abort transitions

src/generators/dom/Block.js

@@ -24,6 +24,7 @@ export default class Block {
 			create: new CodeBuilder(),
 			mount: new CodeBuilder(),
 			update: new CodeBuilder(),
+			intro: new CodeBuilder(),
 			outro: new CodeBuilder(),
 			detach: new CodeBuilder(),
 			detachRaw: new CodeBuilder(),
@@ -105,6 +106,12 @@ export default class Block {
 	}
 
 	render () {
+		let introing;
+		if ( this.hasIntroTransitions ) {
+			introing = this.getUniqueName( 'introing' );
+			this.addVariable( introing );
+		}
+
 		let outroing;
 		if ( this.hasOutroTransitions ) {
 			outroing = this.getUniqueName( 'outroing' );
@@ -168,6 +175,24 @@ export default class Block {
 			}
 		}
 
+		if ( this.hasIntroTransitions ) {
+			if ( this.builders.outro.isEmpty() ) {
+				properties.addBlock( `intro: ${this.generator.helper( 'noop' )},` );
+			} else {
+				properties.addBlock( deindent`
+					intro: function ( ${this.target}, anchor ) {
+						if ( ${introing} ) return;
+						${introing} = true;
+						${this.hasOutroTransitions && `${outroing} = false;`}
+
+						${this.builders.intro}
+
+						this.mount( ${this.target}, anchor );
+					},
+				` );
+			}
+		}
+
 		if ( this.hasOutroTransitions ) {
 			if ( this.builders.outro.isEmpty() ) {
 				properties.addBlock( `outro: ${this.generator.helper( 'noop' )},` );
@@ -176,6 +201,7 @@ export default class Block {
 					outro: function ( ${this.alias( 'outrocallback' )} ) {
 						if ( ${outroing} ) return;
 						${outroing} = true;
+						${this.hasIntroTransitions && `${introing} = false;`}
 
 						var ${this.alias( 'outros' )} = ${this.outros};
 

src/generators/dom/visitors/Element/addTransitions.js

@@ -17,7 +17,11 @@ export default function addTransitions ( generator, block, state, node, intro, o
 
 		const fn = `${generator.alias( 'template' )}.transitions.${intro.name}`; // TODO add built-in transitions?
 
-		block.builders.create.addBlock( deindent`
+		if ( outro ) {
+			block.builders.intro.addBlock( `if ( ${outroName} ) ${outroName}.abort();` );
+		}
+
+		block.builders.intro.addBlock( deindent`
 			${block.component}._renderHooks.push( function () {
 				${introName} = ${wrapTransition}( ${state.name}, ${fn}, ${introSnippet}, true, null, function () {
 					${block.component}.fire( 'intro.end', { node: ${state.name} });

src/generators/dom/visitors/IfBlock.js

@@ -10,6 +10,7 @@ function getBranches ( generator, block, state, node ) {
 		condition: block.contextualise( node.expression ).snippet,
 		block: node._block.name,
 		dynamic: node._block.dependencies.size > 0,
+		hasIntroTransitions: node._block.hasIntroTransitions,
 		hasOutroTransitions: node._block.hasOutroTransitions
 	}];
 
@@ -24,6 +25,7 @@ function getBranches ( generator, block, state, node ) {
 			condition: null,
 			block: node.else ? node.else._block.name : null,
 			dynamic: node.else ? node.else._block.dependencies.size > 0 : false,
+			hasIntroTransitions: node.else ? node.else._block.hasIntroTransitions : false,
 			hasOutroTransitions: node.else ? node.else._block.hasOutroTransitions : false
 		});
 
@@ -74,16 +76,17 @@ function simple ( generator, block, state, node, branch, dynamic, { name, anchor
 	` );
 
 	const isToplevel = !state.parentNode;
+	const mountOrIntro = branch.hasIntroTransitions ? 'intro' : 'mount';
 
 	if ( isToplevel ) {
-		block.builders.mount.addLine( `if ( ${name} ) ${name}.mount( ${block.target}, null );` );
+		block.builders.mount.addLine( `if ( ${name} ) ${name}.${mountOrIntro}( ${block.target}, null );` );
 	} else {
-		block.builders.create.addLine( `if ( ${name} ) ${name}.mount( ${state.parentNode}, null );` );
+		block.builders.create.addLine( `if ( ${name} ) ${name}.${mountOrIntro}( ${state.parentNode}, null );` );
 	}
 
 	const parentNode = state.parentNode || `${anchor}.parentNode`;
 
-	const remove = branch.hasOutroTransitions ?
+	const exit = branch.hasOutroTransitions ?
 		deindent`
 			${name}.outro( function () {
 				${name} = null;
@@ -95,6 +98,10 @@ function simple ( generator, block, state, node, branch, dynamic, { name, anchor
 		`;
 
 	if ( dynamic ) {
+		if ( branch.hasIntroTransitions ) {
+			throw new Error( 'TODO simple dynamic if-block with intro transitions' );
+		}
+
 		block.builders.update.addBlock( deindent`
 			if ( ${branch.condition} ) {
 				if ( ${name} ) {
@@ -104,18 +111,27 @@ function simple ( generator, block, state, node, branch, dynamic, { name, anchor
 					${name}.mount( ${parentNode}, ${anchor} );
 				}
 			} else if ( ${name} ) {
-				${remove}
+				${exit}
 			}
 		` );
 	} else {
-		block.builders.update.addBlock( deindent`
+		const enter = branch.hasIntroTransitions ?
-			if ( ${branch.condition} ) {
+			deindent`
+				if ( !${name} ) ${name} = ${branch.block}( ${params}, ${block.component} );
+				${name}.intro( ${parentNode}, ${anchor} );
+			` :
+			deindent`
 				if ( !${name} ) {
 					${name} = ${branch.block}( ${params}, ${block.component} );
 					${name}.mount( ${parentNode}, ${anchor} );
 				}
+			`;
+
+		block.builders.update.addBlock( deindent`
+			if ( ${branch.condition} ) {
+				${enter}
 			} else if ( ${name} ) {
-				${remove}
+				${exit}
 			}
 		` );
 	}

src/shared/transitions.js

@@ -27,7 +27,10 @@ export function wrapTransition ( node, fn, params, intro, outgroup, callback ) {
 				obj.tick( intro ? 1 : 0 );
 				callback();
 			},
-			abort: noop
+			abort: function () {
+				if ( !intro ) obj.tick( 1 ); // reset styles for intro
+				this.aborted = true;
+			}
 		};
 	} else {
 		// CSS transition
@@ -71,6 +74,7 @@ export function wrapTransition ( node, fn, params, intro, outgroup, callback ) {
 			},
 			abort: function () {
 				node.style.cssText = getComputedStyle( node ).cssText;
+				this.aborted = true;
 			}
 		};
 	}
@@ -105,12 +109,13 @@ export var transitionManager = {
 
 		while ( i-- ) {
 			var transition = transitionManager.transitions[i];
-			if ( now >= transition.end ) {
+
-				transition.done();
+			if ( now < transition.end && !transition.aborted ) {
-				transitionManager.transitions.splice( i, 1 );
-			} else {
 				if ( now > transition.start ) transition.update( now );
 				transitionManager.running = true;
+			} else {
+				if ( !transition.aborted ) transition.done();
+				transitionManager.transitions.splice( i, 1 );
 			}
 		}