Transforms

With CSS3 came new ways to position and alter elements. Now general layout techniques can be revisited with alternative ways to size, position, and change elements. All of these new techniques are made possible by the transform property.

The transform property comes in two different settings, two-dimensional and three-dimensional. Each of these come with their own individual properties and values.

Within this lesson we’ll take a look at both two-dimensional and three-dimensional transforms. Generally speaking, browser support for the transform property isn’t great, but it is getting better every day. For the best support vendor prefixes are encouraged, however you may need to download the nightly version of Chrome to see all of these transforms in action.

Transform Syntax

The actual syntax for the transform property is quite simple, including the transform property followed by the value. The value specifies the transform type followed by a specific amount inside parentheses.

 div {
  -webkit-transform: scale(1.5);
    -moz-transform: scale(1.5);
       -o-transform: scale(1.5);
         transform: scale(1.5);
           }



           Notice how the transform property includes multiple vendor prefixes to gain the best support across all browsers. The un-prefixed declaration comes last to overwrite the prefixed versions, should a browser fully support the transform property.

In the interest of brevity, the remainder of this lesson will not include vendor prefixes. They are, however, strongly encouraged for any code in a production environment. Over time we will be able to remove these prefixes, however keeping them in is the safest approach for the time being.

2D Transforms

Elements may be distorted, or transformed, on both a two-dimensional plane or a three-dimensional plane. Two-dimensional transforms work on the x and y axes, known as horizontal and vertical axes. Three-dimensional transforms work on both the x and y axes, as well as the z axis. These three-dimensional transforms help define not only the length and width of an element, but also the depth. We’ll start by discussing how to transform elements on a two-dimensional plane, and then work our way into three-dimensional transforms.

• 2D Rotate

The transform property accepts a handful of different values. The rotate value provides the ability to rotate an element from 0 to 360 degrees. Using a positive value will rotate an element clockwise, and using a negative value will rotate the element counterclockwise. The default point of rotation is the center of the element, 50% 50%, both horizontally and vertically. Later we will discuss how you can change this default point of rotation.

      HTML
      <figure class="box-1">Box 1</figure>
         <figure class="box-2">Box 2</figure>

          
       CSS
      .box-1 {
        transform: rotate(20deg);
       }
       .box-2 {
        transform: rotate(-55deg);
         }

Transitions & Animations

One evolution with CSS3 was the ability to write behaviors for transitions and animations. Front end developers have been asking for the ability to design these interactions within HTML and CSS, without the use of JavaScript or Flash, for years. Now their wish has come true.

With CSS3 transitions you have the potential to alter the appearance and behavior of an element whenever a state change occurs, such as when it is hovered over, focused on, active, or targeted.

Animations within CSS3 allow the appearance and behavior of an element to be altered in multiple keyframes. Transitions provide a change from one state to another, while animations can set multiple points of transition upon different keyframes.

• Transitions

As mentioned, for a transition to take place, an element must have a change in state, and different styles must be identified for each state. The easiest way for determining styles for different states is by using the :hover, :focus, :active, and :target pseudo-classes.

There are four transition related properties in total, including transition-property, transition-duration, transition-timing-function, and transition-delay. Not all of these are required to build a transition, with the first three are the most popular.

In the example below the box will change its background color over the course of 1 second in a linear fashion.

       .box {
         background: #2db34a;
        transition-property: background;
         transition-duration: 1s;
          transition-timing-function: linear;
         }
           .box:hover {
           background: #ff7b29;
            }