Waveform: add track end markers

[ronso0]

https://bugs.launchpad.net/mixxx/+bug/1799576
This should help understand that no loops can be created (or resized) that would cross the track end, as well as the
the protective loop move limitation in #3117 .

We could also use the end-of-track warning color for the post-roll triangles?

[daschuer]

Good Idea, Thank you.
Unfortunately it does not work for short tracks where the lead in is visible as well.

[ronso0]

Good point, didn't think of that.
I replaced if(preRollVisible) {} else {} with if(preRollVisible) {} if(postRollVisible) {} and squashed all changes.
It now can paint both pre and post roll:

[ronso0]

And now I think it's okay to paint both with SignalColor instead of potentially causing confusion with another color.

[daschuer]

Unfortunatly the clang-format is complaining:

clang-format.............................................................Failed
- hook id: clang-format
- files were modified by this hook
[INFO] First pass: Reformatting added/changed lines...
[INFO] Reformatting src/waveform/renderers/waveformrendererpreroll.cpp [35-54, 73-94, 97-114]...
[INFO] Reformatting src/waveform/renderers/waveformwidgetrenderer.cpp [38-38, 137-138]...
[INFO] Reformatting src/waveform/renderers/waveformwidgetrenderer.h [80-80, 144-144]...
[INFO] Second pass: Breaking long added/changed lines...

[ronso0]

Unfortunatly the clang-format is complaining:

Now this is only asking to break https://github.com/mixxxdj/mixxx/pull/3137/files#diff-81fd0f5d9e826ea64cfcaac0c081a865R80 into multiple lines. See my question on Zulip https://mixxx.zulipchat.com/#narrow/stream/247620-development-help/topic/suppress.20certain.20clang-format.20changes

[daschuer]

I don't mind in this case, because the surrounding code is written like that. So let's merge it.

In general I very much in favor that's all functions should be formated the same with no exceptions.
This improves readability IMHO.

[daschuer]

Lgtm