/jQuery-Knob

Nice, downward compatible, touchable, jQuery dial

Primary LanguageJavaScriptMIT LicenseMIT

jQuery Knob

  • canvas based ; no png or jpg sprites.
  • touch, mouse and mousewheel, keyboard events implemented.
  • downward compatible ; overloads an input element.

Example

<input type="text" value="75" class="dial">

<script>
$(function() {
    $(".dial").knob();
});
</script>

Options

Options are provided as attributes 'data-option':

<input type="text" class="dial" data-min="-50" data-max="50">

... or in the "knob()" call :

$(".dial").knob({
                'min':-50
                ,'max':50
                });

The following options are supported :

Behaviors :

  • min : min value | default=0.
  • max : max value | default=100.
  • step : step size | default=1.
  • angleOffset : starting angle in degrees | default=0.
  • angleArc : arc size in degrees | default=360.
  • stopper : stop at min & max on keydown/mousewheel | default=true.
  • readOnly : disable input and events | default=false.

UI :

  • cursor : display mode "cursor", cursor size could be changed passing a numeric value to the option, default width is used when passing boolean value "true" | default=gauge.
  • thickness : gauge thickness.
  • lineCap : gauge stroke endings. | default=butt, round=rounded line endings
  • width : dial width.
  • displayInput : default=true | false=hide input.
  • displayPrevious : default=false | true=displays the previous value with transparency.
  • fgColor : foreground color.
  • inputColor : input value (number) color.
  • font : font family.
  • fontWeight : font weight.
  • bgColor : background color.

Hooks

<script>
$(".dial").knob({
                    'release' : function (v) { /*make something*/ }
                });
</script>

  • 'release' : executed on release

    Parameters :

    • value : int, current value

  • 'change' : executed at each change of the value

    Parameters :

    • value : int, current value

  • 'draw' : when drawing the canvas

    Context :

    • this.g : canvas context 2D (see Canvas documentation)
    • this.$ : jQuery wrapped element
    • this.o : options
    • this.i : input
    • ... console.log(this);

  • 'cancel' : triggered on [esc] keydown

  • 'error' : called if the browser doesn't support canvases and the plugin didn't initialize as a result

The scope (this) of each hook function is the current Knob instance (refer to the demo code).

Example

<input type="text" value="75" class="dial">

<script>
$(".dial").knob({
                 'change' : function (v) { console.log(v); }
                });
</script>

Dynamically configure

<script>
$('.dial')
    .trigger(
        'configure',
        {
        "min":10,
        "max":40,
        "fgColor":"#FF0000",
        "skin":"tron",
        "cursor":true
        }
    );
</script>

Set the value

<script>
$('.dial')
    .val(27)
    .trigger('change');
</script>

Supported browser

Tested on Chrome, Safari, Firefox, IE>=8.0 (IE8.0 with excanvas).

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