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Custom Views

When a host opens your audio unit, it asks if there’s a custom view available. If so, it can use it as described in “View Instantiation and Initialization.”

Here’s the custom view for the same audio unit described in “The Generic View,” namely, the FilterDemo audio unit from the Core Audio SDK:

The primary feature of this custom view is a realtime frequency response curve. This makes the custom view (and, by association, the audio unit) more attractive and far more useful. Instead of seeing just a pair of numbers, a user can now see the frequency response, including how filter resonance and cutoff frequency influence the response. No matter what sort of audio unit you build, you can provide similar benefits to users when you include a custom view with your audio unit.

The advantages of custom views over generic views include:

• The ability to hide unneeded detail, or to provide progressive disclosure of controls

• The ability to provide support for parameter automation

• Choice of user-interface controls, for example knobs, faders, or horizontal sliders

• Much more information for the user through real-time graphs, such as frequency response curves

• A branding opportunity for your company

The SDK’s FilterDemo audio unit project is a good example to follow when creating a custom view for your audio unit. See “Tutorial: Demonstrating Parameter Gestures and Audio Unit Events” later in this chapter for more on custom views.

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