Bug 31290 – Flash object that is offscreen does not update when its browser tab is not in focus

• Status: RESOLVED
• Resolution: WONTFIX
• Component: Plug-ins

[Rob Crowell]

When a flash object is embedded in a page but positioned off screen using CSS (top: -1000px), the flash object can't use ExternalInterface to call javascript when the browser tab is not in focus.

I boiled it down to the simplest test case I could come up with (linked, .as source available for download).  The .swf calls a function in index.html which adds "pong!<br/>" to the page.  This pattern repeats every 1 second, so you should see "pong!" scrolling down the page indefinitely.  As long as its browser tab is selected it works fine (a new "pong!" appears every 1 second); as soon as you flip to another tab it pauses until you bring focus back to the tab, when it resumes.

If I reposition the flash object to be on the page (top: 0px) it works as expected.

If I try this example in Chromium for the mac it works fine too.

[Mark Rowe (bdash)]

<rdar://problem/7380435>

[Alexey Proskuryakov]

Mass closing plug-in bugs, as plug-in support has been removed from WebKit.

Please comment and/or reopen if this still affects WebKit in some way.