/* Part of XPCE --- The SWI-Prolog GUI toolkit Author: Jan Wielemaker and Anjo Anjewierden E-mail: wielemak@science.uva.nl WWW: http://www.swi-prolog.org/packages/xpce/ Copyright (c) 2006-2011, University of Amsterdam All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ :- module(pce_arm, []). :- use_module(pce). :- use_module(pce_template). :- use_module(library(debug)). /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Library pce_arm.pl provides a mechanism for feedback on active graphicals while to mouse is moving over them. It guaranteed that at most one graphical is `armed' at any time. Graphical objects that wishes to play a role in this must * Ensure to ->event activates @arm_recogniser * define the method ->arm: Bool, where @on is send to arm the object and @off to unarm it. Objects that accepted @on are guaranteed to receive ->arm: @off. The currently armed object can be requested using ?- get(@display, armed, Graphical). The arm library was initially developed for Triple20. It has been moved to the XPCE core library in version 5.6.9 for use in the cross-referencing GUI (See pce_xref.pl). - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ :- pce_begin_class(arm, template, "(Un)arm objects in a window"). :- pce_group(event). define_event(Name, Parent) :- ( get(@event_tree, node, Name, Node) -> ( get(Node?parent, value, Parent) -> true ; print_message(error, format('Redefined event ~w', [Name])) ) ; new(_, event_node(Name, Parent)) ). :- pce_global(@arm_recogniser, new(handler(arm, message(@event?display, try_arm, @event?receiver)))). :- initialization define_event(arm, user). event(W, Ev:event) :-> ( send(Ev, is_a, loc_move), get(W, arm, _Target) -> true ; send(Ev, is_a, area_exit) -> send(@display, arm_object, @nil) ; true ), send_super(W, event, Ev). :- pce_group(arm). arm(W, For:[name|code], Target:graphical) :<- ( get(@event, position, W, point(X, Y)), get(W, slot, scroll_offset, point(OX, OY)), AX is X + OX, AY is Y+OY, new(Ev, event(arm, W, AX, AY)), ( For == @default -> true ; send(Ev, attribute, arm_for, For) ), debug(arm, 'Posting arm to ~p at ~d,~d', [W, AX, AY]), send(Ev, post, W) -> get(@display, hypered, arm, Target) ; send(@display, arm_object, @nil), fail ). :- pce_end_class(arm). :- pce_extend_class(display). try_arm(W, Gr:graphical) :-> ( get(@event, attribute, arm_for, For) -> ( atom(For) -> send(Gr, has_send_method, For) ; send(For, forward_receiver, Gr) ) ; true ), send(W, arm_object, Gr). arm_object(W, Gr:graphical*) :-> ( get(W, hypered, arm, Old) -> ( Old == Gr -> true % no change ; send(W, delete_hypers, arm), send(Old, arm, @off), ( Gr \== @nil -> send(Gr, arm, @on), new(_, hyper(W, Gr, arm, arm_window)) ; true ) ) ; ( Gr \== @nil -> send(Gr, arm, @on), new(_, hyper(W, Gr, arm, arm_window)) ; true ) ). armed(W, Gr:graphical) :<- "Find currently armed graphical":: get(W, hypered, arm, Gr). :- pce_end_class(display).