[gmime-devel] [PATCH] GMimeFilterHtml: add option to enclose citation in blockquotes

[Gaute Hope <eg gaute vetsj com>]

The option GMIME_FILTER_HTML_BLOCKQUOTE_CITATION encloses citations in
blockquotes. This allows for easier customization using CSS of the
resulting HTML.

Each blockquote is not closed untill the citation depth level is closed,
all blockquotes are closed at the end.

GMIME_FILTER_HTML_MARK_CITATION is disabled when
GMIME_FILTER_HTML_BLOCKQUOTE_CITATION is enabled.
---
 gmime/gmime-filter-html.c | 41 ++++++++++++++++++++++++++++++++++++++++-
 gmime/gmime-filter-html.h | 15 ++++++++++++---
 2 files changed, 52 insertions(+), 4 deletions(-)

diff --git a/gmime/gmime-filter-html.c b/gmime/gmime-filter-html.c
index edb4615..4bffb42 100644
--- a/gmime/gmime-filter-html.c
+++ b/gmime/gmime-filter-html.c
@@ -140,6 +140,7 @@ g_mime_filter_html_init (GMimeFilterHTML *filter, GMimeFilterHTMLClass *klass)
        filter->colour = 0;
        filter->column = 0;
        filter->pre_open = FALSE;
+  filter->prev_cit_depth = 0;
 }
 
 static void
@@ -353,7 +354,25 @@ html_convert (GMimeFilter *filter, char *in, size_t inlen, size_t prespace,
                html->column = 0;
                depth = 0;
                
-               if (html->flags & GMIME_FILTER_HTML_MARK_CITATION) {
+               if (html->flags & GMIME_FILTER_HTML_BLOCKQUOTE_CITATION) {
+                       if ((depth = citation_depth (start, inend)) > html->prev_cit_depth) {
+                               char bq[33];
+        int ldepth = depth > 999 ? 999 : depth;
+                               g_snprintf (bq, 33, "<blockquote class=\"level_%03d\">", depth);
+
+                               outptr = check_size (filter, outptr, &outend, 33);
+                               outptr = g_stpcpy (outptr, bq);
+
+        /* remove '>' */
+        while (*start == '>') start++;
+
+        html->prev_cit_depth = depth;
+
+                       } else if (*start == '>') {
+                               /* >From line */
+                               start++;
+                       }
+    } else if (html->flags & GMIME_FILTER_HTML_MARK_CITATION) {
                        if ((depth = citation_depth (start, inend)) > 0) {
                                char font[25];
                                
@@ -419,6 +438,15 @@ html_convert (GMimeFilter *filter, char *in, size_t inlen, size_t prespace,
                } else {
                        outptr = writeln (filter, start, inptr, outptr, &outend);
                }
+
+               if ((html->flags & GMIME_FILTER_HTML_BLOCKQUOTE_CITATION) &&
+        (depth < html->prev_cit_depth)) {
+      while (html->prev_cit_depth > depth) {
+        outptr = check_size (filter, outptr, &outend, 14);
+        outptr = g_stpcpy (outptr, "</blockquote>");
+        html->prev_cit_depth--;
+      }
+    }
                
                if ((html->flags & GMIME_FILTER_HTML_MARK_CITATION) && depth > 0) {
                        outptr = check_size (filter, outptr, &outend, 8);
@@ -442,6 +470,16 @@ html_convert (GMimeFilter *filter, char *in, size_t inlen, size_t prespace,
                        outptr = check_size (filter, outptr, &outend, 10);
                        outptr = g_stpcpy (outptr, "</pre>");
                }
+
+               if ((html->flags & GMIME_FILTER_HTML_BLOCKQUOTE_CITATION) &&
+        (html->prev_cit_depth > 0)) {
+      /* close open blockquotes */
+      while (html->prev_cit_depth > 0) {
+        outptr = check_size (filter, outptr, &outend, 14);
+        outptr = g_stpcpy (outptr, "</blockquote>");
+        html->prev_cit_depth--;
+      }
+    }
        } else if (start < inend) {
                /* backup */
                g_mime_filter_backup (filter, start, (unsigned) (inend - start));
@@ -473,6 +511,7 @@ filter_reset (GMimeFilter *filter)
        
        html->column = 0;
        html->pre_open = FALSE;
+  html->prev_cit_depth = 0;
 }
 
 
diff --git a/gmime/gmime-filter-html.h b/gmime/gmime-filter-html.h
index 4edf5d4..d74cccc 100644
--- a/gmime/gmime-filter-html.h
+++ b/gmime/gmime-filter-html.h
@@ -77,13 +77,20 @@ typedef struct _GMimeFilterHTMLClass GMimeFilterHTMLClass;
  **/
 #define GMIME_FILTER_HTML_MARK_CITATION     (1 << 4)
 
+/**
+ * GMIME_FILTER_HTML_MARK_CITATION_BLOCKQUOTE:
+ *
+ * Enclose citation text in blockquotes.
+ **/
+#define GMIME_FILTER_HTML_BLOCKQUOTE_CITATION     (1 << 5)
+
 
 /**
  * GMIME_FILTER_HTML_CONVERT_ADDRESSES:
  *
  * Wrap email addresses in "mailto:"; href tags.
  **/
-#define GMIME_FILTER_HTML_CONVERT_ADDRESSES (1 << 5)
+#define GMIME_FILTER_HTML_CONVERT_ADDRESSES (1 << 6)
 
 
 /**
@@ -91,7 +98,7 @@ typedef struct _GMimeFilterHTMLClass GMimeFilterHTMLClass;
  *
  * Converts 8bit characters to '?'.
  **/
-#define GMIME_FILTER_HTML_ESCAPE_8BIT       (1 << 6)
+#define GMIME_FILTER_HTML_ESCAPE_8BIT       (1 << 7)
 
 
 /**
@@ -99,7 +106,7 @@ typedef struct _GMimeFilterHTMLClass GMimeFilterHTMLClass;
  *
  * Cites text by prepending "&gt; " to each cited line.
  **/
-#define GMIME_FILTER_HTML_CITE              (1 << 7)
+#define GMIME_FILTER_HTML_CITE              (1 << 8)
 
 
 /**
@@ -110,6 +117,7 @@ typedef struct _GMimeFilterHTMLClass GMimeFilterHTMLClass;
  * @colour: cite colour
  * @column: current column
  * @pre_open: currently inside of a 'pre' tag.
+ * @prev_cit_depth: current citation depth level.
  *
  * A filter for converting text/plain into text/html.
  **/
@@ -123,6 +131,7 @@ struct _GMimeFilterHTML {
        
        guint32 column       : 31;
        guint32 pre_open     : 1;
+  guint32 prev_cit_depth : 31;
 };
 
 struct _GMimeFilterHTMLClass {
-- 
2.8.0