[WIP] animations

src/compile/Compiler.ts

@@ -99,6 +99,7 @@ export default class Compiler {
 	components: Set<string>;
 	events: Set<string>;
 	methods: Set<string>;
+	animations: Set<string>;
 	transitions: Set<string>;
 	actions: Set<string>;
 	importedComponents: Map<string, string>;
@@ -149,6 +150,7 @@ export default class Compiler {
 		this.components = new Set();
 		this.events = new Set();
 		this.methods = new Set();
+		this.animations = new Set();
 		this.transitions = new Set();
 		this.actions = new Set();
 		this.importedComponents = new Map();
@@ -475,7 +477,7 @@ export default class Compiler {
 					templateProperties[getName(prop.key)] = prop;
 				});
 
-				['helpers', 'events', 'components', 'transitions', 'actions'].forEach(key => {
+				['helpers', 'events', 'components', 'transitions', 'actions', 'animations'].forEach(key => {
 					if (templateProperties[key]) {
 						templateProperties[key].value.properties.forEach((prop: Node) => {
 							this[key].add(getName(prop.key));
@@ -685,6 +687,12 @@ export default class Compiler {
 					});
 				}
 
+				if (templateProperties.animations) {
+					templateProperties.animations.value.properties.forEach((property: Node) => {
+						addDeclaration(getName(property.key), property.value, false, 'animations');
+					});
+				}
+
 				if (templateProperties.actions) {
 					templateProperties.actions.value.properties.forEach((property: Node) => {
 						addDeclaration(getName(property.key), property.value, false, 'actions');

src/compile/dom/Block.ts

@@ -40,6 +40,7 @@ export default class Block {
 	};
 
 	maintainContext: boolean;
+	animation?: string;
 	hasIntroMethod: boolean;
 	hasOutroMethod: boolean;
 	outros: number;
@@ -77,6 +78,7 @@ export default class Block {
 			destroy: new CodeBuilder(),
 		};
 
+		this.animation = null;
 		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;
@@ -127,6 +129,10 @@ export default class Block {
 		this.outros += 1;
 	}
 
+	addAnimation(name) {
+		this.animation = name;
+	}
+
 	addVariable(name: string, init?: string) {
 		if (this.variables.has(name) && this.variables.get(name) !== init) {
 			throw new Error(
@@ -183,6 +189,11 @@ 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 {

src/compile/nodes/Animation.ts

@@ -0,0 +1,18 @@
+import Node from './shared/Node';
+import Expression from './shared/Expression';
+
+export default class Animation extends Node {
+	type: 'Animation';
+	name: string;
+	expression: Expression;
+
+	constructor(compiler, parent, scope, info) {
+		super(compiler, parent, scope, info);
+
+		this.name = info.name;
+
+		this.expression = info.expression
+			? new Expression(compiler, this, scope, info.expression)
+			: null;
+	}
+}

src/compile/nodes/EachBlock.ts

@@ -315,10 +315,12 @@ export default class EachBlock extends Node {
 		const dynamic = this.block.hasUpdateMethod;
 
 		block.builders.update.addBlock(deindent`
-			var ${this.each_block_value} = ${snippet};
+			const ${this.each_block_value} = ${snippet};
 
 			${this.block.hasOutroMethod && `@transitionManager.groupOutros();`}
+			${this.block.animation && `const rects = @measure(${blocks});`}
 			${blocks} = @updateKeyedEach(${blocks}, #component, changed, ${get_key}, ${dynamic ? '1' : '0'}, ctx, ${this.each_block_value}, ${lookup}, ${updateMountNode}, ${String(this.block.hasOutroMethod)}, ${create_each_block}, "${mountOrIntro}", ${anchor}, ${this.get_each_context});
+			${this.block.animation && `@animate(${blocks}, rects, %animations-${this.children[0].animation.name}, {});`}
 		`);
 
 		if (this.compiler.options.nestedTransitions) {

src/compile/nodes/Element.ts

@@ -13,6 +13,7 @@ import Attribute from './Attribute';
 import Binding from './Binding';
 import EventHandler from './EventHandler';
 import Transition from './Transition';
+import Animation from './Animation';
 import Action from './Action';
 import Text from './Text';
 import * as namespaces from '../../utils/namespaces';
@@ -30,8 +31,9 @@ export default class Element extends Node {
 	actions: Action[];
 	bindings: Binding[];
 	handlers: EventHandler[];
-	intro: Transition;
-	outro: Transition;
+	intro?: Transition;
+	outro?: Transition;
+	animation?: Animation;
 	children: Node[];
 
 	ref: string;
@@ -54,6 +56,7 @@ export default class Element extends Node {
 
 		this.intro = null;
 		this.outro = null;
+		this.animation = null;
 
 		if (this.name === 'textarea') {
 			// this is an egregious hack, but it's the easiest way to get <textarea>
@@ -113,6 +116,10 @@ export default class Element extends Node {
 					if (node.outro) this.outro = transition;
 					break;
 
+				case 'Animation':
+					this.animation = new Animation(compiler, this, scope, node);
+					break;
+
 				case 'Ref':
 					// TODO catch this in validation
 					if (this.ref) throw new Error(`Duplicate refs`);
@@ -126,8 +133,6 @@ export default class Element extends Node {
 			}
 		});
 
-		// TODO break out attributes and directives here
-
 		this.children = mapChildren(compiler, this, scope, info.children);
 
 		compiler.stylesheet.apply(this);
@@ -142,6 +147,10 @@ export default class Element extends Node {
 			this.cannotUseInnerHTML();
 		}
 
+		this.var = block.getUniqueName(
+			this.name.replace(/[^a-zA-Z0-9_$]/g, '_')
+		);
+
 		this.attributes.forEach(attr => {
 			if (attr.dependencies.size) {
 				this.parent.cannotUseInnerHTML();
@@ -180,19 +189,13 @@ export default class Element extends Node {
 			block.addDependencies(handler.dependencies);
 		});
 
-		if (this.intro) {
-			this.parent.cannotUseInnerHTML();
-			block.addIntro();
-		}
-
-		if (this.outro) {
+		if (this.intro || this.outro || this.animation || this.ref) {
 			this.parent.cannotUseInnerHTML();
-			block.addOutro();
 		}
 
-		if (this.ref) {
-			this.parent.cannotUseInnerHTML();
-		}
+		if (this.intro) block.addIntro();
+		if (this.outro) block.addOutro();
+		if (this.animation) block.addAnimation(this.var);
 
 		const valueAttribute = this.attributes.find((attribute: Attribute) => attribute.name === 'value');
 
@@ -229,10 +232,6 @@ export default class Element extends Node {
 			component._slots.add(slot);
 		}
 
-		this.var = block.getUniqueName(
-			this.name.replace(/[^a-zA-Z0-9_$]/g, '_')
-		);
-
 		if (this.children.length) {
 			if (this.name === 'pre' || this.name === 'textarea') stripWhitespace = false;
 			this.initChildren(block, stripWhitespace, nextSibling);

src/parse/read/directives.ts

@@ -63,8 +63,17 @@ const DIRECTIVES: Record<string, {
 		error: 'Transition argument must be an object literal, e.g. `{ duration: 400 }`'
 	},
 
+	Animation: {
+		names: ['animate'],
+		attribute(start, end, type, name, expression) {
+			return { start, end, type, name, expression };
+		},
+		allowedExpressionTypes: ['ObjectExpression'],
+		error: 'Animation argument must be an object literal, e.g. `{ duration: 400 }`'
+	},
+
 	Action: {
-		names: [ 'use' ],
+		names: ['use'],
 		attribute(start, end, type, name, expression) {
 			return { start, end, type, name, expression };
 		},

src/shared/keyed-each.js

@@ -1,3 +1,5 @@
+import { transitionManager, linear, generateRule, hash } from './transitions';
+
 export function destroyBlock(block, lookup) {
 	block.d(1);
 	lookup[block.key] = null;
@@ -95,4 +97,87 @@ export function updateKeyedEach(old_blocks, component, changed, get_key, dynamic
 	while (n) insert(new_blocks[n - 1]);
 
 	return new_blocks;
+}
+
+export function measure(blocks) {
+	const measurements = {};
+	let i = blocks.length;
+	while (i--) measurements[blocks[i].key] = blocks[i].node.getBoundingClientRect();
+	return measurements;
+}
+
+export function animate(blocks, rects, fn, params) {
+	let i = blocks.length;
+	while (i--) {
+		const block = blocks[i];
+		const from = rects[block.key];
+
+		if (!from) continue;
+		const to = block.node.getBoundingClientRect();
+
+		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();
+	}
 }

src/validate/html/validateElement.ts

@@ -78,6 +78,7 @@ export default function validateElement(
 	let hasIntro: boolean;
 	let hasOutro: boolean;
 	let hasTransition: boolean;
+	let hasAnimation: boolean;
 
 	node.attributes.forEach((attribute: Node) => {
 		if (attribute.type === 'Ref') {
@@ -228,6 +229,40 @@ export default function validateElement(
 					message: `Missing transition '${attribute.name}'`
 				});
 			}
+		} else if (attribute.type === 'Animation') {
+			validator.used.animations.add(attribute.name);
+
+			if (hasAnimation) {
+				validator.error(attribute, {
+					code: `duplicate-animation`,
+					message: `An element can only have one 'animate' directive`
+				});
+			}
+
+			if (!validator.animations.has(attribute.name)) {
+				validator.error(attribute, {
+					code: `missing-animation`,
+					message: `Missing animation '${attribute.name}'`
+				});
+			}
+
+			const parent = stack[stack.length - 1];
+			if (!parent || parent.type !== 'EachBlock' || !parent.key) {
+				// TODO can we relax the 'immediate child' rule?
+				validator.error(attribute, {
+					code: `invalid-animation`,
+					message: `An element that use the animate directive must be the immediate child of a keyed each block`
+				});
+			}
+
+			if (parent.children.length > 1) {
+				validator.error(attribute, {
+					code: `invalid-animation`,
+					message: `An element that use the animate directive must be the sole child of a keyed each block`
+				});
+			}
+
+			hasAnimation = true;
 		} else if (attribute.type === 'Attribute') {
 			if (attribute.name === 'value' && node.name === 'textarea') {
 				if (node.children.length) {

src/validate/index.ts

@@ -21,6 +21,7 @@ export class Validator {
 	components: Map<string, Node>;
 	methods: Map<string, Node>;
 	helpers: Map<string, Node>;
+	animations: Map<string, Node>;
 	transitions: Map<string, Node>;
 	actions: Map<string, Node>;
 	slots: Set<string>;
@@ -29,6 +30,7 @@ export class Validator {
 		components: Set<string>;
 		helpers: Set<string>;
 		events: Set<string>;
+		animations: Set<string>;
 		transitions: Set<string>;
 		actions: Set<string>;
 	};
@@ -47,6 +49,7 @@ export class Validator {
 		this.components = new Map();
 		this.methods = new Map();
 		this.helpers = new Map();
+		this.animations = new Map();
 		this.transitions = new Map();
 		this.actions = new Map();
 		this.slots = new Set();
@@ -55,6 +58,7 @@ export class Validator {
 			components: new Set(),
 			helpers: new Set(),
 			events: new Set(),
+			animations: new Set(),
 			transitions: new Set(),
 			actions: new Set(),
 		};