Pick average color of chat background image

src/components/sidebarLeft/tabs/background.ts

@@ -1,6 +1,8 @@
 import { generateSection } from "..";
+import { averageColor } from "../../../helpers/averageColor";
 import blur from "../../../helpers/blur";
 import { deferredPromise } from "../../../helpers/cancellablePromise";
+import { rgbToHsl } from "../../../helpers/color";
 import { attachClickEvent, findUpClassName } from "../../../helpers/dom";
 import { AccountWallPapers, WallPaper } from "../../../layer";
 import appDocsManager, { MyDocument } from "../../../lib/appManagers/appDocsManager";
@@ -51,16 +53,28 @@ export default class AppBackgroundTab extends SliderSuperTab {
     const grid = document.createElement('div');
     grid.classList.add('grid');
 
-    const saveToCache = (url: string) => {
+    const saveToCache = (slug: string, url: string) => {
       fetch(url).then(response => {
-        appDownloadManager.cacheStorage.save('background-image', response);
+        appDownloadManager.cacheStorage.save('backgrounds/' + slug, response);
       });
     };
 
+    // * https://github.com/TelegramMessenger/Telegram-iOS/blob/3d062fff78cc6b287c74e6171f855a3500c0156d/submodules/TelegramPresentationData/Sources/PresentationData.swift#L453
+    const highlightningColor = (pixel: Uint8ClampedArray) => {
+      let {h, s, l} = rgbToHsl(pixel[0], pixel[1], pixel[2]);
+      if(s > 0.0) {
+        s = Math.min(1.0, s + 0.05 + 0.1 * (1.0 - s));
+      }
+      l = Math.max(0.0, l * 0.65);
+      
+      const hsla = `hsla(${h * 360}, ${s * 100}%, ${l * 100}%, .4)`;
+      return hsla;
+    };
+
+    let tempId = 0;
     const setBackgroundDocument = (slug: string, doc: MyDocument) => {
-      rootScope.settings.background.slug = slug;
-      rootScope.settings.background.type = 'image';
-      appStateManager.pushToState('settings', rootScope.settings);
+      let _tempId = ++tempId;
+      const middleware = () => _tempId === tempId;
 
       const download = appDocsManager.downloadDoc(doc, appImManager.chat.bubbles ? appImManager.chat.bubbles.lazyLoadQueue.queueId : 0);
 
@@ -69,26 +83,44 @@ export default class AppBackgroundTab extends SliderSuperTab {
       deferred.cancel = download.cancel;
 
       download.then(() => {
-        if(rootScope.settings.background.slug !== slug || rootScope.settings.background.type !== 'image') {
+        if(!middleware()) {
           return;
         }
 
+        const onReady = (url: string) => {
+          //const perf = performance.now();
+          averageColor(url).then(pixel => {
+            if(!middleware()) {
+              return;
+            }
+            
+            const hsla = highlightningColor(pixel);
+            //console.log(doc, hsla, performance.now() - perf);
+
+            rootScope.settings.background.slug = slug;
+            rootScope.settings.background.type = 'image';
+            rootScope.settings.background.highlightningColor = hsla;
+            document.documentElement.style.setProperty('--message-highlightning-color', rootScope.settings.background.highlightningColor);
+            appStateManager.pushToState('settings', rootScope.settings);
+
+            saveToCache(slug, url);
+            appImManager.setBackground(url).then(deferred.resolve);
+          });
+        };
+
         if(rootScope.settings.background.blur) {
           setTimeout(() => {
             blur(doc.url, 12, 4)
             .then(url => {
-              if(rootScope.settings.background.slug !== slug || rootScope.settings.background.type !== 'image') {
+              if(!middleware()) {
                 return;
               }
 
-              saveToCache(url);
-              return appImManager.setBackground(url);
-            })
-            .then(deferred.resolve);
+              onReady(url);
+            });
           }, 200);
         } else {
-          saveToCache(doc.url);
-          appImManager.setBackground(doc.url).then(deferred.resolve);
+          onReady(doc.url);
         }
       });
 
@@ -183,10 +215,10 @@ export default class AppBackgroundTab extends SliderSuperTab {
 
         load();
 
-        console.log(doc);
+        //console.log(doc);
       });
 
-      console.log(accountWallpapers);
+      //console.log(accountWallpapers);
     });
 
     this.scrollable.append(grid);

src/helpers/averageColor.ts

@@ -0,0 +1,41 @@
+import { renderImageFromUrl } from "../components/misc";
+
+export const averageColor = (imageUrl: string): Promise<Uint8ClampedArray> => {
+  const img = document.createElement('img');
+  return new Promise<Uint8ClampedArray>((resolve) => {
+    renderImageFromUrl(img, imageUrl, () => {
+      const canvas = document.createElement('canvas');
+      const ratio = img.naturalWidth / img.naturalHeight;
+      const DIMENSIONS = 50;
+      if(ratio === 1) {
+        canvas.width = DIMENSIONS;
+        canvas.height = canvas.width / ratio;
+      } else if(ratio > 1) {
+        canvas.height = DIMENSIONS;
+        canvas.width = canvas.height / ratio;
+      } else {
+        canvas.width = canvas.height = DIMENSIONS;
+      }
+      
+      const context = canvas.getContext('2d');
+      context.drawImage(img, 0, 0, img.naturalWidth, img.naturalHeight, 0, 0, canvas.width, canvas.height);
+
+      const pixel = new Array(4).fill(0);
+      const pixels = context.getImageData(0, 0, canvas.width, canvas.height).data;
+      for(let i = 0; i < pixels.length; i += 4) {
+        pixel[0] += pixels[i];
+        pixel[1] += pixels[i + 1];
+        pixel[2] += pixels[i + 2];
+        pixel[3] += pixels[i + 3];
+      }
+
+      const pixelsLength = pixels.length / 4;
+      const outPixel = new Uint8ClampedArray(4);
+      outPixel[0] = pixel[0] / pixelsLength;
+      outPixel[1] = pixel[1] / pixelsLength;
+      outPixel[2] = pixel[2] / pixelsLength;
+      outPixel[3] = pixel[3] / pixelsLength;
+      resolve(outPixel);
+    });
+  });
+};

src/helpers/color.ts

@@ -0,0 +1,31 @@
+export function rgbToHsl(r: number, g: number, b: number) {
+  r /= 255, g /= 255, b /= 255;
+  let max = Math.max(r, g, b),
+      min = Math.min(r, g, b);
+  let h, s, l = (max + min) / 2;
+
+  if(max === min) {
+    h = s = 0; // achromatic
+  } else {
+    let d = max - min;
+    s = l > 0.5 ? d / (2 - max - min) : d / (max + min);
+    switch (max) {
+      case r:
+        h = (g - b) / d + (g < b ? 6 : 0);
+        break;
+      case g:
+        h = (b - r) / d + 2;
+        break;
+      case b:
+        h = (r - g) / d + 4;
+        break;
+    }
+    h /= 6;
+  }
+
+  return ({
+    h: h,
+    s: s,
+    l: l,
+  });
+}

src/hooks/useHeavyAnimationCheck.ts

@@ -6,6 +6,7 @@ import ListenerSetter from '../helpers/listenerSetter';
 import { CancellablePromise, deferredPromise } from '../helpers/cancellablePromise';
 import { pause } from '../helpers/schedulers';
 import rootScope from '../lib/rootScope';
+import { DEBUG } from '../lib/mtproto/mtproto_config';
 
 const ANIMATION_START_EVENT = 'event-heavy-animation-start';
 const ANIMATION_END_EVENT = 'event-heavy-animation-end';
@@ -14,16 +15,18 @@ let isAnimating = false;
 let heavyAnimationPromise: CancellablePromise<void> = Promise.resolve();
 let promisesInQueue = 0;
 
+const log = console.log.bind(console.log, '[HEAVY-ANIMATION]:');
+
 export const dispatchHeavyAnimationEvent = (promise: Promise<any>, timeout?: number) => {
   if(!isAnimating) {
     heavyAnimationPromise = deferredPromise<void>();
     rootScope.broadcast(ANIMATION_START_EVENT);
     isAnimating = true;
-    console.log('dispatchHeavyAnimationEvent: start');
+    DEBUG && log('start');
   }
   
   ++promisesInQueue;
-  console.log('dispatchHeavyAnimationEvent: attach promise, length:', promisesInQueue, timeout);
+  DEBUG && log('attach promise, length:', promisesInQueue, timeout);
 
   const promises = [
     timeout !== undefined ? pause(timeout) : undefined,
@@ -33,14 +36,14 @@ export const dispatchHeavyAnimationEvent = (promise: Promise<any>, timeout?: num
   const perf = performance.now();
   Promise.race(promises).then(() => {
     --promisesInQueue;
-    console.log('dispatchHeavyAnimationEvent: promise end, length:', promisesInQueue, performance.now() - perf);
+    DEBUG && log('promise end, length:', promisesInQueue, performance.now() - perf);
     if(!promisesInQueue) {
       isAnimating = false;
       promisesInQueue = 0;
       rootScope.broadcast(ANIMATION_END_EVENT);
       heavyAnimationPromise.resolve();
 
-      console.log('dispatchHeavyAnimationEvent: end');
+      DEBUG && log('end');
     }
   });
 

src/lib/appManagers/appImManager.ts

@@ -169,7 +169,7 @@ export class AppImManager {
     const isDefaultBackground = rootScope.settings.background.blur === AppStateManager.STATE_INIT.settings.background.blur && 
       rootScope.settings.background.slug === AppStateManager.STATE_INIT.settings.background.slug;
     if(!isDefaultBackground) {
-      appDownloadManager.cacheStorage.getFile('background-image').then(blob => {
+      appDownloadManager.cacheStorage.getFile('backgrounds/' + rootScope.settings.background.slug).then(blob => {
         this.setBackground(URL.createObjectURL(blob), false);
       }, () => { // * if NO_ENTRY_FOUND
         this.setBackground('');
@@ -223,6 +223,12 @@ export class AppImManager {
   private setSettings() {
     document.documentElement.style.setProperty('--messages-text-size', rootScope.settings.messagesTextSize + 'px');
 
+    if(rootScope.settings.background.highlightningColor) {
+      document.documentElement.style.setProperty('--message-highlightning-color', rootScope.settings.background.highlightningColor);
+    } else {
+      document.documentElement.style.removeProperty('--message-highlightning-color');
+    }
+
     document.body.classList.toggle('animation-level-0', !rootScope.settings.animationsEnabled);
     document.body.classList.toggle('animation-level-1', false);
     document.body.classList.toggle('animation-level-2', rootScope.settings.animationsEnabled);

src/lib/appManagers/appStateManager.ts

@@ -58,6 +58,7 @@ export type State = Partial<{
     background: {
       type: 'color' | 'image' | 'default',
       blur: boolean,
+      highlightningColor?: string,
       color?: string,
       slug?: string,
     }

src/scss/partials/_chatBubble.scss

@@ -51,7 +51,6 @@ $bubble-margin: .25rem;
   --background-color: #fff;
   --accent-color: $color-blue;
   --secondary-color: $color-gray;
-  --highlightning-color: rgba(77, 142, 80, .4);
 
   &.is-highlighted, &.is-selected, /* .bubbles.is-selecting */ & {
     &:after {
@@ -88,7 +87,7 @@ $bubble-margin: .25rem;
 
   &.is-highlighted:after {
     //background-color: rgba(0, 132, 255, .3);
-    background-color: var(--highlightning-color);
+    background-color: var(--message-highlightning-color);
 
     body:not(.animation-level-0) & {
       animation: bubbleSelected 2s linear;
@@ -125,7 +124,7 @@ $bubble-margin: .25rem;
 
   &.is-selected {
     &:after {
-      background-color: rgba(77, 142, 80, .4);
+      background-color: var(--message-highlightning-color);
     }
 
     body:not(.animation-level-0) & {
@@ -989,7 +988,7 @@ $bubble-margin: .25rem;
 
       &.is-highlighted {
         .document-selection {
-          background-color: var(--highlightning-color);
+          background-color: var(--message-highlightning-color);
         }
 
         body:not(.animation-level-0) & {
@@ -1001,7 +1000,7 @@ $bubble-margin: .25rem;
 
       &.is-selected {
         .document-selection {
-          background-color: rgba(77, 142, 80, .4);
+          background-color: var(--message-highlightning-color);
         }
 
         body:not(.animation-level-0) & {

src/scss/style.scss

@@ -56,6 +56,7 @@ $chat-padding-handhelds: .5rem;
   --message-handhelds-margin: 5.5625rem;
   --message-beside-button-margin: 2.875rem;
   --message-time-background: rgba(0, 0, 0, .35);
+  --message-highlightning-color: rgba(77, 142, 80, .4);
   --messages-container-width: #{$messages-container-width};
   --messages-text-size: 16px;
   --messages-secondary-text-size: calc(var(--messages-text-size) - 1px);