Call elm_genlist_add() to create a genlist. Then, new entries can be added. In this example, the basic windows is created first, then a genlist is added to it, and then 100 elements with text and a colored block on each side of it.

Evas_Object *list = elm_genlist_add(win);

Before adding new entries, it is necessary to build a basic item class.

When adding an item, genlist_item_{append, prepend, insert} function needs item class of the item. Given callback parameters are used at retrieving {text, content} of added item. Set as NULL if it's not used. If there's no available memory, return can be NULL.

The code for the minimal genlist item class is below:

Elm_Genlist_Item_Class *_itc = elm_genlist_item_class_new();
_itc->item_style = "default";
_itc->func.text_get = NULL;
_itc->func.content_get = NULL;
_itc->func.state_get = NULL;
_itc->func.del = NULL;

It creates a simple item class, sets the item_style to “default” and every other field to NULL. However, this leaves out the text_get and content_get fields which are used to add text and an icon to the list entry. This is explained in another section.

Once the genlist item class object is created, a new element is added to the list by calling elm_genlist_item_append().

elm_genlist_item_append(list,
   _itc,
   NULL,                    // Item data
   NULL,                    // Parent item for trees, NULL if none
   ELM_GENLIST_ITEM_NONE,   // Item type; this is the common one
   NULL,                    // Callback on selection of the item
   NULL                     // Data for that callback function
);

With most parameters as NULL and _itc having most of its members NULL, too, the elements of that list are blank and will not trigger anything when selected.

Use text_get field to add text in the items in the Elm_Genlist_Item_Class structure.

_itc->func.text_get = text_get;

These callbacks must have a prototype matching to the following:

char * text_get(void *data, Evas_Object *obj, const char *part);

This callback returns a C string that is displayed in the part named after the part parameter. This callback is called for each user-settable text part according to the current theme.

If you are not familiar with the concept of parts in the EFLs, read the Write a Simple EDC File section.

For the default theme there is one part named elm.text. A possible implementation of the text_get callback is therefore:

static char *
_genlist_text_get(void *data, Evas_Object *obj, const char *part)
{
   // Check this is text for the part we're expecting
   if (strcmp(part, "elm.text") == 0)
     {
        return strdup("Some text");
     }
   else return NULL;
}

It is possible to behave differently according to data that is given to the EFLs during the call to elm_genlist_item_append() in the data parameter. For example, given an integer in that field through casting with (void *)(uintptr_t) i, its value is got back using (int)(uintptr_t)data:

static char *
_genlist_text_get(void *data, Evas_Object *obj __UNUSED__, const char *part)
{
   if (strcmp(part, "elm.text") == 0)
     {
        char *buf = malloc(16);
        snprintf(buf, 16, "Entry %d.", (int)(uintptr_t)data);
 
        return buf;
     }
   else return NULL;
}

Icons are added in a similar fashion: there is a callback named content_get which returns a pointer to an Evas_Object and is called for each part which contents can be set.

_itc->func.content_get = content_get;

The prototype of the callback must match this one:

Evas_Object * content_get(void *data, Evas_Object *obj, const char *part);

The only difference with the text_get callback is that it returns an Evas_Object* rather than a char *.

This leads to a fairly simple dummy implementation with colored rectangles in the parts that are to be set:

static Evas_Object *
_genlist_content_get(void *data, Evas_Object *obj, const char *part)
{
   int i = (int) (uintptr_t) data;
 
   //the left part
   if (strcmp(part, "elm.swallow.icon") == 0)
     {
        Evas_Object *bg = elm_bg_add(obj);
        elm_bg_color_set(bg, 255 * cos(i / (double) 10), 0, i % 255);
 
        return bg;
     }
   //the right part
   else if (strcmp(part, "elm.swallow.end") == 0)
     {
        Evas_Object *bg = elm_bg_add(obj);
        elm_bg_color_set(bg, 0, 255 * sin(i / (double) 10), i % 255);
 
        return bg;
     }
   else return NULL;
}

For the default theme, this displays a red rectangle on the left of each list item and a green one on their right.

Genlist items triggers a callback when clicked. This callback is chosen when adding the new item (for example, when calling elm_genlist_item_append()):

Elm_Genlist_Item_Class *_itc2 = elm_genlist_item_class_new();
_itc2->item_style        = "group_index";
_itc2->func.text_get     = _genlist_text_get;
_itc2->func.content_get  = _genlist_content_get;
_itc2->func.state_get    = NULL;
_itc2->func.del          = NULL;
 
elm_genlist_item_append(list,
   itc,
   NULL,                    // item data
   NULL,                    // parent item for trees, NULL if none
   ELM_GENLIST_ITEM_NONE,   // item type, other values are used for trees
   _genlist_selected_cb,      // callback on selection of the item
   _itc2                     // data for that callback function
);

This callback adheres to the following prototype:

void _contact_selected_cb(void *data, Evas_Object *obj, void *event_info)

The implementation below changes the item style of items when they are selected:

static void
_genlist_selected_cb(void *data, Evas_Object *obj, void *event_info)
{
    Elm_Object_Item *it = (Elm_Object_Item*) event_info;
    Elm_Genlist_Item_Class *itc2 = (Elm_Genlist_Item_Class *)data;
te
 
    //change to group index style
    elm_genlist_item_item_class_update(it, itc2);
}

The whole code: set-up_genlist.c

Modifications