dict_item.md
In rswipl: Embed 'SWI'-'Prolog'

class dict_item {#class-dict_item}

A dict_item object is an entry in a dictionary (dict object). It consists of four fields: a <-key, used for indexing purposes; a <-label to be displayed when the dict_item is visualised in a browser object and and an <-object, which can be anything that is to be associated with the dict_item and finally a <-style to indicate the category the object belongs too. Each category may be displayed using another font, colour or attributes. See list_browser->style.

The <-label defaults to the <-key, the object and style default to @nil.

@see class dict

dict_item<-dict: dict* Dict object I'm part of. When @nil, I'm not part of a dict. Otherwise I'm member of the chain dict <-members.
dict_item<-index: int Index-number of the dict_item in the dict. The first item has number 0. Used to speed up changes forwarding and repaint.
dict_item<-key: any The key value of this dict_item. This should be a unique value with respect to the other members of the dict object holding this dict_item. See also <-label, dict ->append and dict <-member.

If the registered key is an instance of class char_array or one of its subclasses, the key is automatically converted to a name object.

@see dict<-member @see dict_item<-label @see dict->append
dict_item-label: [char_array] When @default, the displayed label is the <-print_name of the <-key. Otherwise the value of this variable is displayed. See <-label.

@see dict_item-key @see dict_item<-label
dict_item<->object: any This value may contain any user-defined information to be associated with this item of the dictionary. It is commonly used for two purposes:
- Store additional info When a dict (normally though a browser object) is used to browse and select some information, <-object is often used to store additional information. For example, the summary browsers of this online manual store the documentation card represented by an entry in the <-object slot.
- Store a frame Dict objects where originally intended to store and visualise structured databases. The object was generally filled with a sheet object to store attributes of this entry. For example, a dict object may be used to store a database of clients, The <-key would be the client's name or identifier. The <-object a sheet or instance of a user-defined class that contains the client's phone, address and other info.
Dict items delegate to their <-object.
dict_item<-style: [name] Logical name of the category the item belongs too. The sheet list_browser <-styles maps these category names onto style objects describing the font, colour and attributes for the item.

dict_item<-contained_in: -> dict Returns the <-dict of the item.
dict_item<-convert: any -> dict_item Convert a name to a dict_item object with default <-label and <-object.
dict_item<-image: -> list_browser Internal method that allows popup menu's to operate on dict_item's. See list_browser ->popup.
dict_item<-label: -> char_array
dict_item<-position: -> point Return a new point object describing the top-left corner of the area used by this dict_item in the coordinate system of the list_browser object it is displayed on.

Fails silently if the dict_item is currently not displayed or outside the visible part of the list_browser.