Calculator

A calculator for the Noctalia bar. It evaluates whole expressions with operator precedence, offers both a keypad and a typed input line in its panel, and keeps the last result visible in the bar.

Plugin

Field	Value
ID	yuuto/calculator
Entries	Bar widget: bar; panel: panel

The panel entry owns the calculator model and publishes it through Noctalia's per-plugin state channel. The bar widget is a thin client: it reads that state and opens the panel.

Usage

Add the bar bar widget to your bar. It shows a calculator glyph, plus the last result once there is one. Left click opens the panel, right click clears the calculator. On a vertical bar only the glyph is shown, with the current expression as its tooltip.

The panel evaluates as you type. The small line shows the expression, the large line the live result, and the copy button next to it puts the result on the clipboard.

Enter expressions either with the keypad or by typing into the input line, where Enter evaluates. Pressing = keeps the result in the input, so the next operator continues from it. The keypad uses plain text labels (AC, +/-, DEL, *, /) rather than symbol glyphs, so it renders with any bar font.

Open the panel over IPC:

noctalia msg panel-toggle yuuto/calculator:panel

Expression syntax

Operators are +, -, *, / and ^, with parentheses and the usual precedence; ^ is right associative. A trailing % divides by 100, so 200*15% is 30. The typed input also accepts ×, ÷ and −.

Available constants: pi, tau, e.

Available functions: sin, cos, tan, asin, acos, atan, atan2, sinh, cosh, tanh, ln, log, log2, log10, exp, sqrt, cbrt, abs, floor, ceil, round, trunc, sign, mod, pow, hypot, min, max.

log(x) is base 10; log(x, b) is base b. mod(a, b) is the remainder, since % means percent here. The trigonometric functions follow the angle unit setting, shown in the panel header as RAD or DEG.

Settings

Plugin

Setting	Type	Default	Description
precision	int	8	Maximum decimals used when formatting results, 0 to 10.
angle_unit	select	rad	Angle unit for the trigonometric functions.

Bar Widget

Setting	Type	Default	Description
show_bar_value	bool	true	Shows the last result next to the calculator glyph.
max_bar_length	int	9	Longer results are shortened with a trailing ~.

IPC

Beyond opening the panel, the panel entry accepts three events. The all target addresses every live instance.

noctalia msg plugin yuuto/calculator:panel all eval "2+3*4"
noctalia msg plugin yuuto/calculator:panel all insert "+8"
noctalia msg plugin yuuto/calculator:panel all clear

eval replaces the expression and evaluates it, insert appends to the current expression, and clear resets the calculator.

Notes

Expressions are tokenized and parsed by the plugin itself, so evaluating never runs a shell command and no external tool is required. Results reach the clipboard through noctalia.copyToClipboard.

The panel keeps its model in the plugin state channel rather than in script locals, so clearing from the bar widget and reopening the panel stay in sync.

Credits

Keypad layout and feature set are modelled on the v4 Quickshell calculator plugin by pir0c0pter0 (MIT).