{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Styling of Jupyter widgets\n",
    "\n",
    "This notebook presents how to style Jupyter interactive widgets to build rich and *reactive* widget-based applications."
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "You can jump directly to these sections:\n",
    "\n",
    "+ [Predefined styles](#Predefined-styles)\n",
    "+ [The style attribute](#The-style-attribute)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Predefined styles\n",
    "\n",
    "If you wish the styling of widgets to make use of colors and styles defined by the environment (to be consistent with e.g. a notebook theme), many widgets enable choosing in a list of pre-defined styles.\n",
    "\n",
    "For example, the `Button` widget has a `button_style` attribute that may take 5 different values:\n",
    "\n",
    " - `'primary'`\n",
    " - `'success'`\n",
    " - `'info'`\n",
    " - `'warning'`\n",
    " - `'danger'`\n",
    "\n",
    "besides the default empty string ''."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "from ipywidgets import Button\n",
    "\n",
    "Button(description='Danger Button', button_style='danger')"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## The `style` attribute\n",
    "\n",
    "While the `layout` attribute only exposes layout-related CSS properties for the top-level DOM element of widgets, the  \n",
    "`style` attribute is used to expose non-layout related styling attributes of widgets.\n",
    "\n",
    "However, the properties of the `style` attribute are specific to each widget type."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "b1 = Button(description='Custom color')\n",
    "b1.style.button_color = 'lightgreen'\n",
    "b1"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "You can get a list of the style attributes for a widget with the `keys` property."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "b1.style.keys"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Just like the `layout` attribute, widget styles can be assigned to other widgets."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "b2 = Button()\n",
    "b2.style = b1.style\n",
    "b2"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Widget styling attributes are specific to each widget type."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "from ipywidgets import IntSlider\n",
    "\n",
    "s1 = IntSlider(description='Blue handle')\n",
    "s1.style.handle_color = 'lightblue'\n",
    "s1"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Styles can be given when a widget is constructed, either as a specific Style instance or as a dictionary."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "b3 = Button(description='Styled button', style=dict(\n",
    "    font_style='italic',\n",
    "    font_weight='bold',\n",
    "    font_variant=\"small-caps\",\n",
    "    text_color='red',\n",
    "    text_decoration='underline'\n",
    "))\n",
    "b3"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Current supported attributes\n",
    "\n",
    "Currently, the styling attributes that are supported vary from widget to widget. Here is the list of which different `Style` widgets are used by the various other widgets:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "from collections import defaultdict\n",
    "from IPython.display import HTML\n",
    "import ipywidgets\n",
    "from pprint import pprint"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "reverse_lut = defaultdict(set)\n",
    "styles = set()\n",
    "for export_name in dir(ipywidgets.widgets):\n",
    "    export = getattr(ipywidgets.widgets, export_name)\n",
    "    try:\n",
    "        if issubclass(export, ipywidgets.Widget) and 'style' in export.class_trait_names():\n",
    "            reverse_lut[export.style.klass.__name__].add(export.__name__)\n",
    "            styles.add(export.style.klass)\n",
    "    except TypeError:\n",
    "        pass\n",
    "\n",
    "html = '<ul>'\n",
    "for style, widgets in reverse_lut.items():\n",
    "    html = f\"{html}\\n<li><b>{style}:</b> {', '.join(sorted(widgets))}</li>\"\n",
    "html += \"</ul>\"\n",
    "HTML(html)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "And here are the different attributes that the different `Style` widgets support:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "attributes = defaultdict(set)\n",
    "base_traits = set(ipywidgets.Style.class_trait_names())\n",
    "\n",
    "for s in styles:\n",
    "    for t in s.class_trait_names():\n",
    "        if not t.startswith(\"_\") and t not in base_traits:\n",
    "            attributes[s.__name__].add(t)\n",
    "all_attributes = set().union(*attributes.values())\n",
    "\n",
    "html = '<table>\\n'\n",
    "html = f\"{html}<tr><th>Attribute</th>{ ''.join(f'<th>{s}</th>' for s in attributes.keys()) }</tr>\"\n",
    "for a in all_attributes:\n",
    "    html = f\"\"\"{html}<tr><td>{a}</td>{ ''.join(f'<td>{\"✓\" if a in attribs else \"\"}</td>' for attribs in attributes.values()) }</tr>\"\"\"\n",
    "html += \"</table>\"\n",
    "HTML(html)"
   ]
  }
 ],
 "metadata": {
  "kernelspec": {
   "display_name": "Python 3 (ipykernel)",
   "language": "python",
   "name": "python3"
  },
  "language_info": {
   "codemirror_mode": {
    "name": "ipython",
    "version": 3
   },
   "file_extension": ".py",
   "mimetype": "text/x-python",
   "name": "python",
   "nbconvert_exporter": "python",
   "pygments_lexer": "ipython3",
   "version": "3.11.0"
  }
 },
 "nbformat": 4,
 "nbformat_minor": 4
}