From ce021e521f580caca6580fbf56caca5b79b555ca Mon Sep 17 00:00:00 2001
From: Donal Linehan <donalin@gmail.com>
Date: Thu, 4 Jul 2024 18:27:48 +0100
Subject: [PATCH] Add animation queue

---
 README.md              | 53 +++++++++++++++++++++++++++
 src/__tests__/queue.ts | 81 ++++++++++++++++++++++++++++++++++++++++++
 src/queue.ts           | 51 ++++++++++++++++++++++++++
 3 files changed, 185 insertions(+)
 create mode 100644 src/__tests__/queue.ts
 create mode 100644 src/queue.ts

diff --git a/README.md b/README.md
index 7d004b8..64bdd54 100644
--- a/README.md
+++ b/README.md
@@ -119,6 +119,40 @@ parallelSequence
 parallelSequence.start();
 ```
 
+### Queue of Animations
+
+```javascript
+import { Animate, Queue, Easing } from 'nimate';
+
+// Create individual animations
+const animate1 = new Animate({
+  from: { x: 0, y: 0 },
+  to: { x: 100, y: 50 },
+  duration: 1000,
+  easing: Easing.easeInOutQuad,
+});
+
+const animate2 = new Animate({
+  from: { x: 100, y: 50 },
+  to: { x: 200, y: 100 },
+  duration: 1000,
+  easing: Easing.easeInOutQuad,
+});
+
+// Create a queue and add animations
+const queue = new Queue();
+queue.add(animate1);
+queue.add(animate2);
+
+// Attach event listeners
+queue
+  .on('start', (animation) => console.log('Queue Animation Start', animation))
+  .on('update', (value, animation) => console.log('Queue Animation Update:', value, animation))
+  .on('complete', (animation) => console.log('Queue Animation Complete', animation))
+  .on('stop', (animation) => console.log('Queue Animation Stop', animation))
+  .on('complete', () => console.log('All animations in the queue are complete'));
+```
+
 ## 📚 API
 
 ### `Animate`
@@ -167,3 +201,22 @@ Creates a sequence of animations.
 - `update`: Emitted on each update with the current value.
 - `complete`: Emitted when the sequence completes.
 - `stop`: Emitted when the sequence is stopped.
+
+### `Queue`
+
+Creates a queue of animations that are executed sequentially.
+
+#### Methods
+
+- `add(animation: Animate)`: Adds an `Animate` instance to the queue.
+- `clear()`: Clears the queue and stops any currently running animation.
+- `stop()`: Stops the currently running animation without clearing the queue.
+
+#### Events
+
+- `start`: Emitted when an animation in the queue starts.
+- `update`: Emitted on each update with the current value and animation.
+- `complete`: Emitted when an animation in the queue completes.
+- `stop`: Emitted when an animation in the queue is stopped.
+- `complete`: Emitted when all animations in the queue are complete.
+```
diff --git a/src/__tests__/queue.ts b/src/__tests__/queue.ts
new file mode 100644
index 0000000..ceb7f74
--- /dev/null
+++ b/src/__tests__/queue.ts
@@ -0,0 +1,81 @@
+import { Animate } from '../animate';
+import { Queue } from '../queue';
+import { easing as e } from '../easing';
+
+describe('Queue', () => {
+  it('should add animations to the queue and start the first one immediately', done => {
+    const animate1 = new Animate({
+      from: 0,
+      to: 100,
+      duration: 50,
+      easing: e.linear,
+    });
+
+    const animate2 = new Animate({
+      from: 0,
+      to: 100,
+      duration: 50,
+      easing: e.linear,
+    });
+
+    const queue = new Queue();
+
+    queue.add(animate1);
+    queue.add(animate2);
+
+    let completeCount = 0;
+
+    queue.on('complete', () => {
+      completeCount++;
+      if (completeCount === 2) {
+        expect(completeCount).toBe(2);
+        done();
+      }
+    });
+  });
+
+  it('should handle stop correctly', done => {
+    const animate1 = new Animate({
+      from: 0,
+      to: 100,
+      duration: 50,
+      easing: e.linear,
+    });
+
+    animate1.on('stop', () => {
+      done();
+    });
+
+    const queue = new Queue();
+
+    queue.add(animate1);
+
+    queue.stop();
+  });
+
+  it('should clear the queue and stop the current animation', done => {
+    const animate1 = new Animate({
+      from: 0,
+      to: 100,
+      duration: 100,
+      easing: e.linear,
+    });
+
+    const animate2 = new Animate({
+      from: 0,
+      to: 100,
+      duration: 100,
+      easing: e.linear,
+    });
+
+    const queue = new Queue();
+
+    queue.add(animate1);
+    queue.add(animate2);
+
+    queue.clear();
+
+    expect(queue['animations'].length).toBe(0);
+    done();
+  });
+});
diff --git a/src/queue.ts b/src/queue.ts
new file mode 100644
index 0000000..a26cb22
--- /dev/null
+++ b/src/queue.ts
@@ -0,0 +1,51 @@
+import EventEmitter from 'eventemitter3';
+import { Animate } from './animate';
+
+export class Queue extends EventEmitter {
+  private animations: Animate[] = [];
+
+  constructor() {
+    super();
+  }
+
+  public add(animation: Animate) {
+    this.animations.push(animation);
+    animation.on('start', () => this.emit('start', animation));
+    animation.on('update', (value: any) => this.emit('update', value, animation));
+    animation.on('complete', () => this.onAnimationComplete(animation));
+    animation.on('stop', () => this.emit('stop', animation));
+
+    // If this is the first animation added and no other animation is running, start it immediately
+    if (this.animations.length === 1) {
+      this.startNextAnimation();
+    }
+  }
+
+  private startNextAnimation() {
+    if (this.animations.length > 0) {
+      const animation = this.animations[0];
+      animation.start();
+    } else {
+      this.emit('complete'); // Emit complete event when all animations in the queue have completed
+    }
+  }
+
+  private onAnimationComplete(animation: Animate) {
+    this.emit('complete', animation);
+    this.animations.shift(); // Remove the completed animation from the queue
+    this.startNextAnimation(); // Start the next animation in the queue
+  }
+
+  public clear() {
+    if (this.animations.length > 0) {
+      this.animations[0].stop();
+    }
+    this.animations = [];
+  }
+
+  public stop() {
+    if (this.animations.length > 0) {
+      this.animations[0].stop();
+    }
+  }
+}