A Widget Base Class

The base class from which all widget classes are derived

Widget(...)

Arguments

...

Arguments passed to the inializer

Functions

• Widget(): A Widget Constructor Function

Super class

RKernel::HasTraits -> Widget

Public fields

_model_id

Identifyer of the frontend Javascript object

_model_name

Name of the Javascript model in the frontend

_model_module

Name of the Javascript module with the model

_model_module_version

Version of the module where the model is defined

_view_name

Name of the Javascript model view in the frontend

_view_module

Version of the module where the view is defined

_view_module_version

Version of the module where the view is defined

_view_count

Number of views that refer to the same frontend model object

traits_to_sync

Names of the traits to be synchronized with the frontend

sync_suspended

Logical value, whether synchronization is suspended

custom_msg_callbacks

A list of functions to be called on receiving a message

event_callbacks

A list of functions to be called on an event

displayed_callbacks

A list of functions to be called when the widget

_comm

The 'comm' connecting to the frontend or NULL

required_version

Minimum required ipywidgets version in which the current widget class is supported.

Active bindings

comm

The 'comm' connecting the frontend (as an active binding)

Methods

Public methods

• WidgetClass$new()

• WidgetClass$open()

• WidgetClass$finalize()

• WidgetClass$close()

• WidgetClass$get_state()

• WidgetClass$set_state()

• WidgetClass$send_state()

• WidgetClass$send()

• WidgetClass$display_data()

• WidgetClass$handle_comm_opened()

• WidgetClass$handle_comm_msg()

• WidgetClass$handle_buffers()

• WidgetClass$handle_custom_msg()

• WidgetClass$on_msg()

• WidgetClass$on_event()

• WidgetClass$handle_event()

• WidgetClass$on_displayed()

• WidgetClass$handle_displayed()

• WidgetClass$_send()

• WidgetClass$check_version()

• WidgetClass$clone()

Inherited methods

• RKernel::HasTraits$notify()
• RKernel::HasTraits$observe()
• RKernel::HasTraits$validate()

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Method new()

Initialize an object

Usage

WidgetClass$new(..., open = TRUE)

Arguments

...

Values used for initialization

open

Logical, whether a connection with the frontend should be opened

---

Method open()

Open a connection to the frontend

Usage

WidgetClass$open()

---

Method finalize()

Finalize the object

Usage

WidgetClass$finalize()

---

Method close()

Close the connection to the frontend

Usage

WidgetClass$close()

---

Method get_state()

Prepare synchronized traits for sending them to the frontend

Usage

WidgetClass$get_state(keys = NULL)

Arguments

keys

Keys/names of the traits to be updated in the frontend

---

Method set_state()

Update the synchronized states, usually with information from the frontend

Usage

WidgetClass$set_state(state)

Arguments

state

A list of values for the synchronized traits

---

Method send_state()

Send updated traits to the frontend

Usage

WidgetClass$send_state(keys = NULL, drop_defaults = FALSE)

Arguments

keys

Keys/names of the traits to be updated in the frontend

drop_defaults

Logical value, not yet used

---

Method send()

Send content and binary buffers to the fronend

Usage

WidgetClass$send(content, buffers = NULL)

Arguments

content

Some user-defined information to be send to the frontend

buffers

Some raw vector buffers

---

Method display_data()

Send display-data of the widget to the frontend

Usage

WidgetClass$display_data()

---

Method handle_comm_opened()

Handle a 'comm' opened in the frontend

Usage

WidgetClass$handle_comm_opened(comm, data)

Arguments

comm

The 'comm' object that is opened

data

Data sent by the frontend

---

Method handle_comm_msg()

Handle a message from the frontend

Usage

WidgetClass$handle_comm_msg(comm, msg)

Arguments

comm

The 'comm' object via which the message is received

msg

Message sent by the frontend

---

Method handle_buffers()

Handle buffers in message. This method should be overwritten by inherting classes that actually process data in buffer components of messages.

Usage

WidgetClass$handle_buffers(msg)

Arguments

msg

A comm message

---

Method handle_custom_msg()

Call the custom message handlers

Usage

WidgetClass$handle_custom_msg(content)

Arguments

content

The data received

---

Method on_msg()

Install a handler for messages being received

Usage

WidgetClass$on_msg(handler, remove = FALSE)

Arguments

handler

A handler function

remove

Logical, should the handler be removed?

---

Method on_event()

Install a handler for events in the frontend

Usage

WidgetClass$on_event(event, handler, remove = FALSE)

Arguments

event

A character that describes the event

handler

A handler function

remove

Logical, should the handler be removed?

---

Method handle_event()

Call the installed event handlers

Usage

WidgetClass$handle_event(event, args)

Arguments

event

A string that describes the event

args

A list of argument passed on with the event

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Method on_displayed()

Install a handler to be called when the widget is displayed

Usage

WidgetClass$on_displayed(handler, remove = FALSE)

Arguments

handler

A handler function

remove

Logical, should the handler be removed?

---

Method handle_displayed()

Call the installed display handlers

Usage

WidgetClass$handle_displayed()

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Method _send()

The internal function to send messages to the frontend

Usage

WidgetClass$_send(msg, buffers = NULL)

Arguments

msg

The message

buffers

Raw data buffers or NULL

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Method check_version()

Check whether current widget class is supported by ipywidgets

Usage

WidgetClass$check_version()

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Method clone()

The objects of this class are cloneable with this method.

Usage

WidgetClass$clone(deep = FALSE)

Arguments

deep

Whether to make a deep clone.