Not working JScrollPane

[kalet fotezu]

Hi,
does anvbody have an idea, why my JScrollPane doesn't work? I put inside it a JTree, and there is no scrollbars when it doesn't fit.
I specify the big size of a tree:

 		tree1.setBounds(0, 0, 1000, 1000);
		tree1.setPreferredSize(new Dimension(1000,1000));   

I noticed, that when I remove the sizing commands from tree1, it takes size of 1 pixel then.
I use no layout manager, don't set the look and feel.
Any ideas?

Swing doesn't rock...

[Ramses Butarbutar]

kalet fotezu wrote:Hi,
does anvbody have an idea, why my JScrollPane doesn't work? I put inside it a JTree, and there is no scrollbars when it doesn't fit.
I specify the big size of a tree:

 		tree1.setBounds(0, 0, 1000, 1000);
		tree1.setPreferredSize(new Dimension(1000,1000));   

I noticed, that when I remove the sizing commands from tree1, it takes size of 1 pixel then.
I use no layout manager, don't set the look and feel.
Any ideas?

Swing doesn't rock...

First.. welcome kalet,

Why don't you use layout manager? So.. how you manage your panel?
Yeah, you don't have to set look and feel... that's only to customize your application to look "beautiful"
Before you say "swing doesn't rock" can you show us snipped code of yours?

Best regards,

Ramses

[Maneesh Godbole]

kalet fotezu wrote:
does anvbody have an idea, why my JScrollPane doesn't work? I put inside it a JTree, and there is no scrollbars when it doesn't fit.

Usually you put the JTree inside a JScrollPane and not the other way round.

JScrollPanel scrollPanel=new JScrollPane(myTree);

kalet fotezu wrote:
Swing doesn't rock...

Yes. It does.

[kalet fotezu]

Hey,
I manage the layout "by hand", i calculate the positions and sizes basing on JFrame size. I know its not good solution ;)

Of course jtree goes inside scrollpane.

I think the point of the problem in my case is, that maybe the size of a jtree seen by scrollpane is 0x0 or 1x1 (thats how it is displayed when I don't mess with tree size). And even when I change the size and see the result (so i see the tree), scrollpane still thinks it is very small and doesn't show scrolbars. But why and how to change it...

I will try to prepare a working example

[kalet fotezu]

Hey again, here is the boxed problem.
Play with resizing the window, see how big the tree are.
Can you see where the problem is?

 
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ComponentEvent;
import java.awt.event.ComponentListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextField;
import javax.swing.JTree;

/**
 * This class is responsible for creating GUI
 * 
 * @author tglinski
 * 
 */
@SuppressWarnings("serial")
public class GUIRenderer2 extends JPanel implements Runnable {
	private JFrame frame;
	private JTree tree1;
	private JTree tree2;
	private JLabel rootFileLabel;
	private JTextField rootFileField;
	private JScrollPane treeScrollPane1;
	private JScrollPane treeScrollPane2;
	private JButton startButton;
	private JLabel normalTreeLabel;
	private JLabel reverseTreeLabel;

	public GUIRenderer2() {
		this("no matter");
	}

	/**
	 * Creates JPanel with all GUI components initialized. Needs run() to be
	 * displayed
	 * 
	 * @param rootFile
	 */
	public GUIRenderer2(String rootFile) {
		// Create components
		rootFileLabel = new JLabel("Investigated file: ");
		rootFileField = new JTextField(rootFile);
		startButton = new JButton("Create inclusion tree");
		normalTreeLabel = new JLabel("Inclusion tree: ");
		reverseTreeLabel = new JLabel("Reverse inclusion tree: ");

		// Add them to the panel
		add(rootFileLabel);
		add(rootFileField);
		add(startButton);
		add(normalTreeLabel);
		add(reverseTreeLabel);

		// Set button listener
		startButton.addActionListener(new CalculateAction());

		// create empty trees inside scroll panes
		tree1 = new JTree();
		treeScrollPane1 = new JScrollPane();

		tree2 = new JTree();
		treeScrollPane2 = new JScrollPane();

		add(treeScrollPane1);
		add(treeScrollPane2);
	}

	/**
	 * Runs the GUI building
	 */
	public void run() {

		// Create and set up the window.
		frame = new JFrame("XMLIncludeTree");
		// frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		// We will do the layout with resizeComponents()
		setLayout(null);
		frame.setPreferredSize(new Dimension(800, 300));

		// Catch window resizing event
		frame.addComponentListener(new ComponentListener() {
			public void componentResized(ComponentEvent e) {
				resizeComponents();
			}

			public void componentShown(ComponentEvent e) {
			}

			public void componentMoved(ComponentEvent e) {
			}

			public void componentHidden(ComponentEvent e) {
			}
		});
		// Add content to the window.
		frame.add(this);

		// Display the window.
		frame.pack();
		frame.setVisible(true);

		(new CalculateAction()).actionPerformed(null);
	}

	/**
	 * Calculates the sizes of components, to fit them to the window. HORRIBLE,
	 * TO BE CHANGED
	 */
	private void resizeComponents() {
		final int MARGIN = 5;
		final int ROW_HEIGHT = 25;
		final int FRAME_WIDTH = frame.getSize().width;
		final int FRAME_HEIGHT = frame.getSize().height;

		// row 1 - root file
		int lastHeight = MARGIN;
		rootFileLabel.setBounds(MARGIN, lastHeight, 100, ROW_HEIGHT);
		rootFileField.setBounds(100 + MARGIN, MARGIN, FRAME_WIDTH - 100 - 4
				* MARGIN, ROW_HEIGHT);

		// row 2 - button
		lastHeight += ROW_HEIGHT;
		startButton.setBounds(MARGIN, lastHeight, startButton
				.getPreferredSize().width,
				startButton.getPreferredSize().height);

		// row 3 - pane 1 label
		lastHeight += startButton.getPreferredSize().height + MARGIN;
		normalTreeLabel.setBounds(MARGIN, lastHeight, 400, ROW_HEIGHT);

		final int SCROLLPANE_HEIGHT = (FRAME_HEIGHT - 7 * ROW_HEIGHT) / 2;

		// row 4 - tree and treePane
		lastHeight += ROW_HEIGHT;
		treeScrollPane1.setBounds(MARGIN, lastHeight, FRAME_WIDTH - 4 * MARGIN,
				SCROLLPANE_HEIGHT);
		tree1.setBounds(0, 0, 1000, 1000);

		// row 5 - pane 2 label
		lastHeight += SCROLLPANE_HEIGHT;
		reverseTreeLabel.setBounds(MARGIN, lastHeight, 400, ROW_HEIGHT);

		// row 6 - tree and treePane
		lastHeight += ROW_HEIGHT;
		treeScrollPane2.setBounds(MARGIN, lastHeight, FRAME_WIDTH - 4 * MARGIN,
				SCROLLPANE_HEIGHT);
		tree2.setBounds(0, 0, 1000, 1000);

	}

	/**
	 * ActionListener for the "Create tree" button
	 * 
	 * @author tglinski
	 * 
	 */
	class CalculateAction implements ActionListener {
		public void actionPerformed(ActionEvent e) {

			// remove old tree from pane
			treeScrollPane1.removeAll();
			treeScrollPane2.removeAll();

			tree1 = new JTree(
					new String[] { "1", "2", "3", "4", "5", "6", "7" });
			tree2 = new JTree(
					new String[] { "1", "2", "3", "4", "5", "6", "7" });
			treeScrollPane1.add(tree1);
			treeScrollPane2.add(tree2);
			resizeComponents();
		}

	}

	public static void main(String[] args) {
		javax.swing.SwingUtilities.invokeLater(new GUIRenderer2());
	}
}
  

[pete stein]

You appear to be adding your JTree to the JScrollPane and not the viewport which is not how JScrollPanes work.

For instance:

         // remove old tree from pane
         treeScrollPane1.removeAll(); // wrong
         treeScrollPane2.getViewport().removeAll(); // right

         tree1 = new JTree(new String[]{"1", "2", "3", "4", "5", "6", "7"});
         tree2 = new JTree(new String[]{"1", "2", "3", "4", "5", "6", "7"});
         treeScrollPane1.add(tree1);  // wrong
         treeScrollPane2.getViewport().add(tree2); // right

Though I agree with the others in that I'd skip absolute positioning and instead would use the layout managers. For instance:

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class GUIRenderer2b {
   private static final int MAX_WIDTH = 2000;
   private static final Dimension MAIN_SIZE = new Dimension(800, 300);
   private JPanel mainPanel = new JPanel();
   private JTextField investigatedFileField = new JTextField(15);
   private JScrollPane scrollpanel1 = new JScrollPane();
   private JScrollPane scrollpanel2 = new JScrollPane();
   private JTree tree1 = new JTree();
   private JTree tree2 = new JTree();

   public GUIRenderer2b() {
      int ebGap = 5;
      mainPanel.setPreferredSize(MAIN_SIZE);
      mainPanel.setBorder(BorderFactory.createEmptyBorder(ebGap, ebGap, ebGap, ebGap));
      mainPanel.setLayout(new BoxLayout(mainPanel, BoxLayout.PAGE_AXIS));
      mainPanel.add(createInvestFilePanel());
      mainPanel.add(Box.createVerticalStrut(3));
      mainPanel.add(createInclusionButtonPanel());
      mainPanel.add(Box.createVerticalStrut(5));
      mainPanel.add(createTreePanel());
      createInclusionTreeBtnAction();
   }

   private JPanel createTreePanel() {
      JPanel treePanel = new JPanel();
      treePanel.setLayout(new GridLayout(0, 1));
      treePanel.add(createSubTreePanel("Inclusion Tree:", scrollpanel1));
      treePanel.add(createSubTreePanel("Reverse Inclusion Tree:", scrollpanel2));
      return treePanel;
   }

   private JPanel createSubTreePanel(String labelText, JScrollPane stScrollPane) {
      JPanel subTreePanel = new JPanel();
      subTreePanel.setLayout(new BoxLayout(subTreePanel, BoxLayout.PAGE_AXIS));
      JPanel labelPanel = new JPanel(new FlowLayout(FlowLayout.LEFT));
      labelPanel.add(new JLabel(labelText, SwingConstants.LEFT));
      labelPanel.setMaximumSize(new Dimension(MAX_WIDTH, labelPanel.getPreferredSize().height));
      subTreePanel.add(labelPanel);
      subTreePanel.add(stScrollPane);
      return subTreePanel;
   }

   private JPanel createInclusionButtonPanel() {
      JPanel inclusionTreePanel = new JPanel();
      inclusionTreePanel.setLayout(new BoxLayout(inclusionTreePanel, BoxLayout.LINE_AXIS));
      JButton createInclusionTreeBtn = new JButton("Create Inclusion Tree");
      createInclusionTreeBtn.addActionListener(new ActionListener() {
         public void actionPerformed(ActionEvent e) {
            createInclusionTreeBtnAction();
         }
      });
      inclusionTreePanel.add(createInclusionTreeBtn);
      inclusionTreePanel.add(Box.createHorizontalGlue());
      return inclusionTreePanel;
   }

   private void createInclusionTreeBtnAction() {
      // a lot of this redundancy here can be removed via refactoring.
      JViewport viewport1 = scrollpanel1.getViewport();
      JViewport viewport2 = scrollpanel2.getViewport();
      viewport1.removeAll();
      viewport2.removeAll();
      
      tree1 = new JTree(new String[]{"1", "2", "3", "4", "5", "6", "7", "8"});
      tree2 = new JTree(new String[]{"1", "2", "3", "4", "5", "6", "7", "8"});
      
      viewport1.add(tree1);
      viewport2.add(tree2);
      
      viewport1.repaint();
      viewport1.revalidate();
      viewport2.repaint();
      viewport2.revalidate();
   }

   private JPanel createInvestFilePanel() {
      JPanel investFilePanel = new JPanel();
      investFilePanel.setLayout(new BoxLayout(investFilePanel, BoxLayout.LINE_AXIS));
      investFilePanel.add(new JLabel("Investigated File:"));
      investFilePanel.add(Box.createHorizontalStrut(10));
      investFilePanel.add(investigatedFileField);
      Dimension ifSize = investFilePanel.getPreferredSize();
      investFilePanel.setMaximumSize(new Dimension(MAX_WIDTH, ifSize.height));
      return investFilePanel;
   }

   public JComponent getComponent() {
      return mainPanel;
   }

   private static void createAndShowUI() {
      JFrame frame = new JFrame("XML Include Tree");
      frame.getContentPane().add(new GUIRenderer2b().getComponent());
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.pack();
      frame.setLocationRelativeTo(null);
      frame.setVisible(true);
   }

   public static void main(String[] args) {
      java.awt.EventQueue.invokeLater(new Runnable() {
         public void run() {
            createAndShowUI();
         }
      });
   }
}

[kalet fotezu]

Pete, you are a god Thank you very much!

Swing (partially) rocks