* @defgroup Elm_Genlist Genlist (Generic list)
* @ingroup Elementary
* @image html genlist_inheritance_tree.png
* @image latex genlist_inheritance_tree.eps
* @image html img/genlist.png
* @image latex img/genlist.eps
* This widget aims to have more expansive list than the simple list in
* Elementary that could have more flexible items and allow many more entries
* while still being fast and low on memory usage. At the same time it was
* also made to be able to do tree structures. But the price to pay is more
* complexity when it comes to usage. If all you want is a simple list with
* icons and a single text, use the normal @ref List object.
* Genlist has a fairly large API, mostly because it's relatively complex,
* trying to be both expansive, powerful and efficient. First we will begin
* an overview on the theory behind genlist.
* This widget inherits from the @ref Layout one, so that all the
* functions acting on it also work for genlist objects.
* This widget implements the @b @ref elm-scrollable-interface
* interface, so that all (non-deprecated) functions for the base @ref
* Scroller widget also work for genlists.
* Some calls on the genlist's API are marked as @b deprecated, as
* they just wrap the scrollable widgets counterpart functions. Use
* the ones we point you to, for each case of deprecation here,
* instead -- eventually the deprecated ones will be discarded (next
* major release).
* @section Genlist_Item_Class Genlist item classes - creating items
* In order to have the ability to add and delete items on the fly, genlist
* implements a class (callback) system where the application provides a
* structure with information about that type of item (genlist may contain
* multiple different items with different classes, states and styles).
* Genlist will call the functions in this struct (methods) when an item is
* "realized" (i.e., created dynamically, while the user is scrolling the
* list). All objects will simply be deleted when no longer needed with
* evas_object_del(). The #Elm_Genlist_Item_Class structure contains the
* following members:
* - @c item_style - This is a constant string and simply defines the name
* of the item style. It @b must be specified and the default should be @c
* - @c decorate_item_style - This is a constant string and simply defines the name
* of the decorate mode item style. It is used to specify decorate mode item style. It can be
* used when you call elm_genlist_item_decorate_mode_set().
* - @c decorate_all_item_style - This is a constant string and simply defines the name
* of the decorate all item style. It is used to specify decorate all item style. It can be
* used to set selection, checking and deletion mode. This is used when you
* call elm_genlist_decorate_mode_set().
* - @c func - A struct with pointers to functions that will be called when
* an item is going to be actually created. All of them receive a @c data
* parameter that will point to the same data passed to
* elm_genlist_item_append() and related item creation functions, and an @c
* obj parameter that points to the genlist object itself.
* The function pointers inside @c func are @c text_get, @c content_get, @c
* state_get and @c del. The 3 first functions also receive a @c part
* parameter described below. A brief description of these functions follows:
* - @c text_get - The @c part parameter is the name string of one of the
* existing text parts in the Edje group implementing the item's theme.
* This function @b must return a strdup'()ed string, as the caller will
* free() it when done. See #Elm_Genlist_Item_Text_Get_Cb.
* - @c content_get - The @c part parameter is the name string of one of the
* existing (content) swallow parts in the Edje group implementing the item's
* theme. It must return @c NULL, when no content is desired, or a valid
* object handle, otherwise. The object will be deleted by the genlist on
* its deletion or when the item is "unrealized".
* See #Elm_Genlist_Item_Content_Get_Cb.
* - @c func.state_get - The @c part parameter is the name string of one of
* the state parts in the Edje group implementing the item's theme. Return
* @c EINA_FALSE for false/off or @c EINA_TRUE for true/on. Genlists will
* emit a signal to its theming Edje object with @c "elm,state,xxx,active"
* and @c "elm" as "emission" and "source" arguments, respectively, when
* the state is true (the default is false), where @c xxx is the name of
* the (state) part. See #Elm_Genlist_Item_State_Get_Cb.
* - @c func.del - This is intended for use when genlist items are deleted,
* so any data attached to the item (e.g. its data parameter on creation)
* can be deleted. See #Elm_Genlist_Item_Del_Cb.
* available item styles:
* - default
* - default_style - The text part is a textblock
* - double_label
* - icon_top_text_bottom
* - group_index
* - one_icon - Only 1 icon (left) (since 1.7)
* - end_icon - Only 1 icon (at end/right) (since 1.7)
* - no_icon - No icon (at end/right) (since 1.7)
* - full - Only 1 icon, elm.swallow.content, which consumes whole area of
* genlist item (since 1.7)
* If one wants to use more icons and texts than are offered in theme, there
* are two solutions. One is to use 'full' style that has one big swallow part.
* You can swallow anything there. The other solution is to customize genlist
* item style in application side by using elm_theme_extension_add() and its
* own edc. Please refer @ref theme_example_01 for that.
* @section Genlist_Items Structure of items
* An item in a genlist can have 0 or more texts (they can be regular
* text or textblock Evas objects - that's up to the style to determine), 0
* or more contents (which are simply objects swallowed into the genlist item's
* theming Edje object) and 0 or more <b>boolean states</b>, which have the
* behavior left to the user to define. The Edje part names for each of
* these properties will be looked up, in the theme file for the genlist,
* under the Edje (string) data items named @c "labels", @c "contents" and @c
* "states", respectively. For each of those properties, if more than one
* part is provided, they must have names listed separated by spaces in the
* data fields. For the default genlist item theme, we have @b one text
* part (@c "elm.text"), @b two content parts (@c "elm.swallow.icon" and @c
* "elm.swallow.end") and @b no state parts.
* A genlist item may be at one of several styles. Elementary provides one
* by default - "default", but this can be extended by system or application
* custom themes/overlays/extensions (see @ref Theme "themes" for more
* @section Genlist_Manipulation Editing and Navigating
* Items can be added by several calls. All of them return a @ref
* Elm_Object_Item handle that is an internal member inside the genlist.
* They all take a data parameter that is meant to be used for a handle to
* the applications internal data (eg. the struct with the original item
* data). The parent parameter is the parent genlist item this belongs to if
* it is a tree or an indexed group, and NULL if there is no parent. The
* flags can be a bitmask of #ELM_GENLIST_ITEM_NONE, #ELM_GENLIST_ITEM_TREE
* and #ELM_GENLIST_ITEM_GROUP. If #ELM_GENLIST_ITEM_TREE is set then this
* item is displayed as an item that is able to expand and have child items.
* If #ELM_GENLIST_ITEM_GROUP is set then this item is group index item that
* is displayed at the top until the next group comes. The func parameter is
* a convenience callback that is called when the item is selected and the
* data parameter will be the func_data parameter, @c obj be the genlist
* object and event_info will be the genlist item.
* elm_genlist_item_append() adds an item to the end of the list, or if
* there is a parent, to the end of all the child items of the parent.
* elm_genlist_item_prepend() is the same but adds to the beginning of
* the list or children list. elm_genlist_item_insert_before() inserts at
* item before another item and elm_genlist_item_insert_after() inserts after
* the indicated item.
* The application can clear the list with elm_genlist_clear() which deletes
* all the items in the list and elm_object_item_del() will delete a specific
* item. elm_genlist_item_subitems_clear() will clear all items that are
* children of the indicated parent item.
* To help inspect list items you can jump to the item at the top of the list
* with elm_genlist_first_item_get() which will return the item pointer, and
* similarly elm_genlist_last_item_get() gets the item at the end of the list.
* elm_genlist_item_next_get() and elm_genlist_item_prev_get() get the next
* and previous items respectively relative to the indicated item. Using
* these calls you can walk the entire item list/tree. Note that as a tree
* the items are flattened in the list, so elm_genlist_item_parent_get() will
* let you know which item is the parent (and thus know how to skip them if
* @section Genlist_Multi_Selection Multi-selection
* If the application wants multiple items to be able to be selected,
* elm_genlist_multi_select_set() can enable this. If the list is
* single-selection only (the default), then elm_genlist_selected_item_get()
* will return the selected item, if any, or NULL if none is selected. If the
* list is multi-select then elm_genlist_selected_items_get() will return a
* list (that is only valid as long as no items are modified (added, deleted,
* selected or unselected)).
* @section Genlist_Usage_Hints Usage hints
* There are also convenience functions. elm_object_item_widget_get() will
* return the genlist object the item belongs to. elm_genlist_item_show()
* will make the scroller scroll to show that specific item so its visible.
* elm_object_item_data_get() returns the data pointer set by the item
* creation functions.
* If an item changes (state of boolean changes, text or contents change),
* then use elm_genlist_item_update() to have genlist update the item with
* the new state. Genlist will re-realize the item and thus call the functions
* in the _Elm_Genlist_Item_Class for that item.
* To programmatically (un)select an item use elm_genlist_item_selected_set().
* To get its selected state use elm_genlist_item_selected_get(). Similarly
* to expand/contract an item and get its expanded state, use
* elm_genlist_item_expanded_set() and elm_genlist_item_expanded_get(). And
* again to make an item disabled (unable to be selected and appear
* differently) use elm_object_item_disabled_set() to set this and
* elm_object_item_disabled_get() to get the disabled state.
* In general to indicate how the genlist should expand items horizontally to
* fill the list area, use elm_genlist_mode_set(). Valid modes are
* ELM_LIST_LIMIT, ELM_LIST_COMPRESS and ELM_LIST_SCROLL. The default is
* ELM_LIST_SCROLL. This mode means that if items are too wide to fit, the
* scroller will scroll horizontally. Otherwise items are expanded to
* fill the width of the viewport of the scroller. If it is
* ELM_LIST_LIMIT, items will be expanded to the viewport width
* if larger than the item, but genlist widget witdh is
* limited to the largest item. Do not use ELM_LIST_LIMIT mode with homogeneous
* mode turned on. ELM_LIST_COMPRESS can be combined with a different style
* that uses edjes' ellipsis feature (cutting text off like this: "tex...").
* Items will call their selection func and callback only once when first becoming
* selected. Any further clicks will do nothing, unless you enable always
* select with elm_genlist_select_mode_set() as ELM_OBJECT_SELECT_MODE_ALWAYS.
* This means even if selected, every click will make the selected callbacks
* be called. elm_genlist_select_mode_set() as ELM_OBJECT_SELECT_MODE_NONE will
* turn off the ability to select items entirely and they will neither
* appear selected nor call selected callback functions.
* Remember that you can create new styles and add your own theme augmentation
* per application with elm_theme_extension_add(). If you absolutely must
* have a specific style that overrides any theme the user or system sets up
* you can use elm_theme_overlay_add() to add such a file.
* @section Genlist_Implementation Implementation
* Evas tracks every object you create. Every time it processes an event
* (mouse move, down, up etc.) it needs to walk through objects and find out
* what event that affects. Even worse every time it renders display updates,
* in order to just calculate what to re-draw, it needs to walk through many
* many many objects. Thus, the more objects you keep active, the more
* overhead Evas has in just doing its work. It is advisable to keep your
* active objects to the minimum working set you need. Also remember that
* object creation and deletion carries an overhead, so there is a
* middle-ground, which is not easily determined. But don't keep massive lists
* of objects you can't see or use. Genlist does this with list objects. It
* creates and destroys them dynamically as you scroll around. It groups them
* into blocks so it can determine the visibility etc. of a whole block at
* once as opposed to having to walk the whole list. This 2-level list allows
* for very large numbers of items to be in the list (tests have used up to
* 2,000,000 items). Also genlist employs a queue for adding items. As items
* may be different sizes, every item added needs to be calculated as to its
* size and thus this presents a lot of overhead on populating the list, this
* genlist employs a queue. Any item added is queued and spooled off over
* time, actually appearing some time later, so if your list has many members
* you may find it takes a while for them to all appear, with your process
* consuming a lot of CPU while it is busy spooling.
* Genlist also implements a tree structure for items, but it does so with
* callbacks to the application, with the application filling in tree
* structures when requested (allowing for efficient building of a very
* deep tree that could even be used for file-management).
* See the above smart signal callbacks for details.
* @section Genlist_Smart_Events Genlist smart events
* This widget emits the following signals, besides the ones sent from
* @ref Layout:
* - @c "activated" - The user has double-clicked or pressed
* (enter|return|spacebar) on an item. The @p event_info parameter is the
* item that was activated.
* - @c "pressed" - The user pressed an item. The @p event_info
* parameter is the item that was pressed.
* - @c "released" - The user released an item. The @p event_info
* parameter is the item that was released.
* - @c "clicked,double" - The user has double-clicked an item. The @c
* event_info parameter is the item that was double-clicked.
* - @c "clicked,right" - The user has right-clicked an item. The @c
* event_info parameter is the item that was right-clicked. (since 1.13)
* - @c "selected" - This is called when a user has made an item selected.
* The event_info parameter is the genlist item that was selected.
* - @c "unselected" - This is called when a user has made an item
* unselected. The event_info parameter is the genlist item that was
* - @c "expanded" - This is called when elm_genlist_item_expanded_set() is
* called and the item is now meant to be expanded. The event_info
* parameter is the genlist item that was indicated to expand. It is the
* job of this callback to then fill in the child items.
* - @c "contracted" - This is called when elm_genlist_item_expanded_set() is
* called and the item is now meant to be contracted. The event_info
* parameter is the genlist item that was indicated to contract. It is the
* job of this callback to then delete the child items.
* - @c "expand,request" - This is called when a user has indicated they want
* to expand a tree branch item. The callback should decide if the item can
* expand (has any children) and then call elm_genlist_item_expanded_set()
* appropriately to set the state. The event_info parameter is the genlist
* item that was indicated to expand.
* - @c "contract,request" - This is called when a user has indicated they
* want to contract a tree branch item. The callback should decide if the
* item can contract (has any children) and then call
* elm_genlist_item_expanded_set() appropriately to set the state. The
* event_info parameter is the genlist item that was indicated to contract.
* - @c "realized" - This is called when the item in the list is created as a
* real evas object. event_info parameter is the genlist item that was
* - @c "unrealized" - This is called just before an item is unrealized.
* After this call content objects provided will be deleted and the item
* object itself delete or be put into a floating cache.
* - @c "drag,start,up" - This is called when the item in the list has been
* dragged (not scrolled) up.
* - @c "drag,start,down" - This is called when the item in the list has been
* dragged (not scrolled) down.
* - @c "drag,start,left" - This is called when the item in the list has been
* dragged (not scrolled) left.
* - @c "drag,start,right" - This is called when the item in the list has
* been dragged (not scrolled) right.
* - @c "drag,stop" - This is called when the item in the list has stopped
* being dragged.
* - @c "drag" - This is called when the item in the list is being dragged.
* - @c "longpressed" - This is called when the item is pressed for a certain
* amount of time. By default it's 1 second. The event_info parameter is the
* longpressed genlist item.
* - @c "scroll" - the content has been scrolled (moved) (since 1.13)
* - @c "scroll,anim,start" - This is called when scrolling animation has
* - @c "scroll,anim,stop" - This is called when scrolling animation has
* - @c "scroll,drag,start" - This is called when dragging the content has
* - @c "scroll,drag,stop" - This is called when dragging the content has
* - @c "edge,top" - This is called when the genlist is scrolled until
* the top edge.
* - @c "edge,bottom" - This is called when the genlist is scrolled
* until the bottom edge.
* - @c "edge,left" - This is called when the genlist is scrolled
* until the left edge.
* - @c "edge,right" - This is called when the genlist is scrolled
* until the right edge.
* - @c "multi,swipe,left" - This is called when the genlist is multi-touch
* swiped left.
* - @c "multi,swipe,right" - This is called when the genlist is multi-touch
* swiped right.
* - @c "multi,swipe,up" - This is called when the genlist is multi-touch
* swiped up.
* - @c "multi,swipe,down" - This is called when the genlist is multi-touch
* swiped down.
* - @c "multi,pinch,out" - This is called when the genlist is multi-touch
* pinched out.
* - @c "multi,pinch,in" - This is called when the genlist is multi-touch
* pinched in.
* - @c "swipe" - This is called when the genlist is swiped.
* - @c "moved" - This is called when a genlist item is moved by a user
* interaction in a reorder mode. The @p event_info parameter is the item that
* was moved.
* - @c "moved,after" - This is called when a genlist item is moved after
* another item in reorder mode. The event_info parameter is the reordered
* item. To get the relative previous item, use elm_genlist_item_prev_get().
* This signal is called along with "moved" signal.
* - @c "moved,before" - This is called when a genlist item is moved before
* another item in reorder mode. The event_info parameter is the reordered
* item. To get the relative previous item, use elm_genlist_item_next_get().
* This signal is called along with "moved" signal.
* - @c "index,update" - This is called when a genlist item index is changed.
* Note that this callback is called while each item is being realized.
* - @c "language,changed" - This is called when the program's language is
* changed. Call the elm_genlist_realized_items_update() if items text should
* be translated.
* - @c "tree,effect,finished" - This is called when a genlist tree effect is finished.
* - @c "highlighted" - an item in the list is highlighted. This is called when
* the user presses an item or keyboard selection is done so the item is
* physically highlighted. The @p event_info parameter is the item that was
* - @c "unhighlighted" - an item in the list is unhighlighted. This is called
* when the user releases an item or keyboard selection is moved so the item
* is physically unhighlighted. The @p event_info parameter is the item that
* was unhighlighted.
* - @c "focused" - When the genlist has received focus. (since 1.8)
* - @c "unfocused" - When the genlist has lost focus. (since 1.8)
* - @c "item,focused" - When the genlist item has received focus. (since 1.10)
* - @c "item,unfocused" - When the genlist item has lost focus. (since 1.10)
* Supported elm_object_item common APIs
* @li @ref elm_object_item_part_content_get
* @li @ref elm_object_item_part_text_get
* @li @ref elm_object_item_disabled_set
* @li @ref elm_object_item_disabled_get
* @li @ref elm_object_item_signal_emit
* Unsupported elm_object_item common APIs due to the genlist concept.
* Genlist fills content/text according to the appropriate callback functions.
* Please use elm_genlist_item_update() or elm_genlist_item_fields_update()
* @li @ref elm_object_item_part_content_set
* @li @ref elm_object_item_part_content_unset
* @li @ref elm_object_item_part_text_set
* @section Genlist_Examples Examples
* Here is a list of examples that use the genlist, trying to show some of
* its capabilities:
* - @ref genlist_example_01
* - @ref genlist_example_02
* - @ref genlist_example_03
* - @ref genlist_example_04
* - @ref genlist_example_05
* @addtogroup Elm_Genlist