Problem with JPanel inside JScrollPane

I want to make a simple graphic editor (like MS-Paint) with Java.
I create the frame using JFrame, and use many Swing component. But I found
some difficult when I tried to create the drawing area (the area where user
performs drawing). I use JPanel as drawing area and I put it in JScrollPane.
I use JScrollPane in case if user want to create a big drawing area.
What I want to do with drawing area is, to put it in JScrollPane with size smaller than JScrollPane but I can't get it because the size of drawing area (JPanel) is always be the same as JScrollPane size. In MS-Paint you can see that the canvas (drawing area) size is able to be resize. And the canvas default color is white, and the Scroll Box around it has darkgray color. How can I make it like that (MS-Paint)? Please help. Thanks...
Irfin

I haven't actually tested this, but I think it should work...
Add a JPanel to the scrollpane setting it's background to grey (i think the dark grey in MSPaint is something easy like 128,128,128). Set the layout on that panel to null, then add a second panel to that panel, at freeze it's size (ie. setMaximumSize). Doing it this way will allow you to set like a (10,10) position or something like that, giving the second panel a position away from the edge of the scrollpane.
Seeing as you will be using mouse listeners anyways, you might even be able to allow for the second panel to be resized by checking the mouse position to see if the mouse is over the edge of the panel. I won't go into detail, that'll ruin the fun for you.
Good luck, hope this helps.
Grant.

Similar Messages

  • Problem with JPanel and JScrollPane

    Hey,
    I have a class which extends JPanel. Inside this class I would like to have a JScrollPane.
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         JScrollPane scrollPane;
         JPanel p;
         public Summary()
              p = new JPanel()
                          public void paintComponent(Graphics g)
                                 /// do painting here!!!!
              setLayout(null);
              setBorder(BorderFactory.createLineBorder(Color.green));
              setBounds(0,0,240,290);
              //p.setLayout(null);
              p.setLayout(new FlowLayout());
              p.setBorder(BorderFactory.createLineBorder(Color.black));
              //p.setBounds(0,0,240,590);
              p.setPreferredSize(new Dimension(240,500));
              p.add(new JButton("test"));
              scrollPane = new JScrollPane(p);
              scrollPane.setLayout(null);
              scrollPane.setBounds(0,0,240,290);
              scrollPane.setBorder(BorderFactory.createLineBorder(Color.GREEN));
              add(scrollPane);
         }Any advice????
    thanks in advance

    Any advice????ditch this
    setLayout(null);

  • Problem with Jpanel repaintingl

    Hi!
    I have a problem with Jpanel.
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    Yair.

    Example code??
    Can't tell what's wrong otherwise.
    First , I add a Jscrollpane to the panel and I don't
    see it.Have you added anything to this JScrollPane? Unless you set the scroll bar policies to always on you won't see anything if you haven't added anything to the scrollpane.
    Also, if you're only adding this scrollPane to your JPanel initilise it with
    JPanel whippet = new JPanel(new BorderLayout())
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  • Problem with JPanel.updateUI()

    Hello,
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                    gbc.gridx = x;
                    gbc.gridy = y;
                    gbc.gridwidth = w;
                    gbc.gridheight = h;
                    gbc.weightx = wx;
                    gbc.weighty = wy;
                    gbc.fill = f;
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                    initButtons();
                    gbc = creategbc(0, 0, 1, 1, 20, 100, GridBagConstraints.NONE);
                    gbc.anchor = GridBagConstraints.NORTH;
                    gbl.setConstraints(m_buttons, gbc);
                    add(m_buttons);
                    initList();
                    JScrollPane sp = new JScrollPane(m_list);
                    gbc = creategbc(1, 0, 1, 1, 100, 100, GridBagConstraints.BOTH);
                    gbl.setConstraints(sp, gbc);
                    add(sp);
            public void addItem (String item)
                    m_listModel.addElement(item);
            public void initList ()
                    m_listModel = new DefaultListModel();
                    m_list = new JList(m_listModel);
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                    m_buttons.add(new JButton("L�schen"));
                    m_buttons.add(new JButton("Abfrage"));
            public static void main (String[] args)
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                    f.setVisible(true);
                    try
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                    catch (Exception e)
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    Hello,
    i have a problem with updateUI(), here's a simple
    example what's wrong. just compile and run the
    following piece of code and look what happens after 2
    seconds: the left panel will be decrease its width
    after calling updateUI(), but why? is it a bug of
    updateUI() or is it my fault?updateUI() its called when the L&F is changed, there is
    rarely a case when you need to call updateUI().
    Why do you call updateUI() if you remove the call to updateUI()
    everything will work OK.
    merry xmas

  • Problem with JPanel in JFrame

    hai ashrivastava..
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    JFrame f = new JFrame();
    JPanel panel = new JPanel();
    f.getContentPane().add(BorderLayout.SOUTH, panel);

    Hi
    JFrame f = new JFrame();
    JPanel panel = new JPanel();
    // Add this line to ur code with ur requiredWidth and requiredHeight
    panel.setPreferredSize(new Dimension(requiredWidth,requiredHeight));
    f.getContentPane().add(BorderLayout.SOUTH, panel);
    This should solve ur problem
    Ashish

  • Problem with JPanel and JDesktopPane

    Hi,
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    Thanks for your response. I will try that when I get home, although I will be surprised if that works because I am already using setPreferredSize() . It seemed to me that once a Jframe's content pane gets assigned to a JDesktopPane, then the JPanel no longer has anywhere to draw itself, as according to the Sun documentation, you can only add a JInternalFrame to a JDesktopPane.
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  • Weird problem with jpanel vs jframe

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    However, as you can see, my main class is a JApplet because ideally I want View to be a JPanel that I add to the applet. All I did was change "extends JFrame" to "extends JApplet" and (...)What do you mean? View extends JApplet? I thought View was meant to extend JPanel in the end...
    When I run it however, it appears really really small. It seems like its drawing the panel to the default size of the applet viewer and doesn't resize it when I resize the applet.Or, the panel has its preferred size, and this latter is too small. Actually the panel has the size its container's layout manager awards it (taking or not the panel's preferred, minimum, and maximum sizes into account). See the tutorial on [layout managers|http://java.sun.com/docs/books/tutorial/uiswing/layout/index.html] .
    In particular, this line adds the myPanel to a parent panel (presumably, it is in class View which extends JPanel, whose default layout is FlowLayout):
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    I don't know if it's a problem with the library or if I'm doing something wrong in my applet.Likely not (presumably the library interfers only in how it computes the Plot3DPanel's preferred size). There's an easy way to tell: try to layout correctly a custom JPanel of yours, containing only e.g. a button with an icon. Once you understand the basics of layout management, revisit the example using ther 3rd-party library.
    N.B.: there are a lot of "likely" and "presumably" in my reply: in order to avoid hardly-educated guesses especially on what is or isn't in your actual code, you'd better provide an SSCCE , which means reproducing the problem without the 3rd party library.

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  • Problem with JPanel in a JScrollPane

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    Hi all,
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    Hi,
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  • Problem with display of JScrollPane

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    I have a JFrame containing to JPanels. The JPanels are
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    >
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    The real question is why are you trying to override the paintComponent() method. Just add the image to a JLabel and add the label to a panel.
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