Uniline

Getting started in 10 seconds

Type M-x uniline-mode
Move cursor with the arrow-keys on the keyboard → ← ↑ ↓
Quit C-c C-c

╷   ╭─────────╮
╰───┤my first ├─╮
    │drawing  │ ╰───╮
    ╰─────────╯     │
       ╭────┬───────╯
       ╰────╯

New

Navigating to the relevant section of the info-mode documentation is now just one or two key-strokes away.

Under Hydra type ?.
Under Transient type ??.

The documentation is also reachable from the menu, in the menu-bar at the top of the screen. The menu is also available by left-clicking on Uniline on the mode-bar at the bottom of the screen.

Note that there is also a standard description of uniline-mode and its key-bindings. Just press C-h m or middle-click on Uniline on the mode-bar at the bottom of the screen.

Pure UNICODE text diagrams in Emacs

Draw diagrams like those:

Document a command

   pdfjam source.pdf 3-5,9
  ╶─────▲────▲────────▲──▲╴
command╶╯    │        │  │
input file╶──╯        │  │
select pages 3,4,5╶───╯  │
and page 9╶──────────────╯

Connect boxes with arrows

            ╭───────────────────────╮
  ╷123╭────▶┤ hundred and something │
  ╰───╯     ╰───────────────────────╯
                             ╭────▶──╮A╷
    ╭───╮    ┏━━━┓    ╔═══╗  │       ╰─╯
0╶─→┤ 1 ┝━━━▶┫ 2 ┣═══▷╣ 3 ╟──●────▶──╮B╷
    ╰───╯    ┗━┯━┛    ╚═╤═╝  │       ╰─╯
               ╰────←───╯    ╰────▶──╮C╷
                                     ╰─╯
   ╔══════════╗
   ║ 1        ║          ▐▀▀▀▀▀▀▀▀▜
   ║    ╭─────╫───╮ ◁──▷ ▐ 3      ▐
   ╚════╪═════╝ 2 │      ▐▄▄▄▄▄▄▄▄▟
        ╰─────────╯

Explain decisions trees

┏━━━━━━━━━━━━┓
┃which color?┃
┗━┯━━━━━━━━━━┛
  │     ╭──────╮
  │  ╭──┤yellow├─▷╮good─choice╭□
  ▽  │  ╰──────╯  ╰═══════════╯
  ╰──●  ╭───╮    ┏━━━━━┓
     ├──┤red├───▷┨dark?┠──╮
     │  ╰───╯    ┗━━━━━┛  │
     │ ╭───◁──────────────╯
     │ │   ╭───╮
     │ ╰─●─┤yes├▷╮regular─red╭─□
     │   │ ╰───╯ ╰═══════════╯
     │   │ ╭──╮
     │   ╰─┤no├─▷╮pink╭────────□
     │     ╰──╯  ╰════╯
     │  ╭────╮
     ├──┤blue├───▷╮next week╭──□
     │  ╰────╯    ╰═════════╯
     │  ╭─────╮
     ╰──┤white├──▷╮available╭──□
        ╰─────╯   ╰═════════╯

Draw lines or blocks

                              ╭─╮←─╮
                         ╭╮   │ │  ╰──╴max 235
                       ╭╮││  ╭╯ │
                       │╰╯│╭─╯  │
      ╭╮               │  ││    │
   ╭─╮││╭╮   ╭──╮╭╮    │  ╰╯    ╰╮
  ╭╯ ╰╯╰╯│  ╭╯  ╰╯╰─╮  │         │ ╭╮
◁─╯      ╰──╯       ╰──╯         ╰─╯╰────▷
◀════════════════════════════════════════▶
                       ╭────────╮
   ▲                   │all time│
   ┃       ▄     ▗▟█ ←─┤highest │
  Qdx      █▌   ████   ╰────────╯
   ┃     ▗▄█▌   █████▙
   ┃   ▟███████▄█████████▄▄▄     ▗▄
   ┃▐▄▄████████████████████████████▄▄▖
    ╺━━━━━━━━━━╸time╺━━━━━━━━━━━━━━━━▶

Outline the General Relativity and the Schrödinger’s equations

     ╭─────────────────────╴G: Einstein tensor
     │                ╭────╴κ: Gravitational coupling constant
  ╭──▽───╮        ╭───▽──╮
┏━┷━━━━━━┷━━━━━━━━┷━━━━━━┷━━━┓
┃ R - gR/2 + Λg = (8πG/c⁴)×T ┃◁╴General Relativity equation
┗━△━━━△△━━━━━△△━━━━━━△━△━━━△━┛
  │   ││     ││      │ │  ╭╯
  │   ││     ││      │ │  ╰╴Energy-impulsion tensor
  │   ││     ││      │ ╰───╴Speed of light
  │   ││     ││      ╰─────╴Gravitational constant
  │   ││     ╰┴────────────╴Cosmological constant
  │   │╰──────┴────────────╴Scalar curvature
  │   ╰───────╰────────────╴Metric tensor
  ╰────────────────────────╴Ricci tensor

       ╭─────────────────────╴Derivative over time
       │     ╭──────────╭────╴State of quantum system at time t
       │     │          │     (the square of its absolute value
      ╭▽─╮ ╭─▽──╮     ╭─▽──╮   is the probability density)
┏━━━━━┷━━┷━┷━━━━┷━━━━━┷━━━━┷━┓
┃ i ħ d/dt |Ψ(t)> = Ĥ |Ψ(t)> ┃◁─╴Schrödinger's equation
┗━△━△━━━━△━━━━△━━━━━△━━━━△━━━┛
  │ │    ╰────╰─────┤────╰───╴Time
  │ │               ╰────────╴Hamiltonian
  │ ╰────────────────────────╴Reduced Plank constant
  ╰──────────────────────────╴Imaginary number i²=-1

Explain the structure of a sentence in a foreign language

(which language?)

┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓
┃ the pretty table is standing ┃
┗┯━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┛
 │    ╭────┬─────┬─────╴radicals
 ↕   ╭┴╮  ╭┴─╮  ╭┴─╮
┏┷━━━┿━┿━━┿━━┿━━┿━━┿━━━┓
┃ la bela tablo staras ┃
┗━━━━┿━┿△━┿━━┿△━┿━━┿△━━┛
     ╰─╯│ ╰──╯│ ╰──╯│  ┏━━━━━suffixes━━━━━┓
        │     │     ╰──╂╴as: present tense┃
        │     │        ┃ os: future tense ┃
        │     │        ┃ is: past tense   ┃
        │     ╰────────╂╴ o: noun         ┃
        ╰──────────────╂╴ a: adjective    ┃
                       ┃  e: adverb       ┃
                       ┗━━━━━━━━━━━━━━━━━━┛

Explain Lisp lists

  '(a b c)
     ┏━━━┳━━━┓   ┏━━━┳━━━┓   ┏━━━┳━━━┓
●━━━▶┫ ● ┃ ●─╂──▷┨ ● ┃ ●─╂──▷┨ ● ┃nil┃
     ┗━┿━┻━━━┛   ┗━┿━┻━━━┛   ┗━┿━┻━━━┛
       │           ╰──────────╮╰╮
       │  ╭─────┬───────────╮ │ │
       ╰─▷┤"a\0"│properties │ │ │
          ├─────┼───────────┤ │ │
          │"b\0"│properties ├◁╯ │
          ├─────┼───────────┤   │
          │"c\0"│properties ├◁──╯
          ├─────┼───────────┤
          │...  │...        │
          ╵     ╵           ╵

Draw sketched objects

 ◀─(-)────────(+)──▶    ~╭──────╮~
  ▗──────────────╮     ~~│ ╭~~╮ │~~
  ▐              ╰╮     ~│ ╵  ╵ │~
╭□▐   1.5 volts  ╭╯□╮    ╰─╖  ╓─╯
│ ▝▀▀▀▀▀▀▀▀▀▀▀▀▀▀▘  │      ╠━━╣
│                   ╰──────╯  │
╰─────────────────────────────╯

 ╶╮       ╭╴
┏┳┥▒▒▒▒▒▒▒┝╸
┃┃│▒▒eau▒▒│
┃┃│▒▒▒▒▒▒▒│ ╔═════╗
┃┃╰──╮▒╭──╯ ║ ╶╮  ▽           ╭╴
┃┃    ▒     ║  │  ░           │
┃┃    ▒     ║  │░░░░░░░░░░░░░░│
┃┃    ╚═════╝  │░░░░░░░░░░░░░░╞════▷▒▒
┃┃             │░░░░░akvo░░░░░│    ╶╮ ▒         ╭╴
┃┃             │░░░░░░░░░░░░░░│     │  ▒        │
┃┃             ╰─┲┳━━━━━━━━┳┱─╯     │▒▒▒▒▒▒▒▒▒▒▒│
┃┃               ┃┃        ┃┃       │▒▒▒water▒▒▒│
┃┃               ┃┃        ┃┃       │▒▒▒▒▒▒▒▒▒▒▒│
┃┃               ┃┃        ┃┃       ╰───────────╯
▝▀▀▀▀▀▀▘        ▝▀▘        ▝▀▘      ▀▀▀▀▀▀▀▀▀▀▀▀▀

Pure text

Those diagrams are pure text. There is nothing graphic. They are achieved using UNICODE characters. Therefore they can be drawn within any text formatted document, like Org Mode, Markdown, txt, comments in any programming language source code (C++, Python, Rust, D, JavaScript, GnuPlot, LaTex, whatever).

Most often, the text file will be encoded as UTF-8. This is becoming the de-facto standard for text and source code files.

Creating such diagrams by hand is painfully slow. Use Uniline to draw lines while you move the cursor with keyboard arrows.

Beware!

If you see those diagrams miss-aligned, most likely the font used to display them does not support UNICODE block characters. See bellow the paragraph Which fonts? for details.

If you get misalignment when drawing, this could come from too wide characters. Emojis are an example. Usual characters may also be considered twice as wide as normal under some “language environments”. See the paragraph Language environment for details.

A minor mode for drawing

Minor mode

Uniline is a minor mode. Activate it temporarily:

M-x uniline-mode

Exit it with:

C-c C-c

The current major mode is still active underneath uniline-mode.

While in uniline-mode, overwriting is active, as well as long lines truncation. Also, a hollow cursor is provided (customizable). Those settings are reset to their previous state when exiting uniline-mode.

Draw lines by moving the cursor

Use keyboard arrows to draw lines.

By default, drawing lines only happens over empty space or over other lines. If there is already text, it will not be erased. However, by hitting the control-key while moving, lines overwrite whatever there is.

The buffer is “infinite” in bottom and right directions. Which means that when the cursor ends up outside the buffer, white space characters are automatically added.

The usual numeric prefix is available. For instance, to draw a line 12 characters wide downward, type: M-12 <down>

Brush style

Set the current brush with:

- single thin line ╭─┬─╮
+ single thick line ┏━┳━┓
= double line ╔═╦═╗
# quarter block ▙▄▟▀
<delete> eraser
<return> move without drawing anything

The current brush and the current text direction (see below) are reflected in the mode-line (at the bottom of the Emacs screen). It looks like this:

 current text                  current
    direction╶────╮       ╭───╴brush
                  ▼       ▼
══════════════════╧═══════╧══════════════
U:** buff    (... →Uniline┼ ...)
═════════════════════════════════════════

Text direction

Usually, inserting text in a buffer moves the cursor to the right. (And sometimes to the left for some locales). Any of the 4 directions can be selected under Uniline. Just type any of:

<insert> C-<up>
<insert> C-<right>
<insert> C-<down>
<insert> C-<left>

The current direction is reflected in the mode-line, just before the word "uniline".

The `<insert>` key

The <insert> key is a prefix for other keys:

for drawing arrows, squares, crosses, o-shapes glyphs,
for handling rectangles,
for inserting # = - + which otherwise change the brush style,
for trying a choice of mono-spaced fonts.

Why <insert>? Because:

Uniline tries to leave their original meaning to as many keys as possible,
the standard meaning of <insert> is to toggle the overwrite-mode; but Uniline is already in overwrite-mode, and de-activating overwrite would break Uniline.

So preempting <insert> does not sacrifices anything.

Customization

Another key may be defined instead of <insert>. Type:

M-x customize-variable uniline-key-insert

Glyphs `▷ ▶ → □ ◆ ╮─` insertion & modification

Individual character glyphs may be inserted and changed.

Put the cursor where a glyphs should be edited or inserted.
Then press <insert> (this key may be customized, see the “Customization” chapter).

Arrows, squares, circles, crosses may be handled. Also lines may be fine tweaked a single character at a time.

Arrows glyphs `▷ ▶ → ▹ ▸ ↔`

When inserting an arrow, it points in the direction that the line drawing follows.

Uniline supports 6 arrows types: ▷ ▶ → ▹ ▸ ↔

□
╰─◁──▷─╮       □─╮ ╭─╮ ╭─╮ ╭─□
╭─◀──▶─╯         △ ▲ ↑ ▵ ▴ ↕
╰─←──→─╮         │ │ │ │ │ │
╭─◃──▹─╯         ▽ ▼ ↓ ▿ ▾ ↕
╰─◂──▸─╮         ╰─╯ ╰─╯ ╰─╯
╭─↔──↔─╯
□

Actually, there are tons of arrows of all styles in the UNICODE standard. Unfortunately, support by fonts is weak. So Uniline restrains itself to those six safe arrows.

To insert an arrow, type: <insert> a or <insert> a a or <insert> a a a. (a cycles through the 6 styles, A cycles backward).

<insert> 4 a is equivalent to <insert> a a a a, which is also equivalent to <insert> A A A. Those 3 shortcuts insert an arrow of this style: ▵▹▿◃. The actual direction where the arrow points follows the last movement of the cursor.

To change the direction of the arrow, use shift-arrow, for example: S-<up> will change from → to ↑.

Intersection glyphs `■ ◆ ●`

There are a few UNICODE characters which are mono-space and symmetric in the 4 directions. They are great at line intersections:

To insert a square □ ■ ▫ ▪ ◆ ◊ type: <insert> s s s... (s cycles, S cycles backward).

To insert a circular shape · ∙ • ● ◦ Ø ø type: <insert> o o o... (o cycles, O cycles backward).

To insert a cross shape ╳ ╱ ╲ ÷ × ± ¤ type: <insert> x x x... (x cycles, X cycles backward).

To insert a usual ASCII letter or symbol, just type it.

As the keys - + = # are preempted by uniline-mode, to type them, prefix them with <insert>. Example: <insert> - inserts a - and <insert> + inserts a +.

<insert>
    │
    ▼
   ╭┴╮   ╭───────╮  ╭──────────────────╮
   │s├─▶─┤squares├──┤ □  ■  ▫  ▪  ◆  ◊ │
   ╰┬╯   ╰───────╯  ╰──────────────────╯
   ╭┴╮   ╭───────╮  ╭─────────────────────╮
   │o├─▶─┼circles┼──┤ ·  ∙  •  ●  ◦  Ø  ø │
   ╰┬╯   ╰───────╯  ╰─────────────────────╯
   ╭┴╮   ╭───────╮  ╭───────────────────╮
   │x├─▶─┼crosses┼──┤ ╳  ╱ ╲ ÷  ×  ±  ¤ │
   ╰┬╯   ╰───────╯  ╰───────────────────╯
   ╭┴╮              ╭───╮
   │+├─▶────────────┤ + │
   ╰┬╯              ╰───╯
   ╭┴╮              ╭───╮
   │-├─▶────────────┤ - │
   ╰┬╯              ╰───╯
   ╭┴╮              ╭───╮
   │=├─▶────────────┤ = │
   ╰┬╯              ╰───╯
   ╭┴╮              ╭───╮
   │#├─▶────────────┤ # │
   ╰─╯              ╰───╯

Fine tweaking of lines

 convert this  ═══▶   into that
╭───────────╮        ╭───────────╮
│╶───┬────▷ │        │╶───╮────▷ │
│    │      │        │    │      │
│           │        │           │
│    ▀▀▀    │        │    ▀▟▀    │
╰───────────╯        ╰───────────╯

At the crossing of lines, it may be appealing to do small adjustments. In the above example, we removed a segment of line which occupies 1/4 of a character. This cannot be achieve with line tracing alone. We also modified a quarter-block line in a non-obvious way.

Put the point (the cursor) on the character where lines cross each other.
type INS S-<right> S-<right>

<right> here refers to the right part of the character under the point. The 1/4 line segment will cycle through all displayable forms. On the second stroke, no segment will be displayed, which is what we want.

Caveat! The UNICODE standard does not define all possible combinations including double line segments. (It does for all combinations of thin and tick lines). So sometimes, when working with double lines, the process may be frustrating.

This works also for lines made of quarter-blocks. There are 4 quarter-blocks in a character, either on or off. Each of the 4 shifted keyboard arrows flips a quarter-block on-and-off.

In the above example, the effect was achieved with: INS S-<up> S-<down> S-<left>

Rectangular actions

Drawing,
filling,
moving,
copying & yanking,
change line & glyph styles,

those actions may be performed on a rectangular selection.

Select a rectangular region with C-SPC or C-x SPC and move the cursor.

You may also use S-<arrow> (<arrow> being any of the 4 directions) to extend the selection. The buffer grows as needed with white spaces to accommodate the selection. Selection extension mode is active when shift-select-mode is non-nil.

Or you may use the mouse to highlight the desired region.

All those region-highlighting are standard in Emacs, and unrelated to Uniline.

Once you have a region highlighted, press <insert> (this key can be customized, see the “Customization” chapter). The selection becomes rectangular if it was not. You are offered a menu of possible actions.

Drawing a rectangle

To draw a rectangle in one shot, select a region, press <insert>, then hit:

r to draw a rectangle inside the selection
S-R to draw a rectangle outside the selection
C-r to overwrite a rectangle inside the selection
C-S-R to overwrite a rectangle outside the selection

If needed, change the brush with any of - + = # <delete>

╭───────╮          r: inside╮╭───────╮
│ one   │          ▗▄▄▄▄▄▄▖╭┤│▛▀▀▀▀▀▜│
│  ┏━━━━┿━━━━━━┓   ▐╭────╮▌│╰┼▌     ▐│
╰──╂────╯ two  ┃   ▐│    │▌│ │▙▄▄▄▄▄▟│
   ┃   ╔═══════╋═╗ ▐│    ├▌╯ ╰─────┬─╯
   ┗━━━╋━━━━━━━┛ ║ ▐╰────╯▌────────┴───╮
       ║  three  ║ ▝▀▀▀▀▀▀▘  R: outside╯
       ╚═════════╝

                       ╭─────────╮
my text I              │my text I│
want to  ╶─<insert>R─▷ │want to  │
box                    │box      │
                       ╰─────────╯

The usual C-_ or C-/ keys may be hit to undo, even with the region still active visually.

Filling a rectangle

While the rectangular mode is active, press i to fill the rectangle. You will be asked to choose a character. You have those options:

for a regular character like t, just type it.
SPC or DEL for a shade of grey " ░▒▓█" among the 5 available in UNICODE. SPC to make it darker and darker. DEL to make the rectangle lighter and lighter.
C-y to chose the first character in the top of the kill ring.

The above selection is the same as for the flood-fill action (see the “Flood-fill” chapter).

Moving a rectangle

Select a region, then press <insert>.

Use arrow keys to move the rectangle around. A numeric prefix may be used to move the rectangle that many characters.

Under Hydra, be sure to specify the numeric prefix with just digits, without the Alt key. Typing 15 <left> moves the rectangle 15 characters to the left. M-15 <left> does not work.
Under Transient, use the Alt key, like anywhere else in Emacs. Type M-15 <left> to move the selected rectangle 15 characters to the left.

Press q, <return>, or C-g to stop moving the rectangle.

The C-_ key may also be used to undo the previous movements, even though the selection is still active.

                ▲
                │
               <up>
          ╭─────┴──────╮
          │this is     │
          │my rectangle│
◀─<left>──┤I want to   ├─<right>─▶
          │move        │
          ╰─────┬──────╯
              <down>
                │
                ▼

Copying, killing, yanking a rectangle

A rectangle can be copied or killed, then yanked somewhere else.

Select a region, press <insert>, then:

c to copy
k to kill
y to yank (aka paste)

This is similar to the Emacs standard rectangle handling:

C-x r r copy rectangle to register
C-x r k kill rectangle
C-x r y yank killed rectangle

The first difference is that Uniline rectangles, when killed and yanked, do not move surrounding characters.

The second difference is that the white characters of the yanked rectangle are considered transparent. As a result, only non-blank parts of the yanked rectangle are over-printed.

Uniline and Emacs standard rectangle share the same storage for copied and killed rectangles, namely the killed-rectangle Lisp variable. So, a rectangle can be killed one way, and yanked another way.

Dashed lines and other styles

╭────▷───╮   ┏━━━━▶━━━┓   ╔════▶═══╗
│ ╭─□──╮ │   ┃ ┏━■━━┓ ┃   ║ ╔═■══╗ ║
△ │    │ ▽   ▲ ┃    ┃ ▼   ▲ ║    ║ ▼
│ ╰───◦╯ │   ┃ ┗━━━•┛ ┃   ║ ╚═══•╝ ║
╰───◁────╯   ┗━━━◀━━━━┛   ╚═══◀════╝

╭╌╌╌╌▷╌╌╌╮   ┏╍╍╍╍▶╍╍╍┓
┆ ╭╌□╌╌╮ ┆   ┇ ┏╍■╍╍┓ ┇
△ ┆    ┆ ▽   ▲ ┇    ┇ ▼
┆ ╰╌╌╌◦╯ ┆   ┇ ┗╍╍╍•┛ ┇
╰╌╌╌◁╌╌╌╌╯   ┗╍╍╍◀╍╍╍╍┛

╭┈┈┈┈▷┈┈┈╮   ┏┉┉┉┉▶┉┉┉┓
┊ ╭┈□┈┈╮ ┊   ┋ ┏┉■┉┉┓ ┋
△ ┊    ┊ ▽   ▲ ┋    ┋ ▼
┊ ╰┈┈┈◦╯ ┊   ┋ ┗┉┉┉•┛ ┋
╰┈┈┈◁┈┈┈┈╯   ┗┉┉┉◀┉┉┉┉┛

A base drawing can be converted to dashed lines. Moreover, lines can be made either thin or thick.

Select the rectangular area you want to operate on (with mouse drag or S-<left>, S-<down> and so on as described earlier).
Type INS, then s (as “style”).

You will be offered a choice of styles:

3: vertical lines will become 3 dashes per character, while horizontal ones will get 2 dashes per character.
4: vertical and horizontal lines will get 4 dashes per character.
h: thin lines corners, which are usually rounded, become hard angles.
+: thin lines and intersections become thick, empty glyphs get filled.
-: thick lines and intersections become thin, filled glyphs are emptied.
=: thick and thin lines become double lines.
0: come back to standard base-line Uniline style: plain, not-dashed lines, thin corner rounded, ASCII art is converted to UNICODE.
a: apply the aa2u-rectangle function from the unrelated ascii-art-to-unicode package, to convert ASCII art to UNICODE (this only works if ascii-art-to-unicode is already installed).

Converting parts of a drawing from one style to another can produce nice looking sketches.

╭───╮   ╭───╮   ╭───╮
│░░░│   │░░░│   │░░░┝━▶┓ ╭╌╌╌╌╌╮
│░░░╰───╯░░░╰───╯░░░│  ┃ ┆░░░░░╰╌╌╌╌╌╮
□░░░░░░░░░░░░░░░░░░░│  ┗━┥░░░░░░░░░░░┆
│░░░╭───╮░░░╭───╮░░░│    ┆░░░░░╭╌╌╌╌╌╯
╰───╯   ╰─┰─╯   ╰─┰─╯    ╰╌╌┰╌╌╯
          ▲       ┃         ▼
          ┗━━━━━━━┻━━━━━━━━━┛

┏━━━┓   ┏━━━┓   ┏━━━┓
┃░░░┃   ┃░░░┃   ┃░░░┠─▷╮ ┏╍╍╍╍╍┓
┃░░░┗━━━┛░░░┗━━━┛░░░┃  │ ┇░░░░░┗╍╍╍╍╍┓
■░░░░░░░░░░░░░░░░░░░┃  ╰─┨░░░░░░░░░░░┇
┃░░░┏━━━┓░░░┏━━━┓░░░┃    ┇░░░░░┏╍╍╍╍╍┛
┗━━━┛   ┗━┯━┛   ┗━┯━┛    ┗╍╍┯╍╍┛
          △       │         ▽
          ╰───────┴─────────╯

ASCII to UNICODE

The standard base-line Uniline (INS s 0) or aa2u-rectangle (INS s a) conversions may be used to convert ASCII art to UNICODE. The original ASCII art may be drawn for instance by the artist-mode or the picture-mode packages.

To use aa2u-rectangle, install the ascii-art-to-unicode package by Thien-Thi Nguyen (RIP), available on ELPA. Uniline does not requires a dependency on this package, by lazy evaluating any call to aa2u-rectangle. See https://elpa.gnu.org/packages/ascii-art-to-unicode.html

+-------------+    +--+
|             +-->-|  +-----+   ASCII art
| 1  +--------+--+ | 3      |   made by
+----+--------+  | +----+---+   Artist-mode
     | 2         +-<----+
     +-----------+

╭─────────────╮    ╭──╮
│             ├──▷─│  ╰─────╮   Converted to
│ 1  ╭────────┼──╮ │ 3      │   Uniline base style
╰────┼────────╯  │ ╰────┬───╯   INS s 0
     │ 2         ├─◁────╯
     ╰───────────╯

┌─────────────┐    ┌──┐
│             ├──>─│  └─────┐   Converted by
│ 1  ┌────────┼──┐ │ 3      │   aa2u-rectangle
└────┼────────┘  │ └────┬───┘   INS s a
     │ 2         ├─<────┘
     └───────────┘

INS s 0 with selection active calls the uniline-change-style-standard function. It converts what looks ASCII-art to UNICODE-art. Of course, there are ambiguities regarding whether a character is part of a sketch or not.

The heuristic is to consider that a character is part of a sketch if it is surrounded by at least one other character which is part of a sketch. So, an isolated - minus character will be left alone, while two such characters -- will be converted to UNICODE. Conversion will happens also for <- for instance.

Here is a fairly convoluted ASCII-art example, along with its conversion by INS s 0:

     ╭─↔--<-◁-◀--━+           +--->------==+
/----/ Rectangle1 |-----+-----+ Rectangle2 v    v
|    | <uni^code> ^     "     | "quote"    +-\  ▼
^^   \------------/   /-+-\   +------------+ "  v
|    \--+------+--/   |   |   +----\----/--+ "  >▷▶>
\>--\   |      |      \---/        |    |    "
    v   \==<===/   a=b 1=2 a-to-b  +----+ ◁==/  >->

     ╭─↔──◁─◁─◀──━┑           ╭───▷──────══╕
╭────┤ Rectangle1 │─────╥─────┤ Rectangle2 ▽    ▽
│    │ <uni^code> △     ║     │ "quote"    ├─╖  ▼
△^   ├────────────┤   ╭─╨─╮   ├────────────┤ ║  ▽
│    ╰──┬──────┬──╯   │   │   ╰────┬────┬──╯ ║  ▷▷▶▷
╰▷──╮   │      │      ╰───╯        │    │    ║
    ▽   ╘══◁═══╛   a=b 1=2 a-to-b  ╰────╯ ◁══╝  ▷─▷

Long range actions: contour and flood-fill

Tracing a contour

  ╭──────────────╮
╭─╯A.written.text╰────────╮
│outlined by the.`contour'│
╰─╮function.gets╶┬────────╯
  ╰╮a.surrounding╰───────╮
   ╰─╮line.in.the.current│
     ╰─╮brush.style╭─────╯
       ╰───────────╯

Choose or change the brush style with any of -,+,=_,#,<delete>. Put the cursor anywhere on the shape or outside but touching it. Then type:

<insert> c

A contour line is traced (or erased if brush style is <delete>) around the contiguous shape close to the cursor.

When hitting capital letter: <insert> S-C the contour is overwritten. This means that if there was already a different style of line on the contour path, it is overwritten.

The shape is distinguished because it floats in a blank characters ocean. For the shake of the contour function, blank characters are those containing lines as drawn by Uniline (including true blank characters). Locations outside the buffer are also considered blank.

The algorithm has an upper limit of 10000 steps. This avoids an infinite loop in which the algorithm may end up in some rare cases. One of those cases is when the contour crosses a new-page character, displayed by Emacs as ^L. 10000 steps require a fraction of a second to run. For shapes really huge, you may launch the contour command once again, at the point where the previous run ended.

This 10000 steps limit is customizable. Type:

M-x customize-variable uniline-contour-max-steps

Flood-fill

this.text.surrounds      this.text.surrounds
.                 /      .▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒/
.                //╶───▷╴.▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒//
...            ////      ...▒▒▒▒▒▒▒▒▒▒▒▒////
  ...a.hole/////           ...a.hole/////

A hollow shape is a contiguous region of identical characters (not necessarily blank), surrounded by a boundary of different characters. The end of the buffer in any direction is also considered a boundary.

Put the cursor anywhere in the hole. Then type:

<insert> i

Answer by giving a character to fill the hole.

If instead of a character, SPC or DEL is typed, then a shade of grey character is picked. SPC selects a darker grey than the one the point is on, while DEL selects a lighter. There are 5 shades of grey in the UNICODE standard: " ░▒▓█". Those grey characters are well supported by the suggested fonts.

C-y is also an option. The first character in the top of the kill ring will be chosen as the filling character. (The kill ring is filled by functions like C-k or M-w, unrelated to Uniline).

Typing <return> or C-g aborts the filling operation.

A rectangular shape may also be filled.

Mark a region
<insert> i
answer which character should be used to fill.

There is no limit on the area to fill. Therefore, the filling operation may flood the entire buffer (but no more).

Macros

Uniline adds directional macros to the Emacs standard macros.

Record a macro as usual with C-x ( … C-x ).

Then call it with the usual C-x e. But then, instead of executing the macro, a menu is offered to execute it in any of the 4 directions.

When a macro is executed in a direction other than the one it was recorded, it is twisted in that direction. This means that recorded hits on the 4 keyboard arrows are rotated. It happens also for shift and control variations of those keys. Direction of text insertion is also rotated.

There is still the classical e option to call the last recorded macro. So instead of the usual C-x e, type C-x e e. And of course, the usual repetition typing repeatedly e is available.

Why are directional macros useful? To create fancy lines. For instance, if we want a doted-line instead of the continuous one, we record a macro for one step:

C-x (             ;; begin recording
INS o             ;; insert a small dot
<right> <right>   ;; draw a line over 2 characters
C-x )             ;; stop recording

Then we call this macro repeatedly in any of the 4 directions:

·─·─·─·─·  ╷     ·──·
        │  │     │  │
        ·  ·     ·  ·
        │  │     │  │
        ·  ·─·─·─·  ·
        │           │
        ·─·─·─·─·─·─·

We can draw complex shapes by just drawing one step. Hereafter, we call a macro in 4 directions, closing a square:

  ╭╮╭╮╭╮╭╮╭╮╭╮     △ △ △ △ △ △       ╭─╮ ╭─╮ ╭─╮ ╭─╮     ╭─╮ ╭─╮ ╭─╮ ╭─╮
╭─╯╰╯╰╯╰╯╰╯╰╯│    ╶╯╶╯╶╯╶╯╶╯╶╯╷   ╭──╯∙╰─╯∙╰─╯∙╰─╯∙│    ▷┤□├▷┤□├▷┤□├▷┤□├▽
╰╮           ╰╮  ◁╮           ╰▷  │∙               │   ╭┴┼─╯ ╰─╯ ╰─╯ ╰─┼┴╮
╭╯           ╭╯   ╵           ╷   ╰╮               ╰╮  │□│             │□│
╰╮           ╰╮  ◁╮           ╰▷   │               ∙│  ╰┬╯             ╰┬╯
╭╯           ╭╯   ╵           ╷   ╭╯               ╭╯   △               ▽
╰╮           ╰╮  ◁╮           ╰▷  │∙               │   ╭┴╮             ╭┴╮
╭╯           ╭╯   ╵           ╷   ╰╮               ╰╮  │□│             │□│
╰╮           ╰╮  ◁╮           ╰▷   │               ∙│  ╰┬┼─╮ ╭─╮ ╭─╮ ╭─┼┬╯
 │╭╮╭╮╭╮╭╮╭╮╭─╯   ╵╭╴╭╴╭╴╭╴╭╴╭╴    │∙╭─╮∙╭─╮∙╭─╮∙╭──╯   △┤□├◁┤□├◁┤□├◁┤□├◁
 ╰╯╰╯╰╯╰╯╰╯╰╯      ▽ ▽ ▽ ▽ ▽ ▽     ╰─╯ ╰─╯ ╰─╯ ╰─╯       ╰─╯ ╰─╯ ╰─╯ ╰─╯

Which fonts?

A mono-space character font must be used. It must also support UNICODE.

Not all fonts are born equal.

(set-frame-font "DejaVu Sans Mono" )
(set-frame-font "Unifont" )
(set-frame-font "Hack" )
(set-frame-font "JetBrains Mono" )
(set-frame-font "Cascadia Mono" )
(set-frame-font "Agave" )
(set-frame-font "JuliaMono" )
(set-frame-font "FreeMono" )
(set-frame-font "Iosevka Comfy Fixed" )
(set-frame-font "Iosevka Comfy Wide Fixed")
(set-frame-font "Aporetic Sans Mono" )
(set-frame-font "Aporetic Serif Mono" )
(set-frame-font "Source Code Pro" )

Those fonts are known to support the required UNICODE characters, AND display them as mono-space. There are fonts advertised as mono-space which give arbitrary widths to non-ASCII characters. That is bad for the kind of drawings done by Uniline.

You may want to try any of the suggested fonts. Just hit the corresponding entry in the Uniline menu, or type <insert> f. You may also execute the above Lisp commands like that:

M-: (set-frame-font "DejaVu Sans Mono")

This setting is for the current session only. If you want to make it permanent, you may use the Emacs customization:

<insert> f *

or

M-x customize-face default

Beware that Emacs tries to compensate for missing UNICODE support by the current font. Emacs substitutes one font for another, character per character. The user may not notice until the drawings done under Emacs are displayed on another text editor or on the Web. Of course, using the suggested fonts and the UNICODEs drawn by Uniline keeps you away from those glitches.

To know which font Emacs has chosen for a given character, type:

C-u C-x =

Note that none of those commands downloads a font from the Web. The font should already be available.

Hydra or Transient?

The basic usage of Uniline should be easy: just move the point, and lines are traced. Change brush to draw thicker lines.

More complex actions are summoned by the <insert> key, with or without selection. This is a single key to remember. Then a textual menu is displayed, giving the possible keys continuations and their meaning. All that is achieved by the Hydra or Transient libraries, which are now part of Emacs (thanks!).

The Hydra and Transient libraries offer similar features. Some users may prefer one or the other.

Uniline was developed from day one with Hydra. Transient is a late addition.

Selecting Hydra or Transient

Two files are compiled when installing Uniline

uniline-hydra.el
uniline-transient.el

One of them should be loaded (but not both). There are several ways. The cleanest is use-package. Add those lines to your ~/.emacs file:

(use-package uniline-hydra
  :bind ("C-<insert>" . uniline-mode))

or:

(use-package uniline-transient
  :bind ("C-<insert>" . uniline-mode))

Note: there used to be a customizable setting to switch between the two interfaces. This had many issues. One of them is that the native-compiler is blind to all user-customized settings.

There is a third file, uniline-code.elc. Loading uniline-hydra.elc or uniline-transient.elc automatically loads uniline-core.elc.

One-liner menus

The multi-lines menus in Hydra and Transient are quite useful for casual users. For seasoned users, those huge textual menus may distract them from their workflow.

It is now possible to switch to less distracting textual menus. They are displayed in the echo-area on a single line.

To do so, type:

C-t within a sub-mode (glyph insertion mode, rectangle handling, etc.)
C-h TAB at the top-level.

This will flip between the two sizes of textual menus. It also affects the welcome message, the one displayed when entering the Uniline minor mode.

The current size is controlled by the uniline-hint-style variable:

t for full fledged messages over several lines
1 for one-liner messages
0 for no message at all

The variable is “buffer-local”, which means that it can take distinct values on distinct buffers.

Its default value can be customized and saved for future sessions:

M-x customize-variable uniline-hint-style

After customization it can be changed later, on a buffer per buffer basis, with the C-t or C-h TAB keys.

Transient natively offers a similar setting: transient-show-popup. (There is no such variable in Hydra). It can be customized with t, nil, 0 (zero), or a number. This is similar but not exactly the same as the Hydra behavior and the uniline-hint-style. the Transient setting stays in effect until the C-t or C-h TAB keys are not used, . As soon as one of those keys is invoked, transient-show-popup is toggled (which does not happens in Transient alone). The change is kept in effect throughout the Uniline session, but no longer.

The Hydra interface

Put that in your ~/.emacs file:

(use-package uniline-hydra
  :bind ("C-<insert>" . uniline-mode))

It has been asked by Transient-only users to avoid installing the Hydra package. Currently, it is not possible to make dependencies conditional in Melpa. And removing the Hydra dependency would hurt Hydra users. Therefore, for the time being, the Hydra package is still installed when installing Uniline through Melpa.

The Transient interface

Put that in your ~/.emacs file:

(use-package uniline-transient
  :bind ("C-<insert>" . uniline-mode))

Transient interface was added recently to Uniline. This leaded to the splitting of the single uniline.el file into 4 source files. Hopefully, the added complexity remains hidden by the Elpa - Melpa packaging system.

Customization

Type: M-x customize-group uniline.

Or Menu bar ⟶ Options ⟶ Customize Emacs ⟶ Specific Group… ⟶ "uniline".

This invokes the standard Emacs customization system. Your settings will be saved in the file pointed to by the custom-file variable if set, or your ~/.emacs file. (Along with all your other settings unrelated to Uniline).

Two settings are special: interface type (obsolete) & the insert key. The other settings are self-explanatory

Interface type (obsolete)

This switch is obsolete. Choosing between Hydra or Transient interface is done by loading one or the other sub-package. See “Installation” for details.

Insert key

By default, the <insert> or INS key is the prefix for most of the Uniline actions. Some computers do not have an INS key, or it is bound to some other command (Apple?).

This can be changed temporarily or permanently. The customization allows to set several keys at the same time.

Depending on whether Emacs is run in a graphical environment or a text-only terminal, either the <insert> or the <insertchar> events are generated by the INS key. Therefore, by default Uniline defines both events as the INS key.

Variable uniline-key-insert.

Maximum steps when drawing a contour

Defaults to 10000. To avoid an infinite loop in some rare cases.

Variable uniline-contour-max-steps.

Cursor type

Hollow by default, so that what is under the cursor remains visible.

There is the option to leave the cursor as it is.

Variable uniline-cursor-type.

Hint style

Currently only applicable to the Hydra. It defaults to “full fledged menus”.

Variable uniline-hint-style.

Transient offers a similar setting: transient-show-popup.

Welcome message visibility

Default is “on”. Turn it “off” for less distraction.

Even when turned of, the welcome message can still be displayed by pressing C-h TAB.

Variable uniline-show-welcome-message.

Line spacing

The line-spacing setting in Emacs can change the display of a sketch. (This setting is unrelated to Uniline).

The best looking effect is given by:

(setq line-spacing nil)

You may want to change your current setting. Uniline may handle this variable some day. Right now, line-spacing is left as a matter of choice for everyone.

╭────┬────────┬────╮   ╺┯━━━━┯┯━━┯┯━┯┯━━━━━━━━┯┯━━━━━━━┯┯━━━━━━┯╸
│▒▒▒▒╰────────╯▒▒▒▒│    │    │╰is╯╰a╯│        ││       │╰around╯
│▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒│    ╰this╯       ╰sentence╯╰hanging╯
│▒▒▒╭─╮▒▒▒▒▒▒╭─╮▒▒▒│            △
│▒▒▒╰─╯▒▒▒▒▒▒╰─╯▒▒▒│            │                  △
│▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒│            ╰─────────┬────────╯
╰──────────────────╯                    verbs
             (setq line-spacing nil)

Font

Face customization is unrelated to Uniline. However, Uniline can assist in choosing a good font and customizing the default face. See the “Which fonts?” chapter.

Type <insert> f to select a font just for the current Uniline session. Type * to enter the Emacs customization of the default face and retain your choice for future sessions.

How Uniline behaves with its environment?

Language environment

The so called “language environment” in Emacs can cause unwanted line breaks, like in this drawing:

╶───────────┬─────╮
                       │           │
                       │           │
                       │           │
                       ╰───────────╯
   unexpected broken lines

╶─────┬───────────╮
      │           │
      │           │
      │           │
      ╰───────────╯
   expected continuous lines

The above example was drawn first with the Chinese-BIG5 language environment, then with the English environment.

There is nothing specific about Chinese-BIG5. It is just an instance picked out from more than 100 language environments.

C-x RET l Chinese-BIG5
C-x RET l English

In Chinese-BIG5, some characters are considered twice as wide as standard characters. Whereas in English, all characters needed by Uniline are 1 unit wide.

Thanks to rumengling (GitHub) for discovering and diagnosing the issue!

To workaround the issue, when entering uniline-mode, the width of all characters Uniline uses is checked. If some of them are more than 1, the char-width-table variable is patched.

What are the consequences of this patch? The char-width-table variable is an Emacs global. Therefore the patch by Uniline will affect all buffers. As the characters touched by the patch are graphic, and have nothing to do with Chinese, it should not have any significance on text written in Chinese.

It was pondered whether Uniline should put back char-width-table at its original value upon exiting uniline-mode, or leaving the patch. For now, it has been decided to leave it. Because anyway, intertwining several uniline-mode and changes to the language environment is intractable.

In case of something, re-setting the language environment to its same value cancels the patch to char-width-table by Uniline.

Compatibility with Picture-mode

Picture-mode and uniline-mode are compatible. Their features overlap somehow:

Both implement an unlimited buffer in east and south directions.
Both visually truncate long lines (actual text is not truncated).
Both set the overwrite mode (uniline-mode activates overwrite-mode, while picture-mode re-implements it)
Both are able to draw rectangles (uniline-mode in UNICODE, picture-mode in ASCII), copy and yank them.

They also have features unique to each:

Picture-mode writes in 8 possible directions
Picture-mode handles TAB stops
Uniline-mode draws lines and arrows

Compatibility with Artist-mode

Artist-mode and uniline-mode are mostly incompatible. This is because artist-mode preempts the arrow keys, which give access to a large part of uniline-mode features.

However, it is possible to use both one after the other.

Compatibility with Whitespace-mode

Whitespace-mode and uniline-mode are mostly compatible.

Why activate whitespace-mode while in uniline-mode? Because Uniline creates a lot of white-spaces to implement an infinite buffer. And it is funny to look at this activity.

To make uniline-mode and whitespace-mode fully compatible, disable the newline visualization:

M-x customize-variable whitespace-style
uncheck (Mark) NEWLINEs

This is due to a glitch in move-to-column when a visual property is attached to newlines. And uniline-mode makes heavy use of move-to-column.

Compatibility with Org Mode

You may want to customize the shift extension mode in Org Mode. This is because Org Mode preempts shift-select-mode for other useful purposes. Just type:

M-x customize-variable org-support-shift-select

and choose “when outside special context”, which sets it to t.

You then get the shift-selection from Org Mode, not from Uniline. The difference is that the Uniline’s one handles the infinite-ness of the buffer.

Other than that, Uniline is compatible with Org Mode

Thanks to jdtsmith (GitHub) for sharing a funny fact he discovered. If a source block is created with the Uniline language (Uniline is not a language like C++, Python, or Bash), then it can be edited (M-x org-edit-special) with uniline-mode automatically activated.

╭───╮   ╭───╮
│ ╷ ╰───╯ ╷ │
│ ╰─    ╶─╯ │
╰╮ ●     ● ╭╯
 │      ╷  │
 ╰╮ ────╯ ╭╯
  ╰───────╯

Org Mode and LaTex

Use the pmboxdraw LaTex module. This gives limited support for “box drawing” characters in LaTex documents.

Example:

#+LATEX_HEADER: \usepackage{pmboxdraw}


this works:
┌─────┐       ┌────────────┐
│     ├───────┤            │
└─────┘       │            │
┌─────┐  ┌────┤            │
│     ├──┘    │            │
└─────┘  ┌────┤            │
┌─────┐  │    │            │
│     ├──┘    └────────────┘
└─────┘

this does not quite work:
   ┏━━━┓  ┏━━┓     ┏━━━━━┓
   ┃   ┃  ┃  ┣━━━━━┫     ┃
   ┃   ┗━━┛  ┃    ┏┛     ┃
   ┗━━━━━━━━━┛    ┗━━━━━━┛

but that is OK:
     ┏━━━┓
     ┃   ┃
     ┗━━━┛

that is OK too:
╺════╦══╗  ╔════╗
     ║ A║  ║ B  ╚══╗
     ╚══╝  ╚═══════╝

this works:

├── dev
└┬┬ release
 │├── new
 │└── old
 ├── graph
 └── non-graph

Note that corners of thin lines should be sharp. There is no support for rounded corners.

To export this Org Mode example to PDF through LaTex, type:

C-c C-E l o

What about `\t` tabs?

Some files may contain tabs (the character \t). Those include programming code (Python, Perl, C++, D, Rust, JavaScript and so on).

When Uniline draws something in the middle of a TAB, or right onto a TAB, it first converts it to spaces, then proceeds as usual. This process is invisible. So be cautious if TABs have a special meaning in the file.

Also, rectangles are first untabified (if there are TABs) before moving them. This avoids some rare instances of misalignment.

One way to see what is going on, is to activate the whitespace-mode.

What about `^L` page separation?

Uniline does not work well with ^L (page separation) character. Nor with similar characters, like ^T. When trying to draw a line over such a character, the cursor may get stuck. This is because those characters occupy twice the width of a normal character.

Just try to get away from ^L, ^T and such when drawing with Uniline.

Emacs on the Linux console

Linux consoles are the 7 non-graphic screens which can be accessed usually typing C-M-F1, C-M-F2, and so on. Such a screen is also presented when connecting through ssh or tls into a non-graphical server.

By default they use a font named “Fixed” with poor support for Unicode. However, it supports lines of the 3 types, mixing all of them in thin lines though.

Another problem is that by default S-<left> and C-<left> are indistinguishable from <left>. Same problem with <right>, <up>, <down> and <insert>. This has nothing to do with Emacs. A solution can be found here: https://www.emacswiki.org/emacs/MissingKeys

Emacs on a graphical terminal emulator

This is the Emacs launched from a terminal typing emacs -nw. In this environment, <insert> does not exist. It is replaced by <insertchar>. This has already been taken into account by Uniline by duplicating the key-bindings for the two flavors of this key.

If you decide to bind globally C-<insert> to the toggling of Uniline minor mode as suggested, then you will have to do the same for C-<insertchar>, for example with use-package in your ~/.emacs file:

(use-package uniline
  :defer t
  :bind ("C-<insert>"     . uniline-mode)
  :bind ("C-<insertchar>" . uniline-mode))

Emacs on Windows

On Windows the only native mono-spaced fonts are Lucida Console and Courier New. They are not mono-spaced for the Unicodes used by Uniline.

Often, the Consolas font is present on Windows. It supports quite well the required Unicodes to draw lines. A few glyphs produce unaligned result though. They should be avoided under Consolas: △▶▹◆

Of course, other fonts may be installed. It is quite easy.

Lisp API

Could Uniline be programmed (versus used interactively)? Yes!

The API is usable programmatically:

Move the cursor

Move cursor while drawing lines by calling any of the 4 directions functions:

uniline-write-up↑
uniline-write-ri→
uniline-write-dw↓
uniline-write-lf←

They expect a repeat count (usually 1) and optionally force=t to overwrite the buffer

Brush

Set the current brush by calling any of the following:

uniline--set-brush-nil ;; write nothing
uniline--set-brush-0 ;; eraser
uniline--set-brush-1 ;; single thin line╶─╴
uniline--set-brush-2 ;; single thick line╺━╸
uniline--set-brush-3 ;; double line╺═╸
uniline--set-brush-block ;; blocks ▙▄▟▀

Those functions are equivalent to:

(setq uniline--brush nil)
(setq uniline--brush 0)
(setq uniline--brush 1)
(setq uniline--brush 2)
(setq uniline--brush 3)
(setq uniline--brush :block)

except the functions also update the mode-line.

Example: Lisp function to draw a plus sign

For instance, if we want to create a function to draw a “plus” sign, we can code it as follows:

(defun uniline-draw-plus ()
  (interactive)
  (uniline-write-ri→ 1)
  (uniline-write-dw↓ 1)
  (uniline-write-ri→ 1)
  (uniline-write-dw↓ 1)
  (uniline-write-lf← 1)
  (uniline-write-dw↓ 1)
  (uniline-write-lf← 1)
  (uniline-write-up↑ 1)
  (uniline-write-lf← 1)
  (uniline-write-up↑ 1)
  (uniline-write-ri→ 1)
  (uniline-write-up↑ 1))

Calling M-x uniline-draw-plus will result in this nice little plus-shape:

 ╭╮
╭╯╰╮
╰╮╭╯
 ╰╯
generated by
M-x uniline-draw-plus

We may modify the function to accept the size of the shape as a parameter:

(defun uniline-draw-plus (size)
  (interactive "Nsize? ")
  (uniline-write-ri→ size)
  (uniline-write-dw↓ size)
  (uniline-write-ri→ size)
  (uniline-write-dw↓ size)
  (uniline-write-lf← size)
  (uniline-write-dw↓ size)
  (uniline-write-lf← size)
  (uniline-write-up↑ size)
  (uniline-write-lf← size)
  (uniline-write-up↑ size)
  (uniline-write-ri→ size)
  (uniline-write-up↑ size))

The (interactive "Nsize? ") form prompts user for the size of the shape if not given as a parameter.

This API works in any mode, not only in Uniline minor mode. It takes care of the infiniteness of the buffer in the right and down directions.

Long range actions (contour, flood-fill, rectangle)

There are other useful functions operating on many characters at once. Contour tracing and flood-filling are among them:

uniline-contour
uniline-fill

The following functions operate on a rectangular region, which must be active prior to calling them:

uniline-draw-inner-rectangle
uniline-draw-outer-rectangle
uniline-copy-rectangle
uniline-kill-rectangle
uniline-yank-rectangle
uniline-fill-rectangle
uniline-move-rect-up↑
uniline-move-rect-ri→
uniline-move-rect-dw↓
uniline-move-rect-lf←

Constants

Constants for the 4 directions:

uniline-direction-up↑ ;; constant 0
uniline-direction-ri→ ;; constant 1
uniline-direction-dw↓ ;; constant 2
uniline-direction-lf← ;; constant 3

Macro and text direction

Changing text direction:

uniline-text-direction-up↑
uniline-text-direction-ri→
uniline-text-direction-dw↓
uniline-text-direction-lf←

or (in this case the mode-line is not updated):

(setq uniline-text-direction uniline-direction-up↑)
(setq uniline-text-direction uniline-direction-ri→)
(setq uniline-text-direction uniline-direction-dw↓)
(setq uniline-text-direction uniline-direction-lf←)

Call macro in any direction:

uniline-call-macro-in-direction-up↑
uniline-call-macro-in-direction-ri→
uniline-call-macro-in-direction-dw↓
uniline-call-macro-in-direction-lf←

Insert and tweak glyphs

uniline-insert-fw-arrow
uniline-insert-fw-square
uniline-insert-fw-oshape
uniline-insert-fw-cross
uniline-insert-bw-arrow
uniline-insert-bw-square
uniline-insert-bw-oshape
uniline-insert-bw-cross

Rotate arrow or tweak 4-half-lines or 4-block characters:

uniline-rotate-up↑
uniline-rotate-ri→
uniline-rotate-dw↓
uniline-rotate-lf←

Here are the lowest level functions. Move point, possibly extending the buffer in right and bottom directions:

uniline-move-to-column
uniline-move-to-line
uniline-move-to-lin-col
uniline-move-to-delta-column
uniline-move-to-delta-line

Change to alternate styles

A drawing in a rectangular selection may have its style changed:

uniline-change-style-dot-3-2 ;; 3 dashes vert. ┆, 2 horiz. ╌
uniline-change-style-dot-4-4 ;; 4 dashes vert. ┊ & horiz. ┈
uniline-change-style-standard ;; back to Uniline base style
uniline-change-style-hard-corners ;; rounded corners╭╴become hard┌
uniline-change-style-thin ;; convert to ╭╴ thin lines
uniline-change-style-thick ;; convert to ┏╸ thick lines
uniline-change-style-double ;; convert to ╔═ thick lines
uniline-aa2u-rectangle ;; call aa2u to convert ASCII to Unicode

The above functions require a region to be marked.

Mouse support

The out-of-the-box mouse support of Emacs works perfectly. Except when the mouse clicks on a position outside the buffer. This happens when clicking past the end of a too short line, or past the end of the buffer.

To handle those cases, a few standard Emacs functions have been extended to add blank characters or blank lines. Doing so, the mouse-click now falls on a valid part of the buffer. Of course, those extensions are only active on uniline-mode activated buffers.

Beware that when the window is at the same time zoomed with C-x C-+ C-- AND horizontally scrolled with C-x <, the cursor positioning is not accurate. This is due to Emacs limitations and bugs. Just click twice to fix the inaccuracy.

Installation

Add the following lines to your .emacs file, and reload it, if not already done:

(add-to-list 'package-archives
             '("melpa" . "http://melpa.org/packages/")
             t)
(package-initialize)

Alternately you may customize this variable:

M-x customize-variable package-archives

Then download the package:

(package-install "uniline")

Alternately, you can download the Lisp files, and load them.

(load-file "uniline-hydra.el")   ;; interpreted form
(load-file "uniline-hydra.elc")  ;; byte-compiled form
(load-file "uniline-hydra.eln")  ;; native-compiled form
;; this automatically
;; loads "uniline-core.el"
;; or    "uniline-core.elc"
;; or    "uniline-core.eln"

or if you prefer the Transient interface over the Hydra one:

(load-file "uniline-transient.el")   ;; interpreted form
(load-file "uniline-transient.elc")  ;; byte-compiled form
(load-file "uniline-transient.eln")  ;; native-compiled form
;; this automatically
;; loads "uniline-core.el"
;; or    "uniline-core.elc"
;; or    "uniline-core.eln"

You should prefer the byte-compiled or native-compiled forms over the interpreted forms, because there are a lot of optimizations performed at compile time.

You may want to give uniline-mode a key-binding. use-package in your $HOME/.emacs file is great for that:

(use-package uniline-hydra
  :bind ("C-<insert>" . uniline-mode))

or:

(use-package uniline-transient
  :bind ("C-<insert>" . uniline-mode))

or as an alias to uniline-hydra:

(use-package uniline
  :bind ("C-<insert>" . uniline-mode))

In this example, C-<insert> was chosen. You can use whatever key combinations you want. <insert> happens to also be the key used inside Uniline.

If you do not have use-package, you can add those lines in your ~/.emacs file:

(require 'uniline-hydra)
(bind-keys :package uniline-hydra ("C-<insert>" . uniline-mode))

The downside is that Uniline will be loaded as soon as Emacs is launched, rather than deferred until invoked.

Related packages

artist-mode: the ASCII art mode built into Emacs.
ascii-art-to-unicode: as the name suggest, converts ASCII drawings to UNICODE, giving results similar to those of Uniline.
picture-mode: as in Uniline, the buffer is infinite in east & south directions.
ascii-art-to-unicode ASCII art to UNICODE in Emacs. This is a standard ELPA package by Thien-Thi Nguyen (rest in peace). Uniline may call it to convert ASCII art drawings to equivalent UNICODE. Uniline arranges to not require a dependency on ascii-art-to-unicode by lazy evaluating a call to aa2u.
org-pretty-table: Org Mode tables appear to be drawn in UNICODE characters (actually they are still in ASCII).
boxes: draws artistic boxes around text, with nice looking unicorns, flowers, parchments, all in ASCII art.
org-drawio: a bridge between the Draw.Io editor and Emacs, producing drawing similar to those of Uniline, but in .svg.
syntree: draws ASCII trees on-the-fly from description.
unicode-enbox: create a UNICODE box around a text; input and output are strings.
unicode-fonts: in Emacs, helps alleviate the lack of full UNICODE coverage of most fonts.
org-superstar: prettify headings and plain lists in Org Mode, using UNICODE glyphs.
charmap: UNICODE table viewer for Emacs.
insert-char-preview: insert UNICODEs with character preview in completion prompt.
list-unicode-display: list all UNICODE characters, or a selection of them.
show-font: show font features in a buffer.
ob-svgbob: convert your ascii diagram scribbles into happy little SVG
el-easydraw: a full featured SVG editor right inside your Emacs
asciiflow: (not Emacs) draw on the web, then copy-paste your UNICODE text
dot-to-ascii.ggerganov.com: (not Emacs) describe your schema in the Graphviz language, and copy-past your UNICODE text.
monosketch: (not Emacs) draw on the web, then copy-paste your UNICODE text
ibm-box-drawing-hydra.el: keyboard interface to insert UNICODE box-drawing characters one at a time
org-excalidraw: integrate SVG images generated by excalidraw into Org Mode
rcd-box: create tables surrounded by box-drawing characters from Lisp descriptions
ob-diagram: generate various diagrams using diagrams backend
ob-mermaid: generate Mermaid diagrams within org-mode babel
quail-boxdrawing.el: input method for box drawing characters
make-box.el: box around part of a buffer
vim drawit ascii diagrams: in Vim, in ASCII

Author, contributors

Thierry Banel, author

Feedback:

Chris Rayner (@riscy), gave recommendations prior to insertion in MELPA
Adam Porter (@alphapapa), suggested submitting Uniline to ELPA; should I?
Joost Kremers https://github.com/joostkremers found a bug in the minor-mode key-binding definitions, and incompatibility with
DogLooksGood https://github.com/DogLooksGood gave feedback on inserting usual characters not moving the cursor
LuciusChen & lhindir on GitHub, arthurno1 & karthink on Reddit, pushed toward Transient as the default interface instead of Hydra
karthink noted that Transient was now built into Emacs, loosening the dependencies conundrum, arthurno1 participated in the Hydra - Transient discussion
karthink pointed to the new Aporetic font family, which was then added to the Uniline supported fonts
rumengling on GitHub found and diagnosed the misaligned lines issue produced by some “language environments” (see Language environment).

Contributors:

JD Smith (jdtsmith on GitHub) rewrote the :lighter for added flexibility (the information in the mode-line about the state of Uniline)
JD Smith also pointed to #+begin_src uniline Org Mode block suprising behavior (editing its content automatically switches to uniline-mode)

Utilities:

Oleh Krehel alias abo-abo for his package Hydra
The Magit team for the Transient library
Thien-Thi Nguyen (RIP) for his package ascii-art-to-unicode

License

Uniline is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

Uniline is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.

Name		Name	Last commit message	Last commit date
Latest commit History 189 Commits
images		images
tests		tests
.gitignore		.gitignore
LICENSE		LICENSE
README.org		README.org
uniline-core.el		uniline-core.el
uniline-hydra.el		uniline-hydra.el
uniline-transient.el		uniline-transient.el
uniline.el		uniline.el
uniline.info		uniline.info