view-timeline-inset
Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.
The view-timeline-inset
CSS property is used to specify one or two values representing an adjustment to the position of the scrollport (see Scroll container for more details) in which the subject element of a named view progress timeline animation is deemed to be visible. Put another way, this allows you to specify start and/or end inset (or outset) values that offset the position of the timeline.
This can be combined with or used instead of animation-range
and its longhand properties, which can be used to set the attachment range of an animation along its timeline.
See CSS scroll-driven animations for more details.
Syntax
css
/* Single value */
view-timeline-inset: auto;
view-timeline-inset: 200px;
view-timeline-inset: 20%;
/* Two values */
view-timeline-inset: 20% auto;
view-timeline-inset: auto 200px;
view-timeline-inset: 20% 200px;
Values
Allowed values for view-timeline-inset
are:
auto
-
If set, the corresponding
scroll-padding
(or equivalent longhand value) for that edge of the scrollport is used. If this is not set (or set toauto
), the value will usually be 0, although some user agents may use heuristics to determine a different default value if appropriate. <length-percentage>
-
Any valid
<length-percentage>
value is accepted as an inset/outset value.- If the value is positive, the position of the animation's start/end will be moved inside the scrollport by the specified length or percentage.
- If the value is negative, the position of the animation's start/end will be moved outside the scrollport by the specified length or percentage, i.e. it will start animating before it appears in the scrollport, or finish animating after it leaves the scrollport.
If two values are provided, the first value represents the start inset/outset in the relevant axis (where the animation begins) and the second value represents the end inset/outset (where the animation ends). If only one value is provided, the start and end inset/outset are both set to the same value.
Formal definition
Formal syntax
Examples
Creating a named view progress timeline with inset
A view progress timeline named --subjectReveal
is defined using the view-timeline
property on a subject element with a class
of animation
.
This is then set as the timeline for the same element using animation-timeline: --subjectReveal;
. The result is that the subject element animates as it moves upwards through the document as it is scrolled.
A view-timeline-inset
declaration is also set to make the animation begin later than expected, and finish earlier.
HTML
The HTML for the example is shown below.
html
<div class="content">
<h1>Content</h1>
<p>
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod
tempor incididunt ut labore et dolore magna aliqua. Risus quis varius quam
quisque id. Et ligula ullamcorper malesuada proin libero nunc consequat
interdum varius. Elit ullamcorper dignissim cras tincidunt lobortis feugiat
vivamus at augue.
</p>
<p>
Dolor sed viverra ipsum nunc aliquet. Sed sed risus pretium quam vulputate
dignissim. Tortor aliquam nulla facilisi cras. A erat nam at lectus urna
duis convallis convallis. Nibh ipsum consequat nisl vel pretium lectus.
Sagittis aliquam malesuada bibendum arcu vitae elementum. Malesuada bibendum
arcu vitae elementum curabitur vitae nunc sed velit.
</p>
<div class="subject animation"></div>
<p>
Adipiscing enim eu turpis egestas pretium aenean pharetra magna ac. Arcu
cursus vitae congue mauris rhoncus aenean vel. Sit amet cursus sit amet
dictum. Augue neque gravida in fermentum et. Gravida rutrum quisque non
tellus orci ac auctor augue mauris. Risus quis varius quam quisque id diam
vel quam elementum. Nibh praesent tristique magna sit amet purus gravida
quis. Duis ultricies lacus sed turpis tincidunt id aliquet. In egestas erat
imperdiet sed euismod nisi. Eget egestas purus viverra accumsan in nisl nisi
scelerisque. Netus et malesuada fames ac.
</p>
</div>
CSS
The subject
element and its containing content
element are styled minimally, and the text content is given some basic font settings:
css
.subject {
width: 300px;
height: 200px;
margin: 0 auto;
background-color: deeppink;
}
.content {
width: 75%;
max-width: 800px;
margin: 0 auto;
}
p,
h1 {
font-family: Arial, Helvetica, sans-serif;
}
h1 {
font-size: 3rem;
}
p {
font-size: 1.5rem;
line-height: 1.5;
}
The <div>
with the class of subject
is also given a class of animation
— this is where view-timeline
is set to define a named view progress timeline. We also give it a view-timeline-inset
declaration to make the animation begin later than expected, and finish earlier. It is also given an animation-timeline
name with the same value to declare that this will be the element animated as the view progress timeline is progressed.
Last, an animation is specified on the element that animates its opacity and scale, causing it to fade in and size up as it moves up the scroller.
css
.animation {
view-timeline: --subjectReveal block;
view-timeline-inset: 70% -100px;
animation-timeline: --subjectReveal;
animation-name: appear;
animation-fill-mode: both;
animation-duration: 1ms; /* Firefox requires this to apply the animation */
}
@keyframes appear {
from {
opacity: 0;
transform: scaleX(0);
}
to {
opacity: 1,
transform: scaleX(1);
}
}
Result
Scroll to see the subject element being animated.
Specifications
Specification |
---|
Scroll-driven Animations # view-timeline-inset |
Browser compatibility
BCD tables only load in the browser