Win32 API programming

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Using Windows Controls and VP Studio Objects
Drag and Drop

First you need to declare Win32Api functions responsible for Drag and Drop.

Predicates Declarations

Clauses

On e_create event in task window include code to activate Drag And Drop:

%BEGIN Task Window, e_Create
task_win_eh(_Win,e_Create(_),0):-
    HWND = cast(HWND, _Win),
    DragAcceptFiles(HWND,b_true),
    win_EnableHook(_Win, b_true),
    fail.

On e_native event you will do Drag and Drop processing:

%BEGIN Task Window, e_Native
task_win_eh(_Win,e_Native(wm_dropfiles,WParam,_LParam),0):-
    collect_dropped_files(WParam,0,FILELIST),
    write("FileList \n",FileList),nl,
    DragFinish(WParam),
    retractall(drag_drop_list(_)),
    assert(drag_drop_list(FILELIST)),
% continue processing of the event via e_user
    win_sendEvent(_Win,e_user(1,1)),
    fail.
%END Task Window, e_Native

Last Updated: August 1, 2002