import javafx.application.Application;
import javafx.geometry.Side;
import javafx.scene.control.Tab;
import javafx.scene.control.TabPane;
import javafx.scene.control.TextArea;
import javafx.scene.control.TabPane.TabClosingPolicy;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.HBox;
import javafx.scene.Scene;
import javafx.stage.Stage;

import java.io.IOException;
import java.util.Calendar;
import java.util.Locale;
import java.util.Map;
import java.util.TreeMap;

public class TabTest extends Application
{ 
private final Calendar cal = Calendar.getInstance(); 

public static void main(String[] args) 
{ 
launch(args); 
} 

@Override 
public void start(Stage primaryStage) throws IOException 
{ 
HBox box = new HBox( createMonthTabs(), createDayTabs() ); 
TextArea text = new TextArea( "Selecting a tab causes it to scroll up !? Selecting from a different set resets the other." ); 
text.setWrapText( true ); 

BorderPane bp = new BorderPane( text ); 
bp.setLeft( box ); 

primaryStage.setTitle( getClass().getSimpleName() ); 
primaryStage.setScene( new Scene( bp, 200, 800 ) ); 
primaryStage.centerOnScreen(); 
primaryStage.show(); 
} 

private TabPane createMonthTabs() 
{ 
Map<String/* month name */, Integer/* month## */> mthMap;	// Unordered 
TreeMap<Integer/* month## */, String/* month name */> mthOrder = new TreeMap<>();	// Ordered 

mthMap = cal.getDisplayNames( Calendar.MONTH, Calendar.SHORT, Locale.getDefault() );	// Unordered months 

for ( Map.Entry<String, Integer> mthEntry : mthMap.entrySet() ) 
{ 
mthOrder.put( mthEntry.getValue(), mthEntry.getKey() );	// Ordered months 
} 

TabPane mthTabs = new TabPane(); 

for ( String mthName : mthOrder.values() ) 
{ 
mthTabs.getTabs().add( new Tab( mthName ) );	// Populate tabs 
} 

mthTabs.getSelectionModel().select( cal.get( Calendar.MONTH ) ); 
mthTabs.setTabClosingPolicy( TabClosingPolicy.UNAVAILABLE ); 
mthTabs.setSide( Side.LEFT ); 

return mthTabs; 
} 

private TabPane createDayTabs() 
{ 
TabPane dayTabs = new TabPane(); 

for ( int day = 1; day <= cal.getActualMaximum( Calendar.DAY_OF_MONTH ); day++ ) 
{ 
dayTabs.getTabs().add( new Tab( "" + day ) ); 
} 

dayTabs.getSelectionModel().select( cal.get( Calendar.DAY_OF_MONTH ) - 1 ); 
dayTabs.setTabClosingPolicy( TabClosingPolicy.UNAVAILABLE ); 
dayTabs.setSide( Side.RIGHT ); 

return dayTabs; 
} 
}