Scrolling in a Stage in Libgdx seems to be laggy - scroll

Question

So I am trying to implement scrolling using this tutorial as a starting point.
I am running the tests on a Desktop.
I added an ActionGestureListener to the stage so I could call the pan(...) function. It works, but when I try to scroll, it looks really laggy, sort of like it's "vibrating".
What am I missing?
Here is what I have so far:
public class Store extends ScreenAdapter {
SpriteBatch spritebatch;
Stage stage;
Texture texture;
Image image;
Group background, foreground;
#Override
public void show() {
spritebatch = new SpriteBatch();
stage = new Stage();
background = new Group();
foreground = new Group();
texture = new Texture("badlogic.jpg");
image = new Image(texture);
//Building background/foreground.
background.addActor(image);
//Adding to stage.
stage.addActor(background);
stage.addActor(foreground);
stage.addListener(new ActorGestureListener() {
// TODO Auto-generated method stub
#Override
public void pan(InputEvent event, float x, float y, float deltaX, float deltaY) {
stage.getCamera().translate(-deltaX, -deltaY, 0);
stage.getCamera().update();
//System.out.println(x + ", " + y + ", " + " " + deltaX + ", " + deltaY);
}
});
Gdx.input.setInputProcessor(stage);
}
#Override
public void render(float delta){
Gdx.gl.glClearColor(1, 1, 1, 1);
Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
spritebatch.setProjectionMatrix(stage.getCamera().combined);
spritebatch.begin();
stage.draw();
spritebatch.end();
}
#Override
public void resize(int width, int height){
System.out.println("resize() executed.");
//stage.getViewport().update(width, height, true);
}
#Override
public void dispose(){
stage.dispose();
texture.dispose();
spritebatch.dispose();
}
}

Answer 1

You should not re-allocate memory for your field objects in your show method. That will drive the garbage collector crazy and probably cause some lag like you're seeing. Move all the new statements from show() into the class constructor or directly onto the field members like this:
public class Store extends ScreenAdapter {
SpriteBatch spritebatch = new SpriteBatch();
Stage stage = new Stage();
// ETC...
That way, the memory for those objects will only be allocated once at object creation.
**EDIT: I just looked and saw that the show method should not be getting repeatedly called like I assumed it was so the above might not work.

Answer 2

I finally got rid of the "vibrating" by editing the translate call.
stage.getCamera().translate(-deltaX / 2, -deltaY / 2, 0);
Instead of dividing by 2, it could be 3 or whatever increment you want. I feel this is solution is more like putting a band-aid on a problem, rather than actually fixing what's wrong. But it has the appearance of something that works, so I will go with it.