Trying to add ScrollPane in Jpanel with null layout inside BorderLayout - java

I am trying to add a scrollbar in jpanel with null layout.
I want to create a form. This should should display few buttons at the bottom at all times.Any content inside form should maintain it's size and ratio even if the parent container is resized.
Here is what I've come with. I have a panel with borderlayout and added buttons at the south of border. Then created another jpanel to contain form that is added at the center of parent jpanel. Since I want form to maintain it's ratio I went with null layout for inner panel. But I want it to display scrollbar when content is not fully visible. enter image description here
Now adding inner jpanel into scrollpane and adding scrollpanel into parent panel (.add(scrollpane, BorderLayout.CENTER)) doesn't give desired format.
Is there any thing that I can do to get desired format?
Here is code Sample:
public static void main(String[] args) {
JFrame jFrame = new JFrame();
jFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
jFrame.setSize(new Dimension(1000, 700));
Container c = jFrame.getContentPane();
c.setLayout(new BorderLayout());
bottomPanel(c);
centerPanel(c); //scrollbar should go in this panel
jFrame.setVisible(true);
}
private static void centerPanel(Container c) {
JPanel centerPanel = new JPanel();
centerPanel.setLayout(null);
JButton button = new JButton("This jObject should not resize when window resizes and also should maintain relative position.");
button.setBounds(new Rectangle(10, 10, 600, 50));
JButton button1 = new JButton("Just like it works in this code. Just Add ScrollPane to centerPanel That is in green backround");
button1.setBounds(new Rectangle(10, 70, 600, 50));
JButton button2 = new JButton("For clearity");
button2.setBounds(new Rectangle(10, 130, 600, 50));
centerPanel.add(button);
centerPanel.add(button1);
centerPanel.add(button2);
centerPanel.setBackground(Color.GREEN);
c.add(centerPanel, BorderLayout.CENTER);
}
private static void bottomPanel(Container c) {
JPanel bottomPanel = new JPanel(); //Buttons that goes at the bottom of screen will go in here
JPanel bottomInnerPanel = new JPanel();
bottomInnerPanel.setLayout(new BorderLayout());
bottomPanel.setLayout(new GridLayout());
bottomInnerPanel.add(new JButton("Add"), BorderLayout.WEST);
bottomInnerPanel.add(new JButton("Search"), BorderLayout.EAST);
bottomPanel.add(bottomInnerPanel);
bottomPanel.setBorder(BorderFactory.createLineBorder(Color.BLACK));
c.add(bottomPanel, BorderLayout.SOUTH);
}

Related

Java Swing Scrollpane not scrolling

I want to be able to scroll down a dynamically generated list of movies. I tried adding a Scrollpane.
I have a navigation bar at the page start and in the center a jpanel with all the movies.
You can recreate this example by using this code:
private static JFrame frame;
public static void main(String[] args) throws HeadlessException {
frame = new JFrame();
frame.setLayout(new BorderLayout());
frame.setBackground(new Color(32, 32, 32));
JPanel navigationPanel = createNavigationBar();
frame.add(navigationPanel, BorderLayout.PAGE_START);
JPanel moviePanel = createMoviePanel();
frame.add(moviePanel, BorderLayout.CENTER);
frame.setPreferredSize(new Dimension(1920, 1080));
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setTitle("Example App");
frame.pack();
frame.setExtendedState(JFrame.MAXIMIZED_BOTH);
frame.setVisible(true);
}
// MoviePanel Class
public static JPanel createMoviePanel() {
JPanel parentMoviePanel = new JPanel(new FlowLayout(FlowLayout.CENTER, 0, 25));
JPanel contentPanel = new JPanel(new GridLayout(0, 1));
JPanel moviePanel = new JPanel(new GridLayout(0, 9, 8, 5));
JScrollPane scrollPane = new JScrollPane(moviePanel);
scrollPane.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);
scrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
scrollPane.getVerticalScrollBar().setPreferredSize(new Dimension(0, 0));
scrollPane.setBorder(new EmptyBorder(0, 0, 0, 0));
parentMoviePanel.setBackground(new Color(32, 32, 32));
contentPanel.setBackground(new Color(32, 32, 32));
moviePanel.setBackground(new Color(32, 32, 32));
final File root = new File("");
for (int i = 0; i < 70; i++) {
// Get the image and scale it down
BufferedImage movieCover=new BufferedImage(150,200,BufferedImage.TYPE_INT_RGB);
Graphics2D g2d=(Graphics2D)movieCover.getGraphics();
g2d.setColor(Color.GRAY);
g2d.fillRect(0,0,movieCover.getWidth(),movieCover.getHeight());
// Create button and change settings
JButton movieButton = new JButton("Movie " + i, new ImageIcon(movieCover));
movieButton.setMargin(new Insets(0, 0, 0, 0));
movieButton.setPreferredSize(new Dimension(180, 250));
movieButton.setForeground(Color.WHITE);
movieButton.setContentAreaFilled(false);
movieButton.setBorderPainted(false);
movieButton.setFocusPainted(false);
movieButton.setHorizontalTextPosition(JButton.CENTER);
movieButton.setVerticalTextPosition(JButton.BOTTOM);
moviePanel.add(movieButton);
scrollPane.revalidate();
}
contentPanel.add(moviePanel);
contentPanel.add(scrollPane);
parentMoviePanel.add(contentPanel);
return parentMoviePanel;
}
// Navbar Class
public static JPanel createNavigationBar() {
JPanel navBar = new JPanel();
navBar.setLayout(new FlowLayout(FlowLayout.LEFT, 30, 20));
navBar.setBackground(new Color(25, 25, 25));
JButton homeButton = new JButton("Home");
homeButton.setContentAreaFilled(false);
homeButton.setBorderPainted(false);
homeButton.setFocusPainted(false);
JButton movieButton = new JButton("Movies");
movieButton.setContentAreaFilled(false);
movieButton.setBorderPainted(false);
movieButton.setFocusPainted(false);
// Add all the buttons to the navbar
navBar.add(homeButton);
navBar.add(movieButton);
return navBar;
}
What I'm trying to do is to scroll down this list of movies, using my mouse wheel without seeing any kind of scrollbar. It should look exactly how it looks now, but I want to be able to scroll down and see all the movies.
I don't know why it isn't working that's why I'm asking here in hope someone can explain to me what I'm doing wrong.
Your usage of a scroll pane is incorrect.
A Swing component can only have a single parent. The following code is creating the scroll pane with a child component. However you then remove the moviePanel from the scroll pane when you add it to the content pane.
So the scroll pane has no child component and will never work.
JScrollPane scrollPane = new JScrollPane(moviePanel);
...
contentPanel.add(moviePanel);
contentPanel.add(scrollPane);
However, even that won't solve your problem because you are now using a FlowLayout on your top level panel so all the child components will always be displayed at their preferred size so there is no need for scroll bars.
Get rid of all the scroll pane logic in your createMoviePanel() method.
Instead you probably want to add the scroll pane to the content pane:
//frame.add(moviePanel, BorderLayout.CENTER);
frame.add(new JScrollPane(moviePanel), BorderLayout.CENTER);
Now the scroll pane will dynamically resize as the frame size changes. Scrollbars will then appear as required.

Why does Java pack does not size frame properly when textarea is used with other components?

I am creating a GUI using GridLayout to arrange multiple panels that are using FlowLayout. I am using pack to determine the size of the frame. If I have only a TextArea then it sizes correctly. If I have only other components it sizes correctly. But if I use both p1 and p2 in the code below the panel with the buttons does not size properly. The test code I am using is below. If I use only p1 or p2 it sizes properly, but not with both: Here is the image I am getting. I don't want all that extra space between the buttons and the textarea.
If I do textarea alone it sizes properly.:
public class GUIPractice extends JFrame
{
//declare GUI objects
JPanel panel;
JPanel p1, p2;
JButton btnAdd, btnShow;
JScrollPane js;
JTextArea taOutput;
//constructor
public GUIPractice()
{
//give frame a title
setTitle("GUI Practice");
panel =new JPanel(new GridLayout(0, 1));
btnAdd = new JButton("Add");
btnShow = new JButton("Show");
taOutput = new JTextArea(10, 20);
js = new JScrollPane(taOutput, JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED,
JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);
p1 = new JPanel();
p1.add(btnAdd);
p1.add(btnShow);
p2 = new JPanel();
p2.add(js);
panel.add(p1);
panel.add(p2);
//add the panel to the frame
add(panel);
}
public static void main(String[] args)
{
GUIPractice frame = new GUIPractice();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setVisible(true);
}
}
It sizes correctly. The GridLayout means that all cells will be the same size. Since the text area is bigger than the buttons, you see extra space in the panel containing the buttons.
I would suggest you just use the default BorderLayout of the frame.
There is no need for your "panel" using the GridLayout.
You just use:
add(p1, BorderLayout.PAGE_START);
add(p2, BorderLayout.CENTER);
Now the p1 and p2 will be the proper height.
Also, there really is no need for "p2". You can just add the scroll pane directly to the frame.

How to set position to JComponent in BoxLayout?

I want to use 2 JPanel as panel and panel_1.
I want to add image automatically to panel using JLabel
and also add JButton to panel_1.
How can I resize button according to the image which is above the button?
public class Testing extends JFrame {
public Testing() {
this.setSize(590, 327);
this.setTitle("JFrame");
getContentPane().setLayout(null);
JPanel panel = new JPanel();
panel.setBounds(118, 136, 321, 89);
getContentPane().add(panel);
panel.setLayout(new BoxLayout(panel, BoxLayout.X_AXIS));
JLabel lblImage = new JLabel("image for button1");
panel.add(lblImage);
JLabel lblImage_1 = new JLabel("image for button2");
panel.add(lblImage_1);
JLabel lblImage_2 = new JLabel("image for button3");
panel.add(lblImage_2);
JPanel panel_1 = new JPanel();
panel_1.setBounds(118, 30, 321, 77);
getContentPane().add(panel_1);
panel_1.setLayout(new BoxLayout(panel_1, BoxLayout.X_AXIS));
JButton btnNewButton = new JButton("New button 1");
panel_1.add(btnNewButton);
JButton btnNewButton_1 = new JButton("New button 2");
panel_1.add(btnNewButton_1);
JButton btnNewButton_2 = new JButton("New button 3");
panel_1.add(btnNewButton_2);
}
public static void main(String[] args) throws Exception {
Testing frame = new Testing();
frame.setVisible(true);
frame.setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
}
}
If your goal is to have the button above the image, and have the button's width expand with the image, then:
Get rid of your use of null layouts and .setBounds(...) (this is just good general advice)
Put the JLabel with the image into a JPanel that uses BorderLayout with the JLabel in the BorderLayout.CENTER position
Put the button above the JLabel in the same JPanel using the BorderLayout.PAGE_START position.
Then put that JPanel wherever it is needed in the GUI, nesting JPanels, each using their own layout manager.
The BorderLayout will allow the center component to fill that position, and will expand the PAGE_START and PAGE_END positions to fill the width necessary. If the top and bottom components are wider, then this will also expand the width of the container.

How to change width size of Jpanels in BorderLayout?

I have main JPanel which is Borderlayout with added 4 JPANELS: NORTH(Green), WEST(Red), CENTER(Gray), SOUTH(Blue). I want to reduce width size of WEST(Red) Jpanel, or increase width size of Center(Grey) Jpanel.
Screenshot:
Here is my code:
frame = new JFrame("FreshPos baza podataka");
frame.setExtendedState(JFrame.MAXIMIZED_BOTH);
// Main paneel
JPanel panel = new JPanel();
panel.setLayout(new BorderLayout());
panel.setBorder( BorderFactory.createEmptyBorder(10,10,10,10) );
frame.getContentPane().add(panel);
//West panel;
JPanel panelWest = new JPanel(new GridLayout(14,0,0,2));
panelWest.setPreferredSize(new Dimension(300, 300));
panelWest.setBorder( BorderFactory.createEmptyBorder(100,0,0,0) );
panel.add(panelWest, BorderLayout.WEST);
panelWest.setBackground(Color.red);
for (int i = 0; i < MAX_TABLES; i++) {
buttonsTables[i] = new JButton(tables[i]);
buttonsTables[i].setMaximumSize(new Dimension(Integer.MAX_VALUE, buttonsTables[i].getMinimumSize().height));
panelWest.add(buttonsTables[i]);
panelWest.add(Box.createVerticalStrut(10));
}
//South panel;
JPanel southPanel = new JPanel(); // Donji layout za dugmice
southPanel.setBorder( BorderFactory.createEmptyBorder(20,0,0,0) );
panel.add(southPanel, BorderLayout.SOUTH);
southPanel.setBackground(Color.BLUE);
JButton buttonDodaj = new JButton("Dodaj");
southPanel.add(buttonDodaj);
JButton buttonIzmeni = new JButton("Izmeni");
southPanel.add(buttonIzmeni);
JButton butonObrisi = new JButton("Obrisi");
southPanel.add(butonObrisi);
//North panel;
JPanel northPanel = new JPanel(); // Donji layout za dugmice
northPanel.setBorder( BorderFactory.createEmptyBorder(0,10,0,0) );
panel.add(northPanel, BorderLayout.NORTH);
northPanel.setBackground(Color.green);
JButton buttonImport = new JButton("Importuj fajl");
buttonImport.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
importActionPerformed(evt);
}
});
northPanel.add(buttonImport, BorderLayout.WEST);
JButton ButtonRecord = new JButton("Snimi fajl");
northPanel.add(ButtonRecord, BorderLayout.WEST);
// Central panel
JPanel centerPanel = new JPanel(new BorderLayout());
centerPanel.setBackground(Color.GRAY);
panel.add(centerPanel, BorderLayout.CENTER);
I want to reduce width size of WEST(Red) Jpanel
panelWest.setBorder( BorderFactory.createEmptyBorder(100,0,0,0) );
So why is the width of your Border so large?
A Border is for "extra" space around the components.
So the width of your panel is the width of the buttons plus the width of the border.
Edit:
panelWest.setPreferredSize(new Dimension(300, 300));
Don't hardcode a preferred size. The layout manager will calculate the size based on the above logic. Get rid of that statement.
Edit 2:
// buttonsTables[i].setMaximumSize(new Dimension(Integer.MAX_VALUE, buttonsTables[i].getMinimumSize().height));
Get rid of any logic that attempts to control the size of a component. The point of using layout managers is to let the layout manager do the size calcualtions.
So for your buttons panel you need to nest panels to prevent the buttons from taking all the space.
You can do something like:
JPanel wrapper = new JPanel();
wrapper.add(buttonsPanel);
...
//panel.add(panelWest, BorderLayout.WEST);
panel.add(wrapper, BorderLayout.WEST);
By default a JPanel uses a FlowLayout which will respect the preferred size of any component added to it.
Another option is to use a GridBagLayout with the wrapper panel. By default the panel will then be displayed in the "center" of the available space. So it will be vertically centered and you won't need the EmptyBorder.

Move a JLabel inside of JPanel without losing hierarchy

So I'm moving a JLabel inside of JPanel and I want the JPanel to automatically show scrolls bars that lead you to the JLabel wich I moved out of it.
The problem is that when I set the new JLabel location and this location is out of the JPanel, it loses its hierarchy so the JLabel stops being part of the JPanel and as a result the panel doesn't scrolls and you can't see the JLabel. So this is my code if you can tell how can I do this. Thanks.
//Panel creation
JPanel panel = new JPanel();
panel.setSize(500, 500);
panel.setAutoscrolls(true);
//Label creation
JLabel label = new JLabel();
label.setText("Hi");
label.setSize(40, 40);
//Adding Jlabel to Panel
panel.add(label);
label.setLocation(800, 200);//this invalidates inherancy
What you need to do it encapsulate the JPanel inside a JScrollPane and increase its size with setPreferredSize()
Note that using setSize() setWidth() or setHeight() will be ignored by the scroll pane
A example code of how to set it up follows:
public class TestFrame extends JFrame {
public TestFrame() {
setLayout(null);
setSize(500, 500);
JPanel panel = new JPanel();
panel.setBackground(Color.BLUE);
JScrollPane scroll = new JScrollPane();
scroll.setViewportView(panel);
add(scroll);
scroll.setBounds(100, 100, 200, 200);
panel.setPreferredSize(new Dimension(800, 800));
}
public static void main(String[] args) {
TestFrame frame = new TestFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
}
In this example, the JScrollPane is fixed with 200x200 size, while the JPanel inside it has a size of 800x800. You can change this value dynamically as you move your JLabel around.
Also, I'd like to mention that null layouts is not the correct approach. In this example, I wanted to minimize the influence of LayoutManagers and underlying calls to setBounds() by them to emphasize the point I'm trying to get across, which is a pure change of size inside a JScrollPane. The whole JFrame is just a "vessel" for the example.

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