Add busy/loading indicators and enable on Template

.travis.yml

@@ -52,6 +52,7 @@ jobs:
       stage: test
       env: DESC="dev test_all"
       before_install:
+        - python --version
         # install doit/pyctdev and use to install miniconda...
         - pip install pyctdev && doit miniconda_install && pip uninstall -y doit pyctdev
         - export PATH="$HOME/miniconda/bin:$PATH" && hash -r

examples/reference/indicators/BooleanStatus.ipynb

@@ -0,0 +1,103 @@
+{
+ "cells": [
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "import panel as pn\n",
+    "\n",
+    "from panel.widgets.indicators import BooleanStatus\n",
+    "\n",
+    "pn.extension()"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "The ``BooleanStatus`` is a boolean indicator providing a visual representation of a boolean status as filled or non-filled circle. If the `value` is set to `True` the indicator will be filled while setting it to `False` will cause it to be non-filled.\n",
+    "\n",
+    "#### Parameters:\n",
+    "\n",
+    "For layout and styling related parameters see the [customization user guide](../../user_guide/Customization.ipynb).\n",
+    "\n",
+    "* **``color``** (str): The color of the bar, one of 'primary', 'secondary', 'success', 'info', 'warn', 'danger', 'light', 'dark'\n",
+    "* **``value``** (int or None): Whether the status indicator is filled or not.\n",
+    "\n",
+    "___"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "The `BooleanStatus` widget can be instantiated as either `False` or `True`:"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "false_status = BooleanStatus(value=False)\n",
+    "true_status = BooleanStatus(value=True)\n",
+    "\n",
+    "pn.Row(false_status, true_status)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "The `BooleanStatus` indicator also supports a range of colors:"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "grid = pn.GridBox('', 'False', 'True', ncols=3)\n",
+    "\n",
+    "for color in BooleanStatus.param.color.objects:\n",
+    "    false = BooleanStatus(width=50, height=50, value=False, color=color)\n",
+    "    true = BooleanStatus(width=50, height=50, value=True, color=color)\n",
+    "    grid.extend((color, false, true))\n",
+    "\n",
+    "grid"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3",
+   "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": "3.7.5"
+  },
+  "widgets": {
+   "application/vnd.jupyter.widget-state+json": {
+    "state": {},
+    "version_major": 2,
+    "version_minor": 0
+   }
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 4
+}

examples/reference/indicators/LoadingSpinner.ipynb

@@ -0,0 +1,104 @@
+{
+ "cells": [
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "import panel as pn\n",
+    "from panel.widgets.indicators import LoadingSpinner\n",
+    "\n",
+    "\n",
+    "pn.extension()"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "The ``LoadingSpinner`` is a boolean indicator providing a visual representation of the loading status. If the `value` is set to `True` the spinner will rotate while setting it to `False` will disable the rotating segment.\n",
+    "\n",
+    "#### Parameters:\n",
+    "\n",
+    "For layout and styling related parameters see the [customization user guide](../../user_guide/Customization.ipynb).\n",
+    "\n",
+    "* **``bgcolor``** (str): The color of spinner background segment, either 'light' or 'dark'\n",
+    "* **``color``** (str): The color of the spinning segment, one of 'primary', 'secondary', 'success', 'info', 'warn', 'danger', 'light', 'dark'\n",
+    "* **``value``** (boolean): Whether the indicator is spinning or not.\n",
+    "\n",
+    "___"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "The `LoadingSpinner` can be instantiated in a spinning or idle state:"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "idle = LoadingSpinner(value=False, width=100, height=100)\n",
+    "loading = LoadingSpinner(value=True, width=100, height=100)\n",
+    "\n",
+    "pn.Row(idle, loading)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "The `LoadingSpinner` indicator also supports a range of spinner colors and backgrounds:"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "grid = pn.GridBox('', 'light', 'dark', ncols=3)\n",
+    "\n",
+    "for color in LoadingSpinner.param.color.objects:\n",
+    "    dark = LoadingSpinner(width=50, height=50, value=True, color=color, bgcolor='dark')\n",
+    "    light = LoadingSpinner(width=50, height=50, value=True, color=color, bgcolor='light')\n",
+    "    grid.extend((color, light, dark))\n",
+    "\n",
+    "grid"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3",
+   "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": "3.7.5"
+  },
+  "widgets": {
+   "application/vnd.jupyter.widget-state+json": {
+    "state": {},
+    "version_major": 2,
+    "version_minor": 0
+   }
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 4
+}

panel/_styles/widgets.css

@@ -139,3 +139,150 @@ progress:not([value])::before {
   from {background-position: 0%}
   to {background-position: 100%}
 }
+
+.bk.loader::after {
+  content: "";
+  border-radius: 50%;
+  -webkit-mask-image: radial-gradient(transparent 50%, rgba(0, 0, 0, 1) 54%);
+  width: 100%;
+  height: 100%;
+  left: 0;
+  top: 0;
+  position: absolute;
+}
+
+.bk-root .bk.loader.dark::after {
+  background: #0f0f0f;
+}
+
+.bk-root .bk.loader.light::after {
+  background: #f0f0f0;
+}
+
+.bk-root .bk.loader.spin::after {
+  animation: spin 2s linear infinite;
+}
+
+.bk-root div.bk.loader.spin.primary-light::after {
+  background: linear-gradient(135deg, #f0f0f0 50%, transparent 50%), linear-gradient(45deg, #f0f0f0 50%, #007bff 50%);
+}
+
+.bk-root div.bk.loader.spin.secondary-light::after {
+  background: linear-gradient(135deg, #f0f0f0 50%, transparent 50%), linear-gradient(45deg, #f0f0f0 50%, #6c757d 50%);
+}
+
+.bk-root div.bk.loader.spin.success-light::after {
+  background: linear-gradient(135deg, #f0f0f0 50%, transparent 50%), linear-gradient(45deg, #f0f0f0 50%, #28a745 50%);
+}
+
+.bk-root div.bk.loader.spin.danger-light::after {
+  background: linear-gradient(135deg, #f0f0f0 50%, transparent 50%), linear-gradient(45deg, #f0f0f0 50%, #dc3545 50%);
+}
+
+.bk-root div.bk.loader.spin.warning-light::after {
+  background: linear-gradient(135deg, #f0f0f0 50%, transparent 50%), linear-gradient(45deg, #f0f0f0 50%, #ffc107 50%);
+}
+
+.bk-root div.bk.loader.spin.info-light::after {
+  background: linear-gradient(135deg, #f0f0f0 50%, transparent 50%), linear-gradient(45deg, #f0f0f0 50%, #17a2b8 50%);
+}
+
+.bk-root div.bk.loader.spin.light-light::after {
+  background: linear-gradient(135deg, #f0f0f0 50%, transparent 50%), linear-gradient(45deg, #f0f0f0 50%, #f8f9fa 50%);
+}
+
+.bk-root div.bk.loader.dark-light::after {
+  background: linear-gradient(135deg, #f0f0f0 50%, transparent 50%), linear-gradient(45deg, #f0f0f0 50%, #343a40 50%);
+}
+
+.bk-root div.bk.loader.spin.primary-dark::after {
+  background: linear-gradient(135deg, #0f0f0f 50%, transparent 50%), linear-gradient(45deg, #0f0f0f 50%, #007bff 50%);
+}
+
+.bk-root div.bk.loader.spin.secondary-dark::after {
+  background: linear-gradient(135deg, #0f0f0f 50%, transparent 50%), linear-gradient(45deg, #0f0f0f 50%, #6c757d 50%);
+}
+
+.bk-root div.bk.loader.spin.success-dark::after {
+  background: linear-gradient(135deg, #0f0f0f 50%, transparent 50%), linear-gradient(45deg, #0f0f0f 50%, #28a745 50%);
+}
+
+.bk-root div.bk.loader.spin.danger-dark::after {
+  background: linear-gradient(135deg, #0f0f0f 50%, transparent 50%), linear-gradient(45deg, #0f0f0f 50%, #dc3545 50%)
+}
+
+.bk-root div.bk.loader.spin.warning-dark::after {
+  background: linear-gradient(135deg, #0f0f0f 50%, transparent 50%), linear-gradient(45deg, #0f0f0f 50%, #ffc107 50%);
+}
+
+.bk-root div.bk.loader.spin.info-dark::after {
+  background: linear-gradient(135deg, #0f0f0f 50%, transparent 50%), linear-gradient(45deg, #0f0f0f 50%, #17a2b8 50%);
+}
+
+.bk-root div.bk.loader.spin.light-dark::after {
+  background: linear-gradient(135deg, #0f0f0f 50%, transparent 50%), linear-gradient(45deg, #0f0f0f 50%, #f8f9fa 50%);
+}
+
+.bk-root div.bk.loader.spin.dark-dark::after {
+  background: linear-gradient(135deg, #0f0f0f 50%, transparent 50%), linear-gradient(45deg, #0f0f0f 50%, #343a40 50%);
+}
+
+/* Safari */
+@-webkit-keyframes spin {
+  0% { -webkit-transform: rotate(0deg); }
+  100% { -webkit-transform: rotate(360deg); }
+}
+
+@keyframes spin {
+  0% { transform: rotate(0deg); }
+  100% { transform: rotate(360deg); }
+}
+
+.dot div {
+  height: 100%;
+  width: 100%;
+  border: 1px solid #000 !important;
+  background-color: #fff;
+  border-radius: 50%;
+  display: inline-block;
+}
+
+.dot-filled div {
+  height: 100%;
+  width: 100%;
+  border: 1px solid #000 !important;
+  border-radius: 50%;
+  display: inline-block;
+}
+
+.dot-filled.primary div {
+  background-color: #007bff;
+}
+
+.dot-filled.secondary div {
+  background-color: #6c757d;
+}
+
+.dot-filled.success div {
+  background-color: #28a745;
+}
+
+.dot-filled.danger div {
+  background-color: #dc3545;
+}
+
+.dot-filled.warning div {
+  background-color: #ffc107;
+}
+
+.dot-filled.info div {
+  background-color: #17a2b8;
+}
+
+.dot-filled.dark div {
+  background-color: #343a40;
+}
+
+.dot-filled.light div {
+  background-color: #f8f9fa;
+}

panel/io/state.py

@@ -117,7 +117,7 @@ def sync_busy(self, indicator):
         """
         self._indicators.append(indicator)
 
-    @param.depends('busy')
+    @param.depends('busy', watch=True)
     def _update_busy(self):
         for indicator in self._indicators:
             indicator.value = self.busy