Conventional zoom behaviour in OS X I would like to replicate the conventional zoom behaviour of 'ctrl +'/'ctrl -' with the mouse scroll functionality. Probably a new feature, but I preferred the original behaviour. Consequently I would prefer the zoom mechanism to only effect the active window as opposed to the entire desktop? How do achieve this?
You only have a couple of options here:


System Preferences → Mouse → Point &amp; Click → Smart zoom. That lets you make zoom on the open window when you double-tap with one finger.
Or, System Preferences → Trackpad → Scroll &amp; Zoom → Smart zoom. Is the same as previously mentioned, but you have to double-tap with two fingers on your trackpad.


Both aren't exactly what you mention, but you have no other choices from now on Yosemite.