add doubleWidthPerfect option.

README.md

@@ -266,6 +266,9 @@ The screen on which every other node renders.
   overlapping, depending on position (__experimental__). for example:
 - __doubleWidth__ - allow for rendering of East Asian double-width characters.
   this is behind an option because it may affect performance negatively.
+- __doubleWidthPerfect__ - handle high code point double-width characters,
+  without this option, high code point double width characters just show up as
+  `?`. that being said, this option will slow content parsing a fair amount.
 
 These border-overlapped elements:
 

lib/widget.js

@@ -2335,6 +2335,29 @@ Element.prototype.parseContent = function(noTags) {
       content = content.replace(wideChars, '?');
     }
 
+    if (this.screen.options.doubleWidthPerfect) {
+      var _content = content;
+      content = '';
+      for (var i = 0; i < _content.length; i++) {
+        var point = _content.codePointAt(i);
+        if ((point >= 0x20000 && point <= 0x2fffd)
+          || (point >= 0x30000 && point <= 0x3fffd)) {
+          if (this.screen.options.doubleWidth
+              && (this.screen.tput.unicode
+              || this.screen.tput.numbers.U8 === 1)) {
+            content += _content[i] + ' ';
+          } else {
+            // NOTE: could use two chars: '? ' depending on what is intended.
+            // if we did, we could remove the unicode checks above in this if
+            // statement.
+            content += '?';
+          }
+        } else {
+          content += _content[i];
+        }
+      }
+    }
+
     if (!noTags) {
       content = this._parseTags(content);
     }
@@ -8591,7 +8614,14 @@ function hsort(obj) {
   });
 }
 
-var wideChars = new RegExp('(['
+var wideChars = new RegExp('('
+  // 0x20000 - 0x2fffd:
+  // + '[\\ud840-\\ud87f][\\udc00-\\udffd]'
+  // + '|'
+  // 0x30000 - 0x3fffd:
+  // + '[\\ud880-\\ud8bf][\\udc00-\\udffd]'
+  // + '|'
+  + '['
   + '\\u1100-\\u115f' /* Hangul Jamo init. consonants */
   + '\\u2329\\u232a'
   + '\\u2e80-\\u303e\\u3040-\\ua4cf' /* CJK ... Yi */
@@ -8606,7 +8636,8 @@ var wideChars = new RegExp('(['
   // however, the next char on the screen will be eaten.
   // + '\\u20000-\\u2fffd'
   // + '\\u30000-\\u3fffd'
-+ '])', 'g');
+  + ']'
+  + ')', 'g');
 
 function findFile(start, target) {
   return (function read(dir) {

test/widget-eaw.js

@@ -5,10 +5,12 @@ screen = blessed.screen({
   dump: __dirname + '/logs/eaw.log',
   smartCSR: true,
   dockBorders: true,
-  doubleWidth: true
+  doubleWidth: true,
+  doubleWidthPerfect: true
 });
 
 var DW = '杜';
+var DW2 = String.fromCodePoint ? String.fromCodePoint(0x30000) : 'a';
 
 // At cols=44, the bug that is avoided by this occurs:
 // || angles[line[x + 1][1]]) {
@@ -59,6 +61,7 @@ var lorem = 'Non eram nescius Brute cum quae summis ingeniis exquisitaque'
 + ' legantur';
 
 lorem = lorem.replace(/e/gi, DW);
+lorem = lorem.replace(/a/gi, DW2);
 
 var main = blessed.box({
   parent: screen,