Check example

This example will show 2 checkboxes, one with just a label and the second one with both a label and an icon. This example also illustrates how to have the checkbox change the value of a variable and how to react to those changes.

We will start with the usual setup code:

EAPI_MAIN int
elm_main(int argc EINA_UNUSED, char **argv EINA_UNUSED)
{
Evas_Object *win, *cb, *cb2, *icon;
Eina_Bool value;
elm_policy_set(ELM_POLICY_QUIT, ELM_POLICY_QUIT_LAST_WINDOW_CLOSED);
win = elm_win_util_standard_add("check", "Check");
elm_win_autodel_set(win, EINA_TRUE);
EINA_TRUE
#define EINA_TRUE
boolean value TRUE (numerical value 1)
Definition eina_types.h:539
Eina_Bool
unsigned char Eina_Bool
Type to mimic a boolean.
Definition eina_types.h:527
EINA_UNUSED
#define EINA_UNUSED
Used to indicate that a function parameter is purposely unused.
Definition eina_types.h:339
elm_policy_set
Eina_Bool elm_policy_set(unsigned int policy, int value)
Set a new policy's value (for a given policy group/identifier).
Definition elm_main.c:1380
ELM_POLICY_QUIT_LAST_WINDOW_CLOSED
@ ELM_POLICY_QUIT_LAST_WINDOW_CLOSED
quit when the application's last window is closed
Definition elm_general.h:248
ELM_POLICY_QUIT
@ ELM_POLICY_QUIT
under which circumstances the application should quit automatically.
Definition elm_general.h:227
elm_win_util_standard_add
Evas_Object * elm_win_util_standard_add(const char *name, const char *title)
Adds a window object with standard setup.
Definition efl_ui_win.c:9587
elm_win_autodel_set
void elm_win_autodel_set(Eo *obj, Eina_Bool autodel)
Set the window's autodel state.
Definition efl_ui_win.c:6199
Evas_Object
Efl_Canvas_Object Evas_Object
An Evas Object handle.
Definition Evas_Common.h:185

And now we create our first checkbox, set its label, tell it to change the value of `value` when the checkbox stats is changed and ask to be notified of state changes:

cb = elm_check_add(win);
elm_object_text_set(cb, "checkbox");
elm_check_state_pointer_set(cb, &value);
evas_object_smart_callback_add(cb, "changed", _print, &value);
evas_object_move(cb, 10, 10);
evas_object_resize(cb, 200, 30);
evas_object_show(cb);
elm_check_add
Evas_Object * elm_check_add(Evas_Object *parent)
Add a new Check object.
Definition efl_ui_check.c:516
elm_check_state_pointer_set
void elm_check_state_pointer_set(Eo *obj, Eina_Bool *statep)
Set a convenience pointer to a boolean to change.
Definition efl_ui_check.c:387
evas_object_show
EVAS_API void evas_object_show(Evas_Object *eo_obj)
Makes the given Evas object visible.
Definition evas_object_main.c:1814
evas_object_move
EVAS_API void evas_object_move(Evas_Object *obj, Evas_Coord x, Evas_Coord y)
Move the given Evas object to the given location inside its canvas' viewport.
Definition evas_object_main.c:1171
evas_object_resize
EVAS_API void evas_object_resize(Evas_Object *obj, Evas_Coord w, Evas_Coord h)
Changes the size of the given Evas object.
Definition evas_object_main.c:1236
evas_object_smart_callback_add
EVAS_API void evas_object_smart_callback_add(Evas_Object *eo_obj, const char *event, Evas_Smart_Cb func, const void *data)
Add (register) a callback function to the smart event specified by event on the smart object obj.
Definition evas_object_smart.c:1040

For our second checkbox we are going to set an icon so we need to create and icon:

icon = evas_object_rectangle_add(evas_object_evas_get(win));
evas_object_color_set(icon, 0, 255, 0, 255);
evas_object_resize(icon, 20, 20);
evas_object_show(icon);
evas_object_color_set
EVAS_API void evas_object_color_set(Evas_Object *obj, int r, int g, int b, int a)
Sets the general/main color of the given Evas object to the given one.
Definition evas_object_main.c:2024
evas_object_evas_get
EVAS_API Evas * evas_object_evas_get(const Eo *eo_obj)
Get the Evas to which this object belongs to.
Definition evas_object_main.c:2662
evas_object_rectangle_add
EVAS_API Evas_Object * evas_object_rectangle_add(Evas *e)
Adds a rectangle to the given evas.
Definition evas_object_rectangle.c:78

Note
  For simplicity we are using a rectangle as icon, but any evas object can be used.

And for our second checkbox we set the label, icon and state to true:

cb2 = elm_check_add(win);
elm_object_text_set(cb2, "another checkbox");
elm_check_state_set(cb2, EINA_TRUE);
elm_object_part_content_set(cb2, "icon", icon);
evas_object_move(cb2, 10, 50);
evas_object_resize(cb2, 200, 30);
evas_object_show(cb2);
elm_check_state_set
void elm_check_state_set(Evas_Object *obj, Eina_Bool state)
Set the on/off state of the check object.
Definition efl_ui_check.c:372
elm_object_part_content_set
void elm_object_part_content_set(Evas_Object *obj, const char *part, Evas_Object *content)
Set the content on part of a given container widget.
Definition elm_main.c:1562

We now do some more setup:

evas_object_resize(win, 200, 100);
evas_object_show(win);
elm_run();
return 0;
}
ELM_MAIN()
ELM_MAIN
#define ELM_MAIN()
macro to be used after the elm_main() function
Definition elm_general.h:556
elm_run
void elm_run(void)
Run Elementary's main loop.
Definition elm_main.c:1357

And finally implement the callback that will be called when the first checkbox's state changes. This callback will use `data` to print a message:

static void
_print(void *data, Evas_Object *obj EINA_UNUSED, void *event_info EINA_UNUSED)
{
printf("check %smarked\n", *((Eina_Bool*)data) ? "" : "un");
}

Note
  This work because `data` is `value(from the main function)` and `value` is changed when the checkbox is changed.

Our example will look like this: