no more string concatenation in graph text writer

libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/helpers/GraphTextWriter.java

@@ -130,6 +130,22 @@ public abstract class GraphTextWriter {
 
     public abstract GraphTextWriter appendWithData(String str, HighlightData data);
 
+    public GraphTextWriter append(char value) {
+        return append(Character.toString(value));
+    }
+
+    public GraphTextWriter append(int value) {
+        return append(Integer.toString(value));
+    }
+
+    public GraphTextWriter append(long value) {
+        return append(Long.toString(value));
+    }
+
+    public GraphTextWriter append(double value) {
+        return append(Double.toString(value));
+    }
+
     public abstract GraphTextWriter append(String str);
 
     public abstract GraphTextWriter append(String str, long offset);

libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/helpers/NulWriter.java

@@ -101,6 +101,24 @@ public class NulWriter extends GraphTextWriter {
         return this;
     }
 
+    @Override
+    public GraphTextWriter append(char value) {
+        stringAdded = true;
+        return this;
+    }
+
+    @Override
+    public GraphTextWriter append(int value) {
+        stringAdded = true;
+        return this;
+    }
+
+    @Override
+    public GraphTextWriter append(long value) {
+        stringAdded = true;
+        return this;
+    }
+
     @Override
     public NulWriter append(String str) {
         stringAdded = true;