Checkbox

Checkbox bind checked + bind flag

A checkbox drives an int subject; a sibling label hides when the subject is zero.

bind_checked connects the checkbox's checked state to subject_flag (0 or 1). The note label uses a subject to enable the hidden flag when subject_flag equals 0 — so the label only shows once the box is ticked.

lv_example_checkbox_bind_checked.c

Checkbox value-changed event

Mirror the toggle state into a sibling label.

LV_EVENT_VALUE_CHANGED fires when the user toggles the checkbox. The state isn't in the payload — read it with lv_obj_has_state(cb, LV_STATE_CHECKED) and use any LVGL call inside the handler (here, lv_label_set_text on a sibling).

lv_example_checkbox_event.c

Checkbox states

Show unchecked, checked, and disabled tick boxes side by side.

Each checkbox carries the same text but advertises a different state. State is toggled at runtime with lv_obj_add_state(cb, LV_STATE_CHECKED) and friends; in XML the same effect is achieved by setting the state attribute directly.

lv_example_checkbox_states.c

Checkbox styling

Style the tick box (INDICATOR) and its checked state separately.

Checkbox exposes MAIN (label text area) and INDICATOR (tick box). The named styles target INDICATOR in both default and checked states so the tick box has a soft, rounded look unchecked and switches to an accent color with a tinted halo when checked. MAIN is styled with local style_* props to recolor the label area.

lv_example_checkbox_styling.c

Checkbox text

Set the label that appears next to the tick box.

Three checkboxes share a layout but each carries a different text: a short word, a longer single-line sentence, and a multi-line label using 
 for the line break. The text attribute is what lv_checkbox_set_text would set in code, and the gap between tick box and label is controlled by pad_column on the main part.

lv_example_checkbox_text.c