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
57 * One element of a Row. It has a set of attributes that can be used
58 * by other methods that need to parse the Row contents.
62 Element(Type const t, pos_type p, Font const & f, Change const & ch)
63 : type(t), pos(p), endpos(p + 1), font(f), change(ch) {}
66 // Return the number of separator in the element (only STRING type)
67 int countSeparators() const;
69 // Return total width of element, including separator overhead
70 // FIXME: Cache this value or the number of expanders?
71 double full_width() const { return dim.wid + extra * countExpanders(); }
72 // Return the number of expanding characters in the element (only STRING
74 int countExpanders() const;
75 // Return the amount of expansion: the number of expanding characters
76 // that get stretched during justification, times the em of the font
77 // (only STRING type).
78 int expansionAmount() const;
79 // set extra proportionally to the font em value.
80 void setExtra(double extra_per_em);
82 /** Return position in pixels (from the left) of position
83 * \param i in the row element.
85 double pos2x(pos_type const i) const;
86 /** Return character position that is the closest to
87 * pixel position \param x. The value \param x is
88 * adjusted to the actual pixel position.
90 pos_type x2pos(int &x) const;
91 /** Break the element in two if possible, so that its width is less
93 * \return a vector of elements containing the remainder of
94 * the text (empty if nothing happened).
95 * \param width maximum width of the row.
96 * \param next_width available width on next row.
97 * \param force: if true, cut string at any place, even for
98 * languages that wrap at word delimiters; if false, do not
99 * break at all if first element would larger than \c width.
101 // FIXME: ideally last parameter should be Elements&, but it is not possible.
102 bool splitAt(int width, int next_width, bool force, std::vector<Element> & tail);
103 // remove trailing spaces (useful for end of row)
107 bool isRTL() const { return font.isVisibleRightToLeft(); }
108 // This is true for virtual elements.
109 bool isVirtual() const { return type == VIRTUAL; }
111 // Returns the position on left side of the element.
112 pos_type left_pos() const { return isRTL() ? endpos : pos; };
113 // Returns the position on right side of the element.
114 pos_type right_pos() const { return isRTL() ? pos : endpos; };
116 // The kind of row element
118 // position of the element in the paragraph
120 // first position after the element in the paragraph
122 // The dimension of the chunk (does not contains the
123 // separator correction)
126 // Non-zero only if element is an inset
127 Inset const * inset = nullptr;
129 // Only non-null for justified rows
132 // Non-empty if element is a string or is virtual
138 // is it possible to add contents to this element?
140 // properties with respect to row breaking (made of RowFlag enums)
141 int row_flags = Inline;
143 friend std::ostream & operator<<(std::ostream & os, Element const & row);
147 typedef Element value_type;
153 * Helper function: set variable \c var to value \c val, and mark
154 * row as changed is the values were different. This is intended
155 * for use when changing members of the row object.
157 template<class T1, class T2>
158 void change(T1 & var, T2 const val) {
164 * Helper function: set variable \c var to value \c val, and mark
165 * row as changed is the values were different. This is intended
166 * for use when changing members of the row object.
167 * This is the const version, useful for mutable members.
169 template<class T1, class T2>
170 void change(T1 & var, T2 const val) const {
176 bool changed() const { return changed_; }
178 void changed(bool c) const { changed_ = c; }
180 bool selection() const;
182 * Set the selection begin and end and whether the left and/or
183 * right margins are selected.
184 * This is const because we update the selection status only at
187 void setSelectionAndMargins(DocIterator const & beg,
188 DocIterator const & end) const;
189 /// no selection on this row.
190 void clearSelectionAndMargins() const;
193 void pit(pit_type p) { pit_ = p; }
195 pit_type pit() const { return pit_; }
197 void pos(pos_type p) { pos_ = p; }
199 pos_type pos() const { return pos_; }
201 void endpos(pos_type p) { end_ = p; }
203 pos_type endpos() const { return end_; }
205 void right_boundary(bool b) { right_boundary_ = b; }
207 bool right_boundary() const { return right_boundary_; }
209 void flushed(bool b) { flushed_ = b; }
211 bool flushed() const { return flushed_; }
214 Dimension const & dim() const { return dim_; }
216 Dimension & dim() { return dim_; }
218 int height() const { return dim_.height(); }
219 /// The width of the row, including the left margin, but not the right one.
220 int width() const { return dim_.wid; }
222 int ascent() const { return dim_.asc; }
224 int descent() const { return dim_.des; }
227 Dimension const & contents_dim() const { return contents_dim_; }
229 Dimension & contents_dim() { return contents_dim_; }
231 /// The offset of the left-most cursor position on the row
233 /// The offset of the right-most cursor position on the row
236 // Return the number of separators in the row
237 int countSeparators() const;
238 // Set the extra spacing for every expanding character in STRING-type
239 // elements. \param w is the total amount of extra width for the row to be
240 // distributed among expanders. \return false if the justification fails.
241 bool setExtraWidth(int w);
244 void add(pos_type pos, Inset const * ins, Dimension const & dim,
245 Font const & f, Change const & ch);
247 void add(pos_type pos, char_type const c,
248 Font const & f, Change const & ch, bool can_break);
250 void addVirtual(pos_type pos, docstring const & s,
251 Font const & f, Change const & ch);
253 void addSpace(pos_type pos, int width, Font const & f, Change const & ch);
256 typedef std::vector<Element> Elements;
258 typedef Elements::iterator iterator;
260 typedef Elements::const_iterator const_iterator;
262 iterator begin() { return elements_.begin(); }
264 iterator end() { return elements_.end(); }
266 const_iterator begin() const { return elements_.begin(); }
268 const_iterator end() const { return elements_.end(); }
271 bool empty() const { return elements_.empty(); }
273 Element & front() { return elements_.front(); }
275 Element const & front() const { return elements_.front(); }
277 Element & back() { return elements_.back(); }
279 Element const & back() const { return elements_.back(); }
280 /// add element at the end and update width
281 void push_back(Element const &);
282 /// remove last element and update width
285 * if row width is too large, remove all elements after last
286 * separator and update endpos if necessary. If all that
287 * remains is a large word, cut it to \param width.
288 * \param width maximum width of the row.
289 * \param next_width available width on next row.
290 * \return list of elements remaining after breaking.
292 Elements shortenIfNeeded(int const width, int const next_width);
295 * If last element of the row is a string, compute its width
301 * Find sequences of right-to-left elements and reverse them.
302 * This should be called once the row is completely built.
306 bool isRTL() const { return rtl_; }
308 void setRTL(bool rtl) { rtl_ = rtl; }
310 bool needsChangeBar() const { return changebar_; }
312 void needsChangeBar(bool ncb) { changebar_ = ncb; }
314 /// Find row element that contains \c pos, and compute x offset.
315 const_iterator const findElement(pos_type pos, bool boundary, double & x) const;
317 friend std::ostream & operator<<(std::ostream & os, Row const & row);
319 /// additional width for separators in justified rows (i.e. space)
320 double separator = 0;
321 /// width of hfills in the label
322 double label_hfill = 0;
323 /// the left margin position of the row
325 /// the right margin of the row
326 int right_margin = 0;
328 mutable pos_type sel_beg = -1;
330 mutable pos_type sel_end = -1;
332 mutable bool begin_margin_sel = false;
334 mutable bool end_margin_sel = false;
337 /// Decides whether the margin is selected.
339 * \param margin_begin
343 bool isMarginSelected(bool left, DocIterator const & beg,
344 DocIterator const & end) const;
345 /// Set the selection begin and end.
346 void setSelection(pos_type sel_beg, pos_type sel_end) const;
349 * Returns true if a char or string with font \c f and change
350 * type \c ch can be added to the current last element of the
353 bool sameString(Font const & f, Change const & ch) const;
358 /// has the Row appearance changed since last drawing?
359 mutable bool changed_ = true;
360 /// Index of the paragraph that contains this row
362 /// first pos covered by this row
364 /// one behind last pos covered by this row
366 // Is there a boundary at the end of the row (display inset...)
367 bool right_boundary_ = false;
368 // Shall the row be flushed when it is supposed to be justified?
369 bool flushed_ = false;
372 /// Row contents dimension. Does not contain the space above/below row.
373 Dimension contents_dim_;
374 /// true when this row lives in a right-to-left paragraph
376 /// true when a changebar should be drawn in the margin
377 bool changebar_ = false;
380 std::ostream & operator<<(std::ostream & os, Row::Elements const & elts);
384 * Each paragraph is broken up into a number of rows on the screen.
385 * This is a list of such on-screen rows, ordered from the top row
388 typedef std::vector<Row> RowList;