4 * This file is part of LyX, the document processor.
5 * Licence details can be found in the file COPYING.
10 * Full author contact details are available in file CREDITS.
13 #ifndef FONT_METRICS_H
14 #define FONT_METRICS_H
16 #include "support/docstring.h"
22 * A namespace holding helper functions for determining
23 * the screen dimensions of fonts.
25 * The geometry is the standard typographical geometry,
28 * --------------+------------------<maxAscent
30 * <-------> (right bearing)
34 * origin>____ | oo oo | oo oo
36 * --------------+---ooooo--|--oooo-<baseline
39 * descent>______| oooo |
41 * --------------+----------+-------<maxDescent
44 namespace font_metrics {
45 /// return the maximum ascent of the font
46 int maxAscent(LyXFont const & f);
47 /// return the maximum descent of the font
48 int maxDescent(LyXFont const & f);
49 /// return the maximum descent of the font
50 inline int maxHeight(LyXFont const & f) {
51 return maxAscent(f) + maxDescent(f);
53 /// return the ascent of the char in the font
54 int ascent(lyx::char_type c, LyXFont const & f);
55 /// return the descent of the char in the font
56 int descent(lyx::char_type c, LyXFont const & f);
57 /// return the descent of the char in the font
58 inline int height(lyx::char_type c, LyXFont const & f)
60 return ascent(c, f) + descent(c, f);
62 /// return the left bearing of the char in the font
63 int lbearing(lyx::char_type c, LyXFont const & f);
64 /// return the right bearing of the char in the font
65 int rbearing(lyx::char_type c, LyXFont const & f);
66 /// return the inner width of the char in the font
67 inline int center(lyx::char_type c, LyXFont const & f) {
68 return (rbearing(c, f) - lbearing(c, f)) / 2;
70 /// return the width of the string in the font
71 int width(lyx::char_type const * s, size_t n, LyXFont const & f);
72 /// return the width of the char in the font
73 inline int width(lyx::char_type c, LyXFont const & f)
75 lyx::char_type tmp[2] = { c, L'\0'};
76 return width(tmp, 1, f);
78 /// return the width of the string in the font
79 inline int width(lyx::docstring const & s, LyXFont const & f)
81 return s.empty() ? 0 : width(s.data(), s.length(), f);
84 int signedWidth(lyx::docstring const & s, LyXFont const & f);
86 * fill in width,ascent,descent with the values for the
87 * given string in the font.
89 void rectText(lyx::docstring const & str, LyXFont const & font,
94 * fill in width,ascent,descent with the values for the
95 * given string in the font for a button.
97 void buttonText(lyx::docstring const & str, LyXFont const & font,
103 #endif // FONT_METRICS_H