Route-manager: is expose is-route property for UI

docs-mini/README-structure.md

@@ -0,0 +1,77 @@
+# Strucutral Overview
+
+## Foundation Components
+
+
+There is a group os basic objects used widely throughout the codebase, which
+are useful building blocks in all major simulation elements. 
+
+### Properties 
+
+Properties form a hierarchy of named, typed values. The hierarchy can be extended
+and modified at runtime by aircraft, simulation components and external protocols.
+
+### Listeners
+
+Listeners are a callback interface `SGPropertyChangeListener` which can implemented
+to receive notification when a property is modified, or its children added/removed.
+Most commonly listeners are used to look for a user input or simulation event
+changing some value (for example, a switch being turned from on to off), but it's
+possible to monitor an entire sub-tree of properties.
+
+It's important than listeners do not block or perform excessive amounts of work, since
+the code modifying the property may not expect this. If non-trivial work needs to be
+performed in response to a property changing, the listener should set a dirty flag
+and a subsystem (etc) should check this in its `update()` method.
+
+### Tied properties
+
+Tied properties allow a property to be defined by a C++ memory location (such as a class
+member variable) or by callback functions implementation the get/set operations. This
+is very convenient for the implementating code. However, by default it has the
+problematic side-effect that listeners do not correctly, since they have no way to be
+notified thst the underlying value (or result of invoking the getter) has changed.
+
+It is therefore critical, when using tied properties, to _manually_ invoke `fireValueChanged`
+on dependent proeprties, when updating the internal state producing them. Care should be 
+taken to only fire the change, when the result of the getters would actually change; it is
+_not_ acceptable to simply call `fireValueChanged` each iteration, since any connected
+listener will be run at the simulation rate.
+
+### Conditions
+
+_Conditions_ are  predicates which can be evaluated on demand. They can contain
+logical operations such as 'and' and 'or', and comparisoms: for example checking that
+a property is equal to a constant value, or that a property is less than another
+property.
+
+Conditions are widely used to drive other state from properties; for example
+enabling or disabling user-interface in a dialog, or activating an autopilot
+element.
+
+### Bindings
+
+_Bindings_ are a command invocation with associated arguments. In the simplest case
+this might be invoking the `property-set` command with an argument of 42. At its
+most complex, the command might invoke a Nasal script, supplied as part of the
+binding, and substituing a runtime value into the Nasal logic.
+
+Bindings are typically used in response to user actions, such as a menu item, key
+press or interacting with a cockpit control, to update some part of the simulator
+state.
+
+## Structural Components
+
+Most code within FlightGear is organized into subsystems. Subsystems are isolated from each other;
+a well designed subsytem can be added, remove or restarting independently. Many subystems do not
+full conform to these goals, especially regarding runtime adding and removal, but an increasing
+number do support it.
+
+=== Subsystems ===
+
+=== Commands ===
+
+
+## Finding data files
+
+## Subsysterm Lifecycle

src/Autopilot/route_mgr.cxx

@@ -1,26 +1,8 @@
 // route_mgr.cxx - manage a route (i.e. a collection of waypoints)
-//
+/*
-// Written by Curtis Olson, started January 2004.
+ * SPDX-FileCopyrightText: (C) 2004 Curtis L. Olson http://www.flightgear.org/~curt
-//            Norman Vine
+ * SPDX-License-Identifier: GPL-2.0-or-later
-//            Melchior FRANZ
+ */
-//
-// Copyright (C) 2004  Curtis L. Olson  - http://www.flightgear.org/~curt
-//
-// 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
-//
-// $Id$
 
 
 #include <config.h>
@@ -372,6 +354,7 @@ void FGRouteMgr::init() {
     
   _edited = fgGetNode(RM "signals/edited", true);
   _flightplanChanged = fgGetNode(RM "signals/flightplan-changed", true);
+  _isRoute = fgGetNode(RM "is-route", true);
 
   _currentWpt = fgGetNode(RM "current-wp", true);
   _currentWpt->setAttribute(SGPropertyNode::LISTENER_SAFE, true);
@@ -411,6 +394,8 @@ void FGRouteMgr::postinit()
     loadRoute(path);
   }
   
+  _isRoute->setBoolValue(_plan->isRoute());
+
 // this code only matters for the --wp option now - perhaps the option
 // should be deprecated in favour of an explicit flight-plan file?
 // then the global initial waypoint list could die.
@@ -486,7 +471,7 @@ void FGRouteMgr::setFlightPlan(const FlightPlanRef& plan)
   
   _plan = plan;
   _plan->addDelegate(this);
-  
+  _isRoute->setBoolValue(_plan->isRoute());
   _flightplanChanged->fireValueChanged();
   
 // fire all the callbacks!

src/Autopilot/route_mgr.hxx

@@ -1,24 +1,8 @@
 // route_mgr.hxx - manage a route (i.e. a collection of waypoints)
-//
+/*
-// Written by Curtis Olson, started January 2004.
+ * SPDX-FileCopyrightText: (C) 2004 Curtis L. Olson http://www.flightgear.org/~curt
-//
+ * SPDX-License-Identifier: GPL-2.0-or-later
-// Copyright (C) 2004  Curtis L. Olson  - http://www.flightgear.org/~curt
+ */
-//
-// 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
-//
-// $Id$
 
 
 #pragma once
@@ -144,7 +128,7 @@ private:
 
     SGPropertyNode_ptr _pathNode;
     SGPropertyNode_ptr _currentWpt;
-
+    SGPropertyNode_ptr _isRoute;
 
     /**
      * Signal property to notify people that the route was edited