# HG changeset patch
# User Lucas Thompson <dev@lucas.im>
# Date 1495731329 -3600
# Node ID 82d476b976e0d2c73eb90a71b6635d9cf58a342e
# Parent  f87a96ab1e3ff262369782aee22ac2aab44d44d0
Move waveform.component and remove all logic not concerned with rendering an audio buffer as a waveform. Wire app in app.component.

diff -r f87a96ab1e3f -r 82d476b976e0 src/app/app.component.html
--- a/src/app/app.component.html	Thu May 25 17:52:46 2017 +0100
+++ b/src/app/app.component.html	Thu May 25 17:55:29 2017 +0100
@@ -34,7 +34,8 @@
       </md-sidenav>
       <ugly-notebook-feed
         [analyses]="analyses.toIterable()"
-        [rootAudioUri]="rootAudioUri"></ugly-notebook-feed>
+        [rootAudioUri]="rootAudioUri"
+        [onSeek]="onSeek"></ugly-notebook-feed>
     </md-sidenav-container>
   </div>
 </div>
diff -r f87a96ab1e3f -r 82d476b976e0 src/app/app.component.ts
--- a/src/app/app.component.ts	Thu May 25 17:52:46 2017 +0100
+++ b/src/app/app.component.ts	Thu May 25 17:55:29 2017 +0100
@@ -9,6 +9,7 @@
 import {MdIconRegistry} from '@angular/material';
 import {Subscription} from 'rxjs/Subscription';
 import {AnalysisItem} from './analysis-item/analysis-item.component';
+import {OnSeekHandler} from './playhead/PlayHeadHelpers';
 
 class PersistentStack<T> {
   private stack: T[];
@@ -74,6 +75,7 @@
   private nRecordings: number; // TODO user control for naming a recording
   private countingId: number; // TODO improve uniquely identifying items
   private rootAudioUri: string;
+  private onSeek: OnSeekHandler;
 
   constructor(private audioService: AudioPlayerService,
               private featureService: FeatureExtractionService,
@@ -83,6 +85,7 @@
     this.canExtract = false;
     this.nRecordings = 0;
     this.countingId = 0;
+    this.onSeek = (time) => this.audioService.seekTo(time);
 
     iconRegistry.addSvgIcon(
       'duck',
@@ -99,6 +102,19 @@
           this.audioBuffer = (resource as AudioResource).samples;
           if (this.audioBuffer) {
             this.canExtract = true;
+            const currentRootIndex = this.analyses.findIndex(val => {
+              return val.rootAudioUri === this.rootAudioUri && val.isRoot;
+            });
+            if (currentRootIndex !== -1) {
+              this.analyses.set(
+                currentRootIndex,
+                Object.assign(
+                  {},
+                  this.analyses.get(currentRootIndex),
+                  {audioData: this.audioBuffer}
+                )
+              );
+            }
           }
         }
       }
diff -r f87a96ab1e3f -r 82d476b976e0 src/app/app.module.ts
--- a/src/app/app.module.ts	Thu May 25 17:52:46 2017 +0100
+++ b/src/app/app.module.ts	Thu May 25 17:55:29 2017 +0100
@@ -4,7 +4,7 @@
 import { HttpModule } from '@angular/http';
 
 import { AppComponent } from './app.component';
-import { WaveformComponent } from './waveform/waveform.component';
+import { WaveformComponent } from './visualisations/waveform/waveform.component';
 import { AudioFileOpenComponent } from './audio-file-open/audio-file-open.component';
 import { PlaybackControlComponent } from './playback-control/playback-control.component';
 import {
@@ -29,6 +29,8 @@
 import {ProgressBarComponent} from './progress-bar/progress-bar';
 import {UglyMaterialModule} from './ugly-material.module';
 import {Observable} from 'rxjs/Observable';
+import {PlayHeadComponent} from './playhead/playhead.component';
+import {LivePlayHeadComponent} from './playhead/live-play-head.component';
 
 export function createAudioContext(): AudioContext {
   return new (
@@ -114,7 +116,9 @@
     ProgressSpinnerComponent,
     AnalysisItemComponent,
     NotebookFeedComponent,
-    ProgressBarComponent
+    ProgressBarComponent,
+    PlayHeadComponent,
+    LivePlayHeadComponent
   ],
   imports: [
     BrowserModule,
diff -r f87a96ab1e3f -r 82d476b976e0 src/app/visualisations/WavesJunk.ts
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/app/visualisations/WavesJunk.ts	Thu May 25 17:55:29 2017 +0100
@@ -0,0 +1,163 @@
+/**
+ * Created by lucast on 24/05/2017.
+ */
+import wavesUI from 'waves-ui-piper';
+import * as Hammer from 'hammerjs';
+import {TimePixelMapper} from '../playhead/PlayHeadHelpers';
+
+// TODO this is named as such as a reminder that it needs to be re-factored
+export function attachTouchHandlerBodges(element: HTMLElement,
+                                         timeline: Timeline) {
+  interface Point {
+    x: number;
+    y: number;
+  }
+
+  let zoomGestureJustEnded = false;
+
+  const pixelToExponent: Function = wavesUI.utils.scales.linear()
+    .domain([0, 100]) // 100px => factor 2
+    .range([0, 1]);
+
+  const calculateDistance: (p1: Point, p2: Point) => number = (p1, p2) => {
+    return Math.pow(
+      Math.pow(p2.x - p1.x, 2) +
+      Math.pow(p2.y - p1.y, 2), 0.5);
+  };
+
+  const calculateMidPoint: (p1: Point, p2: Point) => Point = (p1, p2) => {
+    return {
+      x: 0.5 * (p1.x + p2.x),
+      y: 0.5 * (p1.y + p2.y)
+    };
+  };
+
+  const hammertime = new Hammer.Manager(element, {
+    recognizers: [
+      [Hammer.Pan, { direction: Hammer.DIRECTION_HORIZONTAL }]
+    ]
+  });
+
+  // it seems HammerJs binds the event to the window?
+  // causing these events to propagate to other components?
+  let initialZoom;
+  let initialDistance;
+  let offsetAtPanStart;
+  let startX;
+  let isZooming;
+
+  const scroll = (ev) => {
+    if (ev.center.x - startX === 0) {
+      return;
+    }
+
+    if (zoomGestureJustEnded) {
+      zoomGestureJustEnded = false;
+      console.log('Skip this event: likely a single touch dangling from pinch');
+      return;
+    }
+    timeline.timeContext.offset = offsetAtPanStart +
+      timeline.timeContext.timeToPixel.invert(ev.deltaX);
+    timeline.tracks.update();
+  };
+
+  const zoom = (ev) => {
+    if (ev.touches.length < 2) {
+      return;
+    }
+
+    ev.preventDefault();
+    const minZoom = timeline.state.minZoom;
+    const maxZoom = timeline.state.maxZoom;
+    const p1: Point = {
+      x: ev.touches[0].clientX,
+      y: ev.touches[0].clientY
+    };
+    const p2: Point = {
+      x: ev.touches[1].clientX,
+      y: ev.touches[1].clientY
+    };
+    const distance = calculateDistance(p1, p2);
+    const midPoint = calculateMidPoint(p1, p2);
+
+    const lastCenterTime =
+      timeline.timeContext.timeToPixel.invert(midPoint.x);
+
+    const exponent = pixelToExponent(distance - initialDistance);
+    const targetZoom = initialZoom * Math.pow(2, exponent);
+
+    timeline.timeContext.zoom =
+      Math.min(Math.max(targetZoom, minZoom), maxZoom);
+
+    const newCenterTime =
+      timeline.timeContext.timeToPixel.invert(midPoint.x);
+
+    timeline.timeContext.offset += newCenterTime - lastCenterTime;
+    timeline.tracks.update();
+  };
+  hammertime.on('panstart', (ev) => {
+    offsetAtPanStart = timeline.timeContext.offset;
+    startX = ev.center.x;
+  });
+  hammertime.on('panleft', scroll);
+  hammertime.on('panright', scroll);
+
+  element.addEventListener('touchstart', (e) => {
+    if (e.touches.length < 2) {
+      return;
+    }
+
+    isZooming = true;
+    initialZoom = timeline.timeContext.zoom;
+
+    initialDistance = calculateDistance({
+      x: e.touches[0].clientX,
+      y: e.touches[0].clientY
+    }, {
+      x: e.touches[1].clientX,
+      y: e.touches[1].clientY
+    });
+  });
+  element.addEventListener('touchend', () => {
+    if (isZooming) {
+      isZooming = false;
+      zoomGestureJustEnded = true;
+    }
+  });
+  element.addEventListener('touchmove', zoom);
+}
+
+export function naivePagingMapper(timeline: Timeline): TimePixelMapper {
+  return (currentTime: number) => {
+    const currentOffset = timeline.timeContext.offset;
+    const offsetTimestamp = currentOffset
+      + currentTime;
+
+    const visibleDuration = timeline.timeContext.visibleDuration;
+    const mustPageForward = offsetTimestamp > visibleDuration;
+    const mustPageBackward = currentTime < -currentOffset;
+
+    if (mustPageForward) {
+      const hasSkippedMultiplePages =
+        offsetTimestamp - visibleDuration > visibleDuration;
+
+      timeline.timeContext.offset = hasSkippedMultiplePages ?
+        -currentTime + 0.5 * visibleDuration :
+        currentOffset - visibleDuration;
+    }
+
+    if (mustPageBackward) {
+      const hasSkippedMultiplePages =
+        currentTime + visibleDuration < -currentOffset;
+      timeline.timeContext.offset = hasSkippedMultiplePages ?
+        -currentTime + 0.5 * visibleDuration :
+        currentOffset + visibleDuration;
+    }
+
+    if (mustPageForward || mustPageBackward) {
+      timeline.tracks.update();
+    }
+    //
+    return timeline.timeContext.timeToPixel(timeline.offset + currentTime);
+  };
+}
diff -r f87a96ab1e3f -r 82d476b976e0 src/app/visualisations/waveform/waveform.component.css
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/app/visualisations/waveform/waveform.component.css	Thu May 25 17:55:29 2017 +0100
@@ -0,0 +1,4 @@
+.track {
+  height: 100%;
+  width: 100%;
+}
diff -r f87a96ab1e3f -r 82d476b976e0 src/app/visualisations/waveform/waveform.component.html
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/app/visualisations/waveform/waveform.component.html	Thu May 25 17:55:29 2017 +0100
@@ -0,0 +1,4 @@
+<div
+  #track class="track"
+  (mousedown)="seekStart()"
+  (mouseup)="seekEnd($event.clientX)"></div>
diff -r f87a96ab1e3f -r 82d476b976e0 src/app/visualisations/waveform/waveform.component.ts
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/app/visualisations/waveform/waveform.component.ts	Thu May 25 17:55:29 2017 +0100
@@ -0,0 +1,177 @@
+import {
+  Component,
+  ViewChild,
+  ElementRef,
+  Input,
+  ChangeDetectorRef
+} from '@angular/core';
+import wavesUI from 'waves-ui-piper';
+import {attachTouchHandlerBodges} from '../WavesJunk';
+import {OnSeekHandler} from '../../playhead/PlayHeadHelpers';
+
+type Layer = any;
+type Track = any;
+
+@Component({
+  selector: 'ugly-waveform',
+  templateUrl: './waveform.component.html',
+  styleUrls: ['./waveform.component.css']
+})
+export class WaveformComponent {
+
+  @ViewChild('track') trackDiv: ElementRef;
+  @Input() set width(width: number) {
+    if (this.timeline) {
+      requestAnimationFrame(() => {
+        this.timeline.timeContext.visibleWidth = width;
+        this.timeline.tracks.update();
+      });
+    }
+  }
+  @Input() timeline: Timeline;
+  @Input() trackIdPrefix: string;
+  @Input() onSeek: OnSeekHandler;
+
+  @Input() set audioBuffer(buffer: AudioBuffer) {
+    this._audioBuffer = buffer || undefined;
+    if (this.audioBuffer) {
+      this.renderWaveform(this.audioBuffer);
+    }
+  }
+
+  get audioBuffer(): AudioBuffer {
+    return this._audioBuffer;
+  }
+
+  private _audioBuffer: AudioBuffer;
+  private layers: Layer[];
+  private zoomOnMouseDown: number;
+  private offsetOnMouseDown: number;
+  private waveTrack: Track;
+
+  constructor(private ref: ChangeDetectorRef) {
+    this.layers = [];
+  }
+
+  renderTimeline(duration: number = 1.0): Timeline {
+    const track: HTMLElement = this.trackDiv.nativeElement;
+    track.innerHTML = '';
+    const height: number = track.getBoundingClientRect().height;
+    const width: number = track.getBoundingClientRect().width;
+    this.timeline.pixelsPerSecond = width / duration;
+    this.timeline.visibleWidth = width;
+    this.waveTrack = this.timeline.createTrack(
+      track,
+      height,
+      `wave-${this.trackIdPrefix || 'default'}`
+    );
+
+    if ('ontouchstart' in window) {
+      attachTouchHandlerBodges(this.trackDiv.nativeElement, this.timeline);
+    }
+  }
+
+  // TODO can likely be removed, or use waves-ui methods
+  clearTimeline(): void {
+    // loop through layers and remove them, waves-ui provides methods for this but it seems to not work properly
+    const timeContextChildren = this.timeline.timeContext._children;
+    for (const track of this.timeline.tracks) {
+      if (track.layers.length === 0) { continue; }
+      const trackLayers = Array.from(track.layers);
+      while (trackLayers.length) {
+        const layer: Layer = trackLayers.pop();
+        if (this.layers.includes(layer)) {
+          track.remove(layer);
+          this.layers.splice(this.layers.indexOf(layer), 1);
+          const index = timeContextChildren.indexOf(layer.timeContext);
+          if (index >= 0) {
+            timeContextChildren.splice(index, 1);
+          }
+          layer.destroy();
+        }
+      }
+    }
+  }
+
+  renderWaveform(buffer: AudioBuffer): void {
+    const height = this.trackDiv.nativeElement.getBoundingClientRect().height;
+    if (this.timeline && this.waveTrack) {
+      // resize
+      const width = this.trackDiv.nativeElement.getBoundingClientRect().width;
+
+      this.clearTimeline();
+      this.timeline.visibleWidth = width;
+      this.timeline.pixelsPerSecond = width / buffer.duration;
+      this.waveTrack.height = height;
+    } else {
+      this.renderTimeline(buffer.duration);
+    }
+    this.timeline.timeContext.offset = 0.5 * this.timeline.timeContext.visibleDuration;
+
+    // time axis
+    const timeAxis = new wavesUI.helpers.TimeAxisLayer({
+      height: height,
+      color: '#b0b0b0'
+    });
+    this.addLayer(timeAxis, this.waveTrack, this.timeline.timeContext, true);
+
+    const nchannels = buffer.numberOfChannels;
+    const totalWaveHeight = height * 0.9;
+    const waveHeight = totalWaveHeight / nchannels;
+
+    for (let ch = 0; ch < nchannels; ++ch) {
+      const waveformLayer = new wavesUI.helpers.WaveformLayer(buffer, {
+        top: (height - totalWaveHeight) / 2 + waveHeight * ch,
+        height: waveHeight,
+        color: '#0868ac',
+        channel: ch
+      });
+      this.addLayer(waveformLayer, this.waveTrack, this.timeline.timeContext);
+    }
+
+    this.timeline.state = new wavesUI.states.CenteredZoomState(this.timeline);
+    this.waveTrack.render();
+    this.waveTrack.update();
+    this.ref.markForCheck();
+  }
+
+  // TODO can likely use methods in waves-ui directly
+  private addLayer(layer: Layer,
+                   track: Track,
+                   timeContext: any,
+                   isAxis: boolean = false): void {
+    timeContext.zoom = 1.0;
+    if (!layer.timeContext) {
+      layer.setTimeContext(isAxis ?
+        timeContext : new wavesUI.core.LayerTimeContext(timeContext));
+    }
+    track.add(layer);
+    this.layers.push(layer);
+    layer.render();
+    layer.update();
+  }
+
+  seekStart(): void {
+    this.zoomOnMouseDown = this.timeline.timeContext.zoom;
+    this.offsetOnMouseDown = this.timeline.timeContext.offset;
+  }
+
+  seekEnd(x: number): void {
+    const hasSameZoom: boolean = this.zoomOnMouseDown ===
+      this.timeline.timeContext.zoom;
+    const hasSameOffset: boolean = this.offsetOnMouseDown ===
+      this.timeline.timeContext.offset;
+    if (hasSameZoom && hasSameOffset) {
+      this.seek(x);
+    }
+  }
+
+  seek(x: number): void {
+    if (this.timeline) {
+      const timeContext: any = this.timeline.timeContext;
+      if (this.onSeek) {
+        this.onSeek(timeContext.timeToPixel.invert(x) - timeContext.offset);
+      }
+    }
+  }
+}
diff -r f87a96ab1e3f -r 82d476b976e0 src/app/visualisations/waveform/waves-ui-piper.d.ts
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/app/visualisations/waveform/waves-ui-piper.d.ts	Thu May 25 17:55:29 2017 +0100
@@ -0,0 +1,119 @@
+/// <reference path="../../../../node_modules/@types/node/index.d.ts"/>
+declare const AmbientInstance: WavesUserInterface;
+
+declare module 'waves-ui-piper' {
+  export default AmbientInstance;
+}
+
+interface WavesUserInterface {
+  core: Core;
+  helpers: any;
+  states: any;
+  utils: Utilities;
+  shapes: any;
+}
+
+interface MatrixEntity {
+  getColumnCount(): number;
+  getColumnHeight(): number;
+  getColumn(n: number): Float32Array | number[];
+  getStepDuration(): number;
+  getStartTime(): number;
+  dispose(): void;
+}
+
+type TimeContext = any; // TODO
+
+interface Area {
+  top: number;
+  left: number;
+  width: number;
+  height: number;
+}
+
+interface Layer extends NodeJS.EventEmitter {
+  start: number;
+  offset: number;
+  duration: number;
+  stretchRatio: number;
+  yDomain: number[];
+  opacity: number;
+  readonly timeToPixel: () => (time: number) => number;
+  readonly valueToPixel: () => (value: number) => number;
+  readonly items: Element[];
+  readonly selectedItems: Element[];
+  data: ArrayLike<any> | Object;
+  destroy(): void;
+  configureTimeContextBehaviour(ctor: ObjectConstructor): void;
+  setTimeContext(context: TimeContext): void;
+  configureShape(ctor: ObjectConstructor /* TODO BaseShape*/,
+                 accessors: Object,
+                 options: Object): void;
+  configureCommonShape(ctor: ObjectConstructor /* TODO BaseShape*/,
+                       accessors: Object,
+                       options: Object): void;
+  setBehaviour(behaviour: Object /* TODO BaseBehavior */): void;
+  select(...$items: Element[]);
+  unselect(...$items: Element[]);
+  toggleSelection(...$items: Element[]);
+  edit($items: Element[], dx: number, dy: number, $target: Element): void;
+  setContextEditable(bool: boolean): void;
+  editContext(dx: number, dy: number, $target: Element): void;
+  stretchContext(dx: number, dy: number, $target: Element): void;
+  getItemFromDOMElement($el: Element): Element | null;
+  getDatumFromItem($item: Element): Object | any[] | null;
+  getDatumFromDOMElement($item: Element): Object | any[] | null;
+  hasItem($item: Element): boolean;
+  hasElement($el: Element): boolean;
+  getItemsInArea(area: Area): Element[];
+  render(): void;
+  update(): void;
+  updateContainer(): void;
+  updateShapes(): void;
+}
+
+interface LayerConstructor {
+  new(dataType: 'entity' | 'collection',
+      data: ArrayLike<any> | Object,
+      options: Object): Layer;
+}
+
+interface MatrixEntityConstructor {
+  new(): MatrixEntity;
+}
+
+interface PrefilledMatrixEntityConstructor {
+  new(data: Float32Array[] | number[][],
+      startTime: number,
+      stepDuration: number): MatrixEntity;
+}
+
+interface Utilities {
+  MatrixEntity: MatrixEntityConstructor;
+  PrefilledMatrixEntity: PrefilledMatrixEntityConstructor;
+  scales: any;
+}
+
+type Timeline = any;
+
+interface Core {
+  Layer: LayerConstructor;
+  LayerTimeContext: any; // TODO
+  Timeline: Timeline; // TODO
+  TimelineTimeContext: TimelineTimeContextConstructor;
+}
+
+interface TimelineTimeContext {
+  pixelsPerSecond: number;
+  readonly computedPixelsPerSecond: number;
+  offset: number;
+  zoom: number;
+  visibleWidth: number;
+  readonly visibleDuration: number;
+  maintainVisibleDuration: boolean;
+  timeToPixel: (time: number) => number;
+}
+
+interface TimelineTimeContextConstructor {
+  new(pixelsPerSecond: number, visibleWidth: number): TimelineTimeContext;
+}
diff -r f87a96ab1e3f -r 82d476b976e0 src/app/waveform/waveform.component.css
--- a/src/app/waveform/waveform.component.css	Thu May 25 17:52:46 2017 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,4 +0,0 @@
-.track {
-  height: 160px;
-  width: 100%;
-}
diff -r f87a96ab1e3f -r 82d476b976e0 src/app/waveform/waveform.component.html
--- a/src/app/waveform/waveform.component.html	Thu May 25 17:52:46 2017 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,7 +0,0 @@
-<div
-  #track class="track"
-  (mousedown)="seekStart()"
-  (mouseup)="seekEnd($event.clientX)"></div>
-<ng-template [ngIf]="isLoading">
-  <ugly-progress-spinner></ugly-progress-spinner>
-</ng-template>
diff -r f87a96ab1e3f -r 82d476b976e0 src/app/waveform/waveform.component.ts
--- a/src/app/waveform/waveform.component.ts	Thu May 25 17:52:46 2017 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,1020 +0,0 @@
-import {
-  Component,
-  OnInit,
-  ViewChild,
-  ElementRef,
-  Input,
-  AfterViewInit,
-  NgZone,
-  OnDestroy,
-  ChangeDetectorRef
-} from '@angular/core';
-import {
-  AudioPlayerService, AudioResource,
-  AudioResourceError
-} from '../services/audio-player/audio-player.service';
-import wavesUI from 'waves-ui-piper';
-import {
-  FeatureExtractionService
-} from '../services/feature-extraction/feature-extraction.service';
-import {Subscription} from 'rxjs/Subscription';
-import {
-  FeatureCollection,
-  SimpleResponse,
-  VectorFeature,
-  MatrixFeature,
-  TracksFeature
-} from 'piper/HigherLevelUtilities';
-import {toSeconds, OutputDescriptor} from 'piper';
-import {FeatureList, Feature} from 'piper/Feature';
-import * as Hammer from 'hammerjs';
-import {WavesSpectrogramLayer} from '../spectrogram/Spectrogram';
-import {iceMapper, sunsetMapper} from 'app/spectrogram/ColourMap';
-import {estimatePercentile} from '../spectrogram/MatrixUtils';
-
-type Layer = any;
-type Track = any;
-type Colour = string;
-
-
-
-function* createColourGenerator(colours) {
-  let index = 0;
-  const nColours = colours.length;
-  while (true) {
-    yield colours[index = ++index % nColours];
-  }
-}
-
-const defaultColourGenerator = createColourGenerator([
-  '#0868ac', // "sapphire blue", our waveform / header colour
-  '#c33c54', // "brick red"
-  '#17bebb', // "tiffany blue"
-  '#001021', // "rich black"
-  '#fa8334', // "mango tango"
-  '#034748' // "deep jungle green"
-]);
-
-type HigherLevelFeatureShape = 'regions' | 'instants' | 'notes';
-type NoteLikeUnit = 'midi' | 'hz' ;
-interface Note {
-  time: number;
-  duration: number;
-  pitch: number;
-  velocity?: number;
-}
-
-@Component({
-  selector: 'ugly-waveform',
-  templateUrl: './waveform.component.html',
-  styleUrls: ['./waveform.component.css']
-})
-
-export class WaveformComponent implements OnInit, AfterViewInit, OnDestroy {
-
-  @ViewChild('track') trackDiv: ElementRef;
-  @Input() set width(width: number) {
-    if (this.timeline) {
-      requestAnimationFrame(() => {
-        this.timeline.timeContext.visibleWidth = width;
-        this.timeline.tracks.update();
-      });
-    }
-  }
-  @Input() timeline: Timeline;
-  @Input() trackIdPrefix: string;
-  @Input() set isSubscribedToExtractionService(isSubscribed: boolean) {
-    if (isSubscribed) {
-      if (this.featureExtractionSubscription) {
-        return;
-      }
-
-      this.featureExtractionSubscription =
-        this.piperService.featuresExtracted$.subscribe(
-          features => {
-            this.renderFeatures(features, defaultColourGenerator.next().value);
-          });
-    } else {
-      if (this.featureExtractionSubscription) {
-        this.featureExtractionSubscription.unsubscribe();
-      }
-    }
-  }
-  @Input() set isSubscribedToAudioService(isSubscribed: boolean) {
-    this._isSubscribedToAudioService = isSubscribed;
-    if (isSubscribed) {
-      if (this.onAudioDataSubscription) {
-        return;
-      }
-
-      this.onAudioDataSubscription =
-        this.audioService.audioLoaded$.subscribe(res => {
-          const wasError = (res as AudioResourceError).message != null;
-
-          if (wasError) {
-            console.warn('No audio, display error?');
-          } else {
-            this.audioBuffer = (res as AudioResource).samples;
-          }
-        });
-    } else {
-      if (this.onAudioDataSubscription) {
-        this.onAudioDataSubscription.unsubscribe();
-      }
-    }
-  }
-
-  get isSubscribedToAudioService(): boolean {
-    return this._isSubscribedToAudioService;
-  }
-
-  @Input() set isOneShotExtractor(isOneShot: boolean) {
-    this._isOneShotExtractor = isOneShot;
-  }
-
-  get isOneShotExtractor(): boolean {
-    return this._isOneShotExtractor;
-  }
-
-  @Input() set isSeeking(isSeeking: boolean) {
-    this._isSeeking = isSeeking;
-    if (isSeeking) {
-      if (this.seekedSubscription) {
-        return;
-      }
-      if (this.playingStateSubscription) {
-        return;
-      }
-
-      this.seekedSubscription = this.audioService.seeked$.subscribe(() => {
-        if (!this.audioService.isPlaying()) {
-          this.animate();
-        }
-      });
-      this.playingStateSubscription =
-        this.audioService.playingStateChange$.subscribe(
-          isPlaying => {
-            if (isPlaying) {
-              this.animate();
-            }
-          });
-    } else {
-      if (this.cursorLayer && this.waveTrack) {
-        this.waveTrack.remove(this.cursorLayer);
-      }
-      if (this.playingStateSubscription) {
-        this.playingStateSubscription.unsubscribe();
-      }
-      if (this.seekedSubscription) {
-        this.seekedSubscription.unsubscribe();
-      }
-    }
-  }
-
-  get isSeeking(): boolean {
-    return this._isSeeking;
-  }
-
-  set audioBuffer(buffer: AudioBuffer) {
-    this._audioBuffer = buffer || undefined;
-    if (this.audioBuffer) {
-      this.renderWaveform(this.audioBuffer);
-      // this.renderSpectrogram(this.audioBuffer);
-    }
-  }
-
-  get audioBuffer(): AudioBuffer {
-    return this._audioBuffer;
-  }
-
-  private _audioBuffer: AudioBuffer;
-  private _isSubscribedToAudioService: boolean;
-  private _isOneShotExtractor: boolean;
-  private _isSeeking: boolean;
-  private cursorLayer: any;
-  private highlightLayer: any;
-  private layers: Layer[];
-  private featureExtractionSubscription: Subscription;
-  private playingStateSubscription: Subscription;
-  private seekedSubscription: Subscription;
-  private onAudioDataSubscription: Subscription;
-  private zoomOnMouseDown: number;
-  private offsetOnMouseDown: number;
-  private hasShot: boolean;
-  private isLoading: boolean;
-  private waveTrack: Track;
-
-  private static changeColour(layer: Layer, colour: string): void {
-    const butcherShapes = (shape) => {
-      shape.install({color: () => colour});
-      shape.params.color = colour;
-      shape.update(layer._renderingContext, layer.data);
-    };
-
-    layer._$itemCommonShapeMap.forEach(butcherShapes);
-    layer._$itemShapeMap.forEach(butcherShapes);
-    layer.render();
-    layer.update();
-  }
-
-  constructor(private audioService: AudioPlayerService,
-              private piperService: FeatureExtractionService,
-              private ngZone: NgZone,
-              private ref: ChangeDetectorRef) {
-    this.isSubscribedToAudioService = true;
-    this.isSeeking = true;
-    this.layers = [];
-    this.audioBuffer = undefined;
-    this.timeline = undefined;
-    this.cursorLayer = undefined;
-    this.highlightLayer = undefined;
-    this.isLoading = true;
-  }
-
-  ngOnInit() {
-  }
-
-  ngAfterViewInit(): void {
-    this.trackIdPrefix = this.trackIdPrefix || 'default';
-    if (this.timeline) {
-      this.renderTimeline(null, true, true);
-    } else {
-      this.renderTimeline();
-    }
-  }
-
-  renderTimeline(duration: number = 1.0,
-                 useExistingDuration: boolean = false,
-                 isInitialRender: boolean = false): Timeline {
-    const track: HTMLElement = this.trackDiv.nativeElement;
-    track.innerHTML = '';
-    const height: number = track.getBoundingClientRect().height;
-    const width: number = track.getBoundingClientRect().width;
-    const pixelsPerSecond = width / duration;
-    const hasExistingTimeline = this.timeline instanceof wavesUI.core.Timeline;
-
-    if (hasExistingTimeline) {
-      if (!useExistingDuration) {
-        this.timeline.pixelsPerSecond = pixelsPerSecond;
-        this.timeline.visibleWidth = width;
-      }
-    } else {
-      this.timeline = new wavesUI.core.Timeline(pixelsPerSecond, width);
-    }
-    this.waveTrack = this.timeline.createTrack(
-      track,
-      height,
-      `wave-${this.trackIdPrefix}`
-    );
-    if (isInitialRender && hasExistingTimeline) {
-      // time axis
-      const timeAxis = new wavesUI.helpers.TimeAxisLayer({
-        height: height,
-        color: '#b0b0b0'
-      });
-      this.addLayer(timeAxis, this.waveTrack, this.timeline.timeContext, true);
-      this.cursorLayer = new wavesUI.helpers.CursorLayer({
-        height: height,
-        color: '#c33c54'
-      });
-      this.addLayer(
-        this.cursorLayer,
-        this.waveTrack,
-        this.timeline.timeContext
-      );
-    }
-    if ('ontouchstart' in window) {
-      interface Point {
-        x: number;
-        y: number;
-      }
-
-      let zoomGestureJustEnded = false;
-
-      const pixelToExponent: Function = wavesUI.utils.scales.linear()
-        .domain([0, 100]) // 100px => factor 2
-        .range([0, 1]);
-
-      const calculateDistance: (p1: Point, p2: Point) => number = (p1, p2) => {
-        return Math.pow(
-          Math.pow(p2.x - p1.x, 2) +
-          Math.pow(p2.y - p1.y, 2), 0.5);
-      };
-
-      const calculateMidPoint: (p1: Point, p2: Point) => Point = (p1, p2) => {
-        return {
-          x: 0.5 * (p1.x + p2.x),
-          y: 0.5 * (p1.y + p2.y)
-        };
-      };
-
-      const hammertime = new Hammer.Manager(this.trackDiv.nativeElement, {
-        recognizers: [
-          [Hammer.Pan, { direction: Hammer.DIRECTION_HORIZONTAL }]
-        ]
-      });
-
-      // it seems HammerJs binds the event to the window?
-      // causing these events to propagate to other components?
-      const componentTimeline = this.timeline;
-      let initialZoom;
-      let initialDistance;
-      let offsetAtPanStart;
-      let startX;
-      let isZooming;
-
-      const scroll = (ev) => {
-        if (ev.center.x - startX === 0) {
-          return;
-        }
-
-        if (zoomGestureJustEnded) {
-          zoomGestureJustEnded = false;
-          console.log('Skip this event: likely a single touch dangling from pinch');
-          return;
-        }
-        componentTimeline.timeContext.offset = offsetAtPanStart +
-          componentTimeline.timeContext.timeToPixel.invert(ev.deltaX);
-        componentTimeline.tracks.update();
-      };
-
-      const zoom = (ev) => {
-        if (ev.touches.length < 2) {
-          return;
-        }
-
-        ev.preventDefault();
-        const minZoom = componentTimeline.state.minZoom;
-        const maxZoom = componentTimeline.state.maxZoom;
-        const p1: Point = {
-          x: ev.touches[0].clientX,
-          y: ev.touches[0].clientY
-        };
-        const p2: Point = {
-          x: ev.touches[1].clientX,
-          y: ev.touches[1].clientY
-        };
-        const distance = calculateDistance(p1, p2);
-        const midPoint = calculateMidPoint(p1, p2);
-
-        const lastCenterTime =
-          componentTimeline.timeContext.timeToPixel.invert(midPoint.x);
-
-        const exponent = pixelToExponent(distance - initialDistance);
-        const targetZoom = initialZoom * Math.pow(2, exponent);
-
-        componentTimeline.timeContext.zoom =
-          Math.min(Math.max(targetZoom, minZoom), maxZoom);
-
-        const newCenterTime =
-          componentTimeline.timeContext.timeToPixel.invert(midPoint.x);
-
-        componentTimeline.timeContext.offset += newCenterTime - lastCenterTime;
-        componentTimeline.tracks.update();
-      };
-      hammertime.on('panstart', (ev) => {
-        offsetAtPanStart = componentTimeline.timeContext.offset;
-        startX = ev.center.x;
-      });
-      hammertime.on('panleft', scroll);
-      hammertime.on('panright', scroll);
-
-
-      const element: HTMLElement = this.trackDiv.nativeElement;
-      element.addEventListener('touchstart', (e) => {
-        if (e.touches.length < 2) {
-          return;
-        }
-
-        isZooming = true;
-        initialZoom = componentTimeline.timeContext.zoom;
-
-        initialDistance = calculateDistance({
-          x: e.touches[0].clientX,
-          y: e.touches[0].clientY
-        }, {
-          x: e.touches[1].clientX,
-          y: e.touches[1].clientY
-        });
-      });
-      element.addEventListener('touchend', () => {
-        if (isZooming) {
-          isZooming = false;
-          zoomGestureJustEnded = true;
-        }
-      });
-      element.addEventListener('touchmove', zoom);
-    }
-    // this.timeline.createTrack(track, height/2, `wave-${this.trackIdPrefix}`);
-    // this.timeline.createTrack(track, height/2, `grid-${this.trackIdPrefix}`);
-  }
-
-  clearTimeline(): void {
-    // loop through layers and remove them, waves-ui provides methods for this but it seems to not work properly
-    const timeContextChildren = this.timeline.timeContext._children;
-    for (const track of this.timeline.tracks) {
-      if (track.layers.length === 0) { continue; }
-      const trackLayers = Array.from(track.layers);
-      while (trackLayers.length) {
-        const layer: Layer = trackLayers.pop();
-        if (this.layers.includes(layer)) {
-          track.remove(layer);
-          this.layers.splice(this.layers.indexOf(layer), 1);
-          const index = timeContextChildren.indexOf(layer.timeContext);
-          if (index >= 0) {
-            timeContextChildren.splice(index, 1);
-          }
-          layer.destroy();
-        }
-      }
-    }
-  }
-
-  renderWaveform(buffer: AudioBuffer): void {
-    const height = this.trackDiv.nativeElement.getBoundingClientRect().height;
-    if (this.timeline) {
-      // resize
-      const width = this.trackDiv.nativeElement.getBoundingClientRect().width;
-
-      this.clearTimeline();
-
-      this.timeline.visibleWidth = width;
-      this.timeline.pixelsPerSecond = width / buffer.duration;
-      this.waveTrack.height = height;
-    } else {
-      this.renderTimeline(buffer.duration);
-    }
-    this.timeline.timeContext.offset = 0.5 * this.timeline.timeContext.visibleDuration;
-
-    // time axis
-    const timeAxis = new wavesUI.helpers.TimeAxisLayer({
-      height: height,
-      color: '#b0b0b0'
-    });
-    this.addLayer(timeAxis, this.waveTrack, this.timeline.timeContext, true);
-
-    const nchannels = buffer.numberOfChannels;
-    const totalWaveHeight = height * 0.9;
-    const waveHeight = totalWaveHeight / nchannels;
-
-    for (let ch = 0; ch < nchannels; ++ch) {
-      console.log('about to construct a waveform layer for channel ' + ch);
-      const waveformLayer = new wavesUI.helpers.WaveformLayer(buffer, {
-        top: (height - totalWaveHeight) / 2 + waveHeight * ch,
-        height: waveHeight,
-        color: '#0868ac',
-        channel: ch
-      });
-      this.addLayer(waveformLayer, this.waveTrack, this.timeline.timeContext);
-    }
-
-    this.cursorLayer = new wavesUI.helpers.CursorLayer({
-      height: height,
-      color: '#c33c54'
-    });
-    this.addLayer(this.cursorLayer, this.waveTrack, this.timeline.timeContext);
-    this.timeline.state = new wavesUI.states.CenteredZoomState(this.timeline);
-    this.waveTrack.render();
-    this.waveTrack.update();
-
-    this.isLoading = false;
-    this.ref.markForCheck();
-    this.animate();
-  }
-
-  renderSpectrogram(buffer: AudioBuffer): void {
-    const height: number = this.trackDiv.nativeElement.getBoundingClientRect().height / 2;
-    const gridTrack = this.timeline.getTrackById(`grid-${this.trackIdPrefix}`);
-
-    const spectrogramLayer = new WavesSpectrogramLayer(buffer, {
-      top: 0,
-      height: height,
-      stepSize: 512,
-      blockSize: 1024,
-      normalise: 'none',
-      mapper: sunsetMapper()
-    });
-    this.addLayer(spectrogramLayer, gridTrack, this.timeline.timeContext);
-
-    this.timeline.tracks.update();
-  }
-
-  private addLineLayers(features: VectorFeature[],
-                        unit: string,
-                        colour: Colour) {
-
-    // Winnow out empty features
-    features = features.filter(feature => (feature.data.length > 0));
-
-    // First establish a [min,max] range across all of the features
-    let [min, max] = features.reduce((acc, feature) => {
-      return feature.data.reduce((acc, val) => {
-        const [min, max] = acc;
-        return [Math.min (min, val), Math.max (max, val)];
-      }, acc);
-    }, [Infinity, -Infinity]);
-
-    console.log('addLineLayers: ' + features.length + ' non-empty features, overall min = ' + min + ', max = ' + max);
-
-    if (min === Infinity) {
-      min = 0;
-      max = 1;
-    }
-
-    if (min !== min || max !== max) {
-      console.log('WARNING: min or max is NaN');
-      min = 0;
-      max = 1;
-    }
-
-    const height = this.trackDiv.nativeElement.getBoundingClientRect().height;
-
-    // Now add a line layer for each vector feature
-    const lineLayers = features.map(feature => {
-
-      let duration = 0;
-
-      // Give the plot items positions relative to the start of the
-      // line, rather than relative to absolute time 0. This is
-      // because we'll be setting the layer timeline start property
-      // later on and these will be positioned relative to that
-
-      const plotData = [...feature.data].map((val, i) => {
-        const t = i * feature.stepDuration;
-        duration = t + feature.stepDuration;
-        return {
-          cx: t,
-          cy: val
-        };
-      });
-
-      const lineLayer = new wavesUI.helpers.LineLayer(plotData, {
-        color: colour,
-        height: height,
-        yDomain: [ min, max ]
-      });
-      this.addLayer(
-        lineLayer,
-        this.waveTrack,
-        this.timeline.timeContext
-      );
-
-      // Set start and duration so that the highlight layer can use
-      // them to determine which line to draw values from
-      lineLayer.start = feature.startTime;
-      lineLayer.duration = duration;
-
-      return lineLayer;
-    });
-
-    this.addScaleAndHighlight(this.waveTrack, lineLayers, unit, colour, min, max);
-  }
-
-  private addScaleAndHighlight(waveTrack,
-                               lineLayers,
-                               unit: string,
-                               colour: Colour,
-                               min: number,
-                               max: number) {
-
-    const height = this.trackDiv.nativeElement.getBoundingClientRect().height;
-
-    // And a single scale layer at left
-    // !!! todo: unit in scale layer
-    const scaleLayer = new wavesUI.helpers.ScaleLayer({
-      tickColor: colour,
-      textColor: colour,
-      height: height,
-      yDomain: [ min, max ]
-    });
-    this.addLayer(
-      scaleLayer,
-      waveTrack,
-      this.timeline.timeContext
-    );
-
-    // And a single highlight layer which uses all of the line layers
-    // as its source material
-    this.highlightLayer = new wavesUI.helpers.HighlightLayer(lineLayers, {
-      opacity: 0.7,
-      height: height,
-      color: '#c33c54',
-      labelOffset: 38,
-      yDomain: [ min, max ],
-      unit
-    });
-    this.addLayer(
-      this.highlightLayer,
-      waveTrack,
-      this.timeline.timeContext
-    );
-  }
-
-  // TODO refactor - this doesn't belong here
-  private renderFeatures(extracted: SimpleResponse, colour: Colour): void {
-    if (this.isOneShotExtractor && !this.hasShot) {
-      this.featureExtractionSubscription.unsubscribe();
-      this.hasShot = true;
-    }
-
-    if (!extracted.hasOwnProperty('features')
-      || !extracted.hasOwnProperty('outputDescriptor')) {
-      return;
-    }
-    if (!extracted.features.hasOwnProperty('shape')
-      || !extracted.features.hasOwnProperty('collected')) {
-      return;
-    }
-    const features: FeatureCollection = (extracted.features as FeatureCollection);
-    const outputDescriptor = extracted.outputDescriptor;
-    const height = this.trackDiv.nativeElement.getBoundingClientRect().height;
-
-    let unit = '';
-    if (outputDescriptor.configured.hasOwnProperty('unit')) {
-      unit = outputDescriptor.configured.unit;
-    }
-
-    // TODO refactor all of this
-    switch (features.shape) {
-
-      case 'vector': {
-        const collected = features.collected as VectorFeature;
-        this.addLineLayers([collected], unit, colour);
-        break;
-      }
-
-      case 'tracks': {
-        const collected = features.collected as TracksFeature;
-        this.addLineLayers(collected, unit, colour);
-        break;
-      }
-
-      case 'list': {
-        const featureData = features.collected as FeatureList;
-        if (featureData.length === 0) {
-          return;
-        }
-
-        // TODO refactor, this is incomprehensible
-        try {
-          const featureShape = deduceHigherLevelFeatureShape(
-            featureData,
-            outputDescriptor
-          );
-          switch (featureShape) {
-            case 'instants':
-              const plotData = featureData.map(feature => ({
-                time: toSeconds(feature.timestamp),
-                label: feature.label
-              }));
-              const featureLayer = new wavesUI.helpers.TickLayer(plotData, {
-                height: height,
-                color: colour,
-                labelPosition: 'bottom',
-                shadeSegments: true
-              });
-              this.addLayer(
-                featureLayer,
-                this.waveTrack,
-                this.timeline.timeContext
-              );
-              break;
-            case 'regions':
-              this.renderRegions(
-                featureData,
-                outputDescriptor,
-                this.waveTrack,
-                height,
-                colour
-              );
-              break;
-            case 'notes':
-              const notes = mapFeaturesToNotes(featureData, outputDescriptor);
-              let [min, max] = notes.reduce((acc, note) => {
-                const [min, max] = acc;
-                return [Math.min (min, note.pitch), Math.max (max, note.pitch)];
-              }, [Infinity, -Infinity]);
-              if (min === Infinity || min < 0 || max < 0) {
-                min = 0;
-                max = 127;
-              }
-              // round min and max to octave boundaries (starting at C as in MIDI)
-              min = 12 * Math.floor(min / 12);
-              max = 12 * Math.ceil(max / 12);
-              const pianoRollLayer = new wavesUI.helpers.PianoRollLayer(
-                notes,
-                {height: height, color: colour, yDomain: [min, max] }
-              );
-              this.addLayer(
-                pianoRollLayer,
-                this.waveTrack,
-                this.timeline.timeContext
-              );
-              this.addScaleAndHighlight(
-                this.waveTrack,
-                [pianoRollLayer],
-                '',
-                colour,
-                min,
-                max
-              );
-              break;
-          }
-        } catch (e) {
-          console.warn(e); // TODO display
-          break;
-        }
-        break;
-      }
-      case 'matrix': {
-        const collected = features.collected as MatrixFeature;
-        const startTime = collected.startTime; // !!! + make use of
-        const stepDuration = collected.stepDuration;
-        const matrixData = collected.data;
-
-        if (matrixData.length === 0) {
-          return;
-        }
-
-        console.log('matrix data length = ' + matrixData.length);
-        console.log('height of first column = ' + matrixData[0].length);
-        const targetValue = estimatePercentile(matrixData, 95);
-        const gain = (targetValue > 0.0 ? (1.0 / targetValue) : 1.0);
-        const matrixEntity =
-          new wavesUI.utils.PrefilledMatrixEntity(matrixData,
-            0, // startTime
-            stepDuration);
-        const matrixLayer = new wavesUI.helpers.MatrixLayer(matrixEntity, {
-          gain,
-          top: 0,
-          height: height,
-          normalise: 'none',
-          mapper: iceMapper()
-        });
-        this.addLayer(
-          matrixLayer,
-          this.waveTrack,
-          this.timeline.timeContext
-        );
-        break;
-      }
-      default:
-        console.log(
-          `Cannot render an appropriate layer for feature shape '${features.shape}'`
-        );
-    }
-
-    this.isLoading = false;
-    this.ref.markForCheck();
-    this.timeline.tracks.update();
-    this.animate();
-  }
-
-  private animate(): void {
-    if (!this.isSeeking) {
-      return;
-    }
-
-    this.ngZone.runOutsideAngular(() => {
-      // listen for time passing...
-      const updateSeekingCursor = () => {
-        const currentTime = this.audioService.getCurrentTime();
-        this.cursorLayer.currentPosition = currentTime;
-        this.cursorLayer.update();
-
-        if (this.highlightLayer) {
-          this.highlightLayer.currentPosition = currentTime;
-          this.highlightLayer.update();
-        }
-
-        const currentOffset = this.timeline.timeContext.offset;
-        const offsetTimestamp = currentOffset
-          + currentTime;
-
-        const visibleDuration = this.timeline.timeContext.visibleDuration;
-        // TODO reduce duplication between directions and make more declarative
-        // this kinda logic should also be tested
-        const mustPageForward = offsetTimestamp > visibleDuration;
-        const mustPageBackward = currentTime < -currentOffset;
-
-        if (mustPageForward) {
-          const hasSkippedMultiplePages = offsetTimestamp - visibleDuration > visibleDuration;
-
-          this.timeline.timeContext.offset = hasSkippedMultiplePages ?
-            -currentTime +  0.5 * visibleDuration :
-            currentOffset - visibleDuration;
-          this.timeline.tracks.update();
-        }
-
-        if (mustPageBackward) {
-          const hasSkippedMultiplePages = currentTime + visibleDuration < -currentOffset;
-          this.timeline.timeContext.offset = hasSkippedMultiplePages ?
-            -currentTime + 0.5 * visibleDuration :
-            currentOffset + visibleDuration;
-          this.timeline.tracks.update();
-        }
-
-        if (this.audioService.isPlaying()) {
-          requestAnimationFrame(updateSeekingCursor);
-        }
-      };
-      updateSeekingCursor();
-    });
-  }
-
-  // TODO not sure how much of the logic in here is actually sensible w.r.t
-  // what it functionally produces
-  private renderRegions(featureData: FeatureList,
-                        outputDescriptor: OutputDescriptor,
-                        waveTrack: any,
-                        height: number,
-                        colour: Colour) {
-    console.log('Output is of region type');
-    const binCount = outputDescriptor.configured.binCount || 0;
-    const isBarRegion = featureData[0].featureValues.length >= 1 || binCount >= 1 ;
-    const getSegmentArgs = () => {
-      if (isBarRegion) {
-
-        // TODO refactor - this is messy
-        interface FoldsToNumber<T> {
-          reduce(fn: (previousValue: number,
-                      currentValue: T,
-                      currentIndex: number,
-                      array: ArrayLike<T>) => number,
-                 initialValue?: number): number;
-        }
-
-        // TODO potentially change impl., i.e avoid reduce
-        const findMin = <T>(arr: FoldsToNumber<T>,
-                            getElement: (x: T) => number): number => {
-          return arr.reduce(
-            (min, val) => Math.min(min, getElement(val)),
-            Infinity
-          );
-        };
-
-        const findMax = <T>(arr: FoldsToNumber<T>,
-                            getElement: (x: T) => number): number => {
-          return arr.reduce(
-            (min, val) => Math.max(min, getElement(val)),
-            -Infinity
-          );
-        };
-
-        const min = findMin<Feature>(featureData, (x: Feature) => {
-          return findMin<number>(x.featureValues, y => y);
-        });
-
-        const max = findMax<Feature>(featureData, (x: Feature) => {
-          return findMax<number>(x.featureValues, y => y);
-        });
-
-        const barHeight = 1.0 / height;
-        return [
-          featureData.reduce((bars, feature) => {
-            const staticProperties = {
-              x: toSeconds(feature.timestamp),
-              width: toSeconds(feature.duration),
-              height: min + barHeight,
-              color: colour,
-              opacity: 0.8
-            };
-            // TODO avoid copying Float32Array to an array - map is problematic here
-            return bars.concat([...feature.featureValues]
-              .map(val => Object.assign({}, staticProperties, {y: val})));
-          }, []),
-          {yDomain: [min, max + barHeight], height: height} as any
-        ];
-      } else {
-        return [featureData.map(feature => ({
-          x: toSeconds(feature.timestamp),
-          width: toSeconds(feature.duration),
-          color: colour,
-          opacity: 0.8
-        })), {height: height}];
-      }
-    };
-
-    const segmentLayer = new wavesUI.helpers.SegmentLayer(
-      ...getSegmentArgs()
-    );
-    this.addLayer(
-      segmentLayer,
-      waveTrack,
-      this.timeline.timeContext
-    );
-  }
-
-  private addLayer(layer: Layer, track: Track, timeContext: any, isAxis: boolean = false): void {
-    timeContext.zoom = 1.0;
-    if (!layer.timeContext) {
-      layer.setTimeContext(isAxis ?
-        timeContext : new wavesUI.core.LayerTimeContext(timeContext));
-    }
-    track.add(layer);
-    this.layers.push(layer);
-    layer.render();
-    layer.update();
-    if (this.cursorLayer && track.$layout.contains(this.cursorLayer.$el)) {
-      track.$layout.appendChild(this.cursorLayer.$el);
-    }
-  }
-
-  ngOnDestroy(): void {
-    if (this.featureExtractionSubscription) {
-      this.featureExtractionSubscription.unsubscribe();
-    }
-    if (this.playingStateSubscription) {
-      this.playingStateSubscription.unsubscribe();
-    }
-    if (this.seekedSubscription) {
-      this.seekedSubscription.unsubscribe();
-    }
-    if (this.onAudioDataSubscription) {
-      this.onAudioDataSubscription.unsubscribe();
-    }
-  }
-
-  seekStart(): void {
-    this.zoomOnMouseDown = this.timeline.timeContext.zoom;
-    this.offsetOnMouseDown = this.timeline.timeContext.offset;
-  }
-
-  seekEnd(x: number): void {
-    const hasSameZoom: boolean = this.zoomOnMouseDown ===
-      this.timeline.timeContext.zoom;
-    const hasSameOffset: boolean = this.offsetOnMouseDown ===
-      this.timeline.timeContext.offset;
-    if (hasSameZoom && hasSameOffset) {
-      this.seek(x);
-    }
-  }
-
-  seek(x: number): void {
-    if (this.timeline) {
-      const timeContext: any = this.timeline.timeContext;
-      const timeX = timeContext.timeToPixel.invert(x) - timeContext.offset;
-      if (this.isSeeking) {
-        this.audioService.seekTo(timeX);
-      } else {
-        if (this.highlightLayer) {
-          this.highlightLayer.currentPosition = timeX;
-          this.highlightLayer.update();
-        }
-      }
-    }
-  }
-}
-
-function deduceHigherLevelFeatureShape(featureData: FeatureList,
-                                       descriptor: OutputDescriptor)
-: HigherLevelFeatureShape {
-  // TODO look at output descriptor instead of directly inspecting features
-  const hasDuration = descriptor.configured.hasDuration;
-  const binCount = descriptor.configured.binCount;
-  const isMarker = !hasDuration
-    && binCount === 0
-    && featureData[0].featureValues == null;
-
-  const isMaybeNote = getCanonicalNoteLikeUnit(descriptor.configured.unit)
-    && [1, 2].find(nBins => nBins === binCount);
-
-  const isRegionLike = hasDuration && featureData[0].timestamp != null;
-
-  const isNote = isMaybeNote && isRegionLike;
-  const isRegion = !isMaybeNote && isRegionLike;
-  if (isMarker) {
-    return 'instants';
-  }
-  if (isNote) {
-    return 'notes';
-  }
-  if (isRegion) {
-    return 'regions';
-  }
-  throw new Error('No shape could be deduced');
-}
-
-function getCanonicalNoteLikeUnit(unit: string): NoteLikeUnit | null {
-  const canonicalUnits: NoteLikeUnit[] = ['midi', 'hz'];
-  return canonicalUnits.find(canonicalUnit => {
-    return unit.toLowerCase().indexOf(canonicalUnit) >= 0;
-  });
-}
-
-function mapFeaturesToNotes(featureData: FeatureList,
-                            descriptor: OutputDescriptor): Note[] {
-  const canonicalUnit = getCanonicalNoteLikeUnit(descriptor.configured.unit);
-  const isHz = canonicalUnit === 'hz';
-  return featureData.map(feature => ({
-    time: toSeconds(feature.timestamp),
-    duration: toSeconds(feature.duration),
-    pitch: isHz ?
-      frequencyToMidiNote(feature.featureValues[0]) : feature.featureValues[0]
-  }));
-}
-
-function frequencyToMidiNote(frequency: number,
-                             concertA: number = 440.0): number {
-  return 69 + 12 * Math.log2(frequency / concertA);
-}
diff -r f87a96ab1e3f -r 82d476b976e0 src/app/waveform/waves-ui-piper.d.ts
--- a/src/app/waveform/waves-ui-piper.d.ts	Thu May 25 17:52:46 2017 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,119 +0,0 @@
-/// <reference path="../../../node_modules/@types/node/index.d.ts"/>
-declare const AmbientInstance: WavesUserInterface;
-
-declare module 'waves-ui-piper' {
-  export default AmbientInstance;
-}
-
-interface WavesUserInterface {
-  core: Core;
-  helpers: any;
-  states: any;
-  utils: Utilities;
-  shapes: any;
-}
-
-interface MatrixEntity {
-  getColumnCount(): number;
-  getColumnHeight(): number;
-  getColumn(n: number): Float32Array | number[];
-  getStepDuration(): number;
-  getStartTime(): number;
-  dispose(): void;
-}
-
-type TimeContext = any; // TODO
-
-interface Area {
-  top: number;
-  left: number;
-  width: number;
-  height: number;
-}
-
-interface Layer extends NodeJS.EventEmitter {
-  start: number;
-  offset: number;
-  duration: number;
-  stretchRatio: number;
-  yDomain: number[];
-  opacity: number;
-  readonly timeToPixel: () => (time: number) => number;
-  readonly valueToPixel: () => (value: number) => number;
-  readonly items: Element[];
-  readonly selectedItems: Element[];
-  data: ArrayLike<any> | Object;
-  destroy(): void;
-  configureTimeContextBehaviour(ctor: ObjectConstructor): void;
-  setTimeContext(context: TimeContext): void;
-  configureShape(ctor: ObjectConstructor /* TODO BaseShape*/,
-                 accessors: Object,
-                 options: Object): void;
-  configureCommonShape(ctor: ObjectConstructor /* TODO BaseShape*/,
-                       accessors: Object,
-                       options: Object): void;
-  setBehaviour(behaviour: Object /* TODO BaseBehavior */): void;
-  select(...$items: Element[]);
-  unselect(...$items: Element[]);
-  toggleSelection(...$items: Element[]);
-  edit($items: Element[], dx: number, dy: number, $target: Element): void;
-  setContextEditable(bool: boolean): void;
-  editContext(dx: number, dy: number, $target: Element): void;
-  stretchContext(dx: number, dy: number, $target: Element): void;
-  getItemFromDOMElement($el: Element): Element | null;
-  getDatumFromItem($item: Element): Object | any[] | null;
-  getDatumFromDOMElement($item: Element): Object | any[] | null;
-  hasItem($item: Element): boolean;
-  hasElement($el: Element): boolean;
-  getItemsInArea(area: Area): Element[];
-  render(): void;
-  update(): void;
-  updateContainer(): void;
-  updateShapes(): void;
-}
-
-interface LayerConstructor {
-  new(dataType: 'entity' | 'collection',
-      data: ArrayLike<any> | Object,
-      options: Object): Layer;
-}
-
-interface MatrixEntityConstructor {
-  new(): MatrixEntity;
-}
-
-interface PrefilledMatrixEntityConstructor {
-  new(data: Float32Array[] | number[][],
-      startTime: number,
-      stepDuration: number): MatrixEntity;
-}
-
-interface Utilities {
-  MatrixEntity: MatrixEntityConstructor;
-  PrefilledMatrixEntity: PrefilledMatrixEntityConstructor;
-  scales: any;
-}
-
-interface Core {
-  Layer: LayerConstructor;
-  LayerTimeContext: any; // TODO
-  Timeline: any; // TODO
-  TimelineTimeContext: TimelineTimeContextConstructor;
-}
-
-type Timeline = any;
-
-interface TimelineTimeContext {
-  pixelsPerSecond: number;
-  readonly computedPixelsPerSecond: number;
-  offset: number;
-  zoom: number;
-  visibleWidth: number;
-  readonly visibleDuration: number;
-  maintainVisibleDuration: boolean;
-  timeToPixel: (time: number) => number;
-}
-
-interface TimelineTimeContextConstructor {
-  new(pixelsPerSecond: number, visibleWidth: number): TimelineTimeContext;
-}