Swing change JScrollPane content - swing

Hi I am trying to change JScrollPane content like
scrollPanel = new JScrollPane(new Welcome().display());
for(final JMenuItem i : items) {
i.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
String txt = i.getText();
if(txt.equals("Open")) {
scrollPanel = new JScrollPane(new Open().display());
} else if(txt.equals("Save")) {
scrollPanel = new JScrollPane(new Save().display());
} else if(txt.equals("Save as")) {
scrollPanel = new JScrollPane(new SaveAs().display());
} else if(txt.equals("Close")) {
new Close().ask();
scrollPanel = new JScrollPane();
}
scrollPanel.revalidate();
scrollPanel.repaint();
}
});
}
scrollPanel.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);
scrollPanel.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED);
menuBar.add(menu);
frame.setJMenuBar(menuBar);
frame.add(scrollPanel);
frame.pack();
frame.setSize(640, 480);
frame.setVisible(true);
frame.setDefaultCloseOperation(frame.EXIT_ON_CLOSE);
But its not working.
Each class Open, Save, SaveAs return JPane with JLabel inside.
Ex.
public class Open {
public JPanel display() {
JPanel panel = new JPanel();
panel.add(new JLabel("Open"));
return panel;
}
}

You're not changing the scrollpane content. You're assigning a new JScrollPane instance to the scrollPanel field. The scroll pane you have added to the frame and which is displayed stays exactly as it is.
If you want to change the scroll pane contents, you should use
scrollPanel.setViewportView(new Open().display());

Related

Is there a way to add a JLabel from a class to another CardLayout?

I'm doing a project for school and my goal here is to design a gallery on Swing. One of the features is the possibility to add new images to my gallery and display the new picture. I created a card where you can add your picture by browsing the file explorer on your computer and then it will copy and add the file to the folder of the app. For the moment this part works fine, but when I go back to my GalleryPage CardLayout the image is not displayed (because I don't know how to add it directly). What I'm trying to do is add this new image to the bottomPanel of my GalleryPage java class from newImg [JLabel] on my NewImage java class. Is there a way to do that? I've been browsing the Internet to find an answer but I can't find a solution.
Here is my code:
Gallery.java
public class Gallery extends JPanel {
private GalleryPage panelGalleryPage;
private NewImage newImage;
protected static CardLayout cardGal;
public Gallery() {
super();
setLayout(new CardLayout());
cardGal = (CardLayout) this.getLayout();
panelGalleryPage = new GalleryPage();
newImage = new NewImage();
add(panelGalleryPage, "GalleryPage");
add(newImage, "NewImage");
}
}
GalleryPage.java
public class GalleryPage extends JPanel {
// preparing my grid of images by sorting the filepath of each image.
File directory = new File("oop_2022/src/main/java/com/phone/common/png/Galery_images");
int fileCount = directory.list().length;
private JButton addImg, delImg;
private JLabel title;
private JLabel[] cache = new JLabel[fileCount];
private ImageIcon[] imgGrid = new ImageIcon[fileCount];
private ImageIcon imgTitle, imgAdd, imgDel;
private JSplitPane splitPanel;
private JPanel bottomPanel, topPanel;
private List<String> results;
public GalleryPage() {
super();
setBackground(PowerOn.userInterface.DARK_GREY);
initComponents();
}
public void initComponents() {
// create a split pane
splitPanel = new JSplitPane();
topPanel = new JPanel(); // top component
bottomPanel = new JPanel(); // bottom component
// configure splitPanel
splitPanel.setOrientation(JSplitPane.VERTICAL_SPLIT);
splitPanel.setDividerLocation(100);
splitPanel.setDividerSize(0);
splitPanel.setTopComponent(topPanel);
splitPanel.setBottomComponent(bottomPanel);
// create title
imgTitle = new ImageIcon("oop_2022/src/main/java/com/phone/common/png/images.png");
imgTitle.setImage(imgTitle.getImage().getScaledInstance(80, 80, Image.SCALE_DEFAULT));
title = new JLabel(imgTitle);
// create add Button
imgAdd = new ImageIcon("oop_2022/src/main/java/com/phone/common/png/add.png");
imgAdd.setImage(imgAdd.getImage().getScaledInstance(40, 40, Image.SCALE_DEFAULT));
addImg = new JButton(imgAdd);
addImg.setPreferredSize(new Dimension(60, 40));
// add Actionlisteneer to addImg Button
addImg.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
Gallery.cardGal.show(PowerOn.gallery, "NewImage");
}
});
// create delete Button
imgDel = new ImageIcon("oop_2022/src/main/java/com/phone/common/png/trash.png");
imgDel.setImage(imgDel.getImage().getScaledInstance(40, 40, Image.SCALE_DEFAULT));
delImg = new JButton(imgDel);
delImg.setPreferredSize(new Dimension(60, 40));
// Add title and buttons to the topPanel
topPanel.add(title);
topPanel.add(addImg);
topPanel.add(delImg);
// add the splitPanel to the frame
this.add(splitPanel);
// set top and bottom panel Background
topPanel.setBackground(PowerOn.userInterface.DARK_GREY);
bottomPanel.setBackground(PowerOn.userInterface.DARK_GREY);
// set a GridLayout for the bottomPanel
this.setLayout(new GridLayout());
GridLayout layout = new GridLayout(0, 3, 10, 10);
bottomPanel.setLayout(layout);
// creating an array of file
results = new ArrayList<String>();
File[] files = new File("oop_2022/src/main/java/com/phone/common/png/Galery_images").listFiles();
// retrieving the name of each images
for (File file : files) {
if (file.isFile()) {
results.add(file.getName());
}
}
// create an array of images
for (int i = 0; i < fileCount; i++) {
imgGrid[i] = new ImageIcon(files[i].toString());
}
// loop to sale and add the images to the bottomPanel
for (int i = 0; i < files.length; i++) {
// scaling the images
imgGrid[i].setImage(imgGrid[i].getImage().getScaledInstance(120, 120,
Image.SCALE_SMOOTH));
// add the images to the grid
cache[i] = new JLabel(imgGrid[i]);
bottomPanel.add(cache[i]);
}
}
}
NewImage.java
public class NewImage extends JPanel {
private JLabel title, newImg;
private ImageIcon cacheImg;
private JPanel display;
private JButton choose, back;
private JFileChooser file;
private File selectedFile;
private Gallery addNew;
public NewImage() {
super();
setBackground(PowerOn.userInterface.DARK_GREY);
initComponents();
}
public void initComponents() {
// configure title JLabel
title = new JLabel("Choose a new image to add (jpg or png only)");
title.setHorizontalAlignment(title.CENTER);
// configurin choose JButton + Actionlistener
choose = new JButton("Explore");
file = new JFileChooser();
choose.setPreferredSize(new Dimension(60, 60));
choose.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
int result = file.showOpenDialog(display);
if (result == JFileChooser.APPROVE_OPTION) {
selectedFile = file.getSelectedFile();
// check the type of the file only jpg and png accepted
String check = selectedFile.getAbsolutePath()
.substring(selectedFile.getAbsolutePath().length() - 3);
System.out.println(check);
// if the fil is ok add the file to the gallery directory
if (check.equals("png") || check.equals("jpg")) {
// retrieving the name of the file and copy on the galery folder
try {
String[] parts = selectedFile.getAbsolutePath().split(Pattern.quote(File.separator));
String dest = "oop_2022/src/main/java/com/phone/common/png/Galery_images/"
+ parts[parts.length - 1];
copyFile(selectedFile, new File(dest));
cacheImg = new ImageIcon(dest);
cacheImg.setImage(cacheImg.getImage().getScaledInstance(120, 120, Image.SCALE_DEFAULT));
newImg = new JLabel(cacheImg);
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
JOptionPane.showMessageDialog(null, "Your image as been succesfully uploaded");
}
// if the file is not a png or a jpg display an error message
else {
JOptionPane.showMessageDialog(null, "You must choose a png or jpg file");
}
}
}
});
// configuring back JButton + Actionlistener
back = new JButton("Return to home page");
back.setPreferredSize(new Dimension(60, 60));
back.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
Gallery.cardGal.show(PowerOn.gallery, "GalleryPage");
}
});
// configure layout of panel
this.setLayout(new GridLayout());
// add panels
display = new JPanel();
display.setLayout(new GridLayout(0, 1));
this.add(display);
display.add(title);
display.add(choose);
display.add(back);
}
public static void copyFile(File from, File to) throws IOException {
Files.copy(from.toPath(), new FileOutputStream(to));
}
}
What I want is that the image I added is directly displayed without running the code again when I go back to my gallery page.
my gallery page

Why JScrollPane does not react to mouse wheel events?

I have a JScrollPane containing a panel with a BoxLayout (PAGE AXIS).
My problem is that the JScrollPane does not react to mouse wheel events. To make it scroll using the mouse wheel i need to be on the JScrollBar.
I found this thread and i have no MouseMotionListener or MouseWheelListener, only a MouseListener. I think my problem come from the fact that my JScrollPane act on a JPanel that contains other panels itself. So when the mouse is on a panel within the JScrollPane it seems that the event is consumed by this panel i never seen by the scroll pane.
Is there a correct way to make the events caught by the children of the scroll pane visible to this scroll pane?
SSCCE:
Here a simple test case trying to show when i try to do in my Swing application.
The frame:
public class NewJFrame extends javax.swing.JFrame {
public NewJFrame() {
initComponents();
for (int i = 0; i < 50; i++) {
jPanel1.add(new TestPanel());
}
}
private void initComponents() {
jScrollPane1 = new javax.swing.JScrollPane();
jPanel1 = new javax.swing.JPanel();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
jPanel1.setLayout(new javax.swing.BoxLayout(jPanel1, javax.swing.BoxLayout.PAGE_AXIS));
jScrollPane1.setViewportView(jPanel1);
getContentPane().add(jScrollPane1, java.awt.BorderLayout.CENTER);
pack();
}
public static void main(String args[]) {
java.awt.EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
new NewJFrame().setVisible(true);
}
});
}
}
And the TestPanel definition:
public class TestPanel extends javax.swing.JPanel {
public TestPanel() {
initComponents();
}
private void initComponents() {
jLabel1 = new javax.swing.JLabel();
jLabel2 = new javax.swing.JLabel();
jScrollPane1 = new javax.swing.JScrollPane();
jTextArea1 = new javax.swing.JTextArea();
jLabel1.setText("jLabel1");
setBackground(new java.awt.Color(255, 51, 51));
setLayout(new java.awt.BorderLayout());
jLabel2.setText("TEST LABEL");
jLabel2.setHorizontalTextPosition(javax.swing.SwingConstants.CENTER);
add(jLabel2, java.awt.BorderLayout.PAGE_START);
jTextArea1.setEditable(false);
jTextArea1.setColumns(20);
jTextArea1.setRows(5);
jTextArea1.setFocusable(false);
jScrollPane1.setViewportView(jTextArea1);
add(jScrollPane1, java.awt.BorderLayout.CENTER);
}
}
The JTextArea seems to consume the event since when the mouse cursor is inside it, the scrolling using wheel does not work. I have to put the mouse cursor outside the text area to make it works again.
Walter beat me to analysing the issue :-)
Adding a bit of detail:
It's correct that a JScrollPane supports mouseWheelHandling. According to the rules of mouseEvent dispatching, the top-most (in z-order) component gets the event, and that's the scrollPane around the textArea. So if wheeling the textarea is not required, a simple solution might be to disable the wheel-support in its scrollPane. And JScrollPane even has api for doing it:
scrollPane.setWheelScrollingEnabled(false);
Unfortunately, that doesn't work. Reason it's not working is that this property has no effect in the event dispatch chain which ultimately calls into eventTypeEnabled:
case MouseEvent.MOUSE_WHEEL:
if ((eventMask & AWTEvent.MOUSE_WHEEL_EVENT_MASK) != 0 ||
mouseWheelListener != null) {
return true;
}
This returns true if a mouseWheelListener is installed - which is done unconditionally by BasicScrollPaneUI, and not removed when the wheelEnabled property is changed (the ui doesn't even listen to that property ...) Plus the listener simply does nothing if the property is false. At least one of those facts is a bug, the ui should
either remove/add the listener depending on wheelEnabled
or: implement the listener such that it dispatches the event up the chain (as Walter does in his example)
The first option can be handled by application code:
scrollPane = new JScrollPane();
scrollPane.removeMouseWheelListener(scrollPane.getMouseWheelListeners()[0]);
it's a bit of a hack (as bug-workarounds always are :-), production code would have to listen to the wheelEnable to re-install if needed plus listen to LAF changes to update/re-remove the listeners installed by the ui.
Implementing the second option in slight modification (as to Walter's dispatching) by subclassing the JScrollPane and dispatch the event to parent if the wheelEnabled is false:
scrollPane = new JScrollPane() {
#Override
protected void processMouseWheelEvent(MouseWheelEvent e) {
if (!isWheelScrollingEnabled()) {
if (getParent() != null)
getParent().dispatchEvent(
SwingUtilities.convertMouseEvent(this, e, getParent()));
return;
}
super.processMouseWheelEvent(e);
}
};
scrollPane.setWheelScrollingEnabled(false);
The mouse wheel event gets consumed by the scroll pane around the text area. You can try to manually pass the event to the parent scroll pane like this:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class TestScrollPane2 {
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
// might want to use a http://tips4java.wordpress.com/2009/12/20/scrollable-panel/
JPanel panel = new JPanel(new GridLayout(0, 1));
for (int i = 0; i < 10; i++) {
panel.add(new JScrollPane(new JTextArea(3, 40)) {
#Override
protected void processMouseWheelEvent(MouseWheelEvent e) {
Point oldPosition = getViewport().getViewPosition();
super.processMouseWheelEvent(e);
if(getViewport().getViewPosition().y == oldPosition.y) {
delegateToParent(e);
}
}
private void delegateToParent(MouseWheelEvent e) {
// even with scroll bar set to never the event doesn't reach the parent scroll frame
JScrollPane ancestor = (JScrollPane) SwingUtilities.getAncestorOfClass(
JScrollPane.class, this);
if (ancestor != null) {
MouseWheelEvent converted = null;
for (MouseWheelListener listener : ancestor
.getMouseWheelListeners()) {
listener.mouseWheelMoved(converted != null ? converted
: (converted = (MouseWheelEvent) SwingUtilities
.convertMouseEvent(this, e, ancestor)));
}
}
}
});
}
JFrame frame = new JFrame("Test");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.getContentPane().add(new JScrollPane(panel));
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
}

Firefox 'Open new tab' on JTabbedPane

I want to add a button to JTabbedPane's title bar (similar to the 'open new tab' ('+') button in Firefox)
I have tried to add to the glass pane of JTabbedPane's container. but since my tabbedpane contains within a JPanel seems it doesn't work for me.
Any suggestion will be a great help for me.
Thank you.
Instead of adding a button I have tried it in a different way and worked for me... I have added a JLabel (with '+') as a hidden tab and when user tries to select that tab i'll be adding a new tab.
public class AddTabButtonDemo extends JFrame{
private JTabbedPane tabbedPane = new JTabbedPane();
public AddTabButtonDemo() {
JLabel tab1Label = new JLabel("tab1");
JPanel tab1 = new JPanel();
tab1.add(tab1Label);
tabbedPane.addTab("tab1", tab1);
tabbedPane.addTab("+", new JLabel());
tabbedPane.addMouseListener(new MouseAdapter() {
#Override
public void mouseClicked(MouseEvent e) {
if (tabbedPane.getSelectedComponent() instanceof JLabel) {
int count = tabbedPane.getTabCount();
JLabel newTabLabel = new JLabel("tab" + count);
JPanel newTab = new JPanel();
newTab.add(newTabLabel);
tabbedPane.add(newTab, count - 1);
tabbedPane.setTitleAt(count - 1, "tab" + count);
tabbedPane.setSelectedComponent(newTab);
}
}
});
this.add(tabbedPane, BorderLayout.CENTER);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.pack();
this.setMinimumSize(new Dimension(300, 300));
this.setVisible(true);
}
public static void main(String[] args) {
new AddTabButtonDemo();
}
}

Reloading component Frame

I'm Working on time schedule booking application , when I run the project it shows component(total frame) , however i want that when the button is pressed to reload ,component should be spitted.(two frames with one below other by spilt) ???
Based on your description I think you need to either add splitpane in frame on click of a button or you already have a splitpane in frame and want to add panel in it on click of button.
For first option you can do something like this:
final JFrame frame = new JFrame("Split test");
frame.setSize(400, 400);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
final JPanel jPanel2 = new JPanel();
JLabel jLabel = new JLabel("I am added by click on button");
jPanel2.add(jLabel);
final JPanel jPanel = new JPanel();
JButton button = new JButton("Click me to add pane in split");
jPanel.add(button);
button.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent arg0) {
JSplitPane pane = new JSplitPane(JSplitPane.VERTICAL_SPLIT);
pane.add(jPanel);
pane.add(jPanel2);
pane.setDividerLocation(frame.getHeight()/2); // set Divider location.
frame.remove(jPanel);
frame.add(pane);
frame.validate();
}
});
frame.add(jPanel);
frame.setVisible(true);
If you are stuck in later one then try this:
final JFrame frame = new JFrame("Split test");
frame.setSize(400, 400);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
final JSplitPane pane = new JSplitPane(JSplitPane.VERTICAL_SPLIT);
frame.add(pane);
pane.setEnabled(false); // stop user from clicking on divider of split pane.
final JPanel jPanel2 = new JPanel();
JLabel jLabel = new JLabel("I am added by click on button");
jPanel2.add(jLabel);
final JPanel jPanel = new JPanel();
JButton button = new JButton("Click me to add pane in split");
jPanel.add(button);
pane.add(jPanel);
button.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent arg0) {
pane.add(jPanel2);
pane.setDividerLocation(frame.getHeight()/2); // set Divider location.
pane.setEnabled(true); // let user change divider location.
}
});
frame.setVisible(true);

Refreshing picture in drawingPanel extends JPanel

I have to load a small icon on the botton of my software. just to have a loading/ok/error icon. as sudgested on "http://www.particle.kth.se/~lindsey/JavaCourse/Book/Part1/Java/Chapter06/images.html" i create a dwowing panel extending JPanel.
class drawingPanel extends JPanel
{
Image img;
drawingPanel (Image img){
this.img = img;
}
public void paintComponent (Graphics g) {
super.paintComponent (g);
// Use the image width & height to find the starting point
int imgX = getSize ().width/2 - img.getWidth (this);
int imgY = getSize ().height/2 - img.getHeight (this);
//Draw image centered in the middle of the panel
g.drawImage (img, imgX, imgY, this);
} // paintComponent
}
I initialize the component in the following way:
// Grab the image.
Image img = new ImageIcon(iconPath+"ok.png").getImage();
// Create an instance of DrawingPanel
iconPanel = new drawingPanel(img);
all works well but at runtime i want to be able to change the icon within the pannel. i tryed all the fo;llowing but none managed to view the new picture:
Image img = new ImageIcon(iconPath+"loading.gif").getImage();
// Create a new instance of DrawingPanel
this.iconPanel = new drawingPanel(img);
this.iconPanel.repaint();
this.iconPanel.revalidate();
this.iconPanel.repaint();
this.repaint();
this.revalidate();
(i tryed this because the class in whic i am writing the code is another extension of JPanel that contains IconPanel. Any idea about why i do not manage to change the picture?
Thanks,
Stefano
First thing don't start class name with small name. Rename drawingPanel to DrawingPanel.
I have tried making a simple demo based on your description and it works fine. The image in panel is changing perfectly.
public class Demo {
public Demo() {
JFrame frame = new JFrame();
frame.setSize(400, 400);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
// Grab the image.
Image img = new ImageIcon("1.png").getImage();
// Create an instance of DrawingPanel
final DrawingPanel iconPanel = new DrawingPanel(img);
frame.add(iconPanel, BorderLayout.CENTER);
JButton button = new JButton("Change image..");
frame.add(button, BorderLayout.NORTH);
button.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
iconPanel.setImg(new ImageIcon("2.png").getImage());
iconPanel.repaint();
}
});
frame.setVisible(true);
}
public static void main(String[] args){
new Demo();
}
}
class DrawingPanel extends JPanel {
Image img;
DrawingPanel(Image img) {
this.img = img;
}
public void setImg(Image img) {
this.img = img;
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
// Use the image width & height to find the starting point
int imgX = getSize().width / 2 - img.getWidth(this);
int imgY = getSize().height / 2 - img.getHeight(this);
// Draw image centered in the middle of the panel
g.drawImage(img, imgX, imgY, this);
} // paintComponent
}
The changes I have made is add a setter method of img in DrawingPanel class. So instead of creating new DrawingPanel you just have to call setImg() with new Image and then call reapint to paint the new image.