September 12, 2000 - The HTML+TIME Timeline | WebReference

September 12, 2000 - The HTML+TIME Timeline

Yehuda Shiran September 12, 2000
The HTML+TIME Timeline
Tips: September 2000

Yehuda Shiran, Ph.D.
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Internet Explorer's HTML+TIME unifies two timing models: the rigid timeline and event-based relationships. Using a rigid timeline, it is easy to generate timeline behaviors, such as sequences and precise synchronization of media elements. A traditional animation is a perfect application for a rigid timeline. The animation's pictures are played according to a pre-defined and rigid sequence. The disadvantage of a rigid timeline is that it is difficult to generate interaction with it. You can overcome the rigidity of a timeline by jumping between timelines. Event-based timing lends itself to interactive behaviors. The drawback of event-based timing is that it is difficult to generate sequences and precise synchronization of elements with it.

HTML+TIME takes the best of each timing model, simplifying the process of authoring both timed and interactive content. The HTML+TIME model lets you use timeline attributes to describe static, rigid timeline relationships. This is how you ensure synchronization among media elements. On the other hand, you can associate timelines with events, such as clicking a button or mousing over text. This unified model lets you synchronize media elements, as well as add interactive elements. These interactive elements can start when the user does something, and can have a duration and a repeat count, just like other rigidly-timed elements.

As you have already noticed from the frequency we use the word timeline in this tip, the concept of a timeline is central to HTML+TIME. HTML+TIME defines a timeline for all affected elements. The document timeline starts as soon as the page loads and continues as long as the browser renders the page. You can specify that an element's timeline will be synchronized to the document's timeline, or to other elements' timelines. You can pause and resume the document timeline using the object model's methods. Media files that are not completely loaded when scheduled to start will begin playing as soon as they are ready.

Learn more about HTML+TIME in Column 67, Introduction to HTML+TIME.