mediawiki-extensions-Visual.../modules/ve2/dm/ve.dm.DocumentSynchronizer.js
Trevor Parscal 58aa0e8137 Whitespace fixes and cleanup
Change-Id: Id2220009ed7af7e895990dd4bb373b43d6089b7b
2012-05-16 20:26:05 -07:00

257 lines
6.9 KiB
JavaScript

/**
* Creates an ve.dm.DocumentSynchronizer object.
*
* This object is a utility for collecting actions to be performed on the model tree in multiple
* steps as the linear model is modified my a transaction processor and then processing those queued
* actions when the transaction is done being processed.
*
* IMPORTANT NOTE: It is assumed that:
* - The linear model has already been updated for the pushed actions
* - Actions are pushed in increasing offset order
* - Actions are non-overlapping
*
* @class
* @constructor
* @param {ve.dm.Document} doc Document to synchronize
*/
ve.dm.DocumentSynchronizer = function( doc ) {
// Properties
this.document = doc;
this.actionQueue = [];
this.eventQueue = [];
};
/* Static Members */
/**
* Synchronization methods.
*
* Each method is specific to a type of action. Methods are called in the context of a document
* synchronizer, so they work similar to normal methods on the object.
*
* @static
* @member
*/
ve.dm.DocumentSynchronizer.synchronizers = {
/* Static Methods */
/**
* Synchronizes an annotation action.
*
* @static
* @method
* @param {Object} action
*/
'annotation': function( action ) {
// Queue events for all leaf nodes covered by the range
// TODO test me
var i, selection = this.document.selectNodes( action.range, 'leaves' );
for ( i = 0; i < selection.length; i++ ) {
this.queueEvent( selection[i].node, 'annotation' );
this.queueEvent( selection[i].node, 'update' );
}
},
/**
* Synchronizes an attribute change action.
*
* @static
* @method
* @param {Object} action
*/
'attributeChange': function( action ) {
this.queueEvent( action.node, 'attributeChange', action.key, action.from, action.to );
this.queueEvent( action.node, 'update' );
},
/**
* Synchronizes a resize action.
*
* @static
* @method
* @param {Object} action
*/
'resize': function( action ) {
action.node.adjustLength( action.adjustment );
this.queueEvent( action.node, 'update' );
},
/**
* Synchronizes a rebuild action.
*
* @static
* @method
* @param {Object} action
*/
'rebuild': function( action ) {
// Find the nodes contained by oldRange
var selection = this.document.selectNodes( action.oldRange, 'siblings' );
if ( selection.length === 0 ) {
// WTF? Nothing to rebuild, I guess. Whatever.
return;
}
var firstNode, parent, index, numNodes;
if ( 'indexInNode' in selection[0] ) {
// Insertion
parent = selection[0].node;
index = selection[0].indexInNode;
numNodes = 0;
} else {
// Rebuild
firstNode = selection[0].node,
parent = firstNode.getParent(),
index = selection[0].index;
numNodes = selection.length;
}
this.document.rebuildNodes( parent, index, numNodes, action.oldRange.from,
action.newRange.getLength()
);
}
};
/* Methods */
/**
* Gets the document being synchronized.
*
* @method
* @returns {ve.dm.Document} Document being synchronized
*/
ve.dm.DocumentSynchronizer.prototype.getDocument = function() {
return this.document;
};
/**
* Add an annotation action to the queue.
*
* This finds all leaf nodes covered wholly or partially by the given range, and emits annotation
* events for all of them.
*
* @method
* @param {ve.Range} range Range that was annotated
*/
ve.dm.DocumentSynchronizer.prototype.pushAnnotation = function( range ) {
this.actionQueue.push( {
'type': 'annotation',
'range': range
} );
};
/**
* Add an attribute change to the queue.
*
* This emits an attributeChange event for the given node with the provided metadata.
*
* @method
* @param {ve.dm.Node} node Node whose attribute changed
* @param {String} key Key of the attribute that changed
* @param {Mixed} from Old value of the attribute
* @param {Mixed} to New value of the attribute
*/
ve.dm.DocumentSynchronizer.prototype.pushAttributeChange = function( node, key, from, to ) {
this.actionQueue.push( {
'type': 'attributeChange',
'node': node,
'key': key,
'from': from,
'to': to
} );
};
/**
* Add a resize action to the queue.
*
* This changes the length of a text node.
*
* @method
* @param {ve.dm.TextNode} node Node to resize
* @param {Integer} adjustment Length adjustment to apply to the node
*/
ve.dm.DocumentSynchronizer.prototype.pushResize = function( node, adjustment ) {
this.actionQueue.push( {
'type': 'resize',
'node': node,
'adjustment': adjustment
} );
};
/**
* Add a rebuild action to the queue.
*
* When a range of data has been changed arbitrarily this can be used to drop the nodes that
* represented the original range and replace them with new nodes that represent the new range.
*
* @method
* @param {ve.Range} oldRange Range of old nodes to be dropped
* @param {ve.Range} newRange Range for new nodes to be built from
*/
ve.dm.DocumentSynchronizer.prototype.pushRebuild = function( oldRange, newRange ) {
this.actionQueue.push( {
'type': 'rebuild',
'oldRange': oldRange,
'newRange': newRange
} );
};
/**
* Queue an event to be emitted on a node.
*
* This method is called by methods defined in {ve.dm.DocumentSynchronizer.synchronizers}.
*
* Duplicate events will be ignored only if all arguments match exactly. Hashes of each event that
* has been queued are stored in the nodes they will eventually be fired on.
*
* @method
* @param {ve.dm.Node} node
* @param {String} event Event name
* @param {Mixed} [...] Additional arguments to be passed to the event when fired
*/
ve.dm.DocumentSynchronizer.prototype.queueEvent = function( node, event ) {
// Check if this is already queued
var args = Array.prototype.slice.call( arguments, 1 );
var hash = $.toJSON( args );
if ( !node.queuedEventHashes ) {
node.queuedEventHashes = {};
}
if ( !node.queuedEventHashes[hash] ) {
node.queuedEventHashes[hash] = true;
this.eventQueue.push( { 'node': node, 'args': args } );
}
};
/**
* Synchronizes node tree using queued actions.
*
* This method uses the static methods defined in {ve.dm.DocumentSynchronizer.synchronizers} and
* calls them in the context of {this}.
*
* After synchronization is complete all queued events will be emitted. Hashes of queued events that
* have been stored on nodes are removed from the nodes after the events have all been emitted.
*
* This method also clears both action and event queues.
*
* @method
*/
ve.dm.DocumentSynchronizer.prototype.synchronize = function() {
var action,
event,
i;
// Execute the actions in the queue
for ( i = 0; i < this.actionQueue.length; i++ ) {
action = this.actionQueue[i];
if ( action.type in ve.dm.DocumentSynchronizer.synchronizers ) {
ve.dm.DocumentSynchronizer.synchronizers[action.type].call( this, action );
} else {
throw 'Invalid action type ' + action.type;
}
}
// Emit events in the event queue
for ( i = 0; i < this.eventQueue.length; i++ ) {
event = this.eventQueue[i];
event.node.emit.apply( event.node, event.args );
delete event.node.queuedEventHashes;
}
// Clear queues
this.actionQueue = [];
this.eventQueue = [];
};