Drawing API cleanup

src/main/java/de/ph87/kindermalen/Environment.java

@@ -8,7 +8,7 @@ import lombok.Getter;
 @Getter
 public class Environment {
 
-  private final Publisher<Drawing> onNewDrawing = new Publisher<>();
+  private final Publisher<Drawing> onDrawingChange = new Publisher<>();
 
   private final Tools tools = new Tools();
 
@@ -19,8 +19,8 @@ public class Environment {
   }
 
   public void newDrawing() {
-    drawing = new Drawing(1920, 1080);
-    onNewDrawing.publish(drawing);
+    drawing = new Drawing(1920, 1080, onDrawingChange::publish);
+    onDrawingChange.publish(drawing);
   }
 
 }

src/main/java/de/ph87/kindermalen/drawing/Drawing.java

@@ -1,5 +1,6 @@
 package de.ph87.kindermalen.drawing;
 
+import lombok.Getter;
 import lombok.ToString;
 import lombok.extern.slf4j.Slf4j;
 
@@ -10,6 +11,7 @@ import java.io.File;
 import java.io.IOException;
 import java.time.ZonedDateTime;
 import java.time.format.DateTimeFormatter;
+import java.util.function.Consumer;
 
 @Slf4j
 @ToString
@@ -19,41 +21,37 @@ public class Drawing {
 
   public final int height;
 
+  private final Consumer<Drawing> onChange;
+
   public final ZonedDateTime created = ZonedDateTime.now();
 
+  @Getter
   @ToString.Exclude
-  private final Layer current;
+  private final Layer layer;
 
-  public Drawing(final int width, final int height) {
+  public Drawing(final int width, final int height, final Consumer<Drawing> onChange) {
     this.width = width;
     this.height = height;
-    current = new Layer(width, height);
+    this.onChange = onChange;
+    layer = new Layer(width, height, l -> onChange.accept(this));
     log.info("New Drawing: {}", this);
   }
 
-  public Graphics2D getGraphics() {
-    return (Graphics2D) current.getCurrent().getGraphics();
-  }
-
-  public void publish() {
-    current.publish();
-  }
-
   public void undo() {
-    current.undo();
+    layer.undo();
   }
 
   public void redo() {
-    current.redo();
+    layer.redo();
   }
 
   public void newRevision() {
-    current.newRevision();
+    layer.newRevision();
   }
 
   public void save(final File dir) throws IOException {
-    final int revision = current.getRevision();
-    final BufferedImage image = current.getCurrent();
+    final int revision = layer.getRevision();
+    final BufferedImage image = layer.getBuffer();
     final File subdir = new File(dir, created.format(DateTimeFormatter.ISO_LOCAL_DATE_TIME));
     final File file = new File(subdir, "%05d".formatted(revision) + ".png");
     if (subdir.mkdirs()) {
@@ -69,7 +67,7 @@ public class Drawing {
   }
 
   public Image getImage() {
-    return current.getCurrent();
+    return layer.getBuffer();
   }
 
 }

src/main/java/de/ph87/kindermalen/drawing/DrawingPanel.java

@@ -37,7 +37,7 @@ public class DrawingPanel extends MyComponent {
   public DrawingPanel(final Environment environment) {
     this.environment = environment;
     subscribe(environment.getTools().getOnSelect(), this::onToolSelect);
-    subscribe(environment.getOnNewDrawing(), drawing -> repaint());
+    subscribe(environment.getOnDrawingChange(), drawing -> repaint());
   }
 
   private void onToolSelect(final Tool tool) {

src/main/java/de/ph87/kindermalen/drawing/Layer.java

@@ -1,12 +1,13 @@
 package de.ph87.kindermalen.drawing;
 
-import de.ph87.kindermalen.util.Publisher;
 import lombok.Getter;
 import lombok.extern.slf4j.Slf4j;
 
+import java.awt.*;
 import java.awt.image.BufferedImage;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.function.Consumer;
 
 import static de.ph87.kindermalen.util.ImageHelper.COPY;
 
@@ -17,25 +18,25 @@ public class Layer {
 
   private final int height;
 
-  @Getter
-  private BufferedImage current;
+  private final Consumer<Layer> onChange;
 
   private List<BufferedImage> history = new ArrayList<>();
 
+  @Getter
+  private BufferedImage buffer;
+
   @Getter
   private int index = 0;
 
   @Getter
   private int revision = 0;
 
-  @Getter
-  private final Publisher<BufferedImage> onChange = new Publisher<>();
-
-  public Layer(final int width, final int height) {
+  public Layer(final int width, final int height, final Consumer<Layer> onChange) {
     this.width = width;
     this.height = height;
-    this.current = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
-    this.history.add(current);
+    this.onChange = onChange;
+    this.buffer = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
+    this.history.add(buffer);
   }
 
   public void newRevision() {
@@ -45,19 +46,19 @@ public class Layer {
       history = history.subList(0, keep);
       log.info("{} Revisions deleted", old - keep);
     }
-    current = COPY(current);
+    buffer = COPY(buffer);
     index = history.size();
     revision++;
-    history.add(current);
+    history.add(buffer);
     log.debug("Revision {} created", index);
   }
 
   public void undo() {
     if (index > 0) {
       index--;
-      current = history.get(index);
+      buffer = history.get(index);
       log.info("UNDO: Revision {} loaded", index);
-      publish();
+      onChange.accept(this);
     } else {
       log.warn("No UNDO steps left.");
     }
@@ -66,9 +67,9 @@ public class Layer {
   public void redo() {
     if (canRedo()) {
       index++;
-      current = history.get(index);
+      buffer = history.get(index);
       log.info("REDO: Revision {} loaded", index);
-      publish();
+      onChange.accept(this);
     } else {
       log.warn("No REDO steps left.");
     }
@@ -78,8 +79,10 @@ public class Layer {
     return index < history.size() - 1;
   }
 
-  public void publish() {
-    onChange.publish(current);
+  public void draw(final BufferedImage image, final int x, final int y) {
+    final Graphics2D g = (Graphics2D) buffer.getGraphics();
+    g.drawImage(image, x, y, null);
+    onChange.accept(this);
   }
 
 }

src/main/java/de/ph87/kindermalen/tools/tool/stamp/StampTool.java

@@ -96,8 +96,9 @@ public class StampTool extends Tool {
   }
 
   private void apply(final Drawing drawing, final Vector point) {
-    drawing.getGraphics().drawImage(prepared, point.intX() - prepared.getWidth() / 2, point.intY() - prepared.getHeight() / 2, null);
-    drawing.publish();
+    final int x = point.intX() - prepared.getWidth() / 2;
+    final int y = point.intY() - prepared.getHeight() / 2;
+    drawing.getLayer().draw(prepared, x, y);
   }
 
   @Override