JList / JTable作为按钮面板

Question

Im about to make a new application, and i stumbled over an very cool sidebar (button-panel) I will try to add to the application (Its the left-sidebar on Spotify). The thing im curious about, is the principble (Take a look at the picture attached).
In the top theres 3 buttons (I assume its either JList or JTable items).

In the middle we have a "YOUR MUSIC" header (JLabel maybe??)

We also have a New Playlist (JButton)

And then the Playlist list (JList or JTable?)

The interresting things i would like to know is:

Firstly, that the three JList (playlistList, appList and yourmusicList, i assume its JLists) share the same JScrollPane, and therefor the JList/JTables(Or whatever it is) have to change size (Height) depended on the amount of items it contains. (For Instance: The playlist list change Height dependen on if have 3 or 17 playlists.)

Secondly: I managed to add Buttons, Labels, JLists in the same JPanel, but i could not figure out how to give them a shared JScrollPane (The problem occured when i tried to give two JLists same ScrollPane).

I think, that i use wrong LayoutManager for the JPanel the items should be contained in, and i use the wrong kind of Component (JList, JTable). If theres a Swing Component called JSideBar or something, it would be great!

Well, thats it! Theres no code example, since it woudlnt really benefit in any way

Regards Oliver

Answer 1

[...] but i could not figure out how to give them a shared JScrollPane (The problem occured when i tried to give two JLists same ScrollPane).

You can add all your components to a JPanel and set this one as the JScrollPane view port. Take a look to How to Use Scroll Panes tutorial.

---

If theres a Swing Component called JSideBar or something, it would be great!

Not provided by default but it's extremely easy to make your own scrollable side-bar with a JPanel and using BoxLayout . Check out the tutorials: How to Use BoxLayout . For instance:

import java.awt.BorderLayout;
import java.awt.Graphics;
import javax.swing.Box;
import javax.swing.BoxLayout;
import javax.swing.JComponent;
import javax.swing.JPanel;
import javax.swing.JScrollPane;

/**
 * @author dic19
 */
public class JSideBar extends JComponent {

    private final JPanel content;

    public JSideBar(boolean scrollable) {
        super();

        content = new JPanel();
        content.setLayout(new BoxLayout(content, BoxLayout.PAGE_AXIS));

        this.setLayout(new BorderLayout());

        if(scrollable) {
            this.add(new JScrollPane(content));
        } else {
            this.add(content);
        }

    }

    /**
     * Adds a component to this side bar.
     * 
     * @param comp The component.
     * @param alignment One of {@code Component.LEFT_ALIGNMENT, Component.CENTER_ALIGNMENT, Component.RIGHT_ALIGNMENT}
     * 
     * @see java.awt.Component#LEFT_ALIGNMENT
     * @see java.awt.Component#CENTER_ALIGNMENT
     * @see java.awt.Component#RIGHT_ALIGNMENT
     */
    public void addItem(JComponent comp, float alignment) {
        comp.setAlignmentX(alignment);
        content.add(comp);
        if(content.isShowing()) {
            revalidate();
            repaint();
        }
    }

    /**
     * Adds a vertical space to this side bar.
     * @param height Height of vertical space.
     */
    public void addVerticalSpace(int height) {
        content.add(Box.createVerticalStrut(height));
    }

    @Override
    protected void paintComponent(Graphics g) {
        super.paintComponent(g); 
        Graphics graphics = g.create();
        graphics.setColor(getBackground());
        graphics.fillRect(0, 0, getWidth(), getHeight());
        graphics.dispose();
    }
}

And here is an example of use based on your case:

JLabel appFinderLabel = new JLabel("AppFinder");        
JLabel musicxMatchLabel = new JLabel("musicXmatch");
JLabel tuneWikiLabel = new JLabel("TuneWiki");

JLabel yourMusicLabel = new JLabel("YOUR MUSIC");
JLabel songsLabel = new JLabel("Songs");
JLabel albumsLabel = new JLabel("Albums");
JLabel artistsLabel = new JLabel("Artists");
JLabel localFilesLabel = new JLabel("Local Files");

/* 
 * Set icons, background and stuff if you need to
 * A good option would be use undecorated JButtons instead of JLabels
 */

JSideBar sideBar = new JSideBar(true);
sideBar.addItem(appFinderLabel, Component.LEFT_ALIGNMENT);
sideBar.addItem(musicxMatchLabel, Component.LEFT_ALIGNMENT);
sideBar.addItem(tuneWikiLabel, Component.LEFT_ALIGNMENT);

sideBar.addVerticalSpace(20);

sideBar.addItem(yourMusicLabel, Component.LEFT_ALIGNMENT);
sideBar.addItem(songsLabel, Component.LEFT_ALIGNMENT);
sideBar.addItem(albumsLabel, Component.LEFT_ALIGNMENT);
sideBar.addItem(artistsLabel, Component.LEFT_ALIGNMENT);
sideBar.addItem(localFilesLabel, Component.LEFT_ALIGNMENT);

Screenshot

Please note the scrollbar: