Table of Contents

Class WaveformView

Namespace
PluginUI
Assembly
PluginUI.dll

Sample display for samplers and audio editors: one lane per channel, zoom and scroll, start / end and loop markers (draggable, optionally bound to parameters), a selection, a play cursor and WAV file drop.

public class WaveformView : Control
Inheritance
WaveformView
Inherited Members

Examples

var wave = new WaveformView { AcceptFileDrop = true, ShowLoop = true, StartParameter = Parameters[model.Start] };
wave.Audio = WavReader.Read(@"C:\Samples\kick.wav");
wave.PlayPositionSource = () => processor.PlayPosition; // normalized, read every frame

Remarks

Mouse. Wheel scrolls, Ctrl + wheel zooms around the pointer, double-click on the background zooms to fit, dragging a marker moves it, Shift + drag selects a range.

Performance. A multi-resolution min/max summary (WaveformPeaks) is built once per channel, so even very long samples are drawn by reading a few values per pixel; when zoomed in to less than one sample per pixel the samples themselves are drawn as a line.

Markers. Positions are normalized (0 = first sample, 1 = last). When a marker parameter is set (StartParameter…), its normalized value is the position and drags send edit gestures.

Constructors

WaveformView()

Creates a waveform view.

public WaveformView()

Properties

AcceptFileDrop

Accepts audio files dropped from the Explorer (WAV files are decoded with WavReader).

public bool AcceptFileDrop { get; set; }

Property Value

bool

Audio

The audio displayed (null = empty). Setting it zooms to fit and clears the selection.

[Browsable(false)]
public AudioData? Audio { get; set; }

Property Value

AudioData

DefaultSize

Natural size used when no explicit size is given.

protected override Size DefaultSize { get; }

Property Value

Size

EndParameter

Parameter holding the sample end.

public IParameter? EndParameter { get; set; }

Property Value

IParameter

EndPosition

Sample end (normalized).

public double EndPosition { get; set; }

Property Value

double

Length

Number of frames of Audio.

[Browsable(false)]
public long Length { get; }

Property Value

long

LoopEnd

Loop end (normalized).

public double LoopEnd { get; set; }

Property Value

double

LoopEndParameter

Parameter holding the loop end.

public IParameter? LoopEndParameter { get; set; }

Property Value

IParameter

LoopStart

Loop start (normalized).

public double LoopStart { get; set; }

Property Value

double

LoopStartParameter

Parameter holding the loop start.

public IParameter? LoopStartParameter { get; set; }

Property Value

IParameter

PlayPosition

Play cursor position (normalized; NaN = hidden).

public double PlayPosition { get; set; }

Property Value

double

PlayPositionSource

Function polled every frame for the play cursor (e.g. a volatile value written by the audio thread).

[Browsable(false)]
public Func<double>? PlayPositionSource { get; set; }

Property Value

Func<double>

SelectionEnd

End frame (exclusive) of the selection; equal to SelectionStart when nothing is selected.

[Browsable(false)]
public long SelectionEnd { get; set; }

Property Value

long

SelectionStart

First frame of the selection.

[Browsable(false)]
public long SelectionStart { get; set; }

Property Value

long

ShowLoop

Shows (and allows dragging) the loop markers.

public bool ShowLoop { get; set; }

Property Value

bool

ShowStartEnd

Shows (and allows dragging) the start and end markers.

public bool ShowStartEnd { get; set; }

Property Value

bool

StartParameter

Parameter holding the sample start (normalized value = position).

public IParameter? StartParameter { get; set; }

Property Value

IParameter

StartPosition

Sample start (normalized); ignored when StartParameter is set.

public double StartPosition { get; set; }

Property Value

double

ViewLength

Number of visible frames.

[Browsable(false)]
public double ViewLength { get; set; }

Property Value

double

ViewStart

First visible frame.

[Browsable(false)]
public double ViewStart { get; set; }

Property Value

double

WaveColor

Waveform color (null = theme accent).

public Color? WaveColor { get; set; }

Property Value

Color?

Methods

MoveMarker(WaveformMarker, double)

Moves a marker as the user would (constrained: start ≤ end, loop start ≤ loop end; bound parameters are edited).

public void MoveMarker(WaveformMarker marker, double position)

Parameters

marker WaveformMarker

The marker.

position double

New normalized position.

OnAttached()

Called when the element joins a host (subscribe to external events here).

protected override void OnAttached()

OnCaptureLost()

The mouse capture was lost without a button release.

protected override void OnCaptureLost()

OnDetached()

Called when the element leaves its host (unsubscribe here).

protected override void OnDetached()

OnFilesDropped(FilesDroppedEventArgs)

Files dropped from the shell (requires AllowFileDrop on this element or an ancestor).

protected override void OnFilesDropped(FilesDroppedEventArgs e)

Parameters

e FilesDroppedEventArgs

OnMouseDown(MouseEventArgs)

Mouse button pressed over the element (or captured).

protected override void OnMouseDown(MouseEventArgs e)

Parameters

e MouseEventArgs

OnMouseMove(MouseEventArgs)

Mouse moved over the element (or captured).

protected override void OnMouseMove(MouseEventArgs e)

Parameters

e MouseEventArgs

OnMouseUp(MouseEventArgs)

Mouse button released.

protected override void OnMouseUp(MouseEventArgs e)

Parameters

e MouseEventArgs

OnMouseWheel(MouseEventArgs)

Mouse wheel over the element.

protected override void OnMouseWheel(MouseEventArgs e)

Parameters

e MouseEventArgs

RenderVector(DrawingContext, Rect, VectorStyle)

Vector rendering of the widget area.

protected override void RenderVector(DrawingContext dc, Rect widget, VectorStyle style)

Parameters

dc DrawingContext
widget Rect
style VectorStyle

Zoom(double, double)

Zooms by a factor around a frame (factor < 1 zooms in).

public void Zoom(double factor, double aroundFrame)

Parameters

factor double

Ratio between the new and the current visible length.

aroundFrame double

Frame that stays under the same pixel.

ZoomToFit()

Shows the whole sample.

public void ZoomToFit()

Events

AudioLoaded

Raised after a dropped WAV file was loaded (argument: path).

public event Action<WaveformView, string>? AudioLoaded

Event Type

Action<WaveformView, string>

FileDropped

Raised for dropped files that are not WAV, or WAV files that could not be decoded (argument: path).

public event Action<WaveformView, string>? FileDropped

Event Type

Action<WaveformView, string>

MarkerMoved

Raised after a marker was moved by the user.

public event Action<WaveformView, WaveformMarker>? MarkerMoved

Event Type

Action<WaveformView, WaveformMarker>

SelectionChanged

Raised after the user changed the selection.

public event Action<WaveformView>? SelectionChanged

Event Type

Action<WaveformView>
Edit this page