Safari: Any way to initiate pinch-to-zoom without trackpad? Command + (Zoom in) and Command - (Zoom out) are different from pinch-to-zoom on a trackpad. The former changes the layout of the page, whereas the latter just enlarges the page as if a magnifier was used.

Is there any way to initiate pinch-to-zoom without a trackpad? Any methods such as a keyboard shortcut or an API.
My mouse has a scroll wheel as its middle button.
For zoom out or in I can use command with scroll up or down.  

I don't remember if that was the default behavior, or I selected it at some past time.

This is set at:

System Preferences &gt; Accessibility &gt; Zoom