drools-eclipse/org.drools.eclipse/src/main/java/org/drools/eclipse/editors/ZoomInAction2.java
public void setZoomManager(ZoomManager newManager) {

        if ( zoomManager != null ) {
            zoomManager.removeZoomListener( this );
        }

        zoomManager = newManager;

        if ( zoomManager != null ) {
            zoomManager.addZoomListener( this );
        }

    }
public void setZoomManager(ZoomManager newManager) {

        if ( zoomManager != null ) {
            zoomManager.removeZoomListener( this );
        }

        zoomManager = newManager;

        if ( zoomManager != null ) {
            zoomManager.addZoomListener( this );
        }

    }
Replaces existing zoomManager with the new one.

Implementation is null-safe.

@param newManager new zoom manager