refactoring of library system to allow separate component tree view

src/main/dig/processor/Processor.dig

@@ -122,7 +122,7 @@ Single-Cycle CPU.</string>
           <boolean>true</boolean>
         </entry>
       </elementAttributes>
-      <pos x="1220" y="40"/>
+      <pos x="1180" y="40"/>
     </visualElement>
     <visualElement>
       <elementName>Branch.dig</elementName>
@@ -188,6 +188,10 @@ Single-Cycle CPU.</string>
     <visualElement>
       <elementName>Driver</elementName>
       <elementAttributes>
+        <entry>
+          <string>rotation</string>
+          <rotation rotation="1"/>
+        </entry>
         <entry>
           <string>Bits</string>
           <int>16</int>
@@ -197,12 +201,12 @@ Single-Cycle CPU.</string>
           <boolean>true</boolean>
         </entry>
       </elementAttributes>
-      <pos x="520" y="120"/>
+      <pos x="520" y="40"/>
     </visualElement>
     <visualElement>
       <elementName>PC.dig</elementName>
       <elementAttributes/>
-      <pos x="360" y="120"/>
+      <pos x="400" y="120"/>
     </visualElement>
     <visualElement>
       <elementName>Clock</elementName>
@@ -477,16 +481,12 @@ Single-Cycle CPU.</string>
     <visualElement>
       <elementName>Tunnel</elementName>
       <elementAttributes>
-        <entry>
-          <string>rotation</string>
-          <rotation rotation="3"/>
-        </entry>
         <entry>
           <string>NetName</string>
           <string>stPC</string>
         </entry>
       </elementAttributes>
-      <pos x="520" y="160"/>
+      <pos x="560" y="40"/>
     </visualElement>
     <visualElement>
       <elementName>Tunnel</elementName>
@@ -528,7 +528,7 @@ Single-Cycle CPU.</string>
           <string>abs</string>
         </entry>
       </elementAttributes>
-      <pos x="340" y="160"/>
+      <pos x="380" y="160"/>
     </visualElement>
     <visualElement>
       <elementName>Tunnel</elementName>
@@ -576,7 +576,7 @@ Single-Cycle CPU.</string>
           <string>ALU2D</string>
         </entry>
       </elementAttributes>
-      <pos x="1260" y="40"/>
+      <pos x="1220" y="40"/>
     </visualElement>
     <visualElement>
       <elementName>Tunnel</elementName>
@@ -662,7 +662,7 @@ Single-Cycle CPU.</string>
           <string>C</string>
         </entry>
       </elementAttributes>
-      <pos x="340" y="140"/>
+      <pos x="380" y="140"/>
     </visualElement>
     <visualElement>
       <elementName>Tunnel</elementName>
@@ -766,7 +766,7 @@ Single-Cycle CPU.</string>
   </visualElements>
   <wires>
     <wire>
-      <p1 x="340" y="320"/>
+      <p1 x="380" y="320"/>
       <p2 x="940" y="320"/>
     </wire>
     <wire>
@@ -782,16 +782,20 @@ Single-Cycle CPU.</string>
       <p2 x="1360" y="320"/>
     </wire>
     <wire>
-      <p1 x="600" y="0"/>
+      <p1 x="520" y="0"/>
+      <p2 x="640" y="0"/>
+    </wire>
+    <wire>
+      <p1 x="640" y="0"/>
       <p2 x="800" y="0"/>
     </wire>
     <wire>
-      <p1 x="1220" y="0"/>
+      <p1 x="800" y="0"/>
-      <p2 x="1440" y="0"/>
+      <p2 x="1180" y="0"/>
     </wire>
     <wire>
-      <p1 x="800" y="0"/>
+      <p1 x="1180" y="0"/>
-      <p2 x="1220" y="0"/>
+      <p2 x="1440" y="0"/>
     </wire>
     <wire>
       <p1 x="740" y="480"/>
@@ -813,10 +817,6 @@ Single-Cycle CPU.</string>
       <p1 x="900" y="160"/>
       <p2 x="1080" y="160"/>
     </wire>
-    <wire>
-      <p1 x="340" y="160"/>
-      <p2 x="360" y="160"/>
-    </wire>
     <wire>
       <p1 x="1160" y="160"/>
       <p2 x="1240" y="160"/>
@@ -829,6 +829,10 @@ Single-Cycle CPU.</string>
       <p1 x="540" y="160"/>
       <p2 x="660" y="160"/>
     </wire>
+    <wire>
+      <p1 x="380" y="160"/>
+      <p2 x="400" y="160"/>
+    </wire>
     <wire>
       <p1 x="640" y="420"/>
       <p2 x="660" y="420"/>
@@ -854,7 +858,7 @@ Single-Cycle CPU.</string>
       <p2 x="1240" y="360"/>
     </wire>
     <wire>
-      <p1 x="320" y="360"/>
+      <p1 x="340" y="360"/>
       <p2 x="360" y="360"/>
     </wire>
     <wire>
@@ -882,16 +886,20 @@ Single-Cycle CPU.</string>
       <p2 x="840" y="40"/>
     </wire>
     <wire>
-      <p1 x="1240" y="40"/>
+      <p1 x="1200" y="40"/>
-      <p2 x="1260" y="40"/>
+      <p2 x="1220" y="40"/>
     </wire>
     <wire>
-      <p1 x="880" y="460"/>
+      <p1 x="540" y="40"/>
-      <p2 x="900" y="460"/>
+      <p2 x="560" y="40"/>
     </wire>
     <wire>
-      <p1 x="820" y="460"/>
+      <p1 x="380" y="140"/>
-      <p2 x="840" y="460"/>
+      <p2 x="400" y="140"/>
+    </wire>
+    <wire>
+      <p1 x="500" y="140"/>
+      <p2 x="520" y="140"/>
     </wire>
     <wire>
       <p1 x="880" y="140"/>
@@ -901,30 +909,30 @@ Single-Cycle CPU.</string>
       <p1 x="760" y="140"/>
       <p2 x="800" y="140"/>
     </wire>
-    <wire>
-      <p1 x="340" y="140"/>
-      <p2 x="360" y="140"/>
-    </wire>
     <wire>
       <p1 x="640" y="140"/>
       <p2 x="660" y="140"/>
     </wire>
-    <wire>
-      <p1 x="460" y="140"/>
-      <p2 x="480" y="140"/>
-    </wire>
     <wire>
       <p1 x="1160" y="140"/>
-      <p2 x="1220" y="140"/>
+      <p2 x="1180" y="140"/>
     </wire>
     <wire>
       <p1 x="1280" y="140"/>
       <p2 x="1360" y="140"/>
     </wire>
     <wire>
-      <p1 x="1220" y="140"/>
+      <p1 x="1180" y="140"/>
       <p2 x="1280" y="140"/>
     </wire>
+    <wire>
+      <p1 x="880" y="460"/>
+      <p2 x="900" y="460"/>
+    </wire>
+    <wire>
+      <p1 x="820" y="460"/>
+      <p2 x="840" y="460"/>
+    </wire>
     <wire>
       <p1 x="1000" y="300"/>
       <p2 x="1060" y="300"/>
@@ -933,6 +941,10 @@ Single-Cycle CPU.</string>
       <p1 x="1140" y="300"/>
       <p2 x="1160" y="300"/>
     </wire>
+    <wire>
+      <p1 x="340" y="240"/>
+      <p2 x="520" y="240"/>
+    </wire>
     <wire>
       <p1 x="1340" y="400"/>
       <p2 x="1360" y="400"/>
@@ -954,12 +966,28 @@ Single-Cycle CPU.</string>
       <p2 x="360" y="400"/>
     </wire>
     <wire>
-      <p1 x="340" y="80"/>
+      <p1 x="380" y="80"/>
-      <p2 x="1220" y="80"/>
+      <p2 x="1180" y="80"/>
     </wire>
     <wire>
-      <p1 x="320" y="240"/>
+      <p1 x="380" y="180"/>
-      <p2 x="480" y="240"/>
+      <p2 x="400" y="180"/>
+    </wire>
+    <wire>
+      <p1 x="1420" y="180"/>
+      <p2 x="1440" y="180"/>
+    </wire>
+    <wire>
+      <p1 x="1160" y="180"/>
+      <p2 x="1220" y="180"/>
+    </wire>
+    <wire>
+      <p1 x="1060" y="180"/>
+      <p2 x="1080" y="180"/>
+    </wire>
+    <wire>
+      <p1 x="560" y="180"/>
+      <p2 x="660" y="180"/>
     </wire>
     <wire>
       <p1 x="1340" y="340"/>
@@ -978,24 +1006,20 @@ Single-Cycle CPU.</string>
       <p2 x="840" y="500"/>
     </wire>
     <wire>
-      <p1 x="1420" y="180"/>
+      <p1 x="500" y="120"/>
-      <p2 x="1440" y="180"/>
+      <p2 x="520" y="120"/>
     </wire>
     <wire>
-      <p1 x="340" y="180"/>
+      <p1 x="380" y="120"/>
-      <p2 x="360" y="180"/>
+      <p2 x="400" y="120"/>
     </wire>
     <wire>
-      <p1 x="1160" y="180"/>
+      <p1 x="760" y="120"/>
-      <p2 x="1220" y="180"/>
+      <p2 x="840" y="120"/>
     </wire>
     <wire>
-      <p1 x="1060" y="180"/>
+      <p1 x="640" y="120"/>
-      <p2 x="1080" y="180"/>
+      <p2 x="660" y="120"/>
-    </wire>
-    <wire>
-      <p1 x="560" y="180"/>
-      <p2 x="660" y="180"/>
     </wire>
     <wire>
       <p1 x="500" y="440"/>
@@ -1013,26 +1037,6 @@ Single-Cycle CPU.</string>
       <p1 x="1000" y="280"/>
       <p2 x="1020" y="280"/>
     </wire>
-    <wire>
-      <p1 x="540" y="120"/>
-      <p2 x="600" y="120"/>
-    </wire>
-    <wire>
-      <p1 x="760" y="120"/>
-      <p2 x="840" y="120"/>
-    </wire>
-    <wire>
-      <p1 x="460" y="120"/>
-      <p2 x="500" y="120"/>
-    </wire>
-    <wire>
-      <p1 x="340" y="120"/>
-      <p2 x="360" y="120"/>
-    </wire>
-    <wire>
-      <p1 x="600" y="120"/>
-      <p2 x="660" y="120"/>
-    </wire>
     <wire>
       <p1 x="1340" y="380"/>
       <p2 x="1360" y="380"/>
@@ -1066,8 +1070,8 @@ Single-Cycle CPU.</string>
       <p2 x="1280" y="320"/>
     </wire>
     <wire>
-      <p1 x="320" y="240"/>
+      <p1 x="640" y="0"/>
-      <p2 x="320" y="360"/>
+      <p2 x="640" y="120"/>
     </wire>
     <wire>
       <p1 x="580" y="380"/>
@@ -1081,25 +1085,21 @@ Single-Cycle CPU.</string>
       <p1 x="900" y="160"/>
       <p2 x="900" y="460"/>
     </wire>
-    <wire>
-      <p1 x="1220" y="60"/>
-      <p2 x="1220" y="80"/>
-    </wire>
-    <wire>
-      <p1 x="1220" y="0"/>
-      <p2 x="1220" y="20"/>
-    </wire>
     <wire>
       <p1 x="1220" y="180"/>
       <p2 x="1220" y="340"/>
     </wire>
     <wire>
-      <p1 x="1220" y="80"/>
+      <p1 x="520" y="140"/>
-      <p2 x="1220" y="140"/>
+      <p2 x="520" y="240"/>
     </wire>
     <wire>
-      <p1 x="520" y="140"/>
+      <p1 x="520" y="60"/>
-      <p2 x="520" y="160"/>
+      <p2 x="520" y="120"/>
+    </wire>
+    <wire>
+      <p1 x="520" y="0"/>
+      <p2 x="520" y="20"/>
     </wire>
     <wire>
       <p1 x="520" y="600"/>
@@ -1118,21 +1118,13 @@ Single-Cycle CPU.</string>
       <p2 x="400" y="620"/>
     </wire>
     <wire>
-      <p1 x="340" y="180"/>
+      <p1 x="340" y="240"/>
-      <p2 x="340" y="320"/>
+      <p2 x="340" y="360"/>
-    </wire>
-    <wire>
-      <p1 x="340" y="80"/>
-      <p2 x="340" y="120"/>
     </wire>
     <wire>
       <p1 x="340" y="600"/>
       <p2 x="340" y="620"/>
     </wire>
-    <wire>
-      <p1 x="600" y="0"/>
-      <p2 x="600" y="120"/>
-    </wire>
     <wire>
       <p1 x="600" y="600"/>
       <p2 x="600" y="620"/>
@@ -1141,6 +1133,18 @@ Single-Cycle CPU.</string>
       <p1 x="1240" y="160"/>
       <p2 x="1240" y="360"/>
     </wire>
+    <wire>
+      <p1 x="1180" y="60"/>
+      <p2 x="1180" y="80"/>
+    </wire>
+    <wire>
+      <p1 x="1180" y="0"/>
+      <p2 x="1180" y="20"/>
+    </wire>
+    <wire>
+      <p1 x="1180" y="80"/>
+      <p2 x="1180" y="140"/>
+    </wire>
     <wire>
       <p1 x="540" y="160"/>
       <p2 x="540" y="380"/>
@@ -1165,10 +1169,6 @@ Single-Cycle CPU.</string>
       <p1 x="1440" y="180"/>
       <p2 x="1440" y="360"/>
     </wire>
-    <wire>
-      <p1 x="480" y="140"/>
-      <p2 x="480" y="240"/>
-    </wire>
     <wire>
       <p1 x="480" y="600"/>
       <p2 x="480" y="620"/>
@@ -1233,6 +1233,14 @@ Single-Cycle CPU.</string>
       <p1 x="440" y="600"/>
       <p2 x="440" y="620"/>
     </wire>
+    <wire>
+      <p1 x="380" y="180"/>
+      <p2 x="380" y="320"/>
+    </wire>
+    <wire>
+      <p1 x="380" y="80"/>
+      <p2 x="380" y="120"/>
+    </wire>
     <wire>
       <p1 x="380" y="600"/>
       <p2 x="380" y="620"/>

src/main/java/de/neemann/digital/draw/library/DescriptionCreator.java

@@ -0,0 +1,20 @@
+package de.neemann.digital.draw.library;
+
+import de.neemann.digital.core.element.ElementTypeDescription;
+
+import java.io.IOException;
+
+/**
+ * Used for lazy loading of the circuits
+ * Created by hneemann on 25.03.17.
+ */
+public interface DescriptionCreator {
+    /**
+     * Is called if the description is needed in the circuit.
+     * Is not called to create the menus
+     *
+     * @return the description
+     * @throws IOException IOException
+     */
+    ElementTypeDescription createDescription() throws IOException;
+}

src/main/java/de/neemann/digital/draw/library/ElementLibrary.java

@@ -3,7 +3,7 @@ package de.neemann.digital.draw.library;
 import de.neemann.digital.core.arithmetic.*;
 import de.neemann.digital.core.arithmetic.Comparator;
 import de.neemann.digital.core.basic.*;
-import de.neemann.digital.core.element.ElementTypeDescription;
+import de.neemann.digital.core.element.*;
 import de.neemann.digital.core.flipflops.FlipflopD;
 import de.neemann.digital.core.flipflops.FlipflopJK;
 import de.neemann.digital.core.flipflops.FlipflopRS;
@@ -19,13 +19,18 @@ import de.neemann.digital.core.switching.PFET;
 import de.neemann.digital.core.switching.Relay;
 import de.neemann.digital.core.switching.Switch;
 import de.neemann.digital.core.wiring.*;
+import de.neemann.digital.draw.elements.Circuit;
+import de.neemann.digital.draw.elements.PinException;
 import de.neemann.digital.draw.elements.Tunnel;
+import de.neemann.digital.draw.shapes.ShapeFactory;
 import de.neemann.digital.gui.components.data.DummyElement;
 import de.neemann.digital.gui.components.graphics.GraphicCard;
 import de.neemann.digital.gui.components.terminal.Keyboard;
 import de.neemann.digital.gui.components.terminal.Terminal;
 import de.neemann.digital.lang.Lang;
 import de.neemann.digital.testing.TestCaseElement;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import java.io.File;
 import java.io.IOException;
@@ -35,110 +40,146 @@ import java.util.*;
  * @author hneemann
  */
 public class ElementLibrary implements Iterable<ElementLibrary.ElementContainer> {
+    private static final Logger LOGGER = LoggerFactory.getLogger(ElementLibrary.class);
 
-    private final HashMap<String, ElementTypeDescription> map = new HashMap<>();
+    private final HashMap<String, LibraryNode> map = new HashMap<>();
-    private ArrayList<ElementContainer> list = new ArrayList<>();
+    private final ArrayList<LibraryListener> listeners = new ArrayList<>();
-    private ElementNotFoundNotification elementNotFoundNotification;
+    private final LibraryNode root;
+    private ShapeFactory shapeFactory;
+    private LibraryNode customNode;
+    private File rootLibraryPath;
 
     /**
      * Creates a new instance.
      */
     public ElementLibrary() {
-        String menu = Lang.get("lib_Logic");
+        root = new LibraryNode("root");
-        add(And.DESCRIPTION, menu);
-        add(NAnd.DESCRIPTION, menu);
-        add(Or.DESCRIPTION, menu);
-        add(NOr.DESCRIPTION, menu);
-        add(XOr.DESCRIPTION, menu);
-        add(XNOr.DESCRIPTION, menu);
-        add(Not.DESCRIPTION, menu);
-        add(LookUpTable.DESCRIPTION, menu);
-        add(Delay.DESCRIPTION, menu);
 
-        menu = Lang.get("lib_io");
+        LibraryNode node = new LibraryNode(Lang.get("lib_Logic"));
-        add(Out.DESCRIPTION, menu);
+        node.add(And.DESCRIPTION);
-        add(Out.LEDDESCRIPTION, menu);
+        node.add(NAnd.DESCRIPTION);
-        add(In.DESCRIPTION, menu);
+        node.add(Or.DESCRIPTION);
-        add(Clock.DESCRIPTION, menu);
+        node.add(NOr.DESCRIPTION);
-        add(Button.DESCRIPTION, menu);
+        node.add(XOr.DESCRIPTION);
-        add(Probe.DESCRIPTION, menu);
+        node.add(XNOr.DESCRIPTION);
-        add(Out.SEVENDESCRIPTION, menu);
+        node.add(Not.DESCRIPTION);
-        add(Out.SEVENHEXDESCRIPTION, menu);
+        node.add(LookUpTable.DESCRIPTION);
-        add(DummyElement.DATADESCRIPTION, menu);
+        node.add(Delay.DESCRIPTION);
-        add(DummyElement.TEXTDESCRIPTION, menu);
+        root.add(node);
-        add(Keyboard.DESCRIPTION, menu);
-        add(Terminal.DESCRIPTION, menu);
 
-        menu = Lang.get("lib_wires");
+        node = new LibraryNode(Lang.get("lib_io"));
-        add(Const.DESCRIPTION, menu);
+        node.add(Out.DESCRIPTION);
-        add(Ground.DESCRIPTION, menu);
+        node.add(Out.LEDDESCRIPTION);
-        add(VDD.DESCRIPTION, menu);
+        node.add(In.DESCRIPTION);
-        add(Tunnel.DESCRIPTION, menu);
+        node.add(Clock.DESCRIPTION);
-        add(Splitter.DESCRIPTION, menu);
+        node.add(Button.DESCRIPTION);
-        add(PullUp.DESCRIPTION, menu);
+        node.add(Probe.DESCRIPTION);
-        add(PullDown.DESCRIPTION, menu);
+        node.add(Out.SEVENDESCRIPTION);
-        add(Driver.DESCRIPTION, menu);
+        node.add(Out.SEVENHEXDESCRIPTION);
-        add(DriverInvSel.DESCRIPTION, menu);
+        node.add(DummyElement.DATADESCRIPTION);
+        node.add(DummyElement.TEXTDESCRIPTION);
+        node.add(Keyboard.DESCRIPTION);
+        node.add(Terminal.DESCRIPTION);
+        root.add(node);
 
-        menu = Lang.get("lib_mux");
+        node = new LibraryNode(Lang.get("lib_wires"));
-        add(Multiplexer.DESCRIPTION, menu);
+        node.add(Const.DESCRIPTION);
-        add(Demultiplexer.DESCRIPTION, menu);
+        node.add(Ground.DESCRIPTION);
-        add(Decoder.DESCRIPTION, menu);
+        node.add(VDD.DESCRIPTION);
+        node.add(Tunnel.DESCRIPTION);
+        node.add(Splitter.DESCRIPTION);
+        node.add(PullUp.DESCRIPTION);
+        node.add(PullDown.DESCRIPTION);
+        node.add(Driver.DESCRIPTION);
+        node.add(DriverInvSel.DESCRIPTION);
+        root.add(node);
 
-        menu = Lang.get("lib_flipFlops");
+        node = new LibraryNode(Lang.get("lib_mux"));
-        add(FlipflopRS.DESCRIPTION, menu);
+        node.add(Multiplexer.DESCRIPTION);
-        add(FlipflopJK.DESCRIPTION, menu);
+        node.add(Demultiplexer.DESCRIPTION);
-        add(FlipflopD.DESCRIPTION, menu);
+        node.add(Decoder.DESCRIPTION);
-        add(FlipflopT.DESCRIPTION, menu);
+        root.add(node);
 
-        menu = Lang.get("lib_memory");
+        node = new LibraryNode(Lang.get("lib_flipFlops"));
-        add(Register.DESCRIPTION, menu);
+        node.add(FlipflopRS.DESCRIPTION);
-        add(ROM.DESCRIPTION, menu);
+        node.add(FlipflopJK.DESCRIPTION);
-        add(RAMDualPort.DESCRIPTION, menu);
+        node.add(FlipflopD.DESCRIPTION);
-        add(RAMSinglePort.DESCRIPTION, menu);
+        node.add(FlipflopT.DESCRIPTION);
-        add(RAMSinglePortSel.DESCRIPTION, menu);
+        root.add(node);
-        add(GraphicCard.DESCRIPTION, menu);
-        add(Counter.DESCRIPTION, menu);
 
-        menu = Lang.get("lib_arithmetic");
+        node = new LibraryNode(Lang.get("lib_memory"));
-        add(Add.DESCRIPTION, menu);
+        node.add(Register.DESCRIPTION);
-        add(Sub.DESCRIPTION, menu);
+        node.add(ROM.DESCRIPTION);
-        add(Mul.DESCRIPTION, menu);
+        node.add(RAMDualPort.DESCRIPTION);
-        add(Comparator.DESCRIPTION, menu);
+        node.add(RAMSinglePort.DESCRIPTION);
-        add(Neg.DESCRIPTION, menu);
+        node.add(RAMSinglePortSel.DESCRIPTION);
-        add(BitCount.DESCRIPTION, menu);
+        node.add(GraphicCard.DESCRIPTION);
+        node.add(Counter.DESCRIPTION);
+        root.add(node);
 
-        menu = Lang.get("lib_cplx");
+        node = new LibraryNode(Lang.get("lib_arithmetic"));
+        node.add(Add.DESCRIPTION);
+        node.add(Sub.DESCRIPTION);
+        node.add(Mul.DESCRIPTION);
+        node.add(Comparator.DESCRIPTION);
+        node.add(Neg.DESCRIPTION);
+        node.add(BitCount.DESCRIPTION);
+        root.add(node);
+
+        node = new LibraryNode(Lang.get("lib_cplx"));
         //  add(Diode.DESCRIPTION, menu); // see class DiodeTest for further information
-        add(DiodeForeward.DESCRIPTION, menu);
+        node.add(DiodeForeward.DESCRIPTION);
-        add(DiodeBackward.DESCRIPTION, menu);
+        node.add(DiodeBackward.DESCRIPTION);
-        add(Switch.DESCRIPTION, menu);
+        node.add(Switch.DESCRIPTION);
-        add(Relay.DESCRIPTION, menu);
+        node.add(Relay.DESCRIPTION);
-        add(NFET.DESCRIPTION, menu);
+        node.add(NFET.DESCRIPTION);
-        add(PFET.DESCRIPTION, menu);
+        node.add(PFET.DESCRIPTION);
-        add(Reset.DESCRIPTION, menu);
+        node.add(Reset.DESCRIPTION);
-        add(Break.DESCRIPTION, menu);
+        node.add(Break.DESCRIPTION);
+        root.add(node);
 
-        menu = Lang.get("lib_test");
+        node = new LibraryNode(Lang.get("lib_test"));
-        add(TestCaseElement.TESTCASEDESCRIPTION, menu);
+        node.add(TestCaseElement.TESTCASEDESCRIPTION);
-    }
+        root.add(node);
 
-    private void add(ElementTypeDescription description, String treePath) {
+        populateNodeMap();
-        String name = description.getName();
-        map.put(name, description);
-        list.add(new ElementContainer(description, treePath));
     }
 
     /**
-     * Adds a description to the library
+     * Sets the shape factory used to import sub circuits
      *
-     * @param description the description
+     * @param shapeFactory the shape factory
-     * @param file        the file which was loaded
      */
-    public void addDescription(ElementTypeDescription description, File file) {
+    public void setShapeFactory(ShapeFactory shapeFactory) {
-        map.put(file.getName(), description);
+        this.shapeFactory = shapeFactory;
     }
 
+    private void populateNodeMap() {
+        map.clear();
+        root.traverse(libraryNode -> {
+            if (libraryNode.isLeaf()) {
+                map.put(libraryNode.getName(), libraryNode);
+            }
+        });
+    }
+
+    /**
+     * sets the root library path
+     *
+     * @param rootLibraryPath the path
+     * @throws IOException IOException
+     */
+    public void setFilePath(File rootLibraryPath) throws IOException {
+        if (rootLibraryPath == null) {
+            if (this.rootLibraryPath != null) {
+                this.rootLibraryPath = null;
+                rescanFolder();
+            }
+        } else if (!rootLibraryPath.equals(this.rootLibraryPath)) {
+            this.rootLibraryPath = rootLibraryPath;
+            rescanFolder();
+        }
+    }
 
     /**
      * Returns a {@link ElementTypeDescription} by a given name.
@@ -149,60 +190,123 @@ public class ElementLibrary implements Iterable<ElementLibrary.ElementContainer>
      * @throws ElementNotFoundException ElementNotFoundException
      */
     public ElementTypeDescription getElementType(String elementName) throws ElementNotFoundException {
-        ElementTypeDescription description = map.get(elementName);
+        try {
-        if (description != null)
+            LibraryNode description = map.get(elementName);
-            return description;
+            if (description != null)
+                return description.getDescription();
 
-        elementName = elementName.replace("\\", "/"); // effects only some old files!
+            // effects only some old files!
-
+            elementName = elementName.replace("\\", "/");
-        File file = new File(elementName);
+            if (elementName.contains("/")) {
-
+                elementName = new File(elementName).getName();
-        description = map.get(file.getName());
-        if (description != null)
-            return description;
-
-        if (elementNotFoundNotification != null)
-            try {
-                description = elementNotFoundNotification.elementNotFound(file);
-            } catch (IOException e) {
-                throw new ElementNotFoundException(Lang.get("msg_errorImportingModel", elementName), e);
             }
 
-        if (description != null)
+            description = map.get(elementName);
-            return description;
+            if (description != null)
+                return description.getDescription();
+
+            if (rootLibraryPath == null)
+                throw new RuntimeException("no root path set");
+
+            rescanFolder();
+
+            description = map.get(elementName);
+            if (description != null)
+                return description.getDescription();
+        } catch (IOException e) {
+            throw new ElementNotFoundException(Lang.get("msg_errorImportingModel"), e);
+        }
 
         throw new ElementNotFoundException(Lang.get("err_element_N_notFound", elementName));
     }
 
-    @Override
+    private void rescanFolder() {
-    public Iterator<ElementContainer> iterator() {
+        LOGGER.debug("rescan folder");
-        HashSet<String> baseElements = new HashSet<>();
+        if (customNode == null) {
-        for (ElementContainer ec : list) {
+            customNode = new LibraryNode(Lang.get("menu_custom"));
-            baseElements.add(ec.getDescription().getName());
+            root.add(customNode);
-        }
+        } else customNode.removeAll();
-        ArrayList<ElementContainer> custom = new ArrayList<>();
-        for (Map.Entry<String, ElementTypeDescription> entry : map.entrySet()) {
-            if (!baseElements.contains(entry.getValue().getName())) {
-                custom.add(new ElementContainer(entry.getValue(), Lang.get("menu_custom")));
-            }
-        }
 
-        if (custom.isEmpty())
+        if (rootLibraryPath != null)
-            return list.iterator();
+            scanFolder(rootLibraryPath, customNode);
-        else {
+
-            Collections.sort(custom, (c1, c2) -> c1.getDescription().getTranslatedName().compareToIgnoreCase(c2.getDescription().getTranslatedName()));
+        populateNodeMap();
-            custom.addAll(list);
+
-            return custom.iterator();
+        fireLibraryChanged();
+    }
+
+    private void fireLibraryChanged() {
+        for (LibraryListener l : listeners)
+            l.libraryChanged();
+    }
+
+    private void scanFolder(File path, LibraryNode node) {
+        File[] list = path.listFiles();
+        if (list != null) {
+            ArrayList<File> orderedList = new ArrayList<>(Arrays.asList(list));
+            orderedList.sort((f1, f2) -> f1.getName().compareToIgnoreCase(f2.getName()));
+            for (File f : orderedList) {
+                if (f.isDirectory()) {
+                    LibraryNode n = new LibraryNode(f.getName());
+                    scanFolder(f, n);
+                    if (!n.isEmpty())
+                        node.add(n);
+                }
+            }
+            for (File f : orderedList) {
+                final String name = f.getName();
+                if (f.isFile() && name.endsWith(".dig"))
+                    node.add(importElement(f));
+            }
         }
     }
 
     /**
-     * Setes the {@link ElementNotFoundNotification} which can be calle if a element is not present.
+     * Adds a listener to this library
      *
-     * @param elementNotFoundNotification elementNotFoundNotification
+     * @param listener the listener to add
      */
-    public void setElementNotFoundNotification(ElementNotFoundNotification elementNotFoundNotification) {
+    public void addListener(LibraryListener listener) {
-        this.elementNotFoundNotification = elementNotFoundNotification;
+        listeners.add(listener);
+    }
+
+    /**
+     * Removes a listener from this library
+     *
+     * @param listener the listener to remove
+     */
+    public void removeListener(LibraryListener listener) {
+        listeners.remove(listener);
+    }
+
+
+    @Override
+    public Iterator<ElementContainer> iterator() {
+        ArrayList<ElementContainer> nodes = new ArrayList<>();
+        for (LibraryNode n : getRoot())
+            addToList(nodes, n, "");
+        return nodes.iterator();
+    }
+
+    private void addToList(ArrayList<ElementContainer> nodes, LibraryNode node, String path) {
+        if (node.isLeaf()) {
+            if (node.isDescriptionLoaded()) {
+                try {
+                    nodes.add(new ElementContainer(node.getDescription(), path));
+                } catch (IOException e) {
+                    // can not happen because description is present!
+                }
+            }
+        } else
+            for (LibraryNode n : node)
+                addToList(nodes, n, concat(path, node.getName()));
+    }
+
+    private String concat(String path, String name) {
+        if (path.length() == 0)
+            return name;
+        return path + " - " + name;
+
     }
 
     /**
@@ -214,6 +318,120 @@ public class ElementLibrary implements Iterable<ElementLibrary.ElementContainer>
         map.remove(name.getName());
     }
 
+    /**
+     * Updates all entries
+     *
+     * @throws IOException IOException
+     */
+    public void updateEntries() throws IOException {
+        rescanFolder();
+    }
+
+    /**
+     * @return the root element
+     */
+    public LibraryNode getRoot() {
+        return root;
+    }
+
+    private LibraryNode importElement(File file) {
+        return new LibraryNode(file.getName(), () -> {
+            try {
+                LOGGER.debug("load element " + file);
+                Circuit circuit = Circuit.loadCircuit(file, shapeFactory);
+                ElementTypeDescriptionCustom description =
+                        new ElementTypeDescriptionCustom(file,
+                                attributes -> new CustomElement(circuit, ElementLibrary.this, file),
+                                circuit.getAttributes(), circuit.getInputNames());
+                description.setShortName(createShortName(file));
+
+                String descriptionText = circuit.getAttributes().get(Keys.DESCRIPTION);
+                if (descriptionText != null && descriptionText.length() > 0) {
+                    description.setDescription(descriptionText);
+                }
+                return description;
+            } catch (PinException e) {
+                throw new IOException(Lang.get("msg_errorImportingModel"), e);
+            }
+        });
+    }
+
+    private String createShortName(File file) {
+        return createShortName(file.getName());
+    }
+
+    private String createShortName(String name) {
+        if (name.endsWith(".dig")) return name.substring(0, name.length() - 4);
+
+        String transName = Lang.getNull("elem_" + name);
+        if (transName == null)
+            return name;
+        else
+            return transName;
+    }
+
+    /**
+     * The description of a nested element.
+     * This is a complete circuit which is used as a element.
+     */
+    public static class ElementTypeDescriptionCustom extends ElementTypeDescription {
+        private final File file;
+        private final ElementAttributes attributes;
+        private String description;
+
+        /**
+         * Creates a new element
+         *
+         * @param file           the file which is loaded
+         * @param elementFactory a element factory which is used to create concrete elements if needed
+         * @param attributes     the attributes of the element
+         * @param inputNames     the names of the input signals
+         */
+        public ElementTypeDescriptionCustom(File file, ElementFactory elementFactory, ElementAttributes attributes, PinDescription... inputNames) {
+            super(file.getName(), elementFactory, inputNames);
+            this.file = file;
+            this.attributes = attributes;
+            setShortName(file.getName());
+            addAttribute(Keys.ROTATE);
+            addAttribute(Keys.LABEL);
+        }
+
+        /**
+         * Returns the filename
+         * the retuned file is opened if the user wants to modify the element
+         *
+         * @return the filename
+         */
+        public File getFile() {
+            return file;
+        }
+
+        /**
+         * @return the elements attributes
+         */
+        public ElementAttributes getAttributes() {
+            return attributes;
+        }
+
+        /**
+         * Sets a custom description for this field
+         *
+         * @param description the description
+         */
+        public void setDescription(String description) {
+            this.description = description;
+        }
+
+        @Override
+        public String getDescription(ElementAttributes elementAttributes) {
+            if (description != null)
+                return description;
+            else
+                return super.getDescription(elementAttributes);
+        }
+    }
+
+
     /**
      * Used to store a elements name and its position in the elements menu.
      */
@@ -227,7 +445,7 @@ public class ElementLibrary implements Iterable<ElementLibrary.ElementContainer>
          * @param typeDescription the elements typeDescription
          * @param treePath        the elements menu path
          */
-        public ElementContainer(ElementTypeDescription typeDescription, String treePath) {
+        ElementContainer(ElementTypeDescription typeDescription, String treePath) {
             this.name = typeDescription;
             this.treePath = treePath;
         }

src/main/java/de/neemann/digital/draw/library/LibraryListener.java

@@ -0,0 +1,13 @@
+package de.neemann.digital.draw.library;
+
+/**
+ * Listener to notify library uses if the library changes
+ * Created by hneemann on 25.03.17.
+ */
+public interface LibraryListener {
+
+    /**
+     * called if library changes
+     */
+    void libraryChanged();
+}

src/main/java/de/neemann/digital/draw/library/LibraryNode.java

@@ -0,0 +1,159 @@
+package de.neemann.digital.draw.library;
+
+import de.neemann.digital.core.element.ElementTypeDescription;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Iterator;
+
+/**
+ * A node in the components library
+ * Created by hneemann on 25.03.17.
+ */
+public class LibraryNode implements Iterable<LibraryNode> {
+
+    private final ArrayList<LibraryNode> children;
+    private final String translatedName;
+    private final String name;
+    private final DescriptionCreator creator;
+    private ElementTypeDescription description;
+
+    /**
+     * Creates a new node with the given name.
+     * The node can have children
+     *
+     * @param name name of the node
+     */
+    LibraryNode(String name) {
+        this.name = name;
+        this.translatedName = name;
+        this.children = new ArrayList<>();
+        this.description = null;
+        this.creator = null;
+    }
+
+    /**
+     * Creates a new leaf
+     *
+     * @param description the description
+     */
+    private LibraryNode(ElementTypeDescription description) {
+        this.children = null;
+        this.description = description;
+        this.name = description.getName();
+        this.translatedName = description.getTranslatedName();
+        this.creator = null;
+    }
+
+    /**
+     * Creates a new leaf
+     *
+     * @param name    the name of the leaf
+     * @param creator used to create the {@link ElementTypeDescription} if necessary
+     */
+    LibraryNode(String name, DescriptionCreator creator) {
+        this.children = null;
+        this.name = name;
+        this.translatedName = name;
+        this.creator = creator;
+    }
+
+    /**
+     * Adds a node.
+     * Throws an exception if this node is a leaf
+     *
+     * @param node
+     */
+    void add(LibraryNode node) {
+        children.add(node);
+    }
+
+    void add(ElementTypeDescription node) {
+        add(new LibraryNode(node));
+    }
+
+    /**
+     * Traverse the tree
+     *
+     * @param v   a visitor
+     * @param <V> the type of the visitor
+     * @return the visitor
+     */
+    public <V extends Visitor> V traverse(V v) {
+        v.visit(this);
+        if (children != null) {
+            for (LibraryNode tn : children)
+                tn.traverse(v);
+        }
+        return v;
+    }
+
+    /**
+     * @return trie if this is a leaf
+     */
+    public boolean isLeaf() {
+        return description != null || creator != null;
+    }
+
+    /**
+     * @return true if the description is already loaded
+     */
+    public boolean isDescriptionLoaded() {
+        return description != null;
+    }
+
+    /**
+     * Returns the description of the element
+     *
+     * @return the description
+     * @throws IOException IOException
+     */
+    public ElementTypeDescription getDescription() throws IOException {
+        if (description == null)
+            description = creator.createDescription();
+        return description;
+    }
+
+    /**
+     * @return the translated name of the element
+     */
+    public String getTranslatedName() {
+        return translatedName;
+    }
+
+    /**
+     * @return the name od id of this element
+     */
+    public String getName() {
+        return name;
+    }
+
+    @Override
+    public Iterator<LibraryNode> iterator() {
+        return children.iterator();
+    }
+
+    /**
+     * all children are removed
+     */
+    public void removeAll() {
+        children.clear();
+    }
+
+    /**
+     * @return true if this node is empty
+     */
+    public boolean isEmpty() {
+        if (isLeaf())
+            return false;
+
+        return children.isEmpty();
+    }
+
+    /**
+     * @return returns the description if present, null otherwise
+     */
+    public ElementTypeDescription getDescriptionOrNull() {
+        return description;
+    }
+}

src/main/java/de/neemann/digital/draw/library/Visitor.java

@@ -0,0 +1,15 @@
+package de.neemann.digital.draw.library;
+
+/**
+ * Visits all elements of the elements tree
+ * Created by hneemann on 25.03.17.
+ */
+public interface Visitor {
+
+    /**
+     * Called on every node
+     *
+     * @param libraryNode the node
+     */
+    void visit(LibraryNode libraryNode);
+}

src/main/java/de/neemann/digital/draw/shapes/ShapeFactory.java

@@ -23,7 +23,6 @@ import de.neemann.digital.draw.shapes.ieee.IEEEAndShape;
 import de.neemann.digital.draw.shapes.ieee.IEEENotShape;
 import de.neemann.digital.draw.shapes.ieee.IEEEOrShape;
 import de.neemann.digital.draw.shapes.ieee.IEEEXOrShape;
-import de.neemann.digital.gui.LibrarySelector;
 import de.neemann.digital.gui.components.data.DummyElement;
 import de.neemann.digital.lang.Lang;
 import de.neemann.digital.testing.TestCaseElement;
@@ -57,6 +56,7 @@ public final class ShapeFactory {
      */
     public ShapeFactory(ElementLibrary library, boolean ieee) {
         this.library = library;
+        library.setShapeFactory(this);
         if (ieee) {
             map.put(And.DESCRIPTION.getName(), (attributes, inputs, outputs) -> new IEEEAndShape(inputs, outputs, false));
             map.put(NAnd.DESCRIPTION.getName(), (attributes, inputs, outputs) -> new IEEEAndShape(inputs, outputs, true));
@@ -136,8 +136,8 @@ public final class ShapeFactory {
                     throw new NodeException(Lang.get("err_noShapeFoundFor_N", elementName));
                 else {
                     ElementTypeDescription pt = library.getElementType(elementName);
-                    if (pt instanceof LibrarySelector.ElementTypeDescriptionCustom) {
+                    if (pt instanceof ElementLibrary.ElementTypeDescriptionCustom) {
-                        LibrarySelector.ElementTypeDescriptionCustom customDescr = (LibrarySelector.ElementTypeDescriptionCustom) pt;
+                        ElementLibrary.ElementTypeDescriptionCustom customDescr = (ElementLibrary.ElementTypeDescriptionCustom) pt;
                         return new GenericShape(
                                 pt.getShortName(),
                                 pt.getInputDescription(elementAttributes),

src/main/java/de/neemann/digital/gui/InsertHistory.java

@@ -3,6 +3,7 @@ package de.neemann.digital.gui;
 import javax.swing.*;
 import java.awt.event.ActionEvent;
 import java.util.ArrayList;
+import java.util.Iterator;
 
 /**
  * The InsertHistory puts the most frequently used elements to the toolbar of the main window.
@@ -41,15 +42,20 @@ public class InsertHistory {
             bar.add(wrapper);
             if (wrappers.size() > MAX_ICONS) {
                 int oldest = findOldestIndex();
-                wrapper = wrappers.get(oldest);
+                removeWrapperFromBar(wrappers.get(oldest));
-                bar.remove(wrapper.componentPosition);
-                for (int i = oldest; i < wrappers.size(); i++)
-                    wrappers.get(i).componentPosition--;
                 wrappers.remove(oldest);
             }
         }
     }
 
+    private void removeWrapperFromBar(WrapperAction wrapper) {
+        final int position = wrapper.componentPosition;
+        bar.remove(position);
+        for (WrapperAction w : wrappers)
+            if (w.componentPosition > position)
+                w.componentPosition--;
+    }
+
     private int findOldestIndex() {
         int found = -1;
         int oldestTime = mainTime;
@@ -70,8 +76,24 @@ public class InsertHistory {
         return false;
     }
 
-    private final class WrapperAction extends AbstractAction {
+    /**
+     * remove custom components
+     */
+    public void removeCustom() {
+        Iterator<WrapperAction> it = wrappers.iterator();
+        while (it.hasNext()) {
+            WrapperAction w = it.next();
+            if (w.action instanceof LibrarySelector.InsertAction) {
+                if (((LibrarySelector.InsertAction) w.action).isCustom()) {
+                    removeWrapperFromBar(w);
+                    it.remove();
+                }
+            }
+        }
+        bar.revalidate();
+    }
 
+    private final class WrapperAction extends AbstractAction {
         private final AbstractAction action;
         private int componentPosition;
         private int time;

src/main/java/de/neemann/digital/gui/LibrarySelector.java

@@ -1,13 +1,10 @@
 package de.neemann.digital.gui;
 
-import de.neemann.digital.core.element.*;
-import de.neemann.digital.draw.elements.Circuit;
-import de.neemann.digital.draw.elements.PinException;
 import de.neemann.digital.draw.elements.VisualElement;
 import de.neemann.digital.draw.graphics.Vector;
-import de.neemann.digital.draw.library.CustomElement;
 import de.neemann.digital.draw.library.ElementLibrary;
-import de.neemann.digital.draw.library.ElementNotFoundNotification;
+import de.neemann.digital.draw.library.LibraryListener;
+import de.neemann.digital.draw.library.LibraryNode;
 import de.neemann.digital.draw.shapes.ShapeFactory;
 import de.neemann.digital.gui.components.CircuitComponent;
 import de.neemann.digital.gui.state.State;
@@ -15,16 +12,10 @@ import de.neemann.digital.lang.Lang;
 import de.neemann.gui.ErrorMessage;
 import de.neemann.gui.StringUtils;
 import de.neemann.gui.ToolTipAction;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 import javax.swing.*;
-import javax.swing.filechooser.FileNameExtensionFilter;
 import java.awt.event.ActionEvent;
-import java.io.File;
 import java.io.IOException;
-import java.util.ArrayList;
-import java.util.HashMap;
 
 /**
  * The LibrarySelector is responsible for building the menu used to select items for adding them to the circuit.
@@ -32,22 +23,17 @@ import java.util.HashMap;
  *
  * @author hneemann
  */
-public class LibrarySelector implements ElementNotFoundNotification {
+public class LibrarySelector implements LibraryListener {
-    private static final Logger LOGGER = LoggerFactory.getLogger(LibrarySelector.class);
-
     private final ElementLibrary library;
     private final ShapeFactory shapeFactory;
     private final State elementState;
-    private File filePath;
+    private JMenu componentsMenu;
-    private JMenu customMenu;
     private InsertHistory insertHistory;
     private CircuitComponent circuitComponent;
-    private ArrayList<ImportedItem> importedElements;
-    private HashMap<String, File> treeFileMap;
 
     /**
      * Creates a new library selector.
-     * the elementState is used to seht the window to the elemetEdit mode if a new element is added to the circuit.
+     * the elementState is used to set the window to the elementEdit mode if a new element is added to the circuit.
      *
      * @param library      the library to select elements from
      * @param shapeFactory The shape factory
@@ -55,10 +41,9 @@ public class LibrarySelector implements ElementNotFoundNotification {
      */
     public LibrarySelector(ElementLibrary library, ShapeFactory shapeFactory, State elementState) {
         this.library = library;
+        library.addListener(this);
         this.shapeFactory = shapeFactory;
         this.elementState = elementState;
-        library.setElementNotFoundNotification(this);
-        importedElements = new ArrayList<>();
     }
 
     /**
@@ -73,64 +58,47 @@ public class LibrarySelector implements ElementNotFoundNotification {
     public JMenu buildMenu(InsertHistory insertHistory, CircuitComponent circuitComponent) {
         this.insertHistory = insertHistory;
         this.circuitComponent = circuitComponent;
-        JMenu parts = new JMenu(Lang.get("menu_elements"));
+        componentsMenu = new JMenu(Lang.get("menu_elements"));
+        libraryChanged();
 
-        customMenu = new JMenu(Lang.get("menu_custom"));
+        return componentsMenu;
-        parts.add(customMenu);
-
-        customMenu.add(new ToolTipAction(Lang.get("menu_import")) {
-            @Override
-            public void actionPerformed(ActionEvent e) {
-                JFileChooser fc = new JFileChooser(filePath);
-                fc.setFileFilter(new FileNameExtensionFilter("Circuit", "dig"));
-                if (fc.showOpenDialog(null) == JFileChooser.APPROVE_OPTION) {
-                    try {
-                        Imported imp = importElement(fc.getSelectedFile());
-                        if (imp != null) {
-                            VisualElement visualElement = new VisualElement(imp.description.getName()).setPos(new Vector(10, 10)).setShapeFactory(shapeFactory);
-                            elementState.enter();
-                            circuitComponent.setPartToInsert(visualElement);
-                            insertHistory.add(imp.insertAction);
-                        }
-                    } catch (IOException e1) {
-                        new ErrorMessage(Lang.get("msg_errorImportingModel")).addCause(e1).show();
-                    }
-                }
-            }
-        }.setToolTip(Lang.get("menu_import_tt")).createJMenuItem());
-
-        customMenu.add(new ToolTipAction(Lang.get("menu_refresh")) {
-            @Override
-            public void actionPerformed(ActionEvent e) {
-                removeCustomElements();
-            }
-        }.setToolTip(Lang.get("menu_refresh_tt")).createJMenuItem());
-
-
-        JMenu subMenu = null;
-        String lastPath = null;
-        for (ElementLibrary.ElementContainer elementContainer : library) {
-            String path = elementContainer.getTreePath();
-            if (!path.equals(lastPath)) {
-                subMenu = new JMenu(path);
-                parts.add(subMenu);
-                lastPath = path;
-            }
-            subMenu.add(new InsertAction(elementContainer.getDescription(), insertHistory, circuitComponent)
-                    .setToolTip(createToolTipText(elementContainer.getDescription().getName()))
-                    .createJMenuItem());
-        }
-
-        return parts;
     }
 
-    /**
+    @Override
-     * removes all custom elements
+    public void libraryChanged() {
-     */
+        componentsMenu.removeAll();
-    public void removeCustomElements() {
+
-        for (ImportedItem item : importedElements) {
+        for (LibraryNode n : library.getRoot())
-            library.removeElement(item.file);
+            addComponents(componentsMenu, n);
-            customMenu.remove(item.menuEntry);
+
+        insertHistory.removeCustom();
+
+        JMenuItem m = componentsMenu.getItem(componentsMenu.getItemCount() - 1);
+        if (m instanceof JMenu) {
+            ((JMenu) m).add(new ToolTipAction(Lang.get("menu_import")) {
+                @Override
+                public void actionPerformed(ActionEvent e) {
+                    try {
+                        library.updateEntries();
+                    } catch (IOException ex) {
+                        SwingUtilities.invokeLater(new ErrorMessage(Lang.get("msg_errorImportingModel")).addCause(ex));
+                    }
+                }
+            }.setToolTip(Lang.get("menu_import_tt")).createJMenuItem());
+        }
+
+    }
+
+    private void addComponents(JMenu parts, LibraryNode node) {
+        if (node.isLeaf()) {
+            parts.add(new InsertAction(node, insertHistory, circuitComponent)
+                    .setToolTip(createToolTipText(node.getName()))
+                    .createJMenuItem());
+        } else {
+            JMenu subMenu = new JMenu(node.getName());
+            for (LibraryNode child : node)
+                addComponents(subMenu, child);
+            parts.add(subMenu);
         }
     }
 
@@ -138,232 +106,50 @@ public class LibrarySelector implements ElementNotFoundNotification {
         return StringUtils.textToHTML(Lang.getNull("elem_" + elementName + "_tt"));
     }
 
-    /**
+    final class InsertAction extends ToolTipAction {
-     * sets the file path which is used to load missing nested elements
+        private final LibraryNode node;
-     *
-     * @param filePath the file path
-     */
-    public void setFilePath(File filePath) {
-        treeFileMap = null;
-        this.filePath = filePath;
-    }
-
-    @Override
-    public ElementTypeDescription elementNotFound(File file) throws IOException {
-        // check if there is a file with the given name in the current directory
-        // if so, load this file!
-        File primary = new File(filePath, file.getName());
-        if (primary.exists())
-            file = primary;
-
-        // check if there is a file with the given name below the current directory
-        // if so, load this file!
-        File f = getFileFromTree(file.getName());
-        if (f != null)
-            return importElement(f).description;
-
-        // than check if the exact given file exists
-        if (file.exists())
-            return importElement(file).description;
-
-        // could not find the given file
-        throw new IOException(Lang.get("err_couldNotFindIncludedFile_N0", file));
-    }
-
-    private File getFileFromTree(String name) throws IOException {
-        if (treeFileMap == null) {
-            treeFileMap = new HashMap<>();
-            populateTreeFileMap(treeFileMap, filePath);
-        } else {
-            if (!treeFileMap.containsKey(name)) {                 // if file not in map rescan folder
-                treeFileMap.clear();
-                populateTreeFileMap(treeFileMap, filePath);
-            }
-        }
-        return treeFileMap.get(name);
-    }
-
-    private void populateTreeFileMap(HashMap<String, File> map, File path) throws IOException {
-        File[] list = path.listFiles();
-        if (list != null) {
-            for (File f : list) {
-                final String name = f.getName();
-                if (f.isFile() && name.endsWith(".dig")) {
-                    if (map.containsKey(name))
-                        throw new IOException(Lang.get("err_file_N0_ExistsTwiceBelow_N1", name, filePath));
-                    map.put(name, f);
-                }
-                if (f.isDirectory())
-                    populateTreeFileMap(map, f);
-            }
-        }
-    }
-
-    private static String getActionName(ElementTypeDescription typeDescription) {
-        if (typeDescription instanceof ElementTypeDescriptionCustom)
-            return typeDescription.getShortName();
-        else
-            return typeDescription.getTranslatedName();
-    }
-
-    private final class InsertAction extends ToolTipAction {
-
-        private final String name;
         private final InsertHistory insertHistory;
         private final CircuitComponent circuitComponent;
 
-        private InsertAction(ElementTypeDescription typeDescription, InsertHistory insertHistory, CircuitComponent circuitComponent) {
+        private InsertAction(LibraryNode node, InsertHistory insertHistory, CircuitComponent circuitComponent) {
-            super(getActionName(typeDescription), new VisualElement(typeDescription.getName()).setShapeFactory(shapeFactory).createIcon(75));
+            super(node.getTranslatedName(), createIcon(node, shapeFactory));
-            this.name = typeDescription.getName();
+            this.node = node;
             this.insertHistory = insertHistory;
             this.circuitComponent = circuitComponent;
         }
 
-
         @Override
         public void actionPerformed(ActionEvent e) {
-            VisualElement visualElement = new VisualElement(name).setPos(new Vector(10, 10)).setShapeFactory(shapeFactory);
+            VisualElement visualElement = new VisualElement(node.getName()).setPos(new Vector(10, 10)).setShapeFactory(shapeFactory);
             elementState.enter();
             circuitComponent.setPartToInsert(visualElement);
+            if (getIcon() == null) {
+                try {
+                    node.getDescription();
+                    setIcon(createIcon(node, shapeFactory));
+                } catch (IOException ex) {
+                    SwingUtilities.invokeLater(new ErrorMessage(Lang.get("msg_errorImportingModel")).addCause(ex));
+                }
+            }
             insertHistory.add(this);
         }
-    }
 
-    private Imported importElement(File file) throws IOException {
+        public boolean isCustom() {
-        try {
+            return node.getDescriptionOrNull() instanceof ElementLibrary.ElementTypeDescriptionCustom;
-            LOGGER.debug("load element " + file);
-            Circuit circuit = Circuit.loadCircuit(file, shapeFactory);
-            ElementTypeDescriptionCustom description =
-                    new ElementTypeDescriptionCustom(file,
-                            attributes -> new CustomElement(circuit, library, file),
-                            circuit.getAttributes(), circuit.getInputNames());
-            description.setShortName(createShortName(file));
-            library.addDescription(description, file);
-
-            InsertAction insertAction = new InsertAction(description, insertHistory, circuitComponent);
-            String descriptionText = circuit.getAttributes().get(Keys.DESCRIPTION);
-            if (descriptionText != null && descriptionText.length() > 0) {
-                insertAction.setToolTip(StringUtils.textToHTML(descriptionText));
-                description.setDescription(descriptionText);
-            }
-
-            JMenuItem menuEntry = insertAction.createJMenuItem();
-            ImportedItem item = findImportedItem(file);
-            if (item != null) {
-                if (customMenu != null) {
-                    customMenu.remove(item.menuEntry);
-                }
-                importedElements.remove(item);
-            }
-            importedElements.add(new ImportedItem(file, menuEntry));
-            if (customMenu != null)
-                customMenu.add(menuEntry);
-            return new Imported(description, insertAction);
-        } catch (PinException e) {
-            throw new IOException(e);
         }
     }
 
-    private ImportedItem findImportedItem(File file) {
+    private static ImageIcon createIcon(LibraryNode node, ShapeFactory shapeFactory) {
-        for (ImportedItem i : importedElements) {
+        // don't load the description if only the icon is needed
-            if (i.file.equals(file))
+        // create action without an icon instead
-                return i;
+        if (node.isDescriptionLoaded()) {
+            try {
+                return new VisualElement(node.getDescription().getName()).setShapeFactory(shapeFactory).createIcon(75);
+            } catch (IOException ex) {
+                SwingUtilities.invokeLater(new ErrorMessage(Lang.get("msg_errorImportingModel")).addCause(ex));
+            }
         }
         return null;
     }
 
-    private String createShortName(File file) {
-        return createShortName(file.getName());
-    }
-
-    private String createShortName(String name) {
-        if (name.endsWith(".dig")) return name.substring(0, name.length() - 4);
-
-        String transName = Lang.getNull("elem_" + name);
-        if (transName == null)
-            return name;
-        else
-            return transName;
-    }
-
-    private final static class ImportedItem {
-        private final File file;
-        private final JMenuItem menuEntry;
-
-        private ImportedItem(File file, JMenuItem menuEntry) {
-            this.file = file;
-            this.menuEntry = menuEntry;
-        }
-    }
-
-    /**
-     * The description of a nested element.
-     * This is a complete circuit which is used as a element.
-     */
-    public static class ElementTypeDescriptionCustom extends ElementTypeDescription {
-        private final File file;
-        private final ElementAttributes attributes;
-        private String description;
-
-        /**
-         * Creates a new element
-         *
-         * @param file           the file which is loaded
-         * @param elementFactory a element factory which is used to create concrete elements if needed
-         * @param attributes     the attributes of the element
-         * @param inputNames     the names of the input signals
-         */
-        public ElementTypeDescriptionCustom(File file, ElementFactory elementFactory, ElementAttributes attributes, PinDescription... inputNames) {
-            super(file.getPath().replace('\\', '/'), elementFactory, inputNames);
-            this.file = file;
-            this.attributes = attributes;
-            setShortName(file.getName());
-            addAttribute(Keys.ROTATE);
-            addAttribute(Keys.LABEL);
-        }
-
-        /**
-         * Returns the filename
-         * the retuned file is opened if the user wants to modify the element
-         *
-         * @return the filename
-         */
-        public File getFile() {
-            return file;
-        }
-
-        /**
-         * @return the elements attributes
-         */
-        public ElementAttributes getAttributes() {
-            return attributes;
-        }
-
-        /**
-         * Sets a custom description for this field
-         *
-         * @param description the description
-         */
-        public void setDescription(String description) {
-            this.description = description;
-        }
-
-        @Override
-        public String getDescription(ElementAttributes elementAttributes) {
-            if (description != null)
-                return description;
-            else
-                return super.getDescription(elementAttributes);
-        }
-    }
-
-    private final static class Imported {
-        private final ElementTypeDescription description;
-        private final InsertAction insertAction;
-
-        private Imported(ElementTypeDescription description, InsertAction insertAction) {
-            this.description = description;
-            this.insertAction = insertAction;
-        }
-    }
 }

src/main/java/de/neemann/digital/gui/Main.java

@@ -127,7 +127,7 @@ public class Main extends JFrame implements ClosingWindowListener.ConfirmSave, E
     private State runModelMicroState;
 
     private Main() {
-        this(null, null, null);
+        this(null, null, null, null);
     }
 
     /**
@@ -137,8 +137,8 @@ public class Main extends JFrame implements ClosingWindowListener.ConfirmSave, E
      * @param fileToOpen    a file to open
      * @param savedListener a listener which is notified if the file is changed on disk
      */
-    public Main(Component parent, File fileToOpen, SavedListener savedListener) {
+    public Main(Component parent, File fileToOpen, SavedListener savedListener, ElementLibrary library) {
-        this(parent, fileToOpen, savedListener, null);
+        this(parent, fileToOpen, savedListener, library, null);
     }
 
     /**
@@ -148,7 +148,7 @@ public class Main extends JFrame implements ClosingWindowListener.ConfirmSave, E
      * @param circuit circuit to show
      */
     public Main(Component parent, Circuit circuit) {
-        this(parent, null, null, circuit);
+        this(parent, null, null, null, circuit);
     }
 
     /**
@@ -159,13 +159,14 @@ public class Main extends JFrame implements ClosingWindowListener.ConfirmSave, E
      * @param savedListener a listener which is notified if the file is changed on disk
      * @param circuit       circuit to show
      */
-    private Main(Component parent, File fileToOpen, SavedListener savedListener, Circuit circuit) {
+    private Main(Component parent, File fileToOpen, SavedListener savedListener, ElementLibrary parentsLibrary, Circuit circuit) {
         super(Lang.get("digital"));
         setDefaultCloseOperation(DO_NOTHING_ON_CLOSE);
         setIconImages(IconCreator.createImages("icon32.png", "icon64.png", "icon128.png"));
         this.savedListener = savedListener;
 
-        library = new ElementLibrary();
+        if (parentsLibrary == null) library = new ElementLibrary();
+        else this.library = parentsLibrary;
         shapeFactory = new ShapeFactory(library, Settings.getInstance().get(Keys.SETTINGS_IEEE_SHAPES));
 
         fileHistory = new FileHistory(this);
@@ -276,8 +277,8 @@ public class Main extends JFrame implements ClosingWindowListener.ConfirmSave, E
                 if (file == null)
                     file = new File(name);
                 try {
-                    LibrarySelector.ElementTypeDescriptionCustom description =
+                    ElementLibrary.ElementTypeDescriptionCustom description =
-                            new LibrarySelector.ElementTypeDescriptionCustom(file,
+                            new ElementLibrary.ElementTypeDescriptionCustom(file,
                                     attributes -> new CustomElement(circuit, library, filename),
                                     circuit.getAttributes(), circuit.getInputNames());
                     description.setShortName(name);
@@ -319,7 +320,6 @@ public class Main extends JFrame implements ClosingWindowListener.ConfirmSave, E
                     setFilename(null, true);
                     circuitComponent.setCircuit(new Circuit());
                     windowPosManager.closeAll();
-                    librarySelector.removeCustomElements();
                 }
             }
         }.setActive(normalMode);
@@ -330,7 +330,6 @@ public class Main extends JFrame implements ClosingWindowListener.ConfirmSave, E
                 if (ClosingWindowListener.checkForSave(Main.this, Main.this)) {
                     JFileChooser fc = getJFileChooser(lastFilename);
                     if (fc.showOpenDialog(Main.this) == JFileChooser.APPROVE_OPTION) {
-                        librarySelector.removeCustomElements();
                         loadFile(fc.getSelectedFile(), true);
                     }
                 }
@@ -342,7 +341,7 @@ public class Main extends JFrame implements ClosingWindowListener.ConfirmSave, E
             public void actionPerformed(ActionEvent e) {
                 JFileChooser fc = getJFileChooser(lastFilename);
                 if (fc.showOpenDialog(Main.this) == JFileChooser.APPROVE_OPTION) {
-                    Main m = new Main(Main.this, fc.getSelectedFile(), null);
+                    Main m = new Main(Main.this, fc.getSelectedFile(), null, null);
                     m.setLocationRelativeTo(Main.this);
                     m.setVisible(true);
                 }
@@ -399,7 +398,7 @@ public class Main extends JFrame implements ClosingWindowListener.ConfirmSave, E
     /**
      * Creates the edit menu
      *
-     * @param menuBar            the menu bar
+     * @param menuBar the menu bar
      */
     private void createEditMenu(JMenuBar menuBar) {
         JMenu edit = new JMenu(Lang.get("menu_edit"));
@@ -496,7 +495,8 @@ public class Main extends JFrame implements ClosingWindowListener.ConfirmSave, E
 
     /**
      * Creates the start menu
-     *  @param menuBar the menu bar
+     *
+     * @param menuBar the menu bar
      * @param toolBar the tool bar
      */
     private void createStartMenu(JMenuBar menuBar, JToolBar toolBar) {
@@ -820,14 +820,13 @@ public class Main extends JFrame implements ClosingWindowListener.ConfirmSave, E
     @Override
     public void open(File file) {
         if (ClosingWindowListener.checkForSave(Main.this, Main.this)) {
-            librarySelector.removeCustomElements();
             loadFile(file, true);
         }
     }
 
     private void loadFile(File filename, boolean toPrefs) {
         try {
-            librarySelector.setFilePath(filename.getParentFile());
+            library.setFilePath(filename.getParentFile());
             Circuit circ = Circuit.loadCircuit(filename, shapeFactory);
             circuitComponent.setCircuit(circ);
             stoppedState.enter();
@@ -855,15 +854,21 @@ public class Main extends JFrame implements ClosingWindowListener.ConfirmSave, E
     }
 
     private void setFilename(File filename, boolean toPrefs) {
-        this.filename = filename;
+        try {
-        if (filename != null) {
+            this.filename = filename;
-            this.lastFilename = filename;
+            if (filename != null) {
-            librarySelector.setFilePath(filename.getParentFile());
+                this.lastFilename = filename;
-            if (toPrefs)
+                library.setFilePath(filename.getParentFile());
-                fileHistory.add(filename);
+                if (toPrefs)
-            setTitle(filename + " - " + Lang.get("digital"));
+                    fileHistory.add(filename);
-        } else
+                setTitle(filename + " - " + Lang.get("digital"));
-            setTitle(Lang.get("digital"));
+            } else {
+                library.setFilePath(null);
+                setTitle(Lang.get("digital"));
+            }
+        } catch (IOException e) {
+            new ErrorMessage(Lang.get("msg_errorReadingFile")).addCause(e).show(this);
+        }
     }
 
     /**

src/main/java/de/neemann/digital/gui/components/CircuitComponent.java

@@ -16,7 +16,6 @@ import de.neemann.digital.draw.library.ElementLibrary;
 import de.neemann.digital.draw.library.ElementNotFoundException;
 import de.neemann.digital.draw.shapes.Drawable;
 import de.neemann.digital.draw.shapes.ShapeFactory;
-import de.neemann.digital.gui.LibrarySelector;
 import de.neemann.digital.gui.Main;
 import de.neemann.digital.gui.SavedListener;
 import de.neemann.digital.gui.sync.NoSync;
@@ -562,20 +561,20 @@ public class CircuitComponent extends JComponent implements Circuit.ChangedListe
                 Point p = new Point(e.getX(), e.getY());
                 SwingUtilities.convertPointToScreen(p, CircuitComponent.this);
                 AttributeDialog attributeDialog = new AttributeDialog(this, p, list, vp.getElementAttributes());
-                if (elementType instanceof LibrarySelector.ElementTypeDescriptionCustom) {
+                if (elementType instanceof ElementLibrary.ElementTypeDescriptionCustom) {
                     attributeDialog.addButton(Lang.get("attr_openCircuitLabel"), new ToolTipAction(Lang.get("attr_openCircuit")) {
                         @Override
                         public void actionPerformed(ActionEvent e) {
                             attributeDialog.dispose();
                             SwingUtilities.invokeLater(() -> new Main(CircuitComponent.this,
-                                    ((LibrarySelector.ElementTypeDescriptionCustom) elementType).getFile(),
+                                    ((ElementLibrary.ElementTypeDescriptionCustom) elementType).getFile(),
                                     filename -> {
                                         if (parentsSavedListener != null)
                                             parentsSavedListener.saved(filename);
                                         library.removeElement(filename);
                                         circuit.clearState();
                                         hasChanged();
-                                    }).setVisible(true));
+                                    }, library).setVisible(true));
                         }
                     }.setToolTip(Lang.get("attr_openCircuit_tt")));
                 }

src/main/java/de/neemann/gui/ToolTipAction.java

@@ -31,6 +31,23 @@ public abstract class ToolTipAction extends AbstractAction {
         this.icon = icon;
     }
 
+    /**
+     * sets the icon
+     *
+     * @param icon the icon to set
+     */
+    public void setIcon(Icon icon) {
+        putValue("SmallIcon", icon);
+        this.icon = icon;
+    }
+
+    /**
+     * @return the icon
+     */
+    public Icon getIcon() {
+        return icon;
+    }
+
     /**
      * Sets the tool tip text
      *

src/main/resources/lang/lang_de.xml

@@ -584,8 +584,8 @@ Es sind nur {1} Variablen erlaubt, es wurden jedoch {2} gefunden.</string>
     <string name="menu_fast_tt">Führt die Schaltung aus, bis ein Stopsignal über ein BRK-Element detektiert wird.</string>
     <string name="menu_file">Datei</string>
     <string name="menu_help">Hilfe</string>
-    <string name="menu_import">Importieren</string>
+    <string name="menu_import">Aktualisieren</string>
-    <string name="menu_import_tt">Importiert eine Schaltung als verwendbares Bauteil</string>
+    <string name="menu_import_tt">Aktualisieren des Bauteile Menüs.</string>
     <string name="menu_maximize">Einpassen</string>
     <string name="menu_micro">Gatterschrittmodus</string>
     <string name="menu_micro_tt">Startet die Schaltung im Gatterschrittmodus</string>

src/main/resources/lang/lang_en.xml

@@ -571,8 +571,8 @@ allowed are {1} variables but {2} are found.</string>
     <string name="menu_fast_tt">Runs the circuit until a break is detected by the BRK component.</string>
     <string name="menu_file">File</string>
     <string name="menu_help">Help</string>
-    <string name="menu_import">Import</string>
+    <string name="menu_import">Update</string>
-    <string name="menu_import_tt">Imports a circuit as a usable component!</string>
+    <string name="menu_import_tt">Updates the components menu!</string>
     <string name="menu_maximize">Fit to window</string>
     <string name="menu_micro">Single gate stepping</string>
     <string name="menu_micro_tt">Runs the circuit in single gate step mode</string>

src/test/java/de/neemann/digital/integration/TestNesting.java

@@ -64,8 +64,7 @@ public class TestNesting extends TestCase {
 
     private TestExecuter createTestExecuterForNesting(String file) throws IOException, NodeException, PinException, ElementNotFoundException {
         ElementLibrary library = new ElementLibrary();
-        LibrarySelector librarySelector = new LibrarySelector(library, new ShapeFactory(library), null);
+        library.setFilePath(new File(Resources.getRoot(), "dig"));
-        librarySelector.setFilePath(new File(Resources.getRoot(), "dig"));
         return TestExecuter.createFromFile(file, library);
     }
 

src/test/java/de/neemann/digital/integration/ToBreakRunner.java

@@ -70,10 +70,9 @@ public class ToBreakRunner {
 
     private ToBreakRunner(File filename, boolean doInit) throws IOException, PinException, NodeException, ElementNotFoundException {
         library = new ElementLibrary();
+        library.setFilePath(filename.getParentFile());
         ShapeFactory shapeFactory = new ShapeFactory(library);
         circuit = Circuit.loadCircuit(filename, shapeFactory);
-        LibrarySelector librarySelector = new LibrarySelector(library, shapeFactory, null);
-        librarySelector.setFilePath(filename.getParentFile());
 
         ModelCreator md = new ModelCreator(circuit, library);
         model = md.createModel(false);

src/test/java/de/neemann/digital/lang/TestElemConsistence.java

@@ -23,6 +23,7 @@ public class TestElemConsistence extends TestCase {
      * @throws NodeException
      */
     public void testConsistence() throws NodeException, PinException {
+        /*
         ElementLibrary library = new ElementLibrary();
         for (ElementLibrary.ElementContainer e : library) {
             ElementTypeDescription etd = e.getDescription();
@@ -37,7 +38,7 @@ public class TestElemConsistence extends TestCase {
                 checkPins(key, etd.getInputDescription(new ElementAttributes()));
                 checkPins(key, etd.getOutputDescriptions(new ElementAttributes()));
             }
-        }
+        }*/ fail();
     }
 
     private void checkPins(String key, PinDescriptions pins) {