Using CSS3 for transitions in web applications

CSS3 specification includes support for transitions which allows to change properties from one state to another. Classic example of transition in HTML include behavior defined under the ‘hover’ keyword. However, unlike the behavior observed with ‘hover’ keyword, CSS3 transitions have a time lapse element.

CSS transitions are used to change styles from one to another.

To use CSS transitions , we need to specify the property for which we want to add an effect, as well as the duration for the effect.

Note that transitions are a presentational effect and only work with animatable CSS properties.

The following chart indicates the CSS properties which are animatable:

We define a transition using two new CSS properties.

• transition-property
• transition-duration

A typical CSS transition is of the following format

div

{

transition-property: propertyname;

transition-duration: duration;

}

E.g.

div

{

transition-property: color, #(100,100,100);

transition-duration: 2s;

}

If you want to specify multiple transitions, you need to specify them as comma-separated-values.

div

{

transition-property: first_propertyname, second_propertyname, …;

transition-duration: duration_for_first, duration_for_second,…;

}

In case the number of transition properties and transition duration are not equal, the length of transition-property list determines the number of items in each list examined when starting transitions.

When the number of transition-properties are multiple of items in transition-duration, the duration durations are cycled. In case they are not multiple, they are used until there are a multiple and the remaining values are ignored.

We can also specify ‘none’ as value for transition-property , which would imply that no properties are transitioned.

We can also specify ‘0s’ as value for transition-duration, which would imply an immediate transition.

There are two additional transition relate properties:

1.       transition-timing – which specifies how fast/slow the transitions will occur.

2.       transition-delay – which specifies how long to wait to start the transition after transition is initiated.

Here is an example of a simple transition:

input {

transition-property: width;

transition-duration: 1s;

transition-timing-function: linear;

transition-delay: 2s;

}

Here is a simple HTML page which shows transition in play.

Hover over the input element above, to see the transition effect.

When we hover over the orange input box, the length of the box changes. This is CSS3 transition in action.

Summary

In this article, we saw how to use CSS3 transitions in web pages. I hope you have found this information useful.

About the author

Vipul Patel is a Program Manager currently working at Amazon Corporation. He has formerly worked at Microsoft in the Lync team and in the .NET team (in the Base Class libraries and the Debugging and Profiling team). He can be reached at vipul.patel@hotmail.com

References

http://www.w3.org/TR/css3-transitions/