added a export helper class

src/main/java/de/neemann/digital/draw/graphics/Export.java

@@ -0,0 +1,56 @@
+package de.neemann.digital.draw.graphics;
+
+import de.neemann.digital.draw.elements.Circuit;
+import de.neemann.digital.draw.graphics.linemerger.GraphicLineCollector;
+import de.neemann.digital.draw.graphics.linemerger.GraphicSkipLines;
+
+import java.io.Closeable;
+import java.io.IOException;
+import java.io.OutputStream;
+
+/**
+ * Helper to export graphics files
+ *
+ * @author hneemann
+ */
+public class Export {
+
+    private final Circuit circuit;
+    private final ExportFactory factory;
+
+    /**
+     * Creates a nw instance
+     *
+     * @param circuit the circuit to export
+     * @param factory the factory to create the graphics instance
+     */
+    public Export(Circuit circuit, ExportFactory factory) {
+        this.circuit = circuit;
+        this.factory = factory;
+    }
+
+    /**
+     * Export the file
+     *
+     * @param out stream to write the file to
+     * @throws IOException IOException
+     */
+    public void export(OutputStream out) throws IOException {
+        GraphicMinMax minMax = new GraphicMinMax();
+        circuit.drawTo(minMax);
+
+        Graphic gr = factory.create(out, minMax.getMin(), minMax.getMax());
+        try {
+
+            GraphicLineCollector glc = new GraphicLineCollector();
+            circuit.drawTo(glc);
+            glc.drawTo(gr);
+
+            circuit.drawTo(new GraphicSkipLines(gr));
+
+        } finally {
+            if (gr instanceof Closeable)
+                ((Closeable) gr).close();
+        }
+    }
+}

src/main/java/de/neemann/digital/draw/graphics/ExportFactory.java

@@ -0,0 +1,22 @@
+package de.neemann.digital.draw.graphics;
+
+import java.io.IOException;
+import java.io.OutputStream;
+
+/**
+ * Factory to create a {@link Graphic} instance suited to create a file.
+ *
+ * @author hneemann
+ */
+public interface ExportFactory {
+    /**
+     * Creates a {@link Graphic} instance
+     *
+     * @param out the stream to write the graphic to
+     * @param min upper right corner of the circuit
+     * @param max lower left corner of the circuit
+     * @return the {@link Graphic} instance to use
+     * @throws IOException IOException
+     */
+    Graphic create(OutputStream out, Vector min, Vector max) throws IOException;
+}

src/main/java/de/neemann/digital/draw/graphics/Exporter.java

@@ -1,22 +0,0 @@
-package de.neemann.digital.draw.graphics;
-
-import java.io.File;
-import java.io.IOException;
-
-/**
- * Factor to create a {@link Graphic} instance suited to create a file.
- *
- * @author hneemann
- */
-public interface Exporter {
-    /**
-     * Creates a {@link Graphic} instance
-     *
-     * @param file the filename to use
-     * @param min  upper right corner of the circuit
-     * @param max  lower left corner of the circuit
-     * @return the {@link Graphic} instance to use
-     * @throws IOException IOException
-     */
-    Graphic create(File file, Vector min, Vector max) throws IOException;
-}

src/main/java/de/neemann/digital/draw/graphics/GraphicSVG.java

@@ -15,13 +15,13 @@ public class GraphicSVG implements Graphic, Closeable {
     /**
      * Creates a new instance.
      *
-     * @param file the file
+     * @param out  the stream
      * @param min  upper left corner
      * @param max  lower right corner
      * @throws IOException IOException
      */
-    public GraphicSVG(File file, Vector min, Vector max) throws IOException {
+    public GraphicSVG(OutputStream out, Vector min, Vector max) throws IOException {
-        this(file, min, max, null, DEF_SCALE);
+        this(out, min, max, null, DEF_SCALE);
     }
 
     /**

src/main/java/de/neemann/digital/draw/graphics/GraphicSVGIndex.java

@@ -15,13 +15,13 @@ public class GraphicSVGIndex extends GraphicSVG {
     /**
      * Creates new instance
      *
-     * @param file the file
+     * @param out the file
      * @param min  upper left corner
      * @param max  lower right corner
      * @throws IOException IOException
      */
-    public GraphicSVGIndex(File file, Vector min, Vector max) throws IOException {
+    public GraphicSVGIndex(OutputStream out, Vector min, Vector max) throws IOException {
-        super(file, min, max);
+        super(out, min, max);
     }
 
     /**

src/main/java/de/neemann/digital/draw/graphics/GraphicSVGLaTeX.java

@@ -18,13 +18,13 @@ public class GraphicSVGLaTeX extends GraphicSVG {
     /**
      * Creates new instance
      *
-     * @param file the file
+     * @param out the file
      * @param min  upper left corner
      * @param max  lower right corner
      * @throws IOException IOException
      */
-    public GraphicSVGLaTeX(File file, Vector min, Vector max) throws IOException {
+    public GraphicSVGLaTeX(OutputStream out, Vector min, Vector max) throws IOException {
-        super(file, min, max);
+        super(out, min, max);
     }
 
     /**

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

@@ -10,8 +10,6 @@ import de.neemann.digital.draw.elements.Circuit;
 import de.neemann.digital.draw.elements.ElementOrder;
 import de.neemann.digital.draw.elements.PinException;
 import de.neemann.digital.draw.graphics.*;
-import de.neemann.digital.draw.graphics.linemerger.GraphicLineCollector;
-import de.neemann.digital.draw.graphics.linemerger.GraphicSkipLines;
 import de.neemann.digital.draw.library.ElementLibrary;
 import de.neemann.digital.draw.model.ModelDescription;
 import de.neemann.digital.draw.model.RealTimeClock;
@@ -31,7 +29,6 @@ import java.awt.*;
 import java.awt.event.ActionEvent;
 import java.awt.event.WindowAdapter;
 import java.awt.event.WindowEvent;
-import java.io.Closeable;
 import java.io.File;
 import java.io.FileOutputStream;
 import java.io.IOException;
@@ -198,8 +195,8 @@ public class Main extends JFrame implements ClosingWindowListener.ConfirmSave, E
         JMenu export = new JMenu(Lang.get("menu_export"));
         export.add(new ExportAction(Lang.get("menu_exportSVG"), "svg", GraphicSVGIndex::new));
         export.add(new ExportAction(Lang.get("menu_exportSVGLaTex"), "svg", GraphicSVGLaTeX::new));
-        export.add(new ExportAction(Lang.get("menu_exportPNGSmall"), "png", (file, min, max) -> GraphicsImage.create(new FileOutputStream(file), min, max, "PNG", 1)));
+        export.add(new ExportAction(Lang.get("menu_exportPNGSmall"), "png", (out, min, max) -> GraphicsImage.create(out, min, max, "PNG", 1)));
-        export.add(new ExportAction(Lang.get("menu_exportPNGLarge"), "png", (file, min, max) -> GraphicsImage.create(new FileOutputStream(file), min, max, "PNG", 2)));
+        export.add(new ExportAction(Lang.get("menu_exportPNGLarge"), "png", (out, min, max) -> GraphicsImage.create(out, min, max, "PNG", 2)));
 
         JMenu file = new JMenu(Lang.get("menu_file"));
         bar.add(file);
@@ -599,13 +596,13 @@ public class Main extends JFrame implements ClosingWindowListener.ConfirmSave, E
     private class ExportAction extends ToolTipAction {
         private final String name;
         private final String suffix;
-        private final Exporter exporter;
+        private final ExportFactory exportFactory;
 
-        ExportAction(String name, String suffix, Exporter exporter) {
+        ExportAction(String name, String suffix, ExportFactory exportFactory) {
             super(name);
             this.name = name;
             this.suffix = suffix;
-            this.exporter = exporter;
+            this.exportFactory = exportFactory;
         }
 
         @Override
@@ -621,21 +618,9 @@ public class Main extends JFrame implements ClosingWindowListener.ConfirmSave, E
             }
             fc.addChoosableFileFilter(new FileNameExtensionFilter(name, suffix));
             if (fc.showSaveDialog(Main.this) == JFileChooser.APPROVE_OPTION) {
-                Circuit circuit = circuitComponent.getCircuit();
-                GraphicMinMax minMax = new GraphicMinMax();
-                circuit.drawTo(minMax);
                 try {
-                    Graphic gr = null;
+                    new Export(circuitComponent.getCircuit(), exportFactory)
-                    try {
+                            .export(new FileOutputStream(fc.getSelectedFile()));
-                        GraphicLineCollector glc = new GraphicLineCollector();
-                        circuit.drawTo(glc);
-                        gr = exporter.create(fc.getSelectedFile(), minMax.getMin(), minMax.getMax());
-                        glc.drawTo(gr);
-                        circuit.drawTo(new GraphicSkipLines(gr));
-                    } finally {
-                        if (gr instanceof Closeable)
-                            ((Closeable) gr).close();
-                    }
                 } catch (IOException e1) {
                     new ErrorMessage(Lang.get("msg_errorWritingFile")).addCause(e1).show(Main.this);
                 }

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

@@ -4,14 +4,10 @@ import de.neemann.digital.core.NodeException;
 import de.neemann.digital.draw.elements.Circuit;
 import de.neemann.digital.draw.elements.PinException;
 import de.neemann.digital.draw.graphics.*;
-import de.neemann.digital.draw.graphics.linemerger.GraphicLineCollector;
-import de.neemann.digital.draw.graphics.linemerger.GraphicSkipLines;
 import junit.framework.TestCase;
 
 import java.io.ByteArrayOutputStream;
-import java.io.Closeable;
 import java.io.IOException;
-import java.io.OutputStream;
 
 /**
  * Only checks that something is written without an error
@@ -20,28 +16,10 @@ import java.io.OutputStream;
  */
 public class TestExport extends TestCase {
 
-    private interface Creator {
+    private static ByteArrayOutputStream export(String file, ExportFactory creator) throws NodeException, PinException, IOException {
-        Graphic create(OutputStream out, Vector min, Vector max) throws IOException;
-    }
-
-    private static ByteArrayOutputStream export(String file, Creator creator) throws NodeException, PinException, IOException {
         Circuit circuit = new ToBreakRunner(file).getCircuit();
-
-        GraphicMinMax minMax = new GraphicMinMax();
-        circuit.drawTo(minMax);
-
         ByteArrayOutputStream baos = new ByteArrayOutputStream();
-        Graphic gr = creator.create(baos, minMax.getMin(), minMax.getMax());
+        new Export(circuit, creator).export(baos);
-
-        GraphicLineCollector glc = new GraphicLineCollector();
-        circuit.drawTo(glc);
-        glc.drawTo(gr);
-
-        circuit.drawTo(new GraphicSkipLines(gr));
-
-        if (gr instanceof Closeable)
-            ((Closeable) gr).close();
-
         return baos;
     }