i do my first game and already read alot about design strategie, programming style, design .. and so on theoretically it works perfect but in practice i dont know if i do thinks "right"

i have three classes my main which starts the view in this i do all my stuff -currently-

it holds an state variable, it has an onDraw method .. and so on

the third class is the game-thread while my game is running, in here are decisions -depending on my current state- what should be done

@Override
public void run() {
    Canvas canvas = null;
    mStartTime = System.currentTimeMillis();
    while (mRun) {
        canvas = mHolder.lockCanvas();
        if (canvas != null) {

            // State Updating State means to manage state transitions, such as a game over, character select or next level.
                            
            switch( mPanel.getModeState() ){
                case Surface.MODE_LOGO_SPLASH :
                break;

                case Surface.MODE_MENU : 
                    // the menu
                        
                break;
                case Surface.MODE_LOADING : 
                    // loading animation
                    
                break;
                case Surface.MODE_GAME_PLAYING : 
                    // game stuff
                                            // GAME START _ RUNNING _ END

                    // Input
                    // AI
                    // Physics
                    
                    // animation
                    //mPanel.animate(mElapsed);
                break;
            }
            
            // draw everyThing
            mPanel.doDraw(mElapsed, canvas);
            // sound
            // Sound and Video.             
            mElapsed = System.currentTimeMillis() - mStartTime;
            mHolder.unlockCanvasAndPost(canvas);
        }
        mStartTime = System.currentTimeMillis();
    }
}

my problem is .. the function onDraw draws everything .. including the menu ? this sounds for me like bad code because everytime doDraw is executet, i have to check in this function which state i am currently in .. this cost time, dosent it ?

public void doDraw(long elapsed, Canvas canvas) {
    canvas.drawColor(Color.BLACK);
    
        // currently just gameLayout
        canvas.drawBitmap(background, 0, 0, mPaint);
    gameLayout.draw(canvas);

}

would it not be better do implement an other thread which draws the menu ? but if so, how can i overlay the menu afer pause the game ?

:
thanks for help erwin