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Adding JScrollPane to JPanel with another panels inside

i been working on some bigger project lately but couldn't figure it out why JScrollPane wouldn't work. I have never used it before and I read many solved problems about it on stackOverflow and other programming forums but non of the code were looking similar to mine to help me implement my method.
this is new project i made to make it short and show some examples.
Red colour is main panel that will contain another panel/JScrollPane inside that will be colour black
and i would like to make this Jpanel with colour black to be scrollable and hold any number of that white JPanels that might be from 0 to a 100+
public class ScrollablePane {
private JFrame frame;
private JPanel panelCopy;
private JPanel panel;
private JPanel container;
/**
* Launch the application.
*/
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
ScrollablePane window = new ScrollablePane();
window.frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
/**
* Create the application.
*/
public ScrollablePane() {
initialize();
}
/**
* Initialize the contents of the frame.
*/
private void initialize() {
frame = new JFrame();
frame.setBounds(100, 100, 450, 300);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().setLayout(null);
panel = new JPanel();
panel.setBackground(Color.RED);
panel.setBounds(0, 0, 434, 261);
frame.getContentPane().add(panel);
panel.setLayout(null);
container = new JPanel();
container.setBackground(Color.BLACK);
container.setBounds(10, 10, 414, 241);
container.setLayout(new FlowLayout(FlowLayout.CENTER, 10, 10));
panel.add(container);
for(int i = 0; i < 20; i++) {
if(i > 0) {
panelCopy = new JPanel();
panelCopy.setPreferredSize(new Dimension(400, 40));
container.add(panelCopy);
}
}
}
}

if you want to use a JScrollPane, then your code actually needs to use a JScrollPane. The code you posted doesn't even create a JScrollPane.
If you want the panels to display vertically then don't use a FlowLayout. The FlowLayout is a horizontal layout. You could use a BoxLayout or a GridBagLayout.
Why do you create the "panel" variable and add it the the content pane? The content pane of the frame already is a JPanel that uses a BorderLayout. There is no need to add another panel
Don't use a null layout!!! Swing was designed to be used with layout managers. Scrolling won't work if the panel added to the scroll pane uses a null layout.
So in your case the basic logic might be something like:
Box container = Box.createVerticalBox();
// add you child panels to the container.
JPanel wrapper = new JPanel( new BorderLayout() );
wrapper.add(container, BorderLayout.PAGE_START);
JScrollPane scrollPane = new JScrollPane(wrapper);
frame.add(scrollPane, BorderLayout.CENTER);
Note the "wrapper" panel is used to prevent the panels from expanding in size when the scroll pane is larger then the preferred size of the "container" panel.
Try:
//JScrollPane scrollPane = new JScrollPane(wrapper);
JScrollPane scrollPane = new JScrollPane(container);
to see the different result.

How to add a ScrollBar at the bottom of the JPanel when using GridLayout?

Hello i wanted to know how to add a ScrollBar at the bottom of a JPanel if i use GridLayout in my desktop app, as far as i know GridLayout only accept as parameter quantity of colums, rows and the horizontal and vertical gap. So how can i add a scroll bar and use it to see the information that's in the JPanel?

Put the JPanel with GridLayout into a JScrollPane. E.G. as seen with the two column GridLayout that displays the labels added to the nested layout example.

If you want the JSrollBar to scroll the JPanel with the gridlayout, then put the grid layout into a scrollpane (remember to extend the scrollable interface)
Read this page of the tutorial to learn how to.
IF you want to use the events from the JScrollBar to change the visible area of your panel then put the panel inside another panel with a JScrollbar on the bottom.
This is an example with a green panel and a scrollbar at the bottom
public class Window extends JFrame {
public Window() {
setPreferredSize(new Dimension(500, 500));
setMinimumSize(new Dimension(500, 500));
setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
JPanel panel = new JPanel();
panel.setPreferredSize(new Dimension(100, 100));
panel.setBackground(Color.GREEN);
getContentPane().add(panel, BorderLayout.CENTER);
JScrollBar scrollBar = new JScrollBar(JScrollBar.HORIZONTAL);
scrollBar.setMinimum(0);
scrollBar.setMaximum(100);
scrollBar.setBlockIncrement(30);
scrollBar.addAdjustmentListener(new AdjustmentListener() {
#Override
public void adjustmentValueChanged(AdjustmentEvent e) {
System.out.println("Adjustment changed");
}
});
getContentPane().add(scrollBar, BorderLayout.SOUTH);
setVisible(true);
}
public static void main(String[] args) {
new Window();
}
}

Java JPanel inside JScrollPane?

I have a JFrame, in this JFrame I have a JPanel that I draw on, this Panel can be any size and so I placed it into a JScrollpane to let me scroll when the panel is larger than the window screen size.
Unfortunately does not work as I expected:
Making the JFrame window smaller than the JPanel size does not show scroll bars
The JScrollPane size now seems locked to the size of the JPanel I have added to it, where as before it resized to the bounds of it's JFrame window (it still kinda does this but only vertically now?!)
The JPanel seems to assume the size of the JScrollpane regardless of what I set for preferred size
I am sure I'm doing something stupid, if someone could point out what I would be most grateful!
JPanel imageCanvas = new JPanel(); // 'Canvas' to draw on
JScrollPane scrollPane = new JScrollPane();
// set size of 'canvas'
imageCanvas.setMinimumSize(new Dimension(100,100));
// Scroll pane smaller then the size of the canvas so we should get scroll bars right?
scrollPane.setMinimumSize(new Dimension(50,50));
// Add a border to 'canvas'
imageCanvas.setBorder(BorderFactory.createLineBorder(new java.awt.Color(0, 0, 0)));
scrollPane.setViewportView(imageCanvas);

setPreferredSize() is the trick, setMinimumSize() and even setSize() on the component will be ignored by JScrollPane. Here's a working example using a red border.
import java.awt.*;
import javax.swing.*;
public class Scroller extends JFrame {
public Scroller() throws HeadlessException {
final JPanel panel = new JPanel();
panel.setBorder(BorderFactory.createLineBorder(Color.red));
panel.setPreferredSize(new Dimension(800, 600));
final JScrollPane scroll = new JScrollPane(panel);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLayout(new BorderLayout());
add(scroll, BorderLayout.CENTER);
setSize(300, 300);
setVisible(true);
}
public static void main(final String[] args) throws Exception {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new Scroller().setVisible(true);
}
});
}
}

// suggest a size of 'canvas'
_ImageCanvas.setPreferredSize(new Dimension(100,100));
// Scroll pane smaller then the size of the canvas so we should get scroll bars right?
_ScrollPane.setPreferredSize(new Dimension(50,50));
// ..later
_Frame.pack();

Set preferred size on the canvas.
Increase dimensions 100,100 is too small atleast on my computer.
You may want to use new GridLayout(1,1); for you JFrame if you want the scrollpane to expand when you expand the frame.

As far as I remember there are 2 options:
define the preferredSize of _ImageCanvas
create a subclass of JPanel and implement Scrollable: http://docs.oracle.com/javase/7/docs/api/javax/swing/Scrollable.html
For more details, see the Javadoc:
http://docs.oracle.com/javase/7/docs/api/javax/swing/JScrollPane.html

Check out the Scrollable interface, this may help with the sizing issues.
These two method maybe helpful:
boolean getScrollableTracksViewportWidth();
boolean getScrollableTracksViewportHeight();

Make a Java JScrollpane only scroll vertically

I would like my entire JFrame to vertically scroll.
I have added the following code, but it only creates a horizontal scrollbar.
frame.setContentPane(new JScrollPane(new GradeQuickResource()));
I want to do the opposite. I ONLY want a vertical scrollbar and NO horizontal scrollbar.
I have seen the horizontal policy code, but it doesn't seem to work. I do not know what to name it. This code looks something like this:
setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);
Thanks!

Try this:
public class AddScrollBarToJFrame {
public static void main(String[] args) {
JPanel panel = new JPanel();
JScrollPane scrollBar = new JScrollPane(panel,
JScrollPane.VERTICAL_SCROLLBAR_ALWAYS,
JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);
JFrame frame = new JFrame("AddScrollBarToJFrame");
frame.add(scrollBar);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(400, 400);
frame.setVisible(true);
}
}
Also, you can have a look at How to use a ScrollBar in both vertical and horizontal direction.

AFIK:
JScrollPane scrollableTa=new JScrollPane(targetComp);
scrollableTa.setHorizontalScrollBar(null);
works

Swing: Showing a transparent Panel hovering over another Panel

I want to show a textArea showing some text (will show log lines) , and have an animated gif hoovering above it. I tried the solution described here , but all I get is a grey screen. Hints?
public class TestLayeredPanes {
private JFrame frame = new JFrame();
private JLayeredPane lpane = new JLayeredPane();
public TestLayeredPanes() {
frame.setPreferredSize(new Dimension(600, 400));
frame.setLayout(new BorderLayout());
frame.add(lpane, BorderLayout.CENTER);
//Build the animated icon
JLabel buildingIcon = new JLabel();
buildingIcon.setIcon(new ImageIcon(this.getClass().getResource(
"/com/ct/tasks/cmviewer/gui/progress_bar.gif")));
JPanel iconPanel = new JPanel();
iconPanel.add(buildingIcon);
//Build the textArea
JTextArea textLog = new JTextArea("Say something");
JPanel textPanel = new JPanel();
textPanel.add(new JScrollPane(textLog));
//Add the panels to the layered pane
lpane.add(textPanel, 0);
lpane.add(iconPanel, 1);
frame.pack();
frame.setVisible(true);
}
public static void main(String[] args) {
new TestLayeredPanes();
}
}

Try putting your animated GIF on the glass pane of your root pane:
http://download.oracle.com/javase/tutorial/uiswing/components/rootpane.html

JXLayer make easier to do that. Look at JXLayer samples.
You also can take a look at code of XSwingX

Since you started with a working example, why did you remove lines of code from the example you copied?
Layered panes don't use a layout manager therefore the size of your components are (0, 0), so there is nothing to display. The setBounds(...) method in the example are there for a reason.