Tizen Native API  5.5
Elementary Store

Store is an abstracting API that is intended to farm off fetching of data to threads running asynchronously from the mainloop that actually fetch data needed for a genlist (or possibly future other widgets) so scrolling never blocks waiting on IO (though normally this should be the users job - if using genlist, to ensure all data genlist needs is in memory at the time it needs it, and if it isn't to queue and defer a fetch and let genlist know later when its ready. Store actually does this and implements the infrastructure of this, leaving the actual fetch and convert up to functions provided by the user).

It is possible for store to run inline without a thread, but this is highly inadvisable. you can disable this with:

elm_store_fetch_thread_set(store, EINA_FALSE);

Store works first by creating a store, setting up functions to list items and fetch items. Currently the only store type supported is the filesystem store, which will list the files inside a directory (not recursively) and then hand each file it finds (the file path) to the list function for evaluation.

The list function may look at filename, may open the file or do anything it likes to determine something about the file. Either it filters it out (returns EINA_FALSE) and it is discarded or it returns EINA_TRUE and also provides a "sort id" which is a string store uses to figure out sorting. This string could be the filename, or some data based on its contents. The strings are sorted alphabetically like any normal ASCII strings, with case being important. As this listing function runs in a thread, it can do blocking IO and parsing without hurting the fluidity of the main loop and GUI. The list function also returns information on how to map fields in the source file to elements of the genlist item. For example, how the fetcher reads the private data struct of the user (what memory offset in the struct the data is at) and what type is there (it's a label of some sort, an icon, or with a custom mapping function that figures it out itself and creates the content needed for the genlist item).

Store then uses this sort id to build (over time) a sorted list of items that then map 1:1 to genlist items. When these items are visible and need content, Store calls the fetch function per item, which is responsible for fetching the data from the given item and returning data to store so it can map this to some item content. This function also runs in a thread, and thus can do blocking IO work to later return the data. Sorting is optional and can be enabled or disabled too.

When items are no longer needed, store will cal the unfetch function to free data in memory about that item that is no longer needed. This function is called in the mainloop and is expected to take minimal or almost no time to simply free up memory resources.

Functions

Elm_Storeelm_store_filesystem_new (void)
void elm_store_free (Elm_Store *st)
void elm_store_filesystem_directory_set (Elm_Store *st, const char *dir)
const char * elm_store_filesystem_directory_get (const Elm_Store *st)
const char * elm_store_item_filesystem_path_get (const Elm_Store_Item *sti)
void elm_store_target_genlist_set (Elm_Store *st, Evas_Object *obj)
void elm_store_cache_set (Elm_Store *st, int max)
int elm_store_cache_get (const Elm_Store *st)
void elm_store_list_func_set (Elm_Store *st, Elm_Store_Item_List_Cb func, const void *data)
void elm_store_fetch_func_set (Elm_Store *st, Elm_Store_Item_Fetch_Cb func, const void *data)
void elm_store_unfetch_func_set (Elm_Store *st, Elm_Store_Item_Unfetch_Cb func, const void *data)
void elm_store_fetch_thread_set (Elm_Store *st, Eina_Bool use_thread)
Eina_Bool elm_store_fetch_thread_get (const Elm_Store *st)
void elm_store_sorted_set (Elm_Store *st, Eina_Bool sorted)
Eina_Bool elm_store_sorted_get (const Elm_Store *st)
void elm_store_item_data_set (Elm_Store_Item *sti, void *data)
void * elm_store_item_data_get (Elm_Store_Item *sti)
const Elm_Storeelm_store_item_store_get (const Elm_Store_Item *sti)
const Elm_Object_Itemelm_store_item_genlist_item_get (const Elm_Store_Item *sti)

Typedefs

typedef struct _Elm_Store Elm_Store
typedef struct _Elm_Store_Item Elm_Store_Item
typedef struct _Elm_Store_Item_Info Elm_Store_Item_Info
typedef struct
_Elm_Store_Item_Info_Filesystem 
Elm_Store_Item_Info_Filesystem
typedef struct
_Elm_Store_Item_Mapping 
Elm_Store_Item_Mapping
typedef struct
_Elm_Store_Item_Mapping_Empty 
Elm_Store_Item_Mapping_Empty
typedef struct
_Elm_Store_Item_Mapping_Photo 
Elm_Store_Item_Mapping_Photo
typedef Eina_Bool(* Elm_Store_Item_List_Cb )(void *data, Elm_Store_Item_Info *info)
typedef void(* Elm_Store_Item_Fetch_Cb )(void *data, Elm_Store_Item *sti)
typedef void(* Elm_Store_Item_Unfetch_Cb )(void *data, Elm_Store_Item *sti)
typedef void *(* Elm_Store_Item_Mapping_Cb )(void *data, Elm_Store_Item *sti, const char *part)

Defines

#define ELM_STORE_ITEM_MAPPING_END   { ELM_STORE_ITEM_MAPPING_NONE, NULL, 0, { .empty = { EINA_TRUE } } }
#define ELM_STORE_ITEM_MAPPING_OFFSET(st, it)   offsetof(st, it)

Define Documentation

#define ELM_STORE_ITEM_MAPPING_END   { ELM_STORE_ITEM_MAPPING_NONE, NULL, 0, { .empty = { EINA_TRUE } } }

Use this to end a list of mappings

#define ELM_STORE_ITEM_MAPPING_OFFSET (   st,
  it 
)    offsetof(st, it)

Use this to get the offset in bytes in memory for where the data for the mapping lives relative to the item data (a private struct pointed to owned by the user


Typedef Documentation

typedef struct _Elm_Store Elm_Store

A store object

typedef struct _Elm_Store_Item Elm_Store_Item

A handle of a store item passed to store fetch/unfetch functions

typedef void(* Elm_Store_Item_Fetch_Cb)(void *data, Elm_Store_Item *sti)

Function to call to fetch item data

typedef struct _Elm_Store_Item_Info Elm_Store_Item_Info

Basic information about a store item - always cast into a specific type like Elm_Store_Item_Info_Filesystem

typedef struct _Elm_Store_Item_Info_Filesystem Elm_Store_Item_Info_Filesystem

Filesystem specific information about a store item

typedef Eina_Bool(* Elm_Store_Item_List_Cb)(void *data, Elm_Store_Item_Info *info)

> The item needs a custom mapping which means calling a function and returning a string from it, as opposed to a static lookup. It should not be allocated, and should live in a buffer in memory that survives the return of this function if its a label, or an allocated icon object if its an icon needed etc. Function to call for listing an item

typedef struct _Elm_Store_Item_Mapping Elm_Store_Item_Mapping

A basic way of telling Store how to take your return data (string, or something else from your struct) and convert it into something genlist can use

typedef void*(* Elm_Store_Item_Mapping_Cb)(void *data, Elm_Store_Item *sti, const char *part)

Custom mapping function to call

typedef struct _Elm_Store_Item_Mapping_Empty Elm_Store_Item_Mapping_Empty

An empty piece of mapping information. Useful for String labels as they get used directly

typedef struct _Elm_Store_Item_Mapping_Photo Elm_Store_Item_Mapping_Photo

The data is a photo, so use these parameters to find it

typedef void(* Elm_Store_Item_Unfetch_Cb)(void *data, Elm_Store_Item *sti)

Function to cal lto un-fetch (free) an item


Enumeration Type Documentation

Possible mappings types.

Since (EFL) :
1.7
Enumerator:
ELM_STORE_ITEM_MAPPING_LABEL 

const char * -> label

ELM_STORE_ITEM_MAPPING_STATE 

Eina_Bool -> state

ELM_STORE_ITEM_MAPPING_ICON 

char * -> icon path

ELM_STORE_ITEM_MAPPING_PHOTO 

char * -> photo path

ELM_STORE_ITEM_MAPPING_CUSTOM 

item->custom(it->data, it, part) -> void * (-> any)


Function Documentation

int elm_store_cache_get ( const Elm_Store st)

Get the maximum number if items to cache

This returns the number of items at most to cache.

Parameters:
stThe store to query
Returns:
The maximum number of items to cache (>= 0)
See also:
elm_store_cache_set()
void elm_store_cache_set ( Elm_Store st,
int  max 
)

Set the maximum number of items that are not visible to keep cached

Store may keep some items around for caching purposes that cannot be seen, so this controls the maximum number. The default is 128, but may change at any point in time in the future.

Parameters:
stThe store to modify
maxThe number of items to keep (should be greater than or equal to 0)
void elm_store_fetch_func_set ( Elm_Store st,
Elm_Store_Item_Fetch_Cb  func,
const void *  data 
)

Set the function used to deal with fetching of items

This function is called per item that needs data to be fetched when it becomes visible and such data is needed. This function is normally run from a thread (unless elm_store_fetch_thread_set() disables this). The fetch function is to read data from the source and fill a structure allocated for this item with fields and then rely on the mapping setup to tell Store how to take a field in the structure and apply it to a genlist item.

Parameters:
stThe store to set the function of
funcThe function to be called
datathe data pointer to be passed to the func function when called

Get the thread enabled fetching option for Store

Returns:
The state set currently for the store.
See also:
elm_store_fetch_thread_set()
void elm_store_fetch_thread_set ( Elm_Store st,
Eina_Bool  use_thread 
)

Enable or disable fetching in a thread for Store

Parameters:
stThe store to modify
use_threadEINA_TRUE to use a thread to fetch, EINA_FALSE don't use a thread.
const char* elm_store_filesystem_directory_get ( const Elm_Store st)

Get the directory set on a filesystem store

This gets the directory set by elm_store_filesystem_directory_set(). This string returned will be valid until elm_store_filesystem_directory_set() changes it or until the store is freed with elm_store_free().

Returns:
A string with the path set, or NULL if none set.
void elm_store_filesystem_directory_set ( Elm_Store st,
const char *  dir 
)

Set the path to the directory to scan for a filesystem store

This sets the directory (dir) to scan and begins scanning in the the background in threads (or not if threading is disabled with elm_store_fetch_thread_set()). Note that Listing is always done in a thread but fetching may not be if disabled here. This should be the last thing called after fetch, list and unfetch functions are set, as well as target genlist etc. You also should not change the directory once set. If you need a new directory scanned, create a new store.

Parameters:
stThe store to modify
dirA string giving the path to the directory to scan

Create a new store object

This creates a new store object to then configure so it works.

Returns:
A new store object, or NULL if creation fails
void elm_store_free ( Elm_Store st)

Free the store object and all items it manages

This frees the given st store and all the items it manages. It will clear the List that it populated, but otherwise leave it alone. It will cancel background threads (and may have to wait for them to complete a pending operation to do this).

Parameters:
stThe store to free

Get the item data

This gets the data pointer set by elm_store_item_data_set().

Parameters:
stiThe store item to query
Returns:
The data pointer set on the item
void elm_store_item_data_set ( Elm_Store_Item sti,
void *  data 
)

Set the item data holding item fields to map to item values in genlist

Once you decode an item, allocate a structure for it and fill the structure, you should set the item data with this function (eg in the fetch function). This item pointer is the base offset to use when mapping fields to item values. Once you unfetch, store will handle NULLing the data pointer for you.

Parameters:
stiThe store item to set the data pointer of
dataThe data pointer to set.
const char* elm_store_item_filesystem_path_get ( const Elm_Store_Item sti)

Get the path of a specific store item

This returns the full path of a store item. This string is valid only during the list function set by elm_store_list_func_set() or during the fetch function set by elm_store_fetch_func_set() or during the unfetch function set by elm_store_unfetch_func_set().

Parameters:
stiThe store item to get the path from
Returns:
A full path in a string or NULL if none available

Fetch the genlist item that this store item controls

Parameters:
stiThe store item to query
Returns:
The genlist object item handle controlled by this store item

Fetch the store than a store item belongs to

This fetches the store object that owns the store item.

Parameters:
stiThe store item to query
Returns:
The store the item belongs to
void elm_store_list_func_set ( Elm_Store st,
Elm_Store_Item_List_Cb  func,
const void *  data 
)

Set the function used to deal with listing of items

This function is called per item that is found so it can examine the item and discard it (return EINA_FALSE to discard, or EINA_TRUE to accept), and work out some sorting ID (that may be filename or anything else based on content). This function is always called from a thread.

Parameters:
stThe store to set the function of
funcThe function to be called
datathe data pointer to be passed to the func function when called

Get the sorting flag

Get the sorted flag as set by elm_store_sorted_set().

Parameters:
stThe store to query
Returns:
EINA_TRUE if sorted, EINA_FALSE if not.
void elm_store_sorted_set ( Elm_Store st,
Eina_Bool  sorted 
)

Set if items are to be sorted or not.

By default items are not sorted, but read "in order" as they are found. If you want to sort, your list function set by elm_store_list_func_set() must provide a sort ID to sort by, and then Store will take care of sorting when it inserts items. You should set this up before you begin listing items in the store and then never change it again.

Parameters:
stThe store to modify
sortedEINA_TRUE if we are to sort, EINA_FALSE if not.

Set the target genlist to fill in from the store

This tells the store the target genlist to use to fill in content from the store. Once a store starts "going" via elm_store_filesystem_directory_set() The target should never be changed again.

Parameters:
stThe store to do the filling.
objThe genlist object to fill in and control the content of from the store.
void elm_store_unfetch_func_set ( Elm_Store st,
Elm_Store_Item_Unfetch_Cb  func,
const void *  data 
)

Set the function used to free the structure allocated for the item

This function is called per item when it is not needed in memory anymore and should free the structure allocated in and filled in the function set by elm_store_fetch_func_set().

Parameters:
stThe store to set the function of
funcThe function to be called
datathe data pointer to be passed to the func function when called