1.94.4 Send methods

list_browser ->_size: pixels=size

Resizes the list_browser to the indicated pixel size. Normally list_browser sizes are communicated in character units. This method is used internally to handle resize requests of the browser window.

See also

graphical->size

list_browser ->_wants_keyboard_focus:

Succeeds if the list_browser has a list_browser<-dict that is not empty. Note that typing in a list_browser searches for an item.

list_browser ->cancel_search:

Cancel the incremental search (see list_browser->typed). Incremental search is normally canceled when the pointer leaves the window and when the user hits ESC or Control-G.

list_browser ->change_selection: action={set,toggle,extend,clear,cancel}, context=[dict_item|chain]

Hook in selection management. This method is invoked from list_browser->event and may be used to keep track of selection changes in the list_browser object. If action is set, the selection will be cleared and then set to the argument dict_item object. Action toggle will toggle the status of the argument dict_item, while clear will empty the selection.

Redefinition of this method may be used to keep track of the selection. See also list_browser->select_message and list_browser->open_message.

list_browser ->clear:

Removes all items from the browser. Invokes dict->clear to the list_browser<-dict.

list_browser ->compute:

list_browser->compute’s the list_browser<-image and list_browser<-scroll_bar. Initialises list_browser<-start_cell to speed up redraw.

list_browser ->enter:

Select current item as double-click. This method is normally invoked through the list_browser<-key_binding when the user hits return to confirm searching for an item.

list_browser ->event: event

Performs the following steps:

1. Invoke device->event and succeed if this succeeds.
2. If the event is a keyboard event, invoke list_browser->typed to realise incremental search.
3. If the event is an area_exit event, cancel an ongoing search.
4. If the event is a right-button-down (ms_right_down) and there is a list_browser<-popup, open the popup using @_popup_gesture.
5. If the event is a left-or middle-click, modify the list_browser<-selection using list_browser->change_selection and, If appropriate, execute one of the messages

   list_browser<-open_message	double-click
   list_browser<-select_message	left-click
   list_browser<-select_middle_message	middle-click

list_browser ->extend_prefix:

Part of incremental search. Determines all items who's‘dict_item list_browser<-label’start with the list_browser<-current_search and extends the search string to the common prefix of the matching items. In other words, it will extend the search string to the next choice-point.

list_browser ->extend_prefix_or_next:

If the list_browser is searching (see list_browser->insert_self), this method extends the current -search_string to the next choice-point (see list_browser->extend_prefix). Otherwise list_browser->next is invoked to advance to the next item requesting the keyboard in the same device.

list_browser ->extend_to_current:

Extends the list_browser<-search_string to the current item. Useful when the user is searching for an item that starts as the current. See also list_browser->extend_prefix.

list_browser ->geometry: x=[int], y=[int], width=[int], height=[int]

Resize the list_browser<-image and list_browser<-scroll_bar.

graphical ->height: int

Inherits description from: list_browser<-height

list_browser ->initialise: dict=[dict], width=[int], height=[int]

Create a list_browser for the specified dict object with specified width and height. If no dict is specified a default dict is created. If no size is specified list_browser.size is used. The size is interpreted in character units.

list_browser ->insert_self: times=[int], character=[char]

Start/Continue incremental search.

list_browser ->label: name

Inherits description from: list_browser<-label

list_browser ->next:

Move caret to next item (device->advance). See also text_item->next.

list_browser ->previous_line: [int]

Set selection to previous item.

list_browser ->next_line: [int]

Move forward by arg lines. If an incremental search is in progress, moves it moves the current search to the next line. If the current search pattern does not match the new item, it is set to the entire next item. If there is no search in progress, the browsercan only select a single object (list_browser->multiple_selection: @off) and the selection is in the visible part of the browser, the selected object is taken as the start of the search. Otherwise, the top of the visible page is choosen.

list_browser->previous_line simply negates the argument before calling list_browser->next_line.

list_browser ->normalise: member:dict_item

Scroll window such that the indicated dict_item is visible. If this requires the window to be scrolled one line up or down the indicated item will be the first or last in the window. Otherwise the item will be centered in the window,

See also list_browser->scroll_to.

See also

list_browser->scroll_to

list_browser ->scroll_to: [int]

Make nth-1 item first of window

Defaults: By default scrolls to the last item.

See also

list_browser->normalise

list_browser ->selected: member:dict_item

Test whether the indicated dict_item object or list_browser<-member is selected.

list_browser ->show_label: show=bool

Inherits description from: list_browser<-show_label

graphical ->size: size

Inherits description from: list_browser-size

See also

list_browser->_size

list_browser ->style: style_name=name, style=style

Display any item with dict_item<->style = name using the attributes from the given style object.

Suppose one has a list_browser that visualises a lexicon and we want the present all items that also appear in a glossary on the same domain in bold-face. This may be achieved using:

show_lexicon :-
        new(B, browser('Lexicon')),
        send(B, style, glossary, style(bold := @on)),
        (   lexicon(Item),
                send(B, append, new(D, dict_item(Item))),
                (   glossary(Item)
                ->  send(D, style, glossary)
                ;   true
                ),
                fail
        ;   true
        ),
        send(B, open).

list_browser ->tab_stops: vector*

Set a number of tabulator stops. The argument is a vector with pixel locations of the tab stops. See also text_image->tab_stops.

This feature may be used for multi-column tables and is especially useful when the items in the browser are displayed in a proportional font. The following example displays a database of persons where each person has a unique id and a name. The database is in the predicate person/2.

?- new(B, browser('Persons')),
   send(B, tab_stops, vector(200)),
   forall(person(Id, Name),
                  send(B, append,
                           dict_item(Id, string('%s\t%s',
                                                                        Id, Name)))),
   send(B, open).

list_browser ->typed: event|event_id

Activates the key_binding object list_browser<-key_binding. list_browser<-key_binding is filled in list_browser->initialise with an empty sub-keybinding of the default key_binding named list_browser from @key_bindings.

The default key_binding object implements incremental search. See also class key_binding and class editor.

list_browser ->unlink:

Unlinks the list_browser<-dict from the list_browser object and then invokes device->unlink.

Bugs: Implicitely created dict objects generally will not be garbage collected as a dict has internal references.

graphical ->width: int

Inherits description from: list_browser<-width