fgdata/gui/dialogs/model-cockpit-view.xml

<?xml version="1.0"?>

<PropertyList>
	<name>model-cockpit-view</name>
	<x>5</x>
	<y>3</y>
	<layout>hbox</layout>
	<default-padding>0</default-padding>

	<color>
		<enabled>false</enabled>
		<red>0</red>
		<green>0</green>
		<blue>0</blue>
		<alpha>0</alpha>
	</color>

	<button>
		<legend>&lt;</legend>
		<pref-width>20</pref-width>
		<pref-height>20</pref-height>
		<color>
			<red>0.5</red>
			<green>0.5</green>
			<blue>0.5</blue>
			<alpha>0.3</alpha>
		</color>
		<binding>
			<command>nasal</command>
			<script>model_cockpit_view.model_cockpit_view_handler.next(-1)</script>
		</binding>
	</button>

	<button>
		<legend>&gt;</legend>
		<pref-width>20</pref-width>
		<pref-height>20</pref-height>
		<color>
			<red>0.5</red>
			<green>0.5</green>
			<blue>0.5</blue>
			<alpha>0.3</alpha>
		</color>
		<binding>
			<command>nasal</command>
			<script>model_cockpit_view.model_cockpit_view_handler.next(1)</script>
		</binding>
	</button>

	<whatever>
		<pref-width>6</pref-width>
	</whatever>

	<text>
		<pref-width>0</pref-width>
		<live>1</live>
		<property>/sim/current-view/model-cockpit-view</property>
		<color>
			<red>1</red>
			<green>1</green>
			<blue>1</blue>
			<alpha>1</alpha>
		</color>
		<font>
            <property>sim/gui/selected-style/fonts/gui-large</property>
        </font>
	</text>

	<button>
		<legend/>
		<pref-width>200</pref-width>
		<border>0</border>
		<color>
			<red>1</red>
			<green>1</green>
			<blue>1</blue>
			<alpha>0</alpha>
		</color>
		<binding>
			<command>nasal</command>
			<script>
        if (size(lsoview.model_cockpit_view_handler.list) &lt;= 1)
        return;
        var isopen = !!getprop("sim/gui/dialogs/model-cockpit-view/open");
        var toggle = isopen ? "dialog-close" : "dialog-show";
        fgcommand(toggle, props.Node.new({ "dialog-name": "model-cockpit-view" }));
      </script>
		</binding>
	</button>
</PropertyList>