Re: [RFC/PATCH] builtin/blame: darken redundant line information

From: Junio C Hamano <gitster@pobox.com>
Date: Jun 13, 2017, 17:00 UTC
Message-ID: <xmqqa85b9626.fsf@gitster.mtv.corp.google.com>
In-Reply-To: <CAGZ79kYR+qh1X-dQixdpDbcr5z-DJ2mkdncaVn_8y90kNco9tw@mail.gmail.com>

Stefan Beller <sbeller@google.com> writes:

> * As you have an individual color setup, maybe you can fix this
>   for you by setting the appropriate slots to your perception of
>   dimmed?

I do not think it is possible with only {new,old}{,alternative} 4 colors.

Consider this diff:

         context
        -B
        -B
        -B
        -A
        -A
        -A
         context
        +A
        +A
        +A
        +B
        +B
        +B
         context

Two blocks (A and B) that are adjacent are moved but swapped to form a pair of new adjacent blocks.

We would like the boundary between the last "-B" and the first "-A" to be highlighted differently; all other "-A" and "-B" lines do not disappear but go elsewhere, so they want to be dimmed.

The newly added 6 lines are actually moved from elsewhere, and we would like the boundary between the last "+A" and the first "+B" to be highlighted differently, and others are dimmed.

So I'd think you would need at least two kinds of highlight colors plus a dimmed color.

         context
        -B		dim
        -B		dim
        -B		highlight
        -A		highlight
        -A		dim
        -A		dim
         context
        +A		dim
        +A		dim
        +A		highlight
        +B		highlight
        +B		dim
        +B		dim
         context

If old_moved and old_moved_alternative are meant for highlighting "-B" and "-A" above differently, while new_moved and new_moved_alternative are for highlighting "+A" and "+B" differently, you'd need a way to specify "dim" for old and new moved lines, which seems to be impossible with only 4 new colors.