Some minor cleanup
[rodin/chimara.git] / libchimara / style.c
1 #include <stdio.h>
2 #include <string.h>
3 #include "chimara-glk-private.h"
4 #include "glk.h"
5 #include "style.h"
6 #include "magic.h"
7 #include "stream.h"
8 #include "strio.h"
9
10 extern GPrivate *glk_data_key;
11
12 static gboolean style_accept(GScanner *scanner, GTokenType token);
13 static gboolean style_accept_style_selector(GScanner *scanner, ChimaraGlk *glk);
14 static gboolean style_accept_style_hint(GScanner *scanner, GtkTextTag *current_tag);
15 static void style_add_tag_to_textbuffer(gpointer key, gpointer tag, gpointer tag_table);
16 static void style_table_copy(gpointer key, gpointer tag, gpointer target_table);
17 static void text_tag_to_attr_list(GtkTextTag *tag, PangoAttrList *list);
18 GtkTextTag* gtk_text_tag_copy(GtkTextTag *tag);
19
20 /**
21  * glk_set_style:
22  * @styl: The style to apply
23  *
24  * Changes the style of the current output stream. @styl should be one of the
25  * <code>style_</code> constants. However, any value is actually legal; if the 
26  * interpreter does not recognize the style value, it will treat it as 
27  * %style_Normal.
28  * <note><para>
29  *  This policy allows for the future definition of styles without breaking old
30  *  Glk libraries.
31  * </para></note>
32  */
33 void
34 glk_set_style(glui32 styl)
35 {
36         ChimaraGlkPrivate *glk_data = g_private_get(glk_data_key);
37         g_return_if_fail(glk_data->current_stream != NULL);
38         glk_set_style_stream(glk_data->current_stream, styl);
39 }
40
41 static const gchar* TAG_NAMES[] = {
42         "normal",
43         "emphasized",
44         "preformatted",
45         "header",
46         "subheader",
47         "alert",
48         "note",
49         "block-quote",
50         "input",
51         "user1",
52         "user2"
53 };
54
55 /* Internal function: mapping from style enum to tag name */
56 static gchar*
57 get_tag_name(glui32 style)
58 {
59         if(style >= style_NUMSTYLES) {
60                 WARNING("Unsupported style");
61                 return "normal";
62         } else {
63                 return (gchar*) TAG_NAMES[style];
64         }
65 }
66
67 /** 
68  * glk_set_style_stream:
69  * @str: Output stream to change the style of
70  * @styl: The style to apply
71  *
72  * This changes the style of the stream @str. See glk_set_style().
73  */
74 void
75 glk_set_style_stream(strid_t str, glui32 styl) {
76         if(str->window == NULL)
77                 return;
78
79         flush_window_buffer(str->window);
80         str->style = get_tag_name(styl);
81 }
82
83 /* Internal function: call this to initialize the layout of the 'more' prompt. */
84 void
85 style_init_more_prompt(winid_t win)
86 {
87         ChimaraGlkPrivate *glk_data = g_private_get(glk_data_key);
88
89         win->pager_layout = gtk_widget_create_pango_layout(win->widget, "More");
90         pango_layout_set_attributes(win->pager_layout, glk_data->pager_attr_list);
91 }
92
93 /* Internal function: call this to initialize the default styles to a textbuffer. */
94 void
95 style_init_textbuffer(GtkTextBuffer *buffer)
96 {
97         g_return_if_fail(buffer != NULL);
98
99         ChimaraGlkPrivate *glk_data = g_private_get(glk_data_key);
100
101         /* Copy the current text tags to the textbuffer's tag table */
102         g_hash_table_foreach(glk_data->current_styles->text_buffer, style_add_tag_to_textbuffer, gtk_text_buffer_get_tag_table(buffer));
103 }
104
105
106 /* Internal function: call this to initialize the default styles to a textgrid. */
107 void
108 style_init_textgrid(GtkTextBuffer *buffer)
109 {
110         g_return_if_fail(buffer != NULL);
111         
112         ChimaraGlkPrivate *glk_data = g_private_get(glk_data_key);
113
114         /* Copy the current text tags to the textgrid's tag table */
115         g_hash_table_foreach(glk_data->current_styles->text_grid, style_add_tag_to_textbuffer, gtk_text_buffer_get_tag_table(buffer));
116 }
117
118 /* Internal function used to iterate over the default text tag table, applying them to a textbuffer */
119 static void
120 style_add_tag_to_textbuffer(gpointer key, gpointer tag, gpointer tag_table)
121 {
122         gtk_text_tag_table_add( tag_table, gtk_text_tag_copy(tag) );
123 }
124
125 /* Internal function used to iterate over a style table, copying it */
126 static void
127 style_table_copy(gpointer key, gpointer tag, gpointer target_table)
128 {
129         g_return_if_fail(key != NULL);
130         g_return_if_fail(tag != NULL);
131         g_return_if_fail(target_table != NULL);
132
133         g_hash_table_insert(target_table, key, gtk_text_tag_copy( GTK_TEXT_TAG(tag) ));
134 }
135
136 /* Internal function that copies a text tag */
137 GtkTextTag *
138 gtk_text_tag_copy(GtkTextTag *tag)
139 {
140         GtkTextTag *copy;
141
142         g_return_val_if_fail(tag != NULL, NULL);
143
144         copy = gtk_text_tag_new(tag->name);
145         gtk_text_attributes_copy_values(tag->values, copy->values);
146         
147         #define _COPY_FLAG(flag) copy->flag = tag->flag
148                 _COPY_FLAG (bg_color_set);
149                 _COPY_FLAG (bg_color_set);
150                 _COPY_FLAG (bg_stipple_set);
151                 _COPY_FLAG (fg_color_set);
152                 _COPY_FLAG (fg_stipple_set);
153                 _COPY_FLAG (justification_set);
154                 _COPY_FLAG (left_margin_set);
155                 _COPY_FLAG (indent_set);
156                 _COPY_FLAG (rise_set);
157                 _COPY_FLAG (strikethrough_set);
158                 _COPY_FLAG (right_margin_set);
159                 _COPY_FLAG (pixels_above_lines_set);
160                 _COPY_FLAG (pixels_below_lines_set);
161                 _COPY_FLAG (pixels_inside_wrap_set);
162                 _COPY_FLAG (tabs_set);
163                 _COPY_FLAG (underline_set);
164                 _COPY_FLAG (wrap_mode_set);
165                 _COPY_FLAG (bg_full_height_set);
166                 _COPY_FLAG (invisible_set);
167                 _COPY_FLAG (editable_set);
168                 _COPY_FLAG (language_set);
169         #undef _COPY_FLAG
170
171         /* Copy the data that was added manually */
172         gpointer reverse_color = g_object_get_data( G_OBJECT(tag), "reverse_color" );
173
174         if(reverse_color)
175                 g_object_set_data( G_OBJECT(copy), "reverse_color", reverse_color );
176
177         return copy;
178 }
179
180 /* Internal function that reads the default styles from a CSS file */
181 void
182 style_init(ChimaraGlk *glk)
183 {
184         CHIMARA_GLK_USE_PRIVATE(glk, priv);
185         
186         GHashTable *default_text_grid_styles = g_hash_table_new_full(g_str_hash, g_str_equal, NULL, g_object_unref);
187         GHashTable *default_text_buffer_styles = g_hash_table_new_full(g_str_hash, g_str_equal, NULL, g_object_unref);
188         GHashTable *current_text_grid_styles = g_hash_table_new_full(g_str_hash, g_str_equal, NULL, g_object_unref);
189         GHashTable *current_text_buffer_styles = g_hash_table_new_full(g_str_hash, g_str_equal, NULL, g_object_unref);
190         GtkTextTag *tag;
191
192         PangoFontDescription *default_font_desc = pango_font_description_from_string("Serif");
193         PangoFontDescription *monospace_font_desc = pango_font_description_from_string("Monospace");
194         
195         /* Initialise the default styles for a text grid */
196         tag = gtk_text_tag_new("normal");
197         g_object_set(tag, "font-desc", monospace_font_desc, NULL);
198         g_hash_table_insert(default_text_grid_styles, "normal", tag);
199
200         tag = gtk_text_tag_new("emphasized");
201         g_object_set(tag, "style", PANGO_STYLE_ITALIC, "style-set", TRUE, NULL);
202         g_hash_table_insert(default_text_grid_styles, "emphasized", tag);
203
204         tag = gtk_text_tag_new("preformatted");
205         g_object_set(tag, "font-desc", monospace_font_desc, NULL);
206         g_hash_table_insert(default_text_grid_styles, "preformatted", tag);
207
208         tag = gtk_text_tag_new("header");
209         g_object_set(tag, "weight", PANGO_WEIGHT_BOLD, NULL);
210         g_hash_table_insert(default_text_grid_styles, "header", tag);
211
212         tag = gtk_text_tag_new("subheader");
213         g_object_set(tag, "weight", PANGO_WEIGHT_BOLD, NULL);
214         g_hash_table_insert(default_text_grid_styles, "subheader", tag);
215
216         tag = gtk_text_tag_new("alert");
217         g_object_set(tag, "foreground", "#aa0000", "weight", PANGO_WEIGHT_BOLD, NULL);
218         g_hash_table_insert(default_text_grid_styles, "alert", tag);
219
220         tag = gtk_text_tag_new("note");
221         g_object_set(tag, "foreground", "#aaaa00", "weight", PANGO_WEIGHT_BOLD, NULL);
222         g_hash_table_insert(default_text_grid_styles, "note", tag);
223
224         tag = gtk_text_tag_new("block-quote");
225         g_object_set(tag, "style", PANGO_STYLE_ITALIC, "style-set", TRUE, NULL);
226         g_hash_table_insert(default_text_grid_styles, "block-quote", tag);
227
228         g_hash_table_insert(default_text_grid_styles, "input", gtk_text_tag_new("input"));
229         g_hash_table_insert(default_text_grid_styles, "user1", gtk_text_tag_new("user1"));
230         g_hash_table_insert(default_text_grid_styles, "user2", gtk_text_tag_new("user2"));
231
232         tag = gtk_text_tag_new("hyperlink");
233         g_object_set(tag, "foreground", "#0000ff", "underline", PANGO_UNDERLINE_SINGLE, "underline-set", TRUE, NULL);
234         g_hash_table_insert(default_text_grid_styles, "hyperlink", tag);
235
236         /* Tags for the textbuffer */
237         tag = gtk_text_tag_new("normal");
238         g_object_set(tag, "font-desc", default_font_desc, NULL);
239         g_hash_table_insert(default_text_buffer_styles, "normal", tag);
240
241         tag = gtk_text_tag_new("emphasized");
242         g_object_set(tag, "style", PANGO_STYLE_ITALIC, "style-set", TRUE, NULL);
243         g_hash_table_insert(default_text_buffer_styles, "emphasized", tag);
244
245         tag = gtk_text_tag_new("preformatted");
246         g_object_set(tag, "font-desc", monospace_font_desc, NULL);
247         g_hash_table_insert(default_text_buffer_styles, "preformatted", tag);
248
249         tag = gtk_text_tag_new("header");
250         g_object_set(tag, "size-points", 18.0, "weight", PANGO_WEIGHT_BOLD, NULL);
251         g_hash_table_insert(default_text_buffer_styles, "header", tag);
252
253         tag = gtk_text_tag_new("subheader");
254         g_object_set(tag, "size-points", 14.0, "weight", PANGO_WEIGHT_BOLD, NULL);
255         g_hash_table_insert(default_text_buffer_styles, "subheader", tag);
256
257         tag = gtk_text_tag_new("alert");
258         g_object_set(tag, "foreground", "#aa0000", "weight", PANGO_WEIGHT_BOLD, NULL);
259         g_hash_table_insert(default_text_buffer_styles, "alert", tag);
260
261         tag = gtk_text_tag_new("note");
262         g_object_set(tag, "foreground", "#aaaa00", "weight", PANGO_WEIGHT_BOLD, NULL);
263         g_hash_table_insert(default_text_buffer_styles, "note", tag);
264
265         tag = gtk_text_tag_new("block-quote");
266         g_object_set(tag, "justification", GTK_JUSTIFY_CENTER, "style", PANGO_STYLE_ITALIC, "style-set", TRUE, NULL);
267         g_hash_table_insert(default_text_buffer_styles, "block-quote", tag);
268
269         g_hash_table_insert(default_text_buffer_styles, "input", gtk_text_tag_new("input"));
270         g_hash_table_insert(default_text_buffer_styles, "user1", gtk_text_tag_new("user1"));
271         g_hash_table_insert(default_text_buffer_styles, "user2", gtk_text_tag_new("user2"));
272
273         tag = gtk_text_tag_new("hyperlink");
274         g_object_set(tag, "foreground", "#0000ff", "underline", PANGO_UNDERLINE_SINGLE, "underline-set", TRUE, NULL);
275         g_hash_table_insert(default_text_buffer_styles, "hyperlink", tag);
276
277         GtkTextTag *pager_tag = gtk_text_tag_new("pager");
278         g_object_set(pager_tag, "foreground", "#ffffff", "background", "#000000", NULL);
279         g_hash_table_insert(default_text_buffer_styles, "pager", pager_tag);
280
281         pango_font_description_free(default_font_desc);
282         pango_font_description_free(monospace_font_desc);
283         
284         priv->default_styles->text_grid = default_text_grid_styles;
285         priv->default_styles->text_buffer = default_text_buffer_styles;
286         priv->current_styles->text_grid = current_text_grid_styles;
287         priv->current_styles->text_buffer = current_text_buffer_styles;
288
289         /* Set the current style to a copy of the default style */
290         copy_default_styles_to_current_styles(glk);
291 }
292
293 /* Reset style tables to the library's internal defaults */
294 void
295 reset_default_styles(ChimaraGlk *glk)
296 {
297         /* TODO: write this function */
298 }
299
300 /* Copy the default styles to the current styles
301  FIXME: This function is temporary and will not be needed later on */
302 void
303 copy_default_styles_to_current_styles(ChimaraGlk *glk)
304 {
305         CHIMARA_GLK_USE_PRIVATE(glk, priv);
306         g_hash_table_foreach(priv->default_styles->text_grid, style_table_copy, priv->current_styles->text_grid);
307         g_hash_table_foreach(priv->default_styles->text_buffer, style_table_copy, priv->current_styles->text_buffer);
308
309         GtkTextTag *pager_tag = GTK_TEXT_TAG( g_hash_table_lookup(priv->default_styles->text_buffer, "pager") );
310         text_tag_to_attr_list(pager_tag, priv->pager_attr_list);
311 }
312
313 /* Create the CSS file scanner */
314 GScanner *
315 create_css_file_scanner(void)
316 {
317         GScanner *scanner = g_scanner_new(NULL);
318         scanner->config->cset_identifier_first = G_CSET_a_2_z G_CSET_A_2_Z "#";
319         scanner->config->cset_identifier_nth = G_CSET_a_2_z G_CSET_A_2_Z "-_" G_CSET_DIGITS;
320         scanner->config->symbol_2_token = TRUE;
321         scanner->config->cpair_comment_single = NULL;
322         scanner->config->scan_float = FALSE;
323         return scanner;
324 }
325
326 /* Run the scanner over the CSS file, overriding the default styles */
327 void
328 scan_css_file(GScanner *scanner, ChimaraGlk *glk)
329 {
330         while( g_scanner_peek_next_token(scanner) != G_TOKEN_EOF) {
331                 if( !style_accept_style_selector(scanner, glk) )
332                         break;
333         }
334
335         g_scanner_destroy(scanner);
336 }
337
338 /* Internal function: parses a token */
339 static gboolean
340 style_accept(GScanner *scanner, GTokenType token)
341 {
342         GTokenType next = g_scanner_get_next_token(scanner);
343         if(next != token) {
344                 g_scanner_unexp_token(scanner, token, NULL, NULL, NULL, "CSS Error", 1);
345                 return FALSE;
346         }
347         return TRUE;
348 }
349
350 /* Internal function: parses a style selector */
351 static gboolean
352 style_accept_style_selector(GScanner *scanner, ChimaraGlk *glk)
353 {
354         CHIMARA_GLK_USE_PRIVATE(glk, priv);
355
356         GtkTextTag *current_tag;
357         gchar *field;
358         GTokenType token = g_scanner_get_next_token(scanner);
359         GTokenValue value = g_scanner_cur_value(scanner);
360
361         if(
362                 token != G_TOKEN_IDENTIFIER ||
363                 ( strcmp(value.v_identifier, "buffer") && strcmp(value.v_identifier, "grid") )
364         ) {
365                 g_scanner_error(scanner, "CSS Error: buffer/grid expected");
366                 return FALSE;
367         }
368
369         field = g_strdup(value.v_identifier);
370
371         if( !style_accept(scanner, '.') )
372                 return FALSE;
373
374         token = g_scanner_get_next_token(scanner);
375         value = g_scanner_cur_value(scanner);
376
377         if(token != G_TOKEN_IDENTIFIER) {
378                 g_scanner_error(scanner, "CSS Error: style selector expected");
379                 return FALSE;
380         }
381
382         if( !strcmp(field, "buffer") )
383                 current_tag = g_hash_table_lookup(priv->default_styles->text_buffer, value.v_identifier);
384         else
385                 current_tag = g_hash_table_lookup(priv->default_styles->text_grid, value.v_identifier);
386
387         if(current_tag == NULL) {
388                 g_scanner_error(scanner, "CSS Error: invalid style identifier");
389                 return FALSE;
390         }
391
392         if( !style_accept(scanner, '{') )
393                 return FALSE;
394
395         while( g_scanner_peek_next_token(scanner) != '}') {
396                 if( !style_accept_style_hint(scanner, current_tag) )
397                         return FALSE;
398         }
399                 
400         if( !style_accept(scanner, '}') )
401                 return FALSE;
402
403         return TRUE;
404 }
405
406 /* Internal function: parses a style hint */
407 static gboolean
408 style_accept_style_hint(GScanner *scanner, GtkTextTag *current_tag)
409 {
410         GTokenType token = g_scanner_get_next_token(scanner);
411         GTokenValue value = g_scanner_cur_value(scanner);
412         gchar *hint;
413
414         if(token != G_TOKEN_IDENTIFIER) {
415                 g_scanner_error(scanner, "CSS Error: style hint expected");
416                 return FALSE;
417         }
418
419         hint = g_strdup(value.v_identifier);
420
421         if( !style_accept(scanner, ':') )
422                 return FALSE;
423
424         token = g_scanner_get_next_token(scanner);
425         value = g_scanner_cur_value(scanner);
426
427         if( !strcmp(hint, "font-family") ) {
428                 if(token != G_TOKEN_STRING) {
429                         g_scanner_error(scanner, "CSS Error: string expected");
430                         return FALSE;
431                 }
432                 g_object_set(current_tag, "family", value.v_string, "family-set", TRUE, NULL);
433         }
434         else if( !strcmp(hint, "font-weight") ) {
435                 if(token != G_TOKEN_IDENTIFIER) {
436                         g_scanner_error(scanner, "CSS Error: bold/normal expected");
437                         return FALSE;
438                 }
439
440                 if( !strcmp(value.v_identifier, "bold") )
441                         g_object_set(current_tag, "weight", PANGO_WEIGHT_BOLD, "weight-set", TRUE, NULL);
442                 else if( !strcmp(value.v_identifier, "normal") )
443                         g_object_set(current_tag, "weight", PANGO_WEIGHT_NORMAL, "weight-set", TRUE, NULL);
444                 else {
445                         g_scanner_error(scanner, "CSS Error: bold/normal expected");
446                         return FALSE;
447                 }
448         }
449         else if( !strcmp(hint, "font-style") ) {
450                 if(token != G_TOKEN_IDENTIFIER) {
451                         g_scanner_error(scanner, "CSS Error: italic/normal expected");
452                         return FALSE;
453                 }
454
455                 if( !strcmp(value.v_identifier, "italic") )
456                         g_object_set(current_tag, "style", PANGO_STYLE_ITALIC, "style-set", TRUE, NULL);
457                 else if( !strcmp(value.v_identifier, "normal") )
458                         g_object_set(current_tag, "style", PANGO_STYLE_NORMAL, "style-set", TRUE, NULL);
459                 else {
460                         g_scanner_error(scanner, "CSS Error: italic/normal expected");
461                         return FALSE;
462                 }
463         }
464         else if( !strcmp(hint, "font-size") ) {
465                 if(token == G_TOKEN_INT) 
466                         g_object_set(current_tag, "size-points", (float)value.v_int, "size-set", TRUE, NULL);
467                 else if(token == G_TOKEN_FLOAT)
468                         g_object_set(current_tag, "size-points", value.v_float, "size-set", TRUE, NULL);
469                 else {
470                         g_scanner_error(scanner, "CSS Error: integer or float expected");
471                         return FALSE;
472                 }
473         }
474         else if( !strcmp(hint, "color") ) {
475                 if(token != G_TOKEN_IDENTIFIER) {
476                         g_scanner_error(scanner, "CSS Error: hex color expected");
477                         return FALSE;
478                 }
479
480                 g_object_set(current_tag, "foreground", value.v_identifier, "foreground-set", TRUE, NULL);
481         }
482         else if( !strcmp(hint, "background-color") ) {
483                 if(token != G_TOKEN_IDENTIFIER) {
484                         g_scanner_error(scanner, "CSS Error: hex color expected");
485                         return FALSE;
486                 }
487                 g_object_set(current_tag, "background", value.v_identifier, "background-set", TRUE, NULL);
488         }
489         else if( !strcmp(hint, "text-align") ) {
490                 if(token != G_TOKEN_IDENTIFIER) {
491                         g_scanner_error(scanner, "CSS Error: left/right/center expected");
492                         return FALSE;
493                 }
494                 
495                 if( !strcmp(value.v_identifier, "left") )
496                         g_object_set(current_tag, "justification", GTK_JUSTIFY_LEFT, "justification-set", TRUE, NULL);
497                 else if( !strcmp(value.v_identifier, "right") )
498                         g_object_set(current_tag, "justification", GTK_JUSTIFY_RIGHT, "justification-set", TRUE, NULL);
499                 else if( !strcmp(value.v_identifier, "center") )
500                         g_object_set(current_tag, "justification", GTK_JUSTIFY_CENTER, "justification-set", TRUE, NULL);
501                 else {
502                         g_scanner_error(scanner, "CSS Error: left/right/center expected");
503                         return FALSE;
504                 }
505         }
506         else if( !strcmp(hint, "margin-left") ) {
507                 if(token != G_TOKEN_INT) {
508                         g_scanner_error(scanner, "CSS Error: integer expected");
509                         return FALSE;
510                 }
511                 g_object_set(current_tag, "left-margin", value.v_int, "left-margin-set", TRUE, NULL);
512         }
513         else if( !strcmp(hint, "margin-right") ) {
514                 if(token != G_TOKEN_INT) {
515                         g_scanner_error(scanner, "CSS Error: integer expected");
516                         return FALSE;
517                 }
518                 g_object_set(current_tag, "right-margin", value.v_int, "right-margin-set", TRUE, NULL);
519         }
520         else if( !strcmp(hint, "margin-top") ) {
521                 if(token != G_TOKEN_INT) {
522                         g_scanner_error(scanner, "CSS Error: integer expected");
523                         return FALSE;
524                 }
525                 g_object_set(current_tag, "pixels-above-lines", value.v_int, "pixels-above-lines-set", TRUE, NULL);
526         }
527         else if( !strcmp(hint, "margin-bottom") ) {
528                 if(token != G_TOKEN_INT) {
529                         g_scanner_error(scanner, "CSS Error: integer expected");
530                         return FALSE;
531                 }
532                 g_object_set(current_tag, "pixels-below-lines", value.v_int, "pixels-below-lines-set", TRUE, NULL);
533         }
534                 
535         else {
536                 g_scanner_error(scanner, "CSS Error: invalid style hint %s", hint);
537                 return FALSE;
538         }
539
540         if( !style_accept(scanner, ';') )
541                 return FALSE;
542
543         return TRUE;
544 }
545
546 /* Internal function: parses a glk color to a #hex-value */
547 static void
548 glkcolor_to_hex(glui32 val, gchar *buffer)
549 {
550         g_return_if_fail(buffer != NULL);
551
552         sprintf(buffer, "#%02X%02X%02X",
553                 ((val & 0xff0000) >> 16),
554                 ((val & 0x00ff00) >> 8),
555                 (val & 0x0000ff)
556         );
557 }
558
559 /* Internal function: parses a glk color to a GdkColor */
560 void
561 glkcolor_to_gdkcolor(glui32 val, GdkColor *color)
562 {
563         color->red = 256 * ((val & 0xff0000) >> 16);
564         color->green = 256 * ((val & 0x00ff00) >> 8);
565         color->blue = 256 * (val & 0x0000ff);
566 }
567
568 /* Internal function: parses a GdkColor to a glk color */
569 static glui32
570 gdkcolor_to_glkcolor(GdkColor *color)
571 {
572         g_return_val_if_fail(color != NULL, 0);
573         return (glui32) color->pixel;
574 }
575
576 /* Internal function: changes a GTK tag to correspond with the given style. */
577 static void
578 apply_stylehint_to_tag(GtkTextTag *tag, glui32 wintype, glui32 hint, glsi32 val)
579 {
580         g_return_if_fail(tag != NULL);
581
582         ChimaraGlkPrivate *glk_data = g_private_get(glk_data_key);
583         GObject *tag_object = G_OBJECT(tag);
584
585         gint reverse_color = GPOINTER_TO_INT( g_object_get_data(tag_object, "reverse-color") );
586
587         int i = 0;
588         gchar color[20];
589         switch(hint) {
590         case stylehint_Indentation:
591                 g_object_set(tag_object, "left-margin", 5*val, "left-margin-set", TRUE, NULL);
592                 g_object_set(tag_object, "right-margin", 5*val, "right-margin-set", TRUE, NULL);
593                 break;
594         
595         case stylehint_ParaIndentation:
596                 g_object_set(tag_object, "indent", 5*val, "indent-set", TRUE, NULL);
597                 break;
598
599         case stylehint_Justification:
600                 switch(val) {
601                         case stylehint_just_LeftFlush:  i = GTK_JUSTIFY_LEFT; break;
602                         case stylehint_just_LeftRight:  i = GTK_JUSTIFY_FILL; break;
603                         case stylehint_just_Centered:   i = GTK_JUSTIFY_CENTER; break;
604                         case stylehint_just_RightFlush: i = GTK_JUSTIFY_RIGHT; break;
605                         default: 
606                                 WARNING("Unknown justification");
607                                 i = GTK_JUSTIFY_LEFT;
608                 }
609                 g_object_set(tag_object, "justification", i, "justification-set", TRUE, NULL);
610                 break;
611
612         case stylehint_Weight:
613                 switch(val) {
614                         case -1: i = PANGO_WEIGHT_LIGHT; break;
615                         case  0: i = PANGO_WEIGHT_NORMAL; break;
616                         case  1: i = PANGO_WEIGHT_BOLD; break;
617                         default: WARNING("Unknown font weight");
618                 }
619                 g_object_set(tag_object, "weight", i, "weight-set", TRUE, NULL);
620                 break;
621
622         case stylehint_Size:
623                 g_object_set(tag_object, "size", 14+(2*val), "size-set", TRUE, NULL);
624                 break;
625
626         case stylehint_Oblique:
627                 g_object_set(tag_object, "style", val ? PANGO_STYLE_ITALIC : PANGO_STYLE_NORMAL, "style-set", TRUE, NULL);
628                 break;
629
630         case stylehint_Proportional:
631         {
632                 gchar *font_family;
633                 GtkTextTag *font_tag = g_hash_table_lookup(
634                     wintype == wintype_TextBuffer? glk_data->default_styles->text_buffer : glk_data->default_styles->text_grid,
635                     val? "normal" : "preformatted");
636                 g_object_get(font_tag, "family", &font_family, NULL);
637                 g_object_set(tag_object, "family", font_family, "family-set", TRUE, NULL);
638                 g_free(font_family);
639         }
640                 break;
641
642         case stylehint_TextColor:
643                 glkcolor_to_hex(val, color);
644
645                 if(!reverse_color)
646                         g_object_set(tag_object, "foreground", color, "foreground-set", TRUE, NULL);
647                 else
648                         g_object_set(tag_object, "background", color, "background-set", TRUE, NULL);
649
650                 break;
651
652         case stylehint_BackColor:
653                 glkcolor_to_hex(val, color);
654
655                 if(!reverse_color)
656                         g_object_set(tag_object, "background", color, "background-set", TRUE, NULL);
657                 else
658                         g_object_set(tag_object, "foreground", color, "background-set", TRUE, NULL);
659
660                 break;
661
662         case stylehint_ReverseColor:
663                 if(reverse_color != val) {
664                         /* Flip the fore- and background colors */
665                         GdkColor* foreground_color;
666                         GdkColor* background_color;
667                         gint f_set, b_set = 0;
668                         g_object_get(tag_object, "foreground-set", &f_set, "background-set", &b_set, NULL);
669
670                         if(f_set)
671                                 g_object_get(tag_object, "foreground-gdk", &foreground_color, NULL);
672                         if(b_set)
673                                 g_object_get(tag_object, "background-gdk", &background_color, NULL);
674
675                         if(b_set)
676                                 g_object_set(tag_object, "foreground-gdk", background_color, NULL);
677                         else
678                                 g_object_set(tag_object, "foreground", "#ffffff", NULL);
679
680                         if(f_set)
681                                 g_object_set(tag_object, "background-gdk", foreground_color, NULL);
682                         else
683                                 g_object_set(tag_object, "background", "#000000", NULL);
684
685                         g_object_set_data( tag_object, "reverse-color", GINT_TO_POINTER(val != 0) );
686                 }
687                 break;
688
689         default:
690                 WARNING("Unknown style hint");
691         }
692 }
693
694 /* Internal function: queries a text tag for the value of a given style hint */
695 static gint
696 query_tag(GtkTextTag *tag, glui32 wintype, glui32 hint)
697 {
698         gint intval;
699         GdkColor *colval;
700
701         g_return_val_if_fail(tag != NULL, 0);
702
703         ChimaraGlkPrivate *glk_data = g_private_get(glk_data_key);
704
705         switch(hint) {
706         case stylehint_Indentation:
707                 g_object_get(tag, "left_margin", &intval, NULL);
708                 return intval/5;
709         
710         case stylehint_ParaIndentation:
711                 g_object_get(tag, "indent", &intval, NULL);
712                 return intval/5;
713
714         case stylehint_Justification:
715                 g_object_get(tag, "justification", &intval, NULL);
716                 switch(intval) {
717                         case GTK_JUSTIFY_LEFT: return stylehint_just_LeftFlush;
718                         case GTK_JUSTIFY_FILL: return stylehint_just_LeftRight;
719                         case GTK_JUSTIFY_CENTER: return stylehint_just_Centered;
720                         case GTK_JUSTIFY_RIGHT: return stylehint_just_RightFlush;
721                         default: 
722                                 WARNING("Unknown justification");
723                                 return stylehint_just_LeftFlush;
724                 }
725
726         case stylehint_Weight:
727                 g_object_get(tag, "weight", &intval, NULL);
728                 switch(intval) {
729                         case PANGO_WEIGHT_LIGHT: return -1;
730                         case PANGO_WEIGHT_NORMAL: return 0;
731                         case PANGO_WEIGHT_BOLD: return 1;
732                         default: WARNING("Unknown font weight"); return 0;
733                 }
734
735         case stylehint_Size:
736                 g_object_get(tag, "size", &intval, NULL);
737                 return (intval/2)-14;
738
739         case stylehint_Oblique:
740                 g_object_get(tag, "style", &intval , NULL);
741                 return intval == PANGO_STYLE_ITALIC ? 1 : 0;
742
743         case stylehint_Proportional:
744                 /* Use pango_font_family_is_monospace()? */
745         {
746                 gchar *font_family, *query_font_family;
747                 GtkTextTag *font_tag = g_hash_table_lookup(
748                     wintype == wintype_TextBuffer? glk_data->default_styles->text_buffer : glk_data->default_styles->text_grid,
749                     "preformatted");
750                 g_object_get(font_tag, "family", &font_family, NULL);
751                 g_object_get(tag, "family", &query_font_family, NULL);
752                 gint retval = strcmp(font_family, query_font_family)? 0 : 1;
753                 g_free(font_family);
754                 g_free(query_font_family);
755                 return retval;
756         }
757
758         case stylehint_TextColor:
759                 g_object_get(tag, "foreground-gdk", &colval, NULL);
760                 return gdkcolor_to_glkcolor(colval);
761
762         case stylehint_BackColor:
763                 g_object_get(tag, "background-gdk", &colval, NULL);
764                 return gdkcolor_to_glkcolor(colval);
765
766         case stylehint_ReverseColor:
767                 return GPOINTER_TO_INT( g_object_get_data(G_OBJECT(tag), "reverse_color") );
768
769         default:
770                 WARNING("Unknown style hint");
771         }
772         
773         return 0;
774 }
775
776 /**
777  * glk_stylehint_set:
778  * @wintype: The window type to set a style hint on, or %wintype_AllTypes.
779  * @styl: The style to set a hint for.
780  * @hint: The type of style hint, one of the <code>stylehint_</code> constants.
781  * @val: The style hint. The meaning of this depends on @hint.
782  *
783  * Sets a hint about the appearance of one style for a particular type of 
784  * window. You can also set @wintype to %wintype_AllTypes, which sets a hint for 
785  * all types of window.
786  * <note><para>
787  *  There is no equivalent constant to set a hint for all styles of a single 
788  *  window type.
789  * </para></note>
790  */
791 void
792 glk_stylehint_set(glui32 wintype, glui32 styl, glui32 hint, glsi32 val)
793 {
794         ChimaraGlkPrivate *glk_data = g_private_get(glk_data_key);
795
796         GtkTextTag *to_change;
797         if(wintype == wintype_TextBuffer || wintype == wintype_AllTypes) {
798                 to_change = g_hash_table_lookup( glk_data->current_styles->text_buffer, get_tag_name(styl) );
799                 apply_stylehint_to_tag(to_change, wintype_TextBuffer, hint, val);
800         }
801
802         if(wintype == wintype_TextGrid || wintype == wintype_AllTypes) {
803                 to_change = g_hash_table_lookup( glk_data->current_styles->text_grid, get_tag_name(styl) );
804                 apply_stylehint_to_tag(to_change, wintype_TextGrid, hint, val);
805         }
806 }
807
808 /**
809  * glk_stylehint_clear:
810  * @wintype: The window type to set a style hint on, or %wintype_AllTypes.
811  * @styl: The style to set a hint for.
812  * @hint: The type of style hint, one of the <code>stylehint_</code> constants.
813  *
814  * Clears a hint about the appearance of one style for a particular type of 
815  * window to its default value. You can also set @wintype to %wintype_AllTypes, 
816  * which clears a hint for all types of window.
817  * <note><para>
818  *  There is no equivalent constant to reset a hint for all styles of a single 
819  *  window type.
820  * </para></note>
821  */
822 void
823 glk_stylehint_clear(glui32 wintype, glui32 styl, glui32 hint)
824 {
825         ChimaraGlkPrivate *glk_data = g_private_get(glk_data_key);
826         GtkTextTag *tag;
827
828         switch(wintype) {
829         case wintype_TextBuffer:
830                 tag = g_hash_table_lookup( glk_data->default_styles->text_buffer, get_tag_name(styl) );
831                 glk_stylehint_set( wintype, styl, hint, query_tag(tag, wintype, hint) );
832                 break;
833         case wintype_TextGrid:
834                 tag = g_hash_table_lookup( glk_data->default_styles->text_grid, get_tag_name(styl) );
835                 glk_stylehint_set( wintype, styl, hint, query_tag(tag, wintype, hint) );
836         default:
837                 return;
838         }
839 }
840
841 /**
842  * glk_style_distinguish:
843  * @win: The window in which the styles are to be distinguished.
844  * @styl1: The first style to be distinguished from the second style.
845  * @styl2: The second style to be distinguished from the first style.
846  * 
847  * Decides whether two styles are visually distinguishable in the given window.
848  * The exact meaning of this is left for the library to determine.
849  * <note><title>Chimara</title><para>
850  *   Currently, all styles of one window are assumed to be mutually
851  *   distinguishable.
852  * </para></note>
853  * 
854  * Returns: %TRUE (1) if the two styles are visually distinguishable. If they 
855  * are not, it returns %FALSE (0).
856  */
857 glui32
858 glk_style_distinguish(winid_t win, glui32 styl1, glui32 styl2)
859 {
860         /* FIXME */
861         return styl1 != styl2;
862 }
863
864 /**
865  * glk_style_measure:
866  * @win: The window from which to take the style.
867  * @styl: The style to perform the measurement on.
868  * @hint: The stylehint to measure.
869  * @result: Address to write the result to.
870  * 
871  * Tries to test an attribute of one style in the given window @win. The library
872  * may not be able to determine the attribute; if not, this returns %FALSE (0).
873  * If it can, it returns %TRUE (1) and stores the value in the location pointed
874  * at by @result. 
875  * <note><para>
876  *   As usual, it is legal for @result to be %NULL, although fairly pointless.
877  * </para></note>
878  *
879  * The meaning of the value depends on the hint which was tested:
880  * <variablelist>
881  * <varlistentry>
882  *   <term>%stylehint_Indentation, %stylehint_ParaIndentation</term>
883  *   <listitem><para>The indentation and paragraph indentation. These are in a
884  *   metric which is platform-dependent.</para>
885  *   <note><para>Most likely either characters or pixels.</para></note>
886  *   </listitem>
887  * </varlistentry>
888  * <varlistentry>
889  *   <term>%stylehint_Justification</term>
890  *   <listitem><para>One of the constants %stylehint_just_LeftFlush,
891  *   %stylehint_just_LeftRight, %stylehint_just_Centered, or
892  *   %stylehint_just_RightFlush.</para></listitem>
893  * </varlistentry>
894  * <varlistentry>
895  *   <term>%stylehint_Size</term>
896  *   <listitem><para>The font size. Again, this is in a platform-dependent
897  *   metric.</para>
898  *   <note><para>Pixels, points, or simply 1 if the library does not support
899  *   varying font sizes.</para></note>
900  *   </listitem>
901  * </varlistentry>
902  * <varlistentry>
903  *   <term>%stylehint_Weight</term>
904  *   <listitem><para>1 for heavy-weight fonts (boldface), 0 for normal weight,
905  *   and -1 for light-weight fonts.</para></listitem>
906  * </varlistentry>
907  * <varlistentry>
908  *   <term>%stylehint_Oblique</term>
909  *   <listitem><para>1 for oblique fonts (italic), or 0 for normal angle.</para>
910  *   </listitem>
911  * </varlistentry>
912  * <varlistentry>
913  *   <term>%stylehint_Proportional</term>
914  *   <listitem><para>1 for proportional-width fonts, or 0 for fixed-width.
915  *   </para></listitem>
916  * </varlistentry>
917  * <varlistentry>
918  *   <term>%stylehint_TextColor, %stylehint_BackColor</term>
919  *   <listitem><para>These are values from 0x00000000 to 0x00FFFFFF, encoded as
920  *   described in <link 
921  *   linkend="chimara-Suggesting-the-Appearance-of-Styles">Suggesting the
922  *   Appearance of Styles</link>.</para></listitem>
923  * </varlistentry>
924  * <varlistentry>
925  *   <term>%stylehint_ReverseColor</term>
926  *   <listitem><para>0 for normal printing, 1 if the foreground and background
927  *   colors are reversed.</para></listitem>
928  * </varlistentry>
929  * </variablelist>
930  * 
931  * Returns: TRUE upon successul retrieval, otherwise FALSE.
932  */
933 glui32
934 glk_style_measure(winid_t win, glui32 styl, glui32 hint, glui32 *result)
935 {
936         ChimaraGlkPrivate *glk_data = g_private_get(glk_data_key);
937         GtkTextTag *tag;
938
939         switch(win->type) {
940         case wintype_TextBuffer:
941                 tag = g_hash_table_lookup( glk_data->current_styles->text_buffer, get_tag_name(styl) );
942                 if(result)
943                         *result = query_tag(tag, win->type, hint);
944                 break;
945         case wintype_TextGrid:
946                 tag = g_hash_table_lookup( glk_data->current_styles->text_grid, get_tag_name(styl) );
947                 if(result)
948                         *result = query_tag(tag, win->type, hint);
949         default:
950                 return FALSE;
951         }
952
953         return TRUE;
954 }
955
956 /* Internal function returning the current default font for a window type
957  * This can be used later for size calculations. Only wintype_TextGrid and wintype_TextBuffer are
958  * supported for now */
959 PangoFontDescription *
960 get_current_font(guint32 wintype)
961 {
962         ChimaraGlkPrivate *glk_data = g_private_get(glk_data_key);
963         GtkTextTag *normal;
964
965         switch(wintype) {
966         case wintype_TextGrid:
967                 normal = g_hash_table_lookup(glk_data->current_styles->text_grid, "normal");
968                 break;
969         case wintype_TextBuffer:
970                 normal = g_hash_table_lookup(glk_data->current_styles->text_buffer, "normal");
971                 break;
972         default:
973                 return NULL;
974         }
975
976         PangoFontDescription *font;
977         g_object_get( G_OBJECT(normal), "font-desc", &font, NULL );
978
979         return font;
980 }
981
982 /* Internal function copying the attributes of a text tag to a pango attribute list */
983 static void
984 text_tag_to_attr_list(GtkTextTag *tag, PangoAttrList *list)
985 {
986         gboolean set;
987         GdkColor *foreground, *background;
988         gchar *string;
989         PangoFontDescription *font_desc;
990         gboolean strikethrough;
991         PangoUnderline underline;
992
993         g_object_get(tag, "foreground-set", &set, "foreground-gdk", &foreground, NULL);
994         if(set) {
995                 pango_attr_list_insert(
996                         list,
997                         pango_attr_foreground_new(foreground->red, foreground->green, foreground->blue)
998                 );
999         }
1000         g_object_get(tag, "background-set", &set, "background-gdk", &background, NULL);
1001         if(set) {
1002                 pango_attr_list_insert(
1003                         list,
1004                         pango_attr_background_new(background->red, background->green, background->blue)
1005                 );
1006         }
1007         g_object_get(tag, "language-set", &set, "language", &string, NULL);
1008         if(set) {
1009                 pango_attr_list_insert(
1010                         list,
1011                         pango_attr_language_new( pango_language_from_string(string) )
1012                 );
1013         }
1014
1015         /* Font description updates the following properties simultaniously:
1016          * family, style, weight, variant, stretch, size
1017          */
1018         g_object_get(tag, "font-desc", &font_desc, NULL);
1019         pango_attr_list_insert(
1020                 list,
1021                 pango_attr_font_desc_new(font_desc)
1022         );
1023
1024         g_object_get(tag, "strikethrough-set", &set, "strikethrough", &strikethrough, NULL);
1025         if(set) {
1026                 pango_attr_list_insert(
1027                         list,
1028                         pango_attr_strikethrough_new(strikethrough)
1029                 );
1030         }
1031         g_object_get(tag, "underline-set", &set, "underline", &underline, NULL);
1032         if(set) {
1033                 pango_attr_list_insert(
1034                         list,
1035                         pango_attr_underline_new(underline)
1036                 );
1037         }
1038 }