Properly resume AudioContext on iOS platform.

[jpauloruschel]

Fixes #3212

This PR makes sure that the AudioContext is properly resumed on the iOS platform when context is switched by using the AudioContext#resume API. It returns a future, so the callback is only triggered once AudioContext is actually resumed. For other platforms, or if AudioContext is not being used, the logic is unchanged.

According to https://developer.mozilla.org/en-US/docs/Web/API/BaseAudioContext/state , iOS Safari sets the state to interrupted.

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[slimbuck]

Suggested change

	const resumeFunction = function () {
	this.suspended = false;
	this.fire('resume');
	}.bind(this);
	const resumeFunction = () => {
	this.suspended = false;
	this.fire('resume');
	}

[willeastcott]

Suggested change

	const resumeFunction = function () {
	this.suspended = false;
	this.fire('resume');
	}.bind(this);
	const resumeFunction = () => {
	this.suspended = false;
	this.fire('resume');
	};

[willeastcott]

I'm assuming the above code suggestion works OK. But using the arrow function should avoid the need to use bind.

[slimbuck]

Beat ya! :D

[willeastcott]

Yeah, except you deleted the trailing semi-colon, @slimbuck! 😆

[willeastcott]

I have a minor concern here. There another bug you might want to check out: #2383
So it seems that pc.platform.ios returns false on iPad at the moment? So your fix here might now work as expected on iPad.

[jpauloruschel]

I have a minor concern here. There another bug you might want to check out: #2383
So it seems that pc.platform.ios returns false on iPad at the moment? So your fix here might now work as expected on iPad.

Calling AudioContext.resume() works on all platforms - it is only the case that on iOS it is required. To be safe, I can remove the platform.ios entirely and always call AudioContext.resume when it is being used. What do you think?

[willeastcott]

Oh interesting. Yeah, that sounds like a good solution to me.