JSplitPane and Jtree

Question

Hi all,
in my window I've got a JSplitPane with the left component that is a JScrollPane with a Jtree (used as a menu), while in the right side a customized JPanel that changes depending on the selection in the tree on the left.
My panels are initially created as follows:
     this.splitter = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT);
     this.splitter.setOneTouchExpandable(true);
JScrollPane leftPanel = new JScrollPane( this.menuTree );
          leftPanel.setMinimumSize( new Dimension(300,300) );     
          leftPanel.setMaximumSize(leftPanel.getMinimumSize());
          // add the leftt and right panels
          this.splitter.setLeftComponent( leftPanel );
          this.imagePanel = new ImagePanel(ComponentBuilder.getLogoPath());
          this.rightPanel = this.imagePanel;
          this.splitter.setRightComponent(this.rightPanel);
          // add the splitter to myself
          this.add(new JScrollPane(this.splitter));where the imagepanel is a working panel that shows the project logo. Now what happens is that:
1) the logo is cutted to a size I don't know how is calculated, since the image panel is working fine (if I place on a separate window I can see the image right)
2) most important when a user selects something in the tree on the left panel, so the right panel changes, the left panel is moved around the window depending on the size of the right panel.
Is it possible to fix the left panel not only as size, but also in the position of the window, thus the remaining part of the window will be occupied by the right panel without moving the left one? In my frame I'm using a BorderLayout, and the panel containing the splitpane is set at the center (no components on the right and on the left).
Thanks,
Luca

Answer 1

Thanks for your reply, but the only thing I noticed is that the code you're showing works a little more with sizes, that is something I've already tried. By the way, the following is a running example that loads a tree/menu and the logo.png image.
Any idea about its behaviour?
Thanks,
Luca
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.event.TreeSelectionEvent;
import javax.swing.tree.*;
import javax.swing.event.*;
import java.util.*;
import java.awt.image.*;
class ImagePanel extends JPanel implements ImageObserver
     * The image to display
    protected Image image=null;
     * This flag indicates if the image is complete or not.
    protected boolean isComplete=false;
     * The dimension of the panel.
    protected int width=0,height=0;
     * This is the message to display during loading.
    protected String message="Loading...";
     * Default constructor.
     * @param image the image object.
    public ImagePanel(Image image)
          super();
          this.image=image;
     * Overloaded constructor. It try to load the image itself. You should use
     * this to avoid image flicking problems. This method use all the
     * capabilities of the ImageObserver.
     * @param image the image file name
    public ImagePanel(String image) {
          super();
          /* now load the image */
          Toolkit tk=Toolkit.getDefaultToolkit();
          this.image=tk.getImage(image);
          /* use the media tracker to wait untill the image is not loaded */
          try{
              MediaTracker tracker=new MediaTracker(this);
              tracker.addImage(this.image,0);
              tracker.waitForID(0);
              this.isComplete=true;
              /* now that the image is fully loaded I need to resize the panel to
              the size of the image */
              this.width=this.image.getWidth(this);
              this.height=this.image.getHeight(this);
              this.setSize(width,height);
              this.setMinimumSize(getSize());
              this.setMaximumSize(getSize());
              this.setVisible(true);
          catch(InterruptedException e){
              this.message="Exception during loading process!";
              this.isComplete=false;
     * Draw the image.
    public void paint(Graphics device)   {
          super.paint(device);
          if(this.isComplete==true)     {
              device.drawImage(this.image,0,0,this.width,this.height,this);
          else     {
              device.setColor(Color.RED);
              device.drawString(this.message,20,20);
     * The update image method. This method is called for every update and or
     * error.
    public boolean imageUpdate(Image image,int infoFlags, int x, int y,
                    int width, int height)
          if((infoFlags & ALLBITS)==0)
              /* the image is complete */
              this.isComplete=true;
              repaint();
              this.setVisible(true);
              return false;
          else
          if((infoFlags & ERROR)==0 || (infoFlags & ABORT)==0 )
              /* error or abort */
              this.isComplete=false;
              this.message="Error during load process (or abort)";
              this.repaint();
              return true;
          else
          if((infoFlags & SOMEBITS)==0)
              /* some other data loaded, show the loading process percent */
              int originalWidth=this.image.getWidth(this);
              int originalHeight=this.image.getHeight(this);
              int currentWidth=image.getWidth(this);
              int currentHeight=image.getHeight(this);
              /* now calculate the total of pixels */
              long originalTotal=originalWidth*originalHeight;
              long currentTotal=currentWidth*currentHeight;
              /* now calculate the percent */
              float percent=(float)currentTotal/(float)originalTotal *100;
              /* set the string */
              this.message="Loading progress: "+(int)percent+" % done";
              this.repaint();
              return true;
          return true;
public class MainPanel extends JPanel {
      * The split pane used for this panel.
     protected JSplitPane splitter = null;
      * The menu tree of this panel.
     protected JTree menuTree = null;
      * The parentFrame frame of this panel
     protected JFrame parentFrame = null;
      * The panel on the right of the window.
     protected JComponent rightPanel = null;
      * The menuTreeRoot node of the menu.
     protected DefaultMutableTreeNode menuTreeRoot = null;
      * The action menu of the JFrame that contains this panel. Such menu is changed depending on the panel
      * shown on the right panel.
     protected JMenu actionMenu = null;
      * The image panel with the image of the logo.
     protected ImagePanel imagePanel = null;
     public final String ROOT_STRING = "Gestione delle risorse umane";
     public final String LEVEL1A_STRING = "Parametrizzazione";
     public final String LEVEL2AA_STRING = "Competenze & Famiglie di competenze";
     public final String LEVEL2AB_STRING = "Gestione dei ruoli";
     public final String LEVEL2AC_STRING = "Associazione ruolo-competenza";
     public final String LEVEL1B_STRING   = "Varie";
     public final String LEVEL2BB_STRING = "Province";
     public final String LEVEL2BC_STRING = "Citta'";
     public final String LEVEL2BD_STRING = "Livelli di istruzione";
     public final String LEVEL2BE_STRING = "Livelli di competenza";
     public final String LEVEL3A_STRING   = "Personale";
     public final String LEVEL3AA_STRING = "Anagrafica di base";
     public final String LEVEL3AB_STRING  = "Ruoli, Competenze e Gradi di Istruzione";
     public final String LEVEL3AC_STRING  = "Storia delle valutazioni delle competenze";
     public final String LEVEL3AD_STRING  = "Valutazione";
      * Default constructor.
      * @param parentFrame the jframe that contains this panel
     public MainPanel(JFrame parent, JMenu actionMenu){
          super();
          this.parentFrame = parent;
          this.initGUI();
          this.actionMenu = actionMenu;
      * Shows the components on the main panel.
     public synchronized void initGUI(){
          // create the split pane
          this.splitter = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT);
          this.splitter.setOneTouchExpandable(true);
          //this.splitter.setResizeWeight(0);                    // the right panel gets all the extra space
          // create the left panel with the tree
          DefaultMutableTreeNode root = new DefaultMutableTreeNode(ROOT_STRING);
               DefaultMutableTreeNode level1a = new DefaultMutableTreeNode(LEVEL1A_STRING);
                    ContainerTreeNode level2aa = new ContainerTreeNode(LEVEL2AA_STRING);     // skills and families
               DefaultMutableTreeNode level2ab = new DefaultMutableTreeNode(LEVEL2AB_STRING);
                    DefaultMutableTreeNode level2ac = new DefaultMutableTreeNode(LEVEL2AC_STRING);
               DefaultMutableTreeNode level1b = new DefaultMutableTreeNode(LEVEL1B_STRING);
                    DefaultMutableTreeNode level2bb = new DefaultMutableTreeNode(LEVEL2BB_STRING);
                    DefaultMutableTreeNode level2bc = new DefaultMutableTreeNode(LEVEL2BC_STRING);
                    DefaultMutableTreeNode level2bd = new DefaultMutableTreeNode(LEVEL2BD_STRING);
                    DefaultMutableTreeNode level2be = new DefaultMutableTreeNode(LEVEL2BE_STRING);
               DefaultMutableTreeNode level3a = new DefaultMutableTreeNode(LEVEL3A_STRING);
                    DefaultMutableTreeNode level3aa = new DefaultMutableTreeNode(LEVEL3AA_STRING);
                    DefaultMutableTreeNode level3ab = new DefaultMutableTreeNode(LEVEL3AB_STRING);
                    DefaultMutableTreeNode level3ac = new DefaultMutableTreeNode(LEVEL3AC_STRING);
                    DefaultMutableTreeNode level3ad = new DefaultMutableTreeNode(LEVEL3AD_STRING);
          // create the tree
          this.menuTreeRoot = root;
          level2ab.add(level2ac);
          level1a.add(level2aa);
          level1b.add(level2bc);
          level1b.add(level2bb);
          level1b.add(level2bd);
          level1b.add(level2be);
          level3a.add(level3aa);
          level3a.add(level3ab);
          level3a.add(level3ac);
          level3a.add(level3ad);
          root.add(level3a);
          root.add(level2ab);
          root.add(level1a);
          root.add(level1b);
          this.menuTree = new JTree(root);
          this.menuTree.setSize(200,200);
          JScrollPane leftPanel = new JScrollPane( this.menuTree );
          leftPanel.setMinimumSize( new Dimension(300,300) );     // it does not affects the dimension, but avoid to resize the left panel
          leftPanel.setMaximumSize(leftPanel.getMinimumSize());
          // add the leftt and right panels
          this.splitter.setLeftComponent( leftPanel );
          this.imagePanel = new ImagePanel("logo.png");
          this.rightPanel = this.imagePanel;
          this.rightPanel.setSize(400,400);
          this.splitter.setRightComponent(this.rightPanel);
          // add the splitter to myself
          this.add(new JScrollPane(this.splitter));
     public static void main(String argv[]){
         JFrame f = new JFrame();
         f.setSize(400,400);
         f.add(new MainPanel(f,null));
         f.setVisible(true);
}