Fix typos 🙈

Adding readme, privacy section, reducing resolution of analytics data.

README.md

@@ -1,5 +1,32 @@
 # Squoosh!
 
-Squoosh will be an image compression web app that allows you to dive into the
-advanced options provided by various image compressors.
+Squoosh is an image compression web app that allows you to dive into the advanced options provided
+by various image compressors.
 
+# Privacy
+
+Google Analytics is used to record the following:
+
+* [Basic visit data](https://support.google.com/analytics/answer/6004245?ref_topic=2919631).
+* Before and after image size once an image is downloaded. These values are rounded to the nearest
+  kilobyte.
+
+Image compression is handled locally; no additional data is sent to the server.
+
+# Building locally
+
+Clone the repo, and:
+
+```sh
+npm install
+npm run build
+```
+
+You'll get an error on first build because of [a stupid bug we haven't fixed
+yet](https://github.com/GoogleChromeLabs/squoosh/issues/251).
+
+You can run the development server with:
+
+```sh
+npm start
+```

package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "squoosh",
-  "version": "0.1.0",
+  "version": "1.0.0",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
@@ -9481,12 +9481,6 @@
       "integrity": "sha1-5aSs0sEB/fPZpNB/DbxNtJ3SgXY=",
       "dev": true
     },
-    "pinch-zoom-element": {
-      "version": "1.0.0",
-      "resolved": "https://registry.npmjs.org/pinch-zoom-element/-/pinch-zoom-element-1.0.0.tgz",
-      "integrity": "sha512-n5yMOhV/zlOsHcTERBZIbGkhfwATAl9l5JLc5nPAhwAgY8f+PGDikh4TWgvPfGooFyQctLtD+3SNlIE3fEM/eQ==",
-      "dev": true
-    },
     "pinkie": {
       "version": "2.0.4",
       "resolved": "https://registry.npmjs.org/pinkie/-/pinkie-2.0.4.tgz",

package.json

@@ -1,7 +1,7 @@
 {
   "private": true,
   "name": "squoosh",
-  "version": "0.1.0",
+  "version": "1.0.2",
   "license": "apache-2.0",
   "scripts": {
     "start": "webpack serve --host 0.0.0.0 --hot",
@@ -47,12 +47,11 @@
     "if-env": "^1.0.4",
     "linkstate": "^1.1.1",
     "loader-utils": "^1.1.0",
-    "mini-css-extract-plugin": "^0.4.4",
+    "pointer-tracker": "^2.0.3",
     "minimatch": "^3.0.4",
+    "mini-css-extract-plugin": "^0.4.4",
     "node-sass": "^4.9.4",
     "optimize-css-assets-webpack-plugin": "^4.0.3",
-    "pinch-zoom-element": "^1.0.0",
-    "pointer-tracker": "^2.0.3",
     "preact": "^8.3.1",
     "prerender-loader": "^1.2.0",
     "pretty-bytes": "^5.1.0",

src/components/Output/custom-els/PinchZoom/index.ts

@@ -0,0 +1,374 @@
+import PointerTracker, { Pointer } from 'pointer-tracker';
+import './styles.css';
+
+interface Point {
+  clientX: number;
+  clientY: number;
+}
+
+interface ChangeOptions {
+  /**
+   * Fire a 'change' event if values are different to current values
+   */
+  allowChangeEvent?: boolean;
+}
+
+interface ApplyChangeOpts extends ChangeOptions {
+  panX?: number;
+  panY?: number;
+  scaleDiff?: number;
+  originX?: number;
+  originY?: number;
+}
+
+interface SetTransformOpts extends ChangeOptions {
+  scale?: number;
+  x?: number;
+  y?: number;
+}
+
+type ScaleRelativeToValues = 'container' | 'content';
+
+export interface ScaleToOpts extends ChangeOptions {
+  /** Transform origin. Can be a number, or string percent, eg "50%" */
+  originX?: number | string;
+  /** Transform origin. Can be a number, or string percent, eg "50%" */
+  originY?: number | string;
+  /** Should the transform origin be relative to the container, or content? */
+  relativeTo?: ScaleRelativeToValues;
+}
+
+function getDistance(a: Point, b?: Point): number {
+  if (!b) return 0;
+  return Math.sqrt((b.clientX - a.clientX) ** 2 + (b.clientY - a.clientY) ** 2);
+}
+
+function getMidpoint(a: Point, b?: Point): Point {
+  if (!b) return a;
+
+  return {
+    clientX: (a.clientX + b.clientX) / 2,
+    clientY: (a.clientY + b.clientY) / 2,
+  };
+}
+
+function getAbsoluteValue(value: string | number, max: number): number {
+  if (typeof value === 'number') return value;
+
+  if (value.trimRight().endsWith('%')) {
+    return max * parseFloat(value) / 100;
+  }
+  return parseFloat(value);
+}
+
+// I'd rather use DOMMatrix/DOMPoint here, but the browser support isn't good enough.
+// Given that, better to use something everything supports.
+let cachedSvg: SVGSVGElement;
+
+function getSVG(): SVGSVGElement {
+  return cachedSvg || (cachedSvg = document.createElementNS('http://www.w3.org/2000/svg', 'svg'));
+}
+
+function createMatrix(): SVGMatrix {
+  return getSVG().createSVGMatrix();
+}
+
+function createPoint(): SVGPoint {
+  return getSVG().createSVGPoint();
+}
+
+const MIN_SCALE = 0.01;
+
+export default class PinchZoom extends HTMLElement {
+  // The element that we'll transform.
+  // Ideally this would be shadow DOM, but we don't have the browser
+  // support yet.
+  private _positioningEl?: Element;
+  // Current transform.
+  private _transform: SVGMatrix = createMatrix();
+
+  constructor() {
+    super();
+
+    // Watch for children changes.
+    // Note this won't fire for initial contents,
+    // so _stageElChange is also called in connectedCallback.
+    new MutationObserver(() => this._stageElChange())
+      .observe(this, { childList: true });
+
+    // Watch for pointers
+    const pointerTracker: PointerTracker = new PointerTracker(this, {
+      start: (pointer, event) => {
+        // We only want to track 2 pointers at most
+        if (pointerTracker.currentPointers.length === 2 || !this._positioningEl) return false;
+        event.preventDefault();
+        return true;
+      },
+      move: (previousPointers) => {
+        this._onPointerMove(previousPointers, pointerTracker.currentPointers);
+      },
+    });
+
+    this.addEventListener('wheel', event => this._onWheel(event));
+  }
+
+  connectedCallback() {
+    this._stageElChange();
+  }
+
+  get x() {
+    return this._transform.e;
+  }
+
+  get y() {
+    return this._transform.f;
+  }
+
+  get scale() {
+    return this._transform.a;
+  }
+
+  /**
+   * Change the scale, adjusting x/y by a given transform origin.
+   */
+  scaleTo(scale: number, opts: ScaleToOpts = {}) {
+    let {
+      originX = 0,
+      originY = 0,
+    } = opts;
+
+    const {
+      relativeTo = 'content',
+      allowChangeEvent = false,
+    } = opts;
+
+    const relativeToEl = (relativeTo === 'content' ? this._positioningEl : this);
+
+    // No content element? Fall back to just setting scale
+    if (!relativeToEl || !this._positioningEl) {
+      this.setTransform({ scale, allowChangeEvent });
+      return;
+    }
+
+    const rect = relativeToEl.getBoundingClientRect();
+    originX = getAbsoluteValue(originX, rect.width);
+    originY = getAbsoluteValue(originY, rect.height);
+
+    if (relativeTo === 'content') {
+      originX += this.x;
+      originY += this.y;
+    } else {
+      const currentRect = this._positioningEl.getBoundingClientRect();
+      originX -= currentRect.left;
+      originY -= currentRect.top;
+    }
+
+    this._applyChange({
+      allowChangeEvent,
+      originX,
+      originY,
+      scaleDiff: scale / this.scale,
+    });
+  }
+
+  /**
+   * Update the stage with a given scale/x/y.
+   */
+  setTransform(opts: SetTransformOpts = {}) {
+    const {
+      scale = this.scale,
+      allowChangeEvent = false,
+    } = opts;
+
+    let {
+      x = this.x,
+      y = this.y,
+    } = opts;
+
+    // If we don't have an element to position, just set the value as given.
+    // We'll check bounds later.
+    if (!this._positioningEl) {
+      this._updateTransform(scale, x, y, allowChangeEvent);
+      return;
+    }
+
+    // Get current layout
+    const thisBounds = this.getBoundingClientRect();
+    const positioningElBounds = this._positioningEl.getBoundingClientRect();
+
+    // Not displayed. May be disconnected or display:none.
+    // Just take the values, and we'll check bounds later.
+    if (!thisBounds.width || !thisBounds.height) {
+      this._updateTransform(scale, x, y, allowChangeEvent);
+      return;
+    }
+
+    // Create points for _positioningEl.
+    let topLeft = createPoint();
+    topLeft.x = positioningElBounds.left - thisBounds.left;
+    topLeft.y = positioningElBounds.top - thisBounds.top;
+    let bottomRight = createPoint();
+    bottomRight.x = positioningElBounds.width + topLeft.x;
+    bottomRight.y = positioningElBounds.height + topLeft.y;
+
+    // Calculate the intended position of _positioningEl.
+    const matrix = createMatrix()
+      .translate(x, y)
+      .scale(scale)
+      // Undo current transform
+      .multiply(this._transform.inverse());
+
+    topLeft = topLeft.matrixTransform(matrix);
+    bottomRight = bottomRight.matrixTransform(matrix);
+
+    // Ensure _positioningEl can't move beyond out-of-bounds.
+    // Correct for x
+    if (topLeft.x > thisBounds.width) {
+      x += thisBounds.width - topLeft.x;
+    } else if (bottomRight.x < 0) {
+      x += -bottomRight.x;
+    }
+
+    // Correct for y
+    if (topLeft.y > thisBounds.height) {
+      y += thisBounds.height - topLeft.y;
+    } else if (bottomRight.y < 0) {
+      y += -bottomRight.y;
+    }
+
+    this._updateTransform(scale, x, y, allowChangeEvent);
+  }
+
+  /**
+   * Update transform values without checking bounds. This is only called in setTransform.
+   */
+  private _updateTransform(scale: number, x: number, y: number, allowChangeEvent: boolean) {
+    // Avoid scaling to zero
+    if (scale < MIN_SCALE) return;
+
+    // Return if there's no change
+    if (
+      scale === this.scale &&
+      x === this.x &&
+      y === this.y
+    ) return;
+
+    this._transform.e = x;
+    this._transform.f = y;
+    this._transform.d = this._transform.a = scale;
+
+    this.style.setProperty('--x', this.x + 'px');
+    this.style.setProperty('--y', this.y + 'px');
+    this.style.setProperty('--scale', this.scale + '');
+
+    if (allowChangeEvent) {
+      const event = new Event('change', { bubbles: true });
+      this.dispatchEvent(event);
+    }
+  }
+
+  /**
+   * Called when the direct children of this element change.
+   * Until we have have shadow dom support across the board, we
+   * require a single element to be the child of <pinch-zoom>, and
+   * that's the element we pan/scale.
+   */
+  private _stageElChange() {
+    this._positioningEl = undefined;
+
+    if (this.children.length === 0) return;
+
+    this._positioningEl = this.children[0];
+
+    if (this.children.length > 1) {
+      console.warn('<pinch-zoom> must not have more than one child.');
+    }
+
+    // Do a bounds check
+    this.setTransform({ allowChangeEvent: true });
+  }
+
+  private _onWheel(event: WheelEvent) {
+    if (!this._positioningEl) return;
+    event.preventDefault();
+
+    const currentRect = this._positioningEl.getBoundingClientRect();
+    let { deltaY } = event;
+    const { ctrlKey, deltaMode } = event;
+
+    if (deltaMode === 1) { // 1 is "lines", 0 is "pixels"
+      // Firefox uses "lines" for some types of mouse
+      deltaY *= 15;
+    }
+
+    // ctrlKey is true when pinch-zooming on a trackpad.
+    const divisor = ctrlKey ? 100 : 300;
+    const scaleDiff = 1 - deltaY / divisor;
+
+    this._applyChange({
+      scaleDiff,
+      originX: event.clientX - currentRect.left,
+      originY: event.clientY - currentRect.top,
+      allowChangeEvent: true,
+    });
+  }
+
+  private _onPointerMove(previousPointers: Pointer[], currentPointers: Pointer[]) {
+    if (!this._positioningEl) return;
+
+    // Combine next points with previous points
+    const currentRect = this._positioningEl.getBoundingClientRect();
+
+    // For calculating panning movement
+    const prevMidpoint = getMidpoint(previousPointers[0], previousPointers[1]);
+    const newMidpoint = getMidpoint(currentPointers[0], currentPointers[1]);
+
+    // Midpoint within the element
+    const originX = prevMidpoint.clientX - currentRect.left;
+    const originY = prevMidpoint.clientY - currentRect.top;
+
+    // Calculate the desired change in scale
+    const prevDistance = getDistance(previousPointers[0], previousPointers[1]);
+    const newDistance = getDistance(currentPointers[0], currentPointers[1]);
+    const scaleDiff = prevDistance ? newDistance / prevDistance : 1;
+
+    this._applyChange({
+      originX, originY, scaleDiff,
+      panX: newMidpoint.clientX - prevMidpoint.clientX,
+      panY: newMidpoint.clientY - prevMidpoint.clientY,
+      allowChangeEvent: true,
+    });
+  }
+
+  /** Transform the view & fire a change event */
+  private _applyChange(opts: ApplyChangeOpts = {}) {
+    const {
+      panX = 0, panY = 0,
+      originX = 0, originY = 0,
+      scaleDiff = 1,
+      allowChangeEvent = false,
+    } = opts;
+
+    const matrix = createMatrix()
+      // Translate according to panning.
+      .translate(panX, panY)
+      // Scale about the origin.
+      .translate(originX, originY)
+      // Apply current translate
+      .translate(this.x, this.y)
+      .scale(scaleDiff)
+      .translate(-originX, -originY)
+      // Apply current scale.
+      .scale(this.scale);
+
+    // Convert the transform into basic translate & scale.
+    this.setTransform({
+      allowChangeEvent,
+      scale: matrix.a,
+      x: matrix.e,
+      y: matrix.f,
+    });
+  }
+}
+
+customElements.define('pinch-zoom', PinchZoom);

src/components/Output/custom-els/PinchZoom/missing-types.d.ts

@@ -0,0 +1,16 @@
+declare interface CSSStyleDeclaration {
+  willChange: string | null;
+}
+
+// TypeScript, you make me sad.
+// https://github.com/Microsoft/TypeScript/issues/18756
+interface Window {
+  PointerEvent: typeof PointerEvent;
+  Touch: typeof Touch;
+}
+
+declare namespace JSX {
+  interface IntrinsicElements {
+    'pinch-zoom': HTMLAttributes;
+  }
+}

src/components/Output/custom-els/PinchZoom/styles.css

@@ -0,0 +1,14 @@
+pinch-zoom {
+  display: block;
+  overflow: hidden;
+  touch-action: none;
+  --scale: 1;
+  --x: 0;
+  --y: 0;
+}
+
+pinch-zoom > * {
+  transform: translate(var(--x), var(--y)) scale(var(--scale));
+  transform-origin: 0 0;
+  will-change: transform;
+}

src/components/Output/index.tsx

@@ -1,6 +1,6 @@
 import { h, Component } from 'preact';
-import PinchZoom, { ScaleToOpts } from 'pinch-zoom-element/lib';
-import 'pinch-zoom-element/lib';
+import PinchZoom, { ScaleToOpts } from './custom-els/PinchZoom';
+import './custom-els/PinchZoom';
 import './custom-els/TwoUp';
 import * as style from './style.scss';
 import { bind, linkRef } from '../../lib/initial-util';
@@ -48,6 +48,15 @@ export default class Output extends Component<Props, State> {
     const leftDraw = this.leftDrawable();
     const rightDraw = this.rightDrawable();
 
+    // Reset the pinch zoom, which may have an position set from the previous view, after pressing
+    // the back button.
+    this.pinchZoomLeft!.setTransform({
+      allowChangeEvent: true,
+      x: 0,
+      y: 0,
+      scale: 1,
+    });
+
     if (this.canvasLeft && leftDraw) {
       drawDataToCanvas(this.canvasLeft, leftDraw);
     }

src/components/Output/missing-types.d.ts

@@ -1,5 +0,0 @@
-declare namespace JSX {
-  interface IntrinsicElements {
-    'pinch-zoom': HTMLAttributes;
-  }
-}

src/components/intro/index.tsx

@@ -129,6 +129,11 @@ export default class Intro extends Component<Props, State> {
         <ul class={style.relatedLinks}>
           <li><a href="https://github.com/GoogleChromeLabs/squoosh/">View the code</a></li>
           <li><a href="https://github.com/GoogleChromeLabs/squoosh/issues">Report a bug</a></li>
+          <li>
+            <a href="https://github.com/GoogleChromeLabs/squoosh/blob/master/README.md#privacy">
+              Privacy
+            </a>
+          </li>
         </ul>
       </div>
     );

src/components/results/index.tsx

@@ -60,11 +60,16 @@ export default class Results extends Component<Props, State> {
 
   @bind
   onDownload() {
+    // GA can’t do floats. So we round to ints. We're deliberately rounding to nearest kilobyte to
+    // avoid cases where exact image sizes leak something interesting about the user.
+    const before = Math.round(this.props.source!.file.size / 1024);
+    const after = Math.round(this.props.imageFile!.size / 1024);
+    const change = Math.round(after / before * 1000);
+
     ga('send', 'event', 'compression', 'download', {
-      // GA can’t do floats. So we round to ints.
-      metric1: Math.floor(this.props.source!.file.size),
-      metric2: Math.floor(this.props.imageFile!.size),
-      metric3: Math.floor(this.props.imageFile!.size / this.props.source!.file.size * 1000),
+      metric1: before,
+      metric2: after,
+      metric3: change,
     });
   }
 

src/index.ts

@@ -13,11 +13,13 @@ if (!('customElements' in self)) {
   init();
 }
 
-window.ga = window.ga || ((...args) => (ga.q = ga.q || []).push(args));
-ga('create', 'UA-128752250-1', 'auto');
-ga('set', 'transport', 'beacon');
-ga('send', 'pageview');
-  // Load the GA script
-const s = document.createElement('script');
-s.src = 'https://www.google-analytics.com/analytics.js';
-document.head!.appendChild(s);
+if (typeof PRERENDER === 'undefined') {
+  window.ga = window.ga || ((...args) => (ga.q = ga.q || []).push(args));
+  ga('create', 'UA-128752250-1', 'auto');
+  ga('set', 'transport', 'beacon');
+  ga('send', 'pageview');
+    // Load the GA script
+  const s = document.createElement('script');
+  s.src = 'https://www.google-analytics.com/analytics.js';
+  document.head!.appendChild(s);
+}

webpack.config.js

@@ -141,8 +141,8 @@ module.exports = function (_, env) {
         },
         {
           test: /\.tsx?$/,
-          loader: 'ts-loader',
-          options: { allowTsInNodeModules: true }
+          exclude: nodeModules,
+          loader: 'ts-loader'
         },
         {
           // All the codec files define a global with the same name as their file name. `exports-loader` attaches those to `module.exports`.
@@ -226,7 +226,7 @@ module.exports = function (_, env) {
       // For now we're not doing SSR.
       new HtmlPlugin({
         filename: path.join(__dirname, 'build/index.html'),
-        template: '!!prerender-loader?string!src/index.html',
+        template: isProd ? '!!prerender-loader?string!src/index.html' : 'src/index.html',
         minify: isProd && {
           collapseWhitespace: true,
           removeScriptTypeAttributes: true,