Develop Reference

Change a JPanel color using the JColorChooser

Im trying to change the color of a JPanel using the JColorChooser when the "apply" button is pressed, but i'm not sure how to actually make the color change. How would I do that?
private class SetColorAction implements ActionListener{
#Override
public void actionPerformed(ActionEvent e) {
setColor(DrawnView.colorChooser.getColor());
//Color color;
}
}
^ is one in class while the stuff below is in a different one
public void setColor(Color color){
this.setBackground(color);
}
public ViewUserActions() {
this.applyColorBtn.setVisible(false);
this.discardChangesBtn.setVisible(false);
this.editBtn.addActionListener((ActionEvent ae) -> {
if (this.editBtn.isSelected()) {
this.applyColorBtn.setVisible(true);
this.discardChangesBtn.setVisible(true);
} else {
this.applyColorBtn.setVisible(false);
this.discardChangesBtn.setVisible(false);
}
});
this.applyColorBtn.addActionListener(new SetColorAction());
this.discardChangesBtn.addActionListener(new SetColorAction());
this.applyColorBtn.addActionListener(new GetInfoAction());
this.discardChangesBtn.addActionListener(new GetInfoAction());
}

Here is a short demo of changing the background color of a JPanel by a button click.
This cam also give you an idea of mcve , doing just that and nothing more:
import java.awt.BorderLayout;
import java.awt.Color;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
public class Frame extends JFrame {
JPanel panel;
Color[] colors = new Color[] {Color.YELLOW, Color.CYAN, Color.LIGHT_GRAY, Color.WHITE};
int counter =0;
Frame() {
setDefaultCloseOperation(DISPOSE_ON_CLOSE);
JButton button = new JButton("Change color");
button.addActionListener( ae -> setColor());
add(button, BorderLayout.NORTH);
panel = new JPanel();
panel.add(new JLabel ("Test panel"));
add(panel, BorderLayout.CENTER);
pack();
setVisible(true);
}
private void setColor() {
panel.setBackground(colors[counter++]);
counter = (counter >= colors.length) ? 0 : counter;
}
public static void main(String[] args) {
new Frame();
}
}

Try this simple source code:
import java.awt.Color;
import java.awt.GridLayout;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.JColorChooser;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class ColorChooserExample {
private static JFrame frame;
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
runColorChangerApp();
}
});
}
private static void runColorChangerApp() {
frame = new JFrame();
frame.setTitle("JPanel Color Changer");
frame.getContentPane().setLayout(new GridLayout(1, 1));
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setBounds(400, 250, 400, 300);
frame.getContentPane().add(getHomePanel());
frame.setVisible(true);
}
private static JPanel getHomePanel() {
final JPanel panel = new JPanel();
panel.setOpaque(true);
panel.addMouseListener(new MouseAdapter() {
#Override
public void mouseClicked(MouseEvent evt) {
//Fire on Mouse Right Click
if(evt.getButton() == MouseEvent.BUTTON3) {
frame.setTitle("Listened Right Click");
Color initColor = panel.getBackground();
Color choosedColor = JColorChooser.showDialog(panel,
"Choose JPanel Background Color", initColor);
frame.setTitle("JPanel Color Changer");
panel.setBackground(choosedColor);
}
}
});
return panel;
}
}

I am going to assume by the "apply" button, you mean the "ok" button of the JColorChooser dialog.
In that case, here is an optimal solution:
Color r = JColorChooser.showDialog(null, "Select Color for JPanel", Color.CYAN);
//null is the parent Component for the dialog,The String is the title, and cyan
//will be the initially selected Color.
if(r==null)
{ //perform whatever you would do if the user cancels the dialog }
else
{ jpanelobj.setBackground(r); }
This should do the trick, but here's my advice for you.
JColorChooser extends JComponent, and this means that IT CAN BE ADDED AS A COMPONENT to a Frame, giving you control such as adding ChangeListeners to instantaneously detect a Color change. Another method you may find helpful is:
JDialog jd=JColorChooser.createDialog(Component c,
String title,
boolean modal,
JColorChooser chooserPane,
ActionListener okListener,
ActionListener cancelListener);
Where c is the parent component-leave it null, usually.
The title is the dialogs Title modal is a boolean value which specifies whether you want the program to wait for the
the dialog to be responded to by the user before continuing the program thread
execution.
chooserPane is the JColorChooser you want as the main chooser->eg:
new JColorChooser(Color.GREEN);
okListener and cancelListener are action listeners for ok and cancel buttons.
This method gives you control over the dialogs buttons, display, etc.

Bind single event to all JLabels in Java

I have 20 JLabels and all of them have to change their background color when mouse enters and change back to original color when mouse outs.
Do I have to individually bind 2 Event-listeners of MouseEntered and MouseExited with all JLabels separately, or is there any work around so I can make just 2 events kind of monitoring all JLabels?
Like in the image below: there are about 6 JLabels and I want each one to change its background color whenever the mouse enters the scene and change back to original color when the mouse outs.
So, do I have to individually set event listeners on all JLabels, or there can be a single event listener for all JLabels?

You can register all 20 JLabels with the same mouse listener. You would do something like this:
MouseListener m = new MouseAdapter() // create our own mouse listener
{
#Override
public void mouseEntered(MouseEvent e)
{
e.getComponent().setBackground(Color.RED);; // this method changes the colours of all the labels
}
#Override
public void mouseExited(MouseEvent e)
{
e.getComponent().setBackground(Color.GREEN); // this method changes the colours back to normal
}
};
for (JLabel label: labels) // iterate over all the labels
{
label.addMouseListener(m); // give them all our mouse listener
}
Where "labels" is some collection (List, Set, array...) of your JLabels, and changeLabelColours() and changeLabelColoursBack() are two methods that you define to change the colours.
hope this helps!
EDIT: reading your edited question, I think I should point out that this code will cause ALL labels to change colour when ANY of the labels is moused-over. I think that's what you mean.

You don't "make events". You make eventListeners. And yes, you can do just 2 event listeners and bound them to all JLabels.
Or, if you prefer, you can extends Jlabel into MyJlabel, that has the event listener built in, and save yourself from the repeated binding, if it bothers you.

You can use one MouseListener reference.
You should differentiate event sources based on references or on component name.
Here is an example
final JLabel label1 = new JLabel("label1");
label1.setName("label1");
final JLabel label2 = new JLabel("label2");
label2.setName("label2");
final JLabel label3 = new JLabel("label3");
label3.setName("label3");
MouseListener mouseListener = new MouseAdapter() {
#Override
public void mouseExited(MouseEvent e) {
// you can check references
if(e.getSource() == label1) {
System.out.println("exited " + label1.getName());
} else if (e.getSource() == label2) {
System.out.println("exited " + label2.getName());
} else if (e.getSource() == label3) {
System.out.println("exited " + label3.getName());
}
}
#Override
public void mouseEntered(MouseEvent e) {
String name = ((JComponent)e.getSource()).getName();
// or you can check name of component
switch (name) {
case "label1":
case "label2":
case "label3":
System.out.println("entered " + name);
break;
}
}
};
for (JLabel l : Arrays.asList(label1, label2, label3)) {
l.addMouseListener(mouseListener);
}

Note that labels need to be opaque in order to change their bg color.
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import javax.swing.BoxLayout;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
public class CrazyLabels extends JFrame {
public CrazyLabels() {
setDefaultCloseOperation(EXIT_ON_CLOSE);
setLayout(new BorderLayout());
JPanel content = new JPanel();
add(content);
content.setLayout(new BoxLayout(content, BoxLayout.Y_AXIS));
MouseAdapter listener = new MouseAdapter() {
#Override
public void mouseEntered(MouseEvent e) {
JLabel label = (JLabel)e.getSource();
label.setBackground(Color.red);
}
#Override
public void mouseExited(MouseEvent e) {
JLabel label = (JLabel)e.getSource();
label.setBackground(UIManager.getColor("Label.background"));
}
};
for (int i = 0; i < 5; i++) {
JLabel label = new MyLabel(listener);
label.setText("---- label ----");
content.add(label);
}
pack();
setLocationRelativeTo(null);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
new CrazyLabels().setVisible(true);
}
});
}
private static class MyLabel extends JLabel {
public MyLabel(MouseListener listener) {
setOpaque(true);
addMouseListener(listener);
}
}
}
In this example a single listener is used to enforce behavior in all labels.

Listen for mouse released event on component on which the mouse was not pressed in Swing

Is it possible to listen for mouse released event on the component on which it was not pressed?
I know that when mouse is released MouseListener.mouseReleased()is invoked on the listeners for that component when mouse press originated even if the cursor is above other component.
How to inform a component or its listeners that the mouse was over it and it was released?

If you add your MouseListener to the container that holds your components of interest, you can find out which component the mouse is over on press or drag. For instance in the code below, I've added my MouseAdapter (a combination MouseListener, MouseMotionListener, and MouseWheelListener) to the containing JPanel, and after getting the location of the mouse event on the container, I call getComponentAt(Point p) on my container to get the child component that the mouse was over:
import java.awt.Component;
import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.*;
#SuppressWarnings("serial")
public class TestMouseRelease extends JPanel {
private String[] panelNames = { "Panel A", "Panel B" };
public TestMouseRelease() {
setLayout(new GridLayout(1, 0));
MouseAdapter mAdapter = new MyMouseAdapter();
addMouseListener(mAdapter);
addMouseMotionListener(mAdapter);
for (String panelName : panelNames) {
JPanel panel = new JPanel();
panel.setName(panelName);
// panel.addMouseListener(mAdapter);
// panel.addMouseMotionListener(mAdapter);
panel.setBorder(BorderFactory.createTitledBorder(panelName));
panel.add(Box.createRigidArea(new Dimension(300, 300)));
add(panel);
}
}
private class MyMouseAdapter extends MouseAdapter {
#Override
public void mousePressed(MouseEvent e) {
displayInfo(e, "mousePressed");
}
#Override
public void mouseReleased(MouseEvent e) {
displayInfo(e, "mouseReleased");
}
#Override
public void mouseDragged(MouseEvent e) {
displayInfo(e, "mouseDragged");
}
private void displayInfo(MouseEvent e, String info) {
JComponent comp = (JComponent) e.getSource();
Component childComp = comp.getComponentAt(e.getPoint());
if (childComp != null) {
String name = childComp.getName();
System.out.println(name + ": " + info);
}
}
}
private static void createAndShowGui() {
JFrame frame = new JFrame("TestMouseRelease");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(new TestMouseRelease());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}

Yeah, I handled something similar in my project. I use getBounds() on all component in the container and check if they contain the x,y coordinates of your mouse. Below is my code:
Component[] components = jPanel1.getComponents();
for (Component c : components) {
if (c.getBounds().contains(ev.getXOnScreen(), ev.getYOnScreen())) {
System.out.println(c.getClass());
y = ch.getPosY();
x = ch.getPosX();
}
}

How can I switch between jpanels?

I'm still very new to java programming, so please help me to correct any mistakes I might have overlooked or give tips on how to improve this program.
Okay, so a lot of problems have been solved, and now I have a CardLayout, but I still have questions about how I should make my pipes show inside it.
When I tried to add in my refresh rate timer and my speed timer, I have problems about how I need to declare and initialize boolean variables.
Also, when I compile and run this game, I get files such as Game$1.class. Is there a way for me to clean this up, and could someone explain why this happens? Do these have an affect on the finished product? (When the game is compiled and packaged into a JAR.)
I want to set playerIsReady to true when the play button is clicked. And from there, when the if statement is true, then switch to a panel that displays the pipes, and start moving the pipe across the screen. Preferably 3 instances of that pipe, each starting at different times, but whatever you can help with is fine.
Some of this code needs work, so I have commented some parts out and left notes.
My other questions about this game can be found here.
This is my current code
Game.java
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;
import javax.swing.border.EmptyBorder;
import javax.swing.SwingUtilities;
public class Game {
public static void main(String[] args) {
Runnable r = new Runnable() {
#Override
public void run() {
// the GUI as seen by the user (without frame)
final CardLayout cl = new CardLayout();
final JPanel gui = new JPanel(cl);
// remove if no border is needed
gui.setBorder(new EmptyBorder(10,10,10,10));
JPanel menu = new JPanel(new GridBagLayout());
JButton playGame = new JButton("Play!");
ActionListener playGameListener = new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
cl.show(gui, "game");
}
};
playGame.addActionListener(playGameListener);
Insets margin = new Insets(20, 50, 20, 50);
playGame.setMargin(margin);
menu.add(playGame);
gui.add(menu);
cl.addLayoutComponent(menu, "menu");
final JPanel pipes = new Pipes();
gui.add(pipes);
cl.addLayoutComponent(pipes, "game");
JFrame f = new JFrame("Pipes Game");
f.add(gui);
// Ensures JVM closes after frame(s) closed and
// all non-daemon threads are finished
f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
// See https://stackoverflow.com/a/7143398/418556 for demo.
f.setLocationByPlatform(true);
// ensures the frame is the minimum size it needs to be
// in order display the components within it
f.pack();
// should be done last, to avoid flickering, moving,
// resizing artifacts.
f.setVisible(true);
/*if (playerIsReady) {
Timer speed = new Timer(10, new ActionListener() { //pipe speed
#Override
public void actionPerformed(ActionEvent e) {
pipes.move();
}
});
speed.start();
Timer refresh = new Timer(30, new ActionListener() { //refresh rate
#Override
public void actionPerformed(ActionEvent e) {
pipes.repaint();
}
});
refresh.start();
}*/
}
};
// Swing GUIs should be created and updated on the EDT
// http://docs.oracle.com/javase/tutorial/uiswing/concurrency
SwingUtilities.invokeLater(r);
}
}
Pipes.java
// What import(s) do I need for ArrayList?
public class Pipes {
List<Pipe> pipes = new ArrayList<Pipe>();
public Pipes() {
pipes.add(new Pipe(50, 100));
pipes.add(new Pipe(150, 100));
pipes.add(new Pipe(250, 100));
}
protected void paintComponent(Graphics g) {
super.paintComponent(g);
for ( Pipe pipe : pipes ){
pipe.drawPipe(g);
}
}
}
PipeObject.java
import java.awt.Graphics;
public class PipeObject {
//Declare and initialiaze variables
int x1 = 754; //xVal start
int x2 = 75; //pipe width
//total width is 83
int y1 = -1; //yVal start
int y2 = setHeightVal(); //pipe height
int gap = 130; //gap height
public void drawPipe(Graphics g) {
g.clearRect(0,0,750,500); //Clear screen
g.drawRect(x1,y1,x2,y2); //Draw part 1
g.drawRect(x1-3,y2-1,x2+6,25); //Draw part 2
g.drawRect(x1-3,y2+25+gap,x2+6,25); //Draw part 3
g.drawRect(x1,y2+25+gap+25,x2,500-y2-49-gap); //Draw part 4
}
public void move() {
x1--;
}
public int getMyX() { //To determine where the pipe is horizontally
return x1-3;
}
public int getMyY() { //To determine where the pipe is vertically
return y2+25;
}
public int setHeightVal() { //Get a random number and select a preset height
int num = (int)(9*Math.random() + 1);
int val = 0;
if (num == 9)
{
val = 295;
}
else if (num == 8)
{
val = 246;
}
else if (num == 7)
{
val = 216;
}
else if (num == 6)
{
val = 185;
}
else if (num == 5)
{
val = 156;
}
else if (num == 4)
{
val = 125;
}
else if (num == 3)
{
val = 96;
}
else if (num == 2)
{
val = 66;
}
else
{
val = 25;
}
return val;
}
}

The best way to approach this is using a CardLayout.
Notes
A button with an ActionListener is far better than a MouseListener over a rectangle.
The button will show focus when the mouse is pointed at it, or the component is tabbed to via the keyboard.
The button is keyboard accessible.
The button has facility to support multiple icons built in (e.g. for 'initial look', focused, pressed etc.)
White space in the GUI is provided around the menu panel and game by adding an EmptyBorder
The button is made larger by setting a margin.
Adjust margins, borders and preferred size according to need. These sizes were set by me so as not to make the screenshots too large.
See more tips in the code comments.
Code
Here is the MCTaRE (Minimal Complete Tested and Readable Example) that produced the above screenshots.
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
import javax.swing.border.EmptyBorder;
public class PipesGame {
public static void main(String[] args) {
Runnable r = new Runnable() {
#Override
public void run() {
// the GUI as seen by the user (without frame)
final CardLayout cl = new CardLayout();
final JPanel gui = new JPanel(cl);
// remove if no border is needed
gui.setBorder(new EmptyBorder(10,10,10,10));
JPanel menu = new JPanel(new GridBagLayout());
JButton playGame = new JButton("Play!");
ActionListener playGameListener = new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
cl.show(gui, "game");
}
};
playGame.addActionListener(playGameListener);
Insets margin = new Insets(20, 50, 20, 50);
playGame.setMargin(margin);
menu.add(playGame);
gui.add(menu);
cl.addLayoutComponent(menu, "menu");
JPanel pipes = new Pipes();
gui.add(pipes);
cl.addLayoutComponent(pipes, "game");
JFrame f = new JFrame("Pipes Game");
f.add(gui);
// Ensures JVM closes after frame(s) closed and
// all non-daemon threads are finished
f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
// See https://stackoverflow.com/a/7143398/418556 for demo.
f.setLocationByPlatform(true);
// ensures the frame is the minimum size it needs to be
// in order display the components within it
f.pack();
// should be done last, to avoid flickering, moving,
// resizing artifacts.
f.setVisible(true);
}
};
// Swing GUIs should be created and updated on the EDT
// http://docs.oracle.com/javase/tutorial/uiswing/concurrency
SwingUtilities.invokeLater(r);
}
}
class Pipes extends JPanel {
Pipes() {
setBackground(Color.BLACK);
setForeground(Color.WHITE);
}
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawString("Pipes game appears here..", 170, 80);
}
#Override
public Dimension getPreferredSize() {
// adjust to need
return new Dimension(500,150);
}
}

"Is there a way for me to add my GameMenu jpanel to my jframe, and then replace it with the Pipes jpanel?"
As other have suggested, for this you want a CardLayout. It is very simple to you. Personally, I always wrap my CardLayout in a JPanel rather than the JFrame, just force of habit.
What you want to do is have a mainPanel that will have the CardLayout
CardLayout card = new CardLayout();
JPanel mainPanel = new JPanel();
Then you want to add your panels to the mainPanel. What the CardLyaout does is layer the panels, making just one visible at a time. The first one you add, will the in the foreground. Also when you add the panel, you'll also want to issue it a key it can be called from. The key, can be any String you like.
mainPanel.add(gameMenu, "menu");
mainPnael.add(pipes, "pipe");
Now gameMenu is the only panel shown. To show pipes, all you do is use this method
public void show(Container parent, String name) - Flips to the parent that was added to this layout with the specified name, using addLayoutComponent. If no such component exists, then nothing happens.
So you'd use, card.show(mainPanel, "pipes");
Whatever even you want to trigger the showing of pipes, just add that line in that event handler. You could add a button or something to the GameMenu that will allow movement to the Pipes panel.

This works with a mouse click on the menu. You can change it later, to a click on some button or whatever you want.
I added a MouseListener to the Game class. When the user presses the mouse on the menu JPanel, it adds the Pipes JPanel to JFrame and calls the pack method.
Game.java:
import java.awt.Point;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.geom.Rectangle2D;
import javax.swing.JFrame;
import javax.swing.SwingUtilities;
import javax.swing.Timer;
public class Game {
GameMenu menu = new GameMenu();
Pipes game;
boolean start = false;
JFrame f;
Rectangle2D menuRect = new Rectangle2D.Double(20, 20, 60, 40);
public Game() {
f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.add(menu);
f.setTitle("Pipe Game");
f.setResizable(false);
f.pack();
f.setLocationRelativeTo(null);
f.setVisible(true);
menu.addMouseListener(new MouseAdapter() {
#Override
public void mousePressed(MouseEvent e) {
Point click = new Point(e.getX(), e.getY());
System.out.println("Clicked on the Panel");
if(menuRect.contains(click))
{
System.out.println("Clicked inside the Rectangle.");
start = true;
menu.setVisible(false);
game = new Pipes();
f.add(game);
f.pack();
Timer timer = new Timer(10, new ActionListener() { //pipe speed
#Override
public void actionPerformed(ActionEvent e) {
game.move();
}
});
timer.start();
Timer refresh = new Timer(30, new ActionListener() { //refresh rate
#Override
public void actionPerformed(ActionEvent e) {
game.repaint();
}
});
refresh.start();
}
}
#Override
public void mouseReleased(MouseEvent e) {
}
});
}
public static void main(String args[]) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new Game();
}
});
}
}

Implementing drag-and-drop from one JPanel to another

I'm new to drag-and-drop in Swing. I have a JPanel that draws an image with a caption superimposed on it. I want to implement drag and drop on this JPanel, but after going through some documentation and tutorials I didn't find any usable pointers on how it's done for this type of component. For starters, it doesn't have a setDragEnabled function.
Can I make a JPanel draggable? I want to use this DnD maneuver to pass a reference to a certain object from one panel to another.

May be this can help you.
Drag and Drop of complex custom objects in Java

You can implement drag-and-drop behavior on any JComponent. See the setTransferHandler method.
The setDragEnabled method is typically provided on components where a good default D&D behavior can be implemented in the JDK. In such cases you can just activate the default D&D by calling that method.
On a JPanel they (=the Swing developers) could probably not think of any decent default D&D behavior, so you will have to implement your own TransferHandler. I strongly suggest to read the Drag-and-drop tutorial before starting

I don't know how viable sounds but when I needed to drag and drop panels I did it this way:
Firstable I implemented action events for dragable panels and containers, it can be both
I used a static variables for selected parent, selected child and current panel
when the mouse is over a panel you set it as the current panel
when you click , mouse down, whatever, you check if currentpanel is the clicked one and set is as child panel
when the mouse is over a panel and child panel is not null, then it seems that you're dragging, current panel will turn into parent panel once you release the mouse
you have to add some validation.
If a panel is being dragged you can use your own implementation, it could be follow the mouse coords or just highlight it and highlight the parent, I used this last option to simulate the drag
ok I wrote this, is so buggy but this is the idea:
import java.awt.Color;
import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.Rectangle;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JDesktopPane;
import javax.swing.JFrame;
import javax.swing.JTextField;
/**
*
* #author porfiriopartida
*/
public class DraggablePanel extends JDesktopPane implements ContainerPanel{
public ContainerPanel parent;
static DraggablePanel over;
static ContainerPanel overParent;
static DraggablePanel dragging;
static ContainerPanel draggingParent;
public DraggablePanel(){
this(null);
}
public DraggablePanel(ContainerPanel parent){
this.parent = parent;
setBorder(BorderFactory.createLineBorder(Color.black));
setBounds(0,0,100,100);
if(parent != null)
addMouseListener(new MouseAdapter(){
#Override
public void mouseEntered(MouseEvent me) {
DraggablePanel src = (DraggablePanel) me.getSource();
DraggablePanel.over = src;
DraggablePanel.overParent = DraggablePanel.over.parent;
}
#Override
public void mouseExited(MouseEvent me) {
}
#Override
public void mouseReleased(MouseEvent me) {
if(DraggablePanel.over != null && DraggablePanel.dragging != null && DraggablePanel.overParent != null){
Rectangle bounds = DraggablePanel.dragging.getBounds();
bounds.x = me.getX();
bounds.y = me.getY();
//Remove child from parent
DraggablePanel.dragging.parent.removePanel(DraggablePanel.dragging);
if(DraggablePanel.dragging.parent != DraggablePanel.overParent){
//add child to new parent
DraggablePanel.overParent.addPanel(DraggablePanel.dragging, bounds);
}
else{
//same parent selected
DraggablePanel.dragging.parent.addPanel(DraggablePanel.dragging, bounds);
};
DraggablePanel.dragging.parent = DraggablePanel.overParent;
}
//cleaning variables
DraggablePanel.dragging = null;
DraggablePanel.over = null;
DraggablePanel.draggingParent = null;
DraggablePanel.overParent = null;
}
#Override
public void mousePressed(MouseEvent me) {
DraggablePanel.dragging = (DraggablePanel) me.getSource();
DraggablePanel.draggingParent = DraggablePanel.dragging.parent;
}
});
addMouseListener(new MouseAdapter() {
#Override
public void mouseEntered(MouseEvent me) {
super.mouseEntered(me);
ContainerPanel src = (ContainerPanel) me.getSource();
DraggablePanel.overParent = src;
if (DraggablePanel.draggingParent == null || DraggablePanel.draggingParent == src) {
setBorder(BorderFactory.createLineBorder(Color.BLACK, 2));
} else {
setBorder(BorderFactory.createLineBorder(Color.blue, 2));
}
}
#Override
public void mouseExited(MouseEvent me) {
}
#Override
public void mouseReleased(MouseEvent me) {
}
});
}
#Override
public void addPanel(DraggablePanel panel) {
panel.parent = this;
add(panel);
repaint();
revalidate();
try {
getParent().repaint();
} catch (Exception e) {
}
}
#Override
public void addPanel(DraggablePanel panel, Rectangle bounds) {
setBounds(bounds);
addPanel(panel);
}
#Override
public void removePanel(DraggablePanel panel) {
remove(panel);
}
public static void main(String args[]){
JFrame frame = new JFrame();
frame.setLayout(new GridLayout(1,1));
JTextField tf = new JTextField("textfield");
JButton btn = new JButton("Button");
DraggablePanel desktop = new DraggablePanel();
frame.add(desktop);
DraggablePanel p1 = new DraggablePanel(desktop);
p1.setLayout(new GridLayout(2,1));
p1.add(tf);
p1.setBounds(0,0,100,50);
tf.setBounds(5,5,80,30);
DraggablePanel p2 = new DraggablePanel(desktop);
p2.setLayout(new GridLayout(2,1));
p2.add(btn);
p2.setBounds(50,50,50,30);
btn.setBounds(5,5,30,20);
desktop.add(p1);
desktop.add(p2);
frame.setPreferredSize(new Dimension(600,400));
frame.pack();
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}