Adding prompt area to non-CodeCells to indent content.

This is a reponse to the problem of having really long lines in
Markdown cells, which makes the content difficult to read. Users
want wide code cells, so we don't want to narrow everything. The
solution here is to give a prompt area to the heading/md cells
to narrow their content area slightly. The only problem is that
this makes it more difficult to distinguish between output
and md content that follows that output. The solve this, we are
adding a narrow line between output and following md.

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

@@ -122,17 +122,16 var IPython = (function (IPython) {
         var cell =  $('<div></div>').addClass('cell border-box-sizing code_cell');
         cell.attr('tabindex','2');
 
-        this.celltoolbar = new IPython.CellToolbar(this);
-
         var input = $('<div></div>').addClass('input');
-        var vbox = $('<div/>').addClass('vbox box-flex1');
-        input.append($('<div/>').addClass('prompt input_prompt'));
-        vbox.append(this.celltoolbar.element);
+        var prompt = $('<div/>').addClass('prompt input_prompt');
+        var inner_cell = $('<div/>').addClass('inner_cell');
+        this.celltoolbar = new IPython.CellToolbar(this);
+        inner_cell.append(this.celltoolbar.element);
         var input_area = $('<div/>').addClass('input_area');
         this.code_mirror = CodeMirror(input_area.get(0), this.cm_config);
         $(this.code_mirror.getInputField()).attr("spellcheck", "false");
-        vbox.append(input_area);
-        input.append(vbox);
+        inner_cell.append(input_area);
+        input.append(prompt).append(inner_cell);
         var output = $('<div></div>');
         cell.append(input).append(output);
         this.element = cell;

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

@@ -72,19 +72,22 var IPython = (function (IPython) {
      */
     TextCell.prototype.create_element = function () {
         IPython.Cell.prototype.create_element.apply(this, arguments);
+
         var cell = $("<div>").addClass('cell text_cell border-box-sizing');
         cell.attr('tabindex','2');
 
+        var prompt = $('<div/>').addClass('prompt input_prompt');
+        cell.append(prompt);
+        var inner_cell = $('<div/>').addClass('inner_cell');
         this.celltoolbar = new IPython.CellToolbar(this);
-        cell.append(this.celltoolbar.element);
-
+        inner_cell.append(this.celltoolbar.element);
         var input_area = $('<div/>').addClass('text_cell_input border-box-sizing');
         this.code_mirror = CodeMirror(input_area.get(0), this.cm_config);
-
         // The tabindex=-1 makes this div focusable.
         var render_area = $('<div/>').addClass('text_cell_render border-box-sizing').
             addClass('rendered_html').attr('tabindex','-1');
-        cell.append(input_area).append(render_area);
+        inner_cell.append(input_area).append(render_area);
+        cell.append(inner_cell);
         this.element = cell;
     };
 

IPython/html/static/notebook/less/cell.less

@@ -24,3 +24,8 div.prompt {
     /* This has to match that of the the CodeMirror class line-height below */	
     line-height: @code_line_height;
 }
+
+div.inner_cell {
+    .vbox();
+    .box-flex1();
+}

IPython/html/static/notebook/less/textcell.less

@@ -1,5 +1,6
 div.text_cell {
     padding: 5px 5px 5px 5px;
+    .hbox();
 }
 
 div.text_cell_input {
@@ -30,3 +31,8 h1,h2,h3,h4,h5,h6 {
         visibility: visible;
     }
 }
+
+.code_cell + .text_cell .inner_cell {
+    border-top: 1px solid @border_color;
+}
+

IPython/html/static/style/ipython.min.css

@@ -56,6 +56,7 input.engine_num_input{height:20px;margin-bottom:2px;padding-top:0;padding-botto
 .ansibggray{background-color:gray;}
 div.cell{border:1px solid transparent;display:-webkit-box;-webkit-box-orient:vertical;-webkit-box-align:stretch;display:-moz-box;-moz-box-orient:vertical;-moz-box-align:stretch;display:box;box-orient:vertical;box-align:stretch;width:100%;padding:5px 5px 5px 0px;margin:2px 0px 2px 7px;outline:none;}div.cell.selected{border-radius:4px;border:thin #ababab solid;}
 div.prompt{min-width:11ex;padding:0.4em;margin:0px;font-family:monospace;text-align:right;line-height:1.231em;}
+div.inner_cell{display:-webkit-box;-webkit-box-orient:vertical;-webkit-box-align:stretch;display:-moz-box;-moz-box-orient:vertical;-moz-box-align:stretch;display:box;box-orient:vertical;box-align:stretch;width:100%;-webkit-box-flex:1;-moz-box-flex:1;box-flex:1;}
 div.input{page-break-inside:avoid;display:-webkit-box;-webkit-box-orient:horizontal;-webkit-box-align:stretch;display:-moz-box;-moz-box-orient:horizontal;-moz-box-align:stretch;display:box;box-orient:horizontal;box-align:stretch;}
 div.input_area{border:1px solid #cfcfcf;border-radius:4px;background:#f7f7f7;}
 div.input_prompt{color:navy;border-top:1px solid transparent;}
@@ -139,8 +140,9 p.p-space{margin-bottom:10px;}
 .rendered_html *+p{margin-top:1em;}
 .rendered_html *+table{margin-top:1em;}
 .rendered_html *+img{margin-top:1em;}
-div.text_cell{padding:5px 5px 5px 5px;}
+div.text_cell{padding:5px 5px 5px 5px;display:-webkit-box;-webkit-box-orient:horizontal;-webkit-box-align:stretch;display:-moz-box;-moz-box-orient:horizontal;-moz-box-align:stretch;display:box;box-orient:horizontal;box-align:stretch;}
 div.text_cell_input{color:#000000;border:1px solid #cfcfcf;border-radius:4px;background:#f7f7f7;}
 div.text_cell_render{outline:none;resize:none;width:inherit;border-style:none;padding:5px;color:#000000;}
 a.anchor-link:link{text-decoration:none;padding:0px 20px;visibility:hidden;}
 h1:hover .anchor-link,h2:hover .anchor-link,h3:hover .anchor-link,h4:hover .anchor-link,h5:hover .anchor-link,h6:hover .anchor-link{visibility:visible;}
+.code_cell+.text_cell .inner_cell{border-top:1px solid #ababab;}

IPython/html/static/style/style.min.css

@@ -1437,6 +1437,7 input.engine_num_input{height:20px;margin-bottom:2px;padding-top:0;padding-botto
 .ansibggray{background-color:gray;}
 div.cell{border:1px solid transparent;display:-webkit-box;-webkit-box-orient:vertical;-webkit-box-align:stretch;display:-moz-box;-moz-box-orient:vertical;-moz-box-align:stretch;display:box;box-orient:vertical;box-align:stretch;width:100%;padding:5px 5px 5px 0px;margin:2px 0px 2px 7px;outline:none;}div.cell.selected{border-radius:4px;border:thin #ababab solid;}
 div.prompt{min-width:11ex;padding:0.4em;margin:0px;font-family:monospace;text-align:right;line-height:1.231em;}
+div.inner_cell{display:-webkit-box;-webkit-box-orient:vertical;-webkit-box-align:stretch;display:-moz-box;-moz-box-orient:vertical;-moz-box-align:stretch;display:box;box-orient:vertical;box-align:stretch;width:100%;-webkit-box-flex:1;-moz-box-flex:1;box-flex:1;}
 div.input{page-break-inside:avoid;display:-webkit-box;-webkit-box-orient:horizontal;-webkit-box-align:stretch;display:-moz-box;-moz-box-orient:horizontal;-moz-box-align:stretch;display:box;box-orient:horizontal;box-align:stretch;}
 div.input_area{border:1px solid #cfcfcf;border-radius:4px;background:#f7f7f7;}
 div.input_prompt{color:navy;border-top:1px solid transparent;}
@@ -1520,11 +1521,12 p.p-space{margin-bottom:10px;}
 .rendered_html *+p{margin-top:1em;}
 .rendered_html *+table{margin-top:1em;}
 .rendered_html *+img{margin-top:1em;}
-div.text_cell{padding:5px 5px 5px 5px;}
+div.text_cell{padding:5px 5px 5px 5px;display:-webkit-box;-webkit-box-orient:horizontal;-webkit-box-align:stretch;display:-moz-box;-moz-box-orient:horizontal;-moz-box-align:stretch;display:box;box-orient:horizontal;box-align:stretch;}
 div.text_cell_input{color:#000000;border:1px solid #cfcfcf;border-radius:4px;background:#f7f7f7;}
 div.text_cell_render{outline:none;resize:none;width:inherit;border-style:none;padding:5px;color:#000000;}
 a.anchor-link:link{text-decoration:none;padding:0px 20px;visibility:hidden;}
 h1:hover .anchor-link,h2:hover .anchor-link,h3:hover .anchor-link,h4:hover .anchor-link,h5:hover .anchor-link,h6:hover .anchor-link{visibility:visible;}
+.code_cell+.text_cell .inner_cell{border-top:1px solid #ababab;}
 body{background-color:#ffffff;}
 body.notebook_app{overflow:hidden;}
 span#notebook_name{height:1em;line-height:1em;padding:3px;border:none;font-size:146.5%;}