Major change:

The "switch" layer type now takes any number of child layers, and will
use the first child that has a condition that evaluates to 'true' (no
condition is automatically true).  Previously, it could take only two
children, controlled by a boolean property.

src/Cockpit/panel.cxx

@@ -904,6 +904,7 @@ void
 FGGroupLayer::draw ()
 {
   if (test()) {
+    transform();
     int nLayers = _layers.size();
     for (int i = 0; i < nLayers; i++)
       _layers[i]->draw();
@@ -1134,28 +1135,22 @@ FGTextLayer::Chunk::getValue () const
 // Implementation of FGSwitchLayer.
 ////////////////////////////////////////////////////////////////////////
 
-FGSwitchLayer::FGSwitchLayer (int w, int h, const SGPropertyNode * node,
-			      FGInstrumentLayer * layer1,
-			      FGInstrumentLayer * layer2)
-  : FGInstrumentLayer(w, h), _node(node), _layer1(layer1), _layer2(layer2)
+FGSwitchLayer::FGSwitchLayer ()
+  : FGGroupLayer()
 {
 }
 
-FGSwitchLayer::~FGSwitchLayer ()
-{
-  delete _layer1;
-  delete _layer2;
-}
-
 void
 FGSwitchLayer::draw ()
 {
   if (test()) {
     transform();
-    if (_node->getBoolValue()) {
-      _layer1->draw();
-    } else {
-      _layer2->draw();
+    int nLayers = _layers.size();
+    for (int i = 0; i < nLayers; i++) {
+      if (_layers[i]->test()) {
+          _layers[i]->draw();
+          return;
+      }
     }
   }
 }

src/Cockpit/panel.hxx

@@ -442,7 +442,7 @@ public:
   virtual void draw ();
 				// transfer pointer ownership
   virtual void addLayer (FGInstrumentLayer * layer);
-private:
+protected:
   vector<FGInstrumentLayer *> _layers;
 };
 
@@ -536,25 +536,18 @@ private:
 
 
 /**
- * A layer that switches between two other layers.
+ * A group layer that switches among its children.
  *
- * The usefulness of this layer is questionable now that all layers
- * can have conditions, and it may be deprecated soon.
+ * The first layer that passes its condition will be drawn, and
+ * any following layers will be ignored.
  */
-class FGSwitchLayer : public FGInstrumentLayer
+class FGSwitchLayer : public FGGroupLayer
 {
 public:
 				// Transfer pointers!!
-  FGSwitchLayer (int w, int h, const SGPropertyNode * node,
-		 FGInstrumentLayer * layer1,
-		 FGInstrumentLayer * layer2);
-  virtual ~FGSwitchLayer ();
-
+  FGSwitchLayer ();
   virtual void draw ();
 
-private:
-  const SGPropertyNode * _node;
-  FGInstrumentLayer * _layer1, * _layer2;
 };
 
 

src/Cockpit/panel_io.cxx

@@ -436,11 +436,8 @@ readLayer (const SGPropertyNode * node, float w_scale, float h_scale)
     layer = new FGGroupLayer();
     for (int i = 0; i < node->nChildren(); i++) {
       const SGPropertyNode * child = node->getChild(i);
-      cerr << "Trying child " << child->getName() << endl;
-      if (!strcmp(child->getName(), "layer")) {
-	cerr << "succeeded!" << endl;
+      if (!strcmp(child->getName(), "layer"))
 	((FGGroupLayer *)layer)->addLayer(readLayer(child, w_scale, h_scale));
-      }
     }
   }
 
@@ -483,13 +480,12 @@ readLayer (const SGPropertyNode * node, float w_scale, float h_scale)
 
 				// A switch instrument layer.
   else if (type == "switch") {
-    SGPropertyNode * target =
-      fgGetNode(node->getStringValue("property"), true);
-    FGInstrumentLayer * layer1 =
-      readLayer(node->getNode("layer[0]"), w_scale, h_scale);
-    FGInstrumentLayer * layer2 =
-      readLayer(node->getNode("layer[1]"), w_scale, h_scale);
-    layer = new FGSwitchLayer(w, h, target, layer1, layer2);
+    layer = new FGSwitchLayer();
+    for (int i = 0; i < node->nChildren(); i++) {
+      const SGPropertyNode * child = node->getChild(i);
+      if (!strcmp(child->getName(), "layer"))
+	((FGGroupLayer *)layer)->addLayer(readLayer(child, w_scale, h_scale));
+    }
   }
 
 				// A built-in instrument layer.