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 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
92 * than the required values.
93 * \return true if something has been done ; false if this is
94 * not needed or not possible.
95 * \param width: maximum width of the row.
96 * \param next_width: available width on next rows.
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.
100 * \param tail: a vector of elements where the remainder of
101 * the text will be appended (empty if nothing happened).
103 // FIXME: ideally last parameter should be Elements&, but it is not possible.
104 bool splitAt(int width, int next_width, bool force, std::vector<Element> & tail);
105 // remove trailing spaces (useful for end of row)
109 bool isRTL() const { return font.isVisibleRightToLeft(); }
110 // This is true for virtual elements.
111 bool isVirtual() const { return type == VIRTUAL; }
113 // Returns the position on left side of the element.
114 pos_type left_pos() const { return isRTL() ? endpos : pos; };
115 // Returns the position on right side of the element.
116 pos_type right_pos() const { return isRTL() ? pos : endpos; };
118 // The kind of row element
120 // position of the element in the paragraph
122 // first position after the element in the paragraph
124 // The dimension of the chunk (does not contain the
125 // separator correction)
127 // The width of the element without trailing spaces
130 // Non-zero only if element is an inset
131 Inset const * inset = nullptr;
133 // Only non-null for justified rows
136 // Non-empty if element is a string or is virtual
142 // is it possible to add contents to this element?
144 // properties with respect to row breaking (made of RowFlag enumerators)
145 int row_flags = Inline;
147 friend std::ostream & operator<<(std::ostream & os, Element const & row);
151 typedef Element value_type;
157 * Helper function: set variable \c var to value \c val, and mark
158 * row as changed is the values were different. This is intended
159 * for use when changing members of the row object.
161 template<class T1, class T2>
162 void change(T1 & var, T2 const val) {
168 * Helper function: set variable \c var to value \c val, and mark
169 * row as changed is the values were different. This is intended
170 * for use when changing members of the row object.
171 * This is the const version, useful for mutable members.
173 template<class T1, class T2>
174 void change(T1 & var, T2 const val) const {
180 bool changed() const { return changed_; }
182 void changed(bool c) const { changed_ = c; }
184 bool selection() const;
186 * Set the selection begin and end and whether the left and/or
187 * right margins are selected.
188 * This is const because we update the selection status only at
191 void setSelectionAndMargins(DocIterator const & beg,
192 DocIterator const & end) const;
193 /// no selection on this row.
194 void clearSelectionAndMargins() const;
197 void pit(pit_type p) { pit_ = p; }
199 pit_type pit() const { return pit_; }
201 void pos(pos_type p) { pos_ = p; }
203 pos_type pos() const { return pos_; }
205 void endpos(pos_type p) { end_ = p; }
207 pos_type endpos() const { return end_; }
209 void end_boundary(bool b) { end_boundary_ = b; }
211 bool end_boundary() const { return end_boundary_; }
213 void flushed(bool b) { flushed_ = b; }
215 bool flushed() const { return flushed_; }
218 Dimension const & dim() const { return dim_; }
220 Dimension & dim() { return dim_; }
222 int height() const { return dim_.height(); }
223 /// The width of the row, including the left margin, but not the right one.
224 int width() const { return dim_.wid; }
226 int ascent() const { return dim_.asc; }
228 int descent() const { return dim_.des; }
231 Dimension const & contents_dim() const { return contents_dim_; }
233 Dimension & contents_dim() { return contents_dim_; }
235 /// The offset of the left-most cursor position on the row
237 /// The offset of the right-most cursor position on the row
240 // Set the extra spacing for every expanding character in STRING-type
241 // elements. \param w is the total amount of extra width for the row to be
242 // distributed among expanders. \return false if the justification fails.
243 bool setExtraWidth(int w);
246 void add(pos_type pos, Inset const * ins, Dimension const & dim,
247 Font const & f, Change const & ch);
249 void add(pos_type pos, char_type const c,
250 Font const & f, Change const & ch);
252 void addVirtual(pos_type pos, docstring const & s,
253 Font const & f, Change const & ch);
255 void addSpace(pos_type pos, int width, Font const & f, Change const & ch);
257 void addMarginSpace(pos_type pos, int width, Font const & f, Change const & ch);
260 typedef std::vector<Element> Elements;
262 typedef Elements::iterator iterator;
264 typedef Elements::const_iterator const_iterator;
266 iterator begin() { return elements_.begin(); }
268 iterator end() { return elements_.end(); }
270 const_iterator begin() const { return elements_.begin(); }
272 const_iterator end() const { return elements_.end(); }
275 bool empty() const { return elements_.empty(); }
277 Element & front() { return elements_.front(); }
279 Element const & front() const { return elements_.front(); }
281 Element & back() { return elements_.back(); }
283 Element const & back() const { return elements_.back(); }
284 /// add element at the end and update width
285 void push_back(Element const &);
286 /// remove last element and update width
289 * if row width is too large, remove all elements after last
290 * separator and update endpos if necessary. If all that
291 * remains is a large word, cut it to \param width.
292 * \param width maximum width of the row.
293 * \param next_width available width on next row.
294 * \return list of elements remaining after breaking.
296 Elements shortenIfNeeded(int const width, int const next_width);
299 * If last element of the row is a string, compute its width
305 * Find sequences of right-to-left elements and reverse them.
306 * This should be called once the row is completely built.
310 bool isRTL() const { return rtl_; }
312 void setRTL(bool rtl) { rtl_ = rtl; }
314 bool needsChangeBar() const { return changebar_; }
316 void needsChangeBar(bool ncb) { changebar_ = ncb; }
318 /// Find row element that contains \c pos, and compute x offset.
319 const_iterator const findElement(pos_type pos, bool boundary, double & x) const;
321 friend std::ostream & operator<<(std::ostream & os, Row const & row);
323 /// additional width for separators in justified rows (i.e. space)
324 double separator = 0;
325 /// width of hfills in the label
326 double label_hfill = 0;
327 /// the left margin position of the row
329 /// the right margin of the row
330 int right_margin = 0;
332 mutable pos_type sel_beg = -1;
334 mutable pos_type sel_end = -1;
336 mutable bool begin_margin_sel = false;
338 mutable bool end_margin_sel = false;
341 /// Decides whether the margin is selected.
343 * \param margin_begin
347 bool isMarginSelected(bool left, DocIterator const & beg,
348 DocIterator const & end) const;
349 /// Set the selection begin and end.
350 void setSelection(pos_type sel_beg, pos_type sel_end) const;
353 * Returns true if a char or string with font \c f and change
354 * type \c ch can be added to the current last element of the
357 bool sameString(Font const & f, Change const & ch) const;
362 /// has the Row appearance changed since last drawing?
363 mutable bool changed_ = true;
364 /// Index of the paragraph that contains this row
366 /// first pos covered by this row
368 /// one behind last pos covered by this row
370 // Is there a boundary at the end of the row (display inset...)
371 bool end_boundary_ = false;
372 // Shall the row be flushed when it is supposed to be justified?
373 bool flushed_ = false;
376 /// Row contents dimension. Does not contain the space above/below row.
377 Dimension contents_dim_;
378 /// true when this row lives in a right-to-left paragraph
380 /// true when a changebar should be drawn in the margin
381 bool changebar_ = false;
384 std::ostream & operator<<(std::ostream & os, Row::Elements const & elts);
388 * Each paragraph is broken up into a number of rows on the screen.
389 * This is a list of such on-screen rows, ordered from the top row
392 typedef std::vector<Row> RowList;