3 * This file is part of LyX, the document processor.
4 * Licence details can be found in the file COPYING.
6 * \author Lars Gullik Bjønnes
10 * \author Jean-Marc Lasgouttes
12 * Full author contact details are available in file CREDITS.
14 * Metrics for an on-screen text row.
21 #include "DocIterator.h"
23 #include "frontends/FontMetrics.h"
25 #include "support/debug.h"
26 #include "support/lassert.h"
27 #include "support/lstrings.h"
28 #include "support/lyxalgo.h"
37 using frontend::FontMetrics;
40 // Maximum length that a space can be stretched when justifying text
41 static double const MAX_SPACE_STRETCH = 1.5; //em
44 int Row::Element::countSeparators() const
48 return count(str.begin(), str.end(), ' ');
52 int Row::Element::countExpanders() const
56 return theFontMetrics(font).countExpanders(str);
60 int Row::Element::expansionAmount() const
64 return countExpanders() * theFontMetrics(font).em();
68 void Row::Element::setExtra(double extra_per_em)
72 extra = extra_per_em * theFontMetrics(font).em();
76 double Row::Element::pos2x(pos_type const i) const
78 // This can happen with inline completion when clicking on the
79 // row after the completion.
80 if (i < pos || i > endpos)
84 //handle first the two bounds of the element
85 if (i == endpos && type != VIRTUAL)
86 w = isRTL() ? 0 : full_width();
87 else if (i == pos || type != STRING)
88 w = isRTL() ? full_width() : 0;
90 FontMetrics const & fm = theFontMetrics(font);
91 w = fm.pos2x(str, i - pos, isRTL(), extra);
98 pos_type Row::Element::x2pos(int &x) const
100 //lyxerr << "x2pos: x=" << x << " w=" << width() << " " << *this;
105 FontMetrics const & fm = theFontMetrics(font);
106 i = fm.x2pos(str, x, isRTL(), extra);
110 // those elements are actually empty (but they have a width)
112 x = isRTL() ? int(full_width()) : 0;
116 // those elements contain only one position. Round to
118 if (x > (full_width() + 1) / 2) {
119 x = int(full_width());
126 //lyxerr << "=> p=" << pos + i << " x=" << x << endl;
131 bool Row::Element::breakAt(int w, bool force)
133 if (type != STRING || dim.wid <= w)
136 FontMetrics const & fm = theFontMetrics(font);
138 if(fm.breakAt(str, x, isRTL(), force)) {
140 endpos = pos + str.length();
141 //lyxerr << "breakAt(" << w << ") Row element Broken at " << x << "(w(str)=" << fm.width(str) << "): e=" << *this << endl;
149 pos_type Row::Element::left_pos() const
151 return isRTL() ? endpos : pos;
155 pos_type Row::Element::right_pos() const
157 return isRTL() ? pos : endpos;
162 : separator(0), label_hfill(0), left_margin(0), right_margin(0),
163 sel_beg(-1), sel_end(-1),
164 begin_margin_sel(false), end_margin_sel(false),
166 pit_(0), pos_(0), end_(0),
167 right_boundary_(false), flushed_(false), rtl_(false),
172 bool Row::isMarginSelected(bool left_margin, DocIterator const & beg,
173 DocIterator const & end) const
175 pos_type const sel_pos = left_margin ? sel_beg : sel_end;
176 pos_type const margin_pos = left_margin ? pos_ : end_;
178 // Is the chosen margin selected ?
179 if (sel_pos == margin_pos) {
180 if (beg.pos() == end.pos())
181 // This is a special case in which the space between after
182 // pos i-1 and before pos i is selected, i.e. the margins
183 // (see DocIterator::boundary_).
184 return beg.boundary() && !end.boundary();
185 else if (end.pos() == margin_pos)
186 // If the selection ends around the margin, it is only
187 // drawn if the cursor is after the margin.
188 return !end.boundary();
189 else if (beg.pos() == margin_pos)
190 // If the selection begins around the margin, it is
191 // only drawn if the cursor is before the margin.
192 return beg.boundary();
200 void Row::setSelectionAndMargins(DocIterator const & beg,
201 DocIterator const & end) const
203 setSelection(beg.pos(), end.pos());
206 end_margin_sel = isMarginSelected(false, beg, end);
207 begin_margin_sel = isMarginSelected(true, beg, end);
212 void Row::setSelection(pos_type beg, pos_type end) const
214 if (pos_ >= beg && pos_ <= end)
216 else if (beg > pos_ && beg <= end_)
221 if (end_ >= beg && end_ <= end)
223 else if (end < end_ && end >= pos_)
230 bool Row::selection() const
232 return sel_beg != -1 && sel_end != -1;
236 ostream & operator<<(ostream & os, Row::Element const & e)
239 os << e.endpos << "<<" << e.pos << " ";
241 os << e.pos << ">>" << e.endpos << " ";
245 os << "STRING: `" << to_utf8(e.str) << "' ("
246 << e.countExpanders() << " expanders.), ";
249 os << "VIRTUAL: `" << to_utf8(e.str) << "', ";
252 os << "INSET: " << to_utf8(e.inset->layoutName()) << ", ";
258 os << "width=" << e.full_width();
263 ostream & operator<<(ostream & os, Row const & row)
265 os << " pos: " << row.pos_ << " end: " << row.end_
266 << " left_margin: " << row.left_margin
267 << " width: " << row.dim_.wid
268 << " right_margin: " << row.right_margin
269 << " ascent: " << row.dim_.asc
270 << " descent: " << row.dim_.des
271 << " separator: " << row.separator
272 << " label_hfill: " << row.label_hfill
273 << " row_boundary: " << row.right_boundary() << "\n";
274 double x = row.left_margin;
275 Row::Elements::const_iterator it = row.elements_.begin();
276 for ( ; it != row.elements_.end() ; ++it) {
277 os << "x=" << x << " => " << *it << endl;
278 x += it->full_width();
284 int Row::left_x() const
286 double x = left_margin;
287 const_iterator const end = elements_.end();
288 const_iterator cit = elements_.begin();
289 while (cit != end && cit->isVirtual()) {
290 x += cit->full_width();
297 int Row::right_x() const
300 const_iterator const begin = elements_.begin();
301 const_iterator cit = elements_.end();
302 while (cit != begin) {
304 if (cit->isVirtual())
305 x -= cit->full_width();
313 int Row::countSeparators() const
316 const_iterator const end = elements_.end();
317 for (const_iterator cit = elements_.begin() ; cit != end ; ++cit)
318 n += cit->countSeparators();
323 bool Row::setExtraWidth(int w)
326 // this is not expected to happen (but it does)
328 // amount of expansion: number of expanders time the em value for each
331 for (Row::Element const & e : elements_)
332 exp_amount += e.expansionAmount();
335 // extra length per expander per em
336 double extra_per_em = double(w) / exp_amount;
337 if (extra_per_em > MAX_SPACE_STRETCH)
338 // do not stretch more than MAX_SPACE_STRETCH em per expander
340 // add extra length to each element proportionally to its em.
341 for (Row::Element & e : elements_)
342 if (e.type == Row::STRING)
343 e.setExtra(extra_per_em);
344 // update row dimension
350 bool Row::sameString(Font const & f, Change const & ch) const
352 if (elements_.empty())
354 Element const & elt = elements_.back();
355 return elt.type == STRING && !elt.final
356 && elt.font == f && elt.change == ch;
360 void Row::finalizeLast()
362 if (elements_.empty())
364 Element & elt = elements_.back();
368 if (elt.change.changed())
371 if (elt.type == STRING) {
372 dim_.wid -= elt.dim.wid;
373 elt.dim.wid = theFontMetrics(elt.font).width(elt.str);
374 dim_.wid += elt.dim.wid;
379 void Row::add(pos_type const pos, Inset const * ins, Dimension const & dim,
380 Font const & f, Change const & ch)
383 Element e(INSET, pos, f, ch);
386 elements_.push_back(e);
391 void Row::add(pos_type const pos, char_type const c,
392 Font const & f, Change const & ch)
394 if (!sameString(f, ch)) {
396 Element e(STRING, pos, f, ch);
397 elements_.push_back(e);
399 if (back().str.length() % 30 == 0) {
400 dim_.wid -= back().dim.wid;
402 back().endpos = pos + 1;
403 back().dim.wid = theFontMetrics(back().font).width(back().str);
404 dim_.wid += back().dim.wid;
407 back().endpos = pos + 1;
412 void Row::addVirtual(pos_type const pos, docstring const & s,
413 Font const & f, Change const & ch)
416 Element e(VIRTUAL, pos, f, ch);
418 e.dim.wid = theFontMetrics(f).width(s);
419 dim_.wid += e.dim.wid;
421 elements_.push_back(e);
426 void Row::addSpace(pos_type const pos, int const width,
427 Font const & f, Change const & ch)
430 Element e(SPACE, pos, f, ch);
432 elements_.push_back(e);
433 dim_.wid += e.dim.wid;
439 dim_.wid -= elements_.back().dim.wid;
440 elements_.pop_back();
444 bool Row::shortenIfNeeded(pos_type const keep, int const w, int const next_width)
446 if (empty() || width() <= w)
449 Elements::iterator const beg = elements_.begin();
450 Elements::iterator const end = elements_.end();
451 int wid = left_margin;
453 // Search for the first element that goes beyond right margin
454 Elements::iterator cit = beg;
455 for ( ; cit != end ; ++cit) {
456 if (wid + cit->dim.wid > w)
462 // This should not happen since the row is too long.
463 LYXERR0("Something is wrong cannot shorten row: " << *this);
467 // Iterate backwards over breakable elements and try to break them
468 Elements::iterator cit_brk = cit;
469 int wid_brk = wid + cit_brk->dim.wid;
471 while (cit_brk != beg) {
473 // make a copy of the element to work on it.
474 Element brk = *cit_brk;
475 wid_brk -= brk.dim.wid;
476 if (brk.countSeparators() == 0 || brk.pos < keep)
478 /* We have found a suitable separable element. This is the common case.
479 * Try to break it cleanly (at word boundary) at a length that is both
480 * - less than the available space on the row
481 * - shorter than the natural width of the element, in order to enforce
484 if (brk.breakAt(min(w - wid_brk, brk.dim.wid - 2), false)) {
485 /* if this element originally did not cause a row overflow
486 * in itself, and the remainder of the row would still be
487 * too large after breaking, then we will have issues in
488 * next row. Thus breaking does not help.
490 if (wid_brk + cit_brk->dim.wid < w
491 && dim_.wid - (wid_brk + brk.dim.wid) >= next_width) {
495 /* after breakAt, there may be spaces at the end of the
496 * string, but they are not counted in the string length
497 * (QTextLayout feature, actually). We remove them, but do
498 * not change the end of the row, since spaces at row
499 * break are invisible.
501 brk.str = rtrim(brk.str);
502 brk.endpos = brk.pos + brk.str.length();
504 dim_.wid = wid_brk + brk.dim.wid;
505 // If there are other elements, they should be removed.
506 elements_.erase(cit_brk + 1, end);
511 if (cit != beg && cit->type == VIRTUAL) {
512 // It is not possible to separate a virtual element from the
519 // There is no usable separator, but several elements have
520 // been added. We can cut right here.
523 elements_.erase(cit, end);
527 /* If we are here, it means that we have not found a separator to
528 * shorten the row. Let's try to break it again, but not at word
529 * boundary this time.
531 if (cit->breakAt(w - wid, true)) {
533 // See comment above.
534 cit->str = rtrim(cit->str);
535 cit->endpos = cit->pos + cit->str.length();
536 dim_.wid = wid + cit->dim.wid;
537 // If there are other elements, they should be removed.
538 elements_.erase(next(cit, 1), end);
545 void Row::reverseRTL(bool const rtl_par)
548 pos_type const end = elements_.size();
550 // gather a sequence of elements with the same direction
551 bool const rtl = elements_[i].isRTL();
553 while (j < end && elements_[j].isRTL() == rtl)
555 // if the direction is not the same as the paragraph
556 // direction, the sequence has to be reverted.
558 reverse(elements_.begin() + i, elements_.begin() + j);
561 // If the paragraph itself is RTL, reverse everything
563 reverse(elements_.begin(), elements_.end());
567 Row::const_iterator const
568 Row::findElement(pos_type const pos, bool const boundary, double & x) const
571 * When boundary is true, position i is in the row element (pos, endpos)
574 * whereas, when boundary is false, the test is
576 * The correction below allows to handle both cases.
578 int const boundary_corr = (boundary && pos) ? -1 : 0;
582 /** Early return in trivial cases
583 * 1) the row is empty
584 * 2) the position is the left-most position of the row; there
585 * is a quirk here however: if the first element is virtual
586 * (end-of-par marker for example), then we have to look
590 || (pos == begin()->left_pos() && !boundary
591 && !begin()->isVirtual()))
594 Row::const_iterator cit = begin();
595 for ( ; cit != end() ; ++cit) {
596 /** Look whether the cursor is inside the element's
597 * span. Note that it is necessary to take the
598 * boundary into account, and to accept virtual
599 * elements, which have pos == endpos.
601 if (pos + boundary_corr >= cit->pos
602 && (pos + boundary_corr < cit->endpos || cit->isVirtual())) {
603 x += cit->pos2x(pos);
606 x += cit->full_width();