nsIDOMWindowUtils has a bunch of sendNative* methods to simulate OS-level events like touch/wheel/etc. We should add a OS-level "pinch" gesture thing too. This makes some kind of pinch zoom tests easier (because you don't have to write complex touch sequences that do it) but also has different characteristics (because it will be accompanied by wheel events to content instead of touch events to content) and so will be important for testing coverage.

The more I look at the sendNative* code the more I want to overhaul it. Punting for now.

We'll probably want this hooked up at least on Linux to be able to write tests for bug 1581126.

(In reply to Kartikaya Gupta (email:kats@mozilla.staktrace.com) from comment #1)

The more I look at the sendNative* code the more I want to overhaul it. Punting for now.

Kats, do you recall what sort of overhaul you had in mind?

We're going to be adding sendNativePinch machinery soon (with implementation on Linux for now) as part of the Outreachy project. Depending on the scope, it may or may not make sense to include some refactoring in that.

Hm, I do not recall exactly what I had in mind. I took a quick look at the relevant functions in the hopes that it would jog my memory but it didn't. I know that I had a long-standing gripe about the async events pref and how that completely modified the behaviour of the non-native send* methods. Maybe that's what I was thinking of here - but in that case it wouldn't affect a sendNativePinch implementation.

https://hg.mozilla.org/mozilla-central/rev/f480a36d566f