Markdown: Handle indents better when appending or inserting sublists

plugins/markdown-actions/markdown-actions.vala

@@ -94,69 +94,86 @@ public class Code.Plugins.MarkdownActions : Peas.ExtensionBase, Scratch.Services
 
         if (keyval == Gdk.Key.Return) {
             char ul_marker;
-            int ol_number = 1;
+            int ol_number;
+            string prefix;
             string item_text;
             var line = get_current_line ();
-            if (parse_unordered_list_item (line, out ul_marker)) {
-                if (line.length <= 3) { // empty item
-                    delete_empty_item ();
+
+            if (parse_ordered_list_item (line, out ol_number, out item_text, out prefix, null)) {
+                if (item_text.strip () == "") {
+                    delete_empty_item (prefix);
                 } else {
-                    string to_insert = "\n%c ".printf (ul_marker);
+                    string to_insert = "\n%s%d. ".printf (prefix, ++ol_number);
                     current_source.buffer.insert_at_cursor (to_insert, to_insert.length);
+                    // Check following lines to see if renumbering required
+                    fix_ordered_list_numbering (prefix.length, ol_number);
                 }
                 return true;
-            } else if (parse_ordered_list_item (line, ref ol_number, out item_text)) {
-                if (item_text.length == 0) {
-                    delete_empty_item ();
-                } else {
-                    string to_insert = "\n%d. ".printf (ol_number + 1);
+            } else if (parse_unordered_list_item (line, out ul_marker, out item_text, out prefix)) {
+                if (item_text.strip () == "") {
+                    delete_empty_item (prefix);
+                } else { // ul_marker is not null here
+                    string to_insert = "\n%s%c ".printf (prefix, ul_marker);
                     current_source.buffer.insert_at_cursor (to_insert, to_insert.length);
-                    fix_ordered_list_numbering ();
                 }
+
                 return true;
             }
         }
 
         return false;
     }
 
-    private void delete_empty_item () {
+    private void delete_empty_item (string prefix = "") {
         Gtk.TextIter start, end;
         var current_buffer = current_source.buffer;
         current_buffer.get_iter_at_offset (out start, current_buffer.cursor_position);
         start.backward_chars (start.get_line_offset ());
         end = start;
         end.forward_to_line_end ();
         current_buffer.delete (ref start, ref end);
-        current_buffer.insert_at_cursor ("\n", 1);
+        var _prefix = prefix;
+        if (prefix.strip () == "") {
+            _prefix = "";
+        }
+        current_buffer.insert_at_cursor ("%s".printf (_prefix), _prefix.length);
+        current_buffer.get_iter_at_offset (out start, current_buffer.cursor_position);
     }
 
-    private void fix_ordered_list_numbering () {
+    // Starting on the line where a numbered list item was inserted, check if renumbering required
+    private void fix_ordered_list_numbering (int indent_spaces, int inserted_number) {
         Gtk.TextIter next;
-        var count = 1;
-        var item_text = "";
         var current_buffer = current_source.buffer;
 
         current_buffer.get_iter_at_offset (out next, current_buffer.cursor_position);
-        var line = get_current_line (next).strip ();
-        // Get list item number from current line
-        parse_ordered_list_item (line, ref count, out item_text);
-        while (
-            next.forward_line () &&
-            parse_ordered_list_item (get_current_line (next).strip (), ref count, out item_text)
+        int point_offset = 0, count = inserted_number, next_count = 0;
+        string item_text = "", next_prefix = "";
+        // Search for ordered list lines at the same level until level falls below or end of doc
+        while (next.forward_line () &&
+               parse_ordered_list_item (
+                    get_current_line (next),
+                    out next_count,
+                    out item_text,
+                    out next_prefix,
+                    out point_offset
+                ) &&
+               next_prefix.length >= indent_spaces
         ) {
-            count++;
-            var next_mark = current_buffer.create_mark (null, next, true);
-            var point_offset = line.index_of_char ('.');
-            var start = next;
-            var end = start;
-            end.forward_chars (point_offset);
-
-            current_buffer.delete (ref start, ref end);
-            current_buffer.get_iter_at_mark (out next, next_mark);
-
-            var to_insert = "%d".printf (count);
-            current_buffer.insert (ref next, to_insert, to_insert.length);
+            // Only update lines at same indent within same block
+            if (next_prefix.length == indent_spaces) {
+                count++;
+                next.forward_chars (indent_spaces);
+                var next_mark = current_buffer.create_mark (null, next, true);
+                var start = next;
+                var end = start;
+                end.forward_chars (point_offset - indent_spaces);
+
+                current_buffer.delete (ref start, ref end);
+                current_buffer.get_iter_at_mark (out next, next_mark);
+
+                var to_insert = "%d".printf (count);
+                current_buffer.insert (ref next, to_insert, to_insert.length);
+            }
         }
     }
 
@@ -172,32 +189,84 @@ public class Code.Plugins.MarkdownActions : Peas.ExtensionBase, Scratch.Services
         end = start;
         end.forward_to_line_end ();
 
-        return current_buffer.get_text (start, end, false);
+        var cl = current_buffer.get_text (start, end, false);
+        return cl;
     }
 
-    private bool parse_ordered_list_item (string line, ref int current_number, out string item_text) {
+    private bool parse_ordered_list_item (
+        string line,
+        out int current_number,
+        out string item_text,
+        out string prefix,
+        out int first_point_pos
+    ) {
         item_text = "";
-        int first_point_character = line.index_of_char ('.');
-        if (first_point_character < 0) {
-            return false;
-        }
+        prefix = "";
+        current_number = -1;
+        // Github does not automatically handle sublists in numbered lists so neither do we for now
+        // We assume the first number point is the only one.
+        first_point_pos = line.index_of_char ('.'); //TODO Handle ")"  Ignored escaped?
+
+        item_text = line.substring (first_point_pos + 1).strip ();
 
-        item_text = line.substring (first_point_character + 1).strip ();
+        var line_start = line.substring (0, first_point_pos);
+        line_start = line_start.replace ("-", " ").replace ("*", " ");
+        prefix = line.substring (0, line_start.last_index_of_char (' ') + 1);
 
-        var line_start = line.substring (0, first_point_character);
         if (!int.try_parse (line_start, out current_number)) {
             return false;
         }
-        return true;
+
+        return current_number >= 1;
     }
 
-    private bool parse_unordered_list_item (string line, out char ul_marker) {
-        if ((line[0] == '*' || line[0] == '-') && line[1] == ' ') {
-            ul_marker = line[0];
-            return true;
+    private bool parse_unordered_list_item (
+        string line,
+        out char ul_marker,
+        out string item_text,
+        out string prefix
+    ) {
+        prefix = "";
+        item_text = "";
+        ul_marker = ' ';
+
+        // Scan line for last unordered list marker
+        unichar uc = 0;
+        int index = 0;
+        uint spaces = 0;
+        char? last_marker = null;
+        while (line.get_next_char (ref index, out uc)) {
+            string buf = "      ";
+            var i = uc.to_utf8 (buf);
+            if (i != 1) {
+                break;
+            }
+
+            var c = buf[0];
+            if (c.isspace ()) {
+                spaces++;
+                // Only allow one space between or after markers but any number before the first
+                if (last_marker != null && spaces > 1) {
+                    break;
+                }
+            } else if (c == '-' || c == '*') {
+                spaces = 0;
+                last_marker = c;
+            } else { // text item starts here
+                break;
+            }
         }
-        ul_marker = '\0';
-        return false;
+
+        if (last_marker == null) {
+            return false;
+        }
+
+        ul_marker = last_marker;
+        item_text = line.substring (index - 1);
+        // The item text might contain marker characters so take care to ignore those
+        prefix = line.substring (0, index - 1);
+        prefix = prefix.substring (0, prefix.last_index_of_char (ul_marker));
+        return true;
     }
 
     private void insert_link () {