cur.selection()? LFUN_DOWN_SELECT: LFUN_DOWN));

        if (cpar == cur.pit() && cpos == cur.pos())
                // we have a row which is taller than the workarea. The
                // simplest solution is to move to the next row instead.
                cur.dispatch(
                        FuncRequest(cur.selection()? LFUN_DOWN_SELECT: LFUN_DOWN));

        cur.finishUndo();
        cur.updateFlags(Update::Force | Update::FitCursor);
}


// the cursor set functions have a special mechanism. When they
// realize you left an empty paragraph, they will delete it.

bool TextMetrics::cursorHome(Cursor & cur)
{
        BOOST_ASSERT(text_ == cur.text());
        ParagraphMetrics const & pm = par_metrics_[cur.pit()];
        Row const & row = pm.getRow(cur.pos(),cur.boundary());
        return text_->setCursor(cur, cur.pit(), row.pos());
}


bool TextMetrics::cursorEnd(Cursor & cur)
{
        BOOST_ASSERT(text_ == cur.text());
        // if not on the last row of the par, put the cursor before
        // the final space exept if I have a spanning inset or one string
        // is so long that we force a break.
        pos_type end = cur.textRow().endpos();
        if (end == 0)
                // empty text, end-1 is no valid position
                return false;
        bool boundary = false;
        if (end != cur.lastpos()) {
                if (!cur.paragraph().isLineSeparator(end-1)
                    && !cur.paragraph().isNewline(end-1))
                        boundary = true;
                else
                        --end;
        }
        return text_->setCursor(cur, cur.pit(), end, true, boundary);
}


void TextMetrics::deleteLineForward(Cursor & cur)
{
        BOOST_ASSERT(text_ == cur.text());
        if (cur.lastpos() == 0) {
                // Paragraph is empty, so we just go forward
                text_->cursorForward(cur);
        } else {
                cur.resetAnchor();
                cur.selection() = true; // to avoid deletion
                cursorEnd(cur);
                cur.setSelection();
                // What is this test for ??? (JMarc)
                if (!cur.selection())
                        text_->deleteWordForward(cur);
                else
                        cap::cutSelection(cur, true, false);
                checkBufferStructure(cur.buffer(), cur);
        }
}


bool TextMetrics::isLastRow(pit_type pit, Row const & row) const
{
        ParagraphList const & pars = text_->paragraphs();
        return row.endpos() >= pars[pit].size()
                && pit + 1 == pit_type(pars.size());
}


bool TextMetrics::isFirstRow(pit_type pit, Row const & row) const
{
        return row.pos() == 0 && pit == 0;
}


int TextMetrics::leftMargin(int max_width, pit_type pit) const
{
        BOOST_ASSERT(pit >= 0);
        BOOST_ASSERT(pit < int(text_->paragraphs().size()));
        return leftMargin(max_width, pit, text_->paragraphs()[pit].size());
}


int TextMetrics::leftMargin(int max_width,
                pit_type const pit, pos_type const pos) const
{
        ParagraphList const & pars = text_->paragraphs();

        BOOST_ASSERT(pit >= 0);
        BOOST_ASSERT(pit < int(pars.size()));
        Paragraph const & par = pars[pit];
        BOOST_ASSERT(pos >= 0);
        BOOST_ASSERT(pos <= par.size());
        Buffer const & buffer = bv_->buffer();
        //lyxerr << "TextMetrics::leftMargin: pit: " << pit << " pos: " << pos << endl;
        TextClass const & tclass = buffer.params().getTextClass();
        LayoutPtr const & layout = par.layout();

        docstring parindent = layout->parindent;

        int l_margin = 0;

        if (text_->isMainText(buffer))
                l_margin += changebarMargin();

        l_margin += theFontMetrics(buffer.params().getFont()).signedWidth(
                tclass.leftmargin());

        if (par.getDepth() != 0) {
                // find the next level paragraph
                pit_type newpar = outerHook(pit, pars);
                if (newpar != pit_type(pars.size())) {
                        if (pars[newpar].layout()->isEnvironment()) {
                                l_margin = leftMargin(max_width, newpar);
                        }
                        if (par.layout() == tclass.defaultLayout()) {
                                if (pars[newpar].params().noindent())
                                        parindent.erase();
                                else
                                        parindent = pars[newpar].layout()->parindent;
                        }
                }
        }

        // This happens after sections in standard classes. The 1.3.x
        // code compared depths too, but it does not seem necessary
        // (JMarc)
        if (par.layout() == tclass.defaultLayout()
            && pit > 0 && pars[pit - 1].layout()->nextnoindent)
                parindent.erase();

        Font const labelfont = text_->getLabelFont(buffer, par);
        FontMetrics const & labelfont_metrics = theFontMetrics(labelfont);

        switch (layout->margintype) {
        case MARGIN_DYNAMIC:
                if (!layout->leftmargin.empty()) {
                        l_margin += theFontMetrics(buffer.params().getFont()).signedWidth(
                                layout->leftmargin);
                }
                if (!par.getLabelstring().empty()) {
                        l_margin += labelfont_metrics.signedWidth(layout->labelindent);
                        l_margin += labelfont_metrics.width(par.getLabelstring());
                        l_margin += labelfont_metrics.width(layout->labelsep);
                }
                break;

        case MARGIN_MANUAL: {
                l_margin += labelfont_metrics.signedWidth(layout->labelindent);
                // The width of an empty par, even with manual label, should be 0
                if (!par.empty() && pos >= par.beginOfBody()) {
                        if (!par.getLabelWidthString().empty()) {
                                docstring labstr = par.getLabelWidthString();
                                l_margin += labelfont_metrics.width(labstr);
                                l_margin += labelfont_metrics.width(layout->labelsep);
                        }
                }
                break;
        }

        case MARGIN_STATIC: {
                l_margin += theFontMetrics(buffer.params().getFont()).
                        signedWidth(layout->leftmargin) * 4     / (par.getDepth() + 4);
                break;
        }

        case MARGIN_FIRST_DYNAMIC:
                if (layout->labeltype == LABEL_MANUAL) {
                        if (pos >= par.beginOfBody()) {
                                l_margin += labelfont_metrics.signedWidth(layout->leftmargin);
                        } else {
                                l_margin += labelfont_metrics.signedWidth(layout->labelindent);
                        }
                } else if (pos != 0
                           // Special case to fix problems with
                           // theorems (JMarc)
                           || (layout->labeltype == LABEL_STATIC
                               && layout->latextype == LATEX_ENVIRONMENT
                               && !isFirstInSequence(pit, pars))) {
                        l_margin += labelfont_metrics.signedWidth(layout->leftmargin);
                } else if (layout->labeltype != LABEL_TOP_ENVIRONMENT
                           && layout->labeltype != LABEL_BIBLIO
                           && layout->labeltype !=
                           LABEL_CENTERED_TOP_ENVIRONMENT) {
                        l_margin += labelfont_metrics.signedWidth(layout->labelindent);
                        l_margin += labelfont_metrics.width(layout->labelsep);
                        l_margin += labelfont_metrics.width(par.getLabelstring());
                }
                break;

        case MARGIN_RIGHT_ADDRESS_BOX: {
#if 0
                // ok, a terrible hack. The left margin depends on the widest
                // row in this paragraph.
                RowList::iterator rit = par.rows().begin();
                RowList::iterator end = par.rows().end();
                // FIXME: This is wrong.
                int minfill = max_width;
                for ( ; rit != end; ++rit)
                        if (rit->fill() < minfill)
                                minfill = rit->fill();
                l_margin += theFontMetrics(params.getFont()).signedWidth(layout->leftmargin);
                l_margin += minfill;
#endif
                // also wrong, but much shorter.
                l_margin += max_width / 2;
                break;
        }
        }

        if (!par.params().leftIndent().zero())
                l_margin += par.params().leftIndent().inPixels(max_width);

        LyXAlignment align;

        if (par.params().align() == LYX_ALIGN_LAYOUT)
                align = layout->align;
        else
                align = par.params().align();

        // set the correct parindent
        if (pos == 0
            && (layout->labeltype == LABEL_NO_LABEL
               || layout->labeltype == LABEL_TOP_ENVIRONMENT
               || layout->labeltype == LABEL_CENTERED_TOP_ENVIRONMENT
               || (layout->labeltype == LABEL_STATIC
                   && layout->latextype == LATEX_ENVIRONMENT
                   && !isFirstInSequence(pit, pars)))
            && align == LYX_ALIGN_BLOCK
            && !par.params().noindent()
            // in some insets, paragraphs are never indented
            && !(par.inInset() && par.inInset()->neverIndent(buffer))
            // display style insets are always centered, omit indentation
            && !(!par.empty()
                    && par.isInset(pos)
                    && par.getInset(pos)->display())
            && (par.layout() != tclass.defaultLayout()
                || buffer.params().paragraph_separation ==
                   BufferParams::PARSEP_INDENT))
        {
                l_margin += theFontMetrics(buffer.params().getFont()).signedWidth(
                        parindent);
        }

        return l_margin;
}


int TextMetrics::singleWidth(pit_type pit, pos_type pos) const
{
        ParagraphMetrics const & pm = par_metrics_[pit];

        return pm.singleWidth(pos, getDisplayFont(pit, pos));
}


// only used for inset right now. should also be used for main text
void TextMetrics::draw(PainterInfo & pi, int x, int y) const
{
        if (par_metrics_.empty())
                return;

        origin_.x_ = x;
        origin_.y_ = y;

        ParMetricsCache::iterator it = par_metrics_.begin();
        ParMetricsCache::iterator const pm_end = par_metrics_.end();
        y -= it->second.ascent();
        for (; it != pm_end; ++it) {
                ParagraphMetrics const & pmi = it->second;
                y += pmi.ascent();
                pit_type const pit = it->first;
                // Save the paragraph position in the cache.
                it->second.setPosition(y);
                drawParagraph(pi, pit, x, y);
                y += pmi.descent();
        }
}


void TextMetrics::drawParagraph(PainterInfo & pi, pit_type pit, int x, int y) const
{
//      lyxerr << "  paintPar: pit: " << pit << " at y: " << y << endl;
        int const ww = bv_->workHeight();

        ParagraphMetrics const & pm = par_metrics_[pit];
        if (pm.rows().empty())
                return;

        RowList::const_iterator const rb = pm.rows().begin();
        RowList::const_iterator const re = pm.rows().end();

        Bidi bidi;

        y -= rb->ascent();
        for (RowList::const_iterator rit = rb; rit != re; ++rit) {
                y += rit->ascent();

                bool const inside = (y + rit->descent() >= 0
                        && y - rit->ascent() < ww);
                // it is not needed to draw on screen if we are not inside.
                pi.pain.setDrawingEnabled(inside);
                RowPainter rp(pi, *text_, pit, *rit, bidi, x, y);

                // Row signature; has row changed since last paint?
                bool row_has_changed = rit->changed();
                
                bool row_selection = rit->sel_beg != -1 && rit->sel_end != -1;

                if (!row_selection && !pi.full_repaint && !row_has_changed) {
                        // Paint the only the insets if the text itself is
                        // unchanged.
                        rp.paintOnlyInsets();
                        y += rit->descent();
                        continue;
                }

                // Paint the row if a full repaint has been requested or it has
                // changed.
                // Clear background of this row
                // (if paragraph background was not cleared)
                if (row_selection || (!pi.full_repaint && row_has_changed)) {
                        pi.pain.fillRectangle(x, y - rit->ascent(),
                                width(), rit->height(),
                                Color_color(Color::color(pi.background_color)));
                }
                if (row_selection) {
                        DocIterator beg = bv_->cursor().selectionBegin();
                        DocIterator end = bv_->cursor().selectionEnd();
                        beg.pit() = pit;
                        beg.pos() = rit->sel_beg;
                        if (pit == end.pit()) {
                                end.pos() = rit->sel_end;
                        } else {
                                end.pit() = pit + 1;
                                end.pos() = 0;
                        }
                        drawSelection(pi, beg, end, x);
                }

                // Instrumentation for testing row cache (see also
                // 12 lines lower):
                if (lyxerr.debugging(Debug::PAINTING)) {
                        if (text_->isMainText(bv_->buffer()))
                                LYXERR(Debug::PAINTING) << "\n{" << inside <<
                                pi.full_repaint << row_has_changed << "}";
                        else
                                LYXERR(Debug::PAINTING) << "[" << inside <<
                                pi.full_repaint << row_has_changed << "]";
                }

                // Backup full_repaint status and force full repaint
                // for inner insets as the Row has been cleared out.
                bool tmp = pi.full_repaint;
                pi.full_repaint = true;
                rp.paintAppendix();
                rp.paintDepthBar();
                rp.paintChangeBar();
                if (rit == rb)
                        rp.paintFirst();
                rp.paintText();
                if (rit + 1 == re)
                        rp.paintLast();
                y += rit->descent();
                // Restore full_repaint status.
                pi.full_repaint = tmp;
        }
        // Re-enable screen drawing for future use of the painter.
        pi.pain.setDrawingEnabled(true);

        //LYXERR(Debug::PAINTING) << "." << endl;
}


// FIXME: only take care of one row!
void TextMetrics::drawSelection(PainterInfo & pi,
        DocIterator const & beg, DocIterator const & end, int x) const
{
        ParagraphMetrics const & pm1 = parMetrics(beg.pit());
        ParagraphMetrics const & pm2 = parMetrics(end.pit());
        Row const & row1 = pm1.getRow(beg.pos(), beg.boundary());
        Row const & row2 = pm2.getRow(end.pos(), end.boundary());

        // clip above
        int middleTop;
        bool const clipAbove = (bv_->cursorStatus(beg) == CUR_ABOVE);
        if (clipAbove)
                middleTop = 0;
        else
                middleTop = bv_->getPos(beg, beg.boundary()).y_ + row1.descent();
        
        // clip below
        int middleBottom;
        bool const clipBelow = (bv_->cursorStatus(end) == CUR_BELOW);
        if (clipBelow)
                middleBottom = bv_->workHeight();
        else
                middleBottom = bv_->getPos(end, end.boundary()).y_ - row2.ascent();

        // start and end in the same line?
        if (!clipAbove && !clipBelow && &row1 == &row2)
                // then only draw this row's selection
                drawRowSelection(pi, x, row1, beg, end, false, false);
        else {
                if (!clipAbove) {
                        // get row end
                        DocIterator begRowEnd = beg;
                        begRowEnd.pos() = row1.endpos();
                        begRowEnd.boundary(true);
                        
                        // draw upper rectangle
                        drawRowSelection(pi, x, row1, beg, begRowEnd, false, true);
                }
                        
                if (middleTop < middleBottom) {
                        // draw middle rectangle
                        pi.pain.fillRectangle(x, middleTop, width(), middleBottom - middleTop,
                                Color::selection);
                }

                if (!clipBelow) {
                        // get row begin
                        DocIterator endRowBeg = end;
                        endRowBeg.pos() = row2.pos();
                        endRowBeg.boundary(false);
                        
                        // draw low rectangle
                        drawRowSelection(pi, x, row2, endRowBeg, end, true, false);
                }
        }
}


void TextMetrics::drawRowSelection(PainterInfo & pi, int x, Row const & row,
                DocIterator const & beg, DocIterator const & end,
                bool drawOnBegMargin, bool drawOnEndMargin) const
{
        Buffer & buffer = bv_->buffer();
        DocIterator cur = beg;
        int x1 = cursorX(beg.top(), beg.boundary());
        int x2 = cursorX(end.top(), end.boundary());
        int y1 = bv_->getPos(cur, cur.boundary()).y_ - row.ascent();
        int y2 = y1 + row.height();
        
        // draw the margins
        if (drawOnBegMargin) {
                if (text_->isRTL(buffer, beg.paragraph()))
                        pi.pain.fillRectangle(x + x1, y1, width() - x1, y2 - y1, Color::selection);
                else
                        pi.pain.fillRectangle(x, y1, x1, y2 - y1, Color::selection);
        }
        
        if (drawOnEndMargin) {
                if (text_->isRTL(buffer, beg.paragraph()))
                        pi.pain.fillRectangle(x, y1, x2, y2 - y1, Color::selection);
                else
                        pi.pain.fillRectangle(x + x2, y1, width() - x2, y2 - y1, Color::selection);
        }
        
        // if we are on a boundary from the beginning, it's probably
        // a RTL boundary and we jump to the other side directly as this
        // segement is 0-size and confuses the logic below
        if (cur.boundary())
                cur.boundary(false);
        
        // go through row and draw from RTL boundary to RTL boundary
        while (cur < end) {
                bool drawNow = false;
                
                // simplified cursorForward code below which does not
                // descend into insets and which does not go into the
                // next line. Compare the logic with the original cursorForward
                
                // if left of boundary -> just jump to right side
                // but for RTL boundaries don't, because: abc|DDEEFFghi -> abcDDEEF|Fghi
                if (cur.boundary()) {
                        cur.boundary(false);
                }       else if (isRTLBoundary(cur.pit(), cur.pos() + 1)) {
                        // in front of RTL boundary -> Stay on this side of the boundary because:
                        //   ab|cDDEEFFghi -> abc|DDEEFFghi
                        ++cur.pos();
                        cur.boundary(true);
                        drawNow = true;
                } else {
                        // move right
                        ++cur.pos();
                        
                        // line end?
                        if (cur.pos() == row.endpos())
                                cur.boundary(true);
                }
                        
                if (x1 == -1) {
                        // the previous segment was just drawn, now the next starts
                        x1 = cursorX(cur.top(), cur.boundary());
                }
                
                if (!(cur < end) || drawNow) {
                        x2 = cursorX(cur.top(), cur.boundary());
                        pi.pain.fillRectangle(x + min(x1,x2), y1, abs(x2 - x1), y2 - y1,
                                Color::selection);
                        
                        // reset x1, so it is set again next round (which will be on the 
                        // right side of a boundary or at the selection end)
                        x1 = -1;
                }
        }
}

//int TextMetrics::pos2x(pit_type pit, pos_type pos) const
//{
//      ParagraphMetrics const & pm = par_metrics_[pit];
//      Row const & r = pm.rows()[row];
//      int x = 0;
//      pos -= r.pos();
//}


int defaultRowHeight()
{
        return int(theFontMetrics(Font(Font::ALL_SANE)).maxHeight() *  1.2);
}

} // namespace lyx