Help!draw a line on JPanel

draw a line on JPanel like VB's drawline command.

Take a look at this thread:
http://forum.java.sun.com/thread.jsp?forum=31&thread=307239

Similar Messages

Custom Control Help: Draw a line and output start and end points

I'm looking to find or make a custom control (or simple subVI) that will appear as a 100x100 unit grid and allow me to draw a line from one point to another on that grid. It will then output the (x,y) of the starting and end point of that line on the grid. Any help or ideas?
Thanks,
Steve
LabVIEW 2009 SP1
Solved!
Go to Solution.

What you basically want is a loop with an event structure where you process Mouse Down, Move and Up events for your controls. There are any number of ways of implementing something like this, but this one will probably be the simplest:
Use a multicolumn listbox or a table for your grid. Hide the scrollbars and headers.
You can use the ActiveCell property with -2,-2 to select all cells. You can then use the cell size property to set the exact size of the cell.
Next, you put a picture control on top of the table and color its background transparent so that the table shows through. You use property node to make sure the two are aligned to exactly the same spot and size.
You use the mouse events on the picture control to detect the clicks and moves.
You use the table's Point to Row Column method to translate the event's position data to a cell.
You use the picture control VIs to draw the line on the picture based on that data.
You can even color the selected cells in the table using the table properties.
If you want to simplify things somewhat, you can also use the timeout event instead of the Mouse Move event to draw the line, but then you'll need to keep the timeout value in a shift register and reset it to -1 (no timeout) when the Mouse Up event happens.
I would also suggest processing Mouse Enter and Leave events to change the cursor and cancel if the user leaves in the middle of dragging.
Try to take over the world!

Help drawing curved line - please!!!

Seriously, I can't find a tool to draw a curved line in PSE 6! I was told to use the "pen tool" but I can't find it. I was told to make the selection right clicming on Pencil and has no options other than for a freehand drawing with the mouse. The "shapes" tool will only give me a straight line. What the heck am I missing?
Thanks!

The pen tool is only in Photoshop, not elements. You can draw freehand with the brush or pencil tools (you can put something on a separate layer below and trace the edge if you need help), or you can draw a selection with the elliptical marquee tool, go to Edit>Stroke (outline) selection to color it, then erase the parts you don't want.
The custom shape tool draws many shapes. It sounds like you have the line tool selected. Hold down its icon in the toolbox and you'll see several other tools in there. The polygon tool with the rounded corners option turned on will draw circles, although it's not supposed to.

Help - drawing curved lines

Hey everyone
This is probably going to have an easy solution but I really cant figure it out!! The problem is drawing a loop in a state machine, ie a path to and from the same node therefore a loop!
Is there a way to actually do this?
Thanks in advance!

try using the GeneralPath class and using a series of curveTo or quadTo calls. Keep nodes colinear to preserve derivative continuity, and you should be able to make the curved shape you want.

Here are my last 3 duke dollars. Can someone please help me draw a line?

I have been BEATING my head on this for well over a week now. I'm new to Java2D and I cannot find even one example of this simple little thing that I am trying to do. Not one.
All I want to do is draw an image, zoom that image, then draw some lines on that image, and then zoom it and have those lines show up where they should.
For example, we have an image which has been zoomed. No lines are yet drawn on it.
A line is added.
The image is then zoomed in or out one more time.
How do we get the line to remap to the newly zoomed image?
What I am doing is:
0) Load up an image from a file.
1) Create a zoomed image by using the Image.getScaledInstance() method.
2) Create a BufferedImage with the width and height of the image AFTER the zoom has taken place.
3) Create a Graphics2D object by the createGraphics from this BufferedImage.
4) Place the image into the BufferedImage by doing a BufferedImage.drawImage
5) Select two points to be the start and end of the line.
6) Draw the line using Graphics2D.drawLine(start.x, start.y, end.x, end.y).
7) Zoom the image again (using the Image.getScaledInstance() method.
8) Create a new ImageIcon using the image from above and override its paintIcon method like this:
ImageIcon newIcon = new ImageIcon(newImage) {
public void paintIcon(Component c, Graphics g, int x, int y)
super.paintIcon(c, g, x, y);
zoom(); //<---- ZOOM call
Now in the zoom routine, what do I need to do to get the lines to draw at the proper location and size?
Remember, the points of the lines (stored in a list as home grown line objects) are in screen coordinates, not image coordinates since they are just click points
Note that when I use these points to draw a line, all is well (the line gets drawn where it should), but I have problems when I zoom the image.
Thanks!

Below is the documentation and method signature of
Graphics.drawImage(Image img, int dx1, int dy1, int dx2, int dy2, int sx1, int sy1, int sx2, int sy2, ImageObserver observer);The important thing to note is that it does scaling on the fly if the size dictated by the source co-ordinates is defferent than the size dictated by the destination co-ordinates. The source image is always left un-touched.
So basically your visual data is located in an offscreen image. You can draw a line on that. Then create a new image, get it's graphics and call drawImage(original_image, co-ordinates that cause it to scale how you like).
Then you can draw lines on the 2nd image, create a 3rd, ...etc
 * Draws as much of the specified area of the specified image as is
 * currently available, scaling it on the fly to fit inside the
 * specified area of the destination drawable surface. Transparent pixels
 * do not affect whatever pixels are already there.
 * 
 * This method returns immediately in all cases, even if the
 * image area to be drawn has not yet been scaled, dithered, and converted
 * for the current output device.
 * If the current output representation is not yet complete then
 * <code>drawImage</code> returns <code>false</code>. As more of
 * the image becomes available, the process that draws the image notifies
 * the specified image observer.
 * 
 * This method always uses the unscaled version of the image
 * to render the scaled rectangle and performs the required
 * scaling on the fly. It does not use a cached, scaled version
 * of the image for this operation. Scaling of the image from source
 * to destination is performed such that the first coordinate
 * of the source rectangle is mapped to the first coordinate of
 * the destination rectangle, and the second source coordinate is
 * mapped to the second destination coordinate. The subimage is
 * scaled and flipped as needed to preserve those mappings.
 * @param img the specified image to be drawn
 * @param dx1 the x coordinate of the first corner of the
 * destination rectangle.
 * @param dy1 the y coordinate of the first corner of the
 * destination rectangle.
 * @param dx2 the x coordinate of the second corner of the
 * destination rectangle.
 * @param dy2 the y coordinate of the second corner of the
 * destination rectangle.
 * @param sx1 the x coordinate of the first corner of the
 * source rectangle.
 * @param sy1 the y coordinate of the first corner of the
 * source rectangle.
 * @param sx2 the x coordinate of the second corner of the
 * source rectangle.
 * @param sy2 the y coordinate of the second corner of the
 * source rectangle.
 * @param observer object to be notified as more of the image is
 * scaled and converted.
 * @return <code>true</code> if the current output representation
 * is complete; <code>false</code> otherwise.
 * @see java.awt.Image
 * @see java.awt.image.ImageObserver
 * @see java.awt.image.ImageObserver#imageUpdate(java.awt.Image, int, int, int, int, int)
 * @since JDK1.1
 public abstract boolean drawImage(Image img,
 int dx1, int dy1, int dx2, int dy2,
 int sx1, int sy1, int sx2, int sy2,
 ImageObserver observer);

How to draw a line(shortest distance) between two ellipse using SWING

how to draw a line(should be shortest distance) between two ellipse using SWING
any help will be appreciated
regards

import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
import javax.swing.*;
import javax.swing.event.MouseInputAdapter;
public class ELine extends JPanel {
 Ellipse2D.Double red = new Ellipse2D.Double(150,110,75,165);
 Ellipse2D.Double blue = new Ellipse2D.Double(150,50,100,50);
 Line2D.Double line = new Line2D.Double();
 protected void paintComponent(Graphics g) {
 super.paintComponent(g);
 Graphics2D g2 = (Graphics2D)g;
 g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
 RenderingHints.VALUE_ANTIALIAS_ON);
 g2.setPaint(Color.green.darker());
 g2.draw(line);
 g2.setPaint(Color.blue);
 g2.draw(blue);
 g2.setPaint(Color.red);
 g2.draw(red);
 private void connect() {
 double flatness = 0.01;
 PathIterator pit = blue.getPathIterator(null, flatness);
 double[] coords = new double[2];
 double x1 = 0, y1 = 0, x2 = 0, y2 = 0;
 double min = Double.MAX_VALUE;
 while(!pit.isDone()) {
 int type = pit.currentSegment(coords);
 switch(type) {
 case PathIterator.SEG_MOVETO:
 case PathIterator.SEG_LINETO:
 Point2D.Double p = getClosestPoint(coords[0], coords[1]);
 double dist = p.distance(coords[0], coords[1]);
 if(dist < min) {
 min = dist;
 x1 = coords[0];
 y1 = coords[1];
 x2 = p.x;
 y2 = p.y;
 break;
 case PathIterator.SEG_CLOSE:
 break;
 default:
 System.out.println("blue type: " + type);
 pit.next();
 line.setLine(x1, y1, x2, y2);
 private Point2D.Double getClosestPoint(double x, double y) {
 double flatness = 0.01;
 PathIterator pit = red.getPathIterator(null, flatness);
 double[] coords = new double[2];
 Point2D.Double p = new Point2D.Double();
 double min = Double.MAX_VALUE;
 while(!pit.isDone()) {
 int type = pit.currentSegment(coords);
 switch(type) {
 case PathIterator.SEG_MOVETO:
 case PathIterator.SEG_LINETO:
 double dist = Point2D.distance(x, y, coords[0], coords[1]);
 if(dist < min) {
 min = dist;
 p.setLocation(coords[0], coords[1]);
 break;
 case PathIterator.SEG_CLOSE:
 break;
 default:
 System.out.println("red type: " + type);
 pit.next();
 return p;
 public static void main(String[] args) {
 final ELine test = new ELine();
 test.addMouseListener(test.mia);
 test.addMouseMotionListener(test.mia);
 JFrame f = new JFrame();
 f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 f.add(test);
 f.setSize(400,400);
 f.setLocation(200,200);
 f.setVisible(true);
 EventQueue.invokeLater(new Runnable() {
 public void run() {
 Graphics g = test.getGraphics();
 g.drawString("drag me", 175, 80);
 g.dispose();
 private MouseInputAdapter mia = new MouseInputAdapter() {
 Point2D.Double offset = new Point2D.Double();
 boolean dragging = false;
 public void mousePressed(MouseEvent e) {
 Point p = e.getPoint();
 if(blue.contains(p)) {
 offset.x = p.x - blue.x;
 offset.y = p.y - blue.y;
 dragging = true;
 public void mouseReleased(MouseEvent e) {
 dragging = false;
 public void mouseDragged(MouseEvent e) {
 if(dragging) {
 double x = e.getX() - offset.x;
 double y = e.getY() - offset.y;
 blue.setFrame(x, y, blue.width, blue.height);
 connect();
 repaint();
}

How to draw multiple lines on same panel??

hiya
i would like to know how can I draw multiple lines on the same panel ?? I have already use repaint(); but it just come out the lastest line (say line 3) i draw .......those previous lines(say line 1 and 2) are disappear ........
Thanks for your help mate

http://www.java2s.com/ExampleCode/2D-Graphics/Line.htm

How to draw horizontal line in smartform after end of the all line items

Hi Friends,
I am working on the smartform. I have created TABLE node in Main window.
i want to draw a horizontal line after end of the main window table node. i mean after printing all the line items of the table, I need to print one horizontal line.
Could you please help me how to resolve this issue.
FYI: I tried with the below two options. But no use.
1. desinged footer area in the table node of the main window.
2. tried with uline and system symbols.
please correct me if i am wrong. please explain in detail how to draw horizontal line after end of the main window table.
this is very urgent.
Thanks in advance
Regards
Raghu

Hello Valter Oliveira,
Thanks for your answer. But I need some more detail about blank line text. i.e thrid point.
Could you please tell me how to insert blank line text.
1 - in your table, create a line type with only one column, with the same width of the table
2 - in table painter, create a line under the line type
3 - insert a blank line text in the footer section with the line type you have created.

How to draw horizontal line at the end of table for multiple line items

Dear Experts,
                   Pls can anyone help me how to draw horizontal line at the end of table for multiple line items . kindly help me regarding this
Thanks
Ramesh Manoharan

Hi
   I tried as per your logic but it is not solving my problem . when i am gone to table painter it is showing line type 1 and line type 2
is below format.. if u see here line type 1 bottom line and line type 2 top line both are same.. so how to avoid this ?
                          line type 1
                         line type 2

Problem in drawing a line in Java Application Program

Hi,
I am trying to draw a line after a message is displayed on the screen. But the line is not at all coming on the screen while running. but I can see a red line is appearing on the screen first and and it is getting overridden.
There is something wrong in the concept what I understood about graphics.Can anybody help to
understand where the problem is ?
Here is the part of the code which used to draw line.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.table.*;
import java.io.*;
import java.sql.*;
import java.util.*;
import java.util.Date.*;
import java.text.*;
import java.lang.*;
import MyPack.*;
class chalan_pay extends JFrame
JTextField jt1,jt2,jt3,jt4,jt5;
JLabel jlh,jl1,jl2,jl3,jl4,jl5,jl10;
JButton bt1,bt2,bt3;
Choice ch1,ch2,ch3,ch4;
Connection con = null;
int i1no,i2no,i3no,i4no,itno;
String idate;
public chalan_pay()
getContentPane().setLayout(null);
jt1= new JTextField(5);
jt1.setBounds(110,150,50,20);
jt2= new JTextField(10);
jt2.setBounds(400,150,100,20);
jt3= new JTextField(3);
jt3.setBounds(590,150,30,20);
jt4= new JTextField(2);
jt4.setBounds(750,150,30,20);
jlh= new JLabel();
jlh.setText("CHALLAN DETAILS");
jlh.setBounds(300,50,200,20);
jl1= new JLabel();
jl1.setText("IGM No. ");
jl1.setBounds(50,150,100,20);
jl2= new JLabel();
jl2.setText("IGM Date ");
jl2.setBounds(340,150,100,20);
jl3= new JLabel();
jl3.setText("Line No. ");
jl3.setBounds(530,150,100,20);
jl4= new JLabel();
jl4.setText("Subline No. ");
jl4.setBounds(680,150,100,20);
jl10= new JLabel();
jl10.setBounds(100,200,300,20);
ch1= new Choice();
ch1.setBounds(170,150,150,20);
getContentPane().add(ch1);
ch1.addItemListener(new Opt1());
bt1= new JButton("Exit");
bt1.setBounds(200,600,100,20);
getContentPane().add(bt1);
bt1.addActionListener(new Ex());
try
con=db_connect.getConnection();
Statement st1 = con.createStatement();
ResultSet rs1 = st1.executeQuery("select igm_no,to_char(igm_dt,'DD-MON-YY'),line_no,subline_no from "+
"det_item order by igm_no");
while(rs1.next())
ch1.addItem(String.valueOf(rs1.getInt(1))+" "+rs1.getString(2)+" "+
String.valueOf(rs1.getInt(3))+" "+String.valueOf(rs1.getInt(4)));
rs1.close();
st1.close();
catch(Exception e){e.printStackTrace();}
getContentPane().add(jlh);
getContentPane().add(jl1);
getContentPane().add(jt1);
getContentPane().add(jl2);
getContentPane().add(jt2);
getContentPane().add(jl3);
getContentPane().add(jt3);
getContentPane().add(jl4);
getContentPane().add(jt4);
getContentPane().add(jl10);
setSize(900,700);
setVisible(true);
show();
public void paint(Graphics g)
g.setColor(Color.red);
g.drawLine(0,300,600,300);
class Ex implements ActionListener
public void actionPerformed(ActionEvent evt)
if(evt.getSource() == bt1)
dispose();
return;
This code is incomplete. The program is compiled and Ran. I am unable to see the Line.
Is it because , I am using contentPane ?. Please help me to cake it clear.
mjava

I have no idea what JTutor is, but if it tells you to override paint() in Swing, it's not worth its disk space.
[http://java.sun.com/docs/books/tutorial/uiswing/painting/closer.html] clearly says that for all practical purposes paintComponent will be the only method that you will ever need to override.

Drawing dashed line or dotted line in a flex line chart

Friends,
I want to draw a line chart which should be either dotted or dashed.
since there is no component like dashed line chart, can anyone help me in creating one.
i think if i extend the line series component, then i can draw that.
but am stuck there. pls help people.
Regards,
Anoop

Try looking [url http://www.macdevcenter.com/pub/a/mac/2002/03/22/vertical_text.html]here.
: jay

How can i use this library to draw squiggly line below word for RichEditable?

Squiggly Release Notes:
AdobeSpellingFramework.swc
A class that facilitates the drawing of squiggly lines below words for various text components.
Im not using squiggly spell check egine bcause it is not supporting arabic language.
Rest of the work i have completed, i just want to draw squiggly lines below word.
Please help me.....Thanks

Did you ever get an answer for this ?

Drawing 2d line chart problem, urgent please!!!

Hello,
can anyone help me with the function GRAPH_MATRIX_2D please,
i couldn't draw a line graph with three data series, i mean with three lines in the graph.
i want to the chart to be drawn as line graph at the beginning, i shouldn't have to change the chart type later,
can anybody send me a sample code that does what i want.
i am expecting your answers,
thanks.

Hi,
have you checked the two reports Matthias mentioned?
After downloading the SAP Chart Designer the general procedure should look like: create your chart settings interactively using the designer. Save these settings as a local XML file. Use this XML in your ABAP application and additionally create a data XML at runtime (the format is described in the pdf of the SAP Chart Designer zip).
Regards, Kai
PS: Please don't use these very outdated function modules graph_matrix* / grstat* in new projects!

Drawing a Line in JAVA

Well Ive got my program to draw a line, but when I drag the mouse across the screen I'd like it to show its actual progress. Ill try to explain this better, if I click my mouse on one point on the screen and drag it to the enxt the line doesnt show up untill I reach my final spot when i release my mouse. What Id like for it to do is to be able to start the line and then have it show the lines progress while Im dragging it. I dont want it to hide the line or whatever. Can anyone give me some help with this? Heres both my java and HTML code.
Java:
import java.applet.*;
import java.awt.*;
import java.awt.event.*;
public class Lab11 extends Applet implements MouseListener {
 int x0, y0, x1, y1;
 public void init() {
 addMouseListener(this);
 public void mouseClicked(MouseEvent e) { }
 public void mouseEntered(MouseEvent e) { }
 public void mouseExited (MouseEvent e) { }
 public void mousePressed(MouseEvent e) {
 x0 = e.getX();
 y0 = e.getY();
 System.out.println("Mouse pressed at: (" +
 x0 + ", " + y0 + ")" );
 public void mouseReleased(MouseEvent e) {
 x1 = e.getX();
 y1 = e.getY();
 System.out.println("Mouse released at: (" +
 x1 + ", " + y1 + ")" );
 this.repaint();
 public void paint(Graphics g) {
 g.drawLine(x0, y0, x1, y1);
}HTML:
<html>
<head>
 <title>Lab 11 Applets</title>
</head>
<body bgcolor=white>
 <applet code="Lab11.class" width=300 height=300>
 </applet>
</body>
</html>Thanks guys!

You forgot to add this to your paint() code ...
g.setColor(Color.BLACK)
You'll never see anything drawn unless you set a color different thatn background.
This works, I added code so you can run it in a frame too because I don't want to be bothered with dealing with applets and html files;
import java.applet.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class Lab11 extends Applet implements MouseListener, MouseMotionListener {
 int x0, y0, x1, y1;
 //public void init() {
 public Lab11() {
 addMouseListener(this);
 addMouseMotionListener(this);
 public void mouseDragged(MouseEvent e)
 x1 = e.getX();
 y1 = e.getY();
 repaint();
 public void mouseMoved(MouseEvent e) { }
 public void mouseClicked(MouseEvent e) { }
 public void mouseEntered(MouseEvent e) { }
 public void mouseExited (MouseEvent e) { }
 public void mousePressed(MouseEvent e) {
 x0 = e.getX();
 y0 = e.getY();
 System.out.println("Mouse pressed at: (" +
 x0 + ", " + y0 + ")" );
 public void mouseReleased(MouseEvent e) {
 x1 = e.getX();
 y1 = e.getY();
 System.out.println("Mouse released at: (" +
 x1 + ", " + y1 + ")" );
 this.repaint();
 public void paint(Graphics g) {
 g.setColor(Color.BLACK);
 g.drawLine(x0, y0, x1, y1);
 public static void main(String[] argv)
 JFrame f = new JFrame("Test");
 f.getContentPane().add(new Lab11());
 f.setVisible(true);
 f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}

How can I get the coordinates to draw a line?

Hi,
I want to draw a line. Here is a part of my Quell-code.
public class Map extends JFrame {
public Map() {
super("Map");
setSize(340, 340);
MapPane map = new MapPane();
getContentPane().add(map);
class MapPane extends JPanel {
public void paintComponent(Graphics comp) {
Graphics2D comp2D = (Graphics2D)comp;
comp2D.drawLine(0,0,340,340);
Now, the line begins exactly top left in the edge, but ends not exactly down right in the edge of my Frame. Is there any possibility to determine the exact coordinates of the frame. I thought, if the size of the window is set by the setSize-Method to (340,340), the line ends exact
in the edge (down right). See: comp2D.drawLine(0,0,340,340).
Can somebody give me a piece of advice, please?
Thanks, joletaxi

Have you tried the getWidth() and getHeoght() methods to determine how long the line should be?

Help!draw a line on JPanel

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