This was such a common thing to test for in fluid layouts under AIR/AS3/Flex, or any previous lingua franca where you had to design and code your own rollover effects or web components. So much is elided in mouseout and mouseover. Really, unless you've coded those events in a stack from movements, you don't understand what they mean. In any UI, it's the #1 thing you have to watch out for (along with stuck hovers, accidental focus and things like that). Mouseover/out depend on the entire screen graph as well as timing to establish user intent. Thrashing the whole UI off that because you shift the layout is the worst example of how to do it wrong. Amateur hour.
Yeah. Any position or size change is almost always a no-no. Even if you don't thrash the layout, you could shift your event targets and get caught in a thrash.
I weep for this new generation of web developers. So much more complexity, leaving little time for studying and nailing well-established HCI principles, which used to be less of an issue when web was simpler.
What vexes me is that I learned these principles from companies like Google in the first place.
I learned them the hard way by designing reflow typography layouts in the late 90s and early 00's, mixed with interactive elements; and later thinking out whole sites with layouts that weren't reliant on a particular DOM or browser. It's a bit stunning to me that Google taught any of these principles at any point beyond eliminating all the art. Which to me was the beautiful part of the early web.
I have literally no idea what people are learning now in academies before being set loose to do front-end work, but obviously it's mediated through so many libraries that they haven't had much time to consider what's going on behind low-level user interactions and load sequences.
This was such a common thing to test for in fluid layouts under AIR/AS3/Flex, or any previous lingua franca where you had to design and code your own rollover effects or web components. So much is elided in mouseout and mouseover. Really, unless you've coded those events in a stack from movements, you don't understand what they mean. In any UI, it's the #1 thing you have to watch out for (along with stuck hovers, accidental focus and things like that). Mouseover/out depend on the entire screen graph as well as timing to establish user intent. Thrashing the whole UI off that because you shift the layout is the worst example of how to do it wrong. Amateur hour.