Change color of state-badge icon according to rgb or brightness (#436)

* Change color of state-badge icon according to rgb or brightness

* Remove unneeded edit

* Set minimum brightness at 15%. Clear previous timeout

src/components/entity/state-badge.html

@@ -1,4 +1,4 @@
-<link rel='import' href='../../../bower_components/polymer/polymer.html'>
+<link rel='import' href='../../../bower_components/polymer/polymer-element.html'>
 
 <link rel='import' href='./ha-state-icon.html'>
 
@@ -45,45 +45,95 @@
 </dom-module>
 
 <script>
-Polymer({
-  is: 'state-badge',
-
-  properties: {
+class StateBadge extends Polymer.Element {
+  static get is() { return 'state-badge'; }
+  static get properties() {
+    return {
       stateObj: {
         type: Object,
         observer: 'updateIconColor',
       },
-  },
+    };
+  }
 
-  computeDomain: function (stateObj) {
+  computeDomain(stateObj) {
     return window.hassUtil.computeDomain(stateObj);
-  },
+  }
+
+  _rgbFromBrightness(brightness) {
+    // Set icon bbroghtness to a scale between 15% bright to 100% bright.
+    const iconBrightness = (brightness + 45) / (255 + 45);
+    const hostBrightness = 1 - iconBrightness;
+    const re = /rgb\((\d+), (\d+), (\d+)\)/;
+    const rgbIconMatch = window.getComputedStyle(this.$.icon).color.match(re);
+    const rgbHostMatch = window.getComputedStyle(this).color.match(re);
+    let rgb;
+    if (rgbIconMatch && rgbHostMatch) {
+      const rgbIcon = rgbIconMatch.slice(1).map(v => Number.parseInt(v, 10));
+      const rgbHost = rgbHostMatch.slice(1).map(v => Number.parseInt(v, 10));
+      rgb = [
+        Math.round((rgbIcon[0] * iconBrightness) + (rgbHost[0] * hostBrightness)),
+        Math.round((rgbIcon[1] * iconBrightness) + (rgbHost[1] * hostBrightness)),
+        Math.round((rgbIcon[2] * iconBrightness) + (rgbHost[2] * hostBrightness)),
+      ];
+      if (rgb.some(v => Number.isNaN(v))) {
+        return undefined;
+      }
+    }
+    return rgb;
+  }
 
   /**
    * Called when an attribute changes that influences the color of the icon.
    */
-  updateIconColor: function (newVal) {
+  updateIconColor(newVal) {
+    const icon = this.$.icon;
     // hide icon if we have entity picture
     if (newVal.attributes.entity_picture) {
       this.style.backgroundImage = 'url(' + newVal.attributes.entity_picture + ')';
-      this.$.icon.style.display = 'none';
+      icon.style.display = 'none';
       return;
     }
 
-    this.style.backgroundImage = '';
-    this.$.icon.style.display = 'inline';
-
-    // for domain light, set color of icon to light color if available and it is
-    // not very white (sum rgb colors < 730)
-    if (window.hassUtil.computeDomain(newVal) === 'light' &&
-        newVal.state === 'on' &&
-        newVal.attributes.rgb_color &&
-        newVal.attributes.rgb_color.reduce(function (cur, tot) { return cur + tot; }, 0) < 730) {
-      this.$.icon.style.color = 'rgb(' + newVal.attributes.rgb_color.join(',') + ')';
-    } else {
-      this.$.icon.style.color = null;
+    if (this._timeoutId) {
+      window.clearTimeout(this._timeoutId);
+      this._timeoutId = null;
     }
-  },
 
-});
+    this.style.backgroundImage = '';
+    icon.style.display = 'inline';
+    if (newVal.state === 'unavailable') return;
+    let rgb;
+    let oldColor;
+    if (newVal.attributes.rgb_color) {
+      rgb = newVal.attributes.rgb_color;
+    } else if (newVal.attributes.brightness && newVal.attributes.brightness !== 255) {
+      if (icon.style.color !== '') {
+        oldColor = icon.style.color;
+        icon.style.transition = 'none';
+        icon.style.color = '';
+      }
+      rgb = this._rgbFromBrightness(newVal.attributes.brightness);
+    }
+    // Set color of icon to rgb color if available and it is not very white (sum rgb colors < 730)
+    if (rgb && rgb.reduce((cur, tot) => cur + tot, 0) < 730) {
+      if (oldColor) {
+        icon.style.color = oldColor;
+      }
+      // If we had to cancel transition - wait after restoring old color so transition will start
+      // from oldColor and not from css 'on' color.
+      if (icon.style.transition && oldColor) {
+        this._timeoutId = window.setTimeout(() => {
+          icon.style.transition = '';
+          icon.style.color = 'rgb(' + rgb.join(',') + ')';
+        }, 10);
+      } else {
+        icon.style.color = 'rgb(' + rgb.join(',') + ')';
+      }
+    } else {
+      icon.style.color = '';
+    }
+  }
+}
+customElements.define(StateBadge.is, StateBadge);
 </script>