- var result = str;
- var ellip = '...';
- var span = $('<b>').css({ visibility:'hidden', padding:'0px' }).appendTo(elem).get(0);
-
- // on first run, check if string fits into the length already.
- span.innerHTML = result;
- if (span.offsetWidth > len) {
- var cut = Math.max(1, Math.floor(str.length * ((span.offsetWidth - len) / span.offsetWidth) / 2)),
- mid = Math.floor(str.length / 2);
- var offLeft = mid, offRight = mid;
- while (true) {
- offLeft = mid - cut;
- offRight = mid + cut;
- span.innerHTML = str.substring(0,offLeft) + ellip + str.substring(offRight);
-
- // break loop if string fits size
- if (span.offsetWidth <= len || offLeft < 3)
- break;
-
- cut++;
- }
-
- // build resulting string
- result = str.substring(0,offLeft) + ellip + str.substring(offRight);
+ var w, span, result = str, ellip = '...';
+
+ if (!rcmail.env.tmp_span) {
+ // it should be appended to elem to use the same css style
+ // but for performance reasons we'll append it to body (once)
+ span = $('<b>').css({visibility: 'hidden', padding: '0px'})
+ .appendTo($('body', document)).get(0);
+ rcmail.env.tmp_span = span;
+ }
+ else {
+ span = rcmail.env.tmp_span;
+ }
+ span.innerHTML = result;
+
+ // on first run, check if string fits into the length already.
+ w = span.offsetWidth;
+ if (w > len) {
+ var cut = Math.max(1, Math.floor(str.length * ((w - len) / w) / 2)),
+ mid = Math.floor(str.length / 2),
+ offLeft = mid,
+ offRight = mid;
+
+ while (true) {
+ offLeft = mid - cut;
+ offRight = mid + cut;
+ span.innerHTML = str.substring(0,offLeft) + ellip + str.substring(offRight);
+
+ // break loop if string fits size
+ if (offLeft < 3 || span.offsetWidth)
+ break;
+
+ cut++;