In Chromium, mouse move events only arrive when mouse button is down

[andybalaam]

I'm not sure whether this is a Chromium bug, or something that can be fixed or worked around in the Elm runtime.

When I launch an Elm program in Chromium I do not see mouse movement events.

In Firefox, I see mouse events whenever I move the mouse (as I would expect).

$ chromium-browser --version
Chromium 47.0.2526.106 Ubuntu 15.04

$ cat Main.elm 
import Mouse
import Graphics.Element exposing ( show )


main = Signal.map show Mouse.position

$ elm-reactor &
elm reactor 0.16.0
Listening on http://0.0.0.0:8000/
$ chromium-browser http://0.0.0.0:8000/Main.elm

When I run the above, the mouse co-ordinates display does not update when I move the mouse over the Chromium window. When I click and drag, or move out of the window and back in, the co-ordinates do update.

If I do the same in Firefox I see the co-ordinates changing whenever I move the mouse (as I would expect).

[andybalaam]

I added a breakpoint in Chromium in this code in Main.elm (for me, line 5465):

    localRuntime.addListener([position.id], node, 'mousemove', function move(e) {
        localRuntime.notify(position.id, Utils.getXY(e));
    });

I don't hit the breakpoint when I move the mouse, but I do when I click and drag.

[andybalaam]

I added a breakpoint in Chromium in this code in Main.elm (for me, line 5465):

    localRuntime.addListener([position.id], node, 'mousemove', function move(e) {
        localRuntime.notify(position.id, Utils.getXY(e));
    });

I don't hit the breakpoint when I move the mouse, but I do when I click and drag.

[andybalaam]

$ elm-make -h
elm-make 0.16 (Elm Platform 0.16.0)

[andybalaam]

$ elm-make -h
elm-make 0.16 (Elm Platform 0.16.0)

[andybalaam]

I tried this with a different version of Chromium and it worked fine so I think this is some weird Chromium-specific corner case. Closing.

[andybalaam]

I tried this with a different version of Chromium and it worked fine so I think this is some weird Chromium-specific corner case. Closing.