What is a Timeline in ATF

A timeline is a graphical representation of a time sequence. It contains events, which start at some time and have an arbitrary duration. In the figure, the ATF Timeline Editor Sample shows a timeline in an opened file. The x-axis represents time.

A timeline consists of a hierarchy of objects:

• Timeline: Time sequence containing all the other timeline objects, such as groups. The figure shows a timeline with one group.
  • Marker: An event of zero-length time duration on all tracks in a timeline. The figure shows several markers, vertical lines through all tracks in the timeline.
  • Timeline Reference: Reference to a timeline (in a file) that can be displayed in another timeline.
  • Group: Container for zero or more tracks. The figure shows that the group has several tracks — labeled horizontal bars extending along the entire x-axis.
    • Track: Contains zero or more events.
      • Interval: An event of zero or greater time duration on a single track. Intervals on a single track do not overlap. The tracks in the illustration have several intervals — horizontal, labeled, colored bands along the track.
      • Key: An event of zero-length time duration on a single track.

There are several types of events:

• Interval
• Key
• Marker

Each of these objects has an associated interface. For a description of what these do, see Timeline Interfaces.

The figure shows expanded and collapsed groups, a (collapsed) reference, keys, intervals, markers and the scrubber. The scrubber is a vertical black line that is visible on the timeline, but is not part of the timeline. Events are raised when you move the scrubber, and your application can take some action in response to these events.

Timeline support resides in two namespaces in two assemblies:

• Sce.Atf.Controls.Timelines: Timeline classes and interfaces that are UI-platform-agnostic (i.e., don't depend on Windows® Forms or WPF). In the Atf.Gui assembly.
• Sce.Atf.Controls.Timelines.Direct2D: Classes for working with timeline elements, including a renderer, control, and manipulators, that are dependent on the Windows® Forms UI platform and use Direct2D to render timeline objects. (There are no WPF counterparts). In the Atf.Gui.WinForms assembly.

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