Make slideshow toolbar add classes to modified cells.

IPython/html/static/notebook/js/celltoolbarpresets/slideshow.js

@@ -11,6 +11,24 @@ define([
     var CellToolbar = celltoolbar.CellToolbar;
     var slideshow_preset = [];
 
+    var _update_cell = function(cell, old_slide_class) {
+        // Remove the old slide DOM class if set.
+        if (old_slide_class && old_slide_class != '-') {
+            cell.element.removeClass('slideshow-'+old_slide_class);
+        }
+        // add a DOM class to the cell
+        var value = _get_cell_type(cell);
+        if (value != '-') { cell.element.addClass('slideshow-'+value); }
+    };
+
+    var _get_cell_type = function(cell) {
+        var ns = cell.metadata.slideshow;
+        // if the slideshow namespace does not exist return `undefined`
+        // (will be interpreted as `false` by checkbox) otherwise
+        // return the value
+        return (ns === undefined)? undefined: ns.slide_type;
+    };
+
     var select_type = CellToolbar.utils.select_ui_generator([
             ["-"            ,"-"            ],
             ["Slide"        ,"slide"        ],
@@ -24,15 +42,13 @@ define([
                 // we check that the slideshow namespace exist and create it if needed
                 if (cell.metadata.slideshow === undefined){cell.metadata.slideshow = {};}
                 // set the value
+                var old = cell.metadata.slideshow.slide_type;
                 cell.metadata.slideshow.slide_type = value;
+                // update the slideshow class set on the cell 
+                _update_cell(cell, old);
                 },
             //geter
-            function(cell){ var ns = cell.metadata.slideshow;
-                // if the slideshow namespace does not exist return `undefined`
-                // (will be interpreted as `false` by checkbox) otherwise
-                // return the value
-                return (ns === undefined)? undefined: ns.slide_type;
-                },
+            _get_cell_type,
             "Slide Type");
 
     var register = function (notebook) {