# Wednesday, 11 December 2013

In my last article in this series, I covered a few of the new features introduced with CSS3. This article introduces some more new CSS features.

A WORD ABOUT COMPATIBILITY

Most browser vendors began working on CSS3 features before they became full recommendations by the W3C. As a result, some implementations are specific to certain browsers. To accommodate these, it is sometimes necessary to precede a style name with a vendor prefix, as in the following example:

#title {
    transform:rotate(-15deg);
    -ms-transform:rotate(-15deg); 
    -moz-transform:rotate(-15deg);
    -webkit-transform:rotate(-15deg);
    -o-transform:rotate(-15deg); 
}

 

Below is a list of prefixes and the browser(s) for which they are intended.

Style feature Browser(s)
feature W3C Standard
-ms-feature Internet Explorer
-moz-feature Firefox
-webkit-feature Safari and Chrome
-o-feature Opera

TRANSFORM

The new “transform” style can be used to rotate skew, or scale an object. Let’s go over each of these.

ROTATE

The “transform:rotate” style rotates an object around its center point. It accepts an argument indicating the amount by which to rotate – positive values rotate clockwise and negative numbers rotate counter-clockwise. The example below rotates an object 15 degrees counter-clockwise from the horizontal.

#Div1 {
   transform:rotate(-15deg);
} 

This is one of the styles that requires vendor-specific prefixes in order to work in all browsers. With the prefixes in place, you will need to add the following styles

#Div1 {
   transform:rotate(-15deg);
   -ms-transform:rotate(-15deg); /* IE  */
   -moz-transform:rotate(-15deg); /* Firefox */
   -webkit-transform:rotate(-15deg); /* Safari, Chrome */
   -o-transform:rotate(-15deg); /* Opera */
} 

The results would look something like this:

image

SKEW

The “transform:skew” style tilts an objects tilt an object. There are three variations of this style: “transform:skewX” (which tilts an object along the x-axis); “transform:skewY” (which tilts an object along the y-axis); and “transform:skew” (which tilts an object along both axes). The first two styles accept a single parameter, indicating how many degrees to tilt the object in the appropriate direction.  The third style accepts 2 parameters: one for the x-tilt and one for the y-tilt. Positive arguments skew an object up or to the right; negative arguments tilt it down or to the left.

This style still requires the vendor-specific prefixes to make it work on all browsers.

An example is below

   #x
   {
    transform: skewX(150deg);
    -ms-transform: skewX(150deg);
    -moz-transform: skewX(150deg);
    -webkit-transform: skewX(150deg);
    -o-transform: skewX(150deg);
   } 

This will skew Div1 similar to the following

image

SCALE

The “transform:scale” style and its variations resize an object. There are three variations of this style: “transform:scaleX” (which resizes an object horizontally); “transform:scaleY” (which resizes an object vertically); and “transform:scale” (which resizes an object along both axes). These styles all accept a parameter to indicate the factor by which to resize the target selected object or objects. A factor greater than 1 will make an object larger, while a factor below 1 will shrink the object.

This style is ideal for event filter selections, such as “:hover”, which is applied when the user move his or her mouse over an object.

The “transform:scale” style still requires the vendor-specific prefixes to make it work on all browsers.

An example is below

#Div1: hover
{
    transform: scale(factor);
    -ms-transform: scale(factor);
    -moz-transform: scale(factor);
    -webkit-transform: scale(factor);
    -o-transform: scale(factor);
} 

ANIMATIONS

The “animation” style allows you to transition from one style to another and to control how and how long that transition takes place. This is done by referencing a keyframes declaration that lists the styles and how the transition should occur. In the following example, the “blackgraywhite” keyframe defines the background color of an object changing from black through various shades of gray to white.

@keyframes blackgraywhite
   {
    0%   {background: #000000;}
    25%  {background: #777777;}
    50%  {background: #aaaaaa;}
    75%  {background: #dddddd;}
    100% {background: #ffffff;}
   }
#Div1
{
 animation:  blackgraywhite 8s;
}

Applying the “animation: blackgraywhite” style to Div1 causes it to start out black and slowly transform to white. The entire transition lasts 8 seconds, thanks to the parameter at the end.

We can reverse the transition (from white, back to black) by adding the optional “alternate” argument and we can keep this transition going forever by adding the optional “infinite” argument.

#Div1
{
 animation:  blackgraywhite 8s infinite alternate;
} 

TRANSITIONS

Transitions are similar to animations in that you can define how long it takes to apply a style; however, they apply to other applied styles and they are typically in response to user event filters, such as “:hover”. By default, when such a style is applied (when the user moves the mouse over an object), the new style is applied instantly. To apply a transition, define two style sets and add the “transition” style to the first one. The transition allows arguments to specify how long a transition will take and what to which styles the transition applies.  The sample below tells the browser to change green text on a white background to white text on a green background and to take 2 seconds to make this transition.

#Div1 {
    background: white;
    color:green
    transition: all 2s;
}
#Div1:hover {
    background: green;
    color:white
}

CONCLUSION

In this and in the previous article of this series, we covered many of the new features of CSS3.

HTML5 | Web