Currently I am trying to have a JFrame which holds two JPanel components - the first JPanel component is meant to hold the various buttons that a user can click to interact with the program & draw images to the screen. The second, and this is where the trouble begins, holds the actual Canvas object to which I am trying to draw to.
The problem I am having is the second panel is not actually being drawn to. I've tried a variety of other approaches and checks, but everything suggests the current code should work.
As a test, I am simply trying to do a fillRect() onto the drawing panel, but to no avail. Here is my code:
//Creating the components & JFrame:
public static void createDisplay() {
JFrame f = new JFrame();//When JFrame flowlayout manager removed, the rectangle was drawn.
c = new Canvas();
width = 500;
height = 500;
f.setLayout(new FlowLayout());
f.add(addButtons()); //private method that covers the button panel
JPanel drawPanel = new JPanel();
drawPanel.add(c);
c.setFocusable(false);
f.add(drawPanel);
f.setPreferredSize(new Dimension(height, width));
lstnr = new Listeners();
f.addKeyListener(lstnr);
f.addMouseListener(lstnr);
f.addMouseMotionListener(lstnr);
f.setLocationRelativeTo(null);
f.pack();
f.setVisible(true);
}
And the code that does the actual drawing to the screen:
private void render() {
bs = c.getBufferStrategy();
if(bs == null) {
c.createBufferStrategy(3);
return;
}
do {
do {
g = bs.getDrawGraphics();
l.setGraphicsObj(g);
g.clearRect(0, 0, width, height);
for(Symbols s : l.getSymbolsArray());
s.renderSymbols();
}
g.fillRect(0, 0, 50, 50); //Just to test & make sure it works
g.dispose();
}while(bs.contentsRestored());
bs.show();
}while(bs.contentsLost());
}
Now I'd like to stress again that the rectangle was drawn when I removed the f.setLayoutManager(new FlowLayout()); snippet from the createDisplay() method. Any help is much appreciated.
You have conflicting painting systems. The one been used to paint the BufferStrategy and the one been used by Swing to paint it's components
Mixing heavy and light weight components is problematic at the best of times, you should do everything you can to reduce the overlap
A Canvas has a default preferred size of 0x0, which is what the FlowLayout will use to determine how best it should be laid out
A "possible" solution might be to focus on placing the Canvas within it's own spot and seperate the Swing elements.
You're still running into a world of trouble, as you will need to manage the data between two distinct thread contexts
import java.awt.BorderLayout;
import java.awt.Canvas;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.image.BufferStrategy;
import java.util.concurrent.atomic.AtomicBoolean;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
PaintPane paintPane = new PaintPane();
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new ButtonPane(), BorderLayout.WEST);
frame.add(paintPane);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
paintPane.start();
}
});
}
public class ButtonPane extends JPanel {
public ButtonPane() {
setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.weightx = 1;
gbc.fill = GridBagConstraints.HORIZONTAL;
gbc.gridwidth = GridBagConstraints.REMAINDER;
for (int index =0; index < 5; index++) {
add(new JButton(Integer.toString(index)), gbc);
}
}
}
public class PaintPane extends Canvas {
private Thread renderThread;
private AtomicBoolean running = new AtomicBoolean(true);
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
public void start() {
if (renderThread != null) {
return;
}
running.set(true);
renderThread = new Thread(new Runnable() {
#Override
public void run() {
while (running.get()) {
render();
try {
Thread.sleep(5);
} catch (InterruptedException ex) {
}
}
}
});
renderThread.start();
}
public void stop() {
if (renderThread != null) {
return;
}
running.set(false);
renderThread.interrupt();
try {
renderThread.join();
} catch (InterruptedException ex) {
}
renderThread = null;
}
protected void render() {
BufferStrategy bs = getBufferStrategy();
if (bs == null) {
createBufferStrategy(3);
return;
}
do {
do {
Graphics g = bs.getDrawGraphics();
// :/
//l.setGraphicsObj(g);
g.clearRect(0, 0, getWidth(), getHeight());
//for (Symbols s : l.getSymbolsArray()) {
// // This is where g should be passed
// s.renderSymbols();
//}
g.setColor(Color.BLUE);
g.fillRect(0, 0, 50, 50); //Just to test & make sure it works
g.dispose();
} while (bs.contentsRestored());
bs.show();
} while (bs.contentsLost());
}
}
}
Related
My objective is to put a button and a circle on the JFrame. When i click the button the circle should move randomly on the panel/frame.
But when i click the button the circle just move once only and after putting SOP statements i found that "frame.repaint()" is getting called multiple times but this call is triggering the "paintComponent" method only once, the very first time (defined in class Panel1). Its very strange!
I have also provided another code which works as expected but has no buttons to trigger the animation. I have read that repaint() requests are coalesced together and executed once, then how come the second program works?
import java.awt.event.*;
import java.awt.Graphics.*;
import javax.swing.*;
import java.awt.*;
public class SimpleGui3c_4 {
public static void main(String args[]) {
Frame1 frame = new Frame1();
frame.go();
}
}
class Frame1 {
JFrame frame;
Panel1 p;
void go() {
frame = new JFrame();
JButton button1 = new JButton("Color Change");
p = new Panel1();
frame.setSize(500,500);
frame.setVisible(true);
frame.getContentPane().add(BorderLayout.SOUTH, button1);
frame.getContentPane().add(BorderLayout.CENTER, p);
frame.setDefaultCloseOperation(frame.EXIT_ON_CLOSE);
button1.addActionListener(new ColorActionListener());
}
class ColorActionListener implements ActionListener {
public void actionPerformed(ActionEvent e) {
for(int i=0;i<130;i++) {
System.out.println("Frame repaint started");
frame.repaint();
try {
Thread.sleep(5000);
}catch(Exception ex) {}
System.out.println("Frame repaint ended");
}
}
}
class Panel1 extends JPanel {
public void paintComponent(Graphics g) {
System.out.println("Inside the paint Component method");
int x = (int)(Math.random()*100);
int y = (int)(Math.random()*100);
g.setColor(Color.BLUE);
g.fillOval(x,y,100,100);
System.out.println("Exiting the paint component method");
}
}
}
Code which works but has no button to trigger the animation, it works as soon as i run the code. I am not sure why the below program works and the above program fails!
import javax.swing.*;
import java.awt.*;
public class SimpleAnimation {
int x = 70;
int y = 70;
public static void main(String args[]) {
SimpleAnimation gui = new SimpleAnimation();
gui.go();
}
public void go() {
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
MyDrawPanel drawPanel = new MyDrawPanel();
frame.getContentPane().add(drawPanel);
frame.setSize(300,300);
frame.setVisible(true);
for(int i = 0;i<130;i++) {
//x++;
//y++;
drawPanel.repaint();
try {
Thread.sleep(50);
}catch(Exception ex) {}
}
}//close go
class MyDrawPanel extends JPanel {
public void paintComponent(Graphics g) {
g.setColor(Color.WHITE);
g.fillRect(0,0,this.getWidth(), this.getHeight());
int x = (int)(Math.random()*70);
int y = (int)(Math.random()*70);
g.setColor(Color.green);
g.fillOval(x,y,40,40);
}
}
}
I have also provided another code which works as expected but has no buttons to trigger the animation.
The difference between the two pieces of code is context within which they are been called.
The code that "works" is actually been updated out side the context of the Even Dispatching Thread, in the "main" thread, which means that doing something like Thread.sleep won't prevent the UI from been updated.
The code which does not work is been updated from with the content of the Event Dispatching Thread (from within the ActionListener), which is prevent the EDT from processing new paint requests until after the actionPerformed method returns
Another issue you will face relates to when you decide to update the position of the circle.
paintComponent can be called for all a number of different reasons, many which you don't control. Painting should focus on painting the current state and should never modify it (directly or indirectly). Instead, you should use some kind of update method, whose job it is, is to update the x/y position of the circle and trigger a new paint cycle.
I would highly recommend that you stop and take the time to read through:
Concurrency in Swing for a more detail explanation
How to use Swing Timers for a possible solution
Performing Custom Painting and Painting in AWT and Swing for a better understanding into how painting actually works in Swing.
Your problem is rookie mistake which comes about from not understanding how the API actually works and not understanding the tools available to solve it
There are a number of other "issues" which would result in undesirable behaviour, like not calling setVisible last, so the UI doesn't need be updated again to ensure that the components been added are visible.
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class SimpleGui3c_4 {
public static void main(String args[]) {
new SimpleGui3c_4();
}
public SimpleGui3c_4() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
Frame1 frame = new Frame1();
frame.go();
}
});
}
public interface Animatable {
public void update();
}
public class Frame1 {
JFrame frame;
Panel1 p;
void go() {
frame = new JFrame();
JButton button1 = new JButton("Color Change");
p = new Panel1();
frame.getContentPane().add(BorderLayout.SOUTH, button1);
frame.getContentPane().add(BorderLayout.CENTER, p);
frame.setDefaultCloseOperation(frame.EXIT_ON_CLOSE);
button1.addActionListener(new ColorActionListener(p));
frame.pack();
frame.setVisible(true);
}
class ColorActionListener implements ActionListener {
private Animatable parent;
public ColorActionListener(Animatable parent) {
this.parent = parent;
}
public void actionPerformed(ActionEvent e) {
JButton btn = (JButton) e.getSource();
btn.setEnabled(false);
Timer timer = new Timer(5000, new ActionListener() {
private int counter = 0;
#Override
public void actionPerformed(ActionEvent e) {
System.out.println("Frame repaint started");
parent.update();
counter++;
if (counter >= 130) {
((Timer)e.getSource()).stop();
btn.setEnabled(true);
}
}
});
timer.setInitialDelay(0);
timer.start();
}
}
class Panel1 extends JPanel implements Animatable {
private int xPos, yPos;
public Panel1() {
update();
}
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
protected void paintComponent(Graphics g) {
super.paintComponent(g);
System.out.println("Inside the paint component method");
g.setColor(Color.BLUE);
g.fillOval(xPos, yPos, 100, 100);
System.out.println("Exiting the paint component method");
}
#Override
public void update() {
System.out.println("Inside the update method");
xPos = (int) (Math.random() * 100);
yPos = (int) (Math.random() * 100);
repaint();
}
}
}
}
I'm trying to have a JPanel of varying size (potentially much wider than the standard screen) inside of a JScrollPanel. Currently it works out great, and I have configured the scrollbars to work fine manually, however I would like the JPanel to "scroll" constantly to the left, so that over time the whole thing is displayed. All of the answers I found are specific to JTextArea and use Carets, or use rectToVisible. Neither of these will work because I'm trying to scroll internally to a single JPanel.
I've included what I believe to be all of the relevant code below.
center is the JPanel (of which Grid is a subclass, used to paint specifically a grid with some specific cells colored) with a BorderLayout that I would like to autoscroll.
public GuiViewFrame(Song playMe) {
String[][] songArray = playMe.to2DArray();
this.displayPanel = new ConcreteGuiViewPanel(playMe);
main = new JPanel();
main.setLayout(new BorderLayout());
displayPanel.setLayout(new BorderLayout());
center = new Grid(playMe);
labels = new Labels(playMe);
horiz = new Horiz(playMe);
center.setPreferredSize(new Dimension(10 * songArray.length, 10 * songArray[0].length));
horiz.setPreferredSize(new Dimension(10 * songArray.length, 10));
horiz.setVisible(true);
main.add(center, BorderLayout.CENTER);
main.add(horiz, BorderLayout.NORTH);
scroll = new JScrollPane(main,
JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED, JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
add(scroll, BorderLayout.CENTER);
labels.setPreferredSize(new Dimension(20, 10 * songArray[0].length));
labels.setVisible(true);
add(labels, BorderLayout.WEST);
JScrollBar horiz = scroll.getHorizontalScrollBar();
InputMap im = horiz.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW);
im.put(KeyStroke.getKeyStroke("RIGHT"), "positiveUnitIncrement");
im.put(KeyStroke.getKeyStroke("LEFT"), "negativeUnitIncrement");
im.put(KeyStroke.getKeyStroke("HOME"), "minScroll");
im.put(KeyStroke.getKeyStroke("END"), "maxScroll");
this.setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
this.pack();
}
The project as a whole is to generate a view for playing music that combines MIDI and a GUI, but right now once MIDI plays enough of the song, the relevant notes are off screen. I would like to scroll at a rate to keep pace with MIDI.
You can set the value of the horizontal scrollbar to control what is currently visible:
JScrollBar horizontal = scroll.getHorizontalScrollBar();
horizontal.setValue( horizontal.getValue() + ??? );
You would need to use a Swing Timer to schedule the scrolling at an appropriate interval.
Simple example of using a Timer to scroll text:
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.*;
public class TimerTest extends JPanel implements ActionListener
{
JLabel timeLabel;
JLabel scrollLabel;
public TimerTest()
{
setLayout( new BorderLayout() );
timeLabel = new JLabel( new Date().toString() );
add(timeLabel, BorderLayout.NORTH);
scrollLabel = new JLabel( "Some continuously scrolling text!! " );
add(scrollLabel, BorderLayout.SOUTH);
int time = 1000;
javax.swing.Timer timer = new javax.swing.Timer(time, this);
timer.setInitialDelay(1);
timer.start();
}
public void actionPerformed(ActionEvent e)
{
timeLabel.setText( new Date().toString() );
String oldText = scrollLabel.getText();
// Scroll right to left
String newText = oldText.substring(1) + oldText.substring(0, 1);
// Scroll left to right
// int length = oldText.length();
// String newText = oldText.substring(length-1, length)
// + oldText.substring(0, length-1);
scrollLabel.setText( newText );
}
private static void createAndShowGUI()
{
JFrame frame = new JFrame("SSCCE");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add( new TimerTest() );
frame.setLocationByPlatform( true );
frame.pack();
frame.setVisible( true );
}
public static void main(String[] args)
{
EventQueue.invokeLater(new Runnable()
{
public void run()
{
createAndShowGUI();
}
});
}
}
One possible solution might be to take advantage of JComponent#scrollRectToVisible and a Swing Timer
For example...
import java.awt.Container;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JViewport;
import javax.swing.Scrollable;
import javax.swing.Timer;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class ScrollTest {
public static void main(String[] args) {
new ScrollTest();
}
public ScrollTest() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new JScrollPane(new TestPane()));
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel implements Scrollable {
public TestPane() {
Timer timer = new Timer(40, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
JViewport viewport = (JViewport) getParent();
Rectangle viewRect = viewport.getViewRect();
if (viewRect.x + viewRect.width < getWidth()) {
viewRect.x += 2;
scrollRectToVisible(viewRect);
} else {
((Timer)e.getSource()).stop();
}
}
});
timer.start();
}
#Override
public Dimension getPreferredSize() {
return new Dimension(1000, 200);
}
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
g2d.drawLine(0, 0, getWidth(), getHeight());
g2d.dispose();
}
#Override
public Dimension getPreferredScrollableViewportSize() {
return new Dimension(200, 200);
}
#Override
public int getScrollableUnitIncrement(Rectangle visibleRect, int orientation, int direction) {
return 64;
}
#Override
public int getScrollableBlockIncrement(Rectangle visibleRect, int orientation, int direction) {
return 64;
}
#Override
public boolean getScrollableTracksViewportWidth() {
return getPreferredSize().width <= getParent().getSize().width;
}
#Override
public boolean getScrollableTracksViewportHeight() {
return getPreferredSize().height <= getParent().getSize().height;
}
}
}
I have a program that is basically just supposed to change the text of a label when your cursor enters a polygon that is shown on the JPanel. I have tried a few different things with nothing working. Currently I am trying an if statement to make it choose which button to add but it still doesn't change if i move my cursor into the polygon. when the cursor is outside of the polygon the label should say "point is not in the polygon" and when inside it should say "point is in the polygon". Any help would be greatly appreciated.
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class Chapter3Lab1 extends JFrame{
private RegularPolygonPanel canvas = new RegularPolygonPanel();
public Chapter3Lab1()
{
JPanel panel = new JPanel();
add(canvas, BorderLayout.CENTER);
add(panel, BorderLayout.SOUTH);
canvas.setFocusable(true);
canvas.requestFocusInWindow();
}
public static void main (String[] args)
{
String isInside = "The point is in the polygon";
String notInside = "The point is not in the polygon";
//Create a Polygon object
Polygon polygon = new Polygon();
polygon.addPoint(40,20);
polygon.addPoint(70,40);
polygon.addPoint(60,80);
polygon.addPoint(45,45);
polygon.addPoint(20,60);
JLabel label = new JLabel(isInside, JLabel.CENTER);
JLabel notlabel = new JLabel(notInside, JLabel.CENTER);
Chapter3Lab1 frame = new Chapter3Lab1();;
frame.setTitle("Chapter 3 Lab 1");
frame.setLayout(new FlowLayout());
frame.setLocationRelativeTo(null);// Center the frame
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(200,200);
while (true)
{
PointerInfo a = MouseInfo.getPointerInfo();
Point b = a.getLocation();
int x = (int) b.getX();
int y = (int) b.getY();
if(polygon.contains(x, y) == false)
{
frame.remove(label);
frame.add(notlabel);
}
else
{
frame.remove(notlabel);
frame.add(label);
}
frame.setVisible(true);
try
{
Thread.sleep(1000);
}
catch (InterruptedException e)
{
e.printStackTrace();
}
}
}
class RegularPolygonPanel extends JPanel
{
protected void paintComponent(Graphics g)
{
super.paintComponent(g);
//Create a Polygon object
Polygon polygon = new Polygon();
polygon.addPoint(40,20);
polygon.addPoint(70,40);
polygon.addPoint(60,80);
polygon.addPoint(45,45);
polygon.addPoint(20,60);
//Draw the polygon
g.drawPolygon(polygon);
}
public Dimension getPreferredSize()
{
return new Dimension(200,200);
}
}
}
Start by taking a look at How to Write a Mouse Listener
You will need to maintain a reference to the Polygon object and make use of it's contains method to determine if the mouse is within the Polygon itself...
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Point;
import java.awt.Polygon;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private RegularPolygonPanel polyPanel;
private JLabel label;
public TestPane() {
polyPanel = new RegularPolygonPanel();
polyPanel.addMouseMotionListener(new MouseAdapter() {
#Override
public void mouseMoved(MouseEvent e) {
if (polyPanel.isWithinPolygon(e.getPoint())) {
label.setText("Is inside");
} else {
label.setText("Is outside");
}
}
});
label = new JLabel("...");
setLayout(new BorderLayout());
add(polyPanel);
add(label, BorderLayout.SOUTH);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
}
class RegularPolygonPanel extends JPanel {
private Polygon polygon;
public RegularPolygonPanel() {
//Create a Polygon object
polygon = new Polygon();
polygon.addPoint(40, 20);
polygon.addPoint(70, 40);
polygon.addPoint(60, 80);
polygon.addPoint(45, 45);
polygon.addPoint(20, 60);
}
public boolean isWithinPolygon(Point p) {
return polygon.contains(p);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
//Draw the polygon
g.drawPolygon(polygon);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
}
}
I have Code where I can move image.
Everything works well.
here I have only one ImagePanel (children of JPanel) on the frame.
Questions:
I need to drag and drop image from one JPanel to another JPanel.
Then I need to move dragged image to current panel.
Can you give me an example code, please?
class ImagePanel extends JPanel {
int x, y;
BufferedImage image;
ImagePanel() {
setBackground(Color.white);
setSize(450, 400);
addMouseMotionListener(new MouseMotionHandler());
Image img = getToolkit().getImage("C:\\2.png");
MediaTracker mt = new MediaTracker(this);
mt.addImage(img, 1);
try {
mt.waitForAll();
} catch (Exception e) {
System.out.println("Image not found.");
}
image = new BufferedImage(img.getWidth(this), img.getHeight(this),BufferedImage.TYPE_INT_ARGB);
Graphics2D g2 = image.createGraphics();
g2.drawImage(img, 0, 0, this);
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2D = (Graphics2D) g;
g2D.drawImage(image, x, y, this);
}
class MouseMotionHandler extends MouseMotionAdapter {
public void mouseDragged(MouseEvent e) {
x = e.getX();
y = e.getY();
repaint();
}
public void mouseMoved(MouseEvent e) {
}
}
}
I need to do that code, with this following design. I need to add image with some layout (I don't need to done this with Point pixels). or how to add image with some layout? for example Grid bag layout. I don't need Points (x,y). because I need to add another components too.
public class DragAndDrop {
private JFrame frame;
/* .. another component here .. */
private JPanel leftPanel; // here is my image
public JPanel rightContentPanel; // destination of dragable image
public static void main(String[] args) {
DragAndDrop window = new DragAndDrop();
}
public DragAndDrop() {
initialize();
}
private void initialize() {
frame = new JFrame();
frame.getContentPane().setLayout(new BorderLayout(0, 0));
leftPanel = new leftPanel();
/* add components to left panel */
rightContentPanel = new rightPanel();
/* add component to right panel */
frame.getContentPane().add(rightContentPanel, BorderLayout.CENTER);
frame.getContentPane().add(leftPanel, BorderLayout.WEST);
frame.setVisible(true);
frame.setResizable(false);
}
}
class leftPanel extends JPanel {
/ ... /
}
class rightPanel extends JPanel{
/ ... /
}
There's probably any number of ways to achieve what you want. You could use the glass pane or JXLayer or you could stop treating the two panels as separate elements and more like they were just windows into a large virtual space.
This example basically treats the parent component as the "virtual space" into which the two image panes are windows.
They both share the same image and image location details. They, individual, convert the image location (which is in virtual coordinates) to local coordinates and draw as much of the image as would appear on them...
Mouse control is maintained by the parent. This greatly simplifies the process, as it can notify both the panels simultaneously
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.GridLayout;
import java.awt.Image;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.border.EmptyBorder;
import javax.swing.border.LineBorder;
public class CrossImage {
public static void main(String[] args) {
new CrossImage();
}
public CrossImage() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private BufferedImage img;
private ImagePane left;
private ImagePane right;
private Point imagePoint;
public TestPane() {
setBorder(new EmptyBorder(10, 10, 10, 10));
setLayout(new GridLayout(0, 2, 10, 10));
left = new ImagePane();
right = new ImagePane();
imagePoint = new Point(10, 10);
left.setImageLocation(imagePoint);
right.setImageLocation(imagePoint);
try {
img = ImageIO.read(new File("Background.jpg"));
left.setImage(img);
right.setImage(img);
} catch (IOException ex) {
ex.printStackTrace();
}
add(left);
add(right);
MouseAdapter mouseHandler = new MouseAdapter() {
private Point delta;
#Override
public void mousePressed(MouseEvent e) {
Point origin = e.getPoint();
Rectangle bounds = new Rectangle(imagePoint, new Dimension(img.getWidth(), img.getHeight()));
if (bounds.contains(origin)) {
delta = new Point(origin.x - imagePoint.x, origin.y - imagePoint.y);
}
}
#Override
public void mouseDragged(MouseEvent e) {
if (delta != null) {
imagePoint = e.getPoint();
imagePoint.translate(-delta.x, -delta.y);
left.setImageLocation(imagePoint);
right.setImageLocation(imagePoint);
}
}
#Override
public void mouseReleased(MouseEvent e) {
delta = null;
}
};
addMouseListener(mouseHandler);
addMouseMotionListener(mouseHandler);
}
}
public class ImagePane extends JPanel {
private Image image;
private Point imageLocation;
public ImagePane() {
setBorder(new LineBorder(Color.DARK_GRAY));
}
#Override
public Dimension getPreferredSize() {
return image == null ? super.getPreferredSize() : new Dimension(image.getWidth(this), image.getHeight(this));
}
public void setImage(Image image) {
this.image = image;
repaint();
}
public void setImageLocation(Point imageLocation) {
this.imageLocation = imageLocation;
repaint();
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
if (image != null && imageLocation != null) {
Point p = SwingUtilities.convertPoint(getParent(), imageLocation, this);
g.drawImage(image, p.x, p.y, this);
}
}
}
}
so I'm trying to insert an image underneath a JTextArea, but I havent had much luck, could anyone please help? Basically what I'm asking is if anybody could help make another class or subclass that does this. Heres my code:
import java.awt.*;
import javax.swing.*;
public class t{
private JFrame f; //Main frame
private JTextArea t; // Text area private JScrollPane sbrText; // Scroll pane for text area
private JButton btnQuit; // Quit Program
public t(){ //Constructor
// Create Frame
f = new JFrame("Test");
f.getContentPane().setLayout(new FlowLayout());
String essay = "Test";
// Create Scrolling Text Area in Swing
t = new JTextArea(essay, 25, 35);
t.setEditable(false);
Font f = new Font("Verdana", Font.BOLD, 12 );
t.setFont( f );
t.setLineWrap(true);
sbrText = new JScrollPane(t);
sbrText.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
// Create Quit Button
btnQuit = new JButton("Quit");
btnQuit.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e){
System.exit(0);
} } );
}
public void launchFrame(){ // Create Layout
// Add text area and button to frame
f.getContentPane().add(sbrText);
f.getContentPane().add(btnQuit);
// Close when the close button is clicked
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//Display Frame
f.pack(); // Adjusts frame to size of components
f.setSize(450,480);
f.setResizable(false);
f.setLocationRelativeTo(null);
f.setVisible(true);
}
public static void main(String args[]){
t gui = new t();
gui.launchFrame();
}
}
The basic issue is that JTextArea will paint it's background and it's text within the paintComponent.
The simplest solution is to make the JTextArea transparent and take over the control of painting the background.
This example basically fills the background with the background color, paints the image and then calls super.paintComponent to allow the text to be rendered.
import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class TransparentTextArea {
public static void main(String[] args) {
new TransparentTextArea();
}
public TransparentTextArea() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Test");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new JScrollPane(new CustomTextArea()));
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class CustomTextArea extends JTextArea {
private BufferedImage image;
public CustomTextArea() {
super(20, 20);
try {
image = ImageIO.read(new File("/Users/swhitehead/Dropbox/MegaTokyo/Miho_Small_02.png"));
} catch (IOException ex) {
ex.printStackTrace();
}
}
#Override
public boolean isOpaque() {
return false;
}
#Override
protected void paintComponent(Graphics g) {
Graphics2D g2d = (Graphics2D) g.create();
g2d.setColor(getBackground());
g2d.fillRect(0, 0, getWidth(), getHeight());
if (image != null) {
int x = getWidth() - image.getWidth();
int y = getHeight() - image.getHeight();
g2d.drawImage(image, x, y, this);
}
super.paintComponent(g2d);
g2d.dispose();
}
}
}
Check out the Background Panel. When you add a scrollpane to the panel it will make the scrollpane, viewport and text area all non-opaque so you can see the image.