lvgl/examples/others/observer/lv_example_observer_5.c

#include "../../lv_examples.h"
#if LV_USE_OBSERVER && LV_USE_ARC && LV_USE_LABEL && LV_USE_BUTTON && LV_USE_SPINNER && LV_BUILD_EXAMPLES

typedef enum {
    FW_UPDATE_STATE_IDLE,
    FW_UPDATE_STATE_CONNECTING,
    FW_UPDATE_STATE_CONNECTED,
    FW_UPDATE_STATE_DOWNLOADING,
    FW_UPDATE_STATE_CANCEL,
    FW_UPDATE_STATE_READY,
} fw_update_state_t;

static void fw_upload_manager_observer_cb(lv_observer_t * observer, lv_subject_t * subject);
static void fw_update_btn_clicked_event_cb(lv_event_t * e);
static void fw_update_close_event_cb(lv_event_t * e);
static void fw_update_win_observer_cb(lv_observer_t * observer, lv_subject_t * subject);

static lv_subject_t fw_download_percent_subject;
static lv_subject_t fw_update_status_subject;

/**
 * Show how to handle a complete firmware update process with observers.
 * Normally it's hard to implement a firmware update process because in some cases
 *   - the App needs to was for the UI (wait for a button press)
 *   - the UI needs to wait for the App (connecting or downloading)
 * With observers these complex mechanisms can be implemented a simple and clean way.
 */
void lv_example_observer_5(void)
{
    lv_subject_init_int(&fw_download_percent_subject, 0);
    lv_subject_init_int(&fw_update_status_subject, FW_UPDATE_STATE_IDLE);

    lv_subject_add_observer(&fw_update_status_subject, fw_upload_manager_observer_cb, NULL);

    /*Create start FW update button*/
    lv_obj_t * btn = lv_button_create(lv_screen_active());
    lv_obj_add_event_cb(btn, fw_update_btn_clicked_event_cb, LV_EVENT_CLICKED, NULL);
    lv_obj_center(btn);
    lv_obj_t * label = lv_label_create(btn);
    lv_label_set_text(label, "Firmware update");
}

static void fw_update_btn_clicked_event_cb(lv_event_t * e)
{
    LV_UNUSED(e);
    lv_obj_t * win = lv_win_create(lv_screen_active());
    lv_obj_set_size(win, lv_pct(90), lv_pct(90));
    lv_obj_set_height(lv_win_get_header(win), 40);
    lv_obj_set_style_radius(win, 8, 0);
    lv_obj_set_style_shadow_width(win, 24, 0);
    lv_obj_set_style_shadow_offset_x(win, 2, 0);
    lv_obj_set_style_shadow_offset_y(win, 3, 0);
    lv_obj_set_style_shadow_color(win, lv_color_hex3(0x888), 0);
    lv_win_add_title(win, "Firmware update");
    lv_obj_t * btn = lv_win_add_button(win, LV_SYMBOL_CLOSE, 40);
    lv_obj_add_event_cb(btn, fw_update_close_event_cb, LV_EVENT_CLICKED, NULL);
    lv_obj_center(win);

    lv_subject_set_int(&fw_update_status_subject, FW_UPDATE_STATE_IDLE);
    lv_subject_add_observer_obj(&fw_update_status_subject, fw_update_win_observer_cb, win, NULL);
}

static void fw_update_close_event_cb(lv_event_t * e)
{
    LV_UNUSED(e);
    lv_subject_set_int(&fw_update_status_subject, FW_UPDATE_STATE_CANCEL);
}

static void restart_btn_click_event_cb(lv_event_t * e)
{
    lv_obj_t * win = lv_event_get_user_data(e);
    lv_obj_delete(win);
    lv_subject_set_int(&fw_update_status_subject, FW_UPDATE_STATE_IDLE);
}

static void fw_update_win_observer_cb(lv_observer_t * observer, lv_subject_t * subject)
{
    lv_obj_t * win = lv_observer_get_target(observer);
    lv_obj_t * cont = lv_win_get_content(win);
    fw_update_state_t status = lv_subject_get_int(&fw_update_status_subject);
    if(status == FW_UPDATE_STATE_IDLE) {
        lv_obj_clean(cont);
        lv_obj_t * spinner = lv_spinner_create(cont);
        lv_obj_center(spinner);
        lv_obj_set_size(spinner, 130, 130);

        lv_obj_t * label = lv_label_create(cont);
        lv_label_set_text(label, "Connecting");
        lv_obj_center(label);

        lv_subject_set_int(subject, FW_UPDATE_STATE_CONNECTING);
    }
    else if(status == FW_UPDATE_STATE_DOWNLOADING) {
        lv_obj_clean(cont);
        lv_obj_t * arc = lv_arc_create(cont);
        lv_arc_bind_value(arc, &fw_download_percent_subject);
        lv_obj_center(arc);
        lv_obj_set_size(arc, 130, 130);
        lv_obj_remove_flag(arc, LV_OBJ_FLAG_CLICKABLE);

        lv_obj_t * label = lv_label_create(cont);
        lv_label_bind_text(label, &fw_download_percent_subject, "%d %%");
        lv_obj_center(label);
    }
    else if(status == FW_UPDATE_STATE_READY) {
        lv_obj_clean(cont);
        lv_obj_t * label = lv_label_create(cont);
        lv_label_set_text(label, "Firmware update is ready");
        lv_obj_align(label, LV_ALIGN_CENTER, 0, -20);

        lv_obj_t * btn = lv_button_create(cont);
        lv_obj_align(btn, LV_ALIGN_CENTER, 0, 20);
        lv_obj_add_event_cb(btn, restart_btn_click_event_cb, LV_EVENT_CLICKED, win);

        label = lv_label_create(btn);
        lv_label_set_text(label, "Restart");
    }
    else if(status == FW_UPDATE_STATE_CANCEL) {
        lv_obj_delete(win);
    }
}

static void connect_timer_cb(lv_timer_t * t)
{
    if(lv_subject_get_int(&fw_update_status_subject) != FW_UPDATE_STATE_CANCEL) {
        lv_subject_set_int(&fw_update_status_subject, FW_UPDATE_STATE_CONNECTED);
    }
    lv_timer_delete(t);
}

static void download_timer_cb(lv_timer_t * t)
{
    if(lv_subject_get_int(&fw_update_status_subject) == FW_UPDATE_STATE_CANCEL) {
        lv_timer_delete(t);
        return;
    }

    int32_t v = lv_subject_get_int(&fw_download_percent_subject);
    if(v < 100) {
        lv_subject_set_int(&fw_download_percent_subject, v + 1);
    }
    else {
        lv_subject_set_int(&fw_update_status_subject, FW_UPDATE_STATE_READY);
        lv_timer_delete(t);
    }
}

/**
 * Emulate connection and FW downloading by timers
 */
static void fw_upload_manager_observer_cb(lv_observer_t * observer, lv_subject_t * subject)
{
    LV_UNUSED(subject);
    LV_UNUSED(observer);

    fw_update_state_t state = lv_subject_get_int(&fw_update_status_subject);
    if(state == FW_UPDATE_STATE_CONNECTING) {
        lv_timer_create(connect_timer_cb, 2000, NULL);
    }
    else if(state == FW_UPDATE_STATE_CONNECTED) {
        lv_subject_set_int(&fw_download_percent_subject, 0);
        lv_subject_set_int(&fw_update_status_subject, FW_UPDATE_STATE_DOWNLOADING);
        lv_timer_create(download_timer_cb, 50, NULL);
    }
}

#endif