lumiera_/src/gui/ctrl/bus-controller.cpp

227 lines
8.1 KiB
C++

/*
BusController - the UI-Bus service
Copyright (C) Lumiera.org
2015, Hermann Vosseler <Ichthyostega@web.de>
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of
the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
* *****************************************************/
/** @file bus-controller.cpp
** Implementation of the UI backbone service for messaging.
** Any globally relevant widget or controller within the Lumiera UI
** is connected to the [UI-Bus](ui-bus.hpp), which is largely implemented
** within this compilation unit. [Clients](\ref gui::model::Tangible) typically
** use the [BusTerm-Interface](bus-term.hpp) to route generic actions and
** receive notifications, state changes and mutations.
**
** @note as of 11/2015 this is complete WIP_WIP
** @todo WIP ///////////////////////TICKET #975
**
** @see ////TODO_test usage example
** @see bus-controller.cpp implementation
**
*/
#include "lib/util.hpp"
//#include "lib/symbol.hpp"
//#include "include/logging.h"
#include "gui/ctrl/bus-term.hpp"
#include "gui/ctrl/bus-controller.hpp"
#include "gui/ctrl/nexus.hpp"
//#include <boost/noncopyable.hpp>
#include <string>
#include <map>
using std::map;
using std::string;
using util::contains;
using util::isnil;
namespace gui {
namespace ctrl {
namespace { // internal details
} // internal details
// emit VTables here...
/** @note detaches the corresponding node automatically */
BusTerm::~BusTerm()
{
theBus_.routeDetach (this->endpointID_);
}
diff_msg::Holder::~Holder() { }
/** Builder function: establish and wire a new BusTerm.
* @param newNode the UI-Element corresponding to and using the new BusTerm
* @remarks automatically establishes a down-link connection to the given
* [Tangible]; the UI-Bus will use this node as target to dispatch
* `mark` messages addressed to the new node's ID. It is expected
* that the Tangible in turn will use the returned BusTerm for
* any up-link communication. Thus, on destruction, the new
* BusTerm will detach this UI-Bus connection altogether.
*/
BusTerm
BusTerm::attach (ID identity, Tangible& newNode)
{
return BusTerm(identity, theBus_.routeAdd (identity,newNode));
}
/* ==== standard implementation of the BusTerm interface ==== */
/** prepare or trigger invocation of a command.
* @param command a GenNode holding parameters invocation trigger
* @remarks some commands can simply be invoked right away, but
* in the general case, command preparation and invocation
* is a multi-step process. The gui::interact::InvocationTrail
* is used to conduct this argument binding process from within
* the UI. Here, at the UI-Bus interface, we're just interested
* in the fact _that_ some command is to be bound or invoked.
* This information is forwarded to the command receiver service,
* which in turn talks to the proc dispatcher.
* @note no information regarding the _origin_ of this command invocation
* is captured. If a command needs a _subject_, this has to be
* bound as an command argument beforehand.
* @see gui::interact::InvocationTrail
* @see gui::model::Tangible::prepareCommand()
* @see gui::model::Tangible::issueCommand()
*/
void
BusTerm::act (GenNode const& command)
{
theBus_.act (command);
}
/** capture and record a "state mark" for later replay for restoring UI state.
* @param subject the [endpoint-ID](BusTerm::endpointID_) of the emitting element
* @param mark the actual state update or notification message to be remembered
* @remarks relevant changes to presentation state, which are to be recalled and
* restored later, are emitted from the place they occur, packaged as
* "state mark" messages. This assumes the presence of some dedicated
* presentation state manager, attached and listening somewhere at
* a core service location. Such a core presentation state service
* has shares additional understanding of the state mark's meaning;
* it is assumed to track cumulated state, which will be replayed
* later when it comes to restoring some presentation state.
*/
void
BusTerm::note (ID subject, GenNode const& mark)
{
theBus_.note (subject,mark);
}
/** route a state update or notification to the given subject.
* @param subject the [endpoint-ID](BusTerm::endpointID_) of the element to address
* @param mark the actual state update or notification message to be delivered
* @remarks each "subject" to be addressed is a gui::model::Tangible, and as such
* holds a BusTerm of its own, which in turn ensures a registration and
* connection from the [central routing hub](gui::ctrl::Nexus) down to
* the element. Thus, the default implementation is just to pass the
* given state mark "up", assuming that it will reach the hub
* eventually, which in turn knows hot to reach the element.
* @return if the target was known and the mark operation dispatched.
* @note messages to unreachable elements will be dropped.
*/
bool
BusTerm::mark (ID subject, GenNode const& mark)
{
return theBus_.mark (subject,mark);
}
/** broadcast a notification message to all currently connected bus terminals.
* @param mark the actual state update or notification message to be delivered
* @return number of notified terminals.
* @remarks this call assumes that "somewhere" within the UI-Bus
* a distribution node or hub is installed, with the ability
* to find all currently connected terminals. In the standard
* configuration this is implemented by the ctrl::Nexus
*/
size_t
BusTerm::markAll (GenNode const& mark)
{
return theBus_.markAll (mark);
}
/** alter and reshape the designated subject by applying the given diff message.
* @param diff encapsulated representation of a concrete diff sequence for the target.
* @return if the target was known and the diff was applied without accident
* @throws lumiera::error::State when diff application fails due to the target's shape
* or state being different than implicitly assumed by the given diff.
* @remark each tangible offers to build a custom TreeMutator, which is appropriately
* wired to receive diff messages targeted towards this specific element. The
* standard implementation within the Nexus uses this ability to create a
* DiffApplicator<DiffMutable>, finally to feed the given diff to the target,
* which consequently will reshape and remould itself accordingly.
*/
bool
BusTerm::change (ID subject, MutationMessage& diff)
{
return theBus_.change(subject, diff);
}
/**
* @internal establish new down-link connection form UI-Bus
* @param node reference to the [Tangible] to be connected.
* @return corresponding up-link for the initiating node to use
*/
BusTerm&
BusTerm::routeAdd (ID identity, Tangible& node)
{
return theBus_.routeAdd (identity, node);
}
/**
* @internal disable down-link connection
* @remarks corresponding node is about to go away.
*/
void
BusTerm::routeDetach(ID node) noexcept
{
if (isConnected())
theBus_.routeDetach (node);
}
BusTerm::operator string() const
{
return "BusTerm-" + string(endpointID_);
}
}} // namespace gui::ctrl