diff --git a/hellocharts-library/src/lecho/lib/hellocharts/ChartCalculator.java b/hellocharts-library/src/lecho/lib/hellocharts/ChartCalculator.java
index 74e726d5..95774cd6 100644
--- a/hellocharts-library/src/lecho/lib/hellocharts/ChartCalculator.java
+++ b/hellocharts-library/src/lecho/lib/hellocharts/ChartCalculator.java
@@ -29,7 +29,11 @@ public class ChartCalculator {
 	protected float minViewportWidth;
 	protected float minViewportHeight;
 
-	private ViewportChangeListener viewportChangeListener = new DummyVieportChangeListener();
+	/**
+	 * Warning! Viewport listener is disabled for all charts beside preview charts to avoid addidtional method calls
+	 * during animations.
+	 */
+	protected ViewportChangeListener viewportChangeListener = new DummyVieportChangeListener();
 
 	/**
 	 * Calculates available width and height. Should be called when chart dimensions or chart data change.
@@ -74,8 +78,6 @@ public void constrainViewport(float left, float top, float right, float bottom)
 		currentViewport.top = Math.max(maxViewport.top, top);
 		currentViewport.bottom = Math.max(Utils.nextUpF(top), Math.min(maxViewport.bottom, bottom));
 		currentViewport.right = Math.max(Utils.nextUpF(left), Math.min(maxViewport.right, right));
-
-		viewportChangeListener.onViewportChanged(currentViewport);
 	}
 
 	/**
diff --git a/hellocharts-library/src/lecho/lib/hellocharts/DummyVieportChangeListener.java b/hellocharts-library/src/lecho/lib/hellocharts/DummyVieportChangeListener.java
index 29cf6f58..79af60ac 100644
--- a/hellocharts-library/src/lecho/lib/hellocharts/DummyVieportChangeListener.java
+++ b/hellocharts-library/src/lecho/lib/hellocharts/DummyVieportChangeListener.java
@@ -1,7 +1,6 @@
 package lecho.lib.hellocharts;
 
 import android.graphics.RectF;
-import android.util.Log;
 
 public class DummyVieportChangeListener implements ViewportChangeListener {
 
diff --git a/hellocharts-library/src/lecho/lib/hellocharts/PreviewChartCalculator.java b/hellocharts-library/src/lecho/lib/hellocharts/PreviewChartCalculator.java
index 7c07169a..b6f46b3d 100644
--- a/hellocharts-library/src/lecho/lib/hellocharts/PreviewChartCalculator.java
+++ b/hellocharts-library/src/lecho/lib/hellocharts/PreviewChartCalculator.java
@@ -22,4 +22,9 @@ public void setVisibleViewport(RectF visibleViewport) {
 		setMaxViewport(visibleViewport);
 	}
 
+	public void constrainViewport(float left, float top, float right, float bottom) {
+		super.constrainViewport(left, top, right, bottom);
+		viewportChangeListener.onViewportChanged(currentViewport);
+	}
+
 }
\ No newline at end of file