Fix scroll jump on key press in plain text mode of the HTML editor (#7622)

1 files changed, 13 insertions, 11 deletions

diff --git a/skins/elastic/ui.js b/skins/elastic/ui.js
index 247aee666..0c6b45d6e 100644
--- a/skins/elastic/ui.js
+++ b/skins/elastic/ui.js
@@ -3742,34 +3742,36 @@ function rcube_elastic_ui()
      */
     function textarea_autoresize_init(textarea)
     {
-        var padding = parseInt($(textarea).css('padding-top')) + parseInt($(textarea).css('padding-bottom')) + 2,
-            // FIXME: Is there a better way to get initial height of the textarea?
-            //        At this moment clientHeight/offsetHeight is 0.
-            min_height = ($(textarea)[0].rows || 5) * 21,
+        var padding, minHeight,
             resize = function() {
                 // Wait until the textarea is visible
                 if (!textarea.scrollHeight) {
                     return setTimeout(resize, 250);
                 }
 
-                if (textarea.scrollHeight - padding <= min_height) {
+                if (!padding) {
+                    padding = parseInt($(textarea).css('padding-top')) + parseInt($(textarea).css('padding-bottom')) + 2;
+                    minHeight = $(textarea).height();
+                }
+
+                if (textarea.scrollHeight - padding <= minHeight) {
                     return;
                 }
 
-                // To fix scroll-jump issue in Edge we'll find the scrolling parent
-                // and re-apply scrollTop value after we reset textarea height
+                // To fix scroll-jump we'll re-apply scrollTop to the (scrolled) parent
+                // after we reset textarea height
                 var scroll_element, scroll_pos = 0;
                 $(textarea).parents().each(function() {
-                    if (textarea.scrollTop > 0) {
-                        scroll_element = textarea;
-                        scroll_pos = textarea.scrollTop;
+                    if (this.scrollTop > 0) {
+                        scroll_element = this;
+                        scroll_pos = this.scrollTop;
                         return false;
                     }
                 });
 
                 var oldHeight = $(textarea).outerHeight();
                 $(textarea).outerHeight(0);
-                var newHeight = Math.max(min_height, textarea.scrollHeight);
+                var newHeight = Math.max(minHeight, textarea.scrollHeight);
                 $(textarea).outerHeight(oldHeight);
                 if (newHeight !== oldHeight) {
                     $(textarea).height(newHeight);