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 // Something that should not happen (for error handling)
59 * One element of a Row. It has a set of attributes that can be used
60 * by other methods that need to parse the Row contents.
66 Element(Type const t, pos_type p, Font const & f, Change const & ch)
67 : type(t), pos(p), endpos(p + 1), font(f), change(ch) {}
70 // Return the number of separator in the element (only STRING type)
71 int countSeparators() const;
73 // Return total width of element, including separator overhead
74 // FIXME: Cache this value or the number of expanders?
75 double full_width() const { return dim.wid + extra * countExpanders(); }
76 // Return the number of expanding characters in the element (only STRING
78 int countExpanders() const;
79 // Return the amount of expansion: the number of expanding characters
80 // that get stretched during justification, times the em of the font
81 // (only STRING type).
82 int expansionAmount() const;
83 // set extra proportionally to the font em value.
84 void setExtra(double extra_per_em);
86 /** Return position in pixels (from the left) of position
87 * \param i in the row element.
89 double pos2x(pos_type const i) const;
90 /** Return character position that is the closest to
91 * pixel position \param x. The value \param x is
92 * adjusted to the actual pixel position.
94 pos_type x2pos(int &x) const;
95 /** Break the element in two if possible, so that its width is less
97 * \return an element containing the remainder of the text, or
98 * an invalid element if nothing happened.
99 * \param w: the desired maximum width
100 * \param force: if true, the string is cut at any place, otherwise it
101 * respects the row breaking rules of characters.
103 Element splitAt(int w, bool force);
106 bool isRTL() const { return font.isVisibleRightToLeft(); }
107 // This is true for virtual elements.
108 bool isVirtual() const { return type == VIRTUAL; }
109 // Invalid element, for error handling
110 bool isValid() const { return type !=INVALID; }
112 // Returns the position on left side of the element.
113 pos_type left_pos() const { return isRTL() ? endpos : pos; };
114 // Returns the position on right side of the element.
115 pos_type right_pos() const { return isRTL() ? pos : endpos; };
117 // The kind of row element
119 // position of the element in the paragraph
121 // first position after the element in the paragraph
123 // The dimension of the chunk (does not contains the
124 // separator correction)
127 // Non-zero only if element is an inset
128 Inset const * inset = nullptr;
130 // Only non-null for justified rows
133 // Non-empty if element is a string or is virtual
139 // is it possible to add contents to this element?
141 // properties with respect to row breaking (made of RowFlag enums)
142 int row_flags = Inline;
144 friend std::ostream & operator<<(std::ostream & os, Element const & row);
148 typedef Element value_type;
154 * Helper function: set variable \c var to value \c val, and mark
155 * row as changed is the values were different. This is intended
156 * for use when changing members of the row object.
158 template<class T1, class T2>
159 void change(T1 & var, T2 const val) {
165 * Helper function: set variable \c var to value \c val, and mark
166 * row as changed is the values were different. This is intended
167 * for use when changing members of the row object.
168 * This is the const version, useful for mutable members.
170 template<class T1, class T2>
171 void change(T1 & var, T2 const val) const {
177 bool changed() const { return changed_; }
179 void changed(bool c) const { changed_ = c; }
181 bool selection() const;
183 * Set the selection begin and end and whether the left and/or
184 * right margins are selected.
185 * This is const because we update the selection status only at
188 void setSelectionAndMargins(DocIterator const & beg,
189 DocIterator const & end) const;
190 /// no selection on this row.
191 void clearSelectionAndMargins() const;
194 void pit(pit_type p) { pit_ = p; }
196 pit_type pit() const { return pit_; }
198 void pos(pos_type p) { pos_ = p; }
200 pos_type pos() const { return pos_; }
202 void endpos(pos_type p) { end_ = p; }
204 pos_type endpos() const { return end_; }
206 void right_boundary(bool b) { right_boundary_ = b; }
208 bool right_boundary() const { return right_boundary_; }
210 void flushed(bool b) { flushed_ = b; }
212 bool flushed() const { return flushed_; }
215 Dimension const & dim() const { return dim_; }
217 Dimension & dim() { return dim_; }
219 int height() const { return dim_.height(); }
220 /// The width of the row, including the left margin, but not the right one.
221 int width() const { return dim_.wid; }
223 int ascent() const { return dim_.asc; }
225 int descent() const { return dim_.des; }
228 Dimension const & contents_dim() const { return contents_dim_; }
230 Dimension & contents_dim() { return contents_dim_; }
232 /// The offset of the left-most cursor position on the row
234 /// The offset of the right-most cursor position on the row
237 // Return the number of separators in the row
238 int countSeparators() const;
239 // Set the extra spacing for every expanding character in STRING-type
240 // elements. \param w is the total amount of extra width for the row to be
241 // distributed among expanders. \return false if the justification fails.
242 bool setExtraWidth(int w);
245 void add(pos_type pos, Inset const * ins, Dimension const & dim,
246 Font const & f, Change const & ch);
248 void add(pos_type pos, char_type const c,
249 Font const & f, Change const & ch, bool can_break);
251 void addVirtual(pos_type pos, docstring const & s,
252 Font const & f, Change const & ch);
254 void addSpace(pos_type pos, int width, Font const & f, Change const & ch);
257 typedef std::vector<Element> Elements;
259 typedef Elements::iterator iterator;
261 typedef Elements::const_iterator const_iterator;
263 iterator begin() { return elements_.begin(); }
265 iterator end() { return elements_.end(); }
267 const_iterator begin() const { return elements_.begin(); }
269 const_iterator end() const { return elements_.end(); }
272 bool empty() const { return elements_.empty(); }
274 Element & front() { return elements_.front(); }
276 Element const & front() const { return elements_.front(); }
278 Element & back() { return elements_.back(); }
280 Element const & back() const { return elements_.back(); }
281 /// add element at the end and update width
282 void push_back(Element const &);
283 /// remove last element and update width
286 * if row width is too large, remove all elements after last
287 * separator and update endpos if necessary. If all that
288 * remains is a large word, cut it to \param width.
289 * \param width maximum width of the row.
290 * \param available width on next row.
291 * \return true if the row has been shortened.
293 Elements shortenIfNeeded(int const width, int const next_width);
296 * If last element of the row is a string, compute its width
302 * Find sequences of right-to-left elements and reverse them.
303 * This should be called once the row is completely built.
305 void reverseRTL(bool rtl_par);
307 bool isRTL() const { return rtl_; }
309 bool needsChangeBar() const { return changebar_; }
311 void needsChangeBar(bool ncb) { changebar_ = ncb; }
313 /// Find row element that contains \c pos, and compute x offset.
314 const_iterator const findElement(pos_type pos, bool boundary, double & x) const;
316 friend std::ostream & operator<<(std::ostream & os, Row const & row);
318 /// additional width for separators in justified rows (i.e. space)
319 double separator = 0;
320 /// width of hfills in the label
321 double label_hfill = 0;
322 /// the left margin position of the row
324 /// the right margin of the row
325 int right_margin = 0;
327 mutable pos_type sel_beg = -1;
329 mutable pos_type sel_end = -1;
331 mutable bool begin_margin_sel = false;
333 mutable bool end_margin_sel = false;
336 /// Decides whether the margin is selected.
338 * \param margin_begin
342 bool isMarginSelected(bool left, DocIterator const & beg,
343 DocIterator const & end) const;
344 /// Set the selection begin and end.
345 void setSelection(pos_type sel_beg, pos_type sel_end) const;
348 * Returns true if a char or string with font \c f and change
349 * type \c ch can be added to the current last element of the
352 bool sameString(Font const & f, Change const & ch) const;
357 /// has the Row appearance changed since last drawing?
358 mutable bool changed_ = true;
359 /// Index of the paragraph that contains this row
361 /// first pos covered by this row
363 /// one behind last pos covered by this row
365 // Is there a boundary at the end of the row (display inset...)
366 bool right_boundary_ = false;
367 // Shall the row be flushed when it is supposed to be justified?
368 bool flushed_ = false;
371 /// Row contents dimension. Does not contain the space above/below row.
372 Dimension contents_dim_;
373 /// true when this row lives in a right-to-left paragraph
375 /// true when a changebar should be drawn in the margin
376 bool changebar_ = false;
381 * Each paragraph is broken up into a number of rows on the screen.
382 * This is a list of such on-screen rows, ordered from the top row
385 typedef std::vector<Row> RowList;