implement a frequency input with switchable exponent

htdocs/lib/settings/FrequencyInput.js

@@ -0,0 +1,21 @@
+$.fn.frequencyInput = function() {
+    this.each(function(){
+        var $group = $(this);
+        var currentExponent = 0;
+        $input = $group.find('input');
+
+        var setExponent = function() {
+            var newExponent = parseInt($exponent.val());
+            var delta = currentExponent - newExponent;
+            $input.val(parseFloat($input.val()) * 10 ** delta);
+            currentExponent = newExponent;
+        };
+
+        $exponent = $group.find('select.frequency-exponent');
+        $exponent.on('change', setExponent);
+
+        // calculate initial exponent
+        $exponent.val(Math.floor(Math.log10($input.val()) / 3) * 3);
+        setExponent();
+    })
+};

htdocs/settings.js

@@ -7,4 +7,5 @@ $(function(){
     $('#rf_gain').gainInput();
     $('.optional-section').optionalSection();
     $('#scheduler').schedulerInput();
+    $('.frequency-input').frequencyInput();
 });

owrx/controllers/assets.py

@@ -153,6 +153,7 @@ class CompiledAssetsController(GzipMixin, ModificationAwareController):
             "lib/settings/GainInput.js",
             "lib/settings/OptionalSection.js",
             "lib/settings/SchedulerInput.js",
+            "lib/settings/FrequencyInput.js",
             "settings.js",
         ],
     }

owrx/form/__init__.py

@@ -319,3 +319,49 @@ class ModesInput(DropdownInput):
     def __init__(self, id, label):
         options = [Option(m.modulation, m.name) for m in Modes.getAvailableModes()]
         super().__init__(id, label, options)
+
+
+class FrequencyInput(Input):
+    def __init__(self, id, label):
+        super().__init__(id, label)
+
+    def defaultConverter(self):
+        return IntConverter()
+
+    def input_properties(self, value):
+        props = super().input_properties(value)
+        props["type"] = "number"
+        props["step"] = "any"
+        return props
+
+    def render_input(self, value):
+        append = """
+            <div class="input-group-append">
+                <select class="input-group-text frequency-exponent" name="{id}-exponent">
+                    <option value="0" selected>Hz</option>
+                    <option value="3">kHz</option>
+                    <option value="6">MHz</option>
+                    <option value="9">GHz</option>
+                    <option value="12">THz</option>
+                </select>
+            </div>
+        """.format(
+            id=self.id,
+        )
+
+        return """
+            <div class="input-group input-group-sm frequency-input">
+                {input}
+                {append}
+            </div>
+        """.format(
+            input=super().render_input(value),
+            append=append,
+        )
+
+    def parse(self, data):
+        exponent_id = "{}-exponent".format(self.id)
+        if self.id in data and exponent_id in data:
+            value = int(float(data[self.id][0]) * 10 ** int(data[exponent_id][0]))
+            return {self.id: value}
+        return {}

owrx/source/__init__.py

@@ -11,7 +11,7 @@ from owrx.command import CommandMapper
 from owrx.socket import getAvailablePort
 from owrx.property import PropertyStack, PropertyLayer, PropertyFilter
 from owrx.property.filter import ByLambda
-from owrx.form import Input, TextInput, NumberInput, CheckboxInput, ModesInput
+from owrx.form import Input, TextInput, NumberInput, CheckboxInput, ModesInput, FrequencyInput
 from owrx.form.converter import OptionalConverter
 from owrx.form.device import GainInput, SchedulerInput, WaterfallLevelsInput
 from owrx.controllers.settings import Section
@@ -503,7 +503,7 @@ class SdrDeviceDescription(object):
             ),
             WaterfallLevelsInput("waterfall_levels", "Waterfall levels"),
             SchedulerInput("scheduler", "Scheduler"),
-            NumberInput("center_freq", "Center frequency", append="Hz"),
+            FrequencyInput("center_freq", "Center frequency"),
             NumberInput("samp_rate", "Sample rate", append="S/s"),
             NumberInput("start_freq", "Initial frequency", append="Hz"),
             ModesInput("start_mod", "Initial modulation"),