<timeline-range-name>

Syntax

Valid <timeline-range-name> values:

cover

Represents the full range of a view progress timeline, from the point where the subject element's start border edge first enters the scrollport's view progress visibility range (0% progress) to the point where the end border edge has completely left it (100% progress).

contain

Represents the range of a view progress timeline where the subject element is fully contained by, or fully contains, the view progress visibility range within the scrollport

• If the subject element is smaller than the scrollport, it ranges from the point where the subject element is first completely contained by the scroll port (0% progress), to the point where it is no longer completely contained by the scroll port (100% progress).
• If the subject element is larger than the scrollport, it ranges from the point where the subject element first completely covers the scroll port (0% progress), to the point where it no longer completely covers the scrollport (100% progress).

entry

Represents the range of a view progress timeline from the point where the subject element first starts to enter the scroll port, to the point where it has completely entered the scrollport. 0% is equivalent to 0% of the cover range. 100% is equivalent to 0% of the contain range.

exit

Represents the range of a view progress timeline from the point where the subject element first starts to exit the scroll port, to the point where it has completely exited the scrollport. 0% is equivalent to 0% of the contain range. 100% is equivalent to 0% of the cover range.

entry-crossing

Represents the range during which the principal box crosses the end border edge. The start (0% progress) of the range occurs when the start border edge of the element's principal box coincides with the end edge of its view progress visibility range. The end (100%) of the range is the point at which the end border edge of the element's principal box coincides with the end edge of its view progress visibility range. The size of the range is the size of the element's principle box in the scroll direction.

exit-crossing

Represents the range where the principal box crosses the start border edge. The range start (0% progress) occurs when the start border edge of the element's principal box coincides with the start edge of its view progress visibility range. The range end (100% progress) is the point at which the end border edge of the element's principal box coincides with the start edge of its view progress visibility range. The size of the range is the size of the element's principle box in the scroll direction.

Formal syntax

<timeline-range-name> = 
  cover           |
  contain         |
  entry           |
  exit            |
  entry-crossing  |
  exit-crossing   

Examples

See the View timeline range visualizer.

Specifications

Browser compatibility

See also

• animation-range-start, animation-range-end, animation-range
• animation-timeline
• scroll-timeline
• view-timeline-inset
• Scroll-driven animation timelines
• CSS scroll-driven animations module
• View timeline range visualizer