<script>
  import { fade } from 'svelte/transition';
  let visible = true;
</script>

<label>
  <input type="checkbox" bind:checked={visible}>
  visible
</label>

{#if visible}
  <p transition:fade>
    Fades in and out
  </p>
{/if}

<script>
  import { fly } from 'svelte/transition';
  let visible = true;
</script>

<label>
  <input type="checkbox" bind:checked={visible}>
  visible
</label>

{#if visible}
  <p transition:fly="{{ y: 200, duration: 2000 }}">
    Flies in and out
  </p>
{/if}

<script>
import { quintOut } from 'svelte/easing';
import { crossfade } from 'svelte/transition';

const [send, receive] = crossfade({
  duration: d => Math.sqrt(d * 200),

  fallback(node, params) {
    const style = getComputedStyle(node);
    const transform = style.transform === 'none' ? '' : style.transform;

    return {
      duration: 600,
      easing: quintOut,
      css: t => `
        transform: ${transform} scale(${t});
        opacity: ${t}
      `
    };
  }
});

let uid = 1;

let todos = [
  { id: uid++, done: false, description: 'write some docs' },
  { id: uid++, done: false, description: 'start writing blog post' },
  { id: uid++, done: true,  description: 'buy some milk' },
];

function add(input) {
  const todo = {
    id: uid++,
    done: false,
    description: input.value
  };

  todos = [todo, ...todos];
  input.value = '';
}

function remove(todo) {
  todos = todos.filter(t => t !== todo);
}

function mark(todo, done) {
  todo.done = done;
  remove(todo);
  todos = todos.concat(todo);
}
</script>

<div class='board'>
<input
  placeholder="what needs to be done?"
  on:keydown={e => e.which === 13 && add(e.target)}
>

<div class='left'>
  <h2>todo</h2>
  {#each todos.filter(t => !t.done) as todo (todo.id)}
    <label
      in:receive="{{key: todo.id}}"
      out:send="{{key: todo.id}}"
    >
      <input type=checkbox on:change={() => mark(todo, true)}>
      {todo.description}
      <button on:click="{() => remove(todo)}">remove</button>
    </label>
  {/each}
</div>

<div class='right'>
  <h2>done</h2>
  {#each todos.filter(t => t.done) as todo (todo.id)}
    <label
      class="done"
      in:receive="{{key: todo.id}}"
      out:send="{{key: todo.id}}"
    >
      <input type=checkbox checked on:change={() => mark(todo, false)}>
      {todo.description}
      <button on:click="{() => remove(todo)}">remove</button>
    </label>
  {/each}
</div>
</div>

<style>
.board {
  display: grid;
  grid-template-columns: 1fr 1fr;
  grid-gap: 1em;
  max-width: 36em;
  margin: 0 auto;
}

.board > input {
  font-size: 1.4em;
  grid-column: 1/3;
}

h2 {
  font-size: 2em;
  font-weight: 200;
  user-select: none;
  margin: 0 0 0.5em 0;
}

label {
  position: relative;
  line-height: 1.2;
  padding: 0.5em 2.5em 0.5em 2em;
  margin: 0 0 0.5em 0;
  border-radius: 2px;
  user-select: none;
  border: 1px solid hsl(240, 8%, 70%);
  background-color:hsl(240, 8%, 93%);
  color: #333;
}

input[type="checkbox"] {
  position: absolute;
  left: 0.5em;
  top: 0.6em;
  margin: 0;
}

.done {
  border: 1px solid hsl(240, 8%, 90%);
  background-color:hsl(240, 8%, 98%);
}

button {
  position: absolute;
  top: 0;
  right: 0.2em;
  width: 2em;
  height: 100%;
  background: no-repeat 50% 50% url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'%3E%3Cpath fill='%23676778' d='M12,2C17.53,2 22,6.47 22,12C22,17.53 17.53,22 12,22C6.47,22 2,17.53 2,12C2,6.47 6.47,2 12,2M17,7H14.5L13.5,6H10.5L9.5,7H7V9H17V7M9,18H15A1,1 0 0,0 16,17V10H8V17A1,1 0 0,0 9,18Z'%3E%3C/path%3E%3C/svg%3E");
  background-size: 1.4em 1.4em;
  border: none;
  opacity: 0;
  transition: opacity 0.2s;
  text-indent: -9999px;
  cursor: pointer;
}

label:hover button {
  opacity: 1;
}
</style>

<script>
  import { fade, fly } from 'svelte/transition';
  let visible = true;
</script>

<label>
  <input type="checkbox" bind:checked={visible}>
  visible
</label>

{#if visible}
  <p in:fly="{{ y: 200, duration: 2000 }}" out:fade>
    Flies in, fades out
  </p>
{/if}

function fade(node, {
  delay = 0,
  duration = 400
}) {
  const o = +getComputedStyle(node).opacity;

  return {
    delay,
    duration,
    css: t => `opacity: ${t * o}`
  };
}

transition = (node: HTMLElement, params: any) => {
  delay?: number,
  duration?: number,
  easing?: (t: number) => number,
  css?: (t: number, u: number) => string,
  tick?: (t: number, u: number) => void
}

<script>
  import { fade } from 'svelte/transition';
  import { elasticOut } from 'svelte/easing';

  let visible = true;

  function spin(node, { duration }) {
    return {
      duration,
      css: t => {
        const eased = elasticOut(t);

        return `
          transform: scale(${eased}) rotate(${eased * 1080}deg);
          color: hsl(
            ${~~(t * 360)},
            ${Math.min(100, 1000 - 1000 * t)}%,
            ${Math.min(50, 500 - 500 * t)}%
          );`
      }
    };
  }
</script>

<style>
  .centered {
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%,-50%);
  }

  span {
    position: absolute;
    transform: translate(-50%,-50%);
    font-size: 4em;
  }
</style>

<label>
  <input type="checkbox" bind:checked={visible}>
  visible
</label>

{#if visible}
  <div class="centered" in:spin="{{duration: 8000}}" out:fade>
    <span>transitions!</span>
  </div>
{/if}

<script>
  let visible = false;

  function typewriter(node, { speed = 50 }) {
    const valid = (
      node.childNodes.length === 1 &&
      node.childNodes[0].nodeType === 3
    );

    if (!valid) {
      throw new Error(`This transition only works on elements with a single text node child`);
    }

    const text = node.textContent;
    const duration = text.length * speed;

    return {
      duration,
      tick: t => {
        const i = ~~(text.length * t);
        node.textContent = text.slice(0, i);
      }
    };
  }
</script>

<label>
  <input type="checkbox" bind:checked={visible}>
  visible
</label>

{#if visible}
  <p in:typewriter>
    The quick brown fox jumps over the lazy dog
  </p>
{/if}

<script>
  import { fly } from 'svelte/transition';

  let visible = true;
  let status = 'waiting...';
</script>

<p>status: {status}</p>

<label>
  <input type="checkbox" bind:checked={visible}>
  visible
</label>

{#if visible}
  <p
    transition:fly="{{ y: 200, duration: 2000 }}"
    on:introstart="{() => status = 'intro started'}"
    on:outrostart="{() => status = 'outro started'}"
    on:introend="{() => status = 'intro ended'}"
    on:outroend="{() => status = 'outro ended'}"
  >
    Flies in and out
  </p>
{/if}

<script>
  import { slide } from 'svelte/transition';

  let showItems = true;
  let i = 5;
  let items = ['one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight', 'nine', 'ten'];
</script>

<style>
  div {
    padding: 0.5em 0;
    border-top: 1px solid #eee;
  }
</style>

<label>
  <input type="checkbox" bind:checked={showItems}>
  show list
</label>

<label>
  <input type="range" bind:value={i} max=10>
</label>

{#if showItems}
  {#each items.slice(0, i) as item}
    <div transition:slide|local>
      {item}
    </div>
  {/each}
{/if}