openwebrx-clone/htdocs/lib/FrequencyDisplay.js

175 lines
5.6 KiB
JavaScript

function FrequencyDisplay(element) {
this.prefixes = {
'k': 3,
'M': 6,
'G': 9,
'T': 12
};
this.element = $(element);
this.digits = [];
this.precision = 2;
this.setupElements();
this.setFrequency(0);
}
FrequencyDisplay.prototype.setupElements = function() {
this.displayContainer = $('<div>');
this.digitContainer = $('<span>');
this.unitContainer = $('<span> Hz</span>');
this.displayContainer.html([this.digitContainer, this.unitContainer]);
this.element.html(this.displayContainer);
};
FrequencyDisplay.prototype.getPrefix = function() {
var me = this;
return Object.keys(me.prefixes).filter(function(key){
return me.prefixes[key] == me.exponent;
})[0] || "";
};
FrequencyDisplay.prototype.setFrequency = function(freq) {
this.frequency = freq;
this.exponent = Math.floor(Math.log10(this.frequency) / 3) * 3;
var digits = Math.max(0, this.exponent - this.precision);
var formatted = (freq / 10 ** this.exponent).toLocaleString(
undefined,
{maximumFractionDigits: digits, minimumFractionDigits: digits}
);
var children = this.digitContainer.children();
for (var i = 0; i < formatted.length; i++) {
if (!this.digits[i]) {
this.digits[i] = $('<span>');
var before = children[i];
if (before) {
$(before).after(this.digits[i]);
} else {
this.digitContainer.append(this.digits[i]);
}
}
this.digits[i][(isNaN(formatted[i]) ? 'remove' : 'add') + 'Class']('digit');
this.digits[i].html(formatted[i]);
}
while (this.digits.length > formatted.length) {
this.digits.pop().remove();
}
this.unitContainer.text(' ' + this.getPrefix() + 'Hz');
};
FrequencyDisplay.prototype.setTuningPrecision = function(precision) {
if (typeof(precision) == 'undefined') return;
this.precision = precision;
this.setFrequency(this.frequency);
};
function TuneableFrequencyDisplay(element) {
FrequencyDisplay.call(this, element);
this.setupEvents();
}
TuneableFrequencyDisplay.prototype = new FrequencyDisplay();
TuneableFrequencyDisplay.prototype.setupElements = function() {
FrequencyDisplay.prototype.setupElements.call(this);
this.input = $('<input>');
this.prefixInput = $('<select>');
this.prefixInput.append($('<option value="0">Hz</option>'));
this.prefixInput.append($.map(this.prefixes, function(e, p) {
return $('<option value="' + e + '">' + p + 'Hz</option>');
}));
this.inputGroup = $('<div class="input-group">');
this.inputGroup.append([this.input, this.prefixInput]);
this.inputGroup.hide();
this.element.append(this.inputGroup);
};
TuneableFrequencyDisplay.prototype.setupEvents = function() {
var me = this;
me.displayContainer.on('wheel', function(e){
e.preventDefault();
e.stopPropagation();
var index = me.digitContainer.find('.digit').index(e.target);
if (index < 0) return;
var delta = 10 ** (Math.floor(Math.max(me.exponent, Math.log10(me.frequency))) - index);
if (e.originalEvent.deltaY > 0) delta *= -1;
var newFrequency = me.frequency + delta;
me.element.trigger('frequencychange', newFrequency);
});
var submit = function(){
var exponent = parseInt(me.prefixInput.val());
var freq = parseFloat(me.input.val()) * 10 ** exponent;
if (!isNaN(freq)) {
me.element.trigger('frequencychange', freq);
}
me.inputGroup.hide();
me.displayContainer.show();
};
$inputs = $.merge($(), me.input);
$inputs = $.merge($inputs, me.prefixInput);
$inputs.on('blur', function(e){
if ($inputs.toArray().indexOf(e.relatedTarget) >= 0) {
return;
}
submit();
});
me.input.on('keydown', function(e){
if (e.keyCode == 13) return submit();
if (e.keyCode == 27) {
me.inputGroup.hide();
me.displayContainer.show();
return;
}
var c = String.fromCharCode(e.which);
Object.entries(me.prefixes).forEach(function(e) {
if (e[0].toUpperCase() == c) {
me.prefixInput.val(e[1]);
return submit();
}
})
});
var currentExponent;
me.prefixInput.on('change', function() {
var newExponent = me.prefixInput.val();
delta = currentExponent - newExponent;
if (delta >= 0) {
me.input.val(parseFloat(me.input.val()) * 10 ** delta);
} else {
// should not be necessary to handle this separately, but floating point precision in javascript
// does not handle this well otherwise
me.input.val(parseFloat(me.input.val()) / 10 ** -delta);
}
currentExponent = newExponent;
me.input.focus();
});
$inputs.on('click', function(e){
e.stopPropagation();
});
me.element.on('click', function(){
currentExponent = me.exponent;
me.input.val(me.frequency / 10 ** me.exponent);
me.prefixInput.val(me.exponent);
me.inputGroup.show();
me.displayContainer.hide();
me.input.focus();
});
};
$.fn.frequencyDisplay = function() {
if (!this.data('frequencyDisplay')) {
this.data('frequencyDisplay', new FrequencyDisplay(this));
}
return this.data('frequencyDisplay');
}
$.fn.tuneableFrequencyDisplay = function() {
if (!this.data('frequencyDisplay')) {
this.data('frequencyDisplay', new TuneableFrequencyDisplay(this));
}
return this.data('frequencyDisplay');
}