fix contextmenu wrapping and submenu displaying bugs

[yhy0217]

Closes #684

• fix the context menu wrapping bug
• stop the context menu and submenu from going outside from the map when clicking at margin
• fix the bug that submenu keeps displaying when moving mouse out from 'Copy Coordinates (C)' button in context menu
• fix the submenu cutting off issue when the whole menu is opened near the bottom of the page
• create a test in mapContextMenu.test.js

[AliyanH]

@yhy0217 found a small bug, when I open the layer context menu, the map contextmenu opens also:

Also, noticed this when opening the context menu for the layer near the margin, if its a simple fix, are you able to replicate the same function for the layer contextmenu as you did for the map contextmenu:

If that's not as simple, you can create a new issue and we can handle it in a separate PR.

[yhy0217]

@yhy0217 found a small bug, when I open the layer context menu, the map contextmenu opens also:

Also, noticed this when opening the context menu for the layer near the margin, if its a simple fix, are you able to replicate the same function for the layer contextmenu as you did for the map contextmenu:

If that's not as simple, you can create a new issue and we can handle it in a separate PR.

Finished to fix the bug that two menus open at the same time; however the layer menu does not wrap up on my laptop, and I think it should not happen because the new codes change the style of all buttons inside both two menus (as they all have same classname ".mapml-contextmenu-item"), but I may be wrong. Could you please run the code again and see if there is any change about the styling?

[AliyanH]

Finished to fix the bug that two menus open at the same time

Nice!

Could you please run the code again and see if there is any change about the styling?

Yup, the wrapping issue was solved, I may not have had the latest CSS.

Good work, this is looking great, the contextmenu is appearing as it should. Just found one other thing when the contextmenu is opened near the bottom of the map (the coordinates menu cuts out). Other than that, its perfect, really good work on this!

[yhy0217]

Just found one other thing when the contextmenu is opened near the bottom of the map (the coordinates menu cuts out).

Yes, it used to look like this, but I fixed this problem in my first commit, and it now works well on my laptop:

So I think a re-run may solve this issue too! :)

[AliyanH]

So I think a re-run may solve this issue too!

I believe this is different, this happens when the right click is initiated from the red spot shown below:

[yhy0217]

I believe this is different, this happens when the right click is initiated from the red spot shown below:

Yes you are right, sorry for my misunderstanding. Have updated the code to fix it

[prushforth]

Looks good to me! Changing the magic numbers to variables would make the code more meaningful, which you have mostly done.

[AliyanH]

LGTM!

[prushforth]

LGTM, please merge / rebase and merge when ready.