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"
22 #include "support/docstring.h"
23 #include "support/types.h"
33 * An on-screen row of text. A paragraph is broken into a RowList for
34 * display. Each Row contains a tokenized description of the contents
39 // Possible types of row elements
41 // a string of character
44 * Something (completion, end-of-par marker)
45 * that occupies space one screen but does not
46 * correspond to any paragraph contents
51 // Some spacing described by its width, not a string
56 * One element of a Row. It has a set of attributes that can be used
57 * by other methods that need to parse the Row contents.
60 Element(Type const t, pos_type p, Font const & f, Change const & ch)
61 : type(t), pos(p), endpos(p + 1), inset(0),
62 extra(0), font(f), change(ch), final(false) {}
64 // Return the number of separator in the element (only STRING type)
65 int countSeparators() const;
67 // Return total width of element, including separator overhead
68 // FIXME: Cache this value or the number of expanders?
69 double full_width() const { return dim.wid + extra * countExpanders(); }
70 // Return the number of expanding characters in the element (only STRING
72 int countExpanders() const;
73 // Return the amount of expansion: the number of expanding characters
74 // that get stretched during justification, times the em of the font
75 // (only STRING type).
76 int expansionAmount() const;
77 // set extra proportionally to the font em value.
78 void setExtra(double extra_per_em);
80 /** Return position in pixels (from the left) of position
81 * \param i in the row element.
83 double pos2x(pos_type i) const;
84 /** Return character position that is the closest to
85 * pixel position \param x. The value \param x is
86 * adjusted to the actual pixel position.
87 * \param select if true, return the right edge when closer.
89 pos_type x2pos(int & x, bool select = false) const;
90 /** Break the element if possible, so that its width is less
91 * than \param w. Returns true on success. When \param force
92 * is true, the string is cut at any place, other wise it
93 * respects the row breaking rules of characters.
95 bool breakAt(int w, bool force);
97 // Returns the position on left side of the element.
98 pos_type left_pos() const;
99 // Returns the position on right side of the element.
100 pos_type right_pos() const;
103 bool isRTL() const { return font.isVisibleRightToLeft(); }
104 // This is true for virtual elements.
105 // Note that we do not use the type here. The two definitions
106 // should be equivalent
107 bool isVirtual() const { return pos == endpos; }
109 // The kind of row element
111 // position of the element in the paragraph
113 // first position after the element in the paragraph
115 // The dimension of the chunk (does not contains the
116 // separator correction)
119 // Non-zero only if element is an inset
122 // Only non-null for justified rows
125 // Non-empty if element is a string or is virtual
131 // is it possible to add contents to this element?
134 friend std::ostream & operator<<(std::ostream & os, Element const & row);
141 bool changed() const { return changed_; }
143 void setChanged(bool c) { changed_ = c; }
145 void setCrc(size_type crc) const;
146 /// Set the selection begin and end.
148 * This is const because we update the selection status only at draw()
151 void setSelection(pos_type sel_beg, pos_type sel_end) const;
153 bool selection() const;
154 /// Set the selection begin and end and whether the left and/or right
155 /// margins are selected.
156 void setSelectionAndMargins(DocIterator const & beg,
157 DocIterator const & end) const;
160 void pit(pit_type p) { pit_ = p; }
162 pit_type pit() const { return pit_; }
164 void pos(pos_type p) { pos_ = p; }
166 pos_type pos() const { return pos_; }
168 void endpos(pos_type p) { end_ = p; }
170 pos_type endpos() const { return end_; }
172 void right_boundary(bool b) { right_boundary_ = b; }
174 bool right_boundary() const { return right_boundary_; }
176 void flushed(bool b) { flushed_ = b; }
178 bool flushed() const { return flushed_; }
181 Dimension const & dimension() const { return dim_; }
183 Dimension & dimension() { return dim_; }
185 int height() const { return dim_.height(); }
186 /// The width of the row, including the left margin, but not the right one.
187 int width() const { return dim_.wid; }
189 int ascent() const { return dim_.asc; }
191 int descent() const { return dim_.des; }
193 /// The offset of the left-most cursor position on the row
195 /// The offset of the right-most cursor position on the row
198 // Return the number of separators in the row
199 int countSeparators() const;
200 // Set the extra spacing for every expanding character in STRING-type
201 // elements. \param w is the total amount of extra width for the row to be
202 // distributed among expanders. \return false if the justification fails.
203 bool setExtraWidth(int w);
206 void add(pos_type pos, Inset const * ins, Dimension const & dim,
207 Font const & f, Change const & ch);
209 void add(pos_type pos, char_type const c,
210 Font const & f, Change const & ch);
212 void addVirtual(pos_type pos, docstring const & s,
213 Font const & f, Change const & ch);
215 void addSpace(pos_type pos, int width, Font const & f, Change const & ch);
218 typedef std::vector<Element> Elements;
220 typedef Elements::iterator iterator;
222 typedef Elements::const_iterator const_iterator;
224 iterator begin() { return elements_.begin(); }
226 iterator end() { return elements_.end(); }
228 const_iterator begin() const { return elements_.begin(); }
230 const_iterator end() const { return elements_.end(); }
233 bool empty() const { return elements_.empty(); }
235 Element & front() { return elements_.front(); }
237 Element const & front() const { return elements_.front(); }
239 Element & back() { return elements_.back(); }
241 Element const & back() const { return elements_.back(); }
242 /// remove last element
244 /// remove all row elements
245 void clear() { elements_.clear(); }
247 * if row width is too large, remove all elements after last
248 * separator and update endpos if necessary. If all that
249 * remains is a large word, cut it to \param width.
250 * \param body_pos minimum amount of text to keep.
251 * \param width maximum width of the row.
252 * \param available width on next row.
253 * \return true if the row has been shortened.
255 bool shortenIfNeeded(pos_type const body_pos, int const width, int const next_width);
258 * If last element of the row is a string, compute its width
264 * Find sequences of right-to-left elements and reverse them.
265 * This should be called once the row is completely built.
267 void reverseRTL(bool rtl_par);
269 bool isRTL() const { return rtl_; }
270 /// Find row element that contains \c pos, and compute x offset.
271 const_iterator const findElement(pos_type pos, bool boundary, double & x) const;
273 friend std::ostream & operator<<(std::ostream & os, Row const & row);
275 /// additional width for separators in justified rows (i.e. space)
277 /// width of hfills in the label
279 /// the left margin position of the row
281 /// the right margin of the row
284 mutable pos_type sel_beg;
286 mutable pos_type sel_end;
288 mutable bool begin_margin_sel;
290 mutable bool end_margin_sel;
293 /// Decides whether the margin is selected.
295 * \param margin_begin
299 bool isMarginSelected(bool left_margin, DocIterator const & beg,
300 DocIterator const & end) const;
303 * Returns true if a char or string with font \c f and change
304 * type \c ch can be added to the current last element of the
307 bool sameString(Font const & f, Change const & ch) const;
312 /// has the Row appearance changed since last drawing?
313 mutable bool changed_;
314 /// CRC of row contents.
315 mutable size_type crc_;
316 /// Index of the paragraph that contains this row
318 /// first pos covered by this row
320 /// one behind last pos covered by this row
322 // Is there a boundary at the end of the row (display inset...)
323 bool right_boundary_;
324 // Shall the row be flushed when it is supposed to be justified?
328 /// true when this row lives in a right-to-left paragraph