The `EventPluginHub` module was getting huge and scary. This pulls out all of the logic required to inject plugins and publish their event registration names into a new `EventPluginRegistry` module.
Functionally, nothing should have changed. I added many error checks to cover edge cases that we were not yet running into, but they are all in `EventPluginRegistry` and unit tested.
This improved browser support for the `wheel` event.
- Try to use `wheel` event (DOM Level 3 Specification).
- Fallback to `mousewheel` event.
- Fallback to `DOMMouseWheel` (older Firefox).
Also, since `wheel` is the standard event name, let's use that in React.
NOTE: The tricky part was detecting if `wheel` is supported for IE9+ because `onwheel` does not exist.
Test Plan:
Execute the following in the console on a page with React:
var React = require('React');
React.renderComponent(React.DOM.div({
style: {
width: 10000,
height: 10000
},
onWheel: function() {
console.log('wheel');
}
}, null), document.body);
Verified that mousewheel events are logged to the console.
Verified in IE8-10, Firefox, Chrome, and Safari.
Summary:
This makes a few changes to React Core, most notably `ReactEventEmitter` and `ReactEventTopLevelCallback`.
- Changed `ReactEventEmitter` to use `EventListener` (instead of `NormalizedEventListener`).
- Deleted `NormalizedEventListener` (which was previously broken).
- Created `getEventTarget` which is used to get a normalized `target` from a native event.
- Changed `ReactEventTopLevelCallback` to use `getEventTarget`.
- Renamed `abstractEventType` to `reactEventType` in `AbstractEvent`.
- Reanmed `abstractTargetID` to `reactTargetID` in `AbstractEvent`.
- Removed `originatingTopLevelEventType` from `AbstractEvent` (unused and violates encapsulation).
- Removed `nativeEvent.target === window` check when refreshing authoritative scroll values (unnecessary).
This actually fixes React because `NormalizedEventListener` does not currently do what it promises to do (which is normalizing `target` on the native event). The `target` event is read-only on native events.
This also revises documentation and adds `@typechecks` to a few modules.
NOTE: Most importantly, this sets the stage for replacing `AbstractEvent` with `ReactEvent` and subclasses, piecemeal.
CommitSyncScript
Paul O’Shannessy