Some experimentation with drag and drop (doesn't work yet)

Made some fixes on itemTreeView to allow for notify() on multiple deletes
	(shifts the row identifier up 1 for each previous delete, etc.)
	One more thing -- this might not happen because the tree calls each Item.erase() or Collection.removeItem() individually.
Bug fix on notifier.js so that register*Tree() actually returns the hash. :-)
	Unfortunately, unregister*Tree() does not seem to actually work, there is still an object at _observers['itemTree'][hash]
(temporary): When you select an item Scholar no longer loads a page into the browser.
	The javascript bugs on those HTML pages were frustrating the debugger.

chrome/chromeFiles/content/scholar/folderTreeView.js

@@ -29,8 +29,16 @@ Scholar.FolderTreeView.prototype.getCellText = function(row, column)
 		return "";
 }
 
-Scholar.FolderTreeView.prototype.isContainer = function(row) 		{ return this._getItemAtRow(row).isCollection(); }
-Scholar.FolderTreeView.prototype.isContainerOpen = function(row)  { return this._dataItems[row][1]; }
+Scholar.FolderTreeView.prototype.isContainer = function(row)
+{
+	return this._getItemAtRow(row).isCollection();
+}
+
+Scholar.FolderTreeView.prototype.isContainerOpen = function(row)
+{
+	return this._dataItems[row][1];
+}
+
 Scholar.FolderTreeView.prototype.isContainerEmpty = function(row)
 {
 	var itemGroup = this._getItemAtRow(row);
@@ -164,6 +172,23 @@ Scholar.FolderTreeView.prototype._refreshHashMap = function()
 	//Scholar.debug(Scholar.varDump(this.objectRowMap));
 }
 
+Scholar.FolderTreeView.prototype.canDrop = function(row, orient)
+{
+	if(orient == this.DROP_ON && this._getItemAtRow(row).isCollection())
+		return true;
+	else
+		return false;
+		
+}
+
+Scholar.FolderTreeView.prototype.drop = function(row, orient)
+{
+	//you can't really do anything here, look to overlay.js - ScholarCollectionsDragObserver
+}
+
+//
+// SCHOLAR ITEMGROUP
+//
 Scholar.ItemGroup = function(type, ref)
 {
 	this.type = type;

chrome/chromeFiles/content/scholar/itemTreeView.js

@@ -119,10 +119,10 @@ Scholar.ItemTreeView.prototype.deleteSelection = function()
 		else if(this._itemGroup.isCollection())
 			this._itemGroup.ref.removeItem(this._getItemAtRow(rows[i]-i).getID());
 
-		
+		/* Don't do this, the notifier tells us?
 		//remove row from tree:
 		this._hideItem(rows[i]-i);
-		this._treebox.rowCountChanged(rows[i]-i, -1);
+		this._treebox.rowCountChanged(rows[i]-i, -1); */
 	}
 	this._treebox.endUpdateBatch();
 	
@@ -159,36 +159,66 @@ Scholar.ItemTreeView.prototype.getCollectionID = function()
 Scholar.ItemTreeView.prototype.notify = function(action, type, ids)
 {
 	ids = Scholar.flattenArguments(ids);
+	var madeChanges = false;
 	
-	for (var i=0, len=ids.length; i<len; i++){
-	
-		var row = this._itemRowMap[ids[i]];
-		if(action == 'remove' && row)
+	if(action == 'remove')
+	{
+		//Since a remove involves
+		
+		//sort the ids by row
+		var rows = new Array();
+		for(var i=0, len=ids.length; i<len; i++)
+			if(this._itemRowMap[ids[i]] != null)
+				rows.push(this._itemRowMap[ids[i]]);
+		
+		if(rows.length > 0)
 		{
-			this._hideItem(row);
-			this._treebox.rowCountChanged(row,-1);
-		}
-		else if(action == 'modify' && row)
-		{
-			this._treebox.invalidateRow(row)
-		}
-		else if(action == 'add' && !row)
-		{
-			var item = Scholar.Items.get(ids[i]);
+			rows.sort(function(a,b) { return a-b });
 			
-			if(this._itemGroup.isLibrary() || item.inCollection(this.getCollectionID()))
+			for(var i=0, len=rows.length; i<len; i++)
 			{
-				this._showItem(item,this.rowCount);
-				this._treebox.rowCountChanged(this.rowCount,1);
+				var row = rows[i];
+				this._hideItem(row-i);
+				this._treebox.rowCountChanged(row-i,-1);
 			}
-			//TODO: sorted? figure it out later
-		}
-		else
-		{
-			return;
-		}
+			
+			madeChanges = true;
+		}		
 		
 	}
+	else
+	{
+		for (var i=0, len=ids.length; i<len; i++)
+		{
+		
+			var row = this._itemRowMap[ids[i]];
+			if(action == 'modify' && row != null) 	//must check for null because it could legitimately be 0
+			{
+				this._treebox.invalidateRow(row)
+			}
+			else if(action == 'add' && row == null)
+			{
+				var item = Scholar.Items.get(ids[i]);
+				
+				if(this._itemGroup.isLibrary() || item.inCollection(this.getCollectionID()))
+				{
+					this._showItem(item,this.rowCount);
+					this._treebox.rowCountChanged(this.rowCount,1);
+				}
+			
+				madeChanges = true;
+				
+				//TODO: sorted? figure it out later
+			}
+			
+		}
+	}
 	
-	this._refreshHashMap();
+	if(madeChanges)
+		this._refreshHashMap();
+}
+
+Scholar.ItemTreeView.prototype.canDrop = function(index, orient)
+{
+	return false;
 }

chrome/chromeFiles/content/scholar/overlay.js

@@ -56,8 +56,8 @@ var ScholarPane = new function()
 	
 	function folderSelected()
 	{
-		//if(itemsView)
-		//	itemsView.unregister();
+		if(itemsView)
+			itemsView.unregister();
 			
 		if(foldersView.selection.count == 1 && foldersView.selection.currentIndex != -1)
 		{
@@ -88,7 +88,7 @@ var ScholarPane = new function()
 			if(!validURL(url))
 				url = 'http://www.google.com/search?q='+encodeURIComponent('"'+item.getField("title")+'"'); //+'&btnI'
 			
-			document.getElementById('content').loadURI(url);
+//			document.getElementById('content').loadURI(url);
 			document.getElementById('scholar-floater').hidden=false;
 		}
 		else
@@ -129,4 +129,30 @@ var ScholarPane = new function()
 	}
 }
 
+var ScholarItemsDragObserver =
+{ 
+	onDragStart: function (evt,transferData,action)
+	{ 
+		transferData.data=new TransferData(); 
+		transferData.data.addDataForFlavour("text/unicode","finally"); 
+		
+	}	
+}; 
+
+var ScholarCollectionsDragObserver =
+{
+	getSupportedFlavours : function () 
+	{ 
+		var flavours = new FlavourSet(); 
+		flavours.appendFlavour("text/unicode"); 
+		
+		return flavours; 
+	}, 
+	onDragOver: function (evt,dropdata,session){}, 
+	onDrop: function (evt,dropdata,session)
+	{ 
+		alert(dropdata.data);
+	}
+}
+
 window.addEventListener("load", function(e) { ScholarPane.init(e); }, false);

chrome/chromeFiles/content/scholar/overlay.xul

@@ -33,6 +33,7 @@
 			<hbox flex="1">				
 				<tree id="folders-tree" hidecolumnpicker="true"
 					onselect="ScholarPane.folderSelected();" seltype="single"
+					ondragover="nsDragAndDrop.dragOver(event,ScholarCollectionsDragObserver)" ondragdrop="nsDragAndDrop.drop(event,ScholarCollectionsDragObserver)"
 					persist="width" flex="1">
 					<treecols>
 						<treecol
@@ -48,6 +49,7 @@
 					id="items-tree" 
 					enableColumnDrag="true" onkeypress="if(event.keyCode == event.DOM_VK_BACK_SPACE || event.keyCode == event.DOM_VK_DELETE){ ScholarPane.deleteSelection(); return false; }"
 					onselect="ScholarPane.itemSelected();"
+					ondraggesture="if (event.target.localName == 'treechildren') nsDragAndDrop.startDrag(event,ScholarItemsDragObserver);"
 					persist="width" flex="5">
 					<treecols>
 						<treecol

chrome/chromeFiles/content/scholar/xpcom/notifier.js

@@ -10,11 +10,11 @@ Scholar.Notifier = new function(){
 	this.trigger = trigger;
 	
 	function registerColumnTree(ref){
-		_register('columnTree', ref);
+		return _register('columnTree', ref);
 	}
 	
 	function registerItemTree(ref){
-		_register('itemTree', ref);
+		return _register('itemTree', ref);
 	}
 	
 	function unregisterColumnTree(hash){