Allow up/down and left/right to resolve using row/cell methods

CHANGES.md

@@ -3,6 +3,13 @@ This document outlines changes since 0.3.0.  For older changelogs, see the
 
 # master (0.3.5-dev)
 
+## Significant changes
+
+* The `up` and `down` methods of `List` will now call `grid.row` internally to
+    resolve whatever argument is passed; the `left` and `right` methods of
+    `Grid` will call `grid.cell`.  (Formerly these methods only accepted a
+    row or cell object directly.)
+
 ## Other changes and fixes
 
 ### General/Core

Grid.js

@@ -143,12 +143,16 @@ function(kernel, declare, listen, has, put, List){
 			}
 			return row;
 		},
+
 		left: function(cell, steps){
+			if(!cell.element){ cell = this.cell(cell); }
 			return this.cell(this._move(cell, -(steps || 1), "dgrid-cell"));
 		},
 		right: function(cell, steps){
+			if(!cell.element){ cell = this.cell(cell); }
 			return this.cell(this._move(cell, steps || 1, "dgrid-cell"));
 		},
+
 		renderRow: function(object, options){
 			var row = this.createRowCells("td", function(td, column){
 				var data = object;

List.js

@@ -647,6 +647,7 @@ function(arrayUtil, kernel, declare, listen, has, miscUtil, TouchScroll, hasClas
 			//		A row object representing the appropriate row.  If the top of the
 			//		list is reached before the given number of steps, the first row will
 			//		be returned.
+			if(!row.element){ row = this.row(row); }
 			return this.row(this._move(row, -(steps || 1), "dgrid-row", visible));
 		},
 		down: function(row, steps, visible){
@@ -664,6 +665,7 @@ function(arrayUtil, kernel, declare, listen, has, miscUtil, TouchScroll, hasClas
 			//		A row object representing the appropriate row.  If the bottom of the
 			//		list is reached before the given number of steps, the last row will
 			//		be returned.
+			if(!row.element){ row = this.row(row); }
 			return this.row(this._move(row, steps || 1, "dgrid-row", visible));
 		},