Handle *bold*, /italic/ etc

3 files changed, 208 insertions, 4 deletions

diff --git a/libstorycode/narrative.c b/libstorycode/narrative.c
index 4d088e4..7db31d9 100644
--- a/libstorycode/narrative.c
+++ b/libstorycode/narrative.c
@@ -75,6 +75,8 @@ static void narrative_item_destroy(struct narrative_item *item)
 	if ( item->layout != NULL ) {
 		g_object_unref(item->layout);
 	}
+	free(item->chars_removed);
+	free(item->layout_text);
 #endif
 #ifdef HAVE_CAIRO
 	if ( item->slide_thumbnail != NULL ) {
@@ -200,7 +202,12 @@ ImageStore *narrative_get_imagestore(Narrative *n)
 
 static void init_item(struct narrative_item *item)
 {
+#ifdef HAVE_PANGO
 	item->layout = NULL;
+	item->layout_text = NULL;
+	item->chars_removed = NULL;
+	item->n_chars_removed = 0;
+#endif
 	item->text = NULL;
 	item->slide = NULL;
 	item->slide_thumbnail = NULL;
diff --git a/libstorycode/narrative_priv.h b/libstorycode/narrative_priv.h
index 9d6e294..ec3ffb5 100644
--- a/libstorycode/narrative_priv.h
+++ b/libstorycode/narrative_priv.h
@@ -64,6 +64,9 @@ struct narrative_item
 	enum alignment align;
 #ifdef HAVE_PANGO
 	PangoLayout *layout;
+	char *layout_text;
+	int *chars_removed;
+	int n_chars_removed;
 #else
 	void *layout;
 #endif
diff --git a/libstorycode/narrative_render_cairo.c b/libstorycode/narrative_render_cairo.c
index c22b7ce..17f22aa 100644
--- a/libstorycode/narrative_render_cairo.c
+++ b/libstorycode/narrative_render_cairo.c
@@ -69,6 +69,199 @@ static PangoAlignment to_pangoalignment(enum alignment align)
 }
 
 
+static int find_pair(const gchar *p, gunichar c, gchar **start, gchar **end)
+{
+	gchar *s;
+	gchar *e;
+	gchar *next;
+
+	/* FIXME: Check it's not escaped */
+	s = g_utf8_strchr(p, -1, c);
+	if ( s == NULL ) return 0;
+
+	next = g_utf8_find_next_char(s, NULL);
+	if ( next == NULL ) return 0;
+
+	e = g_utf8_strchr(next, -1, c);
+	if ( e == NULL ) return 0;
+
+	*start = s;
+	*end = e;
+	return 1;
+}
+
+
+struct attr_to_add
+{
+	int start;
+	int end;
+	char type;  /* b=bold, i=italic, u=underline */
+};
+
+
+static int add_range(struct narrative_item *item, int *max_chars_removed,
+                     int start, int end, int *n_add, int *max_add,
+                     struct attr_to_add **add, char type)
+{
+	if ( item->n_chars_removed == *max_chars_removed ) {
+		(*max_chars_removed) += 256;
+		item->chars_removed = realloc(item->chars_removed, *max_chars_removed*sizeof(int));
+		if ( item->chars_removed == NULL ) return 1;
+	}
+
+	item->chars_removed[item->n_chars_removed++] = start;
+	item->chars_removed[item->n_chars_removed++] = end;
+
+	if ( *n_add == *max_add ) {
+		*max_add += 64;
+		*add = realloc(*add, *max_add*sizeof(struct attr_to_add));
+		if ( *add == NULL ) return 1;
+	}
+
+	(*add)[*n_add].start = start;
+	(*add)[*n_add].end = end;
+	(*add)[*n_add].type = type;
+	(*n_add)++;
+
+	return 0;
+}
+
+
+/* How many bytes were removed up to idx? */
+int index_before_removal(int *chars_removed, int n_chars_removed, int idx)
+{
+	int i;
+
+	for ( i=0; i<n_chars_removed; i++ ) {
+		if ( chars_removed[i] > idx ) break;
+	}
+
+	return idx + i;
+}
+
+
+/* How many bytes were removed up to idx? */
+int index_with_removal(int *chars_removed, int n_chars_removed, int idx)
+{
+	int i;
+
+	for ( i=0; i<n_chars_removed; i++ ) {
+		if ( chars_removed[i] > idx ) break;
+	}
+
+	return idx - i;
+}
+
+
+static int cmpi(const void *a, const void *b)
+{
+	return *(int *)a - *(int *)b;
+}
+
+
+static void process_tags(struct narrative_item *item, PangoAttrList *attrs)
+{
+	gchar *efstart;
+	gchar *efend;
+	gchar *text;
+	PangoAttribute *attr;
+	struct attr_to_add *add;
+	int n_add;
+	int max_add;
+	int max_chars_removed;
+	int i, j, k;
+	size_t len;
+
+	item->n_chars_removed = 0;
+	free(item->chars_removed);
+	item->chars_removed = NULL;
+	max_chars_removed = 0;
+
+	add = NULL;
+	n_add = 0;
+	max_add = 0;
+
+	/* Scan the text, identify characters to remove and character ranges
+	 * (in the original text) which need attributes applied */
+	text = item->text;
+	while ( find_pair(text, '*', &efstart, &efend) ) {
+		if ( add_range(item, &max_chars_removed,
+		               efstart - item->text, efend - item->text,
+		               &n_add, &max_add, &add, 'b') ) return;
+		text = g_utf8_find_next_char(efend, NULL);
+	}
+	text = item->text;
+	while ( find_pair(text, '/', &efstart, &efend) ) {
+		if ( add_range(item, &max_chars_removed,
+		               efstart - item->text, efend - item->text,
+		               &n_add, &max_add, &add, 'i') ) return;
+		text = g_utf8_find_next_char(efend, NULL);
+	}
+	text = item->text;
+	while ( find_pair(text, '_', &efstart, &efend) ) {
+		if ( add_range(item, &max_chars_removed,
+		               efstart - item->text, efend - item->text,
+		               &n_add, &max_add, &add, 'u') ) return;
+		text = g_utf8_find_next_char(efend, NULL);
+	}
+
+	/* Sort the list of removed characters */
+	qsort(item->chars_removed, item->n_chars_removed, sizeof(int), cmpi);
+
+	/* Go through the list of attributes, and correct the character ranges
+	 * so that they refer to the text with characters removed, and add them
+	 * to the PangoAttrList */
+	for ( i=0; i<n_add; i++ ) {
+
+		switch ( add[i].type ) {
+
+			case 'b' :
+			attr = pango_attr_weight_new(PANGO_WEIGHT_BOLD);
+			break;
+
+			case 'i' :
+			attr = pango_attr_style_new(PANGO_STYLE_ITALIC);
+			break;
+
+			case 'u' :
+			attr = pango_attr_underline_new(PANGO_UNDERLINE_SINGLE);
+			break;
+
+		}
+
+		attr->start_index = index_with_removal(item->chars_removed,
+		                                       item->n_chars_removed,
+		                                       add[i].start);
+
+		attr->end_index = index_with_removal(item->chars_removed,
+		                                     item->n_chars_removed,
+		                                     add[i].end) + 1;
+
+		pango_attr_list_insert(attrs, attr);
+
+	}
+
+	/* Create the version of the text with characters removed */
+	if ( item->n_chars_removed == 0 ) {
+		   item->layout_text = strdup(item->text);
+	} else {
+		len = strlen(item->text);
+		item->layout_text = malloc(len);
+		if ( item->layout_text == NULL ) return;
+		j = 0;
+		for ( i=0; i<len+1; i++ ) {  /* \0 terminator please */
+			if ( item->chars_removed[k] == i ) {
+				k++;
+			} else {
+				item->layout_text[j++] = item->text[i];
+			}
+		}
+	}
+
+	free(add);
+}
+
+
 static void wrap_text(struct narrative_item *item, PangoContext *pc,
                       Stylesheet *ss, const char *stn, double w,
                       size_t sel_start, size_t sel_end)
@@ -120,14 +313,15 @@ static void wrap_text(struct narrative_item *item, PangoContext *pc,
 		item->layout = pango_layout_new(pc);
 	}
 	pango_layout_set_width(item->layout, pango_units_from_double(wrap_w));
-	pango_layout_set_text(item->layout, item->text, -1);
 	pango_layout_set_alignment(item->layout, palignment);
 	pango_layout_set_font_description(item->layout, fontdesc);
+
+	/* Handle *bold*, _underline_, /italic/ etc. */
+	process_tags(item, attrs);
 	pango_layout_set_attributes(item->layout, attrs);
+	pango_attr_list_unref(attrs);
 
-	/* FIXME: Handle *bold*, _underline_, /italic/ etc. */
-	//pango_layout_set_attributes(item->layout, attrs);
-	//pango_attr_list_unref(attrs);
+	pango_layout_set_text(item->layout, item->layout_text, -1);
 
 	pango_layout_get_extents(item->layout, NULL, &rect);
 	item->obj_w = pango_units_to_double(rect.width);