Update version to 1.6.0

Remove unused sounds, interior and exterior sound

CHANGELOG.md

@@ -1,15 +1,23 @@
 # CHANGELOG
 
+## v.1.6.0
+
+- Add sound support from internal and external view for C-74 aircraft (thanks to wlbragg)
+
+## v.1.5.0
+
+- Add Towrope Configuration dialog
+
 ## v.1.4.1
 
-- Fix carsh by missing parameter
+- Fix crash by missing parameter
 
 ## v.1.4.0
 
-- Add Douglas C-47 as a tow plane
+- Add Douglas C-47 as a tow plane (thanks to wlbragg)
 - Add possibility to take off in the bush
 - Add a separate engine sound for the DR400
-- Add French translation of meta data
+- Add French translation of meta data (thanks to Florent)
 - Add possibility to save/load route waypoints with description
 
 ## v.1.3.0

FGData/AI/Aircraft/Aerotow/C-47/Sound/sound.xml

@@ -2,11 +2,39 @@
 <PropertyList>
     <fx>
         <engine>
-            <name>engine</name>
+            <name>engineINT</name>
+            <mode>looped</mode>
+            <path>Croisiere_int_2.wav</path>
+            <condition>
+                <and>
+                    <property>/addons/by-id/org.flightgear.addons.Aerotow/addon-devel/sound/enable</property>
+                    <property>/sim/current-view/internal</property>
+                </and>
+            </condition>
+            <volume>
+                <offset>-0.80</offset>
+            </volume>
+            <pitch>
+                <property>velocities/true-airspeed-kt</property>
+                <factor>0.012</factor>
+                <offset>0.3</offset>
+                <min>0.3</min>
+                <max>1.0</max>
+            </pitch>
+            <reference-dist>150.0</reference-dist>
+            <max-dist>5000.0</max-dist>
+        </engine>
+        <engine>
+            <name>engineEXT</name>
             <mode>looped</mode>
             <path>Croisiere_ext_2.wav</path>
             <condition>
-                <property>/addons/by-id/org.flightgear.addons.Aerotow/addon-devel/sound/enable</property>
+                <and>
+                    <property>/addons/by-id/org.flightgear.addons.Aerotow/addon-devel/sound/enable</property>
+                    <not>
+                        <property>/sim/current-view/internal</property>
+                    </not>
+                </and>
             </condition>
             <volume>
                 <offset>-0.80</offset>

addon-main.nas

@@ -42,6 +42,7 @@ var main = func(addon) {
 #
 var loadExtraNasalFiles = func (addon) {
     var modules = [
+        "nasal/timer",
         "nasal/aircraft",
         "nasal/message",
         "nasal/dialogs/route",

addon-menubar-items.xml

@@ -36,6 +36,13 @@
                     <dialog-name>route-aerotow</dialog-name>
                 </binding>
             </item>
+            <item>
+                <label>Towrope Configuration</label>
+                <binding>
+                    <command>dialog-show</command>
+                    <dialog-name>towrope-config</dialog-name>
+                </binding>
+            </item>
             <item>
                 <label>Call for Piper J3 Cub aircraft</label>
                 <binding>
@@ -79,11 +86,9 @@
                     <command>nasal</command>
                     <script><![CDATA[
                         # Run stopAerotow() with a delay to ensure that the engine sound turns off
-                        var timer = maketimer(1, func () {
+                        aerotow.Timer.new().singleShot(1, aerotow.g_Aerotow, func () {
                             aerotow.g_Aerotow.stopAerotow();
                         });
-                        timer.singleShot = 1;
-                        timer.start();
                     ]]></script>
                 </binding>
             </item>

addon-metadata.xml

@@ -21,7 +21,7 @@
     <addon>
         <identifier type="string">org.flightgear.addons.Aerotow</identifier>
         <name type="string">Aerotow Everywhere</name>
-        <version type="string">1.4.1</version>
+        <version type="string">1.6.0</version>
 
         <authors>
             <author>

aerotow.nas

@@ -9,6 +9,16 @@
 # under the GNU Public License v3 (GPLv3)
 #
 
+#
+# Global aliases for boolean types to distinguish the use of "int" from "bool".
+# NOTE: unfortunately, it doesn't work as an assignment of a default value for a function parameter!
+#
+var true  = 1;
+var false = 0;
+
+#
+# Global object of Aerotow
+#
 var g_Aerotow = nil;
 
 #

gui/dialogs/about-aerotow.xml

@@ -45,7 +45,7 @@
     <hrule/>
 
     <text>
-        <label>Aerotow Everywhere version 1.4.1 - 20th August 2022</label>
+        <label>Aerotow Everywhere version 1.6.0 - 23nd August 2022</label>
     </text>
 
     <text>

gui/dialogs/towrope-configuration.xml

@@ -0,0 +1,342 @@
+<?xml version="1.0"?>
+
+<PropertyList>
+    <name>towrope-config</name>
+    <layout>vbox</layout>
+    <default-padding>5</default-padding>
+    <modal>false</modal>
+    <width>680</width>
+
+    <!-- title bar -->
+    <group>
+        <layout>hbox</layout>
+        <empty>
+            <stretch>true</stretch>
+        </empty>
+        <text>
+            <label>Towrope Configuration</label>
+        </text>
+        <empty>
+            <stretch>true</stretch>
+        </empty>
+        <button>
+            <legend/>
+            <key>Esc</key>
+            <pref-width>16</pref-width>
+            <pref-height>16</pref-height>
+            <border>2</border>
+            <binding>
+                <command>dialog-close</command>
+            </binding>
+        </button>
+    </group>
+
+    <hrule/>
+
+    <!-- aerotow parameters -->
+    <group>
+        <layout>hbox</layout>
+
+        <group>
+            <layout>table</layout>
+
+            <!-- tow length -->
+            <text>
+                <row>0</row>
+                <col>0</col>
+                <halign>right</halign>
+                <label>Towrope Length</label>
+            </text>
+            <text>
+                <row>0</row>
+                <col>1</col>
+                <halign>right</halign>
+                <label></label>
+                <live>true</live>
+                <format>%.0f m </format>
+                <property>/sim/hitches/aerotow/tow/length</property>
+                <color>
+                    <red>0.2</red>
+                    <green>0.9</green>
+                    <blue>0.2</blue>
+                </color>
+            </text>
+
+            <!-- break force -->
+            <text>
+                <row>1</row>
+                <col>0</col>
+                <halign>right</halign>
+                <label>Weak Link Break Force</label>
+            </text>
+            <text>
+                <row>1</row>
+                <col>1</col>
+                <halign>right</halign>
+                <label></label>
+                <live>true</live>
+                <format>%.0f N </format>
+                <property>/sim/hitches/aerotow/tow/brake-force</property>
+                <color>
+                    <red>0.2</red>
+                    <green>0.9</green>
+                    <blue>0.2</blue>
+                </color>
+            </text>
+
+            <!-- tow characteristic -->
+            <text>
+                <row>2</row>
+                <col>0</col>
+                <halign>right</halign>
+                <label>Towrope Elastic Constant</label>
+            </text>
+            <text>
+                <row>2</row>
+                <col>1</col>
+                <halign>right</halign>
+                <label></label>
+                <live>true</live>
+                <format>%.0f N</format>
+                <property>/sim/hitches/aerotow/tow/elastic-constant</property>
+                <color>
+                    <red>0.2</red>
+                    <green>0.9</green>
+                    <blue>0.2</blue>
+                </color>
+            </text>
+
+            <!-- tow thickness -->
+            <text>
+                <row>3</row>
+                <col>0</col>
+                <halign>right</halign>
+                <label>Towrope Diameter</label>
+            </text>
+            <text>
+                <row>3</row>
+                <col>1</col>
+                <halign>right</halign>
+                <label></label>
+                <live>true</live>
+                <format>%.0f mm</format>
+                <property>/sim/hitches/aerotow/rope/rope-diameter-mm</property>
+                <color>
+                    <red>0.2</red>
+                    <green>0.9</green>
+                    <blue>0.2</blue>
+                </color>
+            </text>
+
+            <!-- tow weight -->
+            <text>
+                <row>4</row>
+                <col>0</col>
+                <halign>right</halign>
+                <label>Towrope Weight per Meter</label>
+            </text>
+            <text>
+                <row>4</row>
+                <col>1</col>
+                <halign>right</halign>
+                <label></label>
+                <live>true</live>
+                <format>%.3f kg/m</format>
+                <property>/sim/hitches/aerotow/tow/weight-per-m-kg-m</property>
+                <color>
+                    <red>0.2</red>
+                    <green>0.9</green>
+                    <blue>0.2</blue>
+                </color>
+            </text>
+        </group>
+        <empty>
+            <stretch>true</stretch>
+        </empty>
+
+        <vrule/>
+
+        <group>
+            <layout>table</layout>
+
+            <!-- tow length -->
+            <text>
+                <row>0</row>
+                <col>1</col>
+                <halign>right</halign>
+                <label>20 m</label>
+            </text>
+            <slider>
+                <row>0</row>
+                <col>2</col>
+                <live>true</live>
+                <halign>fill</halign>
+                <pref-width>300</pref-width>
+                <name>tow_length</name>
+                <property>/sim/hitches/aerotow/tow/length</property>
+                <min>20</min>
+                <max>200</max>
+                <step>5</step>
+                <binding>
+                    <command>dialog-apply</command>
+                </binding>
+            </slider>
+            <text>
+                <row>0</row>
+                <col>3</col>
+                <halign>left</halign>
+                <label>200 m</label>
+            </text>
+
+            <!-- break force -->
+            <text>
+                <row>1</row>
+                <col>1</col>
+                <halign>right</halign>
+                <label>100 N</label>
+            </text>
+            <slider>
+                <row>1</row>
+                <col>2</col>
+                <live>true</live>
+                <halign>fill</halign>
+                <pref-width>300</pref-width>
+                <name>break_force</name>
+                <property>/sim/hitches/aerotow/tow/brake-force</property>
+                <min>100</min>
+                <max>100000</max>
+                <step>100</step>
+                <binding>
+                    <command>dialog-apply</command>
+                </binding>
+            </slider>
+            <text>
+                <row>1</row>
+                <col>3</col>
+                <halign>left</halign>
+                <label>100,000 N</label>
+            </text>
+
+            <!-- tow characteristic -->
+            <text>
+                <row>2</row>
+                <col>1</col>
+                <halign>right</halign>
+                <label>0 N</label>
+            </text>
+            <slider>
+                <row>2</row>
+                <col>2</col>
+                <live>true</live>
+                <halign>fill</halign>
+                <pref-width>300</pref-width>
+                <name>elastic_constant</name>
+                <property>/sim/hitches/aerotow/tow/elastic-constant</property>
+                <min>0</min>
+                <max>1500000</max>
+                <step>200</step>
+                <binding>
+                    <command>dialog-apply</command>
+                </binding>
+            </slider>
+            <text>
+                <row>2</row>
+                <col>3</col>
+                <halign>left</halign>
+                <label>1,500,000 N</label>
+            </text>
+
+            <!-- tow thickness -->
+            <text>
+                <row>3</row>
+                <col>1</col>
+                <halign>right</halign>
+                <label>0 mm</label>
+            </text>
+            <slider>
+                <row>3</row>
+                <col>2</col>
+                <live>true</live>
+                <halign>fill</halign>
+                <pref-width>300</pref-width>
+                <name>rope_diameter</name>
+                <property>/sim/hitches/aerotow/rope/rope-diameter-mm</property>
+                <min>0</min>
+                <max>50</max>
+                <step>1</step>
+                <binding>
+                    <command>dialog-apply</command>
+                </binding>
+            </slider>
+            <text>
+                <row>3</row>
+                <col>3</col>
+                <halign>left</halign>
+                <label>50 mm</label>
+            </text>
+
+            <!-- tow weight -->
+            <text>
+                <row>4</row>
+                <col>1</col>
+                <halign>right</halign>
+                <label>0 kg/m</label>
+            </text>
+            <slider>
+                <row>4</row>
+                <col>2</col>
+                <live>true</live>
+                <halign>fill</halign>
+                <pref-width>300</pref-width>
+                <name>weight_per_m</name>
+                <property>/sim/hitches/aerotow/tow/weight-per-m-kg-m</property>
+                <min>0</min>
+                <max>1</max>
+                <step>0.001</step>
+                <binding>
+                    <command>dialog-apply</command>
+                </binding>
+            </slider>
+            <text>
+                <row>4</row>
+                <col>3</col>
+                <halign>left</halign>
+                <label>1 kg/m</label>
+            </text>
+        </group>
+    </group>
+
+    <hrule/>
+
+    <!-- bottom line -->
+    <group>
+        <layout>hbox</layout>
+        <empty>
+            <stretch>true</stretch>
+        </empty>
+        <button>
+            <legend>Close</legend>
+            <equal>true</equal>
+            <binding>
+                <command>dialog-close</command>
+            </binding>
+        </button>
+        <button>
+            <legend>Default</legend>
+            <equal>true</equal>
+            <binding>
+                <command>nasal</command>
+                <script><![CDATA[
+                    setprop("/sim/hitches/aerotow/tow/length", 60.0);              # hitch.nas 60.0
+                    setprop("/sim/hitches/aerotow/tow/brake-force", 100000.0);     # hitch.nas 12345.0
+                    setprop("/sim/hitches/aerotow/tow/elastic-constant", 10000.0); # hitch.nas 9111.0
+                    setprop("/sim/hitches/aerotow/rope/rope-diameter-mm", 20);     # hitch.nas 20
+                    setprop("/sim/hitches/aerotow/tow/weight-per-m-kg-m", 0.35);   # hitch.nas 0.35
+                ]]></script>
+            </binding>
+        </button>
+        <empty>
+            <stretch>true</stretch>
+        </empty>
+    </group>
+</PropertyList>

nasal/aerotow.nas

@@ -10,7 +10,7 @@
 #
 
 #
-# Aerotow object
+# Class Aerotow for enable and disable scenario with aerotow aircraft.
 #
 var Aerotow = {
     #
@@ -51,20 +51,16 @@ var Aerotow = {
     #
     # Function for restart AI scenario with delay when the sound has to stop.
     #
-    # Return 1 on successful, otherwise 0.
-    #
     restartAerotow: func () {
         me.message.success("Aerotow on the way");
 
         # Stop playing engine sound
-        setprop(me.addonNodePath ~ "/addon-devel/sound/enable", 0);
+        setprop(me.addonNodePath ~ "/addon-devel/sound/enable", false);
 
         # Wait a second for the engine sound to turn off
-        var timer = maketimer(1, func () {
+        Timer.new().singleShot(1, me, func () {
             me.unloadScenario();
         });
-        timer.singleShot = 1;
-        timer.start();
     },
 
     #
@@ -76,25 +72,23 @@ var Aerotow = {
         }
 
         # Start aerotow with delay to avoid duplicate engine sound playing
-        var timer = maketimer(1, func () {
+        Timer.new().singleShot(1, me, func () {
             me.startAerotow();
         });
-        timer.singleShot = 1;
-        timer.start();
     },
 
     #
     # Main function to prepare AI scenario and run it.
     #
-    # Return 1 on successful, otherwise 0.
+    # Return true on successful, otherwise false.
     #
     startAerotow: func () {
         if (!me.scenario.unload()) {
-            return 0;
+            return false;
         }
 
         if (!me.scenario.generateXml()) {
-            return 0;
+            return false;
         }
 
         return me.scenario.load();
@@ -103,10 +97,10 @@ var Aerotow = {
     #
     # Function for unload our AI scenario.
     #
-    # Return 1 on successful, otherwise 0.
+    # Return true on successful, otherwise false.
     #
     stopAerotow: func () {
-        var withMessages = 1;
+        var withMessages = true;
         return me.scenario.unload(withMessages);
     },
 };

nasal/aircraft.nas

@@ -10,7 +10,7 @@
 #
 
 #
-# Parent object of Aircraft
+# Parent class of Aircraft
 #
 var Aircraft = {
     #
@@ -50,7 +50,7 @@ var Aircraft = {
     #
     # name - Name of aircraft to check.
     #
-    # Return 1 when match, otherwise 0.
+    # Return true when match, otherwise false.
     #
     isModelName: func (name) {
         return name == me.name or name == me.nameMenuCall;
@@ -69,8 +69,8 @@ var Aircraft = {
     # Return selected Aircraft object
     #
     # addon - Addon object
-    # isRouteMode - Use 1 to get the plane for the "Aerotow Route" dialog,
+    # isRouteMode - Use true to get the plane for the "Aerotow Route" dialog,
-    #               use 0 (default) for call the airplane for towing.
+    #               use false (default) for call the airplane for towing.
     #
     getSelected: func (addon, isRouteMode = 0) {
         var name = Aircraft.getSelectedAircraftName(addon, isRouteMode);
@@ -89,10 +89,10 @@ var Aircraft = {
     #
     #
     # addon - Addon object
-    # isRouteMode - Use 1 to get the plane for the "Aerotow Route" dialog,
+    # isRouteMode - Use true to get the plane for the "Aerotow Route" dialog,
-    #               use 0 (default) for call the airplane for towing.
+    #               use false (default) for call the airplane for towing.
     #
-    getSelectedAircraftName: func (addon, isRouteMode = 0) {
+    getSelectedAircraftName: func (addon, isRouteMode) {
         if (isRouteMode) {
             return getprop(addon.node.getPath() ~ "/addon-devel/route/ai-model") or g_Aircrafts[0].name;
         }

nasal/dialogs/route.nas

@@ -10,7 +10,7 @@
 #
 
 #
-# Object for hande Route Dialog
+# Class for hande Route Dialog
 #
 var RouteDialog = {
     #
@@ -64,9 +64,9 @@ var RouteDialog = {
     calculateAltChangeAndTotals: func () {
         var totalDistance = 0.0;
         var totalAlt = 0.0;
-        var isEnd = 0;
+        var isEnd = false;
 
-        var isRouteMode = 1;
+        var isRouteMode = true;
         var aircraft = Aircraft.getSelected(me.addon, isRouteMode);
 
         for (var i = 0; i < me.maxRouteWaypoints; i += 1) {
@@ -84,7 +84,7 @@ var RouteDialog = {
                     totalAlt += altChange;
                 }
                 else {
-                    isEnd = 1;
+                    isEnd = true;
                 }
             }
         }

nasal/dialogs/thermal.nas

@@ -9,6 +9,9 @@
 # under the GNU Public License v3 (GPLv3)
 #
 
+#
+# Class Thermal for handle add new thermal.
+#
 var Thermal = {
     #
     # Constructor
@@ -59,7 +62,7 @@ var Thermal = {
     #
     # Add thermal 300 m before glider position.
     #
-    # Return 1 on successful, otherwise 0.
+    # Return true on successful, otherwise false.
     #
     add: func () {
         var heading = getprop("/orientation/heading-deg") or 0;
@@ -84,10 +87,10 @@ var Thermal = {
 
         if (fgcommand("add-aiobject", args)) {
             me.message.success("The thermal has been added");
-            return 1;
+            return true;
         }
 
         me.message.error("Adding thermal failed");
-        return 0;
+        return false;
     },
 };

nasal/flight-plan.nas

@@ -10,7 +10,7 @@
 #
 
 #
-# Flight Plan object
+# Class FlightPlan for crate and save as XML file the flight plan for AI scenario.
 #
 var FlightPlan = {
     #
@@ -93,7 +93,7 @@ var FlightPlan = {
             "lat"     : rwyResult.runway.lat,
             "lon"     : rwyResult.runway.lon,
             "heading" : rwyResult.runway.heading,
-        }
+        };
     },
 
     #
@@ -124,17 +124,17 @@ var FlightPlan = {
     #
     # Initialize flight plan and set it to property tree
     #
-    # Return 1 on successful, otherwise 0.
+    # Return true on successful, otherwise false.
     #
     initial: func () {
         var location = me.getLocation();
         if (location == nil) {
-            return 0;
+            return false;
         }
 
         var aircraft = Aircraft.getSelected(me.addon);
 
-        var isGliderPos = 0;
+        var isGliderPos = false;
         me.initAircraftVariable(location, isGliderPos);
 
         # inittial readonly waypoint
@@ -189,28 +189,28 @@ var FlightPlan = {
 
         setprop(me.addonNodePath ~ "/addon-devel/route/wpts/description", "Default route around the start location");
 
-        return 1;
+        return true;
     },
 
     #
     # Generate the XML file with the flight plane for our plane for AI scenario.
-    # The file will be stored to $Fobj.HOME/Export/aerotown-addon-flightplan.xml.
+    # The file will be stored to $FG_HOME/Export/Addons/org.flightgear.addons.Aerotow/AI/FlightPlans/aerotown-addon-flightplan.xml.
     #
-    # Return 1 on successful, otherwise 0.
+    # Return true on successful, otherwise false.
     #
     generateXml: func () {
         me.wptCount = 0;
 
         var location = me.getLocation();
         if (location == nil) {
-            return 0;
+            return false;
         }
 
         me.flightPlanWriter.open();
 
         var aircraft = Aircraft.getSelected(me.addon);
 
-        var isGliderPos = 1;
+        var isGliderPos = true;
         me.initAircraftVariable(location, isGliderPos);
 
         # Start at 2 o'clock from the glider...
@@ -218,13 +218,13 @@ var FlightPlan = {
         me.addWptGround({"hdgChange": 60, "dist": 25}, {"altChange": 0, "ktas": 5});
 
         # Reset coord and heading
-        isGliderPos = 0;
+        isGliderPos = false;
         me.initAircraftVariable(location, isGliderPos);
 
         var gliderOffsetM = me.getGliderOffsetFromRunwayThreshold(location);
 
         # ... and line up with the runway
-        me.addWptGround({"hdgChange": 0, "dist": 30 + gliderOffsetM}, {"altChange": 0, "ktas": 2.5});
+        me.addWptGround({"hdgChange": 0, "dist": me.getInitialDistance() + gliderOffsetM}, {"altChange": 0, "ktas": 2.5});
 
         # Rolling
         me.addWptGround({"hdgChange": 0, "dist": 10}, {"altChange": 0, "ktas": 5});
@@ -268,16 +268,27 @@ var FlightPlan = {
 
         me.flightPlanWriter.close();
 
-        return 1;
+        return true;
+    },
+
+    #
+    # Get initial distance AI plane from the glider that the tow is nearly tautened.
+    #
+    # Return distance in meters.
+    #
+    getInitialDistance: func () {
+        var ropeLengthM = getprop("/sim/hitches/aerotow/tow/length") or 60;
+        var tautenRelative = 0.68;
+        return ropeLengthM * tautenRelative;
     },
 
     #
     # Initialize AI aircraft variable
     #
     # location - Object of location from which the glider start.
-    # isGliderPos - Pass 1 for set AI aircraft's coordinates as glider position, 0 set coordinates as runway threshold.
+    # isGliderPos - Pass true for set AI aircraft's coordinates as glider position, false set coordinates as runway threshold.
     #
-    initAircraftVariable: func (location, isGliderPos = 1) {
+    initAircraftVariable: func (location, isGliderPos) {
         var gliderCoord = geo.aircraft_position();
 
         # Set coordinates as glider position or runway threshold
@@ -307,7 +318,7 @@ var FlightPlan = {
             return rwyThreshold.distance_to(gliderCoord);
         }
 
-        # We are not on runway
+        # We are not on the runway, return 0 distance
         return 0;
     },
 

nasal/io/flight-plan-writer.nas

@@ -10,7 +10,7 @@
 #
 
 #
-# Object for write flight plan to the XML file
+# Class FlightPlanWriter for write flight plan to the XML file
 #
 var FlightPlanWriter = {
     #

nasal/message.nas

@@ -10,7 +10,7 @@
 #
 
 #
-# Object for display messages
+# Class Message for display messages on the screen with read by speech synthesizer.
 #
 var Message = {
     #

nasal/scenario.nas

@@ -10,16 +10,16 @@
 #
 
 #
-# Scenario object
+# Class Scenario for create AI scenario XML file and attach it to scenario property list for load it.
 #
 var Scenario = {
     #
     # Constants
     #
-    SCENARIO_ID:         "aerotow_addon",
+    SCENARIO_ID:       "aerotow_addon",
-    SCENARIO_NAME:       "Aerotow Add-on",
+    SCENARIO_NAME:     "Aerotow Add-on",
-    SCENARIO_DESC:       "This scenario starts the towing plane at the airport where the pilot with the glider is located. Use Ctrl-o to hook the plane.",
+    SCENARIO_DESC:     "This scenario starts the towing plane at the airport where the pilot with the glider is located. Use Ctrl-o to hook the plane.",
-    FILENAME_SCENARIO:   "aerotown-addon.xml",
+    FILENAME_SCENARIO: "aerotown-addon.xml",
 
     #
     # Constructor
@@ -38,7 +38,7 @@ var Scenario = {
         obj.listeners = [];
         obj.routeDialog = RouteDialog.new(addon, message);
         obj.flightPlan = FlightPlan.new(addon, message, obj.routeDialog);
-        obj.isScenarioLoaded = 0;
+        obj.isScenarioLoaded = false;
         obj.scenarioPath = addon.storagePath ~ "/" ~ Scenario.FILENAME_SCENARIO;
 
         obj.flightPlan.initial();
@@ -64,11 +64,13 @@ var Scenario = {
 
     #
     # Generate the XML file with the AI scenario.
-    # The file will be stored to $FG_HOME/Export/aerotown-addon.xml.
+    # The file will be stored to $FG_HOME/Export/Addons/org.flightgear.addons.Aerotow/aerotown-addon.xml.
+    #
+    # Return true on successful, otherwise false
     #
     generateXml: func () {
         if (!me.flightPlan.generateXml()) {
-            return 0;
+            return false;
         }
 
         var scenarioXml = {
@@ -82,7 +84,7 @@ var Scenario = {
                         "class":      "aerotow-dragger",
                         "model":      Aircraft.getSelected(me.addon).modelPath,
                         "flightplan": FlightPlan.FILENAME_FLIGHTPLAN,
-                        "repeat":     1,
+                        "repeat":     true, # start again indefinitely
                     }
                 }
             }
@@ -93,7 +95,7 @@ var Scenario = {
 
         me.addScenarioToPropertyList();
 
-        return 1;
+        return true;
     },
 
     #
@@ -114,67 +116,67 @@ var Scenario = {
     },
 
     #
-    # Return 1 if scenario is already added to "/sim/ai/scenarios" property list, otherwise return 0.
+    # Return true if scenario is already added to "/sim/ai/scenarios" property list, otherwise return false.
     #
     isAlreadyAdded: func () {
         foreach (var scenario; props.globals.getNode("/sim/ai/scenarios").getChildren("scenario")) {
             var id = scenario.getChild("id");
             if (id != nil and id.getValue() == Scenario.SCENARIO_ID) {
-                return 1;
+                return true;
             }
         }
 
-        return 0;
+        return false;
     },
 
     #
     # Load scenario
     #
-    # Return 1 on successful, otherwise 0.
+    # Return true on successful, otherwise false.
     #
     load: func () {
         var args = props.Node.new({ "name": Scenario.SCENARIO_ID });
         if (fgcommand("load-scenario", args)) {
-            me.isScenarioLoaded = 1;
+            me.isScenarioLoaded = true;
             me.message.success("Let's fly!");
 
             # Enable engine sound
-            setprop(me.addonNodePath ~ "/addon-devel/sound/enable", 1);
+            setprop(me.addonNodePath ~ "/addon-devel/sound/enable", true);
-            return 1;
+            return true;
         }
 
         me.message.error("Tow failed!");
-        return 0;
+        return false;
     },
 
     #
     # Unload scenario
     #
-    # withMessages - Set 1 to display messages.
+    # withMessages - Set true to display messages.
     #
-    # Return 1 on successful, otherwise 0.
+    # Return true on successful, otherwise false.
     #
     unload: func (withMessages = 0) {
         if (me.isScenarioLoaded) {
             var args = props.Node.new({ "name": Scenario.SCENARIO_ID });
             if (fgcommand("unload-scenario", args)) {
-                me.isScenarioLoaded = 0;
+                me.isScenarioLoaded = false;
 
                 if (withMessages) {
                     me.message.success("Aerotown disabled");
                 }
-                return 1;
+                return true;
             }
 
             if (withMessages) {
                 me.message.error("Aerotown disable failed");
             }
-            return 0;
+            return false;
         }
 
         if (withMessages) {
             me.message.success("Aerotown already disabled");
         }
-        return 1;
+        return true;
     },
 };

nasal/timer.nas

@@ -0,0 +1,41 @@
+#
+# Aerotow Everywhere - Add-on for FlightGear
+#
+# Written and developer by Roman Ludwicki (PlayeRom, SP-ROM)
+#
+# Copyright (C) 2022 Roman Ludwicki
+#
+# Aerotow Everywhere is an Open Source project and it is licensed
+# under the GNU Public License v3 (GPLv3)
+#
+
+#
+# Class Timer for wrapping maketimer() function.
+#
+var Timer = {
+    #
+    # Constructor
+    #
+    new: func () {
+        return { parents: [Timer] };
+    },
+
+    #
+    # Run timer as single shot
+    #
+    # delaySec - Delay in seconds for execute timer's callback.
+    # self - Specifying what any "me" references in the function being called will refer to.
+    # callback - Function to be called after given delay.
+    #
+    # Return timer handler object
+    #
+    singleShot: func (delaySec, self, callback) {
+        var timer = maketimer(delaySec, self, func () {
+            callback();
+        });
+        timer.singleShot = true;
+        timer.start();
+
+        return timer;
+    },
+};