CSS Aliases for Webkit Prefixes in Opera Presto 2.11

Introduction

Opera supports certain -webkit- prefixes and will use these when applying styles as described here.

Supported Properties

Two different types of prefixes are supported, details regarding how they are supported are below.

  1. -webkit-linear-gradient

    -webkit-linear-gradient and -o-linear-gradient will behave identically and the following rules will be obeyed when evaluating styles.

    • Duplicate properties will not be preserved when both -webkit-linear-gradient and -o-linear-gradient are found. Whichever comes last will override the other.
    • Which name is in use will be tracked, so if the value is retreived from JavaScript, the prefix is remembered.
  2. Properties

    -webkit- prefixed properties are supported through a CSS property aliasing mechanism, and also will obey the following rules.

    • As above, when a -webkit- prefixed property and an -o- prefixed property are encountered, they are treated as instances of the same property, so the latest one (according to usual cascade rules) wins.
    • When accessing or setting the value of a property through JavaScript, all the aliased names of a property are visible as members of the CSSStyleDeclaration object, and they map to the same value.
      • However, the CSSStyleDeclaration .item(*) function will return the canonical name of the alias, not the name actually used. This point may be changed in the future if it is found to cause problems.
    • removeProperty, setProperty, getPropertyValue, and getPropertyPriority all will work with aliases as described above.
    • webkitTransitionEnd is aliased to oTransitionEnd enabling the use of addEventListener("webkitTransitionEnd"...)
      • If both addEventListener("webkitTransitionEnd"...) and addEventListener("oTransitionEnd"...) have been used to register a listener, only the oTransitionEvent will be fired.
    • If the property name is used as the value of another property (as is the case with transition-property), the name that was used is preserved.
    • The properties that have been aliased in this fashion are:
      -o- -webkit-
      box-shadow-webkit-box-shadow
      -o-transform-webkit-transform
      -o-transform-origin-webkit-transform-origin
      border-radius-webkit-border-radius
      border-top-left-radius-webkit-border-top-left-radius
      border-top-right-radius-webkit-border-top-right-radius
      border-bottom-left-radius-webkit-border-bottom-left-radius
      border-bottom-right-radius-webkit-border-bottom-right-radius
      -o-transition-webkit-transition
      -o-transition-delay-webkit-transition-delay
      -o-transition-duration-webkit-transition-duration
      -o-transition-property-webkit-transition-property
      -o-transition-timing-function-webkit-transition-timing-function

Documentation

Opera Help

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