Audio Display

Seriously needs a rewrite, some of the most horrible code present in Aegisub. Nobody wants to touch it.

Table of Contents

1. Audio Display
   1. Timeline
   2. Audio view
   3. Secondary markers
   4. Audio selection

Here's an order it should draw things in. Each thing is also a component, and for each, that components's responsibilities and other properties are listed.

Timeline

At the bottom of the display. Shows the range of time currently in view, with hours:minutes:seconds markers, sub-second markers. Dragging it scrolls the view.

Audio view

A view of the actual audio data.

• Drawn by one of several different renderers (waveform, spectrum...)
• Possibly an internal bitmap cache
• Has to know the selected area from a later stage

Secondary markers

These are helper lines showing additional information to the user.

• Have a list of "providers", each supplies a list of visible markers given the range of samples visible.
• Each provider also supplies a visual style for itself.
• Markers from a provider can be snappable or not. (Dragging an audio selection point can snap to that marker or not.)
• Examples of these markers: Scene change points, current video frame's time, a marker every second, start/end times of unselected lines...

Audio selection

The primary thing the user interacts with: The selected audio.

• Different "mode" providers, switching from line timing to karaoke timing changes to a different selection provider. Possibly add more modes in the future, such as time shifting.
• Supplies a list of draggable markers, each with a style. A marker may be allowed to snap to secondary markers or not.
• Receives dragging and clicking events that don't go to anything else.
• Dragging a marker is handled by the audio display, only the "marker was moved" event is sent, not raw mouse down/up/move when a drag is going on.
• Knows about the "selection" range, has to supply this to the audio view renderer.