Java - change JPanel image with mouse - java

I am trying to create a panel with pictures that are changed with the mouse.
I have 10 images (0.png to 9.png). My problem is, I want to move image and I am currently viewing the second picture. I used the JScrollPane to scroll back to the first image, but only the first image is moving. How can I refresh my panel and be able to move all images?
This is my code:
import java.awt.*;
import java.awt.event.*;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import java.io.File;
import javax.imageio.ImageIO;
import javax.swing.*;
class MapFrame extends JPanel {
/**
*
*/
private static final long serialVersionUID = (long) 1.0;
private static Image image;
private static JLabel label = new JLabel();
private static int ind =0;
private static JFrame frame;
private static String str;
//-----------------------------------------------------------------
public MapFrame(){ }
//-----------------------------------------------------------------
public MapFrame(String pathe) {
super(new BorderLayout());
image = new ImageIcon(getClass().getResource(pathe)).getImage();
label = new JLabel(new ImageIcon(image));
JScrollPane scroll = new JScrollPane(label,JScrollPane.VERTICAL_SCROLLBAR_NEVER,JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);
add(scroll);
HandLcalss hand = new HandLcalss(label);
JViewport v = scroll.getViewport();
v.addMouseListener(hand);
v.addMouseMotionListener(hand);
v.addMouseWheelListener(hand);
}
//-----------------------------------------------------------------
public static void ShowGUI(String pathe) {
frame = new JFrame("Bladi_map");
frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
frame.getContentPane().add(new MapFrame(pathe));
frame.setSize(500,400);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
//-----------------------------------------------------------------
public static void ChangImage(String pathe){
frame.getContentPane().add(new MapFrame(pathe));
label.revalidate();
frame.setVisible(true);
}
//-----------------------------------------------------------------
class HandLcalss implements MouseListener,MouseMotionListener,MouseWheelListener{
private static final int DELAY = 10;
private Cursor hc = Cursor.getPredefinedCursor(Cursor.HAND_CURSOR);
private Timer scroller;
private JComponent label;
private Point startPt = new Point();
private Point move = new Point();
//-----------------------------------------------------------------
public HandLcalss(JComponent comp) {
this.label = comp;
comp.getCursor();
this.scroller = new Timer(DELAY, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
}
});
}
//-----------------------------------------------------------------
#Override public void mouseDragged(MouseEvent e) {
JViewport vport = (JViewport)e.getSource();
Point pt = e.getPoint();
int dx = startPt.x - pt.x;
int dy = startPt.y - pt.y;
Point vp = vport.getViewPosition();
vp.translate(dx, dy);
label.scrollRectToVisible(new Rectangle(vp, vport.getSize()));
startPt.setLocation(pt);
}
#Override
public void mousePressed(MouseEvent e) {
((JComponent)e.getSource()).setCursor(hc);
startPt.setLocation(e.getPoint());
move.setLocation(0, 0);
scroller.stop();
}
#Override
public void mouseWheelMoved(MouseWheelEvent e) {
int notches = e.getWheelRotation();
if (notches < 0) {
ind++;
if(ind <0){ind=0;}
if(ind<=9){
str="/resources/"+ind+".png";
ChangImage(str);
System.out.println("indink"+str);
}
} else {
ind--;
if(ind >9){ind=8;}
if(ind>=0){
str="/resources/"+ind+".png";
ChangImage(str);
System.out.println("ind"+ind);
}
}
}
#Override
public void mouseClicked(MouseEvent e) {
// TODO Auto-generated method stub
}
#Override
public void mouseMoved(MouseEvent arg0) {
// TODO Auto-generated method stub
}
#Override
public void mouseEntered(MouseEvent arg0) {
// TODO Auto-generated method stub
}
#Override
public void mouseExited(MouseEvent arg0) {
// TODO Auto-generated method stub
}
#Override
public void mouseReleased(MouseEvent arg0) {
// TODO Auto-generated method stub
}
}
//-----------------------------------------------------------------
}
This is the main class:
public class main {
public static void main(String[] args) {
MapFrame.ShowGUI("/resources/0.png");
}
}

You have 2 problems in your code:
The first:
public static void ChangImage(String pathe){
frame.getContentPane().add(new MapFrame(pathe));
label.revalidate();
frame.setVisible(true);
}
When you change image (invoked on mouse wheel event) you simply add new panel (MapFrame) with image to existing container: (Container pane = frame.getContentPane()). The old ones are still there and are overlapping with the new panel. The above method should be:
public static void ChangImage(String pathe) {
frame.getContentPane().removeAll();
frame.getContentPane().add(new MapFrame(pathe));
label.revalidate();
frame.setVisible(true);
}
The second thing:
Why complicate? (also there is an error on 0 value of ind):
#Override
public void mouseWheelMoved(MouseWheelEvent e) {
int notches = e.getWheelRotation() * -1;
ind += notches;
if(ind < 0) {
ind = 0;
}
else if(ind > 9) {
ind = 9;
}
str = "/resources/" + ind + ".png";
ChangImage(str);
}
And the last thing:
If you are implementing all mouse interfaces - you can extend MouseAdapter. Now you needn't override methods you don't want.

Related

Why does this program only display the last graphic?

Im using JPanel and JFrame to create a program that can draw lines and circles. The problem is that my program only redraws the last object added.
I have tried moving around the repaint. For some reason, when I directly draw shapes onto the graphic in paintComponent(), they show up and refresh each frame. However, I have methods inside of paintComponent that pass the graphic variable to elsewhere methods that draw to the graphic object, these are the shapes that do not show up.
Painter Class
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class Painter implements ActionListener, MouseListener, MouseMotionListener {
/**
*
*/
Color temp = Color.RED;
// 0 = line, 1 = circle
int object = 0;
PaintingPanel canvas;
Point startPoint = new Point();
Point endPoint = new Point();
Painter() {
//buttons
JButton circleBut = new JButton();
JButton lineBut = new JButton();
//frame
//close operation
//resizes
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(500, 500);
//holder holds the information
JPanel holder = new JPanel();
JPanel leftPanel = new JPanel();
holder.setLayout(new BorderLayout());
leftPanel.setLayout(new GridLayout(3, 1)); // 3 by 1 grid
JPanel northPanel = new JPanel();
northPanel.setLayout(new GridLayout(1, 2)); // 3 by 1 grid
frame.add(holder);
// circle and line buttons
circleBut.setText("Circle");
lineBut.setText("Line");
northPanel.add(circleBut);
northPanel.add(lineBut);
circleBut.setActionCommand("1");
lineBut.setActionCommand("0");
//
holder.add(northPanel, BorderLayout.NORTH);
// red
JButton redPaint = new JButton();
redPaint.setBackground(Color.RED);
redPaint.setOpaque(true);
redPaint.setBorderPainted(false);
leftPanel.add(redPaint);
redPaint.setActionCommand("red");
// green
JButton greenPaint = new JButton();
greenPaint.setBackground(Color.GREEN);
greenPaint.setOpaque(true);
greenPaint.setBorderPainted(false);
leftPanel.add(greenPaint);
greenPaint.setActionCommand("green");
// blue
JButton bluePaint = new JButton();
bluePaint.setBackground(Color.BLUE);
bluePaint.setOpaque(true);
bluePaint.setBorderPainted(false);
leftPanel.add(bluePaint);
bluePaint.setActionCommand("blue");
holder.add(leftPanel, BorderLayout.WEST);
// still need to add painting panel to the CENTER panel
canvas = new PaintingPanel();
holder.add(canvas, BorderLayout.CENTER);
circleBut.addActionListener(this);
lineBut.addActionListener(this);
redPaint.addActionListener(this);
greenPaint.addActionListener(this);
bluePaint.addActionListener(this);
canvas.addMouseListener(this);
//holder.addMouseMotionListener(this);
// still need to add chat panel to the SOUTH panel
frame.setContentPane(holder);
frame.setVisible(true);
}
#Override
public void actionPerformed(ActionEvent e) {
if (e.getActionCommand().equals("red")) {
temp = Color.RED;
System.out.println("received r");
} else if (e.getActionCommand().equals("green")) {
temp = Color.GREEN;
System.out.println("received g");
} else if (e.getActionCommand().equals("blue")) {
temp = Color.BLUE;
System.out.println("received b");
} else if (e.getActionCommand().equals("0")) {
object = 0;
System.out.println("received 0");
} else if (e.getActionCommand().equals("1")) {
object = 1;
System.out.println("received 1");
}
}
#Override
public void mouseDragged(MouseEvent e) {
// TODO Auto-generated method stub
}
#Override
public void mouseMoved(MouseEvent e) {
// TODO Auto-generated method stub
}
#Override
public void mouseClicked(MouseEvent e) {
}
#Override
public void mousePressed(MouseEvent e) {
startPoint.setLocation(e.getPoint());
}
#Override
public void mouseReleased(MouseEvent e) {
// and this one
endPoint.setLocation(e.getPoint());
if (object == 0) {
canvas.addPrimitive(new Line(startPoint, endPoint, temp));
}
if (object == 1){
canvas.addPrimitive(new Circle(startPoint, endPoint, temp));
}
canvas.repaint();
}
#Override
public void mouseEntered(MouseEvent e) {
// TODO Auto-generated method stub
}
#Override
public void mouseExited(MouseEvent e) {
// TODO Auto-generated method stub
}
public static void main(String[] args) {
Painter game1 = new Painter();
}
}
PaintingPrimitives:
`
import java.awt.Graphics;
import java.awt.Color;
public abstract class PaintingPrimitive{
Color color;
PaintingPrimitive(Color color) {
this.color = color;
}
// This is an example of the Template Design Pattern
// this is all invariant code
public final void draw(Graphics g) {
g.setColor(color);
drawGeometry(g);
}
public void setColor(Color color) {
this.color = color;
}
protected abstract void drawGeometry(Graphics g);
}
Line Class:
import java.awt.Graphics;
import java.awt.Point;
import java.awt.Color;
public class Line extends PaintingPrimitive{
Point startPoint = new Point();
Point endPoint = new Point();
public Line(Point start, Point end, Color c) {
super(c);
this.startPoint = start;
this.endPoint = end;
}
public void drawGeometry(Graphics g) {
System.out.println("graw geo called");
g.drawLine(startPoint.x, startPoint.y, endPoint.x, endPoint.y);
}
#Override
public String toString() {
return "Line";
}
}
Painting Panel:
import java.util.ArrayList;
import javax.swing.JPanel;
import java.awt.Graphics;
import java.awt.Color;
public class PaintingPanel extends JPanel {
ArrayList<PaintingPrimitive> primitives = new ArrayList<PaintingPrimitive>();
PaintingPanel() {
setBackground(Color.WHITE);
}
public void addPrimitive(PaintingPrimitive obj) {
primitives.add(obj);
this.repaint();
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
// i'm confident that this is not painting to the right graphics
for (PaintingPrimitive shape : primitives) {
//g.dispose();
//this line works. this line is drawn each time its updated.
g.drawLine(0,0,100,100);
shape.draw(g);
}
}
}
`
Okay, that was weird, until it wasn't. Your problem basic centers around...
public void mousePressed(MouseEvent e) {
startPoint.setLocation(e.getPoint());
}
#Override
public void mouseReleased(MouseEvent e) {
// and this one
endPoint.setLocation(e.getPoint());
if (object == 0) {
canvas.addPrimitive(new Line(startPoint, endPoint, temp));
}
You create a single instance of startPoint and endPoint and simply update the location of each Point. You then pass these to each primitive you create. This means that each primitive is using the SAME instance of startPoint and endPoint. So, each time you call setLocation ALL the primitives are been updated.
Instead, do something more like...
#Override
public void mousePressed(MouseEvent e) {
startPoint = new Point(e.getPoint());
}
#Override
public void mouseReleased(MouseEvent e) {
// and this one
endPoint = new Point(e.getPoint());
And because I'm paranoid and don't trust any one, I'd probably also do...
public class Line extends PaintingPrimitive {
Point startPoint = new Point();
Point endPoint = new Point();
public Line(Point start, Point end, Color c) {
super(c);
this.startPoint = new Point(start);
this.endPoint = new Point(end);
}
Just to be sure

How to let user draw inside a canvas and save image afterwards?

I am trying to implement a free hand drawing Java applet which allows user to draw something in canvas (canvas is not the priority, it could be anything else as long I can save the image after (need to save it, because I have to display it later in a different place after pressing a button, any other solutions are welcome)). I found a code, which allows me to draw, but now I am having a trouble with drawing inside the canvas... And I have already spent few days with no results on that. Here is the code I have by now and a description below it:
import java.awt.*;
import java.awt.event.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;
import javax.swing.*;
import java.applet.*;
public class paintMozApplet extends Applet implements ActionListener
{
int xPressed,yPressed;
int xReleased,yReleased;
int xDragged,yDragged;
private GridLayout gL;
private JPanel buttons;
private JPanel panel;
private Button clear, createMoz;
private Label result_here;
private javax.swing.JPanel drawing;
private JPanel moz;
private Canvas canvas;
private draw draw;
public paintMozApplet()
{
draw = new draw();
gL = new GridLayout(1, 0);
buttons = new JPanel();
drawing = new JPanel();
moz = new JPanel();
canvas = new Canvas();
clear = new Button("clear");
createMoz = new Button("Create Moz");
buttons.add(clear);
buttons.add(createMoz);
result_here = new Label("Result here!");
moz.add(result_here);
drawing.add(canvas);
clear.addActionListener(this);
//canvas.add(draw);
//canvas.addMouseMotionListener(this);
canvas.setPreferredSize(new Dimension(200, 200));
canvas.setBackground(Color.green);
add(drawing);
add(buttons);
add(moz);
add(draw);
setPreferredSize(new Dimension(1000, 1000));
setSize(1000, 1000);
setLayout(gL);
}
public void actionPerformed(ActionEvent e)
{
if(e.getSource()==clear)
{
//setOpaque(false);
repaint();
}
}
}
class draw extends JFrame implements MouseListener, MouseMotionListener, ActionListener {
int xPressed,yPressed;
int xReleased,yReleased;
int xDragged,yDragged;
private JButton clear;
public draw()
{
setPreferredSize(new Dimension(1200, 500));
setBounds(0, 0, 480, 500);
clear=new JButton("CLEAR");
add(clear);
clear.setBounds(540, 5, 100, 25);
clear.addActionListener(this);
addMouseListener(this);
addMouseMotionListener(this);
}
protected void paintComponent(Graphics g)
{
g.drawLine(xPressed,yPressed,xDragged,yDragged);
xPressed=xDragged;
yPressed=yDragged;
}
#Override
public void mouseDragged(MouseEvent arg0) {
Graphics g = getGraphics();
g.drawLine(xPressed, yPressed, arg0.getX(), arg0.getY());
xDragged = arg0.getX();
yDragged = arg0.getY();
repaint();
}
#Override
public void mouseMoved(MouseEvent arg0) {
}
#Override
public void mouseClicked(MouseEvent arg0) {
}
#Override
public void mouseEntered(MouseEvent arg0) {
}
#Override
public void mouseExited(MouseEvent arg0) {
}
#Override
public void mousePressed(MouseEvent arg0) {
xPressed = arg0.getX();
yPressed = arg0.getY();
}
#Override
public void mouseReleased(MouseEvent arg0) {
}
#Override
public void actionPerformed(ActionEvent e) {
}
}
So my idea is to create two classes where one is used to draw and other to create place where to draw and everything else. I have tried lots of things and now I am here and cant figure out, how to cal the draw class on my canvas so it will draw only there. Before I had everything in one class and called mouse events on my canvas. Result was that it drawed only when I clicked on canvas, but the actual drawing went also out of canvas if I did not let go of my mouse and dragged it out of canvas. Also it did not draw in canvas, but on the background of applet, at least it looked like that.
I really hope I explained my self understanding and I am sure, that this can be solved easily since there are lots of solutions online but I can't seem to find one that would work as I intend.
I suggest starting with this approach based around a BufferedImage as the painting surface..
import java.awt.*;
import java.awt.RenderingHints.Key;
import java.awt.event.*;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import javax.imageio.ImageIO;
import javax.swing.*;
import javax.swing.border.*;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
import javax.swing.filechooser.FileFilter;
import javax.swing.filechooser.FileNameExtensionFilter;
public class BasicPaint {
/** Reference to the original image. */
private BufferedImage originalImage;
/** Image used to make changes. */
private BufferedImage canvasImage;
/** The main GUI that might be added to a frame or applet. */
private JPanel gui;
/** The color to use when calling clear, text or other
* drawing functionality. */
private Color color = Color.WHITE;
/** General user messages. */
private JLabel output = new JLabel("You DooDoodle!");
private BufferedImage colorSample = new BufferedImage(
16,16,BufferedImage.TYPE_INT_RGB);
private JLabel imageLabel;
private int activeTool;
public static final int SELECTION_TOOL = 0;
public static final int DRAW_TOOL = 1;
public static final int TEXT_TOOL = 2;
private Point selectionStart;
private Rectangle selection;
private boolean dirty = false;
private Stroke stroke = new BasicStroke(
3,BasicStroke.CAP_ROUND,BasicStroke.JOIN_ROUND,1.7f);
private RenderingHints renderingHints;
public JComponent getGui() {
if (gui==null) {
Map<Key, Object> hintsMap = new HashMap<RenderingHints.Key,Object>();
hintsMap.put(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
hintsMap.put(RenderingHints.KEY_DITHERING, RenderingHints.VALUE_DITHER_ENABLE);
hintsMap.put(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
renderingHints = new RenderingHints(hintsMap);
setImage(new BufferedImage(320,240,BufferedImage.TYPE_INT_RGB));
gui = new JPanel(new BorderLayout(4,4));
gui.setBorder(new EmptyBorder(5,3,5,3));
JPanel imageView = new JPanel(new GridBagLayout());
imageView.setPreferredSize(new Dimension(480,320));
imageLabel = new JLabel(new ImageIcon(canvasImage));
JScrollPane imageScroll = new JScrollPane(imageView);
imageView.add(imageLabel);
imageLabel.addMouseMotionListener(new ImageMouseMotionListener());
imageLabel.addMouseListener(new ImageMouseListener());
gui.add(imageScroll,BorderLayout.CENTER);
JToolBar tb = new JToolBar();
tb.setFloatable(false);
JButton colorButton = new JButton("Color");
colorButton.setMnemonic('o');
colorButton.setToolTipText("Choose a Color");
ActionListener colorListener = new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
Color c = JColorChooser.showDialog(
gui, "Choose a color", color);
if (c!=null) {
setColor(c);
}
}
};
colorButton.addActionListener(colorListener);
colorButton.setIcon(new ImageIcon(colorSample));
tb.add(colorButton);
setColor(color);
final SpinnerNumberModel strokeModel =
new SpinnerNumberModel(3,1,16,1);
JSpinner strokeSize = new JSpinner(strokeModel);
ChangeListener strokeListener = new ChangeListener() {
#Override
public void stateChanged(ChangeEvent arg0) {
Object o = strokeModel.getValue();
Integer i = (Integer)o;
stroke = new BasicStroke(
i.intValue(),
BasicStroke.CAP_ROUND,
BasicStroke.JOIN_ROUND,
1.7f);
}
};
strokeSize.addChangeListener(strokeListener);
strokeSize.setMaximumSize(strokeSize.getPreferredSize());
JLabel strokeLabel = new JLabel("Stroke");
strokeLabel.setLabelFor(strokeSize);
strokeLabel.setDisplayedMnemonic('t');
tb.add(strokeLabel);
tb.add(strokeSize);
tb.addSeparator();
ActionListener clearListener = new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
int result = JOptionPane.OK_OPTION;
if (dirty) {
result = JOptionPane.showConfirmDialog(
gui, "Erase the current painting?");
}
if (result==JOptionPane.OK_OPTION) {
clear(canvasImage);
}
}
};
JButton clearButton = new JButton("Clear");
tb.add(clearButton);
clearButton.addActionListener(clearListener);
gui.add(tb, BorderLayout.PAGE_START);
JToolBar tools = new JToolBar(JToolBar.VERTICAL);
tools.setFloatable(false);
JButton crop = new JButton("Crop");
final JRadioButton select = new JRadioButton("Select", true);
final JRadioButton draw = new JRadioButton("Draw");
final JRadioButton text = new JRadioButton("Text");
tools.add(crop);
tools.add(select);
tools.add(draw);
tools.add(text);
ButtonGroup bg = new ButtonGroup();
bg.add(select);
bg.add(text);
bg.add(draw);
ActionListener toolGroupListener = new ActionListener() {
#Override
public void actionPerformed(ActionEvent ae) {
if (ae.getSource()==select) {
activeTool = SELECTION_TOOL;
} else if (ae.getSource()==draw) {
activeTool = DRAW_TOOL;
} else if (ae.getSource()==text) {
activeTool = TEXT_TOOL;
}
}
};
select.addActionListener(toolGroupListener);
draw.addActionListener(toolGroupListener);
text.addActionListener(toolGroupListener);
gui.add(tools, BorderLayout.LINE_END);
gui.add(output,BorderLayout.PAGE_END);
clear(colorSample);
clear(canvasImage);
}
return gui;
}
/** Clears the entire image area by painting it with the current color. */
public void clear(BufferedImage bi) {
Graphics2D g = bi.createGraphics();
g.setRenderingHints(renderingHints);
g.setColor(color);
g.fillRect(0, 0, bi.getWidth(), bi.getHeight());
g.dispose();
imageLabel.repaint();
}
public void setImage(BufferedImage image) {
this.originalImage = image;
int w = image.getWidth();
int h = image.getHeight();
canvasImage = new BufferedImage(w,h,BufferedImage.TYPE_INT_ARGB);
Graphics2D g = this.canvasImage.createGraphics();
g.setRenderingHints(renderingHints);
g.drawImage(image, 0, 0, gui);
g.dispose();
selection = new Rectangle(0,0,w,h);
if (this.imageLabel!=null) {
imageLabel.setIcon(new ImageIcon(canvasImage));
this.imageLabel.repaint();
}
if (gui!=null) {
gui.invalidate();
}
}
/** Set the current painting color and refresh any elements needed. */
public void setColor(Color color) {
this.color = color;
clear(colorSample);
}
private JMenu getFileMenu(boolean webstart){
JMenu file = new JMenu("File");
file.setMnemonic('f');
JMenuItem newImageItem = new JMenuItem("New");
newImageItem.setMnemonic('n');
ActionListener newImage = new ActionListener() {
#Override
public void actionPerformed(ActionEvent arg0) {
BufferedImage bi = new BufferedImage(
360, 300, BufferedImage.TYPE_INT_ARGB);
clear(bi);
setImage(bi);
}
};
newImageItem.addActionListener(newImage);
file.add(newImageItem);
if (webstart) {
//TODO Add open/save functionality using JNLP API
} else {
//TODO Add save functionality using J2SE API
file.addSeparator();
ActionListener openListener = new ActionListener() {
#Override
public void actionPerformed(ActionEvent arg0) {
if (!dirty) {
JFileChooser ch = getFileChooser();
int result = ch.showOpenDialog(gui);
if (result==JFileChooser.APPROVE_OPTION ) {
try {
BufferedImage bi = ImageIO.read(
ch.getSelectedFile());
setImage(bi);
} catch (IOException e) {
showError(e);
e.printStackTrace();
}
}
} else {
// TODO
JOptionPane.showMessageDialog(
gui, "TODO - prompt save image..");
}
}
};
JMenuItem openItem = new JMenuItem("Open");
openItem.setMnemonic('o');
openItem.addActionListener(openListener);
file.add(openItem);
ActionListener saveListener = new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
JFileChooser ch = getFileChooser();
int result = ch.showSaveDialog(gui);
if (result==JFileChooser.APPROVE_OPTION ) {
try {
File f = ch.getSelectedFile();
ImageIO.write(BasicPaint.this.canvasImage, "png", f);
BasicPaint.this.originalImage = BasicPaint.this.canvasImage;
dirty = false;
} catch (IOException ioe) {
showError(ioe);
ioe.printStackTrace();
}
}
}
};
JMenuItem saveItem = new JMenuItem("Save");
saveItem.addActionListener(saveListener);
saveItem.setMnemonic('s');
file.add(saveItem);
}
if (canExit()) {
ActionListener exit = new ActionListener() {
#Override
public void actionPerformed(ActionEvent arg0) {
// TODO Auto-generated method stub
System.exit(0);
}
};
JMenuItem exitItem = new JMenuItem("Exit");
exitItem.setMnemonic('x');
file.addSeparator();
exitItem.addActionListener(exit);
file.add(exitItem);
}
return file;
}
private void showError(Throwable t) {
JOptionPane.showMessageDialog(
gui,
t.getMessage(),
t.toString(),
JOptionPane.ERROR_MESSAGE);
}
JFileChooser chooser = null;
public JFileChooser getFileChooser() {
if (chooser==null) {
chooser = new JFileChooser();
FileFilter ff = new FileNameExtensionFilter("Image files", ImageIO.getReaderFileSuffixes());
chooser.setFileFilter(ff);
}
return chooser;
}
public boolean canExit() {
boolean canExit = false;
SecurityManager sm = System.getSecurityManager();
if (sm==null) {
canExit = true;
} else {
try {
sm.checkExit(0);
canExit = true;
} catch(Exception stayFalse) {
}
}
return canExit;
}
public JMenuBar getMenuBar(boolean webstart){
JMenuBar mb = new JMenuBar();
mb.add(this.getFileMenu(webstart));
return mb;
}
public static void main(String[] args) {
Runnable r = new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(
UIManager.getSystemLookAndFeelClassName());
} catch (Exception e) {
// use default
}
BasicPaint bp = new BasicPaint();
JFrame f = new JFrame("DooDoodle!");
f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
f.setLocationByPlatform(true);
f.setContentPane(bp.getGui());
f.setJMenuBar(bp.getMenuBar(false));
f.pack();
f.setMinimumSize(f.getSize());
f.setVisible(true);
}
};
SwingUtilities.invokeLater(r);
}
public void text(Point point) {
String text = JOptionPane.showInputDialog(gui, "Text to add", "Text");
if (text!=null) {
Graphics2D g = this.canvasImage.createGraphics();
g.setRenderingHints(renderingHints);
g.setColor(this.color);
g.setStroke(stroke);
int n = 0;
g.drawString(text,point.x,point.y);
g.dispose();
this.imageLabel.repaint();
}
}
public void draw(Point point) {
Graphics2D g = this.canvasImage.createGraphics();
g.setRenderingHints(renderingHints);
g.setColor(this.color);
g.setStroke(stroke);
int n = 0;
g.drawLine(point.x, point.y, point.x+n, point.y+n);
g.dispose();
this.imageLabel.repaint();
}
class ImageMouseListener extends MouseAdapter {
#Override
public void mousePressed(MouseEvent arg0) {
// TODO Auto-generated method stub
if (activeTool==BasicPaint.SELECTION_TOOL) {
selectionStart = arg0.getPoint();
} else if (activeTool==BasicPaint.DRAW_TOOL) {
// TODO
draw(arg0.getPoint());
} else if (activeTool==BasicPaint.TEXT_TOOL) {
// TODO
text(arg0.getPoint());
} else {
JOptionPane.showMessageDialog(
gui,
"Application error. :(",
"Error!",
JOptionPane.ERROR_MESSAGE);
}
}
#Override
public void mouseReleased(MouseEvent arg0) {
if (activeTool==BasicPaint.SELECTION_TOOL) {
selection = new Rectangle(
selectionStart.x,
selectionStart.y,
arg0.getPoint().x,
arg0.getPoint().y);
}
}
}
class ImageMouseMotionListener implements MouseMotionListener {
#Override
public void mouseDragged(MouseEvent arg0) {
reportPositionAndColor(arg0);
if (activeTool==BasicPaint.SELECTION_TOOL) {
selection = new Rectangle(
selectionStart.x,
selectionStart.y,
arg0.getPoint().x-selectionStart.x,
arg0.getPoint().y-selectionStart.y);
} else if (activeTool==BasicPaint.DRAW_TOOL) {
draw(arg0.getPoint());
}
}
#Override
public void mouseMoved(MouseEvent arg0) {
reportPositionAndColor(arg0);
}
}
private void reportPositionAndColor(MouseEvent me) {
String text = "";
if (activeTool==BasicPaint.SELECTION_TOOL) {
text += "Selection (X,Y:WxH): " +
(int)selection.getX() +
"," +
(int)selection.getY() +
":" +
(int)selection.getWidth() +
"x" +
(int)selection.getHeight();
} else {
text += "X,Y: " + (me.getPoint().x+1) + "," + (me.getPoint().y+1);
}
output.setText(text);
}
}
This source is very patchy.
It has many parts with // TODO
A dirty attribute is declared but never used in any meaningful way. ..
It is just something I hacked together today and thought should be shown before it hit the posting limit.
Oh, and don't go looking for any 'OO design' since I did not put any in. If there is any, it is only by accident. This code is intended to demonstrate what is possible and how to start doing it.

label that shows Coordinates of mouse

At university we started Java programming and got the task to write a program that draws a vertical and a horizontal line at the location where the mouse currently is. Also we should add a Label that shows the coordinates of the mouse. I got the drawing thing working but when I try to add a label, it won't show up? I started with a test-label, but even that isn't shown inside the frame. Can someone help me?
public class Coordinates extends JPanel implements MouseListener, MouseMotionListener {
private Point currentPoint = new Point(-50, -50);
public Coordinates(){
addMouseListener(this);
addMouseMotionListener(this);
}
public void paint(Graphics g) {
super.paint(g);
g.setColor(Color.blue);
g.drawLine(currentPoint.x, currentPoint.y+1000, currentPoint.x, currentPoint.y-1000);
g.drawLine(currentPoint.x+1000, currentPoint.y, currentPoint.x-1000, currentPoint.y);
}
public void mousePressed(MouseEvent e){
currentPoint = e.getPoint();
repaint();
};
static JLabel label = new JLabel();
public static void main(String[] args) {
JFrame frame = new JFrame("Koordinaten");
frame.setSize(600, 400);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
frame.add(label);
JComponent newContentPane = new Coordinaten();
newContentPane.setOpaque(true);
frame.setContentPane(newContentPane);
}
public void mouseClicked(MouseEvent e) {
// TODO Auto-generated method stub
}
public void mouseReleased(MouseEvent e) {
// TODO Auto-generated method stub
}
public void mouseEntered(MouseEvent e) {
// TODO Auto-generated method stub
}
public void mouseExited(MouseEvent e) {
// TODO Auto-generated method stub
}
public void mouseDragged(MouseEvent e) {
// TODO Auto-generated method stub
}
public void mouseMoved(MouseEvent e) {
// TODO Auto-generated method stub
label.setText(currentPoint.toString());
currentPoint = e.getPoint();
repaint();
}
}
Do all your painting within the JPanel's paintComponent method not the paint method, and be sure to call the super's paintComponent method within your override, usually at the start of the override method.
You need to add a JLabel to your JPanel to have it display anything. Your code does not do this. And then in the MouseMotionListener, set the JLabel's text with the mouse coordinates.
For example:
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.*;
#SuppressWarnings("serial")
public class DrawPanel extends JPanel {
private static final int PREF_W = 600;
private static final int PREF_H = PREF_W;
private JLabel locationLabel = new JLabel();
public DrawPanel() {
add(locationLabel);
addMouseMotionListener(new MyMouseAdapter());
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g); // this allows JPanel to do housekeeping painting first
// do drawing here!
}
#Override
public Dimension getPreferredSize() {
if (isPreferredSizeSet()) {
return super.getPreferredSize();
}
return new Dimension(PREF_W, PREF_H);
}
private class MyMouseAdapter extends MouseAdapter {
#Override
public void mouseMoved(MouseEvent e) {
// get Point location and turn into a String
String location = String.format("[%d, %d]", e.getX(), e.getY());
// set the label's text with this String
locationLabel.setText(location);
}
}
private static void createAndShowGui() {
JFrame frame = new JFrame("DrawPanel");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(new DrawPanel());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
With the cross-hairs:
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.*;
#SuppressWarnings("serial")
public class DrawPanel extends JPanel {
private static final int PREF_W = 600;
private static final int PREF_H = PREF_W;
private JLabel locationLabel = new JLabel();
private int mouseX = 0;
private int mouseY = 0;
public DrawPanel() {
add(locationLabel);
addMouseMotionListener(new MyMouseAdapter());
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g); // this allows JPanel to do housekeeping
// painting first
// do drawing here!
g.drawLine(0, mouseY, getWidth(), mouseY);
g.drawLine(mouseX, 0, mouseX, getHeight());
}
#Override
public Dimension getPreferredSize() {
if (isPreferredSizeSet()) {
return super.getPreferredSize();
}
return new Dimension(PREF_W, PREF_H);
}
private class MyMouseAdapter extends MouseAdapter {
#Override
public void mouseMoved(MouseEvent e) {
mouseX = e.getX();
mouseY = e.getY();
// get Point location and turn into a String
String location = String.format("[%d, %d]", mouseX, mouseY);
// set the label's text with this String
locationLabel.setText(location);
repaint();
}
}
private static void createAndShowGui() {
JFrame frame = new JFrame("DrawPanel");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(new DrawPanel());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
Basically, a JLabel is made like this, defined outside of the main method:
static JLabel label = new JLabel();
In your main method
frame.add(label);
And in your mouseMoved method you would put this:
label.setText(currentPoint.toString());

Drawing on JPanel with paint(Graphics gr)

I tried to draw a simple rectangle on a JPanel wich is on a JFrame, but it didn't work. Can someone please give me some advices? Would be happy if someone could... I really tried hard, but I couldn figure out how to do this. This code is part of my "Snake" -program. All the rest works, in excep of this. Here is my Code:
package initialising_Package;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridLayout;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import java.awt.event.WindowEvent;
import java.awt.event.WindowListener;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JSlider;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
public class Initialising extends JPanel implements WindowListener,
ItemListener, ChangeListener, Runnable {
/**
* #param args
*/
private String name;
private JFrame frame;
private boolean fall = false;
private JSlider slider;
private JLabel lbl1, lbl2, lbl3, lbl4;
private JComboBox box1, box2, box3;
private String[] positionsx, positionsy, laenge;
private JPanel pnl1, pnl2, pnl3, pnlpnl;
private JButton btn;
private int beginningLenght, posX, posY;
private boolean start = false;
public Initialising() {
initStartFrame("Initialising");
}
public void initStartFrame(String name) {
frame = new JFrame(name);
frame.setLocation(300, 300);
frame.setSize(500, 350);
frame.setUndecorated(false);
frame.getContentPane().setLayout(new GridLayout(5, 1));
frame.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);
frame.setVisible(true);
frame.addWindowListener(this);
// GUI
slider = new JSlider(1, 100, 50);
slider.addChangeListener(this);
slider.setPaintTicks(false);
slider.setPaintTrack(true);
positionsx = new String[50];
positionsy = new String[50];
for (int i = 0, j = 0; i < 50; i++, j = j + 10) {
positionsx[i] = new String("" + j);
positionsy[i] = new String("" + j);
}
laenge = new String[45];
for (int i = 0; i < 45; i++) {
laenge[i] = "" + (i + 1);
}
box1 = new JComboBox(positionsx);
box1.addItemListener(this);
box2 = new JComboBox(positionsy);
box2.addItemListener(this);
box3 = new JComboBox(laenge);
box3.addItemListener(this);
lbl1 = new JLabel("Geschwindigkeit: ");
lbl2 = new JLabel("Startlaenge: ");
lbl3 = new JLabel("Position: ");
pnlpnl = new JPanel();
pnlpnl.setPreferredSize(new Dimension(95, 490));
pnlpnl.setBackground(Color.BLACK);
pnl1 = new JPanel();
pnl1.setLayout(new GridLayout(1, 2));
pnl2 = new JPanel();
pnl2.setLayout(new GridLayout(1, 2));
pnl3 = new JPanel();
pnl3.setLayout(new GridLayout(1, 3));
btn = new JButton("Snake!");
btn.setPreferredSize(new Dimension(80, 490));
pnl1.add(lbl1);
pnl1.add(slider);
pnl2.add(lbl2);
pnl2.add(box3);
pnl3.add(lbl3);
pnl3.add(box1);
pnl3.add(box2);
frame.add(pnlpnl);
frame.add(pnl1);
frame.add(pnl2);
frame.add(pnl3);
frame.add(btn);
// GUI
frame.validate();
frame.repaint();
}
public int getSpeed() {
return slider.getValue();
}
public int getBeginningLenght() {
return beginningLenght;
}
public int getPosX() {
return posX;
}
public int getPosY() {
return posY;
}
#Override
public void windowActivated(WindowEvent arg0) {
// TODO Auto-generated method stub
}
#Override
public void windowClosed(WindowEvent arg0) {
// TODO Auto-generated method stub
}
#Override
public void windowClosing(WindowEvent arg0) {
int z = JOptionPane.showConfirmDialog(frame,
"Willst du wirklich benden?", "Warnung", 0);
if (z == JOptionPane.YES_OPTION) {
System.exit(0);
}
}
#Override
public void windowDeactivated(WindowEvent arg0) {
// TODO Auto-generated method stub
}
#Override
public void windowDeiconified(WindowEvent arg0) {
// TODO Auto-generated method stub
}
#Override
public void windowIconified(WindowEvent arg0) {
// TODO Auto-generated method stub
}
#Override
public void windowOpened(WindowEvent arg0) {
// TODO Auto-generated method stub
}
public static void main(String[] args) {
// TODO Auto-generated method stub
Initialising init = new Initialising();
new Thread(init).start();
}
#Override
public void itemStateChanged(ItemEvent e) {
// TODO Auto-generated method stub
if (e.getSource().equals(box1)) {
posX = Integer.parseInt((String) box1.getSelectedItem());
System.out.println("PosX: " + posX);
} else if (e.getSource().equals(box2)) {
posY = Integer.parseInt((String) box2.getSelectedItem());
System.out.println("PosY: " + posY);
} else if (e.getSource().equals(box3)) {
beginningLenght = Integer.parseInt((String) box3.getSelectedItem());
System.out.println("Beginning Lenght: " + beginningLenght);
System.out.println("H: " + pnlpnl.getHeight() + " B: "
+ pnlpnl.getWidth());
}
}
#Override
public void stateChanged(ChangeEvent e) {
// TODO Auto-generated method stub
if (e.getSource().equals(slider)) {
System.out.println("Speed: " + slider.getValue());
}
}
#Override
public void paintComponent(Graphics gr) {
super.paint(gr);
gr.setColor(Color.CYAN);
gr.fillRect(0, 0, 200, 200);
}
#Override
public void run() {
// TODO Auto-generated method stub
while (true) {
System.out.println("It works!!");
try {
Thread.sleep(800);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
if (!start) {
}
repaint();
validate();
}
}
}
Remove the paintComponent from the JFrame. That did also call super.paint i.o. super.paintComponent.
pnlpnl = new JPanel() {
#Override
public void paintComponent(Graphics gr) {
super.paintComponent(gr);
gr.setColor(Color.CYAN);
gr.fillRect(0, 0, 200, 200);
}
};
In this paintComponent you can use the JFrame's fields.
As initStartFrame is called in the constructor it should not be overridable (the child class's version then would be called, without the child class being entirely initialized).
//Sometimes: public final void initStartFrame(String name) {
private void initStartFrame(String name) {
Start the frame as such:
// GUI
frame.validate();
//frame.repaint();
frame.pack();
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
frame.setVisible(true);
}
});

Drawing transculent rectangle

I was a problem with drawing rectangle using mouse. I have solve my problem and I get results what I want. But I have a small problem. If I want to start draw rectangle when I click mouse button, text in my button change. This is small difference but I don't want see this. Here is code:
package draw;
import java.awt.*;
import java.awt.event.*;
import java.util.ArrayList;
import java.util.List;
import javax.swing.*;
import javax.swing.event.*;
public class Selection extends JPanel
implements ChangeListener {
/**
*
*/
private static final long serialVersionUID = 1L;
private static final int WIDE = 640;
private static final int HIGH = 640;
private List<Node> nodes = new ArrayList<Node>();
private Point mousePt = new Point(WIDE / 2, HIGH / 2);
private Rectangle mouseRect = new Rectangle();
private boolean selecting = false;
public static void main(String[] args) throws Exception {
EventQueue.invokeLater(new Runnable() {
public void run() {
JFrame f = new JFrame("GraphPanel");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Selection gp = new Selection();
gp.add(new JButton("Button"));
f.add(new JScrollPane(gp), BorderLayout.CENTER);
f.pack();
f.setVisible(true);
}
});
}
Selection() {
this.setPreferredSize(new Dimension(WIDE, HIGH));
this.addMouseListener(new MouseHandler());
this.addMouseMotionListener(new MouseMotionHandler());
}
#Override
public void paintComponent(Graphics g) {
g.setColor(new Color(0x00f0f0f0));
g.fillRect(0, 0, getWidth(), getHeight());
for (Node n : nodes) {
n.draw(g);
}
if (selecting) {
g.setColor(Color.BLACK
);
((Graphics2D) g).setComposite(AlphaComposite.getInstance(rule, alpha));
g.fillRect(mouseRect.x, mouseRect.y,
mouseRect.width, mouseRect.height);
g.drawRect(mouseRect.x, mouseRect.y,
mouseRect.width, mouseRect.height);
}
}
int rule = AlphaComposite.SRC_OVER;
float alpha = 0.9F;
private class MouseHandler extends MouseAdapter {
#Override
public void mouseReleased(MouseEvent e) {
selecting = false;
mouseRect.setBounds(0, 0, 0, 0);
if (e.isPopupTrigger()) {
}
e.getComponent().repaint();
}
#Override
public void mousePressed(MouseEvent e) {
mousePt = e.getPoint();
Node.selectNone(nodes);
selecting = true;
e.getComponent().repaint();
}
}
private class MouseMotionHandler extends MouseMotionAdapter {
Point delta = new Point();
#Override
public void mouseDragged(MouseEvent e) {
if (selecting) {
mouseRect.setBounds(
Math.min(mousePt.x, e.getX()),
Math.min(mousePt.y, e.getY()),
Math.abs(mousePt.x - e.getX()),
Math.abs(mousePt.y - e.getY()));
} else {
delta.setLocation(
e.getX() - mousePt.x,
e.getY() - mousePt.y);
mousePt = e.getPoint();
}
e.getComponent().repaint();
}
}
/** A Node represents a node in a graph. */
private static class Node {
private Color color;
private boolean selected = false;
private Rectangle b = new Rectangle();
/** Draw this node. */
public void draw(Graphics g) {
g.setColor(this.color);
if (selected) {
g.setColor(Color.darkGray);
g.drawRect(b.x, b.y, b.width, b.height);
}
}
/** Mark this node as slected. */
public void setSelected(boolean selected) {
this.selected = selected;
}
/** Select no nodes. */
public static void selectNone(List<Node> list) {
for (Node n : list) {
n.setSelected(false);
}
}
}
#Override
public void stateChanged(ChangeEvent arg0) {
// TODO Auto-generated method stub
}
}
I think that can be a problem with place where I implement my button. I use eclipse SDK.
Can you help me?
Change your main to this. The reason is that you are setting alpha to < 1 for the entire panel and so the button is getting lighter shade. Simply move the button out of the panel and you are set.
public static void main(String[] args) throws Exception {
EventQueue.invokeLater(new Runnable() {
public void run() {
JFrame f = new JFrame("GraphPanel");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel panel = new JPanel(new BorderLayout());
JButton button = new JButton("Button");
panel.add(button, BorderLayout.PAGE_START);
Selection gp = new Selection();
panel.add(gp, BorderLayout.CENTER);
f.add(new JScrollPane(panel), BorderLayout.CENTER);
f.pack();
f.setVisible(true);
}
});
}

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