A LibGDX ScrollPane with page support. It center-locks on pages after scrolling.

PagedScrollPane.java

package com.badlogic.gdx.tests.examples;

import com.badlogic.gdx.math.MathUtils;
import com.badlogic.gdx.scenes.scene2d.Actor;
import com.badlogic.gdx.scenes.scene2d.ui.ScrollPane;
import com.badlogic.gdx.scenes.scene2d.ui.Skin;
import com.badlogic.gdx.scenes.scene2d.ui.Table;
import com.badlogic.gdx.utils.Array;
import com.esotericsoftware.tablelayout.Cell;

public class PagedScrollPane extends ScrollPane {

	private float pickAmountX;
	private float pickDifferenceX = -1;

	private boolean wasPanDragFling = false;

	private float scrollToPageSpeed = 1000;

	private float pageSpacing;

	private Table content;

	public PagedScrollPane () {
		super(null);
		content = new Table();
		content.defaults().space(50);
		setWidget(content);
	}

	public PagedScrollPane (Skin skin) {
		super(null, skin);
		content = new Table();
		content.defaults().space(50);
		setWidget(content);
	}

	public PagedScrollPane (Skin skin, String styleName) {
		super(null, skin, styleName);
		content = new Table();
		content.defaults().space(50);
		setWidget(content);
	}

	public PagedScrollPane (Actor widget, ScrollPaneStyle style) {
		super(null, style);
		content = new Table();
		content.defaults().space(50);
		setWidget(content);
	}

	public void addPages (Actor... pages) {
		for (Actor page : pages) {
			content.add(page).expandY().fillY();
		}
	}

	public void addPage (Actor page) {
		content.add(page).expandY().fillY();
	}

	@Override
	public void act (float delta) {
		super.act(delta);
		if (wasPanDragFling && !isPanning() && !isDragging() && !isFlinging()) {
			wasPanDragFling = false;
			scrollToPage();
		} else {
			if (isPanning() || isDragging() || isFlinging()) {
				wasPanDragFling = true;
			}
		}
	}

	@Override
	public void setWidth (float width) {
		super.setWidth(width);
		if (content != null) {
			for (Cell cell : content.getCells()) {
				cell.width(width);
			}
			content.invalidate();
		}
	}

	public void setPageSpacing (float pageSpacing) {
		if (content != null) {
			content.defaults().space(pageSpacing);
			for (Cell cell : content.getCells()) {
				cell.space(pageSpacing);
			}
			content.invalidate();
		}
	}

	private void scrollToPage () {
		final float width = getWidth();
		final float scrollX = getScrollX();
		final float maxX = getMaxX();

		if (scrollX >= maxX || scrollX <= 0) return;

		Array<Actor> pages = content.getChildren();
		float pageX = 0;
		float pageWidth = 0;
		if (pages.size > 0) {
			for (Actor a : pages) {
				pageX = a.getX();
				pageWidth = a.getWidth();
				if (scrollX < (pageX + pageWidth * 0.5)) {
					break;
				}
			}
			setScrollX(MathUtils.clamp(pageX - (width - pageWidth) / 2, 0, maxX));
		}
	}

}

PagedScrollPaneTest.java

/*******************************************************************************
 * Copyright 2011 See AUTHORS file.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 ******************************************************************************/

package com.badlogic.gdx.tests.examples;

import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.graphics.Color;
import com.badlogic.gdx.graphics.GL10;
import com.badlogic.gdx.math.MathUtils;
import com.badlogic.gdx.scenes.scene2d.Actor;
import com.badlogic.gdx.scenes.scene2d.InputEvent;
import com.badlogic.gdx.scenes.scene2d.InputListener;
import com.badlogic.gdx.scenes.scene2d.Stage;
import com.badlogic.gdx.scenes.scene2d.ui.Button;
import com.badlogic.gdx.scenes.scene2d.ui.Button.ButtonStyle;
import com.badlogic.gdx.scenes.scene2d.ui.Image;
import com.badlogic.gdx.scenes.scene2d.ui.Label;
import com.badlogic.gdx.scenes.scene2d.ui.ScrollPane;
import com.badlogic.gdx.scenes.scene2d.ui.Skin;
import com.badlogic.gdx.scenes.scene2d.ui.Slider;
import com.badlogic.gdx.scenes.scene2d.ui.Table;
import com.badlogic.gdx.scenes.scene2d.ui.TextButton;
import com.badlogic.gdx.scenes.scene2d.ui.Skin.TintedDrawable;
import com.badlogic.gdx.scenes.scene2d.ui.TextButton.TextButtonStyle;
import com.badlogic.gdx.scenes.scene2d.utils.Align;
import com.badlogic.gdx.scenes.scene2d.utils.ChangeListener;
import com.badlogic.gdx.scenes.scene2d.utils.ClickListener;
import com.badlogic.gdx.scenes.scene2d.utils.Drawable;
import com.badlogic.gdx.tests.utils.GdxTest;
import com.esotericsoftware.tablelayout.Value;

public class PagedScrollPaneTest extends GdxTest {
	
	private Skin skin;
	private Stage stage;
	private Table container;

	public void create () {
		stage = new Stage(0, 0, false);
		skin = new Skin(Gdx.files.internal("data/uiskin.json"));
		Gdx.input.setInputProcessor(stage);

		container = new Table();
		stage.addActor(container);
		container.setFillParent(true);

		PagedScrollPane scroll = new PagedScrollPane();
		scroll.setFlingTime(0.1f);
		scroll.setPageSpacing(25);
		int c = 1;
		for (int l = 0; l < 10; l++) {
			Table levels = new Table().pad(50);
			levels.defaults().pad(20, 40, 20, 40);
			for (int y = 0; y < 3; y++) {
				levels.row();
				for (int x = 0; x < 4; x++) {
					levels.add(getLevelButton(c++)).expand().fill();
				}
			}
			scroll.addPage(levels);
		}
		container.add(scroll).expand().fill();
	}

	public void render () {
		Gdx.gl.glClear(GL10.GL_COLOR_BUFFER_BIT);
		stage.act(Gdx.graphics.getDeltaTime());
		stage.draw();
		Table.drawDebug(stage);
	}

	public void resize (int width, int height) {
		stage.setViewport(width, height, false);
	}

	public void dispose () {
		stage.dispose();
		skin.dispose();
	}

	public boolean needsGL20 () {
		return false;
	}

	
	/**
	 * Creates a button to represent the level
	 * 
	 * @param level
	 * @return The button to use for the level
	 */
	public Button getLevelButton(int level) {
		Button button = new Button(skin);
		ButtonStyle style = button.getStyle();
		style.up = 	style.down = null;
		Label label = new Label(Integer.toString(level), skin);
		label.setFontScale(2f);
		label.setAlignment(Align.center);		
		
		button.stack(new Image(skin.newDrawable("default-round-large", Color.RED)), label).expand().fill();

		skin.add("star-filled", skin.newDrawable("white", Color.YELLOW), Drawable.class); 
		skin.add("star-unfilled", skin.newDrawable("white", Color.GRAY), Drawable.class);
		
		int stars = MathUtils.random(-1, +3);
		Table starTable = new Table();
		starTable.defaults().pad(5);
		if (stars >= 0) {
			for (int star = 0; star < 3; star++) {
				if (stars > star) {
					starTable.add(new Image(skin.getDrawable("star-filled"))).width(20).height(20);
				} else {
					starTable.add(new Image(skin.getDrawable("star-unfilled"))).width(20).height(20);
				}
			}			
		}
		
		button.row();
		button.add(starTable).height(30);
		
		button.setName("Level" + Integer.toString(level));
		button.addListener(levelClickListener);		
		return button;
	}
	
	/**
	 * Handle the click - in real life, we'd go to the level
	 */
	public ClickListener levelClickListener = new ClickListener() {
		@Override
		public void clicked (InputEvent event, float x, float y) {
			System.out.println("Click: " + event.getListenerActor().getName());
		}
	};

}

Nice idea, thanks a lot!