Using scrollbars with absolute layout in Swing - java

I am not able to use scroll bars with absolute layout in Swing.
I don't wish to use this layout but I have to display dynamic objects on my panel on click of a button and align them using setBounds which can be done using this layout only (I guess).
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class clothes2 extends javax.swing.JFrame {
JTextField n=null;
JButton m=null;
public clothes2(){
initComponents();
}
public void initComponents() {
Container contentPane = getContentPane();
contentPane.setLayout(new BorderLayout());
final JPanel jp = new JPanel();
contentPane.setPreferredSize(new Dimension(320,200));
jp.setLayout(null);
m=new JButton("add");
m.setBounds(0,0,50,50);
jp.add(m);
m.addMouseListener( new MouseAdapter() {
int x=0;
int y=0;
public void mouseClicked(MouseEvent me){
x+=100;
y+=100;
jp.add(n=new JTextField("Name"));
n.setBounds(x, y, 50, 50);
jp.add(n=new JTextField("code"));
x+=100;
n.setBounds(x,y, 50, 50);
jp.revalidate();
jp.repaint();
x=0;
}
});
int v = ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS;
int h = ScrollPaneConstants.HORIZONTAL_SCROLLBAR_ALWAYS;
JScrollPane jsp = new JScrollPane(jp, v, h);
contentPane.add(jsp, BorderLayout.CENTER);
}
public static void main(String args[]) {
EventQueue.invokeLater(new Runnable() {
public void run() {
JFrame f= new clothes2();
f.setVisible(true);
f.setSize(640,320);
}
});
}
}

Set preferred size of the container.

JScrollBar uses the preferred size of the component inside it to determine how large the scroll bars should be, and if they should be displayed.
Usually, the layout manager handles this using the preferredLayoutSize method. This can be overriden by explicitly setting the preferred size of the component.
So either you have to set the preferred size, or use a custom layout manager that calculates it for you.
see also here
might help you.

display dynamic objects .. which can be done using this layout only (I guess).
You guess wrong.
See this GUI, that can not only change PLAFs at run-time, but also dynamically add new components1. Click to..
Add Another Label
This example adds the new labels to a GridLayout - but the principle is the same for any layout (or any component).

add layout
jp.setLayout(new FlowLayout());

Related

Why doesn't the image paint over my JPanel?

I have been struggling with this for some time. At first, I only used ActionListener, then I added the paintComponent, but I have no idea what to put there. I read some tutorials and used their code as an example, but it still doesn't work. Right now, the end result is the same as it was without PaintComponent.
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
public class Scream extends JPanel {
private JButton button = new JButton("OK");
private Color screenColor;
private JPanel panel = new JPanel();
private JFrame frame;
private Dimension screenSize;
private ImageIcon image;
private JLabel label = new JLabel(image);
private int x;
private int y;
private boolean mouseClicked;
public Scream() {
button.addActionListener(new ActionListener(){
#Override
public void actionPerformed(ActionEvent e ) {
if (e.getSource() == button) {
mouseClicked = true;
frame.getContentPane().add(label);
frame.setSize(image.getIconWidth(), image.getIconHeight());
panel.repaint();
}
}
});
frame = new JFrame ("Existential angst");
screenColor = new Color(150, 100, 0);
panel.setBackground( screenColor );
frame.add(button, BorderLayout.PAGE_END);
frame.add(panel);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(1300, 700);
frame.setVisible(true);
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
image.paintComponent(this, g, 1300, 700);
}
public static void main (String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
Scream scream = new Scream();
}
});
}
}
If you are trying to dynamically add an image to a panel then you need to add the label to the panel. There is no need for any custom painting.
The basic code for adding components to a visible GUI is:
panel.add(...);
panel.revalidate();
panel.repaint();
Also, don't attempt to set the size of the frame to the size of the image. A frame contains a titlebar and borders. Instead you can use frame.pack();
I noticed a couple of issues:
image is never initialized to anything so it is null, effectively making the label empty. I assume maybe your example was just incomplete?
Once I initialized the image to something, your example still did not work. Turns out adding label without specifying any constraint basically does nothing (I assume since adding a component to a border layout without a constraint puts it in the center where panel already is). When I added the label to BorderLayout.NORTH, everything worked (though resizing the frame to the size of the image makes it only partially visible since the frame includes the OK button)

Why doesn't my button position properly on my JFrame no layout?

So I've got a JFrame which uses setLayout(null) so I can position my elements by hand.
However, when accessing the content pane and getting the size for the frame, it says its height is 1.0.
Does anyone know how I can fix this?
Here is the code:
import javax.swing.*;
import java.awt.*;
public class Launcher extends JFrame
{
public Launcher(String title) {
super(title);
setLayout(null);
pack();
setSize(new Dimension(LauncherUtil.LAUNCHER_WIDTH, LauncherUtil.LAUNCHER_HEIGHT));
setLocationRelativeTo(null);
setResizable(false);
setDefaultCloseOperation(EXIT_ON_CLOSE);
displayComponents();
}
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
Launcher launch = new Launcher(LauncherUtil.LAUNCHER_TITLE);
launch.setVisible(true);
}
});
}
private void displayComponents() {
Dimension size = getContentPane().getSize();
JButton launchButton = new JButton("Launch Game");
System.out.println(size.getHeight());
launchButton.setBounds(0, (int)size.getHeight() - 60, (int)size.getWidth(), 60);
add(launchButton);
}
}
may be if you try to get the screen size by using Toolkit would be work like you want
Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
it brings you the screen size where java program is running. Hope it helps.
The content pane is a JPanel whose default size is 1x1px. Since you did not put any components into the content pane and have not set a preferred size for the panel, the content pane's size remains 1x1px.
One way to fix this is to call these three methods in the following order:
setLayout(null);
setPreferredSize(new Dimension(300, 400));
pack();
However, you should be using a layout manager instead of managing
the size and position of your components by hand.

JButton not changing size

I've researched the ways to change the size of a jbutton to be displayed on a JFrame.
I am trying both the button.setSize(200,200) and button.setPreferredSize(new Dimension(200,200)), but it does not change. Here's the code:
import java.awt.Color;
import java.awt.Dimension;
import javax.swing.JButton;
import javax.swing.JFrame;
public class Index extends JFrame{
private String title = "This is the motherfucking title";
Dimension dim = new Dimension(500,500);
public Index(){
this.setResizable(false);
this.setTitle(title);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setSize(dim);
this.getContentPane().setBackground(Color.BLACK);
JButton button = new JButton("Button");
button.setSize(200,200);
this.add(button);
}
public static void main(String args[]){
Index ih = new Index();
ih.setVisible(true);
}
}
Here's the result: http://i.imgur.com/Llj0pfo.png
What am I doing wrong?
try this:
JButton button = new JButton("Button");
button.setSize(200,200);
getContentPane().setLayout(null);
getContentPane().add(button);
setVisible(true);
inside your constructor.
this.add(button);
You are adding the button to the content pane of the frame. By default the content uses a BorderLayout and the component is added to the CENTER. Any component added to the CENTER will automatically get the extra space available in the frame. Since you set the size of the frame to (500, 500) there is lots of space available.
As a general rule you should NOT attempt to set the preferred size of a component, since only the component know how big it should be in order to paint itself properly. So your basic code should be:
JButton button = new JButton("...");
frame.add(button);
frame.pack();
frame.setVisible(true);
Now the button will be at its preferred size. However, the button will change size if you resize the frame. If you don't want this behaviour, then you need to use a different Layout Manager.
Use SwingUtilities.invokeLater(); create your Index() inside it, then call setVisible(true); at the end of constructor. At the same time remeber that by default JFrame uses BorderLayout.
SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
new Index();
}
});

JButton and jgraphx wont show up at the same time

I have tried several ways, but still havent found the solution. I have a jgraph in a frame and I want to add a Jbutton in that frame also in a specific location. However I only get one of them when i run the program, because they expand to the whole window. Any ideas how to fix this?
Thanks in advance.
public class GUIquery extends JFrame {
JFrame frame;
static JGraph jgraph;
final mxGraph graph = new mxGraph();
final mxGraphComponent graphComponent = new mxGraphComponent(graph);
public GUIquery() {
super("Test");
GraphD();
imgbtn();
}
public void GraphD() {
Object parent = graph.getDefaultParent();
graph.getModel().beginUpdate();
try {
........
}catch {
........
} finally {
graph.getModel().endUpdate();
}
getContentPane().add(graphComponent);
}
public void imgbtn() {
JPanel jpanel = new JPanel();
jpanel.setSize(100, 100);
jpanel.setLocation(1200, 60);
JButton imgbtn = new JButton("Export as Image");
imgbtn.setSize(100, 100);
imgbtn.setLocation(1200, 60);
jpanel.add(imgbtn);
add(jpanel);
}
public static void main(String[] args) {
GUIquery frame = new GUIquery();
frame.setLayout(null);
frame.pack();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(400, 320);
frame.setVisible(true);
}
}
Don't use null layouts. They inevitably result in trouble.
From your code snippet it is impossible to tell where you want them to be relative to each other, the following puts the button below the graph.
The content pane uses BorderLayout by default. For BorderLayout, you need to use place components at different positions:
// the default position, but it does not hurt to be explicit
add(graph, BorderLayout.CENTER);
...
// and the panel
add(jpanel, BorderLayout.SOUTH);
If the positioning is not what you want, take a look at the visual guide to layout managers to pick the layout manager that suits your needs best.
In the button panel the setLocation() and setSize() calls are useless. The layout manager of the panel is responsible for setting the button's bounds. If the default FlowLayout is not what you want for it, use the guide to pick another for the panel too.

placing a transparent JPanel on top of another JPanel not working

I am trying to place a JPanel on top of another JPanel which contains a JTextArea and a button and i want to the upper apnel to be transparent. I have tried it by making the setOpaque(false) of the upper panel. but it is not working. Can anyone help me to get through this? Thanks in advance!
public class JpanelTest extends JPanel
{
public JpanelTest()
{
super();
onInit();
}
private void onInit()
{
setLayout(new BorderLayout());
JPanel panel = new JPanel();
panel.setLayout(new BorderLayout());
panel.add(new JTextArea(100,100),BorderLayout.CENTER);
panel.add(new JButton("submit"),BorderLayout.SOUTH);
JPanel glass = new JPanel();
glass.setOpaque(false);
add(panel,BorderLayout.CENTER);
add(glass,BorderLayout.CENTER);
setVisible(true);
}
public static void main(String args[])
{
new JpanelTest();
}
}
Indeed, it would be useful to tell the reason why you want panels one over another.
Starting with your code, and changing it a lot, I got it to work, but it might not do what you expect...
import java.awt.*;
import javax.swing.*;
public class Test extends JFrame
{
public Test()
{
super();
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(500, 200);
onInit();
setVisible(true);
}
private void onInit()
{
JLayeredPane lp = getLayeredPane();
JPanel panel = new JPanel();
panel.setLayout(new BorderLayout());
panel.add(new JTextArea(), BorderLayout.CENTER);
panel.add(new JButton("Submit"), BorderLayout.SOUTH);
panel.setSize(300, 150); // Size is needed here, as there is no layout in lp
JPanel glass = new JPanel();
glass.setOpaque(false); // Set to true to see it
glass.setBackground(Color.GREEN);
glass.setSize(300, 150);
glass.setLocation(10, 10);
lp.add(panel, Integer.valueOf(1));
lp.add(glass, Integer.valueOf(2));
}
public static void main(String args[])
{
// Schedule a job for the event-dispatching thread:
// creating and showing this application's GUI.
javax.swing.SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
new Test();
}
});
}
}
If totally transparent, well, it is like it isn't here! When opaque, it just covers some of the GUI, but doesn't prevent mouse clicks, for example.
1) there are a few ways, there no issue to put JPanel, with covering full JFrames/JPanel area or only part of Rectangle / Dimension that returns JFrames/JPanel
use JLayer(Java7) based on JXLayer (Java6)
use GlassPane
use JViewport
use OverlayLayout
use transucent JDialog / JWindow
2) everything depends of if you want to protect against mouse and key events from the top layer to bottom, or not (to avoiding redispatch events from - to and vice versa)
Check out this tutorial on using Swing Root Panes.
The glass pane is useful when you want to be able to catch events or paint over an area that already contains one or more components. For example, you can deactivate mouse events for a multi-component region by having the glass pane intercept the events. Or you can display an image over multiple components using the glass pane.

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