Index

This feature is supported in wearable applications only.

An index component gives you an index for fast access to whichever group of other UI items you have. The index component is by default hidden, but it appears when the user clicks over its reserved area in the canvas. In the default theme, it is a one finger wide area on the right side of the index component's container. Generally, an index is used together with lists, generic lists, or generic grids.

Figure: Index component

Figure: Index hierarchy

Adding an Index Component

Call the elm_index_add() function to create a new index component.

Evas_Object *index, *parent;
index = elm_index_add(parent);

Adding Items

The following example shows how to add the listitem object at the letter A, calling the smart callback it_select_cb() when this item is selected.

Elm_Object_Item *list_item1, *list_item2;
elm_index_item_append(index, "A", it_select_cb, list_item1);

The following example shows how to add item objects, calling the smart callback it_select_cb() when the item is selected.

Elm_Object_Item *it[5];
for (i = 0; i < 5; ++i)
{
   it[i] = elm_index_item_append(index, NULL, it_select_cb, (void *) i);
}

The following example shows how to define the smart callback.

// Callback function called when the list_item1 object
// is selected
void it_select_cb(void *data, Evas_Object *obj, void *event_info)
{
   dlog_print(DLOG_INFO, LOG_TAG, "Item1 selected\n");
}

In the previous case, the indexes are appended to the existing ones. It is also possible to prepend index items with elm_index_item_prepend().

Using Index Callbacks

The index component emits the following signals:

• changed: The selected index item changes. event_info is the selected item's data pointer.
• delay,changed: The selected index item changes, but after a small idling period. event_info is the selected item's data pointer.
• selected: The user releases a mouse button and selects an item. event_info is the selected item's data pointer.
• level,up: The user moves a finger from the first level to the second level.
• level,down: The user moves a finger from the second level to the first level.

When the user selects an item in the index, the selected signal is emitted. The developer can then implement the associated callback to do the appropriate action (to show a given area or child object depending on the index item selected, for example). Here is an example of such a callback.

static void
_index_selected_cb(void *data, Evas_Object *obj, void *event_info)
{
   Elm_Object_Item *lit = event_info;

   // Code that does the desired action
}

After that, the callback to the selected signal is registered.

evas_object_smart_callback_add(index, "selected", _index_selected_cb, NULL);