@sjaakp/knob
v1.1.2
Published
Rotary web control
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Knob 1.1
Knob 1.1 is a JavaScript widget that changes <input type="number"> into
a rotary control (dial), which can be manipulated by the mouse or touch device.
Knob 1.1 should work in any modern browser. It is small code, slightly under 3kB in size.
You can see Knob 1.1 in action here.
Here is Knob 1.1's GitHub page.
Install
Install Knob 1.1 with npm:
npm i @sjaakp/knobYou can also manually install Knob 1.1 by downloading the source in ZIP-format.
Dependencies
Knob 1.1 has no dependencies.
Usage
Load resources
Copy knob.js from the dist directory to a reachable subdirectory of your
website. At the end of the body part of the HTML page,
load the Knob 1.1 code like this:
<script src="/<your subdirectory>/knob.js"></script>Load from CDN
You may also load the Knob 1.1 file from a content distribution network (CDN), like so:
<script src="https://unpkg.com/@sjaakp/knob/dist/knob.js"></script>Set-up
Knob 1.1 creates itself around a HTML <input> of the number-type,
most probably inside an HTML <form>. The <input> should have a name,
as is common for <form> elements, and an id.
The <input> should also
have an attribute data-knob. This doesn't need to have a value (although
it can, see under 'Appearance').
The HTML could look something like:
<html>
<head> ... </head>
<body>
... other stuff ...
<form>
... other form elements ...
<input type="number" data-knob id="knob1" name="speed">
... more form elements ...
<button type="submit">Submit</button>
</form>
... more stuff ...
<script src="/js/dist/knob.js"></script>
</body>
</html>No further initializing is needed.
Knob 1.1 uses the attributes of the
number input,
min, max, and value in particular. There is no additional API.
A limitation is that Knob 1.1 only works with whole numbers. It won't act
well with decimal fractions. Also, the attribute step should be kept at its
default value of "1".
Appearance
If the attribute data-knob has a value of "flip" Knob 1.1's ring
will be upside down. If the value is "ccw", Knob 1.1 will work in
counter-clockwise mode. Both values can also be combined.
The size of the gap in the ring can be changed by setting by the
attribute data-gap to a number between 0 and 90. It is the gap size in
degrees. The default is 30.
A few aspects of Knob 1.1's appearance can be adapted by setting
CSS custom properties inside the ruleset for the class of Knob 1.1's
surrounding <div>: .knob (or, of course, any DOM-element
higher in the cascade). The surrounding <div> will have an id identical
to the id of the <input> supplemented with "-knob".
The properties, together with their default value:
- --knob-diameter, default:
6em - --knob-inner-diameter, default:
75% - --knob-color, default:
orange - --knob-grey, default:
lightgrey
Inspiration
Knob 1.1 was inspired by Anthony Terrien's jQuery-Knob. As the name implies, this depends on jQuery, while Knob 1.1 does not. On the other hand, jQuery-Knob has a few more options.