Added TextAreaInput widget (#658)

examples/reference/widgets/TextAreaInput.ipynb

@@ -0,0 +1,87 @@
+{
+ "cells": [
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "import panel as pn\n",
+    "pn.extension()"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "from panel.widgets.input import TextAreaInput"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "The ``TextAreaInput`` allows entering any string using a obfuscated text input box.\n",
+    "\n",
+    "For more information about listening to widget events and laying out widgets refer to the [widgets user guide](../../user_guide/Widgets.ipynb). Alternatively you can learn how to build GUIs by declaring parameters independently of any specific widgets in the [param user guide](../../user_guide/Param.ipynb). To express interactivity entirely using Javascript without the need for a Python server take a look at the [links user guide](../../user_guide/Param.ipynb).\n",
+    "\n",
+    "#### Parameters:\n",
+    "\n",
+    "For layout and styling related parameters see the [customization user guide](../../user_guide/Customization.ipynb).\n",
+    "\n",
+    "##### Core\n",
+    "\n",
+    "* **``value``** (str): Any string\n",
+    "\n",
+    "##### Display\n",
+    "\n",
+    "* **``disabled``** (boolean): Whether the widget is editable\n",
+    "* **``name``** (str): The title of the widget\n",
+    "* **``placeholder``** (str): A placeholder string displayed when no value is entered\n",
+    "* **``max_length``** (int): Max character length of the input field. Defaults to 5000\n",
+    "\n",
+    "___"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "text_area_input = pn.widgets.input.TextAreaInput(name='Text Area Input', placeholder='Enter a string here...')\n",
+    "text_area_input"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "``TextAreaInput.value`` returns a string type that can be read out and set like other widgets:"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "text_area_input.value"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "text_area_input.name"
+   ]
+  }
+ ],
+ "metadata": {},
+ "nbformat": 4,
+ "nbformat_minor": 2
+}

panel/widgets/input.py

@@ -16,7 +16,7 @@
     CheckboxGroup as _BkCheckboxGroup, ColorPicker as _BkColorPicker,
     DatePicker as _BkDatePicker, Div as _BkDiv, TextInput as _BkTextInput,
     PasswordInput as _BkPasswordInput, Spinner as _BkSpinner, 
-    FileInput as _BkFileInput)
+    FileInput as _BkFileInput, TextAreaInput as _BkTextAreaInput)
 
 from ..util import as_unicode
 from .base import Widget
@@ -38,6 +38,16 @@ class PasswordInput(Widget):
 
     _widget_type = _BkPasswordInput
 
+class TextAreaInput(Widget):
+
+    value = param.String(default='', allow_None=True)
+
+    placeholder = param.String(default='')
+
+    max_length = param.Integer(default=5000)
+
+    _widget_type = _BkTextAreaInput
+
 class FileInput(Widget):
 
     accept = param.String(default=None)