Merge pull request #6670 from jdfreder/output_widget

Output widget

IPython/html/static/widgets/js/widget_output.js

@@ -0,0 +1,57 b''
+// Copyright (c) IPython Development Team.
+// Distributed under the terms of the Modified BSD License.
+
+define([
+    "widgets/js/widget",
+    "jquery",
+    'notebook/js/outputarea',
+], function(widget, $, outputarea) {
+    'use strict';
+
+    var OutputView = widget.DOMWidgetView.extend({
+        initialize: function (parameters) {
+            // Public constructor
+            OutputView.__super__.initialize.apply(this, [parameters]);
+            this.model.on('msg:custom', this._handle_route_msg, this);
+        },
+
+        render: function(){
+            // Called when view is rendered.
+            this.output_area = new outputarea.OutputArea({
+                selector: this.$el, 
+                prompt_area: false, 
+                events: this.model.widget_manager.notebook.events, 
+                keyboard_manager: this.model.widget_manager.keyboard_manager });
+
+            // Make output area reactive.
+            var that = this;
+            this.output_area.element.on('changed', function() {
+                that.model.set('contents', that.output_area.element.html());
+            });
+            this.model.on('change:contents', function(){
+                var html = this.model.get('contents');
+                if (this.output_area.element.html() != html) {
+                    this.output_area.element.html(html);
+                }
+            }, this);
+
+            // Set initial contents.
+            this.output_area.element.html(this.model.get('contents'));
+        },
+        
+        _handle_route_msg: function(content) {
+            var cell = this.options.cell;
+            if (content && cell) {
+                if (content.method == 'push') {
+                    cell.push_output_area(this.output_area);
+                } else if (content.method == 'pop') {
+                    cell.pop_output_area(this.output_area);
+                }
+            }
+        },
+    });
+
+    return {
+        'OutputView': OutputView,
+    };
+});

IPython/html/widgets/widget_output.py

@@ -0,0 +1,50 b''
+"""Output class.  
+
+Represents a widget that can be used to display output within the widget area.
+"""
+
+# Copyright (c) IPython Development Team.
+# Distributed under the terms of the Modified BSD License.
+
+from .widget import DOMWidget
+import sys
+from IPython.utils.traitlets import Unicode, List
+from IPython.display import clear_output
+from IPython.testing.skipdoctest import skip_doctest
+
+@skip_doctest
+class Output(DOMWidget):
+    """Widget used as a context manager to display output.
+
+    This widget can capture and display stdout, stderr, and rich output.  To use
+    it, create an instance of it and display it.  Then use it as a context
+    manager.  Any output produced while in it's context will be captured and
+    displayed in it instead of the standard output area.
+
+    Example
+        from IPython.html import widgets
+        from IPython.display import display
+        out = widgets.Output()
+        display(out)
+        
+        print('prints to output area')
+
+        with out:
+            print('prints to output widget')"""
+    _view_name = Unicode('OutputView', sync=True)
+
+    def clear_output(self, *pargs, **kwargs):
+        with self:
+            clear_output(*pargs, **kwargs)
+
+    def __enter__(self):
+        self._flush()
+        self.send({'method': 'push'})
+
+    def __exit__(self, exception_type, exception_value, traceback):
+        self._flush()
+        self.send({'method': 'pop'})
+
+    def _flush(self):
+        sys.stdout.flush()
+        sys.stderr.flush()

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

@@ -23,6 +23,7 b' define(['
     'notebook/js/codemirror-ipython'
 ], function(IPython, $, utils, keyboard, cell, outputarea, completer, celltoolbar, CodeMirror, cmpython, cmip) {
     "use strict";
+    
     var Cell = cell.Cell;
 
     /* local util for codemirror */
@@ -79,6 +80,23 b' define(['
         this.input_prompt_number = null;
         this.celltoolbar = null;
         this.output_area = null;
+        // Keep a stack of the 'active' output areas (where active means the 
+        // output area that recieves output).  When a user activates an output
+        // area, it gets pushed to the stack.  Then, when the output area is
+        // deactivated, it's popped from the stack.  When the stack is empty,
+        // the cell's output area is used.
+        this.active_output_areas = [];
+        var that = this;
+        Object.defineProperty(this, 'active_output_area', {
+            get: function() {
+                if (that.active_output_areas && that.active_output_areas.length > 0) {
+                    return that.active_output_areas[that.active_output_areas.length-1];
+                } else {
+                    return that.output_area;
+                }
+            },
+        });
+
         this.last_msg_id = null;
         this.completer = null;
 
@@ -91,8 +109,6 b' define(['
 
         // Attributes we want to override in this subclass.
         this.cell_type = "code";
-
-        var that = this;
         this.element.focusout(
             function() { that.auto_highlight(); }
         );
@@ -118,6 +134,23 b' define(['
     CodeCell.prototype = Object.create(Cell.prototype);
 
     /**
+     * @method push_output_area
+     */
+    CodeCell.prototype.push_output_area = function (output_area) {
+        this.active_output_areas.push(output_area);
+    };
+
+    /**
+     * @method pop_output_area
+     */
+    CodeCell.prototype.pop_output_area = function (output_area) {
+        var index = this.active_output_areas.lastIndexOf(output_area);
+        if (index > -1) {
+            this.active_output_areas.splice(index, 1);
+        }
+    };
+
+    /**
      * @method auto_highlight
      */
     CodeCell.prototype.auto_highlight = function () {
@@ -282,8 +315,8 b' define(['
             console.log("Can't execute, kernel is not connected.");
             return;
         }
-        
-        this.output_area.clear_output();
+
+        this.active_output_area.clear_output();
         
         // Clear widget area
         this.widget_subarea.html('');
@@ -312,6 +345,7 b' define(['
      * @method get_callbacks
      */
     CodeCell.prototype.get_callbacks = function () {
+        var that = this;
         return {
             shell : {
                 reply : $.proxy(this._handle_execute_reply, this),
@@ -321,8 +355,12 b' define(['
                 }
             },
             iopub : {
-                output : $.proxy(this.output_area.handle_output, this.output_area),
-                clear_output : $.proxy(this.output_area.handle_clear_output, this.output_area),
+                output : function() { 
+                    that.active_output_area.handle_output.apply(that.active_output_area, arguments);
+                }, 
+                clear_output : function() { 
+                    that.active_output_area.handle_clear_output.apply(that.active_output_area, arguments);
+                }, 
             },
             input : $.proxy(this._handle_input_request, this)
         };
@@ -356,7 +394,7 b' define(['
      * @private
      */
     CodeCell.prototype._handle_input_request = function (msg) {
-        this.output_area.append_raw_input(msg);
+        this.active_output_area.append_raw_input(msg);
     };
 
 
@@ -459,7 +497,7 b' define(['
 
 
     CodeCell.prototype.clear_output = function (wait) {
-        this.output_area.clear_output(wait);
+        this.active_output_area.clear_output(wait);
         this.set_input_prompt();
     };
 

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

@@ -400,6 +400,9 b' define(['
             this._append_javascript_error(err, subarea);
             this.element.append(toinsert);
         }
+
+        // Notify others of changes.
+        this.element.trigger('changed');
     };
 
 
@@ -832,6 +835,10 b' define(['
             // them to fire if the image is never added to the page.
             this.element.find('img').off('load');
             this.element.html("");
+
+            // Notify others of changes.
+            this.element.trigger('changed');
+            
             this.outputs = [];
             this.trusted = true;
             this.unscroll_area();

IPython/html/static/widgets/js/init.js

@@ -9,6 +9,7 b' define(['
     "widgets/js/widget_float",
     "widgets/js/widget_image",
     "widgets/js/widget_int",
+    "widgets/js/widget_output",
     "widgets/js/widget_selection",
     "widgets/js/widget_selectioncontainer",
     "widgets/js/widget_string",

IPython/html/widgets/__init__.py

@@ -6,6 +6,7 b' from .widget_box import Box, Popup, FlexBox, HBox, VBox'
 from .widget_float import FloatText, BoundedFloatText, FloatSlider, FloatProgress, FloatRangeSlider
 from .widget_image import Image
 from .widget_int import IntText, BoundedIntText, IntSlider, IntProgress, IntRangeSlider
+from .widget_output import Output
 from .widget_selection import RadioButtons, ToggleButtons, Dropdown, Select
 from .widget_selectioncontainer import Tab, Accordion
 from .widget_string import HTML, Latex, Text, Textarea