Drag outside window

[alexcjohnson]

document keeps getting mousemove events even outside the window, until mouseup. Who knew?!? Not me anyway... but now that I do, this quick change allows dragging to keep going outside the window. Tested manually in all my local browsers, IE9 - 11 and iOS on Browserstack, and of course the test suites still work (after removing mouseout which is no longer part of the interaction).

Two notes:

• I kept coverSlip around, because that's an easy way to prevent selecting text as you drag around.
• Some tips say you need to use setCapture / releaseCapture in IE, but a) that seems to be older versions than we target, and b) might have been mitigated by coverSlip anyway. I saw no difference if I included it in our code.
• I included the IE polyfills in test_dashboard, commented out, to make it easier to test down to IE9 in the future.

cc @etpinard

[etpinard]

Looks good to me.

I'm curious though, what made you investigate document mouse events on drag in the first place?

[alexcjohnson]

Looks good to me.

is that a 💃 ?

I'm curious though, what made you investigate document mouse events on drag in the first place?

Just noticed that google maps allows dragging like that and wondered how 🤔

[etpinard]

💃

I asked the question in case we could have locked down some behavior in a meaningful test.

[alexcjohnson]

I asked the question in case we could have locked down some behavior in a meaningful test.

I thought about that a little and didn't see anything. Our own mouse_event helper will fail outside the window (document.elementFromPoint returns null) so I don't really see a way to trigger the browser's internal behavior.

Fortunately the new behavior is actually simpler on our side than the old, as it doesn't need to worry about mouseOut.