saving JSON plus PNG preview

src/main/java/de/ph87/electro/Window.java

@@ -1,5 +1,6 @@
 package de.ph87.electro;
 
+import de.ph87.electro.circuit.CircuitIOService;
 import de.ph87.electro.circuit.CircuitPanel;
 import de.ph87.electro.sidebar.Sidebar;
 
@@ -17,7 +18,7 @@ public class Window extends JFrame {
     setExtendedState(MAXIMIZED_BOTH);
 
     final CircuitPanel circuitPanel = new CircuitPanel();
-    final Sidebar sidebar = new Sidebar(circuitPanel::newCircuit, circuitPanel::save);
+    final Sidebar sidebar = new Sidebar(circuitPanel::newCircuit, () -> CircuitIOService.save(circuitPanel.getCircuit()));
     final JSplitPane splitter = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT, sidebar, circuitPanel);
 
     sidebar.setRepaintCallback(circuitPanel::repaint);

src/main/java/de/ph87/electro/circuit/Circuit.java

@@ -9,11 +9,9 @@ import de.ph87.electro.circuit.wire.Wire;
 import de.ph87.electro.circuit.wire.WireDto;
 import lombok.Getter;
 import lombok.NonNull;
-import lombok.extern.slf4j.Slf4j;
+import lombok.Setter;
 
 import java.io.File;
-import java.io.FileOutputStream;
-import java.io.IOException;
 import java.time.ZonedDateTime;
 import java.time.format.DateTimeFormatter;
 import java.util.ArrayList;
@@ -21,9 +19,6 @@ import java.util.List;
 import java.util.Optional;
 import java.util.stream.Stream;
 
-import static de.ph87.electro.circuit.CircuitIOService.write;
-
-@Slf4j
 public class Circuit {
 
   @Getter
@@ -34,13 +29,19 @@ public class Circuit {
 
   private final List<Wire> wires = new ArrayList<>();
 
+  @Setter
+  @Getter
   private boolean dirty = false;
 
+  @Setter
+  @Getter
+  private File file = null;
+
   public Circuit() {
     this.created = ZonedDateTime.now().format(DateTimeFormatter.ISO_OFFSET_DATE_TIME);
   }
 
-  public Circuit(final CircuitDto dto) {
+  public Circuit(final File file, final CircuitDto dto) {
     created = dto.getCreated();
     for (PartDto partDto : dto.getParts()) {
       final Part part = Part.of(this, partDto);
@@ -96,22 +97,6 @@ public class Circuit {
     parts.forEach(Part::render);
   }
 
-  public void save() {
-    if (!dirty) {
-      return;
-    }
-    try {
-      final File file = new File("./data/%s.json".formatted(created));
-      if (file.getParentFile().mkdirs()) {
-        log.info("Directory created: {}", file.getParent());
-      }
-      write(this, new FileOutputStream(file));
-      dirty = false;
-    } catch (IOException e) {
-      log.error(e.toString());
-    }
-  }
-
   private void verifyFree(final Position position) {
     if (parts.stream().anyMatch(part -> part.getPosition().equals(position))) {
       throw new RuntimeException();
@@ -146,4 +131,11 @@ public class Circuit {
     return wires.stream().filter(wire -> wire.intersects(position)).findFirst();
   }
 
+  public File getPreviewFile() {
+    if (file == null) {
+      return null;
+    }
+    return new File(file.getAbsolutePath().replaceAll("\\.json$", ".png"));
+  }
+
 }

src/main/java/de/ph87/electro/circuit/CircuitIOService.java

@@ -1,21 +1,55 @@
 package de.ph87.electro.circuit;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
+import lombok.extern.slf4j.Slf4j;
 
-import java.io.IOException;
+import javax.imageio.ImageIO;
-import java.io.InputStream;
+import java.awt.image.BufferedImage;
-import java.io.OutputStream;
+import java.io.*;
 
+import static de.ph87.electro.circuit.CircuitPainter.paintCircuit;
+
+@Slf4j
 public class CircuitIOService {
 
   private static final ObjectMapper objectMapper = new ObjectMapper().findAndRegisterModules();
 
-  public static void write(final Circuit circuit, final OutputStream stream) throws IOException {
+  public static void save(final Circuit circuit) {
+    if (!circuit.isDirty()) {
+      return;
+    }
+    if (circuit.getFile() == null) {
+      circuit.setFile(new File("./data/%s.json".formatted(circuit.getCreated())));
+    }
+    try {
+      if (circuit.getFile().getParentFile().mkdirs()) {
+        log.info("Directory created: {}", circuit.getFile().getParent());
+      }
+      CircuitIOService.serialize(circuit, new FileOutputStream(circuit.getFile()));
+      circuit.setDirty(false);
+    } catch (IOException e) {
+      log.error(e.toString());
+    }
+
+    final BufferedImage img = paintCircuit(circuit, 1920, 1080);
+    try {
+      ImageIO.write(img, "PNG", circuit.getPreviewFile());
+    } catch (IOException e) {
+      log.error(e.toString());
+    }
+  }
+
+  public static Circuit load(final File file) throws IOException {
+    return load(null, new FileInputStream(file));
+  }
+
+  public static Circuit load(final File file, final InputStream stream) throws IOException {
+    final CircuitDto dto = objectMapper.readValue(stream, CircuitDto.class);
+    return new Circuit(file, dto);
+  }
+
+  public static void serialize(final Circuit circuit, final OutputStream stream) throws IOException {
     objectMapper.writeValue(stream, new CircuitDto(circuit));
   }
 
-  public static Circuit read(final InputStream stream) throws IOException {
-    return new Circuit(objectMapper.readValue(stream, CircuitDto.class));
-  }
-
 }

src/main/java/de/ph87/electro/circuit/CircuitPainter.java

@@ -0,0 +1,86 @@
+package de.ph87.electro.circuit;
+
+import de.ph87.electro.circuit.part.Part;
+import de.ph87.electro.circuit.part.junction.Junction;
+
+import java.awt.*;
+import java.awt.geom.Rectangle2D;
+import java.awt.image.BufferedImage;
+
+import static de.ph87.electro.CONFIG.*;
+
+public class CircuitPainter {
+
+  public static BufferedImage paintCircuit(final Circuit circuit, final int w, final int h) {
+    final BufferedImage img = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);
+    final Graphics2D g = img.createGraphics();
+    paintCircuit(circuit, g, w, h);
+    return img;
+  }
+
+  public static void paintCircuit(final Circuit circuit, final Graphics2D g, final int w, final int h) {
+    drawBack(g, w, h);
+    drawParts(circuit, g);
+    drawRaster(g, w, h);
+    drawWires(circuit, g);
+    drawVoltages(circuit, g);
+  }
+
+  private static void drawBack(final Graphics2D g, final int w, final int h) {
+    g.setColor(Color.white);
+    g.fillRect(0, 0, w, h);
+  }
+
+  private static void drawParts(final Circuit circuit, final Graphics2D g) {
+    circuit.streamParts().forEach(part -> part.paint(g));
+  }
+
+  private static void drawRaster(final Graphics2D g, final int w, final int h) {
+    g.setStroke(RASTER_STROKE);
+    g.setColor(RASTER_COLOR);
+    for (int x = 0; x < w; x += RASTER) {
+      g.drawLine(x, 0, x, h);
+    }
+    for (int y = 0; y < h; y += RASTER) {
+      g.drawLine(0, y, w, y);
+    }
+  }
+
+  private static void drawWires(final Circuit circuit, final Graphics2D g) {
+    circuit.streamWires().forEach(wire -> wire.draw(g));
+  }
+
+  private static void drawVoltages(final Circuit circuit, final Graphics2D g) {
+    if (!SHOW_JUNCTION_VOLTAGES && !SHOW_JUNCTION_NAMES) {
+      return;
+    }
+
+    g.setColor(Color.BLACK);
+    g.setFont(LABEL_FONT);
+    final int third = g.getFont().getSize() / 3;
+
+    for (Part part : circuit.getParts()) {
+      for (final Junction junction : part.getJunctions()) {
+        if (SHOW_JUNCTION_NAMES) {
+          int offsetY = third;
+          if (SHOW_JUNCTION_VOLTAGES) {
+            offsetY -= third;
+          }
+          final String string = junction.getName();
+          final Rectangle2D bounds = g.getFontMetrics().getStringBounds(string, g);
+          g.drawString(string, junction.getPosition().absolute.x - (int) (bounds.getWidth() / 2), junction.getPosition().absolute.y + offsetY);
+        }
+        if (SHOW_JUNCTION_VOLTAGES) {
+          int offsetY = third;
+          if (SHOW_JUNCTION_NAMES) {
+            offsetY += 2 * third;
+          }
+          final String string = "%.1fV".formatted(junction.getVoltage());
+          final Rectangle2D bounds = g.getFontMetrics().getStringBounds(string, g);
+          g.drawString(string, junction.getPosition().absolute.x - (int) (bounds.getWidth() / 2), junction.getPosition().absolute.y + offsetY);
+        }
+      }
+    }
+  }
+
+}

src/main/java/de/ph87/electro/circuit/CircuitPanel.java

@@ -1,7 +1,5 @@
 package de.ph87.electro.circuit;
 
-import de.ph87.electro.circuit.part.Part;
-import de.ph87.electro.circuit.part.junction.Junction;
 import de.ph87.electro.circuit.part.parts.Battery;
 import de.ph87.electro.circuit.part.parts.Light;
 import lombok.Getter;
@@ -9,9 +7,8 @@ import lombok.extern.slf4j.Slf4j;
 
 import javax.swing.*;
 import java.awt.*;
-import java.awt.geom.Rectangle2D;
 
-import static de.ph87.electro.CONFIG.*;
+import static de.ph87.electro.circuit.CircuitPainter.paintCircuit;
 import static de.ph87.electro.circuit.part.Position.RST;
 
 @Slf4j
@@ -34,81 +31,14 @@ public class CircuitPanel extends JPanel {
   @Override
   public void paint(final Graphics _g) {
     final Graphics2D g = (Graphics2D) _g;
-    final int w = getWidth();
+    paintCircuit(circuit, g, getWidth(), getHeight());
-    final int h = getHeight();
-    drawBack(g, w, h);
-    drawParts(g);
-    drawRaster(g, w, h);
-    drawWires(g);
-    drawVoltages(g);
     mouseAdapter.drawHover(g);
     mouseAdapter.drawDrag(g);
   }
 
-  private void drawBack(final Graphics2D g, final int w, final int h) {
-    g.setColor(Color.white);
-    g.fillRect(0, 0, w, h);
-  }
-
-  private void drawParts(final Graphics2D g) {
-    circuit.streamParts().forEach(part -> part.paint(g));
-  }
-
-  private void drawRaster(final Graphics2D g, final int w, final int h) {
-    g.setStroke(RASTER_STROKE);
-    g.setColor(RASTER_COLOR);
-    for (int x = 0; x < w; x += RASTER) {
-      g.drawLine(x, 0, x, h);
-    }
-    for (int y = 0; y < h; y += RASTER) {
-      g.drawLine(0, y, w, y);
-    }
-  }
-
-  private void drawWires(final Graphics2D g) {
-    circuit.streamWires().forEach(wire -> wire.draw(g));
-  }
-
-  private void drawVoltages(final Graphics2D g) {
-    if (!SHOW_JUNCTION_VOLTAGES && !SHOW_JUNCTION_NAMES) {
-      return;
-    }
-
-    g.setColor(Color.BLACK);
-    g.setFont(LABEL_FONT);
-    final int third = g.getFont().getSize() / 3;
-
-    for (Part part : circuit.getParts()) {
-      for (final Junction junction : part.getJunctions()) {
-        if (SHOW_JUNCTION_NAMES) {
-          int offsetY = third;
-          if (SHOW_JUNCTION_VOLTAGES) {
-            offsetY -= third;
-          }
-          final String string = junction.getName();
-          final Rectangle2D bounds = g.getFontMetrics().getStringBounds(string, g);
-          g.drawString(string, junction.getPosition().absolute.x - (int) (bounds.getWidth() / 2), junction.getPosition().absolute.y + offsetY);
-        }
-        if (SHOW_JUNCTION_VOLTAGES) {
-          int offsetY = third;
-          if (SHOW_JUNCTION_NAMES) {
-            offsetY += 2 * third;
-          }
-          final String string = "%.1fV".formatted(junction.getVoltage());
-          final Rectangle2D bounds = g.getFontMetrics().getStringBounds(string, g);
-          g.drawString(string, junction.getPosition().absolute.x - (int) (bounds.getWidth() / 2), junction.getPosition().absolute.y + offsetY);
-        }
-      }
-    }
-  }
-
   public void newCircuit() {
     circuit = new Circuit();
     repaint();
   }
 
-  public void save() {
-    circuit.save();
-  }
-
 }

src/test/java/de/ph87/electro/circuit/io/CircuitIOServiceTest.java

@@ -1,6 +1,7 @@
 package de.ph87.electro.circuit.io;
 
 import de.ph87.electro.circuit.Circuit;
+import de.ph87.electro.circuit.CircuitIOService;
 import de.ph87.electro.circuit.part.Part;
 import de.ph87.electro.circuit.part.junction.Junction;
 import de.ph87.electro.circuit.part.parts.Battery;
@@ -12,8 +13,7 @@ import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.nio.charset.StandardCharsets;
 
-import static de.ph87.electro.circuit.CircuitIOService.read;
+import static de.ph87.electro.circuit.CircuitIOService.serialize;
-import static de.ph87.electro.circuit.CircuitIOService.write;
 import static de.ph87.electro.circuit.part.Position.RST;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
@@ -31,12 +31,12 @@ class CircuitIOServiceTest {
 
   private void check(final Circuit original) throws IOException {
     final ByteArrayOutputStream output = new ByteArrayOutputStream();
-    write(original, output);
+    serialize(original, output);
 
     System.out.println(output.toString(StandardCharsets.UTF_8));
 
     final ByteArrayInputStream input = new ByteArrayInputStream(output.toByteArray());
-    final Circuit reloaded = read(input);
+    final Circuit reloaded = CircuitIOService.load(null, input);
 
     assertEquals(original.getCreated(), reloaded.getCreated());
     assertEquals(original.getPartCount(), reloaded.getPartCount());