Narrator is not announcing "state of links"(enable or disable) under Edit tab. #3958 (#4733)

* Solved issue #3939

Further fixes issue #3939 and #3958 to work on windows browsers

* Made some changes requested in the PR

* Made some small tweaks

* Restore missing semicolon

Author: fabihaahmed

notebook/static/notebook/js/notebook.js

@@ -1134,6 +1134,7 @@ define([
         var cell = this.get_cell(i);
 
         $('#undelete_cell').addClass('disabled');
+        $('#undelete_cell > a').attr('aria-disabled','true');
         if (this.is_valid_cell_index(i)) {
             var old_ncells = this.ncells();
             var ce = this.get_cell_element(i);
@@ -1213,7 +1214,7 @@ define([
         // where they came from. It will do until we have proper undo support.
         undelete_backup.index = cursor_ix_after;
         $('#undelete_cell').removeClass('disabled');
-
+        $('#undelete_cell > a').attr('aria-disabled','false');
         this.undelete_backup_stack.push(undelete_backup);
         this.set_dirty(true);
 
@@ -1256,6 +1257,7 @@ define([
         }
         if (this.undelete_backup_stack.length === 0) {
             $('#undelete_cell').addClass('disabled');
+            $('#undelete_cell > a').attr('aria-disabled','true');
         }
     };
 
@@ -1618,12 +1620,15 @@ define([
             $('#paste_cell_replace').removeClass('disabled')
                 .on('click', function () {that.keyboard_manager.actions.call(
                     'jupyter-notebook:paste-cell-replace');});
+            $('#paste_cell_replace > a').attr('aria-disabled', 'false'); 
             $('#paste_cell_above').removeClass('disabled')
                 .on('click', function () {that.keyboard_manager.actions.call(
                     'jupyter-notebook:paste-cell-above');});
+            $('#paste_cell_above > a').attr('aria-disabled', 'false'); 
             $('#paste_cell_below').removeClass('disabled')
                 .on('click', function () {that.keyboard_manager.actions.call(
                     'jupyter-notebook:paste-cell-below');});
+            $('#paste_cell_below > a').attr('aria-disabled', 'false');         
             this.paste_enabled = true;
         }
     };
@@ -1634,8 +1639,11 @@ define([
     Notebook.prototype.disable_paste = function () {
         if (this.paste_enabled) {
             $('#paste_cell_replace').addClass('disabled').off('click');
+            $('#paste_cell_replace > a').attr('aria-disabled', 'true'); 
             $('#paste_cell_above').addClass('disabled').off('click');
+            $('#paste_cell_above > a').attr('aria-disabled', 'true'); 
             $('#paste_cell_below').addClass('disabled').off('click');
+            $('#paste_cell_below > a').attr('aria-disabled', 'true'); 
             this.paste_enabled = false;
         }
     };
@@ -1924,6 +1932,7 @@ define([
     Notebook.prototype.disable_attachments_paste = function () {
         if (this.paste_attachments_enabled) {
             $('#paste_cell_attachments').addClass('disabled');
+            $('#paste_cell_attachments > a').attr('disabled','true');
             this.paste_attachments_enabled = false;
         }
     };
@@ -1934,6 +1943,7 @@ define([
     Notebook.prototype.enable_attachments_paste = function () {
         if (!this.paste_attachments_enabled) {
             $('#paste_cell_attachments').removeClass('disabled');
+            $('#paste_cell_attachments > a').attr('aria-disabled','false');
             this.paste_attachments_enabled = true;
         }
     };
@@ -1944,8 +1954,10 @@ define([
     Notebook.prototype.set_insert_image_enabled = function(enabled) {
         if (enabled) {
             $('#insert_image').removeClass('disabled');
+            $('#insert_image > a').attr('aria-disabled', 'false');
         } else {
             $('#insert_image').addClass('disabled');
+            $('#insert_image > a').attr('aria-disabled', 'true');
         }
     };
 

notebook/templates/notebook.html

@@ -136,11 +136,11 @@
                     <ul id="edit_menu" class="dropdown-menu" role="menu" aria-labelledby="editlink">
                         <li id="cut_cell" role="none"><a href="#" role="menuitem">{% trans %}Cut Cells{% endtrans %}</a></li>
                         <li id="copy_cell" role="none"><a href="#" role="menuitem">{% trans %}Copy Cells{% endtrans %}</a></li>
-                        <li id="paste_cell_above" class="disabled role="none"><a href="#" role="menuitem">{% trans %}Paste Cells Above{% endtrans %}</a></li>
-                        <li id="paste_cell_below" class="disabled" role="none"><a href="#" role="menuitem">{% trans %}Paste Cells Below{% endtrans %}</a></li>
-                        <li id="paste_cell_replace" class="disabled" role="none"><a href="#" role="menuitem">{% trans %}Paste Cells &amp; Replace{% endtrans %}</a></li>
+                        <li id="paste_cell_above" class="disabled" role="none"><a href="#" role="menuitem" aria-disabled="true">{% trans %}Paste Cells Above{% endtrans %}</a></li>
+                        <li id="paste_cell_below" class="disabled" role="none"><a href="#" role="menuitem" aria-disabled="true">{% trans %}Paste Cells Below{% endtrans %}</a></li>
+                        <li id="paste_cell_replace" class="disabled" role="none"><a href="#" role="menuitem" aria-disabled="true">{% trans %}Paste Cells &amp; Replace{% endtrans %}</a></li>
                         <li id="delete_cell" role="none"><a href="#" role="menuitem">{% trans %}Delete Cells{% endtrans %}</a></li>
-                        <li id="undelete_cell" class="disabled" role="none"><a href="#" role="menuitem">{% trans %}Undo Delete Cells{% endtrans %}</a></li>
+                        <li id="undelete_cell" class="disabled" role="none"><a href="#" role="menuitem" aria-disabled="true">{% trans %}Undo Delete Cells{% endtrans %}</a></li>
                         <li class="divider" role="none"></li>
                         <li id="split_cell" role="none"><a href="#" role="menuitem">{% trans %}Split Cell{% endtrans %}</a></li>
                         <li id="merge_cell_above" role="none"><a href="#" role="menuitem">{% trans %}Merge Cell Above{% endtrans %}</a></li>
@@ -155,9 +155,9 @@
                         <li class="divider" role="none"></li>
                         <li id="cut_cell_attachments" role="none"><a href="#" role="menuitem">{% trans %}Cut Cell Attachments{% endtrans %}</a></li>
                         <li id="copy_cell_attachments" role="none"><a href="#" role="menuitem">{% trans %}Copy Cell Attachments{% endtrans %}</a></li>
-                        <li id="paste_cell_attachments" class="disabled" role="none"><a href="#" role="menuitem">{% trans %}Paste Cell Attachments{% endtrans %}</a></li>
+                        <li id="paste_cell_attachments"  class="disabled" role="none"><a href="#" role="menuitem" aria-disabled="true">{% trans %}Paste Cell Attachments{% endtrans %}</a></li>
                         <li class="divider" role="none"></li>
-                        <li id="insert_image" class="disabled" role="none"><a href="#" role="menuitem"> {% trans %}Insert Image{% endtrans %} </a></li>
+                        <li id="insert_image" class="disabled" role="none"><a href="#" role="menuitem" aria-disabled="true">  {% trans %}Insert Image{% endtrans %} </a></li>
                     </ul>
                 </li>
                 <li class="dropdown"><a href="#" class="dropdown-toggle" id="viewlink" data-toggle="dropdown" aria-haspopup="true" aria-controls="view_menu">{% trans %}View{% endtrans %}</a>