make system and aircraft views configurable in Menu->Views->View Options.

These are then skipped with view.stepView(n), unless the second, optional
argument is set to 1:  view.stepView(n, 1);
Whether a view is enabled or not, is saved in $FG_ROOT/.fgfs/autosave.xml
(system views) or $FG_ROOT/.fgfs/aircraft-data/<aircraft>.xml

Nasal/view.nas

@@ -70,14 +70,19 @@ var resetViewDir = func {
 }
 
 ##
-# Handler.  Step to the next view.
+# Handler.  Step to the next (force=1) or next enabled view.
 #
-var stepView = func(n) {
+var stepView = func(n, force = 0) {
-    var i = getprop("/sim/current-view/view-number") + n;
+    var i = getprop("/sim/current-view/view-number");
-    if (i < 0)
+    while (1) {
-        i = size(views) - 1;
+        i += n;
-    elsif (i >= size(views))
+        if (i < 0)
-        i = 0;
+            i = size(views) - 1;
+        elsif (i >= size(views))
+            i = 0;
+        if (!i or force or (var e = views[i].getNode("enabled")) == nil or e.getValue())
+            break;
+    }
     setprop("/sim/current-view/view-number", i);
 
     # And pop up a nice reminder

gui/dialogs/view.xml

@@ -0,0 +1,72 @@
+<?xml version="1.0"?>
+
+<PropertyList>
+	<name>view</name>
+	<modal>false</modal>
+	<layout>vbox</layout>
+
+	<text>
+		<label>Configure Active Views</label>
+	</text>
+
+	<hrule/>
+
+	<nasal>
+		<open>
+			var group = cmdarg().getNode("group");
+			var ac = getprop("/sim/aircraft");
+			group.removeChildren("checkbox");
+			group.removeChildren("hrule");
+			group.removeChildren("text");
+			var system = 1;
+			foreach (var v; view.views) {
+				var index = v.getIndex();
+				if (index == 0 or index >= 200)
+					continue;
+
+				if (index >= 100) {
+					if (system) {
+						group.getNode("hrule", 1);
+						var t = group.getNode("text", 1);
+						t.getNode("label", 1).setValue("\"" ~ ac ~ "\" Specific Views");
+						system = 0;
+					}
+					aircraft.data.add(v.getPath() ~ "/enabled");
+				}
+				if (v.getNode("enabled") == nil)
+					v.getNode("enabled", 1).setBoolValue(1);
+
+				var target = group.getChild("checkbox", index, 1);
+				props.copy(group.getNode("checkbox-template"), target);
+				target.getNode("label").setValue(v.getNode("name").getValue());
+				target.getNode("property").setValue(v.getPath() ~ "/enabled");
+			}
+		</open>
+	</nasal>
+
+	<group>
+		<layout>vbox</layout>
+		<halign>center</halign>
+
+		<checkbox-template>
+			<halign>left</halign>
+			<label><!----></label>
+			<property><!----></property>
+			<binding>
+				<command>dialog-apply</command>
+			</binding>
+		</checkbox-template>
+	</group>
+
+	<button>
+		<legend>Close</legend>
+		<default>true</default>
+		<key>Esc</key>
+		<binding>
+			<command>dialog-apply</command>
+		</binding>
+		<binding>
+			<command>dialog-close</command>
+		</binding>
+	</button>
+</PropertyList>

gui/menubar.xml

@@ -19,16 +19,6 @@
    </binding>
   </item>
 
-<!--
-  <item>
-   <label>Load Aircraft</label>
-   <binding>
-    <command>dialog-show</command>
-    <dialog-name>aircraft</dialog-name>
-   </binding>
-  </item>
--->
-
   <item>
    <label>Reset</label>
    <binding>
@@ -117,7 +107,15 @@
   </item>
 
   <item>
-   <label>Rendering options</label>
+   <label>View Options</label>
+   <binding>
+    <command>dialog-show</command>
+    <dialog-name>view</dialog-name>
+   </binding>
+  </item>
+
+  <item>
+   <label>Rendering Options</label>
    <binding>
     <command>dialog-show</command>
     <dialog-name>rendering</dialog-name>
@@ -156,7 +154,6 @@
    </binding>
   </item>
 
-
   <item>
    <label>Chat</label>
    <binding>
@@ -164,7 +161,7 @@
     <dialog-name>chat</dialog-name>
    </binding>
   </item>
-  
+
  </menu>
 
  <menu>
@@ -380,7 +377,7 @@
     <command>ATC-freq-search</command>
    </binding>
   </item>
- 
+
   <item>
    <label>Options</label>
    <binding>
@@ -388,7 +385,7 @@
     <dialog-name>atc-ai</dialog-name>
    </binding>
   </item>
-  
+
  </menu>
 
  <menu>
@@ -463,6 +460,7 @@
     <command>dump-scenegraph</command>
    </binding>
   </item>
+
  </menu>
 
  <menu>

preferences.xml

@@ -260,6 +260,7 @@ Started September 2000 by David Megginson, david@megginson.com
 
   <view>
     <name>Cockpit View</name>
+    <enabled type="bool" userarchive="y">true</enabled>
     <type>lookfrom</type>
     <internal type="bool">false</internal>
     <config>
@@ -283,6 +284,7 @@ Started September 2000 by David Megginson, david@megginson.com
 
   <view>
     <name>Helicopter View</name>
+    <enabled type="bool" userarchive="y">true</enabled>
     <type>lookat</type>
     <config>
       <from-model type="bool">false</from-model>
@@ -308,6 +310,7 @@ Started September 2000 by David Megginson, david@megginson.com
 
   <view>
     <name>Chase View</name>
+    <enabled type="bool" userarchive="y">true</enabled>
     <type>lookat</type>
     <config>
       <from-model type="bool">false</from-model>
@@ -337,6 +340,7 @@ Started September 2000 by David Megginson, david@megginson.com
 
   <view>
     <name>Tower View</name>
+    <enabled type="bool" userarchive="y">true</enabled>
     <type>lookat</type>
     <config>
       <eye-lat-deg-path>/sim/tower/latitude-deg</eye-lat-deg-path>
@@ -360,6 +364,7 @@ Started September 2000 by David Megginson, david@megginson.com
 
   <view>
     <name>Tower View Look From</name>
+    <enabled type="bool" userarchive="y">true</enabled>
     <type>lookfrom</type>
     <config>
       <eye-lat-deg-path>/sim/tower/latitude-deg</eye-lat-deg-path>
@@ -380,6 +385,7 @@ Started September 2000 by David Megginson, david@megginson.com
 
   <view>
     <name>Chase View wo yaw</name>
+    <enabled type="bool" userarchive="y">true</enabled>
     <type>lookat</type>
     <config>
       <from-model type="bool">false</from-model>
@@ -402,6 +408,7 @@ Started September 2000 by David Megginson, david@megginson.com
 
   <view>
     <name>Fly-By View</name>
+    <enabled type="bool" userarchive="y">true</enabled>
     <type>lookat</type>
     <config>
       <eye-lon-deg-path>/sim/viewer/longitude-deg</eye-lon-deg-path>