I need to show an image in a java applet, with a text element (label) to move to a point chosen by the user. Is it possible by dragging and dropping the text over the image? What methods would I need to use?
I am looking for something similar to this.
Edit: Thanks you for your useful response. The code below works fine! But how to get a text position by x,y coordinates within the image?
public class MouseDragTest extends JPanel {
private static final String TITLE = "Drag me!";
private static final int W = 640;
private static final int H = 480;
private Point textPt = new Point(W / 2, H / 2);
private Point mousePt;
Image img;
public MouseDragTest() {
img = Toolkit.getDefaultToolkit().createImage("my_image.jpg");
this.setFont(new Font("Serif", Font.ITALIC + Font.BOLD, 32));
this.addMouseListener(new MouseAdapter() {
#Override
public void mousePressed(MouseEvent e) {
mousePt = e.getPoint();
repaint();
}
});
this.addMouseMotionListener(new MouseMotionAdapter() {
#Override
public void mouseDragged(MouseEvent e) {
int dx = e.getX() - mousePt.x;
int dy = e.getY() - mousePt.y;
textPt.setLocation(textPt.x + dx, textPt.y + dy);
mousePt = e.getPoint();
repaint();
}
});
}
#Override
public Dimension getPreferredSize() {
return new Dimension(W, H);
}
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
int w2 = g.getFontMetrics().stringWidth(TITLE) / 2;
g.drawImage(img, 0, 0, null);
g.drawString(TITLE, textPt.x - w2, textPt.y);
}
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
JFrame f = new JFrame(TITLE);
f.add(new MouseDragTest());
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.pack();
f.setLocationRelativeTo(null);
f.setVisible(true);
}
});
}
}
You can use drawImage() in paintComponent() to show your invoice, like they show here, and drag the text, like they show here. Another way is to use the The Glass Pane.
How to get a text position by x,y coordinates within the image?
It sounds like you want to edit the text and location repeatedly. When you're done dragging, textPt will be the point at which you want to draw the text when you next load that image. You can store the details in java.util.Preferences and restore them when you restart.
private static class AnnotatedImage {
File file;
List<String> notes;
List<Point> points;
}
As you are using createImage(), use this as the image observer when drawing.
g.drawImage(img, 0, 0, this);
Related
This question already has answers here:
How to serialize Java 2D Shape objects as XML?
(2 answers)
Closed 8 years ago.
I have a program that lets the user add rectangles and circles to JPanel using Graphics. What I want to be able to do is save the current state of the current JPanel (i.e. all of the shapes and their locations) into a file and be able to load that file back and restore that state. I have a Shapes class that extends JPanel and does all of the drawing and keeps track of the shapes with an ArrayList.
Will I be able to just simply save the state of the panel? Or will I have to just save the Shapes data into a file and redraw the shapes when a file is "opened"?
Can anyone guide me on how I can save the current state of my JPanel and re-open it? Thanks
public class UMLEditor {
public static void main(String[] args) {
JFrame frame = new UMLWindow();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setBounds(30, 30, 1000, 700);
frame.getContentPane().setBackground(Color.white);
frame.setVisible(true);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
}
class UMLWindow extends JFrame {
Shapes shapeList = new Shapes();
public UMLWindow() {
addMenus();
}
public void addMenus() {
getContentPane().add(shapeList);
JMenuBar menubar = new JMenuBar();
JMenu file = new JMenu("File");
JMenuItem openMenuItem = new JMenuItem("Open File");
openMenuItem.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent event) {
// Open saved state
});
JMenuItem saveMenuItem = new JMenuItem("Save");
saveMenuItem.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent event) {
// Save current state
}
});
file.add(openMenuItem);
file.add(saveMenuItem);
JMenu shapes = new JMenu("Shapes");
file.setMnemonic(KeyEvent.VK_F);
JMenuItem rectangleMenuItem = new JMenuItem("New Rectangle");
rectangleMenuItem.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent event) {
shapeList.addSquare(100, 100);
}
});
JMenuItem circleMenuItem = new JMenuItem("New Circle");
circleMenuItem.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent event) {
shapeList.addCircle(100, 100);
}
});
shapes.add(rectangleMenuItem);
shapes.add(circleMenuItem);
menubar.add(file);
menubar.add(shapes);
setJMenuBar(menubar);
setSize(300, 200);
setLocationRelativeTo(null);
setDefaultCloseOperation(EXIT_ON_CLOSE);
}
}
// Shapes class, used to draw the shapes on the panel
// as well as implements the MouseListener for dragging
class Shapes extends JPanel {
private static final long serialVersionUID = 1L;
private List<Path2D> shapes = new ArrayList<Path2D>();
int currentIndex;
public Shapes() {
MyMouseAdapter myMouseAdapter = new MyMouseAdapter();
addMouseListener(myMouseAdapter);
addMouseMotionListener(myMouseAdapter);
}
public void addSquare(int width, int height) {
Path2D rect2 = new Path2D.Double();
rect2.append(new Rectangle(getWidth() / 2 - width / 2, getHeight() / 2
- height / 2, width, height), true);
shapes.add(rect2);
repaint();
}
public void addCircle(int width, int height) {
Path2D rect2 = new Path2D.Double();
rect2.append(new Ellipse2D.Double(getWidth() / 2 - width / 2,
getHeight() / 2 - height / 2, width, height), true);
shapes.add(rect2);
repaint();
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
this.setOpaque(true);
this.setBackground(Color.WHITE);
Graphics2D g2 = (Graphics2D) g;
for (Path2D rect : shapes) {
g2.draw(rect);
}
}
class MyMouseAdapter extends MouseAdapter {
private boolean pressed = false;
private Point point;
#Override
public void mousePressed(MouseEvent e) {
if (e.getButton() != MouseEvent.BUTTON1) {
return;
}
for (int i = 0; i < shapes.size(); i++) {
if (shapes.get(i) != null
&& shapes.get(i).contains(e.getPoint())) {
currentIndex = i;
pressed = true;
this.point = e.getPoint();
}
}
}
#Override
public void mouseDragged(MouseEvent e) {
if (pressed) {
int deltaX = e.getX() - point.x;
int deltaY = e.getY() - point.y;
shapes.get(currentIndex).transform(
AffineTransform.getTranslateInstance(deltaX, deltaY));
point = e.getPoint();
repaint();
}
}
#Override
public void mouseReleased(MouseEvent e) {
pressed = false;
}
}
}
You could add a line of code in addCircle and addSquare that stores their H and W (or instances of the shapes themselves) in a serialized array (which could be saved to a .dat file). Then read the file and shapes.add(tehShape) for each shape entry in the dat file and repaint when needed. Used this method on an android app when i needed a persistent storage of customized ListView items. Not pretty, but it worked like a charm once properly set up. Upside of this is that you will be saving identical object instances in the dat file, downside is that they wont be human-readable.
I have create a program in Java which allows dragging of two oval shapes. Now I want to convert it to a JApplet so I made the class extend JApplet instead of original JPanel. The problem with this is that super.paintComponent(g) does not work as it is no longer a parent class.
I have tried creating a JPanel within the class then referring to this but I get the error: The method paintComponent(Graphics) from the type JComponent is not visible
Any heads up on what I need to do or any help would be much appreciated thanks.
Here is my code.
public class Main extends JPanel
{
private static final String TITLE = "Drag me!";
private static final int W = 640;
private static final int H = 480;
private Point origin = new Point(W / 2, H / 2);
private Point mousePt;
public Main() {
this.setCursor(Cursor.getPredefinedCursor(Cursor.HAND_CURSOR));
this.addMouseListener(new MouseAdapter()
{
#Override
public void mousePressed(MouseEvent e)
{
mousePt = e.getPoint();
repaint();
}
});
this.addMouseMotionListener(new MouseMotionAdapter()
{
#Override
public void mouseDragged(MouseEvent e)
{
int dx = e.getX() - mousePt.x;
int dy = e.getY() - mousePt.y;
origin.setLocation(origin.x + dx, origin.y + dy);
mousePt = e.getPoint();
repaint();
}
});
}
#Override
public Dimension getPreferredSize() {
return new Dimension(W, H);
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawOval(0, origin.y, getWidth(), origin.y);
g.drawOval(origin.x, 0, origin.x, getHeight());
}
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
JFrame f = new JFrame(TITLE);
f.add(new Main());
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.pack();
f.setLocationRelativeTo(null);
f.setVisible(true);
}
});
}
}
Instead of modifying your JPanel, keep it and create a new class, your JApplet class:
public class YourJApplet extends JApplet{
public void init(){
final JPanel panel = new YourPanel();
this.setContentPane(panel);
}
}
That's it--now whatever was going on with your panel is now your JApplet.
I'm trying to draw over an image (with the mouse) in a JPanel, this is working, but when I try to take an screenshot of the panel and generate an image of this, I only can see the image background without drawn with the mouse.
This is my code to generate the background Panel.java
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(this.createImage("/imagenes/cuerpoHumano.png").getImage(), 0, 0, null);
}
This is my code to draw as a pencil over the image: Panel.java
private void formMouseDragged(java.awt.event.MouseEvent evt) {
x = evt.getX();
y = evt.getY();
this.getGraphics().setColor(Color.RED);
this.getGraphics().fillOval(x, y, 4, 4);
}
This is the code to generate an screenshot
Dimension size = panel.getSize();
BufferedImage image = (BufferedImage) panel.createImage(size.width, size.height);
Graphics g = image.getGraphics();
panel.paint(g);
g.dispose();
try {
String fileName = UUID.randomUUID().toString().substring(0, 18);
ImageIO.write(image, "jpg", new File(path, fileName + ".jpg"));
} catch (IOException e) {
e.printStackTrace();
}
When you are taking the screenshot, the paintComponent() method is called. This means it will only paint you the image. You have to store the mouse move inside some model and paint the contents of the model in the paintComponent() method. This method is triggered by calling repaint() on the panel during the mouse move.
I think this is code that works .
public class PanelImagenCuerpoHumano extends JPanel {
private int x = -1;
private int y = -1;
private Image image = null;
private ArrayList<Point> puntos = new ArrayList<Point>();
public PanelImagenCuerpoHumano() {
image = new ImageIcon(getClass()
.getResource("/imagenes/cuerpoHumano.png")).getImage();
this.addMouseMotionListener(new MouseMotionListener() {
#Override
public void mouseDragged(MouseEvent e) {
x = e.getX();
y = e.getY();
puntos.add(new Point(x, y));
repaint();
}
#Override
public void mouseMoved(MouseEvent e) {
}
});
}
#Override
protected void paintComponent(Graphics g) {
g.drawImage(image, 0, 0, null);
for (Point p : puntos) {
g.setColor(Color.red);
g.fillOval(p.x, p.y, 3, 3);
}
}
}
I want to allow users to be able to "draw" with their mouse (click and drag) to create and size a JTextArea. As well, I would like to have the text areas as resizeable.
Something like this:
comes to mind, but as a JTextArea instead of just a square.
Is there something in Java that would allow me to easily do this? I first thought to allow the user to draw a rectangle and just grab the co-ordinates and size to create the JTextArea. I am unsure on how to do the resizing though.
Edit: "Component Resizer / Reszing" was the term I was looking for and I'm adding it here in case someone else is looking for something similar!
You can found a solution here
I have already try it and the result is very well. In the tutorial there is a reference to another implementation here.
The resizing the JTextArea can be done easily enough via calling setBounds(...) on it -- or better on the JScrollPane that holds it, but you will need to use a null or similar (JLayeredPane) layout on the container that holds the JTextArea and will likely need to repaint the container after resizing the JScrollPane. You will also have to revalidate the scrollpane's viewport so it will re-layout the textarea that it holds.
e.g.,
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
#SuppressWarnings("serial")
public class ResizeableTextArea extends JPanel {
private static final int PREF_WIDTH = 700;
private static final int PREF_HEIGHT = 500;
private static final int ROWS = 60;
private static final int COLS = 80;
private static final Color RECT_COLOR = new Color(180, 180, 255);
private JTextArea textArea = new JTextArea(ROWS, COLS);
private JScrollPane scrollPane = new JScrollPane(textArea);
private int x, y, width, height;
private boolean drawRect = false;
public ResizeableTextArea() {
setLayout(null);
add(scrollPane);
MyMouseAdapter myMouseAdapter = new MyMouseAdapter();
addMouseListener(myMouseAdapter);
addMouseMotionListener(myMouseAdapter);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
if (drawRect) {
g.setColor(RECT_COLOR);
g.drawRect(x, y, width, height);
}
}
#Override
public Dimension getPreferredSize() {
return new Dimension(PREF_WIDTH, PREF_HEIGHT);
}
private class MyMouseAdapter extends MouseAdapter {
private int innerX, innerY;
#Override
public void mousePressed(MouseEvent e) {
x = e.getX();
y = e.getY();
innerX = x;
innerY = y;
width = 0;
height = 0;
drawRect = true;
}
#Override
public void mouseDragged(MouseEvent e) {
calcBounds(e);
drawRect = true;
ResizeableTextArea.this.repaint();
}
#Override
public void mouseReleased(MouseEvent e) {
calcBounds(e);
drawRect = false;
scrollPane.setBounds(x, y, width, height);
scrollPane.getViewport().revalidate();
ResizeableTextArea.this.repaint();
}
private void calcBounds(MouseEvent e) {
width = Math.abs(innerX - e.getX());
height = Math.abs(innerY - e.getY());
x = Math.min(innerX, e.getX());
y = Math.min(innerY, e.getY());
}
}
private static void createAndShowUI() {
JFrame frame = new JFrame("ResizeableTextArea");
frame.getContentPane().add(new ResizeableTextArea());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
createAndShowUI();
}
});
}
}
You should be able to use the Component Resizer.
that not really good idea, sure is possible to put Image or ImageIcon as BackGround, better would be use for that JLabel with Icon, then you can painting selection easily
Just out of intellectual interest can you make a Canvas not flicker when doing a manual resize.
public class FlickerAWT extends Canvas {
public static void main(String[] args) {
Frame f = new Frame(str);
//this line change nothing
//JFrame f = new JFrame(str);
f.add(new FlickerAWT());
f.pack();
int frameWidth = f.getWidth();
int frameHeight = f.getHeight();
Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
f.setLocation(screenSize.width / 2 - frameWidth / 2, screenSize.height / 2 - frameHeight / 2);
f.setVisible(true);
f.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
public void windowDeiconified(WindowEvent e) {
}
public void windowIconified(WindowEvent e) {
}
});
}
private Color bgColor; private Color contentColor;
Font f = new Font("Georgia", Font.BOLD, 16);
static String str = "AWT Canvas Resize Flickering";
public FlickerAWT() {
Random r = new Random();
bgColor = new Color(r.nextInt(256), r.nextInt(256), r.nextInt(256));
contentColor = new Color(r.nextInt(256), r.nextInt(256), r.nextInt(256));
}
public Dimension getPreferredSize() {
FontMetrics fm = getFontMetrics(f);
return new Dimension(fm.stringWidth(str) + 20, fm.getHeight() + 10);
}
public void paint(java.awt.Graphics g) {
g.setColor(bgColor);
g.fillRect(0, 0, getWidth(), getHeight());
g.setColor(contentColor);
g.setFont(f);
FontMetrics fm = g.getFontMetrics(f);
int dx = getWidth() / 2 - (fm.stringWidth(str) / 2);
int dy = getHeight() / 2 + (fm.getHeight() / 2);
g.drawString(str, dx, dy);
}
}
You can copy paste in a Java editor and run the example.
You can add this to the beginning of your main method to avoid the background flicker:
System.setProperty("sun.awt.noerasebackground", "true");
I know this question is ancient, but it came up during my search and I meanwhile found a solution:
There are two problems:
On the one hand, the update(...) method of java.awt.Container looks like the following:
public void update(Graphics g) {
if (isShowing()) {
if (! (peer instanceof LightweightPeer)) {
g.clearRect(0, 0, width, height);
}
paint(g);
}
}
I.e. it calls g.clearRect(...) to erase the current content before painting its children.
Therefore, you need to override update(...) in every descendant of java.awt.Container in your view-stack, that doesn't already do so, with something like:
public void update(Graphics g) {
if (isShowing()) paint(g);
}
Also, it seems that AWT or the JVM or whoever (haven't figured this out yet) also clears the background of the main window, independent of any Container's update-methods. To prevent this, follow #WhiteFang34's suggestion and add the following line to your code somewhere:
System.setProperty("sun.awt.noerasebackground", "true");
Only doing both of these things finally solved my flicker issues...
The key I believe is to use double buffering, and one way to possibly solve this is to use Swing which double buffers by default:
import java.awt.*;
import java.util.Random;
import javax.swing.*;
public class FlickerSwing extends JPanel {
public static void main(String[] args) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
private static void createAndShowGui() {
JFrame f = new JFrame(str);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.add(new FlickerSwing());
f.setLocationRelativeTo(null);
f.pack();
f.setVisible(true);
}
private Color bgColor;
private Color contentColor;
Font f = new Font("Georgia", Font.BOLD, 16);
static String str = "Swing Resize Flickering";
public FlickerSwing() {
Random r = new Random();
bgColor = new Color(r.nextInt(256), r.nextInt(256), r.nextInt(256));
contentColor = new Color(r.nextInt(256), r.nextInt(256), r.nextInt(256));
setBackground(bgColor);
}
public Dimension getPreferredSize() {
FontMetrics fm = getFontMetrics(f);
return new Dimension(fm.stringWidth(str) + 20, fm.getHeight() + 10);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(contentColor);
g.setFont(f);
FontMetrics fm = g.getFontMetrics(f);
int dx = getWidth() / 2 - (fm.stringWidth(str) / 2);
int dy = getHeight() / 2 + (fm.getHeight() / 2);
g.drawString(str, dx, dy);
}
}