The expected prototype for a transitionHandler is as follows:
function handler(name, reverse, $to, $from)
The name parameter is the name of the transition as specified by @data-transition attribute, reverse is a boolean that is false for a normal transition, and true for a reverse transition. The $to param is a jQuery collection containing the page that is being transitioned "to", and $from is an optional collection that tells us what page we are transitioning "from". Because $from is optional, handler developers should take care and check $from to make sure it is not undefined before attempting to dereference it.
In addition to registering custom transition by name, developers can specify a handler to use in the case where a transition name is specified and does not exist within the $.mobile.transitionHanlders dictionary. Within jQuery Mobile, the default handler for unknown transition types is the $.mobile.css3Transition() handler. This handler always assumes that the transition name is to be used as a CSS class to be placed on the $to and $from elements. To change the default handler, simply set $.mobile.defaultTransitionHandler to you function handler:
$.mobile.defaultTransitionHandler = myTransitionHandler;
The changes to make all this necessary are as follows:
- Created $.mobile.noneTransitionHandler which is the default transitionHandler for the framework that simply adds and removes the page active class on the $from and $to pages with no animations.
- Moved class based transition code into a new plugin jquery.mobile.transition.js file. This plugin, when present, overrides the noneTransitionHandler as the defaultTranstionHandler for the framework so that CSS3 animation transitions are available.
- Removed code related to the setting/removal of the ui-mobile-viewport-perspective class. The css3TransitionHandler plugin takes care of automatically placing a "viewport-<transition name>" class on the viewport (body) element. This allows any other transition to specify properties on the viewport that are necessary to accomplish the transition.
- changed the CSS class ui-mobile-viewport-perspective to viewport-flip to match code changes. This makes it more apparent that setting -webkit-perspective is only used with the flip transition.
- Updated js/index.php, Makefile and build.xml to include the new jquery.mobile.transition.js file.
