1 files changed, 57 insertions, 0 deletions
diff --git a/plugins/org.eclipse.xpand/src/org/eclipse/xpand2/output/BlankLineSkippingOutput.java b/plugins/org.eclipse.xpand/src/org/eclipse/xpand2/output/BlankLineSkippingOutput.java
new file mode 100644
index 00000000..0cbf88f4
--- /dev/null
+++ b/plugins/org.eclipse.xpand/src/org/eclipse/xpand2/output/BlankLineSkippingOutput.java
@@ -0,0 +1,57 @@
+package org.eclipse.xpand2.output;
+
+import org.eclipse.internal.xpand2.ast.TextStatement;
+import org.eclipse.internal.xtend.expression.ast.SyntaxElement;
+import org.eclipse.xpand2.XpandExecutionContext;
+
+
+/**
+ * This output implementation avoids writing of unnecessary blank lines.  
+ * @author Karsten Thoms
+ * @since 4.1.2
+ */
+public class BlankLineSkippingOutput extends OutputImpl {
+    private final static char NEWLINE = '\n';
+    private StringBuffer buffer = null;
+    private boolean evaluateLine = false;
+    public void write(final String bytes) {
+        if (current() != null) {
+        	int idxNL = bytes.indexOf(NEWLINE);
+        	if (buffer==null && idxNL>=0) {
+        		buffer = new StringBuffer();
+        		((StringBuffer) current().getBuffer()).append(bytes.substring(0, idxNL));
+        		if (idxNL<bytes.length()) buffer.append(bytes.substring(idxNL));
+        	} else if (buffer!=null && idxNL>=0) {
+        		buffer.append(bytes.substring(0, idxNL));
+        		if (evaluateLine && !buffer.toString().trim().equals("")) {
+        		    ((StringBuffer) current().getBuffer()).append (buffer.toString());
+        		}
+        		buffer = null;
+        		evaluateLine = false;
+        		if (idxNL<bytes.length()) write(bytes.substring(idxNL));
+        	} else if (buffer!=null) {
+        		buffer.append(bytes);
+        	} else {
+        	    ((StringBuffer) current().getBuffer()).append(bytes);
+            }
+        }
+    }
+
+    public void closeFile() {
+    	if (buffer!=null && current()!=null) {
+    	    ((StringBuffer) current().getBuffer()).append(buffer);
+    		buffer=null;
+    	}
+        super.closeFile();
+    }
+
+	@Override
+	public void pushStatement(SyntaxElement stmt, XpandExecutionContext ctx) {
+		if (buffer!=null && !(stmt instanceof TextStatement)) {
+			evaluateLine = true;
+		}
+		super.pushStatement(stmt, ctx);
+	}
+    
+    
+}