Methoden, um vorhandene Formen gezielt abzufragen

src/schule/ngb/zm/shapes/ShapesLayer.java

@@ -2,7 +2,7 @@ package schule.ngb.zm.shapes;
 
 import schule.ngb.zm.Layer;
 
-import java.awt.*;
+import java.awt.Graphics2D;
 import java.util.LinkedList;
 
 public class ShapesLayer extends Layer {
@@ -21,14 +21,53 @@ public class ShapesLayer extends Layer {
 		shapes = new LinkedList<Shape>();
 	}
 
-	public void add( Shape... pFormen ) {
+	public Shape getShape( int index ) {
+		return shapes.get(index);
+	}
+
+	public <ST extends Shape> ST getShape( Class<ST> shapeClass ) {
+		for( Shape s : shapes ) {
+			if( shapeClass.isInstance(s) ) {
+				return (ST) s;
+			}
+		}
+		return null;
+	}
+
+	public java.util.List<Shape> getShapes() {
+		return shapes;
+	}
+
+	public <ST extends Shape> java.util.List<ST> getShapes( Class<ST> shapeClass ) {
+		java.util.List<ST> result = new LinkedList<>();
+		for( Shape s : shapes ) {
+			if( shapeClass.isInstance(s) ) {
+				result.add((ST) s);
+			}
+		}
+		return result;
+	}
+
+	public void add( Shape... shape ) {
 		synchronized( shapes ) {
-			for( Shape f : pFormen ) {
+			for( Shape f : shape ) {
 				shapes.add(f);
 			}
 		}
 	}
 
+	public void remove( Shape shape ) {
+		synchronized( shapes ) {
+			shapes.remove(shape);
+		}
+	}
+
+	public void removeAll() {
+		synchronized( shapes ) {
+			shapes.clear();
+		}
+	}
+
 	public void showAll() {
 		synchronized( shapes ) {
 			for( Shape pShape : shapes ) {
@@ -45,10 +84,6 @@ public class ShapesLayer extends Layer {
 		}
 	}
 
-	public java.util.List<Shape> getShapes() {
-		return shapes;
-	}
-
 	@Override
 	public void draw( Graphics2D pGraphics ) {
 		if( clearBeforeDraw ) {