Tactility/Modules/lvgl-module/source/devices/keyboard.cpp

// SPDX-License-Identifier: Apache-2.0
#include <lvgl/devices/keyboard.h>
#include <lvgl/devices/device_context.h>
#include <lvgl/lvgl.h>

#include <tactility/drivers/keyboard.h>

#include <vector>

static LvglSoftwareKeyboard last_software_keyboard = {
    .object = nullptr
};

static lv_group_t* keyboard_group;

extern "C" {

void lvgl_keyboard_on_start_lvgl() {
    lvgl_lock();
    keyboard_group = lv_group_create();
    check(keyboard_group);
    lvgl_unlock();
}

void lvgl_keyboard_on_stop_lvgl() {
    last_software_keyboard = {
        .object = nullptr
    };

    lvgl_lock();
    lv_group_delete(keyboard_group);
    lvgl_unlock();

    keyboard_group = nullptr;
}

static void lvgl_keyboard_read_cb(lv_indev_t* indev, lv_indev_data_t* data) {
    auto* wrapper = static_cast<LvglDeviceContext*>(lv_indev_get_driver_data(indev));

    KeyboardKeyData key_data = {};
    if (keyboard_read_key(wrapper->device, &key_data) != ERROR_NONE) {
        data->state = LV_INDEV_STATE_RELEASED;
        data->continue_reading = false;
        return;
    }

    // KeyboardKeyData deliberately mirrors lv_indev_data_t's key/continue_reading fields, so no translation is needed.
    data->key = key_data.key;
    data->state = key_data.pressed ? LV_INDEV_STATE_PRESSED : LV_INDEV_STATE_RELEASED;
    data->continue_reading = key_data.continue_reading;
}

error_t lvgl_keyboard_add(struct Device* device, lv_display_t* display, lv_indev_t** out_indev) {
    if (device == NULL || out_indev == NULL) {
        return ERROR_INVALID_ARGUMENT;
    }
    if (device_get_type(device) != &KEYBOARD_TYPE) {
        return ERROR_INVALID_ARGUMENT;
    }

    auto* wrapper = new(std::nothrow) LvglDeviceContext(nullptr);
    if (wrapper == NULL) {
        return ERROR_OUT_OF_MEMORY;
    }
    wrapper->device = device;

    lv_indev_t* indev = lv_indev_create();
    if (indev == NULL) {
        delete wrapper;
        return ERROR_OUT_OF_MEMORY;
    }

    lv_indev_set_type(indev, LV_INDEV_TYPE_KEYPAD);
    lv_indev_set_read_cb(indev, lvgl_keyboard_read_cb);
    lv_indev_set_driver_data(indev, wrapper);
    if (display != NULL) {
        lv_indev_set_display(indev, display);
    }

    *out_indev = indev;
    return ERROR_NONE;
}

void lvgl_keyboard_remove(lv_indev_t* indev) {
    if (indev == NULL) {
        return;
    }

    auto* wrapper = static_cast<LvglDeviceContext*>(lv_indev_get_driver_data(indev));
    lv_indev_delete(indev);
    delete wrapper;
}

void lvgl_keyboard_enable(lv_indev_t* indev) {
    check(keyboard_group != nullptr);
    lv_indev_set_group(indev, keyboard_group);
}

void lvgl_keyboard_disable(lv_indev_t* indev) {
    lv_indev_set_group(indev, nullptr);
}

bool lvgl_hardware_keyboard_is_available() {
    Device* keyboard_device;
    if (device_get_first_active_by_type(&KEYBOARD_TYPE, &keyboard_device) != ERROR_NONE) {
        return false;
    }

    // TODO: Refactor the driver subsystem to so it does proper probing/releasing of such devices
    // This work-around exists for the Tab5 keyboard driver.
    bool present = keyboard_is_present(keyboard_device);
    device_put(keyboard_device);
    return present;
}

void lvgl_hardware_keyboard_add_custom(lv_indev_t* indev) {
    auto* wrapper = new(std::nothrow) LvglDeviceContext(nullptr);
    if (wrapper == nullptr) {
        return;
    }

    lv_indev_set_driver_data(indev, wrapper);

    lvgl_keyboard_enable(indev);
}

void lvgl_hardware_keyboard_remove_custom(lv_indev_t* indev) {
    lvgl_keyboard_disable(indev);
    auto* wrapper = static_cast<LvglDeviceContext*>(lv_indev_get_driver_data(indev));
    lv_indev_set_driver_data(indev, nullptr);
    delete wrapper;
}

static void textarea_show_keyboard(lv_event_t* event) {
    lv_obj_t* target = lv_event_get_current_target_obj(event);
    if (last_software_keyboard.object != nullptr) {
        lvgl_software_keyboard_show(&last_software_keyboard, target);
        lv_obj_scroll_to_view(target, LV_ANIM_ON);
    }
}

static void textarea_hide_keyboard(lv_event_t* event) {
    if (last_software_keyboard.object == nullptr) {
        return;
    }
    // Only hide if the keyboard is actually bound to the textarea that triggered this
    lv_obj_t* target = lv_event_get_current_target_obj(event);
    if (lv_keyboard_get_textarea(last_software_keyboard.object) != target) {
        return;
    }
    lvgl_software_keyboard_hide(&last_software_keyboard);
}

void lvgl_software_keyboard_construct(LvglSoftwareKeyboard* keyboard, lv_obj_t* parent) {
    keyboard->object = lv_keyboard_create(parent);
    lv_obj_add_flag(keyboard->object, LV_OBJ_FLAG_HIDDEN);
    last_software_keyboard = *keyboard;
}

void lvgl_software_keyboard_destruct(LvglSoftwareKeyboard* keyboard) {
    check(keyboard->object);

    lv_obj_delete(keyboard->object);
    keyboard->object = nullptr;

    last_software_keyboard = *keyboard;
}

void lvgl_software_keyboard_show(LvglSoftwareKeyboard* keyboard, lv_obj_t* textarea) {
    assert(keyboard->object != nullptr);
    lv_obj_clear_flag(keyboard->object, LV_OBJ_FLAG_HIDDEN);
    lv_keyboard_set_textarea(keyboard->object, textarea);
}

void lvgl_software_keyboard_hide(LvglSoftwareKeyboard* keyboard) {
    assert(keyboard->object != nullptr);
    lv_obj_add_flag(keyboard->object, LV_OBJ_FLAG_HIDDEN);
}

bool lvgl_software_keyboard_is_enabled() {
    return !lvgl_hardware_keyboard_is_available();
}

LvglSoftwareKeyboard* lvgl_software_keyboard_get_last() {
    return &last_software_keyboard;
}

void lvgl_keyboard_add_textarea(LvglSoftwareKeyboard* keyboard, lv_obj_t* textarea) {
    // Only the on-screen keyboard's show/hide wiring is specific to "no hardware keyboard"
    // mode. Group membership must NOT be gated on it: a hardware keypad indev (see
    // lvgl_keyboard_enable()/lvgl_software_keyboard_activate()) is bound to keyboard_group
    // regardless of whether a software keyboard is in use, so skipping lv_group_add_obj()
    // here left every textarea unreachable from a hardware keyboard - it was never a member
    // of the group its indev delivers key events through.
    if (lvgl_software_keyboard_is_enabled()) {
        lv_obj_add_event_cb(textarea, textarea_show_keyboard, LV_EVENT_FOCUSED, nullptr);
        lv_obj_add_event_cb(textarea, textarea_hide_keyboard, LV_EVENT_DEFOCUSED, nullptr);
        lv_obj_add_event_cb(textarea, textarea_hide_keyboard, LV_EVENT_READY, nullptr);
        lv_obj_add_event_cb(textarea, textarea_hide_keyboard, LV_EVENT_DELETE, nullptr);
    }

    // lv_obj_t auto-remove themselves from the group when they are destroyed (last checked in LVGL 8.3)
    lv_group_add_obj(keyboard_group, textarea);

    lvgl_software_keyboard_activate(keyboard);
}

void lvgl_software_keyboard_activate(LvglSoftwareKeyboard* keyboard) {
    auto* indev = lv_indev_get_next(nullptr);
    check(keyboard_group);
    while (indev) {
        if (lv_indev_get_type(indev) == LV_INDEV_TYPE_KEYPAD) {
            lv_indev_set_group(indev, keyboard_group);
        }
        indev = lv_indev_get_next(indev);
    }
}

void lvgl_software_keyboard_deactivate(LvglSoftwareKeyboard* keyboard) {
    auto* indev = lv_indev_get_next(nullptr);
    while (indev) {
        if (lv_indev_get_type(indev) == LV_INDEV_TYPE_KEYPAD) {
            lv_indev_set_group(indev, nullptr);
        }
        indev = lv_indev_get_next(indev);
    }
}

}