drools-eclipse/org.drools.eclipse/src/main/java/org/drools/eclipse/editors/DRLRuleEditorActionContributor.java
public void contributeToToolBar(IToolBarManager toolBarManager) {
        super.contributeToToolBar( toolBarManager );
        toolBarManager.add( new Separator() );
        String[] zoomStrings = new String[]{ZoomManager.FIT_ALL, ZoomManager.FIT_HEIGHT, ZoomManager.FIT_WIDTH};

        zitem = new ZoomComboContributionItem( getPage(),
                                               zoomStrings );
        zitem.setZoomManager( null );
        zitem.setVisible( false );

        zoomIn = new ZoomInAction2();
        zoomIn.setEnabled( false );

        zoomOut = new ZoomOutAction2();
        zoomOut.setEnabled( false );

        toolBarManager.add( zitem );
        toolBarManager.add( zoomIn );
        toolBarManager.add( zoomOut );

    }
public void contributeToToolBar(IToolBarManager toolBarManager) {
        super.contributeToToolBar( toolBarManager );
        toolBarManager.add( new Separator() );
        String[] zoomStrings = new String[]{ZoomManager.FIT_ALL, ZoomManager.FIT_HEIGHT, ZoomManager.FIT_WIDTH};

        zitem = new ZoomComboContributionItem( getPage(),
                                               zoomStrings );
        zitem.setZoomManager( null );
        zitem.setVisible( false );

        zoomIn = new ZoomInAction2();
        zoomIn.setEnabled( false );

        zoomOut = new ZoomOutAction2();
        zoomOut.setEnabled( false );

        toolBarManager.add( zitem );
        toolBarManager.add( zoomIn );
        toolBarManager.add( zoomOut );

    }
Adds Zoom-related contributions.

@see org.eclipse.ui.part.EditorActionBarContributor#contributeToToolBar(org.eclipse.jface.action.IToolBarManager)