4 * This file is part of LyX, the document processor.
5 * Licence details can be found in the file COPYING.
7 * \author Matthias Ettrich
8 * \author Lars Gullik Bjønnes
10 * Full author contact details are available in file CREDITS.
12 * Metrics for an on-screen text row.
19 #include "Dimension.h"
23 #include "support/docstring.h"
24 #include "support/types.h"
34 * An on-screen row of text. A paragraph is broken into a RowList for
35 * display. Each Row contains a tokenized description of the contents
40 // Possible types of row elements
42 // a string of character
45 * Something (completion, end-of-par marker)
46 * that occupies space one screen but does not
47 * correspond to any paragraph contents
52 // Some spacing described by its width, not a string
54 // Spacing until the left margin, with a minimal value given
55 // by the initial width
60 * One element of a Row. It has a set of attributes that can be used
61 * by other methods that need to parse the Row contents.
65 Element(Type const t, pos_type p, Font const & f, Change const & ch)
66 : type(t), pos(p), endpos(p + 1), font(f), change(ch) {}
69 // Return the number of separator in the element (only STRING type)
70 int countSeparators() const;
72 // Return total width of element, including separator overhead
73 // FIXME: Cache this value or the number of expanders?
74 double full_width() const { return dim.wid + extra * countExpanders(); }
75 // Return the number of expanding characters in the element (only STRING
77 int countExpanders() const;
78 // Return the amount of expansion: the number of expanding characters
79 // that get stretched during justification, times the em of the font
80 // (only STRING type).
81 int expansionAmount() const;
82 // set extra proportionally to the font em value.
83 void setExtra(double extra_per_em);
85 /** Return position in pixels (from the left) of position
86 * \param i in the row element.
88 double pos2x(pos_type const i) const;
89 /** Return character position that is the closest to
90 * pixel position \param x. The value \param x is
91 * adjusted to the actual pixel position.
93 pos_type x2pos(int &x) const;
94 /** Break the element in two if possible, so that its width is less
96 * \return a vector of elements containing the remainder of
97 * the text (empty if nothing happened).
98 * \param width maximum width of the row.
99 * \param next_width available width on next row.
100 * \param force: if true, cut string at any place, even for
101 * languages that wrap at word delimiters; if false, do not
102 * break at all if first element would larger than \c width.
104 // FIXME: ideally last parameter should be Elements&, but it is not possible.
105 bool splitAt(int width, int next_width, bool force, std::vector<Element> & tail);
106 // remove trailing spaces (useful for end of row)
110 bool isRTL() const { return font.isVisibleRightToLeft(); }
111 // This is true for virtual elements.
112 bool isVirtual() const { return type == VIRTUAL; }
114 // Returns the position on left side of the element.
115 pos_type left_pos() const { return isRTL() ? endpos : pos; };
116 // Returns the position on right side of the element.
117 pos_type right_pos() const { return isRTL() ? pos : endpos; };
119 // The kind of row element
121 // position of the element in the paragraph
123 // first position after the element in the paragraph
125 // The dimension of the chunk (does not contain the
126 // separator correction)
128 // The width of the element without trailing spaces
131 // Non-zero only if element is an inset
132 Inset const * inset = nullptr;
134 // Only non-null for justified rows
137 // Non-empty if element is a string or is virtual
143 // is it possible to add contents to this element?
145 // properties with respect to row breaking (made of RowFlag enums)
146 int row_flags = Inline;
148 friend std::ostream & operator<<(std::ostream & os, Element const & row);
152 typedef Element value_type;
158 * Helper function: set variable \c var to value \c val, and mark
159 * row as changed is the values were different. This is intended
160 * for use when changing members of the row object.
162 template<class T1, class T2>
163 void change(T1 & var, T2 const val) {
169 * Helper function: set variable \c var to value \c val, and mark
170 * row as changed is the values were different. This is intended
171 * for use when changing members of the row object.
172 * This is the const version, useful for mutable members.
174 template<class T1, class T2>
175 void change(T1 & var, T2 const val) const {
181 bool changed() const { return changed_; }
183 void changed(bool c) const { changed_ = c; }
185 bool selection() const;
187 * Set the selection begin and end and whether the left and/or
188 * right margins are selected.
189 * This is const because we update the selection status only at
192 void setSelectionAndMargins(DocIterator const & beg,
193 DocIterator const & end) const;
194 /// no selection on this row.
195 void clearSelectionAndMargins() const;
198 void pit(pit_type p) { pit_ = p; }
200 pit_type pit() const { return pit_; }
202 void pos(pos_type p) { pos_ = p; }
204 pos_type pos() const { return pos_; }
206 void endpos(pos_type p) { end_ = p; }
208 pos_type endpos() const { return end_; }
210 void right_boundary(bool b) { right_boundary_ = b; }
212 bool right_boundary() const { return right_boundary_; }
214 void flushed(bool b) { flushed_ = b; }
216 bool flushed() const { return flushed_; }
219 Dimension const & dim() const { return dim_; }
221 Dimension & dim() { return dim_; }
223 int height() const { return dim_.height(); }
224 /// The width of the row, including the left margin, but not the right one.
225 int width() const { return dim_.wid; }
227 int ascent() const { return dim_.asc; }
229 int descent() const { return dim_.des; }
232 Dimension const & contents_dim() const { return contents_dim_; }
234 Dimension & contents_dim() { return contents_dim_; }
236 /// The offset of the left-most cursor position on the row
238 /// The offset of the right-most cursor position on the row
241 // Return the number of separators in the row
242 int countSeparators() const;
243 // Set the extra spacing for every expanding character in STRING-type
244 // elements. \param w is the total amount of extra width for the row to be
245 // distributed among expanders. \return false if the justification fails.
246 bool setExtraWidth(int w);
249 void add(pos_type pos, Inset const * ins, Dimension const & dim,
250 Font const & f, Change const & ch);
252 void add(pos_type pos, char_type const c,
253 Font const & f, Change const & ch);
255 void addVirtual(pos_type pos, docstring const & s,
256 Font const & f, Change const & ch);
258 void addSpace(pos_type pos, int width, Font const & f, Change const & ch);
260 void addMarginSpace(pos_type pos, int width, Font const & f, Change const & ch);
263 typedef std::vector<Element> Elements;
265 typedef Elements::iterator iterator;
267 typedef Elements::const_iterator const_iterator;
269 iterator begin() { return elements_.begin(); }
271 iterator end() { return elements_.end(); }
273 const_iterator begin() const { return elements_.begin(); }
275 const_iterator end() const { return elements_.end(); }
278 bool empty() const { return elements_.empty(); }
280 Element & front() { return elements_.front(); }
282 Element const & front() const { return elements_.front(); }
284 Element & back() { return elements_.back(); }
286 Element const & back() const { return elements_.back(); }
287 /// add element at the end and update width
288 void push_back(Element const &);
289 /// remove last element and update width
292 * if row width is too large, remove all elements after last
293 * separator and update endpos if necessary. If all that
294 * remains is a large word, cut it to \param width.
295 * \param width maximum width of the row.
296 * \param next_width available width on next row.
297 * \return list of elements remaining after breaking.
299 Elements shortenIfNeeded(int const width, int const next_width);
302 * If last element of the row is a string, compute its width
308 * Find sequences of right-to-left elements and reverse them.
309 * This should be called once the row is completely built.
313 bool isRTL() const { return rtl_; }
315 void setRTL(bool rtl) { rtl_ = rtl; }
317 bool needsChangeBar() const { return changebar_; }
319 void needsChangeBar(bool ncb) { changebar_ = ncb; }
321 /// Find row element that contains \c pos, and compute x offset.
322 const_iterator const findElement(pos_type pos, bool boundary, double & x) const;
324 friend std::ostream & operator<<(std::ostream & os, Row const & row);
326 /// additional width for separators in justified rows (i.e. space)
327 double separator = 0;
328 /// width of hfills in the label
329 double label_hfill = 0;
330 /// the left margin position of the row
332 /// the right margin of the row
333 int right_margin = 0;
335 mutable pos_type sel_beg = -1;
337 mutable pos_type sel_end = -1;
339 mutable bool begin_margin_sel = false;
341 mutable bool end_margin_sel = false;
344 /// Decides whether the margin is selected.
346 * \param margin_begin
350 bool isMarginSelected(bool left, DocIterator const & beg,
351 DocIterator const & end) const;
352 /// Set the selection begin and end.
353 void setSelection(pos_type sel_beg, pos_type sel_end) const;
356 * Returns true if a char or string with font \c f and change
357 * type \c ch can be added to the current last element of the
360 bool sameString(Font const & f, Change const & ch) const;
365 /// has the Row appearance changed since last drawing?
366 mutable bool changed_ = true;
367 /// Index of the paragraph that contains this row
369 /// first pos covered by this row
371 /// one behind last pos covered by this row
373 // Is there a boundary at the end of the row (display inset...)
374 bool right_boundary_ = false;
375 // Shall the row be flushed when it is supposed to be justified?
376 bool flushed_ = false;
379 /// Row contents dimension. Does not contain the space above/below row.
380 Dimension contents_dim_;
381 /// true when this row lives in a right-to-left paragraph
383 /// true when a changebar should be drawn in the margin
384 bool changebar_ = false;
387 std::ostream & operator<<(std::ostream & os, Row::Elements const & elts);
391 * Each paragraph is broken up into a number of rows on the screen.
392 * This is a list of such on-screen rows, ordered from the top row
395 typedef std::vector<Row> RowList;