add coordsChar method

Author: marijnh

lib/codemirror.js

@@ -125,6 +125,11 @@ var CodeMirror = (function() {
         return pageCoords(start ? sel.from : sel.to);
       },
       charCoords: function(pos){return pageCoords(clipPos(pos));},
+      coordsChar: function(coords) {
+        var off = eltOffset(lineSpace);
+        var line = Math.min(showingTo - 1, showingFrom + Math.floor(coords.y / lineHeight()));
+        return clipPos({line: line, ch: charFromX(clipLine(line), coords.x)});
+      },
       getSearchCursor: function(query, pos, caseFold) {return new SearchCursor(query, pos, caseFold);},
       markText: operation(function(a, b, c){return operation(markText(a, b, c));}),
       setMarker: addGutterMarker,

manual.html

@@ -368,6 +368,10 @@ <h2 id="api">Programming API</h2>
       <dd>Like <code>cursorCoords</code>, but returns the position of
       an arbitrary characters. <code>pos</code> should be
       a <code>{line, ch}</code> object.</dd>
+      <dt id="coordsChar"><code>coordsChar(object) → pos</code></dt>
+      <dd>Given an <code>{x, y}</code> object (in page coordinates),
+      returns the <code>{line, ch}</code> position that corresponds to
+      it.</dd>
 
       <dt id="undo"><code>undo()</code></dt>
       <dd>Undo one edit (if any undo events are stored).</dd>