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
59 // split string to fit requested width, fail if string remains too long
61 // if the requested width is too small, accept the first possible break
63 // cut string at any place, even for languages that wrap at word delimiters
68 * One element of a Row. It has a set of attributes that can be used
69 * by other methods that need to parse the Row contents.
73 Element(Type const t, pos_type p, Font const & f, Change const & ch)
74 : type(t), pos(p), endpos(p + 1), font(f), change(ch) {}
77 // Return total width of element, including separator overhead
78 // FIXME: Cache this value or the number of expanders?
79 double full_width() const { return dim.wid + extra * countExpanders(); }
80 // Return the number of expanding characters in the element (only STRING
82 int countExpanders() const;
83 // Return the amount of expansion: the number of expanding characters
84 // that get stretched during justification, times the em of the font
85 // (only STRING type).
86 int expansionAmount() const;
87 // set extra proportionally to the font em value.
88 void setExtra(double extra_per_em);
90 /** Return position in pixels (from the left) of position
91 * \param i in the row element.
93 double pos2x(pos_type const i) const;
94 /** Return character position that is the closest to
95 * pixel position \param x. The value \param x is
96 * adjusted to the actual pixel position.
98 pos_type x2pos(int &x) const;
99 /** Break the element in two if possible, so that its width is less
100 * than the required values.
101 * \return true if something has been done ; false if this is
102 * not needed or not possible.
103 * \param width: maximum width of the row.
104 * \param next_width: available width on next rows.
105 * \param split_type: indicate how the string should be split.
106 * \param tail: a vector of elements where the remainder of
107 * the text will be appended (empty if nothing happened).
109 // FIXME: ideally last parameter should be Elements&, but it is not possible.
110 bool splitAt(int width, int next_width, SplitType split_type, std::vector<Element> & tail);
111 // remove trailing spaces (useful for end of row)
115 bool isRTL() const { return font.isVisibleRightToLeft(); }
116 // This is true for virtual elements.
117 bool isVirtual() const { return type == VIRTUAL; }
119 // Returns the position on left side of the element.
120 pos_type left_pos() const { return isRTL() ? endpos : pos; };
121 // Returns the position on right side of the element.
122 pos_type right_pos() const { return isRTL() ? pos : endpos; };
124 // The kind of row element
126 // position of the element in the paragraph
128 // first position after the element in the paragraph
130 // The dimension of the chunk (does not contain the
131 // separator correction)
133 // The width of the element without trailing spaces
136 // Non-zero only if element is an inset
137 Inset const * inset = nullptr;
139 // Only non-null for justified rows
142 // Non-empty if element is a string or is virtual
148 // is it possible to add contents to this element?
150 // properties with respect to row breaking (made of RowFlag enumerators)
151 int row_flags = Inline;
153 friend std::ostream & operator<<(std::ostream & os, Element const & row);
157 typedef Element value_type;
163 * Helper function: set variable \c var to value \c val, and mark
164 * row as changed is the values were different. This is intended
165 * for use when changing members of the row object.
167 template<class T1, class T2>
168 void change(T1 & var, T2 const val) {
174 * Helper function: set variable \c var to value \c val, and mark
175 * row as changed is the values were different. This is intended
176 * for use when changing members of the row object.
177 * This is the const version, useful for mutable members.
179 template<class T1, class T2>
180 void change(T1 & var, T2 const val) const {
186 bool changed() const { return changed_; }
188 void changed(bool c) const { changed_ = c; }
190 bool selection() const;
192 * Set the selection begin and end and whether the left and/or
193 * right margins are selected.
194 * This is const because we update the selection status only at
197 void setSelectionAndMargins(DocIterator const & beg,
198 DocIterator const & end) const;
199 /// no selection on this row.
200 void clearSelectionAndMargins() const;
203 void pit(pit_type p) { pit_ = p; }
205 pit_type pit() const { return pit_; }
207 void pos(pos_type p) { pos_ = p; }
209 pos_type pos() const { return pos_; }
211 void endpos(pos_type p) { end_ = p; }
213 pos_type endpos() const { return end_; }
215 void end_boundary(bool b) { end_boundary_ = b; }
217 bool end_boundary() const { return end_boundary_; }
219 void flushed(bool b) { flushed_ = b; }
221 bool flushed() const { return flushed_; }
224 Dimension const & dim() const { return dim_; }
226 Dimension & dim() { return dim_; }
228 int height() const { return dim_.height(); }
229 /// The width of the row, including the left margin, but not the right one.
230 int width() const { return dim_.wid; }
232 int ascent() const { return dim_.asc; }
234 int descent() const { return dim_.des; }
237 Dimension const & contents_dim() const { return contents_dim_; }
239 Dimension & contents_dim() { return contents_dim_; }
241 /// The offset of the left-most cursor position on the row
243 /// The offset of the right-most cursor position on the row
246 // Set the extra spacing for every expanding character in STRING-type
247 // elements. \param w is the total amount of extra width for the row to be
248 // distributed among expanders. \return false if the justification fails.
249 bool setExtraWidth(int w);
252 void add(pos_type pos, Inset const * ins, Dimension const & dim,
253 Font const & f, Change const & ch);
255 void add(pos_type pos, char_type const c,
256 Font const & f, Change const & ch);
258 void addVirtual(pos_type pos, docstring const & s,
259 Font const & f, Change const & ch);
261 void addSpace(pos_type pos, int width, Font const & f, Change const & ch);
263 void addMarginSpace(pos_type pos, int width, Font const & f, Change const & ch);
266 typedef std::vector<Element> Elements;
268 typedef Elements::iterator iterator;
270 typedef Elements::const_iterator const_iterator;
272 iterator begin() { return elements_.begin(); }
274 iterator end() { return elements_.end(); }
276 const_iterator begin() const { return elements_.begin(); }
278 const_iterator end() const { return elements_.end(); }
281 bool empty() const { return elements_.empty(); }
283 Element & front() { return elements_.front(); }
285 Element const & front() const { return elements_.front(); }
287 Element & back() { return elements_.back(); }
289 Element const & back() const { return elements_.back(); }
290 /// add element at the end and update width
291 void push_back(Element const &);
292 /// remove last element and update width
295 * if row width is too large, remove all elements after last
296 * separator and update endpos if necessary. If all that
297 * remains is a large word, cut it to \c max_width.
298 * \param max_width maximum width of the row.
299 * \param next_width available width on next row.
300 * \return list of elements remaining after breaking.
302 Elements shortenIfNeeded(int const max_width, int const next_width);
305 * If last element of the row is a string, compute its width
311 * Find sequences of right-to-left elements and reverse them.
312 * This should be called once the row is completely built.
316 bool isRTL() const { return rtl_; }
318 void setRTL(bool rtl) { rtl_ = rtl; }
320 bool needsChangeBar() const { return changebar_; }
322 void needsChangeBar(bool ncb) { changebar_ = ncb; }
324 /// Find row element that contains \c pos, and compute x offset.
325 const_iterator const findElement(pos_type pos, bool boundary, double & x) const;
327 friend std::ostream & operator<<(std::ostream & os, Row const & row);
329 /// additional width for separators in justified rows (i.e. space)
330 double separator = 0;
331 /// width of hfills in the label
332 double label_hfill = 0;
333 /// the left margin position of the row
335 /// the right margin of the row
336 int right_margin = 0;
338 mutable pos_type sel_beg = -1;
340 mutable pos_type sel_end = -1;
342 mutable bool begin_margin_sel = false;
344 mutable bool end_margin_sel = false;
347 /// Decides whether the margin is selected.
349 * \param margin_begin
353 bool isMarginSelected(bool left, DocIterator const & beg,
354 DocIterator const & end) const;
355 /// Set the selection begin and end.
356 void setSelection(pos_type sel_beg, pos_type sel_end) const;
359 * Returns true if a char or string with font \c f and change
360 * type \c ch can be added to the current last element of the
363 bool sameString(Font const & f, Change const & ch) const;
368 /// has the Row appearance changed since last drawing?
369 mutable bool changed_ = true;
370 /// Index of the paragraph that contains this row
372 /// first pos covered by this row
374 /// one behind last pos covered by this row
376 // Is there a boundary at the end of the row (display inset...)
377 bool end_boundary_ = false;
378 // Shall the row be flushed when it is supposed to be justified?
379 bool flushed_ = false;
382 /// Row contents dimension. Does not contain the space above/below row.
383 Dimension contents_dim_;
384 /// true when this row lives in a right-to-left paragraph
386 /// true when a changebar should be drawn in the margin
387 bool changebar_ = false;
390 std::ostream & operator<<(std::ostream & os, Row::Elements const & elts);
394 * Each paragraph is broken up into a number of rows on the screen.
395 * This is a list of such on-screen rows, ordered from the top row
398 typedef std::vector<Row> RowList;