Pause UI with <SPACE>

[zhangxp1998]

An attempt to issue #74

When the UI is paused, text will turn yellow, and there will be a "[PAUSED]" string displayed

[imsnif]

Hah! This looks cool :)
I only gave it a quick glance - will look at it more thoroughly over the weekend, but for now if you want to continue, things to add:

1. Tests (essentially, a test where the SPACE key is pressed and we make sure traffic is not updated - the test should fail without this feature).
2. Do you think we can maybe communicate this to the user somehow? My idea right now is to write something like "Press SPACE to pause/resume" on the upper right corner. What do you think?

[ebroto]

Do you think we can maybe communicate this to the user somehow?

What about a help section a la top? Maybe not for now, but if we add more interaction the UI could end up cluttered otherwise

[Ma27]

Nice 🎉

[Ma27]

This seems rather verbose. Shouldn't we optionally append the [PAUSED] string if self.paused?

[zhangxp1998]

Unfortunately rust requires that format strings must be literals... Plus, the color argument will have to be different, so I just expanded this expression

[zhangxp1998]

Hah! This looks cool :)
I only gave it a quick glance - will look at it more thoroughly over the weekend, but for now if you want to continue, things to add:

1. Tests (essentially, a test where the SPACE key is pressed and we make sure traffic is not updated - the test should fail without this feature).
2. Do you think we can maybe communicate this to the user somehow? My idea right now is to write something like "Press SPACE to pause/resume" on the upper right corner. What do you think?

Added a test case for this... Regarding communicating this to user, I'm worried about cluttering the UI. This needs some discussion

[ebroto]

This is neat!

I left a couple comments, the rest LGTM!