Disable double-click on the list when preview pane is on (#5199)

This eliminates delay when opening a message in preview pane.

program/js/app.js

@@ -1834,7 +1834,7 @@ function rcube_webmail()
 
     // start timer for message preview (wait for double click)
     if (selected && this.env.contentframe && !list.multi_selecting && !this.dummy_select)
-      this.preview_timer = setTimeout(function() { ref.msglist_get_preview(); }, this.dblclick_time);
+      this.preview_timer = setTimeout(function() { ref.msglist_get_preview(); }, list.dblclick_time);
     else if (this.env.contentframe)
       this.show_contentframe(false);
   };
@@ -1854,7 +1854,7 @@ function rcube_webmail()
       if (this.preview_timer)
         clearTimeout(this.preview_timer);
 
-      this.preview_timer = setTimeout(function() { ref.msglist_get_preview(); }, this.dblclick_time);
+      this.preview_timer = setTimeout(function() { ref.msglist_get_preview(); }, list.dblclick_time);
     }
   };
 
@@ -2605,6 +2605,11 @@ function rcube_webmail()
     if (page)
       url._page = page;
 
+    // disable double-click on the list when preview pane is on
+    // this eliminates delay when opening a message in preview pane (#5199)
+    if (this.message_list)
+      this.message_list.dblclick_time = this.env.layout != 'list' ? 10 : this.dblclick_time;
+
     this.http_request('list', url, lock);
     this.update_state({ _mbox: mbox, _page: (page && page > 1 ? page : null) });
   };
@@ -5571,9 +5576,9 @@ function rcube_webmail()
       selected = list.selection.length,
       source = this.env.source ? this.env.address_sources[this.env.source] : null;
 
-    // we don't have dblclick handler here, so use 200 instead of this.dblclick_time
+    // we don't have dblclick handler here, so use 50 instead of this.dblclick_time
     if (this.env.contentframe && (id = list.get_single_selection()))
-      this.preview_timer = setTimeout(function(){ ref.load_contact(id, 'show'); }, 200);
+      this.preview_timer = setTimeout(function(){ ref.load_contact(id, 'show'); }, 50);
     else if (this.env.contentframe)
       this.show_contentframe(false);