pango_layout_set_text

89 static PangoLayout *
90 make_layout(PangoContext *context,
91	    const char   *text,
92	    double        size)
93 {
94     static PangoFontDescription *font_description;
95     PangoAlignment align;
96     PangoLayout *layout;
97
98     layout = pango_layout_new (context);
99     if (opt_markup)
100       pango_layout_set_markup (layout, text, -1);
101     else
102       pango_layout_set_text (layout, text, -1); <==
103
104     pango_layout_set_auto_dir (layout, opt_auto_dir);
105     pango_layout_set_ellipsize (layout, opt_ellipsize);
106     pango_layout_set_justify (layout, opt_justify);
107     pango_layout_set_single_paragraph_mode (layout, opt_single_par);
108     pango_layout_set_wrap (layout, opt_wrap);
109
110     font_description = pango_font_description_from_string (opt_font);
111     if (size > 0)
112       pango_font_description_set_size (font_description, size * PANGO_SCALE);
113
114     if (opt_width > 0)
115       pango_layout_set_width (layout, (opt_width * opt_dpi * PANGO_SCALE + 36) / 72);
116
117     if (opt_height > 0)
118       pango_layout_set_height (layout, (opt_height * opt_dpi * PANGO_SCALE + 36) / 72);
119     else
120       pango_layout_set_height (layout, opt_height);
121
122     if (opt_indent != 0)
123       pango_layout_set_indent (layout, (opt_indent * opt_dpi * PANGO_SCALE + 36) / 72);
124
125     align = opt_align;
126     if (align != PANGO_ALIGN_CENTER &&
127         pango_context_get_base_dir (context) != PANGO_DIRECTION_LTR) {
128       /* pango reverses left and right if base dir ir rtl.  so we should
129        * reverse to cancel that.  unfortunately it also does that for
130        * rtl paragraphs, so we cannot really get left/right.  all we get
131        * is default/other-side. */
132       align = PANGO_ALIGN_LEFT + PANGO_ALIGN_RIGHT - align;
133     }
134     pango_layout_set_alignment (layout, align);
135
136     pango_layout_set_font_description (layout, font_description);
137
138     pango_font_description_free (font_description);
139
140     return layout;
141 }

length
maximum length of text , in bytes. -1 indicates that the string is nul-terminated and the length should be calculated. The text will also be truncated on encountering a nul-termination even when length is positive.

1082 pango_layout_set_text (PangoLayout *layout,
1083		       const char  *text,
1084		       int          length)
1085 {
1086     char *old_text, *start, *end;
1087
1088     g_return_if_fail (layout != NULL);
1089     g_return_if_fail (length == 0 || text != NULL);
1090
1091     old_text = layout->text;
1092
1093     if (length < 0)
1094         layout->text = g_strdup (text);
1095     else if (length > 0)
1096         /* This is not exactly what we want.  We don't need the padding...
1097          */
1098         layout->text = g_strndup (text, length);
1099     else
1100           layout->text = g_malloc0 (1);
1101
1102      layout->length = strlen (layout->text);
1103
1104      /* validate it, and replace invalid bytes with '?'
1105      */
1106      start = layout->text;
1107      for (;;) {
1108        gboolean valid;
1109
1110       valid = g_utf8_validate (start, -1, (const char **)&end);
1111
1112       if (!*end)
1113         break;
1114
1115      /* Replace invalid bytes with -1.  The -1 will be converted to
1116       * ((gunichar) -1) by glib, and that in turn yields a glyph value of
1117       * ((PangoGlyph) -1) by PANGO_GET_UNKNOWN_GLYPH(-1),
1118       * and that's PANGO_GLYPH_INVALID_INPUT.
1119       */
1120      if (!valid)
1121        *end++ = -1;
1122
1123       start = end;
1124     }
1125
1126     if (start != layout->text)
1127         /* TODO: Write out the beginning excerpt of text? */
1128         g_warning ("Invalid UTF-8 string passed to pango_layout_set_text()");
1129
1130     layout->n_chars = pango_utf8_strlen (layout->text, -1);
1131
1132     layout_changed (layout);
1133
1134     g_free (old_text);
1135 }