Fix Try Dart handling of Backspace that joins lines

site/try/src/interaction_manager.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library trydart.interaction_manager;
 
 import 'dart:html';
 
 import 'dart:convert' show
     JSON;
@@ skipping 1216 matching lines @@
     node.replaceWith(newNode);
     if (selectionOffset != -1) {
       selection.anchorNode = newNode;
       selection.anchorOffset = selectionOffset;
     }
   }
   if (!record.removedNodes.isEmpty) {
     var first = record.removedNodes.first;
     var line = findLine(record.target);
 
-    if (first is Text && first.data=="\n" && line.nextNode != null) {
+    if (first is Text && line.nextNode != null) {

[ahe, 2014/09/04 11:42:36]

Does this have a significant impact on when we can detect single line changes
when you hit backspace?

[aam-me, 2014/09/04 12:01:06]

Your question is about impact in those cases when lines are not being merged?
Certainly there is impact(we always normalize current plus next line), not sure
how to measure it though.

We can try to limit this change to only those cases when we are certain lines
are being merged.(selection is at the end of the line/start of the line?)
Do you remember what was the rationale for checking first.data=='\n'? Must be
something along similar lines.

[ahe, 2014/09/04 12:11:10]

I normally just look at the console and make some changes.
It was an attempt to identify this problem more precisely.

Perhaps a better approach is to change the "single line change" to "consecutive
lines changed".

       normalizedNodes.add(line.nextNode);
     }
     normalizedNodes.add(line);
   }
   if (record.type == "characterData" && record.target.parentNode != null) {
     // At least Firefox sends a "characterData" record whose target is the
     // deleted text node. It also sends a record where "removedNodes" isn't
     // empty whose target is the parent (which we are interested in).
     normalizedNodes.add(findLine(record.target));
   }
@@ skipping 94 matching lines @@
     token = token.next;
     kind = token.kind;
   }
   return token;
 }
 
 String extractQuote(String string) {
   StringQuoting q = StringValidator.quotingFromString(string);
   return (q.raw ? 'r' : '') + (q.quoteChar * q.leftQuoteLength);
 }