Houdini Breakout Session

Chrome Dev Summit 2016

Transcript

1. Houdini
2. Houdini
3. Typed Object Model
4. Typed Object Model $('#element').styleMap .set('opacity', new CSSNumberValue(0.5)); $('#element').styleMap .set('height', new CSSSimpleLength(50, 'px'));
5. Typed Object Model $('#element').styleMap .set('height', new CSSSimpleLength(50, 'px')); $('#element').styleMap .get('height').value; // 50 $('#element').styleMap .get('height').type; // ‘px’
6. Typed Object Model $('#element').styleMap .set('height', new CSSCalcLength('50vh - 20px')); $('#element').styleMap.get('height').vh; // 50 $('#element').styleMap.get('height').px; // -20
7. Typed Object Model $('#element').styleMap .set("height", new CSSCalcLength({ vh: 50, px: -20, }));
8. Typed Object Model const h = new CSSSimpleLength(50, 'vh') .subtract(new CSSSimpleLength(20, ‘px')); $('#element').styleMap.set('height', h);
9. Typed Object Model const h = new CSSSimpleLength(50, 'vh') .subtract(new CSSSimpleLength(20, ‘px')); $('#element').styleMap.set('height', h); // h == calc(50vh - 20px);
11. Houdini
12. Houdini X AnimationWorklet
13. Animation Worklet
16. bit.ly/best-effort-scroll position: static;
17. bit.ly/best-effort-scroll position: static; position: fixed; + JS transform
18. Animation Worklet <style> :root { animator-root: parallax; } .bg { animator: parallax; } </style> <div class='bg' style='--parallax-rate: 0.2'></div> <div class='bg' style='--parallax-rate: 0.5'></div> Experimental
19. Animation Worklet registerAnimator('parallax', class ParallaxAnimator { static inputProperties = ['transform', '--parallax-rate']; static outputProperties = ['transform']; static rootInputScroll = true; animate(root, children) { const scrollTop = root.scrollOffsets.top; children.forEach(background => parallaxMath(elem, background.styleMap.get('--parallax-rate'))); } }); Experimental
21. Houdini
22. Paint Worklet
23. Paint Worklet <div id="myElement"></div> <style> #myElement { --image: url('#someUrlWhichIsLoading'); background-image: paint(image-with-placeholder); } </style> Experimental
24. Paint Worklet <script> document.registerProperty({ name: '--image', syntax: '<image>' }); window.paintWorklet.import('paintworklet.js'); </script> Experimental
25. Paint Worklet registerPaint('image-with-placeholder', class { static get inputProperties() { return ['--image']; } paint(ctx, geom, properties) { // ... } }); Experimental
26. Paint Worklet paint(ctx, geom, properties) { const img = properties.get('--image'); switch (img.state) { case 'ready': ctx.drawImage(img, 0, 0, geom.width, geom.height); break; case 'pending': drawMountains(ctx); break; case 'invalid': default: drawSadFace(ctx); } } Experimental
28. bit.ly/houdini-updates