Blocks: Don't show the block toolbar if we press ctrl, shift... on Safari

[youknowriad]

closes #1349

It appears that safari trigger an "mousemove" event when we click on the meta keys (shift, ctrl...) even if the mouse didn't move. Some details on the weird mousemove event in Safari here https://transitory.technology/mouse-move-in-safari/

The workaround here is to check that the mouse position effectively changed before showing the toolbar.

[mtias]

Lovely Safari.

[ellatrix]

Where is the logic that normally prevents it for meta keys?

[youknowriad]

@iseulde We just check the mouse position compared to the previous mouse position. that way, we ensure we're effectively moving the mouse

[ellatrix]

@youknowriad No I mean, in other browsers, currently in master, what prevents the UI from showing up on shift or ctrl etc.?

[youknowriad]

On other browsers this event is not triggered at all when we hit shift, ctrl...

[ellatrix]

Ok, I see. Allow me to quickly see if there's no other solution.

[ellatrix]

You're right, I thought maybe we could prevent default behaviour somehow.

[ellatrix]

How about this to avoid duplicate assignment?

stopTypingOnMouseMove( { clientX, clientY } ) {
	const { lastClientX, lastClientY } = this;

	// We need to check that the mouse really moved
	// Because Safari trigger mousemove event when we press shift, ctrl...
	if ( lastClientX && lastClientY && ( lastClientX !== clientX || lastClientY !== clientY ) ) {
		this.props.onStopTyping();
	}

	this.lastClientX = clientX;
	this.lastClientY = clientY;
}

[youknowriad]

LGTM updating