Colours and styles

Every element of the bar takes a foreground colour (<element>_color_fg), a background colour (<element>_color_bg) and a style (<element>_style), by name. The names are those of FACE, which writes them as ANSI escape sequences; they are case insensitive (red, RED, Red). A colour may also be a 24-bit value, #rrggbb.

A name that is not in these lists, or a malformed #rrggbb, stops the program in initialize, with a message that names it.

Colours

The same 17 names for the foreground and the background:

Name	Foreground code	Background code
black	30	40
red	31	41
green	32	42
yellow	33	43
blue	34	44
magenta	35	45
cyan	36	46
white	37	47
default	39	49
black_intense	90	100
red_intense	91	101
green_intense	92	102
yellow_intense	93	103
blue_intense	94	104
magenta_intense	95	105
cyan_intense	96	106
white_intense	97	107

How a named colour looks depends on the palette of the terminal.

24-bit colours

#rrggbb, three hexadecimal pairs in any case (#2EF5C0, #2ef5c0), is written as ESC[38;2;r;g;bm in the foreground and ESC[48;2;r;g;bm in the background: the exact colour, whatever the palette of the terminal. Most modern terminals support it; one that does not shows an approximation, or no colour. The short form #rgb is not accepted.

Styles

One style for each element:

Name	Code
bold_on	1
italics_on	3
underline_on	4
inverse_on (foreground and background swapped)	7
strikethrough_on	9
framed_on	51
encircled_on	52
overlined_on	53

The _off names (bold_off, italics_off, underline_off, inverse_off, strikethrough_off, framed_off, encircled_off, overlined_off) exist too, but have no use here: every element ends with a reset of all colours and styles. Many terminals do not support framed_on, encircled_on and overlined_on.

Zones

bar_zones colours each filled cell of the bar body by its position, as the tachometer of a car turns amber, then red, towards the end of its scale. It is a list of limit:colour items separated by blanks:

• the limit is a fraction of the body, in (0, 1], increasing from item to item;
• the colour is a name or #rrggbb, and replaces the foreground colour of filled_char (its background and style stay).

A filled cell takes the colour of the first zone whose limit reaches the end of the cell: with width=40 and '0.7:… 0.88:… 1:…', cells 1–28, 29–35 and 36–40. Cells beyond the last limit keep the filled_char colour; empty cells keep the empty_char colours. The partial block of partial_blocks takes the colour of its cell, and so do the block of an indeterminate bar and its full body at the end. A log has no colours: the zones change nothing there.

A wrong item stops the program in initialize, with a message that names it: no colon, a limit that is not a number, not in (0, 1] or not above the previous one, an unknown colour.

call bar%initialize(prefix_string='RPM ', prefix_color_fg='#2EF5C0', prefix_style='bold_on',               &
                    filled_char_string='▌', empty_char_string='▌', empty_char_color_fg='#0E342C',          &
                    bar_zones='0.7:#2EF5C0 0.88:#FFB000 1:#FF3B30',                                        &
                    add_progress_percent=.true., progress_percent_color_fg='#FFB000',                      &
                    width=40, max_value=real(steps, R8P))

At 80%, the dark empty_char cells are the unlit segments:

$ tach
RPM ▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌  80%

Themes

theme gives a bar the look of a 1980s dashboard display in one keyword: the segments of the bar, lit and unlit, and the colours of every element. Every keyword passed explicitly wins over the theme, so a theme is a starting point:

Theme	Looks like	Lit	Unlit	Numbers	Pulse trail
vfd	a vacuum fluorescent display, blue-green	#2EF5C0	#0E342C	#FFB000	#1FB08A #137057 #0B3F31
amber	an amber liquid crystal display	#FFB000	#3A2800	#FFB000	#C08400 #7A5400 #3F2B00
kitt	the red scanner of a talking car	#FF3B30	#3C0C0A	#FFB000	#C0281E #7A1912 #4A0F0B

A theme sets:

• the filled and empty strings to ▌, a segment with the gap of its right half (unless partial_blocks);
• the filled colour to lit and the empty colour to unlit, which a ramp uses too;
• the prefix, suffix and spinner to lit, the prefix in bold;
• the percent, count, speed, ETA, scale, date and summary to numbers;
• the unlit 8s of segment digits to #3A2800;
• on an indeterminate bar, the pulse trail.

It sets no zones, no profile and no segment digits: add them as you like. An unknown theme stops the program.

call vfd%initialize(theme='vfd', prefix_string='vfd   ', add_progress_percent=.true., width=30, &
                    max_value=real(steps, R8P))
call amber%initialize(theme='amber', prefix_string='amber ', bar_profile='ramp', add_progress_percent=.true., &
                      width=30, max_value=real(steps, R8P), position=1)
call kitt%initialize(theme='kitt', prefix_string='kitt  ', indeterminate=.true., add_progress_count=.true., &
                     width=30, position=2)

Three bars, one per theme, the second with a ramp:

$ march
vfd   ▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌  58%
amber ▁▁▁▁▁▂▂▂▂▃▃▃▃▄▄▄▄▅▅▅▅▆▆▆▆▇▇▇▇█  58%
kitt  ▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌▌ 29

Example

call bar%initialize(prefix_string='march ', prefix_color_fg='cyan', prefix_style='bold_on',             &
                    bracket_left_string='[', bracket_right_string=']',                                  &
                    filled_char_string='█', filled_char_color_fg='green',                               &
                    empty_char_string='█', empty_char_color_fg='black_intense',                         &
                    suffix_string=' time steps', suffix_color_fg='yellow', suffix_style='italics_on', &
                    width=40, max_value=real(steps, R8P))

$ march
march [████████████████████████████████████████] time steps