adds a not connected symbol

src/main/java/de/neemann/digital/core/io/NotConnected.java

@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 2016 Helmut Neemann
+ * Use of this source code is governed by the GPL v3 license
+ * that can be found in the LICENSE file.
+ */
+package de.neemann.digital.core.io;
+
+import de.neemann.digital.core.Model;
+import de.neemann.digital.core.NodeException;
+import de.neemann.digital.core.ObservableValue;
+import de.neemann.digital.core.ObservableValues;
+import de.neemann.digital.core.element.Element;
+import de.neemann.digital.core.element.ElementAttributes;
+import de.neemann.digital.core.element.ElementTypeDescription;
+import de.neemann.digital.core.element.Keys;
+import de.neemann.digital.lang.Lang;
+
+/**
+ * A constant
+ */
+public class NotConnected implements Element {
+
+    /**
+     * The Constant description
+     */
+    public static final ElementTypeDescription DESCRIPTION = new ElementTypeDescription(NotConnected.class)
+            .addAttribute(Keys.BITS);
+
+    private final ObservableValue output;
+
+    /**
+     * Creates a new instance
+     *
+     * @param attributes the attributes
+     */
+    public NotConnected(ElementAttributes attributes) {
+        output = new ObservableValue("out", attributes.get(Keys.BITS)).setPinDescription(DESCRIPTION);
+        output.setToHighZ();
+        output.setConstant();
+    }
+
+    @Override
+    public void setInputs(ObservableValues inputs) throws NodeException {
+        throw new NodeException(Lang.get("err_noInputsAvailable"));
+    }
+
+    @Override
+    public ObservableValues getOutputs() {
+        return output.asList();
+    }
+
+    @Override
+    public void registerNodes(Model model) {
+    }
+}

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

@@ -162,7 +162,8 @@ public class ElementLibrary implements Iterable<ElementLibrary.ElementContainer>
                         .add(DriverInvSel.DESCRIPTION)
                         .add(Delay.DESCRIPTION)
                         .add(PullUp.DESCRIPTION)
-                        .add(PullDown.DESCRIPTION))
+                        .add(PullDown.DESCRIPTION)
+                        .add(NotConnected.DESCRIPTION))
                 .add(new LibraryNode(Lang.get("lib_mux"))
                         .add(Multiplexer.DESCRIPTION)
                         .add(Demultiplexer.DESCRIPTION)

src/main/java/de/neemann/digital/draw/model/Net.java

@@ -186,6 +186,14 @@ public class Net {
                 value = new DataBus(this, m, outputs).getReadableOutput();
         }
 
+        if (outputs.size() > 1) {
+            for (Pin o : outputs) {
+                ObservableValue ov = o.getValue();
+                if (ov.isConstant() && ov.isHighZ())
+                    throw new PinException(Lang.get("err_notConnectedNotAllowed", o), this);
+            }
+        }
+
         if (value == null)
             throw new PinException(Lang.get("err_output_N_notDefined", outputs.get(0)), this);
 

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

@@ -0,0 +1,53 @@
+/*
+ * Copyright (c) 2016 Helmut Neemann
+ * Use of this source code is governed by the GPL v3 license
+ * that can be found in the LICENSE file.
+ */
+package de.neemann.digital.draw.shapes;
+
+import de.neemann.digital.core.element.ElementAttributes;
+import de.neemann.digital.core.element.PinDescriptions;
+import de.neemann.digital.draw.elements.IOState;
+import de.neemann.digital.draw.elements.Pin;
+import de.neemann.digital.draw.elements.Pins;
+import de.neemann.digital.draw.graphics.Graphic;
+import de.neemann.digital.draw.graphics.Style;
+import de.neemann.digital.draw.graphics.Vector;
+
+import static de.neemann.digital.draw.shapes.GenericShape.SIZE2;
+
+/**
+ * The ground shape
+ */
+public class NotConnectedShape implements Shape {
+
+    private final PinDescriptions outputs;
+
+    /**
+     * Creates a new instance
+     *
+     * @param attr    the attributes
+     * @param inputs  the inputs
+     * @param outputs the outputs
+     */
+    public NotConnectedShape(ElementAttributes attr, PinDescriptions inputs, PinDescriptions outputs) {
+        this.outputs = outputs;
+    }
+
+    @Override
+    public Pins getPins() {
+        return new Pins().add(new Pin(new Vector(0, 0), outputs.get(0)));
+    }
+
+    @Override
+    public Interactor applyStateMonitor(IOState ioState) {
+        return null;
+    }
+
+    @Override
+    public void drawTo(Graphic graphic, Style heighLight) {
+        int rad = SIZE2 / 5 * 3;
+        graphic.drawLine(new Vector(-rad, -rad), new Vector(rad, rad), Style.NORMAL);
+        graphic.drawLine(new Vector(-rad, rad), new Vector(rad, -rad), Style.NORMAL);
+    }
+}

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

@@ -105,6 +105,7 @@ public final class ShapeFactory {
         map.put(Const.DESCRIPTION.getName(), ConstShape::new);
         map.put(Ground.DESCRIPTION.getName(), GroundShape::new);
         map.put(VDD.DESCRIPTION.getName(), VDDShape::new);
+        map.put(NotConnected.DESCRIPTION.getName(), NotConnectedShape::new);
         map.put(Out.DESCRIPTION.getName(), OutputShape::new);
         map.put(Out.LEDDESCRIPTION.getName(), LEDShape::new);
         map.put(LightBulb.DESCRIPTION.getName(), LightBulbShape::new);

src/main/resources/lang/lang_de.xml

@@ -334,6 +334,10 @@
     <string name="elem_VDD">Betriebsspannung</string>
     <string name="elem_VDD_tt">Anschluss zur Betriebsspannung. Gibt immer Eins aus.</string>
     <string name="elem_VDD_pin_out">Dieser Ausgang gibt immer 1 aus.</string>
+    <string name="elem_NotConnected">Nicht Verbunden</string>
+    <string name="elem_NotConnected_tt">Kann verwendet werden, um eine Leitung auf High-Z zu legen.</string>
+    <string name="elem_NotConnected_pin_out">Dieser Ausgang gibt immer High-Z aus.</string>
+    <string name="err_notConnectedNotAllowed">Das Nicht-Verbunden Symbol ist hier nicht erlaubt!</string>
     <string name="elem_Const">Konstante</string>
     <string name="elem_Const_tt">Ein Element, welches einen konstanten Wert ausgibt. Die Konstante kann über den Attribute-Dialog festgelegt werden.</string>
     <string name="elem_Const_pin_out">Gibt den gesetzten Wert als Konstante aus.</string>

src/main/resources/lang/lang_en.xml

@@ -331,6 +331,10 @@
     <string name="elem_VDD">Supply voltage</string>
     <string name="elem_VDD_tt">A connection to the supply voltage. Output is always one.</string>
     <string name="elem_VDD_pin_out">This output always returns 1.</string>
+    <string name="elem_NotConnected">Not Connected</string>
+    <string name="elem_NotConnected_tt">Can be used to set a wire to High-Z.</string>
+    <string name="elem_NotConnected_pin_out">This output always outputs High-Z.</string>
+    <string name="err_notConnectedNotAllowed">The NotConnected symbol is not allowed here!</string>
     <string name="elem_Const">Constant value</string>
     <string name="elem_Const_tt">A component which returns a given value as a simple constant value. The value can be set in the attribute dialog.</string>
     <string name="elem_Const_pin_out">Returns the given value as a constant.</string>

src/test/resources/dig/backtrack/AllComponents.dig

@@ -663,6 +663,11 @@
       <elementAttributes/>
       <pos x="100" y="440"/>
     </visualElement>
+    <visualElement>
+      <elementName>NotConnected</elementName>
+      <elementAttributes/>
+      <pos x="120" y="620"/>
+    </visualElement>
   </visualElements>
   <wires>
     <wire>