Total overhaul!

src/controller.js

@@ -0,0 +1,59 @@
+export class Controller {
+  constructor(config) {
+    this._config = config;
+  }
+
+  set hass(hass) {
+    this._hass = hass;
+    this.stateObj = this._config.entity in hass.states ? hass.states[this._config.entity] : null;
+  }
+
+  get value() {
+    if(this._value)
+      return Math.round(this._value/this.step)*this.step;
+    return 0;
+  }
+  set value(value) {
+    if (value !== this.value)
+      this._value = value;
+  }
+
+  get string() {
+    return `${this.value}`;
+  }
+  get hidden() {
+    return false;
+  }
+  get hasSlider() {
+    return true;
+  }
+  get hasToggle() {
+    return true;
+  }
+
+  get isOff() {
+    return this.value === 0;
+  }
+
+  get min() {
+    if (this._config.min !== undefined)
+      return this._config.min;
+    if (this._min !== undefined)
+      return this._min;
+    return 0;
+  }
+  get max() {
+    if (this._config.max !== undefined)
+      return this._config.max;
+    if (this._max !== undefined)
+      return this._max;
+    return 100;
+  }
+  get step() {
+    if (this._config.step !== undefined)
+      return this._config.step;
+    if (this._step !== undefined)
+      return this._step;
+    return 5;
+  }
+}