ScrollPane offsets widget by bar size

[dermetfan]

This bug was introduced in 1.5.3. Here's a comparision between 1.5.2 (left) and 1.5.3 (right):

The bar for scrolling on x is not currently visible but notice the widget is offset by its height in 1.5.3.

I believe this commit introduced the problem. Since this commit scrollbarHeight is only subtracted from areaHeight if scrolling on both axes is enabled which in my picture is not the case. Undoing the changes to ScrollPane in this commit should fix the issue.

[NathanSweet]

Can you please edit scroll pane test to show the problem?

[dermetfan]

I didn't get the ScrollPaneTest to show the issue without major changes so I provide my code as a separate test instead. Note you have to resize the window for the issue to actually show by making it thinner and thinner.

package com.badlogic.gdx.tests;

import com.badlogic.gdx.tests.utils.GdxTest;
import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.Screen;
import com.badlogic.gdx.graphics.GL20;
import com.badlogic.gdx.scenes.scene2d.Stage;
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.Table;
import com.badlogic.gdx.scenes.scene2d.ui.TextButton;
import com.badlogic.gdx.scenes.scene2d.ui.VerticalGroup;
import com.badlogic.gdx.scenes.scene2d.utils.BaseDrawable;
import com.badlogic.gdx.utils.viewport.ExtendViewport;

public class ScrollPaneTest extends GdxTest implements Screen {

    private Stage stage;

    public ScrollPaneTest() {
        stage = new Stage(new ExtendViewport(320, 568, 568, 0));

        Skin skin = new Skin(Gdx.files.internal("data/uiskin.json"));

        Table table = new Table(skin);
        table.setFillParent(true);
        stage.addActor(table);

        // achievement list
        VerticalGroup achievements = new VerticalGroup();
        achievements.fill();
        for(int i = 0; i < 10; i++) {
            String name;
            switch(i) {
            case 0:
                name = "Warming Up: Played 5 times";
                break;
            case 1:
                name = "Committed: Played 10 minutes";
                break;
            case 2:
                name = "One Good Deed A Day: Donated $1 to charity!";
                break;
            default:
                name = "-";
            }

            Label label = new Label(String.valueOf(i + 1).concat(". ").concat(name), skin);
            Image medal = new Image(new BaseDrawable() {{
                setMinWidth(25);
                setMinHeight(25);
            }});

            Table inner = new Table();
            inner.add(label).expand().left();
            inner.add(medal);

            achievements.addActor(inner);
        }
        ScrollPane achievementsPane = new ScrollPane(achievements, skin);

        // GPGS button
        TextButton gpgs = new TextButton("GPGS", skin);

        // dare button
        TextButton dare = new TextButton("Dare!", skin);

        // build table
        table.add("Achievements").top().pad(10).colspan(2).row();
        table.add(achievementsPane).expand().fill().colspan(2).row();
        table.add(gpgs);
        table.add(dare);
    }

    @Override
    public void render () {
        Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
        stage.act();
        stage.draw();
    }

    @Override
    public void resize (int width, int height) {
        stage.getViewport().update(width, height, true);
    }

    @Override
    public void dispose () {
        stage.dispose();
    }

    public boolean needsGL20 () {
        return false;
    }

    // if used as screen

    @Override
    public void show() {
        create();
    }

    @Override
    public void render(float delta) {
        render();
    }

    @Override
    public void hide() {}

}