Cache used icons in memory, use inline icon for dev-tools (#5927)

src/components/ha-icon.ts

@@ -28,6 +28,8 @@ checkCacheVersion();
 
 const debouncedWriteCache = debounce(() => writeCache(chunks), 2000);
 
+const cachedIcons: { [key: string]: string } = {};
+
 @customElement("ha-icon")
 export class HaIcon extends LitElement {
   @property() public icon?: string;
@@ -83,9 +85,15 @@ export class HaIcon extends LitElement {
 
     this._legacy = false;
 
-    const cachedPath: string = await getIcon(iconName);
+    if (iconName in cachedIcons) {
-    if (cachedPath) {
+      this._path = cachedIcons[iconName];
-      this._path = cachedPath;
+      return;
+    }
+
+    const databaseIcon: string = await getIcon(iconName);
+    if (databaseIcon) {
+      this._path = databaseIcon;
+      cachedIcons[iconName] = databaseIcon;
       return;
     }
     const chunk = findIconChunk(iconName);
@@ -111,6 +119,7 @@ export class HaIcon extends LitElement {
   private async _setPath(promise: Promise<Icons>, iconName: string) {
     const iconPack = await promise;
     this._path = iconPack[iconName];
+    cachedIcons[iconName] = iconPack[iconName];
   }
 
   static get styles(): CSSResult {

src/components/ha-markdown.ts

@@ -53,7 +53,7 @@ class HaMarkdown extends UpdatingElement {
         node.rel = "noreferrer noopener";
 
         // Fire a resize event when images loaded to notify content resized
-      } else if (node) {
+      } else if (node instanceof HTMLImageElement) {
         node.addEventListener("load", this._resize);
       }
     }

src/panels/developer-tools/state/developer-tools-state.js

@@ -1,4 +1,5 @@
 import "@material/mwc-button";
+import "@material/mwc-icon-button";
 import "@polymer/paper-checkbox/paper-checkbox";
 import "@polymer/paper-input/paper-input";
 import { html } from "@polymer/polymer/lib/utils/html-tag";
@@ -6,11 +7,13 @@ import { html } from "@polymer/polymer/lib/utils/html-tag";
 import { PolymerElement } from "@polymer/polymer/polymer-element";
 import { safeDump, safeLoad } from "js-yaml";
 import "../../../components/entity/ha-entity-picker";
+import "../../../components/ha-svg-icon";
 import "../../../components/ha-code-editor";
 import { showAlertDialog } from "../../../dialogs/generic/show-dialog-box";
 import { EventsMixin } from "../../../mixins/events-mixin";
 import LocalizeMixin from "../../../mixins/localize-mixin";
 import "../../../resources/ha-style";
+import { mdiInformationOutline } from "@mdi/js";
 
 const ERROR_SENTINEL = {};
 /*
@@ -56,8 +59,9 @@ class HaPanelDevState extends EventsMixin(LocalizeMixin(PolymerElement)) {
         .entities td {
           padding: 4px;
         }
-        .entities ha-icon-button {
+        .entities mwc-icon-button {
           --mdc-icon-button-size: 24px;
+          --mdc-icon-size: 20px;
         }
         .entities td:nth-child(3) {
           white-space: pre-wrap;
@@ -149,13 +153,12 @@ class HaPanelDevState extends EventsMixin(LocalizeMixin(PolymerElement)) {
         <template is="dom-repeat" items="[[_entities]]" as="entity">
           <tr>
             <td>
-              <ha-icon-button
+              <mwc-icon-button
                 on-click="entityMoreInfo"
-                icon="hass:information-outline"
                 alt="[[localize('ui.panel.developer-tools.tabs.states.more_info')]]"
                 title="[[localize('ui.panel.developer-tools.tabs.states.more_info')]]"
-              >
+                ><ha-svg-icon path="[[informationOutlineIcon()]]"></ha-svg-icon>
-              </ha-icon-button>
+              </mwc-icon-button>
               <a href="#" on-click="entitySelected">[[entity.entity_id]]</a>
             </td>
             <td>[[entity.state]]</td>
@@ -272,6 +275,10 @@ class HaPanelDevState extends EventsMixin(LocalizeMixin(PolymerElement)) {
     });
   }
 
+  informationOutlineIcon() {
+    return mdiInformationOutline;
+  }
+
   computeEntities(hass, _entityFilter, _stateFilter, _attributeFilter) {
     return Object.keys(hass.states)
       .map(function (key) {