Added scroll mode selector,

fixed rebase conflicts.

IPython/html/static/notebook/js/keyboardmanager.js

@@ -1,7 +1,12
 // Copyright (c) IPython Development Team.
 // Distributed under the terms of the Modified BSD License.
 
-var IPython = (function (IPython) {
+define([
+    'base/js/namespace',
+    'jquery',
+    'base/js/utils',
+    'base/js/keyboard',
+], function(IPython, $, utils, keyboard) {
     "use strict";
 
     var browser = utils.browser[0];
@@ -98,386 +103,386 var IPython = (function (IPython) {
     KeyboardManager.prototype.get_default_edit_shortcuts = function() {
         var that = this;
         return {
-        'esc' : {
-            help    : 'command mode',
-            help_index : 'aa',
-            handler : function (event) {
-                    that.notebook.command_mode();
-                return false;
-            }
-        },
-        'ctrl-m' : {
-            help    : 'command mode',
-            help_index : 'ab',
-            handler : function (event) {
-                    that.notebook.command_mode();
-                return false;
-            }
-        },
-        'up' : {
-            help    : '',
-            help_index : '',
-            handler : function (event) {
-                    var index = that.notebook.get_selected_index();
-                    var cell = that.notebook.get_cell(index);
-                if (cell && cell.at_top() && index !== 0) {
-                    event.preventDefault();
+            'esc' : {
+                help    : 'command mode',
+                help_index : 'aa',
+                handler : function (event) {
                         that.notebook.command_mode();
-                        that.notebook.select_prev();
-                        that.notebook.edit_mode();
-                        var cm = that.notebook.get_selected_cell().code_mirror;
-                    cm.setCursor(cm.lastLine(), 0);
-                    return false;
-                } else if (cell) {
-                    var cm = cell.code_mirror;
-                    cm.execCommand('goLineUp');
                     return false;
                 }
-            }
-        },
-        'down' : {
-            help    : '',
-            help_index : '',
-            handler : function (event) {
-                    var index = that.notebook.get_selected_index();
-                    var cell = that.notebook.get_cell(index);
-                    if (cell.at_bottom() && index !== (that.notebook.ncells()-1)) {
-                    event.preventDefault();
+            },
+            'ctrl-m' : {
+                help    : 'command mode',
+                help_index : 'ab',
+                handler : function (event) {
                         that.notebook.command_mode();
-                        that.notebook.select_next();
-                        that.notebook.edit_mode();
-                        var cm = that.notebook.get_selected_cell().code_mirror;
-                    cm.setCursor(0, 0);
                     return false;
-                } else {
-                    var cm = cell.code_mirror;
-                    cm.execCommand('goLineDown');
+                }
+            },
+            'up' : {
+                help    : '',
+                help_index : '',
+                handler : function (event) {
+                        var index = that.notebook.get_selected_index();
+                        var cell = that.notebook.get_cell(index);
+                    if (cell && cell.at_top() && index !== 0) {
+                        event.preventDefault();
+                            that.notebook.command_mode();
+                            that.notebook.select_prev();
+                            that.notebook.edit_mode();
+                            var cm = that.notebook.get_selected_cell().code_mirror;
+                        cm.setCursor(cm.lastLine(), 0);
+                        return false;
+                    } else if (cell) {
+                        var cm = cell.code_mirror;
+                        cm.execCommand('goLineUp');
+                        return false;
+                    }
+                }
+            },
+            'down' : {
+                help    : '',
+                help_index : '',
+                handler : function (event) {
+                        var index = that.notebook.get_selected_index();
+                        var cell = that.notebook.get_cell(index);
+                        if (cell.at_bottom() && index !== (that.notebook.ncells()-1)) {
+                        event.preventDefault();
+                            that.notebook.command_mode();
+                            that.notebook.select_next();
+                            that.notebook.edit_mode();
+                            var cm = that.notebook.get_selected_cell().code_mirror;
+                        cm.setCursor(0, 0);
+                        return false;
+                    } else {
+                        var cm = cell.code_mirror;
+                        cm.execCommand('goLineDown');
+                        return false;
+                    }
+                }
+            },
+            'ctrl-shift--' : {
+                help    : 'split cell',
+                help_index : 'ea',
+                handler : function (event) {
+                        that.notebook.split_cell();
                     return false;
                 }
-            }
-        },
-        'ctrl-shift--' : {
-            help    : 'split cell',
-            help_index : 'ea',
-            handler : function (event) {
-                    that.notebook.split_cell();
-                return false;
-            }
-        },
-        'ctrl-shift-subtract' : {
-            help    : '',
-            help_index : 'eb',
-            handler : function (event) {
-                    that.notebook.split_cell();
-                return false;
-            }
-        },
-    };
+            },
+            'ctrl-shift-subtract' : {
+                help    : '',
+                help_index : 'eb',
+                handler : function (event) {
+                        that.notebook.split_cell();
+                    return false;
+                }
+            },
+        };
     };
 
     KeyboardManager.prototype.get_default_command_shortcuts = function() {
         var that = this;
         return {
-        'space': {
-            help: "Scroll down to next H1 cell",
-            handler: function(event) {
-                return that.notebook.scrollmanager.scroll(1);
+            'space': {
+                help: "Scroll down to next H1 cell",
+                handler: function(event) {
+                    return that.notebook.scrollmanager.scroll(1);
+                },
             },
-        },
-        'shift-space': {
-            help: "Scroll up to previous H1 cell",
-            handler: function(event) {
-                return that.notebook.scrollmanager.scroll(-1);
+            'shift-space': {
+                help: "Scroll up to previous H1 cell",
+                handler: function(event) {
+                    return that.notebook.scrollmanager.scroll(-1);
+                },
             },
-        },
-        'enter' : {
-            help    : 'edit mode',
-            help_index : 'aa',
-            handler : function (event) {
-                    that.notebook.edit_mode();
-                return false;
-            }
-        },
-        'up' : {
-            help    : 'select previous cell',
-            help_index : 'da',
-            handler : function (event) {
-                    var index = that.notebook.get_selected_index();
-                if (index !== 0 && index !== null) {
-                        that.notebook.select_prev();
-                        that.notebook.focus_cell();
+            'enter' : {
+                help    : 'edit mode',
+                help_index : 'aa',
+                handler : function (event) {
+                        that.notebook.edit_mode();
+                    return false;
                 }
-                return false;
-            }
-        },
-        'down' : {
-            help    : 'select next cell',
-            help_index : 'db',
-            handler : function (event) {
-                    var index = that.notebook.get_selected_index();
-                    if (index !== (that.notebook.ncells()-1) && index !== null) {
-                        that.notebook.select_next();
-                        that.notebook.focus_cell();
+            },
+            'up' : {
+                help    : 'select previous cell',
+                help_index : 'da',
+                handler : function (event) {
+                        var index = that.notebook.get_selected_index();
+                    if (index !== 0 && index !== null) {
+                            that.notebook.select_prev();
+                            that.notebook.focus_cell();
+                    }
+                    return false;
                 }
-                return false;
-            }
-        },
-        'k' : {
-            help    : 'select previous cell',
-            help_index : 'dc',
-            handler : function (event) {
-                    var index = that.notebook.get_selected_index();
-                if (index !== 0 && index !== null) {
+            },
+            'down' : {
+                help    : 'select next cell',
+                help_index : 'db',
+                handler : function (event) {
+                        var index = that.notebook.get_selected_index();
+                        if (index !== (that.notebook.ncells()-1) && index !== null) {
+                            that.notebook.select_next();
+                            that.notebook.focus_cell();
+                    }
+                    return false;
+                }
+            },
+            'k' : {
+                help    : 'select previous cell',
+                help_index : 'dc',
+                handler : function (event) {
+                        var index = that.notebook.get_selected_index();
+                    if (index !== 0 && index !== null) {
+                            that.notebook.select_prev();
+                            that.notebook.focus_cell();
+                    }
+                    return false;
+                }
+            },
+            'j' : {
+                help    : 'select next cell',
+                help_index : 'dd',
+                handler : function (event) {
+                        var index = that.notebook.get_selected_index();
+                        if (index !== (that.notebook.ncells()-1) && index !== null) {
+                            that.notebook.select_next();
+                            that.notebook.focus_cell();
+                    }
+                    return false;
+                }
+            },
+            'x' : {
+                help    : 'cut cell',
+                help_index : 'ee',
+                handler : function (event) {
+                        that.notebook.cut_cell();
+                    return false;
+                }
+            },
+            'c' : {
+                help    : 'copy cell',
+                help_index : 'ef',
+                handler : function (event) {
+                        that.notebook.copy_cell();
+                    return false;
+                }
+            },
+            'shift-v' : {
+                help    : 'paste cell above',
+                help_index : 'eg',
+                handler : function (event) {
+                        that.notebook.paste_cell_above();
+                    return false;
+                }
+            },
+            'v' : {
+                help    : 'paste cell below',
+                help_index : 'eh',
+                handler : function (event) {
+                        that.notebook.paste_cell_below();
+                    return false;
+                }
+            },
+            'd' : {
+                help    : 'delete cell (press twice)',
+                help_index : 'ej',
+                count: 2,
+                handler : function (event) {
+                        that.notebook.delete_cell();
+                    return false;
+                }
+            },
+            'a' : {
+                help    : 'insert cell above',
+                help_index : 'ec',
+                handler : function (event) {
+                        that.notebook.insert_cell_above();
                         that.notebook.select_prev();
                         that.notebook.focus_cell();
+                    return false;
                 }
-                return false;
-            }
-        },
-        'j' : {
-            help    : 'select next cell',
-            help_index : 'dd',
-            handler : function (event) {
-                    var index = that.notebook.get_selected_index();
-                    if (index !== (that.notebook.ncells()-1) && index !== null) {
+            },
+            'b' : {
+                help    : 'insert cell below',
+                help_index : 'ed',
+                handler : function (event) {
+                        that.notebook.insert_cell_below();
                         that.notebook.select_next();
                         that.notebook.focus_cell();
+                    return false;
                 }
-                return false;
-            }
-        },
-        'x' : {
-            help    : 'cut cell',
-            help_index : 'ee',
-            handler : function (event) {
-                    that.notebook.cut_cell();
-                return false;
-            }
-        },
-        'c' : {
-            help    : 'copy cell',
-            help_index : 'ef',
-            handler : function (event) {
-                    that.notebook.copy_cell();
-                return false;
-            }
-        },
-        'shift-v' : {
-            help    : 'paste cell above',
-            help_index : 'eg',
-            handler : function (event) {
-                    that.notebook.paste_cell_above();
-                return false;
-            }
-        },
-        'v' : {
-            help    : 'paste cell below',
-            help_index : 'eh',
-            handler : function (event) {
-                    that.notebook.paste_cell_below();
-                return false;
-            }
-        },
-        'd' : {
-            help    : 'delete cell (press twice)',
-            help_index : 'ej',
-            count: 2,
-            handler : function (event) {
-                    that.notebook.delete_cell();
-                return false;
-            }
-        },
-        'a' : {
-            help    : 'insert cell above',
-            help_index : 'ec',
-            handler : function (event) {
-                    that.notebook.insert_cell_above();
-                    that.notebook.select_prev();
-                    that.notebook.focus_cell();
-                return false;
-            }
-        },
-        'b' : {
-            help    : 'insert cell below',
-            help_index : 'ed',
-            handler : function (event) {
-                    that.notebook.insert_cell_below();
-                    that.notebook.select_next();
-                    that.notebook.focus_cell();
-                return false;
-            }
-        },
-        'y' : {
-            help    : 'to code',
-            help_index : 'ca',
-            handler : function (event) {
-                    that.notebook.to_code();
-                return false;
-            }
-        },
-        'm' : {
-            help    : 'to markdown',
-            help_index : 'cb',
-            handler : function (event) {
-                    that.notebook.to_markdown();
-                return false;
-            }
-        },
-        'r' : {
-            help    : 'to raw',
-            help_index : 'cc',
-            handler : function (event) {
-                    that.notebook.to_raw();
-                return false;
-            }
-        },
-        '1' : {
-            help    : 'to heading 1',
-            help_index : 'cd',
-            handler : function (event) {
-                    that.notebook.to_heading(undefined, 1);
-                return false;
-            }
-        },
-        '2' : {
-            help    : 'to heading 2',
-            help_index : 'ce',
-            handler : function (event) {
-                    that.notebook.to_heading(undefined, 2);
-                return false;
-            }
-        },
-        '3' : {
-            help    : 'to heading 3',
-            help_index : 'cf',
-            handler : function (event) {
-                    that.notebook.to_heading(undefined, 3);
-                return false;
-            }
-        },
-        '4' : {
-            help    : 'to heading 4',
-            help_index : 'cg',
-            handler : function (event) {
-                    that.notebook.to_heading(undefined, 4);
-                return false;
-            }
-        },
-        '5' : {
-            help    : 'to heading 5',
-            help_index : 'ch',
-            handler : function (event) {
-                    that.notebook.to_heading(undefined, 5);
-                return false;
-            }
-        },
-        '6' : {
-            help    : 'to heading 6',
-            help_index : 'ci',
-            handler : function (event) {
-                    that.notebook.to_heading(undefined, 6);
-                return false;
-            }
-        },
-        'o' : {
-            help    : 'toggle output',
-            help_index : 'gb',
-            handler : function (event) {
-                    that.notebook.toggle_output();
-                return false;
-            }
-        },
-        'shift-o' : {
-            help    : 'toggle output scrolling',
-            help_index : 'gc',
-            handler : function (event) {
-                    that.notebook.toggle_output_scroll();
-                return false;
-            }
-        },
-        's' : {
-            help    : 'save notebook',
-            help_index : 'fa',
-            handler : function (event) {
-                    that.notebook.save_checkpoint();
-                return false;
-            }
-        },
-        'ctrl-j' : {
-            help    : 'move cell down',
-            help_index : 'eb',
-            handler : function (event) {
-                    that.notebook.move_cell_down();
-                return false;
-            }
-        },
-        'ctrl-k' : {
-            help    : 'move cell up',
-            help_index : 'ea',
-            handler : function (event) {
-                    that.notebook.move_cell_up();
-                return false;
-            }
-        },
-        'l' : {
-            help    : 'toggle line numbers',
-            help_index : 'ga',
-            handler : function (event) {
-                    that.notebook.cell_toggle_line_numbers();
-                return false;
-            }
-        },
-        'i' : {
-            help    : 'interrupt kernel (press twice)',
-            help_index : 'ha',
-            count: 2,
-            handler : function (event) {
-                    that.notebook.kernel.interrupt();
-                return false;
-            }
-        },
-        '0' : {
-            help    : 'restart kernel (press twice)',
-            help_index : 'hb',
-            count: 2,
-            handler : function (event) {
-                    that.notebook.restart_kernel();
-                return false;
-            }
-        },
-        'h' : {
-            help    : 'keyboard shortcuts',
-            help_index : 'ge',
-            handler : function (event) {
-                    that.quick_help.show_keyboard_shortcuts();
-                return false;
-            }
-        },
-        'z' : {
-            help    : 'undo last delete',
-            help_index : 'ei',
-            handler : function (event) {
-                    that.notebook.undelete_cell();
-                return false;
-            }
-        },
-        'shift-m' : {
-            help    : 'merge cell below',
-            help_index : 'ek',
-            handler : function (event) {
-                    that.notebook.merge_cell_below();
-                return false;
-            }
-        },
-        'q' : {
-            help    : 'close pager',
-            help_index : 'gd',
-            handler : function (event) {
-                    that.pager.collapse();
-                return false;
-            }
-        },
-    };
+            },
+            'y' : {
+                help    : 'to code',
+                help_index : 'ca',
+                handler : function (event) {
+                        that.notebook.to_code();
+                    return false;
+                }
+            },
+            'm' : {
+                help    : 'to markdown',
+                help_index : 'cb',
+                handler : function (event) {
+                        that.notebook.to_markdown();
+                    return false;
+                }
+            },
+            'r' : {
+                help    : 'to raw',
+                help_index : 'cc',
+                handler : function (event) {
+                        that.notebook.to_raw();
+                    return false;
+                }
+            },
+            '1' : {
+                help    : 'to heading 1',
+                help_index : 'cd',
+                handler : function (event) {
+                        that.notebook.to_heading(undefined, 1);
+                    return false;
+                }
+            },
+            '2' : {
+                help    : 'to heading 2',
+                help_index : 'ce',
+                handler : function (event) {
+                        that.notebook.to_heading(undefined, 2);
+                    return false;
+                }
+            },
+            '3' : {
+                help    : 'to heading 3',
+                help_index : 'cf',
+                handler : function (event) {
+                        that.notebook.to_heading(undefined, 3);
+                    return false;
+                }
+            },
+            '4' : {
+                help    : 'to heading 4',
+                help_index : 'cg',
+                handler : function (event) {
+                        that.notebook.to_heading(undefined, 4);
+                    return false;
+                }
+            },
+            '5' : {
+                help    : 'to heading 5',
+                help_index : 'ch',
+                handler : function (event) {
+                        that.notebook.to_heading(undefined, 5);
+                    return false;
+                }
+            },
+            '6' : {
+                help    : 'to heading 6',
+                help_index : 'ci',
+                handler : function (event) {
+                        that.notebook.to_heading(undefined, 6);
+                    return false;
+                }
+            },
+            'o' : {
+                help    : 'toggle output',
+                help_index : 'gb',
+                handler : function (event) {
+                        that.notebook.toggle_output();
+                    return false;
+                }
+            },
+            'shift-o' : {
+                help    : 'toggle output scrolling',
+                help_index : 'gc',
+                handler : function (event) {
+                        that.notebook.toggle_output_scroll();
+                    return false;
+                }
+            },
+            's' : {
+                help    : 'save notebook',
+                help_index : 'fa',
+                handler : function (event) {
+                        that.notebook.save_checkpoint();
+                    return false;
+                }
+            },
+            'ctrl-j' : {
+                help    : 'move cell down',
+                help_index : 'eb',
+                handler : function (event) {
+                        that.notebook.move_cell_down();
+                    return false;
+                }
+            },
+            'ctrl-k' : {
+                help    : 'move cell up',
+                help_index : 'ea',
+                handler : function (event) {
+                        that.notebook.move_cell_up();
+                    return false;
+                }
+            },
+            'l' : {
+                help    : 'toggle line numbers',
+                help_index : 'ga',
+                handler : function (event) {
+                        that.notebook.cell_toggle_line_numbers();
+                    return false;
+                }
+            },
+            'i' : {
+                help    : 'interrupt kernel (press twice)',
+                help_index : 'ha',
+                count: 2,
+                handler : function (event) {
+                        that.notebook.kernel.interrupt();
+                    return false;
+                }
+            },
+            '0' : {
+                help    : 'restart kernel (press twice)',
+                help_index : 'hb',
+                count: 2,
+                handler : function (event) {
+                        that.notebook.restart_kernel();
+                    return false;
+                }
+            },
+            'h' : {
+                help    : 'keyboard shortcuts',
+                help_index : 'ge',
+                handler : function (event) {
+                        that.quick_help.show_keyboard_shortcuts();
+                    return false;
+                }
+            },
+            'z' : {
+                help    : 'undo last delete',
+                help_index : 'ei',
+                handler : function (event) {
+                        that.notebook.undelete_cell();
+                    return false;
+                }
+            },
+            'shift-m' : {
+                help    : 'merge cell below',
+                help_index : 'ek',
+                handler : function (event) {
+                        that.notebook.merge_cell_below();
+                    return false;
+                }
+            },
+            'q' : {
+                help    : 'close pager',
+                help_index : 'gd',
+                handler : function (event) {
+                        that.pager.collapse();
+                    return false;
+                }
+            },
+        };
     };
 
     KeyboardManager.prototype.bind_events = function () {

IPython/html/static/notebook/js/main.js

@@ -19,7 +19,6 require([
     'notebook/js/keyboardmanager',
     'notebook/js/config',
     'notebook/js/kernelselector',
-    'notebook/js/scrollmanager'
     // only loaded, not used:
     'custom/custom',
 ], function(
@@ -39,8 +38,7 require([
     savewidget, 
     keyboardmanager,
     config,
-    kernelselector,
-    scrollmanager
+    kernelselector
     ) {
     "use strict";
 
@@ -69,7 +67,6 require([
         save_widget: save_widget,
         config: user_config},
         common_options));
-    var scrollmanager = new scrollmanager.ScrollManager(notebook);
     var login_widget = new loginwidget.LoginWidget('span#login_widget', common_options);
     var toolbar = new maintoolbar.MainToolBar('#maintoolbar-container', {
         notebook: notebook, 
@@ -135,7 +132,6 require([
     IPython.save_widget = save_widget;
     IPython.config = user_config;
     IPython.tooltip = notebook.tooltip;
-    IPython.scrollmanager = scrollmanager;
 
     events.trigger('app_initialized.NotebookApp');
     notebook.load_notebook(common_options.notebook_name, common_options.notebook_path);

IPython/html/static/notebook/js/maintoolbar.js

@@ -6,7 +6,8 define([
     'jquery',
     'notebook/js/toolbar',
     'notebook/js/celltoolbar',
-], function(IPython, $, toolbar, celltoolbar) {
+    'notebook/js/scrollmanager'
+], function(IPython, $, toolbar, celltoolbar, scrollmanager) {
     "use strict";
 
     var MainToolBar = function (selector, options) {
@@ -24,6 +25,7 define([
         this.construct();
         this.add_celltype_list();
         this.add_celltoolbar_list();
+        this.add_scrollmanager_list();
         this.bind_events();
     };
 
@@ -187,6 +189,11 define([
     };
 
 
+    MainToolBar.prototype.add_scrollmanager_list = function () {
+        this._scrollselector = new scrollmanager.ScrollSelector(this.element, this.notebook);
+    };
+
+
     MainToolBar.prototype.bind_events = function () {
         var that = this;
         

IPython/html/static/notebook/js/notebook.js

@@ -18,6 +18,7 define([
     'notebook/js/celltoolbarpresets/default',
     'notebook/js/celltoolbarpresets/rawcell',
     'notebook/js/celltoolbarpresets/slideshow',
+    'notebook/js/scrollmanager'
 ], function (
     IPython, 
     $, 
@@ -34,7 +35,8 define([
     tooltip,
     default_celltoolbar,
     rawcell_celltoolbar,
-    slideshow_celltoolbar
+    slideshow_celltoolbar,
+    scrollmanager
     ) {
 
     var Notebook = function (selector, options) {
@@ -64,6 +66,9 define([
         this.ws_url = options.ws_url;
         this._session_starting = false;
         this.default_cell_type = this.config.default_cell_type || 'code';
+
+        //  Create and register scroll managers.
+        this.scrollmanager = new scrollmanager.ScrollManager(this);
         // default_kernel_name is a temporary measure while we implement proper
         // kernel selection and delayed start. Do not rely on it.
         this.default_kernel_name = 'python';
@@ -135,7 +140,7 define([
         rawcell_celltoolbar.register(this);
         slideshow_celltoolbar.register(this);
     };
-    
+
     Notebook.options_default = {
         // can be any cell type, or the special values of
         // 'above', 'below', or 'selected' to get the value from another cell.

IPython/html/static/notebook/js/scrollmanager.js

@@ -1,9 +1,51
 // Copyright (c) IPython Development Team.
 // Distributed under the terms of the Modified BSD License.
-define([], function(){
+define(['jquery'], function($){
     "use strict";
 
-    var ScrollManager = function (notebook) {
+    var ScrollSelector = function(element, notebook) {
+        // Public constructor.
+        this.notebook = notebook;
+        $('<span />')
+            .addClass('nabar-text')
+            .text('Scrolling Mode:')
+            .appendTo(element);
+        this._combo = $('<select />')
+            .addClass('form-control select-xs')
+            .appendTo(element);
+
+        // Redirect class level manager registration to this instance.
+        this._registered = {};
+        ScrollSelector.register = $.proxy(this.register, this);
+
+        // Register cached managers.
+        for (var i =0; i < ScrollSelector.registered.length; i++) {
+            this.register.apply(this, ScrollSelector.registered[i]);
+        }
+
+        // Listen for scroll manager change, apply it to the notebook.
+        var that = this;
+        this._combo.change(function(){
+            var manager = that._registered[$(this).find("option:selected").val()];
+            that.notebook.ScrollSelector = manager;
+        });
+    };
+
+    // Cache scroll managers registered before the construction of a scroll 
+    // manager.
+    ScrollSelector.registered = [];
+    ScrollSelector.register = function(name, manager) {
+        ScrollSelector.registered.push(arguments);
+    };
+    ScrollSelector.prototype.register = function(name, manager) {
+        this._registered[name] = manager;
+        this._combo.append($('<option />')
+            .val(name)
+            .text(name));
+    };
+
+
+    var ScrollManager = function(notebook) {
         // Public constructor.
         this.notebook = notebook;
         this.animation_speed = 250; //ms
@@ -16,6 +58,62 define([], function(){
         // ----------
         // delta: integer
         //  direction to scroll the document.  Positive is downwards.
+        this.scroll_some(delta);
+        return false;
+    };
+
+    ScrollManager.prototype.scroll_to = function(destination) {
+        // Scroll to an element in the notebook.
+        $('#notebook').animate({'scrollTop': $(destination).offset().top + $('#notebook').scrollTop() - $('#notebook').offset().top}, this.animation_speed);
+    };
+
+    ScrollManager.prototype.scroll_some = function(pages) {
+        // Scroll up or down a given number of pages.
+        $('#notebook').animate({'scrollTop': $('#notebook').scrollTop() + pages * $('#notebook').height()}, this.animation_speed);
+    };
+
+    ScrollManager.prototype.get_first_visible_cell = function() {
+        // Gets the index of the first visible cell in the document.
+
+        // First, attempt to be smart by guessing the index of the cell we are
+        // scrolled to.  Then, walk from there up or down until the right cell 
+        // is found.  To guess the index, get the top of the last cell, and
+        // divide that by the number of cells to get an average cell height.  
+        // Then divide the scroll height by the average cell height.
+        var cell_count = that.notebook.ncells();
+        var first_cell_top = that.notebook.get_cell(0).element.offset.top();
+        var last_cell_top = that.notebook.get_cell(cell_count-1).element.offset.top();
+        var avg_cell_height = (last_cell_top - first_cell_top) / cell_count;
+        var $notebook = $('#notebook').scrollTop();
+        var i = Math.ceil($notebook.scrollTop() / avg_cell_height);
+        i = min(max(i , 0), cell_count - 1);
+
+        while (that.notebook.get_cell(i).element.offset.top() - first_cell_top < $notebook.scrollTop() && i < cell_count - 1) {
+            i += 1;
+        } 
+
+        while (that.notebook.get_cell(i).element.offset.top() - first_cell_top > $notebook.scrollTop() && i >= 0) {
+            i -= 1;
+        } 
+        return min(i + 1, cell_count - 1);
+    };
+
+
+    var HeadingScrollManager = function(notebook, heading_level) {
+        // Public constructor.
+    };
+
+
+    var SlideScrollManager = function(notebook) {
+        // Public constructor.
+    };
+
+/*// Scroll the document.
+        //
+        // Parameters
+        // ----------
+        // delta: integer
+        //  direction to scroll the document.  Positive is downwards.
 
         // If one or more slides exist, scroll to the slide.
         var $slide_cells = $('.slideshow-slide');
@@ -66,19 +164,13 define([], function(){
         } else {
             this.scroll_some(delta);
             return false;
-        }
-    };
-
-    ScrollManager.prototype.scroll_to = function(destination) {
-        // Scroll to an element in the notebook.
-        $('#notebook').animate({'scrollTop': $(destination).offset().top + $('#notebook').scrollTop() - $('#notebook').offset().top}, this.animation_speed);
-    };
-
-    ScrollManager.prototype.scroll_some = function(pages) {
-        // Scroll up or down a given number of pages.
-        $('#notebook').animate({'scrollTop': $('#notebook').scrollTop() + pages * $('#notebook').height()}, this.animation_speed);
-    };
+        }*/
 
     // Return naemspace for require.js loads
-    return ScrollManager;
+    return {
+        'ScrollSelector': ScrollSelector,
+        'ScrollManager': ScrollManager,
+        'SlideScrollManager': SlideScrollManager,
+        'HeadingScrollManager': HeadingScrollManager
+    };
 });