/*	Copyright (c) 2004-2006, The Dojo Foundation	All Rights Reserved.	Licensed under the Academic Free License version 2.1 or above OR the	modified BSD license. For more information on Dojo licensing, see:		http://dojotoolkit.org/community/licensing.shtml*/dojo.provide("dojo.selection.Selection");dojo.require("dojo.lang.array");dojo.require("dojo.lang.func");dojo.require("dojo.lang.common");dojo.require("dojo.math");dojo.declare("dojo.selection.Selection", null,	{		initializer: function(items, isCollection){			this.items = [];			this.selection = [];			this._pivotItems = [];			this.clearItems();			if(items) {				if(isCollection) {					this.setItemsCollection(items);				} else {					this.setItems(items);				}			}		},		// Array: items to select from, order matters for growable selections		items: null,		// Array: items selected, aren't stored in order (see sorted())		selection: null, 		lastSelected: null, // last item selected		// Boolean: if true, grow selection will start from 0th item when nothing is selected		allowImplicit: true, 		// Integer: number of *selected* items		length: 0, 		// Boolean:		//		if true, the selection is treated as an in-order and can grow		//		by ranges, not just by single item		isGrowable: true,		_pivotItems: null, // stack of pivot items		_pivotItem: null, // item we grow selections from, top of stack		// event handlers		onSelect: function(item){			// summary: slot to be connect()'d to		},		onDeselect: function(item){			// summary: slot to be connect()'d to		},		onSelectChange: function(item, selected){			// summary: slot to be connect()'d to		},		_find: function(item, inSelection) {			if(inSelection) {				return dojo.lang.find(this.selection, item);			} else {				return dojo.lang.find(this.items, item);			}		},		isSelectable: function(/*Object*/item){			// summary:			//		user-customizable and should be over-ridden, will filter			//		items through this			return true; // boolean		},		setItems: function(/* ... */){			// summary:			//		adds all passed arguments to the items array, removing any			//		previously selected items.			this.clearItems();			this.addItems.call(this, arguments);		}, 		setItemsCollection: function(/*Object*/collection){			// summary:			//		like setItems, but use in case you have an active			//		collection array-like object (i.e. getElementsByTagName			//		collection) that manages its own order and item list			this.items = collection;		},		addItems: function(/* ... */){			// summary:			//		adds all passed arguments to the items array			var args = dojo.lang.unnest(arguments);			for(var i = 0; i < args.length; i++){				this.items.push(args[i]);			}		},		addItemsAt: function(/*Object*/item, /*Object*/before /* ... */){			// summary:			//		add items to the array after the the passed "before" item.			if(this.items.length == 0){ // work for empy case				return this.addItems(dojo.lang.toArray(arguments, 2));			}			if(!this.isItem(item)){				item = this.items[item];			}			if(!item){ throw new Error("addItemsAt: item doesn't exist"); }			var idx = this._find(item);			if(idx > 0 && before){ idx--; }			for(var i = 2; i < arguments.length; i++){				if(!this.isItem(arguments[i])){					this.items.splice(idx++, 0, arguments[i]);				}			}		},		removeItem: function(/*Object*/item){			// summary: remove item			var idx = this._find(item);			if(idx > -1) {				this.items.splice(idx, 1);			}			// remove from selection			// FIXME: do we call deselect? I don't think so because this isn't how			// you usually want to deselect an item. For example, if you deleted an			// item, you don't really want to deselect it -- you want it gone. -DS			idx = this._find(item, true);			if(idx > -1) {				this.selection.splice(idx, 1);			}		},		clearItems: function(){			// summary: remove and uselect all items			this.items = [];			this.deselectAll();		},		isItem: function(/*Object*/item){			// summary: do we already "know" about the passed item?			return this._find(item) > -1; // boolean		},		isSelected: function(/*Object*/item){			// summary:			//		do we know about the item and is it selected by this			//		selection?			return this._find(item, true) > -1; // boolean		},		/**		 * allows you to filter item in or out of the selection		 * depending on the current selection and action to be taken		**/		selectFilter: function(item, selection, add, grow) {			return true;		},		update: function(/*Object*/item, /*Boolean*/add, /*Boolean*/grow, noToggle) {			// summary: manages selections, most selecting should be done here			// item: item which may be added/grown to/only selected/deselected			// add: behaves like ctrl in windows selection world			// grow: behaves like shift			// noToggle: if true, don't toggle selection on item			if(!this.isItem(item)){ return false; } // boolean			if(this.isGrowable && grow){				if( (!this.isSelected(item)) && 					this.selectFilter(item, this.selection, false, true) ){					this.grow(item);					this.lastSelected = item;				}			}else if(add){				if(this.selectFilter(item, this.selection, true, false)){					if(noToggle){						if(this.select(item)){							this.lastSelected = item;						}					}else if(this.toggleSelected(item)){						this.lastSelected = item;					}				}			}else{				this.deselectAll();				this.select(item);			}			this.length = this.selection.length;			return true; // Boolean		},		grow: function(/*Object*/toItem, /*Object*/fromItem){			// summary:			//		Grow a selection. Any items in (fromItem, lastSelected]			//		that aren't part of (fromItem, toItem] will be deselected			// toItem: which item to grow selection to			// fromItem: which item to start the growth from (it won't be selected)			if(!this.isGrowable){ return; }			if(arguments.length == 1){				fromItem = this._pivotItem;				if(!fromItem && this.allowImplicit){					fromItem = this.items[0];				}			}			if(!toItem || !fromItem){ return false; }			var fromIdx = this._find(fromItem);			// get items to deselect (fromItem, lastSelected]			var toDeselect = {};			var lastIdx = -1;			if(this.lastSelected){				lastIdx = this._find(this.lastSelected);				var step = fromIdx < lastIdx ? -1 : 1;				var range = dojo.math.range(lastIdx, fromIdx, step);				for(var i = 0; i < range.length; i++){					toDeselect[range[i]] = true;				}			}			// add selection (fromItem, toItem]			var toIdx = this._find(toItem);			var step = fromIdx < toIdx ? -1 : 1;			var shrink = lastIdx >= 0 && step == 1 ? lastIdx < toIdx : lastIdx > toIdx;			var range = dojo.math.range(toIdx, fromIdx, step);			if(range.length){				for(var i = range.length-1; i >= 0; i--){					var item = this.items[range[i]];					if(this.selectFilter(item, this.selection, false, true)){						if(this.select(item, true) || shrink){							this.lastSelected = item;						}						if(range[i] in toDeselect){							delete toDeselect[range[i]];						}					}				}			}else{				this.lastSelected = fromItem;			}			// now deselect...			for(var i in toDeselect){				if(this.items[i] == this.lastSelected){					//dojo.debug("oops!");				}				this.deselect(this.items[i]);			}			// make sure everything is all kosher after selections+deselections			this._updatePivot();		},		growUp: function(){			// summary: Grow selection upwards one item from lastSelected			if(!this.isGrowable){ return; }			var idx = this._find(this.lastSelected) - 1;			while(idx >= 0){				if(this.selectFilter(this.items[idx], this.selection, false, true)){					this.grow(this.items[idx]);					break;				}				idx--;			}		},		growDown: function(){			// summary: Grow selection downwards one item from lastSelected			if(!this.isGrowable){ return; }			var idx = this._find(this.lastSelected);			if(idx < 0 && this.allowImplicit){				this.select(this.items[0]);				idx = 0;			}			idx++;			while(idx > 0 && idx < this.items.length){				if(this.selectFilter(this.items[idx], this.selection, false, true)){					this.grow(this.items[idx]);					break;				}				idx++;			}		},		toggleSelected: function(/*Object*/item, /*Boolean*/noPivot){			// summary:			//		like it says on the tin. If noPivot is true, no selection			//		pivot is added (or removed) from the selection. Returns 1			//		if the item is selected, -1 if it is deselected, and 0 if			//		the item is not under management.			if(this.isItem(item)){				if(this.select(item, noPivot)){ return 1; }				if(this.deselect(item)){ return -1; }			}			return 0;		},		select: function(/*Object*/item, /*Boolean*/noPivot){			// summary:			//		like it says on the tin. If noPivot is true, no selection			//		pivot is added  from the selection.			if(this.isItem(item) && !this.isSelected(item)				&& this.isSelectable(item)){				this.selection.push(item);				this.lastSelected = item;				this.onSelect(item);				this.onSelectChange(item, true);				if(!noPivot){					this._addPivot(item);				}				this.length = this.selection.length;				return true;			}			return false;		},		deselect: function(item){			// summary: deselects the item if it's selected.			var idx = this._find(item, true);			if(idx > -1){				this.selection.splice(idx, 1);				this.onDeselect(item);				this.onSelectChange(item, false);				if(item == this.lastSelected){					this.lastSelected = null;				}				this._removePivot(item);				this.length = this.selection.length;				return true;			}			return false;		},		selectAll: function(){			// summary: selects all known items			for(var i = 0; i < this.items.length; i++){				this.select(this.items[i]);			}		},		deselectAll: function(){			// summary: deselects all currently selected items			while(this.selection && this.selection.length){				this.deselect(this.selection[0]);			}		},		selectNext: function(){			// summary:			//		clobbers the existing selection (if any) and selects the			//		next item "below" the previous "bottom" selection. Returns			//		whether or not selection was successful.			var idx = this._find(this.lastSelected);			while(idx > -1 && ++idx < this.items.length){				if(this.isSelectable(this.items[idx])){					this.deselectAll();					this.select(this.items[idx]);					return true;				}			}			return false;		},		selectPrevious: function(){			// summary:			//		clobbers the existing selection (if any) and selects the			//		item "above" the previous "top" selection. Returns whether			//		or not selection was successful.			var idx = this._find(this.lastSelected);			while(idx-- > 0){				if(this.isSelectable(this.items[idx])){					this.deselectAll();					this.select(this.items[idx]);					return true;				}			}			return false;		},		selectFirst: function(){			// summary:			//		select first selectable item. Returns whether or not an			//		item was selected.			this.deselectAll();			var idx = 0;			while(this.items[idx] && !this.select(this.items[idx])){				idx++;			}			return this.items[idx] ? true : false;		},		selectLast: function(){			// summary: select last selectable item			this.deselectAll();			var idx = this.items.length-1;			while(this.items[idx] && !this.select(this.items[idx])) {				idx--;			}			return this.items[idx] ? true : false;		},		_addPivot: function(item, andClear){			this._pivotItem = item;			if(andClear){				this._pivotItems = [item];			}else{				this._pivotItems.push(item);			}		},		_removePivot: function(item){			var i = dojo.lang.find(this._pivotItems, item);			if(i > -1){				this._pivotItems.splice(i, 1);				this._pivotItem = this._pivotItems[this._pivotItems.length-1];			}			this._updatePivot();		},		_updatePivot: function(){			if(this._pivotItems.length == 0){				if(this.lastSelected){					this._addPivot(this.lastSelected);				}			}		},		sorted: function(){			// summary: returns an array of items in sort order			return dojo.lang.toArray(this.selection).sort(				dojo.lang.hitch(this, function(a, b){					var A = this._find(a), B = this._find(b);					if(A > B){						return 1;					}else if(A < B){						return -1;					}else{						return 0;					}				})			);		},		updateSelected: function(){			// summary: 			//		remove any items from the selection that are no longer in			//		this.items			for(var i = 0; i < this.selection.length; i++) {				if(this._find(this.selection[i]) < 0) {					var removed = this.selection.splice(i, 1);					this._removePivot(removed[0]);				}			}			this.length = this.selection.length;		}	});