dojo.provide("dojo.dnd.Selector");

dojo.require("dojo.dnd.common");
dojo.require("dojo.dnd.Container");

/*
	Container item states:
		""			- an item is not selected
		"Selected"	- an item is selected
		"Anchor"	- an item is selected, and is an anchor for a "shift" selection
*/

dojo.declare("dojo.dnd.Selector", dojo.dnd.Container, {
	// summary: a Selector object, which knows how to select its children
	
	constructor: function(node, params){
		// summary: a constructor of the Selector
		// node: Node: node or node's id to build the selector on
		// params: Object: a dict of parameters, recognized parameters are:
		//	singular: Boolean
		//		allows selection of only one element, if true
		//		the rest of parameters are passed to the container
		//	autoSync: Boolean
		//		autosynchronizes the source with its list of DnD nodes,
		//		false by default
		if(!params){ params = {}; }
		this.singular = params.singular;
		this.autoSync = params.autoSync;
		// class-specific variables
		this.selection = {};
		this.anchor = null;
		this.simpleSelection = false;
		// set up events
		this.events.push(
			dojo.connect(this.node, "onmousedown", this, "onMouseDown"),
			dojo.connect(this.node, "onmouseup",   this, "onMouseUp"));
	},
	
	// object attributes (for markup)
	singular: false,	// is singular property
	
	// methods
	getSelectedNodes: function(){
		// summary: returns a list (an array) of selected nodes
		var t = new dojo.NodeList();
		var e = dojo.dnd._empty;
		for(var i in this.selection){
			if(i in e){ continue; }
			t.push(dojo.byId(i));
		}
		return t;	// Array
	},
	selectNone: function(){
		// summary: unselects all items
		return this._removeSelection()._removeAnchor();	// self
	},
	selectAll: function(){
		// summary: selects all items
		this.forInItems(function(data, id){
			this._addItemClass(dojo.byId(id), "Selected");
			this.selection[id] = 1;
		}, this);
		return this._removeAnchor();	// self
	},
	deleteSelectedNodes: function(){
		// summary: deletes all selected items
		var e = dojo.dnd._empty;
		for(var i in this.selection){
			if(i in e){ continue; }
			var n = dojo.byId(i);
			this.delItem(i);
			dojo._destroyElement(n);
		}
		this.anchor = null;
		this.selection = {};
		return this;	// self
	},
	forInSelectedItems: function(/*Function*/ f, /*Object?*/ o){
		// summary: iterates over selected items,
		// see dojo.dnd.Container.forInItems() for details
		o = o || dojo.global;
		var s = this.selection, e = dojo.dnd._empty;
		for(var i in s){
			if(i in e){ continue; }
			f.call(o, this.getItem(i), i, this);
		}
	},
	sync: function(){
		// summary: synch up the node list with the data map
		
		dojo.dnd.Selector.superclass.sync.call(this);
		
		// fix the anchor
		if(this.anchor){
			if(!this.getItem(this.anchor.id)){
				this.anchor = null;
			}
		}
		
		// fix the selection
		var t = [], e = dojo.dnd._empty;
		for(var i in this.selection){
			if(i in e){ continue; }
			if(!this.getItem(i)){
				t.push(i);
			}
		}
		dojo.forEach(t, function(i){
			delete this.selection[i];
		}, this);
		
		return this;	// self
	},
	insertNodes: function(addSelected, data, before, anchor){
		// summary: inserts new data items (see Container's insertNodes method for details)
		// addSelected: Boolean: all new nodes will be added to selected items, if true, no selection change otherwise
		// data: Array: a list of data items, which should be processed by the creator function
		// before: Boolean: insert before the anchor, if true, and after the anchor otherwise
		// anchor: Node: the anchor node to be used as a point of insertion
		var oldCreator = this._normalizedCreator;
		this._normalizedCreator = function(item, hint){
			var t = oldCreator.call(this, item, hint);
			if(addSelected){
				if(!this.anchor){
					this.anchor = t.node;
					this._removeItemClass(t.node, "Selected");
					this._addItemClass(this.anchor, "Anchor");
				}else if(this.anchor != t.node){
					this._removeItemClass(t.node, "Anchor");
					this._addItemClass(t.node, "Selected");
				}
				this.selection[t.node.id] = 1;
			}else{
				this._removeItemClass(t.node, "Selected");
				this._removeItemClass(t.node, "Anchor");
			}
			return t;
		};
		dojo.dnd.Selector.superclass.insertNodes.call(this, data, before, anchor);
		this._normalizedCreator = oldCreator;
		return this;	// self
	},
	destroy: function(){
		// summary: prepares the object to be garbage-collected
		dojo.dnd.Selector.superclass.destroy.call(this);
		this.selection = this.anchor = null;
	},

	// markup methods
	markupFactory: function(params, node){
		params._skipStartup = true;
		return new dojo.dnd.Selector(node, params);
	},

	// mouse events
	onMouseDown: function(e){
		// summary: event processor for onmousedown
		// e: Event: mouse event
		if(this.autoSync){ this.sync(); }
		if(!this.current){ return; }
		if(!this.singular && !dojo.dnd.getCopyKeyState(e) && !e.shiftKey && (this.current.id in this.selection)){
			this.simpleSelection = true;
			dojo.stopEvent(e);
			return;
		}
		if(!this.singular && e.shiftKey){
			if(!dojo.dnd.getCopyKeyState(e)){
				this._removeSelection();
			}
			var c = this.getAllNodes();
			if(c.length){
				if(!this.anchor){
					this.anchor = c[0];
					this._addItemClass(this.anchor, "Anchor");
				}
				this.selection[this.anchor.id] = 1;
				if(this.anchor != this.current){
					var i = 0;
					for(; i < c.length; ++i){
						var node = c[i];
						if(node == this.anchor || node == this.current){ break; }
					}
					for(++i; i < c.length; ++i){
						var node = c[i];
						if(node == this.anchor || node == this.current){ break; }
						this._addItemClass(node, "Selected");
						this.selection[node.id] = 1;
					}
					this._addItemClass(this.current, "Selected");
					this.selection[this.current.id] = 1;
				}
			}
		}else{
			if(this.singular){
				if(this.anchor == this.current){
					if(dojo.dnd.getCopyKeyState(e)){
						this.selectNone();
					}
				}else{
					this.selectNone();
					this.anchor = this.current;
					this._addItemClass(this.anchor, "Anchor");
					this.selection[this.current.id] = 1;
				}
			}else{
				if(dojo.dnd.getCopyKeyState(e)){
					if(this.anchor == this.current){
						delete this.selection[this.anchor.id];
						this._removeAnchor();
					}else{
						if(this.current.id in this.selection){
							this._removeItemClass(this.current, "Selected");
							delete this.selection[this.current.id];
						}else{
							if(this.anchor){
								this._removeItemClass(this.anchor, "Anchor");
								this._addItemClass(this.anchor, "Selected");
							}
							this.anchor = this.current;
							this._addItemClass(this.current, "Anchor");
							this.selection[this.current.id] = 1;
						}
					}
				}else{
					if(!(this.current.id in this.selection)){
						this.selectNone();
						this.anchor = this.current;
						this._addItemClass(this.current, "Anchor");
						this.selection[this.current.id] = 1;
					}
				}
			}
		}
		dojo.stopEvent(e);
	},
	onMouseUp: function(e){
		// summary: event processor for onmouseup
		// e: Event: mouse event
		if(!this.simpleSelection){ return; }
		this.simpleSelection = false;
		this.selectNone();
		if(this.current){
			this.anchor = this.current;
			this._addItemClass(this.anchor, "Anchor");
			this.selection[this.current.id] = 1;
		}
	},
	onMouseMove: function(e){
		// summary: event processor for onmousemove
		// e: Event: mouse event
		this.simpleSelection = false;
	},
	
	// utilities
	onOverEvent: function(){
		// summary: this function is called once, when mouse is over our container
		this.onmousemoveEvent = dojo.connect(this.node, "onmousemove", this, "onMouseMove");
	},
	onOutEvent: function(){
		// summary: this function is called once, when mouse is out of our container
		dojo.disconnect(this.onmousemoveEvent);
		delete this.onmousemoveEvent;
	},
	_removeSelection: function(){
		// summary: unselects all items
		var e = dojo.dnd._empty;
		for(var i in this.selection){
			if(i in e){ continue; }
			var node = dojo.byId(i);
			if(node){ this._removeItemClass(node, "Selected"); }
		}
		this.selection = {};
		return this;	// self
	},
	_removeAnchor: function(){
		if(this.anchor){
			this._removeItemClass(this.anchor, "Anchor");
			this.anchor = null;
		}
		return this;	// self
	}
});