This is the code I wrote. It works only problem I can't resize the images. I've tried out getScaledInstance wasn't working. Any ideas on how to fix this. Also, why did I have to use a container to show the pictures shouldn't the panels be enough to show the results but until I added the container I wasn't getting any outputs.
package split;
import javax.swing.event.*;
import java.awt.*;
import javax.swing.*;
import javax.swing.event.ListSelectionEvent;
import javax.swing.event.ListSelectionListener;
import java.awt.Container;
public class Split extends JFrame implements ListSelectionListener{
JFrame f;
JSplitPane s1;
JList list1;
JPanel listP,ImgP;
JLabel img;
Container contentPane;
String a[] = {"Mercury", "Venus", "Earth", "Mars", "Jupiter", "Saturn", "Uranus", "Neptune"};
Split(){
list1 = new JList(a);
list1.addListSelectionListener(new ListSelectionListener(){
@Override
public void valueChanged(ListSelectionEvent e) {
switch(list1.getSelectedIndex()){
case 0:
img.setIcon(new ImageIcon("C:\\Users\\DELL\\Desktop\\Planets\\Mercury_profile_MDIS_MESSENGER.jpg"));
break;
case 1:
img.setIcon(new ImageIcon("C:\\Users\\DELL\\Desktop\\Planets\\Venus_from_Mariner_10.jpg"));
break;
case 2:
img.setIcon(new ImageIcon("C:\\Users\\DELL\\Desktop\\Planets\\download.jpg"));
break;
case 3:
img.setIcon(new ImageIcon("C:\\Users\\DELL\\Desktop\\Planets\\download (1).jpg"));
break;
case 4:
img.setIcon(new ImageIcon("C:\\Users\\DELL\\Desktop\\Planets\\Jupiter_and_its_shrunken_Great_Red_Spot.jpg"));
break;
case 5:
img.setIcon(new ImageIcon("C:\\Users\\DELL\\Desktop\\Planets\\download (2).jpg"));
break;
case 6:
img.setIcon(new ImageIcon("C:\\Users\\DELL\\Desktop\\Planets\\download (3).jpg"));
break;
case 7:
img.setIcon(new ImageIcon("C:\\Users\\DELL\\Desktop\\Planets\\Neptune_-_Voyager_2_(29347980845)_flatten_crop.jpg"));
break;
}
}
});
listP = new JPanel();
listP.add(list1);
img = new JLabel();
ImgP = new JPanel();
ImgP.add(img);
s1 = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT,listP, ImgP);
s1.setOneTouchExpandable(true);
s1.setDividerLocation(150);
contentPane = getContentPane();
contentPane.add(s1);
setSize(500,500);
setVisible(true);
}
public static void main(String[] args) {
new Split();
}
@Override
public void valueChanged(ListSelectionEvent e) {
throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
}
}
CodePudding user response：
When using a JList, any resizing that is required can be done in the renderer. E.G. the images in the list on the left are 10% of the size of the main view when selected.
Here is the renderer:
class ScaledImageListCellRenderer extends DefaultListCellRenderer {
@Override
public Component getListCellRendererComponent(
JList list, Object value, int index, boolean isSelected, boolean cellHasFocus) {
Component c = super.getListCellRendererComponent(
list, value, index, isSelected, cellHasFocus);
JLabel l = (JLabel)c;
BufferedImage bi = (BufferedImage)value;
int w = bi.getWidth();
int h = bi.getHeight();
String s = w "x" h;
l.setText(s);
l.setIcon(new ImageIcon(bi.getScaledInstance(w/10, h/10, BufferedImage.SCALE_FAST)));
return l;
}
};
Here is the self-contained source code that uses the renderer:
import java.awt.*;
import java.awt.image.*;
import java.util.Random;
import javax.swing.*;
import javax.swing.event.*;
public class ScaleBigImages {
int sz = 50;
int s = 10;
Random random = new Random();
JLabel imageLabel = new JLabel();
ScaleBigImages() {
init();
}
protected final void init() {
JPanel gui = new JPanel(new BorderLayout(2,2));
JList list = new JList();
gui.add(new JScrollPane(list), BorderLayout.LINE_START);
DefaultListModel dlm = new DefaultListModel();
for (int ii=0; ii<19; ii ) {
dlm.addElement(getBigImage());
}
list.setModel(dlm);
list.setCellRenderer(new ScaledImageListCellRenderer());
imageLabel.setIcon(new ImageIcon(new BufferedImage(
s*sz,s*sz, BufferedImage.TYPE_INT_ARGB)));
JPanel center = new JPanel(new GridBagLayout());
center.add(imageLabel);
gui.add(center);
ListSelectionListener lsl = new ListSelectionListener() {
@Override
public void valueChanged(ListSelectionEvent e) {
BufferedImage bi = (BufferedImage) list.getSelectedValue();
imageLabel.setIcon(new ImageIcon(bi));
}
};
list.addListSelectionListener(lsl);
list.getSelectionModel().setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
JFrame f = new JFrame("Scale Big Images");
f.setLocationByPlatform(true);
f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
f.add(gui);
f.pack();
f.setMinimumSize(f.getSize());
f.setVisible(true);
}
class ScaledImageListCellRenderer extends DefaultListCellRenderer {
@Override
public Component getListCellRendererComponent(
JList list, Object value, int index, boolean isSelected, boolean cellHasFocus) {
Component c = super.getListCellRendererComponent(
list, value, index, isSelected, cellHasFocus);
JLabel l = (JLabel)c;
BufferedImage bi = (BufferedImage)value;
int w = bi.getWidth();
int h = bi.getHeight();
String s = w "x" h;
l.setText(s);
l.setIcon(new ImageIcon(bi.getScaledInstance(w/10, h/10, BufferedImage.SCALE_FAST)));
return l;
}
};
private BufferedImage getBigImage() {
int w = s*sz;
int h = s*sz;
int r = random.nextInt(s/2);
if (random.nextBoolean()) {
w -= r*sz;
} else {
h -= r*sz;
}
return new BufferedImage(w,h,BufferedImage.TYPE_INT_RGB);
}
public static void main(String[] args) {
Runnable r = new Runnable() {
@Override
public void run() {
new ScaleBigImages();
}
};
SwingUtilities.invokeLater(r);
}
}
CodePudding user response：
I might suggest using a JScrollPane, which would allow your JLabel/image to occupy more space then is currently available to the window, for example...
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JList;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JSplitPane;
import javax.swing.event.ListSelectionEvent;
import javax.swing.event.ListSelectionListener;
public final class Main {
public static void main(String[] args) {
new Main();
}
public Main() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
JFrame frame = new Split();
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class Split extends JFrame {
public Split() {
String a[] = {"Mercury", "Venus", "Earth", "Mars", "Jupiter", "Saturn", "Uranus", "Neptune"};
JList list1 = new JList(a);
final JLabel img = new JLabel();
list1.addListSelectionListener(new ListSelectionListener() {
@Override
public void valueChanged(ListSelectionEvent e) {
if (e.getValueIsAdjusting()) {
return;
}
try {
switch (list1.getSelectedIndex()) {
case 0:
img.setIcon(new ImageIcon(ImageIO.read(getClass().getResource("/images/Cute1.png"))));
break;
case 1:
img.setIcon(new ImageIcon(ImageIO.read(getClass().getResource("/images/Cute2.png"))));
break;
case 2:
img.setIcon(new ImageIcon(ImageIO.read(getClass().getResource("/images/Cute3.png"))));
break;
case 3:
img.setIcon(new ImageIcon(ImageIO.read(getClass().getResource("/images/Cute4.png"))));
break;
case 4:
img.setIcon(new ImageIcon(ImageIO.read(getClass().getResource("/images/Cute5.png"))));
break;
case 5:
img.setIcon(new ImageIcon(ImageIO.read(getClass().getResource("/images/Cute6.png"))));
break;
case 6:
img.setIcon(new ImageIcon(ImageIO.read(getClass().getResource("/images/Cute7.png"))));
break;
case 7:
img.setIcon(new ImageIcon(ImageIO.read(getClass().getResource("/images/Cute8.png"))));
break;
}
} catch (IOException ex) {
JOptionPane.showMessageDialog(img, "Could not load image", "Error", JOptionPane.ERROR_MESSAGE);
}
}
});
JPanel basePane = new JPanel(new BorderLayout()) {
@Override
public Dimension getPreferredSize() {
return new Dimension(400, 400);
}
};
basePane.add(new JScrollPane(img));
JSplitPane s1 = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT, new JScrollPane(list1), basePane);
s1.setOneTouchExpandable(true);
s1.setDividerLocation(150);
add(s1);
}
}
}
See How to Use Scroll Panes for more details.
You should also learn to make use of ImageIO.read, it will save you a lot of issues and hair pulling in the long run, see Reading/Loading an Image
If you still want to resize the image, then you could also have a look at ...
- Drawn image inside panel seems to have wrong x,y offset
- How do I resize images inside an application when the application window is resized?
- Quality of Image after resize very low -- Java
- Java: maintaining aspect ratio of JPanel background image
- Scale the ImageIcon automatically to label size
as few examples