Open Radar

 
Summary:
There's an issue with the NSStatusItem blinking when changing the NSStatusBarButton template image if:
1. the button is currently highlighted
2. the user has more than one display (status item window replicants are used)

The issue is particularly severe in my application, which has a timer and its representation in a status item. If the timer is short enough, the template image might update multiple times a second (which causes it to blink a lot)

Steps to Reproduce:
1. Create an NSStatusItem
2. Create an NSTimer which periodically updates the status item's image (as the NSStatusItem header suggests in beta 3, I'm using the button property directly — I'm setting the statusItem.button.image)
3. Highlight the status item (I'm programatically setting statusItem.button.highlighted = true)
4. Make sure you have two displays connected (in my case, Retina MacBook Pro + a non-retina display)

Expected Results:
The status item image smoothly changes

Actual Results:
Every few frames, there's a white blink.

Version:
Yosemite beta 3

Notes:
If it's a new bug to you, I can prepare a test case.

Configuration:
More than one display

Attachments:

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[engineering asked for a test case]

Here's the test case.

I observed that the flicker happens more often in certain situations, e.g. when there are more screen updates going on. A sure way to trigger the flickering is to Ctrl+scroll to zoom in on the status item while it's highlighted.

Also note that in Beta 4, in addition to the flickering problem, the status item on inactive screen (on the replicant window) has a weird black "highlight" (when the status item is highlighted)