refactor export of style attributes

1. mark all attributes that are used
2. find the outermost attribute that is no longer used
3. close all tags upto this attribute
4. open all tags that are used and not open
(5. close all open tags)

src/node/utils/ExportHtml.js

@@ -246,87 +246,45 @@ function getHTMLFromAtext(pad, atext, authorColors)
       {
         var o = iter.next();
         var propChanged = false;
+        var usedAttribs = [];
+
+        // mark all attribs as used
         Changeset.eachAttribNumber(o.attribs, function (a)
         {
           if (a in anumMap)
           {
-            var i = anumMap[a]; // i = 0 => bold, etc.
+            usedAttribs.push(anumMap[a]); // i = 0 => bold, etc.
-
-            //true branch: if false or undefined or LEAVE set ENTER and propChanged
-            //false branch: if its true (the tag was opened in one of previous op) set it STAY
-            if (!propVals[i])
-            {
-              propVals[i] = ENTER;
-              propChanged = true;
-            }
-            else if(propVals[i] === true)
-            {
-              propVals[i] = STAY;
-            }
           }
-        }); // now all attribs of this op have been parsed
+        });
-
+        var outermostTag = -1;
-        // if an attrib is no longer used in this op but was used in the previous set it to LEAVE
+        // find the outer most open tag that is no longer used
-        // otherwise if its STAY(was previously open and still is) set it true
+        for (var i = openTags.length - 1; i >= 0; i--)
-        for (var i = 0; i < propVals.length; i++)
         {
-          if (propVals[i] === true)
+          if (usedAttribs.indexOf(openTags[i]) === -1)
           {
-            propVals[i] = LEAVE;
+            outermostTag = i;
-            propChanged = true;
+            break;
-          }
-          else if (propVals[i] === STAY)
-          {
-            propVals[i] = true; // set it back
           }
         }
 
-        // now each member of propVal is in {false,LEAVE,ENTER,true}
+        // close all tags upto the outer most
-        // false if not in this and not in previous, LEAVE if in previous, ENTER if new or true if
+        if (outermostTag != -1)
-        // in this and in the previous
-        // propChanged is true if any tag should be closed/opened
-        if (propChanged)
         {
-          for (var i = 0; i < propVals.length; i++)
+          for (var i=0; i <= outermostTag; outermostTag--)
           {
-            var v = propVals[i];
+            emitCloseTag(openTags[0])
-            if (v === true && propVals.indexOf(LEAVE) != -1)
-            {
-              propVals[i] = STAY; // tag will be closed and re-opened
-            }
           }
+        }
 
-          // close all tags that are open in previous op but not in this one
+        // open all tags that are used but not open
-          var tags2close = [];
+        for (var i=0; i < usedAttribs.length; i++)
-          for (var i = propVals.length - 1; i >= 0; i--)
+        {
+          if (openTags.indexOf(usedAttribs[i]) === -1)
           {
-            if (propVals[i] === LEAVE)
+            emitOpenTag(usedAttribs[i])
-            {
-              //emitCloseTag(i);
-              tags2close.push(i);
-              propVals[i] = false;
-            }
-            else if (propVals[i] === STAY && openTags[openTags.length - 1] != i)
-            {
-              //emitCloseTag(i);
-              tags2close.push(i);
-            }
           }
-          orderdCloseTags(tags2close);
+        }
 
-          // open all tags that are used in this op or got closed to satisfy order
-          // e.g. <em><s><u>em&strikethrough&underline</u>strikethrough&em</s></em><s>strikethrough</s>
-          // TODO?: ensure the best ie shortest resolution
-          for (var i = 0; i < propVals.length; i++)
-          {
-            if (propVals[i] === ENTER || (propVals[i] === STAY && openTags[openTags.length - 1] != i))
-            {
-              emitOpenTag(i);
-              propVals[i] = true;
-            }
-          }
-          // propVals is now all {true,false} again
-        } // end if (propChanged)
         var chars = o.chars;
         if (o.lines)
         {
@@ -343,17 +301,10 @@ function getHTMLFromAtext(pad, atext, authorColors)
       } // end iteration over spans in line
 
       // close all the tags that are open after the last op
-      tags2close = [];
+      while (openTags.length > 0)
-      for (var i = propVals.length - 1; i >= 0; i--)
       {
-        if (propVals[i])
+        emitCloseTag(openTags[0])
-        {
-          tags2close.push(i);
-          propVals[i] = false;
-        }
       }
-
-      orderdCloseTags(tags2close);
     } // end processNextChars
     if (urls)
     {