diff src/app/visualisations/waveform/waveform.component.ts @ 347:82d476b976e0

Move waveform.component and remove all logic not concerned with rendering an audio buffer as a waveform. Wire app in app.component.

--- /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);
+      }
+    }
+  }
+}