Update slider range after initial set up, what happened to lv_task_t?

How-to
1

I want to update/change the range of a slider after initial set. LVGL v7 suggest that this can be done using by creating a task (lv_task_t * myTask) with a task periodic task call back. But I can find no reference to this in the V8 documentation. So my question is how do change the range of a slider after initial set. The min and max range values are in this case set by the user with a pair of rollers with the change of value event initiating the update of the slider range.

Thank you for your suggestions.

2

Hey, you tried to use the set range value?

3

Actually I can change the range, the problem was that my image button event is not working which was used to make the change in the range.

lv_obj_add_event_cb(ui_BTN_Setmax, event_ui_BTN_Setmax, LV_EVENT_VALUE_CHANGED, NULL);

with the call back

static void event_ui_BTN_Setmax(lv_event_t * e)
{
lv_event_code_t code = lv_event_get_code(e);
Serial.println(“pressed”);
}

The call back is not happening on the button press. Any ideas why does an image button work differently to a normal button

Thank you

4

Actually I can change the range, the problem was that my image button event is not working which was used to make the change in the range.

lv_obj_add_event_cb(ui_BTN_Setmax, event_ui_BTN_Setmax, LV_EVENT_VALUE_CHANGED, NULL);

with the call back

static void event_ui_BTN_Setmax(lv_event_t * e)
{
lv_event_code_t code = lv_event_get_code(e);
Serial.println(“pressed”);
}

The call back is not happening on the button press. Any ideas why does an image button work differently to a normal button

Thank you

5

Without more of the code i cant help much, but you can try to change the event filtering to all

                                                         /*      thisguy    */
lv_obj_add_event_cb(ui_BTN_Setmax, event_ui_BTN_Setmax, LV_EVENT_VALUE_CHANGED, NULL);

to

lv_obj_add_event_cb(ui_BTN_Setmax, event_ui_BTN_Setmax, LV_EVENT_ALL, NULL);

I`m pretty sure that will work, i normally use the LV_EVENT_CLICKED to filter my buttons, but just to be sure use the all flag and filter inside the cb.

Edit: also are you adding the btn to the keygroup??

6

Thanks

I also had to add
lv_obj_add_flag(ui_BTN_Setmax, LV_OBJ_FLAG_CLICKABLE )

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