remove empty lines when removing certain nodes

javaparser-core/src/main/java/com/github/javaparser/printer/lexicalpreservation/LexicalPreservingPrinter.java

@@ -256,7 +256,7 @@ public Iterator<TokenTextElement> tokensPreceeding(final Node node) {
         NodeText parentNodeText = getOrCreateNodeText(node.getParentNode().get());
         int index = parentNodeText.findChild(node);
         return new TextElementIteratorsFactory.CascadingIterator<>(
-                TextElementIteratorsFactory.reverseIterator(parentNodeText, index - 1),
+                TextElementIteratorsFactory.partialReverseIterator(parentNodeText, index - 1),
                 () -> tokensPreceeding(node.getParentNode().get()));
     }
 
@@ -311,6 +311,20 @@ private void updateTextBecauseOfRemovedChild(NodeList nodeList, int index, Optio
             }
         }
 
+        if (property.isInOwnLine()) {
+            for (Iterator<TokenTextElement> it = tokensPreceeding(child); it.hasNext();) {
+               // Removing preceeding whitespace tokens until we reach a newline
+               TokenTextElement tte = it.next();
+               if (tte.getTokenKind() != 1 && tte.getTokenKind() !=3) {
+                   break;
+               }
+               it.remove();
+               if (tte.getTokenKind() == 3) {
+                   break;
+               }
+            }
+        }
+
         textForNodes.get(parent).removeElementForChild(child);
     }
 

javaparser-core/src/main/java/com/github/javaparser/printer/lexicalpreservation/NodeText.java

@@ -256,4 +256,8 @@ public void removeAllBefore(Node child) {
             elements.remove(0);
         }
     }
+
+    public void removeElement(int index) {
+        elements.remove(index);
+    }
 }

javaparser-core/src/main/java/com/github/javaparser/printer/lexicalpreservation/TextElementIteratorsFactory.java

@@ -24,7 +24,6 @@
 import java.util.Iterator;
 import java.util.LinkedList;
 import java.util.List;
-import java.util.Optional;
 
 public class TextElementIteratorsFactory {
 
@@ -35,13 +34,15 @@ interface Provider<E> {
 
         private Provider<E> nextProvider;
         private Iterator<E> current;
+        private Iterator<E> next;
+        private boolean lastReturnedFromCurrent = false;
+        private boolean lastReturnedFromNext = false;
 
         public CascadingIterator(Iterator<E> current, Provider<E> nextProvider) {
             this.nextProvider = nextProvider;
             this.current = current;
         }
 
-        private Iterator<E> next;
 
         @Override
         public boolean hasNext() {
@@ -57,13 +58,30 @@ public boolean hasNext() {
         @Override
         public E next() {
             if (current.hasNext()) {
+                lastReturnedFromCurrent = true;
+                lastReturnedFromNext = false;
                 return current.next();
             }
             if (next == null) {
                 next = nextProvider.provide();
             }
+            lastReturnedFromCurrent = false;
+            lastReturnedFromNext = true;
             return next.next();
         }
+
+        @Override
+        public void remove() {
+            if (lastReturnedFromCurrent) {
+                current.remove();
+                return;
+            }
+            if (lastReturnedFromNext) {
+                next.remove();
+                return;
+            }
+            throw new IllegalArgumentException();
+        }
     }
 
     static class EmptyIterator<E> implements Iterator<E> {
@@ -96,6 +114,11 @@ public E next() {
             returned = true;
             return element;
         }
+
+        @Override
+        public void remove() {
+
+        }
     }
 
     static class ComposedIterator<E> implements Iterator<E> {
@@ -126,11 +149,22 @@ public E next() {
             }
             return elements.get(currIndex).next();
         }
+
+        @Override
+        public void remove() {
+            elements.get(currIndex).remove();
+        }
     }
 
-    public static Iterator<TokenTextElement> reverseIterator(TextElement textElement) {
+    private static Iterator<TokenTextElement> reverseIterator(NodeText nodeText, int index) {
+        TextElement textElement = nodeText.getTextElement(index);
         if (textElement instanceof TokenTextElement) {
-            return new SingleElementIterator<>((TokenTextElement)textElement);
+            return new SingleElementIterator<TokenTextElement>((TokenTextElement)textElement) {
+                @Override
+                public void remove() {
+                    nodeText.removeElement(index);
+                }
+            };
         } else if (textElement instanceof ChildTextElement) {
             ChildTextElement childTextElement = (ChildTextElement)textElement;
             NodeText textForChild = childTextElement.getNodeTextForWrappedNode();
@@ -141,13 +175,13 @@ public static Iterator<TokenTextElement> reverseIterator(TextElement textElement
     }
 
     public static Iterator<TokenTextElement> reverseIterator(NodeText nodeText) {
-        return reverseIterator(nodeText, nodeText.numberOfElements() - 1);
+        return partialReverseIterator(nodeText, nodeText.numberOfElements() - 1);
     }
 
-    public static Iterator<TokenTextElement> reverseIterator(NodeText nodeText, int fromIndex) {
+    public static Iterator<TokenTextElement> partialReverseIterator(NodeText nodeText, int fromIndex) {
         List<Iterator<TokenTextElement>> elements = new LinkedList<>();
         for (int i=fromIndex;i>=0;i--) {
-            elements.add(reverseIterator(nodeText.getTextElement(i)));
+            elements.add(reverseIterator(nodeText, i));
         }
         return new ComposedIterator<>(elements);
     }