Steps to Reproduce

1. visit the zul with safari on ipad (iOS 5.1.1) / iphone6s

<zk xmlns:w="client">
    <textbox id="test"/>
    <button label="java focus" onClick="test.focus()"></button>
</zk>

2. click the button

Current Result

the textbox doesn't get the focus

Expected Result

the textbox gets the focus and virtual keyboard popup

Debug Info

• this issue doesn't happen on desktop browsers
• ASUS zenfone doesn't have such issue.
• safari on ipad (iOS 5.1.1) / iphone6s have such issue, so other Apple mobile devices might have

Root Cause

https://developer.apple.com/documentation/uikit/uiwebview/1617967-keyboarddisplayrequiresuseractio

In mobile Safari, the user must explicitly tap the elements in the web view to display the keyboard.

Workaround

<button label="client focus" w:onClick="zk.Widget.$('$test').$n().focus();"></button>