2.3 KiB
Checkbox (lv_checkbox)
Overview
The Checkbox object is created from a "tick box" and a label. When the Checkbox is clicked the tick box is toggled.
Parts and Styles
LV_PART_MAIN
The is the background of the Checkbox and it uses the text and all the typical background style properties.pad_column
adjusts the spacing between the tickbox and the labelLV_PART_INDICATOR
The "tick box" is a square that uses all the typical background style properties. By default, its size is equal to the height of the main part's font. Padding properties make the tick box larger in the respective directions.
The Checkbox is added to the default group (if it is set).
Usage
Text
The text can be modified with the lv_checkbox_set_text(cb, "New text")
function and will be dynamically allocated.
To set a static text,
use lv_checkbox_set_static_text(cb, txt)
. This way, only a pointer to txt
will be stored. The text then shouldn't be deallocated while the checkbox exists.
Check, uncheck, disable
You can manually check, un-check, and disable the Checkbox by using the common state add/clear function:
lv_obj_add_state(cb, LV_STATE_CHECKED); /*Make the chekbox checked*/
lv_obj_clear_state(cb, LV_STATE_CHECKED); /*MAke the checkbox unchecked*/
lv_obj_add_state(cb, LV_STATE_CHECKED | LV_STATE_DISABLED); /*Make the checkbox checked and disabled*/
Events
LV_EVENT_VALUE_CHANGED
Sent when the checkbox is toggled.LV_EVENT_DRAW_PART_BEGIN
andLV_EVENT_DRAW_PART_END
are sent for the following types:LV_CHECKBOX_DRAW_PART_BOX
The tickbox of the checkboxpart
:LV_PART_INDICATOR
draw_area
: the area of the tickboxrect_dsc
See the events of the Base object too.
Learn more about Events.
Keys
The following Keys are processed by the 'Buttons':
LV_KEY_RIGHT/UP
Go to toggled state if toggling is enabledLV_KEY_LEFT/DOWN
Go to non-toggled state if toggling is enabledLV_KEY_ENTER
Clicks the checkbox and toggles it
Note that, as usual, the state of LV_KEY_ENTER
is translated to LV_EVENT_PRESSED/PRESSING/RELEASED
etc.
Learn more about Keys.
Example
.. include:: ../../../examples/widgets/checkbox/index.rst
API
.. doxygenfile:: lv_checkbox.h
:project: lvgl