Directory Browser

What is directory browser?

Grid Object is a Visual Prolog custom control for file selection implemented as Visual Prolog Class.

To include Grid Object - open your project.inc file with VP Studio Setup utility and checkout option . Please save your changes and open Visual Prolog project.

Object usage: - create custom control with custom class "directory_browser".

Download Source code for Directory Browser (VIP 5.2 project - 68KB)

Custom control event handler will retrieve reference to callback function from the system object of the parent window.

%BEGIN win_directory_browser_eh, e_Create
win_directory_browser_eh(_Win,e_Create(_),0):-!,
    SysObject = system_object::new(_Win),
    BrowserRef = cast(long, directory_callback),
    SysObject:save_object_ref("browser_callback",BrowserRef),
.........<call for custom control creation>........
% setup browser object properties
    CtrlWin = win_GetCtlHandle(_Win, browser_id),
    get_browser_object(CtrlWin,DirObject),
    FileTypeList = [
        file_type("All Files","*.*"),
        file_type("Prolog Source","*.pro"),
        file_type("Internet HTM","*.htm*")
        ],
    DirObject:set_file_types(FileTypeList),
    !.

If you would like to use directory_browser object inside a dialog - you need to change a call to dialog creation predicate:

1) Parent window should have a system object created and should have reference to the browser_callback predicated stored (see explanations above)
2). You need to pass reference to the parent window system object via ApplicationCreationData.
dlg_file_open_Create(Parent):-
    DialogCreationData = win_GetData(Parent),
    dialog_CreateModal(Parent,dlg_file_open_ResID,"",
        [],
        dlg_file_open_eh,
        DialogCreationData,VALLIST,ANSWER),
......

%BEGIN File Open, e_Create
dlg_file_open_eh(_Win,e_Create(_CreationData),0):-!,
    CtrlWin = win_GetCtlHandle(_Win, browser_id),
    get_browser_object(CtrlWin,DirObject),
    FileTypeList = [
        file_type("All Files","*.*"),
        file_type("Prolog Source","*.pro"),
        file_type("Internet HTM","*.htm*")
        ],
    DirObject:set_file_types(FileTypeList),!.
%END File Open, e_Create

Use this code to retrieve direcotry_browser object and access it's properties and methods.

...CtrlWin = win_GetCtlHandle(_Win, browser_id),
get_browser_object(CtrlWin,DirObject),
DirObject:<object_method_call>

Last Updated: 03/20/02