+int Row::left_x() const
+{
+ double x = left_margin;
+ const_iterator const end = elements_.end();
+ const_iterator cit = elements_.begin();
+ while (cit != end && cit->isVirtual()) {
+ x += cit->full_width();
+ ++cit;
+ }
+ return int(x + 0.5);
+}
+
+
+int Row::right_x() const
+{
+ double x = dim_.wid;
+ const_iterator const begin = elements_.begin();
+ const_iterator cit = elements_.end();
+ while (cit != begin) {
+ --cit;
+ if (cit->isVirtual())
+ x -= cit->full_width();
+ else
+ break;
+ }
+ return int(x + 0.5);
+}
+
+
+int Row::countSeparators() const
+{
+ int n = 0;
+ const_iterator const end = elements_.end();
+ for (const_iterator cit = elements_.begin() ; cit != end ; ++cit)
+ n += cit->countSeparators();
+ return n;
+}
+
+
+bool Row::setExtraWidth(int w)
+{
+ if (w < 0)
+ // this is not expected to happen (but it does)
+ return false;
+ // amount of expansion: number of expanders time the em value for each
+ // string element
+ int exp_amount = 0;
+ for (Row::Element const & e : elements_)
+ exp_amount += e.expansionAmount();
+ if (!exp_amount)
+ return false;
+ // extra length per expander per em
+ double extra_per_em = double(w) / exp_amount;
+ if (extra_per_em > MAX_SPACE_STRETCH)
+ // do not stretch more than MAX_SPACE_STRETCH em per expander
+ return false;
+ // add extra length to each element proportionally to its em.
+ for (Row::Element & e : elements_)
+ if (e.type == Row::STRING)
+ e.setExtra(extra_per_em);
+ // update row dimension
+ dim_.wid += w;
+ return true;
+}
+
+
+bool Row::sameString(Font const & f, Change const & ch) const
+{
+ if (elements_.empty())
+ return false;
+ Element const & elt = elements_.back();
+ return elt.type == STRING && !elt.final
+ && elt.font == f && elt.change == ch;
+}
+
+
+void Row::finalizeLast()
+{
+ if (elements_.empty())
+ return;
+ Element & elt = elements_.back();
+ if (elt.final)
+ return;
+ elt.final = true;
+
+ if (elt.type == STRING) {
+ dim_.wid -= elt.dim.wid;
+ elt.dim.wid = theFontMetrics(elt.font).width(elt.str);
+ dim_.wid += elt.dim.wid;
+ }
+}
+
+
+void Row::add(pos_type const pos, Inset const * ins, Dimension const & dim,
+ Font const & f, Change const & ch)
+{
+ finalizeLast();
+ Element e(INSET, pos, f, ch);
+ e.inset = ins;
+ e.dim = dim;
+ elements_.push_back(e);
+ dim_.wid += dim.wid;
+}
+
+
+void Row::add(pos_type const pos, char_type const c,
+ Font const & f, Change const & ch)
+{
+ if (!sameString(f, ch)) {
+ finalizeLast();
+ Element e(STRING, pos, f, ch);
+ elements_.push_back(e);
+ }
+ if (back().str.length() % 30 == 0) {
+ dim_.wid -= back().dim.wid;
+ back().str += c;
+ back().endpos = pos + 1;
+ back().dim.wid = theFontMetrics(back().font).width(back().str);
+ dim_.wid += back().dim.wid;
+ } else {
+ back().str += c;
+ back().endpos = pos + 1;
+ }
+}
+
+
+void Row::addVirtual(pos_type const pos, docstring const & s,
+ Font const & f, Change const & ch)
+{
+ finalizeLast();
+ Element e(VIRTUAL, pos, f, ch);
+ e.str = s;
+ e.dim.wid = theFontMetrics(f).width(s);
+ dim_.wid += e.dim.wid;
+ e.endpos = pos;
+ elements_.push_back(e);
+ finalizeLast();
+}
+
+
+void Row::addSpace(pos_type const pos, int const width,
+ Font const & f, Change const & ch)
+{
+ finalizeLast();
+ Element e(SPACE, pos, f, ch);
+ e.dim.wid = width;
+ elements_.push_back(e);
+ dim_.wid += e.dim.wid;
+}
+
+
+void Row::pop_back()
+{
+ dim_.wid -= elements_.back().dim.wid;
+ elements_.pop_back();
+}
+
+
+bool Row::shortenIfNeeded(pos_type const keep, int const w)
+{
+ if (empty() || width() <= w)
+ return false;
+
+ Elements::iterator const beg = elements_.begin();
+ Elements::iterator const end = elements_.end();
+ int wid = left_margin;
+
+ // Search for the first element that goes beyond right margin
+ Elements::iterator cit = beg;
+ for ( ; cit != end ; ++cit) {
+ if (wid + cit->dim.wid > w)
+ break;
+ wid += cit->dim.wid;
+ }
+
+ if (cit == end) {
+ // This should not happen since the row is too long.
+ LYXERR0("Something is wrong cannot shorten row: " << *this);
+ return false;
+ }
+
+ // Iterate backwards over breakable elements and try to break them
+ Elements::iterator cit_brk = cit;
+ int wid_brk = wid + cit_brk->dim.wid;
+ ++cit_brk;
+ while (cit_brk != beg) {
+ --cit_brk;
+ // make a copy of the element to work on it.
+ Element brk = *cit_brk;
+ wid_brk -= brk.dim.wid;
+ if (brk.countSeparators() == 0 || brk.pos < keep)
+ continue;
+ /* We have found a suitable separable element. This is the common case.
+ * Try to break it cleanly (at word boundary) at a length that is both
+ * - less than the available space on the row
+ * - shorter than the natural width of the element, in order to enforce
+ * break-up.
+ */
+ if (brk.breakAt(min(w - wid_brk, brk.dim.wid - 2), false)) {
+ /* if this element originally did not cause a row overflow
+ * in itself, and the remainder of the row would still be
+ * too large after breaking, then we will have issues in
+ * next row. Thus breaking does not help.
+ */
+ if (wid_brk + cit_brk->dim.wid < w
+ && dim_.wid - (wid_brk + brk.dim.wid) >= w) {
+ break;
+ }
+ end_ = brk.endpos;
+ /* after breakAt, there may be spaces at the end of the
+ * string, but they are not counted in the string length
+ * (QTextLayout feature, actually). We remove them, but do
+ * not change the end of the row, since spaces at row
+ * break are invisible.
+ */
+ brk.str = rtrim(brk.str);
+ brk.endpos = brk.pos + brk.str.length();
+ *cit_brk = brk;
+ dim_.wid = wid_brk + brk.dim.wid;
+ // If there are other elements, they should be removed.
+ elements_.erase(cit_brk + 1, end);
+ return true;
+ }
+ }
+
+ if (cit != beg && cit->type == VIRTUAL) {
+ // It is not possible to separate a virtual element from the
+ // previous one.
+ --cit;
+ wid -= cit->dim.wid;
+ }
+
+ if (cit != beg) {
+ // There is no usable separator, but several elements have
+ // been added. We can cut right here.
+ end_ = cit->pos;
+ dim_.wid = wid;
+ elements_.erase(cit, end);
+ return true;
+ }
+
+ /* If we are here, it means that we have not found a separator to
+ * shorten the row. Let's try to break it again, but not at word
+ * boundary this time.
+ */
+ if (cit->breakAt(w - wid, true)) {
+ end_ = cit->endpos;
+ // See comment above.
+ cit->str = rtrim(cit->str);
+ cit->endpos = cit->pos + cit->str.length();
+ dim_.wid = wid + cit->dim.wid;
+ // If there are other elements, they should be removed.
+ elements_.erase(next(cit, 1), end);
+ return true;
+ }
+ return false;
+}
+
+
+void Row::reverseRTL(bool const rtl_par)
+{
+ pos_type i = 0;
+ pos_type const end = elements_.size();
+ while (i < end) {
+ // gather a sequence of elements with the same direction
+ bool const rtl = elements_[i].isRTL();
+ pos_type j = i;
+ while (j < end && elements_[j].isRTL() == rtl)
+ ++j;
+ // if the direction is not the same as the paragraph
+ // direction, the sequence has to be reverted.
+ if (rtl != rtl_par)
+ reverse(elements_.begin() + i, elements_.begin() + j);
+ i = j;
+ }
+ // If the paragraph itself is RTL, reverse everything
+ if (rtl_par)
+ reverse(elements_.begin(), elements_.end());
+}
+