allow animations to be aborted

src/compile/dom/Block.ts

@@ -33,14 +33,17 @@ export default class Block {
 		claim: CodeBuilder;
 		hydrate: CodeBuilder;
 		mount: CodeBuilder;
+		measure: CodeBuilder;
+		fix: CodeBuilder;
+		animate: CodeBuilder;
 		intro: CodeBuilder;
 		update: CodeBuilder;
 		outro: CodeBuilder;
 		destroy: CodeBuilder;
 	};
 
 	maintainContext: boolean;
-	animation?: string;
+	hasAnimation: boolean;
 	hasIntroMethod: boolean;
 	hasOutroMethod: boolean;
 	outros: number;
@@ -72,13 +75,16 @@ export default class Block {
 			claim: new CodeBuilder(),
 			hydrate: new CodeBuilder(),
 			mount: new CodeBuilder(),
+			measure: new CodeBuilder(),
+			fix: new CodeBuilder(),
+			animate: new CodeBuilder(),
 			intro: new CodeBuilder(),
 			update: new CodeBuilder(),
 			outro: new CodeBuilder(),
 			destroy: new CodeBuilder(),
 		};
 
-		this.animation = null;
+		this.hasAnimation = false;
 		this.hasIntroMethod = false; // a block could have an intro method but not intro transitions, e.g. if a sibling block has intros
 		this.hasOutroMethod = false;
 		this.outros = 0;
@@ -129,8 +135,8 @@ export default class Block {
 		this.outros += 1;
 	}
 
-	addAnimation(name) {
-		this.animation = name;
+	addAnimation() {
+		this.hasAnimation = true;
 	}
 
 	addVariable(name: string, init?: string) {
@@ -189,11 +195,6 @@ export default class Block {
 			this.builders.hydrate.addLine(`this.first = ${this.first};`);
 		}
 
-		if (this.animation) {
-			properties.addBlock(`node: null,`);
-			this.builders.hydrate.addLine(`this.node = ${this.animation};`);
-		}
-
 		if (this.builders.create.isEmpty() && this.builders.hydrate.isEmpty()) {
 			properties.addBlock(`c: @noop,`);
 		} else {
@@ -255,6 +256,22 @@ export default class Block {
 			}
 		}
 
+		if (this.hasAnimation) {
+			properties.addBlock(deindent`
+				${dev ? `r: function measure` : `r`}() {
+					${this.builders.measure}
+				},
+
+				${dev ? `f: function fix` : `f`}() {
+					${this.builders.fix}
+				},
+
+				${dev ? `a: function animate` : `a`}() {
+					${this.builders.animate}
+				},
+			`);
+		}
+
 		if (this.hasIntroMethod || this.hasOutroMethod) {
 			if (hasIntros) {
 				properties.addBlock(deindent`

src/compile/nodes/Animation.ts

@@ -1,3 +1,4 @@
+import Block from '../dom/Block';
 import Node from './shared/Node';
 import Expression from './shared/Expression';
 
@@ -15,4 +16,12 @@ export default class Animation extends Node {
 			? new Expression(compiler, this, scope, info.expression)
 			: null;
 	}
+
+	build(
+		block: Block,
+		parentNode: string,
+		parentNodes: string
+	) {
+
+	}
 }

src/compile/nodes/EachBlock.ts

@@ -315,7 +315,7 @@ export default class EachBlock extends Node {
 		const dynamic = this.block.hasUpdateMethod;
 
 		const rects = block.getUniqueName('rects');
-		const destroy = this.block.animation
+		const destroy = this.block.hasAnimation
 			? `@fixAndOutroAndDestroyBlock`
 			: this.block.hasOutroMethod
 				? `@outroAndDestroyBlock`
@@ -325,9 +325,9 @@ export default class EachBlock extends Node {
 			const ${this.each_block_value} = ${snippet};
 
 			${this.block.hasOutroMethod && `@transitionManager.groupOutros();`}
-			${this.block.animation && `const ${rects} = @measure(${blocks});`}
+			${this.block.hasAnimation && `for (let #i = 0; #i < ${blocks}.length; #i += 1) ${blocks}[#i].r();`}
 			${blocks} = @updateKeyedEach(${blocks}, #component, changed, ${get_key}, ${dynamic ? '1' : '0'}, ctx, ${this.each_block_value}, ${lookup}, ${updateMountNode}, ${destroy}, ${create_each_block}, "${mountOrIntro}", ${anchor}, ${this.get_each_context});
-			${this.block.animation && `@animate(${blocks}, ${rects}, %animations-${this.children[0].animation.name}, {});`}
+			${this.block.hasAnimation && `for (let #i = 0; #i < ${blocks}.length; #i += 1) ${blocks}[#i].a();`}
 		`);
 
 		if (this.compiler.options.nestedTransitions) {

src/compile/nodes/Element.ts

@@ -195,7 +195,7 @@ export default class Element extends Node {
 
 		if (this.intro) block.addIntro();
 		if (this.outro) block.addOutro();
-		if (this.animation) block.addAnimation(this.var);
+		if (this.animation) block.addAnimation();
 
 		const valueAttribute = this.attributes.find((attribute: Attribute) => attribute.name === 'value');
 
@@ -367,6 +367,7 @@ export default class Element extends Node {
 		if (this.ref) this.addRef(block);
 		this.addAttributes(block);
 		this.addTransitions(block);
+		this.addAnimation(block);
 		this.addActions(block);
 
 		if (this.initialUpdate) {
@@ -763,6 +764,31 @@ export default class Element extends Node {
 		}
 	}
 
+	addAnimation(block: Block) {
+		if (!this.animation) return;
+
+		const rect = block.getUniqueName('rect');
+		const animation = block.getUniqueName('animation');
+
+		block.addVariable(rect);
+		block.addVariable(animation);
+
+		block.builders.measure.addBlock(deindent`
+			${rect} = ${this.var}.getBoundingClientRect();
+		`);
+
+		block.builders.fix.addBlock(deindent`
+			@fixPosition(${this.var});
+			if (${animation}) ${animation}.stop();
+		`);
+
+		const params = this.animation.expression ? this.animation.expression.snippet : '{}';
+		block.builders.animate.addBlock(deindent`
+			if (${animation}) ${animation}.stop();
+			${animation} = @wrapAnimation(${this.var}, ${rect}, %animations-${this.animation.name}, ${params});
+		`);
+	}
+
 	addActions(block: Block) {
 		this.actions.forEach(action => {
 			const { expression } = action;

src/shared/animations.js

@@ -0,0 +1,102 @@
+import { transitionManager, linear, generateRule, hash } from './transitions.js';
+
+export function wrapAnimation(node, from, fn, params) {
+	if (!from) return;
+
+	const to = node.getBoundingClientRect();
+	if (from.left === to.left && from.right === to.right && from.top === to.top && from.bottom === to.bottom) return;
+
+	const info = fn(node, { from, to }, params);
+
+	const duration = 'duration' in info ? info.duration : 300;
+	const delay = 'delay' in info ? info.delay : 0;
+	const ease = info.easing || linear;
+	const start = window.performance.now() + delay;
+	const end = start + duration;
+
+	const program = {
+		a: 0,
+		t: 0,
+		b: 1,
+		delta: 1,
+		duration,
+		start,
+		end
+	};
+
+	const cssText = node.style.cssText;
+
+	const animation = {
+		pending: delay ? program : null,
+		program: delay ? null : program,
+		running: true,
+
+		start() {
+			if (info.css) {
+				if (delay) node.style.cssText = cssText;
+
+				const rule = generateRule(program, ease, info.css);
+				program.name = `__svelte_${hash(rule)}`;
+
+				transitionManager.addRule(rule, program.name);
+
+				node.style.animation = (node.style.animation || '')
+					.split(', ')
+					.filter(anim => anim && (program.delta < 0 || !/__svelte/.test(anim)))
+					.concat(`${program.name} ${program.duration}ms linear 1 forwards`)
+					.join(', ');
+			}
+
+			animation.program = program;
+			animation.pending = null;
+		},
+
+		update: now => {
+			const p = now - program.start;
+			const t = program.a + program.delta * ease(p / program.duration);
+			if (info.tick) info.tick(t, 1 - t);
+		},
+
+		done() {
+			if (info.tick) info.tick(1, 0);
+			animation.stop();
+		},
+
+		stop() {
+			if (info.css) transitionManager.deleteRule(node, program.name);
+			animation.running = false;
+		}
+	};
+
+	transitionManager.add(animation);
+
+	if (info.tick) info.tick(0, 1);
+
+	if (delay) {
+		if (info.css) node.style.cssText += info.css(0, 1);
+	} else {
+		animation.start();
+	}
+
+	return animation;
+}
+
+export function fixPosition(node) {
+	const style = getComputedStyle(node);
+
+	if (style.position !== 'absolute' && style.position !== 'fixed') {
+		const { width, height } = style;
+		const a = node.getBoundingClientRect();
+		node.style.position = 'absolute';
+		node.style.width = width;
+		node.style.height = height;
+		const b = node.getBoundingClientRect();
+
+		if (a.left !== b.left || a.top !== b.top) {
+			const style = getComputedStyle(node);
+			const transform = style.transform === 'none' ? '' : style.transform;
+
+			node.style.transform = `${transform} translate(${a.left - b.left}px, ${a.top - b.top}px)`;
+		}
+	}
+}

src/shared/index.js

@@ -1,5 +1,6 @@
 import { assign } from './utils.js';
 import { noop } from './utils.js';
+export * from './animations.js';
 export * from './await-block.js';
 export * from './dom.js';
 export * from './keyed-each.js';

src/shared/keyed-each.js

@@ -12,25 +12,7 @@ export function outroAndDestroyBlock(block, lookup) {
 }
 
 export function fixAndOutroAndDestroyBlock(block, lookup) {
-	const { node } = block;
-	const style = getComputedStyle(node);
-
-	if (style.position !== 'absolute' && style.position !== 'fixed') {
-		const { width, height } = style;
-		const a = node.getBoundingClientRect();
-		node.style.position = 'absolute';
-		node.style.width = width;
-		node.style.height = height;
-		const b = node.getBoundingClientRect();
-
-		if (a.left !== b.left || a.top !== b.top) {
-			const style = getComputedStyle(node);
-			const transform = style.transform === 'none' ? '' : style.transform;
-
-			node.style.transform = `${transform} translate(${a.left - b.left}px, ${a.top - b.top}px)`;
-		}
-	}
-
+	block.f();
 	outroAndDestroyBlock(block, lookup);
 }
 
@@ -121,10 +103,10 @@ export function updateKeyedEach(old_blocks, component, changed, get_key, dynamic
 }
 
 export function measure(blocks) {
-	const measurements = {};
+	const rects = {};
 	let i = blocks.length;
-	while (i--) measurements[blocks[i].key] = blocks[i].node.getBoundingClientRect();
-	return measurements;
+	while (i--) rects[blocks[i].key] = blocks[i].node.getBoundingClientRect();
+	return rects;
 }
 
 export function animate(blocks, rects, fn, params) {
@@ -138,67 +120,6 @@ export function animate(blocks, rects, fn, params) {
 
 		if (from.left === to.left && from.right === to.right && from.top === to.top && from.bottom === to.bottom) continue;
 
-		const info = fn(block.node, { from, to }, params);
-
-		const duration = 'duration' in info ? info.duration : 300;
-		const delay = 'delay' in info ? info.delay : 0;
-		const ease = info.easing || linear;
-		const start = window.performance.now() + delay;
-		const end = start + duration;
-
-		const program = {
-			a: 0,
-			t: 0,
-			b: 1,
-			delta: 1,
-			duration,
-			start,
-			end
-		};
-
-		const animation = {
-			pending: delay ? program : null,
-			program: delay ? null : program,
-			running: !delay,
-
-			start() {
-				if (info.css) {
-					const rule = generateRule(program, ease, info.css);
-					program.name = `__svelte_${hash(rule)}`;
-
-					transitionManager.addRule(rule, program.name);
-
-					block.node.style.animation = (block.node.style.animation || '')
-						.split(', ')
-						.filter(anim => anim && (program.delta < 0 || !/__svelte/.test(anim)))
-						.concat(`${program.name} ${program.duration}ms linear 1 forwards`)
-						.join(', ');
-				}
-			},
-
-			update: now => {
-				const p = now - program.start;
-				const t = program.a + program.delta * ease(p / program.duration);
-				if (info.tick) info.tick(t, 1 - t);
-			},
-
-			done() {
-				if (info.css) {
-					transitionManager.deleteRule(block.node, program.name);
-				}
-
-				if (info.tick) {
-					info.tick(1, 0);
-				}
-
-				animation.running = false;
-			}
-		};
-
-		transitionManager.add(animation);
-
-		if (info.tick) info.tick(0, 1);
-
-		if (!delay) animation.start();
+
 	}
 }