lvgl/docs/widgets/extra/keyboard.md

.. include:: /header.rst 
:github_url: |github_link_base|/widgets/keyboard.md

Keyboard (lv_keyboard)

Overview

The Keyboard object is a special Button matrix with predefined keymaps and other features to realize a virtual keyboard to write texts into a Text area.

Parts and Styles

Similarly to Button matrices Keyboards consist of 2 part:

• LV_PART_MAIN The main part. Uses all the typical background properties
• LV_PART_ITEMS The buttons. Also uses all typical background properties as well as the text properties.

Usage

Modes

The Keyboards have the following modes:

• LV_KEYBOARD_MODE_TEXT_LOWER Display lower case letters
• LV_KEYBOARD_MODE_TEXT_UPPER Display upper case letters
• LV_KEYBOARD_MODE_TEXT_SPECIAL Display special characters
• LV_KEYBOARD_MODE_NUM Display numbers, +/- sign, and decimal dot.

The TEXT modes' layout contains buttons to change mode.

To set the mode manually, use lv_keyboard_set_mode(kb, mode). The default mode is LV_KEYBOARD_MODE_TEXT_UPPER.

Assign Text area

You can assign a Text area to the Keyboard to automatically put the clicked characters there. To assign the text area, use lv_keyboard_set_textarea(kb, ta).

New Keymap

You can specify a new map (layout) for the keyboard with lv_keyboard_set_map(kb, map) and lv_keyboard_set_ctrl_map(kb, ctrl_map). Learn more about the Button matrix object. Keep in mind that using following keywords will have the same effect as with the original map:

• LV_SYMBOL_OK Apply.
• LV_SYMBOL_CLOSE or LV_SYMBOL_KEYBOARD Close.
• LV_SYMBOL_BACKSPACE Delete on the left.
• LV_SYMBOL_LEFT Move the cursor left.
• LV_SYMBOL_RIGHT Move the cursor right.
• LV_SYMBOL_NEW_LINE New line.
• "ABC" Load the uppercase map.
• "abc" Load the lower case map.
• "1#" Load the lower case map.

Events

• LV_EVENT_VALUE_CHANGED Sent when the button is pressed/released or repeated after long press. The event data is set to the ID of the pressed/released button.
• LV_EVENT_READY - The Ok button is clicked.
• LV_EVENT_CANCEL - The Close button is clicked.

The keyboard has a default event handler callback called lv_keyboard_def_event_cb, which handles the button pressing, map changing, the assigned text area, etc. You can remove it and replace it with a custom event handler if you wish.

Learn more about Events.

Keys

• LV_KEY_RIGHT/UP/LEFT/RIGHT To navigate among the buttons and select one.
• LV_KEY_ENTER To press/release the selected button.

Learn more about Keys.

Examples

.. include:: ../../../examples/widgets/keyboard/index.rst

API

.. doxygenfile:: lv_keyboard.h
  :project: lvgl