added item grouping and sorting by traversability...

Signed-off-by: Alex A. Naanou <alex.nanou@gmail.com>

ui (gen4)/lib/widget/browse-walk.js

@@ -229,6 +229,8 @@ WalkPrototype.options = {
 	traversable: true,
 	flat: false,
 
+	sortTraversable: 'first',
+
 	//actionButton: '⋯',
 	actionButton: '⊙',
 	pushButton: false,

ui (gen4)/lib/widget/browse.js

@@ -244,6 +244,14 @@ var BrowserPrototype = {
 		// 		affected...
 		toggleDisabledDrawing: true,
 
+		// Group traversable elements...
+		//
+		// Possible values:
+		// 	null | false | 'none'	- show items as-is
+		// 	'first'					- group traversable items at top
+		// 	'last'					- group traversable items at bottom
+		sortTraversable: null,
+
 		// Controls the display of the action button on each list item...
 		//
 		// Possible values:
@@ -735,6 +743,8 @@ var BrowserPrototype = {
 			p.scrollLeft(0)
 		}
 
+		var sort_traversable = this.options.sortTraversable
+		var section_tail
 		// fill the children list...
 		// NOTE: this will be set to true if make(..) is called at least once...
 		var interactive = false
@@ -767,10 +777,9 @@ var BrowserPrototype = {
 				.append($('<div>')
 					.addClass('text')
 					.text(p))
-				.appendTo(l)
+
 			if(!traversable){
 				res.addClass('not-traversable')
-
 			} 
 			if(disabled){
 				res.addClass('disabled')
@@ -832,6 +841,24 @@ var BrowserPrototype = {
 						}))
 				})
 
+			// place in list...
+			// as-is...
+			if(!sort_traversable || sort_traversable == 'none'){
+				res.appendTo(l)
+
+			// traversable first/last...
+			} else {
+				if(sort_traversable == 'first' ? traversable : !traversable){
+					section_tail == null ?
+						l.prepend(res)
+						: section_tail.after(res)
+					section_tail = res
+
+				} else {
+					res.appendTo(l)
+				}
+			}
+
 			return res
 		}