Display path of current source file in header bar

[qhuy4119]

Currently, the full path of the current source file will be displayed. This usually results in long path. When the path can't be displayed fully in 1 row for whatever reason (the window is resized, not enough space from the beginning,...), after a Ctrl-L (hotkey for redraw screen), it will wrap automatically, creating more rows as needed.

We have multiple options to resolve this:

• Leave as is
• Only display the filename
• Calculate the length of the string somehow (from shutil.get_terminal_size(), for example)
• Let user decide in config file
• Other....

Let's discuss this

fixes #170

[qhuy4119]

I updated it to calculate the path string automatically to fit on 1 line

Currently, path will be updated if the user executes the next line of code by pressing n, s, c in the Source window(every time DebuggerUI.interaction gets called). Ctrl-l to redraw will only redraw the current path. I don't know if it's possible for Ctrl-l to update the path as well.

[mvanderkamp]

A thought on this: an optional footer might be a better place. The header currently displays very useful information that helps new users get started with using the debugger, and I don't think we should lose that.