```eval_rst .. include:: /header.rst :github_url: |github_link_base|/widgets/keyboard.md ``` # Keyboard (lv_keyboard) ## Overview The Keyboard object is a special [Button matrix](/widgets/btnmatrix) with predefined keymaps and other features to realize a virtual keyboard to write text. ## Parts and Styles Similarly to Button matices Keyboards consist of 2 part: - `LV_KEYBOARD_PART_BG` which is the main part and uses all the typical background properties - `LV_KEYBOARD_PART_BTN` which is virtual part for the buttons. It also uses all typical backround proeprties and the *text* properties. ## Usage ### Modes The Keyboards have thefollowing 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 more is `LV_KEYBOARD_MODE_TEXT_UPPER`. ### Assign Text area You can assign a [Text area](/widgets/textarea) to the Keyboard to automatically put the clicked characters there. To assign the text area, use `lv_keyboard_set_textarea(kb, ta)`. The assigned text area's **cursor can be managed** by the keyboard: when the keyboard is assigned, the previous text area's cursor will be hidden and the new one will be shown. When the keyboard is closed by the *Ok* or *Close* buttons, the cursor also will be hidden. The cursor manager feature is enabled by `lv_keyboard_set_cursor_manage(kb, true)`. The default is not managed. ### 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](/widgets/btnmatrix) 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* - Close. - *LV_SYMBOL_BACKSPACE* - Delete on the left. - *LV_SYMBOL_LEFT* - Move the cursor left. - *LV_SYMBOL_RIGHT* - Move the cursor right. - *"ABC"* - Load the uppercase map. - *"abc"* - Load the lower case map. - *"Enter"* - New line. ## Events Besides the [Generic events](../overview/event.html#generic-events), the following [Special events](../overview/event.html#special-events) are sent by the keyboards: - **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_APPLY** - 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`. It handles the button pressing, map changing, the assigned text area, etc. You can completely replace it with your custom event handler however, you can call `lv_keyboard_def_event_cb` at the beginning of your event handler to handle the same things as before. Learn more about [Events](/overview/event). ## Keys The following *Keys* are processed by the buttons: - **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](/overview/indev). ## Examples ```eval_rst .. include:: /lv_examples/src/lv_ex_widgets/lv_ex_keyboard/index.rst ``` ## API ```eval_rst .. doxygenfile:: lv_keyboard.h :project: lvgl ```